Hi Emil, regarding this patch, I now think we can indeed drop the second part (the one that adds the g++4.4 test), because it would only check whether one sets the -std=c++11 flag somewhere accidently. Checking that no c++11 code makes it into core mesa is already happening as long as travis uses a pre g++6 compiler.
Considerig the choice between checking for support of the flag -std=c++11 and checking whether the compiler supports c++11 features by default the discussion on debian-devel started by this mail https://lists.debian.org/debian-devel/2017/10/msg00174.html might be of interest. In short it is preferred that the code is compiled with the standard the compiler sets by default. From that point of view the version of the patch that checks for the features would be better, or I could rework the patch to check whether g++ is >= 6.0, but that is, of course, not as generic. Another consideration is that with g++ >= 6 with the current approach of setting the flags we end up with the somewhat paradox situation where the "more modern" code requiring -std=c++11 is compiled like this, but the "older" code is compiled with the default, newer, c++14, so no setting flags unless it is really needed would IMHO be more consistent. Best, Gert Am Dienstag, den 03.10.2017, 16:47 +0200 schrieb Gert Wollny: > > Following Emils comments I've updated the patches. > > Compiling was tested on travis on top of 677edff5cf (wayland-egl: > rework ...) > plus the patch "wayland-egl: redistribute wayland.egl.h include" > proposed by > Tobias Klausmann: https://travis-ci.org/gerddie/mesa/builds/282591233 > to fix > some build configurations. > > Changes versus v3: > > patch 1: > - use AX_CHECK_COMPILE_FLAG to test for support of -std=c++11, this > avoids adding a new custom m4 file > - use if-then tests instead of calling the macro various times > - remove undocumented changes to .travis.yml > > patch 2: > - use llvm-3.3 when building with g++-4.4 since llvm-3.6 actually > sets the -std=c++11 flag resulting in build failure with g++4.4 that > doesn't support this flag. > > Regarding adding yet anouther build configuration to travis: > I propose to add this test, because mesa is supposed to support > compilers gcc/g++ 4.2, and -std=c++11 was not supported before g++- > 4.7. Given that g++ >= 6 is now the standard in Debian stable and > derivatives, and defaults to c++14, developers using these distros > might not be aware when they add c++11 (or c++14) code. > > Changes w.r.t. v2: > - complete rewrite > > best regards, > Gert > > Gert Wollny (2): > configure+mesa/st: unify check for -std=c++11 support and enable > accordingly > travis: Add test for gcc-4.4 compiler tool chain > > .travis.yml | 31 > +++++++++++++++++++++++++++ > configure.ac | 18 ++++++++++------ > src/gallium/drivers/swr/Makefile.am | 4 ++-- > src/gallium/state_trackers/clover/Makefile.am | 6 +++--- > src/mesa/state_tracker/tests/Makefile.am | 7 +++++- > 5 files changed, 54 insertions(+), 12 deletions(-) > _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
