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 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"
45 static tree convert_for_assignment (tree, tree, const char *, tree, int);
46 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
47 static tree rationalize_conditional_expr (enum tree_code, tree);
48 static int comp_ptr_ttypes_real (tree, tree, int);
49 static int comp_ptr_ttypes_const (tree, tree);
50 static bool comp_except_types (tree, tree, bool);
51 static bool comp_array_types (tree, tree, bool);
52 static tree common_base_type (tree, tree);
53 static tree pointer_diff (tree, tree, tree);
54 static tree get_delta_difference (tree, tree, int);
55 static void casts_away_constness_r (tree *, tree *);
56 static bool casts_away_constness (tree, tree);
57 static void maybe_warn_about_returning_address_of_local (tree);
58 static tree lookup_destructor (tree, tree, tree);
60 /* Return the target type of TYPE, which means return T for:
61 T*, T&, T[], T (...), and otherwise, just T. */
64 target_type (tree type)
66 type = non_reference (type);
67 while (TREE_CODE (type) == POINTER_TYPE
68 || TREE_CODE (type) == ARRAY_TYPE
69 || TREE_CODE (type) == FUNCTION_TYPE
70 || TREE_CODE (type) == METHOD_TYPE
71 || TYPE_PTRMEM_P (type))
72 type = TREE_TYPE (type);
76 /* Do `exp = require_complete_type (exp);' to make sure exp
77 does not have an incomplete type. (That includes void types.)
78 Returns the error_mark_node if the VALUE does not have
79 complete type when this function returns. */
82 require_complete_type (tree value)
86 if (processing_template_decl || value == error_mark_node)
89 if (TREE_CODE (value) == OVERLOAD)
90 type = unknown_type_node;
92 type = TREE_TYPE (value);
94 if (type == error_mark_node)
95 return error_mark_node;
97 /* First, detect a valid value with a complete type. */
98 if (COMPLETE_TYPE_P (type))
101 if (complete_type_or_else (type, value))
104 return error_mark_node;
107 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
108 a template instantiation, do the instantiation. Returns TYPE,
109 whether or not it could be completed, unless something goes
110 horribly wrong, in which case the error_mark_node is returned. */
113 complete_type (tree type)
115 if (type == NULL_TREE)
116 /* Rather than crash, we return something sure to cause an error
118 return error_mark_node;
120 if (type == error_mark_node || COMPLETE_TYPE_P (type))
122 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
124 tree t = complete_type (TREE_TYPE (type));
125 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
127 TYPE_NEEDS_CONSTRUCTING (type)
128 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
129 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
130 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
132 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
133 instantiate_class_template (TYPE_MAIN_VARIANT (type));
138 /* Like complete_type, but issue an error if the TYPE cannot be completed.
139 VALUE is used for informative diagnostics. DIAG_TYPE indicates the type
140 of diagnostic: 0 for an error, 1 for a warning, 2 for a pedwarn.
141 Returns NULL_TREE if the type cannot be made complete. */
144 complete_type_or_diagnostic (tree type, tree value, int diag_type)
146 type = complete_type (type);
147 if (type == error_mark_node)
148 /* We already issued an error. */
150 else if (!COMPLETE_TYPE_P (type))
152 cxx_incomplete_type_diagnostic (value, type, diag_type);
159 /* Return truthvalue of whether type of EXP is instantiated. */
162 type_unknown_p (tree exp)
164 return (TREE_CODE (exp) == TREE_LIST
165 || TREE_TYPE (exp) == unknown_type_node);
169 /* Return the common type of two parameter lists.
170 We assume that comptypes has already been done and returned 1;
171 if that isn't so, this may crash.
173 As an optimization, free the space we allocate if the parameter
174 lists are already common. */
177 commonparms (tree p1, tree p2)
179 tree oldargs = p1, newargs, n;
183 len = list_length (p1);
184 newargs = tree_last (p1);
186 if (newargs == void_list_node)
195 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
200 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
202 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
204 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
207 else if (! TREE_PURPOSE (p1))
209 if (TREE_PURPOSE (p2))
211 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
217 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
219 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
221 if (TREE_VALUE (p1) != TREE_VALUE (p2))
224 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
227 TREE_VALUE (n) = TREE_VALUE (p1);
235 /* Given a type, perhaps copied for a typedef,
236 find the "original" version of it. */
238 original_type (tree t)
240 while (TYPE_NAME (t) != NULL_TREE)
242 tree x = TYPE_NAME (t);
243 if (TREE_CODE (x) != TYPE_DECL)
245 x = DECL_ORIGINAL_TYPE (x);
253 /* T1 and T2 are arithmetic or enumeration types. Return the type
254 that will result from the "usual arithmetic conversions" on T1 and
255 T2 as described in [expr]. */
258 type_after_usual_arithmetic_conversions (tree t1, tree t2)
260 enum tree_code code1 = TREE_CODE (t1);
261 enum tree_code code2 = TREE_CODE (t2);
264 /* FIXME: Attributes. */
265 my_friendly_assert (ARITHMETIC_TYPE_P (t1)
266 || TREE_CODE (t1) == COMPLEX_TYPE
267 || TREE_CODE (t1) == ENUMERAL_TYPE,
269 my_friendly_assert (ARITHMETIC_TYPE_P (t2)
270 || TREE_CODE (t2) == COMPLEX_TYPE
271 || TREE_CODE (t2) == ENUMERAL_TYPE,
274 /* In what follows, we slightly generalize the rules given in [expr] so
275 as to deal with `long long' and `complex'. First, merge the
277 attributes = (*targetm.merge_type_attributes) (t1, t2);
279 /* If one type is complex, form the common type of the non-complex
280 components, then make that complex. Use T1 or T2 if it is the
282 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
284 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
285 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
287 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
289 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
290 return build_type_attribute_variant (t1, attributes);
291 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
292 return build_type_attribute_variant (t2, attributes);
294 return build_type_attribute_variant (build_complex_type (subtype),
298 /* If only one is real, use it as the result. */
299 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
300 return build_type_attribute_variant (t1, attributes);
301 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
302 return build_type_attribute_variant (t2, attributes);
304 /* Perform the integral promotions. */
305 if (code1 != REAL_TYPE)
307 t1 = type_promotes_to (t1);
308 t2 = type_promotes_to (t2);
311 /* Both real or both integers; use the one with greater precision. */
312 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
313 return build_type_attribute_variant (t1, attributes);
314 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
315 return build_type_attribute_variant (t2, attributes);
317 /* The types are the same; no need to do anything fancy. */
318 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
319 return build_type_attribute_variant (t1, attributes);
321 if (code1 != REAL_TYPE)
323 /* If one is a sizetype, use it so size_binop doesn't blow up. */
324 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
325 return build_type_attribute_variant (t1, attributes);
326 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
327 return build_type_attribute_variant (t2, attributes);
329 /* If one is unsigned long long, then convert the other to unsigned
331 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
332 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
333 return build_type_attribute_variant (long_long_unsigned_type_node,
335 /* If one is a long long, and the other is an unsigned long, and
336 long long can represent all the values of an unsigned long, then
337 convert to a long long. Otherwise, convert to an unsigned long
338 long. Otherwise, if either operand is long long, convert the
341 Since we're here, we know the TYPE_PRECISION is the same;
342 therefore converting to long long cannot represent all the values
343 of an unsigned long, so we choose unsigned long long in that
345 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
346 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
348 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
349 ? long_long_unsigned_type_node
350 : long_long_integer_type_node);
351 return build_type_attribute_variant (t, attributes);
354 /* Go through the same procedure, but for longs. */
355 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
356 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
357 return build_type_attribute_variant (long_unsigned_type_node,
359 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
360 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
362 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
363 ? long_unsigned_type_node : long_integer_type_node);
364 return build_type_attribute_variant (t, attributes);
366 /* Otherwise prefer the unsigned one. */
367 if (TYPE_UNSIGNED (t1))
368 return build_type_attribute_variant (t1, attributes);
370 return build_type_attribute_variant (t2, attributes);
374 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
375 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
376 return build_type_attribute_variant (long_double_type_node,
378 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
379 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
380 return build_type_attribute_variant (double_type_node,
382 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
383 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
384 return build_type_attribute_variant (float_type_node,
387 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
388 the standard C++ floating-point types. Logic earlier in this
389 function has already eliminated the possibility that
390 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
391 compelling reason to choose one or the other. */
392 return build_type_attribute_variant (t1, attributes);
396 /* Subroutine of composite_pointer_type to implement the recursive
397 case. See that function for documentation fo the parameters. */
400 composite_pointer_type_r (tree t1, tree t2, const char* location)
407 /* Determine the types pointed to by T1 and T2. */
408 if (TREE_CODE (t1) == POINTER_TYPE)
410 pointee1 = TREE_TYPE (t1);
411 pointee2 = TREE_TYPE (t2);
415 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
416 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
421 Otherwise, the composite pointer type is a pointer type
422 similar (_conv.qual_) to the type of one of the operands,
423 with a cv-qualification signature (_conv.qual_) that is the
424 union of the cv-qualification signatures of the operand
426 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
427 result_type = pointee1;
428 else if ((TREE_CODE (pointee1) == POINTER_TYPE
429 && TREE_CODE (pointee2) == POINTER_TYPE)
430 || (TYPE_PTR_TO_MEMBER_P (pointee1)
431 && TYPE_PTR_TO_MEMBER_P (pointee2)))
432 result_type = composite_pointer_type_r (pointee1, pointee2, location);
435 pedwarn ("%s between distinct pointer types `%T' and `%T' "
438 result_type = void_type_node;
440 result_type = cp_build_qualified_type (result_type,
441 (cp_type_quals (pointee1)
442 | cp_type_quals (pointee2)));
443 /* If the original types were pointers to members, so is the
445 if (TYPE_PTR_TO_MEMBER_P (t1))
447 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
448 TYPE_PTRMEM_CLASS_TYPE (t2)))
449 pedwarn ("%s between distinct pointer types `%T' and `%T' "
452 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
456 result_type = build_pointer_type (result_type);
458 /* Merge the attributes. */
459 attributes = (*targetm.merge_type_attributes) (t1, t2);
460 return build_type_attribute_variant (result_type, attributes);
463 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
464 ARG1 and ARG2 are the values with those types. The LOCATION is a
465 string describing the current location, in case an error occurs.
467 This routine also implements the computation of a common type for
468 pointers-to-members as per [expr.eq]. */
471 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
472 const char* location)
479 If one operand is a null pointer constant, the composite pointer
480 type is the type of the other operand. */
481 if (null_ptr_cst_p (arg1))
483 if (null_ptr_cst_p (arg2))
490 If one of the operands has type "pointer to cv1 void*", then
491 the other has type "pointer to cv2T", and the composite pointer
492 type is "pointer to cv12 void", where cv12 is the union of cv1
495 If either type is a pointer to void, make sure it is T1. */
496 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
504 /* Now, if T1 is a pointer to void, merge the qualifiers. */
505 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
510 if (pedantic && TYPE_PTRFN_P (t2))
511 pedwarn ("ISO C++ forbids %s between pointer of type `void *' and pointer-to-function", location);
513 = cp_build_qualified_type (void_type_node,
514 (cp_type_quals (TREE_TYPE (t1))
515 | cp_type_quals (TREE_TYPE (t2))));
516 result_type = build_pointer_type (result_type);
517 /* Merge the attributes. */
518 attributes = (*targetm.merge_type_attributes) (t1, t2);
519 return build_type_attribute_variant (result_type, attributes);
522 /* [expr.eq] permits the application of a pointer conversion to
523 bring the pointers to a common type. */
524 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
525 && CLASS_TYPE_P (TREE_TYPE (t1))
526 && CLASS_TYPE_P (TREE_TYPE (t2))
527 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
530 class1 = TREE_TYPE (t1);
531 class2 = TREE_TYPE (t2);
533 if (DERIVED_FROM_P (class1, class2))
534 t2 = (build_pointer_type
535 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
536 else if (DERIVED_FROM_P (class2, class1))
537 t1 = (build_pointer_type
538 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
541 error ("%s between distinct pointer types `%T' and `%T' "
542 "lacks a cast", location, t1, t2);
543 return error_mark_node;
546 /* [expr.eq] permits the application of a pointer-to-member
547 conversion to change the class type of one of the types. */
548 else if (TYPE_PTR_TO_MEMBER_P (t1)
549 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
550 TYPE_PTRMEM_CLASS_TYPE (t2)))
552 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
553 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
555 if (DERIVED_FROM_P (class1, class2))
556 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
557 else if (DERIVED_FROM_P (class2, class1))
558 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
561 error ("%s between distinct pointer-to-member types `%T' and `%T' "
562 "lacks a cast", location, t1, t2);
563 return error_mark_node;
567 return composite_pointer_type_r (t1, t2, location);
570 /* Return the merged type of two types.
571 We assume that comptypes has already been done and returned 1;
572 if that isn't so, this may crash.
574 This just combines attributes and default arguments; any other
575 differences would cause the two types to compare unalike. */
578 merge_types (tree t1, tree t2)
580 enum tree_code code1;
581 enum tree_code code2;
584 /* Save time if the two types are the same. */
587 if (original_type (t1) == original_type (t2))
590 /* If one type is nonsense, use the other. */
591 if (t1 == error_mark_node)
593 if (t2 == error_mark_node)
596 /* Merge the attributes. */
597 attributes = (*targetm.merge_type_attributes) (t1, t2);
599 if (TYPE_PTRMEMFUNC_P (t1))
600 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
601 if (TYPE_PTRMEMFUNC_P (t2))
602 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
604 code1 = TREE_CODE (t1);
605 code2 = TREE_CODE (t2);
611 /* For two pointers, do this recursively on the target type. */
613 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
614 int quals = cp_type_quals (t1);
616 if (code1 == POINTER_TYPE)
617 t1 = build_pointer_type (target);
619 t1 = build_reference_type (target);
620 t1 = build_type_attribute_variant (t1, attributes);
621 t1 = cp_build_qualified_type (t1, quals);
623 if (TREE_CODE (target) == METHOD_TYPE)
624 t1 = build_ptrmemfunc_type (t1);
633 quals = cp_type_quals (t1);
634 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
635 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
636 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
638 t1 = cp_build_qualified_type (t1, quals);
644 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
645 /* Save space: see if the result is identical to one of the args. */
646 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
647 return build_type_attribute_variant (t1, attributes);
648 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
649 return build_type_attribute_variant (t2, attributes);
650 /* Merge the element types, and have a size if either arg has one. */
651 t1 = build_cplus_array_type
652 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
657 /* Function types: prefer the one that specified arg types.
658 If both do, merge the arg types. Also merge the return types. */
660 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
661 tree p1 = TYPE_ARG_TYPES (t1);
662 tree p2 = TYPE_ARG_TYPES (t2);
665 /* Save space: see if the result is identical to one of the args. */
666 if (valtype == TREE_TYPE (t1) && ! p2)
667 return cp_build_type_attribute_variant (t1, attributes);
668 if (valtype == TREE_TYPE (t2) && ! p1)
669 return cp_build_type_attribute_variant (t2, attributes);
671 /* Simple way if one arg fails to specify argument types. */
672 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
674 rval = build_function_type (valtype, p2);
675 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
676 rval = build_exception_variant (rval, raises);
677 return cp_build_type_attribute_variant (rval, attributes);
679 raises = TYPE_RAISES_EXCEPTIONS (t1);
680 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
682 rval = build_function_type (valtype, p1);
684 rval = build_exception_variant (rval, raises);
685 return cp_build_type_attribute_variant (rval, attributes);
688 rval = build_function_type (valtype, commonparms (p1, p2));
689 t1 = build_exception_variant (rval, raises);
695 /* Get this value the long way, since TYPE_METHOD_BASETYPE
696 is just the main variant of this. */
697 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
698 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
701 /* If this was a member function type, get back to the
702 original type of type member function (i.e., without
703 the class instance variable up front. */
704 t1 = build_function_type (TREE_TYPE (t1),
705 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
706 t2 = build_function_type (TREE_TYPE (t2),
707 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
708 t3 = merge_types (t1, t2);
709 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
710 TYPE_ARG_TYPES (t3));
711 t1 = build_exception_variant (t3, raises);
716 /* There is no need to merge attributes into a TYPENAME_TYPE.
717 When the type is instantiated it will have whatever
718 attributes result from the instantiation. */
723 return cp_build_type_attribute_variant (t1, attributes);
726 /* Return the common type of two types.
727 We assume that comptypes has already been done and returned 1;
728 if that isn't so, this may crash.
730 This is the type for the result of most arithmetic operations
731 if the operands have the given two types. */
734 common_type (tree t1, tree t2)
736 enum tree_code code1;
737 enum tree_code code2;
739 /* If one type is nonsense, bail. */
740 if (t1 == error_mark_node || t2 == error_mark_node)
741 return error_mark_node;
743 code1 = TREE_CODE (t1);
744 code2 = TREE_CODE (t2);
746 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
747 || code1 == COMPLEX_TYPE)
748 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
749 || code2 == COMPLEX_TYPE))
750 return type_after_usual_arithmetic_conversions (t1, t2);
752 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
753 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
754 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
755 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
761 /* Compare two exception specifier types for exactness or subsetness, if
762 allowed. Returns false for mismatch, true for match (same, or
765 [except.spec] "If a class X ... objects of class X or any class publicly
766 and unambiguously derived from X. Similarly, if a pointer type Y * ...
767 exceptions of type Y * or that are pointers to any type publicly and
768 unambiguously derived from Y. Otherwise a function only allows exceptions
769 that have the same type ..."
