Author: vsapsai Date: Wed May 2 10:50:43 2018 New Revision: 331378 URL: http://llvm.org/viewvc/llvm-project?rev=331378&view=rev Log: 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 Added: cfe/trunk/test/Headers/stdatomic.cpp Modified: cfe/trunk/lib/Headers/stdatomic.h Modified: cfe/trunk/lib/Headers/stdatomic.h URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Headers/stdatomic.h?rev=331378&r1=331377&r2=331378&view=diff ============================================================================== --- cfe/trunk/lib/Headers/stdatomic.h (original) +++ cfe/trunk/lib/Headers/stdatomic.h Wed May 2 10:50:43 2018 @@ -31,6 +31,10 @@ # include_next <stdatomic.h> #else +#if !defined(__ALLOW_STDC_ATOMICS_IN_CXX__) && defined(__cplusplus) +#error "<stdatomic.h> is incompatible with the C++ standard library; define __ALLOW_STDC_ATOMICS_IN_CXX__ to proceed." +#endif + #include <stddef.h> #include <stdint.h> Added: cfe/trunk/test/Headers/stdatomic.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Headers/stdatomic.cpp?rev=331378&view=auto ============================================================================== --- cfe/trunk/test/Headers/stdatomic.cpp (added) +++ cfe/trunk/test/Headers/stdatomic.cpp Wed May 2 10:50:43 2018 @@ -0,0 +1,10 @@ +// RUN: %clang_cc1 %s -verify +// RUN: %clang_cc1 -D__ALLOW_STDC_ATOMICS_IN_CXX__ %s -verify + +#include <stdatomic.h> + +#ifndef __ALLOW_STDC_ATOMICS_IN_CXX__ +// expected-error@stdatomic.h:* {{<stdatomic.h> is incompatible with the C++ standard library}} +#else +// expected-no-diagnostics +#endif _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
