1 /* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4 Hacked by Michael Tiemann (tiemann@cygnus.com)
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to
20 the Free Software Foundation, 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
24 /* This file is part of the C++ front end.
25 It contains routines to build C++ expressions given their operands,
26 including computing the types of the result, C and C++ specific error
27 checks, and some optimization. */
31 #include "coretypes.h"
41 #include "diagnostic.h"
46 static tree convert_for_assignment (tree, tree, const char *, tree, int);
47 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
48 static tree rationalize_conditional_expr (enum tree_code, tree);
49 static int comp_ptr_ttypes_real (tree, tree, int);
50 static int comp_ptr_ttypes_const (tree, tree);
51 static bool comp_except_types (tree, tree, bool);
52 static bool comp_array_types (tree, tree, bool);
53 static tree common_base_type (tree, tree);
54 static tree pointer_diff (tree, tree, tree);
55 static tree get_delta_difference (tree, tree, bool, bool);
56 static void casts_away_constness_r (tree *, tree *);
57 static bool casts_away_constness (tree, tree);
58 static void maybe_warn_about_returning_address_of_local (tree);
59 static tree lookup_destructor (tree, tree, tree);
60 static tree convert_arguments (tree, tree, tree, int);
62 /* Do `exp = require_complete_type (exp);' to make sure exp
63 does not have an incomplete type. (That includes void types.)
64 Returns the error_mark_node if the VALUE does not have
65 complete type when this function returns. */
68 require_complete_type (tree value)
72 if (processing_template_decl || value == error_mark_node)
75 if (TREE_CODE (value) == OVERLOAD)
76 type = unknown_type_node;
78 type = TREE_TYPE (value);
80 if (type == error_mark_node)
81 return error_mark_node;
83 /* First, detect a valid value with a complete type. */
84 if (COMPLETE_TYPE_P (type))
87 if (complete_type_or_else (type, value))
90 return error_mark_node;
93 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
94 a template instantiation, do the instantiation. Returns TYPE,
95 whether or not it could be completed, unless something goes
96 horribly wrong, in which case the error_mark_node is returned. */
99 complete_type (tree type)
101 if (type == NULL_TREE)
102 /* Rather than crash, we return something sure to cause an error
104 return error_mark_node;
106 if (type == error_mark_node || COMPLETE_TYPE_P (type))
108 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
110 tree t = complete_type (TREE_TYPE (type));
111 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
113 TYPE_NEEDS_CONSTRUCTING (type)
114 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
115 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
116 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
118 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
119 instantiate_class_template (TYPE_MAIN_VARIANT (type));
124 /* Like complete_type, but issue an error if the TYPE cannot be completed.
125 VALUE is used for informative diagnostics.
126 Returns NULL_TREE if the type cannot be made complete. */
129 complete_type_or_else (tree type, tree value)
131 type = complete_type (type);
132 if (type == error_mark_node)
133 /* We already issued an error. */
135 else if (!COMPLETE_TYPE_P (type))
137 cxx_incomplete_type_diagnostic (value, type, 0);
144 /* Return truthvalue of whether type of EXP is instantiated. */
147 type_unknown_p (tree exp)
149 return (TREE_CODE (exp) == TREE_LIST
150 || TREE_TYPE (exp) == unknown_type_node);
154 /* Return the common type of two parameter lists.
155 We assume that comptypes has already been done and returned 1;
156 if that isn't so, this may crash.
158 As an optimization, free the space we allocate if the parameter
159 lists are already common. */
162 commonparms (tree p1, tree p2)
164 tree oldargs = p1, newargs, n;
168 len = list_length (p1);
169 newargs = tree_last (p1);
171 if (newargs == void_list_node)
180 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
185 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
187 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
189 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
192 else if (! TREE_PURPOSE (p1))
194 if (TREE_PURPOSE (p2))
196 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
202 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
204 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
206 if (TREE_VALUE (p1) != TREE_VALUE (p2))
209 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
212 TREE_VALUE (n) = TREE_VALUE (p1);
220 /* Given a type, perhaps copied for a typedef,
221 find the "original" version of it. */
223 original_type (tree t)
225 while (TYPE_NAME (t) != NULL_TREE)
227 tree x = TYPE_NAME (t);
228 if (TREE_CODE (x) != TYPE_DECL)
230 x = DECL_ORIGINAL_TYPE (x);
238 /* T1 and T2 are arithmetic or enumeration types. Return the type
239 that will result from the "usual arithmetic conversions" on T1 and
240 T2 as described in [expr]. */
243 type_after_usual_arithmetic_conversions (tree t1, tree t2)
245 enum tree_code code1 = TREE_CODE (t1);
246 enum tree_code code2 = TREE_CODE (t2);
249 /* FIXME: Attributes. */
250 gcc_assert (ARITHMETIC_TYPE_P (t1)
251 || TREE_CODE (t1) == COMPLEX_TYPE
252 || TREE_CODE (t1) == VECTOR_TYPE
253 || TREE_CODE (t1) == ENUMERAL_TYPE);
254 gcc_assert (ARITHMETIC_TYPE_P (t2)
255 || TREE_CODE (t2) == COMPLEX_TYPE
256 || TREE_CODE (t1) == VECTOR_TYPE
257 || TREE_CODE (t2) == ENUMERAL_TYPE);
259 /* In what follows, we slightly generalize the rules given in [expr] so
260 as to deal with `long long' and `complex'. First, merge the
262 attributes = (*targetm.merge_type_attributes) (t1, t2);
264 /* If one type is complex, form the common type of the non-complex
265 components, then make that complex. Use T1 or T2 if it is the
267 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
269 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
270 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
272 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
274 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
275 return build_type_attribute_variant (t1, attributes);
276 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
277 return build_type_attribute_variant (t2, attributes);
279 return build_type_attribute_variant (build_complex_type (subtype),
283 if (code1 == VECTOR_TYPE)
285 /* When we get here we should have two vectors of the same size.
286 Just prefer the unsigned one if present. */
287 if (TYPE_UNSIGNED (t1))
288 return build_type_attribute_variant (t1, attributes);
290 return build_type_attribute_variant (t2, attributes);
293 /* If only one is real, use it as the result. */
294 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
295 return build_type_attribute_variant (t1, attributes);
296 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
297 return build_type_attribute_variant (t2, attributes);
299 /* Perform the integral promotions. */
300 if (code1 != REAL_TYPE)
302 t1 = type_promotes_to (t1);
303 t2 = type_promotes_to (t2);
306 /* Both real or both integers; use the one with greater precision. */
307 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
308 return build_type_attribute_variant (t1, attributes);
309 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
310 return build_type_attribute_variant (t2, attributes);
312 /* The types are the same; no need to do anything fancy. */
313 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
314 return build_type_attribute_variant (t1, attributes);
316 if (code1 != REAL_TYPE)
318 /* If one is a sizetype, use it so size_binop doesn't blow up. */
319 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
320 return build_type_attribute_variant (t1, attributes);
321 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
322 return build_type_attribute_variant (t2, attributes);
324 /* If one is unsigned long long, then convert the other to unsigned
326 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
327 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
328 return build_type_attribute_variant (long_long_unsigned_type_node,
330 /* If one is a long long, and the other is an unsigned long, and
331 long long can represent all the values of an unsigned long, then
332 convert to a long long. Otherwise, convert to an unsigned long
333 long. Otherwise, if either operand is long long, convert the
336 Since we're here, we know the TYPE_PRECISION is the same;
337 therefore converting to long long cannot represent all the values
338 of an unsigned long, so we choose unsigned long long in that
340 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
341 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
343 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
344 ? long_long_unsigned_type_node
345 : long_long_integer_type_node);
346 return build_type_attribute_variant (t, attributes);
349 /* Go through the same procedure, but for longs. */
350 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
351 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
352 return build_type_attribute_variant (long_unsigned_type_node,
354 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
355 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
357 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
358 ? long_unsigned_type_node : long_integer_type_node);
359 return build_type_attribute_variant (t, attributes);
361 /* Otherwise prefer the unsigned one. */
362 if (TYPE_UNSIGNED (t1))
363 return build_type_attribute_variant (t1, attributes);
365 return build_type_attribute_variant (t2, attributes);
369 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
370 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
371 return build_type_attribute_variant (long_double_type_node,
373 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
374 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
375 return build_type_attribute_variant (double_type_node,
377 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
378 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
379 return build_type_attribute_variant (float_type_node,
382 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
383 the standard C++ floating-point types. Logic earlier in this
384 function has already eliminated the possibility that
385 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
386 compelling reason to choose one or the other. */
387 return build_type_attribute_variant (t1, attributes);
391 /* Subroutine of composite_pointer_type to implement the recursive
392 case. See that function for documentation fo the parameters. */
395 composite_pointer_type_r (tree t1, tree t2, const char* location)
402 /* Determine the types pointed to by T1 and T2. */
403 if (TREE_CODE (t1) == POINTER_TYPE)
405 pointee1 = TREE_TYPE (t1);
406 pointee2 = TREE_TYPE (t2);
410 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
411 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
416 Otherwise, the composite pointer type is a pointer type
417 similar (_conv.qual_) to the type of one of the operands,
418 with a cv-qualification signature (_conv.qual_) that is the
419 union of the cv-qualification signatures of the operand
421 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
422 result_type = pointee1;
423 else if ((TREE_CODE (pointee1) == POINTER_TYPE
424 && TREE_CODE (pointee2) == POINTER_TYPE)
425 || (TYPE_PTR_TO_MEMBER_P (pointee1)
426 && TYPE_PTR_TO_MEMBER_P (pointee2)))
427 result_type = composite_pointer_type_r (pointee1, pointee2, location);
430 pedwarn ("%s between distinct pointer types %qT and %qT "
433 result_type = void_type_node;
435 result_type = cp_build_qualified_type (result_type,
436 (cp_type_quals (pointee1)
437 | cp_type_quals (pointee2)));
438 /* If the original types were pointers to members, so is the
440 if (TYPE_PTR_TO_MEMBER_P (t1))
442 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
443 TYPE_PTRMEM_CLASS_TYPE (t2)))
444 pedwarn ("%s between distinct pointer types %qT and %qT "
447 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
451 result_type = build_pointer_type (result_type);
453 /* Merge the attributes. */
454 attributes = (*targetm.merge_type_attributes) (t1, t2);
455 return build_type_attribute_variant (result_type, attributes);
458 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
459 ARG1 and ARG2 are the values with those types. The LOCATION is a
460 string describing the current location, in case an error occurs.
462 This routine also implements the computation of a common type for
463 pointers-to-members as per [expr.eq]. */
466 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
467 const char* location)
474 If one operand is a null pointer constant, the composite pointer
475 type is the type of the other operand. */
476 if (null_ptr_cst_p (arg1))
478 if (null_ptr_cst_p (arg2))
485 If one of the operands has type "pointer to cv1 void*", then
486 the other has type "pointer to cv2T", and the composite pointer
487 type is "pointer to cv12 void", where cv12 is the union of cv1
490 If either type is a pointer to void, make sure it is T1. */
491 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
499 /* Now, if T1 is a pointer to void, merge the qualifiers. */
500 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
505 if (pedantic && TYPE_PTRFN_P (t2))
506 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
507 "and pointer-to-function", location);
509 = cp_build_qualified_type (void_type_node,
510 (cp_type_quals (TREE_TYPE (t1))
511 | cp_type_quals (TREE_TYPE (t2))));
512 result_type = build_pointer_type (result_type);
513 /* Merge the attributes. */
514 attributes = (*targetm.merge_type_attributes) (t1, t2);
515 return build_type_attribute_variant (result_type, attributes);
518 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
519 && TREE_CODE (t2) == POINTER_TYPE)
521 if (objc_compare_types (t1, t2, -3, NULL_TREE))
525 /* [expr.eq] permits the application of a pointer conversion to
526 bring the pointers to a common type. */
527 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
528 && CLASS_TYPE_P (TREE_TYPE (t1))
529 && CLASS_TYPE_P (TREE_TYPE (t2))
530 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
533 class1 = TREE_TYPE (t1);
534 class2 = TREE_TYPE (t2);
536 if (DERIVED_FROM_P (class1, class2))
537 t2 = (build_pointer_type
538 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
539 else if (DERIVED_FROM_P (class2, class1))
540 t1 = (build_pointer_type
541 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
544 error ("%s between distinct pointer types %qT and %qT "
545 "lacks a cast", location, t1, t2);
546 return error_mark_node;
549 /* [expr.eq] permits the application of a pointer-to-member
550 conversion to change the class type of one of the types. */
551 else if (TYPE_PTR_TO_MEMBER_P (t1)
552 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
553 TYPE_PTRMEM_CLASS_TYPE (t2)))
555 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
556 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
558 if (DERIVED_FROM_P (class1, class2))
559 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
560 else if (DERIVED_FROM_P (class2, class1))
561 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
564 error ("%s between distinct pointer-to-member types %qT and %qT "
565 "lacks a cast", location, t1, t2);
566 return error_mark_node;
570 return composite_pointer_type_r (t1, t2, location);
573 /* Return the merged type of two types.
574 We assume that comptypes has already been done and returned 1;
575 if that isn't so, this may crash.
577 This just combines attributes and default arguments; any other
578 differences would cause the two types to compare unalike. */
581 merge_types (tree t1, tree t2)
583 enum tree_code code1;
584 enum tree_code code2;
587 /* Save time if the two types are the same. */
590 if (original_type (t1) == original_type (t2))
593 /* If one type is nonsense, use the other. */
594 if (t1 == error_mark_node)
596 if (t2 == error_mark_node)
599 /* Merge the attributes. */
600 attributes = (*targetm.merge_type_attributes) (t1, t2);
602 if (TYPE_PTRMEMFUNC_P (t1))
603 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
604 if (TYPE_PTRMEMFUNC_P (t2))
605 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
607 code1 = TREE_CODE (t1);
608 code2 = TREE_CODE (t2);
614 /* For two pointers, do this recursively on the target type. */
616 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
617 int quals = cp_type_quals (t1);
619 if (code1 == POINTER_TYPE)
620 t1 = build_pointer_type (target);
622 t1 = build_reference_type (target);
623 t1 = build_type_attribute_variant (t1, attributes);
624 t1 = cp_build_qualified_type (t1, quals);
626 if (TREE_CODE (target) == METHOD_TYPE)
627 t1 = build_ptrmemfunc_type (t1);
636 quals = cp_type_quals (t1);
637 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
638 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
639 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
641 t1 = cp_build_qualified_type (t1, quals);
647 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
648 /* Save space: see if the result is identical to one of the args. */
649 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
650 return build_type_attribute_variant (t1, attributes);
651 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
652 return build_type_attribute_variant (t2, attributes);
653 /* Merge the element types, and have a size if either arg has one. */
654 t1 = build_cplus_array_type
655 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
660 /* Function types: prefer the one that specified arg types.
661 If both do, merge the arg types. Also merge the return types. */
663 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
664 tree p1 = TYPE_ARG_TYPES (t1);
665 tree p2 = TYPE_ARG_TYPES (t2);
668 /* Save space: see if the result is identical to one of the args. */
669 if (valtype == TREE_TYPE (t1) && ! p2)
670 return cp_build_type_attribute_variant (t1, attributes);
671 if (valtype == TREE_TYPE (t2) && ! p1)
672 return cp_build_type_attribute_variant (t2, attributes);
674 /* Simple way if one arg fails to specify argument types. */
675 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
677 rval = build_function_type (valtype, p2);
678 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
679 rval = build_exception_variant (rval, raises);
680 return cp_build_type_attribute_variant (rval, attributes);
682 raises = TYPE_RAISES_EXCEPTIONS (t1);
683 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
685 rval = build_function_type (valtype, p1);
687 rval = build_exception_variant (rval, raises);
688 return cp_build_type_attribute_variant (rval, attributes);
691 rval = build_function_type (valtype, commonparms (p1, p2));
692 t1 = build_exception_variant (rval, raises);
698 /* Get this value the long way, since TYPE_METHOD_BASETYPE
699 is just the main variant of this. */
700 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
701 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
704 /* If this was a member function type, get back to the
705 original type of type member function (i.e., without
706 the class instance variable up front. */
707 t1 = build_function_type (TREE_TYPE (t1),
708 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
709 t2 = build_function_type (TREE_TYPE (t2),
710 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
711 t3 = merge_types (t1, t2);
712 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
713 TYPE_ARG_TYPES (t3));
714 t1 = build_exception_variant (t3, raises);
719 /* There is no need to merge attributes into a TYPENAME_TYPE.
720 When the type is instantiated it will have whatever
721 attributes result from the instantiation. */
726 return cp_build_type_attribute_variant (t1, attributes);
729 /* Return the common type of two types.
730 We assume that comptypes has already been done and returned 1;
731 if that isn't so, this may crash.
733 This is the type for the result of most arithmetic operations
734 if the operands have the given two types. */
737 common_type (tree t1, tree t2)
739 enum tree_code code1;
740 enum tree_code code2;
742 /* If one type is nonsense, bail. */
743 if (t1 == error_mark_node || t2 == error_mark_node)
744 return error_mark_node;
746 code1 = TREE_CODE (t1);
747 code2 = TREE_CODE (t2);
749 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
750 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
751 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
752 || code2 == COMPLEX_TYPE || code2 == VECTOR_TYPE))
753 return type_after_usual_arithmetic_conversions (t1, t2);
755 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
756 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
757 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
758 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
764 /* Compare two exception specifier types for exactness or subsetness, if
765 allowed. Returns false for mismatch, true for match (same, or
768 [except.spec] "If a class X ... objects of class X or any class publicly
769 and unambiguously derived from X. Similarly, if a pointer type Y * ...
770 exceptions of type Y * or that are pointers to any type publicly and
771 unambiguously derived from Y. Otherwise a function only allows exceptions
772 that have the same type ..."
