c++: Report invalid id-expression in decltype [PR100482]
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Commit Message
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 <nathanieloshead@gmail.com>
---
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
Comments
On 8/7/23 22:48, Nathaniel Shead wrote:
> 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.
Pushed, thanks!
> -- 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 <nathanieloshead@gmail.com>
> ---
> 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 d7ef5b34d42..119a14d03b9 100644
> --- a/gcc/cp/parser.cc
> +++ b/gcc/cp/parser.cc
> @@ -16506,10 +16506,6 @@ 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
> @@ -16530,13 +16526,17 @@ 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 00000000000..1df8b162743
> --- /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 <typename T>
> +struct U {};
> +decltype(U) z; // { dg-error "missing template arguments" }
@@ -16506,10 +16506,6 @@ 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
@@ -16530,13 +16526,17 @@ 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
new file mode 100644
@@ -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 <typename T>
+struct U {};
+decltype(U) z; // { dg-error "missing template arguments" }