cmake: fixes for windows

cmake/CMakeLists.txt

 # Boilerplate.
 cmake_minimum_required (VERSION 3.1)   # First version with CMAKE_CXX_STANDARD.
 project (skimake)
 set (CMAKE_CXX_STANDARD 11)
 
 # Default to Release mode.  We're mainly targeting Skia users, not Skia developers.
 if (NOT CMAKE_BUILD_TYPE)
     set (CMAKE_BUILD_TYPE Release)
 endif ()
 
@@ skipping 105 matching lines @@
     else()
         remove_srcs(../src/ports/SkFontMgr_win_gdi_factory.cpp)
     endif()
 endif()
 
 # Certain files must be compiled with support for SSSE3, SSE4.1, AVX, or AVX2 intrinsics.
 file (GLOB_RECURSE ssse3_srcs ../src/*ssse3*.cpp ../src/*SSSE3*.cpp)
 file (GLOB_RECURSE sse41_srcs ../src/*sse4*.cpp ../src/*SSE4*.cpp)
 file (GLOB_RECURSE avx_srcs   ../src/*_avx.cpp)
 file (GLOB_RECURSE avx2_srcs  ../src/*_avx2.cpp)
-set_source_files_properties(${ssse3_srcs} PROPERTIES COMPILE_FLAGS -mssse3)
-set_source_files_properties(${sse41_srcs} PROPERTIES COMPILE_FLAGS -msse4.1)
-set_source_files_properties(${avx_srcs}   PROPERTIES COMPILE_FLAGS -mavx)
-set_source_files_properties(${avx2_srcs}  PROPERTIES COMPILE_FLAGS -mavx2)
+if (NOT WIN32)
+    set_source_files_properties(${ssse3_srcs} PROPERTIES COMPILE_FLAGS -mssse3)
+    set_source_files_properties(${sse41_srcs} PROPERTIES COMPILE_FLAGS -msse4.1)
+    set_source_files_properties(${avx_srcs}   PROPERTIES COMPILE_FLAGS -mavx)
+    set_source_files_properties(${avx2_srcs}  PROPERTIES COMPILE_FLAGS -mavx2)
+endif()
 
 # Detect our optional dependencies.
 # If we can't find them, don't build the parts of Skia that use them.
 find_package (EXPAT)
 find_package (Lua)
 find_package (ZLIB)
 # No find_package for libwebp as far as I can tell, so simulate it here.
 find_path (WEBP_INCLUDE_DIRS "webp/decode.h")
 find_library (WEBP_LIBRARIES webp)
 find_path (OSMESA_INCLUDE_DIRS "GL/osmesa.h")
@@ skipping 118 matching lines @@
 
 target_include_directories(skia
     PUBLIC  ${public_includes}
     PRIVATE ${private_includes})
 
 target_link_libraries(skia
     PUBLIC
     PRIVATE ${libs})
 
 if (MSVC)
+    string(REGEX REPLACE " /W3 " " " CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
     set(cc_flags "/w /GR-")
 else()
     set(cc_flags "-w -fno-rtti -fno-exceptions")
 endif()
 
 set_target_properties(skia PROPERTIES
     COMPILE_FLAGS ${cc_flags}
     CXX_VISIBILITY_PRESET hidden
     VISIBILITY_INLINES_HIDDEN true)
 
@@ skipping 51 matching lines @@
         file (APPEND ${skia_h_path} "#include \"${filename_component}\"\n")
       endif ()
     endforeach()
   endif()
 endforeach()
 file(APPEND ${skia_h_path} "\n#endif  // skia_DEFINED\n")
 
 # Now build a simple example app that uses Skia via libskia.so.
 add_executable(example example.cpp)
 target_link_libraries(example skia ${OPENGL_LIBRARIES})