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.
29 There are also routines to build RETURN_STMT nodes and CASE_STMT nodes,
30 and to process initializations in declarations (since they work
31 like a strange sort of assignment). */
35 #include "coretypes.h"
45 #include "diagnostic.h"
49 static tree convert_for_assignment (tree, tree, const char *, tree, int);
50 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
51 static tree rationalize_conditional_expr (enum tree_code, tree);
52 static int comp_ptr_ttypes_real (tree, tree, int);
53 static int comp_ptr_ttypes_const (tree, tree);
54 static bool comp_except_types (tree, tree, bool);
55 static bool comp_array_types (tree, tree, bool);
56 static tree common_base_type (tree, tree);
57 static tree pointer_diff (tree, tree, tree);
58 static tree get_delta_difference (tree, tree, int);
59 static void casts_away_constness_r (tree *, tree *);
60 static bool casts_away_constness (tree, tree);
61 static void maybe_warn_about_returning_address_of_local (tree);
62 static tree lookup_destructor (tree, tree, tree);
64 /* Return the target type of TYPE, which means return T for:
65 T*, T&, T[], T (...), and otherwise, just T. */
68 target_type (tree type)
70 type = non_reference (type);
71 while (TREE_CODE (type) == POINTER_TYPE
72 || TREE_CODE (type) == ARRAY_TYPE
73 || TREE_CODE (type) == FUNCTION_TYPE
74 || TREE_CODE (type) == METHOD_TYPE
75 || TYPE_PTRMEM_P (type))
76 type = TREE_TYPE (type);
80 /* Do `exp = require_complete_type (exp);' to make sure exp
81 does not have an incomplete type. (That includes void types.)
82 Returns the error_mark_node if the VALUE does not have
83 complete type when this function returns. */
86 require_complete_type (tree value)
90 if (processing_template_decl || value == error_mark_node)
93 if (TREE_CODE (value) == OVERLOAD)
94 type = unknown_type_node;
96 type = TREE_TYPE (value);
98 if (type == error_mark_node)
99 return error_mark_node;
101 /* First, detect a valid value with a complete type. */
102 if (COMPLETE_TYPE_P (type))
105 if (complete_type_or_else (type, value))
108 return error_mark_node;
111 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
112 a template instantiation, do the instantiation. Returns TYPE,
113 whether or not it could be completed, unless something goes
114 horribly wrong, in which case the error_mark_node is returned. */
117 complete_type (tree type)
119 if (type == NULL_TREE)
120 /* Rather than crash, we return something sure to cause an error
122 return error_mark_node;
124 if (type == error_mark_node || COMPLETE_TYPE_P (type))
126 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
128 tree t = complete_type (TREE_TYPE (type));
129 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
131 TYPE_NEEDS_CONSTRUCTING (type)
132 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
133 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
134 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
136 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
137 instantiate_class_template (TYPE_MAIN_VARIANT (type));
142 /* Like complete_type, but issue an error if the TYPE cannot be completed.
143 VALUE is used for informative diagnostics. DIAG_TYPE indicates the type
144 of diagnostic: 0 for an error, 1 for a warning, 2 for a pedwarn.
145 Returns NULL_TREE if the type cannot be made complete. */
148 complete_type_or_diagnostic (tree type, tree value, int diag_type)
150 type = complete_type (type);
151 if (type == error_mark_node)
152 /* We already issued an error. */
154 else if (!COMPLETE_TYPE_P (type))
156 cxx_incomplete_type_diagnostic (value, type, diag_type);
163 /* Return truthvalue of whether type of EXP is instantiated. */
166 type_unknown_p (tree exp)
168 return (TREE_CODE (exp) == TREE_LIST
169 || TREE_TYPE (exp) == unknown_type_node);
173 /* Return the common type of two parameter lists.
174 We assume that comptypes has already been done and returned 1;
175 if that isn't so, this may crash.
177 As an optimization, free the space we allocate if the parameter
178 lists are already common. */
181 commonparms (tree p1, tree p2)
183 tree oldargs = p1, newargs, n;
187 len = list_length (p1);
188 newargs = tree_last (p1);
190 if (newargs == void_list_node)
199 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
204 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
206 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
208 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
211 else if (! TREE_PURPOSE (p1))
213 if (TREE_PURPOSE (p2))
215 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
221 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
223 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
225 if (TREE_VALUE (p1) != TREE_VALUE (p2))
228 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
231 TREE_VALUE (n) = TREE_VALUE (p1);
239 /* Given a type, perhaps copied for a typedef,
240 find the "original" version of it. */
242 original_type (tree t)
244 while (TYPE_NAME (t) != NULL_TREE)
246 tree x = TYPE_NAME (t);
247 if (TREE_CODE (x) != TYPE_DECL)
249 x = DECL_ORIGINAL_TYPE (x);
257 /* T1 and T2 are arithmetic or enumeration types. Return the type
258 that will result from the "usual arithmetic conversions" on T1 and
259 T2 as described in [expr]. */
262 type_after_usual_arithmetic_conversions (tree t1, tree t2)
264 enum tree_code code1 = TREE_CODE (t1);
265 enum tree_code code2 = TREE_CODE (t2);
268 /* FIXME: Attributes. */
269 my_friendly_assert (ARITHMETIC_TYPE_P (t1)
270 || TREE_CODE (t1) == COMPLEX_TYPE
271 || TREE_CODE (t1) == ENUMERAL_TYPE,
273 my_friendly_assert (ARITHMETIC_TYPE_P (t2)
274 || TREE_CODE (t2) == COMPLEX_TYPE
275 || TREE_CODE (t2) == ENUMERAL_TYPE,
278 /* In what follows, we slightly generalize the rules given in [expr] so
279 as to deal with `long long' and `complex'. First, merge the
281 attributes = (*targetm.merge_type_attributes) (t1, t2);
283 /* If one type is complex, form the common type of the non-complex
284 components, then make that complex. Use T1 or T2 if it is the
286 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
288 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
289 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
291 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
293 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
294 return build_type_attribute_variant (t1, attributes);
295 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
296 return build_type_attribute_variant (t2, attributes);
298 return build_type_attribute_variant (build_complex_type (subtype),
302 /* If only one is real, use it as the result. */
303 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
304 return build_type_attribute_variant (t1, attributes);
305 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
306 return build_type_attribute_variant (t2, attributes);
308 /* Perform the integral promotions. */
309 if (code1 != REAL_TYPE)
311 t1 = type_promotes_to (t1);
312 t2 = type_promotes_to (t2);
315 /* Both real or both integers; use the one with greater precision. */
316 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
317 return build_type_attribute_variant (t1, attributes);
318 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
319 return build_type_attribute_variant (t2, attributes);
321 /* The types are the same; no need to do anything fancy. */
322 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
323 return build_type_attribute_variant (t1, attributes);
325 if (code1 != REAL_TYPE)
327 /* If one is a sizetype, use it so size_binop doesn't blow up. */
328 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
329 return build_type_attribute_variant (t1, attributes);
330 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
331 return build_type_attribute_variant (t2, attributes);
333 /* If one is unsigned long long, then convert the other to unsigned
335 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
336 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
337 return build_type_attribute_variant (long_long_unsigned_type_node,
339 /* If one is a long long, and the other is an unsigned long, and
340 long long can represent all the values of an unsigned long, then
341 convert to a long long. Otherwise, convert to an unsigned long
342 long. Otherwise, if either operand is long long, convert the
345 Since we're here, we know the TYPE_PRECISION is the same;
346 therefore converting to long long cannot represent all the values
347 of an unsigned long, so we choose unsigned long long in that
349 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
350 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
352 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
353 ? long_long_unsigned_type_node
354 : long_long_integer_type_node);
355 return build_type_attribute_variant (t, attributes);
358 /* Go through the same procedure, but for longs. */
359 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
360 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
361 return build_type_attribute_variant (long_unsigned_type_node,
363 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
364 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
366 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
367 ? long_unsigned_type_node : long_integer_type_node);
368 return build_type_attribute_variant (t, attributes);
370 /* Otherwise prefer the unsigned one. */
371 if (TYPE_UNSIGNED (t1))
372 return build_type_attribute_variant (t1, attributes);
374 return build_type_attribute_variant (t2, attributes);
378 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
379 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
380 return build_type_attribute_variant (long_double_type_node,
382 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
383 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
384 return build_type_attribute_variant (double_type_node,
386 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
387 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
388 return build_type_attribute_variant (float_type_node,
391 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
392 the standard C++ floating-point types. Logic earlier in this
393 function has already eliminated the possibility that
394 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
395 compelling reason to choose one or the other. */
396 return build_type_attribute_variant (t1, attributes);
400 /* Subroutine of composite_pointer_type to implement the recursive
401 case. See that function for documentation fo the parameters. */
404 composite_pointer_type_r (tree t1, tree t2, const char* location)
411 /* Determine the types pointed to by T1 and T2. */
412 if (TREE_CODE (t1) == POINTER_TYPE)
414 pointee1 = TREE_TYPE (t1);
415 pointee2 = TREE_TYPE (t2);
419 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
420 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
425 Otherwise, the composite pointer type is a pointer type
426 similar (_conv.qual_) to the type of one of the operands,
427 with a cv-qualification signature (_conv.qual_) that is the
428 union of the cv-qualification signatures of the operand
430 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
431 result_type = pointee1;
432 else if ((TREE_CODE (pointee1) == POINTER_TYPE
433 && TREE_CODE (pointee2) == POINTER_TYPE)
434 || (TYPE_PTR_TO_MEMBER_P (pointee1)
435 && TYPE_PTR_TO_MEMBER_P (pointee2)))
436 result_type = composite_pointer_type_r (pointee1, pointee2, location);
439 pedwarn ("%s between distinct pointer types `%T' and `%T' "
442 result_type = void_type_node;
444 result_type = cp_build_qualified_type (result_type,
445 (cp_type_quals (pointee1)
446 | cp_type_quals (pointee2)));
447 /* If the original types were pointers to members, so is the
449 if (TYPE_PTR_TO_MEMBER_P (t1))
451 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
452 TYPE_PTRMEM_CLASS_TYPE (t2)))
453 pedwarn ("%s between distinct pointer types `%T' and `%T' "
456 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
460 result_type = build_pointer_type (result_type);
462 /* Merge the attributes. */
463 attributes = (*targetm.merge_type_attributes) (t1, t2);
464 return build_type_attribute_variant (result_type, attributes);
467 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
468 ARG1 and ARG2 are the values with those types. The LOCATION is a
469 string describing the current location, in case an error occurs.
471 This routine also implements the computation of a common type for
472 pointers-to-members as per [expr.eq]. */
475 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
476 const char* location)
483 If one operand is a null pointer constant, the composite pointer
484 type is the type of the other operand. */
485 if (null_ptr_cst_p (arg1))
487 if (null_ptr_cst_p (arg2))
494 If one of the operands has type "pointer to cv1 void*", then
495 the other has type "pointer to cv2T", and the composite pointer
496 type is "pointer to cv12 void", where cv12 is the union of cv1
499 If either type is a pointer to void, make sure it is T1. */
500 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
508 /* Now, if T1 is a pointer to void, merge the qualifiers. */
509 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
514 if (pedantic && TYPE_PTRFN_P (t2))
515 pedwarn ("ISO C++ forbids %s between pointer of type `void *' and pointer-to-function", location);
517 = cp_build_qualified_type (void_type_node,
518 (cp_type_quals (TREE_TYPE (t1))
519 | cp_type_quals (TREE_TYPE (t2))));
520 result_type = build_pointer_type (result_type);
521 /* Merge the attributes. */
522 attributes = (*targetm.merge_type_attributes) (t1, t2);
523 return build_type_attribute_variant (result_type, attributes);
526 /* [expr.eq] permits the application of a pointer conversion to
527 bring the pointers to a common type. */
528 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
529 && CLASS_TYPE_P (TREE_TYPE (t1))
530 && CLASS_TYPE_P (TREE_TYPE (t2))
531 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
534 class1 = TREE_TYPE (t1);
535 class2 = TREE_TYPE (t2);
537 if (DERIVED_FROM_P (class1, class2))
538 t2 = (build_pointer_type
539 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
540 else if (DERIVED_FROM_P (class2, class1))
541 t1 = (build_pointer_type
542 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
545 error ("%s between distinct pointer types `%T' and `%T' "
546 "lacks a cast", location, t1, t2);
547 return error_mark_node;
550 /* [expr.eq] permits the application of a pointer-to-member
551 conversion to change the class type of one of the types. */
552 else if (TYPE_PTR_TO_MEMBER_P (t1)
553 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
554 TYPE_PTRMEM_CLASS_TYPE (t2)))
556 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
557 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
559 if (DERIVED_FROM_P (class1, class2))
560 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
561 else if (DERIVED_FROM_P (class2, class1))
562 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
565 error ("%s between distinct pointer-to-member types `%T' and `%T' "
566 "lacks a cast", location, t1, t2);
567 return error_mark_node;
571 return composite_pointer_type_r (t1, t2, location);
574 /* Return the merged type of two types.
575 We assume that comptypes has already been done and returned 1;
576 if that isn't so, this may crash.
578 This just combines attributes and default arguments; any other
579 differences would cause the two types to compare unalike. */
582 merge_types (tree t1, tree t2)
584 enum tree_code code1;
585 enum tree_code code2;
588 /* Save time if the two types are the same. */
591 if (original_type (t1) == original_type (t2))
594 /* If one type is nonsense, use the other. */
595 if (t1 == error_mark_node)
597 if (t2 == error_mark_node)
600 /* Merge the attributes. */
601 attributes = (*targetm.merge_type_attributes) (t1, t2);
603 if (TYPE_PTRMEMFUNC_P (t1))
604 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
605 if (TYPE_PTRMEMFUNC_P (t2))
606 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
608 code1 = TREE_CODE (t1);
609 code2 = TREE_CODE (t2);
615 /* For two pointers, do this recursively on the target type. */
617 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
618 int quals = cp_type_quals (t1);
620 if (code1 == POINTER_TYPE)
621 t1 = build_pointer_type (target);
623 t1 = build_reference_type (target);
624 t1 = build_type_attribute_variant (t1, attributes);
625 t1 = cp_build_qualified_type (t1, quals);
627 if (TREE_CODE (target) == METHOD_TYPE)
628 t1 = build_ptrmemfunc_type (t1);
637 quals = cp_type_quals (t1);
638 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
639 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
640 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
642 t1 = cp_build_qualified_type (t1, quals);
648 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
649 /* Save space: see if the result is identical to one of the args. */
650 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
651 return build_type_attribute_variant (t1, attributes);
652 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
653 return build_type_attribute_variant (t2, attributes);
654 /* Merge the element types, and have a size if either arg has one. */
655 t1 = build_cplus_array_type
656 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
661 /* Function types: prefer the one that specified arg types.
662 If both do, merge the arg types. Also merge the return types. */
664 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
665 tree p1 = TYPE_ARG_TYPES (t1);
666 tree p2 = TYPE_ARG_TYPES (t2);
669 /* Save space: see if the result is identical to one of the args. */
670 if (valtype == TREE_TYPE (t1) && ! p2)
671 return cp_build_type_attribute_variant (t1, attributes);
672 if (valtype == TREE_TYPE (t2) && ! p1)
673 return cp_build_type_attribute_variant (t2, attributes);
675 /* Simple way if one arg fails to specify argument types. */
676 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
678 rval = build_function_type (valtype, p2);
679 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
680 rval = build_exception_variant (rval, raises);
681 return cp_build_type_attribute_variant (rval, attributes);
683 raises = TYPE_RAISES_EXCEPTIONS (t1);
684 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
686 rval = build_function_type (valtype, p1);
688 rval = build_exception_variant (rval, raises);
689 return cp_build_type_attribute_variant (rval, attributes);
692 rval = build_function_type (valtype, commonparms (p1, p2));
693 t1 = build_exception_variant (rval, raises);
699 /* Get this value the long way, since TYPE_METHOD_BASETYPE
700 is just the main variant of this. */
701 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
702 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
705 /* If this was a member function type, get back to the
706 original type of type member function (i.e., without
707 the class instance variable up front. */
708 t1 = build_function_type (TREE_TYPE (t1),
709 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
710 t2 = build_function_type (TREE_TYPE (t2),
711 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
712 t3 = merge_types (t1, t2);
713 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
714 TYPE_ARG_TYPES (t3));
715 t1 = build_exception_variant (t3, raises);
720 /* There is no need to merge attributes into a TYPENAME_TYPE.
721 When the type is instantiated it will have whatever
722 attributes result from the instantiation. */
727 return cp_build_type_attribute_variant (t1, attributes);
730 /* Return the common type of two types.
731 We assume that comptypes has already been done and returned 1;
732 if that isn't so, this may crash.
734 This is the type for the result of most arithmetic operations
735 if the operands have the given two types. */
738 common_type (tree t1, tree t2)
740 enum tree_code code1;
741 enum tree_code code2;
743 /* If one type is nonsense, bail. */
744 if (t1 == error_mark_node || t2 == error_mark_node)
745 return error_mark_node;
747 code1 = TREE_CODE (t1);
748 code2 = TREE_CODE (t2);
750 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
751 || code1 == COMPLEX_TYPE)
752 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
753 || code2 == COMPLEX_TYPE))
754 return type_after_usual_arithmetic_conversions (t1, t2);
756 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
757 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
758 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
759 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
765 /* Compare two exception specifier types for exactness or subsetness, if
766 allowed. Returns false for mismatch, true for match (same, or
769 [except.spec] "If a class X ... objects of class X or any class publicly
770 and unambiguously derived from X. Similarly, if a pointer type Y * ...
771 exceptions of type Y * or that are pointers to any type publicly and
772 unambiguously derived from Y. Otherwise a function only allows exceptions
773 that have the same type ..."
