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author | Thiago Macieira <thiago.macieira@intel.com> | 2015-09-08 20:35:33 -0300 |
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committer | Thiago Macieira <thiago.macieira@intel.com> | 2015-09-22 22:46:08 +0000 |
commit | 3d7586b760550b7d89594c8d7462fc30b868ecc6 (patch) | |
tree | 926b254d3b72385365c9dd51d66d311b31b71209 /config.tests/common/atomic64/atomic64.pro | |
parent | 847d5d1309a4365af7d0f4fa1bff5754b8286e34 (diff) |
Auto-detect whether 64-bit std::atomic really works
The C++ standard says it must, but some badly-configured toolchains seem
to be lacking support.
In particular, for some 32-bit platforms without native support for
them, GCC implements 64-bit atomics via out-of-line functions in
libatomic. If that library is missing... well, then std::atomic 64-bit
doesn't work and we mustn't try to use it.
This was found when trying to compile Qt 5.6 for MIPS 32-bit:
Linking library libQt5Core.so.5.6.0
.obj/qsimd.o: In function `std::__atomic_base<unsigned long long>::load(std::memory_order) const':
/opt/poky/1.7/sysroots/mips32r2-poky-linux/usr/include/c++/4.9.1/bits/atomic_base.h:500: undefined reference to `__atomic_load_8'
.obj/qsimd.o: In function `std::__atomic_base<unsigned long long>::store(unsigned long long, std::memory_order)':
/opt/poky/1.7/sysroots/mips32r2-poky-linux/usr/include/c++/4.9.1/bits/atomic_base.h:478: undefined reference to `__atomic_store_8'
Yocto bug report: https://bugzilla.yoctoproject.org/show_bug.cgi?id=8274
Change-Id: I42e7ef1a481840699a8dffff140224d6614e5c36
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Diffstat (limited to 'config.tests/common/atomic64/atomic64.pro')
-rw-r--r-- | config.tests/common/atomic64/atomic64.pro | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/config.tests/common/atomic64/atomic64.pro b/config.tests/common/atomic64/atomic64.pro new file mode 100644 index 0000000000..c9a85817ca --- /dev/null +++ b/config.tests/common/atomic64/atomic64.pro @@ -0,0 +1,3 @@ +SOURCES = atomic64.cpp +CONFIG += c++11 console +CONFIG -= qt |