I built boringssl with cmake and msvc Then I tried to build with clang-cl so I used -T"LLVM-vs2014" in vmake arguments
Clang-cl uses cl arguments however cmake used gcc style arguments without adding -Xclang
The proper way to handle this case is checking for
if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND CMAKE_CXX_SIMULATE_ID STREQUAL "MSVC")