Re: [PATCH 1/2] checkpolicy: use YYerror only when available

[James Carter <jwcart2@gmail.com>]

On Fri, Mar 22, 2024 at 10:54 AM Christian Göttsche
<cgzones@googlemail.com> wrote:
>
> The special error value YYerror is only available since bison 3.6
> (released 2020).  For example the version used by oss-fuzz does not
> support it.
>
> Use a special token in case YYerror is not available.  Only downside is
> a duplicate error message, one from the manual yyerror() call and one
> from within bison for the unexpected special token (which would be
> omitted by using YYerror).
>
> Signed-off-by: Christian Göttsche <cgzones@googlemail.com>

For these two patches:
Acked-by: James Carter <jwcart2@gmail.com>

> ---
>  checkpolicy/policy_parse.y | 1 +
>  checkpolicy/policy_scan.l  | 9 ++++++++-
>  2 files changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/checkpolicy/policy_parse.y b/checkpolicy/policy_parse.y
> index e0103502..1b275ebc 100644
> --- a/checkpolicy/policy_parse.y
> +++ b/checkpolicy/policy_parse.y
> @@ -153,6 +153,7 @@ typedef int (* require_func_t)(int pass);
>  %token FILESYSTEM
>  %token DEFAULT_USER DEFAULT_ROLE DEFAULT_TYPE DEFAULT_RANGE
>  %token LOW_HIGH LOW HIGH GLBLUB
> +%token INVALID_CHAR
>
>  %left OR
>  %left XOR
> diff --git a/checkpolicy/policy_scan.l b/checkpolicy/policy_scan.l
> index 1926129c..c4d8e937 100644
> --- a/checkpolicy/policy_scan.l
> +++ b/checkpolicy/policy_scan.l
> @@ -308,7 +308,14 @@ GLBLUB                             { return(GLBLUB); }
>  "]" |
>  "~" |
>  "*"                            { return(yytext[0]); }
> -.                               { yyerror("unrecognized character"); return YYerror; }
> +.                               { yyerror("unrecognized character");
> +/* Available since bison 3.6, avoids duplicate error message */
> +#ifdef YYerror
> +                                 return YYerror;
> +#else
> +                                 return INVALID_CHAR;
> +#endif
> +                               }
>  %%
>  int yyerror(const char *msg)
>  {
> --
> 2.43.0
>
>