773 This does not mention cv qualifiers and is different to what throw
774 [except.throw] and catch [except.catch] will do. They will ignore the
775 top level cv qualifiers, and allow qualifiers in the pointer to class
778 We implement the letter of the standard. */
781 comp_except_types (tree a, tree b, bool exact)
783 if (same_type_p (a, b))
787 if (cp_type_quals (a) || cp_type_quals (b))
790 if (TREE_CODE (a) == POINTER_TYPE
791 && TREE_CODE (b) == POINTER_TYPE)
795 if (cp_type_quals (a) || cp_type_quals (b))
799 if (TREE_CODE (a) != RECORD_TYPE
800 || TREE_CODE (b) != RECORD_TYPE)
803 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
809 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
810 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
811 otherwise it must be exact. Exception lists are unordered, but
812 we've already filtered out duplicates. Most lists will be in order,
813 we should try to make use of that. */
816 comp_except_specs (tree t1, tree t2, bool exact)
825 if (t1 == NULL_TREE) /* T1 is ... */
826 return t2 == NULL_TREE || !exact;
827 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
828 return t2 != NULL_TREE && !TREE_VALUE (t2);
829 if (t2 == NULL_TREE) /* T2 is ... */
831 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
834 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
835 Count how many we find, to determine exactness. For exact matching and
836 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
838 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
840 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
842 tree a = TREE_VALUE (probe);
843 tree b = TREE_VALUE (t2);
845 if (comp_except_types (a, b, exact))
847 if (probe == base && exact)
848 base = TREE_CHAIN (probe);
853 if (probe == NULL_TREE)
856 return !exact || base == NULL_TREE || length == list_length (t1);
859 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
860 [] can match [size]. */
863 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
872 /* The type of the array elements must be the same. */
873 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
876 d1 = TYPE_DOMAIN (t1);
877 d2 = TYPE_DOMAIN (t2);
882 /* If one of the arrays is dimensionless, and the other has a
883 dimension, they are of different types. However, it is valid to
891 declarations for an array object can specify
892 array types that differ by the presence or absence of a major
893 array bound (_dcl.array_). */
895 return allow_redeclaration;
897 /* Check that the dimensions are the same. */
899 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
901 max1 = TYPE_MAX_VALUE (d1);
902 max2 = TYPE_MAX_VALUE (d2);
903 if (processing_template_decl && !abi_version_at_least (2)
904 && !value_dependent_expression_p (max1)
905 && !value_dependent_expression_p (max2))
907 /* With abi-1 we do not fold non-dependent array bounds, (and
908 consequently mangle them incorrectly). We must therefore
909 fold them here, to verify the domains have the same
915 if (!cp_tree_equal (max1, max2))
921 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
922 is a bitwise-or of the COMPARE_* flags. */
925 comptypes (tree t1, tree t2, int strict)
930 /* Suppress errors caused by previously reported errors. */
931 if (t1 == error_mark_node || t2 == error_mark_node)
934 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
936 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
937 current instantiation. */
938 if (TREE_CODE (t1) == TYPENAME_TYPE)
940 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
942 if (resolved != error_mark_node)
946 if (TREE_CODE (t2) == TYPENAME_TYPE)
948 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
950 if (resolved != error_mark_node)
954 /* If either type is the internal version of sizetype, use the
956 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
957 && TYPE_ORIG_SIZE_TYPE (t1))
958 t1 = TYPE_ORIG_SIZE_TYPE (t1);
960 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
961 && TYPE_ORIG_SIZE_TYPE (t2))
962 t2 = TYPE_ORIG_SIZE_TYPE (t2);
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 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1097 at_least_as_qualified_p (tree type1, tree type2)
1099 int q1 = cp_type_quals (type1);
1100 int q2 = cp_type_quals (type2);
1102 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1103 return (q1 & q2) == q2;
1106 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1107 more cv-qualified that TYPE1, and 0 otherwise. */
1110 comp_cv_qualification (tree type1, tree type2)
1112 int q1 = cp_type_quals (type1);
1113 int q2 = cp_type_quals (type2);
1118 if ((q1 & q2) == q2)
1120 else if ((q1 & q2) == q1)
1126 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1127 subset of the cv-qualification signature of TYPE2, and the types
1128 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1131 comp_cv_qual_signature (tree type1, tree type2)
1133 if (comp_ptr_ttypes_real (type2, type1, -1))
1135 else if (comp_ptr_ttypes_real (type1, type2, -1))
1141 /* If two types share a common base type, return that basetype.
1142 If there is not a unique most-derived base type, this function
1143 returns ERROR_MARK_NODE. */
1146 common_base_type (tree tt1, tree tt2)
1148 tree best = NULL_TREE;
1151 /* If one is a baseclass of another, that's good enough. */
1152 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1154 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1157 /* Otherwise, try to find a unique baseclass of TT1
1158 that is shared by TT2, and follow that down. */
1159 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1161 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1162 tree trial = common_base_type (basetype, tt2);
1166 if (trial == error_mark_node)
1168 if (best == NULL_TREE)
1170 else if (best != trial)
1171 return error_mark_node;
1176 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1178 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1179 tree trial = common_base_type (tt1, basetype);
1183 if (trial == error_mark_node)
1185 if (best == NULL_TREE)
1187 else if (best != trial)
1188 return error_mark_node;
1194 /* Subroutines of `comptypes'. */
1196 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1197 equivalent in the sense that functions with those parameter types
1198 can have equivalent types. The two lists must be equivalent,
1199 element by element. */
1202 compparms (tree parms1, tree parms2)
1206 /* An unspecified parmlist matches any specified parmlist
1207 whose argument types don't need default promotions. */
1209 for (t1 = parms1, t2 = parms2;
1211 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1213 /* If one parmlist is shorter than the other,
1214 they fail to match. */
1217 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1224 /* Process a sizeof or alignof expression where the operand is a
1228 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1230 enum tree_code type_code;
1232 const char *op_name;
1234 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1235 if (type == error_mark_node)
1236 return error_mark_node;
1238 if (dependent_type_p (type))
1240 value = build_min (op, size_type_node, type);
1241 TREE_READONLY (value) = 1;
1245 op_name = operator_name_info[(int) op].name;
1247 type = non_reference (type);
1248 type_code = TREE_CODE (type);
1250 if (type_code == METHOD_TYPE)
1252 if (complain && (pedantic || warn_pointer_arith))
1253 pedwarn ("invalid application of %qs to a member function", op_name);
1254 value = size_one_node;
1257 value = c_sizeof_or_alignof_type (complete_type (type),
1264 /* Process a sizeof or alignof expression where the operand is an
1268 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1270 const char *op_name = operator_name_info[(int) op].name;
1272 if (e == error_mark_node)
1273 return error_mark_node;
1275 if (processing_template_decl)
1277 e = build_min (op, size_type_node, e);
1278 TREE_SIDE_EFFECTS (e) = 0;
1279 TREE_READONLY (e) = 1;
1284 if (TREE_CODE (e) == COMPONENT_REF
1285 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1286 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1288 error ("invalid application of %qs to a bit-field", op_name);
1291 else if (is_overloaded_fn (e))
1293 pedwarn ("ISO C++ forbids applying %qs to an expression of "
1294 "function type", op_name);
1297 else if (type_unknown_p (e))
1299 cxx_incomplete_type_error (e, TREE_TYPE (e));
1305 return cxx_sizeof_or_alignof_type (e, op, true);
1309 /* EXPR is being used in a context that is not a function call.
1314 The expression can be used only as the left-hand operand of a
1315 member function call.
1317 [expr.mptr.operator]
1319 If the result of .* or ->* is a function, then that result can be
1320 used only as the operand for the function call operator ().
1322 by issuing an error message if appropriate. Returns true iff EXPR
1323 violates these rules. */
1326 invalid_nonstatic_memfn_p (tree expr)
1328 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1330 error ("invalid use of non-static member function");
1336 /* Perform the conversions in [expr] that apply when an lvalue appears
1337 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1338 function-to-pointer conversions.
1340 In addition manifest constants are replaced by their values. */
1343 decay_conversion (tree exp)
1346 enum tree_code code;
1348 type = TREE_TYPE (exp);
1349 code = TREE_CODE (type);
1351 if (type == error_mark_node)
1352 return error_mark_node;
1354 if (type_unknown_p (exp))
1356 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1357 return error_mark_node;
1360 exp = integral_constant_value (exp);
1362 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1363 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1365 if (code == VOID_TYPE)
1367 error ("void value not ignored as it ought to be");
1368 return error_mark_node;
1370 if (invalid_nonstatic_memfn_p (exp))
1371 return error_mark_node;
1372 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1373 return build_unary_op (ADDR_EXPR, exp, 0);
1374 if (code == ARRAY_TYPE)
1379 if (TREE_CODE (exp) == INDIRECT_REF)
1380 return build_nop (build_pointer_type (TREE_TYPE (type)),
1381 TREE_OPERAND (exp, 0));
1383 if (TREE_CODE (exp) == COMPOUND_EXPR)
1385 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1386 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1387 TREE_OPERAND (exp, 0), op1);
1391 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1393 error ("invalid use of non-lvalue array");
1394 return error_mark_node;
1397 ptrtype = build_pointer_type (TREE_TYPE (type));
1399 if (TREE_CODE (exp) == VAR_DECL)
1401 if (!cxx_mark_addressable (exp))
1402 return error_mark_node;
1403 adr = build_nop (ptrtype, build_address (exp));
1406 /* This way is better for a COMPONENT_REF since it can
1407 simplify the offset for a component. */
1408 adr = build_unary_op (ADDR_EXPR, exp, 1);
1409 return cp_convert (ptrtype, adr);
1412 /* [basic.lval]: Class rvalues can have cv-qualified types; non-class
1413 rvalues always have cv-unqualified types. */
1414 if (! CLASS_TYPE_P (type))
1415 exp = cp_convert (TYPE_MAIN_VARIANT (type), exp);
1421 default_conversion (tree exp)
1423 exp = decay_conversion (exp);
1425 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1426 exp = perform_integral_promotions (exp);
1431 /* EXPR is an expression with an integral or enumeration type.
1432 Perform the integral promotions in [conv.prom], and return the
1436 perform_integral_promotions (tree expr)
1441 type = TREE_TYPE (expr);
1442 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1443 promoted_type = type_promotes_to (type);
1444 if (type != promoted_type)
1445 expr = cp_convert (promoted_type, expr);
1449 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1453 inline_conversion (tree exp)
1455 if (TREE_CODE (exp) == FUNCTION_DECL)
1456 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1461 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1462 decay_conversion to one. */
1465 string_conv_p (tree totype, tree exp, int warn)
1469 if (! flag_const_strings || TREE_CODE (totype) != POINTER_TYPE)
1472 t = TREE_TYPE (totype);
1473 if (!same_type_p (t, char_type_node)
1474 && !same_type_p (t, wchar_type_node))
1477 if (TREE_CODE (exp) == STRING_CST)
1479 /* Make sure that we don't try to convert between char and wchar_t. */
1480 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1485 /* Is this a string constant which has decayed to 'const char *'? */
1486 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1487 if (!same_type_p (TREE_TYPE (exp), t))
1490 if (TREE_CODE (exp) != ADDR_EXPR
1491 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1495 /* This warning is not very useful, as it complains about printf. */
1496 if (warn && warn_write_strings)
1497 warning (0, "deprecated conversion from string constant to %qT'", totype);
1502 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1503 can, for example, use as an lvalue. This code used to be in
1504 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1505 expressions, where we're dealing with aggregates. But now it's again only
1506 called from unary_complex_lvalue. The case (in particular) that led to
1507 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1511 rationalize_conditional_expr (enum tree_code code, tree t)
1513 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1514 the first operand is always the one to be used if both operands
1515 are equal, so we know what conditional expression this used to be. */
1516 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1518 /* The following code is incorrect if either operand side-effects. */
1519 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
1520 && !TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)));
1522 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1523 ? LE_EXPR : GE_EXPR),
1524 TREE_OPERAND (t, 0),
1525 TREE_OPERAND (t, 1),
1526 /*overloaded_p=*/NULL),
1527 build_unary_op (code, TREE_OPERAND (t, 0), 0),
1528 build_unary_op (code, TREE_OPERAND (t, 1), 0));
1532 build_conditional_expr (TREE_OPERAND (t, 0),
1533 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1534 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1537 /* Given the TYPE of an anonymous union field inside T, return the
1538 FIELD_DECL for the field. If not found return NULL_TREE. Because
1539 anonymous unions can nest, we must also search all anonymous unions
1540 that are directly reachable. */
1543 lookup_anon_field (tree t, tree type)
1547 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1549 if (TREE_STATIC (field))
1551 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1554 /* If we find it directly, return the field. */
1555 if (DECL_NAME (field) == NULL_TREE
1556 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1561 /* Otherwise, it could be nested, search harder. */
1562 if (DECL_NAME (field) == NULL_TREE
1563 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1565 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1573 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1574 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1575 non-NULL, it indicates the path to the base used to name MEMBER.
1576 If PRESERVE_REFERENCE is true, the expression returned will have
1577 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1578 returned will have the type referred to by the reference.
1580 This function does not perform access control; that is either done
1581 earlier by the parser when the name of MEMBER is resolved to MEMBER
1582 itself, or later when overload resolution selects one of the
1583 functions indicated by MEMBER. */
1586 build_class_member_access_expr (tree object, tree member,
1587 tree access_path, bool preserve_reference)
1591 tree result = NULL_TREE;
1593 if (object == error_mark_node || member == error_mark_node)
1594 return error_mark_node;
1596 gcc_assert (DECL_P (member) || BASELINK_P (member));
1600 The type of the first expression shall be "class object" (of a
1602 object_type = TREE_TYPE (object);
1603 if (!currently_open_class (object_type)
1604 && !complete_type_or_else (object_type, object))
1605 return error_mark_node;
1606 if (!CLASS_TYPE_P (object_type))
1608 error ("request for member %qD in %qE, which is of non-class type %qT",
1609 member, object, object_type);
1610 return error_mark_node;
1613 /* The standard does not seem to actually say that MEMBER must be a
1614 member of OBJECT_TYPE. However, that is clearly what is
1616 if (DECL_P (member))
1618 member_scope = DECL_CLASS_CONTEXT (member);
1620 if (TREE_DEPRECATED (member))
1621 warn_deprecated_use (member);
1624 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1625 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1626 presently be the anonymous union. Go outwards until we find a
1627 type related to OBJECT_TYPE. */
1628 while (ANON_AGGR_TYPE_P (member_scope)
1629 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1631 member_scope = TYPE_CONTEXT (member_scope);
1632 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1634 if (TREE_CODE (member) == FIELD_DECL)
1635 error ("invalid use of nonstatic data member %qE", member);
1637 error ("%qD is not a member of %qT", member, object_type);
1638 return error_mark_node;
1641 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1642 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1643 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1645 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1647 object = build_indirect_ref (temp, NULL);
1650 /* In [expr.ref], there is an explicit list of the valid choices for
1651 MEMBER. We check for each of those cases here. */
1652 if (TREE_CODE (member) == VAR_DECL)
1654 /* A static data member. */
1656 /* If OBJECT has side-effects, they are supposed to occur. */
1657 if (TREE_SIDE_EFFECTS (object))
1658 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1660 else if (TREE_CODE (member) == FIELD_DECL)
1662 /* A non-static data member. */
1667 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1668 && integer_zerop (TREE_OPERAND (object, 0)));
1670 /* Convert OBJECT to the type of MEMBER. */
1671 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1672 TYPE_MAIN_VARIANT (member_scope)))
1677 binfo = lookup_base (access_path ? access_path : object_type,
1678 member_scope, ba_unique, &kind);
1679 if (binfo == error_mark_node)
1680 return error_mark_node;
1682 /* It is invalid to try to get to a virtual base of a
1683 NULL object. The most common cause is invalid use of
1685 if (null_object_p && kind == bk_via_virtual)
1687 error ("invalid access to non-static data member %qD of "
1690 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1691 return error_mark_node;
1694 /* Convert to the base. */
1695 object = build_base_path (PLUS_EXPR, object, binfo,
1697 /* If we found the base successfully then we should be able
1698 to convert to it successfully. */
1699 gcc_assert (object != error_mark_node);
1702 /* Complain about other invalid uses of offsetof, even though they will
1703 give the right answer. Note that we complain whether or not they
1704 actually used the offsetof macro, since there's no way to know at this
1705 point. So we just give a warning, instead of a pedwarn. */
1706 /* Do not produce this warning for base class field references, because
1707 we know for a fact that didn't come from offsetof. This does occur
1708 in various testsuite cases where a null object is passed where a
1709 vtable access is required. */
1710 if (null_object_p && warn_invalid_offsetof
1711 && CLASSTYPE_NON_POD_P (object_type)
1712 && !DECL_FIELD_IS_BASE (member)
1713 && !skip_evaluation)
1715 warning (0, "invalid access to non-static data member %qD of NULL object",
1717 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1720 /* If MEMBER is from an anonymous aggregate, we have converted
1721 OBJECT so that it refers to the class containing the
1722 anonymous union. Generate a reference to the anonymous union
1723 itself, and recur to find MEMBER. */
1724 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1725 /* When this code is called from build_field_call, the
1726 object already has the type of the anonymous union.
1727 That is because the COMPONENT_REF was already
1728 constructed, and was then disassembled before calling
1729 build_field_call. After the function-call code is
1730 cleaned up, this waste can be eliminated. */
1731 && (!same_type_ignoring_top_level_qualifiers_p
1732 (TREE_TYPE (object), DECL_CONTEXT (member))))
1734 tree anonymous_union;
1736 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1737 DECL_CONTEXT (member));
1738 object = build_class_member_access_expr (object,
1740 /*access_path=*/NULL_TREE,
1741 preserve_reference);
1744 /* Compute the type of the field, as described in [expr.ref]. */
1745 type_quals = TYPE_UNQUALIFIED;
1746 member_type = TREE_TYPE (member);
1747 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1749 type_quals = (cp_type_quals (member_type)
1750 | cp_type_quals (object_type));
1752 /* A field is const (volatile) if the enclosing object, or the
1753 field itself, is const (volatile). But, a mutable field is
1754 not const, even within a const object. */
1755 if (DECL_MUTABLE_P (member))
1756 type_quals &= ~TYPE_QUAL_CONST;
1757 member_type = cp_build_qualified_type (member_type, type_quals);
1760 result = build3 (COMPONENT_REF, member_type, object, member,
1762 result = fold_if_not_in_template (result);
1764 /* Mark the expression const or volatile, as appropriate. Even
1765 though we've dealt with the type above, we still have to mark the
1766 expression itself. */
1767 if (type_quals & TYPE_QUAL_CONST)
1768 TREE_READONLY (result) = 1;
1769 if (type_quals & TYPE_QUAL_VOLATILE)
1770 TREE_THIS_VOLATILE (result) = 1;
1772 else if (BASELINK_P (member))
1774 /* The member is a (possibly overloaded) member function. */
1778 /* If the MEMBER is exactly one static member function, then we
1779 know the type of the expression. Otherwise, we must wait
1780 until overload resolution has been performed. */
1781 functions = BASELINK_FUNCTIONS (member);
1782 if (TREE_CODE (functions) == FUNCTION_DECL
1783 && DECL_STATIC_FUNCTION_P (functions))
1784 type = TREE_TYPE (functions);
1786 type = unknown_type_node;
1787 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1788 base. That will happen when the function is called. */
1789 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1791 else if (TREE_CODE (member) == CONST_DECL)
1793 /* The member is an enumerator. */
1795 /* If OBJECT has side-effects, they are supposed to occur. */
1796 if (TREE_SIDE_EFFECTS (object))
1797 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1802 error ("invalid use of %qD", member);
1803 return error_mark_node;
1806 if (!preserve_reference)
1809 If E2 is declared to have type "reference to T", then ... the
1810 type of E1.E2 is T. */
1811 result = convert_from_reference (result);
1816 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1817 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1820 lookup_destructor (tree object, tree scope, tree dtor_name)
1822 tree object_type = TREE_TYPE (object);
1823 tree dtor_type = TREE_OPERAND (dtor_name, 0);
1826 if (scope && !check_dtor_name (scope, dtor_name))
1828 error ("qualified type %qT does not match destructor name ~%qT",
1830 return error_mark_node;
1832 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
1834 error ("the type being destroyed is %qT, but the destructor refers to %qT",
1835 TYPE_MAIN_VARIANT (object_type), dtor_type);
1836 return error_mark_node;
1838 expr = lookup_member (dtor_type, complete_dtor_identifier,
1839 /*protect=*/1, /*want_type=*/false);
1840 expr = (adjust_result_of_qualified_name_lookup
1841 (expr, dtor_type, object_type));
1845 /* This function is called by the parser to process a class member
1846 access expression of the form OBJECT.NAME. NAME is a node used by
1847 the parser to represent a name; it is not yet a DECL. It may,
1848 however, be a BASELINK where the BASELINK_FUNCTIONS is a
1849 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
1850 there is no reason to do the lookup twice, so the parser keeps the
1854 finish_class_member_access_expr (tree object, tree name)
1859 tree access_path = NULL_TREE;
1860 tree orig_object = object;
1861 tree orig_name = name;
1863 if (object == error_mark_node || name == error_mark_node)
1864 return error_mark_node;
1866 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
1867 if (!objc_is_public (object, name))
1868 return error_mark_node;
1870 object_type = TREE_TYPE (object);
1872 if (processing_template_decl)
1874 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
1875 dependent_type_p (object_type)
1876 /* If NAME is just an IDENTIFIER_NODE, then the expression
1878 || TREE_CODE (object) == IDENTIFIER_NODE
1879 /* If NAME is "f<args>", where either 'f' or 'args' is
1880 dependent, then the expression is dependent. */
1881 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
1882 && dependent_template_id_p (TREE_OPERAND (name, 0),
1883 TREE_OPERAND (name, 1)))
1884 /* If NAME is "T::X" where "T" is dependent, then the
1885 expression is dependent. */
1886 || (TREE_CODE (name) == SCOPE_REF
1887 && TYPE_P (TREE_OPERAND (name, 0))
1888 && dependent_type_p (TREE_OPERAND (name, 0))))
1889 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
1890 object = build_non_dependent_expr (object);
1895 The type of the first expression shall be "class object" (of a
1897 if (!currently_open_class (object_type)
1898 && !complete_type_or_else (object_type, object))
1899 return error_mark_node;
1900 if (!CLASS_TYPE_P (object_type))
1902 error ("request for member %qD in %qE, which is of non-class type %qT",
1903 name, object, object_type);
1904 return error_mark_node;
1907 if (BASELINK_P (name))
1909 /* A member function that has already been looked up. */
1910 gcc_assert (TREE_CODE (BASELINK_FUNCTIONS (name)) == TEMPLATE_ID_EXPR);
1915 bool is_template_id = false;
1916 tree template_args = NULL_TREE;
1919 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
1921 is_template_id = true;
1922 template_args = TREE_OPERAND (name, 1);
1923 name = TREE_OPERAND (name, 0);
1925 if (TREE_CODE (name) == OVERLOAD)
1926 name = DECL_NAME (get_first_fn (name));
1927 else if (DECL_P (name))
1928 name = DECL_NAME (name);
1931 if (TREE_CODE (name) == SCOPE_REF)
1933 /* A qualified name. The qualifying class or namespace `S' has
1934 already been looked up; it is either a TYPE or a
1935 NAMESPACE_DECL. The member name is either an IDENTIFIER_NODE
1936 or a BIT_NOT_EXPR. */
1937 scope = TREE_OPERAND (name, 0);
1938 name = TREE_OPERAND (name, 1);
1939 gcc_assert (CLASS_TYPE_P (scope)
1940 || TREE_CODE (scope) == NAMESPACE_DECL);
1941 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
1942 || TREE_CODE (name) == BIT_NOT_EXPR);
1944 /* If SCOPE is a namespace, then the qualified name does not
1945 name a member of OBJECT_TYPE. */
1946 if (TREE_CODE (scope) == NAMESPACE_DECL)
1948 error ("%<%D::%D%> is not a member of %qT",
1949 scope, name, object_type);
1950 return error_mark_node;
1953 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
1954 access_path = lookup_base (object_type, scope, ba_check, NULL);
1955 if (access_path == error_mark_node)
1956 return error_mark_node;
1959 error ("%qT is not a base of %qT", scope, object_type);
1960 return error_mark_node;
1966 access_path = object_type;
1969 if (TREE_CODE (name) == BIT_NOT_EXPR)
1970 member = lookup_destructor (object, scope, name);
1973 /* Look up the member. */
1974 member = lookup_member (access_path, name, /*protect=*/1,
1975 /*want_type=*/false);
1976 if (member == NULL_TREE)
1978 error ("%qD has no member named %qE", object_type, name);
1979 return error_mark_node;
1981 if (member == error_mark_node)
1982 return error_mark_node;
1987 tree template = member;
1989 if (BASELINK_P (template))
1990 template = lookup_template_function (template, template_args);
1993 error ("%qD is not a member template function", name);
1994 return error_mark_node;
1999 if (TREE_DEPRECATED (member))
2000 warn_deprecated_use (member);
2002 expr = build_class_member_access_expr (object, member, access_path,
2003 /*preserve_reference=*/false);
2004 if (processing_template_decl && expr != error_mark_node)
2005 return build_min_non_dep (COMPONENT_REF, expr,
2006 orig_object, orig_name, NULL_TREE);
2010 /* Return an expression for the MEMBER_NAME field in the internal
2011 representation of PTRMEM, a pointer-to-member function. (Each
2012 pointer-to-member function type gets its own RECORD_TYPE so it is
2013 more convenient to access the fields by name than by FIELD_DECL.)
