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_Waddress, "comparison with string literal results in unspecified behaviour");
3324 build_type = boolean_type_node;
3325 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3326 || code0 == COMPLEX_TYPE)
3327 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3328 || code1 == COMPLEX_TYPE))
3330 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3331 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3332 result_type = composite_pointer_type (type0, type1, op0, op1,
3334 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3335 && null_ptr_cst_p (op1))
3337 if (TREE_CODE (op0) == ADDR_EXPR
3338 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
3339 warning (OPT_Waddress, "the address of %qD will never be NULL",
3340 TREE_OPERAND (op0, 0));
3341 result_type = type0;
3343 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3344 && null_ptr_cst_p (op0))
3346 if (TREE_CODE (op1) == ADDR_EXPR
3347 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
3348 warning (OPT_Waddress, "the address of %qD will never be NULL",
3349 TREE_OPERAND (op1, 0));
3350 result_type = type1;
3352 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3354 result_type = type0;
3355 error ("ISO C++ forbids comparison between pointer and integer");
3357 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3359 result_type = type1;
3360 error ("ISO C++ forbids comparison between pointer and integer");
3362 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3364 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3365 == ptrmemfunc_vbit_in_delta)
3367 tree pfn0 = pfn_from_ptrmemfunc (op0);
3368 tree delta0 = build_ptrmemfunc_access_expr (op0,
3370 tree e1 = cp_build_binary_op (EQ_EXPR,
3372 fold_convert (TREE_TYPE (pfn0),
3373 integer_zero_node));
3374 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3377 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3378 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2);
3379 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3383 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3384 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3386 result_type = TREE_TYPE (op0);
3388 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3389 return cp_build_binary_op (code, op1, op0);
3390 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3391 && same_type_p (type0, type1))
3393 /* E will be the final comparison. */
3395 /* E1 and E2 are for scratch. */
3403 if (TREE_SIDE_EFFECTS (op0))
3404 op0 = save_expr (op0);
3405 if (TREE_SIDE_EFFECTS (op1))
3406 op1 = save_expr (op1);
3408 pfn0 = pfn_from_ptrmemfunc (op0);
3409 pfn1 = pfn_from_ptrmemfunc (op1);
3410 delta0 = build_ptrmemfunc_access_expr (op0,
3412 delta1 = build_ptrmemfunc_access_expr (op1,
3414 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3415 == ptrmemfunc_vbit_in_delta)
3420 && ((op0.delta == op1.delta)
3421 || (!op0.pfn && op0.delta & 1 == 0
3422 && op1.delta & 1 == 0))
3424 The reason for the `!op0.pfn' bit is that a NULL
3425 pointer-to-member is any member with a zero PFN and
3426 LSB of the DELTA field is 0. */
3428 e1 = cp_build_binary_op (BIT_AND_EXPR,
3431 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node);
3432 e2 = cp_build_binary_op (BIT_AND_EXPR,
3435 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3436 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3437 e2 = cp_build_binary_op (EQ_EXPR,
3439 fold_convert (TREE_TYPE (pfn0),
3440 integer_zero_node));
3441 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3442 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3443 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3450 && (!op0.pfn || op0.delta == op1.delta))
3452 The reason for the `!op0.pfn' bit is that a NULL
3453 pointer-to-member is any member with a zero PFN; the
3454 DELTA field is unspecified. */
3456 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3457 e2 = cp_build_binary_op (EQ_EXPR,
3459 fold_convert (TREE_TYPE (pfn0),
3460 integer_zero_node));
3461 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3463 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3464 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3465 if (code == EQ_EXPR)
3467 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3471 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3472 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3474 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3475 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3483 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3484 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3486 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3487 result_type = composite_pointer_type (type0, type1, op0, op1,
3495 if (TREE_CODE (orig_op0) == STRING_CST
3496 || TREE_CODE (orig_op1) == STRING_CST)
3497 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3499 build_type = boolean_type_node;
3500 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3501 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3503 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3504 result_type = composite_pointer_type (type0, type1, op0, op1,
3506 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3507 && integer_zerop (op1))
3508 result_type = type0;
3509 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3510 && integer_zerop (op0))
3511 result_type = type1;
3512 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3514 result_type = type0;
3515 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3517 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3519 result_type = type1;
3520 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3524 case UNORDERED_EXPR:
3531 build_type = integer_type_node;
3532 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3534 error ("unordered comparison on non-floating point argument");
3535 return error_mark_node;
3544 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3545 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3546 || code1 == COMPLEX_TYPE)))
3547 arithmetic_types_p = 1;
3550 arithmetic_types_p = 0;
3551 /* Vector arithmetic is only allowed when both sides are vectors. */
3552 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3554 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3555 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3558 binary_op_error (code);
3559 return error_mark_node;
3561 arithmetic_types_p = 1;
3564 /* Determine the RESULT_TYPE, if it is not already known. */
3566 && arithmetic_types_p
3567 && (shorten || common || short_compare))
3568 result_type = common_type (type0, type1);
3572 error ("invalid operands of types %qT and %qT to binary %qO",
3573 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3574 return error_mark_node;
3577 /* If we're in a template, the only thing we need to know is the
3579 if (processing_template_decl)
3580 return build2 (resultcode,
3581 build_type ? build_type : result_type,
3584 if (arithmetic_types_p)
3586 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3588 /* For certain operations (which identify themselves by shorten != 0)
3589 if both args were extended from the same smaller type,
3590 do the arithmetic in that type and then extend.
3592 shorten !=0 and !=1 indicates a bitwise operation.
3593 For them, this optimization is safe only if
3594 both args are zero-extended or both are sign-extended.
3595 Otherwise, we might change the result.
3596 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3597 but calculated in (unsigned short) it would be (unsigned short)-1. */
3599 if (shorten && none_complex)
3601 int unsigned0, unsigned1;
3602 tree arg0 = get_narrower (op0, &unsigned0);
3603 tree arg1 = get_narrower (op1, &unsigned1);
3604 /* UNS is 1 if the operation to be done is an unsigned one. */
3605 int uns = TYPE_UNSIGNED (result_type);
3608 final_type = result_type;
3610 /* Handle the case that OP0 does not *contain* a conversion
3611 but it *requires* conversion to FINAL_TYPE. */
3613 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3614 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3615 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3616 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3618 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3620 /* For bitwise operations, signedness of nominal type
3621 does not matter. Consider only how operands were extended. */
3625 /* Note that in all three cases below we refrain from optimizing
3626 an unsigned operation on sign-extended args.
3627 That would not be valid. */
3629 /* Both args variable: if both extended in same way
3630 from same width, do it in that width.
3631 Do it unsigned if args were zero-extended. */
3632 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3633 < TYPE_PRECISION (result_type))
3634 && (TYPE_PRECISION (TREE_TYPE (arg1))
3635 == TYPE_PRECISION (TREE_TYPE (arg0)))
3636 && unsigned0 == unsigned1
3637 && (unsigned0 || !uns))
3638 result_type = c_common_signed_or_unsigned_type
3639 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3640 else if (TREE_CODE (arg0) == INTEGER_CST
3641 && (unsigned1 || !uns)
3642 && (TYPE_PRECISION (TREE_TYPE (arg1))
3643 < TYPE_PRECISION (result_type))
3644 && (type = c_common_signed_or_unsigned_type
3645 (unsigned1, TREE_TYPE (arg1)),
3646 int_fits_type_p (arg0, type)))
3648 else if (TREE_CODE (arg1) == INTEGER_CST
3649 && (unsigned0 || !uns)
3650 && (TYPE_PRECISION (TREE_TYPE (arg0))
3651 < TYPE_PRECISION (result_type))
3652 && (type = c_common_signed_or_unsigned_type
3653 (unsigned0, TREE_TYPE (arg0)),
3654 int_fits_type_p (arg1, type)))
3658 /* Shifts can be shortened if shifting right. */
3663 tree arg0 = get_narrower (op0, &unsigned_arg);
3665 final_type = result_type;
3667 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3668 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3670 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3671 /* We can shorten only if the shift count is less than the
3672 number of bits in the smaller type size. */
3673 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3674 /* If arg is sign-extended and then unsigned-shifted,
3675 we can simulate this with a signed shift in arg's type
3676 only if the extended result is at least twice as wide
3677 as the arg. Otherwise, the shift could use up all the
3678 ones made by sign-extension and bring in zeros.
3679 We can't optimize that case at all, but in most machines
3680 it never happens because available widths are 2**N. */
3681 && (!TYPE_UNSIGNED (final_type)
3683 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3684 <= TYPE_PRECISION (result_type))))
3686 /* Do an unsigned shift if the operand was zero-extended. */
3688 = c_common_signed_or_unsigned_type (unsigned_arg,
3690 /* Convert value-to-be-shifted to that type. */
3691 if (TREE_TYPE (op0) != result_type)
3692 op0 = cp_convert (result_type, op0);
3697 /* Comparison operations are shortened too but differently.
3698 They identify themselves by setting short_compare = 1. */
3702 /* Don't write &op0, etc., because that would prevent op0
3703 from being kept in a register.
3704 Instead, make copies of the our local variables and
3705 pass the copies by reference, then copy them back afterward. */
3706 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3707 enum tree_code xresultcode = resultcode;
3709 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3711 return cp_convert (boolean_type_node, val);
3712 op0 = xop0, op1 = xop1;
3714 resultcode = xresultcode;
3717 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3718 && warn_sign_compare
3719 /* Do not warn until the template is instantiated; we cannot
3720 bound the ranges of the arguments until that point. */
3721 && !processing_template_decl)
3723 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3724 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3726 int unsignedp0, unsignedp1;
3727 tree primop0 = get_narrower (op0, &unsignedp0);
3728 tree primop1 = get_narrower (op1, &unsignedp1);
3730 /* Check for comparison of different enum types. */
3731 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3732 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3733 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3734 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3736 warning (0, "comparison between types %q#T and %q#T",
3737 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3740 /* Give warnings for comparisons between signed and unsigned
3741 quantities that may fail. */
3742 /* Do the checking based on the original operand trees, so that
3743 casts will be considered, but default promotions won't be. */
3745 /* Do not warn if the comparison is being done in a signed type,
3746 since the signed type will only be chosen if it can represent
3747 all the values of the unsigned type. */
3748 if (!TYPE_UNSIGNED (result_type))
3750 /* Do not warn if both operands are unsigned. */
3751 else if (op0_signed == op1_signed)
3753 /* Do not warn if the signed quantity is an unsuffixed
3754 integer literal (or some static constant expression
3755 involving such literals or a conditional expression
3756 involving such literals) and it is non-negative. */
3757 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3758 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3760 /* Do not warn if the comparison is an equality operation,
3761 the unsigned quantity is an integral constant and it does
3762 not use the most significant bit of result_type. */
3763 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3764 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3765 && int_fits_type_p (orig_op1, c_common_signed_type
3767 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3768 && int_fits_type_p (orig_op0, c_common_signed_type
3772 warning (0, "comparison between signed and unsigned integer expressions");
3774 /* Warn if two unsigned values are being compared in a size
3775 larger than their original size, and one (and only one) is the
3776 result of a `~' operator. This comparison will always fail.