770 This does not mention cv qualifiers and is different to what throw
771 [except.throw] and catch [except.catch] will do. They will ignore the
772 top level cv qualifiers, and allow qualifiers in the pointer to class
775 We implement the letter of the standard. */
778 comp_except_types (tree a, tree b, bool exact)
780 if (same_type_p (a, b))
784 if (cp_type_quals (a) || cp_type_quals (b))
787 if (TREE_CODE (a) == POINTER_TYPE
788 && TREE_CODE (b) == POINTER_TYPE)
792 if (cp_type_quals (a) || cp_type_quals (b))
796 if (TREE_CODE (a) != RECORD_TYPE
797 || TREE_CODE (b) != RECORD_TYPE)
800 if (ACCESSIBLY_UNIQUELY_DERIVED_P (a, b))
806 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
807 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
808 otherwise it must be exact. Exception lists are unordered, but
809 we've already filtered out duplicates. Most lists will be in order,
810 we should try to make use of that. */
813 comp_except_specs (tree t1, tree t2, bool exact)
822 if (t1 == NULL_TREE) /* T1 is ... */
823 return t2 == NULL_TREE || !exact;
824 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
825 return t2 != NULL_TREE && !TREE_VALUE (t2);
826 if (t2 == NULL_TREE) /* T2 is ... */
828 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
831 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
832 Count how many we find, to determine exactness. For exact matching and
833 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
835 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
837 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
839 tree a = TREE_VALUE (probe);
840 tree b = TREE_VALUE (t2);
842 if (comp_except_types (a, b, exact))
844 if (probe == base && exact)
845 base = TREE_CHAIN (probe);
850 if (probe == NULL_TREE)
853 return !exact || base == NULL_TREE || length == list_length (t1);
856 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
857 [] can match [size]. */
860 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
869 /* The type of the array elements must be the same. */
870 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
873 d1 = TYPE_DOMAIN (t1);
874 d2 = TYPE_DOMAIN (t2);
879 /* If one of the arrays is dimensionless, and the other has a
880 dimension, they are of different types. However, it is valid to
888 declarations for an array object can specify
889 array types that differ by the presence or absence of a major
890 array bound (_dcl.array_). */
892 return allow_redeclaration;
894 /* Check that the dimensions are the same. */
896 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
898 max1 = TYPE_MAX_VALUE (d1);
899 max2 = TYPE_MAX_VALUE (d2);
900 if (processing_template_decl && !abi_version_at_least (2)
901 && !value_dependent_expression_p (max1)
902 && !value_dependent_expression_p (max2))
904 /* With abi-1 we do not fold non-dependent array bounds, (and
905 consequently mangle them incorrectly). We must therefore
906 fold them here, to verify the domains have the same
912 if (!cp_tree_equal (max1, max2))
918 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
919 is a bitwise-or of the COMPARE_* flags. */
922 comptypes (tree t1, tree t2, int strict)
927 /* Suppress errors caused by previously reported errors. */
928 if (t1 == error_mark_node || t2 == error_mark_node)
931 my_friendly_assert (TYPE_P (t1) && TYPE_P (t2), 20030623);
933 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
934 current instantiation. */
935 if (TREE_CODE (t1) == TYPENAME_TYPE)
937 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
939 if (resolved != error_mark_node)
943 if (TREE_CODE (t2) == TYPENAME_TYPE)
945 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
947 if (resolved != error_mark_node)
951 /* If either type is the internal version of sizetype, use the
953 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
954 && TYPE_ORIG_SIZE_TYPE (t1))
955 t1 = TYPE_ORIG_SIZE_TYPE (t1);
957 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
958 && TYPE_ORIG_SIZE_TYPE (t2))
959 t2 = TYPE_ORIG_SIZE_TYPE (t2);
961 if (TYPE_PTRMEMFUNC_P (t1))
962 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
963 if (TYPE_PTRMEMFUNC_P (t2))
964 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
966 /* Different classes of types can't be compatible. */
967 if (TREE_CODE (t1) != TREE_CODE (t2))
970 /* Qualifiers must match. For array types, we will check when we
971 recur on the array element types. */
972 if (TREE_CODE (t1) != ARRAY_TYPE
973 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
975 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
978 /* Allow for two different type nodes which have essentially the same
979 definition. Note that we already checked for equality of the type
980 qualifiers (just above). */
982 if (TREE_CODE (t1) != ARRAY_TYPE
983 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
986 if (!(*targetm.comp_type_attributes) (t1, t2))
989 switch (TREE_CODE (t1))
991 case TEMPLATE_TEMPLATE_PARM:
992 case BOUND_TEMPLATE_TEMPLATE_PARM:
993 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
994 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
996 if (!comp_template_parms
997 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
998 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1000 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1002 /* Don't check inheritance. */
1003 strict = COMPARE_STRICT;
1008 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1009 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1010 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1011 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1014 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1016 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1022 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1023 strict & ~COMPARE_REDECLARATION))
1028 case REFERENCE_TYPE:
1029 return same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1033 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1035 return compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2));
1038 /* Target types must match incl. qualifiers. */
1039 return comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION));
1041 case TEMPLATE_TYPE_PARM:
1042 return (TEMPLATE_TYPE_IDX (t1) == TEMPLATE_TYPE_IDX (t2)
1043 && TEMPLATE_TYPE_LEVEL (t1) == TEMPLATE_TYPE_LEVEL (t2));
1046 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1047 TYPENAME_TYPE_FULLNAME (t2)))
1049 return same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2));
1051 case UNBOUND_CLASS_TEMPLATE:
1052 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1054 return same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2));
1057 return same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1060 return TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
1061 && same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1070 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1073 at_least_as_qualified_p (tree type1, tree type2)
1075 int q1 = cp_type_quals (type1);
1076 int q2 = cp_type_quals (type2);
1078 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1079 return (q1 & q2) == q2;
1082 /* Returns 1 if TYPE1 is more qualified than TYPE2. */
1085 more_qualified_p (tree type1, tree type2)
1087 int q1 = cp_type_quals (type1);
1088 int q2 = cp_type_quals (type2);
1090 return q1 != q2 && (q1 & q2) == q2;
1093 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1094 more cv-qualified that TYPE1, and 0 otherwise. */
1097 comp_cv_qualification (tree type1, tree type2)
1099 int q1 = cp_type_quals (type1);
1100 int q2 = cp_type_quals (type2);
1105 if ((q1 & q2) == q2)
1107 else if ((q1 & q2) == q1)
1113 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1114 subset of the cv-qualification signature of TYPE2, and the types
1115 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1118 comp_cv_qual_signature (tree type1, tree type2)
1120 if (comp_ptr_ttypes_real (type2, type1, -1))
1122 else if (comp_ptr_ttypes_real (type1, type2, -1))
1128 /* If two types share a common base type, return that basetype.
1129 If there is not a unique most-derived base type, this function
1130 returns ERROR_MARK_NODE. */
1133 common_base_type (tree tt1, tree tt2)
1135 tree best = NULL_TREE;
1138 /* If one is a baseclass of another, that's good enough. */
1139 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1141 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1144 /* Otherwise, try to find a unique baseclass of TT1
1145 that is shared by TT2, and follow that down. */
1146 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1148 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1149 tree trial = common_base_type (basetype, tt2);
1153 if (trial == error_mark_node)
1155 if (best == NULL_TREE)
1157 else if (best != trial)
1158 return error_mark_node;
1163 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1165 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1166 tree trial = common_base_type (tt1, basetype);
1170 if (trial == error_mark_node)
1172 if (best == NULL_TREE)
1174 else if (best != trial)
1175 return error_mark_node;
1181 /* Subroutines of `comptypes'. */
1183 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1184 equivalent in the sense that functions with those parameter types
1185 can have equivalent types. The two lists must be equivalent,
1186 element by element. */
1189 compparms (tree parms1, tree parms2)
1193 /* An unspecified parmlist matches any specified parmlist
1194 whose argument types don't need default promotions. */
1196 for (t1 = parms1, t2 = parms2;
1198 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1200 /* If one parmlist is shorter than the other,
1201 they fail to match. */
1204 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1211 /* Process a sizeof or alignof expression where the operand is a
1215 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1217 enum tree_code type_code;
1219 const char *op_name;
1221 my_friendly_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR, 20020720);
1222 if (type == error_mark_node)
1223 return error_mark_node;
1225 if (processing_template_decl)
1227 value = build_min (op, size_type_node, type);
1228 TREE_READONLY (value) = 1;
1232 op_name = operator_name_info[(int) op].name;
1234 type = non_reference (type);
1235 type_code = TREE_CODE (type);
1237 if (type_code == METHOD_TYPE)
1239 if (complain && (pedantic || warn_pointer_arith))
1240 pedwarn ("invalid application of `%s' to a member function", op_name);
1241 value = size_one_node;
1244 value = c_sizeof_or_alignof_type (complete_type (type), op, complain);
1249 /* Process a sizeof or alignof expression where the operand is an
1253 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1255 const char *op_name = operator_name_info[(int) op].name;
1257 if (e == error_mark_node)
1258 return error_mark_node;
1260 if (processing_template_decl)
1262 e = build_min (op, size_type_node, e);
1263 TREE_SIDE_EFFECTS (e) = 0;
1264 TREE_READONLY (e) = 1;
1269 if (TREE_CODE (e) == COMPONENT_REF
1270 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1271 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1273 error ("invalid application of `%s' to a bit-field", op_name);
1276 else if (is_overloaded_fn (e))
1278 pedwarn ("ISO C++ forbids applying `%s' to an expression of function type", op_name);
1281 else if (type_unknown_p (e))
1283 cxx_incomplete_type_error (e, TREE_TYPE (e));
1289 return cxx_sizeof_or_alignof_type (e, op, true);
1293 /* EXPR is being used in a context that is not a function call.
1298 The expression can be used only as the left-hand operand of a
1299 member function call.
1301 [expr.mptr.operator]
1303 If the result of .* or ->* is a function, then that result can be
1304 used only as the operand for the function call operator ().
1306 by issuing an error message if appropriate. Returns true iff EXPR
1307 violates these rules. */
1310 invalid_nonstatic_memfn_p (tree expr)
1312 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1314 error ("invalid use of non-static member function");
1320 /* Perform the conversions in [expr] that apply when an lvalue appears
1321 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1322 function-to-pointer conversions.
1324 In addition manifest constants are replaced by their values. */
1327 decay_conversion (tree exp)
1330 enum tree_code code;
1332 type = TREE_TYPE (exp);
1333 code = TREE_CODE (type);
1335 if (code == REFERENCE_TYPE)
1337 exp = convert_from_reference (exp);
1338 type = TREE_TYPE (exp);
1339 code = TREE_CODE (type);
1342 if (type == error_mark_node)
1343 return error_mark_node;
1345 if (type_unknown_p (exp))
1347 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1348 return error_mark_node;
1351 /* Constants can be used directly unless they're not loadable. */
1352 if (TREE_CODE (exp) == CONST_DECL)
1353 exp = DECL_INITIAL (exp);
1354 /* Replace a nonvolatile const static variable with its value. We
1355 don't do this for arrays, though; we want the address of the
1356 first element of the array, not the address of the first element
1357 of its initializing constant. */
1358 else if (code != ARRAY_TYPE)
1360 exp = decl_constant_value (exp);
1361 type = TREE_TYPE (exp);
1364 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1365 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1367 if (code == VOID_TYPE)
1369 error ("void value not ignored as it ought to be");
1370 return error_mark_node;
1372 if (invalid_nonstatic_memfn_p (exp))
1373 return error_mark_node;
1374 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1375 return build_unary_op (ADDR_EXPR, exp, 0);
1376 if (code == ARRAY_TYPE)
1381 if (TREE_CODE (exp) == INDIRECT_REF)
1382 return build_nop (build_pointer_type (TREE_TYPE (type)),
1383 TREE_OPERAND (exp, 0));
1385 if (TREE_CODE (exp) == COMPOUND_EXPR)
1387 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1388 return build (COMPOUND_EXPR, TREE_TYPE (op1),
1389 TREE_OPERAND (exp, 0), op1);
1393 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1395 error ("invalid use of non-lvalue array");
1396 return error_mark_node;
1399 ptrtype = build_pointer_type (TREE_TYPE (type));
1401 if (TREE_CODE (exp) == VAR_DECL)
1403 if (!cxx_mark_addressable (exp))
1404 return error_mark_node;
1405 adr = build_nop (ptrtype, build_address (exp));
1408 /* This way is better for a COMPONENT_REF since it can
1409 simplify the offset for a component. */
1410 adr = build_unary_op (ADDR_EXPR, exp, 1);
1411 return cp_convert (ptrtype, adr);
1414 /* [basic.lval]: Class rvalues can have cv-qualified types; non-class
1415 rvalues always have cv-unqualified types. */
1416 if (! CLASS_TYPE_P (type))
1417 exp = cp_convert (TYPE_MAIN_VARIANT (type), exp);
1423 default_conversion (tree exp)
1425 exp = decay_conversion (exp);
1427 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1428 exp = perform_integral_promotions (exp);
1433 /* EXPR is an expression with an integral or enumeration type.
1434 Perform the integral promotions in [conv.prom], and return the
1438 perform_integral_promotions (tree expr)
1443 type = TREE_TYPE (expr);
1444 my_friendly_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type), 20030703);
1445 promoted_type = type_promotes_to (type);
1446 if (type != promoted_type)
1447 expr = cp_convert (promoted_type, expr);
1451 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1455 inline_conversion (tree exp)
1457 if (TREE_CODE (exp) == FUNCTION_DECL)
1458 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1463 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1464 decay_conversion to one. */
1467 string_conv_p (tree totype, tree exp, int warn)
1471 if (! flag_const_strings || TREE_CODE (totype) != POINTER_TYPE)
1474 t = TREE_TYPE (totype);
1475 if (!same_type_p (t, char_type_node)
1476 && !same_type_p (t, wchar_type_node))
1479 if (TREE_CODE (exp) == STRING_CST)
1481 /* Make sure that we don't try to convert between char and wchar_t. */
1482 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1487 /* Is this a string constant which has decayed to 'const char *'? */
1488 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1489 if (!same_type_p (TREE_TYPE (exp), t))
1492 if (TREE_CODE (exp) != ADDR_EXPR
1493 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1497 /* This warning is not very useful, as it complains about printf. */
1498 if (warn && warn_write_strings)
1499 warning ("deprecated conversion from string constant to `%T'", totype);
1504 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1505 can, for example, use as an lvalue. This code used to be in
1506 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1507 expressions, where we're dealing with aggregates. But now it's again only
1508 called from unary_complex_lvalue. The case (in particular) that led to
1509 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1513 rationalize_conditional_expr (enum tree_code code, tree t)
1515 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1516 the first operand is always the one to be used if both operands
1517 are equal, so we know what conditional expression this used to be. */
1518 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1521 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1522 ? LE_EXPR : GE_EXPR),
1523 TREE_OPERAND (t, 0),
1524 TREE_OPERAND (t, 1),
1525 /*overloaded_p=*/NULL),
1526 build_unary_op (code, TREE_OPERAND (t, 0), 0),
1527 build_unary_op (code, TREE_OPERAND (t, 1), 0));
1531 build_conditional_expr (TREE_OPERAND (t, 0),
1532 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1533 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1536 /* Given the TYPE of an anonymous union field inside T, return the
1537 FIELD_DECL for the field. If not found return NULL_TREE. Because
1538 anonymous unions can nest, we must also search all anonymous unions
1539 that are directly reachable. */
1542 lookup_anon_field (tree t, tree type)
1546 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1548 if (TREE_STATIC (field))
1550 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1553 /* If we find it directly, return the field. */
1554 if (DECL_NAME (field) == NULL_TREE
1555 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1560 /* Otherwise, it could be nested, search harder. */
1561 if (DECL_NAME (field) == NULL_TREE
1562 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1564 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1572 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1573 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1574 non-NULL, it indicates the path to the base used to name MEMBER.
1575 If PRESERVE_REFERENCE is true, the expression returned will have
1576 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1577 returned will have the type referred to by the reference.
1579 This function does not perform access control; that is either done
1580 earlier by the parser when the name of MEMBER is resolved to MEMBER
1581 itself, or later when overload resolution selects one of the
1582 functions indicated by MEMBER. */
1585 build_class_member_access_expr (tree object, tree member,
1586 tree access_path, bool preserve_reference)
1590 tree result = NULL_TREE;
1592 if (object == error_mark_node || member == error_mark_node)
1593 return error_mark_node;
1595 if (TREE_CODE (member) == PSEUDO_DTOR_EXPR)
1598 my_friendly_assert (DECL_P (member) || BASELINK_P (member),
1603 The type of the first expression shall be "class object" (of a
1605 object_type = TREE_TYPE (object);
1606 if (!currently_open_class (object_type)
1607 && !complete_type_or_else (object_type, object))
1608 return error_mark_node;
1609 if (!CLASS_TYPE_P (object_type))
1611 error ("request for member `%D' in `%E', which is of non-class type `%T'",
1612 member, object, object_type);
1613 return error_mark_node;
1616 /* The standard does not seem to actually say that MEMBER must be a
1617 member of OBJECT_TYPE. However, that is clearly what is
1619 if (DECL_P (member))
1621 member_scope = DECL_CLASS_CONTEXT (member);
1623 if (TREE_DEPRECATED (member))
1624 warn_deprecated_use (member);
1627 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1628 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1629 presently be the anonymous union. Go outwards until we find a
1630 type related to OBJECT_TYPE. */
1631 while (ANON_AGGR_TYPE_P (member_scope)
1632 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1634 member_scope = TYPE_CONTEXT (member_scope);
1635 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1637 if (TREE_CODE (member) == FIELD_DECL)
1638 error ("invalid use of nonstatic data member '%E'", member);
1640 error ("`%D' is not a member of `%T'", member, object_type);
1641 return error_mark_node;
1644 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1645 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1646 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1648 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1650 object = build_indirect_ref (temp, NULL);
1653 /* In [expr.ref], there is an explicit list of the valid choices for
1654 MEMBER. We check for each of those cases here. */
1655 if (TREE_CODE (member) == VAR_DECL)
1657 /* A static data member. */
1659 /* If OBJECT has side-effects, they are supposed to occur. */
1660 if (TREE_SIDE_EFFECTS (object))
1661 result = build (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1663 else if (TREE_CODE (member) == FIELD_DECL)
1665 /* A non-static data member. */
1670 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1671 && integer_zerop (TREE_OPERAND (object, 0)));
1673 /* Convert OBJECT to the type of MEMBER. */
1674 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1675 TYPE_MAIN_VARIANT (member_scope)))
1680 binfo = lookup_base (access_path ? access_path : object_type,
1681 member_scope, ba_ignore, &kind);
1682 if (binfo == error_mark_node)
1683 return error_mark_node;
1685 /* It is invalid to try to get to a virtual base of a
1686 NULL object. The most common cause is invalid use of
1688 if (null_object_p && kind == bk_via_virtual)
1690 error ("invalid access to non-static data member `%D' of NULL object",
1692 error ("(perhaps the `offsetof' macro was used incorrectly)");
1693 return error_mark_node;
1696 /* Convert to the base. */
1697 object = build_base_path (PLUS_EXPR, object, binfo,
1699 /* If we found the base successfully then we should be able
1700 to convert to it successfully. */
1701 my_friendly_assert (object != error_mark_node,
1705 /* Complain about other invalid uses of offsetof, even though they will
1706 give the right answer. Note that we complain whether or not they
1707 actually used the offsetof macro, since there's no way to know at this
1708 point. So we just give a warning, instead of a pedwarn. */
1709 if (null_object_p && warn_invalid_offsetof
1710 && CLASSTYPE_NON_POD_P (object_type)
1711 && ! skip_evaluation)
1713 warning ("invalid access to non-static data member `%D' of NULL object",
1715 warning ("(perhaps the `offsetof' macro was used incorrectly)");
1718 /* If MEMBER is from an anonymous aggregate, we have converted
1719 OBJECT so that it refers to the class containing the
1720 anonymous union. Generate a reference to the anonymous union
1721 itself, and recur to find MEMBER. */
1722 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1723 /* When this code is called from build_field_call, the
1724 object already has the type of the anonymous union.
