[libcxx] r277380 - atomics.align: XFAIL GCC

[JF Bastien via cfe-commits]

Author: jfb
Date: Mon Aug  1 15:28:13 2016
New Revision: 277380

URL: http://llvm.org/viewvc/llvm-project?rev=277380&view=rev
Log:
atomics.align: XFAIL GCC

It currently fails because GCC changed the mangling of templates, which affects std::atomic using __attribute__((vector(X))). The bot using GCC 4.9 generates the following message:

In file included from /home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/test/libcxx/atomics/atomics.align/align.pass.sh.cpp:24:0:
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic: In instantiation of 'atomic_test<T>::atomic_test() [with T = __vector(2) int]':
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/test/libcxx/atomics/atomics.align/align.pass.sh.cpp:66:3:   required from here
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:583:5: error: 'std::__1::__gcc_atomic::__gcc_atomic_t<_Tp>::__gcc_atomic_t() [with _Tp = __vector(2) int]' conflicts with a previous declaration
     __gcc_atomic_t() _NOEXCEPT = default;
     ^
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:583:5: note: previous declaration 'std::__1::__gcc_atomic::__gcc_atomic_t<_Tp>::__gcc_atomic_t() [with _Tp = __vector(1) int]'
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:583:5: note: -fabi-version=6 (or =0) avoids this error with a change in mangling
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:583:5: error: 'std::__1::__gcc_atomic::__gcc_atomic_t<_Tp>::__gcc_atomic_t() [with _Tp = __vector(2) int]' conflicts with a previous declaration
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:583:5: note: previous declaration 'std::__1::__gcc_atomic::__gcc_atomic_t<_Tp>::__gcc_atomic_t() [with _Tp = __vector(1) int]'
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:583:5: note: -fabi-version=6 (or =0) avoids this error with a change in mangling
/home/llvm-builder/llvm-buildslave-root/libcxx-libcxxabi-x86_64-linux-ubuntu-gcc49-cxx11/llvm/projects/libcxx/include/atomic:939:5: note: synthesized method 'std::__1::__gcc_atomic::__gcc_atomic_t<_Tp>::__gcc_atomic_t() [with _Tp = __vector(2) int]' first required here
     __atomic_base() _NOEXCEPT = default;
     ^

GCC's docs say the following about ABI version 6:
Version 6, which first appeared in G++ 4.7, corrects the promotion behavior of C++11 scoped enums and the mangling of template argument packs, const/static_cast, prefix ++ and –, and a class scope function used as a template argument.

Modified:
    libcxx/trunk/test/libcxx/atomics/atomics.align/align.pass.sh.cpp

Modified: libcxx/trunk/test/libcxx/atomics/atomics.align/align.pass.sh.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/libcxx/atomics/atomics.align/align.pass.sh.cpp?rev=277380&r1=277379&r2=277380&view=diff
==============================================================================
--- libcxx/trunk/test/libcxx/atomics/atomics.align/align.pass.sh.cpp (original)
+++ libcxx/trunk/test/libcxx/atomics/atomics.align/align.pass.sh.cpp Mon Aug  1 15:28:13 2016
@@ -11,6 +11,10 @@
 // REQUIRES: libatomic
 // RUN: %build -latomic
 // RUN: %run
+//
+// GCC currently fails because it needs -fabi-version=6 to fix mangling of
+// std::atomic when used with __attribute__((vector(X))).
+// XFAIL: gcc
 
 // <atomic>