774 This does not mention cv qualifiers and is different to what throw
775 [except.throw] and catch [except.catch] will do. They will ignore the
776 top level cv qualifiers, and allow qualifiers in the pointer to class
779 We implement the letter of the standard. */
782 comp_except_types (tree a, tree b, bool exact)
784 if (same_type_p (a, b))
788 if (cp_type_quals (a) || cp_type_quals (b))
791 if (TREE_CODE (a) == POINTER_TYPE
792 && TREE_CODE (b) == POINTER_TYPE)
796 if (cp_type_quals (a) || cp_type_quals (b))
800 if (TREE_CODE (a) != RECORD_TYPE
801 || TREE_CODE (b) != RECORD_TYPE)
804 if (ACCESSIBLY_UNIQUELY_DERIVED_P (a, b))
810 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
811 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
812 otherwise it must be exact. Exception lists are unordered, but
813 we've already filtered out duplicates. Most lists will be in order,
814 we should try to make use of that. */
817 comp_except_specs (tree t1, tree t2, bool exact)
826 if (t1 == NULL_TREE) /* T1 is ... */
827 return t2 == NULL_TREE || !exact;
828 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
829 return t2 != NULL_TREE && !TREE_VALUE (t2);
830 if (t2 == NULL_TREE) /* T2 is ... */
832 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
835 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
836 Count how many we find, to determine exactness. For exact matching and
837 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
839 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
841 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
843 tree a = TREE_VALUE (probe);
844 tree b = TREE_VALUE (t2);
846 if (comp_except_types (a, b, exact))
848 if (probe == base && exact)
849 base = TREE_CHAIN (probe);
854 if (probe == NULL_TREE)
857 return !exact || base == NULL_TREE || length == list_length (t1);
860 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
861 [] can match [size]. */
864 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
873 /* The type of the array elements must be the same. */
874 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
877 d1 = TYPE_DOMAIN (t1);
878 d2 = TYPE_DOMAIN (t2);
883 /* If one of the arrays is dimensionless, and the other has a
884 dimension, they are of different types. However, it is valid to
892 declarations for an array object can specify
893 array types that differ by the presence or absence of a major
894 array bound (_dcl.array_). */
896 return allow_redeclaration;
898 /* Check that the dimensions are the same. */
900 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
902 max1 = TYPE_MAX_VALUE (d1);
903 max2 = TYPE_MAX_VALUE (d2);
904 if (processing_template_decl && !abi_version_at_least (2)
905 && !value_dependent_expression_p (max1)
906 && !value_dependent_expression_p (max2))
908 /* With abi-1 we do not fold non-dependent array bounds, (and
909 consequently mangle them incorrectly). We must therefore
910 fold them here, to verify the domains have the same
916 if (!cp_tree_equal (max1, max2))
922 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
923 is a bitwise-or of the COMPARE_* flags. */
926 comptypes (tree t1, tree t2, int strict)
931 /* Suppress errors caused by previously reported errors. */
932 if (t1 == error_mark_node || t2 == error_mark_node)
935 my_friendly_assert (TYPE_P (t1) && TYPE_P (t2), 20030623);
937 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
938 current instantiation. */
939 if (TREE_CODE (t1) == TYPENAME_TYPE)
941 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
943 if (resolved != error_mark_node)
947 if (TREE_CODE (t2) == TYPENAME_TYPE)
949 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
951 if (resolved != error_mark_node)
955 /* If either type is the internal version of sizetype, use the
957 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
958 && TYPE_ORIG_SIZE_TYPE (t1))
959 t1 = TYPE_ORIG_SIZE_TYPE (t1);
961 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
962 && TYPE_ORIG_SIZE_TYPE (t2))
963 t2 = TYPE_ORIG_SIZE_TYPE (t2);
965 if (TYPE_PTRMEMFUNC_P (t1))
966 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
967 if (TYPE_PTRMEMFUNC_P (t2))
968 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
970 /* Different classes of types can't be compatible. */
971 if (TREE_CODE (t1) != TREE_CODE (t2))
974 /* Qualifiers must match. For array types, we will check when we
975 recur on the array element types. */
976 if (TREE_CODE (t1) != ARRAY_TYPE
977 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
979 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
982 /* Allow for two different type nodes which have essentially the same
983 definition. Note that we already checked for equality of the type
984 qualifiers (just above). */
986 if (TREE_CODE (t1) != ARRAY_TYPE
987 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
990 if (!(*targetm.comp_type_attributes) (t1, t2))
993 switch (TREE_CODE (t1))
995 case TEMPLATE_TEMPLATE_PARM:
996 case BOUND_TEMPLATE_TEMPLATE_PARM:
997 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
998 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1000 if (!comp_template_parms
1001 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
1002 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1004 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1006 /* Don't check inheritance. */
1007 strict = COMPARE_STRICT;
1012 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1013 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1014 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1015 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1018 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1020 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1026 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1027 strict & ~COMPARE_REDECLARATION))
1032 case REFERENCE_TYPE:
1033 return same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1037 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1039 return compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2));
1042 /* Target types must match incl. qualifiers. */
1043 return comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION));
1045 case TEMPLATE_TYPE_PARM:
1046 return (TEMPLATE_TYPE_IDX (t1) == TEMPLATE_TYPE_IDX (t2)
1047 && TEMPLATE_TYPE_LEVEL (t1) == TEMPLATE_TYPE_LEVEL (t2));
1050 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1051 TYPENAME_TYPE_FULLNAME (t2)))
1053 return same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2));
1055 case UNBOUND_CLASS_TEMPLATE:
1056 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1058 return same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2));
1061 return same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1064 return TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
1065 && same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1074 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1077 at_least_as_qualified_p (tree type1, tree type2)
1079 int q1 = cp_type_quals (type1);
1080 int q2 = cp_type_quals (type2);
1082 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1083 return (q1 & q2) == q2;
1086 /* Returns 1 if TYPE1 is more qualified than TYPE2. */
1089 more_qualified_p (tree type1, tree type2)
1091 int q1 = cp_type_quals (type1);
1092 int q2 = cp_type_quals (type2);
1094 return q1 != q2 && (q1 & q2) == q2;
1097 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1098 more cv-qualified that TYPE1, and 0 otherwise. */
1101 comp_cv_qualification (tree type1, tree type2)
1103 int q1 = cp_type_quals (type1);
1104 int q2 = cp_type_quals (type2);
1109 if ((q1 & q2) == q2)
1111 else if ((q1 & q2) == q1)
1117 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1118 subset of the cv-qualification signature of TYPE2, and the types
1119 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1122 comp_cv_qual_signature (tree type1, tree type2)
1124 if (comp_ptr_ttypes_real (type2, type1, -1))
1126 else if (comp_ptr_ttypes_real (type1, type2, -1))
1132 /* If two types share a common base type, return that basetype.
1133 If there is not a unique most-derived base type, this function
1134 returns ERROR_MARK_NODE. */
1137 common_base_type (tree tt1, tree tt2)
1139 tree best = NULL_TREE;
1142 /* If one is a baseclass of another, that's good enough. */
1143 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1145 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1148 /* Otherwise, try to find a unique baseclass of TT1
1149 that is shared by TT2, and follow that down. */
1150 for (i = CLASSTYPE_N_BASECLASSES (tt1)-1; i >= 0; i--)
1152 tree basetype = TYPE_BINFO_BASETYPE (tt1, i);
1153 tree trial = common_base_type (basetype, tt2);
1156 if (trial == error_mark_node)
1158 if (best == NULL_TREE)
1160 else if (best != trial)
1161 return error_mark_node;
1166 for (i = CLASSTYPE_N_BASECLASSES (tt2)-1; i >= 0; i--)
1168 tree basetype = TYPE_BINFO_BASETYPE (tt2, i);
1169 tree trial = common_base_type (tt1, basetype);
1172 if (trial == error_mark_node)
1174 if (best == NULL_TREE)
1176 else if (best != trial)
1177 return error_mark_node;
1183 /* Subroutines of `comptypes'. */
1185 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1186 equivalent in the sense that functions with those parameter types
1187 can have equivalent types. The two lists must be equivalent,
1188 element by element. */
1191 compparms (tree parms1, tree parms2)
1195 /* An unspecified parmlist matches any specified parmlist
1196 whose argument types don't need default promotions. */
1198 for (t1 = parms1, t2 = parms2;
1200 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1202 /* If one parmlist is shorter than the other,
1203 they fail to match. */
1206 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1213 /* Process a sizeof or alignof expression where the operand is a
1217 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1219 enum tree_code type_code;
1221 const char *op_name;
1223 my_friendly_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR, 20020720);
1224 if (type == error_mark_node)
1225 return error_mark_node;
1227 if (processing_template_decl)
1229 value = build_min (op, size_type_node, type);
1230 TREE_READONLY (value) = 1;
1234 op_name = operator_name_info[(int) op].name;
1236 type = non_reference (type);
1237 type_code = TREE_CODE (type);
1239 if (type_code == METHOD_TYPE)
1241 if (complain && (pedantic || warn_pointer_arith))
1242 pedwarn ("invalid application of `%s' to a member function", op_name);
1243 value = size_one_node;
1246 value = c_sizeof_or_alignof_type (complete_type (type), op, complain);
1251 /* Process a sizeof or alignof expression where the operand is an
1255 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1257 const char *op_name = operator_name_info[(int) op].name;
1259 if (e == error_mark_node)
1260 return error_mark_node;
1262 if (processing_template_decl)
1264 e = build_min (op, size_type_node, e);
1265 TREE_SIDE_EFFECTS (e) = 0;
1266 TREE_READONLY (e) = 1;
1271 if (TREE_CODE (e) == COMPONENT_REF
1272 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1273 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1275 error ("invalid application of `%s' to a bit-field", op_name);
1278 else if (is_overloaded_fn (e))
1280 pedwarn ("ISO C++ forbids applying `%s' to an expression of function type", op_name);
1283 else if (type_unknown_p (e))
1285 cxx_incomplete_type_error (e, TREE_TYPE (e));
1291 return cxx_sizeof_or_alignof_type (e, op, true);
1295 /* EXPR is being used in a context that is not a function call.
1300 The expression can be used only as the left-hand operand of a
1301 member function call.
1303 [expr.mptr.operator]
1305 If the result of .* or ->* is a function, then that result can be
1306 used only as the operand for the function call operator ().
1308 by issuing an error message if appropriate. Returns true iff EXPR
1309 violates these rules. */
1312 invalid_nonstatic_memfn_p (tree expr)
1314 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1316 error ("invalid use of non-static member function");
1322 /* Perform the conversions in [expr] that apply when an lvalue appears
1323 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1324 function-to-pointer conversions.
1326 In addition manifest constants are replaced by their values. */
1329 decay_conversion (tree exp)
1332 enum tree_code code;
1334 type = TREE_TYPE (exp);
1335 code = TREE_CODE (type);
1337 if (code == REFERENCE_TYPE)
1339 exp = convert_from_reference (exp);
1340 type = TREE_TYPE (exp);
1341 code = TREE_CODE (type);
1344 if (type == error_mark_node)
1345 return error_mark_node;
1347 if (type_unknown_p (exp))
1349 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1350 return error_mark_node;
1353 /* Constants can be used directly unless they're not loadable. */
1354 if (TREE_CODE (exp) == CONST_DECL)
1355 exp = DECL_INITIAL (exp);
1356 /* Replace a nonvolatile const static variable with its value. We
1357 don't do this for arrays, though; we want the address of the
1358 first element of the array, not the address of the first element
1359 of its initializing constant. */
1360 else if (code != ARRAY_TYPE)
1362 exp = decl_constant_value (exp);
1363 type = TREE_TYPE (exp);
1366 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1367 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1369 if (code == VOID_TYPE)
1371 error ("void value not ignored as it ought to be");
1372 return error_mark_node;
1374 if (invalid_nonstatic_memfn_p (exp))
1375 return error_mark_node;
1376 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1377 return build_unary_op (ADDR_EXPR, exp, 0);
1378 if (code == ARRAY_TYPE)
1383 if (TREE_CODE (exp) == INDIRECT_REF)
1384 return build_nop (build_pointer_type (TREE_TYPE (type)),
1385 TREE_OPERAND (exp, 0));
1387 if (TREE_CODE (exp) == COMPOUND_EXPR)
1389 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1390 return build (COMPOUND_EXPR, TREE_TYPE (op1),
1391 TREE_OPERAND (exp, 0), op1);
1395 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1397 error ("invalid use of non-lvalue array");
1398 return error_mark_node;
1401 ptrtype = build_pointer_type (TREE_TYPE (type));
1403 if (TREE_CODE (exp) == VAR_DECL)
1405 if (!cxx_mark_addressable (exp))
1406 return error_mark_node;
1407 adr = build_nop (ptrtype, build_address (exp));
1410 /* This way is better for a COMPONENT_REF since it can
1411 simplify the offset for a component. */
1412 adr = build_unary_op (ADDR_EXPR, exp, 1);
1413 return cp_convert (ptrtype, adr);
1416 /* [basic.lval]: Class rvalues can have cv-qualified types; non-class
1417 rvalues always have cv-unqualified types. */
1418 if (! CLASS_TYPE_P (type))
1419 exp = cp_convert (TYPE_MAIN_VARIANT (type), exp);
1425 default_conversion (tree exp)
1427 exp = decay_conversion (exp);
1429 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1430 exp = perform_integral_promotions (exp);
1435 /* EXPR is an expression with an integral or enumeration type.
1436 Perform the integral promotions in [conv.prom], and return the
1440 perform_integral_promotions (tree expr)
1445 type = TREE_TYPE (expr);
1446 my_friendly_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type), 20030703);
1447 promoted_type = type_promotes_to (type);
1448 if (type != promoted_type)
1449 expr = cp_convert (promoted_type, expr);
1453 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1457 inline_conversion (tree exp)
1459 if (TREE_CODE (exp) == FUNCTION_DECL)
1460 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1465 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1466 decay_conversion to one. */
1469 string_conv_p (tree totype, tree exp, int warn)
1473 if (! flag_const_strings || TREE_CODE (totype) != POINTER_TYPE)
1476 t = TREE_TYPE (totype);
1477 if (!same_type_p (t, char_type_node)
1478 && !same_type_p (t, wchar_type_node))
1481 if (TREE_CODE (exp) == STRING_CST)
1483 /* Make sure that we don't try to convert between char and wchar_t. */
1484 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1489 /* Is this a string constant which has decayed to 'const char *'? */
1490 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1491 if (!same_type_p (TREE_TYPE (exp), t))
1494 if (TREE_CODE (exp) != ADDR_EXPR
1495 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1499 /* This warning is not very useful, as it complains about printf. */
1500 if (warn && warn_write_strings)
1501 warning ("deprecated conversion from string constant to `%T'", totype);
1506 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1507 can, for example, use as an lvalue. This code used to be in
1508 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1509 expressions, where we're dealing with aggregates. But now it's again only
1510 called from unary_complex_lvalue. The case (in particular) that led to
1511 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1515 rationalize_conditional_expr (enum tree_code code, tree t)
1517 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1518 the first operand is always the one to be used if both operands
1519 are equal, so we know what conditional expression this used to be. */
1520 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1523 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1524 ? LE_EXPR : GE_EXPR),
1525 TREE_OPERAND (t, 0),
1526 TREE_OPERAND (t, 1),
1527 /*overloaded_p=*/NULL),
1528 build_unary_op (code, TREE_OPERAND (t, 0), 0),
1529 build_unary_op (code, TREE_OPERAND (t, 1), 0));
1533 build_conditional_expr (TREE_OPERAND (t, 0),
1534 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1535 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1538 /* Given the TYPE of an anonymous union field inside T, return the
1539 FIELD_DECL for the field. If not found return NULL_TREE. Because
1540 anonymous unions can nest, we must also search all anonymous unions
1541 that are directly reachable. */
1544 lookup_anon_field (tree t, tree type)
1548 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1550 if (TREE_STATIC (field))
1552 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1555 /* If we find it directly, return the field. */
1556 if (DECL_NAME (field) == NULL_TREE
1557 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1562 /* Otherwise, it could be nested, search harder. */
1563 if (DECL_NAME (field) == NULL_TREE
1564 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1566 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1574 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1575 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1576 non-NULL, it indicates the path to the base used to name MEMBER.
1577 If PRESERVE_REFERENCE is true, the expression returned will have
1578 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1579 returned will have the type referred to by the reference.
1581 This function does not perform access control; that is either done
1582 earlier by the parser when the name of MEMBER is resolved to MEMBER
1583 itself, or later when overload resolution selects one of the
1584 functions indicated by MEMBER. */
1587 build_class_member_access_expr (tree object, tree member,
1588 tree access_path, bool preserve_reference)
1592 tree result = NULL_TREE;
1594 if (object == error_mark_node || member == error_mark_node)
1595 return error_mark_node;
1597 if (TREE_CODE (member) == PSEUDO_DTOR_EXPR)
1600 my_friendly_assert (DECL_P (member) || BASELINK_P (member),
1605 The type of the first expression shall be "class object" (of a
1607 object_type = TREE_TYPE (object);
1608 if (!currently_open_class (object_type)
1609 && !complete_type_or_else (object_type, object))
1610 return error_mark_node;
1611 if (!CLASS_TYPE_P (object_type))
1613 error ("request for member `%D' in `%E', which is of non-class type `%T'",
1614 member, object, object_type);
1615 return error_mark_node;
1618 /* The standard does not seem to actually say that MEMBER must be a
1619 member of OBJECT_TYPE. However, that is clearly what is
1621 if (DECL_P (member))
1623 member_scope = DECL_CLASS_CONTEXT (member);
1625 if (TREE_DEPRECATED (member))
1626 warn_deprecated_use (member);
1629 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1630 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1631 presently be the anonymous union. Go outwards until we find a
1632 type related to OBJECT_TYPE. */
1633 while (ANON_AGGR_TYPE_P (member_scope)
1634 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1636 member_scope = TYPE_CONTEXT (member_scope);
1637 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1639 if (TREE_CODE (member) == FIELD_DECL)
1640 error ("invalid use of nonstatic data member '%E'", member);
1642 error ("`%D' is not a member of `%T'", member, object_type);
1643 return error_mark_node;
1646 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1647 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1648 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1650 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1652 object = build_indirect_ref (temp, NULL);
1655 /* In [expr.ref], there is an explicit list of the valid choices for
1656 MEMBER. We check for each of those cases here. */
1657 if (TREE_CODE (member) == VAR_DECL)
1659 /* A static data member. */
1661 /* If OBJECT has side-effects, they are supposed to occur. */
1662 if (TREE_SIDE_EFFECTS (object))
1663 result = build (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1665 else if (TREE_CODE (member) == FIELD_DECL)
1667 /* A non-static data member. */
1672 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1673 && integer_zerop (TREE_OPERAND (object, 0)));
1675 /* Convert OBJECT to the type of MEMBER. */
1676 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1677 TYPE_MAIN_VARIANT (member_scope)))
1682 binfo = lookup_base (access_path ? access_path : object_type,
1683 member_scope, ba_ignore, &kind);
1684 if (binfo == error_mark_node)
1685 return error_mark_node;
1687 /* It is invalid to try to get to a virtual base of a
1688 NULL object. The most common cause is invalid use of
1690 if (null_object_p && kind == bk_via_virtual)
1692 error ("invalid access to non-static data member `%D' of NULL object",
1694 error ("(perhaps the `offsetof' macro was used incorrectly)");
1695 return error_mark_node;
1698 /* Convert to the base. */
1699 object = build_base_path (PLUS_EXPR, object, binfo,
1701 /* If we found the base successfully then we should be able
1702 to convert to it successfully. */
1703 my_friendly_assert (object != error_mark_node,
1707 /* Complain about other invalid uses of offsetof, even though they will
1708 give the right answer. Note that we complain whether or not they
1709 actually used the offsetof macro, since there's no way to know at this
1710 point. So we just give a warning, instead of a pedwarn. */
1711 if (null_object_p && warn_invalid_offsetof
1712 && CLASSTYPE_NON_POD_P (object_type))
1714 warning ("invalid access to non-static data member `%D' of NULL object",
1716 warning ("(perhaps the `offsetof' macro was used incorrectly)");
1719 /* If MEMBER is from an anonymous aggregate, we have converted
1720 OBJECT so that it refers to the class containing the
1721 anonymous union. Generate a reference to the anonymous union
1722 itself, and recur to find MEMBER. */
1723 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1724 /* When this code is called from build_field_call, the
1725 object already has the type of the anonymous union.