3778 Also warn if one operand is a constant, and the constant does not
3779 have all bits set that are set in the ~ operand when it is
3782 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3783 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3785 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3786 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3787 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3788 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3790 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3793 HOST_WIDE_INT constant, mask;
3797 if (host_integerp (primop0, 0))
3800 unsignedp = unsignedp1;
3801 constant = tree_low_cst (primop0, 0);
3806 unsignedp = unsignedp0;
3807 constant = tree_low_cst (primop1, 0);
3810 bits = TYPE_PRECISION (TREE_TYPE (primop));
3811 if (bits < TYPE_PRECISION (result_type)
3812 && bits < HOST_BITS_PER_LONG && unsignedp)
3814 mask = (~ (HOST_WIDE_INT) 0) << bits;
3815 if ((mask & constant) != mask)
3816 warning (0, "comparison of promoted ~unsigned with constant");
3819 else if (unsignedp0 && unsignedp1
3820 && (TYPE_PRECISION (TREE_TYPE (primop0))
3821 < TYPE_PRECISION (result_type))
3822 && (TYPE_PRECISION (TREE_TYPE (primop1))
3823 < TYPE_PRECISION (result_type)))
3824 warning (0, "comparison of promoted ~unsigned with unsigned");
3829 /* Issue warnings about peculiar, but valid, uses of NULL. */
3830 if ((orig_op0 == null_node || orig_op1 == null_node)
3831 /* It's reasonable to use pointer values as operands of &&
3832 and ||, so NULL is no exception. */
3833 && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR
3834 && ( /* Both are NULL (or 0) and the operation was not a comparison. */
3835 (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1)
3836 && code != EQ_EXPR && code != NE_EXPR)
3837 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
3838 || (!null_ptr_cst_p (orig_op0) && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3839 || (!null_ptr_cst_p (orig_op1) && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)))
3840 /* Some sort of arithmetic operation involving NULL was
3841 performed. Note that pointer-difference and pointer-addition
3842 have already been handled above, and so we don't end up here in
3844 warning (OPT_Wpointer_arith, "NULL used in arithmetic");
3847 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3848 Then the expression will be built.
3849 It will be given type FINAL_TYPE if that is nonzero;
3850 otherwise, it will be given type RESULT_TYPE. */
3853 if (TREE_TYPE (op0) != result_type)
3854 op0 = cp_convert (result_type, op0);
3855 if (TREE_TYPE (op1) != result_type)
3856 op1 = cp_convert (result_type, op1);
3858 if (op0 == error_mark_node || op1 == error_mark_node)
3859 return error_mark_node;
3862 if (build_type == NULL_TREE)
3863 build_type = result_type;
3865 result = build2 (resultcode, build_type, op0, op1);
3866 result = fold_if_not_in_template (result);
3867 if (final_type != 0)
3868 result = cp_convert (final_type, result);
3870 if (TREE_OVERFLOW_P (result)
3871 && !TREE_OVERFLOW_P (op0)
3872 && !TREE_OVERFLOW_P (op1))
3873 overflow_warning (result);
3878 /* Return a tree for the sum or difference (RESULTCODE says which)
3879 of pointer PTROP and integer INTOP. */
3882 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3884 tree res_type = TREE_TYPE (ptrop);
3886 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3887 in certain circumstance (when it's valid to do so). So we need
3888 to make sure it's complete. We don't need to check here, if we
3889 can actually complete it at all, as those checks will be done in
3890 pointer_int_sum() anyway. */
3891 complete_type (TREE_TYPE (res_type));
3893 return pointer_int_sum (resultcode, ptrop,
3894 fold_if_not_in_template (intop));
3897 /* Return a tree for the difference of pointers OP0 and OP1.
3898 The resulting tree has type int. */
3901 pointer_diff (tree op0, tree op1, tree ptrtype)
3904 tree restype = ptrdiff_type_node;
3905 tree target_type = TREE_TYPE (ptrtype);
3907 if (!complete_type_or_else (target_type, NULL_TREE))
3908 return error_mark_node;
3910 if (pedantic || warn_pointer_arith)
3912 if (TREE_CODE (target_type) == VOID_TYPE)
3913 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3914 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3915 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3916 if (TREE_CODE (target_type) == METHOD_TYPE)
3917 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3920 /* First do the subtraction as integers;
3921 then drop through to build the divide operator. */
3923 op0 = cp_build_binary_op (MINUS_EXPR,
3924 cp_convert (restype, op0),
3925 cp_convert (restype, op1));
3927 /* This generates an error if op1 is a pointer to an incomplete type. */
3928 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3929 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3931 op1 = (TYPE_PTROB_P (ptrtype)
3932 ? size_in_bytes (target_type)
3933 : integer_one_node);
3935 /* Do the division. */
3937 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3938 return fold_if_not_in_template (result);
3941 /* Construct and perhaps optimize a tree representation
3942 for a unary operation. CODE, a tree_code, specifies the operation
3943 and XARG is the operand. */
3946 build_x_unary_op (enum tree_code code, tree xarg)
3948 tree orig_expr = xarg;
3952 if (processing_template_decl)
3954 if (type_dependent_expression_p (xarg))
3955 return build_min_nt (code, xarg, NULL_TREE);
3957 xarg = build_non_dependent_expr (xarg);
3962 /* [expr.unary.op] says:
3964 The address of an object of incomplete type can be taken.
3966 (And is just the ordinary address operator, not an overloaded
3967 "operator &".) However, if the type is a template
3968 specialization, we must complete the type at this point so that
3969 an overloaded "operator &" will be available if required. */
3970 if (code == ADDR_EXPR
3971 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3972 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3973 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3974 || (TREE_CODE (xarg) == OFFSET_REF)))
3975 /* Don't look for a function. */;
3977 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3978 /*overloaded_p=*/NULL);
3979 if (!exp && code == ADDR_EXPR)
3981 /* A pointer to member-function can be formed only by saying
3983 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3984 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3986 if (TREE_CODE (xarg) != OFFSET_REF
3987 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3989 error ("invalid use of %qE to form a pointer-to-member-function",
3991 if (TREE_CODE (xarg) != OFFSET_REF)
3992 inform (" a qualified-id is required");
3993 return error_mark_node;
3997 error ("parentheses around %qE cannot be used to form a"
3998 " pointer-to-member-function",
4000 PTRMEM_OK_P (xarg) = 1;
4004 if (TREE_CODE (xarg) == OFFSET_REF)
4006 ptrmem = PTRMEM_OK_P (xarg);
4008 if (!ptrmem && !flag_ms_extensions
4009 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
4011 /* A single non-static member, make sure we don't allow a
4012 pointer-to-member. */
4013 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
4014 TREE_OPERAND (xarg, 0),
4015 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
4016 PTRMEM_OK_P (xarg) = ptrmem;
4019 else if (TREE_CODE (xarg) == TARGET_EXPR)
4020 warning (0, "taking address of temporary");
4021 exp = build_unary_op (ADDR_EXPR, xarg, 0);
4024 if (processing_template_decl && exp != error_mark_node)
4025 exp = build_min_non_dep (code, exp, orig_expr,
4026 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
4027 if (TREE_CODE (exp) == ADDR_EXPR)
4028 PTRMEM_OK_P (exp) = ptrmem;
4032 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4033 constants, where a null value is represented by an INTEGER_CST of
4037 cp_truthvalue_conversion (tree expr)
4039 tree type = TREE_TYPE (expr);
4040 if (TYPE_PTRMEM_P (type))
4041 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
4043 return c_common_truthvalue_conversion (expr);
4046 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4049 condition_conversion (tree expr)
4052 if (processing_template_decl)
4054 t = perform_implicit_conversion (boolean_type_node, expr);
4055 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4059 /* Return an ADDR_EXPR giving the address of T. This function
4060 attempts no optimizations or simplifications; it is a low-level
4064 build_address (tree t)
4068 if (error_operand_p (t) || !cxx_mark_addressable (t))
4069 return error_mark_node;
4071 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4076 /* Return a NOP_EXPR converting EXPR to TYPE. */
4079 build_nop (tree type, tree expr)
4081 if (type == error_mark_node || error_operand_p (expr))
4083 return build1 (NOP_EXPR, type, expr);
4086 /* C++: Must handle pointers to members.
4088 Perhaps type instantiation should be extended to handle conversion
4089 from aggregates to types we don't yet know we want? (Or are those
4090 cases typically errors which should be reported?)
4092 NOCONVERT nonzero suppresses the default promotions
4093 (such as from short to int). */
4096 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4098 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4101 const char *errstring = NULL;
4103 const char *invalid_op_diag;
4105 if (arg == error_mark_node)
4106 return error_mark_node;
4108 if ((invalid_op_diag
4109 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4114 error (invalid_op_diag);
4115 return error_mark_node;
4120 case UNARY_PLUS_EXPR:
4123 int flags = WANT_ARITH | WANT_ENUM;
4124 /* Unary plus (but not unary minus) is allowed on pointers. */
4125 if (code == UNARY_PLUS_EXPR)
4126 flags |= WANT_POINTER;
4127 arg = build_expr_type_conversion (flags, arg, true);
4129 errstring = (code == NEGATE_EXPR
4130 ? "wrong type argument to unary minus"
4131 : "wrong type argument to unary plus");
4134 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4135 arg = perform_integral_promotions (arg);
4137 /* Make sure the result is not an lvalue: a unary plus or minus
4138 expression is always a rvalue. */
4145 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4149 arg = default_conversion (arg);
4151 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4154 errstring = "wrong type argument to bit-complement";
4155 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4156 arg = perform_integral_promotions (arg);
4160 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4161 errstring = "wrong type argument to abs";
4162 else if (!noconvert)
4163 arg = default_conversion (arg);
4167 /* Conjugating a real value is a no-op, but allow it anyway. */
4168 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4169 errstring = "wrong type argument to conjugation";
4170 else if (!noconvert)
4171 arg = default_conversion (arg);
4174 case TRUTH_NOT_EXPR:
4175 arg = perform_implicit_conversion (boolean_type_node, arg);
4176 val = invert_truthvalue (arg);
4177 if (arg != error_mark_node)
4179 errstring = "in argument to unary !";
4186 if (TREE_CODE (arg) == COMPLEX_CST)
4187 return TREE_REALPART (arg);
4188 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4190 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4191 return fold_if_not_in_template (arg);
4197 if (TREE_CODE (arg) == COMPLEX_CST)
4198 return TREE_IMAGPART (arg);
4199 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4201 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4202 return fold_if_not_in_template (arg);
4205 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4207 case PREINCREMENT_EXPR:
4208 case POSTINCREMENT_EXPR:
4209 case PREDECREMENT_EXPR:
4210 case POSTDECREMENT_EXPR:
4211 /* Handle complex lvalues (when permitted)
4212 by reduction to simpler cases. */
4214 val = unary_complex_lvalue (code, arg);
4218 /* Increment or decrement the real part of the value,
4219 and don't change the imaginary part. */
4220 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4224 arg = stabilize_reference (arg);
4225 real = build_unary_op (REALPART_EXPR, arg, 1);
4226 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4227 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4228 build_unary_op (code, real, 1), imag);
4231 /* Report invalid types. */
4233 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4236 if (code == PREINCREMENT_EXPR)
4237 errstring ="no pre-increment operator for type";
4238 else if (code == POSTINCREMENT_EXPR)
4239 errstring ="no post-increment operator for type";
4240 else if (code == PREDECREMENT_EXPR)
4241 errstring ="no pre-decrement operator for type";
4243 errstring ="no post-decrement operator for type";
4247 /* Report something read-only. */
4249 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4250 || TREE_READONLY (arg))
4251 readonly_error (arg, ((code == PREINCREMENT_EXPR
4252 || code == POSTINCREMENT_EXPR)
4253 ? "increment" : "decrement"),
4258 tree result_type = TREE_TYPE (arg);
4260 arg = get_unwidened (arg, 0);
4261 argtype = TREE_TYPE (arg);
4263 /* ARM $5.2.5 last annotation says this should be forbidden. */
4264 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4265 pedwarn ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4266 ? G_("ISO C++ forbids incrementing an enum")
4267 : G_("ISO C++ forbids decrementing an enum"));
4269 /* Compute the increment. */
4271 if (TREE_CODE (argtype) == POINTER_TYPE)
4273 tree type = complete_type (TREE_TYPE (argtype));
4275 if (!COMPLETE_OR_VOID_TYPE_P (type))
4276 error (((code == PREINCREMENT_EXPR
4277 || code == POSTINCREMENT_EXPR))
4278 ? G_("cannot increment a pointer to incomplete type %qT")
4279 : G_("cannot decrement a pointer to incomplete type %qT"),
4280 TREE_TYPE (argtype));
4281 else if ((pedantic || warn_pointer_arith)
4282 && !TYPE_PTROB_P (argtype))
4283 pedwarn ((code == PREINCREMENT_EXPR
4284 || code == POSTINCREMENT_EXPR)
4285 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4286 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4288 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4291 inc = integer_one_node;
4293 inc = cp_convert (argtype, inc);
4295 /* Handle incrementing a cast-expression. */
4297 switch (TREE_CODE (arg))
4302 case FIX_TRUNC_EXPR:
4304 tree incremented, modify, value, compound;
4305 if (! lvalue_p (arg) && pedantic)
4306 pedwarn ("cast to non-reference type used as lvalue");
4307 arg = stabilize_reference (arg);
4308 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
4311 value = save_expr (arg);
4312 incremented = build2 (((code == PREINCREMENT_EXPR
4313 || code == POSTINCREMENT_EXPR)
4314 ? PLUS_EXPR : MINUS_EXPR),
4315 argtype, value, inc);
4317 modify = build_modify_expr (arg, NOP_EXPR, incremented);
4318 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
4321 /* Eliminate warning about unused result of + or -. */
4322 TREE_NO_WARNING (compound) = 1;
4330 /* Complain about anything else that is not a true lvalue. */
4331 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4332 || code == POSTINCREMENT_EXPR)
4333 ? lv_increment : lv_decrement)))
4334 return error_mark_node;
4336 /* Forbid using -- on `bool'. */
4337 if (same_type_p (TREE_TYPE (arg), boolean_type_node))
4339 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4341 error ("invalid use of %<--%> on bool variable %qD", arg);
4342 return error_mark_node;
4344 val = boolean_increment (code, arg);
4347 val = build2 (code, TREE_TYPE (arg), arg, inc);
4349 TREE_SIDE_EFFECTS (val) = 1;
4350 return cp_convert (result_type, val);
4354 /* Note that this operation never does default_conversion
4355 regardless of NOCONVERT. */
4357 argtype = lvalue_type (arg);
4359 if (TREE_CODE (arg) == OFFSET_REF)
4362 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4364 tree type = build_pointer_type (TREE_TYPE (argtype));
4365 arg = build1 (CONVERT_EXPR, type, arg);
4368 else if (pedantic && DECL_MAIN_P (arg))
4370 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4372 /* Let &* cancel out to simplify resulting code. */
4373 if (TREE_CODE (arg) == INDIRECT_REF)
4375 /* We don't need to have `current_class_ptr' wrapped in a
4376 NON_LVALUE_EXPR node. */
4377 if (arg == current_class_ref)
4378 return current_class_ptr;
4380 arg = TREE_OPERAND (arg, 0);
4381 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4383 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4384 arg = build1 (CONVERT_EXPR, type, arg);
4387 /* Don't let this be an lvalue. */
4392 /* Uninstantiated types are all functions. Taking the
4393 address of a function is a no-op, so just return the
4396 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4397 || !IDENTIFIER_OPNAME_P (arg));
4399 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4400 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4402 /* They're trying to take the address of a unique non-static
4403 member function. This is ill-formed (except in MS-land),
4404 but let's try to DTRT.
