Hi, On Sun, 7 Aug 2016, Ken Moffat wrote:
> On Sun, Aug 07, 2016 at 12:20:23PM -0500, Bruce Dubbs wrote: > > Ken Moffat wrote: > > > > Isn't -flto the gold linker? I'm not sure. > > > > Didn't someone once say that if you don't follow the book and something > > breaks, that you get to keep the pieces? > > > > [snip] > > Probably (-flto), certainly the book doesn't enable the plugins. > And yes, I'm keeping all the pieces. The book neither explicitly disable the linker plugin. So as we are using up to date binutils which supports the linker plugin, on a non exotic plateform like using ELF, then by default both binutils and gcc will be built with LTO and linker plugin support, whether you use gold or not. About the build failures you are reporting, you only show the ones in the "guality" test folders. For me, whatever the gcc/binutils/gdb versions, these tests are always very flacky and I could never got them to work at 100% whatever the configuration I use. What are the "guality" tests ? Simply tests that checks that the generated debug symbols are fine. In other words, in these tests, gcc compiles some dummy programs with different options, then start them with gdb, and tries to put breakpoint and print values. In all the case I investigated on my side, the issue were that when printing values of variables in gdb, it often ended up printing "optimized out" rather than the real value. These tests are highly dependent on the gdb version you use. So in the end, gcc may be wrong, or maybe it is gcc that cannot properly read the gcc DWARF data, but the resulting code is fine, just the debugging may not be. Apparently I am not the only one where these tests are very flacky. I discovered that in Google branch of gcc they ended up completely disabling all these tests because they were always broken at different places. See https://gcc.gnu.org/ml/gcc-patches/2011-03/msg02120.html Even today, these tests seems to pass for some gcc developers, but not for others. Just check the gcc "testresults" mailing list: https://gcc.gnu.org/ml/gcc-testresults/2016-08/ For example a run executed on gcc 6 x86_64 by H.J. Lu: https://gcc.gnu.org/ml/gcc-testresults/2016-08/msg00767.html you can see that a lot of guality tests are failing as well. So I wouldn't care that much about "guality" tests (on my side, I have disabled them since they never worked, even when using the very latest git revision of all involved components). Cheers, Romain -- http://lists.linuxfromscratch.org/listinfo/lfs-dev FAQ: http://www.linuxfromscratch.org/faq/ Unsubscribe: See the above information page
