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| author | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
|---|---|---|
| committer | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
| commit | 554fd8c5195424bdbcabf5de30fdc183aba391bd (patch) | |
| tree | 976dc5ab7fddf506dadce60ae936f43f58787092 /gcc/cp/typeck.c | |
| download | cbb-gcc-4.6.4-upstream.tar.bz2 cbb-gcc-4.6.4-upstream.tar.xz | |
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Diffstat (limited to 'gcc/cp/typeck.c')
| -rw-r--r-- | gcc/cp/typeck.c | 8293 |
1 files changed, 8293 insertions, 0 deletions
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c new file mode 100644 index 000000000..b2a08a3b9 --- /dev/null +++ b/gcc/cp/typeck.c @@ -0,0 +1,8293 @@ +/* Build expressions with type checking for C++ compiler. + Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, + 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 + Free Software Foundation, Inc. + Hacked by Michael Tiemann (tiemann@cygnus.com) + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 3, or (at your option) +any later version. + +GCC is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +<http://www.gnu.org/licenses/>. */ + + +/* This file is part of the C++ front end. + It contains routines to build C++ expressions given their operands, + including computing the types of the result, C and C++ specific error + checks, and some optimization. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "tree.h" +#include "cp-tree.h" +#include "flags.h" +#include "output.h" +#include "diagnostic.h" +#include "intl.h" +#include "target.h" +#include "convert.h" +#include "c-family/c-common.h" +#include "c-family/c-objc.h" +#include "params.h" + +static tree pfn_from_ptrmemfunc (tree); +static tree delta_from_ptrmemfunc (tree); +static tree convert_for_assignment (tree, tree, impl_conv_rhs, tree, int, + tsubst_flags_t, int); +static tree cp_pointer_int_sum (enum tree_code, tree, tree); +static tree rationalize_conditional_expr (enum tree_code, tree, + tsubst_flags_t); +static int comp_ptr_ttypes_real (tree, tree, int); +static bool comp_except_types (tree, tree, bool); +static bool comp_array_types (const_tree, const_tree, bool); +static tree pointer_diff (tree, tree, tree); +static tree get_delta_difference (tree, tree, bool, bool, tsubst_flags_t); +static void casts_away_constness_r (tree *, tree *); +static bool casts_away_constness (tree, tree); +static void maybe_warn_about_returning_address_of_local (tree); +static tree lookup_destructor (tree, tree, tree); +static void warn_args_num (location_t, tree, bool); +static int convert_arguments (tree, VEC(tree,gc) **, tree, int, + tsubst_flags_t); + +/* Do `exp = require_complete_type (exp);' to make sure exp + does not have an incomplete type. (That includes void types.) + Returns error_mark_node if the VALUE does not have + complete type when this function returns. */ + +tree +require_complete_type_sfinae (tree value, tsubst_flags_t complain) +{ + tree type; + + if (processing_template_decl || value == error_mark_node) + return value; + + if (TREE_CODE (value) == OVERLOAD) + type = unknown_type_node; + else + type = TREE_TYPE (value); + + if (type == error_mark_node) + return error_mark_node; + + /* First, detect a valid value with a complete type. */ + if (COMPLETE_TYPE_P (type)) + return value; + + if (complete_type_or_maybe_complain (type, value, complain)) + return value; + else + return error_mark_node; +} + +tree +require_complete_type (tree value) +{ + return require_complete_type_sfinae (value, tf_warning_or_error); +} + +/* Try to complete TYPE, if it is incomplete. For example, if TYPE is + a template instantiation, do the instantiation. Returns TYPE, + whether or not it could be completed, unless something goes + horribly wrong, in which case the error_mark_node is returned. */ + +tree +complete_type (tree type) +{ + if (type == NULL_TREE) + /* Rather than crash, we return something sure to cause an error + at some point. */ + return error_mark_node; + + if (type == error_mark_node || COMPLETE_TYPE_P (type)) + ; + else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type)) + { + tree t = complete_type (TREE_TYPE (type)); + unsigned int needs_constructing, has_nontrivial_dtor; + if (COMPLETE_TYPE_P (t) && !dependent_type_p (type)) + layout_type (type); + needs_constructing + = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t)); + has_nontrivial_dtor + = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t)); + for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t)) + { + TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing; + TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor; + } + } + else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type)) + instantiate_class_template (TYPE_MAIN_VARIANT (type)); + + return type; +} + +/* Like complete_type, but issue an error if the TYPE cannot be completed. + VALUE is used for informative diagnostics. + Returns NULL_TREE if the type cannot be made complete. */ + +tree +complete_type_or_maybe_complain (tree type, tree value, tsubst_flags_t complain) +{ + type = complete_type (type); + if (type == error_mark_node) + /* We already issued an error. */ + return NULL_TREE; + else if (!COMPLETE_TYPE_P (type)) + { + if (complain & tf_error) + cxx_incomplete_type_diagnostic (value, type, DK_ERROR); + return NULL_TREE; + } + else + return type; +} + +tree +complete_type_or_else (tree type, tree value) +{ + return complete_type_or_maybe_complain (type, value, tf_warning_or_error); +} + +/* Return truthvalue of whether type of EXP is instantiated. */ + +int +type_unknown_p (const_tree exp) +{ + return (TREE_CODE (exp) == TREE_LIST + || TREE_TYPE (exp) == unknown_type_node); +} + + +/* Return the common type of two parameter lists. + We assume that comptypes has already been done and returned 1; + if that isn't so, this may crash. + + As an optimization, free the space we allocate if the parameter + lists are already common. */ + +static tree +commonparms (tree p1, tree p2) +{ + tree oldargs = p1, newargs, n; + int i, len; + int any_change = 0; + + len = list_length (p1); + newargs = tree_last (p1); + + if (newargs == void_list_node) + i = 1; + else + { + i = 0; + newargs = 0; + } + + for (; i < len; i++) + newargs = tree_cons (NULL_TREE, NULL_TREE, newargs); + + n = newargs; + + for (i = 0; p1; + p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++) + { + if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2)) + { + TREE_PURPOSE (n) = TREE_PURPOSE (p1); + any_change = 1; + } + else if (! TREE_PURPOSE (p1)) + { + if (TREE_PURPOSE (p2)) + { + TREE_PURPOSE (n) = TREE_PURPOSE (p2); + any_change = 1; + } + } + else + { + if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2))) + any_change = 1; + TREE_PURPOSE (n) = TREE_PURPOSE (p2); + } + if (TREE_VALUE (p1) != TREE_VALUE (p2)) + { + any_change = 1; + TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2)); + } + else + TREE_VALUE (n) = TREE_VALUE (p1); + } + if (! any_change) + return oldargs; + + return newargs; +} + +/* Given a type, perhaps copied for a typedef, + find the "original" version of it. */ +static tree +original_type (tree t) +{ + int quals = cp_type_quals (t); + while (t != error_mark_node + && TYPE_NAME (t) != NULL_TREE) + { + tree x = TYPE_NAME (t); + if (TREE_CODE (x) != TYPE_DECL) + break; + x = DECL_ORIGINAL_TYPE (x); + if (x == NULL_TREE) + break; + t = x; + } + return cp_build_qualified_type (t, quals); +} + +/* Return the common type for two arithmetic types T1 and T2 under the + usual arithmetic conversions. The default conversions have already + been applied, and enumerated types converted to their compatible + integer types. */ + +static tree +cp_common_type (tree t1, tree t2) +{ + enum tree_code code1 = TREE_CODE (t1); + enum tree_code code2 = TREE_CODE (t2); + tree attributes; + + + /* In what follows, we slightly generalize the rules given in [expr] so + as to deal with `long long' and `complex'. First, merge the + attributes. */ + attributes = (*targetm.merge_type_attributes) (t1, t2); + + if (SCOPED_ENUM_P (t1) || SCOPED_ENUM_P (t2)) + { + if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2)) + return build_type_attribute_variant (t1, attributes); + else + return NULL_TREE; + } + + /* FIXME: Attributes. */ + gcc_assert (ARITHMETIC_TYPE_P (t1) + || TREE_CODE (t1) == VECTOR_TYPE + || UNSCOPED_ENUM_P (t1)); + gcc_assert (ARITHMETIC_TYPE_P (t2) + || TREE_CODE (t2) == VECTOR_TYPE + || UNSCOPED_ENUM_P (t2)); + + /* If one type is complex, form the common type of the non-complex + components, then make that complex. Use T1 or T2 if it is the + required type. */ + if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE) + { + tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1; + tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2; + tree subtype + = type_after_usual_arithmetic_conversions (subtype1, subtype2); + + if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype) + return build_type_attribute_variant (t1, attributes); + else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype) + return build_type_attribute_variant (t2, attributes); + else + return build_type_attribute_variant (build_complex_type (subtype), + attributes); + } + + if (code1 == VECTOR_TYPE) + { + /* When we get here we should have two vectors of the same size. + Just prefer the unsigned one if present. */ + if (TYPE_UNSIGNED (t1)) + return build_type_attribute_variant (t1, attributes); + else + return build_type_attribute_variant (t2, attributes); + } + + /* If only one is real, use it as the result. */ + if (code1 == REAL_TYPE && code2 != REAL_TYPE) + return build_type_attribute_variant (t1, attributes); + if (code2 == REAL_TYPE && code1 != REAL_TYPE) + return build_type_attribute_variant (t2, attributes); + + /* Both real or both integers; use the one with greater precision. */ + if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2)) + return build_type_attribute_variant (t1, attributes); + else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1)) + return build_type_attribute_variant (t2, attributes); + + /* The types are the same; no need to do anything fancy. */ + if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2)) + return build_type_attribute_variant (t1, attributes); + + if (code1 != REAL_TYPE) + { + /* If one is unsigned long long, then convert the other to unsigned + long long. */ + if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node) + || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node)) + return build_type_attribute_variant (long_long_unsigned_type_node, + attributes); + /* If one is a long long, and the other is an unsigned long, and + long long can represent all the values of an unsigned long, then + convert to a long long. Otherwise, convert to an unsigned long + long. Otherwise, if either operand is long long, convert the + other to long long. + + Since we're here, we know the TYPE_PRECISION is the same; + therefore converting to long long cannot represent all the values + of an unsigned long, so we choose unsigned long long in that + case. */ + if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node) + || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node)) + { + tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2)) + ? long_long_unsigned_type_node + : long_long_integer_type_node); + return build_type_attribute_variant (t, attributes); + } + if (int128_integer_type_node != NULL_TREE + && (same_type_p (TYPE_MAIN_VARIANT (t1), + int128_integer_type_node) + || same_type_p (TYPE_MAIN_VARIANT (t2), + int128_integer_type_node))) + { + tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2)) + ? int128_unsigned_type_node + : int128_integer_type_node); + return build_type_attribute_variant (t, attributes); + } + + /* Go through the same procedure, but for longs. */ + if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node) + || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node)) + return build_type_attribute_variant (long_unsigned_type_node, + attributes); + if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node) + || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node)) + { + tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2)) + ? long_unsigned_type_node : long_integer_type_node); + return build_type_attribute_variant (t, attributes); + } + /* Otherwise prefer the unsigned one. */ + if (TYPE_UNSIGNED (t1)) + return build_type_attribute_variant (t1, attributes); + else + return build_type_attribute_variant (t2, attributes); + } + else + { + if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node) + || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node)) + return build_type_attribute_variant (long_double_type_node, + attributes); + if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node) + || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node)) + return build_type_attribute_variant (double_type_node, + attributes); + if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node) + || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node)) + return build_type_attribute_variant (float_type_node, + attributes); + + /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of + the standard C++ floating-point types. Logic earlier in this + function has already eliminated the possibility that + TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no + compelling reason to choose one or the other. */ + return build_type_attribute_variant (t1, attributes); + } +} + +/* T1 and T2 are arithmetic or enumeration types. Return the type + that will result from the "usual arithmetic conversions" on T1 and + T2 as described in [expr]. */ + +tree +type_after_usual_arithmetic_conversions (tree t1, tree t2) +{ + gcc_assert (ARITHMETIC_TYPE_P (t1) + || TREE_CODE (t1) == VECTOR_TYPE + || UNSCOPED_ENUM_P (t1)); + gcc_assert (ARITHMETIC_TYPE_P (t2) + || TREE_CODE (t2) == VECTOR_TYPE + || UNSCOPED_ENUM_P (t2)); + + /* Perform the integral promotions. We do not promote real types here. */ + if (INTEGRAL_OR_ENUMERATION_TYPE_P (t1) + && INTEGRAL_OR_ENUMERATION_TYPE_P (t2)) + { + t1 = type_promotes_to (t1); + t2 = type_promotes_to (t2); + } + + return cp_common_type (t1, t2); +} + +static void +composite_pointer_error (diagnostic_t kind, tree t1, tree t2, + composite_pointer_operation operation) +{ + switch (operation) + { + case CPO_COMPARISON: + emit_diagnostic (kind, input_location, 0, + "comparison between " + "distinct pointer types %qT and %qT lacks a cast", + t1, t2); + break; + case CPO_CONVERSION: + emit_diagnostic (kind, input_location, 0, + "conversion between " + "distinct pointer types %qT and %qT lacks a cast", + t1, t2); + break; + case CPO_CONDITIONAL_EXPR: + emit_diagnostic (kind, input_location, 0, + "conditional expression between " + "distinct pointer types %qT and %qT lacks a cast", + t1, t2); + break; + default: + gcc_unreachable (); + } +} + +/* Subroutine of composite_pointer_type to implement the recursive + case. See that function for documentation of the parameters. */ + +static tree +composite_pointer_type_r (tree t1, tree t2, + composite_pointer_operation operation, + tsubst_flags_t complain) +{ + tree pointee1; + tree pointee2; + tree result_type; + tree attributes; + + /* Determine the types pointed to by T1 and T2. */ + if (TREE_CODE (t1) == POINTER_TYPE) + { + pointee1 = TREE_TYPE (t1); + pointee2 = TREE_TYPE (t2); + } + else + { + pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1); + pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2); + } + + /* [expr.rel] + + Otherwise, the composite pointer type is a pointer type + similar (_conv.qual_) to the type of one of the operands, + with a cv-qualification signature (_conv.qual_) that is the + union of the cv-qualification signatures of the operand + types. */ + if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2)) + result_type = pointee1; + else if ((TREE_CODE (pointee1) == POINTER_TYPE + && TREE_CODE (pointee2) == POINTER_TYPE) + || (TYPE_PTR_TO_MEMBER_P (pointee1) + && TYPE_PTR_TO_MEMBER_P (pointee2))) + result_type = composite_pointer_type_r (pointee1, pointee2, operation, + complain); + else + { + if (complain & tf_error) + composite_pointer_error (DK_PERMERROR, t1, t2, operation); + else + return error_mark_node; + result_type = void_type_node; + } + result_type = cp_build_qualified_type (result_type, + (cp_type_quals (pointee1) + | cp_type_quals (pointee2))); + /* If the original types were pointers to members, so is the + result. */ + if (TYPE_PTR_TO_MEMBER_P (t1)) + { + if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1), + TYPE_PTRMEM_CLASS_TYPE (t2))) + { + if (complain & tf_error) + composite_pointer_error (DK_PERMERROR, t1, t2, operation); + else + return error_mark_node; + } + result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1), + result_type); + } + else + result_type = build_pointer_type (result_type); + + /* Merge the attributes. */ + attributes = (*targetm.merge_type_attributes) (t1, t2); + return build_type_attribute_variant (result_type, attributes); +} + +/* Return the composite pointer type (see [expr.rel]) for T1 and T2. + ARG1 and ARG2 are the values with those types. The OPERATION is to + describe the operation between the pointer types, + in case an error occurs. + + This routine also implements the computation of a common type for + pointers-to-members as per [expr.eq]. */ + +tree +composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2, + composite_pointer_operation operation, + tsubst_flags_t complain) +{ + tree class1; + tree class2; + + /* [expr.rel] + + If one operand is a null pointer constant, the composite pointer + type is the type of the other operand. */ + if (null_ptr_cst_p (arg1)) + return t2; + if (null_ptr_cst_p (arg2)) + return t1; + + /* We have: + + [expr.rel] + + If one of the operands has type "pointer to cv1 void*", then + the other has type "pointer to cv2T", and the composite pointer + type is "pointer to cv12 void", where cv12 is the union of cv1 + and cv2. + + If either type is a pointer to void, make sure it is T1. */ + if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2))) + { + tree t; + t = t1; + t1 = t2; + t2 = t; + } + + /* Now, if T1 is a pointer to void, merge the qualifiers. */ + if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1))) + { + tree attributes; + tree result_type; + + if (TYPE_PTRFN_P (t2) && (complain & tf_error)) + { + switch (operation) + { + case CPO_COMPARISON: + pedwarn (input_location, OPT_pedantic, + "ISO C++ forbids comparison between " + "pointer of type %<void *%> and pointer-to-function"); + break; + case CPO_CONVERSION: + pedwarn (input_location, OPT_pedantic, + "ISO C++ forbids conversion between " + "pointer of type %<void *%> and pointer-to-function"); + break; + case CPO_CONDITIONAL_EXPR: + pedwarn (input_location, OPT_pedantic, + "ISO C++ forbids conditional expression between " + "pointer of type %<void *%> and pointer-to-function"); + break; + default: + gcc_unreachable (); + } + } + result_type + = cp_build_qualified_type (void_type_node, + (cp_type_quals (TREE_TYPE (t1)) + | cp_type_quals (TREE_TYPE (t2)))); + result_type = build_pointer_type (result_type); + /* Merge the attributes. */ + attributes = (*targetm.merge_type_attributes) (t1, t2); + return build_type_attribute_variant (result_type, attributes); + } + + if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE + && TREE_CODE (t2) == POINTER_TYPE) + { + if (objc_have_common_type (t1, t2, -3, NULL_TREE)) + return objc_common_type (t1, t2); + } + + /* [expr.eq] permits the application of a pointer conversion to + bring the pointers to a common type. */ + if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE + && CLASS_TYPE_P (TREE_TYPE (t1)) + && CLASS_TYPE_P (TREE_TYPE (t2)) + && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1), + TREE_TYPE (t2))) + { + class1 = TREE_TYPE (t1); + class2 = TREE_TYPE (t2); + + if (DERIVED_FROM_P (class1, class2)) + t2 = (build_pointer_type + (cp_build_qualified_type (class1, cp_type_quals (class2)))); + else if (DERIVED_FROM_P (class2, class1)) + t1 = (build_pointer_type + (cp_build_qualified_type (class2, cp_type_quals (class1)))); + else + { + if (complain & tf_error) + composite_pointer_error (DK_ERROR, t1, t2, operation); + return error_mark_node; + } + } + /* [expr.eq] permits the application of a pointer-to-member + conversion to change the class type of one of the types. */ + else if (TYPE_PTR_TO_MEMBER_P (t1) + && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1), + TYPE_PTRMEM_CLASS_TYPE (t2))) + { + class1 = TYPE_PTRMEM_CLASS_TYPE (t1); + class2 = TYPE_PTRMEM_CLASS_TYPE (t2); + + if (DERIVED_FROM_P (class1, class2)) + t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1)); + else if (DERIVED_FROM_P (class2, class1)) + t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2)); + else + { + if (complain & tf_error) + switch (operation) + { + case CPO_COMPARISON: + error ("comparison between distinct " + "pointer-to-member types %qT and %qT lacks a cast", + t1, t2); + break; + case CPO_CONVERSION: + error ("conversion between distinct " + "pointer-to-member types %qT and %qT lacks a cast", + t1, t2); + break; + case CPO_CONDITIONAL_EXPR: + error ("conditional expression between distinct " + "pointer-to-member types %qT and %qT lacks a cast", + t1, t2); + break; + default: + gcc_unreachable (); + } + return error_mark_node; + } + } + + return composite_pointer_type_r (t1, t2, operation, complain); +} + +/* Return the merged type of two types. + We assume that comptypes has already been done and returned 1; + if that isn't so, this may crash. + + This just combines attributes and default arguments; any other + differences would cause the two types to compare unalike. */ + +tree +merge_types (tree t1, tree t2) +{ + enum tree_code code1; + enum tree_code code2; + tree attributes; + + /* Save time if the two types are the same. */ + if (t1 == t2) + return t1; + if (original_type (t1) == original_type (t2)) + return t1; + + /* If one type is nonsense, use the other. */ + if (t1 == error_mark_node) + return t2; + if (t2 == error_mark_node) + return t1; + + /* Merge the attributes. */ + attributes = (*targetm.merge_type_attributes) (t1, t2); + + if (TYPE_PTRMEMFUNC_P (t1)) + t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1); + if (TYPE_PTRMEMFUNC_P (t2)) + t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2); + + code1 = TREE_CODE (t1); + code2 = TREE_CODE (t2); + if (code1 != code2) + { + gcc_assert (code1 == TYPENAME_TYPE || code2 == TYPENAME_TYPE); + if (code1 == TYPENAME_TYPE) + { + t1 = resolve_typename_type (t1, /*only_current_p=*/true); + code1 = TREE_CODE (t1); + } + else + { + t2 = resolve_typename_type (t2, /*only_current_p=*/true); + code2 = TREE_CODE (t2); + } + } + + switch (code1) + { + case POINTER_TYPE: + case REFERENCE_TYPE: + /* For two pointers, do this recursively on the target type. */ + { + tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2)); + int quals = cp_type_quals (t1); + + if (code1 == POINTER_TYPE) + t1 = build_pointer_type (target); + else + t1 = cp_build_reference_type (target, TYPE_REF_IS_RVALUE (t1)); + t1 = build_type_attribute_variant (t1, attributes); + t1 = cp_build_qualified_type (t1, quals); + + if (TREE_CODE (target) == METHOD_TYPE) + t1 = build_ptrmemfunc_type (t1); + + return t1; + } + + case OFFSET_TYPE: + { + int quals; + tree pointee; + quals = cp_type_quals (t1); + pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1), + TYPE_PTRMEM_POINTED_TO_TYPE (t2)); + t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1), + pointee); + t1 = cp_build_qualified_type (t1, quals); + break; + } + + case ARRAY_TYPE: + { + tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2)); + /* Save space: see if the result is identical to one of the args. */ + if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1)) + return build_type_attribute_variant (t1, attributes); + if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2)) + return build_type_attribute_variant (t2, attributes); + /* Merge the element types, and have a size if either arg has one. */ + t1 = build_cplus_array_type + (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2)); + break; + } + + case FUNCTION_TYPE: + /* Function types: prefer the one that specified arg types. + If both do, merge the arg types. Also merge the return types. */ + { + tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2)); + tree p1 = TYPE_ARG_TYPES (t1); + tree p2 = TYPE_ARG_TYPES (t2); + tree parms; + tree rval, raises; + + /* Save space: see if the result is identical to one of the args. */ + if (valtype == TREE_TYPE (t1) && ! p2) + return cp_build_type_attribute_variant (t1, attributes); + if (valtype == TREE_TYPE (t2) && ! p1) + return cp_build_type_attribute_variant (t2, attributes); + + /* Simple way if one arg fails to specify argument types. */ + if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node) + parms = p2; + else if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node) + parms = p1; + else + parms = commonparms (p1, p2); + + rval = build_function_type (valtype, parms); + gcc_assert (type_memfn_quals (t1) == type_memfn_quals (t2)); + rval = apply_memfn_quals (rval, type_memfn_quals (t1)); + raises = merge_exception_specifiers (TYPE_RAISES_EXCEPTIONS (t1), + TYPE_RAISES_EXCEPTIONS (t2)); + t1 = build_exception_variant (rval, raises); + break; + } + + case METHOD_TYPE: + { + /* Get this value the long way, since TYPE_METHOD_BASETYPE + is just the main variant of this. */ + tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2))); + tree raises = merge_exception_specifiers (TYPE_RAISES_EXCEPTIONS (t1), + TYPE_RAISES_EXCEPTIONS (t2)); + tree t3; + + /* If this was a member function type, get back to the + original type of type member function (i.e., without + the class instance variable up front. */ + t1 = build_function_type (TREE_TYPE (t1), + TREE_CHAIN (TYPE_ARG_TYPES (t1))); + t2 = build_function_type (TREE_TYPE (t2), + TREE_CHAIN (TYPE_ARG_TYPES (t2))); + t3 = merge_types (t1, t2); + t3 = build_method_type_directly (basetype, TREE_TYPE (t3), + TYPE_ARG_TYPES (t3)); + t1 = build_exception_variant (t3, raises); + break; + } + + case TYPENAME_TYPE: + /* There is no need to merge attributes into a TYPENAME_TYPE. + When the type is instantiated it will have whatever + attributes result from the instantiation. */ + return t1; + + default:; + } + + if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes)) + return t1; + else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes)) + return t2; + else + return cp_build_type_attribute_variant (t1, attributes); +} + +/* Return the ARRAY_TYPE type without its domain. */ + +tree +strip_array_domain (tree type) +{ + tree t2; + gcc_assert (TREE_CODE (type) == ARRAY_TYPE); + if (TYPE_DOMAIN (type) == NULL_TREE) + return type; + t2 = build_cplus_array_type (TREE_TYPE (type), NULL_TREE); + return cp_build_type_attribute_variant (t2, TYPE_ATTRIBUTES (type)); +} + +/* Wrapper around cp_common_type that is used by c-common.c and other + front end optimizations that remove promotions. + + Return the common type for two arithmetic types T1 and T2 under the + usual arithmetic conversions. The default conversions have already + been applied, and enumerated types converted to their compatible + integer types. */ + +tree +common_type (tree t1, tree t2) +{ + /* If one type is nonsense, use the other */ + if (t1 == error_mark_node) + return t2; + if (t2 == error_mark_node) + return t1; + + return cp_common_type (t1, t2); +} + +/* Return the common type of two pointer types T1 and T2. This is the + type for the result of most arithmetic operations if the operands + have the given two types. + + We assume that comp_target_types has already been done and returned + nonzero; if that isn't so, this may crash. */ + +tree +common_pointer_type (tree t1, tree t2) +{ + gcc_assert ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2)) + || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2)) + || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2))); + + return composite_pointer_type (t1, t2, error_mark_node, error_mark_node, + CPO_CONVERSION, tf_warning_or_error); +} + +/* Compare two exception specifier types for exactness or subsetness, if + allowed. Returns false for mismatch, true for match (same, or + derived and !exact). + + [except.spec] "If a class X ... objects of class X or any class publicly + and unambiguously derived from X. Similarly, if a pointer type Y * ... + exceptions of type Y * or that are pointers to any type publicly and + unambiguously derived from Y. Otherwise a function only allows exceptions + that have the same type ..." + This does not mention cv qualifiers and is different to what throw + [except.throw] and catch [except.catch] will do. They will ignore the + top level cv qualifiers, and allow qualifiers in the pointer to class + example. + + We implement the letter of the standard. */ + +static bool +comp_except_types (tree a, tree b, bool exact) +{ + if (same_type_p (a, b)) + return true; + else if (!exact) + { + if (cp_type_quals (a) || cp_type_quals (b)) + return false; + + if (TREE_CODE (a) == POINTER_TYPE + && TREE_CODE (b) == POINTER_TYPE) + { + a = TREE_TYPE (a); + b = TREE_TYPE (b); + if (cp_type_quals (a) || cp_type_quals (b)) + return false; + } + + if (TREE_CODE (a) != RECORD_TYPE + || TREE_CODE (b) != RECORD_TYPE) + return false; + + if (PUBLICLY_UNIQUELY_DERIVED_P (a, b)) + return true; + } + return false; +} + +/* Return true if TYPE1 and TYPE2 are equivalent exception specifiers. + If EXACT is ce_derived, T2 can be stricter than T1 (according to 15.4/5). + If EXACT is ce_normal, the compatibility rules in 15.4/3 apply. + If EXACT is ce_exact, the specs must be exactly the same. Exception lists + are unordered, but we've already filtered out duplicates. Most lists will + be in order, we should try to make use of that. */ + +bool +comp_except_specs (const_tree t1, const_tree t2, int exact) +{ + const_tree probe; + const_tree base; + int length = 0; + + if (t1 == t2) + return true; + + /* First handle noexcept. */ + if (exact < ce_exact) + { + /* noexcept(false) is compatible with no exception-specification, + and stricter than any spec. */ + if (t1 == noexcept_false_spec) + return t2 == NULL_TREE || exact == ce_derived; + /* Even a derived noexcept(false) is compatible with no + exception-specification. */ + if (t2 == noexcept_false_spec) + return t1 == NULL_TREE; + + /* Otherwise, if we aren't looking for an exact match, noexcept is + equivalent to throw(). */ + if (t1 == noexcept_true_spec) + t1 = empty_except_spec; + if (t2 == noexcept_true_spec) + t2 = empty_except_spec; + } + + /* If