1726 That is because the COMPONENT_REF was already
1727 constructed, and was then disassembled before calling
1728 build_field_call. After the function-call code is
1729 cleaned up, this waste can be eliminated. */
1730 && (!same_type_ignoring_top_level_qualifiers_p
1731 (TREE_TYPE (object), DECL_CONTEXT (member))))
1733 tree anonymous_union;
1735 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1736 DECL_CONTEXT (member));
1737 object = build_class_member_access_expr (object,
1739 /*access_path=*/NULL_TREE,
1740 preserve_reference);
1743 /* Compute the type of the field, as described in [expr.ref]. */
1744 type_quals = TYPE_UNQUALIFIED;
1745 member_type = TREE_TYPE (member);
1746 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1748 type_quals = (cp_type_quals (member_type)
1749 | cp_type_quals (object_type));
1751 /* A field is const (volatile) if the enclosing object, or the
1752 field itself, is const (volatile). But, a mutable field is
1753 not const, even within a const object. */
1754 if (DECL_MUTABLE_P (member))
1755 type_quals &= ~TYPE_QUAL_CONST;
1756 member_type = cp_build_qualified_type (member_type, type_quals);
1759 result = 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);
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);
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);
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));
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);
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;
2418 tree name = NULL_TREE;
2420 tree original = function;
2422 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2423 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2424 if (TREE_CODE (function) == NOP_EXPR
2425 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2426 function = TREE_OPERAND (function, 0);
2428 if (TREE_CODE (function) == FUNCTION_DECL)
2430 name = DECL_NAME (function);
2432 mark_used (function);
2435 /* Convert anything with function type to a pointer-to-function. */
2436 if (pedantic && DECL_MAIN_P (function))
2437 pedwarn ("ISO C++ forbids calling `::main' from within program");
2439 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2440 (because calling an inline function does not mean the function
2441 needs to be separately compiled). */
2443 if (DECL_INLINE (function))
2444 function = inline_conversion (function);
2446 function = build_addr_func (function);
2452 function = build_addr_func (function);
2455 if (function == error_mark_node)
2456 return error_mark_node;
2458 fntype = TREE_TYPE (function);
2460 if (TYPE_PTRMEMFUNC_P (fntype))
2462 error ("must use .* or ->* to call pointer-to-member function in `%E (...)'",
2464 return error_mark_node;
2467 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2468 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2470 if (!((TREE_CODE (fntype) == POINTER_TYPE
2471 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2473 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2475 error ("`%E' cannot be used as a function", original);
2476 return error_mark_node;
2479 /* fntype now gets the type of function pointed to. */
2480 fntype = TREE_TYPE (fntype);
2482 /* Convert the parameters to the types declared in the
2483 function prototype, or apply default promotions. */
2485 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2486 params, fndecl, LOOKUP_NORMAL);
2487 if (coerced_params == error_mark_node)
2488 return error_mark_node;
2490 /* Check for errors in format strings. */
2493 check_function_format (NULL, TYPE_ATTRIBUTES (fntype), coerced_params);
2495 /* Recognize certain built-in functions so we can make tree-codes
2496 other than CALL_EXPR. We do this when it enables fold-const.c
2497 to do something useful. */
2499 if (TREE_CODE (function) == ADDR_EXPR
2500 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL
2501 && DECL_BUILT_IN (TREE_OPERAND (function, 0)))
2503 result = expand_tree_builtin (TREE_OPERAND (function, 0),
2504 params, coerced_params);
2509 return build_cxx_call (function, params, coerced_params);
2512 /* Convert the actual parameter expressions in the list VALUES
2513 to the types in the list TYPELIST.
2514 If parmdecls is exhausted, or when an element has NULL as its type,
2515 perform the default conversions.
2517 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2519 This is also where warnings about wrong number of args are generated.
2521 Return a list of expressions for the parameters as converted.
2523 Both VALUES and the returned value are chains of TREE_LIST nodes
2524 with the elements of the list in the TREE_VALUE slots of those nodes.
2526 In C++, unspecified trailing parameters can be filled in with their
2527 default arguments, if such were specified. Do so here. */
2530 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2532 tree typetail, valtail;
2533 tree result = NULL_TREE;
2534 const char *called_thing = 0;
2537 /* Argument passing is always copy-initialization. */
2538 flags |= LOOKUP_ONLYCONVERTING;
2542 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2544 if (DECL_NAME (fndecl) == NULL_TREE
2545 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2546 called_thing = "constructor";
2548 called_thing = "member function";
2551 called_thing = "function";
2554 for (valtail = values, typetail = typelist;
2556 valtail = TREE_CHAIN (valtail), i++)
2558 tree type = typetail ? TREE_VALUE (typetail) : 0;
2559 tree val = TREE_VALUE (valtail);
2561 if (val == error_mark_node)
2562 return error_mark_node;
2564 if (type == void_type_node)
2568 cp_error_at ("too many arguments to %s `%+#D'", called_thing,
2570 error ("at this point in file");
2573 error ("too many arguments to function");
2574 /* In case anybody wants to know if this argument
2577 TREE_TYPE (tree_last (result)) = error_mark_node;
2581 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2582 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2583 if (TREE_CODE (val) == NOP_EXPR
2584 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2585 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2586 val = TREE_OPERAND (val, 0);
2588 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2590 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2591 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2592 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2593 val = decay_conversion (val);
2596 if (val == error_mark_node)
2597 return error_mark_node;
2601 /* Formal parm type is specified by a function prototype. */
2604 if (!COMPLETE_TYPE_P (complete_type (type)))
2607 error ("parameter %P of `%D' has incomplete type `%T'",
2610 error ("parameter %P has incomplete type `%T'", i, type);
2611 parmval = error_mark_node;
2615 parmval = convert_for_initialization
2616 (NULL_TREE, type, val, flags,
2617 "argument passing", fndecl, i);
2618 parmval = convert_for_arg_passing (type, parmval);
2621 if (parmval == error_mark_node)
2622 return error_mark_node;
2624 result = tree_cons (NULL_TREE, parmval, result);
2628 if (TREE_CODE (TREE_TYPE (val)) == REFERENCE_TYPE)
2629 val = convert_from_reference (val);
2631 if (fndecl && DECL_BUILT_IN (fndecl)
2632 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2633 /* Don't do ellipsis conversion for __built_in_constant_p
2634 as this will result in spurious warnings for non-POD
2636 val = require_complete_type (val);
2638 val = convert_arg_to_ellipsis (val);
2640 result = tree_cons (NULL_TREE, val, result);
2644 typetail = TREE_CHAIN (typetail);
2647 if (typetail != 0 && typetail != void_list_node)
2649 /* See if there are default arguments that can be used. */
2650 if (TREE_PURPOSE (typetail)
2651 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2653 for (; typetail != void_list_node; ++i)
2656 = convert_default_arg (TREE_VALUE (typetail),
2657 TREE_PURPOSE (typetail),
2660 if (parmval == error_mark_node)
2661 return error_mark_node;
2663 result = tree_cons (0, parmval, result);
2664 typetail = TREE_CHAIN (typetail);
2665 /* ends with `...'. */
2666 if (typetail == NULL_TREE)
2674 cp_error_at ("too few arguments to %s `%+#D'",
2675 called_thing, fndecl);
2676 error ("at this point in file");
2679 error ("too few arguments to function");
2680 return error_mark_list;
2684 return nreverse (result);
2687 /* Build a binary-operation expression, after performing default
2688 conversions on the operands. CODE is the kind of expression to build. */
2691 build_x_binary_op (enum tree_code code, tree arg1, tree arg2,
2701 if (processing_template_decl)
2703 if (type_dependent_expression_p (arg1)
2704 || type_dependent_expression_p (arg2))
2705 return build_min_nt (code, arg1, arg2);
2706 arg1 = build_non_dependent_expr (arg1);
2707 arg2 = build_non_dependent_expr (arg2);
2710 if (code == DOTSTAR_EXPR)
2711 expr = build_m_component_ref (arg1, arg2);
2713 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2716 if (processing_template_decl && expr != error_mark_node)
2717 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2722 /* Build a binary-operation expression without default conversions.
2723 CODE is the kind of expression to build.
2724 This function differs from `build' in several ways:
2725 the data type of the result is computed and recorded in it,
2726 warnings are generated if arg data types are invalid,
2727 special handling for addition and subtraction of pointers is known,
2728 and some optimization is done (operations on narrow ints
2729 are done in the narrower type when that gives the same result).
2730 Constant folding is also done before the result is returned.
2732 Note that the operands will never have enumeral types
2733 because either they have just had the default conversions performed
2734 or they have both just been converted to some other type in which
2735 the arithmetic is to be done.
2737 C++: must do special pointer arithmetic when implementing
2738 multiple inheritance, and deal with pointer to member functions. */
2741 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2742 int convert_p ATTRIBUTE_UNUSED)
2745 enum tree_code code0, code1;
2748 /* Expression code to give to the expression when it is built.
2749 Normally this is CODE, which is what the caller asked for,
2750 but in some special cases we change it. */
2751 enum tree_code resultcode = code;
2753 /* Data type in which the computation is to be performed.
2754 In the simplest cases this is the common type of the arguments. */
2755 tree result_type = NULL;
2757 /* Nonzero means operands have already been type-converted
2758 in whatever way is necessary.
2759 Zero means they need to be converted to RESULT_TYPE. */
2762 /* Nonzero means create the expression with this type, rather than
2764 tree build_type = 0;
2766 /* Nonzero means after finally constructing the expression
2767 convert it to this type. */
2768 tree final_type = 0;
2770 /* Nonzero if this is an operation like MIN or MAX which can
2771 safely be computed in short if both args are promoted shorts.
2772 Also implies COMMON.
2773 -1 indicates a bitwise operation; this makes a difference
2774 in the exact conditions for when it is safe to do the operation
2775 in a narrower mode. */
2778 /* Nonzero if this is a comparison operation;
2779 if both args are promoted shorts, compare the original shorts.
2780 Also implies COMMON. */
2781 int short_compare = 0;
2783 /* Nonzero if this is a right-shift operation, which can be computed on the
2784 original short and then promoted if the operand is a promoted short. */
2785 int short_shift = 0;
2787 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2790 /* Apply default conversions. */
2794 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2795 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2796 || code == TRUTH_XOR_EXPR)
2798 if (!really_overloaded_fn (op0))
2799 op0 = decay_conversion (op0);
2800 if (!really_overloaded_fn (op1))
2801 op1 = decay_conversion (op1);
2805 if (!really_overloaded_fn (op0))
2806 op0 = default_conversion (op0);
2807 if (!really_overloaded_fn (op1))
2808 op1 = default_conversion (op1);
2811 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2812 STRIP_TYPE_NOPS (op0);
2813 STRIP_TYPE_NOPS (op1);
2815 /* DTRT if one side is an overloaded function, but complain about it. */
2816 if (type_unknown_p (op0))
2818 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
2819 if (t != error_mark_node)
2821 pedwarn ("assuming cast to type `%T' from overloaded function",
2826 if (type_unknown_p (op1))
2828 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
2829 if (t != error_mark_node)
2831 pedwarn ("assuming cast to type `%T' from overloaded function",
2837 type0 = TREE_TYPE (op0);
2838 type1 = TREE_TYPE (op1);
2840 /* The expression codes of the data types of the arguments tell us
2841 whether the arguments are integers, floating, pointers, etc. */
2842 code0 = TREE_CODE (type0);
2843 code1 = TREE_CODE (type1);
2845 /* If an error was already reported for one of the arguments,
2846 avoid reporting another error. */
2848 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
2849 return error_mark_node;
2854 /* Handle the pointer + int case. */
2855 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2856 return cp_pointer_int_sum (PLUS_EXPR, op0, op1);
2857 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
2858 return cp_pointer_int_sum (PLUS_EXPR, op1, op0);
2864 /* Subtraction of two similar pointers.
2865 We must subtract them as integers, then divide by object size. */
2866 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
2867 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
2869 return pointer_diff (op0, op1, common_type (type0, type1));
2870 /* Handle pointer minus int. Just like pointer plus int. */
2871 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2872 return cp_pointer_int_sum (MINUS_EXPR, op0, op1);
2881 case TRUNC_DIV_EXPR:
2883 case FLOOR_DIV_EXPR:
2884 case ROUND_DIV_EXPR:
2885 case EXACT_DIV_EXPR:
2886 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2887 || code0 == COMPLEX_TYPE)
2888 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2889 || code1 == COMPLEX_TYPE))
2891 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
2892 warning ("division by zero in `%E / 0'", op0);
2893 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
2894 warning ("division by zero in `%E / 0.'", op0);
2896 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
2897 resultcode = RDIV_EXPR;
2899 /* When dividing two signed integers, we have to promote to int.
2900 unless we divide by a constant != -1. Note that default
2901 conversion will have been performed on the operands at this
2902 point, so we have to dig out the original type to find out if
2904 shorten = ((TREE_CODE (op0) == NOP_EXPR
2905 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2906 || (TREE_CODE (op1) == INTEGER_CST
2907 && ! integer_all_onesp (op1)));
2916 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2920 case TRUNC_MOD_EXPR:
2921 case FLOOR_MOD_EXPR:
2922 if (code1 == INTEGER_TYPE && integer_zerop (op1))
2923 warning ("division by zero in `%E %% 0'", op0);
2924 else if (code1 == REAL_TYPE && real_zerop (op1))
2925 warning ("division by zero in `%E %% 0.'", op0);
2927 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2929 /* Although it would be tempting to shorten always here, that loses
2930 on some targets, since the modulo instruction is undefined if the
2931 quotient can't be represented in the computation mode. We shorten
2932 only if unsigned or if dividing by something we know != -1. */
2933 shorten = ((TREE_CODE (op0) == NOP_EXPR
2934 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2935 || (TREE_CODE (op1) == INTEGER_CST
2936 && ! integer_all_onesp (op1)));
2941 case TRUTH_ANDIF_EXPR:
2942 case TRUTH_ORIF_EXPR:
2943 case TRUTH_AND_EXPR:
2945 result_type = boolean_type_node;
2948 /* Shift operations: result has same type as first operand;
2949 always convert second operand to int.