4405 Note: We only handle unique functions here because we don't
4406 want to complain if there's a static overload; non-unique
4407 cases will be handled by instantiate_type. But we need to
4408 handle this case here to allow casts on the resulting PMF.
4409 We could defer this in non-MS mode, but it's easier to give
4410 a useful error here. */
4412 /* Inside constant member functions, the `this' pointer
4413 contains an extra const qualifier. TYPE_MAIN_VARIANT
4414 is used here to remove this const from the diagnostics
4415 and the created OFFSET_REF. */
4416 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4417 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4420 if (! flag_ms_extensions)
4422 tree name = DECL_NAME (fn);
4423 if (current_class_type
4424 && TREE_OPERAND (arg, 0) == current_class_ref)
4425 /* An expression like &memfn. */
4426 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4427 " or parenthesized non-static member function to form"
4428 " a pointer to member function. Say %<&%T::%D%>",
4431 pedwarn ("ISO C++ forbids taking the address of a bound member"
4432 " function to form a pointer to member function."
4436 arg = build_offset_ref (base, fn, /*address_p=*/true);
4440 if (type_unknown_p (arg))
4441 return build1 (ADDR_EXPR, unknown_type_node, arg);
4443 /* Handle complex lvalues (when permitted)
4444 by reduction to simpler cases. */
4445 val = unary_complex_lvalue (code, arg);
4449 switch (TREE_CODE (arg))
4454 case FIX_TRUNC_EXPR:
4455 if (! lvalue_p (arg) && pedantic)
4456 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4460 arg = BASELINK_FUNCTIONS (arg);
4464 arg = OVL_CURRENT (arg);
4468 /* Turn a reference to a non-static data member into a
4469 pointer-to-member. */
4474 if (!PTRMEM_OK_P (arg))
4475 return build_unary_op (code, arg, 0);
4477 t = TREE_OPERAND (arg, 1);
4478 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4480 error ("cannot create pointer to reference member %qD", t);
4481 return error_mark_node;
4484 type = build_ptrmem_type (context_for_name_lookup (t),
4486 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4494 /* Anything not already handled and not a true memory reference
4496 if (TREE_CODE (argtype) != FUNCTION_TYPE
4497 && TREE_CODE (argtype) != METHOD_TYPE
4498 && TREE_CODE (arg) != OFFSET_REF
4499 && !lvalue_or_else (arg, lv_addressof))
4500 return error_mark_node;
4502 if (argtype != error_mark_node)
4503 argtype = build_pointer_type (argtype);
4505 /* In a template, we are processing a non-dependent expression
4506 so we can just form an ADDR_EXPR with the correct type. */
4507 if (processing_template_decl)
4509 val = build_address (arg);
4510 if (TREE_CODE (arg) == OFFSET_REF)
4511 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4515 if (TREE_CODE (arg) != COMPONENT_REF)
4517 val = build_address (arg);
4518 if (TREE_CODE (arg) == OFFSET_REF)
4519 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4521 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4523 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4525 /* We can only get here with a single static member
4527 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4528 && DECL_STATIC_FUNCTION_P (fn));
4530 val = build_address (fn);
4531 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4532 /* Do not lose object's side effects. */
4533 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4534 TREE_OPERAND (arg, 0), val);
4536 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4538 error ("attempt to take address of bit-field structure member %qD",
4539 TREE_OPERAND (arg, 1));
4540 return error_mark_node;
4544 tree object = TREE_OPERAND (arg, 0);
4545 tree field = TREE_OPERAND (arg, 1);
4546 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4547 (TREE_TYPE (object), decl_type_context (field)));
4548 val = build_address (arg);
4551 if (TREE_CODE (argtype) == POINTER_TYPE
4552 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4554 build_ptrmemfunc_type (argtype);
4555 val = build_ptrmemfunc (argtype, val, 0,
4556 /*c_cast_p=*/false);
4568 argtype = TREE_TYPE (arg);
4569 return fold_if_not_in_template (build1 (code, argtype, arg));
4572 error ("%s", errstring);
4573 return error_mark_node;
4576 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4577 for certain kinds of expressions which are not really lvalues
4578 but which we can accept as lvalues.
4580 If ARG is not a kind of expression we can handle, return
4584 unary_complex_lvalue (enum tree_code code, tree arg)
4586 /* Inside a template, making these kinds of adjustments is
4587 pointless; we are only concerned with the type of the
4589 if (processing_template_decl)
4592 /* Handle (a, b) used as an "lvalue". */
4593 if (TREE_CODE (arg) == COMPOUND_EXPR)
4595 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4596 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4597 TREE_OPERAND (arg, 0), real_result);
4600 /* Handle (a ? b : c) used as an "lvalue". */
4601 if (TREE_CODE (arg) == COND_EXPR
4602 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4603 return rationalize_conditional_expr (code, arg);
4605 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4606 if (TREE_CODE (arg) == MODIFY_EXPR
4607 || TREE_CODE (arg) == PREINCREMENT_EXPR
4608 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4610 tree lvalue = TREE_OPERAND (arg, 0);
4611 if (TREE_SIDE_EFFECTS (lvalue))
4613 lvalue = stabilize_reference (lvalue);
4614 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4615 lvalue, TREE_OPERAND (arg, 1));
4617 return unary_complex_lvalue
4618 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4621 if (code != ADDR_EXPR)
4624 /* Handle (a = b) used as an "lvalue" for `&'. */
4625 if (TREE_CODE (arg) == MODIFY_EXPR
4626 || TREE_CODE (arg) == INIT_EXPR)
4628 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4629 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4631 TREE_NO_WARNING (arg) = 1;
4635 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4636 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4637 || TREE_CODE (arg) == OFFSET_REF)
4640 /* We permit compiler to make function calls returning
4641 objects of aggregate type look like lvalues. */
4645 if (TREE_CODE (targ) == SAVE_EXPR)
4646 targ = TREE_OPERAND (targ, 0);
4648 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4650 if (TREE_CODE (arg) == SAVE_EXPR)
4653 targ = build_cplus_new (TREE_TYPE (arg), arg);
4654 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4657 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4658 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4659 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4662 /* Don't let anything else be handled specially. */
4666 /* Mark EXP saying that we need to be able to take the
4667 address of it; it should not be allocated in a register.
