1 /* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
5 Hacked by Michael Tiemann (tiemann@cygnus.com)
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2, or (at your option)
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING. If not, write to
21 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
22 Boston, MA 02110-1301, USA. */
25 /* This file is part of the C++ front end.
26 It contains routines to build C++ expressions given their operands,
27 including computing the types of the result, C and C++ specific error
28 checks, and some optimization. */
32 #include "coretypes.h"
42 #include "diagnostic.h"
49 static tree pfn_from_ptrmemfunc (tree);
50 static tree convert_for_assignment (tree, tree, const char *, tree, int);
51 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
52 static tree rationalize_conditional_expr (enum tree_code, tree);
53 static int comp_ptr_ttypes_real (tree, tree, int);
54 static bool comp_except_types (tree, tree, bool);
55 static bool comp_array_types (tree, tree, bool);
56 static tree common_base_type (tree, tree);
57 static tree pointer_diff (tree, tree, tree);
58 static tree get_delta_difference (tree, tree, bool, bool);
59 static void casts_away_constness_r (tree *, tree *);
60 static bool casts_away_constness (tree, tree);
61 static void maybe_warn_about_returning_address_of_local (tree);
62 static tree lookup_destructor (tree, tree, tree);
63 static tree convert_arguments (tree, tree, tree, int);
65 /* Do `exp = require_complete_type (exp);' to make sure exp
66 does not have an incomplete type. (That includes void types.)
67 Returns the error_mark_node if the VALUE does not have
68 complete type when this function returns. */
71 require_complete_type (tree value)
75 if (processing_template_decl || value == error_mark_node)
78 if (TREE_CODE (value) == OVERLOAD)
79 type = unknown_type_node;
81 type = TREE_TYPE (value);
83 if (type == error_mark_node)
84 return error_mark_node;
86 /* First, detect a valid value with a complete type. */
87 if (COMPLETE_TYPE_P (type))
90 if (complete_type_or_else (type, value))
93 return error_mark_node;
96 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
97 a template instantiation, do the instantiation. Returns TYPE,
98 whether or not it could be completed, unless something goes
99 horribly wrong, in which case the error_mark_node is returned. */
102 complete_type (tree type)
104 if (type == NULL_TREE)
105 /* Rather than crash, we return something sure to cause an error
107 return error_mark_node;
109 if (type == error_mark_node || COMPLETE_TYPE_P (type))
111 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
113 tree t = complete_type (TREE_TYPE (type));
114 unsigned int needs_constructing, has_nontrivial_dtor;
115 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
118 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
120 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
121 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
123 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
124 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
127 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
128 instantiate_class_template (TYPE_MAIN_VARIANT (type));
133 /* Like complete_type, but issue an error if the TYPE cannot be completed.
134 VALUE is used for informative diagnostics.
135 Returns NULL_TREE if the type cannot be made complete. */
138 complete_type_or_else (tree type, tree value)
140 type = complete_type (type);
141 if (type == error_mark_node)
142 /* We already issued an error. */
144 else if (!COMPLETE_TYPE_P (type))
146 cxx_incomplete_type_diagnostic (value, type, 0);
153 /* Return truthvalue of whether type of EXP is instantiated. */
156 type_unknown_p (tree exp)
158 return (TREE_CODE (exp) == TREE_LIST
159 || TREE_TYPE (exp) == unknown_type_node);
163 /* Return the common type of two parameter lists.
164 We assume that comptypes has already been done and returned 1;
165 if that isn't so, this may crash.
167 As an optimization, free the space we allocate if the parameter
168 lists are already common. */
171 commonparms (tree p1, tree p2)
173 tree oldargs = p1, newargs, n;
177 len = list_length (p1);
178 newargs = tree_last (p1);
180 if (newargs == void_list_node)
189 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
194 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
196 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
198 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
201 else if (! TREE_PURPOSE (p1))
203 if (TREE_PURPOSE (p2))
205 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
211 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
213 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
215 if (TREE_VALUE (p1) != TREE_VALUE (p2))
218 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
221 TREE_VALUE (n) = TREE_VALUE (p1);
229 /* Given a type, perhaps copied for a typedef,
230 find the "original" version of it. */
232 original_type (tree t)
234 int quals = cp_type_quals (t);
235 while (t != error_mark_node
236 && TYPE_NAME (t) != NULL_TREE)
238 tree x = TYPE_NAME (t);
239 if (TREE_CODE (x) != TYPE_DECL)
241 x = DECL_ORIGINAL_TYPE (x);
246 return cp_build_qualified_type (t, quals);
249 /* T1 and T2 are arithmetic or enumeration types. Return the type
250 that will result from the "usual arithmetic conversions" on T1 and
251 T2 as described in [expr]. */
254 type_after_usual_arithmetic_conversions (tree t1, tree t2)
256 enum tree_code code1 = TREE_CODE (t1);
257 enum tree_code code2 = TREE_CODE (t2);
260 /* FIXME: Attributes. */
261 gcc_assert (ARITHMETIC_TYPE_P (t1)
262 || TREE_CODE (t1) == COMPLEX_TYPE
263 || TREE_CODE (t1) == VECTOR_TYPE
264 || TREE_CODE (t1) == ENUMERAL_TYPE);
265 gcc_assert (ARITHMETIC_TYPE_P (t2)
266 || TREE_CODE (t2) == COMPLEX_TYPE
267 || TREE_CODE (t2) == VECTOR_TYPE
268 || TREE_CODE (t2) == ENUMERAL_TYPE);
270 /* In what follows, we slightly generalize the rules given in [expr] so
271 as to deal with `long long' and `complex'. First, merge the
273 attributes = (*targetm.merge_type_attributes) (t1, t2);
275 /* If one type is complex, form the common type of the non-complex
276 components, then make that complex. Use T1 or T2 if it is the
278 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
280 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
281 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
283 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
285 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
286 return build_type_attribute_variant (t1, attributes);
287 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
288 return build_type_attribute_variant (t2, attributes);
290 return build_type_attribute_variant (build_complex_type (subtype),
294 if (code1 == VECTOR_TYPE)
296 /* When we get here we should have two vectors of the same size.
297 Just prefer the unsigned one if present. */
298 if (TYPE_UNSIGNED (t1))
299 return build_type_attribute_variant (t1, attributes);
301 return build_type_attribute_variant (t2, attributes);
304 /* If only one is real, use it as the result. */
305 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
306 return build_type_attribute_variant (t1, attributes);
307 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
308 return build_type_attribute_variant (t2, attributes);
310 /* Perform the integral promotions. */
311 if (code1 != REAL_TYPE)
313 t1 = type_promotes_to (t1);
314 t2 = type_promotes_to (t2);
317 /* Both real or both integers; use the one with greater precision. */
318 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
319 return build_type_attribute_variant (t1, attributes);
320 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
321 return build_type_attribute_variant (t2, attributes);
323 /* The types are the same; no need to do anything fancy. */
324 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
325 return build_type_attribute_variant (t1, attributes);
327 if (code1 != REAL_TYPE)
329 /* If one is unsigned long long, then convert the other to unsigned
331 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
332 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
333 return build_type_attribute_variant (long_long_unsigned_type_node,
335 /* If one is a long long, and the other is an unsigned long, and
336 long long can represent all the values of an unsigned long, then
337 convert to a long long. Otherwise, convert to an unsigned long
338 long. Otherwise, if either operand is long long, convert the
341 Since we're here, we know the TYPE_PRECISION is the same;
342 therefore converting to long long cannot represent all the values
343 of an unsigned long, so we choose unsigned long long in that
345 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
346 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
348 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
349 ? long_long_unsigned_type_node
350 : long_long_integer_type_node);
351 return build_type_attribute_variant (t, attributes);
354 /* Go through the same procedure, but for longs. */
355 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
356 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
357 return build_type_attribute_variant (long_unsigned_type_node,
359 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
360 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
362 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
363 ? long_unsigned_type_node : long_integer_type_node);
364 return build_type_attribute_variant (t, attributes);
366 /* Otherwise prefer the unsigned one. */
367 if (TYPE_UNSIGNED (t1))
368 return build_type_attribute_variant (t1, attributes);
370 return build_type_attribute_variant (t2, attributes);
374 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
375 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
376 return build_type_attribute_variant (long_double_type_node,
378 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
379 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
380 return build_type_attribute_variant (double_type_node,
382 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
383 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
384 return build_type_attribute_variant (float_type_node,
387 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
388 the standard C++ floating-point types. Logic earlier in this
389 function has already eliminated the possibility that
390 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
391 compelling reason to choose one or the other. */
392 return build_type_attribute_variant (t1, attributes);
396 /* Subroutine of composite_pointer_type to implement the recursive
397 case. See that function for documentation fo the parameters. */
400 composite_pointer_type_r (tree t1, tree t2, const char* location)
407 /* Determine the types pointed to by T1 and T2. */
408 if (TREE_CODE (t1) == POINTER_TYPE)
410 pointee1 = TREE_TYPE (t1);
411 pointee2 = TREE_TYPE (t2);
415 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
416 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
421 Otherwise, the composite pointer type is a pointer type
422 similar (_conv.qual_) to the type of one of the operands,
423 with a cv-qualification signature (_conv.qual_) that is the
424 union of the cv-qualification signatures of the operand
426 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
427 result_type = pointee1;
428 else if ((TREE_CODE (pointee1) == POINTER_TYPE
429 && TREE_CODE (pointee2) == POINTER_TYPE)
430 || (TYPE_PTR_TO_MEMBER_P (pointee1)
431 && TYPE_PTR_TO_MEMBER_P (pointee2)))
432 result_type = composite_pointer_type_r (pointee1, pointee2, location);
435 pedwarn ("%s between distinct pointer types %qT and %qT "
438 result_type = void_type_node;
440 result_type = cp_build_qualified_type (result_type,
441 (cp_type_quals (pointee1)
442 | cp_type_quals (pointee2)));
443 /* If the original types were pointers to members, so is the
445 if (TYPE_PTR_TO_MEMBER_P (t1))
447 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
448 TYPE_PTRMEM_CLASS_TYPE (t2)))
449 pedwarn ("%s between distinct pointer types %qT and %qT "
452 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
456 result_type = build_pointer_type (result_type);
458 /* Merge the attributes. */
459 attributes = (*targetm.merge_type_attributes) (t1, t2);
460 return build_type_attribute_variant (result_type, attributes);
463 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
464 ARG1 and ARG2 are the values with those types. The LOCATION is a
465 string describing the current location, in case an error occurs.
467 This routine also implements the computation of a common type for
468 pointers-to-members as per [expr.eq]. */
471 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
472 const char* location)
479 If one operand is a null pointer constant, the composite pointer
480 type is the type of the other operand. */
481 if (null_ptr_cst_p (arg1))
483 if (null_ptr_cst_p (arg2))
490 If one of the operands has type "pointer to cv1 void*", then
491 the other has type "pointer to cv2T", and the composite pointer
492 type is "pointer to cv12 void", where cv12 is the union of cv1
495 If either type is a pointer to void, make sure it is T1. */
496 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
504 /* Now, if T1 is a pointer to void, merge the qualifiers. */
505 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
510 if (pedantic && TYPE_PTRFN_P (t2))
511 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
512 "and pointer-to-function", location);
514 = cp_build_qualified_type (void_type_node,
515 (cp_type_quals (TREE_TYPE (t1))
516 | cp_type_quals (TREE_TYPE (t2))));
517 result_type = build_pointer_type (result_type);
518 /* Merge the attributes. */
519 attributes = (*targetm.merge_type_attributes) (t1, t2);
520 return build_type_attribute_variant (result_type, attributes);
523 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
524 && TREE_CODE (t2) == POINTER_TYPE)
526 if (objc_compare_types (t1, t2, -3, NULL_TREE))
530 /* [expr.eq] permits the application of a pointer conversion to
531 bring the pointers to a common type. */
532 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
533 && CLASS_TYPE_P (TREE_TYPE (t1))
534 && CLASS_TYPE_P (TREE_TYPE (t2))
535 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
538 class1 = TREE_TYPE (t1);
539 class2 = TREE_TYPE (t2);
541 if (DERIVED_FROM_P (class1, class2))
542 t2 = (build_pointer_type
543 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
544 else if (DERIVED_FROM_P (class2, class1))
545 t1 = (build_pointer_type
546 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
549 error ("%s between distinct pointer types %qT and %qT "
550 "lacks a cast", location, t1, t2);
551 return error_mark_node;
554 /* [expr.eq] permits the application of a pointer-to-member
555 conversion to change the class type of one of the types. */
556 else if (TYPE_PTR_TO_MEMBER_P (t1)
557 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
558 TYPE_PTRMEM_CLASS_TYPE (t2)))
560 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
561 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
563 if (DERIVED_FROM_P (class1, class2))
564 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
565 else if (DERIVED_FROM_P (class2, class1))
566 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
569 error ("%s between distinct pointer-to-member types %qT and %qT "
570 "lacks a cast", location, t1, t2);
571 return error_mark_node;
575 return composite_pointer_type_r (t1, t2, location);
578 /* Return the merged type of two types.
579 We assume that comptypes has already been done and returned 1;
580 if that isn't so, this may crash.
582 This just combines attributes and default arguments; any other
583 differences would cause the two types to compare unalike. */
586 merge_types (tree t1, tree t2)
588 enum tree_code code1;
589 enum tree_code code2;
592 /* Save time if the two types are the same. */
595 if (original_type (t1) == original_type (t2))
598 /* If one type is nonsense, use the other. */
599 if (t1 == error_mark_node)
601 if (t2 == error_mark_node)
604 /* Merge the attributes. */
605 attributes = (*targetm.merge_type_attributes) (t1, t2);
607 if (TYPE_PTRMEMFUNC_P (t1))
608 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
609 if (TYPE_PTRMEMFUNC_P (t2))
610 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
612 code1 = TREE_CODE (t1);
613 code2 = TREE_CODE (t2);
619 /* For two pointers, do this recursively on the target type. */
621 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
622 int quals = cp_type_quals (t1);
624 if (code1 == POINTER_TYPE)
625 t1 = build_pointer_type (target);
627 t1 = build_reference_type (target);
628 t1 = build_type_attribute_variant (t1, attributes);
629 t1 = cp_build_qualified_type (t1, quals);
631 if (TREE_CODE (target) == METHOD_TYPE)
632 t1 = build_ptrmemfunc_type (t1);
641 quals = cp_type_quals (t1);
642 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
643 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
644 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
646 t1 = cp_build_qualified_type (t1, quals);
652 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
653 /* Save space: see if the result is identical to one of the args. */
654 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
655 return build_type_attribute_variant (t1, attributes);
656 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
657 return build_type_attribute_variant (t2, attributes);
658 /* Merge the element types, and have a size if either arg has one. */
659 t1 = build_cplus_array_type
660 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
665 /* Function types: prefer the one that specified arg types.
666 If both do, merge the arg types. Also merge the return types. */
668 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
669 tree p1 = TYPE_ARG_TYPES (t1);
670 tree p2 = TYPE_ARG_TYPES (t2);
673 /* Save space: see if the result is identical to one of the args. */
674 if (valtype == TREE_TYPE (t1) && ! p2)
675 return cp_build_type_attribute_variant (t1, attributes);
676 if (valtype == TREE_TYPE (t2) && ! p1)
677 return cp_build_type_attribute_variant (t2, attributes);
679 /* Simple way if one arg fails to specify argument types. */
680 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
682 rval = build_function_type (valtype, p2);
683 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
684 rval = build_exception_variant (rval, raises);
685 return cp_build_type_attribute_variant (rval, attributes);
687 raises = TYPE_RAISES_EXCEPTIONS (t1);
688 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
690 rval = build_function_type (valtype, p1);
692 rval = build_exception_variant (rval, raises);
693 return cp_build_type_attribute_variant (rval, attributes);
696 rval = build_function_type (valtype, commonparms (p1, p2));
697 t1 = build_exception_variant (rval, raises);
703 /* Get this value the long way, since TYPE_METHOD_BASETYPE
704 is just the main variant of this. */
705 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
706 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
709 /* If this was a member function type, get back to the
710 original type of type member function (i.e., without
711 the class instance variable up front. */
712 t1 = build_function_type (TREE_TYPE (t1),
713 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
714 t2 = build_function_type (TREE_TYPE (t2),
715 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
716 t3 = merge_types (t1, t2);
717 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
718 TYPE_ARG_TYPES (t3));
719 t1 = build_exception_variant (t3, raises);
724 /* There is no need to merge attributes into a TYPENAME_TYPE.
725 When the type is instantiated it will have whatever
726 attributes result from the instantiation. */
732 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
734 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
737 return cp_build_type_attribute_variant (t1, attributes);
740 /* Return the common type of two types.
741 We assume that comptypes has already been done and returned 1;
742 if that isn't so, this may crash.
744 This is the type for the result of most arithmetic operations
745 if the operands have the given two types. */
748 common_type (tree t1, tree t2)
750 enum tree_code code1;
751 enum tree_code code2;
753 /* If one type is nonsense, bail. */
754 if (t1 == error_mark_node || t2 == error_mark_node)
755 return error_mark_node;
757 code1 = TREE_CODE (t1);
758 code2 = TREE_CODE (t2);
760 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
761 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
762 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
763 || code2 == COMPLEX_TYPE || code2 == VECTOR_TYPE))
764 return type_after_usual_arithmetic_conversions (t1, t2);
766 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
767 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
768 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
769 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
775 /* Compare two exception specifier types for exactness or subsetness, if
776 allowed. Returns false for mismatch, true for match (same, or
779 [except.spec] "If a class X ... objects of class X or any class publicly
780 and unambiguously derived from X. Similarly, if a pointer type Y * ...
781 exceptions of type Y * or that are pointers to any type publicly and
782 unambiguously derived from Y. Otherwise a function only allows exceptions
783 that have the same type ..."