1725 That is because the COMPONENT_REF was already
1726 constructed, and was then disassembled before calling
1727 build_field_call. After the function-call code is
1728 cleaned up, this waste can be eliminated. */
1729 && (!same_type_ignoring_top_level_qualifiers_p
1730 (TREE_TYPE (object), DECL_CONTEXT (member))))
1732 tree anonymous_union;
1734 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1735 DECL_CONTEXT (member));
1736 object = build_class_member_access_expr (object,
1738 /*access_path=*/NULL_TREE,
1739 preserve_reference);
1742 /* Compute the type of the field, as described in [expr.ref]. */
1743 type_quals = TYPE_UNQUALIFIED;
1744 member_type = TREE_TYPE (member);
1745 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1747 type_quals = (cp_type_quals (member_type)
1748 | cp_type_quals (object_type));
1750 /* A field is const (volatile) if the enclosing object, or the
1751 field itself, is const (volatile). But, a mutable field is
1752 not const, even within a const object. */
1753 if (DECL_MUTABLE_P (member))
1754 type_quals &= ~TYPE_QUAL_CONST;
1755 member_type = cp_build_qualified_type (member_type, type_quals);
1758 result = fold (build (COMPONENT_REF, member_type, object, member,
1761 /* Mark the expression const or volatile, as appropriate. Even
1762 though we've dealt with the type above, we still have to mark the
1763 expression itself. */
1764 if (type_quals & TYPE_QUAL_CONST)
1765 TREE_READONLY (result) = 1;
1766 else if (type_quals & TYPE_QUAL_VOLATILE)
1767 TREE_THIS_VOLATILE (result) = 1;
1769 else if (BASELINK_P (member))
1771 /* The member is a (possibly overloaded) member function. */
1775 /* If the MEMBER is exactly one static member function, then we
1776 know the type of the expression. Otherwise, we must wait
1777 until overload resolution has been performed. */
1778 functions = BASELINK_FUNCTIONS (member);
1779 if (TREE_CODE (functions) == FUNCTION_DECL
1780 && DECL_STATIC_FUNCTION_P (functions))
1781 type = TREE_TYPE (functions);
1783 type = unknown_type_node;
1784 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1785 base. That will happen when the function is called. */
1786 result = build (COMPONENT_REF, type, object, member, NULL_TREE);
1788 else if (TREE_CODE (member) == CONST_DECL)
1790 /* The member is an enumerator. */
1792 /* If OBJECT has side-effects, they are supposed to occur. */
1793 if (TREE_SIDE_EFFECTS (object))
1794 result = build (COMPOUND_EXPR, TREE_TYPE (result),
1799 error ("invalid use of `%D'", member);
1800 return error_mark_node;
1803 if (!preserve_reference)
1806 If E2 is declared to have type "reference to T", then ... the
1807 type of E1.E2 is T. */
1808 result = convert_from_reference (result);
1813 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1814 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1817 lookup_destructor (tree object, tree scope, tree dtor_name)
1819 tree object_type = TREE_TYPE (object);
1820 tree dtor_type = TREE_OPERAND (dtor_name, 0);
1823 if (scope && !check_dtor_name (scope, dtor_name))
1825 error ("qualified type `%T' does not match destructor name `~%T'",
1827 return error_mark_node;
1829 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
1831 error ("the type being destroyed is `%T', but the destructor refers to `%T'",
1832 TYPE_MAIN_VARIANT (object_type), dtor_type);
1833 return error_mark_node;
1835 if (!TYPE_HAS_DESTRUCTOR (dtor_type))
1836 return build (PSEUDO_DTOR_EXPR, void_type_node, object, scope,
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 object_type = TREE_TYPE (object);
1868 if (processing_template_decl)
1870 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
1871 dependent_type_p (object_type)
1872 /* If NAME is just an IDENTIFIER_NODE, then the expression
1874 || TREE_CODE (object) == IDENTIFIER_NODE
1875 /* If NAME is "f<args>", where either 'f' or 'args' is
1876 dependent, then the expression is dependent. */
1877 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
1878 && dependent_template_id_p (TREE_OPERAND (name, 0),
1879 TREE_OPERAND (name, 1)))
1880 /* If NAME is "T::X" where "T" is dependent, then the
1881 expression is dependent. */
1882 || (TREE_CODE (name) == SCOPE_REF
1883 && TYPE_P (TREE_OPERAND (name, 0))
1884 && dependent_type_p (TREE_OPERAND (name, 0))))
1885 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
1886 object = build_non_dependent_expr (object);
1889 if (TREE_CODE (object_type) == REFERENCE_TYPE)
1891 object = convert_from_reference (object);
1892 object_type = TREE_TYPE (object);
1897 The type of the first expression shall be "class object" (of a
1899 if (!currently_open_class (object_type)
1900 && !complete_type_or_else (object_type, object))
1901 return error_mark_node;
1902 if (!CLASS_TYPE_P (object_type))
1904 error ("request for member `%D' in `%E', which is of non-class type `%T'",
1905 name, object, object_type);
1906 return error_mark_node;
1909 if (BASELINK_P (name))
1911 /* A member function that has already been looked up. */
1912 my_friendly_assert ((TREE_CODE (BASELINK_FUNCTIONS (name))
1913 == TEMPLATE_ID_EXPR),
1919 bool is_template_id = false;
1920 tree template_args = NULL_TREE;
1923 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
1925 is_template_id = true;
1926 template_args = TREE_OPERAND (name, 1);
1927 name = TREE_OPERAND (name, 0);
1929 if (TREE_CODE (name) == OVERLOAD)
1930 name = DECL_NAME (get_first_fn (name));
1931 else if (DECL_P (name))
1932 name = DECL_NAME (name);
1935 if (TREE_CODE (name) == SCOPE_REF)
1937 /* A qualified name. The qualifying class or namespace `S' has
1938 already been looked up; it is either a TYPE or a
1939 NAMESPACE_DECL. The member name is either an IDENTIFIER_NODE
1940 or a BIT_NOT_EXPR. */
1941 scope = TREE_OPERAND (name, 0);
1942 name = TREE_OPERAND (name, 1);
1943 my_friendly_assert ((CLASS_TYPE_P (scope)
1944 || TREE_CODE (scope) == NAMESPACE_DECL),
1946 my_friendly_assert ((TREE_CODE (name) == IDENTIFIER_NODE
1947 || TREE_CODE (name) == BIT_NOT_EXPR),
1950 /* If SCOPE is a namespace, then the qualified name does not
1951 name a member of OBJECT_TYPE. */
1952 if (TREE_CODE (scope) == NAMESPACE_DECL)
1954 error ("`%D::%D' is not a member of `%T'",
1955 scope, name, object_type);
1956 return error_mark_node;
1959 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
1960 access_path = lookup_base (object_type, scope, ba_check, NULL);
1961 if (access_path == error_mark_node)
1962 return error_mark_node;
1965 error ("`%T' is not a base of `%T'", scope, object_type);
1966 return error_mark_node;
1972 access_path = object_type;
1975 if (TREE_CODE (name) == BIT_NOT_EXPR)
1976 member = lookup_destructor (object, scope, name);
1979 /* Look up the member. */
1980 member = lookup_member (access_path, name, /*protect=*/1,
1981 /*want_type=*/false);
1982 if (member == NULL_TREE)
1984 error ("'%D' has no member named '%E'", object_type, name);
1985 return error_mark_node;
1987 if (member == error_mark_node)
1988 return error_mark_node;
1993 tree template = member;
1995 if (BASELINK_P (template))
1996 template = lookup_template_function (template, template_args);
1999 error ("`%D' is not a member template function", name);
2000 return error_mark_node;
2005 if (TREE_DEPRECATED (member))
2006 warn_deprecated_use (member);
2008 expr = build_class_member_access_expr (object, member, access_path,
2009 /*preserve_reference=*/false);
2010 if (processing_template_decl && expr != error_mark_node)
2011 return build_min_non_dep (COMPONENT_REF, expr,
2012 orig_object, orig_name, NULL_TREE);
2016 /* Return an expression for the MEMBER_NAME field in the internal
2017 representation of PTRMEM, a pointer-to-member function. (Each
2018 pointer-to-member function type gets its own RECORD_TYPE so it is
2019 more convenient to access the fields by name than by FIELD_DECL.)
2020 This routine converts the NAME to a FIELD_DECL and then creates the
2021 node for the complete expression. */
2024 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2030 /* This code is a stripped down version of
2031 build_class_member_access_expr. It does not work to use that
2032 routine directly because it expects the object to be of class
2034 ptrmem_type = TREE_TYPE (ptrmem);
2035 my_friendly_assert (TYPE_PTRMEMFUNC_P (ptrmem_type), 20020804);
2036 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2037 /*want_type=*/false);
2038 member_type = cp_build_qualified_type (TREE_TYPE (member),
2039 cp_type_quals (ptrmem_type));
2040 return fold (build (COMPONENT_REF, member_type, ptrmem, member, NULL_TREE));
2043 /* Given an expression PTR for a pointer, return an expression
2044 for the value pointed to.
2045 ERRORSTRING is the name of the operator to appear in error messages.
2047 This function may need to overload OPERATOR_FNNAME.
2048 Must also handle REFERENCE_TYPEs for C++. */
2051 build_x_indirect_ref (tree expr, const char *errorstring)
2053 tree orig_expr = expr;
2056 if (processing_template_decl)
2058 if (type_dependent_expression_p (expr))
2059 return build_min_nt (INDIRECT_REF, expr);
2060 expr = build_non_dependent_expr (expr);
2063 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2064 NULL_TREE, /*overloaded_p=*/NULL);
2066 rval = build_indirect_ref (expr, errorstring);
2068 if (processing_template_decl && rval != error_mark_node)
2069 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2075 build_indirect_ref (tree ptr, const char *errorstring)
2079 if (ptr == error_mark_node)
2080 return error_mark_node;
2082 if (ptr == current_class_ptr)
2083 return current_class_ref;
2085 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2086 ? ptr : decay_conversion (ptr));
2087 type = TREE_TYPE (pointer);
2089 if (TYPE_PTR_P (type) || TREE_CODE (type) == REFERENCE_TYPE)
2093 If the type of the expression is "pointer to T," the type
2094 of the result is "T."
2096 We must use the canonical variant because certain parts of
2097 the back end, like fold, do pointer comparisons between
2099 tree t = canonical_type_variant (TREE_TYPE (type));
2101 if (VOID_TYPE_P (t))
2103 /* A pointer to incomplete type (other than cv void) can be
2104 dereferenced [expr.unary.op]/1 */
2105 error ("`%T' is not a pointer-to-object type", type);
2106 return error_mark_node;
2108 else if (TREE_CODE (pointer) == ADDR_EXPR
2109 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2110 /* The POINTER was something like `&x'. We simplify `*&x' to
2112 return TREE_OPERAND (pointer, 0);
2115 tree ref = build1 (INDIRECT_REF, t, pointer);
2117 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2118 so that we get the proper error message if the result is used
2119 to assign to. Also, &* is supposed to be a no-op. */
2120 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2121 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2122 TREE_SIDE_EFFECTS (ref)
2123 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2127 /* `pointer' won't be an error_mark_node if we were given a
2128 pointer to member, so it's cool to check for this here. */
2129 else if (TYPE_PTR_TO_MEMBER_P (type))
2130 error ("invalid use of `%s' on pointer to member", errorstring);
2131 else if (pointer != error_mark_node)
2134 error ("invalid type argument of `%s'", errorstring);
2136 error ("invalid type argument");
2138 return error_mark_node;
2141 /* This handles expressions of the form "a[i]", which denotes
2144 This is logically equivalent in C to *(a+i), but we may do it differently.
2145 If A is a variable or a member, we generate a primitive ARRAY_REF.
2146 This avoids forcing the array out of registers, and can work on
2147 arrays that are not lvalues (for example, members of structures returned
2150 If INDEX is of some user-defined type, it must be converted to
2151 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2152 will inherit the type of the array, which will be some pointer type. */
2155 build_array_ref (tree array, tree idx)
2159 error ("subscript missing in array reference");
2160 return error_mark_node;
2163 if (TREE_TYPE (array) == error_mark_node
2164 || TREE_TYPE (idx) == error_mark_node)
2165 return error_mark_node;
2167 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2169 switch (TREE_CODE (array))
2173 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2174 return build (COMPOUND_EXPR, TREE_TYPE (value),
2175 TREE_OPERAND (array, 0), value);
2179 return build_conditional_expr
2180 (TREE_OPERAND (array, 0),
2181 build_array_ref (TREE_OPERAND (array, 1), idx),
2182 build_array_ref (TREE_OPERAND (array, 2), idx));
2188 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2192 /* Subscripting with type char is likely to lose
2193 on a machine where chars are signed.
2194 So warn on any machine, but optionally.
2195 Don't warn for unsigned char since that type is safe.
2196 Don't warn for signed char because anyone who uses that
2197 must have done so deliberately. */
2198 if (warn_char_subscripts
2199 && TYPE_MAIN_VARIANT (TREE_TYPE (idx)) == char_type_node)
2200 warning ("array subscript has type `char'");
2202 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2204 error ("array subscript is not an integer");
2205 return error_mark_node;
2208 /* Apply integral promotions *after* noticing character types.
2209 (It is unclear why we do these promotions -- the standard
2210 does not say that we should. In fact, the natual thing would
2211 seem to be to convert IDX to ptrdiff_t; we're performing
2212 pointer arithmetic.) */
2213 idx = perform_integral_promotions (idx);
2215 /* An array that is indexed by a non-constant
2216 cannot be stored in a register; we must be able to do
2217 address arithmetic on its address.
2218 Likewise an array of elements of variable size. */
2219 if (TREE_CODE (idx) != INTEGER_CST
2220 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2221 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2224 if (!cxx_mark_addressable (array))
2225 return error_mark_node;
2228 /* An array that is indexed by a constant value which is not within
2229 the array bounds cannot be stored in a register either; because we
2230 would get a crash in store_bit_field/extract_bit_field when trying
2231 to access a non-existent part of the register. */
2232 if (TREE_CODE (idx) == INTEGER_CST
2233 && TYPE_DOMAIN (TREE_TYPE (array))
2234 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2236 if (!cxx_mark_addressable (array))
2237 return error_mark_node;
2240 if (pedantic && !lvalue_p (array))
2241 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2243 /* Note in C++ it is valid to subscript a `register' array, since
2244 it is valid to take the address of something with that
2245 storage specification. */
2249 while (TREE_CODE (foo) == COMPONENT_REF)
2250 foo = TREE_OPERAND (foo, 0);
2251 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2252 warning ("subscripting array declared `register'");
2255 type = TREE_TYPE (TREE_TYPE (array));
2256 rval = build (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2257 /* Array ref is const/volatile if the array elements are
2258 or if the array is.. */
2259 TREE_READONLY (rval)
2260 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2261 TREE_SIDE_EFFECTS (rval)
2262 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2263 TREE_THIS_VOLATILE (rval)
2264 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2265 return require_complete_type (fold (rval));
2269 tree ar = default_conversion (array);
2270 tree ind = default_conversion (idx);
2272 /* Put the integer in IND to simplify error checking. */
2273 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2280 if (ar == error_mark_node)
2283 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2285 error ("subscripted value is neither array nor pointer");
2286 return error_mark_node;
2288 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2290 error ("array subscript is not an integer");
2291 return error_mark_node;
2294 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2299 /* Resolve a pointer to member function. INSTANCE is the object
2300 instance to use, if the member points to a virtual member.
2302 This used to avoid checking for virtual functions if basetype
2303 has no virtual functions, according to an earlier ANSI draft.
2304 With the final ISO C++ rules, such an optimization is
2305 incorrect: A pointer to a derived member can be static_cast
2306 to pointer-to-base-member, as long as the dynamic object
2307 later has the right member. */
2310 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2312 if (TREE_CODE (function) == OFFSET_REF)
2313 function = TREE_OPERAND (function, 1);
2315 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2317 tree idx, delta, e1, e2, e3, vtbl, basetype;
2318 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2320 tree instance_ptr = *instance_ptrptr;
2321 tree instance_save_expr = 0;
2322 if (instance_ptr == error_mark_node)
2324 if (TREE_CODE (function) == PTRMEM_CST)
2326 /* Extracting the function address from a pmf is only
2327 allowed with -Wno-pmf-conversions. It only works for
2329 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2330 e1 = convert (fntype, e1);
2335 error ("object missing in use of `%E'", function);
2336 return error_mark_node;
2340 if (TREE_SIDE_EFFECTS (instance_ptr))
2341 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2343 if (TREE_SIDE_EFFECTS (function))
2344 function = save_expr (function);
2346 /* Start by extracting all the information from the PMF itself. */
2347 e3 = PFN_FROM_PTRMEMFUNC (function);
2348 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2349 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2350 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2352 case ptrmemfunc_vbit_in_pfn:
2353 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2354 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2357 case ptrmemfunc_vbit_in_delta:
2358 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2359 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2366 /* Convert down to the right base before using the instance. First
2368 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2369 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2370 basetype, ba_check, NULL);
2371 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype, 1);
2372 if (instance_ptr == error_mark_node)
2373 return error_mark_node;
2374 /* ...and then the delta in the PMF. */
2375 instance_ptr = build (PLUS_EXPR, TREE_TYPE (instance_ptr),
2376 instance_ptr, delta);
2378 /* Hand back the adjusted 'this' argument to our caller. */
2379 *instance_ptrptr = instance_ptr;
2381 /* Next extract the vtable pointer from the object. */
2382 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2384 vtbl = build_indirect_ref (vtbl, NULL);
2386 /* Finally, extract the function pointer from the vtable. */
2387 e2 = fold (build (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx));
2388 e2 = build_indirect_ref (e2, NULL);
2389 TREE_CONSTANT (e2) = 1;
2390 TREE_INVARIANT (e2) = 1;
2392 /* When using function descriptors, the address of the
2393 vtable entry is treated as a function pointer. */
2394 if (TARGET_VTABLE_USES_DESCRIPTORS)
2395 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2396 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2398 TREE_TYPE (e2) = TREE_TYPE (e3);
2399 e1 = build_conditional_expr (e1, e2, e3);
2401 /* Make sure this doesn't get evaluated first inside one of the
2402 branches of the COND_EXPR. */
2403 if (instance_save_expr)
2404 e1 = build (COMPOUND_EXPR, TREE_TYPE (e1),
2405 instance_save_expr, e1);
2413 build_function_call (tree function, tree params)
2415 tree fntype, fndecl;
2416 tree coerced_params;
2417 tree name = NULL_TREE;
2419 tree original = function;
2421 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2422 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2423 if (TREE_CODE (function) == NOP_EXPR
2424 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2425 function = TREE_OPERAND (function, 0);
2427 if (TREE_CODE (function) == FUNCTION_DECL)
2429 name = DECL_NAME (function);
2431 mark_used (function);
2434 /* Convert anything with function type to a pointer-to-function. */
2435 if (pedantic && DECL_MAIN_P (function))
2436 pedwarn ("ISO C++ forbids calling `::main' from within program");
2438 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2439 (because calling an inline function does not mean the function
2440 needs to be separately compiled). */
2442 if (DECL_INLINE (function))
2443 function = inline_conversion (function);
2445 function = build_addr_func (function);
2451 function = build_addr_func (function);
2454 if (function == error_mark_node)
2455 return error_mark_node;
2457 fntype = TREE_TYPE (function);
2459 if (TYPE_PTRMEMFUNC_P (fntype))
2461 error ("must use .* or ->* to call pointer-to-member function in `%E (...)'",
2463 return error_mark_node;
2466 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2467 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2469 if (!((TREE_CODE (fntype) == POINTER_TYPE
2470 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2472 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2474 error ("`%E' cannot be used as a function", original);
2475 return error_mark_node;
2478 /* fntype now gets the type of function pointed to. */
2479 fntype = TREE_TYPE (fntype);
2481 /* Convert the parameters to the types declared in the
2482 function prototype, or apply default promotions. */
2484 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2485 params, fndecl, LOOKUP_NORMAL);
2486 if (coerced_params == error_mark_node)
2487 return error_mark_node;
2489 /* Check for errors in format strings and inappropriately
2492 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params);
2494 return build_cxx_call (function, coerced_params);
2497 /* Convert the actual parameter expressions in the list VALUES
2498 to the types in the list TYPELIST.
2499 If parmdecls is exhausted, or when an element has NULL as its type,
2500 perform the default conversions.
2502 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2504 This is also where warnings about wrong number of args are generated.
2506 Return a list of expressions for the parameters as converted.
2508 Both VALUES and the returned value are chains of TREE_LIST nodes
2509 with the elements of the list in the TREE_VALUE slots of those nodes.
