PCH: Enable Fem App PCH

src/Mod/Fem/App/CMakeLists.txt

@@ -179,6 +179,11 @@ SET(Fem_SRCS
     ${Python_SRCS}
 )
 
+if(FREECAD_USE_PCH)
+    add_definitions(-D_PreComp_)
+    GET_MSVC_PRECOMPILED_SOURCE("PreCompiled.cpp" Fem_CPP_SRCS ${Fem_SRCS})
+    ADD_MSVC_PRECOMPILED_HEADER(Fem PreCompiled.h PreCompiled.cpp Fem_CPP_SRCS)
+endif(FREECAD_USE_PCH)
 
 add_library(Fem SHARED ${Fem_SRCS})
 target_link_libraries(Fem ${Fem_LIBS} ${VTK_LIBRARIES})