From 64f42782dc7586de0955c8347b264e92e03f7790 Mon Sep 17 00:00:00 2001 From: Nathaniel Shead Date: Tue, 8 Aug 2023 12:48:43 +1000 Subject: [PATCH] c++: Report invalid id-expression in decltype [PR100482] Sorry, noticed I provided the wrong version of the test. Here is the correct version (not relying on 'namespace std' being implicitly defined). Bootstrapped + regtested on x86_64-pc-linux-gnu. -- 8< -- This patch ensures that any errors raised by finish_id_expression when parsing a decltype expression are properly reported, rather than potentially going ignored and causing invalid code to be accepted. We can also now remove the separate check for templates without args as this is also checked for in finish_id_expression. PR c++/100482 gcc/cp/ChangeLog: * parser.cc (cp_parser_decltype_expr): Report errors raised by finish_id_expression. gcc/testsuite/ChangeLog: * g++.dg/cpp0x/decltype-100482.C: New test. Signed-off-by: Nathaniel Shead --- gcc/cp/parser.cc | 22 ++++++++++---------- gcc/testsuite/g++.dg/cpp0x/decltype-100482.C | 12 +++++++++++ 2 files changed, 23 insertions(+), 11 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/decltype-100482.C diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc index 5feed77c7acd..9b714ef8d318 100644 --- a/gcc/cp/parser.cc +++ b/gcc/cp/parser.cc @@ -16508,10 +16508,6 @@ cp_parser_decltype_expr (cp_parser *parser, expr = cp_parser_lookup_name_simple (parser, expr, id_expr_start_token->location); - if (expr && TREE_CODE (expr) == TEMPLATE_DECL) - /* A template without args is not a complete id-expression. */ - expr = error_mark_node; - if (expr && expr != error_mark_node && TREE_CODE (expr) != TYPE_DECL @@ -16532,13 +16528,17 @@ cp_parser_decltype_expr (cp_parser *parser, &error_msg, id_expr_start_token->location)); - if (expr == error_mark_node) - /* We found an id-expression, but it was something that we - should not have found. This is an error, not something - we can recover from, so note that we found an - id-expression and we'll recover as gracefully as - possible. */ - id_expression_or_member_access_p = true; + if (error_msg) + { + /* We found an id-expression, but it was something that we + should not have found. This is an error, not something + we can recover from, so report the error we found and + we'll recover as gracefully as possible. */ + cp_parser_parse_definitely (parser); + cp_parser_error (parser, error_msg); + id_expression_or_member_access_p = true; + return error_mark_node; + } } if (expr diff --git a/gcc/testsuite/g++.dg/cpp0x/decltype-100482.C b/gcc/testsuite/g++.dg/cpp0x/decltype-100482.C new file mode 100644 index 000000000000..1df8b1627437 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/decltype-100482.C @@ -0,0 +1,12 @@ +// PR c++/100482 +// { dg-do compile { target c++11 } } + +namespace N {} +decltype(N) x; // { dg-error "expected primary-expression" } + +struct S {}; +decltype(S) y; // { dg-error "argument to .decltype. must be an expression" } + +template +struct U {}; +decltype(U) z; // { dg-error "missing template arguments" }