2511 In C++, unspecified trailing parameters can be filled in with their
2512 default arguments, if such were specified. Do so here. */
2515 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2517 tree typetail, valtail;
2518 tree result = NULL_TREE;
2519 const char *called_thing = 0;
2522 /* Argument passing is always copy-initialization. */
2523 flags |= LOOKUP_ONLYCONVERTING;
2527 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2529 if (DECL_NAME (fndecl) == NULL_TREE
2530 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2531 called_thing = "constructor";
2533 called_thing = "member function";
2536 called_thing = "function";
2539 for (valtail = values, typetail = typelist;
2541 valtail = TREE_CHAIN (valtail), i++)
2543 tree type = typetail ? TREE_VALUE (typetail) : 0;
2544 tree val = TREE_VALUE (valtail);
2546 if (val == error_mark_node)
2547 return error_mark_node;
2549 if (type == void_type_node)
2553 cp_error_at ("too many arguments to %s `%+#D'", called_thing,
2555 error ("at this point in file");
2558 error ("too many arguments to function");
2559 /* In case anybody wants to know if this argument
2562 TREE_TYPE (tree_last (result)) = error_mark_node;
2566 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2567 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2568 if (TREE_CODE (val) == NOP_EXPR
2569 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2570 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2571 val = TREE_OPERAND (val, 0);
2573 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2575 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2576 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2577 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2578 val = decay_conversion (val);
2581 if (val == error_mark_node)
2582 return error_mark_node;
2586 /* Formal parm type is specified by a function prototype. */
2589 if (!COMPLETE_TYPE_P (complete_type (type)))
2592 error ("parameter %P of `%D' has incomplete type `%T'",
2595 error ("parameter %P has incomplete type `%T'", i, type);
2596 parmval = error_mark_node;
2600 parmval = convert_for_initialization
2601 (NULL_TREE, type, val, flags,
2602 "argument passing", fndecl, i);
2603 parmval = convert_for_arg_passing (type, parmval);
2606 if (parmval == error_mark_node)
2607 return error_mark_node;
2609 result = tree_cons (NULL_TREE, parmval, result);
2613 if (TREE_CODE (TREE_TYPE (val)) == REFERENCE_TYPE)
2614 val = convert_from_reference (val);
2616 if (fndecl && DECL_BUILT_IN (fndecl)
2617 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2618 /* Don't do ellipsis conversion for __built_in_constant_p
2619 as this will result in spurious warnings for non-POD
2621 val = require_complete_type (val);
2623 val = convert_arg_to_ellipsis (val);
2625 result = tree_cons (NULL_TREE, val, result);
2629 typetail = TREE_CHAIN (typetail);
2632 if (typetail != 0 && typetail != void_list_node)
2634 /* See if there are default arguments that can be used. */
2635 if (TREE_PURPOSE (typetail)
2636 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2638 for (; typetail != void_list_node; ++i)
2641 = convert_default_arg (TREE_VALUE (typetail),
2642 TREE_PURPOSE (typetail),
2645 if (parmval == error_mark_node)
2646 return error_mark_node;
2648 result = tree_cons (0, parmval, result);
2649 typetail = TREE_CHAIN (typetail);
2650 /* ends with `...'. */
2651 if (typetail == NULL_TREE)
2659 cp_error_at ("too few arguments to %s `%+#D'",
2660 called_thing, fndecl);
2661 error ("at this point in file");
2664 error ("too few arguments to function");
2665 return error_mark_list;
2669 return nreverse (result);
2672 /* Build a binary-operation expression, after performing default
2673 conversions on the operands. CODE is the kind of expression to build. */
2676 build_x_binary_op (enum tree_code code, tree arg1, tree arg2,
2686 if (processing_template_decl)
2688 if (type_dependent_expression_p (arg1)
2689 || type_dependent_expression_p (arg2))
2690 return build_min_nt (code, arg1, arg2);
2691 arg1 = build_non_dependent_expr (arg1);
2692 arg2 = build_non_dependent_expr (arg2);
2695 if (code == DOTSTAR_EXPR)
2696 expr = build_m_component_ref (arg1, arg2);
2698 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2701 if (processing_template_decl && expr != error_mark_node)
2702 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2707 /* Build a binary-operation expression without default conversions.
2708 CODE is the kind of expression to build.
2709 This function differs from `build' in several ways:
2710 the data type of the result is computed and recorded in it,
2711 warnings are generated if arg data types are invalid,
2712 special handling for addition and subtraction of pointers is known,
2713 and some optimization is done (operations on narrow ints
2714 are done in the narrower type when that gives the same result).
2715 Constant folding is also done before the result is returned.
2717 Note that the operands will never have enumeral types
2718 because either they have just had the default conversions performed
2719 or they have both just been converted to some other type in which
2720 the arithmetic is to be done.
2722 C++: must do special pointer arithmetic when implementing
2723 multiple inheritance, and deal with pointer to member functions. */
2726 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2727 int convert_p ATTRIBUTE_UNUSED)
2730 enum tree_code code0, code1;
2733 /* Expression code to give to the expression when it is built.
2734 Normally this is CODE, which is what the caller asked for,
2735 but in some special cases we change it. */
2736 enum tree_code resultcode = code;
2738 /* Data type in which the computation is to be performed.
2739 In the simplest cases this is the common type of the arguments. */
2740 tree result_type = NULL;
2742 /* Nonzero means operands have already been type-converted
2743 in whatever way is necessary.
2744 Zero means they need to be converted to RESULT_TYPE. */
2747 /* Nonzero means create the expression with this type, rather than
2749 tree build_type = 0;
2751 /* Nonzero means after finally constructing the expression
2752 convert it to this type. */
2753 tree final_type = 0;
2755 /* Nonzero if this is an operation like MIN or MAX which can
2756 safely be computed in short if both args are promoted shorts.
2757 Also implies COMMON.
2758 -1 indicates a bitwise operation; this makes a difference
2759 in the exact conditions for when it is safe to do the operation
2760 in a narrower mode. */
2763 /* Nonzero if this is a comparison operation;
2764 if both args are promoted shorts, compare the original shorts.
2765 Also implies COMMON. */
2766 int short_compare = 0;
2768 /* Nonzero if this is a right-shift operation, which can be computed on the
2769 original short and then promoted if the operand is a promoted short. */
2770 int short_shift = 0;
2772 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2775 /* Apply default conversions. */
2779 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2780 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2781 || code == TRUTH_XOR_EXPR)
2783 if (!really_overloaded_fn (op0))
2784 op0 = decay_conversion (op0);
2785 if (!really_overloaded_fn (op1))
2786 op1 = decay_conversion (op1);
2790 if (!really_overloaded_fn (op0))
2791 op0 = default_conversion (op0);
2792 if (!really_overloaded_fn (op1))
2793 op1 = default_conversion (op1);
2796 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2797 STRIP_TYPE_NOPS (op0);
2798 STRIP_TYPE_NOPS (op1);
2800 /* DTRT if one side is an overloaded function, but complain about it. */
2801 if (type_unknown_p (op0))
2803 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
2804 if (t != error_mark_node)
2806 pedwarn ("assuming cast to type `%T' from overloaded function",
2811 if (type_unknown_p (op1))
2813 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
2814 if (t != error_mark_node)
2816 pedwarn ("assuming cast to type `%T' from overloaded function",
2822 type0 = TREE_TYPE (op0);
2823 type1 = TREE_TYPE (op1);
2825 /* The expression codes of the data types of the arguments tell us
2826 whether the arguments are integers, floating, pointers, etc. */
2827 code0 = TREE_CODE (type0);
2828 code1 = TREE_CODE (type1);
2830 /* If an error was already reported for one of the arguments,
2831 avoid reporting another error. */
2833 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
2834 return error_mark_node;
2839 /* Handle the pointer + int case. */
2840 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2841 return cp_pointer_int_sum (PLUS_EXPR, op0, op1);
2842 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
2843 return cp_pointer_int_sum (PLUS_EXPR, op1, op0);
2849 /* Subtraction of two similar pointers.
2850 We must subtract them as integers, then divide by object size. */
2851 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
2852 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
2854 return pointer_diff (op0, op1, common_type (type0, type1));
2855 /* Handle pointer minus int. Just like pointer plus int. */
2856 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2857 return cp_pointer_int_sum (MINUS_EXPR, op0, op1);
2866 case TRUNC_DIV_EXPR:
2868 case FLOOR_DIV_EXPR:
2869 case ROUND_DIV_EXPR:
2870 case EXACT_DIV_EXPR:
2871 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2872 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2873 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2874 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
2876 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
2877 warning ("division by zero in `%E / 0'", op0);
2878 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
2879 warning ("division by zero in `%E / 0.'", op0);
2881 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2882 code0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
2883 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
2884 code1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
2886 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
2887 resultcode = RDIV_EXPR;
2889 /* When dividing two signed integers, we have to promote to int.
2890 unless we divide by a constant != -1. Note that default
2891 conversion will have been performed on the operands at this
2892 point, so we have to dig out the original type to find out if
2894 shorten = ((TREE_CODE (op0) == NOP_EXPR
2895 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2896 || (TREE_CODE (op1) == INTEGER_CST
2897 && ! integer_all_onesp (op1)));
2906 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2910 case TRUNC_MOD_EXPR:
2911 case FLOOR_MOD_EXPR:
2912 if (code1 == INTEGER_TYPE && integer_zerop (op1))
2913 warning ("division by zero in `%E %% 0'", op0);
2914 else if (code1 == REAL_TYPE && real_zerop (op1))
2915 warning ("division by zero in `%E %% 0.'", op0);
2917 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2919 /* Although it would be tempting to shorten always here, that loses
2920 on some targets, since the modulo instruction is undefined if the
2921 quotient can't be represented in the computation mode. We shorten
2922 only if unsigned or if dividing by something we know != -1. */
2923 shorten = ((TREE_CODE (op0) == NOP_EXPR
2924 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2925 || (TREE_CODE (op1) == INTEGER_CST
2926 && ! integer_all_onesp (op1)));
2931 case TRUTH_ANDIF_EXPR:
2932 case TRUTH_ORIF_EXPR:
2933 case TRUTH_AND_EXPR:
2935 result_type = boolean_type_node;
2938 /* Shift operations: result has same type as first operand;
2939 always convert second operand to int.
2940 Also set SHORT_SHIFT if shifting rightward. */
2943 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2945 result_type = type0;
2946 if (TREE_CODE (op1) == INTEGER_CST)
2948 if (tree_int_cst_lt (op1, integer_zero_node))
2949 warning ("right shift count is negative");
2952 if (! integer_zerop (op1))
2954 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2955 warning ("right shift count >= width of type");
2958 /* Convert the shift-count to an integer, regardless of
2959 size of value being shifted. */
2960 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2961 op1 = cp_convert (integer_type_node, op1);
2962 /* Avoid converting op1 to result_type later. */
2968 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2970 result_type = type0;
2971 if (TREE_CODE (op1) == INTEGER_CST)
2973 if (tree_int_cst_lt (op1, integer_zero_node))
2974 warning ("left shift count is negative");
2975 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2976 warning ("left shift count >= width of type");
2978 /* Convert the shift-count to an integer, regardless of
2979 size of value being shifted. */
2980 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2981 op1 = cp_convert (integer_type_node, op1);
2982 /* Avoid converting op1 to result_type later. */
2989 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2991 result_type = type0;
2992 if (TREE_CODE (op1) == INTEGER_CST)
2994 if (tree_int_cst_lt (op1, integer_zero_node))
2995 warning ("%s rotate count is negative",
2996 (code == LROTATE_EXPR) ? "left" : "right");
2997 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2998 warning ("%s rotate count >= width of type",
2999 (code == LROTATE_EXPR) ? "left" : "right");
3001 /* Convert the shift-count to an integer, regardless of
3002 size of value being shifted. */
3003 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3004 op1 = cp_convert (integer_type_node, op1);
3010 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE))
3011 warning ("comparing floating point with == or != is unsafe");
3013 build_type = boolean_type_node;
3014 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3015 || code0 == COMPLEX_TYPE)
3016 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3017 || code1 == COMPLEX_TYPE))
3019 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3020 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3021 result_type = composite_pointer_type (type0, type1, op0, op1,
3023 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3024 && null_ptr_cst_p (op1))
3025 result_type = type0;
3026 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3027 && null_ptr_cst_p (op0))
3028 result_type = type1;
3029 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3031 result_type = type0;
3032 error ("ISO C++ forbids comparison between pointer and integer");
3034 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3036 result_type = type1;
3037 error ("ISO C++ forbids comparison between pointer and integer");
3039 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3041 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3042 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3043 result_type = TREE_TYPE (op0);
3045 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3046 return cp_build_binary_op (code, op1, op0);
3047 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3048 && same_type_p (type0, type1))
3050 /* E will be the final comparison. */
3052 /* E1 and E2 are for scratch. */
3060 if (TREE_SIDE_EFFECTS (op0))
3061 op0 = save_expr (op0);
3062 if (TREE_SIDE_EFFECTS (op1))
3063 op1 = save_expr (op1);
3068 && (!op0.pfn || op0.delta == op1.delta))
3070 The reason for the `!op0.pfn' bit is that a NULL
3071 pointer-to-member is any member with a zero PFN; the
3072 DELTA field is unspecified. */
3073 pfn0 = pfn_from_ptrmemfunc (op0);
3074 pfn1 = pfn_from_ptrmemfunc (op1);
3075 delta0 = build_ptrmemfunc_access_expr (op0,
3077 delta1 = build_ptrmemfunc_access_expr (op1,
3079 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3080 e2 = cp_build_binary_op (EQ_EXPR,
3082 cp_convert (TREE_TYPE (pfn0),
3083 integer_zero_node));
3084 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3085 e2 = build (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3086 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3087 if (code == EQ_EXPR)
3089 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3091 else if ((TYPE_PTRMEMFUNC_P (type0)
3092 && same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0), type1))
3093 || (TYPE_PTRMEMFUNC_P (type1)
3094 && same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1), type0)))
3100 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3101 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3103 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3104 result_type = composite_pointer_type (type0, type1, op0, op1,
3112 build_type = boolean_type_node;
3113 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3114 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3116 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3117 result_type = composite_pointer_type (type0, type1, op0, op1,
3119 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3120 && integer_zerop (op1))
3121 result_type = type0;
3122 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3123 && integer_zerop (op0))
3124 result_type = type1;
3125 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3127 result_type = type0;
3128 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3130 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3132 result_type = type1;
3133 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3137 case UNORDERED_EXPR:
3144 build_type = integer_type_node;
3145 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3147 error ("unordered comparison on non-floating point argument");
3148 return error_mark_node;
3157 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3159 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE))
3161 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3163 if (shorten || common || short_compare)
3164 result_type = common_type (type0, type1);
3166 /* For certain operations (which identify themselves by shorten != 0)
3167 if both args were extended from the same smaller type,
3168 do the arithmetic in that type and then extend.
3170 shorten !=0 and !=1 indicates a bitwise operation.
3171 For them, this optimization is safe only if
3172 both args are zero-extended or both are sign-extended.
3173 Otherwise, we might change the result.
3174 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3175 but calculated in (unsigned short) it would be (unsigned short)-1. */
3177 if (shorten && none_complex)
3179 int unsigned0, unsigned1;
3180 tree arg0 = get_narrower (op0, &unsigned0);
3181 tree arg1 = get_narrower (op1, &unsigned1);
3182 /* UNS is 1 if the operation to be done is an unsigned one. */
3183 int uns = TYPE_UNSIGNED (result_type);
3186 final_type = result_type;
3188 /* Handle the case that OP0 does not *contain* a conversion
3189 but it *requires* conversion to FINAL_TYPE. */
3191 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3192 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3193 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3194 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3196 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3198 /* For bitwise operations, signedness of nominal type
3199 does not matter. Consider only how operands were extended. */
3203 /* Note that in all three cases below we refrain from optimizing
3204 an unsigned operation on sign-extended args.
3205 That would not be valid. */
3207 /* Both args variable: if both extended in same way
3208 from same width, do it in that width.
3209 Do it unsigned if args were zero-extended. */
3210 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3211 < TYPE_PRECISION (result_type))
3212 && (TYPE_PRECISION (TREE_TYPE (arg1))
3213 == TYPE_PRECISION (TREE_TYPE (arg0)))
3214 && unsigned0 == unsigned1
3215 && (unsigned0 || !uns))
3216 result_type = c_common_signed_or_unsigned_type
3217 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3218 else if (TREE_CODE (arg0) == INTEGER_CST
3219 && (unsigned1 || !uns)
3220 && (TYPE_PRECISION (TREE_TYPE (arg1))
3221 < TYPE_PRECISION (result_type))
3222 && (type = c_common_signed_or_unsigned_type
3223 (unsigned1, TREE_TYPE (arg1)),
3224 int_fits_type_p (arg0, type)))
3226 else if (TREE_CODE (arg1) == INTEGER_CST
3227 && (unsigned0 || !uns)
3228 && (TYPE_PRECISION (TREE_TYPE (arg0))
3229 < TYPE_PRECISION (result_type))
3230 && (type = c_common_signed_or_unsigned_type
3231 (unsigned0, TREE_TYPE (arg0)),
3232 int_fits_type_p (arg1, type)))
3236 /* Shifts can be shortened if shifting right. */
3241 tree arg0 = get_narrower (op0, &unsigned_arg);
3243 final_type = result_type;
3245 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3246 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3248 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3249 /* We can shorten only if the shift count is less than the
3250 number of bits in the smaller type size. */
3251 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3252 /* If arg is sign-extended and then unsigned-shifted,
3253 we can simulate this with a signed shift in arg's type
3254 only if the extended result is at least twice as wide
3255 as the arg. Otherwise, the shift could use up all the
3256 ones made by sign-extension and bring in zeros.
3257 We can't optimize that case at all, but in most machines
3258 it never happens because available widths are 2**N. */
3259 && (!TYPE_UNSIGNED (final_type)
3261 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3262 <= TYPE_PRECISION (result_type))))
3264 /* Do an unsigned shift if the operand was zero-extended. */
3266 = c_common_signed_or_unsigned_type (unsigned_arg,
3268 /* Convert value-to-be-shifted to that type. */
3269 if (TREE_TYPE (op0) != result_type)
3270 op0 = cp_convert (result_type, op0);
3275 /* Comparison operations are shortened too but differently.
3276 They identify themselves by setting short_compare = 1. */
3280 /* Don't write &op0, etc., because that would prevent op0
3281 from being kept in a register.
3282 Instead, make copies of the our local variables and
3283 pass the copies by reference, then copy them back afterward. */
3284 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3285 enum tree_code xresultcode = resultcode;
3287 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3289 return cp_convert (boolean_type_node, val);
3290 op0 = xop0, op1 = xop1;
3292 resultcode = xresultcode;
3295 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3296 && warn_sign_compare
3297 /* Do not warn until the template is instantiated; we cannot
3298 bound the ranges of the arguments until that point. */
3299 && !processing_template_decl)
3301 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3302 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3304 int unsignedp0, unsignedp1;
3305 tree primop0 = get_narrower (op0, &unsignedp0);
3306 tree primop1 = get_narrower (op1, &unsignedp1);
3308 /* Check for comparison of different enum types. */
3309 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3310 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3311 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3312 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3314 warning ("comparison between types `%#T' and `%#T'",
3315 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3318 /* Give warnings for comparisons between signed and unsigned
3319 quantities that may fail. */
3320 /* Do the checking based on the original operand trees, so that
3321 casts will be considered, but default promotions won't be. */
3323 /* Do not warn if the comparison is being done in a signed type,
3324 since the signed type will only be chosen if it can represent
3325 all the values of the unsigned type. */
3326 if (!TYPE_UNSIGNED (result_type))
3328 /* Do not warn if both operands are unsigned. */
3329 else if (op0_signed == op1_signed)
3331 /* Do not warn if the signed quantity is an unsuffixed
3332 integer literal (or some static constant expression
3333 involving such literals or a conditional expression
3334 involving such literals) and it is non-negative. */
3335 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3336 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3338 /* Do not warn if the comparison is an equality operation,
3339 the unsigned quantity is an integral constant and it does
3340 not use the most significant bit of result_type. */
3341 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3342 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3343 && int_fits_type_p (orig_op1, c_common_signed_type
3345 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3346 && int_fits_type_p (orig_op0, c_common_signed_type
3350 warning ("comparison between signed and unsigned integer expressions");
3352 /* Warn if two unsigned values are being compared in a size
3353 larger than their original size, and one (and only one) is the
3354 result of a `~' operator. This comparison will always fail.
3356 Also warn if one operand is a constant, and the constant does not
3357 have all bits set that are set in the ~ operand when it is
3360 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3361 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3363 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3364 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3365 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3366 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3368 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3371 HOST_WIDE_INT constant, mask;
3375 if (host_integerp (primop0, 0))
3378 unsignedp = unsignedp1;
3379 constant = tree_low_cst (primop0, 0);
3384 unsignedp = unsignedp0;
3385 constant = tree_low_cst (primop1, 0);
3388 bits = TYPE_PRECISION (TREE_TYPE (primop));
3389 if (bits < TYPE_PRECISION (result_type)
3390 && bits < HOST_BITS_PER_LONG && unsignedp)
3392 mask = (~ (HOST_WIDE_INT) 0) << bits;
3393 if ((mask & constant) != mask)
3394 warning ("comparison of promoted ~unsigned with constant");
3397 else if (unsignedp0 && unsignedp1
3398 && (TYPE_PRECISION (TREE_TYPE (primop0))
3399 < TYPE_PRECISION (result_type))
3400 && (TYPE_PRECISION (TREE_TYPE (primop1))
3401 < TYPE_PRECISION (result_type)))
3402 warning ("comparison of promoted ~unsigned with unsigned");
3407 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
3408 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3409 Then the expression will be built.
