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, 51 Franklin Street, Fifth Floor,
21 Boston, MA 02110-1301, 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 bool comp_except_types (tree, tree, bool);
51 static bool comp_array_types (tree, tree, bool);
52 static tree common_base_type (tree, tree);
53 static tree pointer_diff (tree, tree, tree);
54 static tree get_delta_difference (tree, tree, bool, bool);
55 static void casts_away_constness_r (tree *, tree *);
56 static bool casts_away_constness (tree, tree);
57 static void maybe_warn_about_returning_address_of_local (tree);
58 static tree lookup_destructor (tree, tree, tree);
59 static tree convert_arguments (tree, tree, tree, int);
61 /* Do `exp = require_complete_type (exp);' to make sure exp
62 does not have an incomplete type. (That includes void types.)
63 Returns the error_mark_node if the VALUE does not have
64 complete type when this function returns. */
67 require_complete_type (tree value)
71 if (processing_template_decl || value == error_mark_node)
74 if (TREE_CODE (value) == OVERLOAD)
75 type = unknown_type_node;
77 type = TREE_TYPE (value);
79 if (type == error_mark_node)
80 return error_mark_node;
82 /* First, detect a valid value with a complete type. */
83 if (COMPLETE_TYPE_P (type))
86 if (complete_type_or_else (type, value))
89 return error_mark_node;
92 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
93 a template instantiation, do the instantiation. Returns TYPE,
94 whether or not it could be completed, unless something goes
95 horribly wrong, in which case the error_mark_node is returned. */
98 complete_type (tree type)
100 if (type == NULL_TREE)
101 /* Rather than crash, we return something sure to cause an error
103 return error_mark_node;
105 if (type == error_mark_node || COMPLETE_TYPE_P (type))
107 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
109 tree t = complete_type (TREE_TYPE (type));
110 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
112 TYPE_NEEDS_CONSTRUCTING (type)
113 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
114 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
115 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
117 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
118 instantiate_class_template (TYPE_MAIN_VARIANT (type));
123 /* Like complete_type, but issue an error if the TYPE cannot be completed.
124 VALUE is used for informative diagnostics.
125 Returns NULL_TREE if the type cannot be made complete. */
128 complete_type_or_else (tree type, tree value)
130 type = complete_type (type);
131 if (type == error_mark_node)
132 /* We already issued an error. */
134 else if (!COMPLETE_TYPE_P (type))
136 cxx_incomplete_type_diagnostic (value, type, 0);
143 /* Return truthvalue of whether type of EXP is instantiated. */
146 type_unknown_p (tree exp)
148 return (TREE_CODE (exp) == TREE_LIST
149 || TREE_TYPE (exp) == unknown_type_node);
153 /* Return the common type of two parameter lists.
154 We assume that comptypes has already been done and returned 1;
155 if that isn't so, this may crash.
157 As an optimization, free the space we allocate if the parameter
158 lists are already common. */
161 commonparms (tree p1, tree p2)
163 tree oldargs = p1, newargs, n;
167 len = list_length (p1);
168 newargs = tree_last (p1);
170 if (newargs == void_list_node)
179 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
184 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
186 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
188 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
191 else if (! TREE_PURPOSE (p1))
193 if (TREE_PURPOSE (p2))
195 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
201 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
203 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
205 if (TREE_VALUE (p1) != TREE_VALUE (p2))
208 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
211 TREE_VALUE (n) = TREE_VALUE (p1);
219 /* Given a type, perhaps copied for a typedef,
220 find the "original" version of it. */
222 original_type (tree t)
224 while (TYPE_NAME (t) != NULL_TREE)
226 tree x = TYPE_NAME (t);
227 if (TREE_CODE (x) != TYPE_DECL)
229 x = DECL_ORIGINAL_TYPE (x);
237 /* T1 and T2 are arithmetic or enumeration types. Return the type
238 that will result from the "usual arithmetic conversions" on T1 and
239 T2 as described in [expr]. */
242 type_after_usual_arithmetic_conversions (tree t1, tree t2)
244 enum tree_code code1 = TREE_CODE (t1);
245 enum tree_code code2 = TREE_CODE (t2);
248 /* FIXME: Attributes. */
249 gcc_assert (ARITHMETIC_TYPE_P (t1)
250 || TREE_CODE (t1) == COMPLEX_TYPE
251 || TREE_CODE (t1) == VECTOR_TYPE
252 || TREE_CODE (t1) == ENUMERAL_TYPE);
253 gcc_assert (ARITHMETIC_TYPE_P (t2)
254 || TREE_CODE (t2) == COMPLEX_TYPE
255 || TREE_CODE (t1) == VECTOR_TYPE
256 || TREE_CODE (t2) == ENUMERAL_TYPE);
258 /* In what follows, we slightly generalize the rules given in [expr] so
259 as to deal with `long long' and `complex'. First, merge the
261 attributes = (*targetm.merge_type_attributes) (t1, t2);
263 /* If one type is complex, form the common type of the non-complex
264 components, then make that complex. Use T1 or T2 if it is the
266 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
268 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
269 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
271 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
273 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
274 return build_type_attribute_variant (t1, attributes);
275 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
276 return build_type_attribute_variant (t2, attributes);
278 return build_type_attribute_variant (build_complex_type (subtype),
282 if (code1 == VECTOR_TYPE)
284 /* When we get here we should have two vectors of the same size.
285 Just prefer the unsigned one if present. */
286 if (TYPE_UNSIGNED (t1))
287 return build_type_attribute_variant (t1, attributes);
289 return build_type_attribute_variant (t2, attributes);
292 /* If only one is real, use it as the result. */
293 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
294 return build_type_attribute_variant (t1, attributes);
295 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
296 return build_type_attribute_variant (t2, attributes);
298 /* Perform the integral promotions. */
299 if (code1 != REAL_TYPE)
301 t1 = type_promotes_to (t1);
302 t2 = type_promotes_to (t2);
305 /* Both real or both integers; use the one with greater precision. */
306 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
307 return build_type_attribute_variant (t1, attributes);
308 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
309 return build_type_attribute_variant (t2, attributes);
311 /* The types are the same; no need to do anything fancy. */
312 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
313 return build_type_attribute_variant (t1, attributes);
315 if (code1 != REAL_TYPE)
317 /* If one is a sizetype, use it so size_binop doesn't blow up. */
318 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
319 return build_type_attribute_variant (t1, attributes);
320 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
321 return build_type_attribute_variant (t2, attributes);
323 /* If one is unsigned long long, then convert the other to unsigned
325 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
326 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
327 return build_type_attribute_variant (long_long_unsigned_type_node,
329 /* If one is a long long, and the other is an unsigned long, and
330 long long can represent all the values of an unsigned long, then
331 convert to a long long. Otherwise, convert to an unsigned long
332 long. Otherwise, if either operand is long long, convert the
335 Since we're here, we know the TYPE_PRECISION is the same;
336 therefore converting to long long cannot represent all the values
337 of an unsigned long, so we choose unsigned long long in that
339 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
340 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
342 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
343 ? long_long_unsigned_type_node
344 : long_long_integer_type_node);
345 return build_type_attribute_variant (t, attributes);
348 /* Go through the same procedure, but for longs. */
349 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
350 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
351 return build_type_attribute_variant (long_unsigned_type_node,
353 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
354 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
356 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
357 ? long_unsigned_type_node : long_integer_type_node);
358 return build_type_attribute_variant (t, attributes);
360 /* Otherwise prefer the unsigned one. */
361 if (TYPE_UNSIGNED (t1))
362 return build_type_attribute_variant (t1, attributes);
364 return build_type_attribute_variant (t2, attributes);
368 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
369 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
370 return build_type_attribute_variant (long_double_type_node,
372 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
373 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
374 return build_type_attribute_variant (double_type_node,
376 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
377 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
378 return build_type_attribute_variant (float_type_node,
381 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
382 the standard C++ floating-point types. Logic earlier in this
383 function has already eliminated the possibility that
384 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
385 compelling reason to choose one or the other. */
386 return build_type_attribute_variant (t1, attributes);
390 /* Subroutine of composite_pointer_type to implement the recursive
391 case. See that function for documentation fo the parameters. */
394 composite_pointer_type_r (tree t1, tree t2, const char* location)
401 /* Determine the types pointed to by T1 and T2. */
402 if (TREE_CODE (t1) == POINTER_TYPE)
404 pointee1 = TREE_TYPE (t1);
405 pointee2 = TREE_TYPE (t2);
409 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
410 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
415 Otherwise, the composite pointer type is a pointer type
416 similar (_conv.qual_) to the type of one of the operands,
417 with a cv-qualification signature (_conv.qual_) that is the
418 union of the cv-qualification signatures of the operand
420 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
421 result_type = pointee1;
422 else if ((TREE_CODE (pointee1) == POINTER_TYPE
423 && TREE_CODE (pointee2) == POINTER_TYPE)
424 || (TYPE_PTR_TO_MEMBER_P (pointee1)
425 && TYPE_PTR_TO_MEMBER_P (pointee2)))
426 result_type = composite_pointer_type_r (pointee1, pointee2, location);
429 pedwarn ("%s between distinct pointer types %qT and %qT "
432 result_type = void_type_node;
434 result_type = cp_build_qualified_type (result_type,
435 (cp_type_quals (pointee1)
436 | cp_type_quals (pointee2)));
437 /* If the original types were pointers to members, so is the
439 if (TYPE_PTR_TO_MEMBER_P (t1))
441 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
442 TYPE_PTRMEM_CLASS_TYPE (t2)))
443 pedwarn ("%s between distinct pointer types %qT and %qT "
446 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
450 result_type = build_pointer_type (result_type);
452 /* Merge the attributes. */
453 attributes = (*targetm.merge_type_attributes) (t1, t2);
454 return build_type_attribute_variant (result_type, attributes);
457 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
458 ARG1 and ARG2 are the values with those types. The LOCATION is a
459 string describing the current location, in case an error occurs.
461 This routine also implements the computation of a common type for
462 pointers-to-members as per [expr.eq]. */
465 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
466 const char* location)
473 If one operand is a null pointer constant, the composite pointer
474 type is the type of the other operand. */
475 if (null_ptr_cst_p (arg1))
477 if (null_ptr_cst_p (arg2))
484 If one of the operands has type "pointer to cv1 void*", then
485 the other has type "pointer to cv2T", and the composite pointer
486 type is "pointer to cv12 void", where cv12 is the union of cv1
489 If either type is a pointer to void, make sure it is T1. */
490 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
498 /* Now, if T1 is a pointer to void, merge the qualifiers. */
499 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
504 if (pedantic && TYPE_PTRFN_P (t2))
505 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
506 "and pointer-to-function", location);
508 = cp_build_qualified_type (void_type_node,
509 (cp_type_quals (TREE_TYPE (t1))
510 | cp_type_quals (TREE_TYPE (t2))));
511 result_type = build_pointer_type (result_type);
512 /* Merge the attributes. */
513 attributes = (*targetm.merge_type_attributes) (t1, t2);
514 return build_type_attribute_variant (result_type, attributes);
517 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
518 && TREE_CODE (t2) == POINTER_TYPE)
520 if (objc_compare_types (t1, t2, -3, NULL_TREE))
524 /* [expr.eq] permits the application of a pointer conversion to
525 bring the pointers to a common type. */
526 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
527 && CLASS_TYPE_P (TREE_TYPE (t1))
528 && CLASS_TYPE_P (TREE_TYPE (t2))
529 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
532 class1 = TREE_TYPE (t1);
533 class2 = TREE_TYPE (t2);
535 if (DERIVED_FROM_P (class1, class2))
536 t2 = (build_pointer_type
537 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
538 else if (DERIVED_FROM_P (class2, class1))
539 t1 = (build_pointer_type
540 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
543 error ("%s between distinct pointer types %qT and %qT "
544 "lacks a cast", location, t1, t2);
545 return error_mark_node;
548 /* [expr.eq] permits the application of a pointer-to-member
549 conversion to change the class type of one of the types. */
550 else if (TYPE_PTR_TO_MEMBER_P (t1)
551 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
552 TYPE_PTRMEM_CLASS_TYPE (t2)))
554 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
555 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
557 if (DERIVED_FROM_P (class1, class2))
558 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
559 else if (DERIVED_FROM_P (class2, class1))
560 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
563 error ("%s between distinct pointer-to-member types %qT and %qT "
564 "lacks a cast", location, t1, t2);
565 return error_mark_node;
569 return composite_pointer_type_r (t1, t2, location);
572 /* Return the merged type of two types.
573 We assume that comptypes has already been done and returned 1;
574 if that isn't so, this may crash.
576 This just combines attributes and default arguments; any other
577 differences would cause the two types to compare unalike. */
580 merge_types (tree t1, tree t2)
582 enum tree_code code1;
583 enum tree_code code2;
586 /* Save time if the two types are the same. */
589 if (original_type (t1) == original_type (t2))
592 /* If one type is nonsense, use the other. */
593 if (t1 == error_mark_node)
595 if (t2 == error_mark_node)
598 /* Merge the attributes. */
599 attributes = (*targetm.merge_type_attributes) (t1, t2);
601 if (TYPE_PTRMEMFUNC_P (t1))
602 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
603 if (TYPE_PTRMEMFUNC_P (t2))
604 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
606 code1 = TREE_CODE (t1);
607 code2 = TREE_CODE (t2);
613 /* For two pointers, do this recursively on the target type. */
615 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
616 int quals = cp_type_quals (t1);
618 if (code1 == POINTER_TYPE)
619 t1 = build_pointer_type (target);
621 t1 = build_reference_type (target);
622 t1 = build_type_attribute_variant (t1, attributes);
623 t1 = cp_build_qualified_type (t1, quals);
625 if (TREE_CODE (target) == METHOD_TYPE)
626 t1 = build_ptrmemfunc_type (t1);
635 quals = cp_type_quals (t1);
636 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
637 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
638 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
640 t1 = cp_build_qualified_type (t1, quals);
646 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
647 /* Save space: see if the result is identical to one of the args. */
648 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
649 return build_type_attribute_variant (t1, attributes);
650 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
651 return build_type_attribute_variant (t2, attributes);
652 /* Merge the element types, and have a size if either arg has one. */
653 t1 = build_cplus_array_type
654 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
659 /* Function types: prefer the one that specified arg types.
660 If both do, merge the arg types. Also merge the return types. */
662 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
663 tree p1 = TYPE_ARG_TYPES (t1);
664 tree p2 = TYPE_ARG_TYPES (t2);
667 /* Save space: see if the result is identical to one of the args. */
668 if (valtype == TREE_TYPE (t1) && ! p2)
669 return cp_build_type_attribute_variant (t1, attributes);
670 if (valtype == TREE_TYPE (t2) && ! p1)
671 return cp_build_type_attribute_variant (t2, attributes);
673 /* Simple way if one arg fails to specify argument types. */
674 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
676 rval = build_function_type (valtype, p2);
677 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
678 rval = build_exception_variant (rval, raises);
679 return cp_build_type_attribute_variant (rval, attributes);
681 raises = TYPE_RAISES_EXCEPTIONS (t1);
682 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
684 rval = build_function_type (valtype, p1);
686 rval = build_exception_variant (rval, raises);
687 return cp_build_type_attribute_variant (rval, attributes);
690 rval = build_function_type (valtype, commonparms (p1, p2));
691 t1 = build_exception_variant (rval, raises);
697 /* Get this value the long way, since TYPE_METHOD_BASETYPE
698 is just the main variant of this. */
699 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
700 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
703 /* If this was a member function type, get back to the
704 original type of type member function (i.e., without
705 the class instance variable up front. */
706 t1 = build_function_type (TREE_TYPE (t1),
707 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
708 t2 = build_function_type (TREE_TYPE (t2),
709 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
710 t3 = merge_types (t1, t2);
711 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
712 TYPE_ARG_TYPES (t3));
713 t1 = build_exception_variant (t3, raises);
718 /* There is no need to merge attributes into a TYPENAME_TYPE.
719 When the type is instantiated it will have whatever
720 attributes result from the instantiation. */
725 return cp_build_type_attribute_variant (t1, attributes);
728 /* Return the common type of two types.
729 We assume that comptypes has already been done and returned 1;
730 if that isn't so, this may crash.
732 This is the type for the result of most arithmetic operations
733 if the operands have the given two types. */
736 common_type (tree t1, tree t2)
738 enum tree_code code1;
739 enum tree_code code2;
741 /* If one type is nonsense, bail. */
742 if (t1 == error_mark_node || t2 == error_mark_node)
743 return error_mark_node;
745 code1 = TREE_CODE (t1);
746 code2 = TREE_CODE (t2);
748 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
749 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
750 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
751 || code2 == COMPLEX_TYPE || code2 == VECTOR_TYPE))
752 return type_after_usual_arithmetic_conversions (t1, t2);
754 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
755 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
756 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
757 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
763 /* Compare two exception specifier types for exactness or subsetness, if
764 allowed. Returns false for mismatch, true for match (same, or
767 [except.spec] "If a class X ... objects of class X or any class publicly
768 and unambiguously derived from X. Similarly, if a pointer type Y * ...
769 exceptions of type Y * or that are pointers to any type publicly and
770 unambiguously derived from Y. Otherwise a function only allows exceptions
771 that have the same type ..."
