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| author | Volodymyr Sapsai <vsapsai@apple.com> | 2018-05-02 17:56:45 +0000 |
|---|---|---|
| committer | Volodymyr Sapsai <vsapsai@apple.com> | 2018-05-02 17:56:45 +0000 |
| commit | dea80d5174178482fad4deb435a1bc849b9c5abb (patch) | |
| tree | 44ceb733e8a439aa023be0e3f6b8621a29edffea /libcxx | |
| parent | c0a278aada533d52ab0f481abdcab582861d05b2 (diff) | |
| download | bcm5719-llvm-dea80d5174178482fad4deb435a1bc849b9c5abb.tar.gz bcm5719-llvm-dea80d5174178482fad4deb435a1bc849b9c5abb.zip | |
Emit an error when mixing <stdatomic.h> and <atomic>
Atomics in C and C++ are incompatible at the moment and mixing the
headers can result in confusing error messages.
Emit an error explicitly telling about the incompatibility. Introduce
the macro `__ALLOW_STDC_ATOMICS_IN_CXX__` that allows to choose in C++
between C atomics and C++ atomics.
rdar://problem/27435938
Reviewers: rsmith, EricWF, mclow.lists
Reviewed By: mclow.lists
Subscribers: jkorous-apple, christof, bumblebritches57, JonChesterfield, smeenai, cfe-commits
Differential Revision: https://reviews.llvm.org/D45470
llvm-svn: 331379
Diffstat (limited to 'libcxx')
| -rw-r--r-- | libcxx/include/atomic | 3 | ||||
| -rw-r--r-- | libcxx/test/libcxx/atomics/c_compatibility.fail.cpp | 28 |
2 files changed, 31 insertions, 0 deletions
diff --git a/libcxx/include/atomic b/libcxx/include/atomic index 34a2a58b20c..adffc354a87 100644 --- a/libcxx/include/atomic +++ b/libcxx/include/atomic @@ -555,6 +555,9 @@ void atomic_signal_fence(memory_order m) noexcept; #if !defined(_LIBCPP_HAS_C_ATOMIC_IMP) && !defined(_LIBCPP_HAS_GCC_ATOMIC_IMP) #error <atomic> is not implemented #endif +#ifdef __ALLOW_STDC_ATOMICS_IN_CXX__ +#error <stdatomic.h> is incompatible with the C++ standard library +#endif #if _LIBCPP_STD_VER > 14 # define __cpp_lib_atomic_is_always_lock_free 201603L diff --git a/libcxx/test/libcxx/atomics/c_compatibility.fail.cpp b/libcxx/test/libcxx/atomics/c_compatibility.fail.cpp new file mode 100644 index 00000000000..092687d5b34 --- /dev/null +++ b/libcxx/test/libcxx/atomics/c_compatibility.fail.cpp @@ -0,0 +1,28 @@ +//===----------------------------------------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is dual licensed under the MIT and the University of Illinois Open +// Source Licenses. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// UNSUPPORTED: libcpp-has-no-threads +// +// <atomic> + +// Test that including <atomic> fails to compile when we want to use C atomics +// in C++ and have corresponding macro defined. + +// MODULES_DEFINES: __ALLOW_STDC_ATOMICS_IN_CXX__ +#ifndef __ALLOW_STDC_ATOMICS_IN_CXX__ +#define __ALLOW_STDC_ATOMICS_IN_CXX__ +#endif + +#include <atomic> +// expected-error@atomic:* {{<stdatomic.h> is incompatible with the C++ standard library}} + +int main() +{ +} + |