4668 Value is true if successful.
4670 C++: we do not allow `current_class_ptr' to be addressable. */
4673 cxx_mark_addressable (tree exp)
4678 switch (TREE_CODE (x))
4685 x = TREE_OPERAND (x, 0);
4689 if (x == current_class_ptr)
4691 error ("cannot take the address of %<this%>, which is an rvalue expression");
4692 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4698 /* Caller should not be trying to mark initialized
4699 constant fields addressable. */
4700 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4701 || DECL_IN_AGGR_P (x) == 0
4703 || DECL_EXTERNAL (x));
4708 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4709 && !DECL_ARTIFICIAL (x))
4711 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4714 ("address of explicit register variable %qD requested", x);
4717 else if (extra_warnings)
4719 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4721 TREE_ADDRESSABLE (x) = 1;
4725 TREE_ADDRESSABLE (x) = 1;
4729 TREE_ADDRESSABLE (x) = 1;
4733 TREE_ADDRESSABLE (x) = 1;
4734 cxx_mark_addressable (TREE_OPERAND (x, 0));
4742 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4745 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4747 tree orig_ifexp = ifexp;
4748 tree orig_op1 = op1;
4749 tree orig_op2 = op2;
4752 if (processing_template_decl)
4754 /* The standard says that the expression is type-dependent if
4755 IFEXP is type-dependent, even though the eventual type of the
4756 expression doesn't dependent on IFEXP. */
4757 if (type_dependent_expression_p (ifexp)
4758 /* As a GNU extension, the middle operand may be omitted. */
4759 || (op1 && type_dependent_expression_p (op1))
4760 || type_dependent_expression_p (op2))
4761 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4762 ifexp = build_non_dependent_expr (ifexp);
4764 op1 = build_non_dependent_expr (op1);
4765 op2 = build_non_dependent_expr (op2);
4768 expr = build_conditional_expr (ifexp, op1, op2);
4769 if (processing_template_decl && expr != error_mark_node)
4770 return build_min_non_dep (COND_EXPR, expr,
4771 orig_ifexp, orig_op1, orig_op2);
4775 /* Given a list of expressions, return a compound expression
4776 that performs them all and returns the value of the last of them. */
4778 tree build_x_compound_expr_from_list (tree list, const char *msg)
4780 tree expr = TREE_VALUE (list);
4782 if (TREE_CHAIN (list))
4785 pedwarn ("%s expression list treated as compound expression", msg);
4787 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4788 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4794 /* Handle overloading of the ',' operator when needed. */
4797 build_x_compound_expr (tree op1, tree op2)
4800 tree orig_op1 = op1;
4801 tree orig_op2 = op2;
4803 if (processing_template_decl)
4805 if (type_dependent_expression_p (op1)
4806 || type_dependent_expression_p (op2))
4807 return build_min_nt (COMPOUND_EXPR, op1, op2);
4808 op1 = build_non_dependent_expr (op1);
4809 op2 = build_non_dependent_expr (op2);
4812 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4813 /*overloaded_p=*/NULL);
4815 result = build_compound_expr (op1, op2);
4817 if (processing_template_decl && result != error_mark_node)
4818 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4823 /* Build a compound expression. */
4826 build_compound_expr (tree lhs, tree rhs)
4828 lhs = convert_to_void (lhs, "left-hand operand of comma");
4830 if (lhs == error_mark_node || rhs == error_mark_node)
4831 return error_mark_node;
4833 if (TREE_CODE (rhs) == TARGET_EXPR)
4835 /* If the rhs is a TARGET_EXPR, then build the compound
4836 expression inside the target_expr's initializer. This
4837 helps the compiler to eliminate unnecessary temporaries. */
4838 tree init = TREE_OPERAND (rhs, 1);
4840 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4841 TREE_OPERAND (rhs, 1) = init;
4846 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4849 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4850 casts away constness. DIAG_FN gives the function to call if we
4851 need to issue a diagnostic; if it is NULL, no diagnostic will be
4852 issued. DESCRIPTION explains what operation is taking place. */
4855 check_for_casting_away_constness (tree src_type, tree dest_type,
4856 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4857 const char *description)
4859 if (diag_fn && casts_away_constness (src_type, dest_type))
4860 diag_fn ("%s from type %qT to type %qT casts away constness",
4861 description, src_type, dest_type);
4864 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4865 (another pointer-to-member type in the same hierarchy) and return
4866 the converted expression. If ALLOW_INVERSE_P is permitted, a
4867 pointer-to-derived may be converted to pointer-to-base; otherwise,
4868 only the other direction is permitted. If C_CAST_P is true, this
4869 conversion is taking place as part of a C-style cast. */
4872 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4875 if (TYPE_PTRMEM_P (type))
4879 if (TREE_CODE (expr) == PTRMEM_CST)
4880 expr = cplus_expand_constant (expr);
4881 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4882 TYPE_PTRMEM_CLASS_TYPE (type),
4885 if (!integer_zerop (delta))
4886 expr = cp_build_binary_op (PLUS_EXPR,
4887 build_nop (ptrdiff_type_node, expr),
4889 return build_nop (type, expr);
4892 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4893 allow_inverse_p, c_cast_p);
4896 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4897 a version of EXPR that has TREE_OVERFLOW set if it is set in ORIG.
4898 Otherwise, return EXPR unchanged. */
4901 ignore_overflows (tree expr, tree orig)
4903 if (TREE_CODE (expr) == INTEGER_CST
4904 && CONSTANT_CLASS_P (orig)
4905 && TREE_CODE (orig) != STRING_CST
4906 && TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig))
4908 if (!TREE_OVERFLOW (orig))
4909 /* Ensure constant sharing. */
4910 expr = build_int_cst_wide (TREE_TYPE (expr),
4911 TREE_INT_CST_LOW (expr),
4912 TREE_INT_CST_HIGH (expr));
4915 /* Avoid clobbering a shared constant. */
4916 expr = copy_node (expr);
4917 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4923 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4924 this static_cast is being attempted as one of the possible casts
4925 allowed by a C-style cast. (In that case, accessibility of base
4926 classes is not considered, and it is OK to cast away
4927 constness.) Return the result of the cast. *VALID_P is set to
4928 indicate whether or not the cast was valid. */
4931 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4937 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4940 /* Assume the cast is valid. */
4943 intype = TREE_TYPE (expr);
4945 /* Save casted types in the function's used types hash table. */
4946 used_types_insert (type);
4948 /* Determine what to do when casting away constness. */
4951 /* C-style casts are allowed to cast away constness. With
4952 WARN_CAST_QUAL, we still want to issue a warning. */
4953 diag_fn = warn_cast_qual ? warning0 : NULL;
4958 /* A static_cast may not cast away constness. */
4960 desc = "static_cast";
4963 /* [expr.static.cast]
4965 An lvalue of type "cv1 B", where B is a class type, can be cast
4966 to type "reference to cv2 D", where D is a class derived (clause
4967 _class.derived_) from B, if a valid standard conversion from
4968 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4969 same cv-qualification as, or greater cv-qualification than, cv1,
4970 and B is not a virtual base class of D. */
4971 /* We check this case before checking the validity of "TYPE t =
4972 EXPR;" below because for this case:
4975 struct D : public B { D(const B&); };
4977 void f() { static_cast<const D&>(b); }
4979 we want to avoid constructing a new D. The standard is not
4980 completely clear about this issue, but our interpretation is
4981 consistent with other compilers. */
4982 if (TREE_CODE (type) == REFERENCE_TYPE
4983 && CLASS_TYPE_P (TREE_TYPE (type))
4984 && CLASS_TYPE_P (intype)
4985 && real_lvalue_p (expr)
4986 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4987 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4988 build_pointer_type (TYPE_MAIN_VARIANT
4989 (TREE_TYPE (type))))
4991 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4995 /* There is a standard conversion from "D*" to "B*" even if "B"
4996 is ambiguous or inaccessible. If this is really a
4997 static_cast, then we check both for inaccessibility and
4998 ambiguity. However, if this is a static_cast being performed
4999 because the user wrote a C-style cast, then accessibility is
5001 base = lookup_base (TREE_TYPE (type), intype,
5002 c_cast_p ? ba_unique : ba_check,
5005 /* Convert from "B*" to "D*". This function will check that "B"
5006 is not a virtual base of "D". */
5007 expr = build_base_path (MINUS_EXPR, build_address (expr),
5008 base, /*nonnull=*/false);
5009 /* Convert the pointer to a reference -- but then remember that
5010 there are no expressions with reference type in C++. */
5011 return convert_from_reference (build_nop (type, expr));
5016 /* [expr.static.cast]
5018 An expression e can be explicitly converted to a type T using a
5019 static_cast of the form static_cast<T>(e) if the declaration T
5020 t(e);" is well-formed, for some invented temporary variable
5022 result = perform_direct_initialization_if_possible (type, expr,
5026 result = convert_from_reference (result);
5028 /* Ignore any integer overflow caused by the cast. */
5029 result = ignore_overflows (result, orig);
5031 /* [expr.static.cast]
5033 If T is a reference type, the result is an lvalue; otherwise,
5034 the result is an rvalue. */
5035 if (TREE_CODE (type) != REFERENCE_TYPE)
5036 result = rvalue (result);
5040 /* [expr.static.cast]
5042 Any expression can be explicitly converted to type cv void. */
5043 if (TREE_CODE (type) == VOID_TYPE)
5044 return convert_to_void (expr, /*implicit=*/NULL);
5046 /* [expr.static.cast]
5048 The inverse of any standard conversion sequence (clause _conv_),
5049 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5050 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5051 (_conv.bool_) conversions, can be performed explicitly using
5052 static_cast subject to the restriction that the explicit
5053 conversion does not cast away constness (_expr.const.cast_), and
5054 the following additional rules for specific cases: */
5055 /* For reference, the conversions not excluded are: integral
5056 promotions, floating point promotion, integral conversions,
5057 floating point conversions, floating-integral conversions,
5058 pointer conversions, and pointer to member conversions. */
5061 A value of integral _or enumeration_ type can be explicitly
5062 converted to an enumeration type. */
5063 /* The effect of all that is that any conversion between any two
5064 types which are integral, floating, or enumeration types can be
5066 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5067 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5069 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5071 /* Ignore any integer overflow caused by the cast. */
5072 expr = ignore_overflows (expr, orig);
5076 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5077 && CLASS_TYPE_P (TREE_TYPE (type))
5078 && CLASS_TYPE_P (TREE_TYPE (intype))
5079 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5080 (TREE_TYPE (intype))),
5081 build_pointer_type (TYPE_MAIN_VARIANT
5082 (TREE_TYPE (type)))))
5087 check_for_casting_away_constness (intype, type, diag_fn, desc);
5088 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5089 c_cast_p ? ba_unique : ba_check,
5091 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5094 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5095 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5102 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5103 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5105 if (TYPE_PTRMEM_P (type))
5107 t1 = (build_ptrmem_type
5109 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5110 t2 = (build_ptrmem_type
5112 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5119 if (can_convert (t1, t2))
5122 check_for_casting_away_constness (intype, type, diag_fn,
5124 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5129 /* [expr.static.cast]
5131 An rvalue of type "pointer to cv void" can be explicitly
5132 converted to a pointer to object type. A value of type pointer
5133 to object converted to "pointer to cv void" and back to the
5134 original pointer type will have its original value. */
5135 if (TREE_CODE (intype) == POINTER_TYPE
5136 && VOID_TYPE_P (TREE_TYPE (intype))
5137 && TYPE_PTROB_P (type))
5140 check_for_casting_away_constness (intype, type, diag_fn, desc);
5141 return build_nop (type, expr);
5145 return error_mark_node;
5148 /* Return an expression representing static_cast<TYPE>(EXPR). */
5151 build_static_cast (tree type, tree expr)
5156 if (type == error_mark_node || expr == error_mark_node)
5157 return error_mark_node;
5159 if (processing_template_decl)
5161 expr = build_min (STATIC_CAST_EXPR, type, expr);
5162 /* We don't know if it will or will not have side effects. */
5163 TREE_SIDE_EFFECTS (expr) = 1;
5164 return convert_from_reference (expr);
5167 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5168 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5169 if (TREE_CODE (type) != REFERENCE_TYPE
5170 && TREE_CODE (expr) == NOP_EXPR
5171 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5172 expr = TREE_OPERAND (expr, 0);