772 This does not mention cv qualifiers and is different to what throw
773 [except.throw] and catch [except.catch] will do. They will ignore the
774 top level cv qualifiers, and allow qualifiers in the pointer to class
777 We implement the letter of the standard. */
780 comp_except_types (tree a, tree b, bool exact)
782 if (same_type_p (a, b))
786 if (cp_type_quals (a) || cp_type_quals (b))
789 if (TREE_CODE (a) == POINTER_TYPE
790 && TREE_CODE (b) == POINTER_TYPE)
794 if (cp_type_quals (a) || cp_type_quals (b))
798 if (TREE_CODE (a) != RECORD_TYPE
799 || TREE_CODE (b) != RECORD_TYPE)
802 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
808 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
809 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
810 otherwise it must be exact. Exception lists are unordered, but
811 we've already filtered out duplicates. Most lists will be in order,
812 we should try to make use of that. */
815 comp_except_specs (tree t1, tree t2, bool exact)
824 if (t1 == NULL_TREE) /* T1 is ... */
825 return t2 == NULL_TREE || !exact;
826 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
827 return t2 != NULL_TREE && !TREE_VALUE (t2);
828 if (t2 == NULL_TREE) /* T2 is ... */
830 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
833 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
834 Count how many we find, to determine exactness. For exact matching and
835 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
837 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
839 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
841 tree a = TREE_VALUE (probe);
842 tree b = TREE_VALUE (t2);
844 if (comp_except_types (a, b, exact))
846 if (probe == base && exact)
847 base = TREE_CHAIN (probe);
852 if (probe == NULL_TREE)
855 return !exact || base == NULL_TREE || length == list_length (t1);
858 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
859 [] can match [size]. */
862 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
871 /* The type of the array elements must be the same. */
872 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
875 d1 = TYPE_DOMAIN (t1);
876 d2 = TYPE_DOMAIN (t2);
881 /* If one of the arrays is dimensionless, and the other has a
882 dimension, they are of different types. However, it is valid to
890 declarations for an array object can specify
891 array types that differ by the presence or absence of a major
892 array bound (_dcl.array_). */
894 return allow_redeclaration;
896 /* Check that the dimensions are the same. */
898 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
900 max1 = TYPE_MAX_VALUE (d1);
901 max2 = TYPE_MAX_VALUE (d2);
902 if (processing_template_decl && !abi_version_at_least (2)
903 && !value_dependent_expression_p (max1)
904 && !value_dependent_expression_p (max2))
906 /* With abi-1 we do not fold non-dependent array bounds, (and
907 consequently mangle them incorrectly). We must therefore
908 fold them here, to verify the domains have the same
914 if (!cp_tree_equal (max1, max2))
920 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
921 is a bitwise-or of the COMPARE_* flags. */
924 comptypes (tree t1, tree t2, int strict)
929 /* Suppress errors caused by previously reported errors. */
930 if (t1 == error_mark_node || t2 == error_mark_node)
933 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
935 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
936 current instantiation. */
937 if (TREE_CODE (t1) == TYPENAME_TYPE)
939 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
941 if (resolved != error_mark_node)
945 if (TREE_CODE (t2) == TYPENAME_TYPE)
947 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
949 if (resolved != error_mark_node)
953 /* If either type is the internal version of sizetype, use the
955 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
956 && TYPE_ORIG_SIZE_TYPE (t1))
957 t1 = TYPE_ORIG_SIZE_TYPE (t1);
959 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
960 && TYPE_ORIG_SIZE_TYPE (t2))
961 t2 = TYPE_ORIG_SIZE_TYPE (t2);
963 if (TYPE_PTRMEMFUNC_P (t1))
964 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
965 if (TYPE_PTRMEMFUNC_P (t2))
966 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
968 /* Different classes of types can't be compatible. */
969 if (TREE_CODE (t1) != TREE_CODE (t2))
972 /* Qualifiers must match. For array types, we will check when we
973 recur on the array element types. */
974 if (TREE_CODE (t1) != ARRAY_TYPE
975 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
977 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
980 /* Allow for two different type nodes which have essentially the same
981 definition. Note that we already checked for equality of the type
982 qualifiers (just above). */
984 if (TREE_CODE (t1) != ARRAY_TYPE
985 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
988 /* Compare the types. Break out if they could be the same. */
989 switch (TREE_CODE (t1))
991 case TEMPLATE_TEMPLATE_PARM:
992 case BOUND_TEMPLATE_TEMPLATE_PARM:
993 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
994 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
996 if (!comp_template_parms
997 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
998 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1000 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1002 /* Don't check inheritance. */
1003 strict = COMPARE_STRICT;
1008 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1009 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1010 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1011 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1014 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1016 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1022 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1023 strict & ~COMPARE_REDECLARATION))
1025 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1030 case REFERENCE_TYPE:
1031 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1032 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1033 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1039 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1041 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1046 /* Target types must match incl. qualifiers. */
1047 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1051 case TEMPLATE_TYPE_PARM:
1052 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1053 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1058 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1059 TYPENAME_TYPE_FULLNAME (t2)))
1061 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1065 case UNBOUND_CLASS_TEMPLATE:
1066 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1068 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1073 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1078 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1079 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1087 /* If we get here, we know that from a target independent POV the
1088 types are the same. Make sure the target attributes are also
1090 return targetm.comp_type_attributes (t1, t2);
1093 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1096 at_least_as_qualified_p (tree type1, tree type2)
1098 int q1 = cp_type_quals (type1);
1099 int q2 = cp_type_quals (type2);
1101 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1102 return (q1 & q2) == q2;
1105 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1106 more cv-qualified that TYPE1, and 0 otherwise. */
1109 comp_cv_qualification (tree type1, tree type2)
1111 int q1 = cp_type_quals (type1);
1112 int q2 = cp_type_quals (type2);
1117 if ((q1 & q2) == q2)
1119 else if ((q1 & q2) == q1)
1125 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1126 subset of the cv-qualification signature of TYPE2, and the types
1127 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1130 comp_cv_qual_signature (tree type1, tree type2)
1132 if (comp_ptr_ttypes_real (type2, type1, -1))
1134 else if (comp_ptr_ttypes_real (type1, type2, -1))
1140 /* If two types share a common base type, return that basetype.
1141 If there is not a unique most-derived base type, this function
1142 returns ERROR_MARK_NODE. */
1145 common_base_type (tree tt1, tree tt2)
1147 tree best = NULL_TREE;
1150 /* If one is a baseclass of another, that's good enough. */
1151 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1153 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1156 /* Otherwise, try to find a unique baseclass of TT1
1157 that is shared by TT2, and follow that down. */
1158 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1160 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1161 tree trial = common_base_type (basetype, tt2);
1165 if (trial == error_mark_node)
1167 if (best == NULL_TREE)
1169 else if (best != trial)
1170 return error_mark_node;
1175 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1177 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1178 tree trial = common_base_type (tt1, basetype);
1182 if (trial == error_mark_node)
1184 if (best == NULL_TREE)
1186 else if (best != trial)
1187 return error_mark_node;
1193 /* Subroutines of `comptypes'. */
1195 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1196 equivalent in the sense that functions with those parameter types
1197 can have equivalent types. The two lists must be equivalent,
1198 element by element. */
1201 compparms (tree parms1, tree parms2)
1205 /* An unspecified parmlist matches any specified parmlist
1206 whose argument types don't need default promotions. */
1208 for (t1 = parms1, t2 = parms2;
1210 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1212 /* If one parmlist is shorter than the other,
1213 they fail to match. */
1216 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1223 /* Process a sizeof or alignof expression where the operand is a
1227 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1229 enum tree_code type_code;
1231 const char *op_name;
1233 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1234 if (type == error_mark_node)
1235 return error_mark_node;
1237 if (dependent_type_p (type))
1239 value = build_min (op, size_type_node, type);
1240 TREE_READONLY (value) = 1;
1244 op_name = operator_name_info[(int) op].name;
1246 type = non_reference (type);
1247 type_code = TREE_CODE (type);
1249 if (type_code == METHOD_TYPE)
1251 if (complain && (pedantic || warn_pointer_arith))
1252 pedwarn ("invalid application of %qs to a member function", op_name);
1253 value = size_one_node;
1256 value = c_sizeof_or_alignof_type (complete_type (type),
1263 /* Process a sizeof or alignof expression where the operand is an
1267 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1269 const char *op_name = operator_name_info[(int) op].name;
1271 if (e == error_mark_node)
1272 return error_mark_node;
1274 if (processing_template_decl)
1276 e = build_min (op, size_type_node, e);
1277 TREE_SIDE_EFFECTS (e) = 0;
1278 TREE_READONLY (e) = 1;
1283 if (TREE_CODE (e) == COMPONENT_REF
1284 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1285 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1287 error ("invalid application of %qs to a bit-field", op_name);
1290 else if (is_overloaded_fn (e))
1292 pedwarn ("ISO C++ forbids applying %qs to an expression of "
1293 "function type", op_name);
1296 else if (type_unknown_p (e))
1298 cxx_incomplete_type_error (e, TREE_TYPE (e));
1304 return cxx_sizeof_or_alignof_type (e, op, true);
1308 /* EXPR is being used in a context that is not a function call.
1313 The expression can be used only as the left-hand operand of a
1314 member function call.
1316 [expr.mptr.operator]
1318 If the result of .* or ->* is a function, then that result can be
1319 used only as the operand for the function call operator ().
1321 by issuing an error message if appropriate. Returns true iff EXPR
1322 violates these rules. */
1325 invalid_nonstatic_memfn_p (tree expr)
1327 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1329 error ("invalid use of non-static member function");
1335 /* Perform the conversions in [expr] that apply when an lvalue appears
1336 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1337 function-to-pointer conversions.
1339 In addition manifest constants are replaced by their values. */
1342 decay_conversion (tree exp)
1345 enum tree_code code;
1347 type = TREE_TYPE (exp);
1348 code = TREE_CODE (type);
1350 if (type == error_mark_node)
1351 return error_mark_node;
1353 if (type_unknown_p (exp))
1355 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1356 return error_mark_node;
1359 exp = integral_constant_value (exp);
1361 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1362 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1364 if (code == VOID_TYPE)
1366 error ("void value not ignored as it ought to be");
1367 return error_mark_node;
1369 if (invalid_nonstatic_memfn_p (exp))
1370 return error_mark_node;
1371 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1372 return build_unary_op (ADDR_EXPR, exp, 0);
1373 if (code == ARRAY_TYPE)
1378 if (TREE_CODE (exp) == INDIRECT_REF)
1379 return build_nop (build_pointer_type (TREE_TYPE (type)),
1380 TREE_OPERAND (exp, 0));
1382 if (TREE_CODE (exp) == COMPOUND_EXPR)
1384 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1385 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1386 TREE_OPERAND (exp, 0), op1);
1390 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1392 error ("invalid use of non-lvalue array");
1393 return error_mark_node;
1396 ptrtype = build_pointer_type (TREE_TYPE (type));
1398 if (TREE_CODE (exp) == VAR_DECL)
1400 if (!cxx_mark_addressable (exp))
1401 return error_mark_node;
1402 adr = build_nop (ptrtype, build_address (exp));
1405 /* This way is better for a COMPONENT_REF since it can
1406 simplify the offset for a component. */
1407 adr = build_unary_op (ADDR_EXPR, exp, 1);
1408 return cp_convert (ptrtype, adr);
1411 /* [basic.lval]: Class rvalues can have cv-qualified types; non-class
1412 rvalues always have cv-unqualified types. */
1413 if (! CLASS_TYPE_P (type))
1414 exp = cp_convert (TYPE_MAIN_VARIANT (type), exp);
1420 default_conversion (tree exp)
1422 exp = decay_conversion (exp);
1424 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1425 exp = perform_integral_promotions (exp);
1430 /* EXPR is an expression with an integral or enumeration type.
1431 Perform the integral promotions in [conv.prom], and return the
1435 perform_integral_promotions (tree expr)
1440 type = TREE_TYPE (expr);
1441 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1442 promoted_type = type_promotes_to (type);
1443 if (type != promoted_type)
1444 expr = cp_convert (promoted_type, expr);
1448 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1452 inline_conversion (tree exp)
1454 if (TREE_CODE (exp) == FUNCTION_DECL)
1455 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1460 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1461 decay_conversion to one. */
1464 string_conv_p (tree totype, tree exp, int warn)
1468 if (! flag_const_strings || TREE_CODE (totype) != POINTER_TYPE)
1471 t = TREE_TYPE (totype);
1472 if (!same_type_p (t, char_type_node)
1473 && !same_type_p (t, wchar_type_node))
1476 if (TREE_CODE (exp) == STRING_CST)
1478 /* Make sure that we don't try to convert between char and wchar_t. */
1479 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1484 /* Is this a string constant which has decayed to 'const char *'? */
1485 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1486 if (!same_type_p (TREE_TYPE (exp), t))
1489 if (TREE_CODE (exp) != ADDR_EXPR
1490 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1494 /* This warning is not very useful, as it complains about printf. */
1495 if (warn && warn_write_strings)
1496 warning (0, "deprecated conversion from string constant to %qT'", totype);
1501 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1502 can, for example, use as an lvalue. This code used to be in
1503 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1504 expressions, where we're dealing with aggregates. But now it's again only
1505 called from unary_complex_lvalue. The case (in particular) that led to
1506 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1510 rationalize_conditional_expr (enum tree_code code, tree t)
1512 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1513 the first operand is always the one to be used if both operands
1514 are equal, so we know what conditional expression this used to be. */
1515 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1517 /* The following code is incorrect if either operand side-effects. */
1518 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
1519 && !TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)));
1521 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1522 ? LE_EXPR : GE_EXPR),
1523 TREE_OPERAND (t, 0),
1524 TREE_OPERAND (t, 1),
1525 /*overloaded_p=*/NULL),
1526 build_unary_op (code, TREE_OPERAND (t, 0), 0),
1527 build_unary_op (code, TREE_OPERAND (t, 1), 0));
1531 build_conditional_expr (TREE_OPERAND (t, 0),
1532 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1533 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1536 /* Given the TYPE of an anonymous union field inside T, return the
1537 FIELD_DECL for the field. If not found return NULL_TREE. Because
1538 anonymous unions can nest, we must also search all anonymous unions
1539 that are directly reachable. */
1542 lookup_anon_field (tree t, tree type)
1546 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1548 if (TREE_STATIC (field))
1550 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1553 /* If we find it directly, return the field. */
1554 if (DECL_NAME (field) == NULL_TREE
1555 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1560 /* Otherwise, it could be nested, search harder. */
1561 if (DECL_NAME (field) == NULL_TREE
1562 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1564 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1572 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1573 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1574 non-NULL, it indicates the path to the base used to name MEMBER.
1575 If PRESERVE_REFERENCE is true, the expression returned will have
1576 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1577 returned will have the type referred to by the reference.
1579 This function does not perform access control; that is either done
1580 earlier by the parser when the name of MEMBER is resolved to MEMBER
1581 itself, or later when overload resolution selects one of the
1582 functions indicated by MEMBER. */
1585 build_class_member_access_expr (tree object, tree member,
1586 tree access_path, bool preserve_reference)
1590 tree result = NULL_TREE;
1592 if (object == error_mark_node || member == error_mark_node)
1593 return error_mark_node;
1595 gcc_assert (DECL_P (member) || BASELINK_P (member));
1599 The type of the first expression shall be "class object" (of a
1601 object_type = TREE_TYPE (object);
1602 if (!currently_open_class (object_type)
1603 && !complete_type_or_else (object_type, object))
1604 return error_mark_node;
1605 if (!CLASS_TYPE_P (object_type))
1607 error ("request for member %qD in %qE, which is of non-class type %qT",
1608 member, object, object_type);
1609 return error_mark_node;
1612 /* The standard does not seem to actually say that MEMBER must be a
1613 member of OBJECT_TYPE. However, that is clearly what is
1615 if (DECL_P (member))
1617 member_scope = DECL_CLASS_CONTEXT (member);
1619 if (TREE_DEPRECATED (member))
1620 warn_deprecated_use (member);
1623 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1624 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1625 presently be the anonymous union. Go outwards until we find a
1626 type related to OBJECT_TYPE. */
1627 while (ANON_AGGR_TYPE_P (member_scope)
1628 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1630 member_scope = TYPE_CONTEXT (member_scope);
1631 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1633 if (TREE_CODE (member) == FIELD_DECL)
1634 error ("invalid use of nonstatic data member %qE", member);
1636 error ("%qD is not a member of %qT", member, object_type);
1637 return error_mark_node;
1640 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1641 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1642 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1644 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1646 object = build_indirect_ref (temp, NULL);
1649 /* In [expr.ref], there is an explicit list of the valid choices for
1650 MEMBER. We check for each of those cases here. */
1651 if (TREE_CODE (member) == VAR_DECL)
1653 /* A static data member. */
1655 /* If OBJECT has side-effects, they are supposed to occur. */
1656 if (TREE_SIDE_EFFECTS (object))
1657 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1659 else if (TREE_CODE (member) == FIELD_DECL)
1661 /* A non-static data member. */
1666 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1667 && integer_zerop (TREE_OPERAND (object, 0)));
1669 /* Convert OBJECT to the type of MEMBER. */
1670 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1671 TYPE_MAIN_VARIANT (member_scope)))
1676 binfo = lookup_base (access_path ? access_path : object_type,
1677 member_scope, ba_unique, &kind);
1678 if (binfo == error_mark_node)
1679 return error_mark_node;
1681 /* It is invalid to try to get to a virtual base of a
1682 NULL object. The most common cause is invalid use of
1684 if (null_object_p && kind == bk_via_virtual)
1686 error ("invalid access to non-static data member %qD of "
1689 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1690 return error_mark_node;
1693 /* Convert to the base. */
1694 object = build_base_path (PLUS_EXPR, object, binfo,
1696 /* If we found the base successfully then we should be able
1697 to convert to it successfully. */
1698 gcc_assert (object != error_mark_node);
1701 /* Complain about other invalid uses of offsetof, even though they will
1702 give the right answer. Note that we complain whether or not they
1703 actually used the offsetof macro, since there's no way to know at this
1704 point. So we just give a warning, instead of a pedwarn. */
1705 /* Do not produce this warning for base class field references, because
1706 we know for a fact that didn't come from offsetof. This does occur
1707 in various testsuite cases where a null object is passed where a
1708 vtable access is required. */
1709 if (null_object_p && warn_invalid_offsetof
1710 && CLASSTYPE_NON_POD_P (object_type)
1711 && !DECL_FIELD_IS_BASE (member)
1712 && !skip_evaluation)
1714 warning (0, "invalid access to non-static data member %qD of NULL object",
1716 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1719 /* If MEMBER is from an anonymous aggregate, we have converted
1720 OBJECT so that it refers to the class containing the
1721 anonymous union. Generate a reference to the anonymous union
1722 itself, and recur to find MEMBER. */
1723 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1724 /* When this code is called from build_field_call, the
1725 object already has the type of the anonymous union.