2950 Also set SHORT_SHIFT if shifting rightward. */
2953 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2955 result_type = type0;
2956 if (TREE_CODE (op1) == INTEGER_CST)
2958 if (tree_int_cst_lt (op1, integer_zero_node))
2959 warning ("right shift count is negative");
2962 if (! integer_zerop (op1))
2964 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2965 warning ("right shift count >= width of type");
2968 /* Convert the shift-count to an integer, regardless of
2969 size of value being shifted. */
2970 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2971 op1 = cp_convert (integer_type_node, op1);
2972 /* Avoid converting op1 to result_type later. */
2978 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2980 result_type = type0;
2981 if (TREE_CODE (op1) == INTEGER_CST)
2983 if (tree_int_cst_lt (op1, integer_zero_node))
2984 warning ("left shift count is negative");
2985 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2986 warning ("left shift count >= width of type");
2988 /* Convert the shift-count to an integer, regardless of
2989 size of value being shifted. */
2990 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2991 op1 = cp_convert (integer_type_node, op1);
2992 /* Avoid converting op1 to result_type later. */
2999 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3001 result_type = type0;
3002 if (TREE_CODE (op1) == INTEGER_CST)
3004 if (tree_int_cst_lt (op1, integer_zero_node))
3005 warning ("%s rotate count is negative",
3006 (code == LROTATE_EXPR) ? "left" : "right");
3007 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3008 warning ("%s rotate count >= width of type",
3009 (code == LROTATE_EXPR) ? "left" : "right");
3011 /* Convert the shift-count to an integer, regardless of
3012 size of value being shifted. */
3013 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3014 op1 = cp_convert (integer_type_node, op1);
3020 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE))
3021 warning ("comparing floating point with == or != is unsafe");
3023 build_type = boolean_type_node;
3024 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3025 || code0 == COMPLEX_TYPE)
3026 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3027 || code1 == COMPLEX_TYPE))
3029 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3030 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3031 result_type = composite_pointer_type (type0, type1, op0, op1,
3033 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3034 && null_ptr_cst_p (op1))
3035 result_type = type0;
3036 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3037 && null_ptr_cst_p (op0))
3038 result_type = type1;
3039 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3041 result_type = type0;
3042 error ("ISO C++ forbids comparison between pointer and integer");
3044 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3046 result_type = type1;
3047 error ("ISO C++ forbids comparison between pointer and integer");
3049 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3051 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3052 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3053 result_type = TREE_TYPE (op0);
3055 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3056 return cp_build_binary_op (code, op1, op0);
3057 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3058 && same_type_p (type0, type1))
3060 /* E will be the final comparison. */
3062 /* E1 and E2 are for scratch. */
3070 if (TREE_SIDE_EFFECTS (op0))
3071 op0 = save_expr (op0);
3072 if (TREE_SIDE_EFFECTS (op1))
3073 op1 = save_expr (op1);
3078 && (!op0.pfn || op0.delta == op1.delta))
3080 The reason for the `!op0.pfn' bit is that a NULL
3081 pointer-to-member is any member with a zero PFN; the
3082 DELTA field is unspecified. */
3083 pfn0 = pfn_from_ptrmemfunc (op0);
3084 pfn1 = pfn_from_ptrmemfunc (op1);
3085 delta0 = build_ptrmemfunc_access_expr (op0,
3087 delta1 = build_ptrmemfunc_access_expr (op1,
3089 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3090 e2 = cp_build_binary_op (EQ_EXPR,
3092 cp_convert (TREE_TYPE (pfn0),
3093 integer_zero_node));
3094 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3095 e2 = build (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3096 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3097 if (code == EQ_EXPR)
3099 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3101 else if ((TYPE_PTRMEMFUNC_P (type0)
3102 && same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0), type1))
3103 || (TYPE_PTRMEMFUNC_P (type1)
3104 && same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1), type0)))
3110 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3111 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3113 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3114 result_type = composite_pointer_type (type0, type1, op0, op1,
3122 build_type = boolean_type_node;
3123 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3124 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3126 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3127 result_type = composite_pointer_type (type0, type1, op0, op1,
3129 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3130 && integer_zerop (op1))
3131 result_type = type0;
3132 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3133 && integer_zerop (op0))
3134 result_type = type1;
3135 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3137 result_type = type0;
3138 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3140 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3142 result_type = type1;
3143 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3147 case UNORDERED_EXPR:
3154 build_type = integer_type_node;
3155 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3157 error ("unordered comparison on non-floating point argument");
3158 return error_mark_node;
3167 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3169 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE))
3171 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3173 if (shorten || common || short_compare)
3174 result_type = common_type (type0, type1);
3176 /* For certain operations (which identify themselves by shorten != 0)
3177 if both args were extended from the same smaller type,
3178 do the arithmetic in that type and then extend.
3180 shorten !=0 and !=1 indicates a bitwise operation.
3181 For them, this optimization is safe only if
3182 both args are zero-extended or both are sign-extended.
3183 Otherwise, we might change the result.
3184 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3185 but calculated in (unsigned short) it would be (unsigned short)-1. */
3187 if (shorten && none_complex)
3189 int unsigned0, unsigned1;
3190 tree arg0 = get_narrower (op0, &unsigned0);
3191 tree arg1 = get_narrower (op1, &unsigned1);
3192 /* UNS is 1 if the operation to be done is an unsigned one. */
3193 int uns = TYPE_UNSIGNED (result_type);
3196 final_type = result_type;
3198 /* Handle the case that OP0 does not *contain* a conversion
3199 but it *requires* conversion to FINAL_TYPE. */
3201 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3202 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3203 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3204 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3206 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3208 /* For bitwise operations, signedness of nominal type
3209 does not matter. Consider only how operands were extended. */
3213 /* Note that in all three cases below we refrain from optimizing
3214 an unsigned operation on sign-extended args.
3215 That would not be valid. */
3217 /* Both args variable: if both extended in same way
3218 from same width, do it in that width.
3219 Do it unsigned if args were zero-extended. */
3220 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3221 < TYPE_PRECISION (result_type))
3222 && (TYPE_PRECISION (TREE_TYPE (arg1))
3223 == TYPE_PRECISION (TREE_TYPE (arg0)))
3224 && unsigned0 == unsigned1
3225 && (unsigned0 || !uns))
3226 result_type = c_common_signed_or_unsigned_type
3227 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3228 else if (TREE_CODE (arg0) == INTEGER_CST
3229 && (unsigned1 || !uns)
3230 && (TYPE_PRECISION (TREE_TYPE (arg1))
3231 < TYPE_PRECISION (result_type))
3232 && (type = c_common_signed_or_unsigned_type
3233 (unsigned1, TREE_TYPE (arg1)),
3234 int_fits_type_p (arg0, type)))
3236 else if (TREE_CODE (arg1) == INTEGER_CST
3237 && (unsigned0 || !uns)
3238 && (TYPE_PRECISION (TREE_TYPE (arg0))
3239 < TYPE_PRECISION (result_type))
3240 && (type = c_common_signed_or_unsigned_type
3241 (unsigned0, TREE_TYPE (arg0)),
3242 int_fits_type_p (arg1, type)))
3246 /* Shifts can be shortened if shifting right. */
3251 tree arg0 = get_narrower (op0, &unsigned_arg);
3253 final_type = result_type;
3255 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3256 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3258 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3259 /* We can shorten only if the shift count is less than the
3260 number of bits in the smaller type size. */
3261 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3262 /* If arg is sign-extended and then unsigned-shifted,
3263 we can simulate this with a signed shift in arg's type
3264 only if the extended result is at least twice as wide
3265 as the arg. Otherwise, the shift could use up all the
3266 ones made by sign-extension and bring in zeros.
3267 We can't optimize that case at all, but in most machines
3268 it never happens because available widths are 2**N. */
3269 && (!TYPE_UNSIGNED (final_type)
3271 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3272 <= TYPE_PRECISION (result_type))))
3274 /* Do an unsigned shift if the operand was zero-extended. */
3276 = c_common_signed_or_unsigned_type (unsigned_arg,
3278 /* Convert value-to-be-shifted to that type. */
3279 if (TREE_TYPE (op0) != result_type)
3280 op0 = cp_convert (result_type, op0);
3285 /* Comparison operations are shortened too but differently.
3286 They identify themselves by setting short_compare = 1. */
3290 /* Don't write &op0, etc., because that would prevent op0
3291 from being kept in a register.
3292 Instead, make copies of the our local variables and
3293 pass the copies by reference, then copy them back afterward. */
3294 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3295 enum tree_code xresultcode = resultcode;
3297 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3299 return cp_convert (boolean_type_node, val);
3300 op0 = xop0, op1 = xop1;
3302 resultcode = xresultcode;
3305 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3306 && warn_sign_compare
3307 /* Do not warn until the template is instantiated; we cannot
3308 bound the ranges of the arguments until that point. */
3309 && !processing_template_decl)
3311 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3312 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3314 int unsignedp0, unsignedp1;
3315 tree primop0 = get_narrower (op0, &unsignedp0);
3316 tree primop1 = get_narrower (op1, &unsignedp1);
3318 /* Check for comparison of different enum types. */
3319 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3320 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3321 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3322 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3324 warning ("comparison between types `%#T' and `%#T'",
3325 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3328 /* Give warnings for comparisons between signed and unsigned
3329 quantities that may fail. */
3330 /* Do the checking based on the original operand trees, so that
3331 casts will be considered, but default promotions won't be. */
3333 /* Do not warn if the comparison is being done in a signed type,
3334 since the signed type will only be chosen if it can represent
3335 all the values of the unsigned type. */
3336 if (!TYPE_UNSIGNED (result_type))
3338 /* Do not warn if both operands are unsigned. */
3339 else if (op0_signed == op1_signed)
3341 /* Do not warn if the signed quantity is an unsuffixed
3342 integer literal (or some static constant expression
3343 involving such literals or a conditional expression
3344 involving such literals) and it is non-negative. */
3345 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3346 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3348 /* Do not warn if the comparison is an equality operation,
3349 the unsigned quantity is an integral constant and it does
3350 not use the most significant bit of result_type. */
3351 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3352 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3353 && int_fits_type_p (orig_op1, c_common_signed_type
3355 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3356 && int_fits_type_p (orig_op0, c_common_signed_type
3360 warning ("comparison between signed and unsigned integer expressions");
3362 /* Warn if two unsigned values are being compared in a size
3363 larger than their original size, and one (and only one) is the
3364 result of a `~' operator. This comparison will always fail.
3366 Also warn if one operand is a constant, and the constant does not
3367 have all bits set that are set in the ~ operand when it is
3370 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3371 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3373 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3374 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3375 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3376 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3378 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3381 HOST_WIDE_INT constant, mask;
3385 if (host_integerp (primop0, 0))
3388 unsignedp = unsignedp1;
3389 constant = tree_low_cst (primop0, 0);
3394 unsignedp = unsignedp0;
3395 constant = tree_low_cst (primop1, 0);
3398 bits = TYPE_PRECISION (TREE_TYPE (primop));
3399 if (bits < TYPE_PRECISION (result_type)
3400 && bits < HOST_BITS_PER_LONG && unsignedp)
3402 mask = (~ (HOST_WIDE_INT) 0) << bits;
3403 if ((mask & constant) != mask)
3404 warning ("comparison of promoted ~unsigned with constant");
3407 else if (unsignedp0 && unsignedp1
3408 && (TYPE_PRECISION (TREE_TYPE (primop0))
3409 < TYPE_PRECISION (result_type))
3410 && (TYPE_PRECISION (TREE_TYPE (primop1))
3411 < TYPE_PRECISION (result_type)))
3412 warning ("comparison of promoted ~unsigned with unsigned");
3417 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
3418 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3419 Then the expression will be built.
3420 It will be given type FINAL_TYPE if that is nonzero;
3421 otherwise, it will be given type RESULT_TYPE. */
3425 error ("invalid operands of types `%T' and `%T' to binary `%O'",
3426 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3427 return error_mark_node;
3430 /* Issue warnings about peculiar, but valid, uses of NULL. */
3431 if (/* It's reasonable to use pointer values as operands of &&
3432 and ||, so NULL is no exception. */
3433 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3434 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3435 (orig_op0 == null_node
3436 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3437 /* Or vice versa. */
3438 || (orig_op1 == null_node
3439 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3440 /* Or, both are NULL and the operation was not a comparison. */
3441 || (orig_op0 == null_node && orig_op1 == null_node
3442 && code != EQ_EXPR && code != NE_EXPR)))
3443 /* Some sort of arithmetic operation involving NULL was
3444 performed. Note that pointer-difference and pointer-addition
3445 have already been handled above, and so we don't end up here in
3447 warning ("NULL used in arithmetic");
3451 if (TREE_TYPE (op0) != result_type)
3452 op0 = cp_convert (result_type, op0);
3453 if (TREE_TYPE (op1) != result_type)
3454 op1 = cp_convert (result_type, op1);
3456 if (op0 == error_mark_node || op1 == error_mark_node)
3457 return error_mark_node;
3460 if (build_type == NULL_TREE)
3461 build_type = result_type;
3464 tree result = fold (build (resultcode, build_type, op0, op1));
3465 if (final_type != 0)
3466 result = cp_convert (final_type, result);
3471 /* Return a tree for the sum or difference (RESULTCODE says which)
3472 of pointer PTROP and integer INTOP. */
3475 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3477 tree res_type = TREE_TYPE (ptrop);
3479 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3480 in certain circumstance (when it's valid to do so). So we need
3481 to make sure it's complete. We don't need to check here, if we
3482 can actually complete it at all, as those checks will be done in
3483 pointer_int_sum() anyway. */
3484 complete_type (TREE_TYPE (res_type));
3486 return pointer_int_sum (resultcode, ptrop, fold (intop));
3489 /* Return a tree for the difference of pointers OP0 and OP1.
3490 The resulting tree has type int. */
3493 pointer_diff (tree op0, tree op1, tree ptrtype)
3496 tree restype = ptrdiff_type_node;
3497 tree target_type = TREE_TYPE (ptrtype);
3499 if (!complete_type_or_else (target_type, NULL_TREE))
3500 return error_mark_node;
3502 if (pedantic || warn_pointer_arith)
3504 if (TREE_CODE (target_type) == VOID_TYPE)
3505 pedwarn ("ISO C++ forbids using pointer of type `void *' in subtraction");
3506 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3507 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3508 if (TREE_CODE (target_type) == METHOD_TYPE)
3509 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3512 /* First do the subtraction as integers;
3513 then drop through to build the divide operator. */
3515 op0 = cp_build_binary_op (MINUS_EXPR,
3516 cp_convert (restype, op0),
3517 cp_convert (restype, op1));
3519 /* This generates an error if op1 is a pointer to an incomplete type. */
3520 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3521 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3523 op1 = (TYPE_PTROB_P (ptrtype)
3524 ? size_in_bytes (target_type)
3525 : integer_one_node);
3527 /* Do the division. */
3529 result = build (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3530 return fold (result);
3533 /* Construct and perhaps optimize a tree representation
3534 for a unary operation. CODE, a tree_code, specifies the operation
3535 and XARG is the operand. */
3538 build_x_unary_op (enum tree_code code, tree xarg)
3540 tree orig_expr = xarg;
3544 if (processing_template_decl)
3546 if (type_dependent_expression_p (xarg))
3547 return build_min_nt (code, xarg, NULL_TREE);
3548 xarg = build_non_dependent_expr (xarg);
3553 /* [expr.unary.op] says:
3555 The address of an object of incomplete type can be taken.
3557 (And is just the ordinary address operator, not an overloaded
3558 "operator &".) However, if the type is a template
3559 specialization, we must complete the type at this point so that
3560 an overloaded "operator &" will be available if required. */
3561 if (code == ADDR_EXPR
3562 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3563 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3564 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3565 || (TREE_CODE (xarg) == OFFSET_REF)))
3566 /* Don't look for a function. */;
3568 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3569 /*overloaded_p=*/NULL);
3570 if (!exp && code == ADDR_EXPR)
3572 /* A pointer to member-function can be formed only by saying
3574 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3575 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3577 if (TREE_CODE (xarg) != OFFSET_REF)
3579 error ("invalid use of '%E' to form a pointer-to-member-function. Use a qualified-id.",
3581 return error_mark_node;
3585 error ("parenthesis around '%E' cannot be used to form a pointer-to-member-function",
3587 PTRMEM_OK_P (xarg) = 1;
3591 if (TREE_CODE (xarg) == OFFSET_REF)
3593 ptrmem = PTRMEM_OK_P (xarg);
3595 if (!ptrmem && !flag_ms_extensions
3596 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3598 /* A single non-static member, make sure we don't allow a
3599 pointer-to-member. */
3600 xarg = build (OFFSET_REF, TREE_TYPE (xarg),
3601 TREE_OPERAND (xarg, 0),
3602 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3603 PTRMEM_OK_P (xarg) = ptrmem;
3606 else if (TREE_CODE (xarg) == TARGET_EXPR)
3607 warning ("taking address of temporary");
3608 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3609 if (TREE_CODE (exp) == ADDR_EXPR)
3610 PTRMEM_OK_P (exp) = ptrmem;
3613 if (processing_template_decl && exp != error_mark_node)
3614 return build_min_non_dep (code, exp, orig_expr,
3615 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3619 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3620 constants, where a null value is represented by an INTEGER_CST of
3624 cp_truthvalue_conversion (tree expr)
3626 tree type = TREE_TYPE (expr);
3627 if (TYPE_PTRMEM_P (type))
3628 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3630 return c_common_truthvalue_conversion (expr);
3633 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3636 condition_conversion (tree expr)
3639 if (processing_template_decl)
3641 t = perform_implicit_conversion (boolean_type_node, expr);
3642 t = fold (build1 (CLEANUP_POINT_EXPR, boolean_type_node, t));
3646 /* Return an ADDR_EXPR giving the address of T. This function
3647 attempts no optimizations or simplifications; it is a low-level
3651 build_address (tree t)
3655 if (error_operand_p (t) || !cxx_mark_addressable (t))
3656 return error_mark_node;
3658 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3663 /* Return a NOP_EXPR converting EXPR to TYPE. */
3666 build_nop (tree type, tree expr)
3668 if (type == error_mark_node || error_operand_p (expr))
3670 return build1 (NOP_EXPR, type, expr);
3673 /* C++: Must handle pointers to members.
3675 Perhaps type instantiation should be extended to handle conversion
3676 from aggregates to types we don't yet know we want? (Or are those
3677 cases typically errors which should be reported?)