5174 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5178 error ("invalid static_cast from type %qT to type %qT",
5179 TREE_TYPE (expr), type);
5180 return error_mark_node;
5183 /* EXPR is an expression with member function or pointer-to-member
5184 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5185 not permitted by ISO C++, but we accept it in some modes. If we
5186 are not in one of those modes, issue a diagnostic. Return the
5187 converted expression. */
5190 convert_member_func_to_ptr (tree type, tree expr)
5195 intype = TREE_TYPE (expr);
5196 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5197 || TREE_CODE (intype) == METHOD_TYPE);
5199 if (pedantic || warn_pmf2ptr)
5200 pedwarn ("converting from %qT to %qT", intype, type);
5202 if (TREE_CODE (intype) == METHOD_TYPE)
5203 expr = build_addr_func (expr);
5204 else if (TREE_CODE (expr) == PTRMEM_CST)
5205 expr = build_address (PTRMEM_CST_MEMBER (expr));
5208 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5209 decl = build_address (decl);
5210 expr = get_member_function_from_ptrfunc (&decl, expr);
5213 return build_nop (type, expr);
5216 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5217 If C_CAST_P is true, this reinterpret cast is being done as part of
5218 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5219 indicate whether or not reinterpret_cast was valid. */
5222 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5227 /* Assume the cast is invalid. */
5231 if (type == error_mark_node || error_operand_p (expr))
5232 return error_mark_node;
5234 intype = TREE_TYPE (expr);
5236 /* Save casted types in the function's used types hash table. */
5237 used_types_insert (type);
5239 /* [expr.reinterpret.cast]
5240 An lvalue expression of type T1 can be cast to the type
5241 "reference to T2" if an expression of type "pointer to T1" can be
5242 explicitly converted to the type "pointer to T2" using a
5243 reinterpret_cast. */
5244 if (TREE_CODE (type) == REFERENCE_TYPE)
5246 if (! real_lvalue_p (expr))
5248 error ("invalid cast of an rvalue expression of type "
5251 return error_mark_node;
5254 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5255 "B" are related class types; the reinterpret_cast does not
5256 adjust the pointer. */
5257 if (TYPE_PTR_P (intype)
5258 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5259 COMPARE_BASE | COMPARE_DERIVED)))
5260 warning (0, "casting %qT to %qT does not dereference pointer",
5263 expr = build_unary_op (ADDR_EXPR, expr, 0);
5264 if (expr != error_mark_node)
5265 expr = build_reinterpret_cast_1
5266 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5268 if (expr != error_mark_node)
5269 expr = build_indirect_ref (expr, 0);
5273 /* As a G++ extension, we consider conversions from member
5274 functions, and pointers to member functions to
5275 pointer-to-function and pointer-to-void types. If
5276 -Wno-pmf-conversions has not been specified,
5277 convert_member_func_to_ptr will issue an error message. */
5278 if ((TYPE_PTRMEMFUNC_P (intype)
5279 || TREE_CODE (intype) == METHOD_TYPE)
5280 && TYPE_PTR_P (type)
5281 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5282 || VOID_TYPE_P (TREE_TYPE (type))))
5283 return convert_member_func_to_ptr (type, expr);
5285 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5286 array-to-pointer, and function-to-pointer conversions are
5288 expr = decay_conversion (expr);
5290 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5291 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5292 if (TREE_CODE (expr) == NOP_EXPR
5293 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5294 expr = TREE_OPERAND (expr, 0);
5296 if (error_operand_p (expr))
5297 return error_mark_node;
5299 intype = TREE_TYPE (expr);
5301 /* [expr.reinterpret.cast]
5302 A pointer can be converted to any integral type large enough to
5304 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5306 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5307 pedwarn ("cast from %qT to %qT loses precision",
5310 /* [expr.reinterpret.cast]
5311 A value of integral or enumeration type can be explicitly
5312 converted to a pointer. */
5313 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5316 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5317 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5318 return fold_if_not_in_template (build_nop (type, expr));
5319 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5320 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5325 check_for_casting_away_constness (intype, type, error,
5326 "reinterpret_cast");
5327 /* Warn about possible alignment problems. */
5328 if (STRICT_ALIGNMENT && warn_cast_align
5329 && !VOID_TYPE_P (type)
5330 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5331 && COMPLETE_TYPE_P (TREE_TYPE (type))
5332 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5333 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5334 warning (0, "cast from %qT to %qT increases required alignment of "
5338 /* We need to strip nops here, because the front end likes to
5339 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5341 strict_aliasing_warning (intype, type, sexpr);
5343 return fold_if_not_in_template (build_nop (type, expr));
5345 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5346 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5349 /* Only issue a warning, as we have always supported this
5350 where possible, and it is necessary in some cases. DR 195
5351 addresses this issue, but as of 2004/10/26 is still in
5353 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5354 return fold_if_not_in_template (build_nop (type, expr));
5356 else if (TREE_CODE (type) == VECTOR_TYPE)
5357 return fold_if_not_in_template (convert_to_vector (type, expr));
5358 else if (TREE_CODE (intype) == VECTOR_TYPE)
5359 return fold_if_not_in_template (convert_to_integer (type, expr));
5364 error ("invalid cast from type %qT to type %qT", intype, type);
5365 return error_mark_node;
5368 return cp_convert (type, expr);
5372 build_reinterpret_cast (tree type, tree expr)
5374 if (type == error_mark_node || expr == error_mark_node)
5375 return error_mark_node;
5377 if (processing_template_decl)
5379 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5381 if (!TREE_SIDE_EFFECTS (t)
5382 && type_dependent_expression_p (expr))
5383 /* There might turn out to be side effects inside expr. */
5384 TREE_SIDE_EFFECTS (t) = 1;
5385 return convert_from_reference (t);
5388 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5392 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5393 return an appropriate expression. Otherwise, return
5394 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5395 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5396 performing a C-style cast, its value upon return will indicate
5397 whether or not the conversion succeeded. */
5400 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5404 tree reference_type;
5406 /* Callers are responsible for handling error_mark_node as a
5407 destination type. */
5408 gcc_assert (dst_type != error_mark_node);
5409 /* In a template, callers should be building syntactic
5410 representations of casts, not using this machinery. */
5411 gcc_assert (!processing_template_decl);
5413 /* Assume the conversion is invalid. */
5417 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5420 error ("invalid use of const_cast with type %qT, "
5421 "which is not a pointer, "
5422 "reference, nor a pointer-to-data-member type", dst_type);
5423 return error_mark_node;
5426 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5429 error ("invalid use of const_cast with type %qT, which is a pointer "
5430 "or reference to a function type", dst_type);
5431 return error_mark_node;
5434 /* Save casted types in the function's used types hash table. */
5435 used_types_insert (dst_type);
5437 src_type = TREE_TYPE (expr);
5438 /* Expressions do not really have reference types. */
5439 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5440 src_type = TREE_TYPE (src_type);
5442 /* [expr.const.cast]
5444 An lvalue of type T1 can be explicitly converted to an lvalue of
5445 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5446 types) if a pointer to T1 can be explicitly converted to the type
5447 pointer to T2 using a const_cast. */
5448 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5450 reference_type = dst_type;
5451 if (! real_lvalue_p (expr))
5454 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5455 src_type, dst_type);
5456 return error_mark_node;
5458 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5459 src_type = build_pointer_type (src_type);
5463 reference_type = NULL_TREE;
5464 /* If the destination type is not a reference type, the
5465 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5466 conversions are performed. */
5467 src_type = type_decays_to (src_type);
5468 if (src_type == error_mark_node)
5469 return error_mark_node;
5472 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5473 && comp_ptr_ttypes_const (dst_type, src_type))
5478 /* This cast is actually a C-style cast. Issue a warning if
5479 the user is making a potentially unsafe cast. */
5481 check_for_casting_away_constness (src_type, dst_type,
5487 expr = build_unary_op (ADDR_EXPR, expr, 0);
5488 expr = build_nop (reference_type, expr);
5489 return convert_from_reference (expr);
5493 expr = decay_conversion (expr);
5494 /* build_c_cast puts on a NOP_EXPR to make the result not an
5495 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5496 non-lvalue context. */
5497 if (TREE_CODE (expr) == NOP_EXPR
5498 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5499 expr = TREE_OPERAND (expr, 0);
5500 return build_nop (dst_type, expr);
5505 error ("invalid const_cast from type %qT to type %qT",
5506 src_type, dst_type);
5507 return error_mark_node;
5511 build_const_cast (tree type, tree expr)
5513 if (type == error_mark_node || error_operand_p (expr))
5514 return error_mark_node;
5516 if (processing_template_decl)
5518 tree t = build_min (CONST_CAST_EXPR, type, expr);
5520 if (!TREE_SIDE_EFFECTS (t)
5521 && type_dependent_expression_p (expr))
5522 /* There might turn out to be side effects inside expr. */
5523 TREE_SIDE_EFFECTS (t) = 1;
5524 return convert_from_reference (t);
5527 return build_const_cast_1 (type, expr, /*complain=*/true,
5531 /* Build an expression representing an explicit C-style cast to type
5532 TYPE of expression EXPR. */
5535 build_c_cast (tree type, tree expr)
5541 if (type == error_mark_node || error_operand_p (expr))
5542 return error_mark_node;
5544 if (processing_template_decl)
5546 tree t = build_min (CAST_EXPR, type,
5547 tree_cons (NULL_TREE, value, NULL_TREE));
5548 /* We don't know if it will or will not have side effects. */
5549 TREE_SIDE_EFFECTS (t) = 1;
5550 return convert_from_reference (t);
5553 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5554 'Class') should always be retained, because this information aids
5555 in method lookup. */
5556 if (objc_is_object_ptr (type)
5557 && objc_is_object_ptr (TREE_TYPE (expr)))
5558 return build_nop (type, expr);
5560 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5561 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5562 if (TREE_CODE (type) != REFERENCE_TYPE
5563 && TREE_CODE (value) == NOP_EXPR
5564 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5565 value = TREE_OPERAND (value, 0);
5567 if (TREE_CODE (type) == ARRAY_TYPE)
5569 /* Allow casting from T1* to T2[] because Cfront allows it.
5570 NIHCL uses it. It is not valid ISO C++ however. */
5571 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5573 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5574 type = build_pointer_type (TREE_TYPE (type));
5578 error ("ISO C++ forbids casting to an array type %qT", type);
5579 return error_mark_node;
5583 if (TREE_CODE (type) == FUNCTION_TYPE
5584 || TREE_CODE (type) == METHOD_TYPE)
5586 error ("invalid cast to function type %qT", type);
5587 return error_mark_node;
5590 /* A C-style cast can be a const_cast. */
5591 result = build_const_cast_1 (type, value, /*complain=*/false,
5596 /* Or a static cast. */
5597 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5599 /* Or a reinterpret_cast. */
5601 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5603 /* The static_cast or reinterpret_cast may be followed by a
5606 /* A valid cast may result in errors if, for example, a
5607 conversion to am ambiguous base class is required. */
5608 && !error_operand_p (result))
5612 /* Non-class rvalues always have cv-unqualified type. */
5613 if (!CLASS_TYPE_P (type))
5614 type = TYPE_MAIN_VARIANT (type);
5615 result_type = TREE_TYPE (result);
5616 if (!CLASS_TYPE_P (result_type))
5617 result_type = TYPE_MAIN_VARIANT (result_type);
5618 /* If the type of RESULT does not match TYPE, perform a
5619 const_cast to make it match. If the static_cast or
5620 reinterpret_cast succeeded, we will differ by at most
5621 cv-qualification, so the follow-on const_cast is guaranteed
5623 if (!same_type_p (non_reference (type), non_reference (result_type)))
5625 result = build_const_cast_1 (type, result, false, &valid_p);
5626 gcc_assert (valid_p);
5631 return error_mark_node;
5634 /* Build an assignment expression of lvalue LHS from value RHS.
5635 MODIFYCODE is the code for a binary operator that we use
5636 to combine the old value of LHS with RHS to get the new value.