2014 This routine converts the NAME to a FIELD_DECL and then creates the
2015 node for the complete expression. */
2018 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2024 /* This code is a stripped down version of
2025 build_class_member_access_expr. It does not work to use that
2026 routine directly because it expects the object to be of class
2028 ptrmem_type = TREE_TYPE (ptrmem);
2029 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2030 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2031 /*want_type=*/false);
2032 member_type = cp_build_qualified_type (TREE_TYPE (member),
2033 cp_type_quals (ptrmem_type));
2034 return fold_build3 (COMPONENT_REF, member_type,
2035 ptrmem, member, NULL_TREE);
2038 /* Given an expression PTR for a pointer, return an expression
2039 for the value pointed to.
2040 ERRORSTRING is the name of the operator to appear in error messages.
2042 This function may need to overload OPERATOR_FNNAME.
2043 Must also handle REFERENCE_TYPEs for C++. */
2046 build_x_indirect_ref (tree expr, const char *errorstring)
2048 tree orig_expr = expr;
2051 if (processing_template_decl)
2053 if (type_dependent_expression_p (expr))
2054 return build_min_nt (INDIRECT_REF, expr);
2055 expr = build_non_dependent_expr (expr);
2058 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2059 NULL_TREE, /*overloaded_p=*/NULL);
2061 rval = build_indirect_ref (expr, errorstring);
2063 if (processing_template_decl && rval != error_mark_node)
2064 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2070 build_indirect_ref (tree ptr, const char *errorstring)
2074 if (ptr == error_mark_node)
2075 return error_mark_node;
2077 if (ptr == current_class_ptr)
2078 return current_class_ref;
2080 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2081 ? ptr : decay_conversion (ptr));
2082 type = TREE_TYPE (pointer);
2084 if (POINTER_TYPE_P (type))
2088 If the type of the expression is "pointer to T," the type
2089 of the result is "T."
2091 We must use the canonical variant because certain parts of
2092 the back end, like fold, do pointer comparisons between
2094 tree t = canonical_type_variant (TREE_TYPE (type));
2096 if (VOID_TYPE_P (t))
2098 /* A pointer to incomplete type (other than cv void) can be
2099 dereferenced [expr.unary.op]/1 */
2100 error ("%qT is not a pointer-to-object type", type);
2101 return error_mark_node;
2103 else if (TREE_CODE (pointer) == ADDR_EXPR
2104 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2105 /* The POINTER was something like `&x'. We simplify `*&x' to
2107 return TREE_OPERAND (pointer, 0);
2110 tree ref = build1 (INDIRECT_REF, t, pointer);
2112 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2113 so that we get the proper error message if the result is used
2114 to assign to. Also, &* is supposed to be a no-op. */
2115 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2116 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2117 TREE_SIDE_EFFECTS (ref)
2118 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2122 /* `pointer' won't be an error_mark_node if we were given a
2123 pointer to member, so it's cool to check for this here. */
2124 else if (TYPE_PTR_TO_MEMBER_P (type))
2125 error ("invalid use of %qs on pointer to member", errorstring);
2126 else if (pointer != error_mark_node)
2129 error ("invalid type argument of %qs", errorstring);
2131 error ("invalid type argument");
2133 return error_mark_node;
2136 /* This handles expressions of the form "a[i]", which denotes
2139 This is logically equivalent in C to *(a+i), but we may do it differently.
2140 If A is a variable or a member, we generate a primitive ARRAY_REF.
2141 This avoids forcing the array out of registers, and can work on
2142 arrays that are not lvalues (for example, members of structures returned
2145 If INDEX is of some user-defined type, it must be converted to
2146 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2147 will inherit the type of the array, which will be some pointer type. */
2150 build_array_ref (tree array, tree idx)
2154 error ("subscript missing in array reference");
2155 return error_mark_node;
2158 if (TREE_TYPE (array) == error_mark_node
2159 || TREE_TYPE (idx) == error_mark_node)
2160 return error_mark_node;
2162 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2164 switch (TREE_CODE (array))
2168 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2169 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2170 TREE_OPERAND (array, 0), value);
2174 return build_conditional_expr
2175 (TREE_OPERAND (array, 0),
2176 build_array_ref (TREE_OPERAND (array, 1), idx),
2177 build_array_ref (TREE_OPERAND (array, 2), idx));
2183 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2187 /* Subscripting with type char is likely to lose
2188 on a machine where chars are signed.
2189 So warn on any machine, but optionally.
2190 Don't warn for unsigned char since that type is safe.
2191 Don't warn for signed char because anyone who uses that
2192 must have done so deliberately. */
2193 if (warn_char_subscripts
2194 && TYPE_MAIN_VARIANT (TREE_TYPE (idx)) == char_type_node)
2195 warning (0, "array subscript has type %<char%>");
2197 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2199 error ("array subscript is not an integer");
2200 return error_mark_node;
2203 /* Apply integral promotions *after* noticing character types.
2204 (It is unclear why we do these promotions -- the standard
2205 does not say that we should. In fact, the natural thing would
2206 seem to be to convert IDX to ptrdiff_t; we're performing
2207 pointer arithmetic.) */
2208 idx = perform_integral_promotions (idx);
2210 /* An array that is indexed by a non-constant
2211 cannot be stored in a register; we must be able to do
2212 address arithmetic on its address.
2213 Likewise an array of elements of variable size. */
2214 if (TREE_CODE (idx) != INTEGER_CST
2215 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2216 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2219 if (!cxx_mark_addressable (array))
2220 return error_mark_node;
2223 /* An array that is indexed by a constant value which is not within
2224 the array bounds cannot be stored in a register either; because we
2225 would get a crash in store_bit_field/extract_bit_field when trying
2226 to access a non-existent part of the register. */
2227 if (TREE_CODE (idx) == INTEGER_CST
2228 && TYPE_DOMAIN (TREE_TYPE (array))
2229 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2231 if (!cxx_mark_addressable (array))
2232 return error_mark_node;
2235 if (pedantic && !lvalue_p (array))
2236 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2238 /* Note in C++ it is valid to subscript a `register' array, since
2239 it is valid to take the address of something with that
2240 storage specification. */
2244 while (TREE_CODE (foo) == COMPONENT_REF)
2245 foo = TREE_OPERAND (foo, 0);
2246 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2247 warning (0, "subscripting array declared %<register%>");
2250 type = TREE_TYPE (TREE_TYPE (array));
2251 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2252 /* Array ref is const/volatile if the array elements are
2253 or if the array is.. */
2254 TREE_READONLY (rval)
2255 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2256 TREE_SIDE_EFFECTS (rval)
2257 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2258 TREE_THIS_VOLATILE (rval)
2259 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2260 return require_complete_type (fold_if_not_in_template (rval));
2264 tree ar = default_conversion (array);
2265 tree ind = default_conversion (idx);
2267 /* Put the integer in IND to simplify error checking. */
2268 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2275 if (ar == error_mark_node)
2278 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2280 error ("subscripted value is neither array nor pointer");
2281 return error_mark_node;
2283 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2285 error ("array subscript is not an integer");
2286 return error_mark_node;
2289 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2294 /* Resolve a pointer to member function. INSTANCE is the object
2295 instance to use, if the member points to a virtual member.
2297 This used to avoid checking for virtual functions if basetype
2298 has no virtual functions, according to an earlier ANSI draft.
2299 With the final ISO C++ rules, such an optimization is
2300 incorrect: A pointer to a derived member can be static_cast
2301 to pointer-to-base-member, as long as the dynamic object
2302 later has the right member. */
2305 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2307 if (TREE_CODE (function) == OFFSET_REF)
2308 function = TREE_OPERAND (function, 1);
2310 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2312 tree idx, delta, e1, e2, e3, vtbl, basetype;
2313 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2315 tree instance_ptr = *instance_ptrptr;
2316 tree instance_save_expr = 0;
2317 if (instance_ptr == error_mark_node)
2319 if (TREE_CODE (function) == PTRMEM_CST)
2321 /* Extracting the function address from a pmf is only
2322 allowed with -Wno-pmf-conversions. It only works for
2324 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2325 e1 = convert (fntype, e1);
2330 error ("object missing in use of %qE", function);
2331 return error_mark_node;
2335 if (TREE_SIDE_EFFECTS (instance_ptr))
2336 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2338 if (TREE_SIDE_EFFECTS (function))
2339 function = save_expr (function);
2341 /* Start by extracting all the information from the PMF itself. */
2342 e3 = pfn_from_ptrmemfunc (function);
2343 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2344 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2345 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2347 case ptrmemfunc_vbit_in_pfn:
2348 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2349 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2352 case ptrmemfunc_vbit_in_delta:
2353 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2354 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2361 /* Convert down to the right base before using the instance. A
2362 special case is that in a pointer to member of class C, C may
2363 be incomplete. In that case, the function will of course be
2364 a member of C, and no conversion is required. In fact,
2365 lookup_base will fail in that case, because incomplete
2366 classes do not have BINFOs. */
2367 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2368 if (!same_type_ignoring_top_level_qualifiers_p
2369 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2371 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2372 basetype, ba_check, NULL);
2373 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2375 if (instance_ptr == error_mark_node)
2376 return error_mark_node;
2378 /* ...and then the delta in the PMF. */
2379 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2380 instance_ptr, delta);
2382 /* Hand back the adjusted 'this' argument to our caller. */
2383 *instance_ptrptr = instance_ptr;
2385 /* Next extract the vtable pointer from the object. */
2386 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2388 vtbl = build_indirect_ref (vtbl, NULL);
2390 /* Finally, extract the function pointer from the vtable. */
2391 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2392 e2 = build_indirect_ref (e2, NULL);
2393 TREE_CONSTANT (e2) = 1;
2394 TREE_INVARIANT (e2) = 1;
2396 /* When using function descriptors, the address of the
2397 vtable entry is treated as a function pointer. */
2398 if (TARGET_VTABLE_USES_DESCRIPTORS)
2399 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2400 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2402 TREE_TYPE (e2) = TREE_TYPE (e3);
2403 e1 = build_conditional_expr (e1, e2, e3);
2405 /* Make sure this doesn't get evaluated first inside one of the
2406 branches of the COND_EXPR. */
2407 if (instance_save_expr)
2408 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2409 instance_save_expr, e1);
2417 build_function_call (tree function, tree params)
2419 tree fntype, fndecl;
2420 tree coerced_params;
2421 tree name = NULL_TREE;
2423 tree original = function;
2425 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2426 expressions, like those used for ObjC messenger dispatches. */
2427 function = objc_rewrite_function_call (function, params);
2429 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2430 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2431 if (TREE_CODE (function) == NOP_EXPR
2432 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2433 function = TREE_OPERAND (function, 0);
2435 if (TREE_CODE (function) == FUNCTION_DECL)
2437 name = DECL_NAME (function);
2439 mark_used (function);
2442 /* Convert anything with function type to a pointer-to-function. */
2443 if (pedantic && DECL_MAIN_P (function))
2444 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2446 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2447 (because calling an inline function does not mean the function
2448 needs to be separately compiled). */
2450 if (DECL_INLINE (function))
2451 function = inline_conversion (function);
2453 function = build_addr_func (function);
2459 function = build_addr_func (function);
2462 if (function == error_mark_node)
2463 return error_mark_node;
2465 fntype = TREE_TYPE (function);
2467 if (TYPE_PTRMEMFUNC_P (fntype))
2469 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2470 "function in %<%E (...)%>",
2472 return error_mark_node;
2475 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2476 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2478 if (!((TREE_CODE (fntype) == POINTER_TYPE
2479 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2481 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2483 error ("%qE cannot be used as a function", original);
2484 return error_mark_node;
2487 /* fntype now gets the type of function pointed to. */
2488 fntype = TREE_TYPE (fntype);
2490 /* Convert the parameters to the types declared in the
2491 function prototype, or apply default promotions. */
2493 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2494 params, fndecl, LOOKUP_NORMAL);
2495 if (coerced_params == error_mark_node)
2496 return error_mark_node;
2498 /* Check for errors in format strings and inappropriately
2501 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params);
2503 return build_cxx_call (function, coerced_params);
2506 /* Convert the actual parameter expressions in the list VALUES
2507 to the types in the list TYPELIST.
2508 If parmdecls is exhausted, or when an element has NULL as its type,
2509 perform the default conversions.
2511 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2513 This is also where warnings about wrong number of args are generated.
2515 Return a list of expressions for the parameters as converted.
2517 Both VALUES and the returned value are chains of TREE_LIST nodes
2518 with the elements of the list in the TREE_VALUE slots of those nodes.
2520 In C++, unspecified trailing parameters can be filled in with their
2521 default arguments, if such were specified. Do so here. */
2524 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2526 tree typetail, valtail;
2527 tree result = NULL_TREE;
2528 const char *called_thing = 0;
2531 /* Argument passing is always copy-initialization. */
2532 flags |= LOOKUP_ONLYCONVERTING;
2536 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2538 if (DECL_NAME (fndecl) == NULL_TREE
2539 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2540 called_thing = "constructor";
2542 called_thing = "member function";
2545 called_thing = "function";
2548 for (valtail = values, typetail = typelist;
2550 valtail = TREE_CHAIN (valtail), i++)
2552 tree type = typetail ? TREE_VALUE (typetail) : 0;
2553 tree val = TREE_VALUE (valtail);
2555 if (val == error_mark_node)
2556 return error_mark_node;
2558 if (type == void_type_node)
2562 cp_error_at ("too many arguments to %s %q+#D", called_thing,
2564 error ("at this point in file");
2567 error ("too many arguments to function");
2568 /* In case anybody wants to know if this argument
2571 TREE_TYPE (tree_last (result)) = error_mark_node;
2575 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2576 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2577 if (TREE_CODE (val) == NOP_EXPR
2578 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2579 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2580 val = TREE_OPERAND (val, 0);
2582 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2584 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2585 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2586 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2587 val = decay_conversion (val);
2590 if (val == error_mark_node)
2591 return error_mark_node;
2595 /* Formal parm type is specified by a function prototype. */
2598 if (!COMPLETE_TYPE_P (complete_type (type)))
2601 error ("parameter %P of %qD has incomplete type %qT",
2604 error ("parameter %P has incomplete type %qT", i, type);
2605 parmval = error_mark_node;
2609 parmval = convert_for_initialization
2610 (NULL_TREE, type, val, flags,
2611 "argument passing", fndecl, i);
2612 parmval = convert_for_arg_passing (type, parmval);
2615 if (parmval == error_mark_node)
2616 return error_mark_node;
2618 result = tree_cons (NULL_TREE, parmval, result);
2622 if (fndecl && DECL_BUILT_IN (fndecl)
2623 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2624 /* Don't do ellipsis conversion for __built_in_constant_p
2625 as this will result in spurious warnings for non-POD
2627 val = require_complete_type (val);
2629 val = convert_arg_to_ellipsis (val);
2631 result = tree_cons (NULL_TREE, val, result);
2635 typetail = TREE_CHAIN (typetail);
2638 if (typetail != 0 && typetail != void_list_node)
2640 /* See if there are default arguments that can be used. */
2641 if (TREE_PURPOSE (typetail)
2642 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2644 for (; typetail != void_list_node; ++i)
2647 = convert_default_arg (TREE_VALUE (typetail),
2648 TREE_PURPOSE (typetail),
2651 if (parmval == error_mark_node)
2652 return error_mark_node;
2654 result = tree_cons (0, parmval, result);
2655 typetail = TREE_CHAIN (typetail);
2656 /* ends with `...'. */
2657 if (typetail == NULL_TREE)
2665 cp_error_at ("too few arguments to %s %q+#D",
2666 called_thing, fndecl);
2667 error ("at this point in file");
2670 error ("too few arguments to function");
2671 return error_mark_list;
2675 return nreverse (result);
2678 /* Build a binary-operation expression, after performing default
2679 conversions on the operands. CODE is the kind of expression to build. */
2682 build_x_binary_op (enum tree_code code, tree arg1, tree arg2,
2692 if (processing_template_decl)
2694 if (type_dependent_expression_p (arg1)
2695 || type_dependent_expression_p (arg2))
2696 return build_min_nt (code, arg1, arg2);
2697 arg1 = build_non_dependent_expr (arg1);
2698 arg2 = build_non_dependent_expr (arg2);
2701 if (code == DOTSTAR_EXPR)
2702 expr = build_m_component_ref (arg1, arg2);
2704 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2707 if (processing_template_decl && expr != error_mark_node)
2708 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2713 /* Build a binary-operation expression without default conversions.