3679 NOCONVERT nonzero suppresses the default promotions
3680 (such as from short to int). */
3683 build_unary_op (enum tree_code code, tree xarg, int noconvert)
3685 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
3688 const char *errstring = NULL;
3691 if (arg == error_mark_node)
3692 return error_mark_node;
3697 /* This is used for unary plus, because a CONVERT_EXPR
3698 is enough to prevent anybody from looking inside for
3699 associativity, but won't generate any code. */
3700 if (!(arg = build_expr_type_conversion
3701 (WANT_ARITH | WANT_ENUM | WANT_POINTER, arg, true)))
3702 errstring = "wrong type argument to unary plus";
3706 arg = default_conversion (arg);
3707 arg = build1 (NON_LVALUE_EXPR, TREE_TYPE (arg), arg);
3712 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3713 errstring = "wrong type argument to unary minus";
3714 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
3715 arg = perform_integral_promotions (arg);
3719 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3723 arg = default_conversion (arg);
3725 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM,
3727 errstring = "wrong type argument to bit-complement";
3728 else if (!noconvert)
3729 arg = perform_integral_promotions (arg);
3733 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3734 errstring = "wrong type argument to abs";
3735 else if (!noconvert)
3736 arg = default_conversion (arg);
3740 /* Conjugating a real value is a no-op, but allow it anyway. */
3741 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3742 errstring = "wrong type argument to conjugation";
3743 else if (!noconvert)
3744 arg = default_conversion (arg);
3747 case TRUTH_NOT_EXPR:
3748 arg = perform_implicit_conversion (boolean_type_node, arg);
3749 val = invert_truthvalue (arg);
3750 if (arg != error_mark_node)
3752 errstring = "in argument to unary !";
3759 if (TREE_CODE (arg) == COMPLEX_CST)
3760 return TREE_REALPART (arg);
3761 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3762 return fold (build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg));
3767 if (TREE_CODE (arg) == COMPLEX_CST)
3768 return TREE_IMAGPART (arg);
3769 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3770 return fold (build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg));
3772 return cp_convert (TREE_TYPE (arg), integer_zero_node);
3774 case PREINCREMENT_EXPR:
3775 case POSTINCREMENT_EXPR:
3776 case PREDECREMENT_EXPR:
3777 case POSTDECREMENT_EXPR:
3778 /* Handle complex lvalues (when permitted)
3779 by reduction to simpler cases. */
3781 val = unary_complex_lvalue (code, arg);
3785 /* Increment or decrement the real part of the value,
3786 and don't change the imaginary part. */
3787 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3791 arg = stabilize_reference (arg);
3792 real = build_unary_op (REALPART_EXPR, arg, 1);
3793 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
3794 return build (COMPLEX_EXPR, TREE_TYPE (arg),
3795 build_unary_op (code, real, 1), imag);
3798 /* Report invalid types. */
3800 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
3803 if (code == PREINCREMENT_EXPR)
3804 errstring ="no pre-increment operator for type";
3805 else if (code == POSTINCREMENT_EXPR)
3806 errstring ="no post-increment operator for type";
3807 else if (code == PREDECREMENT_EXPR)
3808 errstring ="no pre-decrement operator for type";
3810 errstring ="no post-decrement operator for type";
3814 /* Report something read-only. */
3816 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
3817 || TREE_READONLY (arg))
3818 readonly_error (arg, ((code == PREINCREMENT_EXPR
3819 || code == POSTINCREMENT_EXPR)
3820 ? "increment" : "decrement"),
3825 tree result_type = TREE_TYPE (arg);
3827 arg = get_unwidened (arg, 0);
3828 argtype = TREE_TYPE (arg);
3830 /* ARM $5.2.5 last annotation says this should be forbidden. */
3831 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
3832 pedwarn ("ISO C++ forbids %sing an enum",
3833 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3834 ? "increment" : "decrement");
3836 /* Compute the increment. */
3838 if (TREE_CODE (argtype) == POINTER_TYPE)
3840 tree type = complete_type (TREE_TYPE (argtype));
3842 if (!COMPLETE_OR_VOID_TYPE_P (type))
3843 error ("cannot %s a pointer to incomplete type `%T'",
3844 ((code == PREINCREMENT_EXPR
3845 || code == POSTINCREMENT_EXPR)
3846 ? "increment" : "decrement"), TREE_TYPE (argtype));
3847 else if ((pedantic || warn_pointer_arith)
3848 && !TYPE_PTROB_P (argtype))
3849 pedwarn ("ISO C++ forbids %sing a pointer of type `%T'",
3850 ((code == PREINCREMENT_EXPR
3851 || code == POSTINCREMENT_EXPR)
3852 ? "increment" : "decrement"), argtype);
3853 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
3856 inc = integer_one_node;
3858 inc = cp_convert (argtype, inc);
3860 /* Handle incrementing a cast-expression. */
3862 switch (TREE_CODE (arg))
3867 case FIX_TRUNC_EXPR:
3868 case FIX_FLOOR_EXPR:
3869 case FIX_ROUND_EXPR:
3872 tree incremented, modify, value, compound;
3873 if (! lvalue_p (arg) && pedantic)
3874 pedwarn ("cast to non-reference type used as lvalue");
3875 arg = stabilize_reference (arg);
3876 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
3879 value = save_expr (arg);
3880 incremented = build (((code == PREINCREMENT_EXPR
3881 || code == POSTINCREMENT_EXPR)
3882 ? PLUS_EXPR : MINUS_EXPR),
3883 argtype, value, inc);
3885 modify = build_modify_expr (arg, NOP_EXPR, incremented);
3886 compound = build (COMPOUND_EXPR, TREE_TYPE (arg), modify, value);
3888 /* Eliminate warning about unused result of + or -. */
3889 TREE_NO_WARNING (compound) = 1;
3897 /* Complain about anything else that is not a true lvalue. */
3898 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
3899 || code == POSTINCREMENT_EXPR)
3900 ? "increment" : "decrement")))
3901 return error_mark_node;
3903 /* Forbid using -- on `bool'. */
3904 if (TREE_TYPE (arg) == boolean_type_node)
3906 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
3908 error ("invalid use of `--' on bool variable `%D'", arg);
3909 return error_mark_node;
3911 val = boolean_increment (code, arg);
3914 val = build (code, TREE_TYPE (arg), arg, inc);
3916 TREE_SIDE_EFFECTS (val) = 1;
3917 return cp_convert (result_type, val);
3921 /* Note that this operation never does default_conversion
3922 regardless of NOCONVERT. */
3924 argtype = lvalue_type (arg);
3926 if (TREE_CODE (arg) == OFFSET_REF)
3929 if (TREE_CODE (argtype) == REFERENCE_TYPE)
3931 tree type = build_pointer_type (TREE_TYPE (argtype));
3932 arg = build1 (CONVERT_EXPR, type, arg);
3935 else if (pedantic && DECL_MAIN_P (arg))
3937 pedwarn ("ISO C++ forbids taking address of function `::main'");
3939 /* Let &* cancel out to simplify resulting code. */
3940 if (TREE_CODE (arg) == INDIRECT_REF)
3942 /* We don't need to have `current_class_ptr' wrapped in a
3943 NON_LVALUE_EXPR node. */
3944 if (arg == current_class_ref)
3945 return current_class_ptr;
3947 arg = TREE_OPERAND (arg, 0);
3948 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
3950 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
3951 arg = build1 (CONVERT_EXPR, type, arg);
3953 else if (lvalue_p (arg))
3954 /* Don't let this be an lvalue. */
3955 return non_lvalue (arg);
3959 /* For &x[y], return x+y. But, in a template, ARG may be an
3960 ARRAY_REF representing a non-dependent expression. In that
3961 case, there may be an overloaded "operator []" that will be
3962 chosen at instantiation time; we must not try to optimize
3964 if (TREE_CODE (arg) == ARRAY_REF && !processing_template_decl)
3966 if (!cxx_mark_addressable (TREE_OPERAND (arg, 0)))
3967 return error_mark_node;
3968 return cp_build_binary_op (PLUS_EXPR, TREE_OPERAND (arg, 0),
3969 TREE_OPERAND (arg, 1));
3972 /* Uninstantiated types are all functions. Taking the
3973 address of a function is a no-op, so just return the
3976 if (TREE_CODE (arg) == IDENTIFIER_NODE
3977 && IDENTIFIER_OPNAME_P (arg))
3980 /* We don't know the type yet, so just work around the problem.
3981 We know that this will resolve to an lvalue. */
3982 return build1 (ADDR_EXPR, unknown_type_node, arg);
3985 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
3986 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
3988 /* They're trying to take the address of a unique non-static
3989 member function. This is ill-formed (except in MS-land),
3990 but let's try to DTRT.
3991 Note: We only handle unique functions here because we don't
3992 want to complain if there's a static overload; non-unique
3993 cases will be handled by instantiate_type. But we need to
3994 handle this case here to allow casts on the resulting PMF.
3995 We could defer this in non-MS mode, but it's easier to give
3996 a useful error here. */
3998 /* Inside constant member functions, the `this' pointer
3999 contains an extra const qualifier. TYPE_MAIN_VARIANT
4000 is used here to remove this const from the diagnostics
4001 and the created OFFSET_REF. */
4002 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4003 tree name = DECL_NAME (get_first_fn (TREE_OPERAND (arg, 1)));
4005 if (! flag_ms_extensions)
4007 if (current_class_type
4008 && TREE_OPERAND (arg, 0) == current_class_ref)
4009 /* An expression like &memfn. */
4010 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4011 " or parenthesized non-static member function to form"
4012 " a pointer to member function. Say `&%T::%D'",
4015 pedwarn ("ISO C++ forbids taking the address of a bound member"
4016 " function to form a pointer to member function."
4020 arg = build_offset_ref (base, name, /*address_p=*/true);
4024 if (type_unknown_p (arg))
4025 return build1 (ADDR_EXPR, unknown_type_node, arg);
4027 /* Handle complex lvalues (when permitted)
4028 by reduction to simpler cases. */
4029 val = unary_complex_lvalue (code, arg);
4033 switch (TREE_CODE (arg))
4038 case FIX_TRUNC_EXPR:
4039 case FIX_FLOOR_EXPR:
4040 case FIX_ROUND_EXPR:
4042 if (! lvalue_p (arg) && pedantic)
4043 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4047 arg = OVL_CURRENT (arg);
4054 /* Allow the address of a constructor if all the elements
4056 if (TREE_CODE (arg) == CONSTRUCTOR && TREE_HAS_CONSTRUCTOR (arg)
4057 && TREE_CONSTANT (arg))
4059 /* Anything not already handled and not a true memory reference
4061 else if (TREE_CODE (argtype) != FUNCTION_TYPE
4062 && TREE_CODE (argtype) != METHOD_TYPE
4063 && !lvalue_or_else (arg, "unary `&'"))
4064 return error_mark_node;
4066 if (argtype != error_mark_node)
4067 argtype = build_pointer_type (argtype);
4072 if (TREE_CODE (arg) != COMPONENT_REF
4073 /* Inside a template, we are processing a non-dependent
4074 expression so we can just form an ADDR_EXPR with the
4076 || processing_template_decl)
4077 addr = build_address (arg);
4078 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4080 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4082 /* We can only get here with a single static member
4084 my_friendly_assert (TREE_CODE (fn) == FUNCTION_DECL
4085 && DECL_STATIC_FUNCTION_P (fn),
4088 addr = build_address (fn);
4089 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4090 /* Do not lose object's side effects. */
4091 addr = build (COMPOUND_EXPR, TREE_TYPE (addr),
4092 TREE_OPERAND (arg, 0), addr);
4094 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4096 error ("attempt to take address of bit-field structure member `%D'",
4097 TREE_OPERAND (arg, 1));
4098 return error_mark_node;
4102 /* Unfortunately we cannot just build an address
4103 expression here, because we would not handle
4104 address-constant-expressions or offsetof correctly. */
4105 tree field = TREE_OPERAND (arg, 1);
4106 tree rval = build_unary_op (ADDR_EXPR, TREE_OPERAND (arg, 0), 0);
4107 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (rval)),
4108 decl_type_context (field),
4111 rval = build_base_path (PLUS_EXPR, rval, binfo, 1);
4112 rval = build_nop (argtype, rval);
4113 addr = fold (build (PLUS_EXPR, argtype, rval,
4114 cp_convert (argtype, byte_position (field))));
4117 if (TREE_CODE (argtype) == POINTER_TYPE
4118 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4120 build_ptrmemfunc_type (argtype);
4121 addr = build_ptrmemfunc (argtype, addr, 0);
4134 argtype = TREE_TYPE (arg);
4135 return fold (build1 (code, argtype, arg));
4138 error ("%s", errstring);
4139 return error_mark_node;
4142 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4143 for certain kinds of expressions which are not really lvalues
4144 but which we can accept as lvalues.
4146 If ARG is not a kind of expression we can handle, return zero. */
4149 unary_complex_lvalue (enum tree_code code, tree arg)
4151 /* Handle (a, b) used as an "lvalue". */
4152 if (TREE_CODE (arg) == COMPOUND_EXPR)
4154 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4155 return build (COMPOUND_EXPR, TREE_TYPE (real_result),
4156 TREE_OPERAND (arg, 0), real_result);
4159 /* Handle (a ? b : c) used as an "lvalue". */
4160 if (TREE_CODE (arg) == COND_EXPR
4161 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4162 return rationalize_conditional_expr (code, arg);
4164 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4165 if (TREE_CODE (arg) == MODIFY_EXPR
4166 || TREE_CODE (arg) == PREINCREMENT_EXPR
4167 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4169 tree lvalue = TREE_OPERAND (arg, 0);
4170 if (TREE_SIDE_EFFECTS (lvalue))
4172 lvalue = stabilize_reference (lvalue);
4173 arg = build (TREE_CODE (arg), TREE_TYPE (arg),
4174 lvalue, TREE_OPERAND (arg, 1));
4176 return unary_complex_lvalue
4177 (code, build (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4180 if (code != ADDR_EXPR)
4183 /* Handle (a = b) used as an "lvalue" for `&'. */
4184 if (TREE_CODE (arg) == MODIFY_EXPR
4185 || TREE_CODE (arg) == INIT_EXPR)
4187 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4188 arg = build (COMPOUND_EXPR, TREE_TYPE (real_result), arg, real_result);
4189 TREE_NO_WARNING (arg) = 1;
4193 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4194 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4195 || TREE_CODE (arg) == OFFSET_REF)
4199 my_friendly_assert (TREE_CODE (arg) != SCOPE_REF, 313);
4201 if (TREE_CODE (arg) != OFFSET_REF)
4204 t = TREE_OPERAND (arg, 1);
4206 /* Check all this code for right semantics. */
4207 if (TREE_CODE (t) == FUNCTION_DECL)
4209 if (DECL_DESTRUCTOR_P (t))
4210 error ("taking address of destructor");
4211 return build_unary_op (ADDR_EXPR, t, 0);
4213 if (TREE_CODE (t) == VAR_DECL)
4214 return build_unary_op (ADDR_EXPR, t, 0);
4219 if (TREE_OPERAND (arg, 0)
4220 && ! is_dummy_object (TREE_OPERAND (arg, 0))
4221 && TREE_CODE (t) != FIELD_DECL)
4223 error ("taking address of bound pointer-to-member expression");
4224 return error_mark_node;
4226 if (!PTRMEM_OK_P (arg))
4227 return build_unary_op (code, arg, 0);
4229 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4231 error ("cannot create pointer to reference member `%D'", t);
4232 return error_mark_node;
4235 type = build_ptrmem_type (context_for_name_lookup (t),
4237 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4243 /* We permit compiler to make function calls returning
4244 objects of aggregate type look like lvalues. */
4248 if (TREE_CODE (targ) == SAVE_EXPR)
4249 targ = TREE_OPERAND (targ, 0);
4251 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4253 if (TREE_CODE (arg) == SAVE_EXPR)
4256 targ = build_cplus_new (TREE_TYPE (arg), arg);
4257 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4260 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4261 return build (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4262 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4265 /* Don't let anything else be handled specially. */
4269 /* Mark EXP saying that we need to be able to take the
4270 address of it; it should not be allocated in a register.