5637 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5639 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5642 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5646 tree lhstype = TREE_TYPE (lhs);
5647 tree olhstype = lhstype;
5648 tree olhs = NULL_TREE;
5649 bool plain_assign = (modifycode == NOP_EXPR);
5651 /* Avoid duplicate error messages from operands that had errors. */
5652 if (error_operand_p (lhs) || error_operand_p (rhs))
5653 return error_mark_node;
5655 /* Handle control structure constructs used as "lvalues". */
5656 switch (TREE_CODE (lhs))
5658 /* Handle --foo = 5; as these are valid constructs in C++. */
5659 case PREDECREMENT_EXPR:
5660 case PREINCREMENT_EXPR:
5661 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5662 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5663 stabilize_reference (TREE_OPERAND (lhs, 0)),
5664 TREE_OPERAND (lhs, 1));
5665 return build2 (COMPOUND_EXPR, lhstype,
5667 build_modify_expr (TREE_OPERAND (lhs, 0),
5670 /* Handle (a, b) used as an "lvalue". */
5672 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5674 if (newrhs == error_mark_node)
5675 return error_mark_node;
5676 return build2 (COMPOUND_EXPR, lhstype,
5677 TREE_OPERAND (lhs, 0), newrhs);
5680 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5681 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5682 stabilize_reference (TREE_OPERAND (lhs, 0)),
5683 TREE_OPERAND (lhs, 1));
5684 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5685 if (newrhs == error_mark_node)
5686 return error_mark_node;
5687 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5691 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5692 when neither operand has side-effects. */
5693 if (!lvalue_or_else (lhs, lv_assign))
5694 return error_mark_node;
5696 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5697 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5699 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5700 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5702 TREE_OPERAND (lhs, 0),
5703 TREE_OPERAND (lhs, 1)),
5704 TREE_OPERAND (lhs, 0),
5705 TREE_OPERAND (lhs, 1));
5708 /* Handle (a ? b : c) used as an "lvalue". */
5711 /* Produce (a ? (b = rhs) : (c = rhs))
5712 except that the RHS goes through a save-expr
5713 so the code to compute it is only emitted once. */
5715 tree preeval = NULL_TREE;
5717 rhs = stabilize_expr (rhs, &preeval);
5719 /* Check this here to avoid odd errors when trying to convert
5720 a throw to the type of the COND_EXPR. */
5721 if (!lvalue_or_else (lhs, lv_assign))
5722 return error_mark_node;
5724 cond = build_conditional_expr
5725 (TREE_OPERAND (lhs, 0),
5726 build_modify_expr (TREE_OPERAND (lhs, 1),
5728 build_modify_expr (TREE_OPERAND (lhs, 2),
5731 if (cond == error_mark_node)
5733 /* Make sure the code to compute the rhs comes out
5734 before the split. */
5736 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5744 if (modifycode == INIT_EXPR)
5746 if (TREE_CODE (rhs) == CONSTRUCTOR)
5748 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5749 /* Call convert to generate an error; see PR 11063. */
5750 rhs = convert (lhstype, rhs);
5751 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5752 TREE_SIDE_EFFECTS (result) = 1;
5755 else if (! IS_AGGR_TYPE (lhstype))
5756 /* Do the default thing. */;
5759 result = build_special_member_call (lhs, complete_ctor_identifier,
5760 build_tree_list (NULL_TREE, rhs),
5761 lhstype, LOOKUP_NORMAL);
5762 if (result == NULL_TREE)
5763 return error_mark_node;
5769 lhs = require_complete_type (lhs);
5770 if (lhs == error_mark_node)
5771 return error_mark_node;
5773 if (modifycode == NOP_EXPR)
5775 /* `operator=' is not an inheritable operator. */
5776 if (! IS_AGGR_TYPE (lhstype))
5777 /* Do the default thing. */;
5780 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5781 lhs, rhs, make_node (NOP_EXPR),
5782 /*overloaded_p=*/NULL);
5783 if (result == NULL_TREE)
5784 return error_mark_node;
5791 /* A binary op has been requested. Combine the old LHS
5792 value with the RHS producing the value we should actually
5793 store into the LHS. */
5795 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5796 lhs = stabilize_reference (lhs);
5797 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5798 if (newrhs == error_mark_node)
5800 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5801 TREE_TYPE (lhs), TREE_TYPE (rhs));
5802 return error_mark_node;
5805 /* Now it looks like a plain assignment. */
5806 modifycode = NOP_EXPR;
5808 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5809 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5812 /* The left-hand side must be an lvalue. */
5813 if (!lvalue_or_else (lhs, lv_assign))
5814 return error_mark_node;
5816 /* Warn about modifying something that is `const'. Don't warn if
5817 this is initialization. */
5818 if (modifycode != INIT_EXPR
5819 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5820 /* Functions are not modifiable, even though they are
5822 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5823 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5824 /* If it's an aggregate and any field is const, then it is
5825 effectively const. */
5826 || (CLASS_TYPE_P (lhstype)
5827 && C_TYPE_FIELDS_READONLY (lhstype))))
5828 readonly_error (lhs, "assignment", 0);
5830 /* If storing into a structure or union member, it has probably been
5831 given type `int'. Compute the type that would go with the actual
5832 amount of storage the member occupies. */
5834 if (TREE_CODE (lhs) == COMPONENT_REF
5835 && (TREE_CODE (lhstype) == INTEGER_TYPE
5836 || TREE_CODE (lhstype) == REAL_TYPE
5837 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5839 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5841 /* If storing in a field that is in actuality a short or narrower
5842 than one, we must store in the field in its actual type. */
5844 if (lhstype != TREE_TYPE (lhs))
5846 /* Avoid warnings converting integral types back into enums for
5848 if (TREE_CODE (lhstype) == INTEGER_TYPE
5849 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5851 if (TREE_SIDE_EFFECTS (lhs))
5852 lhs = stabilize_reference (lhs);
5855 lhs = copy_node (lhs);
5856 TREE_TYPE (lhs) = lhstype;
5860 /* Convert new value to destination type. */
5862 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5866 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5867 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5869 error ("incompatible types in assignment of %qT to %qT",
5870 TREE_TYPE (rhs), lhstype);
5871 return error_mark_node;
5874 /* Allow array assignment in compiler-generated code. */
5875 if (! DECL_ARTIFICIAL (current_function_decl))
5877 /* This routine is used for both initialization and assignment.
5878 Make sure the diagnostic message differentiates the context. */
5879 if (modifycode == INIT_EXPR)
5880 error ("array used as initializer");
5882 error ("invalid array assignment");
5883 return error_mark_node;
5886 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5887 ? 1 + (modifycode != INIT_EXPR): 0;
5888 return build_vec_init (lhs, NULL_TREE, newrhs,
5889 /*explicit_default_init_p=*/false,
5893 if (modifycode == INIT_EXPR)
5894 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5895 "initialization", NULL_TREE, 0);
5898 /* Avoid warnings on enum bit fields. */
5899 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5900 && TREE_CODE (lhstype) == INTEGER_TYPE)
5902 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5904 newrhs = convert_force (lhstype, newrhs, 0);
5907 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5909 if (TREE_CODE (newrhs) == CALL_EXPR
5910 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5911 newrhs = build_cplus_new (lhstype, newrhs);
5913 /* Can't initialize directly from a TARGET_EXPR, since that would
5914 cause the lhs to be constructed twice, and possibly result in
5915 accidental self-initialization. So we force the TARGET_EXPR to be
5916 expanded without a target. */
5917 if (TREE_CODE (newrhs) == TARGET_EXPR)
5918 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5919 TREE_OPERAND (newrhs, 0));
5922 if (newrhs == error_mark_node)
5923 return error_mark_node;
5925 if (c_dialect_objc () && flag_objc_gc)
5927 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5933 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5934 lhstype, lhs, newrhs);
5936 TREE_SIDE_EFFECTS (result) = 1;
5938 TREE_NO_WARNING (result) = 1;
5940 /* If we got the LHS in a different type for storing in,
5941 convert the result back to the nominal type of LHS
5942 so that the value we return always has the same type
5943 as the LHS argument. */
5945 if (olhstype == TREE_TYPE (result))
5949 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5950 TREE_NO_WARNING (result) = 1;
5953 return convert_for_assignment (olhstype, result, "assignment",
5958 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5960 if (processing_template_decl)
5961 return build_min_nt (MODOP_EXPR, lhs,
5962 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5964 if (modifycode != NOP_EXPR)
5966 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5967 make_node (modifycode),
5968 /*overloaded_p=*/NULL);
5971 TREE_NO_WARNING (rval) = 1;
5975 return build_modify_expr (lhs, modifycode, rhs);
5979 /* Get difference in deltas for different pointer to member function
5980 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5981 the conversion is invalid, the constant is zero. If
5982 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5983 If C_CAST_P is true this conversion is taking place as part of a
5986 Note that the naming of FROM and TO is kind of backwards; the return
5987 value is what we add to a TO in order to get a FROM. They are named
5988 this way because we call this function to find out how to convert from
5989 a pointer to member of FROM to a pointer to member of TO. */
5992 get_delta_difference (tree from, tree to,
5993 bool allow_inverse_p,
6000 /* Assume no conversion is required. */
6001 result = integer_zero_node;
6002 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
6003 if (kind == bk_inaccessible || kind == bk_ambig)
6004 error (" in pointer to member function conversion");
6007 if (kind != bk_via_virtual)
6008 result = BINFO_OFFSET (binfo);
6011 tree virt_binfo = binfo_from_vbase (binfo);
6013 /* This is a reinterpret cast, we choose to do nothing. */
6014 if (allow_inverse_p)
6015 warning (0, "pointer to member cast via virtual base %qT",
6016 BINFO_TYPE (virt_binfo));
6018 error ("pointer to member conversion via virtual base %qT",
6019 BINFO_TYPE (virt_binfo));
6022 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
6023 /* Pointer to member of incomplete class is permitted*/;
6024 else if (!allow_inverse_p)
6026 error_not_base_type (from, to);
6027 error (" in pointer to member conversion");
6031 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
6034 if (kind != bk_via_virtual)
6035 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
6038 /* This is a reinterpret cast, we choose to do nothing. */
6039 tree virt_binfo = binfo_from_vbase (binfo);
6041 warning (0, "pointer to member cast via virtual base %qT",
6042 BINFO_TYPE (virt_binfo));
6047 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6051 /* Return a constructor for the pointer-to-member-function TYPE using
6052 the other components as specified. */
6055 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6060 VEC(constructor_elt, gc) *v;
6062 /* Pull the FIELD_DECLs out of the type. */
6063 pfn_field = TYPE_FIELDS (type);
6064 delta_field = TREE_CHAIN (pfn_field);
6066 /* Make sure DELTA has the type we want. */
6067 delta = convert_and_check (delta_type_node, delta);
6069 /* Finish creating the initializer. */
6070 v = VEC_alloc(constructor_elt, gc, 2);
6071 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6072 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6073 u = build_constructor (type, v);
6074 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6075 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6076 TREE_STATIC (u) = (TREE_CONSTANT (u)
6077 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6079 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6084 /* Build a constructor for a pointer to member function. It can be
6085 used to initialize global variables, local variable, or used
6086 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6089 If FORCE is nonzero, then force this conversion, even if
6090 we would rather not do it. Usually set when using an explicit
6091 cast. A C-style cast is being processed iff C_CAST_P is true.