2714 CODE is the kind of expression to build.
2715 This function differs from `build' in several ways:
2716 the data type of the result is computed and recorded in it,
2717 warnings are generated if arg data types are invalid,
2718 special handling for addition and subtraction of pointers is known,
2719 and some optimization is done (operations on narrow ints
2720 are done in the narrower type when that gives the same result).
2721 Constant folding is also done before the result is returned.
2723 Note that the operands will never have enumeral types
2724 because either they have just had the default conversions performed
2725 or they have both just been converted to some other type in which
2726 the arithmetic is to be done.
2728 C++: must do special pointer arithmetic when implementing
2729 multiple inheritance, and deal with pointer to member functions. */
2732 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2733 int convert_p ATTRIBUTE_UNUSED)
2736 enum tree_code code0, code1;
2739 /* Expression code to give to the expression when it is built.
2740 Normally this is CODE, which is what the caller asked for,
2741 but in some special cases we change it. */
2742 enum tree_code resultcode = code;
2744 /* Data type in which the computation is to be performed.
2745 In the simplest cases this is the common type of the arguments. */
2746 tree result_type = NULL;
2748 /* Nonzero means operands have already been type-converted
2749 in whatever way is necessary.
2750 Zero means they need to be converted to RESULT_TYPE. */
2753 /* Nonzero means create the expression with this type, rather than
2755 tree build_type = 0;
2757 /* Nonzero means after finally constructing the expression
2758 convert it to this type. */
2759 tree final_type = 0;
2763 /* Nonzero if this is an operation like MIN or MAX which can
2764 safely be computed in short if both args are promoted shorts.
2765 Also implies COMMON.
2766 -1 indicates a bitwise operation; this makes a difference
2767 in the exact conditions for when it is safe to do the operation
2768 in a narrower mode. */
2771 /* Nonzero if this is a comparison operation;
2772 if both args are promoted shorts, compare the original shorts.
2773 Also implies COMMON. */
2774 int short_compare = 0;
2776 /* Nonzero if this is a right-shift operation, which can be computed on the
2777 original short and then promoted if the operand is a promoted short. */
2778 int short_shift = 0;
2780 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2783 /* True if both operands have arithmetic type. */
2784 bool arithmetic_types_p;
2786 /* Apply default conversions. */
2790 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2791 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2792 || code == TRUTH_XOR_EXPR)
2794 if (!really_overloaded_fn (op0))
2795 op0 = decay_conversion (op0);
2796 if (!really_overloaded_fn (op1))
2797 op1 = decay_conversion (op1);
2801 if (!really_overloaded_fn (op0))
2802 op0 = default_conversion (op0);
2803 if (!really_overloaded_fn (op1))
2804 op1 = default_conversion (op1);
2807 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2808 STRIP_TYPE_NOPS (op0);
2809 STRIP_TYPE_NOPS (op1);
2811 /* DTRT if one side is an overloaded function, but complain about it. */
2812 if (type_unknown_p (op0))
2814 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
2815 if (t != error_mark_node)
2817 pedwarn ("assuming cast to type %qT from overloaded function",
2822 if (type_unknown_p (op1))
2824 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
2825 if (t != error_mark_node)
2827 pedwarn ("assuming cast to type %qT from overloaded function",
2833 type0 = TREE_TYPE (op0);
2834 type1 = TREE_TYPE (op1);
2836 /* The expression codes of the data types of the arguments tell us
2837 whether the arguments are integers, floating, pointers, etc. */
2838 code0 = TREE_CODE (type0);
2839 code1 = TREE_CODE (type1);
2841 /* If an error was already reported for one of the arguments,
2842 avoid reporting another error. */
2844 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
2845 return error_mark_node;
2850 /* Handle the pointer + int case. */
2851 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2852 return cp_pointer_int_sum (PLUS_EXPR, op0, op1);
2853 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
2854 return cp_pointer_int_sum (PLUS_EXPR, op1, op0);
2860 /* Subtraction of two similar pointers.
2861 We must subtract them as integers, then divide by object size. */
2862 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
2863 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
2865 return pointer_diff (op0, op1, common_type (type0, type1));
2866 /* Handle pointer minus int. Just like pointer plus int. */
2867 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2868 return cp_pointer_int_sum (MINUS_EXPR, op0, op1);
2877 case TRUNC_DIV_EXPR:
2879 case FLOOR_DIV_EXPR:
2880 case ROUND_DIV_EXPR:
2881 case EXACT_DIV_EXPR:
2882 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2883 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2884 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2885 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
2887 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
2888 warning (0, "division by zero in %<%E / 0%>", op0);
2889 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
2890 warning (0, "division by zero in %<%E / 0.%>", op0);
2892 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2893 code0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
2894 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
2895 code1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
2897 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
2898 resultcode = RDIV_EXPR;
2900 /* When dividing two signed integers, we have to promote to int.
2901 unless we divide by a constant != -1. Note that default
2902 conversion will have been performed on the operands at this
2903 point, so we have to dig out the original type to find out if
2905 shorten = ((TREE_CODE (op0) == NOP_EXPR
2906 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2907 || (TREE_CODE (op1) == INTEGER_CST
2908 && ! integer_all_onesp (op1)));
2917 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2918 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
2922 case TRUNC_MOD_EXPR:
2923 case FLOOR_MOD_EXPR:
2924 if (code1 == INTEGER_TYPE && integer_zerop (op1))
2925 warning (0, "division by zero in %<%E %% 0%>", op0);
2926 else if (code1 == REAL_TYPE && real_zerop (op1))
2927 warning (0, "division by zero in %<%E %% 0.%>", op0);
2929 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2931 /* Although it would be tempting to shorten always here, that loses
2932 on some targets, since the modulo instruction is undefined if the
2933 quotient can't be represented in the computation mode. We shorten
2934 only if unsigned or if dividing by something we know != -1. */
2935 shorten = ((TREE_CODE (op0) == NOP_EXPR
2936 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2937 || (TREE_CODE (op1) == INTEGER_CST
2938 && ! integer_all_onesp (op1)));
2943 case TRUTH_ANDIF_EXPR:
2944 case TRUTH_ORIF_EXPR:
2945 case TRUTH_AND_EXPR:
2947 result_type = boolean_type_node;
2950 /* Shift operations: result has same type as first operand;
2951 always convert second operand to int.
2952 Also set SHORT_SHIFT if shifting rightward. */
2955 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2957 result_type = type0;
2958 if (TREE_CODE (op1) == INTEGER_CST)
2960 if (tree_int_cst_lt (op1, integer_zero_node))
2961 warning (0, "right shift count is negative");
2964 if (! integer_zerop (op1))
2966 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2967 warning (0, "right shift count >= width of type");
2970 /* Convert the shift-count to an integer, regardless of
2971 size of value being shifted. */
2972 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2973 op1 = cp_convert (integer_type_node, op1);
2974 /* Avoid converting op1 to result_type later. */
2980 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2982 result_type = type0;
2983 if (TREE_CODE (op1) == INTEGER_CST)
2985 if (tree_int_cst_lt (op1, integer_zero_node))
2986 warning (0, "left shift count is negative");
2987 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2988 warning (0, "left shift count >= width of type");
2990 /* Convert the shift-count to an integer, regardless of
2991 size of value being shifted. */
2992 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2993 op1 = cp_convert (integer_type_node, op1);
2994 /* Avoid converting op1 to result_type later. */
3001 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3003 result_type = type0;
3004 if (TREE_CODE (op1) == INTEGER_CST)
3006 if (tree_int_cst_lt (op1, integer_zero_node))
3007 warning (0, "%s rotate count is negative",
3008 (code == LROTATE_EXPR) ? "left" : "right");
3009 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3010 warning (0, "%s rotate count >= width of type",
3011 (code == LROTATE_EXPR) ? "left" : "right");
3013 /* Convert the shift-count to an integer, regardless of
3014 size of value being shifted. */
3015 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3016 op1 = cp_convert (integer_type_node, op1);
3022 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE))
3023 warning (0, "comparing floating point with == or != is unsafe");
3025 build_type = boolean_type_node;
3026 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3027 || code0 == COMPLEX_TYPE)
3028 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3029 || code1 == COMPLEX_TYPE))
3031 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3032 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3033 result_type = composite_pointer_type (type0, type1, op0, op1,
3035 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3036 && null_ptr_cst_p (op1))
3037 result_type = type0;
3038 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3039 && null_ptr_cst_p (op0))
3040 result_type = type1;
3041 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3043 result_type = type0;
3044 error ("ISO C++ forbids comparison between pointer and integer");
3046 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3048 result_type = type1;
3049 error ("ISO C++ forbids comparison between pointer and integer");
3051 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3053 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3054 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3055 result_type = TREE_TYPE (op0);
3057 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3058 return cp_build_binary_op (code, op1, op0);
3059 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3060 && same_type_p (type0, type1))
3062 /* E will be the final comparison. */
3064 /* E1 and E2 are for scratch. */
3072 if (TREE_SIDE_EFFECTS (op0))
3073 op0 = save_expr (op0);
3074 if (TREE_SIDE_EFFECTS (op1))
3075 op1 = save_expr (op1);
3080 && (!op0.pfn || op0.delta == op1.delta))
3082 The reason for the `!op0.pfn' bit is that a NULL
3083 pointer-to-member is any member with a zero PFN; the
3084 DELTA field is unspecified. */
3085 pfn0 = pfn_from_ptrmemfunc (op0);
3086 pfn1 = pfn_from_ptrmemfunc (op1);
3087 delta0 = build_ptrmemfunc_access_expr (op0,
3089 delta1 = build_ptrmemfunc_access_expr (op1,
3091 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3092 e2 = cp_build_binary_op (EQ_EXPR,
3094 cp_convert (TREE_TYPE (pfn0),
3095 integer_zero_node));
3096 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3097 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3098 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3099 if (code == EQ_EXPR)
3101 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3105 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3106 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3108 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3109 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3117 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3118 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3120 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3121 result_type = composite_pointer_type (type0, type1, op0, op1,
3129 build_type = boolean_type_node;
3130 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3131 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3133 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3134 result_type = composite_pointer_type (type0, type1, op0, op1,
3136 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3137 && integer_zerop (op1))
3138 result_type = type0;
3139 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3140 && integer_zerop (op0))
3141 result_type = type1;
3142 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3144 result_type = type0;
3145 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3147 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3149 result_type = type1;
3150 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3154 case UNORDERED_EXPR:
3161 build_type = integer_type_node;
3162 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3164 error ("unordered comparison on non-floating point argument");
3165 return error_mark_node;
3174 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3175 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3176 || code1 == COMPLEX_TYPE)))
3177 arithmetic_types_p = 1;
3180 arithmetic_types_p = 0;
3181 /* Vector arithmetic is only allowed when both sides are vectors. */
3182 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3184 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3185 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3188 binary_op_error (code);
3189 return error_mark_node;
3191 arithmetic_types_p = 1;
3194 /* Determine the RESULT_TYPE, if it is not already known. */
3196 && arithmetic_types_p
3197 && (shorten || common || short_compare))
3198 result_type = common_type (type0, type1);
3202 error ("invalid operands of types %qT and %qT to binary %qO",
3203 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3204 return error_mark_node;
3207 /* If we're in a template, the only thing we need to know is the
3209 if (processing_template_decl)
3210 return build2 (resultcode,
3211 build_type ? build_type : result_type,
3214 if (arithmetic_types_p)
3216 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3218 /* For certain operations (which identify themselves by shorten != 0)
3219 if both args were extended from the same smaller type,
3220 do the arithmetic in that type and then extend.
3222 shorten !=0 and !=1 indicates a bitwise operation.
3223 For them, this optimization is safe only if
3224 both args are zero-extended or both are sign-extended.
3225 Otherwise, we might change the result.
3226 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3227 but calculated in (unsigned short) it would be (unsigned short)-1. */
3229 if (shorten && none_complex)
3231 int unsigned0, unsigned1;
3232 tree arg0 = get_narrower (op0, &unsigned0);
3233 tree arg1 = get_narrower (op1, &unsigned1);
3234 /* UNS is 1 if the operation to be done is an unsigned one. */
3235 int uns = TYPE_UNSIGNED (result_type);
3238 final_type = result_type;
3240 /* Handle the case that OP0 does not *contain* a conversion
3241 but it *requires* conversion to FINAL_TYPE. */
3243 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3244 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3245 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3246 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3248 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3250 /* For bitwise operations, signedness of nominal type
3251 does not matter. Consider only how operands were extended. */
3255 /* Note that in all three cases below we refrain from optimizing
3256 an unsigned operation on sign-extended args.
3257 That would not be valid. */
3259 /* Both args variable: if both extended in same way
3260 from same width, do it in that width.
3261 Do it unsigned if args were zero-extended. */
3262 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3263 < TYPE_PRECISION (result_type))
3264 && (TYPE_PRECISION (TREE_TYPE (arg1))
3265 == TYPE_PRECISION (TREE_TYPE (arg0)))
3266 && unsigned0 == unsigned1
3267 && (unsigned0 || !uns))
3268 result_type = c_common_signed_or_unsigned_type
3269 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3270 else if (TREE_CODE (arg0) == INTEGER_CST
3271 && (unsigned1 || !uns)
3272 && (TYPE_PRECISION (TREE_TYPE (arg1))
3273 < TYPE_PRECISION (result_type))
3274 && (type = c_common_signed_or_unsigned_type
3275 (unsigned1, TREE_TYPE (arg1)),
3276 int_fits_type_p (arg0, type)))
3278 else if (TREE_CODE (arg1) == INTEGER_CST
3279 && (unsigned0 || !uns)
3280 && (TYPE_PRECISION (TREE_TYPE (arg0))
3281 < TYPE_PRECISION (result_type))
3282 && (type = c_common_signed_or_unsigned_type
3283 (unsigned0, TREE_TYPE (arg0)),
3284 int_fits_type_p (arg1, type)))
3288 /* Shifts can be shortened if shifting right. */
3293 tree arg0 = get_narrower (op0, &unsigned_arg);
3295 final_type = result_type;
3297 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3298 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3300 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3301 /* We can shorten only if the shift count is less than the
3302 number of bits in the smaller type size. */
3303 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3304 /* If arg is sign-extended and then unsigned-shifted,
3305 we can simulate this with a signed shift in arg's type
3306 only if the extended result is at least twice as wide
3307 as the arg. Otherwise, the shift could use up all the
3308 ones made by sign-extension and bring in zeros.
3309 We can't optimize that case at all, but in most machines
3310 it never happens because available widths are 2**N. */
3311 && (!TYPE_UNSIGNED (final_type)
3313 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3314 <= TYPE_PRECISION (result_type))))
3316 /* Do an unsigned shift if the operand was zero-extended. */
3318 = c_common_signed_or_unsigned_type (unsigned_arg,
3320 /* Convert value-to-be-shifted to that type. */
3321 if (TREE_TYPE (op0) != result_type)
3322 op0 = cp_convert (result_type, op0);
3327 /* Comparison operations are shortened too but differently.
3328 They identify themselves by setting short_compare = 1. */
3332 /* Don't write &op0, etc., because that would prevent op0
3333 from being kept in a register.
3334 Instead, make copies of the our local variables and
3335 pass the copies by reference, then copy them back afterward. */
3336 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3337 enum tree_code xresultcode = resultcode;
3339 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3341 return cp_convert (boolean_type_node, val);
3342 op0 = xop0, op1 = xop1;
3344 resultcode = xresultcode;
3347 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3348 && warn_sign_compare
3349 /* Do not warn until the template is instantiated; we cannot
3350 bound the ranges of the arguments until that point. */
3351 && !processing_template_decl)
3353 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3354 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3356 int unsignedp0, unsignedp1;
3357 tree primop0 = get_narrower (op0, &unsignedp0);
3358 tree primop1 = get_narrower (op1, &unsignedp1);
3360 /* Check for comparison of different enum types. */
3361 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3362 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3363 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3364 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3366 warning (0, "comparison between types %q#T and %q#T",
3367 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3370 /* Give warnings for comparisons between signed and unsigned
3371 quantities that may fail. */
3372 /* Do the checking based on the original operand trees, so that
3373 casts will be considered, but default promotions won't be. */
3375 /* Do not warn if the comparison is being done in a signed type,
3376 since the signed type will only be chosen if it can represent
3377 all the values of the unsigned type. */
3378 if (!TYPE_UNSIGNED (result_type))
3380 /* Do not warn if both operands are unsigned. */
3381 else if (op0_signed == op1_signed)
3383 /* Do not warn if the signed quantity is an unsuffixed
3384 integer literal (or some static constant expression
3385 involving such literals or a conditional expression
3386 involving such literals) and it is non-negative. */
3387 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3388 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3390 /* Do not warn if the comparison is an equality operation,
3391 the unsigned quantity is an integral constant and it does
3392 not use the most significant bit of result_type. */
3393 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3394 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3395 && int_fits_type_p (orig_op1, c_common_signed_type
3397 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3398 && int_fits_type_p (orig_op0, c_common_signed_type
3402 warning (0, "comparison between signed and unsigned integer expressions");
3404 /* Warn if two unsigned values are being compared in a size
3405 larger than their original size, and one (and only one) is the
3406 result of a `~' operator. This comparison will always fail.
3408 Also warn if one operand is a constant, and the constant does not
3409 have all bits set that are set in the ~ operand when it is
3412 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3413 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3415 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3416 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3417 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3418 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3420 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3423 HOST_WIDE_INT constant, mask;
3427 if (host_integerp (primop0, 0))
3430 unsignedp = unsignedp1;
3431 constant = tree_low_cst (primop0, 0);
3436 unsignedp = unsignedp0;
3437 constant = tree_low_cst (primop1, 0);
3440 bits = TYPE_PRECISION (TREE_TYPE (primop));
3441 if (bits < TYPE_PRECISION (result_type)
3442 && bits < HOST_BITS_PER_LONG && unsignedp)
3444 mask = (~ (HOST_WIDE_INT) 0) << bits;
3445 if ((mask & constant) != mask)
3446 warning (0, "comparison of promoted ~unsigned with constant");
3449 else if (unsignedp0 && unsignedp1
3450 && (TYPE_PRECISION (TREE_TYPE (primop0))
3451 < TYPE_PRECISION (result_type))
3452 && (TYPE_PRECISION (TREE_TYPE (primop1))
3453 < TYPE_PRECISION (result_type)))
3454 warning (0, "comparison of promoted ~unsigned with unsigned");
3459 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3460 Then the expression will be built.
