[cfe-dev] [Release-testers] [7.0.0 Release] rc1 has been tagged

Dimitry Andric via cfe-dev cfe-dev at lists.llvm.org
Sun Aug 5 08:49:09 PDT 2018


On 3 Aug 2018, at 13:37, Hans Wennborg via Release-testers <release-testers at lists.llvm.org> wrote:
> 
> 7.0.0-rc1 was just tagged (from the branch at r338847).
> 
> It's early in the release process, but I'd like to find out what the
> status is of the branch on our various platforms.
> 
> Please run the test script, share the results, and upload binaries.

Hmm, I'm running into a rather nasty snag now on i386-freebsd11, due to our lack of atomic 64 bit primitives; Phase2's configure dies with:

    -- Performing Test HAVE_CXX_ATOMICS_WITHOUT_LIB
    -- Performing Test HAVE_CXX_ATOMICS_WITHOUT_LIB - Success
    -- Performing Test HAVE_CXX_ATOMICS64_WITHOUT_LIB
    -- Performing Test HAVE_CXX_ATOMICS64_WITHOUT_LIB - Failed
    -- Looking for __atomic_load_8 in atomic
    -- Looking for __atomic_load_8 in atomic - not found
    CMake Error at cmake/modules/CheckAtomic.cmake:75 (message):
      Host compiler appears to require libatomic, but cannot find it.

Interestingly, Phase1 does *not* suffer from this, but there the "host compiler" is clang 6.0.0.

Phase1 CMake output:

    Performing C++ SOURCE FILE Test HAVE_CXX_ATOMICS64_WITHOUT_LIB succeeded with the following output:
    Change Dir: /home/dim/llvm/7.0.0/rc1/Phase1/Release/llvmCore-7.0.0-rc1.obj/CMakeFiles/CMakeTmp

    Run Build Command:"/usr/local/bin/gmake" "cmTC_845df/fast"
    /usr/local/bin/gmake -f CMakeFiles/cmTC_845df.dir/build.make CMakeFiles/cmTC_845df.dir/build
    gmake[1]: Entering directory '/home/dim/llvm/7.0.0/rc1/Phase1/Release/llvmCore-7.0.0-rc1.obj/CMakeFiles/CMakeTmp'
    Building CXX object CMakeFiles/cmTC_845df.dir/src.cxx.o
    /usr/bin/c++    -DHAVE_CXX_ATOMICS64_WITHOUT_LIB -std=c++11  -Werror=unguarded-availability-new   -o CMakeFiles/cmTC_845df.dir/src.cxx.o -c /home/dim/llvm/7.0.0/rc1/Phase1/Release/llvmCore-7.0.0-rc1.obj/CMakeFiles/CMakeTmp/src.cxx
    Linking CXX executable cmTC_845df
    /usr/local/bin/cmake -E cmake_link_script CMakeFiles/cmTC_845df.dir/link.txt --verbose=1
    /usr/bin/c++   -DHAVE_CXX_ATOMICS64_WITHOUT_LIB -std=c++11  -Werror=unguarded-availability-new    CMakeFiles/cmTC_845df.dir/src.cxx.o  -o cmTC_845df -lm
    gmake[1]: Leaving directory '/home/dim/llvm/7.0.0/rc1/Phase1/Release/llvmCore-7.0.0-rc1.obj/CMakeFiles/CMakeTmp'

    Source file was:

    #include <atomic>
    #include <cstdint>
    std::atomic<uint64_t> x (0);
    int main() {
      uint64_t i = x.load(std::memory_order_relaxed);
      return 0;
    }

Phase2 CMake output:

    Performing C++ SOURCE FILE Test HAVE_CXX_ATOMICS64_WITHOUT_LIB failed with the following output:
    Change Dir: /home/dim/llvm/7.0.0/rc1/Phase2/Release/llvmCore-7.0.0-rc1.obj/CMakeFiles/CMakeTmp

    Run Build Command:"/usr/local/bin/gmake" "cmTC_720f3/fast"
    /usr/local/bin/gmake -f CMakeFiles/cmTC_720f3.dir/build.make CMakeFiles/cmTC_720f3.dir/build
    gmake[1]: Entering directory '/home/dim/llvm/7.0.0/rc1/Phase2/Release/llvmCore-7.0.0-rc1.obj/CMakeFiles/CMakeTmp'
    Building CXX object CMakeFiles/cmTC_720f3.dir/src.cxx.o
    /home/dim/llvm/7.0.0/rc1/Phase1/Release/llvmCore-7.0.0-rc1.install/usr/local/bin/clang++    -DHAVE_CXX_ATOMICS64_WITHOUT_LIB -std=c++11  -Werror=unguarded-availability-new   -o CMakeFiles/cmTC_720f3.dir/src.cxx.o -c /home/dim/llvm/7.0.0/rc1/Phase2/Release/llvmCore-7.0.0-rc1.obj/CMakeFiles/CMakeTmp/src.cxx
    Linking CXX executable cmTC_720f3
    /usr/local/bin/cmake -E cmake_link_script CMakeFiles/cmTC_720f3.dir/link.txt --verbose=1
    /home/dim/llvm/7.0.0/rc1/Phase1/Release/llvmCore-7.0.0-rc1.install/usr/local/bin/clang++   -DHAVE_CXX_ATOMICS64_WITHOUT_LIB -std=c++11  -Werror=unguarded-availability-new    CMakeFiles/cmTC_720f3.dir/src.cxx.o  -o cmTC_720f3 -lm
    CMakeFiles/cmTC_720f3.dir/src.cxx.o: In function `main':
    src.cxx:(.text+0x33): undefined reference to `__atomic_load_8'
    clang-7: error: linker command failed with exit code 1 (use -v to see invocation)
    gmake[1]: *** [CMakeFiles/cmTC_720f3.dir/build.make:98: cmTC_720f3] Error 1
    gmake[1]: Leaving directory '/home/dim/llvm/7.0.0/rc1/Phase2/Release/llvmCore-7.0.0-rc1.obj/CMakeFiles/CMakeTmp'
    gmake: *** [Makefile:126: cmTC_720f3/fast] Error 2

    Source file was:

    #include <atomic>
    #include <cstdint>
    std::atomic<uint64_t> x (0);
    int main() {
      uint64_t i = x.load(std::memory_order_relaxed);
      return 0;
    }

Apparently, with clang 6.0 it didn't generate libcalls to atomic functions, but just put in cmpxchg8b's, I guess?  And with clang 7.0 this seems to have changed.

For now, I can only test on amd64 due to this, since I don't have an easy workaround.

-Dimitry

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