6093 Return error_mark_node, if something goes wrong. */
6096 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6102 if (error_operand_p (pfn))
6103 return error_mark_node;
6105 pfn_type = TREE_TYPE (pfn);
6106 to_type = build_ptrmemfunc_type (type);
6108 /* Handle multiple conversions of pointer to member functions. */
6109 if (TYPE_PTRMEMFUNC_P (pfn_type))
6111 tree delta = NULL_TREE;
6112 tree npfn = NULL_TREE;
6116 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6117 error ("invalid conversion to type %qT from type %qT",
6120 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6121 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6125 /* We don't have to do any conversion to convert a
6126 pointer-to-member to its own type. But, we don't want to
6127 just return a PTRMEM_CST if there's an explicit cast; that
6128 cast should make the expression an invalid template argument. */
6129 if (TREE_CODE (pfn) != PTRMEM_CST)
6131 if (same_type_p (to_type, pfn_type))
6133 else if (integer_zerop (n))
6134 return build_reinterpret_cast (to_type, pfn);
6137 if (TREE_SIDE_EFFECTS (pfn))
6138 pfn = save_expr (pfn);
6140 /* Obtain the function pointer and the current DELTA. */
6141 if (TREE_CODE (pfn) == PTRMEM_CST)
6142 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6145 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6146 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6149 /* Just adjust the DELTA field. */
6150 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6151 (TREE_TYPE (delta), ptrdiff_type_node));
6152 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6153 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6154 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6155 return build_ptrmemfunc1 (to_type, delta, npfn);
6158 /* Handle null pointer to member function conversions. */
6159 if (integer_zerop (pfn))
6161 pfn = build_c_cast (type, integer_zero_node);
6162 return build_ptrmemfunc1 (to_type,
6167 if (type_unknown_p (pfn))
6168 return instantiate_type (type, pfn, tf_warning_or_error);
6170 fn = TREE_OPERAND (pfn, 0);
6171 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6172 /* In a template, we will have preserved the
6174 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6175 return make_ptrmem_cst (to_type, fn);
6178 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6181 ??? There is no consistency as to the types returned for the above
6182 values. Some code acts as if it were a sizetype and some as if it were
6183 integer_type_node. */
6186 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6188 tree type = TREE_TYPE (cst);
6189 tree fn = PTRMEM_CST_MEMBER (cst);
6190 tree ptr_class, fn_class;
6192 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6194 /* The class that the function belongs to. */
6195 fn_class = DECL_CONTEXT (fn);
6197 /* The class that we're creating a pointer to member of. */
6198 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6200 /* First, calculate the adjustment to the function's class. */
6201 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6204 if (!DECL_VIRTUAL_P (fn))
6205 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6208 /* If we're dealing with a virtual function, we have to adjust 'this'
6209 again, to point to the base which provides the vtable entry for
6210 fn; the call will do the opposite adjustment. */
6211 tree orig_class = DECL_CONTEXT (fn);
6212 tree binfo = binfo_or_else (orig_class, fn_class);
6213 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6214 *delta, BINFO_OFFSET (binfo));
6215 *delta = fold_if_not_in_template (*delta);
6217 /* We set PFN to the vtable offset at which the function can be
6218 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6219 case delta is shifted left, and then incremented). */
6220 *pfn = DECL_VINDEX (fn);
6221 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6222 TYPE_SIZE_UNIT (vtable_entry_type));
6223 *pfn = fold_if_not_in_template (*pfn);
6225 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6227 case ptrmemfunc_vbit_in_pfn:
6228 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6230 *pfn = fold_if_not_in_template (*pfn);
6233 case ptrmemfunc_vbit_in_delta:
6234 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6235 *delta, integer_one_node);
6236 *delta = fold_if_not_in_template (*delta);
6237 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6238 *delta, integer_one_node);
6239 *delta = fold_if_not_in_template (*delta);
6246 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6247 *pfn = fold_if_not_in_template (*pfn);
6251 /* Return an expression for PFN from the pointer-to-member function
6255 pfn_from_ptrmemfunc (tree t)
6257 if (TREE_CODE (t) == PTRMEM_CST)
6262 expand_ptrmemfunc_cst (t, &delta, &pfn);
6267 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6270 /* Convert value RHS to type TYPE as preparation for an assignment to
6271 an lvalue of type TYPE. ERRTYPE is a string to use in error
6272 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6273 are doing the conversion in order to pass the PARMNUMth argument of
6277 convert_for_assignment (tree type, tree rhs,
6278 const char *errtype, tree fndecl, int parmnum)
6281 enum tree_code coder;
6283 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6284 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6285 rhs = TREE_OPERAND (rhs, 0);
6287 rhstype = TREE_TYPE (rhs);
6288 coder = TREE_CODE (rhstype);
6290 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6291 && vector_types_convertible_p (type, rhstype, true))
6292 return convert (type, rhs);
6294 if (rhs == error_mark_node || rhstype == error_mark_node)
6295 return error_mark_node;
6296 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6297 return error_mark_node;
6299 /* The RHS of an assignment cannot have void type. */
6300 if (coder == VOID_TYPE)
6302 error ("void value not ignored as it ought to be");
6303 return error_mark_node;
6306 /* Simplify the RHS if possible. */
6307 if (TREE_CODE (rhs) == CONST_DECL)
6308 rhs = DECL_INITIAL (rhs);
6310 if (c_dialect_objc ())
6313 tree rname = fndecl;
6315 if (!strcmp (errtype, "assignment"))
6317 else if (!strcmp (errtype, "initialization"))
6321 tree selector = objc_message_selector ();
6325 if (selector && parmno > 1)
6332 if (objc_compare_types (type, rhstype, parmno, rname))
6333 return convert (type, rhs);
6338 The expression is implicitly converted (clause _conv_) to the
6339 cv-unqualified type of the left operand.
6341 We allow bad conversions here because by the time we get to this point
6342 we are committed to doing the conversion. If we end up doing a bad
6343 conversion, convert_like will complain. */
6344 if (!can_convert_arg_bad (type, rhstype, rhs))
6346 /* When -Wno-pmf-conversions is use, we just silently allow
6347 conversions from pointers-to-members to plain pointers. If
6348 the conversion doesn't work, cp_convert will complain. */
6350 && TYPE_PTR_P (type)
6351 && TYPE_PTRMEMFUNC_P (rhstype))
6352 rhs = cp_convert (strip_top_quals (type), rhs);
6355 /* If the right-hand side has unknown type, then it is an
6356 overloaded function. Call instantiate_type to get error
6358 if (rhstype == unknown_type_node)
6359 instantiate_type (type, rhs, tf_warning_or_error);
6361 error ("cannot convert %qT to %qT for argument %qP to %qD",
6362 rhstype, type, parmnum, fndecl);
6364 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6365 return error_mark_node;
6368 if (warn_missing_format_attribute)
6370 const enum tree_code codel = TREE_CODE (type);
6371 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6373 && check_missing_format_attribute (type, rhstype))
6374 warning (OPT_Wmissing_format_attribute,
6375 "%s might be a candidate for a format attribute",
6379 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6381 if (warn_parentheses
6382 && type == boolean_type_node
6383 && TREE_CODE (rhs) == MODIFY_EXPR
6384 && !TREE_NO_WARNING (rhs)
6385 && TREE_TYPE (rhs) != boolean_type_node)
6387 warning (OPT_Wparentheses,
6388 "suggest parentheses around assignment used as truth value");
6389 TREE_NO_WARNING (rhs) = 1;
6392 return perform_implicit_conversion (strip_top_quals (type), rhs);
6395 /* Convert RHS to be of type TYPE.
6396 If EXP is nonzero, it is the target of the initialization.
6397 ERRTYPE is a string to use in error messages.
6399 Two major differences between the behavior of
6400 `convert_for_assignment' and `convert_for_initialization'
6401 are that references are bashed in the former, while
6402 copied in the latter, and aggregates are assigned in
6403 the former (operator=) while initialized in the
6406 If using constructor make sure no conversion operator exists, if one does
6407 exist, an ambiguity exists.
6409 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6412 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6413 const char *errtype, tree fndecl, int parmnum)
6415 enum tree_code codel = TREE_CODE (type);
6417 enum tree_code coder;
6419 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6420 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6421 if (TREE_CODE (rhs) == NOP_EXPR
6422 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6423 && codel != REFERENCE_TYPE)
6424 rhs = TREE_OPERAND (rhs, 0);
6426 if (type == error_mark_node
6427 || rhs == error_mark_node
6428 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6429 return error_mark_node;
6431 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6432 && TREE_CODE (type) != ARRAY_TYPE
6433 && (TREE_CODE (type) != REFERENCE_TYPE
6434 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6435 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6436 && (TREE_CODE (type) != REFERENCE_TYPE
6437 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6438 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6439 rhs = decay_conversion (rhs);
6441 rhstype = TREE_TYPE (rhs);
6442 coder = TREE_CODE (rhstype);
6444 if (coder == ERROR_MARK)
6445 return error_mark_node;
6447 /* We accept references to incomplete types, so we can
6448 return here before checking if RHS is of complete type. */
6450 if (codel == REFERENCE_TYPE)
6452 /* This should eventually happen in convert_arguments. */
6453 int savew = 0, savee = 0;
6456 savew = warningcount, savee = errorcount;
6457 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6461 if (warningcount > savew)
6462 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6463 else if (errorcount > savee)
6464 error ("in passing argument %P of %q+D", parmnum, fndecl);
6470 exp = require_complete_type (exp);
6471 if (exp == error_mark_node)
6472 return error_mark_node;
6474 rhstype = non_reference (rhstype);
6476 type = complete_type (type);
6478 if (IS_AGGR_TYPE (type))
6479 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6481 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6484 /* If RETVAL is the address of, or a reference to, a local variable or
6485 temporary give an appropriate warning. */
6488 maybe_warn_about_returning_address_of_local (tree retval)
6490 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6491 tree whats_returned = retval;
6495 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6496 whats_returned = TREE_OPERAND (whats_returned, 1);
6497 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6498 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6499 || TREE_CODE (whats_returned) == NOP_EXPR)
6500 whats_returned = TREE_OPERAND (whats_returned, 0);
6505 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6507 whats_returned = TREE_OPERAND (whats_returned, 0);
6509 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6511 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6512 || TREE_CODE (whats_returned) == TARGET_EXPR)
6514 warning (0, "returning reference to temporary");
6517 if (TREE_CODE (whats_returned) == VAR_DECL
6518 && DECL_NAME (whats_returned)
6519 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6521 warning (0, "reference to non-lvalue returned");
6526 while (TREE_CODE (whats_returned) == COMPONENT_REF
6527 || TREE_CODE (whats_returned) == ARRAY_REF)
6528 whats_returned = TREE_OPERAND (whats_returned, 0);
6530 if (DECL_P (whats_returned)
6531 && DECL_NAME (whats_returned)
6532 && DECL_FUNCTION_SCOPE_P (whats_returned)
6533 && !(TREE_STATIC (whats_returned)
6534 || TREE_PUBLIC (whats_returned)))
6536 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6537 warning (0, "reference to local variable %q+D returned",
6540 warning (0, "address of local variable %q+D returned",
6546 /* Check that returning RETVAL from the current function is valid.
6547 Return an expression explicitly showing all conversions required to
6548 change RETVAL into the function return type, and to assign it to
6549 the DECL_RESULT for the function. Set *NO_WARNING to true if
6550 code reaches end of non-void function warning shouldn't be issued
6551 on this RETURN_EXPR. */
6554 check_return_expr (tree retval, bool *no_warning)
6557 /* The type actually returned by the function, after any
6560 int fn_returns_value_p;
6562 *no_warning = false;
6564 /* A `volatile' function is one that isn't supposed to return, ever.
6565 (This is a G++ extension, used to get better code for functions
6566 that call the `volatile' function.) */
6567 if (TREE_THIS_VOLATILE (current_function_decl))
6568 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6570 /* Check for various simple errors. */
6571 if (DECL_DESTRUCTOR_P (current_function_decl))
6574 error ("returning a value from a destructor");
6577 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6579 if (in_function_try_handler)
6580 /* If a return statement appears in a handler of the
6581 function-try-block of a constructor, the program is ill-formed. */
6582 error ("cannot return from a handler of a function-try-block of a constructor");
6584 /* You can't return a value from a constructor. */
6585 error ("returning a value from a constructor");
6589 if (processing_template_decl)
6591 current_function_returns_value = 1;
6595 /* When no explicit return-value is given in a function with a named
6596 return value, the named return value is used. */
6597 result = DECL_RESULT (current_function_decl);
6598 valtype = TREE_TYPE (result);
6599 gcc_assert (valtype != NULL_TREE);
6600 fn_returns_value_p = !VOID_TYPE_P (valtype);
6601 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6604 /* Check for a return statement with no return value in a function
6605 that's supposed to return a value. */
6606 if (!retval && fn_returns_value_p)
6608 pedwarn ("return-statement with no value, in function returning %qT",
6610 /* Clear this, so finish_function won't say that we reach the
6611 end of a non-void function (which we don't, we gave a
6613 current_function_returns_null = 0;
6614 /* And signal caller that TREE_NO_WARNING should be set on the
6615 RETURN_EXPR to avoid control reaches end of non-void function
6616 warnings in tree-cfg.c. */
6619 /* Check for a return statement with a value in a function that
6620 isn't supposed to return a value. */
6621 else if (retval && !fn_returns_value_p)
6623 if (VOID_TYPE_P (TREE_TYPE (retval)))
6624 /* You can return a `void' value from a function of `void'
6625 type. In that case, we have to evaluate the expression for
6626 its side-effects. */
6627 finish_expr_stmt (retval);
6629 pedwarn ("return-statement with a value, in function "
6630 "returning 'void'");
6632 current_function_returns_null = 1;
6634 /* There's really no value to return, after all. */
6638 /* Remember that this function can sometimes return without a
6640 current_function_returns_null = 1;
6642 /* Remember that this function did return a value. */
6643 current_function_returns_value = 1;
6645 /* Check for erroneous operands -- but after giving ourselves a
6646 chance to provide an error about returning a value from a void
6648 if (error_operand_p (retval))
6650 current_function_return_value = error_mark_node;
6651 return error_mark_node;
6654 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6655 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6656 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6657 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6659 && null_ptr_cst_p (retval))
6660 warning (0, "%<operator new%> must not return NULL unless it is "
6661 "declared %<throw()%> (or -fcheck-new is in effect)");
6663 /* Effective C++ rule 15. See also start_function. */
6665 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6669 /* The function return type must be a reference to the current
6671 if (TREE_CODE (valtype) == REFERENCE_TYPE
6672 && same_type_ignoring_top_level_qualifiers_p
6673 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6675 /* Returning '*this' is obviously OK. */
6676 if (retval == current_class_ref)
6678 /* If we are calling a function whose return type is the same of
6679 the current class reference, it is ok. */
6680 else if (TREE_CODE (retval) == INDIRECT_REF
6681 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6686 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6689 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6691 [...] For a function with a class return type, if the expression
6692 in the return statement is the name of a local object, and the cv-
6693 unqualified type of the local object is the same as the function
6694 return type, an implementation is permitted to omit creating the tem-
6695 porary object to hold the function return value [...]
