如何確定何時使用-fsanitize = memory？

Question

當內存清潔劑正在使用時，我想清除FD_ZERO和FD_SET上的誤報。清除它有點容易：

#include <sanitizer/msan_interface.h> 
... 

__msan_unpoison(&readfds, sizeof(readfds)); 
__msan_unpoison(&writefds, sizeof(writefds)); 

但是，我不知道如何檢測何時使用內存消毒劑。即，在命令行上指定-fsanitize=memory時檢測。預處理似乎並不被幫助：

$ clang -dM -E -fsanitize=memory - </dev/null | egrep -i 'memory|sanitize|msan' 
$ 

我怎麼能確定何時-fsanitize=memory在使用？

Answer 1

根據Konstantin Serebryany的Memory Sanitizer mailing list，沒有預處理宏。應該使用__has_feature(memory_sanitizer)：

#if defined(__has_feature) 
# if __has_feature(memory_sanitizer) 
# define MEMORY_SANITIZER 1 
# endif 
#endif 
... 

#ifdef MEMORY_SANITIZER 
# include <sanitizer/msan_interface.h> 
#endif 
... 

#ifdef MEMORY_SANITIZER 
__msan_unpoison(&readfds, sizeof(readfds)); 
__msan_unpoison(&writefds, sizeof(writefds)); 
#endif 
...