1726 That is because the COMPONENT_REF was already
1727 constructed, and was then disassembled before calling
1728 build_field_call. After the function-call code is
1729 cleaned up, this waste can be eliminated. */
1730 && (!same_type_ignoring_top_level_qualifiers_p
1731 (TREE_TYPE (object), DECL_CONTEXT (member))))
1733 tree anonymous_union;
1735 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1736 DECL_CONTEXT (member));
1737 object = build_class_member_access_expr (object,
1739 /*access_path=*/NULL_TREE,
1740 preserve_reference);
1743 /* Compute the type of the field, as described in [expr.ref]. */
1744 type_quals = TYPE_UNQUALIFIED;
1745 member_type = TREE_TYPE (member);
1746 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1748 type_quals = (cp_type_quals (member_type)
1749 | cp_type_quals (object_type));
1751 /* A field is const (volatile) if the enclosing object, or the
1752 field itself, is const (volatile). But, a mutable field is
1753 not const, even within a const object. */
1754 if (DECL_MUTABLE_P (member))
1755 type_quals &= ~TYPE_QUAL_CONST;
1756 member_type = cp_build_qualified_type (member_type, type_quals);
1759 result = build3 (COMPONENT_REF, member_type, object, member,
1761 result = fold_if_not_in_template (result);
1763 /* Mark the expression const or volatile, as appropriate. Even
1764 though we've dealt with the type above, we still have to mark the
1765 expression itself. */
1766 if (type_quals & TYPE_QUAL_CONST)
1767 TREE_READONLY (result) = 1;
1768 if (type_quals & TYPE_QUAL_VOLATILE)
1769 TREE_THIS_VOLATILE (result) = 1;
1771 else if (BASELINK_P (member))
1773 /* The member is a (possibly overloaded) member function. */
1777 /* If the MEMBER is exactly one static member function, then we
1778 know the type of the expression. Otherwise, we must wait
1779 until overload resolution has been performed. */
1780 functions = BASELINK_FUNCTIONS (member);
1781 if (TREE_CODE (functions) == FUNCTION_DECL
1782 && DECL_STATIC_FUNCTION_P (functions))
1783 type = TREE_TYPE (functions);
1785 type = unknown_type_node;
1786 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1787 base. That will happen when the function is called. */
1788 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1790 else if (TREE_CODE (member) == CONST_DECL)
1792 /* The member is an enumerator. */
1794 /* If OBJECT has side-effects, they are supposed to occur. */
1795 if (TREE_SIDE_EFFECTS (object))
1796 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1801 error ("invalid use of %qD", member);
1802 return error_mark_node;
1805 if (!preserve_reference)
1808 If E2 is declared to have type "reference to T", then ... the
1809 type of E1.E2 is T. */
1810 result = convert_from_reference (result);
1815 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1816 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1819 lookup_destructor (tree object, tree scope, tree dtor_name)
1821 tree object_type = TREE_TYPE (object);
1822 tree dtor_type = TREE_OPERAND (dtor_name, 0);
1825 if (scope && !check_dtor_name (scope, dtor_name))
1827 error ("qualified type %qT does not match destructor name ~%qT",
1829 return error_mark_node;
1831 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
1833 error ("the type being destroyed is %qT, but the destructor refers to %qT",
1834 TYPE_MAIN_VARIANT (object_type), dtor_type);
1835 return error_mark_node;
1837 expr = lookup_member (dtor_type, complete_dtor_identifier,
1838 /*protect=*/1, /*want_type=*/false);
1839 expr = (adjust_result_of_qualified_name_lookup
1840 (expr, dtor_type, object_type));
1844 /* This function is called by the parser to process a class member
1845 access expression of the form OBJECT.NAME. NAME is a node used by
1846 the parser to represent a name; it is not yet a DECL. It may,
1847 however, be a BASELINK where the BASELINK_FUNCTIONS is a
1848 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
1849 there is no reason to do the lookup twice, so the parser keeps the
1853 finish_class_member_access_expr (tree object, tree name)
1858 tree access_path = NULL_TREE;
1859 tree orig_object = object;
1860 tree orig_name = name;
1862 if (object == error_mark_node || name == error_mark_node)
1863 return error_mark_node;
1865 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
1866 if (!objc_is_public (object, name))
1867 return error_mark_node;
1869 object_type = TREE_TYPE (object);
1871 if (processing_template_decl)
1873 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
1874 dependent_type_p (object_type)
1875 /* If NAME is just an IDENTIFIER_NODE, then the expression
1877 || TREE_CODE (object) == IDENTIFIER_NODE
1878 /* If NAME is "f<args>", where either 'f' or 'args' is
1879 dependent, then the expression is dependent. */
1880 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
1881 && dependent_template_id_p (TREE_OPERAND (name, 0),
1882 TREE_OPERAND (name, 1)))
1883 /* If NAME is "T::X" where "T" is dependent, then the
1884 expression is dependent. */
1885 || (TREE_CODE (name) == SCOPE_REF
1886 && TYPE_P (TREE_OPERAND (name, 0))
1887 && dependent_type_p (TREE_OPERAND (name, 0))))
1888 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
1889 object = build_non_dependent_expr (object);
1894 The type of the first expression shall be "class object" (of a
1896 if (!currently_open_class (object_type)
1897 && !complete_type_or_else (object_type, object))
1898 return error_mark_node;
1899 if (!CLASS_TYPE_P (object_type))
1901 error ("request for member %qD in %qE, which is of non-class type %qT",
1902 name, object, object_type);
1903 return error_mark_node;
1906 if (BASELINK_P (name))
1908 /* A member function that has already been looked up. */
1909 gcc_assert (TREE_CODE (BASELINK_FUNCTIONS (name)) == TEMPLATE_ID_EXPR);
1914 bool is_template_id = false;
1915 tree template_args = NULL_TREE;
1918 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
1920 is_template_id = true;
1921 template_args = TREE_OPERAND (name, 1);
1922 name = TREE_OPERAND (name, 0);
1924 if (TREE_CODE (name) == OVERLOAD)
1925 name = DECL_NAME (get_first_fn (name));
1926 else if (DECL_P (name))
1927 name = DECL_NAME (name);
1930 if (TREE_CODE (name) == SCOPE_REF)
1932 /* A qualified name. The qualifying class or namespace `S' has
1933 already been looked up; it is either a TYPE or a
1934 NAMESPACE_DECL. The member name is either an IDENTIFIER_NODE
1935 or a BIT_NOT_EXPR. */
1936 scope = TREE_OPERAND (name, 0);
1937 name = TREE_OPERAND (name, 1);
1938 gcc_assert (CLASS_TYPE_P (scope)
1939 || TREE_CODE (scope) == NAMESPACE_DECL);
1940 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
1941 || TREE_CODE (name) == BIT_NOT_EXPR);
1943 /* If SCOPE is a namespace, then the qualified name does not
1944 name a member of OBJECT_TYPE. */
1945 if (TREE_CODE (scope) == NAMESPACE_DECL)
1947 error ("%<%D::%D%> is not a member of %qT",
1948 scope, name, object_type);
1949 return error_mark_node;
1952 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
1953 access_path = lookup_base (object_type, scope, ba_check, NULL);
1954 if (access_path == error_mark_node)
1955 return error_mark_node;
1958 error ("%qT is not a base of %qT", scope, object_type);
1959 return error_mark_node;
1965 access_path = object_type;
1968 if (TREE_CODE (name) == BIT_NOT_EXPR)
1969 member = lookup_destructor (object, scope, name);
1972 /* Look up the member. */
1973 member = lookup_member (access_path, name, /*protect=*/1,
1974 /*want_type=*/false);
1975 if (member == NULL_TREE)
1977 error ("%qD has no member named %qE", object_type, name);
1978 return error_mark_node;
1980 if (member == error_mark_node)
1981 return error_mark_node;
1986 tree template = member;
1988 if (BASELINK_P (template))
1989 template = lookup_template_function (template, template_args);
1992 error ("%qD is not a member template function", name);
1993 return error_mark_node;
1998 if (TREE_DEPRECATED (member))
1999 warn_deprecated_use (member);
2001 expr = build_class_member_access_expr (object, member, access_path,
2002 /*preserve_reference=*/false);
2003 if (processing_template_decl && expr != error_mark_node)
2004 return build_min_non_dep (COMPONENT_REF, expr,
2005 orig_object, orig_name, NULL_TREE);
2009 /* Return an expression for the MEMBER_NAME field in the internal
2010 representation of PTRMEM, a pointer-to-member function. (Each
2011 pointer-to-member function type gets its own RECORD_TYPE so it is
2012 more convenient to access the fields by name than by FIELD_DECL.)
2013 This routine converts the NAME to a FIELD_DECL and then creates the
2014 node for the complete expression. */
2017 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2023 /* This code is a stripped down version of
2024 build_class_member_access_expr. It does not work to use that
2025 routine directly because it expects the object to be of class
2027 ptrmem_type = TREE_TYPE (ptrmem);
2028 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2029 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2030 /*want_type=*/false);
2031 member_type = cp_build_qualified_type (TREE_TYPE (member),
2032 cp_type_quals (ptrmem_type));
2033 return fold_build3 (COMPONENT_REF, member_type,
2034 ptrmem, member, NULL_TREE);
2037 /* Given an expression PTR for a pointer, return an expression
2038 for the value pointed to.
2039 ERRORSTRING is the name of the operator to appear in error messages.
2041 This function may need to overload OPERATOR_FNNAME.
2042 Must also handle REFERENCE_TYPEs for C++. */
2045 build_x_indirect_ref (tree expr, const char *errorstring)
2047 tree orig_expr = expr;
2050 if (processing_template_decl)
2052 if (type_dependent_expression_p (expr))
2053 return build_min_nt (INDIRECT_REF, expr);
2054 expr = build_non_dependent_expr (expr);
2057 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2058 NULL_TREE, /*overloaded_p=*/NULL);
2060 rval = build_indirect_ref (expr, errorstring);
2062 if (processing_template_decl && rval != error_mark_node)
2063 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2069 build_indirect_ref (tree ptr, const char *errorstring)
2073 if (ptr == error_mark_node)
2074 return error_mark_node;
2076 if (ptr == current_class_ptr)
2077 return current_class_ref;
2079 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2080 ? ptr : decay_conversion (ptr));
2081 type = TREE_TYPE (pointer);
2083 if (POINTER_TYPE_P (type))
2087 If the type of the expression is "pointer to T," the type
2088 of the result is "T."
2090 We must use the canonical variant because certain parts of
2091 the back end, like fold, do pointer comparisons between
2093 tree t = canonical_type_variant (TREE_TYPE (type));
2095 if (VOID_TYPE_P (t))
2097 /* A pointer to incomplete type (other than cv void) can be
2098 dereferenced [expr.unary.op]/1 */
2099 error ("%qT is not a pointer-to-object type", type);
2100 return error_mark_node;
2102 else if (TREE_CODE (pointer) == ADDR_EXPR
2103 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2104 /* The POINTER was something like `&x'. We simplify `*&x' to
2106 return TREE_OPERAND (pointer, 0);
2109 tree ref = build1 (INDIRECT_REF, t, pointer);
2111 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2112 so that we get the proper error message if the result is used
2113 to assign to. Also, &* is supposed to be a no-op. */
2114 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2115 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2116 TREE_SIDE_EFFECTS (ref)
2117 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2121 /* `pointer' won't be an error_mark_node if we were given a
2122 pointer to member, so it's cool to check for this here. */
2123 else if (TYPE_PTR_TO_MEMBER_P (type))
2124 error ("invalid use of %qs on pointer to member", errorstring);
2125 else if (pointer != error_mark_node)
2128 error ("invalid type argument of %qs", errorstring);
2130 error ("invalid type argument");
2132 return error_mark_node;
2135 /* This handles expressions of the form "a[i]", which denotes
2138 This is logically equivalent in C to *(a+i), but we may do it differently.
2139 If A is a variable or a member, we generate a primitive ARRAY_REF.
2140 This avoids forcing the array out of registers, and can work on
2141 arrays that are not lvalues (for example, members of structures returned
2144 If INDEX is of some user-defined type, it must be converted to
2145 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2146 will inherit the type of the array, which will be some pointer type. */
2149 build_array_ref (tree array, tree idx)
2153 error ("subscript missing in array reference");
2154 return error_mark_node;
2157 if (TREE_TYPE (array) == error_mark_node
2158 || TREE_TYPE (idx) == error_mark_node)
2159 return error_mark_node;
2161 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2163 switch (TREE_CODE (array))
2167 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2168 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2169 TREE_OPERAND (array, 0), value);
2173 return build_conditional_expr
2174 (TREE_OPERAND (array, 0),
2175 build_array_ref (TREE_OPERAND (array, 1), idx),
2176 build_array_ref (TREE_OPERAND (array, 2), idx));
2182 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2186 /* Subscripting with type char is likely to lose
2187 on a machine where chars are signed.
2188 So warn on any machine, but optionally.
2189 Don't warn for unsigned char since that type is safe.
2190 Don't warn for signed char because anyone who uses that
2191 must have done so deliberately. */
2192 if (warn_char_subscripts
2193 && TYPE_MAIN_VARIANT (TREE_TYPE (idx)) == char_type_node)
2194 warning (0, "array subscript has type %<char%>");
2196 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2198 error ("array subscript is not an integer");
2199 return error_mark_node;
2202 /* Apply integral promotions *after* noticing character types.
2203 (It is unclear why we do these promotions -- the standard
2204 does not say that we should. In fact, the natural thing would
2205 seem to be to convert IDX to ptrdiff_t; we're performing
2206 pointer arithmetic.) */
2207 idx = perform_integral_promotions (idx);
2209 /* An array that is indexed by a non-constant
2210 cannot be stored in a register; we must be able to do
2211 address arithmetic on its address.
2212 Likewise an array of elements of variable size. */
2213 if (TREE_CODE (idx) != INTEGER_CST
2214 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2215 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2218 if (!cxx_mark_addressable (array))
2219 return error_mark_node;
2222 /* An array that is indexed by a constant value which is not within
2223 the array bounds cannot be stored in a register either; because we
2224 would get a crash in store_bit_field/extract_bit_field when trying
2225 to access a non-existent part of the register. */
2226 if (TREE_CODE (idx) == INTEGER_CST
2227 && TYPE_DOMAIN (TREE_TYPE (array))
2228 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2230 if (!cxx_mark_addressable (array))
2231 return error_mark_node;
2234 if (pedantic && !lvalue_p (array))
2235 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2237 /* Note in C++ it is valid to subscript a `register' array, since
2238 it is valid to take the address of something with that
2239 storage specification. */
2243 while (TREE_CODE (foo) == COMPONENT_REF)
2244 foo = TREE_OPERAND (foo, 0);
2245 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2246 warning (0, "subscripting array declared %<register%>");
2249 type = TREE_TYPE (TREE_TYPE (array));
2250 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2251 /* Array ref is const/volatile if the array elements are
2252 or if the array is.. */
2253 TREE_READONLY (rval)
2254 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2255 TREE_SIDE_EFFECTS (rval)
2256 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2257 TREE_THIS_VOLATILE (rval)
2258 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2259 return require_complete_type (fold_if_not_in_template (rval));
2263 tree ar = default_conversion (array);
2264 tree ind = default_conversion (idx);
2266 /* Put the integer in IND to simplify error checking. */
2267 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2274 if (ar == error_mark_node)
2277 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2279 error ("subscripted value is neither array nor pointer");
2280 return error_mark_node;
2282 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2284 error ("array subscript is not an integer");
2285 return error_mark_node;
2288 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2293 /* Resolve a pointer to member function. INSTANCE is the object
2294 instance to use, if the member points to a virtual member.
2296 This used to avoid checking for virtual functions if basetype
2297 has no virtual functions, according to an earlier ANSI draft.
2298 With the final ISO C++ rules, such an optimization is
2299 incorrect: A pointer to a derived member can be static_cast
2300 to pointer-to-base-member, as long as the dynamic object
2301 later has the right member. */
2304 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2306 if (TREE_CODE (function) == OFFSET_REF)
2307 function = TREE_OPERAND (function, 1);
2309 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2311 tree idx, delta, e1, e2, e3, vtbl, basetype;
2312 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2314 tree instance_ptr = *instance_ptrptr;
2315 tree instance_save_expr = 0;
2316 if (instance_ptr == error_mark_node)
2318 if (TREE_CODE (function) == PTRMEM_CST)
2320 /* Extracting the function address from a pmf is only
2321 allowed with -Wno-pmf-conversions. It only works for
2323 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2324 e1 = convert (fntype, e1);
2329 error ("object missing in use of %qE", function);
2330 return error_mark_node;
2334 if (TREE_SIDE_EFFECTS (instance_ptr))
2335 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2337 if (TREE_SIDE_EFFECTS (function))
2338 function = save_expr (function);
2340 /* Start by extracting all the information from the PMF itself. */
2341 e3 = pfn_from_ptrmemfunc (function);
2342 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2343 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2344 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2346 case ptrmemfunc_vbit_in_pfn:
2347 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2348 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2351 case ptrmemfunc_vbit_in_delta:
2352 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2353 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2360 /* Convert down to the right base before using the instance. A
2361 special case is that in a pointer to member of class C, C may
2362 be incomplete. In that case, the function will of course be
2363 a member of C, and no conversion is required. In fact,
2364 lookup_base will fail in that case, because incomplete
2365 classes do not have BINFOs. */
2366 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2367 if (!same_type_ignoring_top_level_qualifiers_p
2368 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2370 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2371 basetype, ba_check, NULL);
2372 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2374 if (instance_ptr == error_mark_node)
2375 return error_mark_node;
2377 /* ...and then the delta in the PMF. */
2378 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2379 instance_ptr, delta);
2381 /* Hand back the adjusted 'this' argument to our caller. */
2382 *instance_ptrptr = instance_ptr;
2384 /* Next extract the vtable pointer from the object. */
2385 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2387 vtbl = build_indirect_ref (vtbl, NULL);
2389 /* Finally, extract the function pointer from the vtable. */
2390 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2391 e2 = build_indirect_ref (e2, NULL);
2392 TREE_CONSTANT (e2) = 1;
2393 TREE_INVARIANT (e2) = 1;
2395 /* When using function descriptors, the address of the
2396 vtable entry is treated as a function pointer. */
2397 if (TARGET_VTABLE_USES_DESCRIPTORS)
2398 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2399 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2401 TREE_TYPE (e2) = TREE_TYPE (e3);
2402 e1 = build_conditional_expr (e1, e2, e3);
2404 /* Make sure this doesn't get evaluated first inside one of the
2405 branches of the COND_EXPR. */
2406 if (instance_save_expr)
2407 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2408 instance_save_expr, e1);
2416 build_function_call (tree function, tree params)
2418 tree fntype, fndecl;
2419 tree coerced_params;
2420 tree name = NULL_TREE;
2422 tree original = function;
2424 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2425 expressions, like those used for ObjC messenger dispatches. */
2426 function = objc_rewrite_function_call (function, params);
2428 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2429 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2430 if (TREE_CODE (function) == NOP_EXPR
2431 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2432 function = TREE_OPERAND (function, 0);
2434 if (TREE_CODE (function) == FUNCTION_DECL)
2436 name = DECL_NAME (function);
2438 mark_used (function);
2441 /* Convert anything with function type to a pointer-to-function. */
2442 if (pedantic && DECL_MAIN_P (function))
2443 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2445 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2446 (because calling an inline function does not mean the function
2447 needs to be separately compiled). */
2449 if (DECL_INLINE (function))
2450 function = inline_conversion (function);
2452 function = build_addr_func (function);
2458 function = build_addr_func (function);
2461 if (function == error_mark_node)
2462 return error_mark_node;
2464 fntype = TREE_TYPE (function);
2466 if (TYPE_PTRMEMFUNC_P (fntype))
2468 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2469 "function in %<%E (...)%>",
2471 return error_mark_node;
2474 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2475 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2477 if (!((TREE_CODE (fntype) == POINTER_TYPE
2478 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2480 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2482 error ("%qE cannot be used as a function", original);
2483 return error_mark_node;
2486 /* fntype now gets the type of function pointed to. */
2487 fntype = TREE_TYPE (fntype);
2489 /* Convert the parameters to the types declared in the
2490 function prototype, or apply default promotions. */
2492 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2493 params, fndecl, LOOKUP_NORMAL);
2494 if (coerced_params == error_mark_node)
2495 return error_mark_node;
2497 /* Check for errors in format strings and inappropriately
2500 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2501 TYPE_ARG_TYPES (fntype));
2503 return build_cxx_call (function, coerced_params);
2506 /* Convert the actual parameter expressions in the list VALUES
2507 to the types in the list TYPELIST.
2508 If parmdecls is exhausted, or when an element has NULL as its type,
2509 perform the default conversions.
2511 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2513 This is also where warnings about wrong number of args are generated.
2515 Return a list of expressions for the parameters as converted.
2517 Both VALUES and the returned value are chains of TREE_LIST nodes
2518 with the elements of the list in the TREE_VALUE slots of those nodes.
2520 In C++, unspecified trailing parameters can be filled in with their
2521 default arguments, if such were specified. Do so here. */
2524 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2526 tree typetail, valtail;
2527 tree result = NULL_TREE;
2528 const char *called_thing = 0;
2531 /* Argument passing is always copy-initialization. */
2532 flags |= LOOKUP_ONLYCONVERTING;
2536 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2538 if (DECL_NAME (fndecl) == NULL_TREE
2539 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2540 called_thing = "constructor";
2542 called_thing = "member function";
2545 called_thing = "function";
2548 for (valtail = values, typetail = typelist;
2550 valtail = TREE_CHAIN (valtail), i++)
2552 tree type = typetail ? TREE_VALUE (typetail) : 0;
2553 tree val = TREE_VALUE (valtail);
2555 if (val == error_mark_node)
2556 return error_mark_node;
2558 if (type == void_type_node)
2562 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2563 error ("at this point in file");
2566 error ("too many arguments to function");
2567 /* In case anybody wants to know if this argument
2570 TREE_TYPE (tree_last (result)) = error_mark_node;
2574 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2575 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2576 if (TREE_CODE (val) == NOP_EXPR
2577 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2578 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2579 val = TREE_OPERAND (val, 0);
2581 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2583 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2584 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2585 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2586 val = decay_conversion (val);
2589 if (val == error_mark_node)
2590 return error_mark_node;
2594 /* Formal parm type is specified by a function prototype. */
2597 if (!COMPLETE_TYPE_P (complete_type (type)))
2600 error ("parameter %P of %qD has incomplete type %qT",
2603 error ("parameter %P has incomplete type %qT", i, type);
2604 parmval = error_mark_node;
2608 parmval = convert_for_initialization
2609 (NULL_TREE, type, val, flags,
2610 "argument passing", fndecl, i);
2611 parmval = convert_for_arg_passing (type, parmval);
2614 if (parmval == error_mark_node)
2615 return error_mark_node;
2617 result = tree_cons (NULL_TREE, parmval, result);
2621 if (fndecl && DECL_BUILT_IN (fndecl)
2622 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2623 /* Don't do ellipsis conversion for __built_in_constant_p
2624 as this will result in spurious warnings for non-POD
2626 val = require_complete_type (val);
2628 val = convert_arg_to_ellipsis (val);
2630 result = tree_cons (NULL_TREE, val, result);
2634 typetail = TREE_CHAIN (typetail);
2637 if (typetail != 0 && typetail != void_list_node)
2639 /* See if there are default arguments that can be used. */
2640 if (TREE_PURPOSE (typetail)
2641 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2643 for (; typetail != void_list_node; ++i)
2646 = convert_default_arg (TREE_VALUE (typetail),
2647 TREE_PURPOSE (typetail),
2650 if (parmval == error_mark_node)
2651 return error_mark_node;
2653 result = tree_cons (0, parmval, result);
2654 typetail = TREE_CHAIN (typetail);
2655 /* ends with `...'. */
2656 if (typetail == NULL_TREE)
2664 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2665 error ("at this point in file");
2668 error ("too few arguments to function");
2669 return error_mark_list;
2673 return nreverse (result);
2676 /* Build a binary-operation expression, after performing default
2677 conversions on the operands. CODE is the kind of expression to build. */
2680 build_x_binary_op (enum tree_code code, tree arg1, tree arg2,
2690 if (processing_template_decl)
2692 if (type_dependent_expression_p (arg1)
2693 || type_dependent_expression_p (arg2))
2694 return build_min_nt (code, arg1, arg2);
2695 arg1 = build_non_dependent_expr (arg1);
2696 arg2 = build_non_dependent_expr (arg2);
2699 if (code == DOTSTAR_EXPR)
2700 expr = build_m_component_ref (arg1, arg2);
2702 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2705 if (processing_template_decl && expr != error_mark_node)
2706 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2711 /* Build a binary-operation expression without default conversions.
