KhronosGroup#2861: If compiling with macOS and GCC, default ENABLE_PCH to false since CMake will generate incompatible Xarch flags for the precompiled headers

Author: n-morales

CMakeLists.txt

@@ -106,7 +106,14 @@ CMAKE_DEPENDENT_OPTION(ENABLE_HLSL
 option(ENABLE_RTTI "Enables RTTI" OFF)
 option(ENABLE_EXCEPTIONS "Enables Exceptions" OFF)
 option(ENABLE_OPT "Enables spirv-opt capability if present" ON)
-option(ENABLE_PCH "Enables Precompiled header" ON)
+
+if (CMAKE_SYSTEM_NAME STREQUAL "Darwin" AND ${CMAKE_CXX_COMPILER_ID} MATCHES "GNU")
+    # Workaround for CMake behavior on Mac OS with gcc, cmake generates -Xarch_* arguments
+    # which gcc rejects
+    option(ENABLE_PCH "Enables Precompiled header" OFF)
+else()
+    option(ENABLE_PCH "Enables Precompiled header" ON)
+endif()
 option(ENABLE_CTEST "Enables testing" ON)
 
 if(ENABLE_GLSLANG_INSTALL AND CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT AND WIN32)