any noexcept is left, it is only comparable to itself; + either we're looking for an exact match or we're redeclaring a + template with dependent noexcept. */ + if ((t1 && TREE_PURPOSE (t1)) + || (t2 && TREE_PURPOSE (t2))) + return (t1 && t2 + && cp_tree_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2))); + + if (t1 == NULL_TREE) /* T1 is ... */ + return t2 == NULL_TREE || exact == ce_derived; + if (!TREE_VALUE (t1)) /* t1 is EMPTY */ + return t2 != NULL_TREE && !TREE_VALUE (t2); + if (t2 == NULL_TREE) /* T2 is ... */ + return false; + if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */ + return exact == ce_derived; + + /* Neither set is ... or EMPTY, make sure each part of T2 is in T1. + Count how many we find, to determine exactness. For exact matching and + ordered T1, T2, this is an O(n) operation, otherwise its worst case is + O(nm). */ + for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2)) + { + for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe)) + { + tree a = TREE_VALUE (probe); + tree b = TREE_VALUE (t2); + + if (comp_except_types (a, b, exact)) + { + if (probe == base && exact > ce_derived) + base = TREE_CHAIN (probe); + length++; + break; + } + } + if (probe == NULL_TREE) + return false; + } + return exact == ce_derived || base == NULL_TREE || length == list_length (t1); +} + +/* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if + [] can match [size]. */ + +static bool +comp_array_types (const_tree t1, const_tree t2, bool allow_redeclaration) +{ + tree d1; + tree d2; + tree max1, max2; + + if (t1 == t2) + return true; + + /* The type of the array elements must be the same. */ + if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2))) + return false; + + d1 = TYPE_DOMAIN (t1); + d2 = TYPE_DOMAIN (t2); + + if (d1 == d2) + return true; + + /* If one of the arrays is dimensionless, and the other has a + dimension, they are of different types. However, it is valid to + write: + + extern int a[]; + int a[3]; + + by [basic.link]: + + declarations for an array object can specify + array types that differ by the presence or absence of a major + array bound (_dcl.array_). */ + if (!d1 || !d2) + return allow_redeclaration; + + /* Check that the dimensions are the same. */ + + if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2))) + return false; + max1 = TYPE_MAX_VALUE (d1); + max2 = TYPE_MAX_VALUE (d2); + if (processing_template_decl && !abi_version_at_least (2) + && !value_dependent_expression_p (max1) + && !value_dependent_expression_p (max2)) + { + /* With abi-1 we do not fold non-dependent array bounds, (and + consequently mangle them incorrectly). We must therefore + fold them here, to verify the domains have the same + value. */ + max1 = fold (max1); + max2 = fold (max2); + } + + if (!cp_tree_equal (max1, max2)) + return false; + + return true; +} + +/* Compare the relative position of T1 and T2 into their respective + template parameter list. + T1 and T2 must be template parameter types. + Return TRUE if T1 and T2 have the same position, FALSE otherwise. */ + +static bool +comp_template_parms_position (tree t1, tree t2) +{ + tree index1, index2; + gcc_assert (t1 && t2 + && TREE_CODE (t1) == TREE_CODE (t2) + && (TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM + || TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM + || TREE_CODE (t1) == TEMPLATE_TYPE_PARM)); + + index1 = TEMPLATE_TYPE_PARM_INDEX (TYPE_MAIN_VARIANT (t1)); + index2 = TEMPLATE_TYPE_PARM_INDEX (TYPE_MAIN_VARIANT (t2)); + + /* If T1 and T2 belong to template parm lists of different size, + let's assume they are different. */ + if (TEMPLATE_PARM_NUM_SIBLINGS (index1) + != TEMPLATE_PARM_NUM_SIBLINGS (index2)) + return false; + + /* Then compare their relative position. */ + if (TEMPLATE_PARM_IDX (index1) != TEMPLATE_PARM_IDX (index2) + || TEMPLATE_PARM_LEVEL (index1) != TEMPLATE_PARM_LEVEL (index2) + || (TEMPLATE_PARM_PARAMETER_PACK (index1) + != TEMPLATE_PARM_PARAMETER_PACK (index2))) + return false; + + return true; +} + +/* Subroutine in comptypes. */ + +static bool +structural_comptypes (tree t1, tree t2, int strict) +{ + if (t1 == t2) + return true; + + /* Suppress errors caused by previously reported errors. */ + if (t1 == error_mark_node || t2 == error_mark_node) + return false; + + gcc_assert (TYPE_P (t1) && TYPE_P (t2)); + + /* TYPENAME_TYPEs should be resolved if the qualifying scope is the + current instantiation. */ + if (TREE_CODE (t1) == TYPENAME_TYPE) + t1 = resolve_typename_type (t1, /*only_current_p=*/true); + + if (TREE_CODE (t2) == TYPENAME_TYPE) + t2 = resolve_typename_type (t2, /*only_current_p=*/true); + + if (TYPE_PTRMEMFUNC_P (t1)) + t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1); + if (TYPE_PTRMEMFUNC_P (t2)) + t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2); + + /* Different classes of types can't be compatible. */ + if (TREE_CODE (t1) != TREE_CODE (t2)) + return false; + + /* Qualifiers must match. For array types, we will check when we + recur on the array element types. */ + if (TREE_CODE (t1) != ARRAY_TYPE + && cp_type_quals (t1) != cp_type_quals (t2)) + return false; + if (TREE_CODE (t1) == FUNCTION_TYPE + && type_memfn_quals (t1) != type_memfn_quals (t2)) + return false; + if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2)) + return false; + + /* Allow for two different type nodes which have essentially the same + definition. Note that we already checked for equality of the type + qualifiers (just above). */ + + if (TREE_CODE (t1) != ARRAY_TYPE + && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2)) + return true; + + + /* Compare the types. Break out if they could be the same. */ + switch (TREE_CODE (t1)) + { + case VOID_TYPE: + case BOOLEAN_TYPE: + /* All void and bool types are the same. */ + break; + + case INTEGER_TYPE: + case FIXED_POINT_TYPE: + case REAL_TYPE: + /* With these nodes, we can't determine type equivalence by + looking at what is stored in the nodes themselves, because + two nodes might have different TYPE_MAIN_VARIANTs but still + represent the same type. For example, wchar_t and int could + have the same properties (TYPE_PRECISION, TYPE_MIN_VALUE, + TYPE_MAX_VALUE, etc.), but have different TYPE_MAIN_VARIANTs + and are distinct types. On the other hand, int and the + following typedef + + typedef int INT __attribute((may_alias)); + + have identical properties, different TYPE_MAIN_VARIANTs, but + represent the same type. The canonical type system keeps + track of equivalence in this case, so we fall back on it. */ + return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2); + + case TEMPLATE_TEMPLATE_PARM: + case BOUND_TEMPLATE_TEMPLATE_PARM: + if (!comp_template_parms_position (t1, t2)) + return false; + if (!comp_template_parms + (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)), + DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2)))) + return false; + if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM) + break; + /* Don't check inheritance. */ + strict = COMPARE_STRICT; + /* Fall through. */ + + case RECORD_TYPE: + case UNION_TYPE: + if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2) + && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2) + || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM) + && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2))) + break; + + if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2)) + break; + else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1)) + break; + + return false; + + case OFFSET_TYPE: + if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2), + strict & ~COMPARE_REDECLARATION)) + return false; + if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2))) + return false; + break; + + case REFERENCE_TYPE: + if (TYPE_REF_IS_RVALUE (t1) != TYPE_REF_IS_RVALUE (t2)) + return false; + /* fall through to checks for pointer types */ + + case POINTER_TYPE: + if (TYPE_MODE (t1) != TYPE_MODE (t2) + || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2) + || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2))) + return false; + break; + + case METHOD_TYPE: + case FUNCTION_TYPE: + if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2))) + return false; + if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2))) + return false; + break; + + case ARRAY_TYPE: + /* Target types must match incl. qualifiers. */ + if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION))) + return false; + break; + + case TEMPLATE_TYPE_PARM: + /* If T1 and T2 don't have the same relative position in their + template parameters set, they can't be equal. */ + if (!comp_template_parms_position (t1, t2)) + return false; + break; + + case TYPENAME_TYPE: + if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1), + TYPENAME_TYPE_FULLNAME (t2))) + return false; + /* Qualifiers don't matter on scopes. */ + if (!same_type_ignoring_top_level_qualifiers_p (TYPE_CONTEXT (t1), + TYPE_CONTEXT (t2))) + return false; + break; + + case UNBOUND_CLASS_TEMPLATE: + if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2))) + return false; + if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2))) + return false; + break; + + case COMPLEX_TYPE: + if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2))) + return false; + break; + + case VECTOR_TYPE: + if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2) + || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2))) + return false; + break; + + case TYPE_PACK_EXPANSION: + return same_type_p (PACK_EXPANSION_PATTERN (t1), + PACK_EXPANSION_PATTERN (t2)); + + case DECLTYPE_TYPE: + if (DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t1) + != DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t2) + || (DECLTYPE_FOR_LAMBDA_CAPTURE (t1) + != DECLTYPE_FOR_LAMBDA_CAPTURE (t2)) + || (DECLTYPE_FOR_LAMBDA_RETURN (t1) + != DECLTYPE_FOR_LAMBDA_RETURN (t2)) + || !cp_tree_equal (DECLTYPE_TYPE_EXPR (t1), + DECLTYPE_TYPE_EXPR (t2))) + return false; + break; + + default: + return false; + } + + /* If we get here, we know that from a target independent POV the + types are the same. Make sure the target attributes are also + the same. */ + return targetm.comp_type_attributes (t1, t2); +} + +/* Return true if T1 and T2 are related as allowed by STRICT. STRICT + is a bitwise-or of the COMPARE_* flags. */ + +bool +comptypes (tree t1, tree t2, int strict) +{ + if (strict == COMPARE_STRICT) + { + if (t1 == t2) + return true; + + if (t1 == error_mark_node || t2 == error_mark_node) + return false; + + if (TYPE_STRUCTURAL_EQUALITY_P (t1) || TYPE_STRUCTURAL_EQUALITY_P (t2)) + /* At least one of the types requires structural equality, so + perform a deep check. */ + return structural_comptypes (t1, t2, strict); + +#ifdef ENABLE_CHECKING + if (USE_CANONICAL_TYPES) + { + bool result = structural_comptypes (t1, t2, strict); + + if (result && TYPE_CANONICAL (t1) != TYPE_CANONICAL (t2)) + /* The two types are structurally equivalent, but their + canonical types were different. This is a failure of the + canonical type propagation code.*/ + internal_error + ("canonical types differ for identical types %T and %T", + t1, t2); + else if (!result && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2)) + /* Two types are structurally different, but the canonical + types are the same. This means we were over-eager in + assigning canonical types. */ + internal_error + ("same canonical type node for different types %T and %T", + t1, t2); + + return result; + } +#else + if (USE_CANONICAL_TYPES) + return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2); +#endif + else + return structural_comptypes (t1, t2, strict); + } + else if (strict == COMPARE_STRUCTURAL) + return structural_comptypes (t1, t2, COMPARE_STRICT); + else + return structural_comptypes (t1, t2, strict); +} + +/* Returns nonzero iff TYPE1 and TYPE2 are the same type, ignoring + top-level qualifiers. */ + +bool +same_type_ignoring_top_level_qualifiers_p (tree type1, tree type2) +{ + if (type1 == error_mark_node || type2 == error_mark_node) + return false; + + return same_type_p (TYPE_MAIN_VARIANT (type1), TYPE_MAIN_VARIANT (type2)); +} + +/* Returns 1 if TYPE1 is at least as qualified as TYPE2. */ + +bool +at_least_as_qualified_p (const_tree type1, const_tree type2) +{ + int q1 = cp_type_quals (type1); + int q2 = cp_type_quals (type2); + + /* All qualifiers for TYPE2 must also appear in TYPE1. */ + return (q1 & q2) == q2; +} + +/* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is + more cv-qualified that TYPE1, and 0 otherwise. */ + +int +comp_cv_qualification (const_tree type1, const_tree type2) +{ + int q1 = cp_type_quals (type1); + int q2 = cp_type_quals (type2); + + if (q1 == q2) + return 0; + + if ((q1 & q2) == q2) + return 1; + else if ((q1 & q2) == q1) + return -1; + + return 0; +} + +/* Returns 1 if the cv-qualification signature of TYPE1 is a proper + subset of the cv-qualification signature of TYPE2, and the types + are similar. Returns -1 if the other way 'round, and 0 otherwise. */ + +int +comp_cv_qual_signature (tree type1, tree type2) +{ + if (comp_ptr_ttypes_real (type2, type1, -1)) + return 1; + else if (comp_ptr_ttypes_real (type1, type2, -1)) + return -1; + else + return 0; +} + +/* Subroutines of `comptypes'. */ + +/* Return true if two parameter type lists PARMS1 and PARMS2 are + equivalent in the sense that functions with those parameter types + can have equivalent types. The two lists must be equivalent, + element by element. */ + +bool +compparms (const_tree parms1, const_tree parms2) +{ + const_tree t1, t2; + + /* An unspecified parmlist matches any specified parmlist + whose argument types don't need default promotions. */ + + for (t1 = parms1, t2 = parms2; + t1 || t2; + t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2)) + { + /* If one parmlist is shorter than the other, + they fail to match. */ + if (!t1 || !t2) + return false; + if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2))) + return false; + } + return true; +} + + +/* Process a sizeof or alignof expression where the operand is a + type. */ + +tree +cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain) +{ + tree value; + bool dependent_p; + + gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR); + if (type == error_mark_node) + return error_mark_node; + + type = non_reference (type); + if (TREE_CODE (type) == METHOD_TYPE) + { + if (complain) + pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith, + "invalid application of %qs to a member function", + operator_name_info[(int) op].name); + value = size_one_node; + } + + dependent_p = dependent_type_p (type); + if (!dependent_p) + complete_type (type); + if (dependent_p + /* VLA types will have a non-constant size. In the body of an + uninstantiated template, we don't need to try to compute the + value, because the sizeof expression is not an integral + constant expression in that case. And, if we do try to + compute the value, we'll likely end up with SAVE_EXPRs, which + the template substitution machinery does not expect to see. */ + || (processing_template_decl + && COMPLETE_TYPE_P (type) + && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)) + { + value = build_min (op, size_type_node, type); + TREE_READONLY (value) = 1; + return value; + } + + return c_sizeof_or_alignof_type (input_location, complete_type (type), + op == SIZEOF_EXPR, + complain); +} + +/* Return the size of the type, without producing any warnings for + types whose size cannot be taken. This routine should be used only + in some other routine that has already produced a diagnostic about + using the size of such a type. */ +tree +cxx_sizeof_nowarn (tree type) +{ + if (TREE_CODE (type) == FUNCTION_TYPE + || TREE_CODE (type) == VOID_TYPE + || TREE_CODE (type) == ERROR_MARK) + return size_one_node; + else if (!COMPLETE_TYPE_P (type)) + return size_zero_node; + else + return cxx_sizeof_or_alignof_type (type, SIZEOF_EXPR, false); +} + +/* Process a sizeof expression where the operand is an expression. */ + +static tree +cxx_sizeof_expr (tree e, tsubst_flags_t complain) +{ + if (e == error_mark_node) + return error_mark_node; + + if (processing_template_decl) + { + e = build_min (SIZEOF_EXPR, size_type_node, e); + TREE_SIDE_EFFECTS (e) = 0; + TREE_READONLY (e) = 1; + + return e; + } + + /* To get the size of a static data member declared as an array of + unknown bound, we need to instantiate it. */ + if (TREE_CODE (e) == VAR_DECL + && VAR_HAD_UNKNOWN_BOUND (e) + && DECL_TEMPLATE_INSTANTIATION (e)) + instantiate_decl (e, /*defer_ok*/true, /*expl_inst_mem*/false); + + e = mark_type_use (e); + + if (TREE_CODE (e) == COMPONENT_REF + && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL + && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1))) + { + if (complain & tf_error) + error ("invalid application of %<sizeof%> to a bit-field"); + else + return error_mark_node; + e = char_type_node; + } + else if (is_overloaded_fn (e)) + { + if (complain & tf_error) + permerror (input_location, "ISO C++ forbids applying %<sizeof%> to an expression of " + "function type"); + else + return error_mark_node; + e = char_type_node; + } + else if (type_unknown_p (e)) + { + if (complain & tf_error) + cxx_incomplete_type_error (e, TREE_TYPE (e)); + else + return error_mark_node; + e = char_type_node; + } + else + e = TREE_TYPE (e); + + return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, complain & tf_error); +} + +/* Implement the __alignof keyword: Return the minimum required + alignment of E, measured in bytes. For VAR_DECL's and + FIELD_DECL's return DECL_ALIGN (which can be set from an + "aligned" __attribute__ specification). */ + +static tree +cxx_alignof_expr (tree e, tsubst_flags_t complain) +{ + tree t; + + if (e == error_mark_node) + return error_mark_node; + + if (processing_template_decl) + { + e = build_min (ALIGNOF_EXPR, size_type_node, e); + TREE_SIDE_EFFECTS (e) = 0; + TREE_READONLY (e) = 1; + + return e; + } + + e = mark_type_use (e); + + if (TREE_CODE (e) == VAR_DECL) + t = size_int (DECL_ALIGN_UNIT (e)); + else if (TREE_CODE (e) == COMPONENT_REF + && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL + && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1))) + { + if (complain & tf_error) + error ("invalid application of %<__alignof%> to a bit-field"); + else + return error_mark_node; + t = size_one_node; + } + else if (TREE_CODE (e) == COMPONENT_REF + && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL) + t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1))); + else if (is_overloaded_fn (e)) + { + if (complain & tf_error) + permerror (input_location, "ISO C++ forbids applying %<__alignof%> to an expression of " + "function type"); + else + return error_mark_node; + if (TREE_CODE (e) == FUNCTION_DECL) + t = size_int (DECL_ALIGN_UNIT (e)); + else + t = size_one_node; + } + else if (type_unknown_p (e)) + { + if (complain & tf_error) + cxx_incomplete_type_error (e, TREE_TYPE (e)); + else + return error_mark_node; + t = size_one_node; + } + else + return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, + complain & tf_error); + + return fold_convert (size_type_node, t); +} + +/* Process a sizeof or alignof expression E with code OP where the operand + is an expression. */ + +tree +cxx_sizeof_or_alignof_expr (tree e, enum tree_code op, bool complain) +{ + if (op == SIZEOF_EXPR) + return cxx_sizeof_expr (e, complain? tf_warning_or_error : tf_none); + else + return cxx_alignof_expr (e, complain? tf_warning_or_error : tf_none); +} + +/* EXPR is being used in a context that is not a function call. + Enforce: + + [expr.ref] + + The expression can be used only as the left-hand operand of a + member function call. + + [expr.mptr.operator] + + If the result of .* or ->* is a function, then that result can be + used only as the operand for the function call operator (). + + by issuing an error message if appropriate. Returns true iff EXPR + violates these rules. */ + +bool +invalid_nonstatic_memfn_p (const_tree expr, tsubst_flags_t complain) +{ + if (expr && DECL_NONSTATIC_MEMBER_FUNCTION_P (expr)) + { + if (complain & tf_error) + error ("invalid use of non-static member function"); + return true; + } + return false; +} + +/* If EXP is a reference to a bitfield, and the type of EXP does not + match the declared type of the bitfield, return the declared type + of the bitfield. Otherwise, return NULL_TREE. */ + +tree +is_bitfield_expr_with_lowered_type (const_tree exp) +{ + switch (TREE_CODE (exp)) + { + case COND_EXPR: + if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1) + ? TREE_OPERAND (exp, 1) + : TREE_OPERAND (exp, 0))) + return NULL_TREE; + return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2)); + + case COMPOUND_EXPR: + return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)); + + case MODIFY_EXPR: + case SAVE_EXPR: + return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0)); + + case COMPONENT_REF: + { + tree field; + + field = TREE_OPERAND (exp, 1); + if (TREE_CODE (field) != FIELD_DECL || !DECL_BIT_FIELD_TYPE (field)) + return NULL_TREE; + if (same_type_ignoring_top_level_qualifiers_p + (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field))) + return NULL_TREE; + return DECL_BIT_FIELD_TYPE (field); + } + + CASE_CONVERT: + if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (exp, 0))) + == TYPE_MAIN_VARIANT (TREE_TYPE (exp))) + return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0)); + /* Fallthrough. */ + + default: + return NULL_TREE; + } +} + +/* Like is_bitfield_with_lowered_type, except that if EXP is not a + bitfield with a lowered type, the type of EXP is returned, rather + than NULL_TREE. */ + +tree +unlowered_expr_type (const_tree exp) +{ + tree type; + + type = is_bitfield_expr_with_lowered_type (exp); + if (!type) + type = TREE_TYPE (exp); + + return type; +} + +/* Perform the conversions in [expr] that apply when an lvalue appears + in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and + function-to-pointer conversions. In addition, manifest constants + are replaced by their values, and bitfield references are converted + to their declared types. Note that this function does not perform the + lvalue-to-rvalue conversion for class types. If you need that conversion + to for class types, then you probably need to use force_rvalue. + + Although the returned value is being used as an rvalue, this + function does not wrap the returned expression in a + NON_LVALUE_EXPR; the caller is expected to be mindful of the fact + that the return value is no longer an lvalue. */ + +tree +decay_conversion (tree exp) +{ + tree type; + enum tree_code code; + + type = TREE_TYPE (exp); + if (type == error_mark_node) + return error_mark_node; + + exp = mark_rvalue_use (exp); + + exp = resolve_nondeduced_context (exp); + if (type_unknown_p (exp)) + { + cxx_incomplete_type_error (exp, TREE_TYPE (exp)); + return error_mark_node; + } + + /* FIXME remove? at least need to remember that this isn't really a + constant expression if EXP isn't decl_constant_var_p, like with + C_MAYBE_CONST_EXPR. */ + exp = decl_constant_value (exp); + if (error_operand_p (exp)) + return error_mark_node; + + if (NULLPTR_TYPE_P (type) && !TREE_SIDE_EFFECTS (exp)) + return nullptr_node; + + /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue. + Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */ + code = TREE_CODE (type); + if (code == VOID_TYPE) + { + error ("void value not ignored as it ought to be"); + return error_mark_node; + } + if (invalid_nonstatic_memfn_p (exp, tf_warning_or_error)) + return error_mark_node; + if (code == FUNCTION_TYPE || is_overloaded_fn (exp)) + return cp_build_addr_expr (exp, tf_warning_or_error); + if (code == ARRAY_TYPE) + { + tree adr; + tree ptrtype; + + if (TREE_CODE (exp) == INDIRECT_REF) + return build_nop (build_pointer_type (TREE_TYPE (type)), + TREE_OPERAND (exp, 0)); + + if (TREE_CODE (exp) == COMPOUND_EXPR) + { + tree op1 = decay_conversion (TREE_OPERAND (exp, 1)); + return build2 (COMPOUND_EXPR, TREE_TYPE (op1), + TREE_OPERAND (exp, 0), op1); + } + + if (!lvalue_p (exp) + && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp))) + { + error ("invalid use of non-lvalue array"); + return error_mark_node; + } + + ptrtype = build_pointer_type (TREE_TYPE (type)); + + if (TREE_CODE (exp) == VAR_DECL) + { + if (!cxx_mark_addressable (exp)) + return error_mark_node; + adr = build_nop (ptrtype, build_address (exp)); + return adr; + } + /* This way is better for a COMPONENT_REF since it can + simplify the offset for a component. */ + adr = cp_build_addr_expr (exp, tf_warning_or_error); + return cp_convert (ptrtype, adr); + } + + /* If a bitfield is used in a context where integral promotion + applies, then the caller is expected to have used + default_conversion. That function promotes bitfields correctly + before calling this function. At this point, if we have a + bitfield referenced, we may assume that is not subject to + promotion, and that, therefore, the type of the resulting rvalue + is the declared type of the bitfield. */ + exp = convert_bitfield_to_declared_type (exp); + + /* We do not call rvalue() here because we do not want to wrap EXP + in a NON_LVALUE_EXPR. */ + + /* [basic.lval] + + Non-class rvalues always have cv-unqualified types. */ + type = TREE_TYPE (exp); + if (!CLASS_TYPE_P (type) && cv_qualified_p (type)) + exp = build_nop (cv_unqualified (type), exp); + + return exp; +} + +/* Perform preparatory conversions, as part of the "usual arithmetic + conversions". In particular, as per [expr]: + + Whenever an lvalue expression appears as an operand of an + operator that expects the rvalue for that operand, the + lvalue-to-rvalue, array-to-pointer, or function-to-pointer + standard conversions are applied to convert the expression to an + rvalue. + + In addition, we perform integral promotions here, as those are + applied to both operands to a binary operator before determining + what additional conversions should apply. */ + +tree +default_conversion (tree exp) +{ + /* Check for target-specific promotions. */ + tree promoted_type = targetm.promoted_type (TREE_TYPE (exp)); + if (promoted_type) + exp = cp_convert (promoted_type, exp); + /* Perform the integral promotions first so that bitfield + expressions (which may promote to "int", even if the bitfield is + declared "unsigned") are promoted correctly. */ + else if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (TREE_TYPE (exp))) + exp = perform_integral_promotions (exp); + /* Perform the other conversions. */ + exp = decay_conversion (exp); + + return exp; +} + +/* EXPR is an expression with an integral or enumeration type. + Perform the integral promotions in [conv.prom], and return the + converted value. */ + +tree +perform_integral_promotions (tree expr) +{ + tree type; + tree promoted_type; + + expr = mark_rvalue_use (expr); + + /* [conv.prom] + + If the bitfield has an enumerated type, it is treated as any + other value of that type for promotion purposes. */ + type = is_bitfield_expr_with_lowered_type (expr); + if (!type || TREE_CODE (type) != ENUMERAL_TYPE) + type = TREE_TYPE (expr); + gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type)); + /* Scoped enums don't promote. */ + if (SCOPED_ENUM_P (type)) + return expr; + promoted_type = type_promotes_to (type); + if (type != promoted_type) + expr = cp_convert (promoted_type, expr); + return expr; +} + +/* Returns nonzero iff exp is a STRING_CST or the result of applying + decay_conversion to one. */ + +int +string_conv_p (const_tree totype, const_tree exp, int warn) +{ + tree t; + + if (TREE_CODE (totype) != POINTER_TYPE) + return 0; + + t = TREE_TYPE (totype); + if (!same_type_p (t, char_type_node) + && !same_type_p (t, char16_type_node) + && !same_type_p (t, char32_type_node) + && !same_type_p (t, wchar_type_node)) + return 0; + + if (TREE_CODE (exp) == STRING_CST) + { + /* Make sure that we don't try to convert between char and wide chars. */ + if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t)) + return 0; + } + else + { + /* Is this a string constant which has decayed to 'const char *'? */ + t = build_pointer_type (cp_build_qualified_type (t, TYPE_QUAL_CONST)); + if (!same_type_p (TREE_TYPE (exp), t)) + return 0; + STRIP_NOPS (exp); + if (TREE_CODE (exp) != ADDR_EXPR + || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST) + return 0; + } + + /* This warning is not very useful, as it complains about printf. */ + if (warn) + warning (OPT_Wwrite_strings, + "deprecated conversion from string constant to %qT", + totype); + + return 1; +} + +/* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we + can, for example, use as an lvalue. This code used to be in + unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c' + expressions, where we're dealing with aggregates. But now it's again only + called from unary_complex_lvalue. The case (in particular) that led to + this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd + get it there. */ + +static tree +rationalize_conditional_expr (enum tree_code code, tree t, + tsubst_flags_t complain) +{ + /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that + the first operand is always the one to be used if both operands + are equal, so we know what conditional expression this used to be. */ + if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR) + { + tree op0 = TREE_OPERAND (t, 0); + tree op1 = TREE_OPERAND (t, 1); + + /* The following code is incorrect if either operand side-effects. */ + gcc_assert (!TREE_SIDE_EFFECTS (op0) + && !TREE_SIDE_EFFECTS (op1)); + return + build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR + ? LE_EXPR : GE_EXPR), + op0, TREE_CODE (op0), + op1, TREE_CODE (op1), + /*overloaded_p=*/NULL, + complain), + cp_build_unary_op (code, op0, 0, complain), + cp_build_unary_op (code, op1, 0, complain), + complain); + } + + return + build_conditional_expr (TREE_OPERAND (t, 0), + cp_build_unary_op (code, TREE_OPERAND (t, 1), 0, + complain), + cp_build_unary_op (code, TREE_OPERAND (t, 2), 0, + complain), + complain); +} + +/* Given the TYPE of an anonymous union field inside T, return the + FIELD_DECL for the field. If not found return NULL_TREE. Because + anonymous unions can nest, we must also search all anonymous unions + that are directly reachable. */ + +tree +lookup_anon_field (tree t, tree type) +{ + tree field; + + for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field)) + { + if (TREE_STATIC (field)) + continue; + if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field)) + continue; + + /* If we find it directly, return the field. */ + if (DECL_NAME (field) == NULL_TREE + && type == TYPE_MAIN_VARIANT (TREE_TYPE (field))) + { + return field; + } + + /* Otherwise, it could be nested, search