2712 CODE is the kind of expression to build.
2713 This function differs from `build' in several ways:
2714 the data type of the result is computed and recorded in it,
2715 warnings are generated if arg data types are invalid,
2716 special handling for addition and subtraction of pointers is known,
2717 and some optimization is done (operations on narrow ints
2718 are done in the narrower type when that gives the same result).
2719 Constant folding is also done before the result is returned.
2721 Note that the operands will never have enumeral types
2722 because either they have just had the default conversions performed
2723 or they have both just been converted to some other type in which
2724 the arithmetic is to be done.
2726 C++: must do special pointer arithmetic when implementing
2727 multiple inheritance, and deal with pointer to member functions. */
2730 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2731 int convert_p ATTRIBUTE_UNUSED)
2734 enum tree_code code0, code1;
2736 const char *invalid_op_diag;
2738 /* Expression code to give to the expression when it is built.
2739 Normally this is CODE, which is what the caller asked for,
2740 but in some special cases we change it. */
2741 enum tree_code resultcode = code;
2743 /* Data type in which the computation is to be performed.
2744 In the simplest cases this is the common type of the arguments. */
2745 tree result_type = NULL;
2747 /* Nonzero means operands have already been type-converted
2748 in whatever way is necessary.
2749 Zero means they need to be converted to RESULT_TYPE. */
2752 /* Nonzero means create the expression with this type, rather than
2754 tree build_type = 0;
2756 /* Nonzero means after finally constructing the expression
2757 convert it to this type. */
2758 tree final_type = 0;
2762 /* Nonzero if this is an operation like MIN or MAX which can
2763 safely be computed in short if both args are promoted shorts.
2764 Also implies COMMON.
2765 -1 indicates a bitwise operation; this makes a difference
2766 in the exact conditions for when it is safe to do the operation
2767 in a narrower mode. */
2770 /* Nonzero if this is a comparison operation;
2771 if both args are promoted shorts, compare the original shorts.
2772 Also implies COMMON. */
2773 int short_compare = 0;
2775 /* Nonzero if this is a right-shift operation, which can be computed on the
2776 original short and then promoted if the operand is a promoted short. */
2777 int short_shift = 0;
2779 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2782 /* True if both operands have arithmetic type. */
2783 bool arithmetic_types_p;
2785 /* Apply default conversions. */
2789 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2790 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2791 || code == TRUTH_XOR_EXPR)
2793 if (!really_overloaded_fn (op0))
2794 op0 = decay_conversion (op0);
2795 if (!really_overloaded_fn (op1))
2796 op1 = decay_conversion (op1);
2800 if (!really_overloaded_fn (op0))
2801 op0 = default_conversion (op0);
2802 if (!really_overloaded_fn (op1))
2803 op1 = default_conversion (op1);
2806 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2807 STRIP_TYPE_NOPS (op0);
2808 STRIP_TYPE_NOPS (op1);
2810 /* DTRT if one side is an overloaded function, but complain about it. */
2811 if (type_unknown_p (op0))
2813 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
2814 if (t != error_mark_node)
2816 pedwarn ("assuming cast to type %qT from overloaded function",
2821 if (type_unknown_p (op1))
2823 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
2824 if (t != error_mark_node)
2826 pedwarn ("assuming cast to type %qT from overloaded function",
2832 type0 = TREE_TYPE (op0);
2833 type1 = TREE_TYPE (op1);
2835 /* The expression codes of the data types of the arguments tell us
2836 whether the arguments are integers, floating, pointers, etc. */
2837 code0 = TREE_CODE (type0);
2838 code1 = TREE_CODE (type1);
2840 /* If an error was already reported for one of the arguments,
2841 avoid reporting another error. */
2843 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
2844 return error_mark_node;
2846 if ((invalid_op_diag
2847 = targetm.invalid_binary_op (code, type0, type1)))
2849 error (invalid_op_diag);
2850 return error_mark_node;
2856 /* Handle the pointer + int case. */
2857 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2858 return cp_pointer_int_sum (PLUS_EXPR, op0, op1);
2859 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
2860 return cp_pointer_int_sum (PLUS_EXPR, op1, op0);
2866 /* Subtraction of two similar pointers.
2867 We must subtract them as integers, then divide by object size. */
2868 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
2869 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
2871 return pointer_diff (op0, op1, common_type (type0, type1));
2872 /* Handle pointer minus int. Just like pointer plus int. */
2873 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2874 return cp_pointer_int_sum (MINUS_EXPR, op0, op1);
2883 case TRUNC_DIV_EXPR:
2885 case FLOOR_DIV_EXPR:
2886 case ROUND_DIV_EXPR:
2887 case EXACT_DIV_EXPR:
2888 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2889 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2890 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2891 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
2893 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
2894 warning (0, "division by zero in %<%E / 0%>", op0);
2895 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
2896 warning (0, "division by zero in %<%E / 0.%>", op0);
2898 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2899 code0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
2900 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
2901 code1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
2903 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
2904 resultcode = RDIV_EXPR;
2906 /* When dividing two signed integers, we have to promote to int.
2907 unless we divide by a constant != -1. Note that default
2908 conversion will have been performed on the operands at this
2909 point, so we have to dig out the original type to find out if
2911 shorten = ((TREE_CODE (op0) == NOP_EXPR
2912 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2913 || (TREE_CODE (op1) == INTEGER_CST
2914 && ! integer_all_onesp (op1)));
2923 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2924 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
2928 case TRUNC_MOD_EXPR:
2929 case FLOOR_MOD_EXPR:
2930 if (code1 == INTEGER_TYPE && integer_zerop (op1))
2931 warning (0, "division by zero in %<%E %% 0%>", op0);
2932 else if (code1 == REAL_TYPE && real_zerop (op1))
2933 warning (0, "division by zero in %<%E %% 0.%>", op0);
2935 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2937 /* Although it would be tempting to shorten always here, that loses
2938 on some targets, since the modulo instruction is undefined if the
2939 quotient can't be represented in the computation mode. We shorten
2940 only if unsigned or if dividing by something we know != -1. */
2941 shorten = ((TREE_CODE (op0) == NOP_EXPR
2942 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2943 || (TREE_CODE (op1) == INTEGER_CST
2944 && ! integer_all_onesp (op1)));
2949 case TRUTH_ANDIF_EXPR:
2950 case TRUTH_ORIF_EXPR:
2951 case TRUTH_AND_EXPR:
2953 result_type = boolean_type_node;
2956 /* Shift operations: result has same type as first operand;
2957 always convert second operand to int.
2958 Also set SHORT_SHIFT if shifting rightward. */
2961 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2963 result_type = type0;
2964 if (TREE_CODE (op1) == INTEGER_CST)
2966 if (tree_int_cst_lt (op1, integer_zero_node))
2967 warning (0, "right shift count is negative");
2970 if (! integer_zerop (op1))
2972 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2973 warning (0, "right shift count >= width of type");
2976 /* Convert the shift-count to an integer, regardless of
2977 size of value being shifted. */
2978 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2979 op1 = cp_convert (integer_type_node, op1);
2980 /* Avoid converting op1 to result_type later. */
2986 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2988 result_type = type0;
2989 if (TREE_CODE (op1) == INTEGER_CST)
2991 if (tree_int_cst_lt (op1, integer_zero_node))
2992 warning (0, "left shift count is negative");
2993 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2994 warning (0, "left shift count >= width of type");
2996 /* Convert the shift-count to an integer, regardless of
2997 size of value being shifted. */
2998 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2999 op1 = cp_convert (integer_type_node, op1);
3000 /* Avoid converting op1 to result_type later. */
3007 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3009 result_type = type0;
3010 if (TREE_CODE (op1) == INTEGER_CST)
3012 if (tree_int_cst_lt (op1, integer_zero_node))
3013 warning (0, "%s rotate count is negative",
3014 (code == LROTATE_EXPR) ? "left" : "right");
3015 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3016 warning (0, "%s rotate count >= width of type",
3017 (code == LROTATE_EXPR) ? "left" : "right");
3019 /* Convert the shift-count to an integer, regardless of
3020 size of value being shifted. */
3021 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3022 op1 = cp_convert (integer_type_node, op1);
3028 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE))
3029 warning (0, "comparing floating point with == or != is unsafe");
3031 build_type = boolean_type_node;
3032 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3033 || code0 == COMPLEX_TYPE)
3034 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3035 || code1 == COMPLEX_TYPE))
3037 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3038 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3039 result_type = composite_pointer_type (type0, type1, op0, op1,
3041 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3042 && null_ptr_cst_p (op1))
3043 result_type = type0;
3044 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3045 && null_ptr_cst_p (op0))
3046 result_type = type1;
3047 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3049 result_type = type0;
3050 error ("ISO C++ forbids comparison between pointer and integer");
3052 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3054 result_type = type1;
3055 error ("ISO C++ forbids comparison between pointer and integer");
3057 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3059 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3060 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3061 result_type = TREE_TYPE (op0);
3063 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3064 return cp_build_binary_op (code, op1, op0);
3065 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3066 && same_type_p (type0, type1))
3068 /* E will be the final comparison. */
3070 /* E1 and E2 are for scratch. */
3078 if (TREE_SIDE_EFFECTS (op0))
3079 op0 = save_expr (op0);
3080 if (TREE_SIDE_EFFECTS (op1))
3081 op1 = save_expr (op1);
3086 && (!op0.pfn || op0.delta == op1.delta))
3088 The reason for the `!op0.pfn' bit is that a NULL
3089 pointer-to-member is any member with a zero PFN; the
3090 DELTA field is unspecified. */
3091 pfn0 = pfn_from_ptrmemfunc (op0);
3092 pfn1 = pfn_from_ptrmemfunc (op1);
3093 delta0 = build_ptrmemfunc_access_expr (op0,
3095 delta1 = build_ptrmemfunc_access_expr (op1,
3097 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3098 e2 = cp_build_binary_op (EQ_EXPR,
3100 cp_convert (TREE_TYPE (pfn0),
3101 integer_zero_node));
3102 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3103 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3104 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3105 if (code == EQ_EXPR)
3107 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3111 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3112 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3114 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3115 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3123 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3124 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3126 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3127 result_type = composite_pointer_type (type0, type1, op0, op1,
3135 build_type = boolean_type_node;
3136 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3137 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3139 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3140 result_type = composite_pointer_type (type0, type1, op0, op1,
3142 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3143 && integer_zerop (op1))
3144 result_type = type0;
3145 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3146 && integer_zerop (op0))
3147 result_type = type1;
3148 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3150 result_type = type0;
3151 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3153 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3155 result_type = type1;
3156 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3160 case UNORDERED_EXPR:
3167 build_type = integer_type_node;
3168 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3170 error ("unordered comparison on non-floating point argument");
3171 return error_mark_node;
3180 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3181 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3182 || code1 == COMPLEX_TYPE)))
3183 arithmetic_types_p = 1;
3186 arithmetic_types_p = 0;
3187 /* Vector arithmetic is only allowed when both sides are vectors. */
3188 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3190 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3191 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3194 binary_op_error (code);
3195 return error_mark_node;
3197 arithmetic_types_p = 1;
3200 /* Determine the RESULT_TYPE, if it is not already known. */
3202 && arithmetic_types_p
3203 && (shorten || common || short_compare))
3204 result_type = common_type (type0, type1);
3208 error ("invalid operands of types %qT and %qT to binary %qO",
3209 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3210 return error_mark_node;
3213 /* If we're in a template, the only thing we need to know is the
3215 if (processing_template_decl)
3216 return build2 (resultcode,
3217 build_type ? build_type : result_type,
3220 if (arithmetic_types_p)
3222 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3224 /* For certain operations (which identify themselves by shorten != 0)
3225 if both args were extended from the same smaller type,
3226 do the arithmetic in that type and then extend.
3228 shorten !=0 and !=1 indicates a bitwise operation.
3229 For them, this optimization is safe only if
3230 both args are zero-extended or both are sign-extended.
3231 Otherwise, we might change the result.
3232 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3233 but calculated in (unsigned short) it would be (unsigned short)-1. */
3235 if (shorten && none_complex)
3237 int unsigned0, unsigned1;
3238 tree arg0 = get_narrower (op0, &unsigned0);
3239 tree arg1 = get_narrower (op1, &unsigned1);
3240 /* UNS is 1 if the operation to be done is an unsigned one. */
3241 int uns = TYPE_UNSIGNED (result_type);
3244 final_type = result_type;
3246 /* Handle the case that OP0 does not *contain* a conversion
3247 but it *requires* conversion to FINAL_TYPE. */
3249 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3250 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3251 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3252 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3254 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3256 /* For bitwise operations, signedness of nominal type
3257 does not matter. Consider only how operands were extended. */
3261 /* Note that in all three cases below we refrain from optimizing
3262 an unsigned operation on sign-extended args.
3263 That would not be valid. */
3265 /* Both args variable: if both extended in same way
3266 from same width, do it in that width.
3267 Do it unsigned if args were zero-extended. */
3268 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3269 < TYPE_PRECISION (result_type))
3270 && (TYPE_PRECISION (TREE_TYPE (arg1))
3271 == TYPE_PRECISION (TREE_TYPE (arg0)))
3272 && unsigned0 == unsigned1
3273 && (unsigned0 || !uns))
3274 result_type = c_common_signed_or_unsigned_type
3275 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3276 else if (TREE_CODE (arg0) == INTEGER_CST
3277 && (unsigned1 || !uns)
3278 && (TYPE_PRECISION (TREE_TYPE (arg1))
3279 < TYPE_PRECISION (result_type))
3280 && (type = c_common_signed_or_unsigned_type
3281 (unsigned1, TREE_TYPE (arg1)),
3282 int_fits_type_p (arg0, type)))
3284 else if (TREE_CODE (arg1) == INTEGER_CST
3285 && (unsigned0 || !uns)
3286 && (TYPE_PRECISION (TREE_TYPE (arg0))
3287 < TYPE_PRECISION (result_type))
3288 && (type = c_common_signed_or_unsigned_type
3289 (unsigned0, TREE_TYPE (arg0)),
3290 int_fits_type_p (arg1, type)))
3294 /* Shifts can be shortened if shifting right. */
3299 tree arg0 = get_narrower (op0, &unsigned_arg);
3301 final_type = result_type;
3303 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3304 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3306 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3307 /* We can shorten only if the shift count is less than the
3308 number of bits in the smaller type size. */
3309 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3310 /* If arg is sign-extended and then unsigned-shifted,
3311 we can simulate this with a signed shift in arg's type
3312 only if the extended result is at least twice as wide
3313 as the arg. Otherwise, the shift could use up all the
3314 ones made by sign-extension and bring in zeros.
3315 We can't optimize that case at all, but in most machines
3316 it never happens because available widths are 2**N. */
3317 && (!TYPE_UNSIGNED (final_type)
3319 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3320 <= TYPE_PRECISION (result_type))))
3322 /* Do an unsigned shift if the operand was zero-extended. */
3324 = c_common_signed_or_unsigned_type (unsigned_arg,
3326 /* Convert value-to-be-shifted to that type. */
3327 if (TREE_TYPE (op0) != result_type)
3328 op0 = cp_convert (result_type, op0);
3333 /* Comparison operations are shortened too but differently.
3334 They identify themselves by setting short_compare = 1. */
3338 /* Don't write &op0, etc., because that would prevent op0
3339 from being kept in a register.
3340 Instead, make copies of the our local variables and
3341 pass the copies by reference, then copy them back afterward. */
3342 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3343 enum tree_code xresultcode = resultcode;
3345 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3347 return cp_convert (boolean_type_node, val);
3348 op0 = xop0, op1 = xop1;
3350 resultcode = xresultcode;
3353 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3354 && warn_sign_compare
3355 /* Do not warn until the template is instantiated; we cannot
3356 bound the ranges of the arguments until that point. */
3357 && !processing_template_decl)
3359 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3360 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3362 int unsignedp0, unsignedp1;
3363 tree primop0 = get_narrower (op0, &unsignedp0);
3364 tree primop1 = get_narrower (op1, &unsignedp1);
3366 /* Check for comparison of different enum types. */
3367 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3368 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3369 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3370 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3372 warning (0, "comparison between types %q#T and %q#T",
3373 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3376 /* Give warnings for comparisons between signed and unsigned
3377 quantities that may fail. */
3378 /* Do the checking based on the original operand trees, so that
3379 casts will be considered, but default promotions won't be. */
3381 /* Do not warn if the comparison is being done in a signed type,
3382 since the signed type will only be chosen if it can represent
3383 all the values of the unsigned type. */
3384 if (!TYPE_UNSIGNED (result_type))
3386 /* Do not warn if both operands are unsigned. */
3387 else if (op0_signed == op1_signed)
3389 /* Do not warn if the signed quantity is an unsuffixed
3390 integer literal (or some static constant expression
3391 involving such literals or a conditional expression
3392 involving such literals) and it is non-negative. */
3393 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3394 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3396 /* Do not warn if the comparison is an equality operation,
3397 the unsigned quantity is an integral constant and it does
3398 not use the most significant bit of result_type. */
3399 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3400 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3401 && int_fits_type_p (orig_op1, c_common_signed_type
3403 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3404 && int_fits_type_p (orig_op0, c_common_signed_type
3408 warning (0, "comparison between signed and unsigned integer expressions");
3410 /* Warn if two unsigned values are being compared in a size
3411 larger than their original size, and one (and only one) is the
3412 result of a `~' operator. This comparison will always fail.
3414 Also warn if one operand is a constant, and the constant does not
3415 have all bits set that are set in the ~ operand when it is
3418 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3419 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3421 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3422 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3423 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3424 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3426 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3429 HOST_WIDE_INT constant, mask;
3433 if (host_integerp (primop0, 0))
3436 unsignedp = unsignedp1;
3437 constant = tree_low_cst (primop0, 0);
3442 unsignedp = unsignedp0;
3443 constant = tree_low_cst (primop1, 0);
3446 bits = TYPE_PRECISION (TREE_TYPE (primop));
3447 if (bits < TYPE_PRECISION (result_type)
3448 && bits < HOST_BITS_PER_LONG && unsignedp)
3450 mask = (~ (HOST_WIDE_INT) 0) << bits;
3451 if ((mask & constant) != mask)
3452 warning (0, "comparison of promoted ~unsigned with constant");
3455 else if (unsignedp0 && unsignedp1
3456 && (TYPE_PRECISION (TREE_TYPE (primop0))
3457 < TYPE_PRECISION (result_type))
3458 && (TYPE_PRECISION (TREE_TYPE (primop1))
3459 < TYPE_PRECISION (result_type)))
3460 warning (0, "comparison of promoted ~unsigned with unsigned");
3465 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3466 Then the expression will be built.