3410 It will be given type FINAL_TYPE if that is nonzero;
3411 otherwise, it will be given type RESULT_TYPE. */
3415 error ("invalid operands of types `%T' and `%T' to binary `%O'",
3416 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3417 return error_mark_node;
3420 /* Issue warnings about peculiar, but valid, uses of NULL. */
3421 if (/* It's reasonable to use pointer values as operands of &&
3422 and ||, so NULL is no exception. */
3423 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3424 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3425 (orig_op0 == null_node
3426 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3427 /* Or vice versa. */
3428 || (orig_op1 == null_node
3429 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3430 /* Or, both are NULL and the operation was not a comparison. */
3431 || (orig_op0 == null_node && orig_op1 == null_node
3432 && code != EQ_EXPR && code != NE_EXPR)))
3433 /* Some sort of arithmetic operation involving NULL was
3434 performed. Note that pointer-difference and pointer-addition
3435 have already been handled above, and so we don't end up here in
3437 warning ("NULL used in arithmetic");
3441 if (TREE_TYPE (op0) != result_type)
3442 op0 = cp_convert (result_type, op0);
3443 if (TREE_TYPE (op1) != result_type)
3444 op1 = cp_convert (result_type, op1);
3446 if (op0 == error_mark_node || op1 == error_mark_node)
3447 return error_mark_node;
3450 if (build_type == NULL_TREE)
3451 build_type = result_type;
3454 tree result = fold (build (resultcode, build_type, op0, op1));
3455 if (final_type != 0)
3456 result = cp_convert (final_type, result);
3461 /* Return a tree for the sum or difference (RESULTCODE says which)
3462 of pointer PTROP and integer INTOP. */
3465 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3467 tree res_type = TREE_TYPE (ptrop);
3469 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3470 in certain circumstance (when it's valid to do so). So we need
3471 to make sure it's complete. We don't need to check here, if we
3472 can actually complete it at all, as those checks will be done in
3473 pointer_int_sum() anyway. */
3474 complete_type (TREE_TYPE (res_type));
3476 return pointer_int_sum (resultcode, ptrop, fold (intop));
3479 /* Return a tree for the difference of pointers OP0 and OP1.
3480 The resulting tree has type int. */
3483 pointer_diff (tree op0, tree op1, tree ptrtype)
3486 tree restype = ptrdiff_type_node;
3487 tree target_type = TREE_TYPE (ptrtype);
3489 if (!complete_type_or_else (target_type, NULL_TREE))
3490 return error_mark_node;
3492 if (pedantic || warn_pointer_arith)
3494 if (TREE_CODE (target_type) == VOID_TYPE)
3495 pedwarn ("ISO C++ forbids using pointer of type `void *' in subtraction");
3496 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3497 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3498 if (TREE_CODE (target_type) == METHOD_TYPE)
3499 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3502 /* First do the subtraction as integers;
3503 then drop through to build the divide operator. */
3505 op0 = cp_build_binary_op (MINUS_EXPR,
3506 cp_convert (restype, op0),
3507 cp_convert (restype, op1));
3509 /* This generates an error if op1 is a pointer to an incomplete type. */
3510 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3511 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3513 op1 = (TYPE_PTROB_P (ptrtype)
3514 ? size_in_bytes (target_type)
3515 : integer_one_node);
3517 /* Do the division. */
3519 result = build (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3520 return fold (result);
3523 /* Construct and perhaps optimize a tree representation
3524 for a unary operation. CODE, a tree_code, specifies the operation
3525 and XARG is the operand. */
3528 build_x_unary_op (enum tree_code code, tree xarg)
3530 tree orig_expr = xarg;
3534 if (processing_template_decl)
3536 if (type_dependent_expression_p (xarg))
3537 return build_min_nt (code, xarg, NULL_TREE);
3539 /* For non-dependent pointer-to-member, the SCOPE_REF will be
3540 processed during template substitution. Just compute the
3541 right type here and build an ADDR_EXPR around it for
3543 if (code == ADDR_EXPR && TREE_CODE (xarg) == SCOPE_REF)
3546 if (TREE_TYPE (xarg) == unknown_type_node)
3547 type = unknown_type_node;
3548 else if (TREE_CODE (TREE_TYPE (xarg)) == FUNCTION_TYPE)
3549 type = build_pointer_type (TREE_TYPE (xarg));
3551 type = build_ptrmem_type (TREE_OPERAND (xarg, 0),
3553 return build_min (code, type, xarg, NULL_TREE);
3556 xarg = build_non_dependent_expr (xarg);
3561 /* [expr.unary.op] says:
3563 The address of an object of incomplete type can be taken.
3565 (And is just the ordinary address operator, not an overloaded
3566 "operator &".) However, if the type is a template
3567 specialization, we must complete the type at this point so that
3568 an overloaded "operator &" will be available if required. */
3569 if (code == ADDR_EXPR
3570 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3571 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3572 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3573 || (TREE_CODE (xarg) == OFFSET_REF)))
3574 /* Don't look for a function. */;
3576 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3577 /*overloaded_p=*/NULL);
3578 if (!exp && code == ADDR_EXPR)
3580 /* A pointer to member-function can be formed only by saying
3582 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3583 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3585 if (TREE_CODE (xarg) != OFFSET_REF)
3587 error ("invalid use of '%E' to form a pointer-to-member-function. Use a qualified-id.",
3589 return error_mark_node;
3593 error ("parenthesis around '%E' cannot be used to form a pointer-to-member-function",
3595 PTRMEM_OK_P (xarg) = 1;
3599 if (TREE_CODE (xarg) == OFFSET_REF)
3601 ptrmem = PTRMEM_OK_P (xarg);
3603 if (!ptrmem && !flag_ms_extensions
3604 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3606 /* A single non-static member, make sure we don't allow a
3607 pointer-to-member. */
3608 xarg = build (OFFSET_REF, TREE_TYPE (xarg),
3609 TREE_OPERAND (xarg, 0),
3610 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3611 PTRMEM_OK_P (xarg) = ptrmem;
3614 else if (TREE_CODE (xarg) == TARGET_EXPR)
3615 warning ("taking address of temporary");
3616 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3617 if (TREE_CODE (exp) == ADDR_EXPR)
3618 PTRMEM_OK_P (exp) = ptrmem;
3621 if (processing_template_decl && exp != error_mark_node)
3622 return build_min_non_dep (code, exp, orig_expr,
3623 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3627 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3628 constants, where a null value is represented by an INTEGER_CST of
3632 cp_truthvalue_conversion (tree expr)
3634 tree type = TREE_TYPE (expr);
3635 if (TYPE_PTRMEM_P (type))
3636 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3638 return c_common_truthvalue_conversion (expr);
3641 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3644 condition_conversion (tree expr)
3647 if (processing_template_decl)
3649 t = perform_implicit_conversion (boolean_type_node, expr);
3650 t = fold (build1 (CLEANUP_POINT_EXPR, boolean_type_node, t));
3654 /* Return an ADDR_EXPR giving the address of T. This function
3655 attempts no optimizations or simplifications; it is a low-level
3659 build_address (tree t)
3663 if (error_operand_p (t) || !cxx_mark_addressable (t))
3664 return error_mark_node;
3666 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3671 /* Return a NOP_EXPR converting EXPR to TYPE. */
3674 build_nop (tree type, tree expr)
3676 if (type == error_mark_node || error_operand_p (expr))
3678 return build1 (NOP_EXPR, type, expr);
3681 /* C++: Must handle pointers to members.
3683 Perhaps type instantiation should be extended to handle conversion
3684 from aggregates to types we don't yet know we want? (Or are those
3685 cases typically errors which should be reported?)
3687 NOCONVERT nonzero suppresses the default promotions
3688 (such as from short to int). */
3691 build_unary_op (enum tree_code code, tree xarg, int noconvert)
3693 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
3696 const char *errstring = NULL;
3699 if (arg == error_mark_node)
3700 return error_mark_node;
3705 /* This is used for unary plus, because a CONVERT_EXPR
3706 is enough to prevent anybody from looking inside for
3707 associativity, but won't generate any code. */
3708 if (!(arg = build_expr_type_conversion
3709 (WANT_ARITH | WANT_ENUM | WANT_POINTER, arg, true)))
3710 errstring = "wrong type argument to unary plus";
3714 arg = default_conversion (arg);
3715 arg = build1 (NON_LVALUE_EXPR, TREE_TYPE (arg), arg);
3720 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3721 errstring = "wrong type argument to unary minus";
3722 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
3723 arg = perform_integral_promotions (arg);
3727 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3731 arg = default_conversion (arg);
3733 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM,
3735 errstring = "wrong type argument to bit-complement";
3736 else if (!noconvert)
3737 arg = perform_integral_promotions (arg);
3741 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3742 errstring = "wrong type argument to abs";
3743 else if (!noconvert)
3744 arg = default_conversion (arg);
3748 /* Conjugating a real value is a no-op, but allow it anyway. */
3749 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3750 errstring = "wrong type argument to conjugation";
3751 else if (!noconvert)
3752 arg = default_conversion (arg);
3755 case TRUTH_NOT_EXPR:
3756 arg = perform_implicit_conversion (boolean_type_node, arg);
3757 val = invert_truthvalue (arg);
3758 if (arg != error_mark_node)
3760 errstring = "in argument to unary !";
3767 if (TREE_CODE (arg) == COMPLEX_CST)
3768 return TREE_REALPART (arg);
3769 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3770 return fold (build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg));
3775 if (TREE_CODE (arg) == COMPLEX_CST)
3776 return TREE_IMAGPART (arg);
3777 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3778 return fold (build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg));
3780 return cp_convert (TREE_TYPE (arg), integer_zero_node);
3782 case PREINCREMENT_EXPR:
3783 case POSTINCREMENT_EXPR:
3784 case PREDECREMENT_EXPR:
3785 case POSTDECREMENT_EXPR:
3786 /* Handle complex lvalues (when permitted)
3787 by reduction to simpler cases. */
3789 val = unary_complex_lvalue (code, arg);
3793 /* Increment or decrement the real part of the value,
3794 and don't change the imaginary part. */
3795 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3799 arg = stabilize_reference (arg);
3800 real = build_unary_op (REALPART_EXPR, arg, 1);
3801 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
3802 return build (COMPLEX_EXPR, TREE_TYPE (arg),
3803 build_unary_op (code, real, 1), imag);
3806 /* Report invalid types. */
3808 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
3811 if (code == PREINCREMENT_EXPR)
3812 errstring ="no pre-increment operator for type";
3813 else if (code == POSTINCREMENT_EXPR)
3814 errstring ="no post-increment operator for type";
3815 else if (code == PREDECREMENT_EXPR)
3816 errstring ="no pre-decrement operator for type";
3818 errstring ="no post-decrement operator for type";
3822 /* Report something read-only. */
3824 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
3825 || TREE_READONLY (arg))
3826 readonly_error (arg, ((code == PREINCREMENT_EXPR
3827 || code == POSTINCREMENT_EXPR)
3828 ? "increment" : "decrement"),
3833 tree result_type = TREE_TYPE (arg);
3835 arg = get_unwidened (arg, 0);
3836 argtype = TREE_TYPE (arg);
3838 /* ARM $5.2.5 last annotation says this should be forbidden. */
3839 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
3840 pedwarn ("ISO C++ forbids %sing an enum",
3841 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3842 ? "increment" : "decrement");
3844 /* Compute the increment. */
3846 if (TREE_CODE (argtype) == POINTER_TYPE)
3848 tree type = complete_type (TREE_TYPE (argtype));
3850 if (!COMPLETE_OR_VOID_TYPE_P (type))
3851 error ("cannot %s a pointer to incomplete type `%T'",
3852 ((code == PREINCREMENT_EXPR
3853 || code == POSTINCREMENT_EXPR)
3854 ? "increment" : "decrement"), TREE_TYPE (argtype));
3855 else if ((pedantic || warn_pointer_arith)
3856 && !TYPE_PTROB_P (argtype))
3857 pedwarn ("ISO C++ forbids %sing a pointer of type `%T'",
3858 ((code == PREINCREMENT_EXPR
3859 || code == POSTINCREMENT_EXPR)
3860 ? "increment" : "decrement"), argtype);
3861 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
3864 inc = integer_one_node;
3866 inc = cp_convert (argtype, inc);
3868 /* Handle incrementing a cast-expression. */
3870 switch (TREE_CODE (arg))
3875 case FIX_TRUNC_EXPR:
3876 case FIX_FLOOR_EXPR:
3877 case FIX_ROUND_EXPR:
3880 tree incremented, modify, value, compound;
3881 if (! lvalue_p (arg) && pedantic)
3882 pedwarn ("cast to non-reference type used as lvalue");
3883 arg = stabilize_reference (arg);
3884 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
3887 value = save_expr (arg);
3888 incremented = build (((code == PREINCREMENT_EXPR
3889 || code == POSTINCREMENT_EXPR)
3890 ? PLUS_EXPR : MINUS_EXPR),
3891 argtype, value, inc);
3893 modify = build_modify_expr (arg, NOP_EXPR, incremented);
3894 compound = build (COMPOUND_EXPR, TREE_TYPE (arg), modify, value);
3896 /* Eliminate warning about unused result of + or -. */
3897 TREE_NO_WARNING (compound) = 1;
3905 /* Complain about anything else that is not a true lvalue. */
3906 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
3907 || code == POSTINCREMENT_EXPR)
3908 ? "increment" : "decrement")))
3909 return error_mark_node;
3911 /* Forbid using -- on `bool'. */
3912 if (TREE_TYPE (arg) == boolean_type_node)
3914 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
3916 error ("invalid use of `--' on bool variable `%D'", arg);
3917 return error_mark_node;
3919 val = boolean_increment (code, arg);
3922 val = build (code, TREE_TYPE (arg), arg, inc);
3924 TREE_SIDE_EFFECTS (val) = 1;
3925 return cp_convert (result_type, val);
3929 /* Note that this operation never does default_conversion
3930 regardless of NOCONVERT. */
3932 argtype = lvalue_type (arg);
3934 if (TREE_CODE (arg) == OFFSET_REF)
3937 if (TREE_CODE (argtype) == REFERENCE_TYPE)
3939 tree type = build_pointer_type (TREE_TYPE (argtype));
3940 arg = build1 (CONVERT_EXPR, type, arg);
3943 else if (pedantic && DECL_MAIN_P (arg))
3945 pedwarn ("ISO C++ forbids taking address of function `::main'");
3947 /* Let &* cancel out to simplify resulting code. */
3948 if (TREE_CODE (arg) == INDIRECT_REF)
3950 /* We don't need to have `current_class_ptr' wrapped in a
3951 NON_LVALUE_EXPR node. */
3952 if (arg == current_class_ref)
3953 return current_class_ptr;
3955 arg = TREE_OPERAND (arg, 0);
3956 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
3958 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
3959 arg = build1 (CONVERT_EXPR, type, arg);
3961 else if (lvalue_p (arg))
3962 /* Don't let this be an lvalue. */
3963 return non_lvalue (arg);
3967 /* For &x[y], return x+y. But, in a template, ARG may be an
3968 ARRAY_REF representing a non-dependent expression. In that
3969 case, there may be an overloaded "operator []" that will be
3970 chosen at instantiation time; we must not try to optimize
3972 if (TREE_CODE (arg) == ARRAY_REF && !processing_template_decl)
3974 if (!cxx_mark_addressable (TREE_OPERAND (arg, 0)))
3975 return error_mark_node;
3976 return cp_build_binary_op (PLUS_EXPR, TREE_OPERAND (arg, 0),
3977 TREE_OPERAND (arg, 1));
3980 /* Uninstantiated types are all functions. Taking the
3981 address of a function is a no-op, so just return the
3984 if (TREE_CODE (arg) == IDENTIFIER_NODE
3985 && IDENTIFIER_OPNAME_P (arg))
3988 /* We don't know the type yet, so just work around the problem.
3989 We know that this will resolve to an lvalue. */
3990 return build1 (ADDR_EXPR, unknown_type_node, arg);
3993 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
3994 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
3996 /* They're trying to take the address of a unique non-static
3997 member function. This is ill-formed (except in MS-land),
3998 but let's try to DTRT.
3999 Note: We only handle unique functions here because we don't
4000 want to complain if there's a static overload; non-unique
4001 cases will be handled by instantiate_type. But we need to
4002 handle this case here to allow casts on the resulting PMF.
4003 We could defer this in non-MS mode, but it's easier to give
4004 a useful error here. */
4006 /* Inside constant member functions, the `this' pointer
4007 contains an extra const qualifier. TYPE_MAIN_VARIANT
4008 is used here to remove this const from the diagnostics
4009 and the created OFFSET_REF. */
4010 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4011 tree name = DECL_NAME (get_first_fn (TREE_OPERAND (arg, 1)));
4013 if (! flag_ms_extensions)
4015 if (current_class_type
4016 && TREE_OPERAND (arg, 0) == current_class_ref)
4017 /* An expression like &memfn. */
4018 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4019 " or parenthesized non-static member function to form"
4020 " a pointer to member function. Say `&%T::%D'",
4023 pedwarn ("ISO C++ forbids taking the address of a bound member"
4024 " function to form a pointer to member function."
4028 arg = build_offset_ref (base, name, /*address_p=*/true);
4032 if (type_unknown_p (arg))
4033 return build1 (ADDR_EXPR, unknown_type_node, arg);
4035 /* Handle complex lvalues (when permitted)
4036 by reduction to simpler cases. */
4037 val = unary_complex_lvalue (code, arg);
4041 switch (TREE_CODE (arg))
4046 case FIX_TRUNC_EXPR:
4047 case FIX_FLOOR_EXPR:
4048 case FIX_ROUND_EXPR:
4050 if (! lvalue_p (arg) && pedantic)
4051 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4055 arg = OVL_CURRENT (arg);
4062 /* Allow the address of a constructor if all the elements
4064 if (TREE_CODE (arg) == CONSTRUCTOR && TREE_HAS_CONSTRUCTOR (arg)
4065 && TREE_CONSTANT (arg))
4067 /* Anything not already handled and not a true memory reference
4069 else if (TREE_CODE (argtype) != FUNCTION_TYPE
4070 && TREE_CODE (argtype) != METHOD_TYPE
4071 && !lvalue_or_else (arg, "unary `&'"))
4072 return error_mark_node;
4074 if (argtype != error_mark_node)
4075 argtype = build_pointer_type (argtype);
4080 if (TREE_CODE (arg) != COMPONENT_REF
4081 /* Inside a template, we are processing a non-dependent
4082 expression so we can just form an ADDR_EXPR with the
4084 || processing_template_decl)
4085 addr = build_address (arg);
4086 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4088 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4090 /* We can only get here with a single static member
4092 my_friendly_assert (TREE_CODE (fn) == FUNCTION_DECL
4093 && DECL_STATIC_FUNCTION_P (fn),
4096 addr = build_address (fn);
4097 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4098 /* Do not lose object's side effects. */
4099 addr = build (COMPOUND_EXPR, TREE_TYPE (addr),
4100 TREE_OPERAND (arg, 0), addr);
4102 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4104 error ("attempt to take address of bit-field structure member `%D'",
4105 TREE_OPERAND (arg, 1));
4106 return error_mark_node;
4110 /* Unfortunately we cannot just build an address
4111 expression here, because we would not handle
4112 address-constant-expressions or offsetof correctly. */
4113 tree field = TREE_OPERAND (arg, 1);
4114 tree rval = build_unary_op (ADDR_EXPR, TREE_OPERAND (arg, 0), 0);
4115 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (rval)),
4116 decl_type_context (field),
4119 rval = build_base_path (PLUS_EXPR, rval, binfo, 1);
4120 rval = build_nop (argtype, rval);
4121 addr = fold (build (PLUS_EXPR, argtype, rval,
4122 cp_convert (argtype, byte_position (field))));
4125 if (TREE_CODE (argtype) == POINTER_TYPE
4126 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4128 build_ptrmemfunc_type (argtype);
4129 addr = build_ptrmemfunc (argtype, addr, 0);
4142 argtype = TREE_TYPE (arg);
4143 return fold (build1 (code, argtype, arg));
4146 error ("%s", errstring);
4147 return error_mark_node;
4150 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4151 for certain kinds of expressions which are not really lvalues
4152 but which we can accept as lvalues.
