Re: Patch RFC: Use internal qsort function in libbacktrace

[Paolo Carlini <paolo dot carlini at oracle dot com>]

Hi,

On 03/07/2014 01:12 PM, Rainer Orth wrote:
> Hi Paolo,
>
> > On 03/05/2014 04:34 AM, Ian Lance Taylor wrote:
> > > The GNU glibc qsort function will call malloc in some cases.  That makes
> > > it unsuitable for libbacktrace, which is intended to work when called
> > > from a signal handler.  This patch changes libbacktrace to use an
> > > internal qsort function.
> > >
> > > I'm posting this for comments in case anybody sees anything wrong with
> > > the implementation.  I'll commit it in a day or two if I don't hear
> > > anything.
> > >
> > > Bootstrapped and ran libbacktrace and Go tests on
> > > x86_64-unknown-linux-gnu.
> > Sorry if I missed some messages or I'm just confused, but today I'm seeing
> > a lot of regressions all of the same form:
> >
> > libsanitizer/asan/.libs/libasan.so: undefined reference to `backtrace_qsort'
> >
> > Confirmed in eg:
> >
> >      http://gcc.gnu.org/ml/gcc-testresults/2014-03/msg00399.html
> >
> > Any idea what's up?
> I suspect the following patch (yet untested) will fix this:
>
> 2014-03-07  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
>
> 	* libbacktrace/Makefile.am (libsanitizer_libbacktrace_la_SOURCES):
> 	Add ../../libbacktrace/sort.c.
> 	* libbacktrace/Makefile.in: Regenerate.
> 	* libbacktrace/backtrace-rename.h (backtrace_qsort): Define.
Thanks Rainer. Makes a lot of sense to me too. In my personal opinion if 
it passes testing you could commit it as obvious.

Paolo.