3467 It will be given type FINAL_TYPE if that is nonzero;
3468 otherwise, it will be given type RESULT_TYPE. */
3470 /* Issue warnings about peculiar, but valid, uses of NULL. */
3471 if (/* It's reasonable to use pointer values as operands of &&
3472 and ||, so NULL is no exception. */
3473 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3474 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3475 (orig_op0 == null_node
3476 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3477 /* Or vice versa. */
3478 || (orig_op1 == null_node
3479 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3480 /* Or, both are NULL and the operation was not a comparison. */
3481 || (orig_op0 == null_node && orig_op1 == null_node
3482 && code != EQ_EXPR && code != NE_EXPR)))
3483 /* Some sort of arithmetic operation involving NULL was
3484 performed. Note that pointer-difference and pointer-addition
3485 have already been handled above, and so we don't end up here in
3487 warning (0, "NULL used in arithmetic");
3491 if (TREE_TYPE (op0) != result_type)
3492 op0 = cp_convert (result_type, op0);
3493 if (TREE_TYPE (op1) != result_type)
3494 op1 = cp_convert (result_type, op1);
3496 if (op0 == error_mark_node || op1 == error_mark_node)
3497 return error_mark_node;
3500 if (build_type == NULL_TREE)
3501 build_type = result_type;
3503 result = build2 (resultcode, build_type, op0, op1);
3504 result = fold_if_not_in_template (result);
3505 if (final_type != 0)
3506 result = cp_convert (final_type, result);
3510 /* Return a tree for the sum or difference (RESULTCODE says which)
3511 of pointer PTROP and integer INTOP. */
3514 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3516 tree res_type = TREE_TYPE (ptrop);
3518 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3519 in certain circumstance (when it's valid to do so). So we need
3520 to make sure it's complete. We don't need to check here, if we
3521 can actually complete it at all, as those checks will be done in
3522 pointer_int_sum() anyway. */
3523 complete_type (TREE_TYPE (res_type));
3525 return pointer_int_sum (resultcode, ptrop,
3526 fold_if_not_in_template (intop));
3529 /* Return a tree for the difference of pointers OP0 and OP1.
3530 The resulting tree has type int. */
3533 pointer_diff (tree op0, tree op1, tree ptrtype)
3536 tree restype = ptrdiff_type_node;
3537 tree target_type = TREE_TYPE (ptrtype);
3539 if (!complete_type_or_else (target_type, NULL_TREE))
3540 return error_mark_node;
3542 if (pedantic || warn_pointer_arith)
3544 if (TREE_CODE (target_type) == VOID_TYPE)
3545 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3546 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3547 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3548 if (TREE_CODE (target_type) == METHOD_TYPE)
3549 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3552 /* First do the subtraction as integers;
3553 then drop through to build the divide operator. */
3555 op0 = cp_build_binary_op (MINUS_EXPR,
3556 cp_convert (restype, op0),
3557 cp_convert (restype, op1));
3559 /* This generates an error if op1 is a pointer to an incomplete type. */
3560 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3561 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3563 op1 = (TYPE_PTROB_P (ptrtype)
3564 ? size_in_bytes (target_type)
3565 : integer_one_node);
3567 /* Do the division. */
3569 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3570 return fold_if_not_in_template (result);
3573 /* Construct and perhaps optimize a tree representation
3574 for a unary operation. CODE, a tree_code, specifies the operation
3575 and XARG is the operand. */
3578 build_x_unary_op (enum tree_code code, tree xarg)
3580 tree orig_expr = xarg;
3584 if (processing_template_decl)
3586 if (type_dependent_expression_p (xarg))
3587 return build_min_nt (code, xarg, NULL_TREE);
3589 xarg = build_non_dependent_expr (xarg);
3594 /* [expr.unary.op] says:
3596 The address of an object of incomplete type can be taken.
3598 (And is just the ordinary address operator, not an overloaded
3599 "operator &".) However, if the type is a template
3600 specialization, we must complete the type at this point so that
3601 an overloaded "operator &" will be available if required. */
3602 if (code == ADDR_EXPR
3603 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3604 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3605 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3606 || (TREE_CODE (xarg) == OFFSET_REF)))
3607 /* Don't look for a function. */;
3609 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3610 /*overloaded_p=*/NULL);
3611 if (!exp && code == ADDR_EXPR)
3613 /* A pointer to member-function can be formed only by saying
3615 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3616 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3618 if (TREE_CODE (xarg) != OFFSET_REF)
3620 error ("invalid use of %qE to form a pointer-to-member-function."
3621 " Use a qualified-id.",
3623 return error_mark_node;
3627 error ("parenthesis around %qE cannot be used to form a"
3628 " pointer-to-member-function",
3630 PTRMEM_OK_P (xarg) = 1;
3634 if (TREE_CODE (xarg) == OFFSET_REF)
3636 ptrmem = PTRMEM_OK_P (xarg);
3638 if (!ptrmem && !flag_ms_extensions
3639 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3641 /* A single non-static member, make sure we don't allow a
3642 pointer-to-member. */
3643 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3644 TREE_OPERAND (xarg, 0),
3645 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3646 PTRMEM_OK_P (xarg) = ptrmem;
3649 else if (TREE_CODE (xarg) == TARGET_EXPR)
3650 warning (0, "taking address of temporary");
3651 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3654 if (processing_template_decl && exp != error_mark_node)
3655 exp = build_min_non_dep (code, exp, orig_expr,
3656 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3657 if (TREE_CODE (exp) == ADDR_EXPR)
3658 PTRMEM_OK_P (exp) = ptrmem;
3662 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3663 constants, where a null value is represented by an INTEGER_CST of
3667 cp_truthvalue_conversion (tree expr)
3669 tree type = TREE_TYPE (expr);
3670 if (TYPE_PTRMEM_P (type))
3671 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3673 return c_common_truthvalue_conversion (expr);
3676 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3679 condition_conversion (tree expr)
3682 if (processing_template_decl)
3684 t = perform_implicit_conversion (boolean_type_node, expr);
3685 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3689 /* Return an ADDR_EXPR giving the address of T. This function
3690 attempts no optimizations or simplifications; it is a low-level
3694 build_address (tree t)
3698 if (error_operand_p (t) || !cxx_mark_addressable (t))
3699 return error_mark_node;
3701 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3706 /* Return a NOP_EXPR converting EXPR to TYPE. */
3709 build_nop (tree type, tree expr)
3711 if (type == error_mark_node || error_operand_p (expr))
3713 return build1 (NOP_EXPR, type, expr);
3716 /* C++: Must handle pointers to members.
3718 Perhaps type instantiation should be extended to handle conversion
3719 from aggregates to types we don't yet know we want? (Or are those
3720 cases typically errors which should be reported?)
3722 NOCONVERT nonzero suppresses the default promotions
3723 (such as from short to int). */
3726 build_unary_op (enum tree_code code, tree xarg, int noconvert)
3728 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
3731 const char *errstring = NULL;
3733 const char *invalid_op_diag;
3735 if (arg == error_mark_node)
3736 return error_mark_node;
3738 if ((invalid_op_diag
3739 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
3744 error (invalid_op_diag);
3745 return error_mark_node;
3750 case UNARY_PLUS_EXPR:
3753 int flags = WANT_ARITH | WANT_ENUM;
3754 /* Unary plus (but not unary minus) is allowed on pointers. */
3755 if (code == UNARY_PLUS_EXPR)
3756 flags |= WANT_POINTER;
3757 arg = build_expr_type_conversion (flags, arg, true);
3759 errstring = (code == NEGATE_EXPR
3760 ? "wrong type argument to unary minus"
3761 : "wrong type argument to unary plus");
3764 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
3765 arg = perform_integral_promotions (arg);
3767 /* Make sure the result is not a lvalue: a unary plus or minus
3768 expression is always a rvalue. */
3769 if (real_lvalue_p (arg))
3770 arg = build1 (NON_LVALUE_EXPR, TREE_TYPE (arg), arg);
3776 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3780 arg = default_conversion (arg);
3782 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM,
3784 errstring = "wrong type argument to bit-complement";
3785 else if (!noconvert)
3786 arg = perform_integral_promotions (arg);
3790 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3791 errstring = "wrong type argument to abs";
3792 else if (!noconvert)
3793 arg = default_conversion (arg);
3797 /* Conjugating a real value is a no-op, but allow it anyway. */
3798 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3799 errstring = "wrong type argument to conjugation";
3800 else if (!noconvert)
3801 arg = default_conversion (arg);
3804 case TRUTH_NOT_EXPR:
3805 arg = perform_implicit_conversion (boolean_type_node, arg);
3806 val = invert_truthvalue (arg);
3807 if (arg != error_mark_node)
3809 errstring = "in argument to unary !";
3816 if (TREE_CODE (arg) == COMPLEX_CST)
3817 return TREE_REALPART (arg);
3818 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3820 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3821 return fold_if_not_in_template (arg);
3827 if (TREE_CODE (arg) == COMPLEX_CST)
3828 return TREE_IMAGPART (arg);
3829 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3831 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3832 return fold_if_not_in_template (arg);
3835 return cp_convert (TREE_TYPE (arg), integer_zero_node);
3837 case PREINCREMENT_EXPR:
3838 case POSTINCREMENT_EXPR:
3839 case PREDECREMENT_EXPR:
3840 case POSTDECREMENT_EXPR:
3841 /* Handle complex lvalues (when permitted)
3842 by reduction to simpler cases. */
3844 val = unary_complex_lvalue (code, arg);
3848 /* Increment or decrement the real part of the value,
3849 and don't change the imaginary part. */
3850 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3854 arg = stabilize_reference (arg);
3855 real = build_unary_op (REALPART_EXPR, arg, 1);
3856 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
3857 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
3858 build_unary_op (code, real, 1), imag);
3861 /* Report invalid types. */
3863 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
3866 if (code == PREINCREMENT_EXPR)
3867 errstring ="no pre-increment operator for type";
3868 else if (code == POSTINCREMENT_EXPR)
3869 errstring ="no post-increment operator for type";
3870 else if (code == PREDECREMENT_EXPR)
3871 errstring ="no pre-decrement operator for type";
3873 errstring ="no post-decrement operator for type";
3877 /* Report something read-only. */
3879 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
3880 || TREE_READONLY (arg))
3881 readonly_error (arg, ((code == PREINCREMENT_EXPR
3882 || code == POSTINCREMENT_EXPR)
3883 ? "increment" : "decrement"),
3888 tree result_type = TREE_TYPE (arg);
3890 arg = get_unwidened (arg, 0);
3891 argtype = TREE_TYPE (arg);
3893 /* ARM $5.2.5 last annotation says this should be forbidden. */
3894 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
3895 pedwarn ("ISO C++ forbids %sing an enum",
3896 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3897 ? "increment" : "decrement");
3899 /* Compute the increment. */
3901 if (TREE_CODE (argtype) == POINTER_TYPE)
3903 tree type = complete_type (TREE_TYPE (argtype));
3905 if (!COMPLETE_OR_VOID_TYPE_P (type))
3906 error ("cannot %s a pointer to incomplete type %qT",
3907 ((code == PREINCREMENT_EXPR
3908 || code == POSTINCREMENT_EXPR)
3909 ? "increment" : "decrement"), TREE_TYPE (argtype));
3910 else if ((pedantic || warn_pointer_arith)
3911 && !TYPE_PTROB_P (argtype))
3912 pedwarn ("ISO C++ forbids %sing a pointer of type %qT",
3913 ((code == PREINCREMENT_EXPR
3914 || code == POSTINCREMENT_EXPR)
3915 ? "increment" : "decrement"), argtype);
3916 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
3919 inc = integer_one_node;
3921 inc = cp_convert (argtype, inc);
3923 /* Handle incrementing a cast-expression. */
3925 switch (TREE_CODE (arg))
3930 case FIX_TRUNC_EXPR:
3931 case FIX_FLOOR_EXPR:
3932 case FIX_ROUND_EXPR:
3935 tree incremented, modify, value, compound;
3936 if (! lvalue_p (arg) && pedantic)
3937 pedwarn ("cast to non-reference type used as lvalue");
3938 arg = stabilize_reference (arg);
3939 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
3942 value = save_expr (arg);
3943 incremented = build2 (((code == PREINCREMENT_EXPR
3944 || code == POSTINCREMENT_EXPR)
3945 ? PLUS_EXPR : MINUS_EXPR),
3946 argtype, value, inc);
3948 modify = build_modify_expr (arg, NOP_EXPR, incremented);
3949 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
3952 /* Eliminate warning about unused result of + or -. */
3953 TREE_NO_WARNING (compound) = 1;
3961 /* Complain about anything else that is not a true lvalue. */
3962 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
3963 || code == POSTINCREMENT_EXPR)
3964 ? lv_increment : lv_decrement)))
3965 return error_mark_node;
3967 /* Forbid using -- on `bool'. */
3968 if (TREE_TYPE (arg) == boolean_type_node)
3970 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
3972 error ("invalid use of %<--%> on bool variable %qD", arg);
3973 return error_mark_node;
3975 val = boolean_increment (code, arg);
3978 val = build2 (code, TREE_TYPE (arg), arg, inc);
3980 TREE_SIDE_EFFECTS (val) = 1;
3981 return cp_convert (result_type, val);
3985 /* Note that this operation never does default_conversion
3986 regardless of NOCONVERT. */
3988 argtype = lvalue_type (arg);
3990 if (TREE_CODE (arg) == OFFSET_REF)
3993 if (TREE_CODE (argtype) == REFERENCE_TYPE)
3995 tree type = build_pointer_type (TREE_TYPE (argtype));
3996 arg = build1 (CONVERT_EXPR, type, arg);
3999 else if (pedantic && DECL_MAIN_P (arg))
4001 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4003 /* Let &* cancel out to simplify resulting code. */
4004 if (TREE_CODE (arg) == INDIRECT_REF)
4006 /* We don't need to have `current_class_ptr' wrapped in a
4007 NON_LVALUE_EXPR node. */
4008 if (arg == current_class_ref)
4009 return current_class_ptr;
4011 arg = TREE_OPERAND (arg, 0);
4012 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4014 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4015 arg = build1 (CONVERT_EXPR, type, arg);
4017 else if (lvalue_p (arg))
4018 /* Don't let this be an lvalue. */
4019 return non_lvalue (arg);
4023 /* Uninstantiated types are all functions. Taking the
4024 address of a function is a no-op, so just return the
4027 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4028 || !IDENTIFIER_OPNAME_P (arg));
4030 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4031 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4033 /* They're trying to take the address of a unique non-static
4034 member function. This is ill-formed (except in MS-land),
4035 but let's try to DTRT.
4036 Note: We only handle unique functions here because we don't
4037 want to complain if there's a static overload; non-unique
4038 cases will be handled by instantiate_type. But we need to
4039 handle this case here to allow casts on the resulting PMF.
4040 We could defer this in non-MS mode, but it's easier to give
4041 a useful error here. */
4043 /* Inside constant member functions, the `this' pointer
4044 contains an extra const qualifier. TYPE_MAIN_VARIANT
4045 is used here to remove this const from the diagnostics
4046 and the created OFFSET_REF. */
4047 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4048 tree name = DECL_NAME (get_first_fn (TREE_OPERAND (arg, 1)));
4050 if (! flag_ms_extensions)
4052 if (current_class_type
4053 && TREE_OPERAND (arg, 0) == current_class_ref)
4054 /* An expression like &memfn. */
4055 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4056 " or parenthesized non-static member function to form"
4057 " a pointer to member function. Say %<&%T::%D%>",
4060 pedwarn ("ISO C++ forbids taking the address of a bound member"
4061 " function to form a pointer to member function."
4065 arg = build_offset_ref (base, name, /*address_p=*/true);
4069 if (type_unknown_p (arg))
4070 return build1 (ADDR_EXPR, unknown_type_node, arg);
4072 /* Handle complex lvalues (when permitted)
4073 by reduction to simpler cases. */
4074 val = unary_complex_lvalue (code, arg);
4078 switch (TREE_CODE (arg))
4083 case FIX_TRUNC_EXPR:
4084 case FIX_FLOOR_EXPR:
4085 case FIX_ROUND_EXPR:
4087 if (! lvalue_p (arg) && pedantic)
4088 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4092 arg = OVL_CURRENT (arg);
4096 /* Turn a reference to a non-static data member into a
4097 pointer-to-member. */
4102 if (!PTRMEM_OK_P (arg))
4103 return build_unary_op (code, arg, 0);
4105 t = TREE_OPERAND (arg, 1);
4106 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4108 error ("cannot create pointer to reference member %qD", t);
4109 return error_mark_node;
4112 type = build_ptrmem_type (context_for_name_lookup (t),
4114 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4122 /* Allow the address of a constructor if all the elements
4124 if (TREE_CODE (arg) == CONSTRUCTOR && TREE_HAS_CONSTRUCTOR (arg)
4125 && TREE_CONSTANT (arg))
4127 /* Anything not already handled and not a true memory reference
4129 else if (TREE_CODE (argtype) != FUNCTION_TYPE
4130 && TREE_CODE (argtype) != METHOD_TYPE
4131 && TREE_CODE (arg) != OFFSET_REF
4132 && !lvalue_or_else (arg, lv_addressof))
4133 return error_mark_node;
4135 if (argtype != error_mark_node)
4136 argtype = build_pointer_type (argtype);
4141 if (TREE_CODE (arg) != COMPONENT_REF
4142 /* Inside a template, we are processing a non-dependent
4143 expression so we can just form an ADDR_EXPR with the
4145 || processing_template_decl)
4147 addr = build_address (arg);
4148 if (TREE_CODE (arg) == OFFSET_REF)
4149 PTRMEM_OK_P (addr) = PTRMEM_OK_P (arg);
4151 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4153 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4155 /* We can only get here with a single static member
4157 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4158 && DECL_STATIC_FUNCTION_P (fn));
4160 addr = build_address (fn);
4161 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4162 /* Do not lose object's side effects. */
4163 addr = build2 (COMPOUND_EXPR, TREE_TYPE (addr),
4164 TREE_OPERAND (arg, 0), addr);
4166 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4168 error ("attempt to take address of bit-field structure member %qD",
4169 TREE_OPERAND (arg, 1));
4170 return error_mark_node;
4174 tree object = TREE_OPERAND (arg, 0);
4175 tree field = TREE_OPERAND (arg, 1);
4176 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4177 (TREE_TYPE (object), decl_type_context (field)));
4178 addr = build_address (arg);
4181 if (TREE_CODE (argtype) == POINTER_TYPE
4182 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4184 build_ptrmemfunc_type (argtype);
4185 addr = build_ptrmemfunc (argtype, addr, 0,
4186 /*c_cast_p=*/false);
4199 argtype = TREE_TYPE (arg);
4200 return fold_if_not_in_template (build1 (code, argtype, arg));
4203 error ("%s", errstring);
4204 return error_mark_node;
4207 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4208 for certain kinds of expressions which are not really lvalues
4209 but which we can accept as lvalues.