4154 If ARG is not a kind of expression we can handle, return zero. */
4157 unary_complex_lvalue (enum tree_code code, tree arg)
4159 /* Handle (a, b) used as an "lvalue". */
4160 if (TREE_CODE (arg) == COMPOUND_EXPR)
4162 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4163 return build (COMPOUND_EXPR, TREE_TYPE (real_result),
4164 TREE_OPERAND (arg, 0), real_result);
4167 /* Handle (a ? b : c) used as an "lvalue". */
4168 if (TREE_CODE (arg) == COND_EXPR
4169 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4170 return rationalize_conditional_expr (code, arg);
4172 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4173 if (TREE_CODE (arg) == MODIFY_EXPR
4174 || TREE_CODE (arg) == PREINCREMENT_EXPR
4175 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4177 tree lvalue = TREE_OPERAND (arg, 0);
4178 if (TREE_SIDE_EFFECTS (lvalue))
4180 lvalue = stabilize_reference (lvalue);
4181 arg = build (TREE_CODE (arg), TREE_TYPE (arg),
4182 lvalue, TREE_OPERAND (arg, 1));
4184 return unary_complex_lvalue
4185 (code, build (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4188 if (code != ADDR_EXPR)
4191 /* Handle (a = b) used as an "lvalue" for `&'. */
4192 if (TREE_CODE (arg) == MODIFY_EXPR
4193 || TREE_CODE (arg) == INIT_EXPR)
4195 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4196 arg = build (COMPOUND_EXPR, TREE_TYPE (real_result), arg, real_result);
4197 TREE_NO_WARNING (arg) = 1;
4201 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4202 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4203 || TREE_CODE (arg) == OFFSET_REF)
4207 my_friendly_assert (TREE_CODE (arg) != SCOPE_REF, 313);
4209 if (TREE_CODE (arg) != OFFSET_REF)
4212 t = TREE_OPERAND (arg, 1);
4214 /* Check all this code for right semantics. */
4215 if (TREE_CODE (t) == FUNCTION_DECL)
4217 if (DECL_DESTRUCTOR_P (t))
4218 error ("taking address of destructor");
4219 return build_unary_op (ADDR_EXPR, t, 0);
4221 if (TREE_CODE (t) == VAR_DECL)
4222 return build_unary_op (ADDR_EXPR, t, 0);
4227 if (TREE_OPERAND (arg, 0)
4228 && ! is_dummy_object (TREE_OPERAND (arg, 0))
4229 && TREE_CODE (t) != FIELD_DECL)
4231 error ("taking address of bound pointer-to-member expression");
4232 return error_mark_node;
4234 if (!PTRMEM_OK_P (arg))
4235 return build_unary_op (code, arg, 0);
4237 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4239 error ("cannot create pointer to reference member `%D'", t);
4240 return error_mark_node;
4243 type = build_ptrmem_type (context_for_name_lookup (t),
4245 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4251 /* We permit compiler to make function calls returning
4252 objects of aggregate type look like lvalues. */
4256 if (TREE_CODE (targ) == SAVE_EXPR)
4257 targ = TREE_OPERAND (targ, 0);
4259 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4261 if (TREE_CODE (arg) == SAVE_EXPR)
4264 targ = build_cplus_new (TREE_TYPE (arg), arg);
4265 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4268 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4269 return build (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4270 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4273 /* Don't let anything else be handled specially. */
4277 /* Mark EXP saying that we need to be able to take the
4278 address of it; it should not be allocated in a register.
4279 Value is true if successful.
4281 C++: we do not allow `current_class_ptr' to be addressable. */
4284 cxx_mark_addressable (tree exp)
4289 switch (TREE_CODE (x))
4296 x = TREE_OPERAND (x, 0);
4300 if (x == current_class_ptr)
4302 error ("cannot take the address of `this', which is an rvalue expression");
4303 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4309 /* Caller should not be trying to mark initialized
4310 constant fields addressable. */
4311 my_friendly_assert (DECL_LANG_SPECIFIC (x) == 0
4312 || DECL_IN_AGGR_P (x) == 0
4314 || DECL_EXTERNAL (x), 314);
4319 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4320 && !DECL_ARTIFICIAL (x) && extra_warnings)
4321 warning ("address requested for `%D', which is declared `register'",
4323 TREE_ADDRESSABLE (x) = 1;
4327 TREE_ADDRESSABLE (x) = 1;
4331 TREE_ADDRESSABLE (x) = 1;
4335 TREE_ADDRESSABLE (x) = 1;
4336 cxx_mark_addressable (TREE_OPERAND (x, 0));
4344 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4347 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4349 tree orig_ifexp = ifexp;
4350 tree orig_op1 = op1;
4351 tree orig_op2 = op2;
4354 if (processing_template_decl)
4356 /* The standard says that the expression is type-dependent if
4357 IFEXP is type-dependent, even though the eventual type of the
4358 expression doesn't dependent on IFEXP. */
4359 if (type_dependent_expression_p (ifexp)
4360 /* As a GNU extension, the middle operand may be omitted. */
4361 || (op1 && type_dependent_expression_p (op1))
4362 || type_dependent_expression_p (op2))
4363 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4364 ifexp = build_non_dependent_expr (ifexp);
4366 op1 = build_non_dependent_expr (op1);
4367 op2 = build_non_dependent_expr (op2);
4370 expr = build_conditional_expr (ifexp, op1, op2);
4371 if (processing_template_decl && expr != error_mark_node)
4372 return build_min_non_dep (COND_EXPR, expr,
4373 orig_ifexp, orig_op1, orig_op2);
4377 /* Given a list of expressions, return a compound expression
4378 that performs them all and returns the value of the last of them. */
4380 tree build_x_compound_expr_from_list (tree list, const char *msg)
4382 tree expr = TREE_VALUE (list);
4384 if (TREE_CHAIN (list))
4387 pedwarn ("%s expression list treated as compound expression", msg);
4389 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4390 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4396 /* Handle overloading of the ',' operator when needed. */
4399 build_x_compound_expr (tree op1, tree op2)
4402 tree orig_op1 = op1;
4403 tree orig_op2 = op2;
4405 if (processing_template_decl)
4407 if (type_dependent_expression_p (op1)
4408 || type_dependent_expression_p (op2))
4409 return build_min_nt (COMPOUND_EXPR, op1, op2);
4410 op1 = build_non_dependent_expr (op1);
4411 op2 = build_non_dependent_expr (op2);
4414 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4415 /*overloaded_p=*/NULL);
4417 result = build_compound_expr (op1, op2);
4419 if (processing_template_decl && result != error_mark_node)
4420 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4425 /* Build a compound expression. */
4428 build_compound_expr (tree lhs, tree rhs)
4430 lhs = decl_constant_value (lhs);
4431 lhs = convert_to_void (lhs, "left-hand operand of comma");
4433 if (lhs == error_mark_node || rhs == error_mark_node)
4434 return error_mark_node;
4436 if (TREE_CODE (rhs) == TARGET_EXPR)
4438 /* If the rhs is a TARGET_EXPR, then build the compound
4439 expression inside the target_expr's initializer. This
4440 helps the compiler to eliminate unnecessary temporaries. */
4441 tree init = TREE_OPERAND (rhs, 1);
4443 init = build (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4444 TREE_OPERAND (rhs, 1) = init;
4449 return build (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4452 /* Issue an error message if casting from SRC_TYPE to DEST_TYPE casts
4453 away constness. DESCRIPTION explains what operation is taking
4457 check_for_casting_away_constness (tree src_type, tree dest_type,
4458 const char *description)
4460 if (casts_away_constness (src_type, dest_type))
4461 error ("%s from type `%T' to type `%T' casts away constness",
4462 description, src_type, dest_type);
4465 /* Return an expression representing static_cast<TYPE>(EXPR). */
4468 build_static_cast (tree type, tree expr)
4473 if (type == error_mark_node || expr == error_mark_node)
4474 return error_mark_node;
4476 if (processing_template_decl)
4478 expr = build_min (STATIC_CAST_EXPR, type, expr);
4479 /* We don't know if it will or will not have side effects. */
4480 TREE_SIDE_EFFECTS (expr) = 1;
4484 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4485 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4486 if (TREE_CODE (type) != REFERENCE_TYPE
4487 && TREE_CODE (expr) == NOP_EXPR
4488 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4489 expr = TREE_OPERAND (expr, 0);
4491 intype = TREE_TYPE (expr);
4493 /* [expr.static.cast]
4495 An lvalue of type "cv1 B", where B is a class type, can be cast
4496 to type "reference to cv2 D", where D is a class derived (clause
4497 _class.derived_) from B, if a valid standard conversion from
4498 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4499 same cv-qualification as, or greater cv-qualification than, cv1,
4500 and B is not a virtual base class of D. */
4501 /* We check this case before checking the validity of "TYPE t =
4502 EXPR;" below because for this case:
4505 struct D : public B { D(const B&); };
4507 void f() { static_cast<const D&>(b); }
4509 we want to avoid constructing a new D. The standard is not
4510 completely clear about this issue, but our interpretation is
4511 consistent with other compilers. */
4512 if (TREE_CODE (type) == REFERENCE_TYPE
4513 && CLASS_TYPE_P (TREE_TYPE (type))
4514 && CLASS_TYPE_P (intype)
4515 && real_lvalue_p (expr)
4516 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4517 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4518 build_pointer_type (TYPE_MAIN_VARIANT
4519 (TREE_TYPE (type))))
4520 && at_least_as_qualified_p (TREE_TYPE (type), intype))
4522 /* There is a standard conversion from "D*" to "B*" even if "B"
4523 is ambiguous or inaccessible. Therefore, we ask lookup_base
4524 to check these conditions. */
4525 tree base = lookup_base (TREE_TYPE (type), intype, ba_check, NULL);
4527 /* Convert from "B*" to "D*". This function will check that "B"
4528 is not a virtual base of "D". */
4529 expr = build_base_path (MINUS_EXPR, build_address (expr),
4530 base, /*nonnull=*/false);
4531 /* Convert the pointer to a reference -- but then remember that
4532 there are no expressions with reference type in C++. */
4533 return convert_from_reference (build_nop (type, expr));
4536 /* [expr.static.cast]
4538 An expression e can be explicitly converted to a type T using a
4539 static_cast of the form static_cast<T>(e) if the declaration T
4540 t(e);" is well-formed, for some invented temporary variable
4542 result = perform_direct_initialization_if_possible (type, expr);
4545 result = convert_from_reference (result);
4546 /* [expr.static.cast]
4548 If T is a reference type, the result is an lvalue; otherwise,
4549 the result is an rvalue. */
4550 if (TREE_CODE (type) != REFERENCE_TYPE
4551 && real_lvalue_p (result))
4552 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (result), result);
4556 /* [expr.static.cast]
4558 Any expression can be explicitly converted to type cv void. */
4559 if (TREE_CODE (type) == VOID_TYPE)
4560 return convert_to_void (expr, /*implicit=*/NULL);
4562 /* [expr.static.cast]
4564 The inverse of any standard conversion sequence (clause _conv_),
4565 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4566 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4567 (_conv.bool_) conversions, can be performed explicitly using
4568 static_cast subject to the restriction that the explicit
4569 conversion does not cast away constness (_expr.const.cast_), and
4570 the following additional rules for specific cases: */
4571 /* For reference, the conversions not excluded are: integral
4572 promotions, floating point promotion, integral conversions,
4573 floating point conversions, floating-integral conversions,
4574 pointer conversions, and pointer to member conversions. */
4575 if ((ARITHMETIC_TYPE_P (type) && ARITHMETIC_TYPE_P (intype))
4578 A value of integral _or enumeration_ type can be explicitly
4579 converted to an enumeration type. */
4580 || (INTEGRAL_OR_ENUMERATION_TYPE_P (type)
4581 && INTEGRAL_OR_ENUMERATION_TYPE_P (intype)))
4582 /* Really, build_c_cast should defer to this function rather
4583 than the other way around. */
4584 return build_c_cast (type, expr);
4586 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4587 && CLASS_TYPE_P (TREE_TYPE (type))
4588 && CLASS_TYPE_P (TREE_TYPE (intype))
4589 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4590 (TREE_TYPE (intype))),
4591 build_pointer_type (TYPE_MAIN_VARIANT
4592 (TREE_TYPE (type)))))
4596 check_for_casting_away_constness (intype, type, "static_cast");
4597 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype), ba_check,
4599 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
4602 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4603 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4610 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
4611 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
4613 if (TYPE_PTRMEM_P (type))
4615 t1 = (build_ptrmem_type
4617 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
4618 t2 = (build_ptrmem_type
4620 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
4627 if (can_convert (t1, t2))
4629 check_for_casting_away_constness (intype, type, "static_cast");
4630 if (TYPE_PTRMEM_P (type))
4634 if (TREE_CODE (expr) == PTRMEM_CST)
4635 expr = cplus_expand_constant (expr);
4636 delta = get_delta_difference (c1, c2, /*force=*/1);
4637 if (!integer_zerop (delta))
4638 expr = cp_build_binary_op (PLUS_EXPR,
4639 build_nop (ptrdiff_type_node, expr),
4641 return build_nop (type, expr);
4644 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4649 /* [expr.static.cast]
4651 An rvalue of type "pointer to cv void" can be explicitly
4652 converted to a pointer to object type. A value of type pointer
4653 to object converted to "pointer to cv void" and back to the
4654 original pointer type will have its original value. */
4655 if (TREE_CODE (intype) == POINTER_TYPE
4656 && VOID_TYPE_P (TREE_TYPE (intype))
4657 && TYPE_PTROB_P (type))
4659 check_for_casting_away_constness (intype, type, "static_cast");
4660 return build_nop (type, expr);
4663 error ("invalid static_cast from type `%T' to type `%T'", intype, type);
4664 return error_mark_node;
4668 build_reinterpret_cast (tree type, tree expr)
4672 if (type == error_mark_node || expr == error_mark_node)
4673 return error_mark_node;
4675 if (processing_template_decl)
4677 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
4679 if (!TREE_SIDE_EFFECTS (t)
4680 && type_dependent_expression_p (expr))
4681 /* There might turn out to be side effects inside expr. */
4682 TREE_SIDE_EFFECTS (t) = 1;
4686 if (TREE_CODE (type) != REFERENCE_TYPE)
4688 expr = decay_conversion (expr);
4690 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4691 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4692 if (TREE_CODE (expr) == NOP_EXPR
4693 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4694 expr = TREE_OPERAND (expr, 0);
4697 intype = TREE_TYPE (expr);
4699 if (TREE_CODE (type) == REFERENCE_TYPE)
4701 if (! real_lvalue_p (expr))
4703 error ("invalid reinterpret_cast of an rvalue expression of type `%T' to type `%T'", intype, type);
4704 return error_mark_node;
4706 expr = build_unary_op (ADDR_EXPR, expr, 0);
4707 if (expr != error_mark_node)
4708 expr = build_reinterpret_cast
4709 (build_pointer_type (TREE_TYPE (type)), expr);
4710 if (expr != error_mark_node)
4711 expr = build_indirect_ref (expr, 0);
4714 else if (same_type_ignoring_top_level_qualifiers_p (intype, type))
4715 return build_static_cast (type, expr);
4717 if (TYPE_PTR_P (type) && (TREE_CODE (intype) == INTEGER_TYPE
4718 || TREE_CODE (intype) == ENUMERAL_TYPE))
4720 else if (TREE_CODE (type) == INTEGER_TYPE && TYPE_PTR_P (intype))
4722 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
4723 pedwarn ("reinterpret_cast from `%T' to `%T' loses precision",
4726 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
4727 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4729 expr = decl_constant_value (expr);
4730 return fold (build1 (NOP_EXPR, type, expr));
4732 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4733 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
4735 check_for_casting_away_constness (intype, type, "reinterpret_cast");
4736 expr = decl_constant_value (expr);
4737 return fold (build1 (NOP_EXPR, type, expr));
4739 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
4740 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
4742 pedwarn ("ISO C++ forbids casting between pointer-to-function and pointer-to-object");
4743 expr = decl_constant_value (expr);
4744 return fold (build1 (NOP_EXPR, type, expr));
4748 error ("invalid reinterpret_cast from type `%T' to type `%T'",
4750 return error_mark_node;
4753 return cp_convert (type, expr);
4757 build_const_cast (tree type, tree expr)
4761 if (type == error_mark_node || expr == error_mark_node)
4762 return error_mark_node;
4764 if (processing_template_decl)
4766 tree t = build_min (CONST_CAST_EXPR, type, expr);
4768 if (!TREE_SIDE_EFFECTS (t)
4769 && type_dependent_expression_p (expr))
4770 /* There might turn out to be side effects inside expr. */
4771 TREE_SIDE_EFFECTS (t) = 1;
4775 if (!POINTER_TYPE_P (type) && !TYPE_PTRMEM_P (type))
4776 error ("invalid use of const_cast with type `%T', which is not a pointer, reference, nor a pointer-to-data-member type", type);
4777 else if (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4779 error ("invalid use of const_cast with type `%T', which is a pointer or reference to a function type", type);
4780 return error_mark_node;
4783 if (TREE_CODE (type) != REFERENCE_TYPE)
4785 expr = decay_conversion (expr);
4787 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4788 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4789 if (TREE_CODE (expr) == NOP_EXPR
4790 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4791 expr = TREE_OPERAND (expr, 0);
4794 intype = TREE_TYPE (expr);
4796 if (same_type_ignoring_top_level_qualifiers_p (intype, type))
4797 return build_static_cast (type, expr);
4798 else if (TREE_CODE (type) == REFERENCE_TYPE)
4800 if (! real_lvalue_p (expr))
4802 error ("invalid const_cast of an rvalue of type `%T' to type `%T'", intype, type);
4803 return error_mark_node;
4806 if (comp_ptr_ttypes_const (TREE_TYPE (type), intype))
4808 expr = build_unary_op (ADDR_EXPR, expr, 0);
4809 expr = build1 (NOP_EXPR, type, expr);
4810 return convert_from_reference (expr);
4813 else if (((TREE_CODE (type) == POINTER_TYPE
4814 && TREE_CODE (intype) == POINTER_TYPE)
4815 || (TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype)))
4816 && comp_ptr_ttypes_const (TREE_TYPE (type), TREE_TYPE (intype)))
4817 return cp_convert (type, expr);
4819 error ("invalid const_cast from type `%T' to type `%T'", intype, type);
4820 return error_mark_node;
4823 /* Build an expression representing a cast to type TYPE of expression EXPR.
4825 ALLOW_NONCONVERTING is true if we should allow non-converting constructors
4826 when doing the cast. */
4829 build_c_cast (tree type, tree expr)
4834 if (type == error_mark_node || expr == error_mark_node)
4835 return error_mark_node;
4837 if (processing_template_decl)
4839 tree t = build_min (CAST_EXPR, type,
4840 tree_cons (NULL_TREE, value, NULL_TREE));
4841 /* We don't know if it will or will not have side effects. */
4842 TREE_SIDE_EFFECTS (t) = 1;
4846 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4847 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4848 if (TREE_CODE (type) != REFERENCE_TYPE
4849 && TREE_CODE (value) == NOP_EXPR
4850 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
4851 value = TREE_OPERAND (value, 0);
4853 if (TREE_CODE (type) == ARRAY_TYPE)
4855 /* Allow casting from T1* to T2[] because Cfront allows it.
