[msan] Put send/recvmmsg behind check for mmsghdr

[mcrosier]

Summary

Internally, we started running into a build failure after r321774 with the following error: "use of undeclared identifier 'mmsghdr'." The underlying issue is that we have machines that are using an older version of glibc, glibc 2.11.3, which don't define mssghdr. I would love to upgrade these machines, but unfortunately that's currently not an option.

This patch just checks for the mmsghdr feature prior to trying to intercept sendmmsg/recvmmsg. Feedback is very much welcome as this is not my area of expertise.

[krytarowski]

2.11.3 has been released in 2010, do we support so old releases?

[mcrosier]

In D42070#976331, @krytarowski wrote:

2.11.3 has been released in 2010, do we support so old releases?

Yes, we know.. :( Despite our best efforts, my team and I have not been able to get these machines upgraded (i.e., it's not in our control).

[krytarowski]

2.11.0 released in 2006. We were already rejecting old Linux patches in LLVM projects as they were adding similar switches, as nobody would really maintain them.

[vitalybuka]

lib/sanitizer_common/CMakeLists.txt

184

is any existing test fails on linux if you comment: add_definitions(-DCOMPILER_RT_HAS_mmsghdr) ?

[vitalybuka]

lib/sanitizer_common/sanitizer_platform_limits_posix.cc

1029

please clang-format this. long line will fail lint check

[vitalybuka]

lib/sanitizer_common/CMakeLists.txt

184

I tried, it fails. So I am OK with this patch if we have the test covering supported case.

[vitalybuka]

Actually check-msan fails even with patch as is

[mcrosier]

I think we've identified a work around internally, so I'm just going to abandon this patch.

cmake/config-ix.cmake

 check_cxx_compiler_flag(/wd4291 COMPILER_RT_HAS_WD4291_FLAG)
 check_cxx_compiler_flag(/wd4221 COMPILER_RT_HAS_WD4221_FLAG)
 check_cxx_compiler_flag(/wd4391 COMPILER_RT_HAS_WD4391_FLAG)
 check_cxx_compiler_flag(/wd4722 COMPILER_RT_HAS_WD4722_FLAG)
 check_cxx_compiler_flag(/wd4800 COMPILER_RT_HAS_WD4800_FLAG)
 
 # Symbols.
 check_symbol_exists(__func__ "" COMPILER_RT_HAS_FUNC_SYMBOL)
+check_symbol_exists(mmsghdr sys/socket.h COMPILER_RT_HAS_mmsghdr)
 
 # Libraries.
 check_library_exists(dl dlopen "" COMPILER_RT_HAS_LIBDL)
 check_library_exists(rt shm_open "" COMPILER_RT_HAS_LIBRT)
 check_library_exists(m pow "" COMPILER_RT_HAS_LIBM)
 check_library_exists(pthread pthread_create "" COMPILER_RT_HAS_LIBPTHREAD)
 if (ANDROID AND COMPILER_RT_HAS_LIBDL)
   # Android's libstdc++ has a dependency on libdl.

lib/sanitizer_common/CMakeLists.txt

if (LLVM_ENABLE_PEDANTIC AND UNIX AND NOT APPLE)
   set_source_files_properties(sanitizer_linux_mips64.S
     PROPERTIES COMPILE_FLAGS "-w")
 endif ()
 
 if(APPLE)
   set(OS_OPTION OS ${SANITIZER_COMMON_SUPPORTED_OS})
 endif()
 
+if(COMPILER_RT_HAS_mmsghdr)
+  add_definitions(-DCOMPILER_RT_HAS_mmsghdr)
+endif()
+
 add_compiler_rt_object_libraries(RTSanitizerCommon
   ${OS_OPTION}
   ARCHS ${SANITIZER_COMMON_SUPPORTED_ARCH}
   SOURCES ${SANITIZER_SOURCES}
   CFLAGS ${SANITIZER_CFLAGS}
   DEFS ${SANITIZER_COMMON_DEFINITIONS})
 add_compiler_rt_object_libraries(RTSanitizerCommonNoTermination
   ${OS_OPTION}

lib/sanitizer_common/sanitizer_platform_interceptors.h

 #define SANITIZER_INTERCEPT_GETHOSTENT_R \
   (SI_FREEBSD || SI_LINUX_NOT_ANDROID || SI_SOLARIS)
 #define SANITIZER_INTERCEPT_GETSOCKOPT SI_POSIX
 #define SANITIZER_INTERCEPT_ACCEPT SI_POSIX
 #define SANITIZER_INTERCEPT_ACCEPT4 SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_MODF SI_POSIX
 #define SANITIZER_INTERCEPT_RECVMSG SI_POSIX
 #define SANITIZER_INTERCEPT_SENDMSG SI_POSIX
+#if COMPILER_RT_HAS_mmsghdr
 #define SANITIZER_INTERCEPT_RECVMMSG SI_LINUX
 #define SANITIZER_INTERCEPT_SENDMMSG SI_LINUX
+#endif
 #define SANITIZER_INTERCEPT_GETPEERNAME SI_POSIX
 #define SANITIZER_INTERCEPT_IOCTL SI_POSIX
 #define SANITIZER_INTERCEPT_INET_ATON SI_POSIX
 #define SANITIZER_INTERCEPT_SYSINFO SI_LINUX
 #define SANITIZER_INTERCEPT_READDIR SI_POSIX
 #define SANITIZER_INTERCEPT_READDIR64 SI_LINUX_NOT_ANDROID || SI_SOLARIS32
 #if SI_LINUX_NOT_ANDROID && \
   (defined(__i386) || defined(__x86_64) || defined(__mips64) || \

lib/sanitizer_common/sanitizer_platform_limits_posix.cc

 CHECK_SIZE_AND_OFFSET(msghdr, msg_controllen);
 CHECK_SIZE_AND_OFFSET(msghdr, msg_flags);
 
 CHECK_TYPE_SIZE(cmsghdr);
 CHECK_SIZE_AND_OFFSET(cmsghdr, cmsg_len);
 CHECK_SIZE_AND_OFFSET(cmsghdr, cmsg_level);
 CHECK_SIZE_AND_OFFSET(cmsghdr, cmsg_type);
 
-#if SANITIZER_LINUX && (!defined(__ANDROID__) || __ANDROID_API__ >= 21)
+#if SANITIZER_LINUX && (!defined(__ANDROID__) || __ANDROID_API__ >= 21) && COMPILER_RT_HAS_mmsghdr
 CHECK_TYPE_SIZE(mmsghdr);
 CHECK_SIZE_AND_OFFSET(mmsghdr, msg_hdr);
 CHECK_SIZE_AND_OFFSET(mmsghdr, msg_len);
 #endif
 
 COMPILER_CHECK(sizeof(__sanitizer_dirent) <= sizeof(dirent));
 CHECK_SIZE_AND_OFFSET(dirent, d_ino);
 #if SANITIZER_MAC