Merge pull request KhronosGroup#2862 from n-morales/2861-macos-gcc-build-failures

KhronosGroup#2861 macos gcc build failures

Author: greg-lunarg

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)
@@ -163,7 +170,7 @@ if(${CMAKE_CXX_COMPILER_ID} MATCHES "GNU")
         add_compile_options(-Werror=deprecated-copy)
     endif()
 
-    if(NOT CMAKE_VERSION VERSION_LESS "3.13")
+    if(NOT CMAKE_VERSION VERSION_LESS "3.13" AND NOT CMAKE_SYSTEM_NAME STREQUAL "Darwin")
         # Error if there's symbols that are not found at link time.
         # add_link_options() was added in CMake 3.13 - if using an earlier
         # version don't set this - it should be caught by presubmits anyway.