Re: [perf/core PATCH v2 2/4] perf buildid-cache: Consolidate .build-id cache path generators

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Tue, Feb 10, 2015 at 06:18:53PM +0900, Masami Hiramatsu escreveu:
> +static int asnprintf(char **strp, size_t size, const char *fmt, ...)
> +{
> +	va_list ap;
> +	int ret;
> +	if (!strp)
> +		return -EINVAL;
> +	va_start(ap, fmt);
> +	if (*strp)
> +		ret = vsnprintf(*strp, size, fmt, ap);
> +	else
> +		ret = vasprintf(strp, fmt, ap);
> +	va_end(ap);
> +	return ret;
> +}
> +static char *build_id__filename(const char *sbuild_id, char *bf, size_t size)
> +{
> +	char *tmp = bf;
> +	int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
> +			    sbuild_id, sbuild_id + 2);
> +	if (ret < 0 || (tmp && size < (unsigned int)ret))
> +		return NULL;

This is a good thing, i.e. checking if the formatting truncated
something, i.e. vsnprintf honours 'size' but may return more than that,
but next time try to get it into a separate patch :-)

Anyway, after scratching my head with this extra thing/re-reading the
vsnprintf man page, I'm applying this patch, thanks.

- Arnaldo