Elia Pinto <gitter.spiros@xxxxxxxxx> writes:
> In glibc >= 2.34 MALLOC_CHECK_ and MALLOC_PERTURB_ environment
> variables have been replaced by GLIBC_TUNABLES. Also the new
Does it hurt to have these older environment variables? If not,
we would prefer to see redundant but less deeply indented code,
I would imagine.
> + if type -p getconf >/dev/null 2>&1; then
> + _GLIBC_VERSION="$(getconf GNU_LIBC_VERSION 2>/dev/null | awk '{ print $2 }')"
> + if [ -n "$_GLIBC_VERSION" -a $(expr "$_GLIBC_VERSION" \>= "2.34") ]; then
> + _HAVE_GLIBC_234="yes"
> + fi
> + fi
Style. We prefer "test ..." over "[ ... ]" and more importantly we
don't use "test X -a Y".
Do we absolutely need "test -p getconf" with an extra indentation?
I suspect we don't.
if _GLIBC_VERSION=$(getconf GNU_LIBC_VERSION 2>/dev/null) &&
_GLIBC_VERSION=${_GLIBC_VERSION#"glibc "} &&
test 2.34 \<= "$_GLIBC_VERSION"
then
USE_GLIBC_TUNABLES=YesPlease
fi
perhaps? I am not sure if glibc 2.4 still matters, getconf reports
it as 2.04 or 2.4, for the above comparison to be OK, though.
In any case, HAVE_GLIBC_234 is a horrible variable name to use for
this purpose, as the primary thing the two use sites care about is
not the version but if they should use the GLIBC_TUNABLES mechanism,
so it would be better to name the variable after the feature.
> setup_malloc_check () {
> - MALLOC_CHECK_=3 MALLOC_PERTURB_=165
> - export MALLOC_CHECK_ MALLOC_PERTURB_
> + if test "x$_HAVE_GLIBC_234" = xyes ; then
> + LD_PRELOAD="libc_malloc_debug.so.0" GLIBC_TUNABLES="glibc.malloc.check=1:glibc.malloc.perturb=165"
> + export LD_PRELOAD GLIBC_TUNABLES
> + else
> + MALLOC_CHECK_=3 MALLOC_PERTURB_=165
> + export MALLOC_CHECK_ MALLOC_PERTURB_
> + fi
Avoid overly long lines when you can easily do so.
MALLOC_CHECK_=3 MALLOC_PERTURB_=165
export MALLOC_CHECK_ MALLOC_PERTURB_
+ case "$USE_GLIBC_TUNABLES" in
+ YesPlease)
+ g=
+ LD_PRELOAD=libc_malloc_debug.so.0
+ for t in \
+ glibc.malloc.check=1 \
+ glibc.malloc.perturb=165 \
+ do
+ g="$g${g:+:}$t"
+ done
+ GLIBC_TUNABLES=$g
+ ;;
+ esac
perhaps?
> }
> teardown_malloc_check () {
> - unset MALLOC_CHECK_ MALLOC_PERTURB_
> + if test "x$_HAVE_GLIBC_234" = xyes ; then
> + unset LD_PRELOAD GLIBC_TUNABLES
> + else
> + unset MALLOC_CHECK_ MALLOC_PERTURB_
> + fi
Similarly.
> }
> fi