784 This does not mention cv qualifiers and is different to what throw
785 [except.throw] and catch [except.catch] will do. They will ignore the
786 top level cv qualifiers, and allow qualifiers in the pointer to class
789 We implement the letter of the standard. */
792 comp_except_types (tree a, tree b, bool exact)
794 if (same_type_p (a, b))
798 if (cp_type_quals (a) || cp_type_quals (b))
801 if (TREE_CODE (a) == POINTER_TYPE
802 && TREE_CODE (b) == POINTER_TYPE)
806 if (cp_type_quals (a) || cp_type_quals (b))
810 if (TREE_CODE (a) != RECORD_TYPE
811 || TREE_CODE (b) != RECORD_TYPE)
814 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
820 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
821 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
822 otherwise it must be exact. Exception lists are unordered, but
823 we've already filtered out duplicates. Most lists will be in order,
824 we should try to make use of that. */
827 comp_except_specs (tree t1, tree t2, bool exact)
836 if (t1 == NULL_TREE) /* T1 is ... */
837 return t2 == NULL_TREE || !exact;
838 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
839 return t2 != NULL_TREE && !TREE_VALUE (t2);
840 if (t2 == NULL_TREE) /* T2 is ... */
842 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
845 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
846 Count how many we find, to determine exactness. For exact matching and
847 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
849 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
851 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
853 tree a = TREE_VALUE (probe);
854 tree b = TREE_VALUE (t2);
856 if (comp_except_types (a, b, exact))
858 if (probe == base && exact)
859 base = TREE_CHAIN (probe);
864 if (probe == NULL_TREE)
867 return !exact || base == NULL_TREE || length == list_length (t1);
870 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
871 [] can match [size]. */
874 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
883 /* The type of the array elements must be the same. */
884 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
887 d1 = TYPE_DOMAIN (t1);
888 d2 = TYPE_DOMAIN (t2);
893 /* If one of the arrays is dimensionless, and the other has a
894 dimension, they are of different types. However, it is valid to
902 declarations for an array object can specify
903 array types that differ by the presence or absence of a major
904 array bound (_dcl.array_). */
906 return allow_redeclaration;
908 /* Check that the dimensions are the same. */
910 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
912 max1 = TYPE_MAX_VALUE (d1);
913 max2 = TYPE_MAX_VALUE (d2);
914 if (processing_template_decl && !abi_version_at_least (2)
915 && !value_dependent_expression_p (max1)
916 && !value_dependent_expression_p (max2))
918 /* With abi-1 we do not fold non-dependent array bounds, (and
919 consequently mangle them incorrectly). We must therefore
920 fold them here, to verify the domains have the same
926 if (!cp_tree_equal (max1, max2))
932 /* Subroutine in comptypes. */
935 structural_comptypes (tree t1, tree t2, int strict)
940 /* Suppress errors caused by previously reported errors. */
941 if (t1 == error_mark_node || t2 == error_mark_node)
944 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
946 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
947 current instantiation. */
948 if (TREE_CODE (t1) == TYPENAME_TYPE)
950 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
952 if (resolved != error_mark_node)
956 if (TREE_CODE (t2) == TYPENAME_TYPE)
958 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
960 if (resolved != error_mark_node)
964 if (TYPE_PTRMEMFUNC_P (t1))
965 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
966 if (TYPE_PTRMEMFUNC_P (t2))
967 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
969 /* Different classes of types can't be compatible. */
970 if (TREE_CODE (t1) != TREE_CODE (t2))
973 /* Qualifiers must match. For array types, we will check when we
974 recur on the array element types. */
975 if (TREE_CODE (t1) != ARRAY_TYPE
976 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
978 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
981 /* Allow for two different type nodes which have essentially the same
982 definition. Note that we already checked for equality of the type
983 qualifiers (just above). */
985 if (TREE_CODE (t1) != ARRAY_TYPE
986 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
989 /* Compare the types. Break out if they could be the same. */
990 switch (TREE_CODE (t1))
992 case TEMPLATE_TEMPLATE_PARM:
993 case BOUND_TEMPLATE_TEMPLATE_PARM:
994 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
995 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
997 if (!comp_template_parms
998 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
999 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1001 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1003 /* Don't check inheritance. */
1004 strict = COMPARE_STRICT;
1009 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1010 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1011 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1012 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1015 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1017 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1023 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1024 strict & ~COMPARE_REDECLARATION))
1026 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1031 case REFERENCE_TYPE:
1032 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1033 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1034 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1040 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1042 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1047 /* Target types must match incl. qualifiers. */
1048 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1052 case TEMPLATE_TYPE_PARM:
1053 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1054 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1059 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1060 TYPENAME_TYPE_FULLNAME (t2)))
1062 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1066 case UNBOUND_CLASS_TEMPLATE:
1067 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1069 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1074 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1079 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1080 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1088 /* If we get here, we know that from a target independent POV the
1089 types are the same. Make sure the target attributes are also
1091 return targetm.comp_type_attributes (t1, t2);
1094 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
1095 is a bitwise-or of the COMPARE_* flags. */
1098 comptypes (tree t1, tree t2, int strict)
1100 if (strict == COMPARE_STRICT)
1107 if (t1 == error_mark_node || t2 == error_mark_node)
1110 if (TYPE_STRUCTURAL_EQUALITY_P (t1) || TYPE_STRUCTURAL_EQUALITY_P (t2))
1111 /* At least one of the types requires structural equality, so
1112 perform a deep check. */
1113 return structural_comptypes (t1, t2, strict);
1115 if (VERIFY_CANONICAL_TYPES)
1117 result = structural_comptypes (t1, t2, strict);
1119 if (result && TYPE_CANONICAL (t1) != TYPE_CANONICAL (t2))
1121 /* The two types are structurally equivalent, but their
1122 canonical types were different. This is a failure of the
1123 canonical type propagation code.*/
1125 "canonical types differ for identical types %T and %T",
1130 else if (!result && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2))
1132 /* Two types are structurally different, but the canonical
1133 types are the same. This means we were over-eager in
1134 assigning canonical types. */
1136 "same canonical type node for different types %T and %T",
1145 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1147 else if (strict == COMPARE_STRUCTURAL)
1148 return structural_comptypes (t1, t2, COMPARE_STRICT);
1150 return structural_comptypes (t1, t2, strict);
1153 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1156 at_least_as_qualified_p (tree type1, tree type2)
1158 int q1 = cp_type_quals (type1);
1159 int q2 = cp_type_quals (type2);
1161 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1162 return (q1 & q2) == q2;
1165 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1166 more cv-qualified that TYPE1, and 0 otherwise. */
1169 comp_cv_qualification (tree type1, tree type2)
1171 int q1 = cp_type_quals (type1);
1172 int q2 = cp_type_quals (type2);
1177 if ((q1 & q2) == q2)
1179 else if ((q1 & q2) == q1)
1185 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1186 subset of the cv-qualification signature of TYPE2, and the types
1187 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1190 comp_cv_qual_signature (tree type1, tree type2)
1192 if (comp_ptr_ttypes_real (type2, type1, -1))
1194 else if (comp_ptr_ttypes_real (type1, type2, -1))
1200 /* If two types share a common base type, return that basetype.
1201 If there is not a unique most-derived base type, this function
1202 returns ERROR_MARK_NODE. */
1205 common_base_type (tree tt1, tree tt2)
1207 tree best = NULL_TREE;
1210 /* If one is a baseclass of another, that's good enough. */
1211 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1213 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1216 /* Otherwise, try to find a unique baseclass of TT1
1217 that is shared by TT2, and follow that down. */
1218 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1220 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1221 tree trial = common_base_type (basetype, tt2);
1225 if (trial == error_mark_node)
1227 if (best == NULL_TREE)
1229 else if (best != trial)
1230 return error_mark_node;
1235 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1237 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1238 tree trial = common_base_type (tt1, basetype);
1242 if (trial == error_mark_node)
1244 if (best == NULL_TREE)
1246 else if (best != trial)
1247 return error_mark_node;
1253 /* Subroutines of `comptypes'. */
1255 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1256 equivalent in the sense that functions with those parameter types
1257 can have equivalent types. The two lists must be equivalent,
1258 element by element. */
1261 compparms (tree parms1, tree parms2)
1265 /* An unspecified parmlist matches any specified parmlist
1266 whose argument types don't need default promotions. */
1268 for (t1 = parms1, t2 = parms2;
1270 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1272 /* If one parmlist is shorter than the other,
1273 they fail to match. */
1276 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1283 /* Process a sizeof or alignof expression where the operand is a
1287 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1292 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1293 if (type == error_mark_node)
1294 return error_mark_node;
1296 type = non_reference (type);
1297 if (TREE_CODE (type) == METHOD_TYPE)
1299 if (complain && (pedantic || warn_pointer_arith))
1300 pedwarn ("invalid application of %qs to a member function",
1301 operator_name_info[(int) op].name);
1302 value = size_one_node;
1305 dependent_p = dependent_type_p (type);
1307 complete_type (type);
1309 /* VLA types will have a non-constant size. In the body of an
1310 uninstantiated template, we don't need to try to compute the
1311 value, because the sizeof expression is not an integral
1312 constant expression in that case. And, if we do try to
1313 compute the value, we'll likely end up with SAVE_EXPRs, which
1314 the template substitution machinery does not expect to see. */
1315 || (processing_template_decl
1316 && COMPLETE_TYPE_P (type)
1317 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1319 value = build_min (op, size_type_node, type);
1320 TREE_READONLY (value) = 1;
1324 return c_sizeof_or_alignof_type (complete_type (type),
1329 /* Process a sizeof expression where the operand is an expression. */
1332 cxx_sizeof_expr (tree e)
1334 if (e == error_mark_node)
1335 return error_mark_node;
1337 if (processing_template_decl)
1339 e = build_min (SIZEOF_EXPR, size_type_node, e);
1340 TREE_SIDE_EFFECTS (e) = 0;
1341 TREE_READONLY (e) = 1;
1346 if (TREE_CODE (e) == COMPONENT_REF
1347 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1348 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1350 error ("invalid application of %<sizeof%> to a bit-field");
1353 else if (is_overloaded_fn (e))
1355 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1359 else if (type_unknown_p (e))
1361 cxx_incomplete_type_error (e, TREE_TYPE (e));
1367 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1370 /* Implement the __alignof keyword: Return the minimum required
1371 alignment of E, measured in bytes. For VAR_DECL's and
1372 FIELD_DECL's return DECL_ALIGN (which can be set from an
1373 "aligned" __attribute__ specification). */
1376 cxx_alignof_expr (tree e)
1380 if (e == error_mark_node)
1381 return error_mark_node;
1383 if (processing_template_decl)
1385 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1386 TREE_SIDE_EFFECTS (e) = 0;
1387 TREE_READONLY (e) = 1;
1392 if (TREE_CODE (e) == VAR_DECL)
1393 t = size_int (DECL_ALIGN_UNIT (e));
1394 else if (TREE_CODE (e) == COMPONENT_REF
1395 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1396 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1398 error ("invalid application of %<__alignof%> to a bit-field");
1401 else if (TREE_CODE (e) == COMPONENT_REF
1402 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1403 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1404 else if (is_overloaded_fn (e))
1406 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1410 else if (type_unknown_p (e))
1412 cxx_incomplete_type_error (e, TREE_TYPE (e));
1416 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1418 return fold_convert (size_type_node, t);
1421 /* Process a sizeof or alignof expression E with code OP where the operand
1422 is an expression. */
1425 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1427 if (op == SIZEOF_EXPR)
1428 return cxx_sizeof_expr (e);
1430 return cxx_alignof_expr (e);
1433 /* EXPR is being used in a context that is not a function call.
1438 The expression can be used only as the left-hand operand of a
1439 member function call.
1441 [expr.mptr.operator]
1443 If the result of .* or ->* is a function, then that result can be
1444 used only as the operand for the function call operator ().
1446 by issuing an error message if appropriate. Returns true iff EXPR
1447 violates these rules. */
1450 invalid_nonstatic_memfn_p (tree expr)
1452 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1454 error ("invalid use of non-static member function");
1460 /* If EXP is a reference to a bitfield, and the type of EXP does not
1461 match the declared type of the bitfield, return the declared type
1462 of the bitfield. Otherwise, return NULL_TREE. */
1465 is_bitfield_expr_with_lowered_type (tree exp)
1469 if (TREE_CODE (exp) == COND_EXPR)
1471 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)))
1473 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1475 if (TREE_CODE (exp) != COMPONENT_REF)
1477 field = TREE_OPERAND (exp, 1);
1478 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1480 if (same_type_ignoring_top_level_qualifiers_p
1481 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1483 return DECL_BIT_FIELD_TYPE (field);
1486 /* Perform the conversions in [expr] that apply when an lvalue appears
1487 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1488 function-to-pointer conversions. In addition, manifest constants
1489 are replaced by their values, and bitfield references are converted
1490 to their declared types.
1492 Although the returned value is being used as an rvalue, this
1493 function does not wrap the returned expression in a
1494 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1495 that the return value is no longer an lvalue. */
1498 decay_conversion (tree exp)
1501 enum tree_code code;
1503 type = TREE_TYPE (exp);
1504 if (type == error_mark_node)
1505 return error_mark_node;
1507 if (type_unknown_p (exp))
1509 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1510 return error_mark_node;
1513 exp = decl_constant_value (exp);
1514 if (error_operand_p (exp))
1515 return error_mark_node;
1517 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1518 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1519 code = TREE_CODE (type);
1520 if (code == VOID_TYPE)
1522 error ("void value not ignored as it ought to be");
1523 return error_mark_node;
1525 if (invalid_nonstatic_memfn_p (exp))
1526 return error_mark_node;
1527 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1528 return build_unary_op (ADDR_EXPR, exp, 0);
1529 if (code == ARRAY_TYPE)
1534 if (TREE_CODE (exp) == INDIRECT_REF)
1535 return build_nop (build_pointer_type (TREE_TYPE (type)),
1536 TREE_OPERAND (exp, 0));
1538 if (TREE_CODE (exp) == COMPOUND_EXPR)
1540 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1541 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1542 TREE_OPERAND (exp, 0), op1);
1546 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1548 error ("invalid use of non-lvalue array");
1549 return error_mark_node;
1552 ptrtype = build_pointer_type (TREE_TYPE (type));
1554 if (TREE_CODE (exp) == VAR_DECL)
1556 if (!cxx_mark_addressable (exp))
1557 return error_mark_node;
1558 adr = build_nop (ptrtype, build_address (exp));
1561 /* This way is better for a COMPONENT_REF since it can
1562 simplify the offset for a component. */
1563 adr = build_unary_op (ADDR_EXPR, exp, 1);
1564 return cp_convert (ptrtype, adr);
1567 /* If a bitfield is used in a context where integral promotion
1568 applies, then the caller is expected to have used
1569 default_conversion. That function promotes bitfields correctly
1570 before calling this function. At this point, if we have a
1571 bitfield referenced, we may assume that is not subject to
1572 promotion, and that, therefore, the type of the resulting rvalue
1573 is the declared type of the bitfield. */
1574 exp = convert_bitfield_to_declared_type (exp);
1576 /* We do not call rvalue() here because we do not want to wrap EXP
1577 in a NON_LVALUE_EXPR. */
1581 Non-class rvalues always have cv-unqualified types. */
1582 type = TREE_TYPE (exp);
1583 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1584 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1589 /* Perform prepatory conversions, as part of the "usual arithmetic
1590 conversions". In particular, as per [expr]:
1592 Whenever an lvalue expression appears as an operand of an
1593 operator that expects the rvalue for that operand, the
1594 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1595 standard conversions are applied to convert the expression to an
1598 In addition, we perform integral promotions here, as those are
1599 applied to both operands to a binary operator before determining
1600 what additional conversions should apply. */
1603 default_conversion (tree exp)
1605 /* Perform the integral promotions first so that bitfield
1606 expressions (which may promote to "int", even if the bitfield is
1607 declared "unsigned") are promoted correctly. */
1608 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1609 exp = perform_integral_promotions (exp);
1610 /* Perform the other conversions. */
1611 exp = decay_conversion (exp);
1616 /* EXPR is an expression with an integral or enumeration type.
1617 Perform the integral promotions in [conv.prom], and return the
1621 perform_integral_promotions (tree expr)
1628 If the bitfield has an enumerated type, it is treated as any
1629 other value of that type for promotion purposes. */
1630 type = is_bitfield_expr_with_lowered_type (expr);
1631 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1632 type = TREE_TYPE (expr);
1633 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1634 promoted_type = type_promotes_to (type);
1635 if (type != promoted_type)
1636 expr = cp_convert (promoted_type, expr);
1640 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1644 inline_conversion (tree exp)
1646 if (TREE_CODE (exp) == FUNCTION_DECL)
1647 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1652 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1653 decay_conversion to one. */
1656 string_conv_p (tree totype, tree exp, int warn)
1660 if (TREE_CODE (totype) != POINTER_TYPE)
1663 t = TREE_TYPE (totype);
1664 if (!same_type_p (t, char_type_node)
1665 && !same_type_p (t, wchar_type_node))
1668 if (TREE_CODE (exp) == STRING_CST)
1670 /* Make sure that we don't try to convert between char and wchar_t. */
1671 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1676 /* Is this a string constant which has decayed to 'const char *'? */
1677 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1678 if (!same_type_p (TREE_TYPE (exp), t))
1681 if (TREE_CODE (exp) != ADDR_EXPR
1682 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1686 /* This warning is not very useful, as it complains about printf. */
1688 warning (OPT_Wwrite_strings,
1689 "deprecated conversion from string constant to %qT",
1695 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1696 can, for example, use as an lvalue. This code used to be in
1697 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1698 expressions, where we're dealing with aggregates. But now it's again only
1699 called from unary_complex_lvalue. The case (in particular) that led to
1700 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1704 rationalize_conditional_expr (enum tree_code code, tree t)
1706 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1707 the first operand is always the one to be used if both operands
1708 are equal, so we know what conditional expression this used to be. */
1709 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1711 tree op0 = TREE_OPERAND (t, 0);
1712 tree op1 = TREE_OPERAND (t, 1);
1714 /* The following code is incorrect if either operand side-effects. */
1715 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1716 && !TREE_SIDE_EFFECTS (op1));
1718 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1719 ? LE_EXPR : GE_EXPR),
1720 op0, TREE_CODE (op0),
1721 op1, TREE_CODE (op1),
1722 /*overloaded_p=*/NULL),
1723 build_unary_op (code, op0, 0),
1724 build_unary_op (code, op1, 0));
1728 build_conditional_expr (TREE_OPERAND (t, 0),
1729 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1730 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1733 /* Given the TYPE of an anonymous union field inside T, return the
1734 FIELD_DECL for the field. If not found return NULL_TREE. Because
1735 anonymous unions can nest, we must also search all anonymous unions
1736 that are directly reachable. */
1739 lookup_anon_field (tree t, tree type)
1743 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1745 if (TREE_STATIC (field))
1747 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1750 /* If we find it directly, return the field. */
1751 if (DECL_NAME (field) == NULL_TREE
1752 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1757 /* Otherwise, it could be nested, search harder. */
1758 if (DECL_NAME (field) == NULL_TREE
1759 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1761 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1769 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1770 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1771 non-NULL, it indicates the path to the base used to name MEMBER.
1772 If PRESERVE_REFERENCE is true, the expression returned will have
1773 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1774 returned will have the type referred to by the reference.
1776 This function does not perform access control; that is either done
1777 earlier by the parser when the name of MEMBER is resolved to MEMBER
1778 itself, or later when overload resolution selects one of the
1779 functions indicated by MEMBER. */
1782 build_class_member_access_expr (tree object, tree member,
1783 tree access_path, bool preserve_reference)
1787 tree result = NULL_TREE;
1789 if (error_operand_p (object) || error_operand_p (member))
1790 return error_mark_node;
1792 gcc_assert (DECL_P (member) || BASELINK_P (member));
1796 The type of the first expression shall be "class object" (of a
1798 object_type = TREE_TYPE (object);
1799 if (!currently_open_class (object_type)
1800 && !complete_type_or_else (object_type, object))
1801 return error_mark_node;
1802 if (!CLASS_TYPE_P (object_type))
1804 error ("request for member %qD in %qE, which is of non-class type %qT",
1805 member, object, object_type);
1806 return error_mark_node;
1809 /* The standard does not seem to actually say that MEMBER must be a
1810 member of OBJECT_TYPE. However, that is clearly what is
1812 if (DECL_P (member))
1814 member_scope = DECL_CLASS_CONTEXT (member);
1816 if (TREE_DEPRECATED (member))
1817 warn_deprecated_use (member);
1820 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1821 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1822 presently be the anonymous union. Go outwards until we find a
1823 type related to OBJECT_TYPE. */
1824 while (ANON_AGGR_TYPE_P (member_scope)
1825 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1827 member_scope = TYPE_CONTEXT (member_scope);
1828 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1830 if (TREE_CODE (member) == FIELD_DECL)
1831 error ("invalid use of nonstatic data member %qE", member);
1833 error ("%qD is not a member of %qT", member, object_type);
1834 return error_mark_node;
1837 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1838 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1839 in the front end; only _DECLs and _REFs are lvalues in the back end. */
1841 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1843 object = build_indirect_ref (temp, NULL);
1846 /* In [expr.ref], there is an explicit list of the valid choices for
1847 MEMBER. We check for each of those cases here. */
1848 if (TREE_CODE (member) == VAR_DECL)
1850 /* A static data member. */
1852 /* If OBJECT has side-effects, they are supposed to occur. */
1853 if (TREE_SIDE_EFFECTS (object))
1854 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1856 else if (TREE_CODE (member) == FIELD_DECL)
1858 /* A non-static data member. */
1863 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1864 && integer_zerop (TREE_OPERAND (object, 0)));
1866 /* Convert OBJECT to the type of MEMBER. */
1867 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1868 TYPE_MAIN_VARIANT (member_scope)))
1873 binfo = lookup_base (access_path ? access_path : object_type,
1874 member_scope, ba_unique, &kind);
1875 if (binfo == error_mark_node)
1876 return error_mark_node;
1878 /* It is invalid to try to get to a virtual base of a
1879 NULL object. The most common cause is invalid use of
1881 if (null_object_p && kind == bk_via_virtual)
1883 error ("invalid access to non-static data member %qD of "
1886 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1887 return error_mark_node;
1890 /* Convert to the base. */
1891 object = build_base_path (PLUS_EXPR, object, binfo,
1893 /* If we found the base successfully then we should be able
1894 to convert to it successfully. */
1895 gcc_assert (object != error_mark_node);
1898 /* Complain about other invalid uses of offsetof, even though they will
1899 give the right answer. Note that we complain whether or not they
1900 actually used the offsetof macro, since there's no way to know at this
1901 point. So we just give a warning, instead of a pedwarn. */
1902 /* Do not produce this warning for base class field references, because
1903 we know for a fact that didn't come from offsetof. This does occur
1904 in various testsuite cases where a null object is passed where a
1905 vtable access is required. */
1906 if (null_object_p && warn_invalid_offsetof
1907 && CLASSTYPE_NON_POD_P (object_type)
1908 && !DECL_FIELD_IS_BASE (member)
1909 && !skip_evaluation)
1911 warning (0, "invalid access to non-static data member %qD of NULL object",
1913 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1916 /* If MEMBER is from an anonymous aggregate, we have converted
1917 OBJECT so that it refers to the class containing the
1918 anonymous union. Generate a reference to the anonymous union
1919 itself, and recur to find MEMBER. */
1920 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1921 /* When this code is called from build_field_call, the
1922 object already has the type of the anonymous union.