harder. */ + if (DECL_NAME (field) == NULL_TREE + && ANON_AGGR_TYPE_P (TREE_TYPE (field))) + { + tree subfield = lookup_anon_field (TREE_TYPE (field), type); + if (subfield) + return subfield; + } + } + return NULL_TREE; +} + +/* Build an expression representing OBJECT.MEMBER. OBJECT is an + expression; MEMBER is a DECL or baselink. If ACCESS_PATH is + non-NULL, it indicates the path to the base used to name MEMBER. + If PRESERVE_REFERENCE is true, the expression returned will have + REFERENCE_TYPE if the MEMBER does. Otherwise, the expression + returned will have the type referred to by the reference. + + This function does not perform access control; that is either done + earlier by the parser when the name of MEMBER is resolved to MEMBER + itself, or later when overload resolution selects one of the + functions indicated by MEMBER. */ + +tree +build_class_member_access_expr (tree object, tree member, + tree access_path, bool preserve_reference, + tsubst_flags_t complain) +{ + tree object_type; + tree member_scope; + tree result = NULL_TREE; + + if (error_operand_p (object) || error_operand_p (member)) + return error_mark_node; + + gcc_assert (DECL_P (member) || BASELINK_P (member)); + + /* [expr.ref] + + The type of the first expression shall be "class object" (of a + complete type). */ + object_type = TREE_TYPE (object); + if (!currently_open_class (object_type) + && !complete_type_or_maybe_complain (object_type, object, complain)) + return error_mark_node; + if (!CLASS_TYPE_P (object_type)) + { + if (complain & tf_error) + error ("request for member %qD in %qE, which is of non-class type %qT", + member, object, object_type); + return error_mark_node; + } + + /* The standard does not seem to actually say that MEMBER must be a + member of OBJECT_TYPE. However, that is clearly what is + intended. */ + if (DECL_P (member)) + { + member_scope = DECL_CLASS_CONTEXT (member); + mark_used (member); + if (TREE_DEPRECATED (member)) + warn_deprecated_use (member, NULL_TREE); + } + else + member_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (member)); + /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will + presently be the anonymous union. Go outwards until we find a + type related to OBJECT_TYPE. */ + while (ANON_AGGR_TYPE_P (member_scope) + && !same_type_ignoring_top_level_qualifiers_p (member_scope, + object_type)) + member_scope = TYPE_CONTEXT (member_scope); + if (!member_scope || !DERIVED_FROM_P (member_scope, object_type)) + { + if (complain & tf_error) + { + if (TREE_CODE (member) == FIELD_DECL) + error ("invalid use of nonstatic data member %qE", member); + else + error ("%qD is not a member of %qT", member, object_type); + } + return error_mark_node; + } + + /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into + `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue + in the front end; only _DECLs and _REFs are lvalues in the back end. */ + { + tree temp = unary_complex_lvalue (ADDR_EXPR, object); + if (temp) + object = cp_build_indirect_ref (temp, RO_NULL, complain); + } + + /* In [expr.ref], there is an explicit list of the valid choices for + MEMBER. We check for each of those cases here. */ + if (TREE_CODE (member) == VAR_DECL) + { + /* A static data member. */ + result = member; + mark_exp_read (object); + /* If OBJECT has side-effects, they are supposed to occur. */ + if (TREE_SIDE_EFFECTS (object)) + result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result); + } + else if (TREE_CODE (member) == FIELD_DECL) + { + /* A non-static data member. */ + bool null_object_p; + int type_quals; + tree member_type; + + null_object_p = (TREE_CODE (object) == INDIRECT_REF + && integer_zerop (TREE_OPERAND (object, 0))); + + /* Convert OBJECT to the type of MEMBER. */ + if (!same_type_p (TYPE_MAIN_VARIANT (object_type), + TYPE_MAIN_VARIANT (member_scope))) + { + tree binfo; + base_kind kind; + + binfo = lookup_base (access_path ? access_path : object_type, + member_scope, ba_unique, &kind); + if (binfo == error_mark_node) + return error_mark_node; + + /* It is invalid to try to get to a virtual base of a + NULL object. The most common cause is invalid use of + offsetof macro. */ + if (null_object_p && kind == bk_via_virtual) + { + if (complain & tf_error) + { + error ("invalid access to non-static data member %qD of " + "NULL object", + member); + error ("(perhaps the %<offsetof%> macro was used incorrectly)"); + } + return error_mark_node; + } + + /* Convert to the base. */ + object = build_base_path (PLUS_EXPR, object, binfo, + /*nonnull=*/1); + /* If we found the base successfully then we should be able + to convert to it successfully. */ + gcc_assert (object != error_mark_node); + } + + /* Complain about other invalid uses of offsetof, even though they will + give the right answer. Note that we complain whether or not they + actually used the offsetof macro, since there's no way to know at this + point. So we just give a warning, instead of a pedwarn. */ + /* Do not produce this warning for base class field references, because + we know for a fact that didn't come from offsetof. This does occur + in various testsuite cases where a null object is passed where a + vtable access is required. */ + if (null_object_p && warn_invalid_offsetof + && CLASSTYPE_NON_STD_LAYOUT (object_type) + && !DECL_FIELD_IS_BASE (member) + && cp_unevaluated_operand == 0 + && (complain & tf_warning)) + { + warning (OPT_Winvalid_offsetof, + "invalid access to non-static data member %qD " + " of NULL object", member); + warning (OPT_Winvalid_offsetof, + "(perhaps the %<offsetof%> macro was used incorrectly)"); + } + + /* If MEMBER is from an anonymous aggregate, we have converted + OBJECT so that it refers to the class containing the + anonymous union. Generate a reference to the anonymous union + itself, and recur to find MEMBER. */ + if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member)) + /* When this code is called from build_field_call, the + object already has the type of the anonymous union. + That is because the COMPONENT_REF was already + constructed, and was then disassembled before calling + build_field_call. After the function-call code is + cleaned up, this waste can be eliminated. */ + && (!same_type_ignoring_top_level_qualifiers_p + (TREE_TYPE (object), DECL_CONTEXT (member)))) + { + tree anonymous_union; + + anonymous_union = lookup_anon_field (TREE_TYPE (object), + DECL_CONTEXT (member)); + object = build_class_member_access_expr (object, + anonymous_union, + /*access_path=*/NULL_TREE, + preserve_reference, + complain); + } + + /* Compute the type of the field, as described in [expr.ref]. */ + type_quals = TYPE_UNQUALIFIED; + member_type = TREE_TYPE (member); + if (TREE_CODE (member_type) != REFERENCE_TYPE) + { + type_quals = (cp_type_quals (member_type) + | cp_type_quals (object_type)); + + /* A field is const (volatile) if the enclosing object, or the + field itself, is const (volatile). But, a mutable field is + not const, even within a const object. */ + if (DECL_MUTABLE_P (member)) + type_quals &= ~TYPE_QUAL_CONST; + member_type = cp_build_qualified_type (member_type, type_quals); + } + + result = build3 (COMPONENT_REF, member_type, object, member, + NULL_TREE); + result = fold_if_not_in_template (result); + + /* Mark the expression const or volatile, as appropriate. Even + though we've dealt with the type above, we still have to mark the + expression itself. */ + if (type_quals & TYPE_QUAL_CONST) + TREE_READONLY (result) = 1; + if (type_quals & TYPE_QUAL_VOLATILE) + TREE_THIS_VOLATILE (result) = 1; + } + else if (BASELINK_P (member)) + { + /* The member is a (possibly overloaded) member function. */ + tree functions; + tree type; + + /* If the MEMBER is exactly one static member function, then we + know the type of the expression. Otherwise, we must wait + until overload resolution has been performed. */ + functions = BASELINK_FUNCTIONS (member); + if (TREE_CODE (functions) == FUNCTION_DECL + && DECL_STATIC_FUNCTION_P (functions)) + type = TREE_TYPE (functions); + else + type = unknown_type_node; + /* Note that we do not convert OBJECT to the BASELINK_BINFO + base. That will happen when the function is called. */ + result = build3 (COMPONENT_REF, type, object, member, NULL_TREE); + } + else if (TREE_CODE (member) == CONST_DECL) + { + /* The member is an enumerator. */ + result = member; + /* If OBJECT has side-effects, they are supposed to occur. */ + if (TREE_SIDE_EFFECTS (object)) + result = build2 (COMPOUND_EXPR, TREE_TYPE (result), + object, result); + } + else + { + if (complain & tf_error) + error ("invalid use of %qD", member); + return error_mark_node; + } + + if (!preserve_reference) + /* [expr.ref] + + If E2 is declared to have type "reference to T", then ... the + type of E1.E2 is T. */ + result = convert_from_reference (result); + + return result; +} + +/* Return the destructor denoted by OBJECT.SCOPE::DTOR_NAME, or, if + SCOPE is NULL, by OBJECT.DTOR_NAME, where DTOR_NAME is ~type. */ + +static tree +lookup_destructor (tree object, tree scope, tree dtor_name) +{ + tree object_type = TREE_TYPE (object); + tree dtor_type = TREE_OPERAND (dtor_name, 0); + tree expr; + + if (scope && !check_dtor_name (scope, dtor_type)) + { + error ("qualified type %qT does not match destructor name ~%qT", + scope, dtor_type); + return error_mark_node; + } + if (TREE_CODE (dtor_type) == IDENTIFIER_NODE) + { + /* In a template, names we can't find a match for are still accepted + destructor names, and we check them here. */ + if (check_dtor_name (object_type, dtor_type)) + dtor_type = object_type; + else + { + error ("object type %qT does not match destructor name ~%qT", + object_type, dtor_type); + return error_mark_node; + } + + } + else if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type))) + { + error ("the type being destroyed is %qT, but the destructor refers to %qT", + TYPE_MAIN_VARIANT (object_type), dtor_type); + return error_mark_node; + } + expr = lookup_member (dtor_type, complete_dtor_identifier, + /*protect=*/1, /*want_type=*/false); + expr = (adjust_result_of_qualified_name_lookup + (expr, dtor_type, object_type)); + return expr; +} + +/* An expression of the form "A::template B" has been resolved to + DECL. Issue a diagnostic if B is not a template or template + specialization. */ + +void +check_template_keyword (tree decl) +{ + /* The standard says: + + [temp.names] + + If a name prefixed by the keyword template is not a member + template, the program is ill-formed. + + DR 228 removed the restriction that the template be a member + template. + + DR 96, if accepted would add the further restriction that explicit + template arguments must be provided if the template keyword is + used, but, as of 2005-10-16, that DR is still in "drafting". If + this DR is accepted, then the semantic checks here can be + simplified, as the entity named must in fact be a template + specialization, rather than, as at present, a set of overloaded + functions containing at least one template function. */ + if (TREE_CODE (decl) != TEMPLATE_DECL + && TREE_CODE (decl) != TEMPLATE_ID_EXPR) + { + if (!is_overloaded_fn (decl)) + permerror (input_location, "%qD is not a template", decl); + else + { + tree fns; + fns = decl; + if (BASELINK_P (fns)) + fns = BASELINK_FUNCTIONS (fns); + while (fns) + { + tree fn = OVL_CURRENT (fns); + if (TREE_CODE (fn) == TEMPLATE_DECL + || TREE_CODE (fn) == TEMPLATE_ID_EXPR) + break; + if (TREE_CODE (fn) == FUNCTION_DECL + && DECL_USE_TEMPLATE (fn) + && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn))) + break; + fns = OVL_NEXT (fns); + } + if (!fns) + permerror (input_location, "%qD is not a template", decl); + } + } +} + +/* This function is called by the parser to process a class member + access expression of the form OBJECT.NAME. NAME is a node used by + the parser to represent a name; it is not yet a DECL. It may, + however, be a BASELINK where the BASELINK_FUNCTIONS is a + TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and + there is no reason to do the lookup twice, so the parser keeps the + BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to + be a template via the use of the "A::template B" syntax. */ + +tree +finish_class_member_access_expr (tree object, tree name, bool template_p, + tsubst_flags_t complain) +{ + tree expr; + tree object_type; + tree member; + tree access_path = NULL_TREE; + tree orig_object = object; + tree orig_name = name; + + if (object == error_mark_node || name == error_mark_node) + return error_mark_node; + + /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */ + if (!objc_is_public (object, name)) + return error_mark_node; + + object_type = TREE_TYPE (object); + + if (processing_template_decl) + { + if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */ + dependent_type_p (object_type) + /* If NAME is just an IDENTIFIER_NODE, then the expression + is dependent. */ + || TREE_CODE (object) == IDENTIFIER_NODE + /* If NAME is "f<args>", where either 'f' or 'args' is + dependent, then the expression is dependent. */ + || (TREE_CODE (name) == TEMPLATE_ID_EXPR + && dependent_template_id_p (TREE_OPERAND (name, 0), + TREE_OPERAND (name, 1))) + /* If NAME is "T::X" where "T" is dependent, then the + expression is dependent. */ + || (TREE_CODE (name) == SCOPE_REF + && TYPE_P (TREE_OPERAND (name, 0)) + && dependent_type_p (TREE_OPERAND (name, 0)))) + return build_min_nt (COMPONENT_REF, object, name, NULL_TREE); + object = build_non_dependent_expr (object); + } + else if (c_dialect_objc () + && TREE_CODE (name) == IDENTIFIER_NODE + && (expr = objc_maybe_build_component_ref (object, name))) + return expr; + + /* [expr.ref] + + The type of the first expression shall be "class object" (of a + complete type). */ + if (!currently_open_class (object_type) + && !complete_type_or_maybe_complain (object_type, object, complain)) + return error_mark_node; + if (!CLASS_TYPE_P (object_type)) + { + if (complain & tf_error) + error ("request for member %qD in %qE, which is of non-class type %qT", + name, object, object_type); + return error_mark_node; + } + + if (BASELINK_P (name)) + /* A member function that has already been looked up. */ + member = name; + else + { + bool is_template_id = false; + tree template_args = NULL_TREE; + tree scope; + + if (TREE_CODE (name) == TEMPLATE_ID_EXPR) + { + is_template_id = true; + template_args = TREE_OPERAND (name, 1); + name = TREE_OPERAND (name, 0); + + if (TREE_CODE (name) == OVERLOAD) + name = DECL_NAME (get_first_fn (name)); + else if (DECL_P (name)) + name = DECL_NAME (name); + } + + if (TREE_CODE (name) == SCOPE_REF) + { + /* A qualified name. The qualifying class or namespace `S' + has already been looked up; it is either a TYPE or a + NAMESPACE_DECL. */ + scope = TREE_OPERAND (name, 0); + name = TREE_OPERAND (name, 1); + + /* If SCOPE is a namespace, then the qualified name does not + name a member of OBJECT_TYPE. */ + if (TREE_CODE (scope) == NAMESPACE_DECL) + { + if (complain & tf_error) + error ("%<%D::%D%> is not a member of %qT", + scope, name, object_type); + return error_mark_node; + } + + gcc_assert (CLASS_TYPE_P (scope)); + gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE + || TREE_CODE (name) == BIT_NOT_EXPR); + + if (constructor_name_p (name, scope)) + { + if (complain & tf_error) + error ("cannot call constructor %<%T::%D%> directly", + scope, name); + return error_mark_node; + } + + /* Find the base of OBJECT_TYPE corresponding to SCOPE. */ + access_path = lookup_base (object_type, scope, ba_check, NULL); + if (access_path == error_mark_node) + return error_mark_node; + if (!access_path) + { + if (complain & tf_error) + error ("%qT is not a base of %qT", scope, object_type); + return error_mark_node; + } + } + else + { + scope = NULL_TREE; + access_path = object_type; + } + + if (TREE_CODE (name) == BIT_NOT_EXPR) + member = lookup_destructor (object, scope, name); + else + { + /* Look up the member. */ + member = lookup_member (access_path, name, /*protect=*/1, + /*want_type=*/false); + if (member == NULL_TREE) + { + if (complain & tf_error) + error ("%qD has no member named %qE", object_type, name); + return error_mark_node; + } + if (member == error_mark_node) + return error_mark_node; + } + + if (is_template_id) + { + tree templ = member; + + if (BASELINK_P (templ)) + templ = lookup_template_function (templ, template_args); + else + { + if (complain & tf_error) + error ("%qD is not a member template function", name); + return error_mark_node; + } + } + } + + if (TREE_DEPRECATED (member)) + warn_deprecated_use (member, NULL_TREE); + + if (template_p) + check_template_keyword (member); + + expr = build_class_member_access_expr (object, member, access_path, + /*preserve_reference=*/false, + complain); + if (processing_template_decl && expr != error_mark_node) + { + if (BASELINK_P (member)) + { + if (TREE_CODE (orig_name) == SCOPE_REF) + BASELINK_QUALIFIED_P (member) = 1; + orig_name = member; + } + return build_min_non_dep (COMPONENT_REF, expr, + orig_object, orig_name, + NULL_TREE); + } + + return expr; +} + +/* Return an expression for the MEMBER_NAME field in the internal + representation of PTRMEM, a pointer-to-member function. (Each + pointer-to-member function type gets its own RECORD_TYPE so it is + more convenient to access the fields by name than by FIELD_DECL.) + This routine converts the NAME to a FIELD_DECL and then creates the + node for the complete expression. */ + +tree +build_ptrmemfunc_access_expr (tree ptrmem, tree member_name) +{ + tree ptrmem_type; + tree member; + tree member_type; + + /* This code is a stripped down version of + build_class_member_access_expr. It does not work to use that + routine directly because it expects the object to be of class + type. */ + ptrmem_type = TREE_TYPE (ptrmem); + gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type)); + member = lookup_member (ptrmem_type, member_name, /*protect=*/0, + /*want_type=*/false); + member_type = cp_build_qualified_type (TREE_TYPE (member), + cp_type_quals (ptrmem_type)); + return fold_build3_loc (input_location, + COMPONENT_REF, member_type, + ptrmem, member, NULL_TREE); +} + +/* Given an expression PTR for a pointer, return an expression + for the value pointed to. + ERRORSTRING is the name of the operator to appear in error messages. + + This function may need to overload OPERATOR_FNNAME. + Must also handle REFERENCE_TYPEs for C++. */ + +tree +build_x_indirect_ref (tree expr, ref_operator errorstring, + tsubst_flags_t complain) +{ + tree orig_expr = expr; + tree rval; + + if (processing_template_decl) + { + /* Retain the type if we know the operand is a pointer so that + describable_type doesn't make auto deduction break. */ + if (TREE_TYPE (expr) && POINTER_TYPE_P (TREE_TYPE (expr))) + return build_min (INDIRECT_REF, TREE_TYPE (TREE_TYPE (expr)), expr); + if (type_dependent_expression_p (expr)) + return build_min_nt (INDIRECT_REF, expr); + expr = build_non_dependent_expr (expr); + } + + rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE, + NULL_TREE, /*overloaded_p=*/NULL, complain); + if (!rval) + rval = cp_build_indirect_ref (expr, errorstring, complain); + + if (processing_template_decl && rval != error_mark_node) + return build_min_non_dep (INDIRECT_REF, rval, orig_expr); + else + return rval; +} + +/* Helper function called from c-common. */ +tree +build_indirect_ref (location_t loc __attribute__ ((__unused__)), + tree ptr, ref_operator errorstring) +{ + return cp_build_indirect_ref (ptr, errorstring, tf_warning_or_error); +} + +tree +cp_build_indirect_ref (tree ptr, ref_operator errorstring, + tsubst_flags_t complain) +{ + tree pointer, type; + + if (ptr == error_mark_node) + return error_mark_node; + + if (ptr == current_class_ptr) + return current_class_ref; + + pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE + ? ptr : decay_conversion (ptr)); + type = TREE_TYPE (pointer); + + if (POINTER_TYPE_P (type)) + { + /* [expr.unary.op] + + If the type of the expression is "pointer to T," the type + of the result is "T." */ + tree t = TREE_TYPE (type); + + if (CONVERT_EXPR_P (ptr) + || TREE_CODE (ptr) == VIEW_CONVERT_EXPR) + { + /* If a warning is issued, mark it to avoid duplicates from + the backend. This only needs to be done at + warn_strict_aliasing > 2. */ + if (warn_strict_aliasing > 2) + if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (ptr, 0)), + type, TREE_OPERAND (ptr, 0))) + TREE_NO_WARNING (ptr) = 1; + } + + if (VOID_TYPE_P (t)) + { + /* A pointer to incomplete type (other than cv void) can be + dereferenced [expr.unary.op]/1 */ + if (complain & tf_error) + error ("%qT is not a pointer-to-object type", type); + return error_mark_node; + } + else if (TREE_CODE (pointer) == ADDR_EXPR + && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0)))) + /* The POINTER was something like `&x'. We simplify `*&x' to + `x'. */ + return TREE_OPERAND (pointer, 0); + else + { + tree ref = build1 (INDIRECT_REF, t, pointer); + + /* We *must* set TREE_READONLY when dereferencing a pointer to const, + so that we get the proper error message if the result is used + to assign to. Also, &* is supposed to be a no-op. */ + TREE_READONLY (ref) = CP_TYPE_CONST_P (t); + TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t); + TREE_SIDE_EFFECTS (ref) + = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer)); + return ref; + } + } + else if (!(complain & tf_error)) + /* Don't emit any errors; we'll just return ERROR_MARK_NODE later. */ + ; + /* `pointer' won't be an error_mark_node if we were given a + pointer to member, so it's cool to check for this here. */ + else if (TYPE_PTR_TO_MEMBER_P (type)) + switch (errorstring) + { + case RO_ARRAY_INDEXING: + error ("invalid use of array indexing on pointer to member"); + break; + case RO_UNARY_STAR: + error ("invalid use of unary %<*%> on pointer to member"); + break; + case RO_IMPLICIT_CONVERSION: + error ("invalid use of implicit conversion on pointer to member"); + break; + default: + gcc_unreachable (); + } + else if (pointer != error_mark_node) + invalid_indirection_error (input_location, type, errorstring); + + return error_mark_node; +} + +/* This handles expressions of the form "a[i]", which denotes + an array reference. + + This is logically equivalent in C to *(a+i), but we may do it differently. + If A is a variable or a member, we generate a primitive ARRAY_REF. + This avoids forcing the array out of registers, and can work on + arrays that are not lvalues (for example, members of structures returned + by functions). + + If INDEX is of some user-defined type, it must be converted to + integer type. Otherwise, to make a compatible PLUS_EXPR, it + will inherit the type of the array, which will be some pointer type. + + LOC is the location to use in building the array reference. */ + +tree +cp_build_array_ref (location_t loc, tree array, tree idx, + tsubst_flags_t complain) +{ + tree ret; + + if (idx == 0) + { + if (complain & tf_error) + error_at (loc, "subscript missing in array reference"); + return error_mark_node; + } + + if (TREE_TYPE (array) == error_mark_node + || TREE_TYPE (idx) == error_mark_node) + return error_mark_node; + + /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference + inside it. */ + switch (TREE_CODE (array)) + { + case COMPOUND_EXPR: + { + tree value = cp_build_array_ref (loc, TREE_OPERAND (array, 1), idx, + complain); + ret = build2 (COMPOUND_EXPR, TREE_TYPE (value), + TREE_OPERAND (array, 0), value); + SET_EXPR_LOCATION (ret, loc); + return ret; + } + + case COND_EXPR: + ret = build_conditional_expr + (TREE_OPERAND (array, 0), + cp_build_array_ref (loc, TREE_OPERAND (array, 1), idx, + complain), + cp_build_array_ref (loc, TREE_OPERAND (array, 2), idx, + complain), + tf_warning_or_error); + protected_set_expr_location (ret, loc); + return ret; + + default: + break; + } + + if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE) + { + tree rval, type; + + warn_array_subscript_with_type_char (idx); + + if (!INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (TREE_TYPE (idx))) + { + if (complain & tf_error) + error_at (loc, "array subscript is not an integer"); + return error_mark_node; + } + + /* Apply integral promotions *after* noticing character types. + (It is unclear why we do these promotions -- the standard + does not say that we should. In fact, the natural thing would + seem to be to convert IDX to ptrdiff_t; we're performing + pointer arithmetic.) */ + idx = perform_integral_promotions (idx); + + /* An array that is indexed by a non-constant + cannot be stored in a register; we must be able to do + address arithmetic on its address. + Likewise an array of elements of variable size. */ + if (TREE_CODE (idx) != INTEGER_CST + || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array))) + && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array)))) + != INTEGER_CST))) + { + if (!cxx_mark_addressable (array)) + return error_mark_node; + } + + /* An array that is indexed by a constant value which is not within + the array bounds cannot be stored in a register either; because we + would get a crash in store_bit_field/extract_bit_field when trying + to access a non-existent part of the register. */ + if (TREE_CODE (idx) == INTEGER_CST + && TYPE_DOMAIN (TREE_TYPE (array)) + && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array)))) + { + if (!cxx_mark_addressable (array)) + return error_mark_node; + } + + if (!lvalue_p (array) && (complain & tf_error)) + pedwarn (loc, OPT_pedantic, + "ISO C++ forbids subscripting non-lvalue array"); + + /* Note in C++ it is valid to subscript a `register' array, since + it is valid to take the address of something with that + storage specification. */ + if (extra_warnings) + { + tree foo = array; + while (TREE_CODE (foo) == COMPONENT_REF) + foo = TREE_OPERAND (foo, 0); + if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo) + && (complain & tf_warning)) + warning_at (loc, OPT_Wextra, + "subscripting array declared %<register%>"); + } + + type = TREE_TYPE (TREE_TYPE (array)); + rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE); + /* Array ref is const/volatile if the array elements are + or if the array is.. */ + TREE_READONLY (rval) + |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array)); + TREE_SIDE_EFFECTS (rval) + |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array)); + TREE_THIS_VOLATILE (rval) + |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array)); + ret = require_complete_type_sfinae (fold_if_not_in_template (rval), + complain); + protected_set_expr_location (ret, loc); + return ret; + } + + { + tree ar = default_conversion (array); + tree ind = default_conversion (idx); + + /* Put the integer in IND to simplify error checking. */ + if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE) + { + tree temp = ar; + ar = ind; + ind = temp; + } + + if (ar == error_mark_node) + return ar; + + if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE) + { + if (complain & tf_error) + error_at (loc, "subscripted value is neither array nor pointer"); + return error_mark_node; + } + if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE) + { + if (complain & tf_error) + error_at (loc, "array subscript is not an integer"); + return error_mark_node; + } + + warn_array_subscript_with_type_char (idx); + + ret = cp_build_indirect_ref (cp_build_binary_op (input_location, + PLUS_EXPR, ar, ind, + complain), + RO_ARRAY_INDEXING, + complain); + protected_set_expr_location (ret, loc); + return ret; + } +} + +/* Entry point for Obj-C++. */ + +tree +build_array_ref (location_t loc, tree array, tree idx) +{ + return cp_build_array_ref (loc, array, idx, tf_warning_or_error); +} + +/* Resolve a pointer to member function. INSTANCE is the object + instance to use, if the member points to a virtual member. + + This used to avoid checking for virtual functions if basetype + has no virtual functions, according to an earlier ANSI draft. + With the final ISO C++ rules, such an optimization is + incorrect: A pointer to a derived member can be static_cast + to pointer-to-base-member, as long as the dynamic object + later has the right member. */ + +tree +get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function) +{ + if (TREE_CODE (function) == OFFSET_REF) + function = TREE_OPERAND (function, 1); + + if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function))) + { + tree idx, delta, e1, e2, e3, vtbl, basetype; + tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function)); + + tree instance_ptr = *instance_ptrptr; + tree instance_save_expr = 0; + if (instance_ptr == error_mark_node) + { + if (TREE_CODE (function) == PTRMEM_CST) + { + /* Extracting the function address from a pmf is only + allowed with -Wno-pmf-conversions. It only works for + pmf constants. */ + e1 = build_addr_func (PTRMEM_CST_MEMBER (function)); + e1 = convert (fntype, e1); + return e1; + } + else + { + error ("object missing in use of %qE", function); + return error_mark_node; + } + } + + if (TREE_SIDE_EFFECTS (instance_ptr)) + instance_ptr = instance_save_expr = save_expr (instance_ptr); + + if (TREE_SIDE_EFFECTS (function)) + function = save_expr (function); + + /* Start by extracting all the information from the PMF itself. */ + e3 = pfn_from_ptrmemfunc (function); + delta = delta_from_ptrmemfunc (function); + idx = build1 (NOP_EXPR, vtable_index_type, e3); + switch (TARGET_PTRMEMFUNC_VBIT_LOCATION) + { + case ptrmemfunc_vbit_in_pfn: + e1 = cp_build_binary_op (input_location, + BIT_AND_EXPR, idx, integer_one_node, + tf_warning_or_error); + idx = cp_build_binary_op (input_location, + MINUS_EXPR, idx, integer_one_node, + tf_warning_or_error); + break; + + case ptrmemfunc_vbit_in_delta: + e1 = cp_build_binary_op (input_location, + BIT_AND_EXPR, delta, integer_one_node, + tf_warning_or_error); + delta = cp_build_binary_op (input_location, + RSHIFT_EXPR, delta, integer_one_node, + tf_warning_or_error); + break; + + default: + gcc_unreachable (); + } + + /* Convert down to the right base before using the instance. A + special case is that in a pointer to member of class C, C may + be incomplete. In that case, the function will of course be + a member of C, and no conversion is required. In fact, + lookup_base will fail in that case, because incomplete + classes do not have BINFOs. */ + basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype)); + if (!same_type_ignoring_top_level_qualifiers_p + (basetype, TREE_TYPE (TREE_TYPE (instance_ptr)))) + { + basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)), + basetype, ba_check, NULL); + instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype, + 1); + if (instance_ptr == error_mark_node) + return error_mark_node; + } + /* ...and then the delta in the PMF. */ + instance_ptr = build2 (POINTER_PLUS_EXPR, TREE_TYPE (instance_ptr), + instance_ptr, fold_convert (sizetype, delta)); + + /* Hand back the adjusted 'this' argument to our caller. */ + *instance_ptrptr = instance_ptr; + + /* Next extract the vtable pointer from the object. */ + vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node), + instance_ptr); + vtbl = cp_build_indirect_ref (vtbl, RO_NULL, tf_warning_or_error); + /* If the object is not dynamic the access invokes undefined + behavior. As it is not executed in this case silence the + spurious warnings it may provoke. */ + TREE_NO_WARNING (vtbl) = 1; + + /* Finally, extract the function pointer from the vtable. */ + e2 = fold_build2_loc (input_location, + POINTER_PLUS_EXPR, TREE_TYPE (vtbl), vtbl, + fold_convert (sizetype, idx)); + e2 = cp_build_indirect_ref (e2, RO_NULL, tf_warning_or_error); + TREE_CONSTANT (e2) = 1; + + /* When using function descriptors, the address of the + vtable entry is treated as a function pointer. */ + if (TARGET_VTABLE_USES_DESCRIPTORS) + e2 = build1 (NOP_EXPR, TREE_TYPE (e2), + cp_build_addr_expr (e2, tf_warning_or_error)); + + e2 = fold_convert (TREE_TYPE (e3), e2); + e1 = build_conditional_expr (e1, e2, e3, tf_warning_or_error); + + /* Make sure this doesn't get evaluated first inside one of the + branches of the COND_EXPR. */ + if (instance_save_expr) + e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1), + instance_save_expr, e1); + + function = e1; + } + return function; +} + +/* Used by the C-common bits. */ +tree +build_function_call (location_t loc ATTRIBUTE_UNUSED, + tree function, tree params) +{ + return cp_build_function_call (function, params, tf_warning_or_error); +} + +/* Used by the C-common bits. */ +tree +build_function_call_vec (location_t loc ATTRIBUTE_UNUSED, + tree function, VEC(tree,gc) *params, + VEC(tree,gc) *origtypes ATTRIBUTE_UNUSED) +{ + VEC(tree,gc) *orig_params = params; + tree ret = cp_build_function_call_vec (function, ¶ms, + tf_warning_or_error); + + /* cp_build_function_call_vec can reallocate PARAMS by adding + default arguments. That should never happen here. Verify + that. */ + gcc_assert (params == orig_params); + + return ret; +} + +/* Build a function call using a tree list of arguments. */ + +tree +cp_build_function_call (tree function, tree params, tsubst_flags_t complain) +{ + VEC(tree,gc) *vec; + tree ret; + + vec = make_tree_vector (); + for (; params != NULL_TREE; params = TREE_CHAIN (params)) + VEC_safe_push (tree, gc, vec, TREE_VALUE (params)); + ret = cp_build_function_call_vec (function, &vec, complain); + release_tree_vector (vec); + return ret; +} + +/* Build a function call using varargs. */ + +tree +cp_build_function_call_nary (tree function, tsubst_flags_t complain, ...) +{ + VEC(tree,gc) *vec; + va_list args; + tree ret, t; + + vec = make_tree_vector (); + va_start (args, complain); + for (t = va_arg (args, tree); t != NULL_TREE; t = va_arg (args, tree)) + VEC_safe_push (tree, gc, vec, t); + va_end (args); + ret = cp_build_function_call_vec (function, &vec, complain); + release_tree_vector (vec); + return ret; +} + +/* Build a function call using a vector of arguments. PARAMS may be + NULL if there are no parameters. This changes the contents of + PARAMS. */ + +tree +cp_build_function_call_vec (tree function, VEC(tree,gc) **params, + tsubst_flags_t complain) +{ + tree fntype, fndecl; + int is_method; + tree original = function; + int nargs; + tree *argarray; + tree parm_types; + VEC(tree,gc) *allocated = NULL; + tree ret; + + /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF + expressions, like those used for ObjC messenger dispatches. */ + if (params != NULL && !VEC_empty (tree, *params)) + function = objc_rewrite_function_call (function, + VEC_index (tree, *params, 0)); + + /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue. + Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */ + if (TREE_CODE (function) == NOP_EXPR + && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0))) + function = TREE_OPERAND (function, 0); + + if (TREE_CODE (function) == FUNCTION_DECL) + { + mark_used (function); + fndecl = function; + + /* Convert anything with function type to a pointer-to-function. */ + if (DECL_MAIN_P (function) && (complain & tf_error)) + pedwarn (input_location, OPT_pedantic, + "ISO C++ forbids calling %<::main%> from within program"); + + function = build_addr_func (function); + } + else + { + fndecl = NULL_TREE; + + function = build_addr_func (function); + } + + if (function == error_mark_node) + return error_mark_node; + + fntype = TREE_TYPE (function); + + if (TYPE_PTRMEMFUNC_P (fntype)) + { + if (complain & tf_error) + error ("must use %<.*%> or %<->*%> to call pointer-to-member " + "function in %<%E (...)%>, e.g. %<(... ->* %E) (...)%>", + original, original); + return error_mark_node; + } + + is_method = (TREE_CODE (fntype) == POINTER_TYPE + && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE); + + if (!((TREE_CODE (fntype) == POINTER_TYPE + && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE) + || is_method + || TREE_CODE (function) == TEMPLATE_ID_EXPR)) + { + if (complain & tf_error) + error ("%qE cannot be used as a function", original); + return error_mark_node; + } + + /* fntype now gets the type of function pointed to. */ + fntype = TREE_TYPE (fntype); + parm_types = TYPE_ARG_TYPES (fntype); + + if (params == NULL) + { + allocated = make_tree_vector (); + params = &allocated; + } + + nargs = convert_arguments (parm_types, params, fndecl, LOOKUP_NORMAL, + complain); + if (nargs < 0) + return error_mark_node; + + argarray = VEC_address (tree, *params); + + /* Check for errors in format strings and inappropriately + null parameters. */ + check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray, + parm_types); + + ret = build_cxx_call (function, nargs, argarray); + + if (allocated != NULL) + release_tree_vector (allocated); + + return ret; +} + +/* Subroutine of convert_arguments. + Warn about wrong number of args are genereted. */ + +static void +warn_args_num (location_t loc, tree fndecl, bool too_many_p) +{ + if (fndecl) + { + if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE) + { + if (DECL_NAME (fndecl) == NULL_TREE + || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl))) + error_at (loc, + too_many_p + ? G_("too many arguments to constructor %q#D") + : G_("too few arguments to constructor %q#D"), + fndecl); + else + error_at (loc, + too_many_p + ? G_("too many arguments to member function %q#D") + : G_("too few arguments to member function %q#D"), + fndecl); + } + else + error_at (loc, + too_many_p + ? G_("too many arguments to function %q#D") + : G_("too few arguments to function %q#D"), + fndecl); + inform (DECL_SOURCE_LOCATION (fndecl), + "declared here"); + } + else + { + if (c_dialect_objc () && objc_message_selector ()) + error_at (loc, + too_many_p + ? G_("too many arguments to method %q#D") + : G_("too few arguments to method %q#D"), + objc_message_selector ()); + else + error_at (loc, too_many_p ? G_("too many arguments to function") + : G_("too few arguments to function")); + } +} + +/* Convert the actual parameter expressions in the list VALUES to the + types in the list TYPELIST. The converted expressions are stored + back in the VALUES vector. + If parmdecls is exhausted, or when an element has NULL as its type, + perform the default conversions. + + NAME is an IDENTIFIER_NODE or 0. It is used only for error messages. + + This is also where warnings about wrong number of args are generated. + + Returns the actual number of arguments processed (which might be less + than the length of the vector), or -1 on error. + + In C++, unspecified trailing parameters can be filled in with their + default arguments, if such were specified. Do so here. */ + +static int +convert_arguments (tree typelist, VEC(tree,gc) **values, tree fndecl, + int flags, tsubst_flags_t complain) +{ + tree typetail; + unsigned int i; + + /* Argument passing is always copy-initialization. */ + flags |= LOOKUP_ONLYCONVERTING; + + for (i = 0, typetail = typelist; + i < VEC_length (tree, *values); + i++) + { + tree type = typetail ? TREE_VALUE (typetail) : 0; + tree val = VEC_index (tree, *values, i); + + if (val == error_mark_node || type == error_mark_node) + return -1; + + if (type == void_type_node) + { + if (complain & tf_error) + { + warn_args_num (input_location, fndecl, /*too_many_p=*/true); + return i; + } + else + return -1; + } + + /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue. + Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */ + if (TREE_CODE (val) == NOP_EXPR + && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0)) + && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)) + val = TREE_OPERAND (val, 0); + + if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE) + { + if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE + || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE + || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE) + val = decay_conversion (val); + } + + if (val == error_mark_node) + return -1; + + if (type != 0) + { + /* Formal parm type is specified by a function prototype. */ + tree parmval; + + if (!COMPLETE_TYPE_P (complete_type (type))) + { + if (complain & tf_error) + { + if (fndecl) + error ("parameter %P of %qD has incomplete type %qT", + i, fndecl, type); + else + error ("parameter %P has incomplete type %qT", i, type); + } + parmval = error_mark_node; + } + else + { + parmval = convert_for_initialization + (NULL_TREE, type, val, flags, + ICR_ARGPASS, fndecl, i, complain); + parmval = convert_for_arg_passing (type, parmval); + } + + if (parmval == error_mark_node) + return -1; + + VEC_replace (tree, *values, i, parmval); + } + else + { + if (fndecl && DECL_BUILT_IN (fndecl) + && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P) + /* Don't do ellipsis conversion for __built_in_constant_p + as this will result in spurious errors for non-trivial + types. */ + val = require_complete_type_sfinae (val, complain); + else + val = convert_arg_to_ellipsis (val); + + VEC_replace (tree, *values, i, val); + } + + if (typetail) + typetail = TREE_CHAIN (typetail); + } + + if (typetail != 0 && typetail != void_list_node) + { + /* See if there are default arguments that can be used. Because + we hold default arguments in the FUNCTION_TYPE (which is so + wrong), we can see default parameters here from deduced + contexts (and via typeof) for indirect function calls. + Fortunately we know whether we have a function decl to + provide default arguments in a language conformant + manner. */ + if (fndecl && TREE_PURPOSE (typetail) + && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG) + { + for (; typetail != void_list_node; ++i) + { + tree parmval + = convert_default_arg (TREE_VALUE (typetail), + TREE_PURPOSE (typetail), + fndecl, i); + + if (parmval == error_mark_node) + return -1; + + VEC_safe_push (tree, gc, *values, parmval); + typetail = TREE_CHAIN (typetail); + /* ends with `...'. */ + if (typetail == NULL_TREE) + break; + } + } + else + { + if (complain & tf_error) + warn_args_num (input_location, fndecl, /*too_many_p=*/false); + return -1; + } + } + + return (int) i; +} + +/* Build a binary-operation expression, after performing default + conversions on the operands. CODE is the kind of expression to + build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE + are the tree codes which correspond to ARG1 and ARG2 when issuing + warnings about possibly misplaced parentheses. They may differ + from the TREE_CODE of ARG1 and ARG2 if the parser has done constant + folding (e.g., if the parser sees "a | 1 + 1", it may call this + routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR). + To avoid issuing any parentheses warnings, pass ARG1_CODE and/or + ARG2_CODE as ERROR_MARK. */ + +tree +build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code, + tree arg2, enum tree_code arg2_code, bool *overloaded_p, + tsubst_flags_t complain) +{ + tree orig_arg1; + tree orig_arg2; + tree expr; + + orig_arg1 = arg1; + orig_arg2 = arg2; + + if (processing_template_decl) + { + if (type_dependent_expression_p (arg1) + || type_dependent_expression_p (arg2)) + return build_min_nt (code, arg1, arg2); + arg1 = build_non_dependent_expr (arg1); + arg2 = build_non_dependent_expr (arg2); + } + + if (code == DOTSTAR_EXPR) + expr = build_m_component_ref (arg1, arg2); + else + expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE, + overloaded_p, complain); + + /* Check for cases such as x+y<<z which users are likely to + misinterpret. But don't warn about obj << x + y, since that is a + common idiom for I/O. */ + if (warn_parentheses + && (complain & tf_warning) + && !processing_template_decl + && !error_operand_p (arg1) + && !error_operand_p (arg2) + && (code != LSHIFT_EXPR + || !CLASS_TYPE_P (TREE_TYPE (arg1)))) + warn_about_parentheses (code, arg1_code, orig_arg1, arg2_code, orig_arg2); + + if (processing_template_decl && expr != error_mark_node) + return build_min_non_dep (code, expr, orig_arg1, orig_arg2); + + return expr; +} + +/* Build and return an ARRAY_REF expression. */ + +tree +build_x_array_ref (tree arg1, tree arg2, tsubst_flags_t complain) +{ + tree orig_arg1 = arg1; + tree orig_arg2 = arg2; + tree expr; + + if (processing_template_decl) + { + if (type_dependent_expression_p (arg1) + || type_dependent_expression_p (arg2)) + return build_min_nt (ARRAY_REF, arg1, arg2, + NULL_TREE, NULL_TREE); + arg1 = build_non_dependent_expr (arg1); + arg2 = build_non_dependent_expr (arg2); + } + + expr = build_new_op (ARRAY_REF, LOOKUP_NORMAL, arg1, arg2, NULL_TREE, + /*overloaded_p=*/NULL, complain); + + if (processing_template_decl && expr != error_mark_node) + return build_min_non_dep (ARRAY_REF, expr, orig_arg1, orig_arg2, + NULL_TREE, NULL_TREE); + return expr; +} + +/* For the c-common bits. */ +tree +build_binary_op (location_t location, enum tree_code code, tree op0, tree op1, + int convert_p ATTRIBUTE_UNUSED) +{ + return cp_build_binary_op (location, code, op0, op1, tf_warning_or_error); +} + + +/* Build a binary-operation expression without default conversions. + CODE is the kind of expression to build. + LOCATION is the location_t of the operator in the source code. + This function differs from `build' in several ways: + the data type of the result is computed and recorded in it, + warnings are generated if arg data types are invalid, + special handling for addition and subtraction of pointers is known, + and some optimization is done (operations on narrow ints + are done in the narrower type when that gives the same result). + Constant folding is also done before the result is returned. + + Note that the operands will never have enumeral types + because either they have just had the default conversions performed + or they have both just been converted to some other type in which + the arithmetic is to be done. + + C++: must do special pointer arithmetic when implementing + multiple inheritance, and deal with pointer to member functions. */ + +tree +cp_build_binary_op (location_t location, + enum tree_code code, tree orig_op0, tree orig_op1, + tsubst_flags_t complain) +{ + tree op0, op1; + enum tree_code code0, code1; + tree type0, type1; + const char *invalid_op_diag; + + /* Expression code to give to the expression when it is built. + Normally this is CODE, which is what the caller asked for, + but in some special cases we change it. */ + enum tree_code resultcode = code; + + /* Data type in which the computation is to be performed. + In the simplest cases this is the common type of the arguments. */ + tree result_type = NULL; + + /* Nonzero means operands have already been type-converted + in whatever way is necessary. + Zero means they need to be converted to RESULT_TYPE. */ + int converted = 0; + + /* Nonzero means create the expression with this type, rather than + RESULT_TYPE. */ + tree build_type = 0; + + /* Nonzero means after finally constructing the expression + convert it to this type. */ + tree final_type = 0; + + tree result; + + /* Nonzero if this is an operation like MIN or MAX which can + safely be computed in short if both args are promoted shorts. + Also implies COMMON. + -1 indicates a bitwise operation; this makes a difference + in the exact conditions for when it is safe to do the operation + in a narrower mode. */ + int shorten = 0; + + /* Nonzero if this is a comparison operation; + if both args are promoted shorts, compare the original shorts. + Also implies COMMON. */ + int short_compare = 0; + + /* Nonzero means set RESULT_TYPE to the common type of the args. */ + int common = 0; + + /* True if both operands have arithmetic type. */ + bool arithmetic_types_p; + + /* Apply default conversions. */ + op0 = orig_op0; + op1 = orig_op1; + + if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR + || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR + || code == TRUTH_XOR_EXPR) + { + if (!really_overloaded_fn (op0)) + op0 = decay_conversion (op0); + if (!really_overloaded_fn (op1)) + op1 = decay_conversion (op1); + } + else + { + if (!really_overloaded_fn (op0)) + op0 = default_conversion (op0); + if (!really_overloaded_fn (op1)) + op1 = default_conversion (op1); + } + + /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */ + STRIP_TYPE_NOPS (op0); + STRIP_TYPE_NOPS (op1); + + /* DTRT if one side is an overloaded function, but complain about it. */ + if (type_unknown_p (op0)) + { + tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none); + if (t != error_mark_node) + { + if (complain & tf_error) + permerror (input_location, "assuming cast to type %qT from overloaded function", + TREE_TYPE (t)); + op0 = t; + } + } + if (type_unknown_p (op1)) + { + tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none); + if (t != error_mark_node) + { + if (complain & tf_error) + permerror (input_location, "assuming cast to type %qT from overloaded function", + TREE_TYPE (t)); + op1 = t; + } + } + + type0 = TREE_TYPE (op0); + type1 = TREE_TYPE (op1); + + /* The expression codes of the data types of the arguments tell us + whether the arguments are integers, floating, pointers, etc. */ + code0 = TREE_CODE (type0); + code1 = TREE_CODE (type1); + + /* If an error was already reported for one of the arguments, + avoid reporting another error. */ + if (code0 == ERROR_MARK || code1 == ERROR_MARK) + return error_mark_node; + + if ((invalid_op_diag + = targetm.invalid_binary_op (code, type0, type1))) + { + error (invalid_op_diag); + return error_mark_node; + } + + /* Issue warnings about peculiar, but valid, uses of NULL. */ + if ((orig_op0 == null_node || orig_op1 == null_node) + /* It's reasonable to use pointer values as operands of && + and ||, so NULL is no exception. */ + && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR + && ( /* Both are NULL (or 0) and the operation was not a + comparison or a pointer subtraction. */ + (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1) + && code != EQ_EXPR && code != NE_EXPR && code != MINUS_EXPR) + /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */ + || (!null_ptr_cst_p (orig_op0) + && !TYPE_PTR_P (type0) && !TYPE_PTR_TO_MEMBER_P (type0)) + || (!null_ptr_cst_p (orig_op1) + && !TYPE_PTR_P (type1) && !TYPE_PTR_TO_MEMBER_P (type1))) + && (complain & tf_warning)) + /* Some sort of arithmetic operation involving NULL was + performed. */ + warning (OPT_Wpointer_arith, "NULL used in arithmetic"); + + switch (code) + { + case MINUS_EXPR: + /* Subtraction of two similar pointers. + We must subtract them as integers, then divide by object size. */ + if (code0 == POINTER_TYPE && code1 == POINTER_TYPE + && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0), + TREE_TYPE (type1))) + return pointer_diff (op0, op1, common_pointer_type (type0, type1)); + /* In all other cases except pointer - int, the usual arithmetic + rules apply. */ + else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE)) + { + common = 1; + break; + } + /* The pointer - int case is just like pointer + int; fall + through. */ + case PLUS_EXPR: + if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE) + && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE)) + { + tree ptr_operand; + tree int_operand; + ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1); + int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1); + if (processing_template_decl) + { + result_type = TREE_TYPE (ptr_operand); + break; + } + return cp_pointer_int_sum (code, + ptr_operand, + int_operand); + } + common = 1; + break; + + case MULT_EXPR: + common = 1; + break; + + case TRUNC_DIV_EXPR: + case CEIL_DIV_EXPR: + case FLOOR_DIV_EXPR: + case ROUND_DIV_EXPR: + case EXACT_DIV_EXPR: + if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE + || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE) + && (code1 == INTEGER_TYPE || code1 == REAL_TYPE + || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)) + { + enum tree_code tcode0 = code0, tcode1 = code1; + + warn_for_div_by_zero (location, op1); + + if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE) + tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0))); + if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE) + tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1))); + + if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE)) + resultcode = RDIV_EXPR; + else + /* When dividing two signed integers, we have to promote to int. + unless we divide by a constant != -1. Note that default + conversion will have been performed on the operands at this + point, so we have to dig out the original type to find out if + it was unsigned. */ + shorten = ((TREE_CODE (op0) == NOP_EXPR + && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0)))) + || (TREE_CODE (op1) == INTEGER_CST + && ! integer_all_onesp (op1))); + + common = 1; + } + break; + + case BIT_AND_EXPR: + case BIT_IOR_EXPR: + case BIT_XOR_EXPR: + if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) + || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE + && !VECTOR_FLOAT_TYPE_P (type0) + && !VECTOR_FLOAT_TYPE_P (type1))) + shorten = -1; + break; + + case TRUNC_MOD_EXPR: + case FLOOR_MOD_EXPR: + warn_for_div_by_zero (location, op1); + + if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE + && TREE_CODE (TREE_TYPE (type0)) == INTEGER_TYPE + && TREE_CODE (TREE_TYPE (type1)) == INTEGER_TYPE) + common = 1; + else if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) + { + /* Although it would be tempting to shorten always here, that loses + on some targets, since the modulo instruction is undefined if the + quotient can't be represented in the computation mode. We shorten + only if unsigned or if dividing by something we know != -1. */ + shorten = ((TREE_CODE (op0) == NOP_EXPR + && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0)))) + || (TREE_CODE (op1) == INTEGER_CST + && ! integer_all_onesp (op1))); + common = 1; + } + break; + + case TRUTH_ANDIF_EXPR: + case TRUTH_ORIF_EXPR: + case TRUTH_AND_EXPR: + case TRUTH_OR_EXPR: + result_type = boolean_type_node; + break; + + /* Shift operations: result has same type as first operand; + always convert second operand to int. + Also set SHORT_SHIFT if shifting rightward. */ + + case RSHIFT_EXPR: + if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) + { + result_type = type0; + if (TREE_CODE (op1) == INTEGER_CST) + { + if (tree_int_cst_lt (op1, integer_zero_node)) + { + if ((complain & tf_warning) + && c_inhibit_evaluation_warnings == 0) + warning (0, "right shift count is negative"); + } + else + { + if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0 + && (complain & tf_warning) + && c_inhibit_evaluation_warnings == 0) + warning (0, "right shift count >= width of type"); + } + } + /* Convert the shift-count to an integer, regardless of + size of value being shifted. */ + if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) + op1 = cp_convert (integer_type_node, op1); + /* Avoid converting op1 to result_type later. */ + converted = 1; + } + break; + + case LSHIFT_EXPR: + if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) + { + result_type = type0; + if (TREE_CODE (op1) == INTEGER_CST) + { + if (tree_int_cst_lt (op1, integer_zero_node)) + { + if ((complain & tf_warning) + && c_inhibit_evaluation_warnings == 0) + warning (0, "left shift count is negative"); + } + else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) + { + if ((complain & tf_warning) + && c_inhibit_evaluation_warnings == 0) + warning (0, "left shift count >= width of type"); + } + } + /* Convert the shift-count to an integer, regardless of + size of value being shifted. */ + if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) + op1 = cp_convert (integer_type_node, op1); + /* Avoid converting op1 to result_type later. */ + converted = 1; + } + break; + + case RROTATE_EXPR: + case LROTATE_EXPR: + if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) + { + result_type = type0; + if (TREE_CODE (op1) == INTEGER_CST) + { + if (tree_int_cst_lt (op1, integer_zero_node)) + { + if (complain & tf_warning) + warning (0, (code == LROTATE_EXPR) + ? G_("left rotate count is negative") + : G_("right rotate count is negative")); + } + else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) + { + if (complain & tf_warning) + warning (0, (code == LROTATE_EXPR) + ? G_("left rotate count >= width of type") + : G_("right rotate count >= width of type")); + } + } + /* Convert the shift-count to an integer, regardless of + size of value being shifted. */ + if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) + op1 = cp_convert (integer_type_node, op1); + } + break; + + case EQ_EXPR: + case NE_EXPR: + if ((complain & tf_warning) + && (FLOAT_TYPE_P (type0) || FLOAT_TYPE_P (type1))) + warning (OPT_Wfloat_equal, + "comparing floating point with == or != is unsafe"); + if ((complain & tf_warning) + && ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1)) + || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))) + warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour"); + + build_type = boolean_type_node; + if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE + || code0 == COMPLEX_TYPE || code0 == ENUMERAL_TYPE) + && (code1 == INTEGER_TYPE || code1 == REAL_TYPE + || code1 == COMPLEX_TYPE || code1 == ENUMERAL_TYPE)) + short_compare = 1; + else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE) + || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1))) + result_type = composite_pointer_type (type0, type1, op0, op1, + CPO_COMPARISON, complain); + else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0)) + && null_ptr_cst_p (op1)) + { + if (TREE_CODE (op0) == ADDR_EXPR + && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0))) + { + if (complain & tf_warning) + warning (OPT_Waddress, "the address of %qD will never be NULL", + TREE_OPERAND (op0, 0)); + } + result_type = type0; + } + else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1)) + && null_ptr_cst_p (op0)) + { + if (TREE_CODE (op1) == ADDR_EXPR + && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0))) + { + if (complain & tf_warning) + warning (OPT_Waddress, "the address of %qD will never be NULL", + TREE_OPERAND (op1, 0)); + } + result_type = type1; + } + else if (null_ptr_cst_p (op0) && null_ptr_cst_p (op1)) + /* One of the operands must be of nullptr_t type. */ + result_type = TREE_TYPE (nullptr_node); + else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) + { + result_type = type0; + if (complain & tf_error) + permerror (input_location, "ISO C++ forbids comparison between pointer and integer"); + else + return error_mark_node; + } + else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE) + { + result_type = type1; + if (complain & tf_error) + permerror (input_location, "ISO C++ forbids comparison between pointer and integer"); + else + return error_mark_node; + } + else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1)) + { + if (TARGET_PTRMEMFUNC_VBIT_LOCATION + == ptrmemfunc_vbit_in_delta) + { + tree pfn0 = pfn_from_ptrmemfunc (op0); + tree delta0 = delta_from_ptrmemfunc (op0); + tree e1 = cp_build_binary_op (location, + EQ_EXPR, + pfn0, + build_zero_cst (TREE_TYPE (pfn0)), + complain); + tree e2 = cp_build_binary_op (location, + BIT_AND_EXPR, + delta0, + integer_one_node, + complain); + e2 = cp_build_binary_op (location, + EQ_EXPR, e2, integer_zero_node, + complain); + op0 = cp_build_binary_op (location, + TRUTH_ANDIF_EXPR, e1, e2, + complain); + op1 = cp_convert (TREE_TYPE (op0), integer_one_node); + } + else + { + op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier); + op1 = cp_convert (TREE_TYPE (op0), integer_zero_node); + } + result_type = TREE_TYPE (op0); + } + else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0)) + return cp_build_binary_op (location, code, op1, op0, complain); + else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)) + { + tree type; + /* E will be the final comparison. */ + tree e; + /* E1 and E2 are for scratch. */ + tree e1; + tree e2; + tree pfn0; + tree pfn1; + tree delta0; + tree delta1; + + type = composite_pointer_type (type0, type1, op0, op1, + CPO_COMPARISON, complain); + + if (!same_type_p (TREE_TYPE (op0), type)) + op0 = cp_convert_and_check (type, op0); + if (!same_type_p (TREE_TYPE (op1), type)) + op1 = cp_convert_and_check (type, op1); + + if (op0 == error_mark_node || op1 == error_mark_node) + return error_mark_node; + + if (TREE_SIDE_EFFECTS (op0)) + op0 = save_expr (op0); + if (TREE_SIDE_EFFECTS (op1)) + op1 = save_expr (op1); + + pfn0 = pfn_from_ptrmemfunc (op0); + pfn1 = pfn_from_ptrmemfunc (op1); + delta0 = delta_from_ptrmemfunc (op0); + delta1 = delta_from_ptrmemfunc (op1); + if (TARGET_PTRMEMFUNC_VBIT_LOCATION + == ptrmemfunc_vbit_in_delta) + { + /* We generate: + + (op0.pfn == op1.pfn + && ((op0.delta == op1.delta) + || (!op0.pfn && op0.delta & 1 == 0 + && op1.delta & 1 == 0)) + + The reason for the `!op0.pfn' bit is that a NULL + pointer-to-member is any member with a zero PFN and + LSB of the DELTA field is 0. */ + + e1 = cp_build_binary_op (location, BIT_AND_EXPR, + delta0, + integer_one_node, + complain); + e1 = cp_build_binary_op (location, + EQ_EXPR, e1, integer_zero_node, + complain); + e2 = cp_build_binary_op (location, BIT_AND_EXPR, + delta1, + integer_one_node, + complain); + e2 = cp_build_binary_op (location, + EQ_EXPR, e2, integer_zero_node, + complain); + e1 = cp_build_binary_op (location, + TRUTH_ANDIF_EXPR, e2, e1, + complain); + e2 = cp_build_binary_op (location, EQ_EXPR, + pfn0, + build_zero_cst (TREE_TYPE (pfn0)), + complain); + e2 = cp_build_binary_op (location, + TRUTH_ANDIF_EXPR, e2, e1, complain); + e1 = cp_build_binary_op (location, + EQ_EXPR, delta0, delta1, complain); + e1 = cp_build_binary_op (location, + TRUTH_ORIF_EXPR, e1, e2, complain); + } + else + { + /* We generate: + + (op0.pfn == op1.pfn + && (!op0.pfn || op0.delta == op1.delta)) + + The reason for the `!op0.pfn' bit is that a NULL + pointer-to-member is any member with a zero PFN; the + DELTA field is unspecified. */ + + e1 = cp_build_binary_op (location, + EQ_EXPR, delta0, delta1, complain); + e2 = cp_build_binary_op (location, + EQ_EXPR, + pfn0, + build_zero_cst (TREE_TYPE (pfn0)), + complain); + e1 = cp_build_binary_op (location, + TRUTH_ORIF_EXPR, e1, e2, complain); + } + e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1); + e = cp_build_binary_op (location, + TRUTH_ANDIF_EXPR, e2, e1, complain); + if (code == EQ_EXPR) + return e; + return cp_build_binary_op (location, + EQ_EXPR, e, integer_zero_node, complain); + } + else + { + gcc_assert (!TYPE_PTRMEMFUNC_P (type0) + || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0), + type1)); + gcc_assert (!TYPE_PTRMEMFUNC_P (type1) + || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1), + type0)); + } + + break; + + case MAX_EXPR: + case MIN_EXPR: + if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE) + && (code1 == INTEGER_TYPE || code1 == REAL_TYPE)) + shorten = 1; + else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) + result_type = composite_pointer_type (type0, type1, op0, op1, + CPO_COMPARISON, complain); + break; + + case LE_EXPR: + case GE_EXPR: + case LT_EXPR: + case GT_EXPR: + if (TREE_CODE (orig_op0) == STRING_CST + || TREE_CODE (orig_op1) == STRING_CST) + { + if (complain & tf_warning) + warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour"); + } + + build_type = boolean_type_node; + if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE + || code0 == ENUMERAL_TYPE) + && (code1 == INTEGER_TYPE || code1 == REAL_TYPE + || code1 == ENUMERAL_TYPE)) + short_compare = 1; + else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) + result_type = composite_pointer_type (type0, type1, op0, op1, + CPO_COMPARISON, complain); + else if (code0 == POINTER_TYPE && null_ptr_cst_p (op1)) + result_type = type0; + else if (code1 == POINTER_TYPE && null_ptr_cst_p (op0)) + result_type = type1; + else if (null_ptr_cst_p (op0) && null_ptr_cst_p (op1)) + /* One of the operands must be of nullptr_t type. */ + result_type = TREE_TYPE (nullptr_node); + else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) + { + result_type = type0; + if (complain & tf_error) + permerror (input_location, "ISO C++ forbids comparison between pointer and integer"); + else + return error_mark_node; + } + else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE) + { + result_type = type1; + if (complain & tf_error) + permerror (input_location, "ISO C++ forbids comparison between pointer and integer"); + else + return error_mark_node; + } + break; + + case UNORDERED_EXPR: + case ORDERED_EXPR: + case UNLT_EXPR: + case UNLE_EXPR: + case UNGT_EXPR: + case UNGE_EXPR: + case UNEQ_EXPR: + build_type = integer_type_node; + if (code0 != REAL_TYPE || code1 != REAL_TYPE) + { + if (complain & tf_error) + error ("unordered comparison on non-floating point argument"); + return error_mark_node; + } + common = 1; + break; + + default: + break; + } + + if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE + || code0 == ENUMERAL_TYPE) + && (code1 == INTEGER_TYPE || code1 == REAL_TYPE + || code1 == COMPLEX_TYPE || code1 == ENUMERAL_TYPE))) + arithmetic_types_p = 1; + else + { + arithmetic_types_p = 0; + /* Vector arithmetic is only allowed when both sides are vectors. */ + if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE) + { + if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1)) + || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0), + TREE_TYPE (type1))) + { + binary_op_error (location, code, type0, type1); + return error_mark_node; + } + arithmetic_types_p = 1; + } + } + /* Determine the RESULT_TYPE, if it is not already known. */ + if (!result_type + && arithmetic_types_p + && (shorten || common || short_compare)) + { + result_type = cp_common_type (type0, type1); + do_warn_double_promotion (result_type, type0, type1, + "implicit conversion from %qT to %qT " + "to match other operand of binary " + "expression", + location); + } + + if (!result_type) + { + if (complain & tf_error) + error ("invalid operands of types %qT and %qT to binary %qO", + TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code); + return error_mark_node; + } + + /* If we're in a template, the only thing we need to know is the + RESULT_TYPE. */ + if (processing_template_decl) + { + /* Since the middle-end checks the type when doing a build2, we + need to build the tree in pieces. This built tree will never + get out of the front-end as we replace it when instantiating + the template. */ + tree tmp = build2 (resultcode, + build_type ? build_type : result_type, + NULL_TREE, op1); + TREE_OPERAND (tmp, 0) = op0; + return tmp; + } + + if (arithmetic_types_p) + { + bool first_complex = (code0 == COMPLEX_TYPE); + bool second_complex = (code1 == COMPLEX_TYPE); + int none_complex = (!first_complex && !second_complex); + + /* Adapted from patch for c/24581. */ + if (first_complex != second_complex + && (code == PLUS_EXPR + || code == MINUS_EXPR + || code == MULT_EXPR + || (code == TRUNC_DIV_EXPR && first_complex)) + && TREE_CODE (TREE_TYPE (result_type)) == REAL_TYPE + && flag_signed_zeros) + { + /* An operation on mixed real/complex operands must be + handled specially, but the language-independent code can + more easily optimize the plain complex arithmetic if + -fno-signed-zeros. */ + tree real_type = TREE_TYPE (result_type); + tree real, imag; + if (first_complex) + { + if (TREE_TYPE (op0) != result_type) + op0 = cp_convert_and_check (result_type, op0); + if (TREE_TYPE (op1) != real_type) + op1 = cp_convert_and_check (real_type, op1); + } + else + { + if (TREE_TYPE (op0) != real_type) + op0 = cp_convert_and_check (real_type, op0); + if (TREE_TYPE (op1) != result_type) + op1 = cp_convert_and_check (result_type, op1); + } + if (TREE_CODE (op0) == ERROR_MARK || TREE_CODE (op1) == ERROR_MARK) + return error_mark_node; + if (first_complex) + { + op0 = save_expr (op0); + real = cp_build_unary_op (REALPART_EXPR, op0, 1, complain); + imag = cp_build_unary_op (IMAGPART_EXPR, op0, 1, complain); + switch (code) + { + case MULT_EXPR: + case TRUNC_DIV_EXPR: + op1 = save_expr (op1); + imag = build2 (resultcode, real_type, imag, op1); + /* Fall through. */ + case PLUS_EXPR: + case MINUS_EXPR: + real = build2 (resultcode, real_type, real, op1); + break; + default: + gcc_unreachable(); + } + } + else + { + op1 = save_expr (op1); + real = cp_build_unary_op (REALPART_EXPR, op1, 1, complain); + imag = cp_build_unary_op (IMAGPART_EXPR, op1, 1, complain); + switch (code) + { + case MULT_EXPR: + op0 = save_expr (op0); + imag = build2 (resultcode, real_type, op0, imag); + /* Fall through. */ + case PLUS_EXPR: + real = build2 (resultcode, real_type, op0, real); + break; + case MINUS_EXPR: + real = build2 (resultcode, real_type, op0, real); + imag = build1 (NEGATE_EXPR, real_type, imag); + break; + default: + gcc_unreachable(); + } + } + real = fold_if_not_in_template (real); + imag = fold_if_not_in_template (imag); + result = build2 (COMPLEX_EXPR, result_type, real, imag); + result = fold_if_not_in_template (result); + return result; + } + + /* For certain operations (which identify themselves by shorten != 0) + if both args were extended from the same smaller type, + do the arithmetic in that type and then extend. + + shorten !=0 and !=1 indicates a bitwise operation. + For them, this optimization is safe only if + both args are zero-extended or both are sign-extended. + Otherwise, we might change the result. + E.g., (short)-1 | (unsigned short)-1 is (int)-1 + but calculated in (unsigned short) it would be (unsigned short)-1. */ + + if (shorten && none_complex) + { + final_type = result_type; + result_type = shorten_binary_op (result_type, op0, op1, + shorten == -1); + } + + /* Comparison operations are shortened too but differently. + They identify themselves by setting short_compare = 1. */ + + if (short_compare) + { + /* Don't write &op0, etc., because that would prevent op0 + from being kept in a register. + Instead, make copies of the our local variables and + pass the copies by reference, then copy them back afterward. */ + tree xop0 = op0, xop1 = op1, xresult_type = result_type; + enum tree_code xresultcode = resultcode; + tree val + = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode); + if (val != 0) + return cp_convert (boolean_type_node, val); + op0 = xop0, op1 = xop1; + converted = 1; + resultcode = xresultcode; + } + + if ((short_compare || code == MIN_EXPR || code == MAX_EXPR) + && warn_sign_compare + && !TREE_NO_WARNING (orig_op0) + && !TREE_NO_WARNING (orig_op1) + /* Do not warn until the template is instantiated; we cannot + bound the ranges of the arguments until that point. */ + && !processing_template_decl + && (complain & tf_warning) + && c_inhibit_evaluation_warnings == 0) + { + warn_for_sign_compare (location, orig_op0, orig_op1, op0, op1, + result_type, resultcode); + } + } + + /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE. + Then the expression will be built. + It will be given type FINAL_TYPE if that is nonzero; + otherwise, it will be given type RESULT_TYPE. */ + if (! converted) + { + if (TREE_TYPE (op0) != result_type) + op0 = cp_convert_and_check (result_type, op0); + if (TREE_TYPE (op1) != result_type) + op1 = cp_convert_and_check (result_type, op1); + + if (op0 == error_mark_node || op1 == error_mark_node) + return error_mark_node; + } + + if (build_type == NULL_TREE) + build_type = result_type; + + result = build2 (resultcode, build_type, op0, op1); + result = fold_if_not_in_template (result); + if (final_type != 0) + result = cp_convert (final_type, result); + + if (TREE_OVERFLOW_P (result) + && !TREE_OVERFLOW_P (op0) + && !TREE_OVERFLOW_P (op1)) + overflow_warning (location, result); + + return result; +} + +/* Return a tree for the sum or difference (RESULTCODE says which) + of pointer PTROP and integer INTOP. */ + +static tree +cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop) +{ + tree res_type = TREE_TYPE (ptrop); + + /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type) + in certain circumstance (when it's valid to do so). So we need + to make sure it's complete. We don't need to check here, if we + can actually complete it at all, as those checks will be done in + pointer_int_sum() anyway. */ + complete_type (TREE_TYPE (res_type)); + + return pointer_int_sum (input_location, resultcode, ptrop, + fold_if_not_in_template (intop)); +} + +/* Return a tree for the difference of pointers OP0 and OP1. + The resulting tree has type int. */ + +static tree +pointer_diff (tree op0, tree op1, tree ptrtype) +{ + tree result; + tree restype = ptrdiff_type_node; + tree target_type = TREE_TYPE (ptrtype); + + if (!complete_type_or_else (target_type, NULL_TREE)) + return error_mark_node; + + if (TREE_CODE (target_type) == VOID_TYPE) + permerror (input_location, "ISO C++ forbids using pointer of type %<void *%> in subtraction"); + if (TREE_CODE (target_type) == FUNCTION_TYPE) + permerror (input_location, "ISO C++ forbids using pointer to a function in subtraction"); + if (TREE_CODE (target_type) == METHOD_TYPE) + permerror (input_location, "ISO C++ forbids using pointer to a method in subtraction"); + + /* First do the subtraction as integers; + then drop through to build the divide operator. */ + + op0 = cp_build_binary_op (input_location, + MINUS_EXPR, + cp_convert (restype, op0), + cp_convert (restype, op1), + tf_warning_or_error); + + /* This generates an error if op1 is a pointer to an incomplete type. */ + if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1)))) + error ("invalid use of a pointer to an incomplete type in pointer arithmetic"); + + op1 = (TYPE_PTROB_P (ptrtype) + ? size_in_bytes (target_type) + : integer_one_node); + + /* Do the division. */ + + result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1)); + return fold_if_not_in_template (result); +} + +/* Construct and perhaps optimize a tree representation + for a unary operation. CODE, a tree_code, specifies the operation + and XARG is the operand. */ + +tree +build_x_unary_op (enum tree_code code, tree xarg, tsubst_flags_t complain) +{ + tree orig_expr = xarg; + tree exp; + int ptrmem = 0; + + if (processing_template_decl) + { + if (type_dependent_expression_p (xarg)) + return build_min_nt (code, xarg, NULL_TREE); + + xarg = build_non_dependent_expr (xarg); + } + + exp = NULL_TREE; + + /* [expr.unary.op] says: + + The address of an object of incomplete type can be taken. + + (And is just the ordinary address operator, not an overloaded + "operator &".) However, if the type is a template + specialization, we must complete the type at this point so that + an overloaded "operator &" will be available if required. */ + if (code == ADDR_EXPR + && TREE_CODE (xarg) != TEMPLATE_ID_EXPR + && ((CLASS_TYPE_P (TREE_TYPE (xarg)) + && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg)))) + || (TREE_CODE (xarg) == OFFSET_REF))) + /* Don't look for a function. */; + else + exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE, + /*overloaded_p=*/NULL, complain); + if (!exp && code == ADDR_EXPR) + { + if (is_overloaded_fn (xarg)) + { + tree fn = get_first_fn (xarg); + if (DECL_CONSTRUCTOR_P (fn) || DECL_DESTRUCTOR_P (fn)) + { + error (DECL_CONSTRUCTOR_P (fn) + ? G_("taking address of constructor %qE") + : G_("taking address of destructor %qE"), + xarg); + return error_mark_node; + } + } + + /* A pointer to member-function can be formed only by saying + &X::mf. */ + if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE + && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg))) + { + if (TREE_CODE (xarg) != OFFSET_REF + || !TYPE_P (TREE_OPERAND (xarg, 0))) + { + error ("invalid use of %qE to form a pointer-to-member-function", + xarg); + if (TREE_CODE (xarg) != OFFSET_REF) + inform (input_location, " a qualified-id is required"); + return error_mark_node; + } + else + { + error ("parentheses around %qE cannot be used to form a" + " pointer-to-member-function", + xarg); + PTRMEM_OK_P (xarg) = 1; + } + } + + if (TREE_CODE (xarg) == OFFSET_REF) + { + ptrmem = PTRMEM_OK_P (xarg); + + if (!ptrmem && !flag_ms_extensions + && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE) + { + /* A single non-static member, make sure we don't allow a + pointer-to-member. */ + xarg = build2 (OFFSET_REF, TREE_TYPE (xarg), + TREE_OPERAND (xarg, 0), + ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE)); + PTRMEM_OK_P (xarg) = ptrmem; + } + } + + exp = cp_build_addr_expr_strict (xarg, complain); + } + + if (processing_template_decl && exp != error_mark_node) + exp = build_min_non_dep (code, exp, orig_expr, + /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE); + if (TREE_CODE (exp) == ADDR_EXPR) + PTRMEM_OK_P (exp) = ptrmem; + return exp; +} + +/* Like c_common_truthvalue_conversion, but handle pointer-to-member + constants, where a null value is represented by an INTEGER_CST of + -1. */ + +tree +cp_truthvalue_conversion (tree expr) +{ + tree type = TREE_TYPE (expr); + if (TYPE_PTRMEM_P (type)) + return build_binary_op (EXPR_LOCATION (expr), + NE_EXPR, expr, integer_zero_node, 1); + else + return c_common_truthvalue_conversion (input_location, expr); +} + +/* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */ + +tree +condition_conversion (tree expr) +{ + tree t; + if (processing_template_decl) + return expr; + t = perform_implicit_conversion_flags (boolean_type_node, expr, + tf_warning_or_error, LOOKUP_NORMAL); + t = fold_build_cleanup_point_expr (boolean_type_node, t); + return t; +} + +/* Returns the address of T. This function will fold away + ADDR_EXPR of INDIRECT_REF. */ + +tree +build_address (tree t) +{ + if (error_operand_p (t) || !cxx_mark_addressable (t)) + return error_mark_node; + t = build_fold_addr_expr (t); + if (TREE_CODE (t) != ADDR_EXPR) + t = rvalue (t); + return t; +} + +/* Returns the address of T with type TYPE. */ + +tree +build_typed_address (tree t, tree type) +{ + if (error_operand_p (t) || !cxx_mark_addressable (t)) + return error_mark_node; + t = build_fold_addr_expr_with_type (t, type); + if (TREE_CODE (t) != ADDR_EXPR) + t = rvalue (t); + return t; +} + +/* Return a NOP_EXPR converting EXPR to TYPE. */ + +tree +build_nop (tree type, tree expr) +{ + if (type == error_mark_node || error_operand_p (expr)) + return expr; + return build1 (NOP_EXPR, type, expr); +} + +/* Take the address of ARG, whatever that means under C++ semantics. + If STRICT_LVALUE is true, require an lvalue; otherwise, allow xvalues + and class rvalues as well. + + Nothing should call this function directly; instead, callers should use + cp_build_addr_expr or cp_build_addr_expr_strict. */ + +static tree +cp_build_addr_expr_1 (tree arg, bool strict_lvalue, tsubst_flags_t complain) +{ + tree argtype; + tree val; + + if (!arg || error_operand_p (arg)) + return error_mark_node; + + arg = mark_lvalue_use (arg); + argtype = lvalue_type (arg); + + gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE + || !IDENTIFIER_OPNAME_P (arg)); + + if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg) + && !really_overloaded_fn (TREE_OPERAND (arg, 1))) + { + /* They're trying to take the address of a unique non-static + member function. This is ill-formed (except in MS-land), + but let's try to DTRT. + Note: We only handle unique functions here because we don't + want to complain if there's a static overload; non-unique + cases will be handled by instantiate_type. But we need to + handle this case here to allow casts on the resulting PMF. + We could defer this in non-MS mode, but it's easier to give + a useful error here. */ + + /* Inside constant member functions, the `this' pointer + contains an extra const qualifier. TYPE_MAIN_VARIANT + is used here to remove this const from the diagnostics + and the created OFFSET_REF. */ + tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0))); + tree fn = get_first_fn (TREE_OPERAND (arg, 1)); + mark_used (fn); + + if (! flag_ms_extensions) + { + tree name = DECL_NAME (fn); + if (!(complain & tf_error)) + return error_mark_node; + else if (current_class_type + && TREE_OPERAND (arg, 0) == current_class_ref) + /* An expression like &memfn. */ + permerror (input_location, "ISO C++ forbids taking the address of an unqualified" + " or parenthesized non-static member function to form" + " a pointer to member function. Say %<&%T::%D%>", + base, name); + else + permerror (input_location, "ISO C++ forbids taking the address of a bound member" + " function to form a pointer to member function." + " Say %<&%T::%D%>", + base, name); + } + arg = build_offset_ref (base, fn, /*address_p=*/true); + } + + /* Uninstantiated types are all functions. Taking the + address of a function is a no-op, so just return the + argument. */ + if (type_unknown_p (arg)) + return build1 (ADDR_EXPR, unknown_type_node, arg); + + if (TREE_CODE (arg) == OFFSET_REF) + /* We want a pointer to member; bypass all the code for actually taking + the address of something. */ + goto offset_ref; + + /* Anything not already handled and not a true memory reference + is an error. */ + if (TREE_CODE (argtype) != FUNCTION_TYPE + && TREE_CODE (argtype) != METHOD_TYPE) + { + cp_lvalue_kind kind = lvalue_kind (arg); + if (kind == clk_none) + { + if (complain & tf_error) + lvalue_error (input_location, lv_addressof); + return error_mark_node; + } + if (strict_lvalue && (kind & (clk_rvalueref|clk_class))) + { + if (!(complain & tf_error)) + return error_mark_node; + if (kind & clk_class) + /* Make this a permerror because we used to accept it. */ + permerror (input_location, "taking address of temporary"); + else + error ("taking address of xvalue (rvalue reference)"); + } + } + + if (TREE_CODE (argtype) == REFERENCE_TYPE) + { + tree type = build_pointer_type (TREE_TYPE (argtype)); + arg = build1 (CONVERT_EXPR, type, arg); + return arg; + } + else if (pedantic && DECL_MAIN_P (arg)) + { + /* ARM $3.4 */ + /* Apparently a lot of autoconf scripts for C++ packages do this, + so only complain if -pedantic. */ + if (complain & (flag_pedantic_errors ? tf_error : tf_warning)) + pedwarn (input_location, OPT_pedantic, + "ISO C++ forbids taking address of function %<::main%>"); + else if (flag_pedantic_errors) + return error_mark_node; + } + + /* Let &* cancel out to simplify resulting code. */ + if (TREE_CODE (arg) == INDIRECT_REF) + { + /* We don't need to have `current_class_ptr' wrapped in a + NON_LVALUE_EXPR node. */ + if (arg == current_class_ref) + return current_class_ptr; + + arg = TREE_OPERAND (arg, 0); + if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE) + { + tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg))); + arg = build1 (CONVERT_EXPR, type, arg); + } + else + /* Don't let this be an lvalue. */ + arg = rvalue (arg); + return arg; + } + + /* ??? Cope with user tricks that amount to offsetof. */ + if (TREE_CODE (argtype) != FUNCTION_TYPE + && TREE_CODE (argtype) != METHOD_TYPE + && argtype != unknown_type_node + && (val = get_base_address (arg)) + && COMPLETE_TYPE_P (TREE_TYPE (val)) + && TREE_CODE (val) == INDIRECT_REF + && TREE_CONSTANT (TREE_OPERAND (val, 0))) + { + tree type = build_pointer_type (argtype); + return fold_convert (type, fold_offsetof_1 (arg)); + } + + /* Handle complex lvalues (when permitted) + by reduction to simpler cases. */ + val = unary_complex_lvalue (ADDR_EXPR, arg); + if (val != 0) + return val; + + switch (TREE_CODE (arg)) + { + CASE_CONVERT: + case FLOAT_EXPR: + case FIX_TRUNC_EXPR: + /* Even if we're not being pedantic, we cannot allow this + extension when we're instantiating in a SFINAE + context. */ + if (! lvalue_p (arg) && complain == tf_none) + { + if (complain & tf_error) + permerror (input_location, "ISO C++ forbids taking the address of a cast to a non-lvalue expression"); + else + return error_mark_node; + } + break; + + case BASELINK: + arg = BASELINK_FUNCTIONS (arg); + /* Fall through. */ + + case OVERLOAD: + arg = OVL_CURRENT (arg); + break; + + case OFFSET_REF: + offset_ref: + /* Turn a reference to a non-static data member into a + pointer-to-member. */ + { + tree type; + tree t; + + gcc_assert (PTRMEM_OK_P (arg)); + + t = TREE_OPERAND (arg, 1); + if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE) + { + if (complain & tf_error) + error ("cannot create pointer to reference member %qD", t); + return error_mark_node; + } + + type = build_ptrmem_type (context_for_name_lookup (t), + TREE_TYPE (t)); + t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1)); + return t; + } + + default: + break; + } + + if (argtype != error_mark_node) + argtype = build_pointer_type (argtype); + + /* In a template, we are processing a non-dependent expression + so we can just form an ADDR_EXPR with the correct type. */ + if (processing_template_decl || TREE_CODE (arg) != COMPONENT_REF) + { + val = build_address (arg); + if (TREE_CODE (arg) == OFFSET_REF) + PTRMEM_OK_P (val) = PTRMEM_OK_P (arg); + } + else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK) + { + tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1)); + + /* We can only get here with a single static member + function. */ + gcc_assert (TREE_CODE (fn) == FUNCTION_DECL + && DECL_STATIC_FUNCTION_P (fn)); + mark_used (fn); + val = build_address (fn); + if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0))) + /* Do not lose object's side effects. */ + val = build2 (COMPOUND_EXPR, TREE_TYPE (val), + TREE_OPERAND (arg, 0), val); + } + else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1))) + { + if (complain & tf_error) + error ("attempt to take address of bit-field structure member %qD", + TREE_OPERAND (arg, 1)); + return error_mark_node; + } + else + { + tree object = TREE_OPERAND (arg, 0); + tree field = TREE_OPERAND (arg, 1); + gcc_assert (same_type_ignoring_top_level_qualifiers_p + (TREE_TYPE (object), decl_type_context (field))); + val = build_address (arg); + } + + if (TREE_CODE (argtype) == POINTER_TYPE + && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE) + { + build_ptrmemfunc_type (argtype); + val = build_ptrmemfunc (argtype, val, 0, + /*c_cast_p=*/false, + tf_warning_or_error); + } + + return val; +} + +/* Take the address of ARG if it has one, even if it's an rvalue. */ + +tree +cp_build_addr_expr (tree arg, tsubst_flags_t complain) +{ + return cp_build_addr_expr_1 (arg, 0, complain); +} + +/* Take the address of ARG, but only if it's an lvalue. */ + +tree +cp_build_addr_expr_strict (tree arg, tsubst_flags_t complain) +{ + return cp_build_addr_expr_1 (arg, 1, complain); +} + +/* C++: Must handle pointers to members. + + Perhaps type instantiation should be extended to handle conversion + from aggregates to types we don't yet know we want? (Or are those + cases typically errors which should be reported?) + + NOCONVERT nonzero suppresses the default promotions + (such as from short to int). */ + +tree +cp_build_unary_op (enum tree_code code, tree xarg, int noconvert, + tsubst_flags_t complain) +{ + /* No default_conversion here. It causes trouble for ADDR_EXPR. */ + tree arg = xarg; + tree argtype = 0; + const char *errstring = NULL; + tree val; + const char *invalid_op_diag; + + if (!arg || error_operand_p (arg)) + return error_mark_node; + + if ((invalid_op_diag + = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR + ? CONVERT_EXPR + : code), + TREE_TYPE (xarg)))) + { + error (invalid_op_diag); + return error_mark_node; + } + + switch (code) + { + case UNARY_PLUS_EXPR: + case NEGATE_EXPR: + { + int flags = WANT_ARITH | WANT_ENUM; + /* Unary plus (but not unary minus) is allowed on pointers. */ + if (code == UNARY_PLUS_EXPR) + flags |= WANT_POINTER; + arg = build_expr_type_conversion (flags, arg, true); + if (!arg) + errstring = (code == NEGATE_EXPR + ? _("wrong type argument to unary minus") + : _("wrong type argument to unary plus")); + else + { + if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg))) + arg = perform_integral_promotions (arg); + + /* Make sure the result is not an lvalue: a unary plus or minus + expression is always a rvalue. */ + arg = rvalue (arg); + } + } + break; + + case BIT_NOT_EXPR: + if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE) + { + code = CONJ_EXPR; + if (!noconvert) + arg = default_conversion (arg); + } + else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM + | WANT_VECTOR_OR_COMPLEX, + arg, true))) + errstring = _("wrong type argument to bit-complement"); + else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg))) + arg = perform_integral_promotions (arg); + break; + + case ABS_EXPR: + if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true))) + errstring = _("wrong type argument to abs"); + else if (!noconvert) + arg = default_conversion (arg); + break; + + case CONJ_EXPR: + /* Conjugating a real value is a no-op, but allow it anyway. */ + if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true))) + errstring = _("wrong type argument to conjugation"); + else if (!noconvert) + arg = default_conversion (arg); + break; + + case TRUTH_NOT_EXPR: + arg = perform_implicit_conversion (boolean_type_node, arg, + complain); + val = invert_truthvalue_loc (input_location, arg); + if (arg != error_mark_node) + return val; + errstring = _("in argument to unary !"); + break; + + case NOP_EXPR: + break; + + case REALPART_EXPR: + case IMAGPART_EXPR: + arg = build_real_imag_expr (input_location, code, arg); + if (arg == error_mark_node) + return arg; + else + return fold_if_not_in_template (arg); + + case PREINCREMENT_EXPR: + case POSTINCREMENT_EXPR: + case PREDECREMENT_EXPR: + case POSTDECREMENT_EXPR: + /* Handle complex lvalues (when permitted) + by reduction to simpler cases. */ + + val = unary_complex_lvalue (code, arg); + if (val != 0) + return val; + + arg = mark_lvalue_use (arg); + + /* Increment or decrement the real part of the value, + and don't change the imaginary part. */ + if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE) + { + tree real, imag; + + arg = stabilize_reference (arg); + real = cp_build_unary_op (REALPART_EXPR, arg, 1, complain); + imag = cp_build_unary_op (IMAGPART_EXPR, arg, 1, complain); + real = cp_build_unary_op (code, real, 1, complain); + if (real == error_mark_node || imag == error_mark_node) + return error_mark_node; + return build2 (COMPLEX_EXPR, TREE_TYPE (arg), + real, imag); + } + + /* Report invalid types. */ + + if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER, + arg, true))) + { + if (code == PREINCREMENT_EXPR) + errstring = _("no pre-increment operator for type"); + else if (code == POSTINCREMENT_EXPR) + errstring = _("no post-increment operator for type"); + else if (code == PREDECREMENT_EXPR) + errstring = _("no pre-decrement operator for type"); + else + errstring = _("no post-decrement operator for type"); + break; + } + else if (arg == error_mark_node) + return error_mark_node; + + /* Report something read-only. */ + + if (CP_TYPE_CONST_P (TREE_TYPE (arg)) + || TREE_READONLY (arg)) + { + if (complain & tf_error) + cxx_readonly_error (arg, ((code == PREINCREMENT_EXPR + || code == POSTINCREMENT_EXPR) + ? lv_increment : lv_decrement)); + else + return error_mark_node; + } + + { + tree inc; + tree declared_type = unlowered_expr_type (arg); + + argtype = TREE_TYPE (arg); + + /* ARM $5.2.5 last annotation says this should be forbidden. */ + if (TREE_CODE (argtype) == ENUMERAL_TYPE) + { + if (complain & tf_error) + permerror (input_location, (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) + ? G_("ISO C++ forbids incrementing an enum") + : G_("ISO C++ forbids decrementing an enum")); + else + return error_mark_node; + } + + /* Compute the increment. */ + + if (TREE_CODE (argtype) == POINTER_TYPE) + { + tree type = complete_type (TREE_TYPE (argtype)); + + if (!COMPLETE_OR_VOID_TYPE_P (type)) + { + if (complain & tf_error) + error (((code == PREINCREMENT_EXPR + || code == POSTINCREMENT_EXPR)) + ? G_("cannot increment a pointer to incomplete type %qT") + : G_("cannot decrement a pointer to incomplete type %qT"), + TREE_TYPE (argtype)); + else + return error_mark_node; + } + else if ((pedantic || warn_pointer_arith) + && !TYPE_PTROB_P (argtype)) + { + if (complain & tf_error) + permerror (input_location, (code == PREINCREMENT_EXPR + || code == POSTINCREMENT_EXPR) + ? G_("ISO C++ forbids incrementing a pointer of type %qT") + : G_("ISO C++ forbids decrementing a pointer of type %qT"), + argtype); + else + return error_mark_node; + } + + inc = cxx_sizeof_nowarn (TREE_TYPE (argtype)); + } + else + inc = integer_one_node; + + inc = cp_convert (argtype, inc); + + /* If 