4271 Value is true if successful.
4273 C++: we do not allow `current_class_ptr' to be addressable. */
4276 cxx_mark_addressable (tree exp)
4281 switch (TREE_CODE (x))
4288 x = TREE_OPERAND (x, 0);
4292 if (x == current_class_ptr)
4294 error ("cannot take the address of `this', which is an rvalue expression");
4295 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4301 /* Caller should not be trying to mark initialized
4302 constant fields addressable. */
4303 my_friendly_assert (DECL_LANG_SPECIFIC (x) == 0
4304 || DECL_IN_AGGR_P (x) == 0
4306 || DECL_EXTERNAL (x), 314);
4311 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4312 && !DECL_ARTIFICIAL (x) && extra_warnings)
4313 warning ("address requested for `%D', which is declared `register'",
4315 TREE_ADDRESSABLE (x) = 1;
4316 put_var_into_stack (x, /*rescan=*/true);
4320 TREE_ADDRESSABLE (x) = 1;
4321 TREE_ADDRESSABLE (DECL_ASSEMBLER_NAME (x)) = 1;
4325 TREE_ADDRESSABLE (x) = 1;
4329 TREE_ADDRESSABLE (x) = 1;
4330 cxx_mark_addressable (TREE_OPERAND (x, 0));
4338 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4341 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4343 tree orig_ifexp = ifexp;
4344 tree orig_op1 = op1;
4345 tree orig_op2 = op2;
4348 if (processing_template_decl)
4350 /* The standard says that the expression is type-dependent if
4351 IFEXP is type-dependent, even though the eventual type of the
4352 expression doesn't dependent on IFEXP. */
4353 if (type_dependent_expression_p (ifexp)
4354 /* As a GNU extension, the middle operand may be omitted. */
4355 || (op1 && type_dependent_expression_p (op1))
4356 || type_dependent_expression_p (op2))
4357 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4358 ifexp = build_non_dependent_expr (ifexp);
4360 op1 = build_non_dependent_expr (op1);
4361 op2 = build_non_dependent_expr (op2);
4364 expr = build_conditional_expr (ifexp, op1, op2);
4365 if (processing_template_decl && expr != error_mark_node)
4366 return build_min_non_dep (COND_EXPR, expr,
4367 orig_ifexp, orig_op1, orig_op2);
4371 /* Given a list of expressions, return a compound expression
4372 that performs them all and returns the value of the last of them. */
4374 tree build_x_compound_expr_from_list (tree list, const char *msg)
4376 tree expr = TREE_VALUE (list);
4378 if (TREE_CHAIN (list))
4381 pedwarn ("%s expression list treated as compound expression", msg);
4383 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4384 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4390 /* Handle overloading of the ',' operator when needed. */
4393 build_x_compound_expr (tree op1, tree op2)
4396 tree orig_op1 = op1;
4397 tree orig_op2 = op2;
4399 if (processing_template_decl)
4401 if (type_dependent_expression_p (op1)
4402 || type_dependent_expression_p (op2))
4403 return build_min_nt (COMPOUND_EXPR, op1, op2);
4404 op1 = build_non_dependent_expr (op1);
4405 op2 = build_non_dependent_expr (op2);
4408 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4409 /*overloaded_p=*/NULL);
4411 result = build_compound_expr (op1, op2);
4413 if (processing_template_decl && result != error_mark_node)
4414 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4419 /* Build a compound expression. */
4422 build_compound_expr (tree lhs, tree rhs)
4424 lhs = decl_constant_value (lhs);
4425 lhs = convert_to_void (lhs, "left-hand operand of comma");
4427 if (lhs == error_mark_node || rhs == error_mark_node)
4428 return error_mark_node;
4430 if (TREE_CODE (rhs) == TARGET_EXPR)
4432 /* If the rhs is a TARGET_EXPR, then build the compound
4433 expression inside the target_expr's initializer. This
4434 helps the compiler to eliminate unnecessary temporaries. */
4435 tree init = TREE_OPERAND (rhs, 1);
4437 init = build (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4438 TREE_OPERAND (rhs, 1) = init;
4443 return build (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4446 /* Issue an error message if casting from SRC_TYPE to DEST_TYPE casts
4447 away constness. DESCRIPTION explains what operation is taking
4451 check_for_casting_away_constness (tree src_type, tree dest_type,
4452 const char *description)
4454 if (casts_away_constness (src_type, dest_type))
4455 error ("%s from type `%T' to type `%T' casts away constness",
4456 description, src_type, dest_type);
4459 /* Return an expression representing static_cast<TYPE>(EXPR). */
4462 build_static_cast (tree type, tree expr)
4467 if (type == error_mark_node || expr == error_mark_node)
4468 return error_mark_node;
4470 if (processing_template_decl)
4472 expr = build_min (STATIC_CAST_EXPR, type, expr);
4473 /* We don't know if it will or will not have side effects. */
4474 TREE_SIDE_EFFECTS (expr) = 1;
4478 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4479 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4480 if (TREE_CODE (type) != REFERENCE_TYPE
4481 && TREE_CODE (expr) == NOP_EXPR
4482 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4483 expr = TREE_OPERAND (expr, 0);
4485 intype = TREE_TYPE (expr);
4487 /* [expr.static.cast]
4489 An lvalue of type "cv1 B", where B is a class type, can be cast
4490 to type "reference to cv2 D", where D is a class derived (clause
4491 _class.derived_) from B, if a valid standard conversion from
4492 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4493 same cv-qualification as, or greater cv-qualification than, cv1,
4494 and B is not a virtual base class of D. */
4495 /* We check this case before checking the validity of "TYPE t =
4496 EXPR;" below because for this case:
4499 struct D : public B { D(const B&); };
4501 void f() { static_cast<const D&>(b); }
4503 we want to avoid constructing a new D. The standard is not
4504 completely clear about this issue, but our interpretation is
4505 consistent with other compilers. */
4506 if (TREE_CODE (type) == REFERENCE_TYPE
4507 && CLASS_TYPE_P (TREE_TYPE (type))
4508 && CLASS_TYPE_P (intype)
4509 && real_lvalue_p (expr)
4510 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4511 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4512 build_pointer_type (TYPE_MAIN_VARIANT
4513 (TREE_TYPE (type))))
4514 && at_least_as_qualified_p (TREE_TYPE (type), intype))
4516 /* There is a standard conversion from "D*" to "B*" even if "B"
4517 is ambiguous or inaccessible. Therefore, we ask lookup_base
4518 to check these conditions. */
4519 tree base = lookup_base (TREE_TYPE (type), intype, ba_check, NULL);
4521 /* Convert from "B*" to "D*". This function will check that "B"
4522 is not a virtual base of "D". */
4523 expr = build_base_path (MINUS_EXPR, build_address (expr),
4524 base, /*nonnull=*/false);
4525 /* Convert the pointer to a reference -- but then remember that
4526 there are no expressions with reference type in C++. */
4527 return convert_from_reference (build_nop (type, expr));
4530 /* [expr.static.cast]
4532 An expression e can be explicitly converted to a type T using a
4533 static_cast of the form static_cast<T>(e) if the declaration T
4534 t(e);" is well-formed, for some invented temporary variable
4536 result = perform_direct_initialization_if_possible (type, expr);
4538 return convert_from_reference (result);
4540 /* [expr.static.cast]
4542 Any expression can be explicitly converted to type cv void. */
4543 if (TREE_CODE (type) == VOID_TYPE)
4544 return convert_to_void (expr, /*implicit=*/NULL);
4546 /* [expr.static.cast]
4548 The inverse of any standard conversion sequence (clause _conv_),
4549 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4550 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4551 (_conv.bool_) conversions, can be performed explicitly using
4552 static_cast subject to the restriction that the explicit
4553 conversion does not cast away constness (_expr.const.cast_), and
4554 the following additional rules for specific cases: */
4555 /* For reference, the conversions not excluded are: integral
4556 promotions, floating point promotion, integral conversions,
4557 floating point conversions, floating-integral conversions,
4558 pointer conversions, and pointer to member conversions. */
4559 if ((ARITHMETIC_TYPE_P (type) && ARITHMETIC_TYPE_P (intype))
4562 A value of integral _or enumeration_ type can be explicitly
4563 converted to an enumeration type. */
4564 || (INTEGRAL_OR_ENUMERATION_TYPE_P (type)
4565 && INTEGRAL_OR_ENUMERATION_TYPE_P (intype)))
4566 /* Really, build_c_cast should defer to this function rather
4567 than the other way around. */
4568 return build_c_cast (type, expr);
4570 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4571 && CLASS_TYPE_P (TREE_TYPE (type))
4572 && CLASS_TYPE_P (TREE_TYPE (intype))
4573 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4574 (TREE_TYPE (intype))),
4575 build_pointer_type (TYPE_MAIN_VARIANT
4576 (TREE_TYPE (type)))))
4580 check_for_casting_away_constness (intype, type, "static_cast");
4581 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype), ba_check,
4583 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
4586 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4587 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4594 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
4595 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
4597 if (TYPE_PTRMEM_P (type))
4599 t1 = (build_ptrmem_type
4601 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
4602 t2 = (build_ptrmem_type
4604 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
4611 if (can_convert (t1, t2))
4613 check_for_casting_away_constness (intype, type, "static_cast");
4614 if (TYPE_PTRMEM_P (type))
4618 if (TREE_CODE (expr) == PTRMEM_CST)
4619 expr = cplus_expand_constant (expr);
4620 delta = get_delta_difference (c1, c2, /*force=*/1);
4621 if (!integer_zerop (delta))
4622 expr = cp_build_binary_op (PLUS_EXPR,
4623 build_nop (ptrdiff_type_node, expr),
4625 return build_nop (type, expr);
4628 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4633 /* [expr.static.cast]
4635 An rvalue of type "pointer to cv void" can be explicitly
4636 converted to a pointer to object type. A value of type pointer
4637 to object converted to "pointer to cv void" and back to the
4638 original pointer type will have its original value. */
4639 if (TREE_CODE (intype) == POINTER_TYPE
4640 && VOID_TYPE_P (TREE_TYPE (intype))
4641 && TYPE_PTROB_P (type))
4643 check_for_casting_away_constness (intype, type, "static_cast");
4644 return build_nop (type, expr);
4647 error ("invalid static_cast from type `%T' to type `%T'", intype, type);
4648 return error_mark_node;
4652 build_reinterpret_cast (tree type, tree expr)
4656 if (type == error_mark_node || expr == error_mark_node)
4657 return error_mark_node;
4659 if (processing_template_decl)
4661 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
4663 if (!TREE_SIDE_EFFECTS (t)
4664 && type_dependent_expression_p (expr))
4665 /* There might turn out to be side effects inside expr. */
4666 TREE_SIDE_EFFECTS (t) = 1;
4670 if (TREE_CODE (type) != REFERENCE_TYPE)
4672 expr = decay_conversion (expr);
4674 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4675 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4676 if (TREE_CODE (expr) == NOP_EXPR
4677 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4678 expr = TREE_OPERAND (expr, 0);
4681 intype = TREE_TYPE (expr);
4683 if (TREE_CODE (type) == REFERENCE_TYPE)
4685 if (! real_lvalue_p (expr))
4687 error ("invalid reinterpret_cast of an rvalue expression of type `%T' to type `%T'", intype, type);
4688 return error_mark_node;
4690 expr = build_unary_op (ADDR_EXPR, expr, 0);
4691 if (expr != error_mark_node)
4692 expr = build_reinterpret_cast
4693 (build_pointer_type (TREE_TYPE (type)), expr);
4694 if (expr != error_mark_node)
4695 expr = build_indirect_ref (expr, 0);
4698 else if (same_type_ignoring_top_level_qualifiers_p (intype, type))
4699 return build_static_cast (type, expr);
4701 if (TYPE_PTR_P (type) && (TREE_CODE (intype) == INTEGER_TYPE
4702 || TREE_CODE (intype) == ENUMERAL_TYPE))
4704 else if (TREE_CODE (type) == INTEGER_TYPE && TYPE_PTR_P (intype))
4706 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
4707 pedwarn ("reinterpret_cast from `%T' to `%T' loses precision",
4710 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
4711 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4713 expr = decl_constant_value (expr);
4714 return fold (build1 (NOP_EXPR, type, expr));
4716 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4717 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
4719 check_for_casting_away_constness (intype, type, "reinterpret_cast");
4720 expr = decl_constant_value (expr);
4721 return fold (build1 (NOP_EXPR, type, expr));
4723 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
4724 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
4726 pedwarn ("ISO C++ forbids casting between pointer-to-function and pointer-to-object");
4727 expr = decl_constant_value (expr);
4728 return fold (build1 (NOP_EXPR, type, expr));
4732 error ("invalid reinterpret_cast from type `%T' to type `%T'",
4734 return error_mark_node;
4737 return cp_convert (type, expr);
4741 build_const_cast (tree type, tree expr)
4745 if (type == error_mark_node || expr == error_mark_node)
4746 return error_mark_node;
4748 if (processing_template_decl)
4750 tree t = build_min (CONST_CAST_EXPR, type, expr);
4752 if (!TREE_SIDE_EFFECTS (t)
4753 && type_dependent_expression_p (expr))
4754 /* There might turn out to be side effects inside expr. */
4755 TREE_SIDE_EFFECTS (t) = 1;
4759 if (!POINTER_TYPE_P (type) && !TYPE_PTRMEM_P (type))
4760 error ("invalid use of const_cast with type `%T', which is not a pointer, reference, nor a pointer-to-data-member type", type);
4761 else if (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4763 error ("invalid use of const_cast with type `%T', which is a pointer or reference to a function type", type);
4764 return error_mark_node;
4767 if (TREE_CODE (type) != REFERENCE_TYPE)
4769 expr = decay_conversion (expr);
4771 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4772 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4773 if (TREE_CODE (expr) == NOP_EXPR
4774 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4775 expr = TREE_OPERAND (expr, 0);
4778 intype = TREE_TYPE (expr);
4780 if (same_type_ignoring_top_level_qualifiers_p (intype, type))
4781 return build_static_cast (type, expr);
4782 else if (TREE_CODE (type) == REFERENCE_TYPE)
4784 if (! real_lvalue_p (expr))
4786 error ("invalid const_cast of an rvalue of type `%T' to type `%T'", intype, type);
4787 return error_mark_node;
4790 if (comp_ptr_ttypes_const (TREE_TYPE (type), intype))
4792 expr = build_unary_op (ADDR_EXPR, expr, 0);
4793 expr = build1 (NOP_EXPR, type, expr);
4794 return convert_from_reference (expr);
4797 else if (((TREE_CODE (type) == POINTER_TYPE
4798 && TREE_CODE (intype) == POINTER_TYPE)
4799 || (TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype)))
4800 && comp_ptr_ttypes_const (TREE_TYPE (type), TREE_TYPE (intype)))
4801 return cp_convert (type, expr);
4803 error ("invalid const_cast from type `%T' to type `%T'", intype, type);
4804 return error_mark_node;
4807 /* Build an expression representing a cast to type TYPE of expression EXPR.
4809 ALLOW_NONCONVERTING is true if we should allow non-converting constructors
4810 when doing the cast. */
4813 build_c_cast (tree type, tree expr)
4818 if (type == error_mark_node || expr == error_mark_node)
4819 return error_mark_node;
4821 if (processing_template_decl)
4823 tree t = build_min (CAST_EXPR, type,
4824 tree_cons (NULL_TREE, value, NULL_TREE));
4825 /* We don't know if it will or will not have side effects. */
4826 TREE_SIDE_EFFECTS (t) = 1;
4830 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4831 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4832 if (TREE_CODE (type) != REFERENCE_TYPE
4833 && TREE_CODE (value) == NOP_EXPR
4834 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
4835 value = TREE_OPERAND (value, 0);
4837 if (TREE_CODE (type) == ARRAY_TYPE)
4839 /* Allow casting from T1* to T2[] because Cfront allows it.
4840 NIHCL uses it. It is not valid ISO C++ however. */
4841 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
4843 pedwarn ("ISO C++ forbids casting to an array type `%T'", type);
4844 type = build_pointer_type (TREE_TYPE (type));
4848 error ("ISO C++ forbids casting to an array type `%T'", type);
4849 return error_mark_node;
4853 if (TREE_CODE (type) == FUNCTION_TYPE
4854 || TREE_CODE (type) == METHOD_TYPE)
4856 error ("invalid cast to function type `%T'", type);
4857 return error_mark_node;
4860 if (TREE_CODE (type) == VOID_TYPE)
4862 /* Conversion to void does not cause any of the normal function to
4863 * pointer, array to pointer and lvalue to rvalue decays. */
4865 value = convert_to_void (value, /*implicit=*/NULL);
4869 if (!complete_type_or_else (type, NULL_TREE))
4870 return error_mark_node;
4872 /* Convert functions and arrays to pointers and
4873 convert references to their expanded types,
4874 but don't convert any other types. If, however, we are
4875 casting to a class type, there's no reason to do this: the
4876 cast will only succeed if there is a converting constructor,
4877 and the default conversions will be done at that point. In
4878 fact, doing the default conversion here is actually harmful
4882 struct S { S(const A&); };
4884 since we don't want the array-to-pointer conversion done. */
4885 if (!IS_AGGR_TYPE (type))
4887 if (TREE_CODE (TREE_TYPE (value)) == FUNCTION_TYPE
4888 || (TREE_CODE (TREE_TYPE (value)) == METHOD_TYPE
4889 /* Don't do the default conversion on a ->* expression. */
4890 && ! (TREE_CODE (type) == POINTER_TYPE
4891 && bound_pmf_p (value)))
4892 || TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE
4893 || TREE_CODE (TREE_TYPE (value)) == REFERENCE_TYPE)
4894 value = decay_conversion (value);
4896 else if (TREE_CODE (TREE_TYPE (value)) == REFERENCE_TYPE)
4897 /* However, even for class types, we still need to strip away
4898 the reference type, since the call to convert_force below
4899 does not expect the input expression to be of reference
4901 value = convert_from_reference (value);
4903 otype = TREE_TYPE (value);
4905 /* Optionally warn about potentially worrisome casts. */
4908 && TREE_CODE (type) == POINTER_TYPE
4909 && TREE_CODE (otype) == POINTER_TYPE
4910 && !at_least_as_qualified_p (TREE_TYPE (type),
4912 warning ("cast from `%T' to `%T' discards qualifiers from pointer target type",
4915 if (TREE_CODE (type) == INTEGER_TYPE
4916 && TYPE_PTR_P (otype)
4917 && TYPE_PRECISION (type) != TYPE_PRECISION (otype))
4918 warning ("cast from pointer to integer of different size");
4920 if (TYPE_PTR_P (type)
4921 && TREE_CODE (otype) == INTEGER_TYPE
4922 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
4923 /* Don't warn about converting any constant. */
4924 && !TREE_CONSTANT (value))
4925 warning ("cast to pointer from integer of different size");
4927 if (TREE_CODE (type) == REFERENCE_TYPE)
4928 value = (convert_from_reference
4929 (convert_to_reference (type, value, CONV_C_CAST,
4930 LOOKUP_COMPLAIN, NULL_TREE)));
4935 value = decl_constant_value (value);
4938 value = convert_force (type, value, CONV_C_CAST);
4940 /* Ignore any integer overflow caused by the cast. */
4941 if (TREE_CODE (value) == INTEGER_CST)
4943 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue);
4945 if (TREE_CODE_CLASS (TREE_CODE (ovalue)) == 'c')
4946 TREE_CONSTANT_OVERFLOW (value) = TREE_CONSTANT_OVERFLOW (ovalue);
4950 /* Warn about possible alignment problems. Do this here when we will have
4951 instantiated any necessary template types. */
4952 if (STRICT_ALIGNMENT && warn_cast_align
4953 && TREE_CODE (type) == POINTER_TYPE
4954 && TREE_CODE (otype) == POINTER_TYPE
4955 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE
4956 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
4957 && COMPLETE_TYPE_P (TREE_TYPE (otype))
4958 && COMPLETE_TYPE_P (TREE_TYPE (type))
4959 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype)))
4960 warning ("cast from `%T' to `%T' increases required alignment of target type",
4963 /* Always produce some operator for an explicit cast,
4964 so we can tell (for -pedantic) that the cast is no lvalue. */
4965 if (TREE_CODE (type) != REFERENCE_TYPE && value == expr
4966 && real_lvalue_p (value))
4967 value = non_lvalue (value);
4972 /* Build an assignment expression of lvalue LHS from value RHS.
4973 MODIFYCODE is the code for a binary operator that we use
4974 to combine the old value of LHS with RHS to get the new value.