3461 It will be given type FINAL_TYPE if that is nonzero;
3462 otherwise, it will be given type RESULT_TYPE. */
3464 /* Issue warnings about peculiar, but valid, uses of NULL. */
3465 if (/* It's reasonable to use pointer values as operands of &&
3466 and ||, so NULL is no exception. */
3467 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3468 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3469 (orig_op0 == null_node
3470 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3471 /* Or vice versa. */
3472 || (orig_op1 == null_node
3473 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3474 /* Or, both are NULL and the operation was not a comparison. */
3475 || (orig_op0 == null_node && orig_op1 == null_node
3476 && code != EQ_EXPR && code != NE_EXPR)))
3477 /* Some sort of arithmetic operation involving NULL was
3478 performed. Note that pointer-difference and pointer-addition
3479 have already been handled above, and so we don't end up here in
3481 warning (0, "NULL used in arithmetic");
3485 if (TREE_TYPE (op0) != result_type)
3486 op0 = cp_convert (result_type, op0);
3487 if (TREE_TYPE (op1) != result_type)
3488 op1 = cp_convert (result_type, op1);
3490 if (op0 == error_mark_node || op1 == error_mark_node)
3491 return error_mark_node;
3494 if (build_type == NULL_TREE)
3495 build_type = result_type;
3497 result = build2 (resultcode, build_type, op0, op1);
3498 result = fold_if_not_in_template (result);
3499 if (final_type != 0)
3500 result = cp_convert (final_type, result);
3504 /* Return a tree for the sum or difference (RESULTCODE says which)
3505 of pointer PTROP and integer INTOP. */
3508 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3510 tree res_type = TREE_TYPE (ptrop);
3512 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3513 in certain circumstance (when it's valid to do so). So we need
3514 to make sure it's complete. We don't need to check here, if we
3515 can actually complete it at all, as those checks will be done in
3516 pointer_int_sum() anyway. */
3517 complete_type (TREE_TYPE (res_type));
3519 return pointer_int_sum (resultcode, ptrop,
3520 fold_if_not_in_template (intop));
3523 /* Return a tree for the difference of pointers OP0 and OP1.
3524 The resulting tree has type int. */
3527 pointer_diff (tree op0, tree op1, tree ptrtype)
3530 tree restype = ptrdiff_type_node;
3531 tree target_type = TREE_TYPE (ptrtype);
3533 if (!complete_type_or_else (target_type, NULL_TREE))
3534 return error_mark_node;
3536 if (pedantic || warn_pointer_arith)
3538 if (TREE_CODE (target_type) == VOID_TYPE)
3539 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3540 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3541 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3542 if (TREE_CODE (target_type) == METHOD_TYPE)
3543 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3546 /* First do the subtraction as integers;
3547 then drop through to build the divide operator. */
3549 op0 = cp_build_binary_op (MINUS_EXPR,
3550 cp_convert (restype, op0),
3551 cp_convert (restype, op1));
3553 /* This generates an error if op1 is a pointer to an incomplete type. */
3554 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3555 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3557 op1 = (TYPE_PTROB_P (ptrtype)
3558 ? size_in_bytes (target_type)
3559 : integer_one_node);
3561 /* Do the division. */
3563 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3564 return fold_if_not_in_template (result);
3567 /* Construct and perhaps optimize a tree representation
3568 for a unary operation. CODE, a tree_code, specifies the operation
3569 and XARG is the operand. */
3572 build_x_unary_op (enum tree_code code, tree xarg)
3574 tree orig_expr = xarg;
3578 if (processing_template_decl)
3580 if (type_dependent_expression_p (xarg))
3581 return build_min_nt (code, xarg, NULL_TREE);
3583 xarg = build_non_dependent_expr (xarg);
3588 /* [expr.unary.op] says:
3590 The address of an object of incomplete type can be taken.
3592 (And is just the ordinary address operator, not an overloaded
3593 "operator &".) However, if the type is a template
3594 specialization, we must complete the type at this point so that
3595 an overloaded "operator &" will be available if required. */
3596 if (code == ADDR_EXPR
3597 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3598 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3599 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3600 || (TREE_CODE (xarg) == OFFSET_REF)))
3601 /* Don't look for a function. */;
3603 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3604 /*overloaded_p=*/NULL);
3605 if (!exp && code == ADDR_EXPR)
3607 /* A pointer to member-function can be formed only by saying
3609 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3610 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3612 if (TREE_CODE (xarg) != OFFSET_REF)
3614 error ("invalid use of %qE to form a pointer-to-member-function."
3615 " Use a qualified-id.",
3617 return error_mark_node;
3621 error ("parenthesis around %qE cannot be used to form a"
3622 " pointer-to-member-function",
3624 PTRMEM_OK_P (xarg) = 1;
3628 if (TREE_CODE (xarg) == OFFSET_REF)
3630 ptrmem = PTRMEM_OK_P (xarg);
3632 if (!ptrmem && !flag_ms_extensions
3633 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3635 /* A single non-static member, make sure we don't allow a
3636 pointer-to-member. */
3637 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3638 TREE_OPERAND (xarg, 0),
3639 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3640 PTRMEM_OK_P (xarg) = ptrmem;
3643 else if (TREE_CODE (xarg) == TARGET_EXPR)
3644 warning (0, "taking address of temporary");
3645 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3648 if (processing_template_decl && exp != error_mark_node)
3649 exp = build_min_non_dep (code, exp, orig_expr,
3650 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3651 if (TREE_CODE (exp) == ADDR_EXPR)
3652 PTRMEM_OK_P (exp) = ptrmem;
3656 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3657 constants, where a null value is represented by an INTEGER_CST of
3661 cp_truthvalue_conversion (tree expr)
3663 tree type = TREE_TYPE (expr);
3664 if (TYPE_PTRMEM_P (type))
3665 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3667 return c_common_truthvalue_conversion (expr);
3670 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3673 condition_conversion (tree expr)
3676 if (processing_template_decl)
3678 t = perform_implicit_conversion (boolean_type_node, expr);
3679 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3683 /* Return an ADDR_EXPR giving the address of T. This function
3684 attempts no optimizations or simplifications; it is a low-level
3688 build_address (tree t)
3692 if (error_operand_p (t) || !cxx_mark_addressable (t))
3693 return error_mark_node;
3695 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3700 /* Return a NOP_EXPR converting EXPR to TYPE. */
3703 build_nop (tree type, tree expr)
3705 if (type == error_mark_node || error_operand_p (expr))
3707 return build1 (NOP_EXPR, type, expr);
3710 /* C++: Must handle pointers to members.
3712 Perhaps type instantiation should be extended to handle conversion
3713 from aggregates to types we don't yet know we want? (Or are those
3714 cases typically errors which should be reported?)
3716 NOCONVERT nonzero suppresses the default promotions
3717 (such as from short to int). */
3720 build_unary_op (enum tree_code code, tree xarg, int noconvert)
3722 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
3725 const char *errstring = NULL;
3728 if (arg == error_mark_node)
3729 return error_mark_node;
3733 case UNARY_PLUS_EXPR:
3736 int flags = WANT_ARITH | WANT_ENUM;
3737 /* Unary plus (but not unary minus) is allowed on pointers. */
3738 if (code == UNARY_PLUS_EXPR)
3739 flags |= WANT_POINTER;
3740 arg = build_expr_type_conversion (flags, arg, true);
3742 errstring = (code == NEGATE_EXPR
3743 ? "wrong type argument to unary minus"
3744 : "wrong type argument to unary plus");
3747 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
3748 arg = perform_integral_promotions (arg);
3750 /* Make sure the result is not a lvalue: a unary plus or minus
3751 expression is always a rvalue. */
3752 if (real_lvalue_p (arg))
3753 arg = build1 (NON_LVALUE_EXPR, TREE_TYPE (arg), arg);
3759 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3763 arg = default_conversion (arg);
3765 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM,
3767 errstring = "wrong type argument to bit-complement";
3768 else if (!noconvert)
3769 arg = perform_integral_promotions (arg);
3773 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3774 errstring = "wrong type argument to abs";
3775 else if (!noconvert)
3776 arg = default_conversion (arg);
3780 /* Conjugating a real value is a no-op, but allow it anyway. */
3781 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3782 errstring = "wrong type argument to conjugation";
3783 else if (!noconvert)
3784 arg = default_conversion (arg);
3787 case TRUTH_NOT_EXPR:
3788 arg = perform_implicit_conversion (boolean_type_node, arg);
3789 val = invert_truthvalue (arg);
3790 if (arg != error_mark_node)
3792 errstring = "in argument to unary !";
3799 if (TREE_CODE (arg) == COMPLEX_CST)
3800 return TREE_REALPART (arg);
3801 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3803 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3804 return fold_if_not_in_template (arg);
3810 if (TREE_CODE (arg) == COMPLEX_CST)
3811 return TREE_IMAGPART (arg);
3812 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3814 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3815 return fold_if_not_in_template (arg);
3818 return cp_convert (TREE_TYPE (arg), integer_zero_node);
3820 case PREINCREMENT_EXPR:
3821 case POSTINCREMENT_EXPR:
3822 case PREDECREMENT_EXPR:
3823 case POSTDECREMENT_EXPR:
3824 /* Handle complex lvalues (when permitted)
3825 by reduction to simpler cases. */
3827 val = unary_complex_lvalue (code, arg);
3831 /* Increment or decrement the real part of the value,
3832 and don't change the imaginary part. */
3833 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3837 arg = stabilize_reference (arg);
3838 real = build_unary_op (REALPART_EXPR, arg, 1);
3839 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
3840 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
3841 build_unary_op (code, real, 1), imag);
3844 /* Report invalid types. */
3846 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
3849 if (code == PREINCREMENT_EXPR)
3850 errstring ="no pre-increment operator for type";
3851 else if (code == POSTINCREMENT_EXPR)
3852 errstring ="no post-increment operator for type";
3853 else if (code == PREDECREMENT_EXPR)
3854 errstring ="no pre-decrement operator for type";
3856 errstring ="no post-decrement operator for type";
3860 /* Report something read-only. */
3862 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
3863 || TREE_READONLY (arg))
3864 readonly_error (arg, ((code == PREINCREMENT_EXPR
3865 || code == POSTINCREMENT_EXPR)
3866 ? "increment" : "decrement"),
3871 tree result_type = TREE_TYPE (arg);
3873 arg = get_unwidened (arg, 0);
3874 argtype = TREE_TYPE (arg);
3876 /* ARM $5.2.5 last annotation says this should be forbidden. */
3877 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
3878 pedwarn ("ISO C++ forbids %sing an enum",
3879 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3880 ? "increment" : "decrement");
3882 /* Compute the increment. */
3884 if (TREE_CODE (argtype) == POINTER_TYPE)
3886 tree type = complete_type (TREE_TYPE (argtype));
3888 if (!COMPLETE_OR_VOID_TYPE_P (type))
3889 error ("cannot %s a pointer to incomplete type %qT",
3890 ((code == PREINCREMENT_EXPR
3891 || code == POSTINCREMENT_EXPR)
3892 ? "increment" : "decrement"), TREE_TYPE (argtype));
3893 else if ((pedantic || warn_pointer_arith)
3894 && !TYPE_PTROB_P (argtype))
3895 pedwarn ("ISO C++ forbids %sing a pointer of type %qT",
3896 ((code == PREINCREMENT_EXPR
3897 || code == POSTINCREMENT_EXPR)
3898 ? "increment" : "decrement"), argtype);
3899 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
3902 inc = integer_one_node;
3904 inc = cp_convert (argtype, inc);
3906 /* Handle incrementing a cast-expression. */
3908 switch (TREE_CODE (arg))
3913 case FIX_TRUNC_EXPR:
3914 case FIX_FLOOR_EXPR:
3915 case FIX_ROUND_EXPR:
3918 tree incremented, modify, value, compound;
3919 if (! lvalue_p (arg) && pedantic)
3920 pedwarn ("cast to non-reference type used as lvalue");
3921 arg = stabilize_reference (arg);
3922 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
3925 value = save_expr (arg);
3926 incremented = build2 (((code == PREINCREMENT_EXPR
3927 || code == POSTINCREMENT_EXPR)
3928 ? PLUS_EXPR : MINUS_EXPR),
3929 argtype, value, inc);
3931 modify = build_modify_expr (arg, NOP_EXPR, incremented);
3932 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
3935 /* Eliminate warning about unused result of + or -. */
3936 TREE_NO_WARNING (compound) = 1;
3944 /* Complain about anything else that is not a true lvalue. */
3945 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
3946 || code == POSTINCREMENT_EXPR)
3947 ? lv_increment : lv_decrement)))
3948 return error_mark_node;
3950 /* Forbid using -- on `bool'. */
3951 if (TREE_TYPE (arg) == boolean_type_node)
3953 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
3955 error ("invalid use of %<--%> on bool variable %qD", arg);
3956 return error_mark_node;
3958 val = boolean_increment (code, arg);
3961 val = build2 (code, TREE_TYPE (arg), arg, inc);
3963 TREE_SIDE_EFFECTS (val) = 1;
3964 return cp_convert (result_type, val);
3968 /* Note that this operation never does default_conversion
3969 regardless of NOCONVERT. */
3971 argtype = lvalue_type (arg);
3973 if (TREE_CODE (arg) == OFFSET_REF)
3976 if (TREE_CODE (argtype) == REFERENCE_TYPE)
3978 tree type = build_pointer_type (TREE_TYPE (argtype));
3979 arg = build1 (CONVERT_EXPR, type, arg);
3982 else if (pedantic && DECL_MAIN_P (arg))
3984 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
3986 /* Let &* cancel out to simplify resulting code. */
3987 if (TREE_CODE (arg) == INDIRECT_REF)
3989 /* We don't need to have `current_class_ptr' wrapped in a
3990 NON_LVALUE_EXPR node. */
3991 if (arg == current_class_ref)
3992 return current_class_ptr;
3994 arg = TREE_OPERAND (arg, 0);
3995 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
3997 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
3998 arg = build1 (CONVERT_EXPR, type, arg);
4000 else if (lvalue_p (arg))
4001 /* Don't let this be an lvalue. */
4002 return non_lvalue (arg);
4006 /* Uninstantiated types are all functions. Taking the
4007 address of a function is a no-op, so just return the
4010 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4011 || !IDENTIFIER_OPNAME_P (arg));
4013 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4014 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4016 /* They're trying to take the address of a unique non-static
4017 member function. This is ill-formed (except in MS-land),
4018 but let's try to DTRT.
4019 Note: We only handle unique functions here because we don't
4020 want to complain if there's a static overload; non-unique
4021 cases will be handled by instantiate_type. But we need to
4022 handle this case here to allow casts on the resulting PMF.
4023 We could defer this in non-MS mode, but it's easier to give
4024 a useful error here. */
4026 /* Inside constant member functions, the `this' pointer
4027 contains an extra const qualifier. TYPE_MAIN_VARIANT
4028 is used here to remove this const from the diagnostics
4029 and the created OFFSET_REF. */
4030 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4031 tree name = DECL_NAME (get_first_fn (TREE_OPERAND (arg, 1)));
4033 if (! flag_ms_extensions)
4035 if (current_class_type
4036 && TREE_OPERAND (arg, 0) == current_class_ref)
4037 /* An expression like &memfn. */
4038 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4039 " or parenthesized non-static member function to form"
4040 " a pointer to member function. Say %<&%T::%D%>",
4043 pedwarn ("ISO C++ forbids taking the address of a bound member"
4044 " function to form a pointer to member function."
4048 arg = build_offset_ref (base, name, /*address_p=*/true);
4052 if (type_unknown_p (arg))
4053 return build1 (ADDR_EXPR, unknown_type_node, arg);
4055 /* Handle complex lvalues (when permitted)
4056 by reduction to simpler cases. */
4057 val = unary_complex_lvalue (code, arg);
4061 switch (TREE_CODE (arg))
4066 case FIX_TRUNC_EXPR:
4067 case FIX_FLOOR_EXPR:
4068 case FIX_ROUND_EXPR:
4070 if (! lvalue_p (arg) && pedantic)
4071 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4075 arg = OVL_CURRENT (arg);
4079 /* Turn a reference to a non-static data member into a
4080 pointer-to-member. */
4085 if (!PTRMEM_OK_P (arg))
4086 return build_unary_op (code, arg, 0);
4088 t = TREE_OPERAND (arg, 1);
4089 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4091 error ("cannot create pointer to reference member %qD", t);
4092 return error_mark_node;
4095 type = build_ptrmem_type (context_for_name_lookup (t),
4097 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4105 /* Allow the address of a constructor if all the elements
4107 if (TREE_CODE (arg) == CONSTRUCTOR && TREE_HAS_CONSTRUCTOR (arg)
4108 && TREE_CONSTANT (arg))
4110 /* Anything not already handled and not a true memory reference
4112 else if (TREE_CODE (argtype) != FUNCTION_TYPE
4113 && TREE_CODE (argtype) != METHOD_TYPE
4114 && TREE_CODE (arg) != OFFSET_REF
4115 && !lvalue_or_else (arg, lv_addressof))
4116 return error_mark_node;
4118 if (argtype != error_mark_node)
4119 argtype = build_pointer_type (argtype);
4124 if (TREE_CODE (arg) != COMPONENT_REF
4125 /* Inside a template, we are processing a non-dependent
4126 expression so we can just form an ADDR_EXPR with the
4128 || processing_template_decl)
4130 addr = build_address (arg);
4131 if (TREE_CODE (arg) == OFFSET_REF)
4132 PTRMEM_OK_P (addr) = PTRMEM_OK_P (arg);
4134 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4136 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4138 /* We can only get here with a single static member
4140 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4141 && DECL_STATIC_FUNCTION_P (fn));
4143 addr = build_address (fn);
4144 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4145 /* Do not lose object's side effects. */
4146 addr = build2 (COMPOUND_EXPR, TREE_TYPE (addr),
4147 TREE_OPERAND (arg, 0), addr);
4149 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4151 error ("attempt to take address of bit-field structure member %qD",
4152 TREE_OPERAND (arg, 1));
4153 return error_mark_node;
4157 tree object = TREE_OPERAND (arg, 0);
4158 tree field = TREE_OPERAND (arg, 1);
4159 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4160 (TREE_TYPE (object), decl_type_context (field)));
4161 addr = build_address (arg);
4164 if (TREE_CODE (argtype) == POINTER_TYPE
4165 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4167 build_ptrmemfunc_type (argtype);
4168 addr = build_ptrmemfunc (argtype, addr, 0,
4169 /*c_cast_p=*/false);
4182 argtype = TREE_TYPE (arg);
4183 return fold_if_not_in_template (build1 (code, argtype, arg));
4186 error ("%s", errstring);
4187 return error_mark_node;
4190 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4191 for certain kinds of expressions which are not really lvalues
4192 but which we can accept as lvalues.
4194 If ARG is not a kind of expression we can handle, return
4198 unary_complex_lvalue (enum tree_code code, tree arg)
4200 /* Inside a template, making these kinds of adjustments is
4201 pointless; we are only concerned with the type of the
4203 if (processing_template_decl)
4206 /* Handle (a, b) used as an "lvalue". */
4207 if (TREE_CODE (arg) == COMPOUND_EXPR)
4209 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4210 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4211 TREE_OPERAND (arg, 0), real_result);
4214 /* Handle (a ? b : c) used as an "lvalue". */
4215 if (TREE_CODE (arg) == COND_EXPR
4216 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4217 return rationalize_conditional_expr (code, arg);
4219 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4220 if (TREE_CODE (arg) == MODIFY_EXPR
4221 || TREE_CODE (arg) == PREINCREMENT_EXPR
4222 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4224 tree lvalue = TREE_OPERAND (arg, 0);
4225 if (TREE_SIDE_EFFECTS (lvalue))
4227 lvalue = stabilize_reference (lvalue);
4228 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4229 lvalue, TREE_OPERAND (arg, 1));
4231 return unary_complex_lvalue
4232 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4235 if (code != ADDR_EXPR)
4238 /* Handle (a = b) used as an "lvalue" for `&'. */
4239 if (TREE_CODE (arg) == MODIFY_EXPR
4240 || TREE_CODE (arg) == INIT_EXPR)
4242 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4243 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4245 TREE_NO_WARNING (arg) = 1;
4249 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4250 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4251 || TREE_CODE (arg) == OFFSET_REF)
4254 /* We permit compiler to make function calls returning
4255 objects of aggregate type look like lvalues. */
4259 if (TREE_CODE (targ) == SAVE_EXPR)
4260 targ = TREE_OPERAND (targ, 0);
4262 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4264 if (TREE_CODE (arg) == SAVE_EXPR)
4267 targ = build_cplus_new (TREE_TYPE (arg), arg);
4268 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4271 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4272 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4273 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4276 /* Don't let anything else be handled specially. */
4280 /* Mark EXP saying that we need to be able to take the
4281 address of it; it should not be allocated in a register.