1923 That is because the COMPONENT_REF was already
1924 constructed, and was then disassembled before calling
1925 build_field_call. After the function-call code is
1926 cleaned up, this waste can be eliminated. */
1927 && (!same_type_ignoring_top_level_qualifiers_p
1928 (TREE_TYPE (object), DECL_CONTEXT (member))))
1930 tree anonymous_union;
1932 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1933 DECL_CONTEXT (member));
1934 object = build_class_member_access_expr (object,
1936 /*access_path=*/NULL_TREE,
1937 preserve_reference);
1940 /* Compute the type of the field, as described in [expr.ref]. */
1941 type_quals = TYPE_UNQUALIFIED;
1942 member_type = TREE_TYPE (member);
1943 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1945 type_quals = (cp_type_quals (member_type)
1946 | cp_type_quals (object_type));
1948 /* A field is const (volatile) if the enclosing object, or the
1949 field itself, is const (volatile). But, a mutable field is
1950 not const, even within a const object. */
1951 if (DECL_MUTABLE_P (member))
1952 type_quals &= ~TYPE_QUAL_CONST;
1953 member_type = cp_build_qualified_type (member_type, type_quals);
1956 result = build3 (COMPONENT_REF, member_type, object, member,
1958 result = fold_if_not_in_template (result);
1960 /* Mark the expression const or volatile, as appropriate. Even
1961 though we've dealt with the type above, we still have to mark the
1962 expression itself. */
1963 if (type_quals & TYPE_QUAL_CONST)
1964 TREE_READONLY (result) = 1;
1965 if (type_quals & TYPE_QUAL_VOLATILE)
1966 TREE_THIS_VOLATILE (result) = 1;
1968 else if (BASELINK_P (member))
1970 /* The member is a (possibly overloaded) member function. */
1974 /* If the MEMBER is exactly one static member function, then we
1975 know the type of the expression. Otherwise, we must wait
1976 until overload resolution has been performed. */
1977 functions = BASELINK_FUNCTIONS (member);
1978 if (TREE_CODE (functions) == FUNCTION_DECL
1979 && DECL_STATIC_FUNCTION_P (functions))
1980 type = TREE_TYPE (functions);
1982 type = unknown_type_node;
1983 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1984 base. That will happen when the function is called. */
1985 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1987 else if (TREE_CODE (member) == CONST_DECL)
1989 /* The member is an enumerator. */
1991 /* If OBJECT has side-effects, they are supposed to occur. */
1992 if (TREE_SIDE_EFFECTS (object))
1993 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1998 error ("invalid use of %qD", member);
1999 return error_mark_node;
2002 if (!preserve_reference)
2005 If E2 is declared to have type "reference to T", then ... the
2006 type of E1.E2 is T. */
2007 result = convert_from_reference (result);
2012 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
2013 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
2016 lookup_destructor (tree object, tree scope, tree dtor_name)
2018 tree object_type = TREE_TYPE (object);
2019 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2022 if (scope && !check_dtor_name (scope, dtor_type))
2024 error ("qualified type %qT does not match destructor name ~%qT",
2026 return error_mark_node;
2028 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2030 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2031 TYPE_MAIN_VARIANT (object_type), dtor_type);
2032 return error_mark_node;
2034 expr = lookup_member (dtor_type, complete_dtor_identifier,
2035 /*protect=*/1, /*want_type=*/false);
2036 expr = (adjust_result_of_qualified_name_lookup
2037 (expr, dtor_type, object_type));
2041 /* An expression of the form "A::template B" has been resolved to
2042 DECL. Issue a diagnostic if B is not a template or template
2046 check_template_keyword (tree decl)
2048 /* The standard says:
2052 If a name prefixed by the keyword template is not a member
2053 template, the program is ill-formed.
2055 DR 228 removed the restriction that the template be a member
2058 DR 96, if accepted would add the further restriction that explicit
2059 template arguments must be provided if the template keyword is
2060 used, but, as of 2005-10-16, that DR is still in "drafting". If
2061 this DR is accepted, then the semantic checks here can be
2062 simplified, as the entity named must in fact be a template
2063 specialization, rather than, as at present, a set of overloaded
2064 functions containing at least one template function. */
2065 if (TREE_CODE (decl) != TEMPLATE_DECL
2066 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2068 if (!is_overloaded_fn (decl))
2069 pedwarn ("%qD is not a template", decl);
2074 if (BASELINK_P (fns))
2075 fns = BASELINK_FUNCTIONS (fns);
2078 tree fn = OVL_CURRENT (fns);
2079 if (TREE_CODE (fn) == TEMPLATE_DECL
2080 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2082 if (TREE_CODE (fn) == FUNCTION_DECL
2083 && DECL_USE_TEMPLATE (fn)
2084 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2086 fns = OVL_NEXT (fns);
2089 pedwarn ("%qD is not a template", decl);
2094 /* This function is called by the parser to process a class member
2095 access expression of the form OBJECT.NAME. NAME is a node used by
2096 the parser to represent a name; it is not yet a DECL. It may,
2097 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2098 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2099 there is no reason to do the lookup twice, so the parser keeps the
2100 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2101 be a template via the use of the "A::template B" syntax. */
2104 finish_class_member_access_expr (tree object, tree name, bool template_p)
2109 tree access_path = NULL_TREE;
2110 tree orig_object = object;
2111 tree orig_name = name;
2113 if (object == error_mark_node || name == error_mark_node)
2114 return error_mark_node;
2116 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2117 if (!objc_is_public (object, name))
2118 return error_mark_node;
2120 object_type = TREE_TYPE (object);
2122 if (processing_template_decl)
2124 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2125 dependent_type_p (object_type)
2126 /* If NAME is just an IDENTIFIER_NODE, then the expression
2128 || TREE_CODE (object) == IDENTIFIER_NODE
2129 /* If NAME is "f<args>", where either 'f' or 'args' is
2130 dependent, then the expression is dependent. */
2131 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2132 && dependent_template_id_p (TREE_OPERAND (name, 0),
2133 TREE_OPERAND (name, 1)))
2134 /* If NAME is "T::X" where "T" is dependent, then the
2135 expression is dependent. */
2136 || (TREE_CODE (name) == SCOPE_REF
2137 && TYPE_P (TREE_OPERAND (name, 0))
2138 && dependent_type_p (TREE_OPERAND (name, 0))))
2139 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2140 object = build_non_dependent_expr (object);
2145 The type of the first expression shall be "class object" (of a
2147 if (!currently_open_class (object_type)
2148 && !complete_type_or_else (object_type, object))
2149 return error_mark_node;
2150 if (!CLASS_TYPE_P (object_type))
2152 error ("request for member %qD in %qE, which is of non-class type %qT",
2153 name, object, object_type);
2154 return error_mark_node;
2157 if (BASELINK_P (name))
2158 /* A member function that has already been looked up. */
2162 bool is_template_id = false;
2163 tree template_args = NULL_TREE;
2166 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2168 is_template_id = true;
2169 template_args = TREE_OPERAND (name, 1);
2170 name = TREE_OPERAND (name, 0);
2172 if (TREE_CODE (name) == OVERLOAD)
2173 name = DECL_NAME (get_first_fn (name));
2174 else if (DECL_P (name))
2175 name = DECL_NAME (name);
2178 if (TREE_CODE (name) == SCOPE_REF)
2180 /* A qualified name. The qualifying class or namespace `S'
2181 has already been looked up; it is either a TYPE or a
2183 scope = TREE_OPERAND (name, 0);
2184 name = TREE_OPERAND (name, 1);
2186 /* If SCOPE is a namespace, then the qualified name does not
2187 name a member of OBJECT_TYPE. */
2188 if (TREE_CODE (scope) == NAMESPACE_DECL)
2190 error ("%<%D::%D%> is not a member of %qT",
2191 scope, name, object_type);
2192 return error_mark_node;
2195 gcc_assert (CLASS_TYPE_P (scope));
2196 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2197 || TREE_CODE (name) == BIT_NOT_EXPR);
2199 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2200 access_path = lookup_base (object_type, scope, ba_check, NULL);
2201 if (access_path == error_mark_node)
2202 return error_mark_node;
2205 error ("%qT is not a base of %qT", scope, object_type);
2206 return error_mark_node;
2212 access_path = object_type;
2215 if (TREE_CODE (name) == BIT_NOT_EXPR)
2216 member = lookup_destructor (object, scope, name);
2219 /* Look up the member. */
2220 member = lookup_member (access_path, name, /*protect=*/1,
2221 /*want_type=*/false);
2222 if (member == NULL_TREE)
2224 error ("%qD has no member named %qE", object_type, name);
2225 return error_mark_node;
2227 if (member == error_mark_node)
2228 return error_mark_node;
2233 tree template = member;
2235 if (BASELINK_P (template))
2236 template = lookup_template_function (template, template_args);
2239 error ("%qD is not a member template function", name);
2240 return error_mark_node;
2245 if (TREE_DEPRECATED (member))
2246 warn_deprecated_use (member);
2249 check_template_keyword (member);
2251 expr = build_class_member_access_expr (object, member, access_path,
2252 /*preserve_reference=*/false);
2253 if (processing_template_decl && expr != error_mark_node)
2255 if (BASELINK_P (member))
2257 if (TREE_CODE (orig_name) == SCOPE_REF)
2258 BASELINK_QUALIFIED_P (member) = 1;
2261 return build_min_non_dep (COMPONENT_REF, expr,
2262 orig_object, orig_name,
2269 /* Return an expression for the MEMBER_NAME field in the internal
2270 representation of PTRMEM, a pointer-to-member function. (Each
2271 pointer-to-member function type gets its own RECORD_TYPE so it is
2272 more convenient to access the fields by name than by FIELD_DECL.)
2273 This routine converts the NAME to a FIELD_DECL and then creates the
2274 node for the complete expression. */
2277 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2283 /* This code is a stripped down version of
2284 build_class_member_access_expr. It does not work to use that
2285 routine directly because it expects the object to be of class
2287 ptrmem_type = TREE_TYPE (ptrmem);
2288 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2289 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2290 /*want_type=*/false);
2291 member_type = cp_build_qualified_type (TREE_TYPE (member),
2292 cp_type_quals (ptrmem_type));
2293 return fold_build3 (COMPONENT_REF, member_type,
2294 ptrmem, member, NULL_TREE);
2297 /* Given an expression PTR for a pointer, return an expression
2298 for the value pointed to.
2299 ERRORSTRING is the name of the operator to appear in error messages.
2301 This function may need to overload OPERATOR_FNNAME.
2302 Must also handle REFERENCE_TYPEs for C++. */
2305 build_x_indirect_ref (tree expr, const char *errorstring)
2307 tree orig_expr = expr;
2310 if (processing_template_decl)
2312 if (type_dependent_expression_p (expr))
2313 return build_min_nt (INDIRECT_REF, expr);
2314 expr = build_non_dependent_expr (expr);
2317 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2318 NULL_TREE, /*overloaded_p=*/NULL);
2320 rval = build_indirect_ref (expr, errorstring);
2322 if (processing_template_decl && rval != error_mark_node)
2323 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2329 build_indirect_ref (tree ptr, const char *errorstring)
2333 if (ptr == error_mark_node)
2334 return error_mark_node;
2336 if (ptr == current_class_ptr)
2337 return current_class_ref;
2339 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2340 ? ptr : decay_conversion (ptr));
2341 type = TREE_TYPE (pointer);
2343 if (POINTER_TYPE_P (type))
2347 If the type of the expression is "pointer to T," the type
2348 of the result is "T."
2350 We must use the canonical variant because certain parts of
2351 the back end, like fold, do pointer comparisons between
2353 tree t = canonical_type_variant (TREE_TYPE (type));
2355 if (VOID_TYPE_P (t))
2357 /* A pointer to incomplete type (other than cv void) can be
2358 dereferenced [expr.unary.op]/1 */
2359 error ("%qT is not a pointer-to-object type", type);
2360 return error_mark_node;
2362 else if (TREE_CODE (pointer) == ADDR_EXPR
2363 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2364 /* The POINTER was something like `&x'. We simplify `*&x' to
2366 return TREE_OPERAND (pointer, 0);
2369 tree ref = build1 (INDIRECT_REF, t, pointer);
2371 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2372 so that we get the proper error message if the result is used
2373 to assign to. Also, &* is supposed to be a no-op. */
2374 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2375 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2376 TREE_SIDE_EFFECTS (ref)
2377 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2381 /* `pointer' won't be an error_mark_node if we were given a
2382 pointer to member, so it's cool to check for this here. */
2383 else if (TYPE_PTR_TO_MEMBER_P (type))
2384 error ("invalid use of %qs on pointer to member", errorstring);
2385 else if (pointer != error_mark_node)
2388 error ("invalid type argument of %qs", errorstring);
2390 error ("invalid type argument");
2392 return error_mark_node;
2395 /* This handles expressions of the form "a[i]", which denotes
2398 This is logically equivalent in C to *(a+i), but we may do it differently.
2399 If A is a variable or a member, we generate a primitive ARRAY_REF.
2400 This avoids forcing the array out of registers, and can work on
2401 arrays that are not lvalues (for example, members of structures returned
2404 If INDEX is of some user-defined type, it must be converted to
2405 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2406 will inherit the type of the array, which will be some pointer type. */
2409 build_array_ref (tree array, tree idx)
2413 error ("subscript missing in array reference");
2414 return error_mark_node;
2417 if (TREE_TYPE (array) == error_mark_node
2418 || TREE_TYPE (idx) == error_mark_node)
2419 return error_mark_node;
2421 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2423 switch (TREE_CODE (array))
2427 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2428 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2429 TREE_OPERAND (array, 0), value);
2433 return build_conditional_expr
2434 (TREE_OPERAND (array, 0),
2435 build_array_ref (TREE_OPERAND (array, 1), idx),
2436 build_array_ref (TREE_OPERAND (array, 2), idx));
2442 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2446 warn_array_subscript_with_type_char (idx);
2448 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2450 error ("array subscript is not an integer");
2451 return error_mark_node;
2454 /* Apply integral promotions *after* noticing character types.
2455 (It is unclear why we do these promotions -- the standard
2456 does not say that we should. In fact, the natural thing would
2457 seem to be to convert IDX to ptrdiff_t; we're performing
2458 pointer arithmetic.) */
2459 idx = perform_integral_promotions (idx);
2461 /* An array that is indexed by a non-constant
2462 cannot be stored in a register; we must be able to do
2463 address arithmetic on its address.
2464 Likewise an array of elements of variable size. */
2465 if (TREE_CODE (idx) != INTEGER_CST
2466 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2467 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2470 if (!cxx_mark_addressable (array))
2471 return error_mark_node;
2474 /* An array that is indexed by a constant value which is not within
2475 the array bounds cannot be stored in a register either; because we
2476 would get a crash in store_bit_field/extract_bit_field when trying
2477 to access a non-existent part of the register. */
2478 if (TREE_CODE (idx) == INTEGER_CST
2479 && TYPE_DOMAIN (TREE_TYPE (array))
2480 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2482 if (!cxx_mark_addressable (array))
2483 return error_mark_node;
2486 if (pedantic && !lvalue_p (array))
2487 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2489 /* Note in C++ it is valid to subscript a `register' array, since
2490 it is valid to take the address of something with that
2491 storage specification. */
2495 while (TREE_CODE (foo) == COMPONENT_REF)
2496 foo = TREE_OPERAND (foo, 0);
2497 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2498 warning (OPT_Wextra, "subscripting array declared %<register%>");
2501 type = TREE_TYPE (TREE_TYPE (array));
2502 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2503 /* Array ref is const/volatile if the array elements are
2504 or if the array is.. */
2505 TREE_READONLY (rval)
2506 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2507 TREE_SIDE_EFFECTS (rval)
2508 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2509 TREE_THIS_VOLATILE (rval)
2510 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2511 return require_complete_type (fold_if_not_in_template (rval));
2515 tree ar = default_conversion (array);
2516 tree ind = default_conversion (idx);
2518 /* Put the integer in IND to simplify error checking. */
2519 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2526 if (ar == error_mark_node)
2529 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2531 error ("subscripted value is neither array nor pointer");
2532 return error_mark_node;
2534 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2536 error ("array subscript is not an integer");
2537 return error_mark_node;
2540 warn_array_subscript_with_type_char (idx);
2542 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2547 /* Resolve a pointer to member function. INSTANCE is the object
2548 instance to use, if the member points to a virtual member.
2550 This used to avoid checking for virtual functions if basetype
2551 has no virtual functions, according to an earlier ANSI draft.
2552 With the final ISO C++ rules, such an optimization is
2553 incorrect: A pointer to a derived member can be static_cast
2554 to pointer-to-base-member, as long as the dynamic object
2555 later has the right member. */
2558 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2560 if (TREE_CODE (function) == OFFSET_REF)
2561 function = TREE_OPERAND (function, 1);
2563 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2565 tree idx, delta, e1, e2, e3, vtbl, basetype;
2566 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2568 tree instance_ptr = *instance_ptrptr;
2569 tree instance_save_expr = 0;
2570 if (instance_ptr == error_mark_node)
2572 if (TREE_CODE (function) == PTRMEM_CST)
2574 /* Extracting the function address from a pmf is only
2575 allowed with -Wno-pmf-conversions. It only works for
2577 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2578 e1 = convert (fntype, e1);
2583 error ("object missing in use of %qE", function);
2584 return error_mark_node;
2588 if (TREE_SIDE_EFFECTS (instance_ptr))
2589 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2591 if (TREE_SIDE_EFFECTS (function))
2592 function = save_expr (function);
2594 /* Start by extracting all the information from the PMF itself. */
2595 e3 = pfn_from_ptrmemfunc (function);
2596 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2597 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2598 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2600 case ptrmemfunc_vbit_in_pfn:
2601 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2602 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2605 case ptrmemfunc_vbit_in_delta:
2606 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2607 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2614 /* Convert down to the right base before using the instance. A
2615 special case is that in a pointer to member of class C, C may
2616 be incomplete. In that case, the function will of course be
2617 a member of C, and no conversion is required. In fact,
2618 lookup_base will fail in that case, because incomplete
2619 classes do not have BINFOs. */
2620 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2621 if (!same_type_ignoring_top_level_qualifiers_p
2622 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2624 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2625 basetype, ba_check, NULL);
2626 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2628 if (instance_ptr == error_mark_node)
2629 return error_mark_node;
2631 /* ...and then the delta in the PMF. */
2632 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2633 instance_ptr, delta);
2635 /* Hand back the adjusted 'this' argument to our caller. */
2636 *instance_ptrptr = instance_ptr;
2638 /* Next extract the vtable pointer from the object. */
2639 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2641 vtbl = build_indirect_ref (vtbl, NULL);
2643 /* Finally, extract the function pointer from the vtable. */
2644 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2645 e2 = build_indirect_ref (e2, NULL);
2646 TREE_CONSTANT (e2) = 1;
2647 TREE_INVARIANT (e2) = 1;
2649 /* When using function descriptors, the address of the
2650 vtable entry is treated as a function pointer. */
2651 if (TARGET_VTABLE_USES_DESCRIPTORS)
2652 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2653 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2655 TREE_TYPE (e2) = TREE_TYPE (e3);
2656 e1 = build_conditional_expr (e1, e2, e3);
2658 /* Make sure this doesn't get evaluated first inside one of the
2659 branches of the COND_EXPR. */
2660 if (instance_save_expr)
2661 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2662 instance_save_expr, e1);
2670 build_function_call (tree function, tree params)
2672 tree fntype, fndecl;
2673 tree coerced_params;
2674 tree name = NULL_TREE;
2676 tree original = function;
2678 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2679 expressions, like those used for ObjC messenger dispatches. */
2680 function = objc_rewrite_function_call (function, params);
2682 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2683 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2684 if (TREE_CODE (function) == NOP_EXPR
2685 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2686 function = TREE_OPERAND (function, 0);
2688 if (TREE_CODE (function) == FUNCTION_DECL)
2690 name = DECL_NAME (function);
2692 mark_used (function);
2695 /* Convert anything with function type to a pointer-to-function. */
2696 if (pedantic && DECL_MAIN_P (function))
2697 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2699 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2700 (because calling an inline function does not mean the function
2701 needs to be separately compiled). */
2703 if (DECL_INLINE (function))
2704 function = inline_conversion (function);
2706 function = build_addr_func (function);
2712 function = build_addr_func (function);
2715 if (function == error_mark_node)
2716 return error_mark_node;
2718 fntype = TREE_TYPE (function);
2720 if (TYPE_PTRMEMFUNC_P (fntype))
2722 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2723 "function in %<%E (...)%>",
2725 return error_mark_node;
2728 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2729 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2731 if (!((TREE_CODE (fntype) == POINTER_TYPE
2732 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2734 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2736 error ("%qE cannot be used as a function", original);
2737 return error_mark_node;
2740 /* fntype now gets the type of function pointed to. */
2741 fntype = TREE_TYPE (fntype);
2743 /* Convert the parameters to the types declared in the
2744 function prototype, or apply default promotions. */
2746 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2747 params, fndecl, LOOKUP_NORMAL);
2748 if (coerced_params == error_mark_node)
2749 return error_mark_node;
2751 /* Check for errors in format strings and inappropriately
2754 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2755 TYPE_ARG_TYPES (fntype));
2757 return build_cxx_call (function, coerced_params);
2760 /* Convert the actual parameter expressions in the list VALUES
2761 to the types in the list TYPELIST.
2762 If parmdecls is exhausted, or when an element has NULL as its type,
2763 perform the default conversions.
2765 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2767 This is also where warnings about wrong number of args are generated.
2769 Return a list of expressions for the parameters as converted.
2771 Both VALUES and the returned value are chains of TREE_LIST nodes
2772 with the elements of the list in the TREE_VALUE slots of those nodes.
