Re: [PATCH 2/2] grep/pcre2: factor out literal variable

From: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Date: Dec 19, 2021, 19:37 UTC
Message-ID: <211219.86o85cwfje.gmgdl@evledraar.gmail.com>
In-Reply-To: <ba503995-866d-fc80-4e38-b4dfd0e5c5bc@web.de>

On Sat, Dec 18 2021, René Scharfe wrote:

Show 31 quoted lines

> Patterns that contain no wildcards and don't have to be case-folded are
> literal.  Give this condition a name to increase the readability of the
> boolean expression for enabling the option PCRE2_UTF.
>
> Signed-off-by: René Scharfe <l.s.r@web.de>
> ---
>  grep.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/grep.c b/grep.c
> index 5badb6d851..2b6ac3205d 100644
> --- a/grep.c
> +++ b/grep.c
> @@ -362,6 +362,7 @@ static void compile_pcre2_pattern(struct grep_pat *p, const struct grep_opt *opt
>  	int jitret;
>  	int patinforet;
>  	size_t jitsizearg;
> +	int literal = !opt->ignore_case && (p->fixed || p->is_fixed);
>
>  	/*
>  	 * Call pcre2_general_context_create() before calling any
> @@ -382,8 +383,7 @@ static void compile_pcre2_pattern(struct grep_pat *p, const struct grep_opt *opt
>  		}
>  		options |= PCRE2_CASELESS;
>  	}
> -	if (!opt->ignore_locale && is_utf8_locale() &&
> -	    !(!opt->ignore_case && (p->fixed || p->is_fixed)))
> +	if (!opt->ignore_locale && is_utf8_locale() && !literal)
>  		options |= (PCRE2_UTF | PCRE2_MATCH_INVALID_UTF);
>
>  #ifdef GIT_PCRE2_VERSION_10_36_OR_HIGHER

I think for this and 1/2 it would be really nice to pick up a version of Hamza's CI changes: https://lore.kernel.org/git/20211118084143.279174-2-someguy@effective-light.com/

Aside: Not needed for this change, but I wonder if we could benefit minutely
from:

    #ifdef PCRE2_LITERAL
    options |= PCRE2_LITERAL;
    #endif

It'll save PCRE2 the small effort of finding that we've got no metacharacters.