'arg' is an Objective-C PROPERTY_REF expression, then we + need to ask Objective-C to build the increment or decrement + expression for it. */ + if (objc_is_property_ref (arg)) + return objc_build_incr_expr_for_property_ref (input_location, code, + arg, inc); + + /* Complain about anything else that is not a true lvalue. */ + if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR + || code == POSTINCREMENT_EXPR) + ? lv_increment : lv_decrement), + complain)) + return error_mark_node; + + /* Forbid using -- on `bool'. */ + if (TREE_CODE (declared_type) == BOOLEAN_TYPE) + { + if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR) + { + if (complain & tf_error) + error ("invalid use of Boolean expression as operand " + "to %<operator--%>"); + return error_mark_node; + } + val = boolean_increment (code, arg); + } + else + val = build2 (code, TREE_TYPE (arg), arg, inc); + + TREE_SIDE_EFFECTS (val) = 1; + return val; + } + + case ADDR_EXPR: + /* Note that this operation never does default_conversion + regardless of NOCONVERT. */ + return cp_build_addr_expr (arg, complain); + + default: + break; + } + + if (!errstring) + { + if (argtype == 0) + argtype = TREE_TYPE (arg); + return fold_if_not_in_template (build1 (code, argtype, arg)); + } + + if (complain & tf_error) + error ("%s", errstring); + return error_mark_node; +} + +/* Hook for the c-common bits that build a unary op. */ +tree +build_unary_op (location_t location ATTRIBUTE_UNUSED, + enum tree_code code, tree xarg, int noconvert) +{ + return cp_build_unary_op (code, xarg, noconvert, tf_warning_or_error); +} + +/* Apply unary lvalue-demanding operator CODE to the expression ARG + for certain kinds of expressions which are not really lvalues + but which we can accept as lvalues. + + If ARG is not a kind of expression we can handle, return + NULL_TREE. */ + +tree +unary_complex_lvalue (enum tree_code code, tree arg) +{ + /* Inside a template, making these kinds of adjustments is + pointless; we are only concerned with the type of the + expression. */ + if (processing_template_decl) + return NULL_TREE; + + /* Handle (a, b) used as an "lvalue". */ + if (TREE_CODE (arg) == COMPOUND_EXPR) + { + tree real_result = cp_build_unary_op (code, TREE_OPERAND (arg, 1), 0, + tf_warning_or_error); + return build2 (COMPOUND_EXPR, TREE_TYPE (real_result), + TREE_OPERAND (arg, 0), real_result); + } + + /* Handle (a ? b : c) used as an "lvalue". */ + if (TREE_CODE (arg) == COND_EXPR + || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR) + return rationalize_conditional_expr (code, arg, tf_warning_or_error); + + /* Handle (a = b), (++a), and (--a) used as an "lvalue". */ + if (TREE_CODE (arg) == MODIFY_EXPR + || TREE_CODE (arg) == PREINCREMENT_EXPR + || TREE_CODE (arg) == PREDECREMENT_EXPR) + { + tree lvalue = TREE_OPERAND (arg, 0); + if (TREE_SIDE_EFFECTS (lvalue)) + { + lvalue = stabilize_reference (lvalue); + arg = build2 (TREE_CODE (arg), TREE_TYPE (arg), + lvalue, TREE_OPERAND (arg, 1)); + } + return unary_complex_lvalue + (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue)); + } + + if (code != ADDR_EXPR) + return NULL_TREE; + + /* Handle (a = b) used as an "lvalue" for `&'. */ + if (TREE_CODE (arg) == MODIFY_EXPR + || TREE_CODE (arg) == INIT_EXPR) + { + tree real_result = cp_build_unary_op (code, TREE_OPERAND (arg, 0), 0, + tf_warning_or_error); + arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result), + arg, real_result); + TREE_NO_WARNING (arg) = 1; + return arg; + } + + if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE + || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE + || TREE_CODE (arg) == OFFSET_REF) + return NULL_TREE; + + /* We permit compiler to make function calls returning + objects of aggregate type look like lvalues. */ + { + tree targ = arg; + + if (TREE_CODE (targ) == SAVE_EXPR) + targ = TREE_OPERAND (targ, 0); + + if (TREE_CODE (targ) == CALL_EXPR && MAYBE_CLASS_TYPE_P (TREE_TYPE (targ))) + { + if (TREE_CODE (arg) == SAVE_EXPR) + targ = arg; + else + targ = build_cplus_new (TREE_TYPE (arg), arg); + return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ); + } + + if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF) + return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)), + TREE_OPERAND (targ, 0), current_function_decl, NULL); + } + + /* Don't let anything else be handled specially. */ + return NULL_TREE; +} + +/* Mark EXP saying that we need to be able to take the + address of it; it should not be allocated in a register. + Value is true if successful. + + C++: we do not allow `current_class_ptr' to be addressable. */ + +bool +cxx_mark_addressable (tree exp) +{ + tree x = exp; + + while (1) + switch (TREE_CODE (x)) + { + case ADDR_EXPR: + case COMPONENT_REF: + case ARRAY_REF: + case REALPART_EXPR: + case IMAGPART_EXPR: + x = TREE_OPERAND (x, 0); + break; + + case PARM_DECL: + if (x == current_class_ptr) + { + error ("cannot take the address of %<this%>, which is an rvalue expression"); + TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */ + return true; + } + /* Fall through. */ + + case VAR_DECL: + /* Caller should not be trying to mark initialized + constant fields addressable. */ + gcc_assert (DECL_LANG_SPECIFIC (x) == 0 + || DECL_IN_AGGR_P (x) == 0 + || TREE_STATIC (x) + || DECL_EXTERNAL (x)); + /* Fall through. */ + + case CONST_DECL: + case RESULT_DECL: + if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x) + && !DECL_ARTIFICIAL (x)) + { + if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x)) + { + error + ("address of explicit register variable %qD requested", x); + return false; + } + else if (extra_warnings) + warning + (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x); + } + TREE_ADDRESSABLE (x) = 1; + return true; + + case FUNCTION_DECL: + TREE_ADDRESSABLE (x) = 1; + return true; + + case CONSTRUCTOR: + TREE_ADDRESSABLE (x) = 1; + return true; + + case TARGET_EXPR: + TREE_ADDRESSABLE (x) = 1; + cxx_mark_addressable (TREE_OPERAND (x, 0)); + return true; + + default: + return true; + } +} + +/* Build and return a conditional expression IFEXP ? OP1 : OP2. */ + +tree +build_x_conditional_expr (tree ifexp, tree op1, tree op2, + tsubst_flags_t complain) +{ + tree orig_ifexp = ifexp; + tree orig_op1 = op1; + tree orig_op2 = op2; + tree expr; + + if (processing_template_decl) + { + /* The standard says that the expression is type-dependent if + IFEXP is type-dependent, even though the eventual type of the + expression doesn't dependent on IFEXP. */ + if (type_dependent_expression_p (ifexp) + /* As a GNU extension, the middle operand may be omitted. */ + || (op1 && type_dependent_expression_p (op1)) + || type_dependent_expression_p (op2)) + return build_min_nt (COND_EXPR, ifexp, op1, op2); + ifexp = build_non_dependent_expr (ifexp); + if (op1) + op1 = build_non_dependent_expr (op1); + op2 = build_non_dependent_expr (op2); + } + + expr = build_conditional_expr (ifexp, op1, op2, complain); + if (processing_template_decl && expr != error_mark_node) + return build_min_non_dep (COND_EXPR, expr, + orig_ifexp, orig_op1, orig_op2); + return expr; +} + +/* Given a list of expressions, return a compound expression + that performs them all and returns the value of the last of them. */ + +tree +build_x_compound_expr_from_list (tree list, expr_list_kind exp, + tsubst_flags_t complain) +{ + tree expr = TREE_VALUE (list); + + if (TREE_CHAIN (list)) + { + if (complain & tf_error) + switch (exp) + { + case ELK_INIT: + permerror (input_location, "expression list treated as compound " + "expression in initializer"); + break; + case ELK_MEM_INIT: + permerror (input_location, "expression list treated as compound " + "expression in mem-initializer"); + break; + case ELK_FUNC_CAST: + permerror (input_location, "expression list treated as compound " + "expression in functional cast"); + break; + default: + gcc_unreachable (); + } + else + return error_mark_node; + + for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list)) + expr = build_x_compound_expr (expr, TREE_VALUE (list), + complain); + } + + return expr; +} + +/* Like build_x_compound_expr_from_list, but using a VEC. */ + +tree +build_x_compound_expr_from_vec (VEC(tree,gc) *vec, const char *msg) +{ + if (VEC_empty (tree, vec)) + return NULL_TREE; + else if (VEC_length (tree, vec) == 1) + return VEC_index (tree, vec, 0); + else + { + tree expr; + unsigned int ix; + tree t; + + if (msg != NULL) + permerror (input_location, + "%s expression list treated as compound expression", + msg); + + expr = VEC_index (tree, vec, 0); + for (ix = 1; VEC_iterate (tree, vec, ix, t); ++ix) + expr = build_x_compound_expr (expr, t, tf_warning_or_error); + + return expr; + } +} + +/* Handle overloading of the ',' operator when needed. */ + +tree +build_x_compound_expr (tree op1, tree op2, tsubst_flags_t complain) +{ + tree result; + tree orig_op1 = op1; + tree orig_op2 = op2; + + if (processing_template_decl) + { + if (type_dependent_expression_p (op1) + || type_dependent_expression_p (op2)) + return build_min_nt (COMPOUND_EXPR, op1, op2); + op1 = build_non_dependent_expr (op1); + op2 = build_non_dependent_expr (op2); + } + + result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE, + /*overloaded_p=*/NULL, complain); + if (!result) + result = cp_build_compound_expr (op1, op2, complain); + + if (processing_template_decl && result != error_mark_node) + return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2); + + return result; +} + +/* Like cp_build_compound_expr, but for the c-common bits. */ + +tree +build_compound_expr (location_t loc ATTRIBUTE_UNUSED, tree lhs, tree rhs) +{ + return cp_build_compound_expr (lhs, rhs, tf_warning_or_error); +} + +/* Build a compound expression. */ + +tree +cp_build_compound_expr (tree lhs, tree rhs, tsubst_flags_t complain) +{ + lhs = convert_to_void (lhs, ICV_LEFT_OF_COMMA, complain); + + if (lhs == error_mark_node || rhs == error_mark_node) + return error_mark_node; + + if (TREE_CODE (rhs) == TARGET_EXPR) + { + /* If the rhs is a TARGET_EXPR, then build the compound + expression inside the target_expr's initializer. This + helps the compiler to eliminate unnecessary temporaries. */ + tree init = TREE_OPERAND (rhs, 1); + + init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init); + TREE_OPERAND (rhs, 1) = init; + + return rhs; + } + + if (type_unknown_p (rhs)) + { + error ("no context to resolve type of %qE", rhs); + return error_mark_node; + } + + return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs); +} + +/* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE + casts away constness. CAST gives the type of cast. + + ??? This function warns for casting away any qualifier not just + const. We would like to specify exactly what qualifiers are casted + away. +*/ + +static void +check_for_casting_away_constness (tree src_type, tree dest_type, + enum tree_code cast) +{ + /* C-style casts are allowed to cast away constness. With + WARN_CAST_QUAL, we still want to issue a warning. */ + if (cast == CAST_EXPR && !warn_cast_qual) + return; + + if (!casts_away_constness (src_type, dest_type)) + return; + + switch (cast) + { + case CAST_EXPR: + warning (OPT_Wcast_qual, + "cast from type %qT to type %qT casts away qualifiers", + src_type, dest_type); + return; + + case STATIC_CAST_EXPR: + error ("static_cast from type %qT to type %qT casts away qualifiers", + src_type, dest_type); + return; + + case REINTERPRET_CAST_EXPR: + error ("reinterpret_cast from type %qT to type %qT casts away qualifiers", + src_type, dest_type); + return; + default: + gcc_unreachable(); + } +} + +/* Convert EXPR (an expression with pointer-to-member type) to TYPE + (another pointer-to-member type in the same hierarchy) and return + the converted expression. If ALLOW_INVERSE_P is permitted, a + pointer-to-derived may be converted to pointer-to-base; otherwise, + only the other direction is permitted. If C_CAST_P is true, this + conversion is taking place as part of a C-style cast. */ + +tree +convert_ptrmem (tree type, tree expr, bool allow_inverse_p, + bool c_cast_p, tsubst_flags_t complain) +{ + if (TYPE_PTRMEM_P (type)) + { + tree delta; + + if (TREE_CODE (expr) == PTRMEM_CST) + expr = cplus_expand_constant (expr); + delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)), + TYPE_PTRMEM_CLASS_TYPE (type), + allow_inverse_p, + c_cast_p, complain); + if (delta == error_mark_node) + return error_mark_node; + + if (!integer_zerop (delta)) + { + tree cond, op1, op2; + + cond = cp_build_binary_op (input_location, + EQ_EXPR, + expr, + build_int_cst (TREE_TYPE (expr), -1), + tf_warning_or_error); + op1 = build_nop (ptrdiff_type_node, expr); + op2 = cp_build_binary_op (input_location, + PLUS_EXPR, op1, delta, + tf_warning_or_error); + + expr = fold_build3_loc (input_location, + COND_EXPR, ptrdiff_type_node, cond, op1, op2); + + } + + return build_nop (type, expr); + } + else + return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr, + allow_inverse_p, c_cast_p, complain); +} + +/* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true, + this static_cast is being attempted as one of the possible casts + allowed by a C-style cast. (In that case, accessibility of base + classes is not considered, and it is OK to cast away + constness.) Return the result of the cast. *VALID_P is set to + indicate whether or not the cast was valid. */ + +static tree +build_static_cast_1 (tree type, tree expr, bool c_cast_p, + bool *valid_p, tsubst_flags_t complain) +{ + tree intype; + tree result; + cp_lvalue_kind clk; + + /* Assume the cast is valid. */ + *valid_p = true; + + intype = unlowered_expr_type (expr); + + /* Save casted types in the function's used types hash table. */ + used_types_insert (type); + + /* [expr.static.cast] + + An lvalue of type "cv1 B", where B is a class type, can be cast + to type "reference to cv2 D", where D is a class derived (clause + _class.derived_) from B, if a valid standard conversion from + "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the + same cv-qualification as, or greater cv-qualification than, cv1, + and B is not a virtual base class of D. */ + /* We check this case before checking the validity of "TYPE t = + EXPR;" below because for this case: + + struct B {}; + struct D : public B { D(const B&); }; + extern B& b; + void f() { static_cast<const D&>(b); } + + we want to avoid constructing a new D. The standard is not + completely clear about this issue, but our interpretation is + consistent with other compilers. */ + if (TREE_CODE (type) == REFERENCE_TYPE + && CLASS_TYPE_P (TREE_TYPE (type)) + && CLASS_TYPE_P (intype) + && (TYPE_REF_IS_RVALUE (type) || real_lvalue_p (expr)) + && DERIVED_FROM_P (intype, TREE_TYPE (type)) + && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)), + build_pointer_type (TYPE_MAIN_VARIANT + (TREE_TYPE (type)))) + && (c_cast_p + || at_least_as_qualified_p (TREE_TYPE (type), intype))) + { + tree base; + + /* There is a standard conversion from "D*" to "B*" even if "B" + is ambiguous or inaccessible. If this is really a + static_cast, then we check both for inaccessibility and + ambiguity. However, if this is a static_cast being performed + because the user wrote a C-style cast, then accessibility is + not considered. */ + base = lookup_base (TREE_TYPE (type), intype, + c_cast_p ? ba_unique : ba_check, + NULL); + + /* Convert from "B*" to "D*". This function will check that "B" + is not a virtual base of "D". */ + expr = build_base_path (MINUS_EXPR, build_address (expr), + base, /*nonnull=*/false); + /* Convert the pointer to a reference -- but then remember that + there are no expressions with reference type in C++. + + We call rvalue so that there's an actual tree code + (NON_LVALUE_EXPR) for the static_cast; otherwise, if the operand + is a variable with the same type, the conversion would get folded + away, leaving just the variable and causing lvalue_kind to give + the wrong answer. */ + return convert_from_reference (rvalue (cp_fold_convert (type, expr))); + } + + /* "An lvalue of type cv1 T1 can be cast to type rvalue reference to + cv2 T2 if cv2 T2 is reference-compatible with cv1 T1 (8.5.3)." */ + if (TREE_CODE (type) == REFERENCE_TYPE + && TYPE_REF_IS_RVALUE (type) + && (clk = real_lvalue_p (expr)) + && reference_related_p (TREE_TYPE (type), intype) + && (c_cast_p || at_least_as_qualified_p (TREE_TYPE (type), intype))) + { + if (clk == clk_ordinary) + { + /* Handle the (non-bit-field) lvalue case here by casting to + lvalue reference and then changing it to an rvalue reference. + Casting an xvalue to rvalue reference will be handled by the + main code path. */ + tree lref = cp_build_reference_type (TREE_TYPE (type), false); + result = (perform_direct_initialization_if_possible + (lref, expr, c_cast_p, complain)); + result = cp_fold_convert (type, result); + /* Make sure we don't fold back down to a named rvalue reference, + because that would be an lvalue. */ + if (DECL_P (result)) + result = build1 (NON_LVALUE_EXPR, type, result); + return convert_from_reference (result); + } + else + /* For a bit-field or packed field, bind to a temporary. */ + expr = rvalue (expr); + } + + /* Resolve overloaded address here rather than once in + implicit_conversion and again in the inverse code below. */ + if (TYPE_PTRMEMFUNC_P (type) && type_unknown_p (expr)) + { + expr = instantiate_type (type, expr, complain); + intype = TREE_TYPE (expr); + } + + /* [expr.static.cast] + + An expression e can be explicitly converted to a type T using a + static_cast of the form static_cast<T>(e) if the declaration T + t(e);" is well-formed, for some invented temporary variable + t. */ + result = perform_direct_initialization_if_possible (type, expr, + c_cast_p, complain); + if (result) + { + result = convert_from_reference (result); + + /* [expr.static.cast] + + If T is a reference type, the result is an lvalue; otherwise, + the result is an rvalue. */ + if (TREE_CODE (type) != REFERENCE_TYPE) + result = rvalue (result); + return result; + } + + /* [expr.static.cast] + + Any expression can be explicitly converted to type cv void. */ + if (TREE_CODE (type) == VOID_TYPE) + return convert_to_void (expr, ICV_CAST, complain); + + /* [expr.static.cast] + + The inverse of any standard conversion sequence (clause _conv_), + other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer + (_conv.array_), function-to-pointer (_conv.func_), and boolean + (_conv.bool_) conversions, can be performed explicitly using + static_cast subject to the restriction that the explicit + conversion does not cast away constness (_expr.const.cast_), and + the following additional rules for specific cases: */ + /* For reference, the conversions not excluded are: integral + promotions, floating point promotion, integral conversions, + floating point conversions, floating-integral conversions, + pointer conversions, and pointer to member conversions. */ + /* DR 128 + + A value of integral _or enumeration_ type can be explicitly + converted to an enumeration type. */ + /* The effect of all that is that any conversion between any two + types which are integral, floating, or enumeration types can be + performed. */ + if ((INTEGRAL_OR_ENUMERATION_TYPE_P (type) + || SCALAR_FLOAT_TYPE_P (type)) + && (INTEGRAL_OR_ENUMERATION_TYPE_P (intype) + || SCALAR_FLOAT_TYPE_P (intype))) + return ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL); + + if (TYPE_PTR_P (type) && TYPE_PTR_P (intype) + && CLASS_TYPE_P (TREE_TYPE (type)) + && CLASS_TYPE_P (TREE_TYPE (intype)) + && can_convert (build_pointer_type (TYPE_MAIN_VARIANT + (TREE_TYPE (intype))), + build_pointer_type (TYPE_MAIN_VARIANT + (TREE_TYPE (type))))) + { + tree base; + + if (!c_cast_p) + check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR); + base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype), + c_cast_p ? ba_unique : ba_check, + NULL); + expr = build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false); + return cp_fold_convert(type, expr); + } + + if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype)) + || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype))) + { + tree c1; + tree c2; + tree t1; + tree t2; + + c1 = TYPE_PTRMEM_CLASS_TYPE (intype); + c2 = TYPE_PTRMEM_CLASS_TYPE (type); + + if (TYPE_PTRMEM_P (type)) + { + t1 = (build_ptrmem_type + (c1, + TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype)))); + t2 = (build_ptrmem_type + (c2, + TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type)))); + } + else + { + t1 = intype; + t2 = type; + } + if (can_convert (t1, t2) || can_convert (t2, t1)) + { + if (!c_cast_p) + check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR); + return convert_ptrmem (type, expr, /*allow_inverse_p=*/1, + c_cast_p, tf_warning_or_error); + } + } + + /* [expr.static.cast] + + An rvalue of type "pointer to cv void" can be explicitly + converted to a pointer to object type. A value of type pointer + to object converted to "pointer to cv void" and back to the + original pointer type will have its original value. */ + if (TREE_CODE (intype) == POINTER_TYPE + && VOID_TYPE_P (TREE_TYPE (intype)) + && TYPE_PTROB_P (type)) + { + if (!c_cast_p) + check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR); + return build_nop (type, expr); + } + + *valid_p = false; + return error_mark_node; +} + +/* Return an expression representing static_cast<TYPE>(EXPR). */ + +tree +build_static_cast (tree type, tree expr, tsubst_flags_t complain) +{ + tree result; + bool valid_p; + + if (type == error_mark_node || expr == error_mark_node) + return error_mark_node; + + if (processing_template_decl) + { + expr = build_min (STATIC_CAST_EXPR, type, expr); + /* We don't know if it will or will not have side effects. */ + TREE_SIDE_EFFECTS (expr) = 1; + return convert_from_reference (expr); + } + + /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue. + Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */ + if (TREE_CODE (type) != REFERENCE_TYPE + && TREE_CODE (expr) == NOP_EXPR + && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0))) + expr = TREE_OPERAND (expr, 0); + + result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p, + complain); + if (valid_p) + return result; + + if (complain & tf_error) + error ("invalid static_cast from type %qT to type %qT", + TREE_TYPE (expr), type); + return error_mark_node; +} + +/* EXPR is an expression with member function or pointer-to-member + function type. TYPE is a pointer type. Converting EXPR to TYPE is + not permitted by ISO C++, but we accept it in some modes. If we + are not in one of those modes, issue a diagnostic. Return the + converted expression. */ + +tree +convert_member_func_to_ptr (tree type, tree expr) +{ + tree intype; + tree decl; + + intype = TREE_TYPE (expr); + gcc_assert (TYPE_PTRMEMFUNC_P (intype) + || TREE_CODE (intype) == METHOD_TYPE); + + if (pedantic || warn_pmf2ptr) + pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpmf_conversions, + "converting from %qT to %qT", intype, type); + + if (TREE_CODE (intype) == METHOD_TYPE) + expr = build_addr_func (expr); + else if (TREE_CODE (expr) == PTRMEM_CST) + expr = build_address (PTRMEM_CST_MEMBER (expr)); + else + { + decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0); + decl = build_address (decl); + expr = get_member_function_from_ptrfunc (&decl, expr); + } + + return build_nop (type, expr); +} + +/* Return a representation for a reinterpret_cast from EXPR to TYPE. + If C_CAST_P is true, this reinterpret cast is being done as part of + a C-style cast. If VALID_P is non-NULL, *VALID_P is set to + indicate whether or not reinterpret_cast was valid. */ + +static tree +build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p, + bool *valid_p, tsubst_flags_t complain) +{ + tree intype; + + /* Assume the cast is invalid. */ + if (valid_p) + *valid_p = true; + + if (type == error_mark_node || error_operand_p (expr)) + return error_mark_node; + + intype = TREE_TYPE (expr); + + /* Save casted types in the function's used types hash table. */ + used_types_insert (type); + + /* [expr.reinterpret.cast] + An lvalue expression of type T1 can be cast to the type + "reference to T2" if an expression of type "pointer to T1" can be + explicitly converted to the type "pointer to T2" using a + reinterpret_cast. */ + if (TREE_CODE (type) == REFERENCE_TYPE) + { + if (! real_lvalue_p (expr)) + { + if (complain & tf_error) + error ("invalid cast of an rvalue expression of type " + "%qT to type %qT", + intype, type); + return error_mark_node; + } + + /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and + "B" are related class types; the reinterpret_cast does not + adjust the pointer. */ + if (TYPE_PTR_P (intype) + && (complain & tf_warning) + && (comptypes (TREE_TYPE (intype), TREE_TYPE (type), + COMPARE_BASE | COMPARE_DERIVED))) + warning (0, "casting %qT to %qT does not dereference pointer", + intype, type); + + expr = cp_build_addr_expr (expr, complain); + + if (warn_strict_aliasing > 2) + strict_aliasing_warning (TREE_TYPE (expr), type, expr); + + if (expr != error_mark_node) + expr = build_reinterpret_cast_1 + (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p, + valid_p, complain); + if (expr != error_mark_node) + /* cp_build_indirect_ref isn't right for rvalue refs. */ + expr = convert_from_reference (fold_convert (type, expr)); + return expr; + } + + /* As a G++ extension, we consider conversions from member + functions, and pointers to member functions to + pointer-to-function and pointer-to-void types. If + -Wno-pmf-conversions has not been specified, + convert_member_func_to_ptr will issue an error message. */ + if ((TYPE_PTRMEMFUNC_P (intype) + || TREE_CODE (intype) == METHOD_TYPE) + && TYPE_PTR_P (type) + && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE + || VOID_TYPE_P (TREE_TYPE (type)))) + return convert_member_func_to_ptr (type, expr); + + /* If the cast is not to a reference type, the lvalue-to-rvalue, + array-to-pointer, and function-to-pointer conversions are + performed. */ + expr = decay_conversion (expr); + + /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue. + Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */ + if (TREE_CODE (expr) == NOP_EXPR + && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0))) + expr = TREE_OPERAND (expr, 0); + + if (error_operand_p (expr)) + return error_mark_node; + + intype = TREE_TYPE (expr); + + /* [expr.reinterpret.cast] + A pointer can be converted to any integral type large enough to + hold it. ... A value of type std::nullptr_t can be converted to + an integral type; the conversion has the same meaning and + validity as a conversion of (void*)0 to the integral type. */ + if (CP_INTEGRAL_TYPE_P (type) + && (TYPE_PTR_P (intype) || NULLPTR_TYPE_P (intype))) + { + if (TYPE_PRECISION (type) < TYPE_PRECISION (intype)) + { + if (complain & tf_error) + permerror (input_location, "cast from %qT to %qT loses precision", + intype, type); + else + return error_mark_node; + } + if (NULLPTR_TYPE_P (intype)) + return build_int_cst (type, 0); + } + /* [expr.reinterpret.cast] + A value of integral or enumeration type can be explicitly + converted to a pointer. */ + else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype)) + /* OK */ + ; + else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype)) + || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype))) + return fold_if_not_in_template (build_nop (type, expr)); + else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype)) + || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype))) + { + tree sexpr = expr; + + if (!c_cast_p) + check_for_casting_away_constness (intype, type, REINTERPRET_CAST_EXPR); + /* Warn about possible alignment problems. */ + if (STRICT_ALIGNMENT && warn_cast_align + && (complain & tf_warning) + && !VOID_TYPE_P (type) + && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE + && COMPLETE_TYPE_P (TREE_TYPE (type)) + && COMPLETE_TYPE_P (TREE_TYPE (intype)) + && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype))) + warning (OPT_Wcast_align, "cast from %qT to %qT " + "increases required alignment of target type", intype, type); + + /* We need to strip nops here, because the front end likes to + create (int *)&a for array-to-pointer decay, instead of &a[0]. */ + STRIP_NOPS (sexpr); + if (warn_strict_aliasing <= 2) + strict_aliasing_warning (intype, type, sexpr); + + return fold_if_not_in_template (build_nop (type, expr)); + } + else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype)) + || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type))) + { + if (pedantic && (complain & tf_warning)) + /* Only issue a warning, as we have always supported this + where possible, and it is necessary in some cases. DR 195 + addresses this issue, but as of 2004/10/26 is still in + drafting. */ + warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object"); + return fold_if_not_in_template (build_nop (type, expr)); + } + else if (TREE_CODE (type) == VECTOR_TYPE) + return fold_if_not_in_template (convert_to_vector (type, expr)); + else if (TREE_CODE (intype) == VECTOR_TYPE + && INTEGRAL_OR_ENUMERATION_TYPE_P (type)) + return fold_if_not_in_template (convert_to_integer (type, expr)); + else + { + if (valid_p) + *valid_p = false; + if (complain & tf_error) + error ("invalid cast from type %qT to type %qT", intype, type); + return error_mark_node; + } + + return cp_convert (type, expr); +} + +tree +build_reinterpret_cast (tree type, tree expr, tsubst_flags_t complain) +{ + if (type == error_mark_node || expr == error_mark_node) + return error_mark_node; + + if (processing_template_decl) + { + tree t = build_min (REINTERPRET_CAST_EXPR, type, expr); + + if (!TREE_SIDE_EFFECTS (t) + && type_dependent_expression_p (expr)) + /* There might turn out to be side effects inside expr. */ + TREE_SIDE_EFFECTS (t) = 1; + return convert_from_reference (t); + } + + return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false, + /*valid_p=*/NULL, complain); +} + +/* Perform a const_cast from EXPR to TYPE. If the cast is valid, + return an appropriate expression. Otherwise, return + error_mark_node. If the cast is not valid, and COMPLAIN is true, + then a diagnostic will be issued. If VALID_P is non-NULL, we are + performing a C-style cast, its value upon return will indicate + whether or not the conversion succeeded. */ + +static tree +build_const_cast_1 (tree dst_type, tree expr, bool complain, + bool *valid_p) +{ + tree src_type; + tree reference_type; + + /* Callers are responsible for handling error_mark_node as a + destination type. */ + gcc_assert (dst_type != error_mark_node); + /* In a template, callers should be building syntactic + representations of casts, not using this machinery. */ + gcc_assert (!processing_template_decl); + + /* Assume