2774 In C++, unspecified trailing parameters can be filled in with their
2775 default arguments, if such were specified. Do so here. */
2778 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2780 tree typetail, valtail;
2781 tree result = NULL_TREE;
2782 const char *called_thing = 0;
2785 /* Argument passing is always copy-initialization. */
2786 flags |= LOOKUP_ONLYCONVERTING;
2790 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2792 if (DECL_NAME (fndecl) == NULL_TREE
2793 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2794 called_thing = "constructor";
2796 called_thing = "member function";
2799 called_thing = "function";
2802 for (valtail = values, typetail = typelist;
2804 valtail = TREE_CHAIN (valtail), i++)
2806 tree type = typetail ? TREE_VALUE (typetail) : 0;
2807 tree val = TREE_VALUE (valtail);
2809 if (val == error_mark_node || type == error_mark_node)
2810 return error_mark_node;
2812 if (type == void_type_node)
2816 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2817 error ("at this point in file");
2820 error ("too many arguments to function");
2821 /* In case anybody wants to know if this argument
2824 TREE_TYPE (tree_last (result)) = error_mark_node;
2828 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2829 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2830 if (TREE_CODE (val) == NOP_EXPR
2831 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2832 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2833 val = TREE_OPERAND (val, 0);
2835 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2837 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2838 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2839 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2840 val = decay_conversion (val);
2843 if (val == error_mark_node)
2844 return error_mark_node;
2848 /* Formal parm type is specified by a function prototype. */
2851 if (!COMPLETE_TYPE_P (complete_type (type)))
2854 error ("parameter %P of %qD has incomplete type %qT",
2857 error ("parameter %P has incomplete type %qT", i, type);
2858 parmval = error_mark_node;
2862 parmval = convert_for_initialization
2863 (NULL_TREE, type, val, flags,
2864 "argument passing", fndecl, i);
2865 parmval = convert_for_arg_passing (type, parmval);
2868 if (parmval == error_mark_node)
2869 return error_mark_node;
2871 result = tree_cons (NULL_TREE, parmval, result);
2875 if (fndecl && DECL_BUILT_IN (fndecl)
2876 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2877 /* Don't do ellipsis conversion for __built_in_constant_p
2878 as this will result in spurious warnings for non-POD
2880 val = require_complete_type (val);
2882 val = convert_arg_to_ellipsis (val);
2884 result = tree_cons (NULL_TREE, val, result);
2888 typetail = TREE_CHAIN (typetail);
2891 if (typetail != 0 && typetail != void_list_node)
2893 /* See if there are default arguments that can be used. */
2894 if (TREE_PURPOSE (typetail)
2895 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2897 for (; typetail != void_list_node; ++i)
2900 = convert_default_arg (TREE_VALUE (typetail),
2901 TREE_PURPOSE (typetail),
2904 if (parmval == error_mark_node)
2905 return error_mark_node;
2907 result = tree_cons (0, parmval, result);
2908 typetail = TREE_CHAIN (typetail);
2909 /* ends with `...'. */
2910 if (typetail == NULL_TREE)
2918 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2919 error ("at this point in file");
2922 error ("too few arguments to function");
2923 return error_mark_node;
2927 return nreverse (result);
2930 /* Build a binary-operation expression, after performing default
2931 conversions on the operands. CODE is the kind of expression to
2932 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
2933 are the tree codes which correspond to ARG1 and ARG2 when issuing
2934 warnings about possibly misplaced parentheses. They may differ
2935 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
2936 folding (e.g., if the parser sees "a | 1 + 1", it may call this
2937 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
2938 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
2939 ARG2_CODE as ERROR_MARK. */
2942 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
2943 tree arg2, enum tree_code arg2_code, bool *overloaded_p)
2952 if (processing_template_decl)
2954 if (type_dependent_expression_p (arg1)
2955 || type_dependent_expression_p (arg2))
2956 return build_min_nt (code, arg1, arg2);
2957 arg1 = build_non_dependent_expr (arg1);
2958 arg2 = build_non_dependent_expr (arg2);
2961 if (code == DOTSTAR_EXPR)
2962 expr = build_m_component_ref (arg1, arg2);
2964 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2967 /* Check for cases such as x+y<<z which users are likely to
2968 misinterpret. But don't warn about obj << x + y, since that is a
2969 common idiom for I/O. */
2970 if (warn_parentheses
2971 && !processing_template_decl
2972 && !error_operand_p (arg1)
2973 && !error_operand_p (arg2)
2974 && (code != LSHIFT_EXPR
2975 || !CLASS_TYPE_P (TREE_TYPE (arg1))))
2976 warn_about_parentheses (code, arg1_code, arg2_code);
2978 if (processing_template_decl && expr != error_mark_node)
2979 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2984 /* Build a binary-operation expression without default conversions.
2985 CODE is the kind of expression to build.
2986 This function differs from `build' in several ways:
2987 the data type of the result is computed and recorded in it,
2988 warnings are generated if arg data types are invalid,
2989 special handling for addition and subtraction of pointers is known,
2990 and some optimization is done (operations on narrow ints
2991 are done in the narrower type when that gives the same result).
2992 Constant folding is also done before the result is returned.
2994 Note that the operands will never have enumeral types
2995 because either they have just had the default conversions performed
2996 or they have both just been converted to some other type in which
2997 the arithmetic is to be done.
2999 C++: must do special pointer arithmetic when implementing
3000 multiple inheritance, and deal with pointer to member functions. */
3003 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
3004 int convert_p ATTRIBUTE_UNUSED)
3007 enum tree_code code0, code1;
3009 const char *invalid_op_diag;
3011 /* Expression code to give to the expression when it is built.
3012 Normally this is CODE, which is what the caller asked for,
3013 but in some special cases we change it. */
3014 enum tree_code resultcode = code;
3016 /* Data type in which the computation is to be performed.
3017 In the simplest cases this is the common type of the arguments. */
3018 tree result_type = NULL;
3020 /* Nonzero means operands have already been type-converted
3021 in whatever way is necessary.
3022 Zero means they need to be converted to RESULT_TYPE. */
3025 /* Nonzero means create the expression with this type, rather than
3027 tree build_type = 0;
3029 /* Nonzero means after finally constructing the expression
3030 convert it to this type. */
3031 tree final_type = 0;
3035 /* Nonzero if this is an operation like MIN or MAX which can
3036 safely be computed in short if both args are promoted shorts.
3037 Also implies COMMON.
3038 -1 indicates a bitwise operation; this makes a difference
3039 in the exact conditions for when it is safe to do the operation
3040 in a narrower mode. */
3043 /* Nonzero if this is a comparison operation;
3044 if both args are promoted shorts, compare the original shorts.
3045 Also implies COMMON. */
3046 int short_compare = 0;
3048 /* Nonzero if this is a right-shift operation, which can be computed on the
3049 original short and then promoted if the operand is a promoted short. */
3050 int short_shift = 0;
3052 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3055 /* True if both operands have arithmetic type. */
3056 bool arithmetic_types_p;
3058 /* Apply default conversions. */
3062 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3063 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3064 || code == TRUTH_XOR_EXPR)
3066 if (!really_overloaded_fn (op0))
3067 op0 = decay_conversion (op0);
3068 if (!really_overloaded_fn (op1))
3069 op1 = decay_conversion (op1);
3073 if (!really_overloaded_fn (op0))
3074 op0 = default_conversion (op0);
3075 if (!really_overloaded_fn (op1))
3076 op1 = default_conversion (op1);
3079 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3080 STRIP_TYPE_NOPS (op0);
3081 STRIP_TYPE_NOPS (op1);
3083 /* DTRT if one side is an overloaded function, but complain about it. */
3084 if (type_unknown_p (op0))
3086 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3087 if (t != error_mark_node)
3089 pedwarn ("assuming cast to type %qT from overloaded function",
3094 if (type_unknown_p (op1))
3096 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3097 if (t != error_mark_node)
3099 pedwarn ("assuming cast to type %qT from overloaded function",
3105 type0 = TREE_TYPE (op0);
3106 type1 = TREE_TYPE (op1);
3108 /* The expression codes of the data types of the arguments tell us
3109 whether the arguments are integers, floating, pointers, etc. */
3110 code0 = TREE_CODE (type0);
3111 code1 = TREE_CODE (type1);
3113 /* If an error was already reported for one of the arguments,
3114 avoid reporting another error. */
3116 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3117 return error_mark_node;
3119 if ((invalid_op_diag
3120 = targetm.invalid_binary_op (code, type0, type1)))
3122 error (invalid_op_diag);
3123 return error_mark_node;
3129 /* Subtraction of two similar pointers.
3130 We must subtract them as integers, then divide by object size. */
3131 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3132 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3134 return pointer_diff (op0, op1, common_type (type0, type1));
3135 /* In all other cases except pointer - int, the usual arithmetic
3137 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3142 /* The pointer - int case is just like pointer + int; fall
3145 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3146 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3150 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3151 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3152 if (processing_template_decl)
3154 result_type = TREE_TYPE (ptr_operand);
3157 return cp_pointer_int_sum (code,
3168 case TRUNC_DIV_EXPR:
3170 case FLOOR_DIV_EXPR:
3171 case ROUND_DIV_EXPR:
3172 case EXACT_DIV_EXPR:
3173 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3174 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3175 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3176 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3178 enum tree_code tcode0 = code0, tcode1 = code1;
3180 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
3181 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0%>", op0);
3182 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
3183 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0.%>", op0);
3185 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3186 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3187 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3188 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3190 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3191 resultcode = RDIV_EXPR;
3193 /* When dividing two signed integers, we have to promote to int.
3194 unless we divide by a constant != -1. Note that default
3195 conversion will have been performed on the operands at this
3196 point, so we have to dig out the original type to find out if
3198 shorten = ((TREE_CODE (op0) == NOP_EXPR
3199 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3200 || (TREE_CODE (op1) == INTEGER_CST
3201 && ! integer_all_onesp (op1)));
3210 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3211 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3215 case TRUNC_MOD_EXPR:
3216 case FLOOR_MOD_EXPR:
3217 if (code1 == INTEGER_TYPE && integer_zerop (op1))
3218 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0%>", op0);
3219 else if (code1 == REAL_TYPE && real_zerop (op1))
3220 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0.%>", op0);
3222 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3224 /* Although it would be tempting to shorten always here, that loses
3225 on some targets, since the modulo instruction is undefined if the
3226 quotient can't be represented in the computation mode. We shorten
3227 only if unsigned or if dividing by something we know != -1. */
3228 shorten = ((TREE_CODE (op0) == NOP_EXPR
3229 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3230 || (TREE_CODE (op1) == INTEGER_CST
3231 && ! integer_all_onesp (op1)));
3236 case TRUTH_ANDIF_EXPR:
3237 case TRUTH_ORIF_EXPR:
3238 case TRUTH_AND_EXPR:
3240 result_type = boolean_type_node;
3243 /* Shift operations: result has same type as first operand;
3244 always convert second operand to int.
3245 Also set SHORT_SHIFT if shifting rightward. */
3248 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3250 result_type = type0;
3251 if (TREE_CODE (op1) == INTEGER_CST)
3253 if (tree_int_cst_lt (op1, integer_zero_node))
3254 warning (0, "right shift count is negative");
3257 if (! integer_zerop (op1))
3259 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3260 warning (0, "right shift count >= width of type");
3263 /* Convert the shift-count to an integer, regardless of
3264 size of value being shifted. */
3265 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3266 op1 = cp_convert (integer_type_node, op1);
3267 /* Avoid converting op1 to result_type later. */
3273 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3275 result_type = type0;
3276 if (TREE_CODE (op1) == INTEGER_CST)
3278 if (tree_int_cst_lt (op1, integer_zero_node))
3279 warning (0, "left shift count is negative");
3280 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3281 warning (0, "left shift count >= width of type");
3283 /* Convert the shift-count to an integer, regardless of
3284 size of value being shifted. */
3285 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3286 op1 = cp_convert (integer_type_node, op1);
3287 /* Avoid converting op1 to result_type later. */
3294 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3296 result_type = type0;
3297 if (TREE_CODE (op1) == INTEGER_CST)
3299 if (tree_int_cst_lt (op1, integer_zero_node))
3300 warning (0, (code == LROTATE_EXPR)
3301 ? G_("left rotate count is negative")
3302 : G_("right rotate count is negative"));
3303 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3304 warning (0, (code == LROTATE_EXPR)
3305 ? G_("left rotate count >= width of type")
3306 : G_("right rotate count >= width of type"));
3308 /* Convert the shift-count to an integer, regardless of
3309 size of value being shifted. */
3310 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3311 op1 = cp_convert (integer_type_node, op1);
3317 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3318 warning (OPT_Wfloat_equal,
3319 "comparing floating point with == or != is unsafe");
3320 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3321 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3322 warning (OPT_Wstring_literal_comparison,
3323 "comparison with string literal");
3325 build_type = boolean_type_node;
3326 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3327 || code0 == COMPLEX_TYPE)
3328 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3329 || code1 == COMPLEX_TYPE))
3331 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3332 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3333 result_type = composite_pointer_type (type0, type1, op0, op1,
3335 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3336 && null_ptr_cst_p (op1))
3338 if (TREE_CODE (op0) == ADDR_EXPR
3339 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
3340 warning (OPT_Walways_true, "the address of %qD will never be NULL",
3341 TREE_OPERAND (op0, 0));
3342 result_type = type0;
3344 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3345 && null_ptr_cst_p (op0))
3347 if (TREE_CODE (op1) == ADDR_EXPR
3348 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
3349 warning (OPT_Walways_true, "the address of %qD will never be NULL",
3350 TREE_OPERAND (op1, 0));
3351 result_type = type1;
3353 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3355 result_type = type0;
3356 error ("ISO C++ forbids comparison between pointer and integer");
3358 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3360 result_type = type1;
3361 error ("ISO C++ forbids comparison between pointer and integer");
3363 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3365 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3366 == ptrmemfunc_vbit_in_delta)
3368 tree pfn0 = pfn_from_ptrmemfunc (op0);
3369 tree delta0 = build_ptrmemfunc_access_expr (op0,
3371 tree e1 = cp_build_binary_op (EQ_EXPR,
3373 fold_convert (TREE_TYPE (pfn0),
3374 integer_zero_node));
3375 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3378 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3379 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2);
3380 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3384 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3385 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3387 result_type = TREE_TYPE (op0);
3389 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3390 return cp_build_binary_op (code, op1, op0);
3391 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3392 && same_type_p (type0, type1))
3394 /* E will be the final comparison. */
3396 /* E1 and E2 are for scratch. */
3404 if (TREE_SIDE_EFFECTS (op0))
3405 op0 = save_expr (op0);
3406 if (TREE_SIDE_EFFECTS (op1))
3407 op1 = save_expr (op1);
3409 pfn0 = pfn_from_ptrmemfunc (op0);
3410 pfn1 = pfn_from_ptrmemfunc (op1);
3411 delta0 = build_ptrmemfunc_access_expr (op0,
3413 delta1 = build_ptrmemfunc_access_expr (op1,
3415 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3416 == ptrmemfunc_vbit_in_delta)
3421 && ((op0.delta == op1.delta)
3422 || (!op0.pfn && op0.delta & 1 == 0
3423 && op1.delta & 1 == 0))
3425 The reason for the `!op0.pfn' bit is that a NULL
3426 pointer-to-member is any member with a zero PFN and
3427 LSB of the DELTA field is 0. */
3429 e1 = cp_build_binary_op (BIT_AND_EXPR,
3432 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node);
3433 e2 = cp_build_binary_op (BIT_AND_EXPR,
3436 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3437 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3438 e2 = cp_build_binary_op (EQ_EXPR,
3440 fold_convert (TREE_TYPE (pfn0),
3441 integer_zero_node));
3442 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3443 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3444 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3451 && (!op0.pfn || op0.delta == op1.delta))
3453 The reason for the `!op0.pfn' bit is that a NULL
3454 pointer-to-member is any member with a zero PFN; the
3455 DELTA field is unspecified. */
3457 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3458 e2 = cp_build_binary_op (EQ_EXPR,
3460 fold_convert (TREE_TYPE (pfn0),
3461 integer_zero_node));
3462 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3464 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3465 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3466 if (code == EQ_EXPR)
3468 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3472 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3473 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3475 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3476 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3484 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3485 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3487 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3488 result_type = composite_pointer_type (type0, type1, op0, op1,
3496 if (TREE_CODE (orig_op0) == STRING_CST
3497 || TREE_CODE (orig_op1) == STRING_CST)
3498 warning (OPT_Wstring_literal_comparison,
3499 "comparison with string literal");
3501 build_type = boolean_type_node;
3502 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3503 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3505 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3506 result_type = composite_pointer_type (type0, type1, op0, op1,
3508 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3509 && integer_zerop (op1))
3510 result_type = type0;
3511 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3512 && integer_zerop (op0))
3513 result_type = type1;
3514 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3516 result_type = type0;
3517 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3519 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3521 result_type = type1;
3522 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3526 case UNORDERED_EXPR:
3533 build_type = integer_type_node;
3534 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3536 error ("unordered comparison on non-floating point argument");
3537 return error_mark_node;
3546 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3547 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3548 || code1 == COMPLEX_TYPE)))
3549 arithmetic_types_p = 1;
3552 arithmetic_types_p = 0;
3553 /* Vector arithmetic is only allowed when both sides are vectors. */
3554 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3556 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3557 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3560 binary_op_error (code);
3561 return error_mark_node;
3563 arithmetic_types_p = 1;
3566 /* Determine the RESULT_TYPE, if it is not already known. */
3568 && arithmetic_types_p
3569 && (shorten || common || short_compare))
3570 result_type = common_type (type0, type1);
3574 error ("invalid operands of types %qT and %qT to binary %qO",
3575 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3576 return error_mark_node;
3579 /* If we're in a template, the only thing we need to know is the
3581 if (processing_template_decl)
3582 return build2 (resultcode,
3583 build_type ? build_type : result_type,
3586 if (arithmetic_types_p)
3588 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3590 /* For certain operations (which identify themselves by shorten != 0)
3591 if both args were extended from the same smaller type,
3592 do the arithmetic in that type and then extend.
3594 shorten !=0 and !=1 indicates a bitwise operation.
3595 For them, this optimization is safe only if
3596 both args are zero-extended or both are sign-extended.
3597 Otherwise, we might change the result.
3598 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3599 but calculated in (unsigned short) it would be (unsigned short)-1. */
3601 if (shorten && none_complex)
3603 int unsigned0, unsigned1;
3604 tree arg0 = get_narrower (op0, &unsigned0);
3605 tree arg1 = get_narrower (op1, &unsigned1);
3606 /* UNS is 1 if the operation to be done is an unsigned one. */
3607 int uns = TYPE_UNSIGNED (result_type);
3610 final_type = result_type;
3612 /* Handle the case that OP0 does not *contain* a conversion
3613 but it *requires* conversion to FINAL_TYPE. */
3615 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3616 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3617 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3618 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3620 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3622 /* For bitwise operations, signedness of nominal type
3623 does not matter. Consider only how operands were extended. */
3627 /* Note that in all three cases below we refrain from optimizing
3628 an unsigned operation on sign-extended args.
3629 That would not be valid. */
3631 /* Both args variable: if both extended in same way
3632 from same width, do it in that width.
3633 Do it unsigned if args were zero-extended. */
3634 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3635 < TYPE_PRECISION (result_type))
3636 && (TYPE_PRECISION (TREE_TYPE (arg1))
3637 == TYPE_PRECISION (TREE_TYPE (arg0)))
3638 && unsigned0 == unsigned1
3639 && (unsigned0 || !uns))
3640 result_type = c_common_signed_or_unsigned_type
3641 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3642 else if (TREE_CODE (arg0) == INTEGER_CST
3643 && (unsigned1 || !uns)
3644 && (TYPE_PRECISION (TREE_TYPE (arg1))
3645 < TYPE_PRECISION (result_type))
3646 && (type = c_common_signed_or_unsigned_type
3647 (unsigned1, TREE_TYPE (arg1)),
3648 int_fits_type_p (arg0, type)))
3650 else if (TREE_CODE (arg1) == INTEGER_CST
3651 && (unsigned0 || !uns)
3652 && (TYPE_PRECISION (TREE_TYPE (arg0))
3653 < TYPE_PRECISION (result_type))
3654 && (type = c_common_signed_or_unsigned_type
3655 (unsigned0, TREE_TYPE (arg0)),
3656 int_fits_type_p (arg1, type)))
3660 /* Shifts can be shortened if shifting right. */
3665 tree arg0 = get_narrower (op0, &unsigned_arg);
3667 final_type = result_type;
3669 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3670 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3672 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3673 /* We can shorten only if the shift count is less than the
3674 number of bits in the smaller type size. */
3675 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3676 /* If arg is sign-extended and then unsigned-shifted,
3677 we can simulate this with a signed shift in arg's type
3678 only if the extended result is at least twice as wide
3679 as the arg. Otherwise, the shift could use up all the
3680 ones made by sign-extension and bring in zeros.
3681 We can't optimize that case at all, but in most machines
3682 it never happens because available widths are 2**N. */
3683 && (!TYPE_UNSIGNED (final_type)
3685 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3686 <= TYPE_PRECISION (result_type))))
3688 /* Do an unsigned shift if the operand was zero-extended. */
3690 = c_common_signed_or_unsigned_type (unsigned_arg,
3692 /* Convert value-to-be-shifted to that type. */
3693 if (TREE_TYPE (op0) != result_type)
3694 op0 = cp_convert (result_type, op0);
3699 /* Comparison operations are shortened too but differently.
