[Fuzzer] Update path to libc++ headers

[phosek]

Summary

The path to headers which are installed into libc++ build directory
has changed in r337727 which broke the libFuzzer build.

[aheejin]

Sorry and thank you for fixing this!

[phosek]

In D49705#1172631, @aheejin wrote:

Sorry and thank you for fixing this!

No problem. However, while this appears to be fixing the problem on Linux, I'm also seeing another build error on macOS, see https://logs.chromium.org/v/?s=fuchsia%2Fbuildbucket%2Fcr-buildbucket.appspot.com%2F8940172878105791200%2F%2B%2Fsteps%2Fclang%2F0%2Fsteps%2Fbuild%2F0%2Fstdout, which I don't quite understand yet because that one is failing in both libFuzzer and XRay.

[aheejin]

I don't have any idea on that failure either. I can try a Mac build on my local mac and see what's wrong, but meanwhile do you think it'd be better to revert rL337727 for now? I'm not sure why the failure rL337727 fixed does not show up on the LLVM buildbots though (it showed up on our local builds).

[phosek]

In D49705#1172662, @aheejin wrote:

I don't have any idea on that failure either. I can try a Mac build on my local mac and see what's wrong, but meanwhile do you think it'd be better to revert rL337727 for now? I'm not sure why the failure rL337727 fixed does not show up on the LLVM buildbots though (it showed up on our local builds).

I'm doing a local build on my macOS machine, let's wait if I can figure out what the problem is.

[aheejin]

Someone reverted rL337727 in rL337782 because of the same errors you mentioned. Were you able to figure out why the errors happened?

lib/fuzzer/CMakeLists.txt

add_custom_libcxx(libcxx_fuzzer_${arch} ${LIBCXX_${arch}_PREFIX}
       CFLAGS ${TARGET_CFLAGS}
              -D_LIBCPP_ABI_VERSION=Fuzzer
              -D_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS=1
              -fvisibility=hidden
       CMAKE_ARGS -DCMAKE_CXX_COMPILER_WORKS=ON
                  -DLIBCXX_ENABLE_EXCEPTIONS=OFF
                  -DLIBCXX_ENABLE_SHARED=OFF
                  -DLIBCXX_CXX_ABI=none)
-    target_compile_options(RTfuzzer.${arch} PRIVATE -isystem ${LIBCXX_${arch}_PREFIX}/include/c++/v1)
+    target_compile_options(RTfuzzer.${arch} PRIVATE -isystem ${LIBCXX_${arch}_PREFIX}-bins/include/c++/v1)
     add_dependencies(RTfuzzer.${arch} libcxx_fuzzer_${arch}-build)
-    target_compile_options(RTfuzzer_main.${arch} PRIVATE -isystem ${LIBCXX_${arch}_PREFIX}/include/c++/v1)
+    target_compile_options(RTfuzzer_main.${arch} PRIVATE -isystem ${LIBCXX_${arch}_PREFIX}-bins/include/c++/v1)
     add_dependencies(RTfuzzer_main.${arch} libcxx_fuzzer_${arch}-build)
     partially_link_libcxx(fuzzer_no_main ${LIBCXX_${arch}_PREFIX} ${arch})
     partially_link_libcxx(fuzzer ${LIBCXX_${arch}_PREFIX} ${arch})
   endforeach()
 endif()
 
 if(COMPILER_RT_INCLUDE_TESTS)
   add_subdirectory(tests)
 endif()