4856 NIHCL uses it. It is not valid ISO C++ however. */
4857 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
4859 pedwarn ("ISO C++ forbids casting to an array type `%T'", type);
4860 type = build_pointer_type (TREE_TYPE (type));
4864 error ("ISO C++ forbids casting to an array type `%T'", type);
4865 return error_mark_node;
4869 if (TREE_CODE (type) == FUNCTION_TYPE
4870 || TREE_CODE (type) == METHOD_TYPE)
4872 error ("invalid cast to function type `%T'", type);
4873 return error_mark_node;
4876 if (TREE_CODE (type) == VOID_TYPE)
4878 /* Conversion to void does not cause any of the normal function to
4879 * pointer, array to pointer and lvalue to rvalue decays. */
4881 value = convert_to_void (value, /*implicit=*/NULL);
4885 if (!complete_type_or_else (type, NULL_TREE))
4886 return error_mark_node;
4888 /* Convert functions and arrays to pointers and
4889 convert references to their expanded types,
4890 but don't convert any other types. If, however, we are
4891 casting to a class type, there's no reason to do this: the
4892 cast will only succeed if there is a converting constructor,
4893 and the default conversions will be done at that point. In
4894 fact, doing the default conversion here is actually harmful
4898 struct S { S(const A&); };
4900 since we don't want the array-to-pointer conversion done. */
4901 if (!IS_AGGR_TYPE (type))
4903 if (TREE_CODE (TREE_TYPE (value)) == FUNCTION_TYPE
4904 || (TREE_CODE (TREE_TYPE (value)) == METHOD_TYPE
4905 /* Don't do the default conversion on a ->* expression. */
4906 && ! (TREE_CODE (type) == POINTER_TYPE
4907 && bound_pmf_p (value)))
4908 || TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE
4909 || TREE_CODE (TREE_TYPE (value)) == REFERENCE_TYPE)
4910 value = decay_conversion (value);
4912 else if (TREE_CODE (TREE_TYPE (value)) == REFERENCE_TYPE)
4913 /* However, even for class types, we still need to strip away
4914 the reference type, since the call to convert_force below
4915 does not expect the input expression to be of reference
4917 value = convert_from_reference (value);
4919 otype = TREE_TYPE (value);
4921 /* Optionally warn about potentially worrisome casts. */
4924 && TREE_CODE (type) == POINTER_TYPE
4925 && TREE_CODE (otype) == POINTER_TYPE
4926 && !at_least_as_qualified_p (TREE_TYPE (type),
4928 warning ("cast from `%T' to `%T' discards qualifiers from pointer target type",
4931 if (TREE_CODE (type) == INTEGER_TYPE
4932 && TYPE_PTR_P (otype)
4933 && TYPE_PRECISION (type) != TYPE_PRECISION (otype))
4934 warning ("cast from pointer to integer of different size");
4936 if (TYPE_PTR_P (type)
4937 && TREE_CODE (otype) == INTEGER_TYPE
4938 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
4939 /* Don't warn about converting any constant. */
4940 && !TREE_CONSTANT (value))
4941 warning ("cast to pointer from integer of different size");
4943 if (TREE_CODE (type) == REFERENCE_TYPE)
4944 value = (convert_from_reference
4945 (convert_to_reference (type, value, CONV_C_CAST,
4946 LOOKUP_COMPLAIN, NULL_TREE)));
4951 value = decl_constant_value (value);
4954 value = convert_force (type, value, CONV_C_CAST);
4956 /* Ignore any integer overflow caused by the cast. */
4957 if (TREE_CODE (value) == INTEGER_CST)
4959 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue);
4961 if (TREE_CODE_CLASS (TREE_CODE (ovalue)) == 'c')
4962 TREE_CONSTANT_OVERFLOW (value) = TREE_CONSTANT_OVERFLOW (ovalue);
4966 /* Warn about possible alignment problems. Do this here when we will have
4967 instantiated any necessary template types. */
4968 if (STRICT_ALIGNMENT && warn_cast_align
4969 && TREE_CODE (type) == POINTER_TYPE
4970 && TREE_CODE (otype) == POINTER_TYPE
4971 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE
4972 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
4973 && COMPLETE_TYPE_P (TREE_TYPE (otype))
4974 && COMPLETE_TYPE_P (TREE_TYPE (type))
4975 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype)))
4976 warning ("cast from `%T' to `%T' increases required alignment of target type",
4979 /* Always produce some operator for an explicit cast,
4980 so we can tell (for -pedantic) that the cast is no lvalue. */
4981 if (TREE_CODE (type) != REFERENCE_TYPE && value == expr
4982 && real_lvalue_p (value))
4983 value = non_lvalue (value);
4988 /* Build an assignment expression of lvalue LHS from value RHS.
4989 MODIFYCODE is the code for a binary operator that we use
4990 to combine the old value of LHS with RHS to get the new value.
4991 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
4993 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
4996 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5000 tree lhstype = TREE_TYPE (lhs);
5001 tree olhstype = lhstype;
5002 tree olhs = NULL_TREE;
5003 bool plain_assign = (modifycode == NOP_EXPR);
5005 /* Avoid duplicate error messages from operands that had errors. */
5006 if (lhs == error_mark_node || rhs == error_mark_node)
5007 return error_mark_node;
5009 /* Handle control structure constructs used as "lvalues". */
5010 switch (TREE_CODE (lhs))
5012 /* Handle --foo = 5; as these are valid constructs in C++. */
5013 case PREDECREMENT_EXPR:
5014 case PREINCREMENT_EXPR:
5015 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5016 lhs = build (TREE_CODE (lhs), TREE_TYPE (lhs),
5017 stabilize_reference (TREE_OPERAND (lhs, 0)),
5018 TREE_OPERAND (lhs, 1));
5019 return build (COMPOUND_EXPR, lhstype,
5021 build_modify_expr (TREE_OPERAND (lhs, 0),
5024 /* Handle (a, b) used as an "lvalue". */
5026 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5028 if (newrhs == error_mark_node)
5029 return error_mark_node;
5030 return build (COMPOUND_EXPR, lhstype,
5031 TREE_OPERAND (lhs, 0), newrhs);
5034 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5035 lhs = build (TREE_CODE (lhs), TREE_TYPE (lhs),
5036 stabilize_reference (TREE_OPERAND (lhs, 0)),
5037 TREE_OPERAND (lhs, 1));
5038 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5039 if (newrhs == error_mark_node)
5040 return error_mark_node;
5041 return build (COMPOUND_EXPR, lhstype, lhs, newrhs);
5043 /* Handle (a ? b : c) used as an "lvalue". */
5046 /* Produce (a ? (b = rhs) : (c = rhs))
5047 except that the RHS goes through a save-expr
5048 so the code to compute it is only emitted once. */
5050 tree preeval = NULL_TREE;
5052 rhs = stabilize_expr (rhs, &preeval);
5054 /* Check this here to avoid odd errors when trying to convert
5055 a throw to the type of the COND_EXPR. */
5056 if (!lvalue_or_else (lhs, "assignment"))
5057 return error_mark_node;
5059 cond = build_conditional_expr
5060 (TREE_OPERAND (lhs, 0),
5061 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5062 TREE_OPERAND (lhs, 1)),
5064 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5065 TREE_OPERAND (lhs, 2)),
5068 if (cond == error_mark_node)
5070 /* Make sure the code to compute the rhs comes out
5071 before the split. */
5073 cond = build (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5081 if (modifycode == INIT_EXPR)
5083 if (TREE_CODE (rhs) == CONSTRUCTOR)
5085 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5086 /* Call convert to generate an error; see PR 11063. */
5087 rhs = convert (lhstype, rhs);
5088 result = build (INIT_EXPR, lhstype, lhs, rhs);
5089 TREE_SIDE_EFFECTS (result) = 1;
5092 else if (! IS_AGGR_TYPE (lhstype))
5093 /* Do the default thing. */;
5096 result = build_special_member_call (lhs, complete_ctor_identifier,
5097 build_tree_list (NULL_TREE, rhs),
5098 lhstype, LOOKUP_NORMAL);
5099 if (result == NULL_TREE)
5100 return error_mark_node;
5106 if (TREE_CODE (lhstype) == REFERENCE_TYPE)
5108 lhs = convert_from_reference (lhs);
5109 olhstype = lhstype = TREE_TYPE (lhs);
5111 lhs = require_complete_type (lhs);
5112 if (lhs == error_mark_node)
5113 return error_mark_node;
5115 if (modifycode == NOP_EXPR)
5117 /* `operator=' is not an inheritable operator. */
5118 if (! IS_AGGR_TYPE (lhstype))
5119 /* Do the default thing. */;
5122 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5123 lhs, rhs, make_node (NOP_EXPR),
5124 /*overloaded_p=*/NULL);
5125 if (result == NULL_TREE)
5126 return error_mark_node;
5133 /* A binary op has been requested. Combine the old LHS
5134 value with the RHS producing the value we should actually
5135 store into the LHS. */
5137 my_friendly_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE),
5139 lhs = stabilize_reference (lhs);
5140 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5141 if (newrhs == error_mark_node)
5143 error (" in evaluation of `%Q(%#T, %#T)'", modifycode,
5144 TREE_TYPE (lhs), TREE_TYPE (rhs));
5145 return error_mark_node;
5148 /* Now it looks like a plain assignment. */
5149 modifycode = NOP_EXPR;
5151 my_friendly_assert (TREE_CODE (lhstype) != REFERENCE_TYPE, 20011220);
5152 my_friendly_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE,
5156 /* The left-hand side must be an lvalue. */
5157 if (!lvalue_or_else (lhs, "assignment"))
5158 return error_mark_node;
5160 /* Warn about modifying something that is `const'. Don't warn if
5161 this is initialization. */
5162 if (modifycode != INIT_EXPR
5163 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5164 /* Functions are not modifiable, even though they are
5166 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5167 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5168 /* If it's an aggregate and any field is const, then it is
5169 effectively const. */
5170 || (CLASS_TYPE_P (lhstype)
5171 && C_TYPE_FIELDS_READONLY (lhstype))))
5172 readonly_error (lhs, "assignment", 0);
5174 /* If storing into a structure or union member, it has probably been
5175 given type `int'. Compute the type that would go with the actual
5176 amount of storage the member occupies. */
5178 if (TREE_CODE (lhs) == COMPONENT_REF
5179 && (TREE_CODE (lhstype) == INTEGER_TYPE
5180 || TREE_CODE (lhstype) == REAL_TYPE
5181 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5183 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5185 /* If storing in a field that is in actuality a short or narrower
5186 than one, we must store in the field in its actual type. */
5188 if (lhstype != TREE_TYPE (lhs))
5190 /* Avoid warnings converting integral types back into enums for
5192 if (TREE_CODE (lhstype) == INTEGER_TYPE
5193 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5195 if (TREE_SIDE_EFFECTS (lhs))
5196 lhs = stabilize_reference (lhs);
5199 lhs = copy_node (lhs);
5200 TREE_TYPE (lhs) = lhstype;
5204 /* Convert new value to destination type. */
5206 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5210 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5211 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5213 error ("incompatible types in assignment of `%T' to `%T'",
5214 TREE_TYPE (rhs), lhstype);
5215 return error_mark_node;
5218 /* Allow array assignment in compiler-generated code. */
5219 if (! DECL_ARTIFICIAL (current_function_decl))
5220 pedwarn ("ISO C++ forbids assignment of arrays");
5222 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5223 ? 1 + (modifycode != INIT_EXPR): 0;
5224 return build_vec_init (lhs, NULL_TREE, newrhs, from_array);
5227 if (modifycode == INIT_EXPR)
5228 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5229 "initialization", NULL_TREE, 0);
5232 /* Avoid warnings on enum bit fields. */
5233 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5234 && TREE_CODE (lhstype) == INTEGER_TYPE)
5236 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5238 newrhs = convert_force (lhstype, newrhs, 0);
5241 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5243 if (TREE_CODE (newrhs) == CALL_EXPR
5244 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5245 newrhs = build_cplus_new (lhstype, newrhs);
5247 /* Can't initialize directly from a TARGET_EXPR, since that would
5248 cause the lhs to be constructed twice, and possibly result in
5249 accidental self-initialization. So we force the TARGET_EXPR to be
5250 expanded without a target. */
5251 if (TREE_CODE (newrhs) == TARGET_EXPR)
5252 newrhs = build (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5253 TREE_OPERAND (newrhs, 0));
5256 if (newrhs == error_mark_node)
5257 return error_mark_node;
5259 result = build (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5260 lhstype, lhs, newrhs);
5262 TREE_SIDE_EFFECTS (result) = 1;
5264 TREE_NO_WARNING (result) = 1;
5266 /* If we got the LHS in a different type for storing in,
5267 convert the result back to the nominal type of LHS
5268 so that the value we return always has the same type
5269 as the LHS argument. */
5271 if (olhstype == TREE_TYPE (result))
5275 result = build (COMPOUND_EXPR, olhstype, result, olhs);
5276 TREE_NO_WARNING (result) = 1;
5279 return convert_for_assignment (olhstype, result, "assignment",
5284 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5286 if (processing_template_decl)
5287 return build_min_nt (MODOP_EXPR, lhs,
5288 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5290 if (modifycode != NOP_EXPR)
5292 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5293 make_node (modifycode),
5294 /*overloaded_p=*/NULL);
5297 TREE_NO_WARNING (rval) = 1;
5301 return build_modify_expr (lhs, modifycode, rhs);
5305 /* Get difference in deltas for different pointer to member function
5306 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5307 the conversion is invalid, the constant is zero. If FORCE is true,
5308 then allow reverse conversions as well.
5310 Note that the naming of FROM and TO is kind of backwards; the return
5311 value is what we add to a TO in order to get a FROM. They are named
5312 this way because we call this function to find out how to convert from
5313 a pointer to member of FROM to a pointer to member of TO. */
5316 get_delta_difference (tree from, tree to, int force)
5323 /* Assume no conversion is required. */
5324 result = integer_zero_node;
5325 binfo = lookup_base (to, from, ba_check, &kind);
5326 if (kind == bk_inaccessible || kind == bk_ambig)
5327 error (" in pointer to member function conversion");
5332 error_not_base_type (from, to);
5333 error (" in pointer to member conversion");
5337 binfo = lookup_base (from, to, ba_check, &kind);
5340 virt_binfo = binfo_from_vbase (binfo);
5342 /* This is a reinterpret cast, we choose to do nothing. */
5343 warning ("pointer to member cast via virtual base `%T'",
5344 BINFO_TYPE (virt_binfo));
5346 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5352 virt_binfo = binfo_from_vbase (binfo);
5354 result = BINFO_OFFSET (binfo);
5357 /* This is a reinterpret cast, we choose to do nothing. */
5359 warning ("pointer to member cast via virtual base `%T'",
5360 BINFO_TYPE (virt_binfo));
5362 error ("pointer to member conversion via virtual base `%T'",
5363 BINFO_TYPE (virt_binfo));
5367 return fold (convert_to_integer (ptrdiff_type_node, result));
5370 /* Return a constructor for the pointer-to-member-function TYPE using
5371 the other components as specified. */
5374 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5380 /* Pull the FIELD_DECLs out of the type. */
5381 pfn_field = TYPE_FIELDS (type);
5382 delta_field = TREE_CHAIN (pfn_field);
5384 /* Make sure DELTA has the type we want. */
5385 delta = convert_and_check (delta_type_node, delta);
5387 /* Finish creating the initializer. */
5388 u = tree_cons (pfn_field, pfn,
5389 build_tree_list (delta_field, delta));
5390 u = build_constructor (type, u);
5391 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5392 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
5393 TREE_STATIC (u) = (TREE_CONSTANT (u)
5394 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5396 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5401 /* Build a constructor for a pointer to member function. It can be
5402 used to initialize global variables, local variable, or used
5403 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5406 If FORCE is nonzero, then force this conversion, even if
5407 we would rather not do it. Usually set when using an explicit
5410 Return error_mark_node, if something goes wrong. */
5413 build_ptrmemfunc (tree type, tree pfn, int force)
5419 if (error_operand_p (pfn))
5420 return error_mark_node;
5422 pfn_type = TREE_TYPE (pfn);
5423 to_type = build_ptrmemfunc_type (type);
5425 /* Handle multiple conversions of pointer to member functions. */
5426 if (TYPE_PTRMEMFUNC_P (pfn_type))
5428 tree delta = NULL_TREE;
5429 tree npfn = NULL_TREE;
5433 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn))
5434 error ("invalid conversion to type `%T' from type `%T'",
5437 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
5438 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
5441 /* We don't have to do any conversion to convert a
5442 pointer-to-member to its own type. But, we don't want to
5443 just return a PTRMEM_CST if there's an explicit cast; that
5444 cast should make the expression an invalid template argument. */
5445 if (TREE_CODE (pfn) != PTRMEM_CST)
5447 if (same_type_p (to_type, pfn_type))
5449 else if (integer_zerop (n))
5450 return build_reinterpret_cast (to_type, pfn);
5453 if (TREE_SIDE_EFFECTS (pfn))
5454 pfn = save_expr (pfn);
5456 /* Obtain the function pointer and the current DELTA. */
5457 if (TREE_CODE (pfn) == PTRMEM_CST)
5458 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
5461 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
5462 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
5465 /* Just adjust the DELTA field. */
5467 (same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (delta),
5470 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
5471 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
5472 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
5473 return build_ptrmemfunc1 (to_type, delta, npfn);
5476 /* Handle null pointer to member function conversions. */
5477 if (integer_zerop (pfn))
5479 pfn = build_c_cast (type, integer_zero_node);
5480 return build_ptrmemfunc1 (to_type,
5485 if (type_unknown_p (pfn))
5486 return instantiate_type (type, pfn, tf_error | tf_warning);
5488 fn = TREE_OPERAND (pfn, 0);
5489 my_friendly_assert (TREE_CODE (fn) == FUNCTION_DECL, 0);
5490 return make_ptrmem_cst (to_type, fn);
5493 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
5496 ??? There is no consistency as to the types returned for the above
5497 values. Some code acts as if it were a sizetype and some as if it were
5498 integer_type_node. */
5501 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
5503 tree type = TREE_TYPE (cst);
5504 tree fn = PTRMEM_CST_MEMBER (cst);
5505 tree ptr_class, fn_class;
5507 my_friendly_assert (TREE_CODE (fn) == FUNCTION_DECL, 0);
5509 /* The class that the function belongs to. */
5510 fn_class = DECL_CONTEXT (fn);
5512 /* The class that we're creating a pointer to member of. */
5513 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
5515 /* First, calculate the adjustment to the function's class. */
5516 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0);
5518 if (!DECL_VIRTUAL_P (fn))
5519 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
5522 /* If we're dealing with a virtual function, we have to adjust 'this'
5523 again, to point to the base which provides the vtable entry for
5524 fn; the call will do the opposite adjustment. */
5525 tree orig_class = DECL_CONTEXT (fn);
5526 tree binfo = binfo_or_else (orig_class, fn_class);
5527 *delta = fold (build (PLUS_EXPR, TREE_TYPE (*delta),
5528 *delta, BINFO_OFFSET (binfo)));
5530 /* We set PFN to the vtable offset at which the function can be
5531 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
5532 case delta is shifted left, and then incremented). */
5533 *pfn = DECL_VINDEX (fn);
5534 *pfn = fold (build (MULT_EXPR, integer_type_node, *pfn,
5535 TYPE_SIZE_UNIT (vtable_entry_type)));
5537 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
5539 case ptrmemfunc_vbit_in_pfn:
5540 *pfn = fold (build (PLUS_EXPR, integer_type_node, *pfn,
5544 case ptrmemfunc_vbit_in_delta:
5545 *delta = fold (build (LSHIFT_EXPR, TREE_TYPE (*delta),
5546 *delta, integer_one_node));
5547 *delta = fold (build (PLUS_EXPR, TREE_TYPE (*delta),
5548 *delta, integer_one_node));
5555 *pfn = fold (build1 (NOP_EXPR, TYPE_PTRMEMFUNC_FN_TYPE (type),
5560 /* Return an expression for PFN from the pointer-to-member function
5564 pfn_from_ptrmemfunc (tree t)
5566 if (TREE_CODE (t) == PTRMEM_CST)
5571 expand_ptrmemfunc_cst (t, &delta, &pfn);
5576 return build_ptrmemfunc_access_expr (t, pfn_identifier);
5579 /* Expression EXPR is about to be implicitly converted to TYPE. Warn
5580 if this is a potentially dangerous thing to do. Returns a possibly
5584 dubious_conversion_warnings (tree type, tree expr,
5585 const char *errtype, tree fndecl, int parmnum)
5587 type = non_reference (type);
5589 /* Issue warnings about peculiar, but valid, uses of NULL. */
5590 if (ARITHMETIC_TYPE_P (type) && expr == null_node)
5593 warning ("passing NULL used for non-pointer %s %P of `%D'",
5594 errtype, parmnum, fndecl);
5596 warning ("%s to non-pointer type `%T' from NULL", errtype, type);
5599 /* Warn about assigning a floating-point type to an integer type. */
5600 if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
5601 && TREE_CODE (type) == INTEGER_TYPE)
5604 warning ("passing `%T' for %s %P of `%D'",
5605 TREE_TYPE (expr), errtype, parmnum, fndecl);
5607 warning ("%s to `%T' from `%T'", errtype, type, TREE_TYPE (expr));
5609 /* And warn about assigning a negative value to an unsigned
5611 else if (TYPE_UNSIGNED (type) && TREE_CODE (type) != BOOLEAN_TYPE)
5613 if (TREE_CODE (expr) == INTEGER_CST && TREE_NEGATED_INT (expr))
5616 warning ("passing negative value `%E' for %s %P of `%D'",
5617 expr, errtype, parmnum, fndecl);
5619 warning ("%s of negative value `%E' to `%T'",
5620 errtype, expr, type);
5623 overflow_warning (expr);
5625 if (TREE_CONSTANT (expr))
5631 /* Convert value RHS to type TYPE as preparation for an assignment to
5632 an lvalue of type TYPE. ERRTYPE is a string to use in error
5633 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
5634 are doing the conversion in order to pass the PARMNUMth argument of
5638 convert_for_assignment (tree type, tree rhs,
5639 const char *errtype, tree fndecl, int parmnum)
5642 enum tree_code coder;
5644 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
5645 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
5646 rhs = TREE_OPERAND (rhs, 0);
5648 rhstype = TREE_TYPE (rhs);
5649 coder = TREE_CODE (rhstype);
5651 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
5652 && vector_types_convertible_p (type, rhstype))
5653 return convert (type, rhs);
5655 if (rhs == error_mark_node || rhstype == error_mark_node)
5656 return error_mark_node;
5657 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
5658 return error_mark_node;
5660 /* The RHS of an assignment cannot have void type. */
5661 if (coder == VOID_TYPE)
5663 error ("void value not ignored as it ought to be");
5664 return error_mark_node;
5667 /* Simplify the RHS if possible. */
5668 if (TREE_CODE (rhs) == CONST_DECL)
5669 rhs = DECL_INITIAL (rhs);
5671 /* We do not use decl_constant_value here because of this case:
5673 const char* const s = "s";
5675 The conversion rules for a string literal are more lax than for a
5676 variable; in particular, a string literal can be converted to a
5677 "char *" but the variable "s" cannot be converted in the same
5678 way. If the conversion is allowed, the optimization should be
5679 performed while creating the converted expression. */
5683 The expression is implicitly converted (clause _conv_) to the
5684 cv-unqualified type of the left operand.