3700 They identify themselves by setting short_compare = 1. */
3704 /* Don't write &op0, etc., because that would prevent op0
3705 from being kept in a register.
3706 Instead, make copies of the our local variables and
3707 pass the copies by reference, then copy them back afterward. */
3708 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3709 enum tree_code xresultcode = resultcode;
3711 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3713 return cp_convert (boolean_type_node, val);
3714 op0 = xop0, op1 = xop1;
3716 resultcode = xresultcode;
3719 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3720 && warn_sign_compare
3721 /* Do not warn until the template is instantiated; we cannot
3722 bound the ranges of the arguments until that point. */
3723 && !processing_template_decl)
3725 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3726 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3728 int unsignedp0, unsignedp1;
3729 tree primop0 = get_narrower (op0, &unsignedp0);
3730 tree primop1 = get_narrower (op1, &unsignedp1);
3732 /* Check for comparison of different enum types. */
3733 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3734 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3735 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3736 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3738 warning (0, "comparison between types %q#T and %q#T",
3739 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3742 /* Give warnings for comparisons between signed and unsigned
3743 quantities that may fail. */
3744 /* Do the checking based on the original operand trees, so that
3745 casts will be considered, but default promotions won't be. */
3747 /* Do not warn if the comparison is being done in a signed type,
3748 since the signed type will only be chosen if it can represent
3749 all the values of the unsigned type. */
3750 if (!TYPE_UNSIGNED (result_type))
3752 /* Do not warn if both operands are unsigned. */
3753 else if (op0_signed == op1_signed)
3755 /* Do not warn if the signed quantity is an unsuffixed
3756 integer literal (or some static constant expression
3757 involving such literals or a conditional expression
3758 involving such literals) and it is non-negative. */
3759 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3760 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3762 /* Do not warn if the comparison is an equality operation,
3763 the unsigned quantity is an integral constant and it does
3764 not use the most significant bit of result_type. */
3765 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3766 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3767 && int_fits_type_p (orig_op1, c_common_signed_type
3769 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3770 && int_fits_type_p (orig_op0, c_common_signed_type
3774 warning (0, "comparison between signed and unsigned integer expressions");
3776 /* Warn if two unsigned values are being compared in a size
3777 larger than their original size, and one (and only one) is the
3778 result of a `~' operator. This comparison will always fail.
3780 Also warn if one operand is a constant, and the constant does not
3781 have all bits set that are set in the ~ operand when it is
3784 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3785 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3787 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3788 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3789 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3790 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3792 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3795 HOST_WIDE_INT constant, mask;
3799 if (host_integerp (primop0, 0))
3802 unsignedp = unsignedp1;
3803 constant = tree_low_cst (primop0, 0);
3808 unsignedp = unsignedp0;
3809 constant = tree_low_cst (primop1, 0);
3812 bits = TYPE_PRECISION (TREE_TYPE (primop));
3813 if (bits < TYPE_PRECISION (result_type)
3814 && bits < HOST_BITS_PER_LONG && unsignedp)
3816 mask = (~ (HOST_WIDE_INT) 0) << bits;
3817 if ((mask & constant) != mask)
3818 warning (0, "comparison of promoted ~unsigned with constant");
3821 else if (unsignedp0 && unsignedp1
3822 && (TYPE_PRECISION (TREE_TYPE (primop0))
3823 < TYPE_PRECISION (result_type))
3824 && (TYPE_PRECISION (TREE_TYPE (primop1))
3825 < TYPE_PRECISION (result_type)))
3826 warning (0, "comparison of promoted ~unsigned with unsigned");
3831 /* Issue warnings about peculiar, but valid, uses of NULL. */
3832 if ((orig_op0 == null_node || orig_op1 == null_node)
3833 /* It's reasonable to use pointer values as operands of &&
3834 and ||, so NULL is no exception. */
3835 && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR
3836 && ( /* Both are NULL (or 0) and the operation was not a comparison. */
3837 (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1)
3838 && code != EQ_EXPR && code != NE_EXPR)
3839 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
3840 || (!null_ptr_cst_p (orig_op0) && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3841 || (!null_ptr_cst_p (orig_op1) && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)))
3842 /* Some sort of arithmetic operation involving NULL was
3843 performed. Note that pointer-difference and pointer-addition
3844 have already been handled above, and so we don't end up here in
3846 warning (OPT_Wpointer_arith, "NULL used in arithmetic");
3849 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3850 Then the expression will be built.
3851 It will be given type FINAL_TYPE if that is nonzero;
3852 otherwise, it will be given type RESULT_TYPE. */
3855 if (TREE_TYPE (op0) != result_type)
3856 op0 = cp_convert (result_type, op0);
3857 if (TREE_TYPE (op1) != result_type)
3858 op1 = cp_convert (result_type, op1);
3860 if (op0 == error_mark_node || op1 == error_mark_node)
3861 return error_mark_node;
3864 if (build_type == NULL_TREE)
3865 build_type = result_type;
3867 result = build2 (resultcode, build_type, op0, op1);
3868 result = fold_if_not_in_template (result);
3869 if (final_type != 0)
3870 result = cp_convert (final_type, result);
3872 if (TREE_OVERFLOW_P (result)
3873 && !TREE_OVERFLOW_P (op0)
3874 && !TREE_OVERFLOW_P (op1))
3875 overflow_warning (result);
3880 /* Return a tree for the sum or difference (RESULTCODE says which)
3881 of pointer PTROP and integer INTOP. */
3884 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3886 tree res_type = TREE_TYPE (ptrop);
3888 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3889 in certain circumstance (when it's valid to do so). So we need
3890 to make sure it's complete. We don't need to check here, if we
3891 can actually complete it at all, as those checks will be done in
3892 pointer_int_sum() anyway. */
3893 complete_type (TREE_TYPE (res_type));
3895 return pointer_int_sum (resultcode, ptrop,
3896 fold_if_not_in_template (intop));
3899 /* Return a tree for the difference of pointers OP0 and OP1.
3900 The resulting tree has type int. */
3903 pointer_diff (tree op0, tree op1, tree ptrtype)
3906 tree restype = ptrdiff_type_node;
3907 tree target_type = TREE_TYPE (ptrtype);
3909 if (!complete_type_or_else (target_type, NULL_TREE))
3910 return error_mark_node;
3912 if (pedantic || warn_pointer_arith)
3914 if (TREE_CODE (target_type) == VOID_TYPE)
3915 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3916 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3917 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3918 if (TREE_CODE (target_type) == METHOD_TYPE)
3919 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3922 /* First do the subtraction as integers;
3923 then drop through to build the divide operator. */
3925 op0 = cp_build_binary_op (MINUS_EXPR,
3926 cp_convert (restype, op0),
3927 cp_convert (restype, op1));
3929 /* This generates an error if op1 is a pointer to an incomplete type. */
3930 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3931 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3933 op1 = (TYPE_PTROB_P (ptrtype)
3934 ? size_in_bytes (target_type)
3935 : integer_one_node);
3937 /* Do the division. */
3939 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3940 return fold_if_not_in_template (result);
3943 /* Construct and perhaps optimize a tree representation
3944 for a unary operation. CODE, a tree_code, specifies the operation
3945 and XARG is the operand. */
3948 build_x_unary_op (enum tree_code code, tree xarg)
3950 tree orig_expr = xarg;
3954 if (processing_template_decl)
3956 if (type_dependent_expression_p (xarg))
3957 return build_min_nt (code, xarg, NULL_TREE);
3959 xarg = build_non_dependent_expr (xarg);
3964 /* [expr.unary.op] says:
3966 The address of an object of incomplete type can be taken.
3968 (And is just the ordinary address operator, not an overloaded
3969 "operator &".) However, if the type is a template
3970 specialization, we must complete the type at this point so that
3971 an overloaded "operator &" will be available if required. */
3972 if (code == ADDR_EXPR
3973 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3974 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3975 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3976 || (TREE_CODE (xarg) == OFFSET_REF)))
3977 /* Don't look for a function. */;
3979 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3980 /*overloaded_p=*/NULL);
3981 if (!exp && code == ADDR_EXPR)
3983 /* A pointer to member-function can be formed only by saying
3985 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3986 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3988 if (TREE_CODE (xarg) != OFFSET_REF
3989 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3991 error ("invalid use of %qE to form a pointer-to-member-function",
3993 if (TREE_CODE (xarg) != OFFSET_REF)
3994 inform (" a qualified-id is required");
3995 return error_mark_node;
3999 error ("parentheses around %qE cannot be used to form a"
4000 " pointer-to-member-function",
4002 PTRMEM_OK_P (xarg) = 1;
4006 if (TREE_CODE (xarg) == OFFSET_REF)
4008 ptrmem = PTRMEM_OK_P (xarg);
4010 if (!ptrmem && !flag_ms_extensions
4011 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
4013 /* A single non-static member, make sure we don't allow a
4014 pointer-to-member. */
4015 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
4016 TREE_OPERAND (xarg, 0),
4017 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
4018 PTRMEM_OK_P (xarg) = ptrmem;
4021 else if (TREE_CODE (xarg) == TARGET_EXPR)
4022 warning (0, "taking address of temporary");
4023 exp = build_unary_op (ADDR_EXPR, xarg, 0);
4026 if (processing_template_decl && exp != error_mark_node)
4027 exp = build_min_non_dep (code, exp, orig_expr,
4028 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
4029 if (TREE_CODE (exp) == ADDR_EXPR)
4030 PTRMEM_OK_P (exp) = ptrmem;
4034 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4035 constants, where a null value is represented by an INTEGER_CST of
4039 cp_truthvalue_conversion (tree expr)
4041 tree type = TREE_TYPE (expr);
4042 if (TYPE_PTRMEM_P (type))
4043 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
4045 return c_common_truthvalue_conversion (expr);
4048 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4051 condition_conversion (tree expr)
4054 if (processing_template_decl)
4056 t = perform_implicit_conversion (boolean_type_node, expr);
4057 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4061 /* Return an ADDR_EXPR giving the address of T. This function
4062 attempts no optimizations or simplifications; it is a low-level
4066 build_address (tree t)
4070 if (error_operand_p (t) || !cxx_mark_addressable (t))
4071 return error_mark_node;
4073 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4078 /* Return a NOP_EXPR converting EXPR to TYPE. */
4081 build_nop (tree type, tree expr)
4083 if (type == error_mark_node || error_operand_p (expr))
4085 return build1 (NOP_EXPR, type, expr);
4088 /* C++: Must handle pointers to members.
4090 Perhaps type instantiation should be extended to handle conversion
4091 from aggregates to types we don't yet know we want? (Or are those
4092 cases typically errors which should be reported?)
4094 NOCONVERT nonzero suppresses the default promotions
4095 (such as from short to int). */
4098 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4100 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4103 const char *errstring = NULL;
4105 const char *invalid_op_diag;
4107 if (arg == error_mark_node)
4108 return error_mark_node;
4110 if ((invalid_op_diag
4111 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4116 error (invalid_op_diag);
4117 return error_mark_node;
4122 case UNARY_PLUS_EXPR:
4125 int flags = WANT_ARITH | WANT_ENUM;
4126 /* Unary plus (but not unary minus) is allowed on pointers. */
4127 if (code == UNARY_PLUS_EXPR)
4128 flags |= WANT_POINTER;
4129 arg = build_expr_type_conversion (flags, arg, true);
4131 errstring = (code == NEGATE_EXPR
4132 ? "wrong type argument to unary minus"
4133 : "wrong type argument to unary plus");
4136 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4137 arg = perform_integral_promotions (arg);
4139 /* Make sure the result is not an lvalue: a unary plus or minus
4140 expression is always a rvalue. */
4147 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4151 arg = default_conversion (arg);
4153 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4156 errstring = "wrong type argument to bit-complement";
4157 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4158 arg = perform_integral_promotions (arg);
4162 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4163 errstring = "wrong type argument to abs";
4164 else if (!noconvert)
4165 arg = default_conversion (arg);
4169 /* Conjugating a real value is a no-op, but allow it anyway. */
4170 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4171 errstring = "wrong type argument to conjugation";
4172 else if (!noconvert)
4173 arg = default_conversion (arg);
4176 case TRUTH_NOT_EXPR:
4177 arg = perform_implicit_conversion (boolean_type_node, arg);
4178 val = invert_truthvalue (arg);
4179 if (arg != error_mark_node)
4181 errstring = "in argument to unary !";
4188 if (TREE_CODE (arg) == COMPLEX_CST)
4189 return TREE_REALPART (arg);
4190 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4192 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4193 return fold_if_not_in_template (arg);
4199 if (TREE_CODE (arg) == COMPLEX_CST)
4200 return TREE_IMAGPART (arg);
4201 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4203 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4204 return fold_if_not_in_template (arg);
4207 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4209 case PREINCREMENT_EXPR:
4210 case POSTINCREMENT_EXPR:
4211 case PREDECREMENT_EXPR:
4212 case POSTDECREMENT_EXPR:
4213 /* Handle complex lvalues (when permitted)
4214 by reduction to simpler cases. */
4216 val = unary_complex_lvalue (code, arg);
4220 /* Increment or decrement the real part of the value,
4221 and don't change the imaginary part. */
4222 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4226 arg = stabilize_reference (arg);
4227 real = build_unary_op (REALPART_EXPR, arg, 1);
4228 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4229 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4230 build_unary_op (code, real, 1), imag);
4233 /* Report invalid types. */
4235 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4238 if (code == PREINCREMENT_EXPR)
4239 errstring ="no pre-increment operator for type";
4240 else if (code == POSTINCREMENT_EXPR)
4241 errstring ="no post-increment operator for type";
4242 else if (code == PREDECREMENT_EXPR)
4243 errstring ="no pre-decrement operator for type";
4245 errstring ="no post-decrement operator for type";
4249 /* Report something read-only. */
4251 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4252 || TREE_READONLY (arg))
4253 readonly_error (arg, ((code == PREINCREMENT_EXPR
4254 || code == POSTINCREMENT_EXPR)
4255 ? "increment" : "decrement"),
4260 tree result_type = TREE_TYPE (arg);
4262 arg = get_unwidened (arg, 0);
4263 argtype = TREE_TYPE (arg);
4265 /* ARM $5.2.5 last annotation says this should be forbidden. */
4266 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4267 pedwarn ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4268 ? G_("ISO C++ forbids incrementing an enum")
4269 : G_("ISO C++ forbids decrementing an enum"));
4271 /* Compute the increment. */
4273 if (TREE_CODE (argtype) == POINTER_TYPE)
4275 tree type = complete_type (TREE_TYPE (argtype));
4277 if (!COMPLETE_OR_VOID_TYPE_P (type))
4278 error (((code == PREINCREMENT_EXPR
4279 || code == POSTINCREMENT_EXPR))
4280 ? G_("cannot increment a pointer to incomplete type %qT")
4281 : G_("cannot decrement a pointer to incomplete type %qT"),
4282 TREE_TYPE (argtype));
4283 else if ((pedantic || warn_pointer_arith)
4284 && !TYPE_PTROB_P (argtype))
4285 pedwarn ((code == PREINCREMENT_EXPR
4286 || code == POSTINCREMENT_EXPR)
4287 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4288 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4290 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4293 inc = integer_one_node;
4295 inc = cp_convert (argtype, inc);
4297 /* Handle incrementing a cast-expression. */
4299 switch (TREE_CODE (arg))
4304 case FIX_TRUNC_EXPR:
4306 tree incremented, modify, value, compound;
4307 if (! lvalue_p (arg) && pedantic)
4308 pedwarn ("cast to non-reference type used as lvalue");
4309 arg = stabilize_reference (arg);
4310 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
4313 value = save_expr (arg);
4314 incremented = build2 (((code == PREINCREMENT_EXPR
4315 || code == POSTINCREMENT_EXPR)
4316 ? PLUS_EXPR : MINUS_EXPR),
4317 argtype, value, inc);
4319 modify = build_modify_expr (arg, NOP_EXPR, incremented);
4320 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
4323 /* Eliminate warning about unused result of + or -. */
4324 TREE_NO_WARNING (compound) = 1;
4332 /* Complain about anything else that is not a true lvalue. */
4333 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4334 || code == POSTINCREMENT_EXPR)
4335 ? lv_increment : lv_decrement)))
4336 return error_mark_node;
4338 /* Forbid using -- on `bool'. */
4339 if (same_type_p (TREE_TYPE (arg), boolean_type_node))
4341 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4343 error ("invalid use of %<--%> on bool variable %qD", arg);
4344 return error_mark_node;
4346 val = boolean_increment (code, arg);
4349 val = build2 (code, TREE_TYPE (arg), arg, inc);
4351 TREE_SIDE_EFFECTS (val) = 1;
4352 return cp_convert (result_type, val);
4356 /* Note that this operation never does default_conversion
4357 regardless of NOCONVERT. */
4359 argtype = lvalue_type (arg);
4361 if (TREE_CODE (arg) == OFFSET_REF)
4364 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4366 tree type = build_pointer_type (TREE_TYPE (argtype));
4367 arg = build1 (CONVERT_EXPR, type, arg);
4370 else if (pedantic && DECL_MAIN_P (arg))
4372 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4374 /* Let &* cancel out to simplify resulting code. */
4375 if (TREE_CODE (arg) == INDIRECT_REF)
4377 /* We don't need to have `current_class_ptr' wrapped in a
4378 NON_LVALUE_EXPR node. */
4379 if (arg == current_class_ref)
4380 return current_class_ptr;
4382 arg = TREE_OPERAND (arg, 0);
4383 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4385 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4386 arg = build1 (CONVERT_EXPR, type, arg);
4389 /* Don't let this be an lvalue. */
4394 /* Uninstantiated types are all functions. Taking the
4395 address of a function is a no-op, so just return the
4398 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4399 || !IDENTIFIER_OPNAME_P (arg));
4401 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4402 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4404 /* They're trying to take the address of a unique non-static
4405 member function. This is ill-formed (except in MS-land),
4406 but let's try to DTRT.
4407 Note: We only handle unique functions here because we don't
4408 want to complain if there's a static overload; non-unique
4409 cases will be handled by instantiate_type. But we need to
4410 handle this case here to allow casts on the resulting PMF.
4411 We could defer this in non-MS mode, but it's easier to give
4412 a useful error here. */
4414 /* Inside constant member functions, the `this' pointer
4415 contains an extra const qualifier. TYPE_MAIN_VARIANT
4416 is used here to remove this const from the diagnostics
4417 and the created OFFSET_REF. */
4418 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4419 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4422 if (! flag_ms_extensions)
4424 tree name = DECL_NAME (fn);
4425 if (current_class_type
4426 && TREE_OPERAND (arg, 0) == current_class_ref)
4427 /* An expression like &memfn. */
4428 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4429 " or parenthesized non-static member function to form"
4430 " a pointer to member function. Say %<&%T::%D%>",
4433 pedwarn ("ISO C++ forbids taking the address of a bound member"
4434 " function to form a pointer to member function."
4438 arg = build_offset_ref (base, fn, /*address_p=*/true);
4442 if (type_unknown_p (arg))
4443 return build1 (ADDR_EXPR, unknown_type_node, arg);
4445 /* Handle complex lvalues (when permitted)
4446 by reduction to simpler cases. */
4447 val = unary_complex_lvalue (code, arg);
4451 switch (TREE_CODE (arg))
4456 case FIX_TRUNC_EXPR:
4457 if (! lvalue_p (arg) && pedantic)
4458 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4462 arg = BASELINK_FUNCTIONS (arg);
4466 arg = OVL_CURRENT (arg);
4470 /* Turn a reference to a non-static data member into a
4471 pointer-to-member. */
4476 if (!PTRMEM_OK_P (arg))
4477 return build_unary_op (code, arg, 0);
4479 t = TREE_OPERAND (arg, 1);
4480 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4482 error ("cannot create pointer to reference member %qD", t);
4483 return error_mark_node;
4486 type = build_ptrmem_type (context_for_name_lookup (t),
4488 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4496 /* Anything not already handled and not a true memory reference
4498 if (TREE_CODE (argtype) != FUNCTION_TYPE
4499 && TREE_CODE (argtype) != METHOD_TYPE
4500 && TREE_CODE (arg) != OFFSET_REF
4501 && !lvalue_or_else (arg, lv_addressof))
4502 return error_mark_node;
4504 if (argtype != error_mark_node)
4505 argtype = build_pointer_type (argtype);
4507 /* In a template, we are processing a non-dependent expression
4508 so we can just form an ADDR_EXPR with the correct type. */
4509 if (processing_template_decl)
4511 val = build_address (arg);
4512 if (TREE_CODE (arg) == OFFSET_REF)
4513 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4517 if (TREE_CODE (arg) != COMPONENT_REF)
4519 val = build_address (arg);
4520 if (TREE_CODE (arg) == OFFSET_REF)
4521 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4523 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4525 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4527 /* We can only get here with a single static member
4529 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4530 && DECL_STATIC_FUNCTION_P (fn));
4532 val = build_address (fn);
4533 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4534 /* Do not lose object's side effects. */
4535 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4536 TREE_OPERAND (arg, 0), val);
4538 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4540 error ("attempt to take address of bit-field structure member %qD",
4541 TREE_OPERAND (arg, 1));
4542 return error_mark_node;
4546 tree object = TREE_OPERAND (arg, 0);
4547 tree field = TREE_OPERAND (arg, 1);
4548 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4549 (TREE_TYPE (object), decl_type_context (field)));
4550 val = build_address (arg);
4553 if (TREE_CODE (argtype) == POINTER_TYPE
4554 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4556 build_ptrmemfunc_type (argtype);
4557 val = build_ptrmemfunc (argtype, val, 0,
4558 /*c_cast_p=*/false);
4570 argtype = TREE_TYPE (arg);
4571 return fold_if_not_in_template (build1 (code, argtype, arg));
4574 error ("%s", errstring);
4575 return error_mark_node;
4578 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4579 for certain kinds of expressions which are not really lvalues
4580 but which we can accept as lvalues.
