Re: [PATCH] Add Rust parser check for end of expression

[Pedro Alves <pedro@palves.net>]

On 2022-03-18 04:44, Tom Tromey wrote:
> I noticed that "print 5," passed in Rust -- the parser wasn't checking
> that the entire input was used.  This patch fixes the problem.  This
> in turn pointed out another bug in the parser, namely that it didn't
> lex the next token after handling a string token.  This is also fixed
> here.

OOC, is the lex-next-token bug something that is also covered by
the added test?  It doesn't seem to use strings.

Pedro Alves

> ---
>  gdb/rust-parse.c                | 6 +++++-
>  gdb/testsuite/gdb.rust/expr.exp | 2 ++
>  2 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/gdb/rust-parse.c b/gdb/rust-parse.c
> index 4006df7086b..7d7d882872c 100644
> --- a/gdb/rust-parse.c
> +++ b/gdb/rust-parse.c
> @@ -271,7 +271,10 @@ struct rust_parser
>    operation_up parse_entry_point ()
>    {
>      lex ();
> -    return parse_expr ();
> +    operation_up result = parse_expr ();
> +    if (current_token != 0)
> +      error (_("Syntax error near '%s'"), pstate->prev_lexptr);
> +    return result;
>    }
>  
>    operation_up parse_tuple ();
> @@ -2020,6 +2023,7 @@ rust_parser::parse_atom (bool required)
>  
>      case STRING:
>        result = parse_string ();
> +      lex ();
>        break;
>  
>      case BYTESTRING:
> diff --git a/gdb/testsuite/gdb.rust/expr.exp b/gdb/testsuite/gdb.rust/expr.exp
> index 0c445897338..bb0222bed4b 100644
> --- a/gdb/testsuite/gdb.rust/expr.exp
> +++ b/gdb/testsuite/gdb.rust/expr.exp
> @@ -145,3 +145,5 @@ gdb_test "print 0x0 as fn(i64) -> ()" " = \\\(\\*mut fn \\\(i64\\\) -> \\\(\\\)\
>  gdb_test "print r#" "No symbol 'r' in current context"
>  
>  gdb_test "printf \"%d %d\\n\", 23+1, 23-1" "24 22"
> +
> +gdb_test "print 5," "Syntax error near ','"