4211 If ARG is not a kind of expression we can handle, return
4215 unary_complex_lvalue (enum tree_code code, tree arg)
4217 /* Inside a template, making these kinds of adjustments is
4218 pointless; we are only concerned with the type of the
4220 if (processing_template_decl)
4223 /* Handle (a, b) used as an "lvalue". */
4224 if (TREE_CODE (arg) == COMPOUND_EXPR)
4226 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4227 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4228 TREE_OPERAND (arg, 0), real_result);
4231 /* Handle (a ? b : c) used as an "lvalue". */
4232 if (TREE_CODE (arg) == COND_EXPR
4233 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4234 return rationalize_conditional_expr (code, arg);
4236 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4237 if (TREE_CODE (arg) == MODIFY_EXPR
4238 || TREE_CODE (arg) == PREINCREMENT_EXPR
4239 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4241 tree lvalue = TREE_OPERAND (arg, 0);
4242 if (TREE_SIDE_EFFECTS (lvalue))
4244 lvalue = stabilize_reference (lvalue);
4245 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4246 lvalue, TREE_OPERAND (arg, 1));
4248 return unary_complex_lvalue
4249 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4252 if (code != ADDR_EXPR)
4255 /* Handle (a = b) used as an "lvalue" for `&'. */
4256 if (TREE_CODE (arg) == MODIFY_EXPR
4257 || TREE_CODE (arg) == INIT_EXPR)
4259 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4260 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4262 TREE_NO_WARNING (arg) = 1;
4266 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4267 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4268 || TREE_CODE (arg) == OFFSET_REF)
4271 /* We permit compiler to make function calls returning
4272 objects of aggregate type look like lvalues. */
4276 if (TREE_CODE (targ) == SAVE_EXPR)
4277 targ = TREE_OPERAND (targ, 0);
4279 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4281 if (TREE_CODE (arg) == SAVE_EXPR)
4284 targ = build_cplus_new (TREE_TYPE (arg), arg);
4285 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4288 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4289 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4290 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4293 /* Don't let anything else be handled specially. */
4297 /* Mark EXP saying that we need to be able to take the
4298 address of it; it should not be allocated in a register.
4299 Value is true if successful.
4301 C++: we do not allow `current_class_ptr' to be addressable. */
4304 cxx_mark_addressable (tree exp)
4309 switch (TREE_CODE (x))
4316 x = TREE_OPERAND (x, 0);
4320 if (x == current_class_ptr)
4322 error ("cannot take the address of %<this%>, which is an rvalue expression");
4323 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4329 /* Caller should not be trying to mark initialized
4330 constant fields addressable. */
4331 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4332 || DECL_IN_AGGR_P (x) == 0
4334 || DECL_EXTERNAL (x));
4339 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4340 && !DECL_ARTIFICIAL (x))
4342 if (DECL_HARD_REGISTER (x) != 0)
4345 ("address of explicit register variable %qD requested", x);
4348 else if (extra_warnings)
4350 (0, "address requested for %qD, which is declared %<register%>", x);
4352 TREE_ADDRESSABLE (x) = 1;
4356 TREE_ADDRESSABLE (x) = 1;
4360 TREE_ADDRESSABLE (x) = 1;
4364 TREE_ADDRESSABLE (x) = 1;
4365 cxx_mark_addressable (TREE_OPERAND (x, 0));
4373 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4376 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4378 tree orig_ifexp = ifexp;
4379 tree orig_op1 = op1;
4380 tree orig_op2 = op2;
4383 if (processing_template_decl)
4385 /* The standard says that the expression is type-dependent if
4386 IFEXP is type-dependent, even though the eventual type of the
4387 expression doesn't dependent on IFEXP. */
4388 if (type_dependent_expression_p (ifexp)
4389 /* As a GNU extension, the middle operand may be omitted. */
4390 || (op1 && type_dependent_expression_p (op1))
4391 || type_dependent_expression_p (op2))
4392 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4393 ifexp = build_non_dependent_expr (ifexp);
4395 op1 = build_non_dependent_expr (op1);
4396 op2 = build_non_dependent_expr (op2);
4399 expr = build_conditional_expr (ifexp, op1, op2);
4400 if (processing_template_decl && expr != error_mark_node)
4401 return build_min_non_dep (COND_EXPR, expr,
4402 orig_ifexp, orig_op1, orig_op2);
4406 /* Given a list of expressions, return a compound expression
4407 that performs them all and returns the value of the last of them. */
4409 tree build_x_compound_expr_from_list (tree list, const char *msg)
4411 tree expr = TREE_VALUE (list);
4413 if (TREE_CHAIN (list))
4416 pedwarn ("%s expression list treated as compound expression", msg);
4418 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4419 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4425 /* Handle overloading of the ',' operator when needed. */
4428 build_x_compound_expr (tree op1, tree op2)
4431 tree orig_op1 = op1;
4432 tree orig_op2 = op2;
4434 if (processing_template_decl)
4436 if (type_dependent_expression_p (op1)
4437 || type_dependent_expression_p (op2))
4438 return build_min_nt (COMPOUND_EXPR, op1, op2);
4439 op1 = build_non_dependent_expr (op1);
4440 op2 = build_non_dependent_expr (op2);
4443 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4444 /*overloaded_p=*/NULL);
4446 result = build_compound_expr (op1, op2);
4448 if (processing_template_decl && result != error_mark_node)
4449 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4454 /* Build a compound expression. */
4457 build_compound_expr (tree lhs, tree rhs)
4459 lhs = convert_to_void (lhs, "left-hand operand of comma");
4461 if (lhs == error_mark_node || rhs == error_mark_node)
4462 return error_mark_node;
4464 if (TREE_CODE (rhs) == TARGET_EXPR)
4466 /* If the rhs is a TARGET_EXPR, then build the compound
4467 expression inside the target_expr's initializer. This
4468 helps the compiler to eliminate unnecessary temporaries. */
4469 tree init = TREE_OPERAND (rhs, 1);
4471 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4472 TREE_OPERAND (rhs, 1) = init;
4477 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4480 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4481 casts away constness. DIAG_FN gives the function to call if we
4482 need to issue a diagnostic; if it is NULL, no diagnostic will be
4483 issued. DESCRIPTION explains what operation is taking place. */
4486 check_for_casting_away_constness (tree src_type, tree dest_type,
4487 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4488 const char *description)
4490 if (diag_fn && casts_away_constness (src_type, dest_type))
4491 error ("%s from type %qT to type %qT casts away constness",
4492 description, src_type, dest_type);
4495 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4496 (another pointer-to-member type in the same hierarchy) and return
4497 the converted expression. If ALLOW_INVERSE_P is permitted, a
4498 pointer-to-derived may be converted to pointer-to-base; otherwise,
4499 only the other direction is permitted. If C_CAST_P is true, this
4500 conversion is taking place as part of a C-style cast. */
4503 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4506 if (TYPE_PTRMEM_P (type))
4510 if (TREE_CODE (expr) == PTRMEM_CST)
4511 expr = cplus_expand_constant (expr);
4512 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4513 TYPE_PTRMEM_CLASS_TYPE (type),
4516 if (!integer_zerop (delta))
4517 expr = cp_build_binary_op (PLUS_EXPR,
4518 build_nop (ptrdiff_type_node, expr),
4520 return build_nop (type, expr);
4523 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4524 allow_inverse_p, c_cast_p);
4527 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4528 this static_cast is being attempted as one of the possible casts
4529 allowed by a C-style cast. (In that case, accessibility of base
4530 classes is not considered, and it is OK to cast away
4531 constness.) Return the result of the cast. *VALID_P is set to
4532 indicate whether or not the cast was valid. */
4535 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4541 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4544 /* Assume the cast is valid. */
4547 intype = TREE_TYPE (expr);
4549 /* Determine what to do when casting away constness. */
4552 /* C-style casts are allowed to cast away constness. With
4553 WARN_CAST_QUAL, we still want to issue a warning. */
4554 diag_fn = warn_cast_qual ? warning0 : NULL;
4559 /* A static_cast may not cast away constness. */
4561 desc = "static_cast";
4564 /* [expr.static.cast]
4566 An lvalue of type "cv1 B", where B is a class type, can be cast
4567 to type "reference to cv2 D", where D is a class derived (clause
4568 _class.derived_) from B, if a valid standard conversion from
4569 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4570 same cv-qualification as, or greater cv-qualification than, cv1,
4571 and B is not a virtual base class of D. */
4572 /* We check this case before checking the validity of "TYPE t =
4573 EXPR;" below because for this case:
4576 struct D : public B { D(const B&); };
4578 void f() { static_cast<const D&>(b); }
4580 we want to avoid constructing a new D. The standard is not
4581 completely clear about this issue, but our interpretation is
4582 consistent with other compilers. */
4583 if (TREE_CODE (type) == REFERENCE_TYPE
4584 && CLASS_TYPE_P (TREE_TYPE (type))
4585 && CLASS_TYPE_P (intype)
4586 && real_lvalue_p (expr)
4587 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4588 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4589 build_pointer_type (TYPE_MAIN_VARIANT
4590 (TREE_TYPE (type))))
4592 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4596 /* There is a standard conversion from "D*" to "B*" even if "B"
4597 is ambiguous or inaccessible. If this is really a
4598 static_cast, then we check both for inaccessibility and
4599 ambiguity. However, if this is a static_cast being performed
4600 because the user wrote a C-style cast, then accessibility is
4602 base = lookup_base (TREE_TYPE (type), intype,
4603 c_cast_p ? ba_unique : ba_check,
4606 /* Convert from "B*" to "D*". This function will check that "B"
4607 is not a virtual base of "D". */
4608 expr = build_base_path (MINUS_EXPR, build_address (expr),
4609 base, /*nonnull=*/false);
4610 /* Convert the pointer to a reference -- but then remember that
4611 there are no expressions with reference type in C++. */
4612 return convert_from_reference (build_nop (type, expr));
4617 /* [expr.static.cast]
4619 An expression e can be explicitly converted to a type T using a
4620 static_cast of the form static_cast<T>(e) if the declaration T
4621 t(e);" is well-formed, for some invented temporary variable
4623 result = perform_direct_initialization_if_possible (type, expr,
4627 result = convert_from_reference (result);
4629 /* Ignore any integer overflow caused by the cast. */
4630 if (TREE_CODE (result) == INTEGER_CST
4631 && CONSTANT_CLASS_P (orig))
4633 TREE_OVERFLOW (result) = TREE_OVERFLOW (orig);
4634 TREE_CONSTANT_OVERFLOW (result)
4635 = TREE_CONSTANT_OVERFLOW (orig);
4637 /* [expr.static.cast]
4639 If T is a reference type, the result is an lvalue; otherwise,
4640 the result is an rvalue. */
4641 if (TREE_CODE (type) != REFERENCE_TYPE
4642 && real_lvalue_p (result))
4643 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (result), result);
4647 /* [expr.static.cast]
4649 Any expression can be explicitly converted to type cv void. */
4650 if (TREE_CODE (type) == VOID_TYPE)
4651 return convert_to_void (expr, /*implicit=*/NULL);
4653 /* [expr.static.cast]
4655 The inverse of any standard conversion sequence (clause _conv_),
4656 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4657 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4658 (_conv.bool_) conversions, can be performed explicitly using
4659 static_cast subject to the restriction that the explicit
4660 conversion does not cast away constness (_expr.const.cast_), and
4661 the following additional rules for specific cases: */
4662 /* For reference, the conversions not excluded are: integral
4663 promotions, floating point promotion, integral conversions,
4664 floating point conversions, floating-integral conversions,
4665 pointer conversions, and pointer to member conversions. */
4668 A value of integral _or enumeration_ type can be explicitly
4669 converted to an enumeration type. */
4670 /* The effect of all that is that any conversion between any two
4671 types which are integral, floating, or enumeration types can be
4673 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
4674 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
4676 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
4678 /* Ignore any integer overflow caused by the cast. */
4679 if (TREE_CODE (expr) == INTEGER_CST
4680 && CONSTANT_CLASS_P (orig))
4682 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4683 TREE_CONSTANT_OVERFLOW (expr) = TREE_CONSTANT_OVERFLOW (orig);
4688 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4689 && CLASS_TYPE_P (TREE_TYPE (type))
4690 && CLASS_TYPE_P (TREE_TYPE (intype))
4691 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4692 (TREE_TYPE (intype))),
4693 build_pointer_type (TYPE_MAIN_VARIANT
4694 (TREE_TYPE (type)))))
4699 check_for_casting_away_constness (intype, type, diag_fn, desc);
4700 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
4701 c_cast_p ? ba_unique : ba_check,
4703 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
4706 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4707 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4714 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
4715 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
4717 if (TYPE_PTRMEM_P (type))
4719 t1 = (build_ptrmem_type
4721 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
4722 t2 = (build_ptrmem_type
4724 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
4731 if (can_convert (t1, t2))
4734 check_for_casting_away_constness (intype, type, diag_fn,
4736 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
4741 /* [expr.static.cast]
4743 An rvalue of type "pointer to cv void" can be explicitly
4744 converted to a pointer to object type. A value of type pointer
4745 to object converted to "pointer to cv void" and back to the
4746 original pointer type will have its original value. */
4747 if (TREE_CODE (intype) == POINTER_TYPE
4748 && VOID_TYPE_P (TREE_TYPE (intype))
4749 && TYPE_PTROB_P (type))
4752 check_for_casting_away_constness (intype, type, diag_fn, desc);
4753 return build_nop (type, expr);
4757 return error_mark_node;
4760 /* Return an expression representing static_cast<TYPE>(EXPR). */
4763 build_static_cast (tree type, tree expr)
4768 if (type == error_mark_node || expr == error_mark_node)
4769 return error_mark_node;
4771 if (processing_template_decl)
4773 expr = build_min (STATIC_CAST_EXPR, type, expr);
4774 /* We don't know if it will or will not have side effects. */
4775 TREE_SIDE_EFFECTS (expr) = 1;
4776 return convert_from_reference (expr);
4779 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4780 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4781 if (TREE_CODE (type) != REFERENCE_TYPE
4782 && TREE_CODE (expr) == NOP_EXPR
4783 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4784 expr = TREE_OPERAND (expr, 0);
4786 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
4790 error ("invalid static_cast from type %qT to type %qT",
4791 TREE_TYPE (expr), type);
4792 return error_mark_node;
4795 /* EXPR is an expression with member function or pointer-to-member
4796 function type. TYPE is a pointer type. Converting EXPR to TYPE is
4797 not permitted by ISO C++, but we accept it in some modes. If we
4798 are not in one of those modes, issue a diagnostic. Return the
4799 converted expression. */
4802 convert_member_func_to_ptr (tree type, tree expr)
4807 intype = TREE_TYPE (expr);
4808 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
4809 || TREE_CODE (intype) == METHOD_TYPE);
4811 if (pedantic || warn_pmf2ptr)
4812 pedwarn ("converting from %qT to %qT", intype, type);
4814 if (TREE_CODE (intype) == METHOD_TYPE)
4815 expr = build_addr_func (expr);
4816 else if (TREE_CODE (expr) == PTRMEM_CST)
4817 expr = build_address (PTRMEM_CST_MEMBER (expr));
4820 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
4821 decl = build_address (decl);
4822 expr = get_member_function_from_ptrfunc (&decl, expr);
4825 return build_nop (type, expr);
4828 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
4829 If C_CAST_P is true, this reinterpret cast is being done as part of
4830 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
4831 indicate whether or not reinterpret_cast was valid. */
4834 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
4839 /* Assume the cast is invalid. */
4843 if (type == error_mark_node || error_operand_p (expr))
4844 return error_mark_node;
4846 intype = TREE_TYPE (expr);
4848 /* [expr.reinterpret.cast]
4849 An lvalue expression of type T1 can be cast to the type
4850 "reference to T2" if an expression of type "pointer to T1" can be
4851 explicitly converted to the type "pointer to T2" using a
4852 reinterpret_cast. */
4853 if (TREE_CODE (type) == REFERENCE_TYPE)
4855 if (! real_lvalue_p (expr))
4857 error ("invalid cast of an rvalue expression of type "
4860 return error_mark_node;
4863 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
4864 "B" are related class types; the reinterpret_cast does not
4865 adjust the pointer. */
4866 if (TYPE_PTR_P (intype)
4867 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
4868 COMPARE_BASE | COMPARE_DERIVED)))
4869 warning (0, "casting %qT to %qT does not dereference pointer",
4872 expr = build_unary_op (ADDR_EXPR, expr, 0);
4873 if (expr != error_mark_node)
4874 expr = build_reinterpret_cast_1
4875 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
4877 if (expr != error_mark_node)
4878 expr = build_indirect_ref (expr, 0);
4882 /* As a G++ extension, we consider conversions from member
4883 functions, and pointers to member functions to
4884 pointer-to-function and pointer-to-void types. If
4885 -Wno-pmf-conversions has not been specified,
4886 convert_member_func_to_ptr will issue an error message. */
4887 if ((TYPE_PTRMEMFUNC_P (intype)
4888 || TREE_CODE (intype) == METHOD_TYPE)
4889 && TYPE_PTR_P (type)
4890 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
4891 || VOID_TYPE_P (TREE_TYPE (type))))
4892 return convert_member_func_to_ptr (type, expr);
4894 /* If the cast is not to a reference type, the lvalue-to-rvalue,
4895 array-to-pointer, and function-to-pointer conversions are
4897 expr = decay_conversion (expr);
4899 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4900 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4901 if (TREE_CODE (expr) == NOP_EXPR
4902 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4903 expr = TREE_OPERAND (expr, 0);
4905 if (error_operand_p (expr))
4906 return error_mark_node;
4908 intype = TREE_TYPE (expr);
4910 /* [expr.reinterpret.cast]
4911 A pointer can be converted to any integral type large enough to
4913 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
4915 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
4916 pedwarn ("cast from %qT to %qT loses precision",
4919 /* [expr.reinterpret.cast]
4920 A value of integral or enumeration type can be explicitly
4921 converted to a pointer. */
4922 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
4925 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
4926 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4927 return fold_if_not_in_template (build_nop (type, expr));
4928 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4929 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
4932 check_for_casting_away_constness (intype, type, error,
4933 "reinterpret_cast");
4934 /* Warn about possible alignment problems. */
4935 if (STRICT_ALIGNMENT && warn_cast_align
4936 && !VOID_TYPE_P (type)
4937 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
4938 && COMPLETE_TYPE_P (TREE_TYPE (type))
4939 && COMPLETE_TYPE_P (TREE_TYPE (intype))
4940 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
4941 warning (0, "cast from %qT to %qT increases required alignment of "
4945 return fold_if_not_in_template (build_nop (type, expr));
4947 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
4948 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
4951 /* Only issue a warning, as we have always supported this
4952 where possible, and it is necessary in some cases. DR 195
4953 addresses this issue, but as of 2004/10/26 is still in
4955 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
4956 return fold_if_not_in_template (build_nop (type, expr));
4958 else if (TREE_CODE (type) == VECTOR_TYPE)
4959 return fold_if_not_in_template (convert_to_vector (type, expr));
4960 else if (TREE_CODE (intype) == VECTOR_TYPE)
4961 return fold_if_not_in_template (convert_to_integer (type, expr));
4966 error ("invalid cast from type %qT to type %qT", intype, type);
4967 return error_mark_node;
4970 return cp_convert (type, expr);
4974 build_reinterpret_cast (tree type, tree expr)
4976 if (type == error_mark_node || expr == error_mark_node)
4977 return error_mark_node;
4979 if (processing_template_decl)
4981 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
4983 if (!TREE_SIDE_EFFECTS (t)
4984 && type_dependent_expression_p (expr))
4985 /* There might turn out to be side effects inside expr. */
4986 TREE_SIDE_EFFECTS (t) = 1;
4987 return convert_from_reference (t);
4990 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
4994 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
4995 return an appropriate expression. Otherwise, return
4996 error_mark_node. If the cast is not valid, and COMPLAIN is true,
4997 then a diagnostic will be issued. If VALID_P is non-NULL, its
4998 value upon return will indicate whether or not the conversion
5002 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5006 tree reference_type;
5008 /* Callers are responsible for handling error_mark_node as a
5009 destination type. */
5010 gcc_assert (dst_type != error_mark_node);
5011 /* In a template, callers should be building syntactic
5012 representations of casts, not using this machinery. */
5013 gcc_assert (!processing_template_decl);
5015 /* Assume the conversion is invalid. */
5019 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5022 error ("invalid use of const_cast with type %qT, "
5023 "which is not a pointer, "
5024 "reference, nor a pointer-to-data-member type", dst_type);
5025 return error_mark_node;
5028 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5031 error ("invalid use of const_cast with type %qT, which is a pointer "
5032 "or reference to a function type", dst_type);
5033 return error_mark_node;
5036 src_type = TREE_TYPE (expr);
5037 /* Expressions do not really have reference types. */
5038 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5039 src_type = TREE_TYPE (src_type);
5041 /* [expr.const.cast]
5043 An lvalue of type T1 can be explicitly converted to an lvalue of
5044 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5045 types) if a pointer to T1 can be explicitly converted to the type
5046 pointer to T2 using a const_cast. */
5047 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5049 reference_type = dst_type;
5050 if (! real_lvalue_p (expr))
5053 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5054 src_type, dst_type);
5055 return error_mark_node;
5057 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5058 src_type = build_pointer_type (src_type);
5062 reference_type = NULL_TREE;
5063 /* If the destination type is not a reference type, the
5064 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5065 conversions are performed. */
5066 src_type = type_decays_to (src_type);
5067 if (src_type == error_mark_node)
5068 return error_mark_node;
5071 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5072 && comp_ptr_ttypes_const (dst_type, src_type))
5078 expr = build_unary_op (ADDR_EXPR, expr, 0);
5079 expr = build_nop (reference_type, expr);
5080 return convert_from_reference (expr);
5084 expr = decay_conversion (expr);
5085 /* build_c_cast puts on a NOP_EXPR to make the result not an
5086 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5087 non-lvalue context. */
5088 if (TREE_CODE (expr) == NOP_EXPR
5089 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5090 expr = TREE_OPERAND (expr, 0);
5091 return build_nop (dst_type, expr);
5096 error ("invalid const_cast from type %qT to type %qT",
5097 src_type, dst_type);
5098 return error_mark_node;
5102 build_const_cast (tree type, tree expr)
5104 if (type == error_mark_node || error_operand_p (expr))
5105 return error_mark_node;
5107 if (processing_template_decl)
5109 tree t = build_min (CONST_CAST_EXPR, type, expr);
5111 if (!TREE_SIDE_EFFECTS (t)
5112 && type_dependent_expression_p (expr))
5113 /* There might turn out to be side effects inside expr. */
5114 TREE_SIDE_EFFECTS (t) = 1;
5115 return convert_from_reference (t);
5118 return build_const_cast_1 (type, expr, /*complain=*/true,
5122 /* Build an expression representing an explicit C-style cast to type
5123 TYPE of expression EXPR. */
5126 build_c_cast (tree type, tree expr)
5132 if (type == error_mark_node || error_operand_p (expr))
5133 return error_mark_node;
5135 if (processing_template_decl)
5137 tree t = build_min (CAST_EXPR, type,
5138 tree_cons (NULL_TREE, value, NULL_TREE));
5139 /* We don't know if it will or will not have side effects. */
5140 TREE_SIDE_EFFECTS (t) = 1;
5141 return convert_from_reference (t);
5144 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5145 'Class') should always be retained, because this information aids
5146 in method lookup. */
5147 if (objc_is_object_ptr (type)
5148 && objc_is_object_ptr (TREE_TYPE (expr)))
5149 return build_nop (type, expr);
5151 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5152 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5153 if (TREE_CODE (type) != REFERENCE_TYPE
5154 && TREE_CODE (value) == NOP_EXPR
5155 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5156 value = TREE_OPERAND (value, 0);
5158 if (TREE_CODE (type) == ARRAY_TYPE)
5160 /* Allow casting from T1* to T2[] because Cfront allows it.