4582 If ARG is not a kind of expression we can handle, return
4586 unary_complex_lvalue (enum tree_code code, tree arg)
4588 /* Inside a template, making these kinds of adjustments is
4589 pointless; we are only concerned with the type of the
4591 if (processing_template_decl)
4594 /* Handle (a, b) used as an "lvalue". */
4595 if (TREE_CODE (arg) == COMPOUND_EXPR)
4597 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4598 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4599 TREE_OPERAND (arg, 0), real_result);
4602 /* Handle (a ? b : c) used as an "lvalue". */
4603 if (TREE_CODE (arg) == COND_EXPR
4604 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4605 return rationalize_conditional_expr (code, arg);
4607 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4608 if (TREE_CODE (arg) == MODIFY_EXPR
4609 || TREE_CODE (arg) == PREINCREMENT_EXPR
4610 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4612 tree lvalue = TREE_OPERAND (arg, 0);
4613 if (TREE_SIDE_EFFECTS (lvalue))
4615 lvalue = stabilize_reference (lvalue);
4616 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4617 lvalue, TREE_OPERAND (arg, 1));
4619 return unary_complex_lvalue
4620 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4623 if (code != ADDR_EXPR)
4626 /* Handle (a = b) used as an "lvalue" for `&'. */
4627 if (TREE_CODE (arg) == MODIFY_EXPR
4628 || TREE_CODE (arg) == INIT_EXPR)
4630 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4631 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4633 TREE_NO_WARNING (arg) = 1;
4637 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4638 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4639 || TREE_CODE (arg) == OFFSET_REF)
4642 /* We permit compiler to make function calls returning
4643 objects of aggregate type look like lvalues. */
4647 if (TREE_CODE (targ) == SAVE_EXPR)
4648 targ = TREE_OPERAND (targ, 0);
4650 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4652 if (TREE_CODE (arg) == SAVE_EXPR)
4655 targ = build_cplus_new (TREE_TYPE (arg), arg);
4656 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4659 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4660 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4661 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4664 /* Don't let anything else be handled specially. */
4668 /* Mark EXP saying that we need to be able to take the
4669 address of it; it should not be allocated in a register.
4670 Value is true if successful.
4672 C++: we do not allow `current_class_ptr' to be addressable. */
4675 cxx_mark_addressable (tree exp)
4680 switch (TREE_CODE (x))
4687 x = TREE_OPERAND (x, 0);
4691 if (x == current_class_ptr)
4693 error ("cannot take the address of %<this%>, which is an rvalue expression");
4694 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4700 /* Caller should not be trying to mark initialized
4701 constant fields addressable. */
4702 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4703 || DECL_IN_AGGR_P (x) == 0
4705 || DECL_EXTERNAL (x));
4710 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4711 && !DECL_ARTIFICIAL (x))
4713 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4716 ("address of explicit register variable %qD requested", x);
4719 else if (extra_warnings)
4721 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4723 TREE_ADDRESSABLE (x) = 1;
4727 TREE_ADDRESSABLE (x) = 1;
4731 TREE_ADDRESSABLE (x) = 1;
4735 TREE_ADDRESSABLE (x) = 1;
4736 cxx_mark_addressable (TREE_OPERAND (x, 0));
4744 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4747 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4749 tree orig_ifexp = ifexp;
4750 tree orig_op1 = op1;
4751 tree orig_op2 = op2;
4754 if (processing_template_decl)
4756 /* The standard says that the expression is type-dependent if
4757 IFEXP is type-dependent, even though the eventual type of the
4758 expression doesn't dependent on IFEXP. */
4759 if (type_dependent_expression_p (ifexp)
4760 /* As a GNU extension, the middle operand may be omitted. */
4761 || (op1 && type_dependent_expression_p (op1))
4762 || type_dependent_expression_p (op2))
4763 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4764 ifexp = build_non_dependent_expr (ifexp);
4766 op1 = build_non_dependent_expr (op1);
4767 op2 = build_non_dependent_expr (op2);
4770 expr = build_conditional_expr (ifexp, op1, op2);
4771 if (processing_template_decl && expr != error_mark_node)
4772 return build_min_non_dep (COND_EXPR, expr,
4773 orig_ifexp, orig_op1, orig_op2);
4777 /* Given a list of expressions, return a compound expression
4778 that performs them all and returns the value of the last of them. */
4780 tree build_x_compound_expr_from_list (tree list, const char *msg)
4782 tree expr = TREE_VALUE (list);
4784 if (TREE_CHAIN (list))
4787 pedwarn ("%s expression list treated as compound expression", msg);
4789 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4790 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4796 /* Handle overloading of the ',' operator when needed. */
4799 build_x_compound_expr (tree op1, tree op2)
4802 tree orig_op1 = op1;
4803 tree orig_op2 = op2;
4805 if (processing_template_decl)
4807 if (type_dependent_expression_p (op1)
4808 || type_dependent_expression_p (op2))
4809 return build_min_nt (COMPOUND_EXPR, op1, op2);
4810 op1 = build_non_dependent_expr (op1);
4811 op2 = build_non_dependent_expr (op2);
4814 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4815 /*overloaded_p=*/NULL);
4817 result = build_compound_expr (op1, op2);
4819 if (processing_template_decl && result != error_mark_node)
4820 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4825 /* Build a compound expression. */
4828 build_compound_expr (tree lhs, tree rhs)
4830 lhs = convert_to_void (lhs, "left-hand operand of comma");
4832 if (lhs == error_mark_node || rhs == error_mark_node)
4833 return error_mark_node;
4835 if (TREE_CODE (rhs) == TARGET_EXPR)
4837 /* If the rhs is a TARGET_EXPR, then build the compound
4838 expression inside the target_expr's initializer. This
4839 helps the compiler to eliminate unnecessary temporaries. */
4840 tree init = TREE_OPERAND (rhs, 1);
4842 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4843 TREE_OPERAND (rhs, 1) = init;
4848 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4851 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4852 casts away constness. DIAG_FN gives the function to call if we
4853 need to issue a diagnostic; if it is NULL, no diagnostic will be
4854 issued. DESCRIPTION explains what operation is taking place. */
4857 check_for_casting_away_constness (tree src_type, tree dest_type,
4858 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4859 const char *description)
4861 if (diag_fn && casts_away_constness (src_type, dest_type))
4862 diag_fn ("%s from type %qT to type %qT casts away constness",
4863 description, src_type, dest_type);
4866 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4867 (another pointer-to-member type in the same hierarchy) and return
4868 the converted expression. If ALLOW_INVERSE_P is permitted, a
4869 pointer-to-derived may be converted to pointer-to-base; otherwise,
4870 only the other direction is permitted. If C_CAST_P is true, this
4871 conversion is taking place as part of a C-style cast. */
4874 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4877 if (TYPE_PTRMEM_P (type))
4881 if (TREE_CODE (expr) == PTRMEM_CST)
4882 expr = cplus_expand_constant (expr);
4883 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4884 TYPE_PTRMEM_CLASS_TYPE (type),
4887 if (!integer_zerop (delta))
4888 expr = cp_build_binary_op (PLUS_EXPR,
4889 build_nop (ptrdiff_type_node, expr),
4891 return build_nop (type, expr);
4894 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4895 allow_inverse_p, c_cast_p);
4898 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4899 a version of EXPR that has TREE_OVERFLOW set if it is set in ORIG.
4900 Otherwise, return EXPR unchanged. */
4903 ignore_overflows (tree expr, tree orig)
4905 if (TREE_CODE (expr) == INTEGER_CST
4906 && CONSTANT_CLASS_P (orig)
4907 && TREE_CODE (orig) != STRING_CST
4908 && TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig))
4910 if (!TREE_OVERFLOW (orig))
4911 /* Ensure constant sharing. */
4912 expr = build_int_cst_wide (TREE_TYPE (expr),
4913 TREE_INT_CST_LOW (expr),
4914 TREE_INT_CST_HIGH (expr));
4917 /* Avoid clobbering a shared constant. */
4918 expr = copy_node (expr);
4919 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4925 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4926 this static_cast is being attempted as one of the possible casts
4927 allowed by a C-style cast. (In that case, accessibility of base
4928 classes is not considered, and it is OK to cast away
4929 constness.) Return the result of the cast. *VALID_P is set to
4930 indicate whether or not the cast was valid. */
4933 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4939 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4942 /* Assume the cast is valid. */
4945 intype = TREE_TYPE (expr);
4947 /* Save casted types in the function's used types hash table. */
4948 used_types_insert (type);
4950 /* Determine what to do when casting away constness. */
4953 /* C-style casts are allowed to cast away constness. With
4954 WARN_CAST_QUAL, we still want to issue a warning. */
4955 diag_fn = warn_cast_qual ? warning0 : NULL;
4960 /* A static_cast may not cast away constness. */
4962 desc = "static_cast";
4965 /* [expr.static.cast]
4967 An lvalue of type "cv1 B", where B is a class type, can be cast
4968 to type "reference to cv2 D", where D is a class derived (clause
4969 _class.derived_) from B, if a valid standard conversion from
4970 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4971 same cv-qualification as, or greater cv-qualification than, cv1,
4972 and B is not a virtual base class of D. */
4973 /* We check this case before checking the validity of "TYPE t =
4974 EXPR;" below because for this case:
4977 struct D : public B { D(const B&); };
4979 void f() { static_cast<const D&>(b); }
4981 we want to avoid constructing a new D. The standard is not
4982 completely clear about this issue, but our interpretation is
4983 consistent with other compilers. */
4984 if (TREE_CODE (type) == REFERENCE_TYPE
4985 && CLASS_TYPE_P (TREE_TYPE (type))
4986 && CLASS_TYPE_P (intype)
4987 && real_lvalue_p (expr)
4988 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4989 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4990 build_pointer_type (TYPE_MAIN_VARIANT
4991 (TREE_TYPE (type))))
4993 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4997 /* There is a standard conversion from "D*" to "B*" even if "B"
4998 is ambiguous or inaccessible. If this is really a
4999 static_cast, then we check both for inaccessibility and
5000 ambiguity. However, if this is a static_cast being performed
5001 because the user wrote a C-style cast, then accessibility is
5003 base = lookup_base (TREE_TYPE (type), intype,
5004 c_cast_p ? ba_unique : ba_check,
5007 /* Convert from "B*" to "D*". This function will check that "B"
5008 is not a virtual base of "D". */
5009 expr = build_base_path (MINUS_EXPR, build_address (expr),
5010 base, /*nonnull=*/false);
5011 /* Convert the pointer to a reference -- but then remember that
5012 there are no expressions with reference type in C++. */
5013 return convert_from_reference (build_nop (type, expr));
5018 /* [expr.static.cast]
5020 An expression e can be explicitly converted to a type T using a
5021 static_cast of the form static_cast<T>(e) if the declaration T
5022 t(e);" is well-formed, for some invented temporary variable
5024 result = perform_direct_initialization_if_possible (type, expr,
5028 result = convert_from_reference (result);
5030 /* Ignore any integer overflow caused by the cast. */
5031 result = ignore_overflows (result, orig);
5033 /* [expr.static.cast]
5035 If T is a reference type, the result is an lvalue; otherwise,
5036 the result is an rvalue. */
5037 if (TREE_CODE (type) != REFERENCE_TYPE)
5038 result = rvalue (result);
5042 /* [expr.static.cast]
5044 Any expression can be explicitly converted to type cv void. */
5045 if (TREE_CODE (type) == VOID_TYPE)
5046 return convert_to_void (expr, /*implicit=*/NULL);
5048 /* [expr.static.cast]
5050 The inverse of any standard conversion sequence (clause _conv_),
5051 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5052 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5053 (_conv.bool_) conversions, can be performed explicitly using
5054 static_cast subject to the restriction that the explicit
5055 conversion does not cast away constness (_expr.const.cast_), and
5056 the following additional rules for specific cases: */
5057 /* For reference, the conversions not excluded are: integral
5058 promotions, floating point promotion, integral conversions,
5059 floating point conversions, floating-integral conversions,
5060 pointer conversions, and pointer to member conversions. */
5063 A value of integral _or enumeration_ type can be explicitly
5064 converted to an enumeration type. */
5065 /* The effect of all that is that any conversion between any two
5066 types which are integral, floating, or enumeration types can be
5068 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5069 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5071 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5073 /* Ignore any integer overflow caused by the cast. */
5074 expr = ignore_overflows (expr, orig);
5078 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5079 && CLASS_TYPE_P (TREE_TYPE (type))
5080 && CLASS_TYPE_P (TREE_TYPE (intype))
5081 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5082 (TREE_TYPE (intype))),
5083 build_pointer_type (TYPE_MAIN_VARIANT
5084 (TREE_TYPE (type)))))
5089 check_for_casting_away_constness (intype, type, diag_fn, desc);
5090 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5091 c_cast_p ? ba_unique : ba_check,
5093 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5096 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5097 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5104 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5105 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5107 if (TYPE_PTRMEM_P (type))
5109 t1 = (build_ptrmem_type
5111 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5112 t2 = (build_ptrmem_type
5114 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5121 if (can_convert (t1, t2))
5124 check_for_casting_away_constness (intype, type, diag_fn,
5126 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5131 /* [expr.static.cast]
5133 An rvalue of type "pointer to cv void" can be explicitly
5134 converted to a pointer to object type. A value of type pointer
5135 to object converted to "pointer to cv void" and back to the
5136 original pointer type will have its original value. */
5137 if (TREE_CODE (intype) == POINTER_TYPE
5138 && VOID_TYPE_P (TREE_TYPE (intype))
5139 && TYPE_PTROB_P (type))
5142 check_for_casting_away_constness (intype, type, diag_fn, desc);
5143 return build_nop (type, expr);
5147 return error_mark_node;
5150 /* Return an expression representing static_cast<TYPE>(EXPR). */
5153 build_static_cast (tree type, tree expr)
5158 if (type == error_mark_node || expr == error_mark_node)
5159 return error_mark_node;
5161 if (processing_template_decl)
5163 expr = build_min (STATIC_CAST_EXPR, type, expr);
5164 /* We don't know if it will or will not have side effects. */
5165 TREE_SIDE_EFFECTS (expr) = 1;
5166 return convert_from_reference (expr);
5169 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5170 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5171 if (TREE_CODE (type) != REFERENCE_TYPE
5172 && TREE_CODE (expr) == NOP_EXPR
5173 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5174 expr = TREE_OPERAND (expr, 0);
5176 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5180 error ("invalid static_cast from type %qT to type %qT",
5181 TREE_TYPE (expr), type);
5182 return error_mark_node;
5185 /* EXPR is an expression with member function or pointer-to-member
5186 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5187 not permitted by ISO C++, but we accept it in some modes. If we
5188 are not in one of those modes, issue a diagnostic. Return the
5189 converted expression. */
5192 convert_member_func_to_ptr (tree type, tree expr)
5197 intype = TREE_TYPE (expr);
5198 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5199 || TREE_CODE (intype) == METHOD_TYPE);
5201 if (pedantic || warn_pmf2ptr)
5202 pedwarn ("converting from %qT to %qT", intype, type);
5204 if (TREE_CODE (intype) == METHOD_TYPE)
5205 expr = build_addr_func (expr);
5206 else if (TREE_CODE (expr) == PTRMEM_CST)
5207 expr = build_address (PTRMEM_CST_MEMBER (expr));
5210 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5211 decl = build_address (decl);
5212 expr = get_member_function_from_ptrfunc (&decl, expr);
5215 return build_nop (type, expr);
5218 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5219 If C_CAST_P is true, this reinterpret cast is being done as part of
5220 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5221 indicate whether or not reinterpret_cast was valid. */
5224 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5229 /* Assume the cast is invalid. */
5233 if (type == error_mark_node || error_operand_p (expr))
5234 return error_mark_node;
5236 intype = TREE_TYPE (expr);
5238 /* Save casted types in the function's used types hash table. */
5239 used_types_insert (type);
5241 /* [expr.reinterpret.cast]
5242 An lvalue expression of type T1 can be cast to the type
5243 "reference to T2" if an expression of type "pointer to T1" can be
5244 explicitly converted to the type "pointer to T2" using a
5245 reinterpret_cast. */
5246 if (TREE_CODE (type) == REFERENCE_TYPE)
5248 if (! real_lvalue_p (expr))
5250 error ("invalid cast of an rvalue expression of type "
5253 return error_mark_node;
5256 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5257 "B" are related class types; the reinterpret_cast does not
5258 adjust the pointer. */
5259 if (TYPE_PTR_P (intype)
5260 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5261 COMPARE_BASE | COMPARE_DERIVED)))
5262 warning (0, "casting %qT to %qT does not dereference pointer",
5265 expr = build_unary_op (ADDR_EXPR, expr, 0);
5266 if (expr != error_mark_node)
5267 expr = build_reinterpret_cast_1
5268 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5270 if (expr != error_mark_node)
5271 expr = build_indirect_ref (expr, 0);
5275 /* As a G++ extension, we consider conversions from member
5276 functions, and pointers to member functions to
5277 pointer-to-function and pointer-to-void types. If
5278 -Wno-pmf-conversions has not been specified,
5279 convert_member_func_to_ptr will issue an error message. */
5280 if ((TYPE_PTRMEMFUNC_P (intype)
5281 || TREE_CODE (intype) == METHOD_TYPE)
5282 && TYPE_PTR_P (type)
5283 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5284 || VOID_TYPE_P (TREE_TYPE (type))))
5285 return convert_member_func_to_ptr (type, expr);
5287 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5288 array-to-pointer, and function-to-pointer conversions are
5290 expr = decay_conversion (expr);
5292 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5293 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5294 if (TREE_CODE (expr) == NOP_EXPR
5295 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5296 expr = TREE_OPERAND (expr, 0);
5298 if (error_operand_p (expr))
5299 return error_mark_node;
5301 intype = TREE_TYPE (expr);
5303 /* [expr.reinterpret.cast]
5304 A pointer can be converted to any integral type large enough to
5306 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5308 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5309 pedwarn ("cast from %qT to %qT loses precision",
5312 /* [expr.reinterpret.cast]
5313 A value of integral or enumeration type can be explicitly
5314 converted to a pointer. */
5315 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5318 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5319 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5320 return fold_if_not_in_template (build_nop (type, expr));
5321 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5322 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5327 check_for_casting_away_constness (intype, type, error,
5328 "reinterpret_cast");
5329 /* Warn about possible alignment problems. */
5330 if (STRICT_ALIGNMENT && warn_cast_align
5331 && !VOID_TYPE_P (type)
5332 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5333 && COMPLETE_TYPE_P (TREE_TYPE (type))
5334 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5335 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5336 warning (0, "cast from %qT to %qT increases required alignment of "
5340 /* We need to strip nops here, because the front end likes to
5341 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5343 strict_aliasing_warning (intype, type, sexpr);
5345 return fold_if_not_in_template (build_nop (type, expr));
5347 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5348 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5351 /* Only issue a warning, as we have always supported this
5352 where possible, and it is necessary in some cases. DR 195
5353 addresses this issue, but as of 2004/10/26 is still in
5355 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5356 return fold_if_not_in_template (build_nop (type, expr));
5358 else if (TREE_CODE (type) == VECTOR_TYPE)
5359 return fold_if_not_in_template (convert_to_vector (type, expr));
5360 else if (TREE_CODE (intype) == VECTOR_TYPE)
5361 return fold_if_not_in_template (convert_to_integer (type, expr));
5366 error ("invalid cast from type %qT to type %qT", intype, type);
5367 return error_mark_node;
5370 return cp_convert (type, expr);
5374 build_reinterpret_cast (tree type, tree expr)
5376 if (type == error_mark_node || expr == error_mark_node)
5377 return error_mark_node;
5379 if (processing_template_decl)
5381 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5383 if (!TREE_SIDE_EFFECTS (t)
5384 && type_dependent_expression_p (expr))
5385 /* There might turn out to be side effects inside expr. */
5386 TREE_SIDE_EFFECTS (t) = 1;
5387 return convert_from_reference (t);
5390 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5394 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5395 return an appropriate expression. Otherwise, return
5396 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5397 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5398 performing a C-style cast, its value upon return will indicate
5399 whether or not the conversion succeeded. */
5402 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5406 tree reference_type;
5408 /* Callers are responsible for handling error_mark_node as a
5409 destination type. */
5410 gcc_assert (dst_type != error_mark_node);
5411 /* In a template, callers should be building syntactic
5412 representations of casts, not using this machinery. */
5413 gcc_assert (!processing_template_decl);
5415 /* Assume the conversion is invalid. */
5419 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5422 error ("invalid use of const_cast with type %qT, "
5423 "which is not a pointer, "
5424 "reference, nor a pointer-to-data-member type", dst_type);
5425 return error_mark_node;
5428 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5431 error ("invalid use of const_cast with type %qT, which is a pointer "
5432 "or reference to a function type", dst_type);
5433 return error_mark_node;
5436 /* Save casted types in the function's used types hash table. */
5437 used_types_insert (dst_type);
5439 src_type = TREE_TYPE (expr);
5440 /* Expressions do not really have reference types. */
5441 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5442 src_type = TREE_TYPE (src_type);
5444 /* [expr.const.cast]
5446 An lvalue of type T1 can be explicitly converted to an lvalue of
5447 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5448 types) if a pointer to T1 can be explicitly converted to the type
5449 pointer to T2 using a const_cast. */
5450 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5452 reference_type = dst_type;
5453 if (! real_lvalue_p (expr))
5456 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5457 src_type, dst_type);
5458 return error_mark_node;
5460 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5461 src_type = build_pointer_type (src_type);
5465 reference_type = NULL_TREE;
5466 /* If the destination type is not a reference type, the
5467 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5468 conversions are performed. */
5469 src_type = type_decays_to (src_type);
5470 if (src_type == error_mark_node)
5471 return error_mark_node;
5474 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5475 && comp_ptr_ttypes_const (dst_type, src_type))
5480 /* This cast is actually a C-style cast. Issue a warning if
5481 the user is making a potentially unsafe cast. */
5483 check_for_casting_away_constness (src_type, dst_type,
5489 expr = build_unary_op (ADDR_EXPR, expr, 0);
5490 expr = build_nop (reference_type, expr);
5491 return convert_from_reference (expr);
5495 expr = decay_conversion (expr);
5496 /* build_c_cast puts on a NOP_EXPR to make the result not an
5497 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5498 non-lvalue context. */
5499 if (TREE_CODE (expr) == NOP_EXPR
5500 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5501 expr = TREE_OPERAND (expr, 0);
5502 return build_nop (dst_type, expr);
5507 error ("invalid const_cast from type %qT to type %qT",
5508 src_type, dst_type);
5509 return error_mark_node;
5513 build_const_cast (tree type, tree expr)
5515 if (type == error_mark_node || error_operand_p (expr))
5516 return error_mark_node;
5518 if (processing_template_decl)
5520 tree t = build_min (CONST_CAST_EXPR, type, expr);
5522 if (!TREE_SIDE_EFFECTS (t)
5523 && type_dependent_expression_p (expr))
5524 /* There might turn out to be side effects inside expr. */
5525 TREE_SIDE_EFFECTS (t) = 1;
5526 return convert_from_reference (t);
5529 return build_const_cast_1 (type, expr, /*complain=*/true,
5533 /* Build an expression representing an explicit C-style cast to type
5534 TYPE of expression EXPR. */
5537 build_c_cast (tree type, tree expr)
5543 if (type == error_mark_node || error_operand_p (expr))
5544 return error_mark_node;
5546 if (processing_template_decl)
5548 tree t = build_min (CAST_EXPR, type,
5549 tree_cons (NULL_TREE, value, NULL_TREE));
5550 /* We don't know if it will or will not have side effects. */
5551 TREE_SIDE_EFFECTS (t) = 1;
5552 return convert_from_reference (t);
5555 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5556 'Class') should always be retained, because this information aids
5557 in method lookup. */
5558 if (objc_is_object_ptr (type)
5559 && objc_is_object_ptr (TREE_TYPE (expr)))
5560 return build_nop (type, expr);
5562 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5563 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5564 if (TREE_CODE (type) != REFERENCE_TYPE
5565 && TREE_CODE (value) == NOP_EXPR
5566 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5567 value = TREE_OPERAND (value, 0);
5569 if (TREE_CODE (type) == ARRAY_TYPE)
5571 /* Allow casting from T1* to T2[] because Cfront allows it.
