[PATCH] D15440: [libc++abi] Use libgcc and libgcc_s to provide _Unwind symbols instead of libgcc_eh.a

[Eric Fiselier via cfe-commits]

EricWF added inline comments.

================
Comment at: cmake/config-ix.cmake:45
@@ -44,3 +44,3 @@
 check_library_exists(pthread pthread_once "" LIBCXXABI_HAS_PTHREAD_LIB)
-check_library_exists(gcc_eh _Unwind_GetRegionStart "" LIBCXXABI_HAS_GCC_EH_LIB)
+check_library_exists(gcc_s __gcc_personality_v0 "" LIBCXXABI_HAS_GCC_S_LIB)
 check_library_exists(c __cxa_thread_atexit_impl ""
----------------
compnerd wrote:
> Might be nice to extend this further to allow building against clang_rt.builtins.  We could of course do that as a follow up if you prefer.
I don't think the clang_rt.builtin libraries are *ever* along the library search path. Maybe we could detect if clang accepts `--rtlib <name>`? (I don't know the flag off hand).

================
Comment at: src/CMakeLists.txt:37
@@ +36,3 @@
+
+remove_flags(-Wl,-z,defs)
+
----------------
compnerd wrote:
> Do we need to worry about an alternative spelling of `-z defs`?
Not sure. I only considered the spellings used within the LLVM source tree `llvm/cmake/modules/HandleLLVMOptions.cmake`.


http://reviews.llvm.org/D15440