[Bug sanitizer/86275] New: gcc-8.1, linux 4.18-rc1, x86_64: error: redefinition of 'struct timespec'

["gcc at nmacleod dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86275

            Bug ID: 86275
           Summary: gcc-8.1, linux 4.18-rc1, x86_64: error: redefinition
                    of 'struct timespec'
           Product: gcc
           Version: 8.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: sanitizer
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gcc at nmacleod dot com
                CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
                    jakub at gcc dot gnu.org, kcc at gcc dot gnu.org, marxin at gcc dot gnu.org
  Target Milestone: ---

Since this kernel commit in 4.18-rc1:

https://github.com/torvalds/linux/commit/7a074e96dee62586c935c80cecd931431bfdd0be#diff-590a640c13a8f3a134e57b84f5c4fb79

building a gcc-8.1 toolchain with 4.18-rc1 for x86_64 will now fail with the
following error:

In file included from
/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/toolchain/x86_64-libreelec-linux-gnu/sysroot/usr/include/asm/signal.h:7,
                 from
/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/toolchain/x86_64-libreelec-linux-gnu/sysroot/usr/include/linux/signal.h:5,
                 from
/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/toolchain/x86_64-libreelec-linux-gnu/sysroot/usr/include/linux/aio_abi.h:32,
                 from
/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/gcc-8.1.0/libsanitizer/include/system/linux/aio_abi.h:2,
                 from
/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/gcc-8.1.0/libsanitizer/sanitizer_common/sanitizer_platform_limits_linux.cc:50:
/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/toolchain/x86_64-libreelec-linux-gnu/sysroot/usr/include/linux/time.h:10:8:
error: redefinition of 'struct timespec'
 struct timespec {
        ^~~~~~~~
In file included from
/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/toolchain/x86_64-libreelec-linux-gnu/sysroot/usr/include/sys/stat.h:30,
                 from
/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/gcc-8.1.0/libsanitizer/sanitizer_common/sanitizer_platform_limits_linux.cc:31:
/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/toolchain/x86_64-libreelec-linux-gnu/sysroot/usr/include/bits/types/struct_timespec.h:8:8:
note: previous definition of 'struct timespec'
 struct timespec
        ^~~~~~~~
make[5]: *** [Makefile:539: sanitizer_platform_limits_linux.lo] Error 1
make[5]: *** Waiting for unfinished jobs....


Prior to the 7a074e96d commit, gcc-8.1 would build the 4.18 and all previous
kernels without a problem. I performed a git bisect on the kernel between 4.17
(good) and 4.18-rc1 (bad), and git bisect identified the above commit as the
first bad commit.

gcc-8.1 is configured as follows:

Executing (host):
/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/gcc-8.1.0/configure
--host=x86_64-linux-gnu --build=x86_64-linux-gnu
--prefix=/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/toolchain
--bindir=/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/toolchain/bin
--sbindir=/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/toolchain/sbin
--sysconfdir=/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/toolchain/etc
--libexecdir=/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/toolchain/lib
--localstatedir=/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/toolchain/var
--disable-static --enable-shared --target=x86_64-libreelec-linux-gnu
--with-sysroot=/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/toolchain/x86_64-libreelec-linux-gnu/sysroot
--with-gmp=/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/toolchain
--with-mpfr=/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/toolchain
--with-mpc=/home/neil/projects/scratch/alternates/LibreELEC.tv/build.LibreELEC-Generic.x86_64-9.0-devel-next/toolchain
--with-gnu-as --with-gnu-ld --enable-plugin --enable-lto --enable-gold
--enable-ld=default --with-linker-hash-style=gnu --disable-multilib
--disable-nls --enable-checking=release
--with-default-libstdcxx-abi=gcc4-compatible --without-ppl --without-cloog
--disable-libada --disable-libmudflap --disable-libatomic --disable-libitm
--disable-libquadmath --disable-libgomp --disable-libmpx --disable-libssp
--enable-languages=c,c++ --enable-__cxa_atexit --enable-decimal-float
--enable-tls --enable-shared --disable-static --enable-c99 --enable-long-long
--enable-threads=posix --disable-libstdcxx-pch --enable-libstdcxx-time
--enable-clocale=gnu

The toolchain is being built with glibc 2.27 and binutils 2.30. The build host
is Ubuntu 17.10.

The complete gcc log can be found here (4MB, txt):
http://milhouse.libreelec.tv/other/gcc-8.1_linux-4.18-rc1.log.txt