5572 NIHCL uses it. It is not valid ISO C++ however. */
5573 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5575 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5576 type = build_pointer_type (TREE_TYPE (type));
5580 error ("ISO C++ forbids casting to an array type %qT", type);
5581 return error_mark_node;
5585 if (TREE_CODE (type) == FUNCTION_TYPE
5586 || TREE_CODE (type) == METHOD_TYPE)
5588 error ("invalid cast to function type %qT", type);
5589 return error_mark_node;
5592 /* A C-style cast can be a const_cast. */
5593 result = build_const_cast_1 (type, value, /*complain=*/false,
5598 /* Or a static cast. */
5599 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5601 /* Or a reinterpret_cast. */
5603 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5605 /* The static_cast or reinterpret_cast may be followed by a
5608 /* A valid cast may result in errors if, for example, a
5609 conversion to am ambiguous base class is required. */
5610 && !error_operand_p (result))
5614 /* Non-class rvalues always have cv-unqualified type. */
5615 if (!CLASS_TYPE_P (type))
5616 type = TYPE_MAIN_VARIANT (type);
5617 result_type = TREE_TYPE (result);
5618 if (!CLASS_TYPE_P (result_type))
5619 result_type = TYPE_MAIN_VARIANT (result_type);
5620 /* If the type of RESULT does not match TYPE, perform a
5621 const_cast to make it match. If the static_cast or
5622 reinterpret_cast succeeded, we will differ by at most
5623 cv-qualification, so the follow-on const_cast is guaranteed
5625 if (!same_type_p (non_reference (type), non_reference (result_type)))
5627 result = build_const_cast_1 (type, result, false, &valid_p);
5628 gcc_assert (valid_p);
5633 return error_mark_node;
5636 /* Build an assignment expression of lvalue LHS from value RHS.
5637 MODIFYCODE is the code for a binary operator that we use
5638 to combine the old value of LHS with RHS to get the new value.
5639 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5641 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5644 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5648 tree lhstype = TREE_TYPE (lhs);
5649 tree olhstype = lhstype;
5650 tree olhs = NULL_TREE;
5651 bool plain_assign = (modifycode == NOP_EXPR);
5653 /* Avoid duplicate error messages from operands that had errors. */
5654 if (error_operand_p (lhs) || error_operand_p (rhs))
5655 return error_mark_node;
5657 /* Handle control structure constructs used as "lvalues". */
5658 switch (TREE_CODE (lhs))
5660 /* Handle --foo = 5; as these are valid constructs in C++. */
5661 case PREDECREMENT_EXPR:
5662 case PREINCREMENT_EXPR:
5663 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5664 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5665 stabilize_reference (TREE_OPERAND (lhs, 0)),
5666 TREE_OPERAND (lhs, 1));
5667 return build2 (COMPOUND_EXPR, lhstype,
5669 build_modify_expr (TREE_OPERAND (lhs, 0),
5672 /* Handle (a, b) used as an "lvalue". */
5674 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5676 if (newrhs == error_mark_node)
5677 return error_mark_node;
5678 return build2 (COMPOUND_EXPR, lhstype,
5679 TREE_OPERAND (lhs, 0), newrhs);
5682 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5683 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5684 stabilize_reference (TREE_OPERAND (lhs, 0)),
5685 TREE_OPERAND (lhs, 1));
5686 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5687 if (newrhs == error_mark_node)
5688 return error_mark_node;
5689 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5693 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5694 when neither operand has side-effects. */
5695 if (!lvalue_or_else (lhs, lv_assign))
5696 return error_mark_node;
5698 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5699 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5701 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5702 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5704 TREE_OPERAND (lhs, 0),
5705 TREE_OPERAND (lhs, 1)),
5706 TREE_OPERAND (lhs, 0),
5707 TREE_OPERAND (lhs, 1));
5710 /* Handle (a ? b : c) used as an "lvalue". */
5713 /* Produce (a ? (b = rhs) : (c = rhs))
5714 except that the RHS goes through a save-expr
5715 so the code to compute it is only emitted once. */
5717 tree preeval = NULL_TREE;
5719 rhs = stabilize_expr (rhs, &preeval);
5721 /* Check this here to avoid odd errors when trying to convert
5722 a throw to the type of the COND_EXPR. */
5723 if (!lvalue_or_else (lhs, lv_assign))
5724 return error_mark_node;
5726 cond = build_conditional_expr
5727 (TREE_OPERAND (lhs, 0),
5728 build_modify_expr (TREE_OPERAND (lhs, 1),
5730 build_modify_expr (TREE_OPERAND (lhs, 2),
5733 if (cond == error_mark_node)
5735 /* Make sure the code to compute the rhs comes out
5736 before the split. */
5738 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5746 if (modifycode == INIT_EXPR)
5748 if (TREE_CODE (rhs) == CONSTRUCTOR)
5750 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5751 /* Call convert to generate an error; see PR 11063. */
5752 rhs = convert (lhstype, rhs);
5753 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5754 TREE_SIDE_EFFECTS (result) = 1;
5757 else if (! IS_AGGR_TYPE (lhstype))
5758 /* Do the default thing. */;
5761 result = build_special_member_call (lhs, complete_ctor_identifier,
5762 build_tree_list (NULL_TREE, rhs),
5763 lhstype, LOOKUP_NORMAL);
5764 if (result == NULL_TREE)
5765 return error_mark_node;
5771 lhs = require_complete_type (lhs);
5772 if (lhs == error_mark_node)
5773 return error_mark_node;
5775 if (modifycode == NOP_EXPR)
5777 /* `operator=' is not an inheritable operator. */
5778 if (! IS_AGGR_TYPE (lhstype))
5779 /* Do the default thing. */;
5782 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5783 lhs, rhs, make_node (NOP_EXPR),
5784 /*overloaded_p=*/NULL);
5785 if (result == NULL_TREE)
5786 return error_mark_node;
5793 /* A binary op has been requested. Combine the old LHS
5794 value with the RHS producing the value we should actually
5795 store into the LHS. */
5797 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5798 lhs = stabilize_reference (lhs);
5799 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5800 if (newrhs == error_mark_node)
5802 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5803 TREE_TYPE (lhs), TREE_TYPE (rhs));
5804 return error_mark_node;
5807 /* Now it looks like a plain assignment. */
5808 modifycode = NOP_EXPR;
5810 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5811 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5814 /* The left-hand side must be an lvalue. */
5815 if (!lvalue_or_else (lhs, lv_assign))
5816 return error_mark_node;
5818 /* Warn about modifying something that is `const'. Don't warn if
5819 this is initialization. */
5820 if (modifycode != INIT_EXPR
5821 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5822 /* Functions are not modifiable, even though they are
5824 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5825 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5826 /* If it's an aggregate and any field is const, then it is
5827 effectively const. */
5828 || (CLASS_TYPE_P (lhstype)
5829 && C_TYPE_FIELDS_READONLY (lhstype))))
5830 readonly_error (lhs, "assignment", 0);
5832 /* If storing into a structure or union member, it has probably been
5833 given type `int'. Compute the type that would go with the actual
5834 amount of storage the member occupies. */
5836 if (TREE_CODE (lhs) == COMPONENT_REF
5837 && (TREE_CODE (lhstype) == INTEGER_TYPE
5838 || TREE_CODE (lhstype) == REAL_TYPE
5839 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5841 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5843 /* If storing in a field that is in actuality a short or narrower
5844 than one, we must store in the field in its actual type. */
5846 if (lhstype != TREE_TYPE (lhs))
5848 /* Avoid warnings converting integral types back into enums for
5850 if (TREE_CODE (lhstype) == INTEGER_TYPE
5851 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5853 if (TREE_SIDE_EFFECTS (lhs))
5854 lhs = stabilize_reference (lhs);
5857 lhs = copy_node (lhs);
5858 TREE_TYPE (lhs) = lhstype;
5862 /* Convert new value to destination type. */
5864 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5868 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5869 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5871 error ("incompatible types in assignment of %qT to %qT",
5872 TREE_TYPE (rhs), lhstype);
5873 return error_mark_node;
5876 /* Allow array assignment in compiler-generated code. */
5877 if (! DECL_ARTIFICIAL (current_function_decl))
5879 /* This routine is used for both initialization and assignment.
5880 Make sure the diagnostic message differentiates the context. */
5881 if (modifycode == INIT_EXPR)
5882 error ("array used as initializer");
5884 error ("invalid array assignment");
5885 return error_mark_node;
5888 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5889 ? 1 + (modifycode != INIT_EXPR): 0;
5890 return build_vec_init (lhs, NULL_TREE, newrhs,
5891 /*explicit_default_init_p=*/false,
5895 if (modifycode == INIT_EXPR)
5896 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5897 "initialization", NULL_TREE, 0);
5900 /* Avoid warnings on enum bit fields. */
5901 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5902 && TREE_CODE (lhstype) == INTEGER_TYPE)
5904 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5906 newrhs = convert_force (lhstype, newrhs, 0);
5909 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5911 if (TREE_CODE (newrhs) == CALL_EXPR
5912 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5913 newrhs = build_cplus_new (lhstype, newrhs);
5915 /* Can't initialize directly from a TARGET_EXPR, since that would
5916 cause the lhs to be constructed twice, and possibly result in
5917 accidental self-initialization. So we force the TARGET_EXPR to be
5918 expanded without a target. */
5919 if (TREE_CODE (newrhs) == TARGET_EXPR)
5920 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5921 TREE_OPERAND (newrhs, 0));
5924 if (newrhs == error_mark_node)
5925 return error_mark_node;
5927 if (c_dialect_objc () && flag_objc_gc)
5929 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5935 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5936 lhstype, lhs, newrhs);
5938 TREE_SIDE_EFFECTS (result) = 1;
5940 TREE_NO_WARNING (result) = 1;
5942 /* If we got the LHS in a different type for storing in,
5943 convert the result back to the nominal type of LHS
5944 so that the value we return always has the same type
5945 as the LHS argument. */
5947 if (olhstype == TREE_TYPE (result))
5951 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5952 TREE_NO_WARNING (result) = 1;
5955 return convert_for_assignment (olhstype, result, "assignment",
5960 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5962 if (processing_template_decl)
5963 return build_min_nt (MODOP_EXPR, lhs,
5964 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5966 if (modifycode != NOP_EXPR)
5968 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5969 make_node (modifycode),
5970 /*overloaded_p=*/NULL);
5973 TREE_NO_WARNING (rval) = 1;
5977 return build_modify_expr (lhs, modifycode, rhs);
5981 /* Get difference in deltas for different pointer to member function
5982 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5983 the conversion is invalid, the constant is zero. If
5984 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5985 If C_CAST_P is true this conversion is taking place as part of a
5988 Note that the naming of FROM and TO is kind of backwards; the return
5989 value is what we add to a TO in order to get a FROM. They are named
5990 this way because we call this function to find out how to convert from
5991 a pointer to member of FROM to a pointer to member of TO. */
5994 get_delta_difference (tree from, tree to,
5995 bool allow_inverse_p,
6002 /* Assume no conversion is required. */
6003 result = integer_zero_node;
6004 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
6005 if (kind == bk_inaccessible || kind == bk_ambig)
6006 error (" in pointer to member function conversion");
6009 if (kind != bk_via_virtual)
6010 result = BINFO_OFFSET (binfo);
6013 tree virt_binfo = binfo_from_vbase (binfo);
6015 /* This is a reinterpret cast, we choose to do nothing. */
6016 if (allow_inverse_p)
6017 warning (0, "pointer to member cast via virtual base %qT",
6018 BINFO_TYPE (virt_binfo));
6020 error ("pointer to member conversion via virtual base %qT",
6021 BINFO_TYPE (virt_binfo));
6024 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
6025 /* Pointer to member of incomplete class is permitted*/;
6026 else if (!allow_inverse_p)
6028 error_not_base_type (from, to);
6029 error (" in pointer to member conversion");
6033 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
6036 if (kind != bk_via_virtual)
6037 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
6040 /* This is a reinterpret cast, we choose to do nothing. */
6041 tree virt_binfo = binfo_from_vbase (binfo);
6043 warning (0, "pointer to member cast via virtual base %qT",
6044 BINFO_TYPE (virt_binfo));
6049 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6053 /* Return a constructor for the pointer-to-member-function TYPE using
6054 the other components as specified. */
6057 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6062 VEC(constructor_elt, gc) *v;
6064 /* Pull the FIELD_DECLs out of the type. */
6065 pfn_field = TYPE_FIELDS (type);
6066 delta_field = TREE_CHAIN (pfn_field);
6068 /* Make sure DELTA has the type we want. */
6069 delta = convert_and_check (delta_type_node, delta);
6071 /* Finish creating the initializer. */
6072 v = VEC_alloc(constructor_elt, gc, 2);
6073 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6074 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6075 u = build_constructor (type, v);
6076 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6077 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6078 TREE_STATIC (u) = (TREE_CONSTANT (u)
6079 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6081 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6086 /* Build a constructor for a pointer to member function. It can be
6087 used to initialize global variables, local variable, or used
6088 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6091 If FORCE is nonzero, then force this conversion, even if
6092 we would rather not do it. Usually set when using an explicit
6093 cast. A C-style cast is being processed iff C_CAST_P is true.
6095 Return error_mark_node, if something goes wrong. */
6098 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6104 if (error_operand_p (pfn))
6105 return error_mark_node;
6107 pfn_type = TREE_TYPE (pfn);
6108 to_type = build_ptrmemfunc_type (type);
6110 /* Handle multiple conversions of pointer to member functions. */
6111 if (TYPE_PTRMEMFUNC_P (pfn_type))
6113 tree delta = NULL_TREE;
6114 tree npfn = NULL_TREE;
6118 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6119 error ("invalid conversion to type %qT from type %qT",
6122 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6123 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6127 /* We don't have to do any conversion to convert a
6128 pointer-to-member to its own type. But, we don't want to
6129 just return a PTRMEM_CST if there's an explicit cast; that
6130 cast should make the expression an invalid template argument. */
6131 if (TREE_CODE (pfn) != PTRMEM_CST)
6133 if (same_type_p (to_type, pfn_type))
6135 else if (integer_zerop (n))
6136 return build_reinterpret_cast (to_type, pfn);
6139 if (TREE_SIDE_EFFECTS (pfn))
6140 pfn = save_expr (pfn);
6142 /* Obtain the function pointer and the current DELTA. */
6143 if (TREE_CODE (pfn) == PTRMEM_CST)
6144 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6147 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6148 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6151 /* Just adjust the DELTA field. */
6152 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6153 (TREE_TYPE (delta), ptrdiff_type_node));
6154 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6155 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6156 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6157 return build_ptrmemfunc1 (to_type, delta, npfn);
6160 /* Handle null pointer to member function conversions. */
6161 if (integer_zerop (pfn))
6163 pfn = build_c_cast (type, integer_zero_node);
6164 return build_ptrmemfunc1 (to_type,
6169 if (type_unknown_p (pfn))
6170 return instantiate_type (type, pfn, tf_warning_or_error);
6172 fn = TREE_OPERAND (pfn, 0);
6173 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6174 /* In a template, we will have preserved the
6176 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6177 return make_ptrmem_cst (to_type, fn);
6180 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6183 ??? There is no consistency as to the types returned for the above
6184 values. Some code acts as if it were a sizetype and some as if it were
6185 integer_type_node. */
6188 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6190 tree type = TREE_TYPE (cst);
6191 tree fn = PTRMEM_CST_MEMBER (cst);
6192 tree ptr_class, fn_class;
6194 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6196 /* The class that the function belongs to. */
6197 fn_class = DECL_CONTEXT (fn);
6199 /* The class that we're creating a pointer to member of. */
6200 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6202 /* First, calculate the adjustment to the function's class. */
6203 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6206 if (!DECL_VIRTUAL_P (fn))
6207 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6210 /* If we're dealing with a virtual function, we have to adjust 'this'
6211 again, to point to the base which provides the vtable entry for
6212 fn; the call will do the opposite adjustment. */
6213 tree orig_class = DECL_CONTEXT (fn);
6214 tree binfo = binfo_or_else (orig_class, fn_class);
6215 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6216 *delta, BINFO_OFFSET (binfo));
6217 *delta = fold_if_not_in_template (*delta);
6219 /* We set PFN to the vtable offset at which the function can be
6220 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6221 case delta is shifted left, and then incremented). */
6222 *pfn = DECL_VINDEX (fn);
6223 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6224 TYPE_SIZE_UNIT (vtable_entry_type));
6225 *pfn = fold_if_not_in_template (*pfn);
6227 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6229 case ptrmemfunc_vbit_in_pfn:
6230 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6232 *pfn = fold_if_not_in_template (*pfn);
6235 case ptrmemfunc_vbit_in_delta:
6236 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6237 *delta, integer_one_node);
6238 *delta = fold_if_not_in_template (*delta);
6239 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6240 *delta, integer_one_node);
6241 *delta = fold_if_not_in_template (*delta);
6248 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6249 *pfn = fold_if_not_in_template (*pfn);
6253 /* Return an expression for PFN from the pointer-to-member function
6257 pfn_from_ptrmemfunc (tree t)
6259 if (TREE_CODE (t) == PTRMEM_CST)
6264 expand_ptrmemfunc_cst (t, &delta, &pfn);
6269 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6272 /* Convert value RHS to type TYPE as preparation for an assignment to
6273 an lvalue of type TYPE. ERRTYPE is a string to use in error
6274 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6275 are doing the conversion in order to pass the PARMNUMth argument of
6279 convert_for_assignment (tree type, tree rhs,
6280 const char *errtype, tree fndecl, int parmnum)
6283 enum tree_code coder;
6285 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6286 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6287 rhs = TREE_OPERAND (rhs, 0);
6289 rhstype = TREE_TYPE (rhs);
6290 coder = TREE_CODE (rhstype);
6292 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6293 && vector_types_convertible_p (type, rhstype, true))
6294 return convert (type, rhs);
6296 if (rhs == error_mark_node || rhstype == error_mark_node)
6297 return error_mark_node;
6298 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6299 return error_mark_node;
6301 /* The RHS of an assignment cannot have void type. */
6302 if (coder == VOID_TYPE)
6304 error ("void value not ignored as it ought to be");
6305 return error_mark_node;
6308 /* Simplify the RHS if possible. */
6309 if (TREE_CODE (rhs) == CONST_DECL)
6310 rhs = DECL_INITIAL (rhs);
6312 if (c_dialect_objc ())
6315 tree rname = fndecl;
6317 if (!strcmp (errtype, "assignment"))
6319 else if (!strcmp (errtype, "initialization"))
6323 tree selector = objc_message_selector ();
6327 if (selector && parmno > 1)
6334 if (objc_compare_types (type, rhstype, parmno, rname))
6335 return convert (type, rhs);
6340 The expression is implicitly converted (clause _conv_) to the
6341 cv-unqualified type of the left operand.