5161 NIHCL uses it. It is not valid ISO C++ however. */
5162 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5164 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5165 type = build_pointer_type (TREE_TYPE (type));
5169 error ("ISO C++ forbids casting to an array type %qT", type);
5170 return error_mark_node;
5174 if (TREE_CODE (type) == FUNCTION_TYPE
5175 || TREE_CODE (type) == METHOD_TYPE)
5177 error ("invalid cast to function type %qT", type);
5178 return error_mark_node;
5181 /* A C-style cast can be a const_cast. */
5182 result = build_const_cast_1 (type, value, /*complain=*/false,
5187 /* Or a static cast. */
5188 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5190 /* Or a reinterpret_cast. */
5192 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5194 /* The static_cast or reinterpret_cast may be followed by a
5197 /* A valid cast may result in errors if, for example, a
5198 conversion to am ambiguous base class is required. */
5199 && !error_operand_p (result))
5203 /* Non-class rvalues always have cv-unqualified type. */
5204 if (!CLASS_TYPE_P (type))
5205 type = TYPE_MAIN_VARIANT (type);
5206 result_type = TREE_TYPE (result);
5207 if (!CLASS_TYPE_P (result_type))
5208 result_type = TYPE_MAIN_VARIANT (result_type);
5209 /* If the type of RESULT does not match TYPE, perform a
5210 const_cast to make it match. If the static_cast or
5211 reinterpret_cast succeeded, we will differ by at most
5212 cv-qualification, so the follow-on const_cast is guaranteed
5214 if (!same_type_p (non_reference (type), non_reference (result_type)))
5216 result = build_const_cast_1 (type, result, false, &valid_p);
5217 gcc_assert (valid_p);
5222 return error_mark_node;
5225 /* Build an assignment expression of lvalue LHS from value RHS.
5226 MODIFYCODE is the code for a binary operator that we use
5227 to combine the old value of LHS with RHS to get the new value.
5228 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5230 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5233 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5237 tree lhstype = TREE_TYPE (lhs);
5238 tree olhstype = lhstype;
5239 tree olhs = NULL_TREE;
5240 bool plain_assign = (modifycode == NOP_EXPR);
5242 /* Avoid duplicate error messages from operands that had errors. */
5243 if (lhs == error_mark_node || rhs == error_mark_node)
5244 return error_mark_node;
5246 /* Handle control structure constructs used as "lvalues". */
5247 switch (TREE_CODE (lhs))
5249 /* Handle --foo = 5; as these are valid constructs in C++. */
5250 case PREDECREMENT_EXPR:
5251 case PREINCREMENT_EXPR:
5252 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5253 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5254 stabilize_reference (TREE_OPERAND (lhs, 0)),
5255 TREE_OPERAND (lhs, 1));
5256 return build2 (COMPOUND_EXPR, lhstype,
5258 build_modify_expr (TREE_OPERAND (lhs, 0),
5261 /* Handle (a, b) used as an "lvalue". */
5263 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5265 if (newrhs == error_mark_node)
5266 return error_mark_node;
5267 return build2 (COMPOUND_EXPR, lhstype,
5268 TREE_OPERAND (lhs, 0), newrhs);
5271 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5272 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5273 stabilize_reference (TREE_OPERAND (lhs, 0)),
5274 TREE_OPERAND (lhs, 1));
5275 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5276 if (newrhs == error_mark_node)
5277 return error_mark_node;
5278 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5282 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5283 when neither operand has side-effects. */
5284 if (!lvalue_or_else (lhs, lv_assign))
5285 return error_mark_node;
5287 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5288 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5290 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5291 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5293 TREE_OPERAND (lhs, 0),
5294 TREE_OPERAND (lhs, 1)),
5295 TREE_OPERAND (lhs, 0),
5296 TREE_OPERAND (lhs, 1));
5299 /* Handle (a ? b : c) used as an "lvalue". */
5302 /* Produce (a ? (b = rhs) : (c = rhs))
5303 except that the RHS goes through a save-expr
5304 so the code to compute it is only emitted once. */
5306 tree preeval = NULL_TREE;
5308 rhs = stabilize_expr (rhs, &preeval);
5310 /* Check this here to avoid odd errors when trying to convert
5311 a throw to the type of the COND_EXPR. */
5312 if (!lvalue_or_else (lhs, lv_assign))
5313 return error_mark_node;
5315 cond = build_conditional_expr
5316 (TREE_OPERAND (lhs, 0),
5317 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5318 TREE_OPERAND (lhs, 1)),
5320 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5321 TREE_OPERAND (lhs, 2)),
5324 if (cond == error_mark_node)
5326 /* Make sure the code to compute the rhs comes out
5327 before the split. */
5329 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5337 if (modifycode == INIT_EXPR)
5339 if (TREE_CODE (rhs) == CONSTRUCTOR)
5341 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5342 /* Call convert to generate an error; see PR 11063. */
5343 rhs = convert (lhstype, rhs);
5344 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5345 TREE_SIDE_EFFECTS (result) = 1;
5348 else if (! IS_AGGR_TYPE (lhstype))
5349 /* Do the default thing. */;
5352 result = build_special_member_call (lhs, complete_ctor_identifier,
5353 build_tree_list (NULL_TREE, rhs),
5354 lhstype, LOOKUP_NORMAL);
5355 if (result == NULL_TREE)
5356 return error_mark_node;
5362 lhs = require_complete_type (lhs);
5363 if (lhs == error_mark_node)
5364 return error_mark_node;
5366 if (modifycode == NOP_EXPR)
5368 /* `operator=' is not an inheritable operator. */
5369 if (! IS_AGGR_TYPE (lhstype))
5370 /* Do the default thing. */;
5373 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5374 lhs, rhs, make_node (NOP_EXPR),
5375 /*overloaded_p=*/NULL);
5376 if (result == NULL_TREE)
5377 return error_mark_node;
5384 /* A binary op has been requested. Combine the old LHS
5385 value with the RHS producing the value we should actually
5386 store into the LHS. */
5388 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5389 lhs = stabilize_reference (lhs);
5390 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5391 if (newrhs == error_mark_node)
5393 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5394 TREE_TYPE (lhs), TREE_TYPE (rhs));
5395 return error_mark_node;
5398 /* Now it looks like a plain assignment. */
5399 modifycode = NOP_EXPR;
5401 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5402 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5405 /* The left-hand side must be an lvalue. */
5406 if (!lvalue_or_else (lhs, lv_assign))
5407 return error_mark_node;
5409 /* Warn about modifying something that is `const'. Don't warn if
5410 this is initialization. */
5411 if (modifycode != INIT_EXPR
5412 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5413 /* Functions are not modifiable, even though they are
5415 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5416 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5417 /* If it's an aggregate and any field is const, then it is
5418 effectively const. */
5419 || (CLASS_TYPE_P (lhstype)
5420 && C_TYPE_FIELDS_READONLY (lhstype))))
5421 readonly_error (lhs, "assignment", 0);
5423 /* If storing into a structure or union member, it has probably been
5424 given type `int'. Compute the type that would go with the actual
5425 amount of storage the member occupies. */
5427 if (TREE_CODE (lhs) == COMPONENT_REF
5428 && (TREE_CODE (lhstype) == INTEGER_TYPE
5429 || TREE_CODE (lhstype) == REAL_TYPE
5430 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5432 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5434 /* If storing in a field that is in actuality a short or narrower
5435 than one, we must store in the field in its actual type. */
5437 if (lhstype != TREE_TYPE (lhs))
5439 /* Avoid warnings converting integral types back into enums for
5441 if (TREE_CODE (lhstype) == INTEGER_TYPE
5442 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5444 if (TREE_SIDE_EFFECTS (lhs))
5445 lhs = stabilize_reference (lhs);
5448 lhs = copy_node (lhs);
5449 TREE_TYPE (lhs) = lhstype;
5453 /* Convert new value to destination type. */
5455 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5459 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5460 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5462 error ("incompatible types in assignment of %qT to %qT",
5463 TREE_TYPE (rhs), lhstype);
5464 return error_mark_node;
5467 /* Allow array assignment in compiler-generated code. */
5468 if (! DECL_ARTIFICIAL (current_function_decl))
5469 pedwarn ("ISO C++ forbids assignment of arrays");
5471 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5472 ? 1 + (modifycode != INIT_EXPR): 0;
5473 return build_vec_init (lhs, NULL_TREE, newrhs, from_array);
5476 if (modifycode == INIT_EXPR)
5477 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5478 "initialization", NULL_TREE, 0);
5481 /* Avoid warnings on enum bit fields. */
5482 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5483 && TREE_CODE (lhstype) == INTEGER_TYPE)
5485 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5487 newrhs = convert_force (lhstype, newrhs, 0);
5490 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5492 if (TREE_CODE (newrhs) == CALL_EXPR
5493 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5494 newrhs = build_cplus_new (lhstype, newrhs);
5496 /* Can't initialize directly from a TARGET_EXPR, since that would
5497 cause the lhs to be constructed twice, and possibly result in
5498 accidental self-initialization. So we force the TARGET_EXPR to be
5499 expanded without a target. */
5500 if (TREE_CODE (newrhs) == TARGET_EXPR)
5501 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5502 TREE_OPERAND (newrhs, 0));
5505 if (newrhs == error_mark_node)
5506 return error_mark_node;
5508 if (c_dialect_objc () && flag_objc_gc)
5510 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5516 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5517 lhstype, lhs, newrhs);
5519 TREE_SIDE_EFFECTS (result) = 1;
5521 TREE_NO_WARNING (result) = 1;
5523 /* If we got the LHS in a different type for storing in,
5524 convert the result back to the nominal type of LHS
5525 so that the value we return always has the same type
5526 as the LHS argument. */
5528 if (olhstype == TREE_TYPE (result))
5532 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5533 TREE_NO_WARNING (result) = 1;
5536 return convert_for_assignment (olhstype, result, "assignment",
5541 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5543 if (processing_template_decl)
5544 return build_min_nt (MODOP_EXPR, lhs,
5545 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5547 if (modifycode != NOP_EXPR)
5549 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5550 make_node (modifycode),
5551 /*overloaded_p=*/NULL);
5554 TREE_NO_WARNING (rval) = 1;
5558 return build_modify_expr (lhs, modifycode, rhs);
5562 /* Get difference in deltas for different pointer to member function
5563 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5564 the conversion is invalid, the constant is zero. If
5565 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5566 If C_CAST_P is true this conversion is taking place as part of a
5569 Note that the naming of FROM and TO is kind of backwards; the return
5570 value is what we add to a TO in order to get a FROM. They are named
5571 this way because we call this function to find out how to convert from
5572 a pointer to member of FROM to a pointer to member of TO. */
5575 get_delta_difference (tree from, tree to,
5576 bool allow_inverse_p,
5583 /* Assume no conversion is required. */
5584 result = integer_zero_node;
5585 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5586 if (kind == bk_inaccessible || kind == bk_ambig)
5587 error (" in pointer to member function conversion");
5590 if (kind != bk_via_virtual)
5591 result = BINFO_OFFSET (binfo);
5594 tree virt_binfo = binfo_from_vbase (binfo);
5596 /* This is a reinterpret cast, we choose to do nothing. */
5597 if (allow_inverse_p)
5598 warning (0, "pointer to member cast via virtual base %qT",
5599 BINFO_TYPE (virt_binfo));
5601 error ("pointer to member conversion via virtual base %qT",
5602 BINFO_TYPE (virt_binfo));
5605 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
5606 /* Pointer to member of incomplete class is permitted*/;
5607 else if (!allow_inverse_p)
5609 error_not_base_type (from, to);
5610 error (" in pointer to member conversion");
5614 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
5617 if (kind != bk_via_virtual)
5618 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5621 /* This is a reinterpret cast, we choose to do nothing. */
5622 tree virt_binfo = binfo_from_vbase (binfo);
5624 warning (0, "pointer to member cast via virtual base %qT",
5625 BINFO_TYPE (virt_binfo));
5630 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5634 /* Return a constructor for the pointer-to-member-function TYPE using
5635 the other components as specified. */
5638 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5644 /* Pull the FIELD_DECLs out of the type. */
5645 pfn_field = TYPE_FIELDS (type);
5646 delta_field = TREE_CHAIN (pfn_field);
5648 /* Make sure DELTA has the type we want. */
5649 delta = convert_and_check (delta_type_node, delta);
5651 /* Finish creating the initializer. */
5652 u = tree_cons (pfn_field, pfn,
5653 build_tree_list (delta_field, delta));
5654 u = build_constructor (type, u);
5655 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5656 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
5657 TREE_STATIC (u) = (TREE_CONSTANT (u)
5658 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5660 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5665 /* Build a constructor for a pointer to member function. It can be
5666 used to initialize global variables, local variable, or used
5667 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5670 If FORCE is nonzero, then force this conversion, even if
5671 we would rather not do it. Usually set when using an explicit
5672 cast. A C-style cast is being processed iff C_CAST_P is true.
5674 Return error_mark_node, if something goes wrong. */
5677 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
5683 if (error_operand_p (pfn))
5684 return error_mark_node;
5686 pfn_type = TREE_TYPE (pfn);
5687 to_type = build_ptrmemfunc_type (type);
5689 /* Handle multiple conversions of pointer to member functions. */
5690 if (TYPE_PTRMEMFUNC_P (pfn_type))
5692 tree delta = NULL_TREE;
5693 tree npfn = NULL_TREE;
5697 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn))
5698 error ("invalid conversion to type %qT from type %qT",
5701 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
5702 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
5706 /* We don't have to do any conversion to convert a
5707 pointer-to-member to its own type. But, we don't want to
5708 just return a PTRMEM_CST if there's an explicit cast; that
5709 cast should make the expression an invalid template argument. */
5710 if (TREE_CODE (pfn) != PTRMEM_CST)
5712 if (same_type_p (to_type, pfn_type))
5714 else if (integer_zerop (n))
5715 return build_reinterpret_cast (to_type, pfn);
5718 if (TREE_SIDE_EFFECTS (pfn))
5719 pfn = save_expr (pfn);
5721 /* Obtain the function pointer and the current DELTA. */
5722 if (TREE_CODE (pfn) == PTRMEM_CST)
5723 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
5726 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
5727 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
5730 /* Just adjust the DELTA field. */
5731 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5732 (TREE_TYPE (delta), ptrdiff_type_node));
5733 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
5734 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
5735 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
5736 return build_ptrmemfunc1 (to_type, delta, npfn);
5739 /* Handle null pointer to member function conversions. */
5740 if (integer_zerop (pfn))
5742 pfn = build_c_cast (type, integer_zero_node);
5743 return build_ptrmemfunc1 (to_type,
5748 if (type_unknown_p (pfn))
5749 return instantiate_type (type, pfn, tf_error | tf_warning);
5751 fn = TREE_OPERAND (pfn, 0);
5752 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
5753 /* In a template, we will have preserved the
5755 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
5756 return make_ptrmem_cst (to_type, fn);
5759 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
5762 ??? There is no consistency as to the types returned for the above
5763 values. Some code acts as if it were a sizetype and some as if it were
5764 integer_type_node. */
5767 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
5769 tree type = TREE_TYPE (cst);
5770 tree fn = PTRMEM_CST_MEMBER (cst);
5771 tree ptr_class, fn_class;
5773 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5775 /* The class that the function belongs to. */
5776 fn_class = DECL_CONTEXT (fn);
5778 /* The class that we're creating a pointer to member of. */
5779 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
5781 /* First, calculate the adjustment to the function's class. */
5782 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
5785 if (!DECL_VIRTUAL_P (fn))
5786 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
5789 /* If we're dealing with a virtual function, we have to adjust 'this'
5790 again, to point to the base which provides the vtable entry for
5791 fn; the call will do the opposite adjustment. */
5792 tree orig_class = DECL_CONTEXT (fn);
5793 tree binfo = binfo_or_else (orig_class, fn_class);
5794 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5795 *delta, BINFO_OFFSET (binfo));
5796 *delta = fold_if_not_in_template (*delta);
5798 /* We set PFN to the vtable offset at which the function can be
5799 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
5800 case delta is shifted left, and then incremented). */
5801 *pfn = DECL_VINDEX (fn);
5802 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
5803 TYPE_SIZE_UNIT (vtable_entry_type));
5804 *pfn = fold_if_not_in_template (*pfn);
5806 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
5808 case ptrmemfunc_vbit_in_pfn:
5809 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
5811 *pfn = fold_if_not_in_template (*pfn);
5814 case ptrmemfunc_vbit_in_delta:
5815 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
5816 *delta, integer_one_node);
5817 *delta = fold_if_not_in_template (*delta);
5818 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5819 *delta, integer_one_node);
5820 *delta = fold_if_not_in_template (*delta);
5827 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
5828 *pfn = fold_if_not_in_template (*pfn);
5832 /* Return an expression for PFN from the pointer-to-member function
5836 pfn_from_ptrmemfunc (tree t)
5838 if (TREE_CODE (t) == PTRMEM_CST)
5843 expand_ptrmemfunc_cst (t, &delta, &pfn);
5848 return build_ptrmemfunc_access_expr (t, pfn_identifier);
5851 /* Convert value RHS to type TYPE as preparation for an assignment to
5852 an lvalue of type TYPE. ERRTYPE is a string to use in error
5853 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
5854 are doing the conversion in order to pass the PARMNUMth argument of
5858 convert_for_assignment (tree type, tree rhs,
5859 const char *errtype, tree fndecl, int parmnum)
5862 enum tree_code coder;
5864 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
5865 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
5866 rhs = TREE_OPERAND (rhs, 0);
5868 rhstype = TREE_TYPE (rhs);
5869 coder = TREE_CODE (rhstype);
5871 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
5872 && vector_types_convertible_p (type, rhstype))
5873 return convert (type, rhs);
5875 if (rhs == error_mark_node || rhstype == error_mark_node)
5876 return error_mark_node;
5877 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
5878 return error_mark_node;
5880 /* The RHS of an assignment cannot have void type. */
5881 if (coder == VOID_TYPE)
5883 error ("void value not ignored as it ought to be");
5884 return error_mark_node;
5887 /* Simplify the RHS if possible. */
5888 if (TREE_CODE (rhs) == CONST_DECL)
5889 rhs = DECL_INITIAL (rhs);
5891 if (c_dialect_objc ())
5894 tree rname = fndecl;
5896 if (!strcmp (errtype, "assignment"))
5898 else if (!strcmp (errtype, "initialization"))
5902 tree selector = objc_message_selector ();
5906 if (selector && parmno > 1)
5913 if (objc_compare_types (type, rhstype, parmno, rname))
5914 return convert (type, rhs);
5919 The expression is implicitly converted (clause _conv_) to the
5920 cv-unqualified type of the left operand.
