diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c index 87e8d37d473..b5e117d5bda 100644 --- a/gcc/cp/parser.c +++ b/gcc/cp/parser.c @@ -22078,6 +22078,37 @@ warn_about_ambiguous_parse (const cp_decl_specifier_seq *decl_specifiers, } } +/* If DECLARATOR with DECL_SPECS is a function declarator that has + the form of a deduction guide, tag it as such. CTOR_DTOR_OR_CONV_P + has the same meaning as in cp_parser_declarator. */ + +static void +cp_parser_maybe_adjust_declarator_for_dguide (cp_parser *parser, + cp_decl_specifier_seq *decl_specs, + cp_declarator *declarator, + int *ctor_dtor_or_conv_p) +{ + if (cxx_dialect >= cxx17 + && *ctor_dtor_or_conv_p <= 0 + && !decl_specs->type + && !decl_specs->any_type_specifiers_p + && function_declarator_p (declarator)) + { + cp_declarator *id = get_id_declarator (declarator); + tree name = id->u.id.unqualified_name; + parser->scope = id->u.id.qualifying_scope; + tree tmpl = cp_parser_lookup_name_simple (parser, name, id->id_loc); + if (tmpl + && (DECL_CLASS_TEMPLATE_P (tmpl) + || DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl))) + { + id->u.id.unqualified_name = dguide_name (tmpl); + id->u.id.sfk = sfk_deduction_guide; + *ctor_dtor_or_conv_p = 1; + } + } +} + /* Declarators [gram.dcl.decl] */ /* Parse an init-declarator. @@ -22254,25 +22285,13 @@ cp_parser_init_declarator (cp_parser* parser, if (function_declarator_p (declarator)) { - /* Handle C++17 deduction guides. */ - if (!decl_specifiers->type - && !decl_specifiers->any_type_specifiers_p - && ctor_dtor_or_conv_p <= 0 - && cxx_dialect >= cxx17) - { - cp_declarator *id = get_id_declarator (declarator); - tree name = id->u.id.unqualified_name; - parser->scope = id->u.id.qualifying_scope; - tree tmpl = cp_parser_lookup_name_simple (parser, name, id->id_loc); - if (tmpl - && (DECL_CLASS_TEMPLATE_P (tmpl) - || DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl))) - { - id->u.id.unqualified_name = dguide_name (tmpl); - id->u.id.sfk = sfk_deduction_guide; - ctor_dtor_or_conv_p = 1; - } - } + /* Handle C++17 deduction guides. Note that class-scope + non-template deduction guides are instead handled in + cp_parser_member_declaration. */ + cp_parser_maybe_adjust_declarator_for_dguide (parser, + decl_specifiers, + declarator, + &ctor_dtor_or_conv_p); if (!member_p && !cp_parser_error_occurred (parser)) warn_about_ambiguous_parse (decl_specifiers, declarator); @@ -26956,6 +26975,12 @@ cp_parser_member_declaration (cp_parser* parser) goto out; } + /* Handle class-scope non-template C++17 deduction guides. */ + cp_parser_maybe_adjust_declarator_for_dguide (parser, + &decl_specifiers, + declarator, + &ctor_dtor_or_conv_p); + if (declares_class_or_enum & 2) cp_parser_check_for_definition_in_return_type (declarator, decl_specifiers.type, diff --git a/gcc/testsuite/g++.dg/cpp1z/class-deduction98.C b/gcc/testsuite/g++.dg/cpp1z/class-deduction98.C new file mode 100644 index 00000000000..bee0ce433ee --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1z/class-deduction98.C @@ -0,0 +1,10 @@ +// PR c++/79501 +// { dg-do compile { target c++17 } } + +template +struct A { + template struct B { template B(V); }; + B(T) -> B; +}; + +A::B b(0);