[OpenMP][libomp] do not try to dlopen libmemkind on macOS

[danieljdouglas-deco]

Summary

libmemkind is only available for linux
calling dlopen here can also be problematic in a client app that fork'ed

[jlpeyton]

LGTM.

For future patches, look at https://llvm.org/docs/Phabricator.html#requesting-a-review-via-the-web-interface for uploading diff with as much context as possible.

[jlpeyton]

Sorry, I should have asked this before, do you need me to commit this on your behalf?

[danieljdouglas-deco]

In D126579#3553633, @jlpeyton wrote:

Sorry, I should have asked this before, do you need me to commit this on your behalf?

Ahh, yes please. I don't believe I have the permissions to do that. Thanks for your help!

openmp/runtime/src/kmp_alloc.cpp

    MA == llvm_omp_target_shared_mem_alloc ||                                   \
    MA == llvm_omp_target_device_mem_alloc)
 
-#if KMP_OS_UNIX && KMP_DYNAMIC_LIB
+#if KMP_OS_UNIX && KMP_DYNAMIC_LIB && !KMP_OS_DARWIN
 static inline void chk_kind(void ***pkind) {
   KMP_DEBUG_ASSERT(pkind);
   if (*pkind) // symbol found

 
 void __kmp_init_memkind() {
 // as of 2018-07-31 memkind does not support Windows*, exclude it for now
-#if KMP_OS_UNIX && KMP_DYNAMIC_LIB
+#if KMP_OS_UNIX && KMP_DYNAMIC_LIB && !KMP_OS_DARWIN
   // use of statically linked memkind is problematic, as it depends on libnuma
   kmp_mk_lib_name = "libmemkind.so";
   h_memkind = dlopen(kmp_mk_lib_name, RTLD_LAZY);