[cmake] Improve pthread_[gs]etname_np detection code

Summary:
Due to some android peculiarities, in some build configurations
(statically linked executables targeting older releases) we could detect
the presence of these functions (because they are present in libc.a,
where check_library_exists searches), but then fail to build because the
headers did not include the definition.

This attempts to remedy that by upgrading the check_library_exists to
check_symbol_exists, which will check that the function is declared too.

I am hoping that a more thorough check will make the messy #ifdef we
have accumulated in the code obsolete, so I optimistically try to remove
them.

Reviewers: zturner, kparzysz, danalbert

Subscribers: srhines, mgorny, krytarowski, llvm-commits

Differential Revision: https://reviews.llvm.org/D45359

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@330251 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Pavel Labath 2018-04-18 13:13:27 +00:00
parent c108ab6989
commit 646d5bb4d1
2 changed files with 9 additions and 8 deletions

View File

@ -252,12 +252,15 @@ endif()
# This check requires _GNU_SOURCE
check_symbol_exists(sched_getaffinity sched.h HAVE_SCHED_GETAFFINITY)
check_symbol_exists(CPU_COUNT sched.h HAVE_CPU_COUNT)
if(HAVE_LIBPTHREAD)
check_library_exists(pthread pthread_getname_np "" HAVE_PTHREAD_GETNAME_NP)
check_library_exists(pthread pthread_setname_np "" HAVE_PTHREAD_SETNAME_NP)
elseif(PTHREAD_IN_LIBC)
check_library_exists(c pthread_getname_np "" HAVE_PTHREAD_GETNAME_NP)
check_library_exists(c pthread_setname_np "" HAVE_PTHREAD_SETNAME_NP)
if (NOT PURE_WINDOWS)
if (LLVM_PTHREAD_LIB)
list(APPEND CMAKE_REQUIRED_LIBRARIES ${LLVM_PTHREAD_LIB})
endif()
check_symbol_exists(pthread_getname_np pthread.h HAVE_PTHREAD_GETNAME_NP)
check_symbol_exists(pthread_setname_np pthread.h HAVE_PTHREAD_SETNAME_NP)
if (LLVM_PTHREAD_LIB)
list(REMOVE_ITEM CMAKE_REQUIRED_LIBRARIES ${LLVM_PTHREAD_LIB})
endif()
endif()
# available programs checks

View File

@ -204,7 +204,6 @@ void llvm::get_thread_name(SmallVectorImpl<char> &Name) {
Name.append(buf, buf + strlen(buf));
#elif defined(__linux__)
#if (defined(__GLIBC__) && defined(_GNU_SOURCE)) || defined(__ANDROID__)
#if HAVE_PTHREAD_GETNAME_NP
constexpr uint32_t len = get_max_thread_name_length_impl();
char Buffer[len] = {'\0'}; // FIXME: working around MSan false positive.
@ -212,5 +211,4 @@ void llvm::get_thread_name(SmallVectorImpl<char> &Name) {
Name.append(Buffer, Buffer + strlen(Buffer));
#endif
#endif
#endif
}