6343 We allow bad conversions here because by the time we get to this point
6344 we are committed to doing the conversion. If we end up doing a bad
6345 conversion, convert_like will complain. */
6346 if (!can_convert_arg_bad (type, rhstype, rhs))
6348 /* When -Wno-pmf-conversions is use, we just silently allow
6349 conversions from pointers-to-members to plain pointers. If
6350 the conversion doesn't work, cp_convert will complain. */
6352 && TYPE_PTR_P (type)
6353 && TYPE_PTRMEMFUNC_P (rhstype))
6354 rhs = cp_convert (strip_top_quals (type), rhs);
6357 /* If the right-hand side has unknown type, then it is an
6358 overloaded function. Call instantiate_type to get error
6360 if (rhstype == unknown_type_node)
6361 instantiate_type (type, rhs, tf_warning_or_error);
6363 error ("cannot convert %qT to %qT for argument %qP to %qD",
6364 rhstype, type, parmnum, fndecl);
6366 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6367 return error_mark_node;
6370 if (warn_missing_format_attribute)
6372 const enum tree_code codel = TREE_CODE (type);
6373 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6375 && check_missing_format_attribute (type, rhstype))
6376 warning (OPT_Wmissing_format_attribute,
6377 "%s might be a candidate for a format attribute",
6381 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6383 if (warn_parentheses
6384 && type == boolean_type_node
6385 && TREE_CODE (rhs) == MODIFY_EXPR
6386 && !TREE_NO_WARNING (rhs)
6387 && TREE_TYPE (rhs) != boolean_type_node)
6389 warning (OPT_Wparentheses,
6390 "suggest parentheses around assignment used as truth value");
6391 TREE_NO_WARNING (rhs) = 1;
6394 return perform_implicit_conversion (strip_top_quals (type), rhs);
6397 /* Convert RHS to be of type TYPE.
6398 If EXP is nonzero, it is the target of the initialization.
6399 ERRTYPE is a string to use in error messages.
6401 Two major differences between the behavior of
6402 `convert_for_assignment' and `convert_for_initialization'
6403 are that references are bashed in the former, while
6404 copied in the latter, and aggregates are assigned in
6405 the former (operator=) while initialized in the
6408 If using constructor make sure no conversion operator exists, if one does
6409 exist, an ambiguity exists.
6411 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6414 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6415 const char *errtype, tree fndecl, int parmnum)
6417 enum tree_code codel = TREE_CODE (type);
6419 enum tree_code coder;
6421 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6422 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6423 if (TREE_CODE (rhs) == NOP_EXPR
6424 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6425 && codel != REFERENCE_TYPE)
6426 rhs = TREE_OPERAND (rhs, 0);
6428 if (type == error_mark_node
6429 || rhs == error_mark_node
6430 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6431 return error_mark_node;
6433 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6434 && TREE_CODE (type) != ARRAY_TYPE
6435 && (TREE_CODE (type) != REFERENCE_TYPE
6436 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6437 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6438 && (TREE_CODE (type) != REFERENCE_TYPE
6439 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6440 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6441 rhs = decay_conversion (rhs);
6443 rhstype = TREE_TYPE (rhs);
6444 coder = TREE_CODE (rhstype);
6446 if (coder == ERROR_MARK)
6447 return error_mark_node;
6449 /* We accept references to incomplete types, so we can
6450 return here before checking if RHS is of complete type. */
6452 if (codel == REFERENCE_TYPE)
6454 /* This should eventually happen in convert_arguments. */
6455 int savew = 0, savee = 0;
6458 savew = warningcount, savee = errorcount;
6459 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6463 if (warningcount > savew)
6464 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6465 else if (errorcount > savee)
6466 error ("in passing argument %P of %q+D", parmnum, fndecl);
6472 exp = require_complete_type (exp);
6473 if (exp == error_mark_node)
6474 return error_mark_node;
6476 rhstype = non_reference (rhstype);
6478 type = complete_type (type);
6480 if (IS_AGGR_TYPE (type))
6481 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6483 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6486 /* If RETVAL is the address of, or a reference to, a local variable or
6487 temporary give an appropriate warning. */
6490 maybe_warn_about_returning_address_of_local (tree retval)
6492 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6493 tree whats_returned = retval;
6497 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6498 whats_returned = TREE_OPERAND (whats_returned, 1);
6499 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6500 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6501 || TREE_CODE (whats_returned) == NOP_EXPR)
6502 whats_returned = TREE_OPERAND (whats_returned, 0);
6507 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6509 whats_returned = TREE_OPERAND (whats_returned, 0);
6511 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6513 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6514 || TREE_CODE (whats_returned) == TARGET_EXPR)
6516 warning (0, "returning reference to temporary");
6519 if (TREE_CODE (whats_returned) == VAR_DECL
6520 && DECL_NAME (whats_returned)
6521 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6523 warning (0, "reference to non-lvalue returned");
6528 while (TREE_CODE (whats_returned) == COMPONENT_REF
6529 || TREE_CODE (whats_returned) == ARRAY_REF)
6530 whats_returned = TREE_OPERAND (whats_returned, 0);
6532 if (DECL_P (whats_returned)
6533 && DECL_NAME (whats_returned)
6534 && DECL_FUNCTION_SCOPE_P (whats_returned)
6535 && !(TREE_STATIC (whats_returned)
6536 || TREE_PUBLIC (whats_returned)))
6538 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6539 warning (0, "reference to local variable %q+D returned",
6542 warning (0, "address of local variable %q+D returned",
6548 /* Check that returning RETVAL from the current function is valid.
6549 Return an expression explicitly showing all conversions required to
6550 change RETVAL into the function return type, and to assign it to
6551 the DECL_RESULT for the function. Set *NO_WARNING to true if
6552 code reaches end of non-void function warning shouldn't be issued
6553 on this RETURN_EXPR. */
6556 check_return_expr (tree retval, bool *no_warning)
6559 /* The type actually returned by the function, after any
6562 int fn_returns_value_p;
6564 *no_warning = false;
6566 /* A `volatile' function is one that isn't supposed to return, ever.
6567 (This is a G++ extension, used to get better code for functions
6568 that call the `volatile' function.) */
6569 if (TREE_THIS_VOLATILE (current_function_decl))
6570 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6572 /* Check for various simple errors. */
6573 if (DECL_DESTRUCTOR_P (current_function_decl))
6576 error ("returning a value from a destructor");
6579 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6581 if (in_function_try_handler)
6582 /* If a return statement appears in a handler of the
6583 function-try-block of a constructor, the program is ill-formed. */
6584 error ("cannot return from a handler of a function-try-block of a constructor");
6586 /* You can't return a value from a constructor. */
6587 error ("returning a value from a constructor");
6591 if (processing_template_decl)
6593 current_function_returns_value = 1;
6597 /* When no explicit return-value is given in a function with a named
6598 return value, the named return value is used. */
6599 result = DECL_RESULT (current_function_decl);
6600 valtype = TREE_TYPE (result);
6601 gcc_assert (valtype != NULL_TREE);
6602 fn_returns_value_p = !VOID_TYPE_P (valtype);
6603 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6606 /* Check for a return statement with no return value in a function
6607 that's supposed to return a value. */
6608 if (!retval && fn_returns_value_p)
6610 pedwarn ("return-statement with no value, in function returning %qT",
6612 /* Clear this, so finish_function won't say that we reach the
6613 end of a non-void function (which we don't, we gave a
6615 current_function_returns_null = 0;
6616 /* And signal caller that TREE_NO_WARNING should be set on the
6617 RETURN_EXPR to avoid control reaches end of non-void function
6618 warnings in tree-cfg.c. */
6621 /* Check for a return statement with a value in a function that
6622 isn't supposed to return a value. */
6623 else if (retval && !fn_returns_value_p)
6625 if (VOID_TYPE_P (TREE_TYPE (retval)))
6626 /* You can return a `void' value from a function of `void'
6627 type. In that case, we have to evaluate the expression for
6628 its side-effects. */
6629 finish_expr_stmt (retval);
6631 pedwarn ("return-statement with a value, in function "
6632 "returning 'void'");
6634 current_function_returns_null = 1;
6636 /* There's really no value to return, after all. */
6640 /* Remember that this function can sometimes return without a
6642 current_function_returns_null = 1;
6644 /* Remember that this function did return a value. */
6645 current_function_returns_value = 1;
6647 /* Check for erroneous operands -- but after giving ourselves a
6648 chance to provide an error about returning a value from a void
6650 if (error_operand_p (retval))
6652 current_function_return_value = error_mark_node;
6653 return error_mark_node;
6656 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6657 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6658 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6659 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6661 && null_ptr_cst_p (retval))
6662 warning (0, "%<operator new%> must not return NULL unless it is "
6663 "declared %<throw()%> (or -fcheck-new is in effect)");
6665 /* Effective C++ rule 15. See also start_function. */
6667 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6671 /* The function return type must be a reference to the current
6673 if (TREE_CODE (valtype) == REFERENCE_TYPE
6674 && same_type_ignoring_top_level_qualifiers_p
6675 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6677 /* Returning '*this' is obviously OK. */
6678 if (retval == current_class_ref)
6680 /* If we are calling a function whose return type is the same of
6681 the current class reference, it is ok. */
6682 else if (TREE_CODE (retval) == INDIRECT_REF
6683 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6688 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6691 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6693 [...] For a function with a class return type, if the expression
6694 in the return statement is the name of a local object, and the cv-
6695 unqualified type of the local object is the same as the function
6696 return type, an implementation is permitted to omit creating the tem-
6697 porary object to hold the function return value [...]
6699 So, if this is a value-returning function that always returns the same
6700 local variable, remember it.
6702 It might be nice to be more flexible, and choose the first suitable
6703 variable even if the function sometimes returns something else, but
6704 then we run the risk of clobbering the variable we chose if the other
6705 returned expression uses the chosen variable somehow. And people expect
6706 this restriction, anyway. (jason 2000-11-19)
6708 See finish_function and finalize_nrv for the rest of this optimization. */
6710 if (fn_returns_value_p && flag_elide_constructors)
6712 if (retval != NULL_TREE
6713 && (current_function_return_value == NULL_TREE
6714 || current_function_return_value == retval)
6715 && TREE_CODE (retval) == VAR_DECL
6716 && DECL_CONTEXT (retval) == current_function_decl
6717 && ! TREE_STATIC (retval)
6718 && (DECL_ALIGN (retval)
6719 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6720 && same_type_p ((TYPE_MAIN_VARIANT
6721 (TREE_TYPE (retval))),
6723 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6724 current_function_return_value = retval;
6726 current_function_return_value = error_mark_node;
6729 /* We don't need to do any conversions when there's nothing being
6734 /* Do any required conversions. */
6735 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6736 /* No conversions are required. */
6740 /* The type the function is declared to return. */
6741 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6743 /* The functype's return type will have been set to void, if it
6744 was an incomplete type. Just treat this as 'return;' */
6745 if (VOID_TYPE_P (functype))
6746 return error_mark_node;
6748 /* First convert the value to the function's return type, then
6749 to the type of return value's location to handle the
6750 case that functype is smaller than the valtype. */
6751 retval = convert_for_initialization
6752 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6753 "return", NULL_TREE, 0);
6754 retval = convert (valtype, retval);
6756 /* If the conversion failed, treat this just like `return;'. */
6757 if (retval == error_mark_node)
6759 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6760 else if (! current_function_returns_struct
6761 && TREE_CODE (retval) == TARGET_EXPR
6762 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6763 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6764 TREE_OPERAND (retval, 0));
6766 maybe_warn_about_returning_address_of_local (retval);
6769 /* Actually copy the value returned into the appropriate location. */
6770 if (retval && retval != result)
6771 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6777 /* Returns nonzero if the pointer-type FROM can be converted to the
6778 pointer-type TO via a qualification conversion. If CONSTP is -1,
6779 then we return nonzero if the pointers are similar, and the
6780 cv-qualification signature of FROM is a proper subset of that of TO.
6782 If CONSTP is positive, then all outer pointers have been
6786 comp_ptr_ttypes_real (tree to, tree from, int constp)
6788 bool to_more_cv_qualified = false;
6790 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6792 if (TREE_CODE (to) != TREE_CODE (from))
6795 if (TREE_CODE (from) == OFFSET_TYPE
6796 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6797 TYPE_OFFSET_BASETYPE (to)))
6800 /* Const and volatile mean something different for function types,
6801 so the usual checks are not appropriate. */
6802 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6804 /* In Objective-C++, some types may have been 'volatilized' by
6805 the compiler for EH; when comparing them here, the volatile
6806 qualification must be ignored. */
6807 bool objc_quals_match = objc_type_quals_match (to, from);
6809 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6812 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6816 to_more_cv_qualified = true;
6820 constp &= TYPE_READONLY (to);
6823 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6824 return ((constp >= 0 || to_more_cv_qualified)
6825 && same_type_ignoring_top_level_qualifiers_p (to, from));
6829 /* When comparing, say, char ** to char const **, this function takes
6830 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6831 types to this function. */
6834 comp_ptr_ttypes (tree to, tree from)
6836 return comp_ptr_ttypes_real (to, from, 1);
6839 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6840 type or inheritance-related types, regardless of cv-quals. */
6843 ptr_reasonably_similar (tree to, tree from)
6845 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6847 /* Any target type is similar enough to void. */
6848 if (TREE_CODE (to) == VOID_TYPE
6849 || TREE_CODE (from) == VOID_TYPE)
6852 if (TREE_CODE (to) != TREE_CODE (from))
6855 if (TREE_CODE (from) == OFFSET_TYPE
6856 && comptypes (TYPE_OFFSET_BASETYPE (to),
6857 TYPE_OFFSET_BASETYPE (from),
6858 COMPARE_BASE | COMPARE_DERIVED))
6861 if (TREE_CODE (to) == VECTOR_TYPE
6862 && vector_types_convertible_p (to, from, false))
6865 if (TREE_CODE (to) == INTEGER_TYPE
6866 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6869 if (TREE_CODE (to) == FUNCTION_TYPE)
6872 if (TREE_CODE (to) != POINTER_TYPE)
6874 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6875 COMPARE_BASE | COMPARE_DERIVED);
6879 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6880 pointer-to-member types) are the same, ignoring cv-qualification at
6884 comp_ptr_ttypes_const (tree to, tree from)
6886 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6888 if (TREE_CODE (to) != TREE_CODE (from))
6891 if (TREE_CODE (from) == OFFSET_TYPE
6892 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6893 TYPE_OFFSET_BASETYPE (to)))
6896 if (TREE_CODE (to) != POINTER_TYPE)
6897 return same_type_ignoring_top_level_qualifiers_p (to, from);
6901 /* Returns the type qualifiers for this type, including the qualifiers on the
6902 elements for an array type. */
6905 cp_type_quals (tree type)
6907 type = strip_array_types (type);
6908 if (type == error_mark_node)
6909 return TYPE_UNQUALIFIED;
6910 return TYPE_QUALS (type);
6913 /* Returns nonzero if the TYPE contains a mutable member. */
6916 cp_has_mutable_p (tree type)
6918 type = strip_array_types (type);
6920 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6923 /* Apply the TYPE_QUALS to the new DECL. */
6925 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6927 tree type = TREE_TYPE (decl);
6929 if (type == error_mark_node)
6932 if (TREE_CODE (type) == FUNCTION_TYPE
6933 && type_quals != TYPE_UNQUALIFIED)
6935 /* This was an error in C++98 (cv-qualifiers cannot be added to
6936 a function type), but DR 295 makes the code well-formed by
6937 dropping the extra qualifiers. */
6940 tree bad_type = build_qualified_type (type, type_quals);
6941 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6945 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6949 /* Avoid setting TREE_READONLY incorrectly. */
6950 if (/* If the object has a constructor, the constructor may modify
6952 TYPE_NEEDS_CONSTRUCTING (type)
6953 /* If the type isn't complete, we don't know yet if it will need
6955 || !COMPLETE_TYPE_P (type)
6956 /* If the type has a mutable component, that component might be
6958 || TYPE_HAS_MUTABLE_P (type))
6959 type_quals &= ~TYPE_QUAL_CONST;
6961 c_apply_type_quals_to_decl (type_quals, decl);
6964 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6965 exemplar types such that casting T1 to T2 is casting away constness
6966 if and only if there is no implicit conversion from T1 to T2. */
6969 casts_away_constness_r (tree *t1, tree *t2)
6974 /* [expr.const.cast]
6976 For multi-level pointer to members and multi-level mixed pointers
6977 and pointers to members (conv.qual), the "member" aspect of a
6978 pointer to member level is ignored when determining if a const
6979 cv-qualifier has been cast away. */
6980 /* [expr.const.cast]
6982 For two pointer types:
6984 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6985 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6988 casting from X1 to X2 casts away constness if, for a non-pointer
6989 type T there does not exist an implicit conversion (clause
6992 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6996 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6997 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6998 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
7000 *t1 = cp_build_qualified_type (void_type_node,
7001 cp_type_quals (*t1));
7002 *t2 = cp_build_qualified_type (void_type_node,
7003 cp_type_quals (*t2));
7007 quals1 = cp_type_quals (*t1);
7008 quals2 = cp_type_quals (*t2);
7010 if (TYPE_PTRMEM_P (*t1))
7011 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
7013 *t1 = TREE_TYPE (*t1);
7014 if (TYPE_PTRMEM_P (*t2))
7015 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
7017 *t2 = TREE_TYPE (*t2);
7019 casts_away_constness_r (t1, t2);
7020 *t1 = build_pointer_type (*t1);
7021 *t2 = build_pointer_type (*t2);
7022 *t1 = cp_build_qualified_type (*t1, quals1);
7023 *t2 = cp_build_qualified_type (*t2, quals2);
7026 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
7030 casts_away_constness (tree t1, tree t2)
7032 if (TREE_CODE (t2) == REFERENCE_TYPE)
7034 /* [expr.const.cast]
7036 Casting from an lvalue of type T1 to an lvalue of type T2
7037 using a reference cast casts away constness if a cast from an
7038 rvalue of type "pointer to T1" to the type "pointer to T2"
7039 casts away constness. */
7040 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
7041 return casts_away_constness (build_pointer_type (t1),
7042 build_pointer_type (TREE_TYPE (t2)));
7045 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
7046 /* [expr.const.cast]
7048 Casting from an rvalue of type "pointer to data member of X
7049 of type T1" to the type "pointer to data member of Y of type
7050 T2" casts away constness if a cast from an rvalue of type
7051 "pointer to T1" to the type "pointer to T2" casts away
7053 return casts_away_constness
7054 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7055 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7057 /* Casting away constness is only something that makes sense for
7058 pointer or reference types. */
7059 if (TREE_CODE (t1) != POINTER_TYPE
7060 || TREE_CODE (t2) != POINTER_TYPE)
7063 /* Top-level qualifiers don't matter. */
7064 t1 = TYPE_MAIN_VARIANT (t1);
7065 t2 = TYPE_MAIN_VARIANT (t2);
7066 casts_away_constness_r (&t1, &t2);
7067 if (!can_convert (t2, t1))
7073 /* If T is a REFERENCE_TYPE return the type to which T refers.
7074 Otherwise, return T itself. */
7077 non_reference (tree t)
7079 if (TREE_CODE (t) == REFERENCE_TYPE)
7085 /* Return nonzero if REF is an lvalue valid for this language;
7086 otherwise, print an error message and return zero. USE says
7087 how the lvalue is being used and so selects the error message. */
7090 lvalue_or_else (tree ref, enum lvalue_use use)
7092 int win = lvalue_p (ref);