Driver: ignore -mbig-obj like /bigobj

[rnk]

Looks good. Maybe we should also fix clang to accept this flag, though?

[martell]

In D41597#964538, @rnk wrote:

Looks good. Maybe we should also fix clang to accept this flag, though?

We should be able to add it as an ignored flag much like the /bigobj flag for clang-cl
Since rL217812 clang implicitly creates bigobj files when needed.
Will update to reflect when I get the chance.

[martell]

Updated to just ignore the flag just like how clang-cl does for /bigobj

[rnk]

lgtm

This works even though we pass -Wa,-mbig-obj?

cmake/modules/HandleLLVMOptions.cmake

if(MSVC)
   # C++ templates in Clang.
   set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /STACK:10000000")
 elseif(MINGW) # FIXME: Also cygwin?
   set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--stack,16777216")
 
   # Pass -mbig-obj to mingw gas on Win64. COFF has a 2**16 section limit, and
   # on Win64, every COMDAT function creates at least 3 sections: .text, .pdata,
   # and .xdata.
-  if (CMAKE_SIZEOF_VOID_P EQUAL 8)
+  if (CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT "${CMAKE_ASM_COMPILER_ID}" MATCHES "Clang")
     append("-Wa,-mbig-obj" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
   endif()
 endif()
 
 if( MSVC )
   if( CMAKE_CXX_COMPILER_VERSION VERSION_LESS 19.0 )
     # For MSVC 2013, disable iterator null pointer checking in debug mode,
     # especially so std::equal(nullptr, nullptr, nullptr) will not assert.