4975 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
4977 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
4980 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
4984 tree lhstype = TREE_TYPE (lhs);
4985 tree olhstype = lhstype;
4986 tree olhs = NULL_TREE;
4988 /* Avoid duplicate error messages from operands that had errors. */
4989 if (lhs == error_mark_node || rhs == error_mark_node)
4990 return error_mark_node;
4992 /* Handle control structure constructs used as "lvalues". */
4993 switch (TREE_CODE (lhs))
4995 /* Handle --foo = 5; as these are valid constructs in C++. */
4996 case PREDECREMENT_EXPR:
4997 case PREINCREMENT_EXPR:
4998 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
4999 lhs = build (TREE_CODE (lhs), TREE_TYPE (lhs),
5000 stabilize_reference (TREE_OPERAND (lhs, 0)),
5001 TREE_OPERAND (lhs, 1));
5002 return build (COMPOUND_EXPR, lhstype,
5004 build_modify_expr (TREE_OPERAND (lhs, 0),
5007 /* Handle (a, b) used as an "lvalue". */
5009 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5011 if (newrhs == error_mark_node)
5012 return error_mark_node;
5013 return build (COMPOUND_EXPR, lhstype,
5014 TREE_OPERAND (lhs, 0), newrhs);
5017 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5018 lhs = build (TREE_CODE (lhs), TREE_TYPE (lhs),
5019 stabilize_reference (TREE_OPERAND (lhs, 0)),
5020 TREE_OPERAND (lhs, 1));
5021 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5022 if (newrhs == error_mark_node)
5023 return error_mark_node;
5024 return build (COMPOUND_EXPR, lhstype, lhs, newrhs);
5026 /* Handle (a ? b : c) used as an "lvalue". */
5029 /* Produce (a ? (b = rhs) : (c = rhs))
5030 except that the RHS goes through a save-expr
5031 so the code to compute it is only emitted once. */
5033 tree preeval = NULL_TREE;
5035 rhs = stabilize_expr (rhs, &preeval);
5037 /* Check this here to avoid odd errors when trying to convert
5038 a throw to the type of the COND_EXPR. */
5039 if (!lvalue_or_else (lhs, "assignment"))
5040 return error_mark_node;
5042 cond = build_conditional_expr
5043 (TREE_OPERAND (lhs, 0),
5044 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5045 TREE_OPERAND (lhs, 1)),
5047 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5048 TREE_OPERAND (lhs, 2)),
5051 if (cond == error_mark_node)
5053 /* Make sure the code to compute the rhs comes out
5054 before the split. */
5056 cond = build (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5064 if (modifycode == INIT_EXPR)
5066 if (TREE_CODE (rhs) == CONSTRUCTOR)
5068 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5069 /* Call convert to generate an error; see PR 11063. */
5070 rhs = convert (lhstype, rhs);
5071 result = build (INIT_EXPR, lhstype, lhs, rhs);
5072 TREE_SIDE_EFFECTS (result) = 1;
5075 else if (! IS_AGGR_TYPE (lhstype))
5076 /* Do the default thing. */;
5079 result = build_special_member_call (lhs, complete_ctor_identifier,
5080 build_tree_list (NULL_TREE, rhs),
5081 TYPE_BINFO (lhstype),
5083 if (result == NULL_TREE)
5084 return error_mark_node;
5090 if (TREE_CODE (lhstype) == REFERENCE_TYPE)
5092 lhs = convert_from_reference (lhs);
5093 olhstype = lhstype = TREE_TYPE (lhs);
5095 lhs = require_complete_type (lhs);
5096 if (lhs == error_mark_node)
5097 return error_mark_node;
5099 if (modifycode == NOP_EXPR)
5101 /* `operator=' is not an inheritable operator. */
5102 if (! IS_AGGR_TYPE (lhstype))
5103 /* Do the default thing. */;
5106 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5107 lhs, rhs, make_node (NOP_EXPR),
5108 /*overloaded_p=*/NULL);
5109 if (result == NULL_TREE)
5110 return error_mark_node;
5117 /* A binary op has been requested. Combine the old LHS
5118 value with the RHS producing the value we should actually
5119 store into the LHS. */
5121 my_friendly_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE),
5123 lhs = stabilize_reference (lhs);
5124 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5125 if (newrhs == error_mark_node)
5127 error (" in evaluation of `%Q(%#T, %#T)'", modifycode,
5128 TREE_TYPE (lhs), TREE_TYPE (rhs));
5129 return error_mark_node;
5132 /* Now it looks like a plain assignment. */
5133 modifycode = NOP_EXPR;
5135 my_friendly_assert (TREE_CODE (lhstype) != REFERENCE_TYPE, 20011220);
5136 my_friendly_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE,
5140 /* The left-hand side must be an lvalue. */
5141 if (!lvalue_or_else (lhs, "assignment"))
5142 return error_mark_node;
5144 /* Warn about modifying something that is `const'. Don't warn if
5145 this is initialization. */
5146 if (modifycode != INIT_EXPR
5147 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5148 /* Functions are not modifiable, even though they are
5150 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5151 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5152 /* If it's an aggregate and any field is const, then it is
5153 effectively const. */
5154 || (CLASS_TYPE_P (lhstype)
5155 && C_TYPE_FIELDS_READONLY (lhstype))))
5156 readonly_error (lhs, "assignment", 0);
5158 /* If storing into a structure or union member, it has probably been
5159 given type `int'. Compute the type that would go with the actual
5160 amount of storage the member occupies. */
5162 if (TREE_CODE (lhs) == COMPONENT_REF
5163 && (TREE_CODE (lhstype) == INTEGER_TYPE
5164 || TREE_CODE (lhstype) == REAL_TYPE
5165 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5167 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5169 /* If storing in a field that is in actuality a short or narrower
5170 than one, we must store in the field in its actual type. */
5172 if (lhstype != TREE_TYPE (lhs))
5174 /* Avoid warnings converting integral types back into enums for
5176 if (TREE_CODE (lhstype) == INTEGER_TYPE
5177 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5179 if (TREE_SIDE_EFFECTS (lhs))
5180 lhs = stabilize_reference (lhs);
5183 lhs = copy_node (lhs);
5184 TREE_TYPE (lhs) = lhstype;
5188 /* Convert new value to destination type. */
5190 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5194 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5195 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5197 error ("incompatible types in assignment of `%T' to `%T'",
5198 TREE_TYPE (rhs), lhstype);
5199 return error_mark_node;
5202 /* Allow array assignment in compiler-generated code. */
5203 if (! DECL_ARTIFICIAL (current_function_decl))
5204 pedwarn ("ISO C++ forbids assignment of arrays");
5206 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5207 ? 1 + (modifycode != INIT_EXPR): 0;
5208 return build_vec_init (lhs, NULL_TREE, newrhs, from_array);
5211 if (modifycode == INIT_EXPR)
5212 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5213 "initialization", NULL_TREE, 0);
5216 /* Avoid warnings on enum bit fields. */
5217 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5218 && TREE_CODE (lhstype) == INTEGER_TYPE)
5220 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5222 newrhs = convert_force (lhstype, newrhs, 0);
5225 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5227 if (TREE_CODE (newrhs) == CALL_EXPR
5228 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5229 newrhs = build_cplus_new (lhstype, newrhs);
5231 /* Can't initialize directly from a TARGET_EXPR, since that would
5232 cause the lhs to be constructed twice, and possibly result in
5233 accidental self-initialization. So we force the TARGET_EXPR to be
5234 expanded without a target. */
5235 if (TREE_CODE (newrhs) == TARGET_EXPR)
5236 newrhs = build (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5237 TREE_OPERAND (newrhs, 0));
5240 if (newrhs == error_mark_node)
5241 return error_mark_node;
5243 result = build (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5244 lhstype, lhs, newrhs);
5246 TREE_SIDE_EFFECTS (result) = 1;
5248 /* If we got the LHS in a different type for storing in,
5249 convert the result back to the nominal type of LHS
5250 so that the value we return always has the same type
5251 as the LHS argument. */
5253 if (olhstype == TREE_TYPE (result))
5257 result = build (COMPOUND_EXPR, olhstype, result, olhs);
5258 TREE_NO_WARNING (result) = 1;
5261 return convert_for_assignment (olhstype, result, "assignment",
5266 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5268 if (processing_template_decl)
5269 return build_min_nt (MODOP_EXPR, lhs,
5270 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5272 if (modifycode != NOP_EXPR)
5274 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5275 make_node (modifycode),
5276 /*overloaded_p=*/NULL);
5280 return build_modify_expr (lhs, modifycode, rhs);
5284 /* Get difference in deltas for different pointer to member function
5285 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5286 the conversion is invalid, the constant is zero. If FORCE is true,
5287 then allow reverse conversions as well.
5289 Note that the naming of FROM and TO is kind of backwards; the return
5290 value is what we add to a TO in order to get a FROM. They are named
5291 this way because we call this function to find out how to convert from
5292 a pointer to member of FROM to a pointer to member of TO. */
5295 get_delta_difference (tree from, tree to, int force)
5302 /* Assume no conversion is required. */
5303 result = integer_zero_node;
5304 binfo = lookup_base (to, from, ba_check, &kind);
5305 if (kind == bk_inaccessible || kind == bk_ambig)
5306 error (" in pointer to member function conversion");
5311 error_not_base_type (from, to);
5312 error (" in pointer to member conversion");
5316 binfo = lookup_base (from, to, ba_check, &kind);
5319 virt_binfo = binfo_from_vbase (binfo);
5321 /* This is a reinterpret cast, we choose to do nothing. */
5322 warning ("pointer to member cast via virtual base `%T'",
5323 BINFO_TYPE (virt_binfo));
5325 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5331 virt_binfo = binfo_from_vbase (binfo);
5333 result = BINFO_OFFSET (binfo);
5336 /* This is a reinterpret cast, we choose to do nothing. */
5338 warning ("pointer to member cast via virtual base `%T'",
5339 BINFO_TYPE (virt_binfo));
5341 error ("pointer to member conversion via virtual base `%T'",
5342 BINFO_TYPE (virt_binfo));
5346 return fold (convert_to_integer (ptrdiff_type_node, result));
5349 /* Return a constructor for the pointer-to-member-function TYPE using
5350 the other components as specified. */
5353 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5359 /* Pull the FIELD_DECLs out of the type. */
5360 pfn_field = TYPE_FIELDS (type);
5361 delta_field = TREE_CHAIN (pfn_field);
5363 /* Make sure DELTA has the type we want. */
5364 delta = convert_and_check (delta_type_node, delta);
5366 /* Finish creating the initializer. */
5367 u = tree_cons (pfn_field, pfn,
5368 build_tree_list (delta_field, delta));
5369 u = build_constructor (type, u);
5370 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5371 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
5372 TREE_STATIC (u) = (TREE_CONSTANT (u)
5373 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5375 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5380 /* Build a constructor for a pointer to member function. It can be
5381 used to initialize global variables, local variable, or used
5382 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5385 If FORCE is nonzero, then force this conversion, even if
5386 we would rather not do it. Usually set when using an explicit
5389 Return error_mark_node, if something goes wrong. */
5392 build_ptrmemfunc (tree type, tree pfn, int force)
5398 if (error_operand_p (pfn))
5399 return error_mark_node;
5401 pfn_type = TREE_TYPE (pfn);
5402 to_type = build_ptrmemfunc_type (type);
5404 /* Handle multiple conversions of pointer to member functions. */
5405 if (TYPE_PTRMEMFUNC_P (pfn_type))
5407 tree delta = NULL_TREE;
5408 tree npfn = NULL_TREE;
5412 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn))
5413 error ("invalid conversion to type `%T' from type `%T'",
5416 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
5417 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
5420 /* We don't have to do any conversion to convert a
5421 pointer-to-member to its own type. But, we don't want to
5422 just return a PTRMEM_CST if there's an explicit cast; that
5423 cast should make the expression an invalid template argument. */
5424 if (TREE_CODE (pfn) != PTRMEM_CST)
5426 if (same_type_p (to_type, pfn_type))
5428 else if (integer_zerop (n))
5429 return build_reinterpret_cast (to_type, pfn);
5432 if (TREE_SIDE_EFFECTS (pfn))
5433 pfn = save_expr (pfn);
5435 /* Obtain the function pointer and the current DELTA. */
5436 if (TREE_CODE (pfn) == PTRMEM_CST)
5437 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
5440 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
5441 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
5444 /* Just adjust the DELTA field. */
5445 my_friendly_assert (TREE_TYPE (delta) == ptrdiff_type_node, 20030727);
5446 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
5447 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
5448 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
5449 return build_ptrmemfunc1 (to_type, delta, npfn);
5452 /* Handle null pointer to member function conversions. */
5453 if (integer_zerop (pfn))
5455 pfn = build_c_cast (type, integer_zero_node);
5456 return build_ptrmemfunc1 (to_type,
5461 if (type_unknown_p (pfn))
5462 return instantiate_type (type, pfn, tf_error | tf_warning);
5464 fn = TREE_OPERAND (pfn, 0);
5465 my_friendly_assert (TREE_CODE (fn) == FUNCTION_DECL, 0);
5466 return make_ptrmem_cst (to_type, fn);
5469 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
5472 ??? There is no consistency as to the types returned for the above
5473 values. Some code acts as if it were a sizetype and some as if it were
5474 integer_type_node. */
5477 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
5479 tree type = TREE_TYPE (cst);
5480 tree fn = PTRMEM_CST_MEMBER (cst);
5481 tree ptr_class, fn_class;
5483 my_friendly_assert (TREE_CODE (fn) == FUNCTION_DECL, 0);
5485 /* The class that the function belongs to. */
5486 fn_class = DECL_CONTEXT (fn);
5488 /* The class that we're creating a pointer to member of. */
5489 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
5491 /* First, calculate the adjustment to the function's class. */
5492 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0);
5494 if (!DECL_VIRTUAL_P (fn))
5495 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
5498 /* If we're dealing with a virtual function, we have to adjust 'this'
5499 again, to point to the base which provides the vtable entry for
5500 fn; the call will do the opposite adjustment. */
5501 tree orig_class = DECL_CONTEXT (fn);
5502 tree binfo = binfo_or_else (orig_class, fn_class);
5503 *delta = fold (build (PLUS_EXPR, TREE_TYPE (*delta),
5504 *delta, BINFO_OFFSET (binfo)));
5506 /* We set PFN to the vtable offset at which the function can be
5507 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
5508 case delta is shifted left, and then incremented). */
5509 *pfn = DECL_VINDEX (fn);
5510 *pfn = fold (build (MULT_EXPR, integer_type_node, *pfn,
5511 TYPE_SIZE_UNIT (vtable_entry_type)));
5513 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
5515 case ptrmemfunc_vbit_in_pfn:
5516 *pfn = fold (build (PLUS_EXPR, integer_type_node, *pfn,
5520 case ptrmemfunc_vbit_in_delta:
5521 *delta = fold (build (LSHIFT_EXPR, TREE_TYPE (*delta),
5522 *delta, integer_one_node));
5523 *delta = fold (build (PLUS_EXPR, TREE_TYPE (*delta),
5524 *delta, integer_one_node));
5531 *pfn = fold (build1 (NOP_EXPR, TYPE_PTRMEMFUNC_FN_TYPE (type),
5536 /* Return an expression for PFN from the pointer-to-member function
5540 pfn_from_ptrmemfunc (tree t)
5542 if (TREE_CODE (t) == PTRMEM_CST)
5547 expand_ptrmemfunc_cst (t, &delta, &pfn);
5552 return build_ptrmemfunc_access_expr (t, pfn_identifier);
5555 /* Expression EXPR is about to be implicitly converted to TYPE. Warn
5556 if this is a potentially dangerous thing to do. Returns a possibly
5560 dubious_conversion_warnings (tree type, tree expr,
5561 const char *errtype, tree fndecl, int parmnum)
5563 type = non_reference (type);
5565 /* Issue warnings about peculiar, but valid, uses of NULL. */
5566 if (ARITHMETIC_TYPE_P (type) && expr == null_node)
5569 warning ("passing NULL used for non-pointer %s %P of `%D'",
5570 errtype, parmnum, fndecl);
5572 warning ("%s to non-pointer type `%T' from NULL", errtype, type);
5575 /* Warn about assigning a floating-point type to an integer type. */
5576 if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
5577 && TREE_CODE (type) == INTEGER_TYPE)
5580 warning ("passing `%T' for %s %P of `%D'",
5581 TREE_TYPE (expr), errtype, parmnum, fndecl);
5583 warning ("%s to `%T' from `%T'", errtype, type, TREE_TYPE (expr));
5585 /* And warn about assigning a negative value to an unsigned
5587 else if (TYPE_UNSIGNED (type) && TREE_CODE (type) != BOOLEAN_TYPE)
5589 if (TREE_CODE (expr) == INTEGER_CST && TREE_NEGATED_INT (expr))
5592 warning ("passing negative value `%E' for %s %P of `%D'",
5593 expr, errtype, parmnum, fndecl);
5595 warning ("%s of negative value `%E' to `%T'",
5596 errtype, expr, type);
5599 overflow_warning (expr);
5601 if (TREE_CONSTANT (expr))
5607 /* Convert value RHS to type TYPE as preparation for an assignment to
5608 an lvalue of type TYPE. ERRTYPE is a string to use in error
5609 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
5610 are doing the conversion in order to pass the PARMNUMth argument of
5614 convert_for_assignment (tree type, tree rhs,
5615 const char *errtype, tree fndecl, int parmnum)
5618 enum tree_code coder;
5620 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
5621 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
5622 rhs = TREE_OPERAND (rhs, 0);
5624 rhstype = TREE_TYPE (rhs);
5625 coder = TREE_CODE (rhstype);
5627 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
5628 && vector_types_convertible_p (type, rhstype))
5629 return convert (type, rhs);
5631 if (rhs == error_mark_node || rhstype == error_mark_node)
5632 return error_mark_node;
5633 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
5634 return error_mark_node;
5636 /* The RHS of an assignment cannot have void type. */
5637 if (coder == VOID_TYPE)
5639 error ("void value not ignored as it ought to be");
5640 return error_mark_node;
5643 /* Simplify the RHS if possible. */
5644 if (TREE_CODE (rhs) == CONST_DECL)
5645 rhs = DECL_INITIAL (rhs);
5647 /* We do not use decl_constant_value here because of this case:
5649 const char* const s = "s";
5651 The conversion rules for a string literal are more lax than for a
5652 variable; in particular, a string literal can be converted to a
5653 "char *" but the variable "s" cannot be converted in the same
5654 way. If the conversion is allowed, the optimization should be
5655 performed while creating the converted expression. */
5659 The expression is implicitly converted (clause _conv_) to the
5660 cv-unqualified type of the left operand.
5662 We allow bad conversions here because by the time we get to this point
5663 we are committed to doing the conversion. If we end up doing a bad
5664 conversion, convert_like will complain. */
5665 if (!can_convert_arg_bad (type, rhstype, rhs))
5667 /* When -Wno-pmf-conversions is use, we just silently allow
5668 conversions from pointers-to-members to plain pointers. If
5669 the conversion doesn't work, cp_convert will complain. */
5671 && TYPE_PTR_P (type)
5672 && TYPE_PTRMEMFUNC_P (rhstype))
5673 rhs = cp_convert (strip_top_quals (type), rhs);
5676 /* If the right-hand side has unknown type, then it is an
5677 overloaded function. Call instantiate_type to get error
5679 if (rhstype == unknown_type_node)
5680 instantiate_type (type, rhs, tf_error | tf_warning);
5682 error ("cannot convert `%T' to `%T' for argument `%P' to `%D'",
5683 rhstype, type, parmnum, fndecl);
5685 error ("cannot convert `%T' to `%T' in %s", rhstype, type,
5687 return error_mark_node;
5690 return perform_implicit_conversion (strip_top_quals (type), rhs);
5693 /* Convert RHS to be of type TYPE.
