gcc-7.1.0 fails to build with flto profiled bootstrap build (with gold linker) + graphite optimisations

[Branko]

Eh, nevermind. I've found the link with hints how to do it properly. It 
seems to be building OK now. With graphite, LTO and PGO.




On 14. 07. 2017 05:15, Branko wrote:
> I have adapted existing gcc-7.1.0 ebuild and flag-o-matic eclass so 
> that it allows me to build gcc with my flags without filtering them.
>
> It works fine, when built with prefiltered flags, but I wanted to 
> compile it with flto and pgo steps ( and later do same with binutils) 
> to see if that would shorten long compile times.
>
> It surely should be noteable on packages like mesa, which I have to 
> compile fort 32/64-ti ABIs and where flto is a practical must - 
> difference in performance is simply too great to ignore.
>
> I'd like to speed up compiling and linking ( which can take eternity 
> on bigger packages, compiled with LTO, even with gold)
>
> So I tried to do a make priofiledboostrap with xxFLAGS and setting below:
>
> COMMON_FLAGS="-march=native -pipe -O3 -flto=8  -ffat-lto-objects 
> -flto-partition=none -fuse-linker-plugin -fuse-ld=gold 
> -fno-delete-null-pointer-checks -fgraphite-identity -floop-nest-optimize"
> CFLAGS="${COMMON_FLAGS}"
> CXXFLAGS="${COMMON_FLAGS} -fpermissive"
> LDFLAGS="-Wl,-O3 -Wl,--sort-common -Wl,-flto -Wl,--as-needed 
> -ffat-lto-objects -fuse-linker-plugin -fuse-ld=gold 
> -fno-delete-null-pointer-checks -fgraphite-identity -floop-nest-optimize"
> LD="/usr/bin/ld.gold"
>
> but build fails somewhere at the end of stage3 with:
>
>  ^
> /var/tmp/portage/sys-devel/gcc-7.1.0-r4/work/gcc-7.1.0/libgcc/libgcov-driver.c:885:1: 
> note: ‘__gcov_exit’ was previously declared here
> /var/tmp/portage/sys-devel/gcc-7.1.0-r4/work/gcc-7.1.0/libstdc++-v3/libsupc++/vterminate.cc:82: 
> error: undefined reference to '_Unwind_Resume'
> collect2: error: ld returned 1 exit status
> make[3]: *** [Makefile:2792: build/genenums] Error 1
> make[3]: *** Waiting for unfinished jobs....
> <built-in>: warning: type of ‘__gcov_exit’ does not match original 
> declaration [-Wlto-type-mismatch]
> /var/tmp/portage/sys-devel/gcc-7.1.0-r4/work/gcc-7.1.0/libgcc/libgcov-driver.c:885:1: 
> note: types have different parameter counts
>  __gcov_exit (void)
>  ^
> /var/tmp/portage/sys-devel/gcc-7.1.0-r4/work/gcc-7.1.0/libgcc/libgcov-driver.c:885:1: 
> note: ‘__gcov_exit’ was previously declared here
> /var/tmp/portage/sys-devel/gcc-7.1.0-r4/work/gcc-7.1.0/libstdc++-v3/libsupc++/vterminate.cc:82: 
> error: undefined reference to '_Unwind_Resume'
> collect2: error: ld returned 1 exit status
> make[3]: *** [Makefile:2792: build/genconstants] Error 1
> <built-in>: warning: type of ‘__gcov_exit’ does not match original 
> declaration [-Wlto-type-mismatch]
> /var/tmp/portage/sys-devel/gcc-7.1.0-r4/work/gcc-7.1.0/libgcc/libgcov-driver.c:885:1: 
> note: types have different parameter counts
>  __gcov_exit (void)
>  ^
> /var/tmp/portage/sys-devel/gcc-7.1.0-r4/work/gcc-7.1.0/libgcc/libgcov-driver.c:885:1: 
> note: ‘__gcov_exit’ was previously declared here
> /var/tmp/portage/sys-devel/gcc-7.1.0-r4/work/gcc-7.1.0/libstdc++-v3/libsupc++/vterminate.cc:82: 
> error: undefined reference to '_Unwind_Resume'
> collect2: error: ld returned 1 exit status
>
>
>
> Has anyone tried to compile gcc-7 with such combination ?
>
> I used gcc-7.1.0 for compilation, along with binutils-2.28
>
>
>
>
>
>
>
>
>
>
>