the conversion is invalid. */ + if (valid_p) + *valid_p = false; + + if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type)) + { + if (complain) + error ("invalid use of const_cast with type %qT, " + "which is not a pointer, " + "reference, nor a pointer-to-data-member type", dst_type); + return error_mark_node; + } + + if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE) + { + if (complain) + error ("invalid use of const_cast with type %qT, which is a pointer " + "or reference to a function type", dst_type); + return error_mark_node; + } + + /* Save casted types in the function's used types hash table. */ + used_types_insert (dst_type); + + src_type = TREE_TYPE (expr); + /* Expressions do not really have reference types. */ + if (TREE_CODE (src_type) == REFERENCE_TYPE) + src_type = TREE_TYPE (src_type); + + /* [expr.const.cast] + + For two object types T1 and T2, if a pointer to T1 can be explicitly + converted to the type "pointer to T2" using a const_cast, then the + following conversions can also be made: + + -- an lvalue of type T1 can be explicitly converted to an lvalue of + type T2 using the cast const_cast<T2&>; + + -- a glvalue of type T1 can be explicitly converted to an xvalue of + type T2 using the cast const_cast<T2&&>; and + + -- if T1 is a class type, a prvalue of type T1 can be explicitly + converted to an xvalue of type T2 using the cast const_cast<T2&&>. */ + + if (TREE_CODE (dst_type) == REFERENCE_TYPE) + { + reference_type = dst_type; + if (!TYPE_REF_IS_RVALUE (dst_type) + ? real_lvalue_p (expr) + : (CLASS_TYPE_P (TREE_TYPE (dst_type)) + ? lvalue_p (expr) + : lvalue_or_rvalue_with_address_p (expr))) + /* OK. */; + else + { + if (complain) + error ("invalid const_cast of an rvalue of type %qT to type %qT", + src_type, dst_type); + return error_mark_node; + } + dst_type = build_pointer_type (TREE_TYPE (dst_type)); + src_type = build_pointer_type (src_type); + } + else + { + reference_type = NULL_TREE; + /* If the destination type is not a reference type, the + lvalue-to-rvalue, array-to-pointer, and function-to-pointer + conversions are performed. */ + src_type = type_decays_to (src_type); + if (src_type == error_mark_node) + return error_mark_node; + } + + if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type)) + && comp_ptr_ttypes_const (dst_type, src_type)) + { + if (valid_p) + { + *valid_p = true; + /* This cast is actually a C-style cast. Issue a warning if + the user is making a potentially unsafe cast. */ + check_for_casting_away_constness (src_type, dst_type, CAST_EXPR); + } + if (reference_type) + { + expr = cp_build_addr_expr (expr, + complain ? tf_warning_or_error : tf_none); + expr = build_nop (reference_type, expr); + return convert_from_reference (expr); + } + else + { + expr = decay_conversion (expr); + /* build_c_cast puts on a NOP_EXPR to make the result not an + lvalue. Strip such NOP_EXPRs if VALUE is being used in + non-lvalue context. */ + if (TREE_CODE (expr) == NOP_EXPR + && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0))) + expr = TREE_OPERAND (expr, 0); + return build_nop (dst_type, expr); + } + } + + if (complain) + error ("invalid const_cast from type %qT to type %qT", + src_type, dst_type); + return error_mark_node; +} + +tree +build_const_cast (tree type, tree expr, tsubst_flags_t complain) +{ + if (type == error_mark_node || error_operand_p (expr)) + return error_mark_node; + + if (processing_template_decl) + { + tree t = build_min (CONST_CAST_EXPR, type, expr); + + if (!TREE_SIDE_EFFECTS (t) + && type_dependent_expression_p (expr)) + /* There might turn out to be side effects inside expr. */ + TREE_SIDE_EFFECTS (t) = 1; + return convert_from_reference (t); + } + + return build_const_cast_1 (type, expr, complain & tf_error, + /*valid_p=*/NULL); +} + +/* Like cp_build_c_cast, but for the c-common bits. */ + +tree +build_c_cast (location_t loc ATTRIBUTE_UNUSED, tree type, tree expr) +{ + return cp_build_c_cast (type, expr, tf_warning_or_error); +} + +/* Build an expression representing an explicit C-style cast to type + TYPE of expression EXPR. */ + +tree +cp_build_c_cast (tree type, tree expr, tsubst_flags_t complain) +{ + tree value = expr; + tree result; + bool valid_p; + + if (type == error_mark_node || error_operand_p (expr)) + return error_mark_node; + + if (processing_template_decl) + { + tree t = build_min (CAST_EXPR, type, + tree_cons (NULL_TREE, value, NULL_TREE)); + /* We don't know if it will or will not have side effects. */ + TREE_SIDE_EFFECTS (t) = 1; + return convert_from_reference (t); + } + + /* Casts to a (pointer to a) specific ObjC class (or 'id' or + 'Class') should always be retained, because this information aids + in method lookup. */ + if (objc_is_object_ptr (type) + && objc_is_object_ptr (TREE_TYPE (expr))) + return build_nop (type, expr); + + /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue. + Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */ + if (TREE_CODE (type) != REFERENCE_TYPE + && TREE_CODE (value) == NOP_EXPR + && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0))) + value = TREE_OPERAND (value, 0); + + if (TREE_CODE (type) == ARRAY_TYPE) + { + /* Allow casting from T1* to T2[] because Cfront allows it. + NIHCL uses it. It is not valid ISO C++ however. */ + if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE) + { + if (complain & tf_error) + permerror (input_location, "ISO C++ forbids casting to an array type %qT", type); + else + return error_mark_node; + type = build_pointer_type (TREE_TYPE (type)); + } + else + { + if (complain & tf_error) + error ("ISO C++ forbids casting to an array type %qT", type); + return error_mark_node; + } + } + + if (TREE_CODE (type) == FUNCTION_TYPE + || TREE_CODE (type) == METHOD_TYPE) + { + if (complain & tf_error) + error ("invalid cast to function type %qT", type); + return error_mark_node; + } + + if (TREE_CODE (type) == POINTER_TYPE + && TREE_CODE (TREE_TYPE (value)) == INTEGER_TYPE + /* Casting to an integer of smaller size is an error detected elsewhere. */ + && TYPE_PRECISION (type) > TYPE_PRECISION (TREE_TYPE (value)) + /* Don't warn about converting any constant. */ + && !TREE_CONSTANT (value)) + warning_at (input_location, OPT_Wint_to_pointer_cast, + "cast to pointer from integer of different size"); + + /* A C-style cast can be a const_cast. */ + result = build_const_cast_1 (type, value, /*complain=*/false, + &valid_p); + if (valid_p) + return result; + + /* Or a static cast. */ + result = build_static_cast_1 (type, value, /*c_cast_p=*/true, + &valid_p, complain); + /* Or a reinterpret_cast. */ + if (!valid_p) + result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true, + &valid_p, complain); + /* The static_cast or reinterpret_cast may be followed by a + const_cast. */ + if (valid_p + /* A valid cast may result in errors if, for example, a + conversion to am ambiguous base class is required. */ + && !error_operand_p (result)) + { + tree result_type; + + /* Non-class rvalues always have cv-unqualified type. */ + if (!CLASS_TYPE_P (type)) + type = TYPE_MAIN_VARIANT (type); + result_type = TREE_TYPE (result); + if (!CLASS_TYPE_P (result_type)) + result_type = TYPE_MAIN_VARIANT (result_type); + /* If the type of RESULT does not match TYPE, perform a + const_cast to make it match. If the static_cast or + reinterpret_cast succeeded, we will differ by at most + cv-qualification, so the follow-on const_cast is guaranteed + to succeed. */ + if (!same_type_p (non_reference (type), non_reference (result_type))) + { + result = build_const_cast_1 (type, result, false, &valid_p); + gcc_assert (valid_p); + } + return result; + } + + return error_mark_node; +} + +/* For use from the C common bits. */ +tree +build_modify_expr (location_t location ATTRIBUTE_UNUSED, + tree lhs, tree lhs_origtype ATTRIBUTE_UNUSED, + enum tree_code modifycode, + location_t rhs_location ATTRIBUTE_UNUSED, tree rhs, + tree rhs_origtype ATTRIBUTE_UNUSED) +{ + return cp_build_modify_expr (lhs, modifycode, rhs, tf_warning_or_error); +} + +/* Build an assignment expression of lvalue LHS from value RHS. + MODIFYCODE is the code for a binary operator that we use + to combine the old value of LHS with RHS to get the new value. + Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. + + C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */ + +tree +cp_build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs, + tsubst_flags_t complain) +{ + tree result; + tree newrhs = rhs; + tree lhstype = TREE_TYPE (lhs); + tree olhstype = lhstype; + bool plain_assign = (modifycode == NOP_EXPR); + + /* Avoid duplicate error messages from operands that had errors. */ + if (error_operand_p (lhs) || error_operand_p (rhs)) + return error_mark_node; + + /* Handle control structure constructs used as "lvalues". */ + switch (TREE_CODE (lhs)) + { + /* Handle --foo = 5; as these are valid constructs in C++. */ + case PREDECREMENT_EXPR: + case PREINCREMENT_EXPR: + if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))) + lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs), + stabilize_reference (TREE_OPERAND (lhs, 0)), + TREE_OPERAND (lhs, 1)); + newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 0), + modifycode, rhs, complain); + if (newrhs == error_mark_node) + return error_mark_node; + return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs); + + /* Handle (a, b) used as an "lvalue". */ + case COMPOUND_EXPR: + newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 1), + modifycode, rhs, complain); + if (newrhs == error_mark_node) + return error_mark_node; + return build2 (COMPOUND_EXPR, lhstype, + TREE_OPERAND (lhs, 0), newrhs); + + case MODIFY_EXPR: + if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))) + lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs), + stabilize_reference (TREE_OPERAND (lhs, 0)), + TREE_OPERAND (lhs, 1)); + newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs, + complain); + if (newrhs == error_mark_node) + return error_mark_node; + return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs); + + case MIN_EXPR: + case MAX_EXPR: + /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues, + when neither operand has side-effects. */ + if (!lvalue_or_else (lhs, lv_assign, complain)) + return error_mark_node; + + gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)) + && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1))); + + lhs = build3 (COND_EXPR, TREE_TYPE (lhs), + build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR, + boolean_type_node, + TREE_OPERAND (lhs, 0), + TREE_OPERAND (lhs, 1)), + TREE_OPERAND (lhs, 0), + TREE_OPERAND (lhs, 1)); + /* Fall through. */ + + /* Handle (a ? b : c) used as an "lvalue". */ + case COND_EXPR: + { + /* Produce (a ? (b = rhs) : (c = rhs)) + except that the RHS goes through a save-expr + so the code to compute it is only emitted once. */ + tree cond; + tree preeval = NULL_TREE; + + if (VOID_TYPE_P (TREE_TYPE (rhs))) + { + if (complain & tf_error) + error ("void value not ignored as it ought to be"); + return error_mark_node; + } + + rhs = stabilize_expr (rhs, &preeval); + + /* Check this here to avoid odd errors when trying to convert + a throw to the type of the COND_EXPR. */ + if (!lvalue_or_else (lhs, lv_assign, complain)) + return error_mark_node; + + cond = build_conditional_expr + (TREE_OPERAND (lhs, 0), + cp_build_modify_expr (TREE_OPERAND (lhs, 1), + modifycode, rhs, complain), + cp_build_modify_expr (TREE_OPERAND (lhs, 2), + modifycode, rhs, complain), + complain); + + if (cond == error_mark_node) + return cond; + /* Make sure the code to compute the rhs comes out + before the split. */ + if (preeval) + cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond); + return cond; + } + + default: + break; + } + + if (modifycode == INIT_EXPR) + { + if (BRACE_ENCLOSED_INITIALIZER_P (rhs)) + /* Do the default thing. */; + else if (TREE_CODE (rhs) == CONSTRUCTOR) + { + /* Compound literal. */ + if (! same_type_p (TREE_TYPE (rhs), lhstype)) + /* Call convert to generate an error; see PR 11063. */ + rhs = convert (lhstype, rhs); + result = build2 (INIT_EXPR, lhstype, lhs, rhs); + TREE_SIDE_EFFECTS (result) = 1; + return result; + } + else if (! MAYBE_CLASS_TYPE_P (lhstype)) + /* Do the default thing. */; + else + { + VEC(tree,gc) *rhs_vec = make_tree_vector_single (rhs); + result = build_special_member_call (lhs, complete_ctor_identifier, + &rhs_vec, lhstype, LOOKUP_NORMAL, + complain); + release_tree_vector (rhs_vec); + if (result == NULL_TREE) + return error_mark_node; + return result; + } + } + else + { + lhs = require_complete_type_sfinae (lhs, complain); + if (lhs == error_mark_node) + return error_mark_node; + + if (modifycode == NOP_EXPR) + { + if (c_dialect_objc ()) + { + result = objc_maybe_build_modify_expr (lhs, rhs); + if (result) + return result; + } + + /* `operator=' is not an inheritable operator. */ + if (! MAYBE_CLASS_TYPE_P (lhstype)) + /* Do the default thing. */; + else + { + result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, + lhs, rhs, make_node (NOP_EXPR), + /*overloaded_p=*/NULL, + complain); + if (result == NULL_TREE) + return error_mark_node; + return result; + } + lhstype = olhstype; + } + else + { + /* A binary op has been requested. Combine the old LHS + value with the RHS producing the value we should actually + store into the LHS. */ + gcc_assert (!((TREE_CODE (lhstype) == REFERENCE_TYPE + && MAYBE_CLASS_TYPE_P (TREE_TYPE (lhstype))) + || MAYBE_CLASS_TYPE_P (lhstype))); + + lhs = stabilize_reference (lhs); + newrhs = cp_build_binary_op (input_location, + modifycode, lhs, rhs, + complain); + if (newrhs == error_mark_node) + { + if (complain & tf_error) + error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode, + TREE_TYPE (lhs), TREE_TYPE (rhs)); + return error_mark_node; + } + + /* Now it looks like a plain assignment. */ + modifycode = NOP_EXPR; + if (c_dialect_objc ()) + { + result = objc_maybe_build_modify_expr (lhs, newrhs); + if (result) + return result; + } + } + gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE); + gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE); + } + + /* The left-hand side must be an lvalue. */ + if (!lvalue_or_else (lhs, lv_assign, complain)) + return error_mark_node; + + /* Warn about modifying something that is `const'. Don't warn if + this is initialization. */ + if (modifycode != INIT_EXPR + && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype) + /* Functions are not modifiable, even though they are + lvalues. */ + || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE + || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE + /* If it's an aggregate and any field is const, then it is + effectively const. */ + || (CLASS_TYPE_P (lhstype) + && C_TYPE_FIELDS_READONLY (lhstype)))) + { + if (complain & tf_error) + cxx_readonly_error (lhs, lv_assign); + else + return error_mark_node; + } + + /* If storing into a structure or union member, it may have been given a + lowered bitfield type. We need to convert to the declared type first, + so retrieve it now. */ + + olhstype = unlowered_expr_type (lhs); + + /* Convert new value to destination type. */ + + if (TREE_CODE (lhstype) == ARRAY_TYPE) + { + int from_array; + + if (BRACE_ENCLOSED_INITIALIZER_P (newrhs)) + { + if (modifycode != INIT_EXPR) + { + if (complain & tf_error) + error ("assigning to an array from an initializer list"); + return error_mark_node; + } + if (check_array_initializer (lhs, lhstype, newrhs)) + return error_mark_node; + newrhs = digest_init (lhstype, newrhs); + } + + else if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype), + TYPE_MAIN_VARIANT (TREE_TYPE (newrhs)))) + { + if (complain & tf_error) + error ("incompatible types in assignment of %qT to %qT", + TREE_TYPE (rhs), lhstype); + return error_mark_node; + } + + /* Allow array assignment in compiler-generated code. */ + else if (!current_function_decl + || !DECL_DEFAULTED_FN (current_function_decl)) + { + /* This routine is used for both initialization and assignment. + Make sure the diagnostic message differentiates the context. */ + if (complain & tf_error) + { + if (modifycode == INIT_EXPR) + error ("array used as initializer"); + else + error ("invalid array assignment"); + } + return error_mark_node; + } + + from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE + ? 1 + (modifycode != INIT_EXPR): 0; + return build_vec_init (lhs, NULL_TREE, newrhs, + /*explicit_value_init_p=*/false, + from_array, complain); + } + + if (modifycode == INIT_EXPR) + /* Calls with INIT_EXPR are all direct-initialization, so don't set + LOOKUP_ONLYCONVERTING. */ + newrhs = convert_for_initialization (lhs, olhstype, newrhs, LOOKUP_NORMAL, + ICR_INIT, NULL_TREE, 0, + complain); + else + newrhs = convert_for_assignment (olhstype, newrhs, ICR_ASSIGN, + NULL_TREE, 0, complain, LOOKUP_IMPLICIT); + + if (!same_type_p (lhstype, olhstype)) + newrhs = cp_convert_and_check (lhstype, newrhs); + + if (modifycode != INIT_EXPR) + { + if (TREE_CODE (newrhs) == CALL_EXPR + && TYPE_NEEDS_CONSTRUCTING (lhstype)) + newrhs = build_cplus_new (lhstype, newrhs); + + /* Can't initialize directly from a TARGET_EXPR, since that would + cause the lhs to be constructed twice, and possibly result in + accidental self-initialization. So we force the TARGET_EXPR to be + expanded without a target. */ + if (TREE_CODE (newrhs) == TARGET_EXPR) + newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs, + TREE_OPERAND (newrhs, 0)); + } + + if (newrhs == error_mark_node) + return error_mark_node; + + if (c_dialect_objc () && flag_objc_gc) + { + result = objc_generate_write_barrier (lhs, modifycode, newrhs); + + if (result) + return result; + } + + result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR, + lhstype, lhs, newrhs); + + TREE_SIDE_EFFECTS (result) = 1; + if (!plain_assign) + TREE_NO_WARNING (result) = 1; + + return result; +} + +tree +build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs, + tsubst_flags_t complain) +{ + if (processing_template_decl) + return build_min_nt (MODOP_EXPR, lhs, + build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs); + + if (modifycode != NOP_EXPR) + { + tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs, + make_node (modifycode), + /*overloaded_p=*/NULL, + complain); + if (rval) + { + TREE_NO_WARNING (rval) = 1; + return rval; + } + } + return cp_build_modify_expr (lhs, modifycode, rhs, complain); +} + +/* Helper function for get_delta_difference which assumes FROM is a base + class of TO. Returns a delta for the conversion of pointer-to-member + of FROM to pointer-to-member of TO. If the conversion is invalid and + tf_error is not set in COMPLAIN returns error_mark_node, otherwise + returns zero. If FROM is not a base class of TO, returns NULL_TREE. + If C_CAST_P is true, this conversion is taking place as part of a + C-style cast. */ + +static tree +get_delta_difference_1 (tree from, tree to, bool c_cast_p, + tsubst_flags_t complain) +{ + tree binfo; + base_kind kind; + base_access access = c_cast_p ? ba_unique : ba_check; + + /* Note: ba_quiet does not distinguish between access control and + ambiguity. */ + if (!(complain & tf_error)) + access |= ba_quiet; + + binfo = lookup_base (to, from, access, &kind); + + if (kind == bk_inaccessible || kind == bk_ambig) + { + if (!(complain & tf_error)) + return error_mark_node; + + error (" in pointer to member function conversion"); + return size_zero_node; + } + else if (binfo) + { + if (kind != bk_via_virtual) + return BINFO_OFFSET (binfo); + else + /* FROM is a virtual base class of TO. Issue an error or warning + depending on whether or not this is a reinterpret cast. */ + { + if (!(complain & tf_error)) + return error_mark_node; + + error ("pointer to member conversion via virtual base %qT", + BINFO_TYPE (binfo_from_vbase (binfo))); + + return size_zero_node; + } + } + else + return NULL_TREE; +} + +/* Get difference in deltas for different pointer to member function + types. If the conversion is invalid and tf_error is not set in + COMPLAIN, returns error_mark_node, otherwise returns an integer + constant of type PTRDIFF_TYPE_NODE and its value is zero if the + conversion is invalid. If ALLOW_INVERSE_P is true, then allow reverse + conversions as well. If C_CAST_P is true this conversion is taking + place as part of a C-style cast. + + Note that the naming of FROM and TO is kind of backwards; the return + value is what we add to a TO in order to get a FROM. They are named + this way because we call this function to find out how to convert from + a pointer to member of FROM to a pointer to member of TO. */ + +static tree +get_delta_difference (tree from, tree to, + bool allow_inverse_p, + bool c_cast_p, tsubst_flags_t complain) +{ + tree result; + + if (same_type_ignoring_top_level_qualifiers_p (from, to)) + /* Pointer to member of incomplete class is permitted*/ + result = size_zero_node; + else + result = get_delta_difference_1 (from, to, c_cast_p, complain); + + if (result == error_mark_node) + return error_mark_node; + + if (!result) + { + if (!allow_inverse_p) + { + if (!(complain & tf_error)) + return error_mark_node; + + error_not_base_type (from, to); + error (" in pointer to member conversion"); + result = size_zero_node; + } + else + { + result = get_delta_difference_1 (to, from, c_cast_p, complain); + + if (result == error_mark_node) + return error_mark_node; + + if (result) + result = size_diffop_loc (input_location, + size_zero_node, result); + else + { + if (!(complain & tf_error)) + return error_mark_node; + + error_not_base_type (from, to); + error (" in pointer to member conversion"); + result = size_zero_node; + } + } + } + + return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node, + result)); +} + +/* Return a constructor for the pointer-to-member-function TYPE using + the other components as specified. */ + +tree +build_ptrmemfunc1 (tree type, tree delta, tree pfn) +{ + tree u = NULL_TREE; + tree delta_field; + tree pfn_field; + VEC(constructor_elt, gc) *v; + + /* Pull the FIELD_DECLs out of the type. */ + pfn_field = TYPE_FIELDS (type); + delta_field = DECL_CHAIN (pfn_field); + + /* Make sure DELTA has the type we want. */ + delta = convert_and_check (delta_type_node, delta); + + /* Convert to the correct target type if necessary. */ + pfn = fold_convert (TREE_TYPE (pfn_field), pfn); + + /* Finish creating the initializer. */ + v = VEC_alloc(constructor_elt, gc, 2); + CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn); + CONSTRUCTOR_APPEND_ELT(v, delta_field, delta); + u = build_constructor (type, v); + TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta); + TREE_STATIC (u) = (TREE_CONSTANT (u) + && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn)) + != NULL_TREE) + && (initializer_constant_valid_p (delta, TREE_TYPE (delta)) + != NULL_TREE)); + return u; +} + +/* Build a constructor for a pointer to member function. It can be + used to initialize global variables, local variable, or used + as a value in expressions. TYPE is the POINTER to METHOD_TYPE we + want to be. + + If FORCE is nonzero, then force this conversion, even if + we would rather not do it. Usually set when using an explicit + cast. A C-style cast is being processed iff C_CAST_P is true. + + Return error_mark_node, if something goes wrong. */ + +tree +build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p, + tsubst_flags_t complain) +{ + tree fn; + tree pfn_type; + tree to_type; + + if (error_operand_p (pfn)) + return error_mark_node; + + pfn_type = TREE_TYPE (pfn); + to_type = build_ptrmemfunc_type (type); + + /* Handle multiple conversions of pointer to member functions. */ + if (TYPE_PTRMEMFUNC_P (pfn_type)) + { + tree delta = NULL_TREE; + tree npfn = NULL_TREE; + tree n; + + if (!force + && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL)) + error ("invalid conversion to type %qT from type %qT", + to_type, pfn_type); + + n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type), + TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type), + force, + c_cast_p, complain); + if (n == error_mark_node) + return error_mark_node; + + /* We don't have to do any conversion to convert a + pointer-to-member to its own type. But, we don't want to + just return a PTRMEM_CST if there's an explicit cast; that + cast should make the expression an invalid template argument. */ + if (TREE_CODE (pfn) != PTRMEM_CST) + { + if (same_type_p (to_type, pfn_type)) + return pfn; + else if (integer_zerop (n)) + return build_reinterpret_cast (to_type, pfn, + tf_warning_or_error); + } + + if (TREE_SIDE_EFFECTS (pfn)) + pfn = save_expr (pfn); + + /* Obtain the function pointer and the current DELTA. */ + if (TREE_CODE (pfn) == PTRMEM_CST) + expand_ptrmemfunc_cst (pfn, &delta, &npfn); + else + { + npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier); + delta = build_ptrmemfunc_access_expr (pfn, delta_identifier); + } + + /* Just adjust the DELTA field. */ + gcc_assert (same_type_ignoring_top_level_qualifiers_p + (TREE_TYPE (delta), ptrdiff_type_node)); + if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta) + n = cp_build_binary_op (input_location, + LSHIFT_EXPR, n, integer_one_node, + tf_warning_or_error); + delta = cp_build_binary_op (input_location, + PLUS_EXPR, delta, n, tf_warning_or_error); + return build_ptrmemfunc1 (to_type, delta, npfn); + } + + /* Handle null pointer to member function conversions. */ + if (null_ptr_cst_p (pfn)) + { + pfn = build_c_cast (input_location, type, integer_zero_node); + return build_ptrmemfunc1 (to_type, + integer_zero_node, + pfn); + } + + if (type_unknown_p (pfn)) + return instantiate_type (type, pfn, tf_warning_or_error); + + fn = TREE_OPERAND (pfn, 0); + gcc_assert (TREE_CODE (fn) == FUNCTION_DECL + /* In a template, we will have preserved the + OFFSET_REF. */ + || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF)); + return make_ptrmem_cst (to_type, fn); +} + +/* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST + given by CST. + + ??? There is no consistency as to the types returned for the above + values. Some code acts as if it were a sizetype and some as if it were + integer_type_node. */ + +void +expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn) +{ + tree type = TREE_TYPE (cst); + tree fn = PTRMEM_CST_MEMBER (cst); + tree ptr_class, fn_class; + + gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); + + /* The class that the function belongs to. */ + fn_class = DECL_CONTEXT (fn); + + /* The class that we're creating a pointer to member of. */ + ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type); + + /* First, calculate the adjustment to the function's class. */ + *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0, + /*c_cast_p=*/0, tf_warning_or_error); + + if (!DECL_VIRTUAL_P (fn)) + *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn)); + else + { + /* If we're dealing with a virtual function, we have to adjust 'this' + again, to point to the base which provides the vtable entry for + fn; the call will do the opposite adjustment. */ + tree orig_class = DECL_CONTEXT (fn); + tree binfo = binfo_or_else (orig_class, fn_class); + *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta), + *delta, BINFO_OFFSET (binfo)); + *delta = fold_if_not_in_template (*delta); + + /* We set PFN to the vtable offset at which the function can be + found, plus one (unless ptrmemfunc_vbit_in_delta, in which + case delta is shifted left, and then incremented). */ + *pfn = DECL_VINDEX (fn); + *pfn = build2 (MULT_EXPR, integer_type_node, *pfn, + TYPE_SIZE_UNIT (vtable_entry_type)); + *pfn = fold_if_not_in_template (*pfn); + + switch (TARGET_PTRMEMFUNC_VBIT_LOCATION) + { + case ptrmemfunc_vbit_in_pfn: + *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn, + integer_one_node); + *pfn = fold_if_not_in_template (*pfn); + break; + + case ptrmemfunc_vbit_in_delta: + *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta), + *delta, integer_one_node); + *delta = fold_if_not_in_template (*delta); + *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta), + *delta, integer_one_node); + *delta = fold_if_not_in_template (*delta); + break; + + default: + gcc_unreachable (); + } + + *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn); + *pfn = fold_if_not_in_template (*pfn); + } +} + +/* Return an expression for PFN from the pointer-to-member function + given by T. */ + +static tree +pfn_from_ptrmemfunc (tree t) +{ + if (TREE_CODE (t) == PTRMEM_CST) + { + tree delta; + tree pfn; + + expand_ptrmemfunc_cst (t, &delta, &pfn); + if (pfn) + return pfn; + } + + return build_ptrmemfunc_access_expr (t, pfn_identifier); +} + +/* Return an expression for DELTA from the pointer-to-member function + given by T. */ + +static tree +delta_from_ptrmemfunc (tree t) +{ + if (TREE_CODE (t) == PTRMEM_CST) + { + tree delta; + tree pfn; + + expand_ptrmemfunc_cst (t, &delta, &pfn); + if (delta) + return delta; + } + + return build_ptrmemfunc_access_expr (t, delta_identifier); +} + +/* Convert value RHS to type TYPE as preparation for an assignment to + an lvalue of type TYPE. ERRTYPE indicates what kind of error the + implicit conversion is. If FNDECL is non-NULL, we are doing the + conversion in order to pass the PARMNUMth argument of FNDECL. + If FNDECL is NULL, we are doing the conversion in function pointer + argument passing, conversion in initialization, etc. */ + +static tree +convert_for_assignment (tree type, tree rhs, + impl_conv_rhs errtype, tree fndecl, int parmnum, + tsubst_flags_t complain, int flags) +{ + tree rhstype; + enum tree_code coder; + + /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */ + if (TREE_CODE (rhs) == NON_LVALUE_EXPR) + rhs = TREE_OPERAND (rhs, 0); + + rhstype = TREE_TYPE (rhs); + coder = TREE_CODE (rhstype); + + if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE + && vector_types_convertible_p (type, rhstype, true)) + { + rhs = mark_rvalue_use (rhs); + return convert (type, rhs); + } + + if (rhs == error_mark_node || rhstype == error_mark_node) + return error_mark_node; + if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node) + return error_mark_node; + + /* The RHS of an assignment cannot have void type. */ + if (coder == VOID_TYPE) + { + if (complain & tf_error) + error ("void value not ignored as it ought to be"); + return error_mark_node; + } + + /* Simplify the RHS if possible. */ + if (TREE_CODE (rhs) == CONST_DECL) + rhs = DECL_INITIAL (rhs); + + if (c_dialect_objc ()) + { + int parmno; + tree selector; + tree rname = fndecl; + + switch (errtype) + { + case ICR_ASSIGN: + parmno = -1; + break; + case ICR_INIT: + parmno = -2; + break; + default: + selector = objc_message_selector (); + parmno = parmnum; + if (selector && parmno > 1) + { + rname = selector; + parmno -= 