4282 Value is true if successful.
4284 C++: we do not allow `current_class_ptr' to be addressable. */
4287 cxx_mark_addressable (tree exp)
4292 switch (TREE_CODE (x))
4299 x = TREE_OPERAND (x, 0);
4303 if (x == current_class_ptr)
4305 error ("cannot take the address of %<this%>, which is an rvalue expression");
4306 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4312 /* Caller should not be trying to mark initialized
4313 constant fields addressable. */
4314 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4315 || DECL_IN_AGGR_P (x) == 0
4317 || DECL_EXTERNAL (x));
4322 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4323 && !DECL_ARTIFICIAL (x))
4325 if (DECL_HARD_REGISTER (x) != 0)
4328 ("address of explicit register variable %qD requested", x);
4331 else if (extra_warnings)
4333 (0, "address requested for %qD, which is declared %<register%>", x);
4335 TREE_ADDRESSABLE (x) = 1;
4339 TREE_ADDRESSABLE (x) = 1;
4343 TREE_ADDRESSABLE (x) = 1;
4347 TREE_ADDRESSABLE (x) = 1;
4348 cxx_mark_addressable (TREE_OPERAND (x, 0));
4356 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4359 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4361 tree orig_ifexp = ifexp;
4362 tree orig_op1 = op1;
4363 tree orig_op2 = op2;
4366 if (processing_template_decl)
4368 /* The standard says that the expression is type-dependent if
4369 IFEXP is type-dependent, even though the eventual type of the
4370 expression doesn't dependent on IFEXP. */
4371 if (type_dependent_expression_p (ifexp)
4372 /* As a GNU extension, the middle operand may be omitted. */
4373 || (op1 && type_dependent_expression_p (op1))
4374 || type_dependent_expression_p (op2))
4375 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4376 ifexp = build_non_dependent_expr (ifexp);
4378 op1 = build_non_dependent_expr (op1);
4379 op2 = build_non_dependent_expr (op2);
4382 expr = build_conditional_expr (ifexp, op1, op2);
4383 if (processing_template_decl && expr != error_mark_node)
4384 return build_min_non_dep (COND_EXPR, expr,
4385 orig_ifexp, orig_op1, orig_op2);
4389 /* Given a list of expressions, return a compound expression
4390 that performs them all and returns the value of the last of them. */
4392 tree build_x_compound_expr_from_list (tree list, const char *msg)
4394 tree expr = TREE_VALUE (list);
4396 if (TREE_CHAIN (list))
4399 pedwarn ("%s expression list treated as compound expression", msg);
4401 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4402 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4408 /* Handle overloading of the ',' operator when needed. */
4411 build_x_compound_expr (tree op1, tree op2)
4414 tree orig_op1 = op1;
4415 tree orig_op2 = op2;
4417 if (processing_template_decl)
4419 if (type_dependent_expression_p (op1)
4420 || type_dependent_expression_p (op2))
4421 return build_min_nt (COMPOUND_EXPR, op1, op2);
4422 op1 = build_non_dependent_expr (op1);
4423 op2 = build_non_dependent_expr (op2);
4426 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4427 /*overloaded_p=*/NULL);
4429 result = build_compound_expr (op1, op2);
4431 if (processing_template_decl && result != error_mark_node)
4432 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4437 /* Build a compound expression. */
4440 build_compound_expr (tree lhs, tree rhs)
4442 lhs = convert_to_void (lhs, "left-hand operand of comma");
4444 if (lhs == error_mark_node || rhs == error_mark_node)
4445 return error_mark_node;
4447 if (TREE_CODE (rhs) == TARGET_EXPR)
4449 /* If the rhs is a TARGET_EXPR, then build the compound
4450 expression inside the target_expr's initializer. This
4451 helps the compiler to eliminate unnecessary temporaries. */
4452 tree init = TREE_OPERAND (rhs, 1);
4454 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4455 TREE_OPERAND (rhs, 1) = init;
4460 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4463 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4464 casts away constness. DIAG_FN gives the function to call if we
4465 need to issue a diagnostic; if it is NULL, no diagnostic will be
4466 issued. DESCRIPTION explains what operation is taking place. */
4469 check_for_casting_away_constness (tree src_type, tree dest_type,
4470 void (*diag_fn)(const char *, ...),
4471 const char *description)
4473 if (diag_fn && casts_away_constness (src_type, dest_type))
4474 error ("%s from type %qT to type %qT casts away constness",
4475 description, src_type, dest_type);
4478 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4479 (another pointer-to-member type in the same hierarchy) and return
4480 the converted expression. If ALLOW_INVERSE_P is permitted, a
4481 pointer-to-derived may be converted to pointer-to-base; otherwise,
4482 only the other direction is permitted. If C_CAST_P is true, this
4483 conversion is taking place as part of a C-style cast. */
4486 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4489 if (TYPE_PTRMEM_P (type))
4493 if (TREE_CODE (expr) == PTRMEM_CST)
4494 expr = cplus_expand_constant (expr);
4495 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4496 TYPE_PTRMEM_CLASS_TYPE (type),
4499 if (!integer_zerop (delta))
4500 expr = cp_build_binary_op (PLUS_EXPR,
4501 build_nop (ptrdiff_type_node, expr),
4503 return build_nop (type, expr);
4506 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4507 allow_inverse_p, c_cast_p);
4510 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4511 this static_cast is being attempted as one of the possible casts
4512 allowed by a C-style cast. (In that case, accessibility of base
4513 classes is not considered, and it is OK to cast away
4514 constness.) Return the result of the cast. *VALID_P is set to
4515 indicate whether or not the cast was valid. */
4518 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4524 void (*diag_fn)(const char*, ...);
4527 /* Assume the cast is valid. */
4530 intype = TREE_TYPE (expr);
4532 /* Determine what to do when casting away constness. */
4535 /* C-style casts are allowed to cast away constness. With
4536 WARN_CAST_QUAL, we still want to issue a warning. */
4537 diag_fn = warn_cast_qual ? warning0 : NULL;
4542 /* A static_cast may not cast away constness. */
4544 desc = "static_cast";
4547 /* [expr.static.cast]
4549 An lvalue of type "cv1 B", where B is a class type, can be cast
4550 to type "reference to cv2 D", where D is a class derived (clause
4551 _class.derived_) from B, if a valid standard conversion from
4552 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4553 same cv-qualification as, or greater cv-qualification than, cv1,
4554 and B is not a virtual base class of D. */
4555 /* We check this case before checking the validity of "TYPE t =
4556 EXPR;" below because for this case:
4559 struct D : public B { D(const B&); };
4561 void f() { static_cast<const D&>(b); }
4563 we want to avoid constructing a new D. The standard is not
4564 completely clear about this issue, but our interpretation is
4565 consistent with other compilers. */
4566 if (TREE_CODE (type) == REFERENCE_TYPE
4567 && CLASS_TYPE_P (TREE_TYPE (type))
4568 && CLASS_TYPE_P (intype)
4569 && real_lvalue_p (expr)
4570 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4571 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4572 build_pointer_type (TYPE_MAIN_VARIANT
4573 (TREE_TYPE (type))))
4575 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4579 /* There is a standard conversion from "D*" to "B*" even if "B"
4580 is ambiguous or inaccessible. If this is really a
4581 static_cast, then we check both for inaccessibility and
4582 ambiguity. However, if this is a static_cast being performed
4583 because the user wrote a C-style cast, then accessibility is
4585 base = lookup_base (TREE_TYPE (type), intype,
4586 c_cast_p ? ba_unique : ba_check,
4589 /* Convert from "B*" to "D*". This function will check that "B"
4590 is not a virtual base of "D". */
4591 expr = build_base_path (MINUS_EXPR, build_address (expr),
4592 base, /*nonnull=*/false);
4593 /* Convert the pointer to a reference -- but then remember that
4594 there are no expressions with reference type in C++. */
4595 return convert_from_reference (build_nop (type, expr));
4600 /* [expr.static.cast]
4602 An expression e can be explicitly converted to a type T using a
4603 static_cast of the form static_cast<T>(e) if the declaration T
4604 t(e);" is well-formed, for some invented temporary variable
4606 result = perform_direct_initialization_if_possible (type, expr,
4610 result = convert_from_reference (result);
4612 /* Ignore any integer overflow caused by the cast. */
4613 if (TREE_CODE (result) == INTEGER_CST
4614 && CONSTANT_CLASS_P (orig))
4616 TREE_OVERFLOW (result) = TREE_OVERFLOW (orig);
4617 TREE_CONSTANT_OVERFLOW (result)
4618 = TREE_CONSTANT_OVERFLOW (orig);
4620 /* [expr.static.cast]
4622 If T is a reference type, the result is an lvalue; otherwise,
4623 the result is an rvalue. */
4624 if (TREE_CODE (type) != REFERENCE_TYPE
4625 && real_lvalue_p (result))
4626 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (result), result);
4630 /* [expr.static.cast]
4632 Any expression can be explicitly converted to type cv void. */
4633 if (TREE_CODE (type) == VOID_TYPE)
4634 return convert_to_void (expr, /*implicit=*/NULL);
4636 /* [expr.static.cast]
4638 The inverse of any standard conversion sequence (clause _conv_),
4639 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4640 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4641 (_conv.bool_) conversions, can be performed explicitly using
4642 static_cast subject to the restriction that the explicit
4643 conversion does not cast away constness (_expr.const.cast_), and
4644 the following additional rules for specific cases: */
4645 /* For reference, the conversions not excluded are: integral
4646 promotions, floating point promotion, integral conversions,
4647 floating point conversions, floating-integral conversions,
4648 pointer conversions, and pointer to member conversions. */
4651 A value of integral _or enumeration_ type can be explicitly
4652 converted to an enumeration type. */
4653 /* The effect of all that is that any conversion between any two
4654 types which are integral, floating, or enumeration types can be
4656 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
4657 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
4659 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
4661 /* Ignore any integer overflow caused by the cast. */
4662 if (TREE_CODE (expr) == INTEGER_CST
4663 && CONSTANT_CLASS_P (orig))
4665 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4666 TREE_CONSTANT_OVERFLOW (expr) = TREE_CONSTANT_OVERFLOW (orig);
4671 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4672 && CLASS_TYPE_P (TREE_TYPE (type))
4673 && CLASS_TYPE_P (TREE_TYPE (intype))
4674 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4675 (TREE_TYPE (intype))),
4676 build_pointer_type (TYPE_MAIN_VARIANT
4677 (TREE_TYPE (type)))))
4682 check_for_casting_away_constness (intype, type, diag_fn, desc);
4683 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
4684 c_cast_p ? ba_unique : ba_check,
4686 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
4689 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4690 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4697 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
4698 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
4700 if (TYPE_PTRMEM_P (type))
4702 t1 = (build_ptrmem_type
4704 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
4705 t2 = (build_ptrmem_type
4707 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
4714 if (can_convert (t1, t2))
4717 check_for_casting_away_constness (intype, type, diag_fn,
4719 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
4724 /* [expr.static.cast]
4726 An rvalue of type "pointer to cv void" can be explicitly
4727 converted to a pointer to object type. A value of type pointer
4728 to object converted to "pointer to cv void" and back to the
4729 original pointer type will have its original value. */
4730 if (TREE_CODE (intype) == POINTER_TYPE
4731 && VOID_TYPE_P (TREE_TYPE (intype))
4732 && TYPE_PTROB_P (type))
4735 check_for_casting_away_constness (intype, type, diag_fn, desc);
4736 return build_nop (type, expr);
4740 return error_mark_node;
4743 /* Return an expression representing static_cast<TYPE>(EXPR). */
4746 build_static_cast (tree type, tree expr)
4751 if (type == error_mark_node || expr == error_mark_node)
4752 return error_mark_node;
4754 if (processing_template_decl)
4756 expr = build_min (STATIC_CAST_EXPR, type, expr);
4757 /* We don't know if it will or will not have side effects. */
4758 TREE_SIDE_EFFECTS (expr) = 1;
4759 return convert_from_reference (expr);
4762 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4763 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4764 if (TREE_CODE (type) != REFERENCE_TYPE
4765 && TREE_CODE (expr) == NOP_EXPR
4766 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4767 expr = TREE_OPERAND (expr, 0);
4769 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
4773 error ("invalid static_cast from type %qT to type %qT",
4774 TREE_TYPE (expr), type);
4775 return error_mark_node;
4778 /* EXPR is an expression with member function or pointer-to-member
4779 function type. TYPE is a pointer type. Converting EXPR to TYPE is
4780 not permitted by ISO C++, but we accept it in some modes. If we
4781 are not in one of those modes, issue a diagnostic. Return the
4782 converted expression. */
4785 convert_member_func_to_ptr (tree type, tree expr)
4790 intype = TREE_TYPE (expr);
4791 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
4792 || TREE_CODE (intype) == METHOD_TYPE);
4794 if (pedantic || warn_pmf2ptr)
4795 pedwarn ("converting from %qT to %qT", intype, type);
4797 if (TREE_CODE (intype) == METHOD_TYPE)
4798 expr = build_addr_func (expr);
4799 else if (TREE_CODE (expr) == PTRMEM_CST)
4800 expr = build_address (PTRMEM_CST_MEMBER (expr));
4803 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
4804 decl = build_address (decl);
4805 expr = get_member_function_from_ptrfunc (&decl, expr);
4808 return build_nop (type, expr);
4811 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
4812 If C_CAST_P is true, this reinterpret cast is being done as part of
4813 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
4814 indicate whether or not reinterpret_cast was valid. */
4817 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
4822 /* Assume the cast is invalid. */
4826 if (type == error_mark_node || error_operand_p (expr))
4827 return error_mark_node;
4829 intype = TREE_TYPE (expr);
4831 /* [expr.reinterpret.cast]
4832 An lvalue expression of type T1 can be cast to the type
4833 "reference to T2" if an expression of type "pointer to T1" can be
4834 explicitly converted to the type "pointer to T2" using a
4835 reinterpret_cast. */
4836 if (TREE_CODE (type) == REFERENCE_TYPE)
4838 if (! real_lvalue_p (expr))
4840 error ("invalid cast of an rvalue expression of type "
4843 return error_mark_node;
4846 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
4847 "B" are related class types; the reinterpret_cast does not
4848 adjust the pointer. */
4849 if (TYPE_PTR_P (intype)
4850 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
4851 COMPARE_BASE | COMPARE_DERIVED)))
4852 warning (0, "casting %qT to %qT does not dereference pointer",
4855 expr = build_unary_op (ADDR_EXPR, expr, 0);
4856 if (expr != error_mark_node)
4857 expr = build_reinterpret_cast_1
4858 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
4860 if (expr != error_mark_node)
4861 expr = build_indirect_ref (expr, 0);
4865 /* As a G++ extension, we consider conversions from member
4866 functions, and pointers to member functions to
4867 pointer-to-function and pointer-to-void types. If
4868 -Wno-pmf-conversions has not been specified,
4869 convert_member_func_to_ptr will issue an error message. */
4870 if ((TYPE_PTRMEMFUNC_P (intype)
4871 || TREE_CODE (intype) == METHOD_TYPE)
4872 && TYPE_PTR_P (type)
4873 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
4874 || VOID_TYPE_P (TREE_TYPE (type))))
4875 return convert_member_func_to_ptr (type, expr);
4877 /* If the cast is not to a reference type, the lvalue-to-rvalue,
4878 array-to-pointer, and function-to-pointer conversions are
4880 expr = decay_conversion (expr);
4882 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4883 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4884 if (TREE_CODE (expr) == NOP_EXPR
4885 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4886 expr = TREE_OPERAND (expr, 0);
4888 if (error_operand_p (expr))
4889 return error_mark_node;
4891 intype = TREE_TYPE (expr);
4893 /* [expr.reinterpret.cast]
4894 A pointer can be converted to any integral type large enough to
4896 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
4898 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
4899 pedwarn ("cast from %qT to %qT loses precision",
4902 /* [expr.reinterpret.cast]
4903 A value of integral or enumeration type can be explicitly
4904 converted to a pointer. */
4905 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
4908 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
4909 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4910 return fold_if_not_in_template (build_nop (type, expr));
4911 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4912 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
4915 check_for_casting_away_constness (intype, type, error,
4916 "reinterpret_cast");
4917 /* Warn about possible alignment problems. */
4918 if (STRICT_ALIGNMENT && warn_cast_align
4919 && !VOID_TYPE_P (type)
4920 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
4921 && COMPLETE_TYPE_P (TREE_TYPE (type))
4922 && COMPLETE_TYPE_P (TREE_TYPE (intype))
4923 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
4924 warning (0, "cast from %qT to %qT increases required alignment of "
4928 return fold_if_not_in_template (build_nop (type, expr));
4930 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
4931 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
4934 /* Only issue a warning, as we have always supported this
4935 where possible, and it is necessary in some cases. DR 195
4936 addresses this issue, but as of 2004/10/26 is still in
4938 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
4939 return fold_if_not_in_template (build_nop (type, expr));
4941 else if (TREE_CODE (type) == VECTOR_TYPE)
4942 return fold_if_not_in_template (convert_to_vector (type, expr));
4943 else if (TREE_CODE (intype) == VECTOR_TYPE)
4944 return fold_if_not_in_template (convert_to_integer (type, expr));
4949 error ("invalid cast from type %qT to type %qT", intype, type);
4950 return error_mark_node;
4953 return cp_convert (type, expr);
4957 build_reinterpret_cast (tree type, tree expr)
4959 if (type == error_mark_node || expr == error_mark_node)
4960 return error_mark_node;
4962 if (processing_template_decl)
4964 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
4966 if (!TREE_SIDE_EFFECTS (t)
4967 && type_dependent_expression_p (expr))
4968 /* There might turn out to be side effects inside expr. */
4969 TREE_SIDE_EFFECTS (t) = 1;
4970 return convert_from_reference (t);
4973 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
4977 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
4978 return an appropriate expression. Otherwise, return
4979 error_mark_node. If the cast is not valid, and COMPLAIN is true,
4980 then a diagnostic will be issued. If VALID_P is non-NULL, its
4981 value upon return will indicate whether or not the conversion
4985 build_const_cast_1 (tree dst_type, tree expr, bool complain,
4989 tree reference_type;
4991 /* Callers are responsible for handling error_mark_node as a
4992 destination type. */
4993 gcc_assert (dst_type != error_mark_node);
4994 /* In a template, callers should be building syntactic
4995 representations of casts, not using this machinery. */
4996 gcc_assert (!processing_template_decl);
4998 /* Assume the conversion is invalid. */
5002 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5005 error ("invalid use of const_cast with type %qT, "
5006 "which is not a pointer, "
5007 "reference, nor a pointer-to-data-member type", dst_type);
5008 return error_mark_node;
5011 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5014 error ("invalid use of const_cast with type %qT, which is a pointer "
5015 "or reference to a function type", dst_type);
5016 return error_mark_node;
5019 src_type = TREE_TYPE (expr);
5020 /* Expressions do not really have reference types. */
5021 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5022 src_type = TREE_TYPE (src_type);
5024 /* [expr.const.cast]
5026 An lvalue of type T1 can be explicitly converted to an lvalue of
5027 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5028 types) if a pointer to T1 can be explicitly converted to the type
5029 pointer to T2 using a const_cast. */
5030 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5032 reference_type = dst_type;
5033 if (! real_lvalue_p (expr))
5036 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5037 src_type, dst_type);
5038 return error_mark_node;
5040 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5041 src_type = build_pointer_type (src_type);
5045 reference_type = NULL_TREE;
5046 /* If the destination type is not a reference type, the
5047 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5048 conversions are performed. */
5049 src_type = type_decays_to (src_type);
5050 if (src_type == error_mark_node)
5051 return error_mark_node;
5054 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5055 && comp_ptr_ttypes_const (dst_type, src_type))
5061 expr = build_unary_op (ADDR_EXPR, expr, 0);
5062 expr = build_nop (reference_type, expr);
5063 return convert_from_reference (expr);
5067 expr = decay_conversion (expr);
5068 /* build_c_cast puts on a NOP_EXPR to make the result not an
5069 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5070 non-lvalue context. */
5071 if (TREE_CODE (expr) == NOP_EXPR
5072 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5073 expr = TREE_OPERAND (expr, 0);
5074 return build_nop (dst_type, expr);
5079 error ("invalid const_cast from type %qT to type %qT",
5080 src_type, dst_type);
5081 return error_mark_node;
5085 build_const_cast (tree type, tree expr)
5087 if (type == error_mark_node || error_operand_p (expr))
5088 return error_mark_node;
5090 if (processing_template_decl)
5092 tree t = build_min (CONST_CAST_EXPR, type, expr);
5094 if (!TREE_SIDE_EFFECTS (t)
5095 && type_dependent_expression_p (expr))
5096 /* There might turn out to be side effects inside expr. */
5097 TREE_SIDE_EFFECTS (t) = 1;
5098 return convert_from_reference (t);
5101 return build_const_cast_1 (type, expr, /*complain=*/true,
5105 /* Build an expression representing an explicit C-style cast to type
5106 TYPE of expression EXPR. */
5109 build_c_cast (tree type, tree expr)
5115 if (type == error_mark_node || error_operand_p (expr))
5116 return error_mark_node;
5118 if (processing_template_decl)
5120 tree t = build_min (CAST_EXPR, type,
5121 tree_cons (NULL_TREE, value, NULL_TREE));
5122 /* We don't know if it will or will not have side effects. */
5123 TREE_SIDE_EFFECTS (t) = 1;
5124 return convert_from_reference (t);
5127 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5128 'Class') should always be retained, because this information aids
5129 in method lookup. */
5130 if (objc_is_object_ptr (type)
5131 && objc_is_object_ptr (TREE_TYPE (expr)))
5132 return build_nop (type, expr);
5134 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5135 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5136 if (TREE_CODE (type) != REFERENCE_TYPE
5137 && TREE_CODE (value) == NOP_EXPR
5138 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5139 value = TREE_OPERAND (value, 0);
5141 if (TREE_CODE (type) == ARRAY_TYPE)
5143 /* Allow casting from T1* to T2[] because Cfront allows it.
