Re: [PATCH 2/2] c++: guard more against undiagnosed error_mark_node [PR112658]

[Jason Merrill <jason@redhat.com>]

On 11/28/23 11:51, Patrick Palka wrote:
> This adds a sanity check to cp_parser_expression_statement similar to
> the one in finish_expr_stmt added by r6-6795-g0fd9d4921f7ba2, which
> effectively downgrades accepts-invalid/wrong-code bugs like this one
> into ice-on-invalid/ice-on-valid ones.

OK.

> 	PR c++/112658
> 
> gcc/cp/ChangeLog:
> 
> 	* parser.cc (cp_parser_expression_statement): If the statement
> 	is erroneous, make sure we've seen an error.
> ---
>   gcc/cp/parser.cc | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
> index 2464d1a0783..743d6517b09 100644
> --- a/gcc/cp/parser.cc
> +++ b/gcc/cp/parser.cc
> @@ -12962,6 +12962,9 @@ cp_parser_expression_statement (cp_parser* parser, tree in_statement_expr)
>         if (statement == error_mark_node
>   	  && !cp_parser_uncommitted_to_tentative_parse_p (parser))
>   	{
> +	  /* If we ran into a problem, make sure we complained.  */
> +	  gcc_assert (seen_error ());
> +
>   	  cp_parser_skip_to_end_of_block_or_statement (parser);
>   	  return error_mark_node;
>   	}