Re: [PATCH 05/10] grep/pcre2: add GREP_PCRE2_DEBUG_MALLOC debug mode

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Feb 10, 2021, 10:38 UTC
Message-ID: <nycvar.QRO.7.76.6.2102101135390.29765@tvgsbejvaqbjf.bet>
In-Reply-To: <20210204210556.25242-6-avarab@gmail.com>

Hi Ævar,

On Thu, 4 Feb 2021, Ævar Arnfjörð Bjarmason wrote:

> Add optional printing of PCREv2 allocations to stderr for a developer
> who manually changes the GREP_PCRE2_DEBUG_MALLOC definition to
> "1".

Maybe clarify in the oneline that this is not an environment variable, but a Makefile knob? I had to read all the way to the diff to understand that aspect.

Otherwise, the patch series so far looks really fine to me.

Thanks, Dscho

Show 44 quoted lines

>
> This will be referenced a subsequent commit, and is generally useful
> to manually see what's going on with PCREv2 allocations while working
> on that code.
>
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> ---
>  grep.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/grep.c b/grep.c
> index f96d86c929..7d262a23d8 100644
> --- a/grep.c
> +++ b/grep.c
> @@ -42,15 +42,25 @@ static struct grep_opt grep_defaults = {
>
>  #ifdef USE_LIBPCRE2
>  static pcre2_general_context *pcre2_global_context;
> +#define GREP_PCRE2_DEBUG_MALLOC 0
>
>  static void *pcre2_malloc(PCRE2_SIZE size, MAYBE_UNUSED void *memory_data)
>  {
>  	void *pointer = malloc(size);
> +#if GREP_PCRE2_DEBUG_MALLOC
> +	static int count = 1;
> +	fprintf(stderr, "PCRE2:%p -> #%02d: alloc(%lu)\n", pointer, count++, size);
> +#endif
>  	return pointer;
>  }
>
>  static void pcre2_free(void *pointer, MAYBE_UNUSED void *memory_data)
>  {
> +#if GREP_PCRE2_DEBUG_MALLOC
> +	static int count = 1;
> +	if (pointer)
> +		fprintf(stderr, "PCRE2:%p -> #%02d: free()\n", pointer, count++);
> +#endif
>  	free(pointer);
>  }
>  #endif
> --
> 2.30.0.284.gd98b1dd5eaa7
>
>