Re: [PATCH] valgrind: do not require valgrind 3.4.0 or newer

[Junio C Hamano <gitster@pobox.com>]

Johannes Schindelin <johannes.schindelin@gmx.de> writes:

> Valgrind 3.4.0 is pretty new, and even if --track-origins is a nice
> feature, it is not the end of the world if that is not available.  So
> play nice and use that option only when only an older version of
> valgrind is available.
>
> In the same spirit, refrain from the use of '...' in suppression
> files, which is also a feature only valgrind 3.4 and newer understand.
>
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Thanks.

> +TRACK_ORIGINS=
> +
> +VALGRIND_VERSION=$(valgrind --version)
> +VALGRIND_MAJOR=$(expr "$VALGRIND_VERSION" : '[^0-9]*\([0-9]*\)')
> +VALGRIND_MINOR=$(expr "$VALGRIND_VERSION" : '[^0-9]*[0-9]*\.\([0-9]*\)')
> +test 3 -gt "$VALGRIND_MAJOR" ||
> +test 3 -eq "$VALGRIND_MAJOR" -a 4 -gt "$VALGRIND_MINOR" ||
> +TRACK_ORIGINS=--track-origins=yes

It took me a while to convince myself that

	"3 > major || (3 == major && 4 > minor) || do-this"

is equivalent to

	"if (3 < major || (3 == major && 4 <= minor)) { do-this }"

which would be:

	if test 3 -lt "$VALGRIND_MAJOR" ||
           test 3 -eq "$VALGRIND_MAJOR" -a 4 -le "$VALGRIND_MINOR"
        then
		TRACK_ORIGINS=--track-origins=yes
	fi
        
or more commonly:

	if test "$VALGRIND_MAJOR" -gt 3 ||
           test "$VALGRIND_MAJOR" -eq 3 -a "$VALGRIND_MINOR" -ge 4
        then
		TRACK_ORIGINS=--track-origins=yes
	fi