5686 We allow bad conversions here because by the time we get to this point
5687 we are committed to doing the conversion. If we end up doing a bad
5688 conversion, convert_like will complain. */
5689 if (!can_convert_arg_bad (type, rhstype, rhs))
5691 /* When -Wno-pmf-conversions is use, we just silently allow
5692 conversions from pointers-to-members to plain pointers. If
5693 the conversion doesn't work, cp_convert will complain. */
5695 && TYPE_PTR_P (type)
5696 && TYPE_PTRMEMFUNC_P (rhstype))
5697 rhs = cp_convert (strip_top_quals (type), rhs);
5700 /* If the right-hand side has unknown type, then it is an
5701 overloaded function. Call instantiate_type to get error
5703 if (rhstype == unknown_type_node)
5704 instantiate_type (type, rhs, tf_error | tf_warning);
5706 error ("cannot convert `%T' to `%T' for argument `%P' to `%D'",
5707 rhstype, type, parmnum, fndecl);
5709 error ("cannot convert `%T' to `%T' in %s", rhstype, type,
5711 return error_mark_node;
5714 return perform_implicit_conversion (strip_top_quals (type), rhs);
5717 /* Convert RHS to be of type TYPE.
5718 If EXP is nonzero, it is the target of the initialization.
5719 ERRTYPE is a string to use in error messages.
5721 Two major differences between the behavior of
5722 `convert_for_assignment' and `convert_for_initialization'
5723 are that references are bashed in the former, while
5724 copied in the latter, and aggregates are assigned in
5725 the former (operator=) while initialized in the
5728 If using constructor make sure no conversion operator exists, if one does
5729 exist, an ambiguity exists.
5731 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
5734 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
5735 const char *errtype, tree fndecl, int parmnum)
5737 enum tree_code codel = TREE_CODE (type);
5739 enum tree_code coder;
5741 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5742 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
5743 if (TREE_CODE (rhs) == NOP_EXPR
5744 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
5745 && codel != REFERENCE_TYPE)
5746 rhs = TREE_OPERAND (rhs, 0);
5748 if (rhs == error_mark_node
5749 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
5750 return error_mark_node;
5752 if (TREE_CODE (TREE_TYPE (rhs)) == REFERENCE_TYPE)
5753 rhs = convert_from_reference (rhs);
5755 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
5756 && TREE_CODE (type) != ARRAY_TYPE
5757 && (TREE_CODE (type) != REFERENCE_TYPE
5758 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
5759 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
5760 && (TREE_CODE (type) != REFERENCE_TYPE
5761 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
5762 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
5763 rhs = decay_conversion (rhs);
5765 rhstype = TREE_TYPE (rhs);
5766 coder = TREE_CODE (rhstype);
5768 if (coder == ERROR_MARK)
5769 return error_mark_node;
5771 /* We accept references to incomplete types, so we can
5772 return here before checking if RHS is of complete type. */
5774 if (codel == REFERENCE_TYPE)
5776 /* This should eventually happen in convert_arguments. */
5777 int savew = 0, savee = 0;
5780 savew = warningcount, savee = errorcount;
5781 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
5785 if (warningcount > savew)
5786 cp_warning_at ("in passing argument %P of `%+D'", parmnum, fndecl);
5787 else if (errorcount > savee)
5788 cp_error_at ("in passing argument %P of `%+D'", parmnum, fndecl);
5794 exp = require_complete_type (exp);
5795 if (exp == error_mark_node)
5796 return error_mark_node;
5798 rhstype = non_reference (rhstype);
5800 type = complete_type (type);
5802 if (IS_AGGR_TYPE (type))
5803 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
5805 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
5808 /* If RETVAL is the address of, or a reference to, a local variable or
5809 temporary give an appropriate warning. */
5812 maybe_warn_about_returning_address_of_local (tree retval)
5814 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
5815 tree whats_returned = retval;
5819 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
5820 whats_returned = TREE_OPERAND (whats_returned, 1);
5821 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
5822 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
5823 || TREE_CODE (whats_returned) == NOP_EXPR)
5824 whats_returned = TREE_OPERAND (whats_returned, 0);
5829 if (TREE_CODE (whats_returned) != ADDR_EXPR)
5831 whats_returned = TREE_OPERAND (whats_returned, 0);
5833 if (TREE_CODE (valtype) == REFERENCE_TYPE)
5835 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
5836 || TREE_CODE (whats_returned) == TARGET_EXPR)
5838 warning ("returning reference to temporary");
5841 if (TREE_CODE (whats_returned) == VAR_DECL
5842 && DECL_NAME (whats_returned)
5843 && TEMP_NAME_P (DECL_NAME (whats_returned)))
5845 warning ("reference to non-lvalue returned");
5850 if (DECL_P (whats_returned)
5851 && DECL_NAME (whats_returned)
5852 && DECL_FUNCTION_SCOPE_P (whats_returned)
5853 && !(TREE_STATIC (whats_returned)
5854 || TREE_PUBLIC (whats_returned)))
5856 if (TREE_CODE (valtype) == REFERENCE_TYPE)
5857 cp_warning_at ("reference to local variable `%D' returned",
5860 cp_warning_at ("address of local variable `%D' returned",
5866 /* Check that returning RETVAL from the current function is valid.
5867 Return an expression explicitly showing all conversions required to
5868 change RETVAL into the function return type, and to assign it to
5869 the DECL_RESULT for the function. */
5872 check_return_expr (tree retval)
5875 /* The type actually returned by the function, after any
5878 int fn_returns_value_p;
5880 /* A `volatile' function is one that isn't supposed to return, ever.
5881 (This is a G++ extension, used to get better code for functions
5882 that call the `volatile' function.) */
5883 if (TREE_THIS_VOLATILE (current_function_decl))
5884 warning ("function declared `noreturn' has a `return' statement");
5886 /* Check for various simple errors. */
5887 if (DECL_DESTRUCTOR_P (current_function_decl))
5890 error ("returning a value from a destructor");
5893 else if (DECL_CONSTRUCTOR_P (current_function_decl))
5895 if (in_function_try_handler)
5896 /* If a return statement appears in a handler of the
5897 function-try-block of a constructor, the program is ill-formed. */
5898 error ("cannot return from a handler of a function-try-block of a constructor");
5900 /* You can't return a value from a constructor. */
5901 error ("returning a value from a constructor");
5905 if (processing_template_decl)
5907 current_function_returns_value = 1;
5911 /* When no explicit return-value is given in a function with a named
5912 return value, the named return value is used. */
5913 result = DECL_RESULT (current_function_decl);
5914 valtype = TREE_TYPE (result);
5915 my_friendly_assert (valtype != NULL_TREE, 19990924);
5916 fn_returns_value_p = !VOID_TYPE_P (valtype);
5917 if (!retval && DECL_NAME (result) && fn_returns_value_p)
5920 /* Check for a return statement with no return value in a function
5921 that's supposed to return a value. */
5922 if (!retval && fn_returns_value_p)
5924 pedwarn ("return-statement with no value, in function returning '%T'",
5926 /* Clear this, so finish_function won't say that we reach the
5927 end of a non-void function (which we don't, we gave a
5929 current_function_returns_null = 0;
5931 /* Check for a return statement with a value in a function that
5932 isn't supposed to return a value. */
5933 else if (retval && !fn_returns_value_p)
5935 if (VOID_TYPE_P (TREE_TYPE (retval)))
5936 /* You can return a `void' value from a function of `void'
5937 type. In that case, we have to evaluate the expression for
5938 its side-effects. */
5939 finish_expr_stmt (retval);
5941 pedwarn ("return-statement with a value, in function "
5942 "returning 'void'");
5944 current_function_returns_null = 1;
5946 /* There's really no value to return, after all. */
5950 /* Remember that this function can sometimes return without a
5952 current_function_returns_null = 1;
5954 /* Remember that this function did return a value. */
5955 current_function_returns_value = 1;
5957 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
5958 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
5959 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
5960 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
5962 && null_ptr_cst_p (retval))
5963 warning ("`operator new' must not return NULL unless it is declared `throw()' (or -fcheck-new is in effect)");
5965 /* Effective C++ rule 15. See also start_function. */
5967 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
5971 /* The function return type must be a reference to the current
5973 if (TREE_CODE (valtype) == REFERENCE_TYPE
5974 && same_type_ignoring_top_level_qualifiers_p
5975 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
5977 /* Returning '*this' is obviously OK. */
5978 if (retval == current_class_ref)
5980 /* If we are calling a function whose return type is the same of
5981 the current class reference, it is ok. */
5982 else if (TREE_CODE (retval) == INDIRECT_REF
5983 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
5988 warning ("`operator=' should return a reference to `*this'");
5991 /* The fabled Named Return Value optimization, as per [class.copy]/15:
5993 [...] For a function with a class return type, if the expression
5994 in the return statement is the name of a local object, and the cv-
5995 unqualified type of the local object is the same as the function
5996 return type, an implementation is permitted to omit creating the tem-
5997 porary object to hold the function return value [...]
5999 So, if this is a value-returning function that always returns the same
6000 local variable, remember it.
6002 It might be nice to be more flexible, and choose the first suitable
6003 variable even if the function sometimes returns something else, but
6004 then we run the risk of clobbering the variable we chose if the other
6005 returned expression uses the chosen variable somehow. And people expect
6006 this restriction, anyway. (jason 2000-11-19)
6008 See finish_function and finalize_nrv for the rest of this optimization. */
6010 if (fn_returns_value_p && flag_elide_constructors)
6012 if (retval != NULL_TREE
6013 && (current_function_return_value == NULL_TREE
6014 || current_function_return_value == retval)
6015 && TREE_CODE (retval) == VAR_DECL
6016 && DECL_CONTEXT (retval) == current_function_decl
6017 && ! TREE_STATIC (retval)
6018 && (DECL_ALIGN (retval)
6019 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6020 && same_type_p ((TYPE_MAIN_VARIANT
6021 (TREE_TYPE (retval))),
6023 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6024 current_function_return_value = retval;
6026 current_function_return_value = error_mark_node;
6029 /* We don't need to do any conversions when there's nothing being
6031 if (!retval || retval == error_mark_node)
6034 /* Do any required conversions. */
6035 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6036 /* No conversions are required. */
6040 /* The type the function is declared to return. */
6041 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6043 /* First convert the value to the function's return type, then
6044 to the type of return value's location to handle the
6045 case that functype is smaller than the valtype. */
6046 retval = convert_for_initialization
6047 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6048 "return", NULL_TREE, 0);
6049 retval = convert (valtype, retval);
6051 /* If the conversion failed, treat this just like `return;'. */
6052 if (retval == error_mark_node)
6054 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6055 else if (! current_function_returns_struct
6056 && TREE_CODE (retval) == TARGET_EXPR
6057 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6058 retval = build (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6059 TREE_OPERAND (retval, 0));
6061 maybe_warn_about_returning_address_of_local (retval);
6064 /* Actually copy the value returned into the appropriate location. */
6065 if (retval && retval != result)
6066 retval = build (INIT_EXPR, TREE_TYPE (result), result, retval);
6072 /* Returns nonzero if the pointer-type FROM can be converted to the
6073 pointer-type TO via a qualification conversion. If CONSTP is -1,
6074 then we return nonzero if the pointers are similar, and the
6075 cv-qualification signature of FROM is a proper subset of that of TO.
6077 If CONSTP is positive, then all outer pointers have been
6081 comp_ptr_ttypes_real (tree to, tree from, int constp)
6083 bool to_more_cv_qualified = false;
6085 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6087 if (TREE_CODE (to) != TREE_CODE (from))
6090 if (TREE_CODE (from) == OFFSET_TYPE
6091 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6092 TYPE_OFFSET_BASETYPE (to)))
6095 /* Const and volatile mean something different for function types,
6096 so the usual checks are not appropriate. */
6097 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6099 if (!at_least_as_qualified_p (to, from))
6102 if (!at_least_as_qualified_p (from, to))
6106 to_more_cv_qualified = true;
6110 constp &= TYPE_READONLY (to);
6113 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6114 return ((constp >= 0 || to_more_cv_qualified)
6115 && same_type_ignoring_top_level_qualifiers_p (to, from));
6119 /* When comparing, say, char ** to char const **, this function takes
6120 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6121 types to this function. */
6124 comp_ptr_ttypes (tree to, tree from)
6126 return comp_ptr_ttypes_real (to, from, 1);
6129 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6130 type or inheritance-related types, regardless of cv-quals. */
6133 ptr_reasonably_similar (tree to, tree from)
6135 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6137 /* Any target type is similar enough to void. */
6138 if (TREE_CODE (to) == VOID_TYPE
6139 || TREE_CODE (from) == VOID_TYPE)
6142 if (TREE_CODE (to) != TREE_CODE (from))
6145 if (TREE_CODE (from) == OFFSET_TYPE
6146 && comptypes (TYPE_OFFSET_BASETYPE (to),
6147 TYPE_OFFSET_BASETYPE (from),
6148 COMPARE_BASE | COMPARE_DERIVED))
6151 if (TREE_CODE (to) == INTEGER_TYPE
6152 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6155 if (TREE_CODE (to) == FUNCTION_TYPE)
6158 if (TREE_CODE (to) != POINTER_TYPE)
6160 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6161 COMPARE_BASE | COMPARE_DERIVED);
6165 /* Like comp_ptr_ttypes, for const_cast. */
6168 comp_ptr_ttypes_const (tree to, tree from)
6170 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6172 if (TREE_CODE (to) != TREE_CODE (from))
6175 if (TREE_CODE (from) == OFFSET_TYPE
6176 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6177 TYPE_OFFSET_BASETYPE (to)))
6180 if (TREE_CODE (to) != POINTER_TYPE)
6181 return same_type_ignoring_top_level_qualifiers_p (to, from);
6185 /* Returns the type qualifiers for this type, including the qualifiers on the
6186 elements for an array type. */
6189 cp_type_quals (tree type)
6191 type = strip_array_types (type);
6192 if (type == error_mark_node)
6193 return TYPE_UNQUALIFIED;
6194 return TYPE_QUALS (type);
6197 /* Returns nonzero if the TYPE contains a mutable member. */
6200 cp_has_mutable_p (tree type)
6202 type = strip_array_types (type);
6204 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6207 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6208 exemplar types such that casting T1 to T2 is casting away castness
6209 if and only if there is no implicit conversion from T1 to T2. */
6212 casts_away_constness_r (tree *t1, tree *t2)
6217 /* [expr.const.cast]
6219 For multi-level pointer to members and multi-level mixed pointers
6220 and pointers to members (conv.qual), the "member" aspect of a
6221 pointer to member level is ignored when determining if a const
6222 cv-qualifier has been cast away. */
6223 if (TYPE_PTRMEM_P (*t1))
6224 *t1 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t1));
6225 if (TYPE_PTRMEM_P (*t2))
6226 *t2 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t2));
6228 /* [expr.const.cast]
6230 For two pointer types:
6232 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6233 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6236 casting from X1 to X2 casts away constness if, for a non-pointer
6237 type T there does not exist an implicit conversion (clause
6240 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6244 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6246 if (TREE_CODE (*t1) != POINTER_TYPE
6247 || TREE_CODE (*t2) != POINTER_TYPE)
6249 *t1 = cp_build_qualified_type (void_type_node,
6250 cp_type_quals (*t1));
6251 *t2 = cp_build_qualified_type (void_type_node,
6252 cp_type_quals (*t2));
6256 quals1 = cp_type_quals (*t1);
6257 quals2 = cp_type_quals (*t2);
6258 *t1 = TREE_TYPE (*t1);
6259 *t2 = TREE_TYPE (*t2);
6260 casts_away_constness_r (t1, t2);
6261 *t1 = build_pointer_type (*t1);
6262 *t2 = build_pointer_type (*t2);
6263 *t1 = cp_build_qualified_type (*t1, quals1);
6264 *t2 = cp_build_qualified_type (*t2, quals2);
6267 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6271 casts_away_constness (tree t1, tree t2)
6273 if (TREE_CODE (t2) == REFERENCE_TYPE)
6275 /* [expr.const.cast]
6277 Casting from an lvalue of type T1 to an lvalue of type T2
6278 using a reference cast casts away constness if a cast from an
6279 rvalue of type "pointer to T1" to the type "pointer to T2"
6280 casts away constness. */
6281 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6282 return casts_away_constness (build_pointer_type (t1),
6283 build_pointer_type (TREE_TYPE (t2)));
6286 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6287 /* [expr.const.cast]
6289 Casting from an rvalue of type "pointer to data member of X
6290 of type T1" to the type "pointer to data member of Y of type
6291 T2" casts away constness if a cast from an rvalue of type
6292 "pointer to T1" to the type "pointer to T2" casts away
6294 return casts_away_constness
6295 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6296 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6298 /* Casting away constness is only something that makes sense for
6299 pointer or reference types. */
6300 if (TREE_CODE (t1) != POINTER_TYPE
6301 || TREE_CODE (t2) != POINTER_TYPE)
6304 /* Top-level qualifiers don't matter. */
6305 t1 = TYPE_MAIN_VARIANT (t1);
6306 t2 = TYPE_MAIN_VARIANT (t2);
6307 casts_away_constness_r (&t1, &t2);
6308 if (!can_convert (t2, t1))
6314 /* If T is a REFERENCE_TYPE return the type to which T refers.
6315 Otherwise, return T itself. */
6318 non_reference (tree t)
6320 if (TREE_CODE (t) == REFERENCE_TYPE)