1; + } + } + + if (objc_compare_types (type, rhstype, parmno, rname)) + { + rhs = mark_rvalue_use (rhs); + return convert (type, rhs); + } + } + + /* [expr.ass] + + The expression is implicitly converted (clause _conv_) to the + cv-unqualified type of the left operand. + + We allow bad conversions here because by the time we get to this point + we are committed to doing the conversion. If we end up doing a bad + conversion, convert_like will complain. */ + if (!can_convert_arg_bad (type, rhstype, rhs, flags)) + { + /* When -Wno-pmf-conversions is use, we just silently allow + conversions from pointers-to-members to plain pointers. If + the conversion doesn't work, cp_convert will complain. */ + if (!warn_pmf2ptr + && TYPE_PTR_P (type) + && TYPE_PTRMEMFUNC_P (rhstype)) + rhs = cp_convert (strip_top_quals (type), rhs); + else + { + if (complain & tf_error) + { + /* If the right-hand side has unknown type, then it is an + overloaded function. Call instantiate_type to get error + messages. */ + if (rhstype == unknown_type_node) + instantiate_type (type, rhs, tf_warning_or_error); + else if (fndecl) + error ("cannot convert %qT to %qT for argument %qP to %qD", + rhstype, type, parmnum, fndecl); + else + switch (errtype) + { + case ICR_DEFAULT_ARGUMENT: + error ("cannot convert %qT to %qT in default argument", + rhstype, type); + break; + case ICR_ARGPASS: + error ("cannot convert %qT to %qT in argument passing", + rhstype, type); + break; + case ICR_CONVERTING: + error ("cannot convert %qT to %qT", + rhstype, type); + break; + case ICR_INIT: + error ("cannot convert %qT to %qT in initialization", + rhstype, type); + break; + case ICR_RETURN: + error ("cannot convert %qT to %qT in return", + rhstype, type); + break; + case ICR_ASSIGN: + error ("cannot convert %qT to %qT in assignment", + rhstype, type); + break; + default: + gcc_unreachable(); + } + } + return error_mark_node; + } + } + if (warn_missing_format_attribute) + { + const enum tree_code codel = TREE_CODE (type); + if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE) + && coder == codel + && check_missing_format_attribute (type, rhstype) + && (complain & tf_warning)) + switch (errtype) + { + case ICR_ARGPASS: + case ICR_DEFAULT_ARGUMENT: + if (fndecl) + warning (OPT_Wmissing_format_attribute, + "parameter %qP of %qD might be a candidate " + "for a format attribute", parmnum, fndecl); + else + warning (OPT_Wmissing_format_attribute, + "parameter might be a candidate " + "for a format attribute"); + break; + case ICR_CONVERTING: + warning (OPT_Wmissing_format_attribute, + "target of conversion might be a candidate " + "for a format attribute"); + break; + case ICR_INIT: + warning (OPT_Wmissing_format_attribute, + "target of initialization might be a candidate " + "for a format attribute"); + break; + case ICR_RETURN: + warning (OPT_Wmissing_format_attribute, + "return type might be a candidate " + "for a format attribute"); + break; + case ICR_ASSIGN: + warning (OPT_Wmissing_format_attribute, + "left-hand side of assignment might be a candidate " + "for a format attribute"); + break; + default: + gcc_unreachable(); + } + } + + /* If -Wparentheses, warn about a = b = c when a has type bool and b + does not. */ + if (warn_parentheses + && TREE_CODE (type) == BOOLEAN_TYPE + && TREE_CODE (rhs) == MODIFY_EXPR + && !TREE_NO_WARNING (rhs) + && TREE_CODE (TREE_TYPE (rhs)) != BOOLEAN_TYPE + && (complain & tf_warning)) + { + location_t loc = EXPR_LOC_OR_HERE (rhs); + + warning_at (loc, OPT_Wparentheses, + "suggest parentheses around assignment used as truth value"); + TREE_NO_WARNING (rhs) = 1; + } + + return perform_implicit_conversion_flags (strip_top_quals (type), rhs, + complain, flags); +} + +/* Convert RHS to be of type TYPE. + If EXP is nonzero, it is the target of the initialization. + ERRTYPE indicates what kind of error the implicit conversion is. + + Two major differences between the behavior of + `convert_for_assignment' and `convert_for_initialization' + are that references are bashed in the former, while + copied in the latter, and aggregates are assigned in + the former (operator=) while initialized in the + latter (X(X&)). + + If using constructor make sure no conversion operator exists, if one does + exist, an ambiguity exists. + + If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */ + +tree +convert_for_initialization (tree exp, tree type, tree rhs, int flags, + impl_conv_rhs errtype, tree fndecl, int parmnum, + tsubst_flags_t complain) +{ + enum tree_code codel = TREE_CODE (type); + tree rhstype; + enum tree_code coder; + + /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue. + Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */ + if (TREE_CODE (rhs) == NOP_EXPR + && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0)) + && codel != REFERENCE_TYPE) + rhs = TREE_OPERAND (rhs, 0); + + if (type == error_mark_node + || rhs == error_mark_node + || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)) + return error_mark_node; + + if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE + && TREE_CODE (type) != ARRAY_TYPE + && (TREE_CODE (type) != REFERENCE_TYPE + || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE)) + || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE + && (TREE_CODE (type) != REFERENCE_TYPE + || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE)) + || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE) + rhs = decay_conversion (rhs); + + rhstype = TREE_TYPE (rhs); + coder = TREE_CODE (rhstype); + + if (coder == ERROR_MARK) + return error_mark_node; + + /* We accept references to incomplete types, so we can + return here before checking if RHS is of complete type. */ + + if (codel == REFERENCE_TYPE) + { + /* This should eventually happen in convert_arguments. */ + int savew = 0, savee = 0; + + if (fndecl) + savew = warningcount, savee = errorcount; + rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE, + /*cleanup=*/NULL, complain); + if (fndecl) + { + if (warningcount > savew) + warning (0, "in passing argument %P of %q+D", parmnum, fndecl); + else if (errorcount > savee) + error ("in passing argument %P of %q+D", parmnum, fndecl); + } + return rhs; + } + + if (exp != 0) + exp = require_complete_type_sfinae (exp, complain); + if (exp == error_mark_node) + return error_mark_node; + + rhstype = non_reference (rhstype); + + type = complete_type (type); + + if (DIRECT_INIT_EXPR_P (type, rhs)) + /* Don't try to do copy-initialization if we already have + direct-initialization. */ + return rhs; + + if (MAYBE_CLASS_TYPE_P (type)) + return perform_implicit_conversion_flags (type, rhs, complain, flags); + + return convert_for_assignment (type, rhs, errtype, fndecl, parmnum, + complain, flags); +} + +/* If RETVAL is the address of, or a reference to, a local variable or + temporary give an appropriate warning. */ + +static void +maybe_warn_about_returning_address_of_local (tree retval) +{ + tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl)); + tree whats_returned = retval; + + for (;;) + { + if (TREE_CODE (whats_returned) == COMPOUND_EXPR) + whats_returned = TREE_OPERAND (whats_returned, 1); + else if (CONVERT_EXPR_P (whats_returned) + || TREE_CODE (whats_returned) == NON_LVALUE_EXPR) + whats_returned = TREE_OPERAND (whats_returned, 0); + else + break; + } + + if (TREE_CODE (whats_returned) != ADDR_EXPR) + return; + whats_returned = TREE_OPERAND (whats_returned, 0); + + if (TREE_CODE (valtype) == REFERENCE_TYPE) + { + if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR + || TREE_CODE (whats_returned) == TARGET_EXPR) + { + warning (0, "returning reference to temporary"); + return; + } + if (TREE_CODE (whats_returned) == VAR_DECL + && DECL_NAME (whats_returned) + && TEMP_NAME_P (DECL_NAME (whats_returned))) + { + warning (0, "reference to non-lvalue returned"); + return; + } + } + + while (TREE_CODE (whats_returned) == COMPONENT_REF + || TREE_CODE (whats_returned) == ARRAY_REF) + whats_returned = TREE_OPERAND (whats_returned, 0); + + if (DECL_P (whats_returned) + && DECL_NAME (whats_returned) + && DECL_FUNCTION_SCOPE_P (whats_returned) + && !(TREE_STATIC (whats_returned) + || TREE_PUBLIC (whats_returned))) + { + if (TREE_CODE (valtype) == REFERENCE_TYPE) + warning (0, "reference to local variable %q+D returned", + whats_returned); + else + warning (0, "address of local variable %q+D returned", + whats_returned); + return; + } +} + +/* Check that returning RETVAL from the current function is valid. + Return an expression explicitly showing all conversions required to + change RETVAL into the function return type, and to assign it to + the DECL_RESULT for the function. Set *NO_WARNING to true if + code reaches end of non-void function warning shouldn't be issued + on this RETURN_EXPR. */ + +tree +check_return_expr (tree retval, bool *no_warning) +{ + tree result; + /* The type actually returned by the function, after any + promotions. */ + tree valtype; + int fn_returns_value_p; + bool named_return_value_okay_p; + + *no_warning = false; + + /* A `volatile' function is one that isn't supposed to return, ever. + (This is a G++ extension, used to get better code for functions + that call the `volatile' function.) */ + if (TREE_THIS_VOLATILE (current_function_decl)) + warning (0, "function declared %<noreturn%> has a %<return%> statement"); + + /* Check for various simple errors. */ + if (DECL_DESTRUCTOR_P (current_function_decl)) + { + if (retval) + error ("returning a value from a destructor"); + return NULL_TREE; + } + else if (DECL_CONSTRUCTOR_P (current_function_decl)) + { + if (in_function_try_handler) + /* If a return statement appears in a handler of the + function-try-block of a constructor, the program is ill-formed. */ + error ("cannot return from a handler of a function-try-block of a constructor"); + else if (retval) + /* You can't return a value from a constructor. */ + error ("returning a value from a constructor"); + return NULL_TREE; + } + + /* As an extension, deduce lambda return type from a return statement + anywhere in the body. */ + if (retval && LAMBDA_FUNCTION_P (current_function_decl)) + { + tree lambda = CLASSTYPE_LAMBDA_EXPR (current_class_type); + if (LAMBDA_EXPR_DEDUCE_RETURN_TYPE_P (lambda)) + { + tree type = lambda_return_type (retval); + tree oldtype = LAMBDA_EXPR_RETURN_TYPE (lambda); + + if (VOID_TYPE_P (type)) + { /* Nothing. */ } + else if (oldtype == NULL_TREE) + { + pedwarn (input_location, OPT_pedantic, "lambda return type " + "can only be deduced when the return statement is " + "the only statement in the function body"); + apply_lambda_return_type (lambda, type); + } + else if (!same_type_p (type, oldtype)) + error ("inconsistent types %qT and %qT deduced for " + "lambda return type", type, oldtype); + } + } + + if (processing_template_decl) + { + current_function_returns_value = 1; + if (check_for_bare_parameter_packs (retval)) + retval = error_mark_node; + return retval; + } + + /* When no explicit return-value is given in a function with a named + return value, the named return value is used. */ + result = DECL_RESULT (current_function_decl); + valtype = TREE_TYPE (result); + gcc_assert (valtype != NULL_TREE); + fn_returns_value_p = !VOID_TYPE_P (valtype); + if (!retval && DECL_NAME (result) && fn_returns_value_p) + retval = result; + + /* Check for a return statement with no return value in a function + that's supposed to return a value. */ + if (!retval && fn_returns_value_p) + { + permerror (input_location, "return-statement with no value, in function returning %qT", + valtype); + /* Clear this, so finish_function won't say that we reach the + end of a non-void function (which we don't, we gave a + return!). */ + current_function_returns_null = 0; + /* And signal caller that TREE_NO_WARNING should be set on the + RETURN_EXPR to avoid control reaches end of non-void function + warnings in tree-cfg.c. */ + *no_warning = true; + } + /* Check for a return statement with a value in a function that + isn't supposed to return a value. */ + else if (retval && !fn_returns_value_p) + { + if (VOID_TYPE_P (TREE_TYPE (retval))) + /* You can return a `void' value from a function of `void' + type. In that case, we have to evaluate the expression for + its side-effects. */ + finish_expr_stmt (retval); + else + permerror (input_location, "return-statement with a value, in function " + "returning 'void'"); + current_function_returns_null = 1; + + /* There's really no value to return, after all. */ + return NULL_TREE; + } + else if (!retval) + /* Remember that this function can sometimes return without a + value. */ + current_function_returns_null = 1; + else + /* Remember that this function did return a value. */ + current_function_returns_value = 1; + + /* Check for erroneous operands -- but after giving ourselves a + chance to provide an error about returning a value from a void + function. */ + if (error_operand_p (retval)) + { + current_function_return_value = error_mark_node; + return error_mark_node; + } + + /* Only operator new(...) throw(), can return NULL [expr.new/13]. */ + if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR + || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR) + && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl)) + && ! flag_check_new + && retval && null_ptr_cst_p (retval)) + warning (0, "%<operator new%> must not return NULL unless it is " + "declared %<throw()%> (or -fcheck-new is in effect)"); + + /* Effective C++ rule 15. See also start_function. */ + if (warn_ecpp + && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR)) + { + bool warn = true; + + /* The function return type must be a reference to the current + class. */ + if (TREE_CODE (valtype) == REFERENCE_TYPE + && same_type_ignoring_top_level_qualifiers_p + (TREE_TYPE (valtype), TREE_TYPE (current_class_ref))) + { + /* Returning '*this' is obviously OK. */ + if (retval == current_class_ref) + warn = false; + /* If we are calling a function whose return type is the same of + the current class reference, it is ok. */ + else if (TREE_CODE (retval) == INDIRECT_REF + && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR) + warn = false; + } + + if (warn) + warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>"); + } + + /* The fabled Named Return Value optimization, as per [class.copy]/15: + + [...] For a function with a class return type, if the expression + in the return statement is the name of a local object, and the cv- + unqualified type of the local object is the same as the function + return type, an implementation is permitted to omit creating the tem- + porary object to hold the function return value [...] + + So, if this is a value-returning function that always returns the same + local variable, remember it. + + It might be nice to be more flexible, and choose the first suitable + variable even if the function sometimes returns something else, but + then we run the risk of clobbering the variable we chose if the other + returned expression uses the chosen variable somehow. And people expect + this restriction, anyway. (jason 2000-11-19) + + See finish_function and finalize_nrv for the rest of this optimization. */ + + named_return_value_okay_p = + (retval != NULL_TREE + /* Must be a local, automatic variable. */ + && TREE_CODE (retval) == VAR_DECL + && DECL_CONTEXT (retval) == current_function_decl + && ! TREE_STATIC (retval) + && ! DECL_ANON_UNION_VAR_P (retval) + && (DECL_ALIGN (retval) + >= DECL_ALIGN (DECL_RESULT (current_function_decl))) + /* The cv-unqualified type of the returned value must be the + same as the cv-unqualified return type of the + function. */ + && same_type_p ((TYPE_MAIN_VARIANT (TREE_TYPE (retval))), + (TYPE_MAIN_VARIANT + (TREE_TYPE (TREE_TYPE (current_function_decl))))) + /* And the returned value must be non-volatile. */ + && ! TYPE_VOLATILE (TREE_TYPE (retval))); + + if (fn_returns_value_p && flag_elide_constructors) + { + if (named_return_value_okay_p + && (current_function_return_value == NULL_TREE + || current_function_return_value == retval)) + current_function_return_value = retval; + else + current_function_return_value = error_mark_node; + } + + /* We don't need to do any conversions when there's nothing being + returned. */ + if (!retval) + return NULL_TREE; + + /* Do any required conversions. */ + if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl)) + /* No conversions are required. */ + ; + else + { + /* The type the function is declared to return. */ + tree functype = TREE_TYPE (TREE_TYPE (current_function_decl)); + int flags = LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING; + + /* The functype's return type will have been set to void, if it + was an incomplete type. Just treat this as 'return;' */ + if (VOID_TYPE_P (functype)) + return error_mark_node; + + /* Under C++0x [12.8/16 class.copy], a returned lvalue is sometimes + treated as an rvalue for the purposes of overload resolution to + favor move constructors over copy constructors. + + Note that these conditions are similar to, but not as strict as, + the conditions for the named return value optimization. */ + if ((cxx_dialect != cxx98) + && (TREE_CODE (retval) == VAR_DECL + || TREE_CODE (retval) == PARM_DECL) + && DECL_CONTEXT (retval) == current_function_decl + && !TREE_STATIC (retval) + && same_type_p ((TYPE_MAIN_VARIANT (TREE_TYPE (retval))), + (TYPE_MAIN_VARIANT + (TREE_TYPE (TREE_TYPE (current_function_decl))))) + /* This is only interesting for class type. */ + && CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl)))) + flags = flags | LOOKUP_PREFER_RVALUE; + + /* First convert the value to the function's return type, then + to the type of return value's location to handle the + case that functype is smaller than the valtype. */ + retval = convert_for_initialization + (NULL_TREE, functype, retval, flags, ICR_RETURN, NULL_TREE, 0, + tf_warning_or_error); + retval = convert (valtype, retval); + + /* If the conversion failed, treat this just like `return;'. */ + if (retval == error_mark_node) + return retval; + /* We can't initialize a register from a AGGR_INIT_EXPR. */ + else if (! cfun->returns_struct + && TREE_CODE (retval) == TARGET_EXPR + && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR) + retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval, + TREE_OPERAND (retval, 0)); + else + maybe_warn_about_returning_address_of_local (retval); + } + + /* Actually copy the value returned into the appropriate location. */ + if (retval && retval != result) + retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval); + + return retval; +} + + +/* Returns nonzero if the pointer-type FROM can be converted to the + pointer-type TO via a qualification conversion. If CONSTP is -1, + then we return nonzero if the pointers are similar, and the + cv-qualification signature of FROM is a proper subset of that of TO. + + If CONSTP is positive, then all outer pointers have been + const-qualified. */ + +static int +comp_ptr_ttypes_real (tree to, tree from, int constp) +{ + bool to_more_cv_qualified = false; + bool is_opaque_pointer = false; + + for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from)) + { + if (TREE_CODE (to) != TREE_CODE (from)) + return 0; + + if (TREE_CODE (from) == OFFSET_TYPE + && !same_type_p (TYPE_OFFSET_BASETYPE (from), + TYPE_OFFSET_BASETYPE (to))) + return 0; + + /* Const and volatile mean something different for function types, + so the usual checks are not appropriate. */ + if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE) + { + if (!at_least_as_qualified_p (to, from)) + return 0; + + if (!at_least_as_qualified_p (from, to)) + { + if (constp == 0) + return 0; + to_more_cv_qualified = true; + } + + if (constp > 0) + constp &= TYPE_READONLY (to); + } + + if (TREE_CODE (to) == VECTOR_TYPE) + is_opaque_pointer = vector_targets_convertible_p (to, from); + + if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to)) + return ((constp >= 0 || to_more_cv_qualified) + && (is_opaque_pointer + || same_type_ignoring_top_level_qualifiers_p (to, from))); + } +} + +/* When comparing, say, char ** to char const **, this function takes + the 'char *' and 'char const *'. Do not pass non-pointer/reference + types to this function. */ + +int +comp_ptr_ttypes (tree to, tree from) +{ + return comp_ptr_ttypes_real (to, from, 1); +} + +/* Returns true iff FNTYPE is a non-class type that involves + error_mark_node. We can get FUNCTION_TYPE with buried error_mark_node + if a parameter type is ill-formed. */ + +bool +error_type_p (const_tree type) +{ + tree t; + + switch (TREE_CODE (type)) + { + case ERROR_MARK: + return true; + + case POINTER_TYPE: + case REFERENCE_TYPE: + case OFFSET_TYPE: + return error_type_p (TREE_TYPE (type)); + + case FUNCTION_TYPE: + case METHOD_TYPE: + if (error_type_p (TREE_TYPE (type))) + return true; + for (t = TYPE_ARG_TYPES (type); t; t = TREE_CHAIN (t)) + if (error_type_p (TREE_VALUE (t))) + return true; + return false; + + case RECORD_TYPE: + if (TYPE_PTRMEMFUNC_P (type)) + return error_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type)); + return false; + + default: + return false; + } +} + +/* Returns 1 if to and from are (possibly multi-level) pointers to the same + type or inheritance-related types, regardless of cv-quals. */ + +int +ptr_reasonably_similar (const_tree to, const_tree from) +{ + for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from)) + { + /* Any target type is similar enough to void. */ + if (TREE_CODE (to) == VOID_TYPE) + return !error_type_p (from); + if (TREE_CODE (from) == VOID_TYPE) + return !error_type_p (to); + + if (TREE_CODE (to) != TREE_CODE (from)) + return 0; + + if (TREE_CODE (from) == OFFSET_TYPE + && comptypes (TYPE_OFFSET_BASETYPE (to), + TYPE_OFFSET_BASETYPE (from), + COMPARE_BASE | COMPARE_DERIVED)) + continue; + + if (TREE_CODE (to) == VECTOR_TYPE + && vector_types_convertible_p (to, from, false)) + return 1; + + if (TREE_CODE (to) == INTEGER_TYPE + && TYPE_PRECISION (to) == TYPE_PRECISION (from)) + return 1; + + if (TREE_CODE (to) == FUNCTION_TYPE) + return !error_type_p (to) && !error_type_p (from); + + if (TREE_CODE (to) != POINTER_TYPE) + return comptypes + (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from), + COMPARE_BASE | COMPARE_DERIVED); + } +} + +/* Return true if TO and FROM (both of which are POINTER_TYPEs or + pointer-to-member types) are the same, ignoring cv-qualification at + all levels. */ + +bool +comp_ptr_ttypes_const (tree to, tree from) +{ + bool is_opaque_pointer = false; + + for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from)) + { + if (TREE_CODE (to) != TREE_CODE (from)) + return false; + + if (TREE_CODE (from) == OFFSET_TYPE + && same_type_p (TYPE_OFFSET_BASETYPE (from), + TYPE_OFFSET_BASETYPE (to))) + continue; + + if (TREE_CODE (to) == VECTOR_TYPE) + is_opaque_pointer = vector_targets_convertible_p (to, from); + + if (TREE_CODE (to) != POINTER_TYPE) + return (is_opaque_pointer + || same_type_ignoring_top_level_qualifiers_p (to, from)); + } +} + +/* Returns the type qualifiers for this type, including the qualifiers on the + elements for an array type. */ + +int +cp_type_quals (const_tree type) +{ + int quals; + /* This CONST_CAST is okay because strip_array_types returns its + argument unmodified and we assign it to a const_tree. */ + type = strip_array_types (CONST_CAST_TREE (type)); + if (type == error_mark_node + /* Quals on a FUNCTION_TYPE are memfn quals. */ + || TREE_CODE (type) == FUNCTION_TYPE) + return TYPE_UNQUALIFIED; + quals = TYPE_QUALS (type); + /* METHOD and REFERENCE_TYPEs should never have quals. */ + gcc_assert ((TREE_CODE (type) != METHOD_TYPE + && TREE_CODE (type) != REFERENCE_TYPE) + || ((quals & (TYPE_QUAL_CONST|TYPE_QUAL_VOLATILE)) + == TYPE_UNQUALIFIED)); + return quals; +} + +/* Returns the function-cv-quals for TYPE, which must be a FUNCTION_TYPE or + METHOD_TYPE. */ + +int +type_memfn_quals (const_tree type) +{ + if (TREE_CODE (type) == FUNCTION_TYPE) + return TYPE_QUALS (type); + else if (TREE_CODE (type) == METHOD_TYPE) + return cp_type_quals (TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (type)))); + else + gcc_unreachable (); +} + +/* Returns the FUNCTION_TYPE TYPE with its function-cv-quals changed to + MEMFN_QUALS. */ + +tree +apply_memfn_quals (tree type, cp_cv_quals memfn_quals) +{ + /* Could handle METHOD_TYPE here if necessary. */ + gcc_assert (TREE_CODE (type) == FUNCTION_TYPE); + if (TYPE_QUALS (type) == memfn_quals) + return type; + /* This should really have a different TYPE_MAIN_VARIANT, but that gets + complex. */ + return build_qualified_type (type, memfn_quals); +} + +/* Returns nonzero if TYPE is const or volatile. */ + +bool +cv_qualified_p (const_tree type) +{ + int quals = cp_type_quals (type); + return (quals & (TYPE_QUAL_CONST|TYPE_QUAL_VOLATILE)) != 0; +} + +/* Returns nonzero if the TYPE contains a mutable member. */ + +bool +cp_has_mutable_p (const_tree type) +{ + /* This CONST_CAST is okay because strip_array_types returns its + argument unmodified and we assign it to a const_tree. */ + type = strip_array_types (CONST_CAST_TREE(type)); + + return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type); +} + +/* Set TREE_READONLY and TREE_VOLATILE on DECL as indicated by the + TYPE_QUALS. For a VAR_DECL, this may be an optimistic + approximation. In particular, consider: + + int f(); + struct S { int i; }; + const S s = { f(); } + + Here, we will make "s" as TREE_READONLY (because it is declared + "const") -- only to reverse ourselves upon seeing that the + initializer is non-constant. */ + +void +cp_apply_type_quals_to_decl (int type_quals, tree decl) +{ + tree type = TREE_TYPE (decl); + + if (type == error_mark_node) + return; + + if (TREE_CODE (decl) == TYPE_DECL) + return; + + gcc_assert (!(TREE_CODE (type) == FUNCTION_TYPE + && type_quals != TYPE_UNQUALIFIED)); + + /* Avoid setting TREE_READONLY incorrectly. */ + if (/* If the object has a constructor, the constructor may modify + the object. */ + TYPE_NEEDS_CONSTRUCTING (type) + /* If the type isn't complete, we don't know yet if it will need + constructing. */ + || !COMPLETE_TYPE_P (type) + /* If the type has a mutable component, that component might be + modified. */ + || TYPE_HAS_MUTABLE_P (type)) + type_quals &= ~TYPE_QUAL_CONST; + + c_apply_type_quals_to_decl (type_quals, decl); +} + +/* Subroutine of casts_away_constness. Make T1 and T2 point at + exemplar types such that casting T1 to T2 is casting away constness + if and only if there is no implicit conversion from T1 to T2. */ + +static void +casts_away_constness_r (tree *t1, tree *t2) +{ + int quals1; + int quals2; + + /* [expr.const.cast] + + For multi-level pointer to members and multi-level mixed pointers + and pointers to members (conv.qual), the "member" aspect of a + pointer to member level is ignored when determining if a const + cv-qualifier has been cast away. */ + /* [expr.const.cast] + + For two pointer types: + + X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type + X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type + K is min(N,M) + + casting from X1 to X2 casts away constness if, for a non-pointer + type T there does not exist an implicit conversion (clause + _conv_) from: + + Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N * + + to + + Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */ + if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1)) + || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2))) + { + *t1 = cp_build_qualified_type (void_type_node, + cp_type_quals (*t1)); + *t2 = cp_build_qualified_type (void_type_node, + cp_type_quals (*t2)); + return; + } + + quals1 = cp_type_quals (*t1); + quals2 = cp_type_quals (*t2); + + if (TYPE_PTRMEM_P (*t1)) + *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1); + else + *t1 = TREE_TYPE (*t1); + if (TYPE_PTRMEM_P (*t2)) + *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2); + else + *t2 = TREE_TYPE (*t2); + + casts_away_constness_r (t1, t2); + *t1 = build_pointer_type (*t1); + *t2 = build_pointer_type (*t2); + *t1 = cp_build_qualified_type (*t1, quals1); + *t2 = cp_build_qualified_type (*t2, quals2); +} + +/* Returns nonzero if casting from TYPE1 to TYPE2 casts away + constness. + + ??? This function returns non-zero if casting away qualifiers not + just const. We would like to return to the caller exactly which + qualifiers are casted away to give more accurate diagnostics. +*/ + +static bool +casts_away_constness (tree t1, tree t2) +{ + if (TREE_CODE (t2) == REFERENCE_TYPE) + { + /* [expr.const.cast] + + Casting from an lvalue of type T1 to an lvalue of type T2 + using a reference cast casts away constness if a cast from an + rvalue of type "pointer to T1" to the type "pointer to T2" + casts away constness. */ + t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1); + return casts_away_constness (build_pointer_type (t1), + build_pointer_type (TREE_TYPE (t2))); + } + + if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2)) + /* [expr.const.cast] + + Casting from an rvalue of type "pointer to data member of X + of type T1" to the type "pointer to data member of Y of type + T2" casts away constness if a cast from an rvalue of type + "pointer to T1" to the type "pointer to T2" casts away + constness. */ + return casts_away_constness + (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)), + build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2))); + + /* Casting away constness is only something that makes sense for + pointer or reference types. */ + if (TREE_CODE (t1) != POINTER_TYPE + || TREE_CODE (t2) != POINTER_TYPE) + return false; + + /* Top-level qualifiers don't matter. */ + t1 = TYPE_MAIN_VARIANT (t1); + t2 = TYPE_MAIN_VARIANT (t2); + casts_away_constness_r (&t1, &t2); + if (!can_convert (t2, t1)) + return true; + + return false; +} + +/* If T is a REFERENCE_TYPE return the type to which T refers. + Otherwise, return T itself. */ + +tree +non_reference (tree t) +{ + if (TREE_CODE (t) == REFERENCE_TYPE) + t = TREE_TYPE (t); + return t; +} + + +/* Return nonzero if REF is an lvalue valid for this language; + otherwise, print an error message and return zero. USE says + how the lvalue is being used and so selects the error message. */ + +int +lvalue_or_else (tree ref, enum lvalue_use use, tsubst_flags_t complain) +{ + cp_lvalue_kind kind = lvalue_kind (ref); + + if (kind == clk_none) + { + if (complain & tf_error) + lvalue_error (input_location, use); + return 0; + } + else if (kind & (clk_rvalueref|clk_class)) + { + if (!(complain & tf_error)) + return 0; + if (kind & clk_class) + /* Make this a permerror because we used to accept it. */ + permerror (input_location, "using temporary as lvalue"); + else + error ("using xvalue (rvalue reference) as lvalue"); + } + return 1; +} + |