diff options
| -rw-r--r-- | include/c99_compat.h | 2 | ||||
| -rw-r--r-- | include/no_extern_c.h | 48 | ||||
| -rw-r--r-- | src/util/u_atomic.h | 2 |
3 files changed, 52 insertions, 0 deletions
diff --git a/include/c99_compat.h b/include/c99_compat.h index f56f6f326f..4fc91bc135 100644 --- a/include/c99_compat.h +++ b/include/c99_compat.h @@ -25,6 +25,8 @@ * **************************************************************************/ +#include "no_extern_c.h" + #ifndef _C99_COMPAT_H_ #define _C99_COMPAT_H_ diff --git a/include/no_extern_c.h b/include/no_extern_c.h new file mode 100644 index 0000000000..f79602c030 --- /dev/null +++ b/include/no_extern_c.h @@ -0,0 +1,48 @@ +/************************************************************************** + * + * Copyright 2014 VMware, Inc. + * All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included + * in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + * + **************************************************************************/ + + +/* + * Including system's headers inside `extern "C" { ... }` is not safe, as system + * headers may have C++ code in them, and C++ code inside extern "C" + * leads to syntatically incorrect code. + * + * This is because putting code inside extern "C" won't make __cplusplus define + * go away, that is, the system header being included thinks is free to use C++ + * as it sees fits. + * + * Including non-system headers inside extern "C" is not safe either, because + * non-system headers end up including system headers, hence fall in the above + * case too. + * + * Conclusion, includes inside extern "C" is simply not portable. + * + * + * This header helps surface these issues. + */ + +#ifdef __cplusplus +template<class T> class _IncludeInsideExternCNotPortable; +#endif diff --git a/src/util/u_atomic.h b/src/util/u_atomic.h index d15398e1e4..e38395ac63 100644 --- a/src/util/u_atomic.h +++ b/src/util/u_atomic.h @@ -6,6 +6,8 @@ * */ +#include "no_extern_c.h" + #ifndef U_ATOMIC_H #define U_ATOMIC_H |