Problems with gcc9

[KlausMeier]

With gcc8 everything works fine for me. But after switching to gcc9 I had no problem to build the packages, but some packages crashed, when I start them. There was mpv, kodi and the plasma system settings. But I think, they crashed because of some libraries. I rebuild mpv with normal cflags, no difference. At the moment I try with -O2.

[InBetweenNames]

I actually just did a full system rebuild so I will try these packages ASAP.

[KlausMeier]

The problem is not the build, that works very well, you had to test every application. They crashed. And then I don't know, where is the reason. Because I rebuild mpv with standard flags but it crashed again with a memory access error.

[pchome]

@KlausMeier
media-video/mpv is OK for me.

I usually don't do (read "never") full system rebuild after GCC upgrade, but only packages containing static libraries (similar to lto-rebuild). So mpv was last built a month ago using gcc8, rebuilt using gcc9 still OK.

media-video/mpv-0.29.1-r1::gentoo was built with the following:
USE="X alsa cli egl iconv jack jpeg lcms libass lua luajit openal opengl pulseaudio uchardet vdpau xv zlib (-aqua) -archive -bluray -cdda (-coreaudio) -cplugins -cuda -doc -drm -dvb -dvd -gbm -javascript -libcaca -libmpv -oss (-raspberry-pi) -rubberband -samba -sdl (-selinux) -test -tools -v4l -vaapi -vulkan -wayland -zsh-completion" ABI_X86="(64)" PYTHON_TARGETS="python2_7 python3_7 -python3_5 -python3_6"
CFLAGS="-march=native -O3 -pipe -fgraphite-identity -ftree-loop-distribution -floop-nest-optimize -fipa-pta -flto=3 -fuse-linker-plugin -Wl,-O1 -Wl,--as-needed -Wl,--hash-style=gnu"
CXXFLAGS="-march=native -O3 -pipe -fgraphite-identity -ftree-loop-distribution -floop-nest-optimize -fipa-pta -flto=3 -fuse-linker-plugin -Wl,-O1 -Wl,--as-needed -Wl,--hash-style=gnu"

[KlausMeier]

Yes, I told you, this is not a problem of mpv. I rebuild mpv with standard flags and it crashed again. But I told you three times, that it is not a problem of mpv but a problem of a library. And i don't know which library. mpv crashed, because I rebuild a library, that you don't rebuild.

[InBetweenNames]

I am getting a crash on systemsettings5 after the rebuild. I'll investigate that.

[javashin]

This Is Why I dont Built with ipa and no-plt and no others strange flags gcc 9.1 worked fine here but i rolled back to my backup with no ipa and no no-plt and fastmath i masked gcc 9.1 and everything works fine this way also i changed from ld.gold to bfd and compiled firefox with clang+pgo+lto+-O3 everything working fine

CC="gcc"
CXX="g++"
AR="gcc-ar"
NM="gcc-nm"
RANLIB="gcc-ranlib"
STRIP="gcc-strip"
LD="ld.bfd"
CFLAGS="-O3 -march=native -mfpmath=both -funroll-loops -falign-functions=32 -fgraphite-identity -floop-nest-optimize -fno-semantic-interposition -flto=3 -fuse-linker-plugin -fuse-ld=bfd -pipe"
CXXFLAGS="-O3 -march=native -mfpmath=both -funroll-loops -falign-functions=32 -fgraphite-identity -floop-nest-optimize -fno-semantic-interposition -flto=3 -fuse-linker-plugin -fuse-ld=bfd -pipe"
CPPFLAGS="-O3 -march=native -mfpmath=both -funroll-loops -falign-functions=32 -fgraphite-identity -floop-nest-optimize -fno-semantic-interposition -flto=3 -fuse-linker-plugin -fuse-ld=bfd -pipe"
FFLAGS="-O3 -march=native -mfpmath=both -funroll-loops -falign-functions=32 -fgraphite-identity -floop-nest-optimize -fno-semantic-interposition -flto=3 -fuse-linker-plugin -fuse-ld=bfd -pipe"
FCFLAGS="-O3 -march=native -mfpmath=both -funroll-loops -falign-functions=32 -fgraphite-identity -floop-nest-optimize -fno-semantic-interposition -flto=3 -fuse-linker-plugin -fuse-ld=bfd -pipe"
F77FLAGS="-O3 -march=native -mfpmath=both -funroll-loops -falign-functions=32 -fgraphite-identity -floop-nest-optimize -fno-semantic-interposition -flto=3 -fuse-linker-plugin -fuse-ld=bfd -pipe"
LDFLAGS="-Wl,-O2 -Wl,--as-needed -Wl,--hash-style=gnu"

[InBetweenNames]

I don't see what any of that has to do with this.

[InBetweenNames]

Getting a:

Failed to create OpenGL context for format QSurfaceFormat(version 2.0, options QFlags<QSurfaceFormat::FormatOption>(), depthBufferSize 24, redBufferSize -1, greenBufferSize -1, blueBufferSize -1, alphaBufferSize -1, stencilBufferSize 8, samples -1, swapBehavior QSurfaceFormat::DoubleBuffer, swapInterval 1, colorSpace QSurfaceFormat::DefaultColorSpace, profile  QSurfaceFormat::NoProfile)

Qt and systemsettings are compiled with GCC 9.1, -O2 -march=native -pipe only just to be sure. It may be a Qt bug.

[InBetweenNames]

My other KDE apps seem fine too

[InBetweenNames]

Updated Qt to 5.13.9999, problem does not seem present anymore!

[Supded]

FFLAGS="-O3 -march=native -mfpmath=both -funroll-loops -falign-functions=32 -fgraphite-identity -floop-nest-optimize -fno-semantic-interposition -flto=3 -fuse-linker-plugin -fuse-ld=bfd -pipe"
Is that legit?

[InBetweenNames]

It's not a supported configuration, but it shouldn't break anything at least.

[InBetweenNames]

Update: Downgraded again to Qt 5.12.3, did a full rebuild of KDE. systemsettings5 problem is still resolved.

[InBetweenNames]

Kodi seems to work fine too.

[InBetweenNames]

@KlausMeier under what circumstances does mpv crash?