5144 NIHCL uses it. It is not valid ISO C++ however. */
5145 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5147 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5148 type = build_pointer_type (TREE_TYPE (type));
5152 error ("ISO C++ forbids casting to an array type %qT", type);
5153 return error_mark_node;
5157 if (TREE_CODE (type) == FUNCTION_TYPE
5158 || TREE_CODE (type) == METHOD_TYPE)
5160 error ("invalid cast to function type %qT", type);
5161 return error_mark_node;
5164 /* A C-style cast can be a const_cast. */
5165 result = build_const_cast_1 (type, value, /*complain=*/false,
5170 /* Or a static cast. */
5171 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5173 /* Or a reinterpret_cast. */
5175 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5177 /* The static_cast or reinterpret_cast may be followed by a
5180 /* A valid cast may result in errors if, for example, a
5181 conversion to am ambiguous base class is required. */
5182 && !error_operand_p (result))
5186 /* Non-class rvalues always have cv-unqualified type. */
5187 if (!CLASS_TYPE_P (type))
5188 type = TYPE_MAIN_VARIANT (type);
5189 result_type = TREE_TYPE (result);
5190 if (!CLASS_TYPE_P (result_type))
5191 result_type = TYPE_MAIN_VARIANT (result_type);
5192 /* If the type of RESULT does not match TYPE, perform a
5193 const_cast to make it match. If the static_cast or
5194 reinterpret_cast succeeded, we will differ by at most
5195 cv-qualification, so the follow-on const_cast is guaranteed
5197 if (!same_type_p (non_reference (type), non_reference (result_type)))
5199 result = build_const_cast_1 (type, result, false, &valid_p);
5200 gcc_assert (valid_p);
5205 return error_mark_node;
5208 /* Build an assignment expression of lvalue LHS from value RHS.
5209 MODIFYCODE is the code for a binary operator that we use
5210 to combine the old value of LHS with RHS to get the new value.
5211 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5213 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5216 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5220 tree lhstype = TREE_TYPE (lhs);
5221 tree olhstype = lhstype;
5222 tree olhs = NULL_TREE;
5223 bool plain_assign = (modifycode == NOP_EXPR);
5225 /* Avoid duplicate error messages from operands that had errors. */
5226 if (lhs == error_mark_node || rhs == error_mark_node)
5227 return error_mark_node;
5229 /* Handle control structure constructs used as "lvalues". */
5230 switch (TREE_CODE (lhs))
5232 /* Handle --foo = 5; as these are valid constructs in C++. */
5233 case PREDECREMENT_EXPR:
5234 case PREINCREMENT_EXPR:
5235 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5236 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5237 stabilize_reference (TREE_OPERAND (lhs, 0)),
5238 TREE_OPERAND (lhs, 1));
5239 return build2 (COMPOUND_EXPR, lhstype,
5241 build_modify_expr (TREE_OPERAND (lhs, 0),
5244 /* Handle (a, b) used as an "lvalue". */
5246 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5248 if (newrhs == error_mark_node)
5249 return error_mark_node;
5250 return build2 (COMPOUND_EXPR, lhstype,
5251 TREE_OPERAND (lhs, 0), newrhs);
5254 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5255 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5256 stabilize_reference (TREE_OPERAND (lhs, 0)),
5257 TREE_OPERAND (lhs, 1));
5258 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5259 if (newrhs == error_mark_node)
5260 return error_mark_node;
5261 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5265 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5266 when neither operand has side-effects. */
5267 if (!lvalue_or_else (lhs, lv_assign))
5268 return error_mark_node;
5270 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5271 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5273 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5274 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5276 TREE_OPERAND (lhs, 0),
5277 TREE_OPERAND (lhs, 1)),
5278 TREE_OPERAND (lhs, 0),
5279 TREE_OPERAND (lhs, 1));
5282 /* Handle (a ? b : c) used as an "lvalue". */
5285 /* Produce (a ? (b = rhs) : (c = rhs))
5286 except that the RHS goes through a save-expr
5287 so the code to compute it is only emitted once. */
5289 tree preeval = NULL_TREE;
5291 rhs = stabilize_expr (rhs, &preeval);
5293 /* Check this here to avoid odd errors when trying to convert
5294 a throw to the type of the COND_EXPR. */
5295 if (!lvalue_or_else (lhs, lv_assign))
5296 return error_mark_node;
5298 cond = build_conditional_expr
5299 (TREE_OPERAND (lhs, 0),
5300 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5301 TREE_OPERAND (lhs, 1)),
5303 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5304 TREE_OPERAND (lhs, 2)),
5307 if (cond == error_mark_node)
5309 /* Make sure the code to compute the rhs comes out
5310 before the split. */
5312 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5320 if (modifycode == INIT_EXPR)
5322 if (TREE_CODE (rhs) == CONSTRUCTOR)
5324 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5325 /* Call convert to generate an error; see PR 11063. */
5326 rhs = convert (lhstype, rhs);
5327 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5328 TREE_SIDE_EFFECTS (result) = 1;
5331 else if (! IS_AGGR_TYPE (lhstype))
5332 /* Do the default thing. */;
5335 result = build_special_member_call (lhs, complete_ctor_identifier,
5336 build_tree_list (NULL_TREE, rhs),
5337 lhstype, LOOKUP_NORMAL);
5338 if (result == NULL_TREE)
5339 return error_mark_node;
5345 lhs = require_complete_type (lhs);
5346 if (lhs == error_mark_node)
5347 return error_mark_node;
5349 if (modifycode == NOP_EXPR)
5351 /* `operator=' is not an inheritable operator. */
5352 if (! IS_AGGR_TYPE (lhstype))
5353 /* Do the default thing. */;
5356 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5357 lhs, rhs, make_node (NOP_EXPR),
5358 /*overloaded_p=*/NULL);
5359 if (result == NULL_TREE)
5360 return error_mark_node;
5367 /* A binary op has been requested. Combine the old LHS
5368 value with the RHS producing the value we should actually
5369 store into the LHS. */
5371 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5372 lhs = stabilize_reference (lhs);
5373 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5374 if (newrhs == error_mark_node)
5376 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5377 TREE_TYPE (lhs), TREE_TYPE (rhs));
5378 return error_mark_node;
5381 /* Now it looks like a plain assignment. */
5382 modifycode = NOP_EXPR;
5384 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5385 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5388 /* The left-hand side must be an lvalue. */
5389 if (!lvalue_or_else (lhs, lv_assign))
5390 return error_mark_node;
5392 /* Warn about modifying something that is `const'. Don't warn if
5393 this is initialization. */
5394 if (modifycode != INIT_EXPR
5395 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5396 /* Functions are not modifiable, even though they are
5398 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5399 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5400 /* If it's an aggregate and any field is const, then it is
5401 effectively const. */
5402 || (CLASS_TYPE_P (lhstype)
5403 && C_TYPE_FIELDS_READONLY (lhstype))))
5404 readonly_error (lhs, "assignment", 0);
5406 /* If storing into a structure or union member, it has probably been
5407 given type `int'. Compute the type that would go with the actual
5408 amount of storage the member occupies. */
5410 if (TREE_CODE (lhs) == COMPONENT_REF
5411 && (TREE_CODE (lhstype) == INTEGER_TYPE
5412 || TREE_CODE (lhstype) == REAL_TYPE
5413 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5415 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5417 /* If storing in a field that is in actuality a short or narrower
5418 than one, we must store in the field in its actual type. */
5420 if (lhstype != TREE_TYPE (lhs))
5422 /* Avoid warnings converting integral types back into enums for
5424 if (TREE_CODE (lhstype) == INTEGER_TYPE
5425 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5427 if (TREE_SIDE_EFFECTS (lhs))
5428 lhs = stabilize_reference (lhs);
5431 lhs = copy_node (lhs);
5432 TREE_TYPE (lhs) = lhstype;
5436 /* Convert new value to destination type. */
5438 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5442 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5443 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5445 error ("incompatible types in assignment of %qT to %qT",
5446 TREE_TYPE (rhs), lhstype);
5447 return error_mark_node;
5450 /* Allow array assignment in compiler-generated code. */
5451 if (! DECL_ARTIFICIAL (current_function_decl))
5452 pedwarn ("ISO C++ forbids assignment of arrays");
5454 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5455 ? 1 + (modifycode != INIT_EXPR): 0;
5456 return build_vec_init (lhs, NULL_TREE, newrhs, from_array);
5459 if (modifycode == INIT_EXPR)
5460 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5461 "initialization", NULL_TREE, 0);
5464 /* Avoid warnings on enum bit fields. */
5465 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5466 && TREE_CODE (lhstype) == INTEGER_TYPE)
5468 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5470 newrhs = convert_force (lhstype, newrhs, 0);
5473 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5475 if (TREE_CODE (newrhs) == CALL_EXPR
5476 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5477 newrhs = build_cplus_new (lhstype, newrhs);
5479 /* Can't initialize directly from a TARGET_EXPR, since that would
5480 cause the lhs to be constructed twice, and possibly result in
5481 accidental self-initialization. So we force the TARGET_EXPR to be
5482 expanded without a target. */
5483 if (TREE_CODE (newrhs) == TARGET_EXPR)
5484 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5485 TREE_OPERAND (newrhs, 0));
5488 if (newrhs == error_mark_node)
5489 return error_mark_node;
5491 if (c_dialect_objc () && flag_objc_gc)
5493 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5499 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5500 lhstype, lhs, newrhs);
5502 TREE_SIDE_EFFECTS (result) = 1;
5504 TREE_NO_WARNING (result) = 1;
5506 /* If we got the LHS in a different type for storing in,
5507 convert the result back to the nominal type of LHS
5508 so that the value we return always has the same type
5509 as the LHS argument. */
5511 if (olhstype == TREE_TYPE (result))
5515 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5516 TREE_NO_WARNING (result) = 1;
5519 return convert_for_assignment (olhstype, result, "assignment",
5524 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5526 if (processing_template_decl)
5527 return build_min_nt (MODOP_EXPR, lhs,
5528 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5530 if (modifycode != NOP_EXPR)
5532 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5533 make_node (modifycode),
5534 /*overloaded_p=*/NULL);
5537 TREE_NO_WARNING (rval) = 1;
5541 return build_modify_expr (lhs, modifycode, rhs);
5545 /* Get difference in deltas for different pointer to member function
5546 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5547 the conversion is invalid, the constant is zero. If
5548 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5549 If C_CAST_P is true this conversion is taking place as part of a
5552 Note that the naming of FROM and TO is kind of backwards; the return
5553 value is what we add to a TO in order to get a FROM. They are named
5554 this way because we call this function to find out how to convert from
5555 a pointer to member of FROM to a pointer to member of TO. */
5558 get_delta_difference (tree from, tree to,
5559 bool allow_inverse_p,
5566 /* Assume no conversion is required. */
5567 result = integer_zero_node;
5568 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5569 if (kind == bk_inaccessible || kind == bk_ambig)
5570 error (" in pointer to member function conversion");
5573 if (kind != bk_via_virtual)
5574 result = BINFO_OFFSET (binfo);
5577 tree virt_binfo = binfo_from_vbase (binfo);
5579 /* This is a reinterpret cast, we choose to do nothing. */
5580 if (allow_inverse_p)
5581 warning (0, "pointer to member cast via virtual base %qT",
5582 BINFO_TYPE (virt_binfo));
5584 error ("pointer to member conversion via virtual base %qT",
5585 BINFO_TYPE (virt_binfo));
5588 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
5589 /* Pointer to member of incomplete class is permitted*/;
5590 else if (!allow_inverse_p)
5592 error_not_base_type (from, to);
5593 error (" in pointer to member conversion");
5597 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
5600 if (kind != bk_via_virtual)
5601 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5604 /* This is a reinterpret cast, we choose to do nothing. */
5605 tree virt_binfo = binfo_from_vbase (binfo);
5607 warning (0, "pointer to member cast via virtual base %qT",
5608 BINFO_TYPE (virt_binfo));
5613 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5617 /* Return a constructor for the pointer-to-member-function TYPE using
5618 the other components as specified. */
5621 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5627 /* Pull the FIELD_DECLs out of the type. */
5628 pfn_field = TYPE_FIELDS (type);
5629 delta_field = TREE_CHAIN (pfn_field);
5631 /* Make sure DELTA has the type we want. */
5632 delta = convert_and_check (delta_type_node, delta);
5634 /* Finish creating the initializer. */
5635 u = tree_cons (pfn_field, pfn,
5636 build_tree_list (delta_field, delta));
5637 u = build_constructor (type, u);
5638 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5639 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
5640 TREE_STATIC (u) = (TREE_CONSTANT (u)
5641 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5643 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5648 /* Build a constructor for a pointer to member function. It can be
5649 used to initialize global variables, local variable, or used
5650 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5653 If FORCE is nonzero, then force this conversion, even if
5654 we would rather not do it. Usually set when using an explicit
5655 cast. A C-style cast is being processed iff C_CAST_P is true.
5657 Return error_mark_node, if something goes wrong. */
5660 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
5666 if (error_operand_p (pfn))
5667 return error_mark_node;
5669 pfn_type = TREE_TYPE (pfn);
5670 to_type = build_ptrmemfunc_type (type);
5672 /* Handle multiple conversions of pointer to member functions. */
5673 if (TYPE_PTRMEMFUNC_P (pfn_type))
5675 tree delta = NULL_TREE;
5676 tree npfn = NULL_TREE;
5680 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn))
5681 error ("invalid conversion to type %qT from type %qT",
5684 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
5685 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
5689 /* We don't have to do any conversion to convert a
5690 pointer-to-member to its own type. But, we don't want to
5691 just return a PTRMEM_CST if there's an explicit cast; that
5692 cast should make the expression an invalid template argument. */
5693 if (TREE_CODE (pfn) != PTRMEM_CST)
5695 if (same_type_p (to_type, pfn_type))
5697 else if (integer_zerop (n))
5698 return build_reinterpret_cast (to_type, pfn);
5701 if (TREE_SIDE_EFFECTS (pfn))
5702 pfn = save_expr (pfn);
5704 /* Obtain the function pointer and the current DELTA. */
5705 if (TREE_CODE (pfn) == PTRMEM_CST)
5706 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
5709 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
5710 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
5713 /* Just adjust the DELTA field. */
5714 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5715 (TREE_TYPE (delta), ptrdiff_type_node));
5716 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
5717 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
5718 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
5719 return build_ptrmemfunc1 (to_type, delta, npfn);
5722 /* Handle null pointer to member function conversions. */
5723 if (integer_zerop (pfn))
5725 pfn = build_c_cast (type, integer_zero_node);
5726 return build_ptrmemfunc1 (to_type,
5731 if (type_unknown_p (pfn))
5732 return instantiate_type (type, pfn, tf_error | tf_warning);
5734 fn = TREE_OPERAND (pfn, 0);
5735 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
5736 /* In a template, we will have preserved the
5738 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
5739 return make_ptrmem_cst (to_type, fn);
5742 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
5745 ??? There is no consistency as to the types returned for the above
5746 values. Some code acts as if it were a sizetype and some as if it were
5747 integer_type_node. */
5750 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
5752 tree type = TREE_TYPE (cst);
5753 tree fn = PTRMEM_CST_MEMBER (cst);
5754 tree ptr_class, fn_class;
5756 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5758 /* The class that the function belongs to. */
5759 fn_class = DECL_CONTEXT (fn);
5761 /* The class that we're creating a pointer to member of. */
5762 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
5764 /* First, calculate the adjustment to the function's class. */
5765 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
5768 if (!DECL_VIRTUAL_P (fn))
5769 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
5772 /* If we're dealing with a virtual function, we have to adjust 'this'
5773 again, to point to the base which provides the vtable entry for
5774 fn; the call will do the opposite adjustment. */
5775 tree orig_class = DECL_CONTEXT (fn);
5776 tree binfo = binfo_or_else (orig_class, fn_class);
5777 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5778 *delta, BINFO_OFFSET (binfo));
5779 *delta = fold_if_not_in_template (*delta);
5781 /* We set PFN to the vtable offset at which the function can be
5782 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
5783 case delta is shifted left, and then incremented). */
5784 *pfn = DECL_VINDEX (fn);
5785 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
5786 TYPE_SIZE_UNIT (vtable_entry_type));
5787 *pfn = fold_if_not_in_template (*pfn);
5789 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
5791 case ptrmemfunc_vbit_in_pfn:
5792 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
5794 *pfn = fold_if_not_in_template (*pfn);
5797 case ptrmemfunc_vbit_in_delta:
5798 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
5799 *delta, integer_one_node);
5800 *delta = fold_if_not_in_template (*delta);
5801 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5802 *delta, integer_one_node);
5803 *delta = fold_if_not_in_template (*delta);
5810 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
5811 *pfn = fold_if_not_in_template (*pfn);
5815 /* Return an expression for PFN from the pointer-to-member function
5819 pfn_from_ptrmemfunc (tree t)
5821 if (TREE_CODE (t) == PTRMEM_CST)
5826 expand_ptrmemfunc_cst (t, &delta, &pfn);
5831 return build_ptrmemfunc_access_expr (t, pfn_identifier);
5834 /* Convert value RHS to type TYPE as preparation for an assignment to
5835 an lvalue of type TYPE. ERRTYPE is a string to use in error
5836 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
5837 are doing the conversion in order to pass the PARMNUMth argument of
5841 convert_for_assignment (tree type, tree rhs,
5842 const char *errtype, tree fndecl, int parmnum)
5845 enum tree_code coder;
5847 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
5848 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
5849 rhs = TREE_OPERAND (rhs, 0);
5851 rhstype = TREE_TYPE (rhs);
5852 coder = TREE_CODE (rhstype);
5854 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
5855 && vector_types_convertible_p (type, rhstype))
5856 return convert (type, rhs);
5858 if (rhs == error_mark_node || rhstype == error_mark_node)
5859 return error_mark_node;
5860 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
5861 return error_mark_node;
5863 /* The RHS of an assignment cannot have void type. */
5864 if (coder == VOID_TYPE)
5866 error ("void value not ignored as it ought to be");
5867 return error_mark_node;
5870 /* Simplify the RHS if possible. */
5871 if (TREE_CODE (rhs) == CONST_DECL)
5872 rhs = DECL_INITIAL (rhs);
5874 if (c_dialect_objc ())
5877 tree rname = fndecl;
5879 if (!strcmp (errtype, "assignment"))
5881 else if (!strcmp (errtype, "initialization"))
5885 tree selector = objc_message_selector ();
5889 if (selector && parmno > 1)
5896 if (objc_compare_types (type, rhstype, parmno, rname))
5897 return convert (type, rhs);
5902 The expression is implicitly converted (clause _conv_) to the
5903 cv-unqualified type of the left operand.