5694 If EXP is nonzero, it is the target of the initialization.
5695 ERRTYPE is a string to use in error messages.
5697 Two major differences between the behavior of
5698 `convert_for_assignment' and `convert_for_initialization'
5699 are that references are bashed in the former, while
5700 copied in the latter, and aggregates are assigned in
5701 the former (operator=) while initialized in the
5704 If using constructor make sure no conversion operator exists, if one does
5705 exist, an ambiguity exists.
5707 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
5710 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
5711 const char *errtype, tree fndecl, int parmnum)
5713 enum tree_code codel = TREE_CODE (type);
5715 enum tree_code coder;
5717 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5718 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
5719 if (TREE_CODE (rhs) == NOP_EXPR
5720 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
5721 && codel != REFERENCE_TYPE)
5722 rhs = TREE_OPERAND (rhs, 0);
5724 if (rhs == error_mark_node
5725 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
5726 return error_mark_node;
5728 if (TREE_CODE (TREE_TYPE (rhs)) == REFERENCE_TYPE)
5729 rhs = convert_from_reference (rhs);
5731 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
5732 && TREE_CODE (type) != ARRAY_TYPE
5733 && (TREE_CODE (type) != REFERENCE_TYPE
5734 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
5735 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
5736 && (TREE_CODE (type) != REFERENCE_TYPE
5737 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
5738 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
5739 rhs = decay_conversion (rhs);
5741 rhstype = TREE_TYPE (rhs);
5742 coder = TREE_CODE (rhstype);
5744 if (coder == ERROR_MARK)
5745 return error_mark_node;
5747 /* We accept references to incomplete types, so we can
5748 return here before checking if RHS is of complete type. */
5750 if (codel == REFERENCE_TYPE)
5752 /* This should eventually happen in convert_arguments. */
5753 int savew = 0, savee = 0;
5756 savew = warningcount, savee = errorcount;
5757 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
5761 if (warningcount > savew)
5762 cp_warning_at ("in passing argument %P of `%+D'", parmnum, fndecl);
5763 else if (errorcount > savee)
5764 cp_error_at ("in passing argument %P of `%+D'", parmnum, fndecl);
5770 exp = require_complete_type (exp);
5771 if (exp == error_mark_node)
5772 return error_mark_node;
5774 rhstype = non_reference (rhstype);
5776 type = complete_type (type);
5778 if (IS_AGGR_TYPE (type))
5779 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
5781 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
5784 /* Expand an ASM statement with operands, handling output operands
5785 that are not variables or INDIRECT_REFS by transforming such
5786 cases into cases that expand_asm_operands can handle.
5788 Arguments are same as for expand_asm_operands.
5790 We don't do default conversions on all inputs, because it can screw
5791 up operands that are expected to be in memory. */
5794 c_expand_asm_operands (tree string, tree outputs, tree inputs, tree clobbers,
5795 int vol, location_t locus)
5797 int noutputs = list_length (outputs);
5799 /* o[I] is the place that output number I should be written. */
5800 tree *o = alloca (noutputs * sizeof (tree));
5803 /* Record the contents of OUTPUTS before it is modified. */
5804 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
5805 o[i] = TREE_VALUE (tail);
5807 /* Generate the ASM_OPERANDS insn;
5808 store into the TREE_VALUEs of OUTPUTS some trees for
5809 where the values were actually stored. */
5810 expand_asm_operands (string, outputs, inputs, clobbers, vol, locus);
5812 /* Copy all the intermediate outputs into the specified outputs. */
5813 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
5815 if (o[i] != TREE_VALUE (tail))
5817 expand_expr (build_modify_expr (o[i], NOP_EXPR, TREE_VALUE (tail)),
5818 const0_rtx, VOIDmode, EXPAND_NORMAL);
5821 /* Restore the original value so that it's correct the next
5822 time we expand this function. */
5823 TREE_VALUE (tail) = o[i];
5825 /* Detect modification of read-only values.
5826 (Otherwise done by build_modify_expr.) */
5829 tree type = TREE_TYPE (o[i]);
5830 if (type != error_mark_node
5831 && (CP_TYPE_CONST_P (type)
5832 || (CLASS_TYPE_P (type) && C_TYPE_FIELDS_READONLY (type))))
5833 readonly_error (o[i], "modification by `asm'", 1);
5837 /* Those MODIFY_EXPRs could do autoincrements. */
5841 /* If RETVAL is the address of, or a reference to, a local variable or
5842 temporary give an appropriate warning. */
5845 maybe_warn_about_returning_address_of_local (tree retval)
5847 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
5848 tree whats_returned = retval;
5852 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
5853 whats_returned = TREE_OPERAND (whats_returned, 1);
5854 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
5855 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
5856 || TREE_CODE (whats_returned) == NOP_EXPR)
5857 whats_returned = TREE_OPERAND (whats_returned, 0);
5862 if (TREE_CODE (whats_returned) != ADDR_EXPR)
5864 whats_returned = TREE_OPERAND (whats_returned, 0);
5866 if (TREE_CODE (valtype) == REFERENCE_TYPE)
5868 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
5869 || TREE_CODE (whats_returned) == TARGET_EXPR)
5871 warning ("returning reference to temporary");
5874 if (TREE_CODE (whats_returned) == VAR_DECL
5875 && DECL_NAME (whats_returned)
5876 && TEMP_NAME_P (DECL_NAME (whats_returned)))
5878 warning ("reference to non-lvalue returned");
5883 if (DECL_P (whats_returned)
5884 && DECL_NAME (whats_returned)
5885 && DECL_FUNCTION_SCOPE_P (whats_returned)
5886 && !(TREE_STATIC (whats_returned)
5887 || TREE_PUBLIC (whats_returned)))
5889 if (TREE_CODE (valtype) == REFERENCE_TYPE)
5890 cp_warning_at ("reference to local variable `%D' returned",
5893 cp_warning_at ("address of local variable `%D' returned",
5899 /* Check that returning RETVAL from the current function is valid.
5900 Return an expression explicitly showing all conversions required to
5901 change RETVAL into the function return type, and to assign it to
5902 the DECL_RESULT for the function. */
5905 check_return_expr (tree retval)
5908 /* The type actually returned by the function, after any
5911 int fn_returns_value_p;
5913 /* A `volatile' function is one that isn't supposed to return, ever.
5914 (This is a G++ extension, used to get better code for functions
5915 that call the `volatile' function.) */
5916 if (TREE_THIS_VOLATILE (current_function_decl))
5917 warning ("function declared `noreturn' has a `return' statement");
5919 /* Check for various simple errors. */
5920 if (DECL_DESTRUCTOR_P (current_function_decl))
5923 error ("returning a value from a destructor");
5926 else if (DECL_CONSTRUCTOR_P (current_function_decl))
5928 if (in_function_try_handler)
5929 /* If a return statement appears in a handler of the
5930 function-try-block of a constructor, the program is ill-formed. */
5931 error ("cannot return from a handler of a function-try-block of a constructor");
5933 /* You can't return a value from a constructor. */
5934 error ("returning a value from a constructor");
5938 if (processing_template_decl)
5940 current_function_returns_value = 1;
5944 /* When no explicit return-value is given in a function with a named
5945 return value, the named return value is used. */
5946 result = DECL_RESULT (current_function_decl);
5947 valtype = TREE_TYPE (result);
5948 my_friendly_assert (valtype != NULL_TREE, 19990924);
5949 fn_returns_value_p = !VOID_TYPE_P (valtype);
5950 if (!retval && DECL_NAME (result) && fn_returns_value_p)
5953 /* Check for a return statement with no return value in a function
5954 that's supposed to return a value. */
5955 if (!retval && fn_returns_value_p)
5957 pedwarn ("return-statement with no value, in function returning '%T'",
5959 /* Clear this, so finish_function won't say that we reach the
5960 end of a non-void function (which we don't, we gave a
5962 current_function_returns_null = 0;
5964 /* Check for a return statement with a value in a function that
5965 isn't supposed to return a value. */
5966 else if (retval && !fn_returns_value_p)
5968 if (VOID_TYPE_P (TREE_TYPE (retval)))
5969 /* You can return a `void' value from a function of `void'
5970 type. In that case, we have to evaluate the expression for
5971 its side-effects. */
5972 finish_expr_stmt (retval);
5974 pedwarn ("return-statement with a value, in function "
5975 "returning 'void'");
5977 current_function_returns_null = 1;
5979 /* There's really no value to return, after all. */
5983 /* Remember that this function can sometimes return without a
5985 current_function_returns_null = 1;
5987 /* Remember that this function did return a value. */
5988 current_function_returns_value = 1;
5990 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
5991 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
5992 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
5993 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
5995 && null_ptr_cst_p (retval))
5996 warning ("`operator new' must not return NULL unless it is declared `throw()' (or -fcheck-new is in effect)");
5998 /* Effective C++ rule 15. See also start_function. */
6000 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR)
6001 && retval != current_class_ref)
6002 warning ("`operator=' should return a reference to `*this'");
6004 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6006 [...] For a function with a class return type, if the expression
6007 in the return statement is the name of a local object, and the cv-
6008 unqualified type of the local object is the same as the function
6009 return type, an implementation is permitted to omit creating the tem-
6010 porary object to hold the function return value [...]
6012 So, if this is a value-returning function that always returns the same
6013 local variable, remember it.
6015 It might be nice to be more flexible, and choose the first suitable
6016 variable even if the function sometimes returns something else, but
6017 then we run the risk of clobbering the variable we chose if the other
6018 returned expression uses the chosen variable somehow. And people expect
6019 this restriction, anyway. (jason 2000-11-19)
6021 See finish_function and finalize_nrv for the rest of this optimization. */
6023 if (fn_returns_value_p && flag_elide_constructors)
6025 if (retval != NULL_TREE
6026 && (current_function_return_value == NULL_TREE
6027 || current_function_return_value == retval)
6028 && TREE_CODE (retval) == VAR_DECL
6029 && DECL_CONTEXT (retval) == current_function_decl
6030 && ! TREE_STATIC (retval)
6031 && (DECL_ALIGN (retval)
6032 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6033 && same_type_p ((TYPE_MAIN_VARIANT
6034 (TREE_TYPE (retval))),
6036 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6037 current_function_return_value = retval;
6039 current_function_return_value = error_mark_node;
6042 /* We don't need to do any conversions when there's nothing being
6044 if (!retval || retval == error_mark_node)
6047 /* Do any required conversions. */
6048 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6049 /* No conversions are required. */
6053 /* The type the function is declared to return. */
6054 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6056 /* First convert the value to the function's return type, then
6057 to the type of return value's location to handle the
6058 case that functype is smaller than the valtype. */
6059 retval = convert_for_initialization
6060 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6061 "return", NULL_TREE, 0);
6062 retval = convert (valtype, retval);
6064 /* If the conversion failed, treat this just like `return;'. */
6065 if (retval == error_mark_node)
6067 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6068 else if (! current_function_returns_struct
6069 && TREE_CODE (retval) == TARGET_EXPR
6070 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6071 retval = build (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6072 TREE_OPERAND (retval, 0));
6074 maybe_warn_about_returning_address_of_local (retval);
6077 /* Actually copy the value returned into the appropriate location. */
6078 if (retval && retval != result)
6079 retval = build (INIT_EXPR, TREE_TYPE (result), result, retval);
6085 /* Returns nonzero if the pointer-type FROM can be converted to the
6086 pointer-type TO via a qualification conversion. If CONSTP is -1,
6087 then we return nonzero if the pointers are similar, and the
6088 cv-qualification signature of FROM is a proper subset of that of TO.
6090 If CONSTP is positive, then all outer pointers have been
6094 comp_ptr_ttypes_real (tree to, tree from, int constp)
6096 bool to_more_cv_qualified = false;
6098 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6100 if (TREE_CODE (to) != TREE_CODE (from))
6103 if (TREE_CODE (from) == OFFSET_TYPE
6104 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6105 TYPE_OFFSET_BASETYPE (to)))
6108 /* Const and volatile mean something different for function types,
6109 so the usual checks are not appropriate. */
6110 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6112 if (!at_least_as_qualified_p (to, from))
6115 if (!at_least_as_qualified_p (from, to))
6119 to_more_cv_qualified = true;
6123 constp &= TYPE_READONLY (to);
6126 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6127 return ((constp >= 0 || to_more_cv_qualified)
6128 && same_type_ignoring_top_level_qualifiers_p (to, from));
6132 /* When comparing, say, char ** to char const **, this function takes
6133 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6134 types to this function. */
6137 comp_ptr_ttypes (tree to, tree from)
6139 return comp_ptr_ttypes_real (to, from, 1);
6142 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6143 type or inheritance-related types, regardless of cv-quals. */
6146 ptr_reasonably_similar (tree to, tree from)
6148 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6150 /* Any target type is similar enough to void. */
6151 if (TREE_CODE (to) == VOID_TYPE
6152 || TREE_CODE (from) == VOID_TYPE)
6155 if (TREE_CODE (to) != TREE_CODE (from))
6158 if (TREE_CODE (from) == OFFSET_TYPE
6159 && comptypes (TYPE_OFFSET_BASETYPE (to),
6160 TYPE_OFFSET_BASETYPE (from),
6161 COMPARE_BASE | COMPARE_DERIVED))
6164 if (TREE_CODE (to) == INTEGER_TYPE
6165 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6168 if (TREE_CODE (to) == FUNCTION_TYPE)
6171 if (TREE_CODE (to) != POINTER_TYPE)
6173 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6174 COMPARE_BASE | COMPARE_DERIVED);
6178 /* Like comp_ptr_ttypes, for const_cast. */
6181 comp_ptr_ttypes_const (tree to, tree from)
6183 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6185 if (TREE_CODE (to) != TREE_CODE (from))
6188 if (TREE_CODE (from) == OFFSET_TYPE
6189 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6190 TYPE_OFFSET_BASETYPE (to)))
6193 if (TREE_CODE (to) != POINTER_TYPE)
6194 return same_type_ignoring_top_level_qualifiers_p (to, from);
6198 /* Returns the type qualifiers for this type, including the qualifiers on the
6199 elements for an array type. */
6202 cp_type_quals (tree type)
6204 type = strip_array_types (type);
6205 if (type == error_mark_node)
6206 return TYPE_UNQUALIFIED;
6207 return TYPE_QUALS (type);
6210 /* Returns nonzero if the TYPE contains a mutable member. */
6213 cp_has_mutable_p (tree type)
6215 type = strip_array_types (type);
6217 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6220 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6221 exemplar types such that casting T1 to T2 is casting away castness
6222 if and only if there is no implicit conversion from T1 to T2. */
6225 casts_away_constness_r (tree *t1, tree *t2)
6230 /* [expr.const.cast]
6232 For multi-level pointer to members and multi-level mixed pointers
6233 and pointers to members (conv.qual), the "member" aspect of a
6234 pointer to member level is ignored when determining if a const
6235 cv-qualifier has been cast away. */
6236 if (TYPE_PTRMEM_P (*t1))
6237 *t1 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t1));
6238 if (TYPE_PTRMEM_P (*t2))
6239 *t2 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t2));
6241 /* [expr.const.cast]
6243 For two pointer types:
6245 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6246 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6249 casting from X1 to X2 casts away constness if, for a non-pointer
6250 type T there does not exist an implicit conversion (clause
6253 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6257 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6259 if (TREE_CODE (*t1) != POINTER_TYPE
6260 || TREE_CODE (*t2) != POINTER_TYPE)
6262 *t1 = cp_build_qualified_type (void_type_node,
6263 cp_type_quals (*t1));
6264 *t2 = cp_build_qualified_type (void_type_node,
6265 cp_type_quals (*t2));
6269 quals1 = cp_type_quals (*t1);
6270 quals2 = cp_type_quals (*t2);
6271 *t1 = TREE_TYPE (*t1);
6272 *t2 = TREE_TYPE (*t2);
6273 casts_away_constness_r (t1, t2);
6274 *t1 = build_pointer_type (*t1);
6275 *t2 = build_pointer_type (*t2);
6276 *t1 = cp_build_qualified_type (*t1, quals1);
6277 *t2 = cp_build_qualified_type (*t2, quals2);
6280 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6284 casts_away_constness (tree t1, tree t2)
6286 if (TREE_CODE (t2) == REFERENCE_TYPE)
6288 /* [expr.const.cast]
6290 Casting from an lvalue of type T1 to an lvalue of type T2
6291 using a reference cast casts away constness if a cast from an
6292 rvalue of type "pointer to T1" to the type "pointer to T2"
6293 casts away constness. */
6294 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6295 return casts_away_constness (build_pointer_type (t1),
6296 build_pointer_type (TREE_TYPE (t2)));
6299 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6300 /* [expr.const.cast]
6302 Casting from an rvalue of type "pointer to data member of X
6303 of type T1" to the type "pointer to data member of Y of type
6304 T2" casts away constness if a cast from an rvalue of type
6305 "pointer to T1" to the type "pointer to T2" casts away
6307 return casts_away_constness
6308 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6309 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6311 /* Casting away constness is only something that makes sense for
6312 pointer or reference types. */
6313 if (TREE_CODE (t1) != POINTER_TYPE
6314 || TREE_CODE (t2) != POINTER_TYPE)
6317 /* Top-level qualifiers don't matter. */
6318 t1 = TYPE_MAIN_VARIANT (t1);
6319 t2 = TYPE_MAIN_VARIANT (t2);
6320 casts_away_constness_r (&t1, &t2);
6321 if (!can_convert (t2, t1))
6327 /* If T is a REFERENCE_TYPE return the type to which T refers.
6328 Otherwise, return T itself. */
6331 non_reference (tree t)
6333 if (TREE_CODE (t) == REFERENCE_TYPE)