cmake: Remove PCH support

Compilers are very picky and don't use PCH when they have been compiled
with different flags. I even got some ICE in MSVC, so removing them for now.

Modules are the solution.

CMakeLists.txt

@@ -11,7 +11,6 @@ option(USE_SHARED_GTEST "Use shared gtest library if found" OFF)
 option(USE_UPNP "Enables UPnP port mapping support" ON)
 option(DISABLE_WX "Disable wxWidgets (use Qt or CLI interface)" OFF)
 option(ENABLE_QT2 "Enable Qt2 (use the other experimental Qt interface)" OFF)
-option(ENABLE_PCH "Use PCH to speed up compilation" ON)
 option(ENABLE_LTO "Enables Link Time Optimization" OFF)
 option(ENABLE_GENERIC "Enables generic build that should run on any little-endian host" OFF)
 option(ENABLE_HEADLESS "Enables running Dolphin as a headless variant" OFF)
@@ -122,34 +121,6 @@ endif()
 # as defined above.
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/Binaries)
 
-# Precompiled header support for MSVC:
-# Call this after setting the source list (and don't add the source file used
-# to generate the pch file, this will be done here automatically)
-function(enable_precompiled_headers PRECOMPILED_HEADER SOURCE_FILE SOURCE_VARIABLE_NAME)
-	if(MSVC)
-		set(files ${${SOURCE_VARIABLE_NAME}})
-
-		# Generate precompiled header translation unit
-		get_filename_component(pch_basename ${PRECOMPILED_HEADER} NAME_WE)
-		set(pch_abs ${CMAKE_CURRENT_SOURCE_DIR}/${PRECOMPILED_HEADER})
-		set(pch_unity ${CMAKE_CURRENT_SOURCE_DIR}/${SOURCE_FILE})
-		set_source_files_properties(${pch_unity}  PROPERTIES COMPILE_FLAGS
-			"/Yc\"${pch_abs}\"")
-
-		# Update properties of source files to use the precompiled header.
-		# Additionally, force the inclusion of the precompiled header at
-		# beginning of each source file.
-		foreach(source_file ${files} )
-			set_source_files_properties(${source_file} PROPERTIES COMPILE_FLAGS
-				"/Yu\"${pch_abs}\" /FI\"${pch_abs}\"")
-		endforeach(source_file)
-
-		# Finally, update the source file collection to contain the
-		# precompiled header translation unit
-		set(${SOURCE_VARIABLE_NAME} ${pch_unity} ${${SOURCE_VARIABLE_NAME}} PARENT_SCOPE)
-	endif(MSVC)
-endfunction(enable_precompiled_headers)
-
 # setup CCache
 include(CCache)
 

Externals/wxWidgets3/CMakeLists.txt

@@ -890,6 +890,5 @@ add_definitions(-DWXBUILDING)
 # wxWidgets warnings are not our problem.
 add_definitions(-w)
 
-#enable_precompiled_headers(include/wx/wxprec.h src/common/dummy.cpp SRCS)
 add_library(wx STATIC ${PNG_SRCS} ${SRCS})
 target_link_libraries(wx ${LIBS})

Source/Android/app/build.gradle

@@ -65,7 +65,7 @@ android {
     defaultConfig {
         externalNativeBuild {
             cmake {
-                arguments "-DANDROID_STL=c++_static", "-DCMAKE_BUILD_TYPE=RelWithDebInfo", "-DENABLE_PCH=OFF" // , "-DENABLE_GENERIC=ON"
+                arguments "-DANDROID_STL=c++_static", "-DCMAKE_BUILD_TYPE=RelWithDebInfo" // , "-DENABLE_GENERIC=ON"
                 abiFilters "arm64-v8a" //, "armeabi-v7a", "x86_64", "x86"
             }
         }

Source/CMakeLists.txt

@@ -8,52 +8,9 @@ endif()
 add_definitions(-D__STDC_LIMIT_MACROS)
 add_definitions(-D__STDC_CONSTANT_MACROS)
 
-set(CMAKE_FAKELANG_CREATE_STATIC_LIBRARY "touch <TARGET>")
-if(ENABLE_PCH)
-	# This is actually a .h file, but trick cmake into compiling it as a source file
-	set(pch_out_filename "${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/pch.dir/pch.h")
-	if (ANDROID)
-		set(pch_lib_filename "${LIBRARY_OUTPUT_PATH}/libpch.a")
-	else()
-		set(pch_lib_filename "${CMAKE_CURRENT_BINARY_DIR}/libpch.a")
-	endif()
-	set(pch_src_filename "${CMAKE_CURRENT_SOURCE_DIR}/PCH/pch.h")
-
-	if(APPLE)
-		set(type objective-c++-header)
-	else()
-		set(type c++-header)
-	endif()
-
-	set_source_files_properties(
-		PCH/pch.h PROPERTIES
-		COMPILE_FLAGS "-x ${type}"
-		HEADER_FILE_ONLY 0
-		LANGUAGE CXX)
-
-	add_library(pch STATIC PCH/pch.h)
-
-	add_custom_command(
-		TARGET pch
-		PRE_LINK
-		COMMAND ln -fs "${pch_out_filename}.o" "${pch_out_filename}.gch"
-		COMMAND ln -fs "${pch_out_filename}.o" "${pch_out_filename}.pch"
-		COMMAND cp "${pch_src_filename}" "${pch_out_filename}")
-
-	set_target_properties(
-		pch PROPERTIES
-		LINKER_LANGUAGE FAKELANG)
-endif(ENABLE_PCH)
 macro(add_dolphin_library lib srcs libs)
 	add_library(${lib} STATIC ${srcs})
 	target_link_libraries(${lib} ${libs})
-	if(ENABLE_PCH)
-		add_dependencies(${lib} pch)
-		set_source_files_properties(
-			${srcs} PROPERTIES
-			COMPILE_FLAGS "-include '${pch_out_filename}'"
-			OBJECT_DEPENDS "${pch_lib_filename}")
-	endif(ENABLE_PCH)
 endmacro(add_dolphin_library)
 
 add_subdirectory(Core)