6697 So, if this is a value-returning function that always returns the same
6698 local variable, remember it.
6700 It might be nice to be more flexible, and choose the first suitable
6701 variable even if the function sometimes returns something else, but
6702 then we run the risk of clobbering the variable we chose if the other
6703 returned expression uses the chosen variable somehow. And people expect
6704 this restriction, anyway. (jason 2000-11-19)
6706 See finish_function and finalize_nrv for the rest of this optimization. */
6708 if (fn_returns_value_p && flag_elide_constructors)
6710 if (retval != NULL_TREE
6711 && (current_function_return_value == NULL_TREE
6712 || current_function_return_value == retval)
6713 && TREE_CODE (retval) == VAR_DECL
6714 && DECL_CONTEXT (retval) == current_function_decl
6715 && ! TREE_STATIC (retval)
6716 && (DECL_ALIGN (retval)
6717 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6718 && same_type_p ((TYPE_MAIN_VARIANT
6719 (TREE_TYPE (retval))),
6721 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6722 current_function_return_value = retval;
6724 current_function_return_value = error_mark_node;
6727 /* We don't need to do any conversions when there's nothing being
6732 /* Do any required conversions. */
6733 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6734 /* No conversions are required. */
6738 /* The type the function is declared to return. */
6739 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6741 /* The functype's return type will have been set to void, if it
6742 was an incomplete type. Just treat this as 'return;' */
6743 if (VOID_TYPE_P (functype))
6744 return error_mark_node;
6746 /* First convert the value to the function's return type, then
6747 to the type of return value's location to handle the
6748 case that functype is smaller than the valtype. */
6749 retval = convert_for_initialization
6750 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6751 "return", NULL_TREE, 0);
6752 retval = convert (valtype, retval);
6754 /* If the conversion failed, treat this just like `return;'. */
6755 if (retval == error_mark_node)
6757 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6758 else if (! current_function_returns_struct
6759 && TREE_CODE (retval) == TARGET_EXPR
6760 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6761 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6762 TREE_OPERAND (retval, 0));
6764 maybe_warn_about_returning_address_of_local (retval);
6767 /* Actually copy the value returned into the appropriate location. */
6768 if (retval && retval != result)
6769 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6775 /* Returns nonzero if the pointer-type FROM can be converted to the
6776 pointer-type TO via a qualification conversion. If CONSTP is -1,
6777 then we return nonzero if the pointers are similar, and the
6778 cv-qualification signature of FROM is a proper subset of that of TO.
6780 If CONSTP is positive, then all outer pointers have been
6784 comp_ptr_ttypes_real (tree to, tree from, int constp)
6786 bool to_more_cv_qualified = false;
6788 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6790 if (TREE_CODE (to) != TREE_CODE (from))
6793 if (TREE_CODE (from) == OFFSET_TYPE
6794 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6795 TYPE_OFFSET_BASETYPE (to)))
6798 /* Const and volatile mean something different for function types,
6799 so the usual checks are not appropriate. */
6800 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6802 /* In Objective-C++, some types may have been 'volatilized' by
6803 the compiler for EH; when comparing them here, the volatile
6804 qualification must be ignored. */
6805 bool objc_quals_match = objc_type_quals_match (to, from);
6807 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6810 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6814 to_more_cv_qualified = true;
6818 constp &= TYPE_READONLY (to);
6821 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6822 return ((constp >= 0 || to_more_cv_qualified)
6823 && same_type_ignoring_top_level_qualifiers_p (to, from));
6827 /* When comparing, say, char ** to char const **, this function takes
6828 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6829 types to this function. */
6832 comp_ptr_ttypes (tree to, tree from)
6834 return comp_ptr_ttypes_real (to, from, 1);
6837 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6838 type or inheritance-related types, regardless of cv-quals. */
6841 ptr_reasonably_similar (tree to, tree from)
6843 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6845 /* Any target type is similar enough to void. */
6846 if (TREE_CODE (to) == VOID_TYPE
6847 || TREE_CODE (from) == VOID_TYPE)
6850 if (TREE_CODE (to) != TREE_CODE (from))
6853 if (TREE_CODE (from) == OFFSET_TYPE
6854 && comptypes (TYPE_OFFSET_BASETYPE (to),
6855 TYPE_OFFSET_BASETYPE (from),
6856 COMPARE_BASE | COMPARE_DERIVED))
6859 if (TREE_CODE (to) == VECTOR_TYPE
6860 && vector_types_convertible_p (to, from, false))
6863 if (TREE_CODE (to) == INTEGER_TYPE
6864 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6867 if (TREE_CODE (to) == FUNCTION_TYPE)
6870 if (TREE_CODE (to) != POINTER_TYPE)
6872 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6873 COMPARE_BASE | COMPARE_DERIVED);
6877 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6878 pointer-to-member types) are the same, ignoring cv-qualification at
6882 comp_ptr_ttypes_const (tree to, tree from)
6884 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6886 if (TREE_CODE (to) != TREE_CODE (from))
6889 if (TREE_CODE (from) == OFFSET_TYPE
6890 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6891 TYPE_OFFSET_BASETYPE (to)))
6894 if (TREE_CODE (to) != POINTER_TYPE)
6895 return same_type_ignoring_top_level_qualifiers_p (to, from);
6899 /* Returns the type qualifiers for this type, including the qualifiers on the
6900 elements for an array type. */
6903 cp_type_quals (tree type)
6905 type = strip_array_types (type);
6906 if (type == error_mark_node)
6907 return TYPE_UNQUALIFIED;
6908 return TYPE_QUALS (type);
6911 /* Returns nonzero if the TYPE contains a mutable member. */
6914 cp_has_mutable_p (tree type)
6916 type = strip_array_types (type);
6918 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6921 /* Apply the TYPE_QUALS to the new DECL. */
6923 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6925 tree type = TREE_TYPE (decl);
6927 if (type == error_mark_node)
6930 if (TREE_CODE (type) == FUNCTION_TYPE
6931 && type_quals != TYPE_UNQUALIFIED)
6933 /* This was an error in C++98 (cv-qualifiers cannot be added to
6934 a function type), but DR 295 makes the code well-formed by
6935 dropping the extra qualifiers. */
6938 tree bad_type = build_qualified_type (type, type_quals);
6939 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6943 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6947 /* Avoid setting TREE_READONLY incorrectly. */
6948 if (/* If the object has a constructor, the constructor may modify
6950 TYPE_NEEDS_CONSTRUCTING (type)
6951 /* If the type isn't complete, we don't know yet if it will need
6953 || !COMPLETE_TYPE_P (type)
6954 /* If the type has a mutable component, that component might be
6956 || TYPE_HAS_MUTABLE_P (type))
6957 type_quals &= ~TYPE_QUAL_CONST;
6959 c_apply_type_quals_to_decl (type_quals, decl);
6962 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6963 exemplar types such that casting T1 to T2 is casting away constness
6964 if and only if there is no implicit conversion from T1 to T2. */
6967 casts_away_constness_r (tree *t1, tree *t2)
6972 /* [expr.const.cast]
6974 For multi-level pointer to members and multi-level mixed pointers
6975 and pointers to members (conv.qual), the "member" aspect of a
6976 pointer to member level is ignored when determining if a const
6977 cv-qualifier has been cast away. */
6978 /* [expr.const.cast]
6980 For two pointer types:
6982 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6983 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6986 casting from X1 to X2 casts away constness if, for a non-pointer
6987 type T there does not exist an implicit conversion (clause
6990 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6994 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6995 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6996 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
6998 *t1 = cp_build_qualified_type (void_type_node,
6999 cp_type_quals (*t1));
7000 *t2 = cp_build_qualified_type (void_type_node,
7001 cp_type_quals (*t2));
7005 quals1 = cp_type_quals (*t1);
7006 quals2 = cp_type_quals (*t2);
7008 if (TYPE_PTRMEM_P (*t1))
7009 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
7011 *t1 = TREE_TYPE (*t1);
7012 if (TYPE_PTRMEM_P (*t2))
7013 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
7015 *t2 = TREE_TYPE (*t2);
7017 casts_away_constness_r (t1, t2);
7018 *t1 = build_pointer_type (*t1);
7019 *t2 = build_pointer_type (*t2);
7020 *t1 = cp_build_qualified_type (*t1, quals1);
7021 *t2 = cp_build_qualified_type (*t2, quals2);
7024 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
7028 casts_away_constness (tree t1, tree t2)
7030 if (TREE_CODE (t2) == REFERENCE_TYPE)
7032 /* [expr.const.cast]
7034 Casting from an lvalue of type T1 to an lvalue of type T2
7035 using a reference cast casts away constness if a cast from an
7036 rvalue of type "pointer to T1" to the type "pointer to T2"
7037 casts away constness. */
7038 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
7039 return casts_away_constness (build_pointer_type (t1),
7040 build_pointer_type (TREE_TYPE (t2)));
7043 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
7044 /* [expr.const.cast]
7046 Casting from an rvalue of type "pointer to data member of X
7047 of type T1" to the type "pointer to data member of Y of type
7048 T2" casts away constness if a cast from an rvalue of type
7049 "pointer to T1" to the type "pointer to T2" casts away
7051 return casts_away_constness
7052 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7053 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7055 /* Casting away constness is only something that makes sense for
7056 pointer or reference types. */
7057 if (TREE_CODE (t1) != POINTER_TYPE
7058 || TREE_CODE (t2) != POINTER_TYPE)
7061 /* Top-level qualifiers don't matter. */
7062 t1 = TYPE_MAIN_VARIANT (t1);
7063 t2 = TYPE_MAIN_VARIANT (t2);
7064 casts_away_constness_r (&t1, &t2);
7065 if (!can_convert (t2, t1))
7071 /* If T is a REFERENCE_TYPE return the type to which T refers.
7072 Otherwise, return T itself. */
7075 non_reference (tree t)
7077 if (TREE_CODE (t) == REFERENCE_TYPE)
7083 /* Return nonzero if REF is an lvalue valid for this language;
7084 otherwise, print an error message and return zero. USE says
7085 how the lvalue is being used and so selects the error message. */
7088 lvalue_or_else (tree ref, enum lvalue_use use)
7090 int win = lvalue_p (ref);