[Bug lto/85132] ffmpeg runtime segfault with lto

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85132

--- Comment #5 from Martin Liška <marxin at gcc dot gnu.org> ---
(In reply to Manuel Lauss from comment #4)
> (In reply to Martin Liška from comment #3)
> > (In reply to Manuel Lauss from comment #2)
> > > This is the most minimal ffmpeg config that can trigger the segfault. The
> > > interesting switch is "--enabled-hardcoded-tables".  I use the "mpv" Player
> > > with a standard mp4 video file to trigger it
> > > (https://github.com/mpv-player/mpv/archive/v0.27.2.zip)
> > 
> > Good. so we have minimal set of options for ffmpeg. Now please explain me
> > how to build the MPV tool? Is it really needed? Can't one trigger that
> > directly with ffmepg? Please upload somewhere the mp4 file so that I can
> > reproduce it.
> 
> The segfault happens during initialization of ffmpeg when mpv player starts.
> I can also trigger it with firefox on e.g. youtube: it crashes the tab.

Ok, so please download following sample video:
http://techslides.com/demos/sample-videos/small.mp4

And try to run ffmpeg to print info:
./ffmpeg -i small.mp4

Does it also segfault?

> 
> 
> ad mpv: unpack, configure with the following line (you need python3):
> CCFLAGS="-O3 -march=znver1 -mtune=znver1 -flto=16 -fno-fat-lto-objects
> -pipe" LINKFLAGS="-O3 -march=znver1 -mtune=znver1 -flto=16
> -fno-fat-lto-objects -pipe -Wl,--no-as-needed" ./waf --prefix=/usr
> --libdir=/usr/lib64 --confdir=/etc/mpv --docdir=/usr/share/doc/mpv-0.27.2
> --htmldir=/usr/share/doc/mpv-0.27.2/html --enable-libmpv-shared
> --disable-libmpv-static --disable-static-build --disable-optimize
> --disable-debug-build --enable-html-build --disable-pdf-build
> --enable-cplugins --disable-zsh-comp --disable-test --disable-android
> --enable-iconv --disable-libsmbclient --enable-lua --lua=luajit
> --disable-javascript --enable-x11  --disable-build-date configure
> 
> ./waf build

How the player knows where to find the built ffmpeg libraries?