5905 We allow bad conversions here because by the time we get to this point
5906 we are committed to doing the conversion. If we end up doing a bad
5907 conversion, convert_like will complain. */
5908 if (!can_convert_arg_bad (type, rhstype, rhs))
5910 /* When -Wno-pmf-conversions is use, we just silently allow
5911 conversions from pointers-to-members to plain pointers. If
5912 the conversion doesn't work, cp_convert will complain. */
5914 && TYPE_PTR_P (type)
5915 && TYPE_PTRMEMFUNC_P (rhstype))
5916 rhs = cp_convert (strip_top_quals (type), rhs);
5919 /* If the right-hand side has unknown type, then it is an
5920 overloaded function. Call instantiate_type to get error
5922 if (rhstype == unknown_type_node)
5923 instantiate_type (type, rhs, tf_error | tf_warning);
5925 error ("cannot convert %qT to %qT for argument %qP to %qD",
5926 rhstype, type, parmnum, fndecl);
5928 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
5929 return error_mark_node;
5932 return perform_implicit_conversion (strip_top_quals (type), rhs);
5935 /* Convert RHS to be of type TYPE.
5936 If EXP is nonzero, it is the target of the initialization.
5937 ERRTYPE is a string to use in error messages.
5939 Two major differences between the behavior of
5940 `convert_for_assignment' and `convert_for_initialization'
5941 are that references are bashed in the former, while
5942 copied in the latter, and aggregates are assigned in
5943 the former (operator=) while initialized in the
5946 If using constructor make sure no conversion operator exists, if one does
5947 exist, an ambiguity exists.
5949 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
5952 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
5953 const char *errtype, tree fndecl, int parmnum)
5955 enum tree_code codel = TREE_CODE (type);
5957 enum tree_code coder;
5959 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5960 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
5961 if (TREE_CODE (rhs) == NOP_EXPR
5962 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
5963 && codel != REFERENCE_TYPE)
5964 rhs = TREE_OPERAND (rhs, 0);
5966 if (rhs == error_mark_node
5967 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
5968 return error_mark_node;
5970 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
5971 && TREE_CODE (type) != ARRAY_TYPE
5972 && (TREE_CODE (type) != REFERENCE_TYPE
5973 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
5974 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
5975 && (TREE_CODE (type) != REFERENCE_TYPE
5976 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
5977 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
5978 rhs = decay_conversion (rhs);
5980 rhstype = TREE_TYPE (rhs);
5981 coder = TREE_CODE (rhstype);
5983 if (coder == ERROR_MARK)
5984 return error_mark_node;
5986 /* We accept references to incomplete types, so we can
5987 return here before checking if RHS is of complete type. */
5989 if (codel == REFERENCE_TYPE)
5991 /* This should eventually happen in convert_arguments. */
5992 int savew = 0, savee = 0;
5995 savew = warningcount, savee = errorcount;
5996 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6000 if (warningcount > savew)
6001 cp_warning_at ("in passing argument %P of %q+D", parmnum, fndecl);
6002 else if (errorcount > savee)
6003 cp_error_at ("in passing argument %P of %q+D", parmnum, fndecl);
6009 exp = require_complete_type (exp);
6010 if (exp == error_mark_node)
6011 return error_mark_node;
6013 rhstype = non_reference (rhstype);
6015 type = complete_type (type);
6017 if (IS_AGGR_TYPE (type))
6018 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6020 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6023 /* If RETVAL is the address of, or a reference to, a local variable or
6024 temporary give an appropriate warning. */
6027 maybe_warn_about_returning_address_of_local (tree retval)
6029 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6030 tree whats_returned = retval;
6034 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6035 whats_returned = TREE_OPERAND (whats_returned, 1);
6036 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6037 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6038 || TREE_CODE (whats_returned) == NOP_EXPR)
6039 whats_returned = TREE_OPERAND (whats_returned, 0);
6044 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6046 whats_returned = TREE_OPERAND (whats_returned, 0);
6048 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6050 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6051 || TREE_CODE (whats_returned) == TARGET_EXPR)
6053 warning (0, "returning reference to temporary");
6056 if (TREE_CODE (whats_returned) == VAR_DECL
6057 && DECL_NAME (whats_returned)
6058 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6060 warning (0, "reference to non-lvalue returned");
6065 if (DECL_P (whats_returned)
6066 && DECL_NAME (whats_returned)
6067 && DECL_FUNCTION_SCOPE_P (whats_returned)
6068 && !(TREE_STATIC (whats_returned)
6069 || TREE_PUBLIC (whats_returned)))
6071 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6072 cp_warning_at ("reference to local variable %qD returned",
6075 cp_warning_at ("address of local variable %qD returned",
6081 /* Check that returning RETVAL from the current function is valid.
6082 Return an expression explicitly showing all conversions required to
6083 change RETVAL into the function return type, and to assign it to
6084 the DECL_RESULT for the function. */
6087 check_return_expr (tree retval)
6090 /* The type actually returned by the function, after any
6093 int fn_returns_value_p;
6095 /* A `volatile' function is one that isn't supposed to return, ever.
6096 (This is a G++ extension, used to get better code for functions
6097 that call the `volatile' function.) */
6098 if (TREE_THIS_VOLATILE (current_function_decl))
6099 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6101 /* Check for various simple errors. */
6102 if (DECL_DESTRUCTOR_P (current_function_decl))
6105 error ("returning a value from a destructor");
6108 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6110 if (in_function_try_handler)
6111 /* If a return statement appears in a handler of the
6112 function-try-block of a constructor, the program is ill-formed. */
6113 error ("cannot return from a handler of a function-try-block of a constructor");
6115 /* You can't return a value from a constructor. */
6116 error ("returning a value from a constructor");
6120 if (processing_template_decl)
6122 current_function_returns_value = 1;
6126 /* When no explicit return-value is given in a function with a named
6127 return value, the named return value is used. */
6128 result = DECL_RESULT (current_function_decl);
6129 valtype = TREE_TYPE (result);
6130 gcc_assert (valtype != NULL_TREE);
6131 fn_returns_value_p = !VOID_TYPE_P (valtype);
6132 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6135 /* Check for a return statement with no return value in a function
6136 that's supposed to return a value. */
6137 if (!retval && fn_returns_value_p)
6139 pedwarn ("return-statement with no value, in function returning %qT",
6141 /* Clear this, so finish_function won't say that we reach the
6142 end of a non-void function (which we don't, we gave a
6144 current_function_returns_null = 0;
6146 /* Check for a return statement with a value in a function that
6147 isn't supposed to return a value. */
6148 else if (retval && !fn_returns_value_p)
6150 if (VOID_TYPE_P (TREE_TYPE (retval)))
6151 /* You can return a `void' value from a function of `void'
6152 type. In that case, we have to evaluate the expression for
6153 its side-effects. */
6154 finish_expr_stmt (retval);
6156 pedwarn ("return-statement with a value, in function "
6157 "returning 'void'");
6159 current_function_returns_null = 1;
6161 /* There's really no value to return, after all. */
6165 /* Remember that this function can sometimes return without a
6167 current_function_returns_null = 1;
6169 /* Remember that this function did return a value. */
6170 current_function_returns_value = 1;
6172 /* Check for erroneous operands -- but after giving ourselves a
6173 chance to provide an error about returning a value from a void
6175 if (error_operand_p (retval))
6177 current_function_return_value = error_mark_node;
6178 return error_mark_node;
6181 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6182 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6183 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6184 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6186 && null_ptr_cst_p (retval))
6187 warning (0, "%<operator new%> must not return NULL unless it is "
6188 "declared %<throw()%> (or -fcheck-new is in effect)");
6190 /* Effective C++ rule 15. See also start_function. */
6192 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6196 /* The function return type must be a reference to the current
6198 if (TREE_CODE (valtype) == REFERENCE_TYPE
6199 && same_type_ignoring_top_level_qualifiers_p
6200 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6202 /* Returning '*this' is obviously OK. */
6203 if (retval == current_class_ref)
6205 /* If we are calling a function whose return type is the same of
6206 the current class reference, it is ok. */
6207 else if (TREE_CODE (retval) == INDIRECT_REF
6208 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6213 warning (0, "%<operator=%> should return a reference to %<*this%>");
6216 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6218 [...] For a function with a class return type, if the expression
6219 in the return statement is the name of a local object, and the cv-
6220 unqualified type of the local object is the same as the function
6221 return type, an implementation is permitted to omit creating the tem-
6222 porary object to hold the function return value [...]
6224 So, if this is a value-returning function that always returns the same
6225 local variable, remember it.
6227 It might be nice to be more flexible, and choose the first suitable
6228 variable even if the function sometimes returns something else, but
6229 then we run the risk of clobbering the variable we chose if the other
6230 returned expression uses the chosen variable somehow. And people expect
6231 this restriction, anyway. (jason 2000-11-19)
6233 See finish_function and finalize_nrv for the rest of this optimization. */
6235 if (fn_returns_value_p && flag_elide_constructors)
6237 if (retval != NULL_TREE
6238 && (current_function_return_value == NULL_TREE
6239 || current_function_return_value == retval)
6240 && TREE_CODE (retval) == VAR_DECL
6241 && DECL_CONTEXT (retval) == current_function_decl
6242 && ! TREE_STATIC (retval)
6243 && (DECL_ALIGN (retval)
6244 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6245 && same_type_p ((TYPE_MAIN_VARIANT
6246 (TREE_TYPE (retval))),
6248 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6249 current_function_return_value = retval;
6251 current_function_return_value = error_mark_node;
6254 /* We don't need to do any conversions when there's nothing being
6259 /* Do any required conversions. */
6260 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6261 /* No conversions are required. */
6265 /* The type the function is declared to return. */
6266 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6268 /* First convert the value to the function's return type, then
6269 to the type of return value's location to handle the
6270 case that functype is smaller than the valtype. */
6271 retval = convert_for_initialization
6272 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6273 "return", NULL_TREE, 0);
6274 retval = convert (valtype, retval);
6276 /* If the conversion failed, treat this just like `return;'. */
6277 if (retval == error_mark_node)
6279 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6280 else if (! current_function_returns_struct
6281 && TREE_CODE (retval) == TARGET_EXPR
6282 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6283 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6284 TREE_OPERAND (retval, 0));
6286 maybe_warn_about_returning_address_of_local (retval);
6289 /* Actually copy the value returned into the appropriate location. */
6290 if (retval && retval != result)
6291 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6297 /* Returns nonzero if the pointer-type FROM can be converted to the
6298 pointer-type TO via a qualification conversion. If CONSTP is -1,
6299 then we return nonzero if the pointers are similar, and the
6300 cv-qualification signature of FROM is a proper subset of that of TO.
6302 If CONSTP is positive, then all outer pointers have been
6306 comp_ptr_ttypes_real (tree to, tree from, int constp)
6308 bool to_more_cv_qualified = false;
6310 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6312 if (TREE_CODE (to) != TREE_CODE (from))
6315 if (TREE_CODE (from) == OFFSET_TYPE
6316 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6317 TYPE_OFFSET_BASETYPE (to)))
6320 /* Const and volatile mean something different for function types,
6321 so the usual checks are not appropriate. */
6322 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6324 /* In Objective-C++, some types may have been 'volatilized' by
6325 the compiler for EH; when comparing them here, the volatile
6326 qualification must be ignored. */
6327 bool objc_quals_match = objc_type_quals_match (to, from);
6329 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6332 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6336 to_more_cv_qualified = true;
6340 constp &= TYPE_READONLY (to);
6343 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6344 return ((constp >= 0 || to_more_cv_qualified)
6345 && same_type_ignoring_top_level_qualifiers_p (to, from));
6349 /* When comparing, say, char ** to char const **, this function takes
6350 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6351 types to this function. */
6354 comp_ptr_ttypes (tree to, tree from)
6356 return comp_ptr_ttypes_real (to, from, 1);
6359 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6360 type or inheritance-related types, regardless of cv-quals. */
6363 ptr_reasonably_similar (tree to, tree from)
6365 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6367 /* Any target type is similar enough to void. */
6368 if (TREE_CODE (to) == VOID_TYPE
6369 || TREE_CODE (from) == VOID_TYPE)
6372 if (TREE_CODE (to) != TREE_CODE (from))
6375 if (TREE_CODE (from) == OFFSET_TYPE
6376 && comptypes (TYPE_OFFSET_BASETYPE (to),
6377 TYPE_OFFSET_BASETYPE (from),
6378 COMPARE_BASE | COMPARE_DERIVED))
6381 if (TREE_CODE (to) == VECTOR_TYPE
6382 && vector_types_convertible_p (to, from))
6385 if (TREE_CODE (to) == INTEGER_TYPE
6386 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6389 if (TREE_CODE (to) == FUNCTION_TYPE)
6392 if (TREE_CODE (to) != POINTER_TYPE)
6394 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6395 COMPARE_BASE | COMPARE_DERIVED);
6399 /* Like comp_ptr_ttypes, for const_cast. */
6402 comp_ptr_ttypes_const (tree to, tree from)
6404 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6406 if (TREE_CODE (to) != TREE_CODE (from))
6409 if (TREE_CODE (from) == OFFSET_TYPE
6410 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6411 TYPE_OFFSET_BASETYPE (to)))
6414 if (TREE_CODE (to) != POINTER_TYPE)
6415 return same_type_ignoring_top_level_qualifiers_p (to, from);
6419 /* Returns the type qualifiers for this type, including the qualifiers on the
6420 elements for an array type. */
6423 cp_type_quals (tree type)
6425 type = strip_array_types (type);
6426 if (type == error_mark_node)
6427 return TYPE_UNQUALIFIED;
6428 return TYPE_QUALS (type);
6431 /* Returns nonzero if the TYPE contains a mutable member. */
6434 cp_has_mutable_p (tree type)
6436 type = strip_array_types (type);
6438 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6441 /* Apply the TYPE_QUALS to the new DECL. */
6443 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6445 tree type = TREE_TYPE (decl);
6447 if (type == error_mark_node)
6450 if (TREE_CODE (type) == FUNCTION_TYPE
6451 && type_quals != TYPE_UNQUALIFIED)
6453 /* This was an error in C++98 (cv-qualifiers cannot be added to
6454 a function type), but DR 295 makes the code well-formed by
6455 dropping the extra qualifiers. */
6458 tree bad_type = build_qualified_type (type, type_quals);
6459 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6463 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6467 /* Avoid setting TREE_READONLY incorrectly. */
6468 if (/* If the object has a constructor, the constructor may modify
6470 TYPE_NEEDS_CONSTRUCTING (type)
6471 /* If the type isn't complete, we don't know yet if it will need
6473 || !COMPLETE_TYPE_P (type)
6474 /* If the type has a mutable component, that component might be
6476 || TYPE_HAS_MUTABLE_P (type))
6477 type_quals &= ~TYPE_QUAL_CONST;
6479 c_apply_type_quals_to_decl (type_quals, decl);
6482 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6483 exemplar types such that casting T1 to T2 is casting away constness
6484 if and only if there is no implicit conversion from T1 to T2. */
6487 casts_away_constness_r (tree *t1, tree *t2)
6492 /* [expr.const.cast]
6494 For multi-level pointer to members and multi-level mixed pointers
6495 and pointers to members (conv.qual), the "member" aspect of a
6496 pointer to member level is ignored when determining if a const
6497 cv-qualifier has been cast away. */
6498 /* [expr.const.cast]
6500 For two pointer types:
6502 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6503 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6506 casting from X1 to X2 casts away constness if, for a non-pointer
6507 type T there does not exist an implicit conversion (clause
6510 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6514 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6515 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6516 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
6518 *t1 = cp_build_qualified_type (void_type_node,
6519 cp_type_quals (*t1));
6520 *t2 = cp_build_qualified_type (void_type_node,
6521 cp_type_quals (*t2));
6525 quals1 = cp_type_quals (*t1);
6526 quals2 = cp_type_quals (*t2);
6528 if (TYPE_PTRMEM_P (*t1))
6529 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
6531 *t1 = TREE_TYPE (*t1);
6532 if (TYPE_PTRMEM_P (*t2))
6533 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
6535 *t2 = TREE_TYPE (*t2);
6537 casts_away_constness_r (t1, t2);
6538 *t1 = build_pointer_type (*t1);
6539 *t2 = build_pointer_type (*t2);
6540 *t1 = cp_build_qualified_type (*t1, quals1);
6541 *t2 = cp_build_qualified_type (*t2, quals2);
6544 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6548 casts_away_constness (tree t1, tree t2)
6550 if (TREE_CODE (t2) == REFERENCE_TYPE)
6552 /* [expr.const.cast]
6554 Casting from an lvalue of type T1 to an lvalue of type T2
6555 using a reference cast casts away constness if a cast from an
6556 rvalue of type "pointer to T1" to the type "pointer to T2"
6557 casts away constness. */
6558 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6559 return casts_away_constness (build_pointer_type (t1),
6560 build_pointer_type (TREE_TYPE (t2)));
6563 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6564 /* [expr.const.cast]
6566 Casting from an rvalue of type "pointer to data member of X
6567 of type T1" to the type "pointer to data member of Y of type
6568 T2" casts away constness if a cast from an rvalue of type
6569 "pointer to T1" to the type "pointer to T2" casts away
6571 return casts_away_constness
6572 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6573 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6575 /* Casting away constness is only something that makes sense for
6576 pointer or reference types. */
6577 if (TREE_CODE (t1) != POINTER_TYPE
6578 || TREE_CODE (t2) != POINTER_TYPE)
6581 /* Top-level qualifiers don't matter. */
6582 t1 = TYPE_MAIN_VARIANT (t1);
6583 t2 = TYPE_MAIN_VARIANT (t2);
6584 casts_away_constness_r (&t1, &t2);
6585 if (!can_convert (t2, t1))
6591 /* If T is a REFERENCE_TYPE return the type to which T refers.
6592 Otherwise, return T itself. */
6595 non_reference (tree t)
6597 if (TREE_CODE (t) == REFERENCE_TYPE)
6603 /* Return nonzero if REF is an lvalue valid for this language;
6604 otherwise, print an error message and return zero. USE says
6605 how the lvalue is being used and so selects the error message. */
6608 lvalue_or_else (tree ref, enum lvalue_use use)
6610 int win = lvalue_p (ref);