5922 We allow bad conversions here because by the time we get to this point
5923 we are committed to doing the conversion. If we end up doing a bad
5924 conversion, convert_like will complain. */
5925 if (!can_convert_arg_bad (type, rhstype, rhs))
5927 /* When -Wno-pmf-conversions is use, we just silently allow
5928 conversions from pointers-to-members to plain pointers. If
5929 the conversion doesn't work, cp_convert will complain. */
5931 && TYPE_PTR_P (type)
5932 && TYPE_PTRMEMFUNC_P (rhstype))
5933 rhs = cp_convert (strip_top_quals (type), rhs);
5936 /* If the right-hand side has unknown type, then it is an
5937 overloaded function. Call instantiate_type to get error
5939 if (rhstype == unknown_type_node)
5940 instantiate_type (type, rhs, tf_error | tf_warning);
5942 error ("cannot convert %qT to %qT for argument %qP to %qD",
5943 rhstype, type, parmnum, fndecl);
5945 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
5946 return error_mark_node;
5949 return perform_implicit_conversion (strip_top_quals (type), rhs);
5952 /* Convert RHS to be of type TYPE.
5953 If EXP is nonzero, it is the target of the initialization.
5954 ERRTYPE is a string to use in error messages.
5956 Two major differences between the behavior of
5957 `convert_for_assignment' and `convert_for_initialization'
5958 are that references are bashed in the former, while
5959 copied in the latter, and aggregates are assigned in
5960 the former (operator=) while initialized in the
5963 If using constructor make sure no conversion operator exists, if one does
5964 exist, an ambiguity exists.
5966 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
5969 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
5970 const char *errtype, tree fndecl, int parmnum)
5972 enum tree_code codel = TREE_CODE (type);
5974 enum tree_code coder;
5976 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5977 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
5978 if (TREE_CODE (rhs) == NOP_EXPR
5979 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
5980 && codel != REFERENCE_TYPE)
5981 rhs = TREE_OPERAND (rhs, 0);
5983 if (rhs == error_mark_node
5984 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
5985 return error_mark_node;
5987 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
5988 && TREE_CODE (type) != ARRAY_TYPE
5989 && (TREE_CODE (type) != REFERENCE_TYPE
5990 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
5991 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
5992 && (TREE_CODE (type) != REFERENCE_TYPE
5993 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
5994 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
5995 rhs = decay_conversion (rhs);
5997 rhstype = TREE_TYPE (rhs);
5998 coder = TREE_CODE (rhstype);
6000 if (coder == ERROR_MARK)
6001 return error_mark_node;
6003 /* We accept references to incomplete types, so we can
6004 return here before checking if RHS is of complete type. */
6006 if (codel == REFERENCE_TYPE)
6008 /* This should eventually happen in convert_arguments. */
6009 int savew = 0, savee = 0;
6012 savew = warningcount, savee = errorcount;
6013 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6017 if (warningcount > savew)
6018 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6019 else if (errorcount > savee)
6020 error ("in passing argument %P of %q+D", parmnum, fndecl);
6026 exp = require_complete_type (exp);
6027 if (exp == error_mark_node)
6028 return error_mark_node;
6030 rhstype = non_reference (rhstype);
6032 type = complete_type (type);
6034 if (IS_AGGR_TYPE (type))
6035 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6037 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6040 /* If RETVAL is the address of, or a reference to, a local variable or
6041 temporary give an appropriate warning. */
6044 maybe_warn_about_returning_address_of_local (tree retval)
6046 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6047 tree whats_returned = retval;
6051 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6052 whats_returned = TREE_OPERAND (whats_returned, 1);
6053 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6054 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6055 || TREE_CODE (whats_returned) == NOP_EXPR)
6056 whats_returned = TREE_OPERAND (whats_returned, 0);
6061 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6063 whats_returned = TREE_OPERAND (whats_returned, 0);
6065 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6067 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6068 || TREE_CODE (whats_returned) == TARGET_EXPR)
6070 warning (0, "returning reference to temporary");
6073 if (TREE_CODE (whats_returned) == VAR_DECL
6074 && DECL_NAME (whats_returned)
6075 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6077 warning (0, "reference to non-lvalue returned");
6082 if (DECL_P (whats_returned)
6083 && DECL_NAME (whats_returned)
6084 && DECL_FUNCTION_SCOPE_P (whats_returned)
6085 && !(TREE_STATIC (whats_returned)
6086 || TREE_PUBLIC (whats_returned)))
6088 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6089 warning (0, "reference to local variable %q+D returned",
6092 warning (0, "address of local variable %q+D returned",
6098 /* Check that returning RETVAL from the current function is valid.
6099 Return an expression explicitly showing all conversions required to
6100 change RETVAL into the function return type, and to assign it to
6101 the DECL_RESULT for the function. */
6104 check_return_expr (tree retval)
6107 /* The type actually returned by the function, after any
6110 int fn_returns_value_p;
6112 /* A `volatile' function is one that isn't supposed to return, ever.
6113 (This is a G++ extension, used to get better code for functions
6114 that call the `volatile' function.) */
6115 if (TREE_THIS_VOLATILE (current_function_decl))
6116 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6118 /* Check for various simple errors. */
6119 if (DECL_DESTRUCTOR_P (current_function_decl))
6122 error ("returning a value from a destructor");
6125 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6127 if (in_function_try_handler)
6128 /* If a return statement appears in a handler of the
6129 function-try-block of a constructor, the program is ill-formed. */
6130 error ("cannot return from a handler of a function-try-block of a constructor");
6132 /* You can't return a value from a constructor. */
6133 error ("returning a value from a constructor");
6137 if (processing_template_decl)
6139 current_function_returns_value = 1;
6143 /* When no explicit return-value is given in a function with a named
6144 return value, the named return value is used. */
6145 result = DECL_RESULT (current_function_decl);
6146 valtype = TREE_TYPE (result);
6147 gcc_assert (valtype != NULL_TREE);
6148 fn_returns_value_p = !VOID_TYPE_P (valtype);
6149 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6152 /* Check for a return statement with no return value in a function
6153 that's supposed to return a value. */
6154 if (!retval && fn_returns_value_p)
6156 pedwarn ("return-statement with no value, in function returning %qT",
6158 /* Clear this, so finish_function won't say that we reach the
6159 end of a non-void function (which we don't, we gave a
6161 current_function_returns_null = 0;
6163 /* Check for a return statement with a value in a function that
6164 isn't supposed to return a value. */
6165 else if (retval && !fn_returns_value_p)
6167 if (VOID_TYPE_P (TREE_TYPE (retval)))
6168 /* You can return a `void' value from a function of `void'
6169 type. In that case, we have to evaluate the expression for
6170 its side-effects. */
6171 finish_expr_stmt (retval);
6173 pedwarn ("return-statement with a value, in function "
6174 "returning 'void'");
6176 current_function_returns_null = 1;
6178 /* There's really no value to return, after all. */
6182 /* Remember that this function can sometimes return without a
6184 current_function_returns_null = 1;
6186 /* Remember that this function did return a value. */
6187 current_function_returns_value = 1;
6189 /* Check for erroneous operands -- but after giving ourselves a
6190 chance to provide an error about returning a value from a void
6192 if (error_operand_p (retval))
6194 current_function_return_value = error_mark_node;
6195 return error_mark_node;
6198 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6199 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6200 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6201 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6203 && null_ptr_cst_p (retval))
6204 warning (0, "%<operator new%> must not return NULL unless it is "
6205 "declared %<throw()%> (or -fcheck-new is in effect)");
6207 /* Effective C++ rule 15. See also start_function. */
6209 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6213 /* The function return type must be a reference to the current
6215 if (TREE_CODE (valtype) == REFERENCE_TYPE
6216 && same_type_ignoring_top_level_qualifiers_p
6217 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6219 /* Returning '*this' is obviously OK. */
6220 if (retval == current_class_ref)
6222 /* If we are calling a function whose return type is the same of
6223 the current class reference, it is ok. */
6224 else if (TREE_CODE (retval) == INDIRECT_REF
6225 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6230 warning (0, "%<operator=%> should return a reference to %<*this%>");
6233 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6235 [...] For a function with a class return type, if the expression
6236 in the return statement is the name of a local object, and the cv-
6237 unqualified type of the local object is the same as the function
6238 return type, an implementation is permitted to omit creating the tem-
6239 porary object to hold the function return value [...]
6241 So, if this is a value-returning function that always returns the same
6242 local variable, remember it.
6244 It might be nice to be more flexible, and choose the first suitable
6245 variable even if the function sometimes returns something else, but
6246 then we run the risk of clobbering the variable we chose if the other
6247 returned expression uses the chosen variable somehow. And people expect
6248 this restriction, anyway. (jason 2000-11-19)
6250 See finish_function and finalize_nrv for the rest of this optimization. */
6252 if (fn_returns_value_p && flag_elide_constructors)
6254 if (retval != NULL_TREE
6255 && (current_function_return_value == NULL_TREE
6256 || current_function_return_value == retval)
6257 && TREE_CODE (retval) == VAR_DECL
6258 && DECL_CONTEXT (retval) == current_function_decl
6259 && ! TREE_STATIC (retval)
6260 && (DECL_ALIGN (retval)
6261 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6262 && same_type_p ((TYPE_MAIN_VARIANT
6263 (TREE_TYPE (retval))),
6265 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6266 current_function_return_value = retval;
6268 current_function_return_value = error_mark_node;
6271 /* We don't need to do any conversions when there's nothing being
6276 /* Do any required conversions. */
6277 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6278 /* No conversions are required. */
6282 /* The type the function is declared to return. */
6283 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6285 /* First convert the value to the function's return type, then
6286 to the type of return value's location to handle the
6287 case that functype is smaller than the valtype. */
6288 retval = convert_for_initialization
6289 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6290 "return", NULL_TREE, 0);
6291 retval = convert (valtype, retval);
6293 /* If the conversion failed, treat this just like `return;'. */
6294 if (retval == error_mark_node)
6296 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6297 else if (! current_function_returns_struct
6298 && TREE_CODE (retval) == TARGET_EXPR
6299 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6300 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6301 TREE_OPERAND (retval, 0));
6303 maybe_warn_about_returning_address_of_local (retval);
6306 /* Actually copy the value returned into the appropriate location. */
6307 if (retval && retval != result)
6308 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6314 /* Returns nonzero if the pointer-type FROM can be converted to the
6315 pointer-type TO via a qualification conversion. If CONSTP is -1,
6316 then we return nonzero if the pointers are similar, and the
6317 cv-qualification signature of FROM is a proper subset of that of TO.
6319 If CONSTP is positive, then all outer pointers have been
6323 comp_ptr_ttypes_real (tree to, tree from, int constp)
6325 bool to_more_cv_qualified = false;
6327 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6329 if (TREE_CODE (to) != TREE_CODE (from))
6332 if (TREE_CODE (from) == OFFSET_TYPE
6333 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6334 TYPE_OFFSET_BASETYPE (to)))
6337 /* Const and volatile mean something different for function types,
6338 so the usual checks are not appropriate. */
6339 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6341 /* In Objective-C++, some types may have been 'volatilized' by
6342 the compiler for EH; when comparing them here, the volatile
6343 qualification must be ignored. */
6344 bool objc_quals_match = objc_type_quals_match (to, from);
6346 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6349 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6353 to_more_cv_qualified = true;
6357 constp &= TYPE_READONLY (to);
6360 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6361 return ((constp >= 0 || to_more_cv_qualified)
6362 && same_type_ignoring_top_level_qualifiers_p (to, from));
6366 /* When comparing, say, char ** to char const **, this function takes
6367 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6368 types to this function. */
6371 comp_ptr_ttypes (tree to, tree from)
6373 return comp_ptr_ttypes_real (to, from, 1);
6376 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6377 type or inheritance-related types, regardless of cv-quals. */
6380 ptr_reasonably_similar (tree to, tree from)
6382 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6384 /* Any target type is similar enough to void. */
6385 if (TREE_CODE (to) == VOID_TYPE
6386 || TREE_CODE (from) == VOID_TYPE)
6389 if (TREE_CODE (to) != TREE_CODE (from))
6392 if (TREE_CODE (from) == OFFSET_TYPE
6393 && comptypes (TYPE_OFFSET_BASETYPE (to),
6394 TYPE_OFFSET_BASETYPE (from),
6395 COMPARE_BASE | COMPARE_DERIVED))
6398 if (TREE_CODE (to) == VECTOR_TYPE
6399 && vector_types_convertible_p (to, from))
6402 if (TREE_CODE (to) == INTEGER_TYPE
6403 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6406 if (TREE_CODE (to) == FUNCTION_TYPE)
6409 if (TREE_CODE (to) != POINTER_TYPE)
6411 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6412 COMPARE_BASE | COMPARE_DERIVED);
6416 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6417 pointer-to-member types) are the same, ignoring cv-qualification at
6421 comp_ptr_ttypes_const (tree to, tree from)
6423 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6425 if (TREE_CODE (to) != TREE_CODE (from))
6428 if (TREE_CODE (from) == OFFSET_TYPE
6429 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6430 TYPE_OFFSET_BASETYPE (to)))
6433 if (TREE_CODE (to) != POINTER_TYPE)
6434 return same_type_ignoring_top_level_qualifiers_p (to, from);
6438 /* Returns the type qualifiers for this type, including the qualifiers on the
6439 elements for an array type. */
6442 cp_type_quals (tree type)
6444 type = strip_array_types (type);
6445 if (type == error_mark_node)
6446 return TYPE_UNQUALIFIED;
6447 return TYPE_QUALS (type);
6450 /* Returns nonzero if the TYPE contains a mutable member. */
6453 cp_has_mutable_p (tree type)
6455 type = strip_array_types (type);
6457 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6460 /* Apply the TYPE_QUALS to the new DECL. */
6462 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6464 tree type = TREE_TYPE (decl);
6466 if (type == error_mark_node)
6469 if (TREE_CODE (type) == FUNCTION_TYPE
6470 && type_quals != TYPE_UNQUALIFIED)
6472 /* This was an error in C++98 (cv-qualifiers cannot be added to
6473 a function type), but DR 295 makes the code well-formed by
6474 dropping the extra qualifiers. */
6477 tree bad_type = build_qualified_type (type, type_quals);
6478 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6482 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6486 /* Avoid setting TREE_READONLY incorrectly. */
6487 if (/* If the object has a constructor, the constructor may modify
6489 TYPE_NEEDS_CONSTRUCTING (type)
6490 /* If the type isn't complete, we don't know yet if it will need
6492 || !COMPLETE_TYPE_P (type)
6493 /* If the type has a mutable component, that component might be
6495 || TYPE_HAS_MUTABLE_P (type))
6496 type_quals &= ~TYPE_QUAL_CONST;
6498 c_apply_type_quals_to_decl (type_quals, decl);
6501 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6502 exemplar types such that casting T1 to T2 is casting away constness
6503 if and only if there is no implicit conversion from T1 to T2. */
6506 casts_away_constness_r (tree *t1, tree *t2)
6511 /* [expr.const.cast]
6513 For multi-level pointer to members and multi-level mixed pointers
6514 and pointers to members (conv.qual), the "member" aspect of a
6515 pointer to member level is ignored when determining if a const
6516 cv-qualifier has been cast away. */
6517 /* [expr.const.cast]
6519 For two pointer types:
6521 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6522 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6525 casting from X1 to X2 casts away constness if, for a non-pointer
6526 type T there does not exist an implicit conversion (clause
6529 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6533 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6534 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6535 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
6537 *t1 = cp_build_qualified_type (void_type_node,
6538 cp_type_quals (*t1));
6539 *t2 = cp_build_qualified_type (void_type_node,
6540 cp_type_quals (*t2));
6544 quals1 = cp_type_quals (*t1);
6545 quals2 = cp_type_quals (*t2);
6547 if (TYPE_PTRMEM_P (*t1))
6548 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
6550 *t1 = TREE_TYPE (*t1);
6551 if (TYPE_PTRMEM_P (*t2))
6552 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
6554 *t2 = TREE_TYPE (*t2);
6556 casts_away_constness_r (t1, t2);
6557 *t1 = build_pointer_type (*t1);
6558 *t2 = build_pointer_type (*t2);
6559 *t1 = cp_build_qualified_type (*t1, quals1);
6560 *t2 = cp_build_qualified_type (*t2, quals2);
6563 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6567 casts_away_constness (tree t1, tree t2)
6569 if (TREE_CODE (t2) == REFERENCE_TYPE)
6571 /* [expr.const.cast]
6573 Casting from an lvalue of type T1 to an lvalue of type T2
6574 using a reference cast casts away constness if a cast from an
6575 rvalue of type "pointer to T1" to the type "pointer to T2"
6576 casts away constness. */
6577 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6578 return casts_away_constness (build_pointer_type (t1),
6579 build_pointer_type (TREE_TYPE (t2)));
6582 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6583 /* [expr.const.cast]
6585 Casting from an rvalue of type "pointer to data member of X
6586 of type T1" to the type "pointer to data member of Y of type
6587 T2" casts away constness if a cast from an rvalue of type
6588 "pointer to T1" to the type "pointer to T2" casts away
6590 return casts_away_constness
6591 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6592 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6594 /* Casting away constness is only something that makes sense for
6595 pointer or reference types. */
6596 if (TREE_CODE (t1) != POINTER_TYPE
6597 || TREE_CODE (t2) != POINTER_TYPE)
6600 /* Top-level qualifiers don't matter. */
6601 t1 = TYPE_MAIN_VARIANT (t1);
6602 t2 = TYPE_MAIN_VARIANT (t2);
6603 casts_away_constness_r (&t1, &t2);
6604 if (!can_convert (t2, t1))
6610 /* If T is a REFERENCE_TYPE return the type to which T refers.
6611 Otherwise, return T itself. */
6614 non_reference (tree t)
6616 if (TREE_CODE (t) == REFERENCE_TYPE)
6622 /* Return nonzero if REF is an lvalue valid for this language;
6623 otherwise, print an error message and return zero. USE says
6624 how the lvalue is being used and so selects the error message. */
6627 lvalue_or_else (tree ref, enum lvalue_use use)
6629 int win = lvalue_p (ref);