libprotobuf for Unreal Engine 4

Link the google's protocol bufffers library as the third party in Unreal Engine 4.

Version

• Protobuf: 3.19.0
• Unreal Engine 4: 4.27.2

Usage

1. Import or copy the folder libprotobuf into <your project>/Source/ThirdParty/libprotobuf.
2. Add the libprotobuf as a module into <your project>.Build.cs

PrivateDependencyModuleNames.AddRange(new string[] { "libprotobuf" });

Compile proto file(s)

1. Compile the proto files for Unreal Engine 4 by generate_for_ue4.py.
   • python generate_for_ue4.py --proto_input <proto_file_or_path> --cpp_out <output_path>
   • ex: python generate_for_ue4.py --proto_input Message.proto --cpp_out d:\Prject\Source\ProtoFiles
2. Include and use the header file(ex: Message.pb.h) in your .cpp file.

Build Library

The environment variables required for compilation

• PB_LIBRARY_PATH The directory where this document is located

Apply the patch

cd %PB_LIBRARY_PATH%\protobuf-source
git apply ..\build\patch\diff-base-on-3.19.0.diff

1. Windows

Visual Studio 2019 and CMake are required

mkdir %PB_LIBRARY_PATH%\build\_win64 & cd %PB_LIBRARY_PATH%\build\_win64
cmake -G "Visual Studio 16 2019" -A x64 ^
 -DCMAKE_INSTALL_PREFIX=%PB_LIBRARY_PATH%/libprotobuf ^
 -DCMAKE_MSVC_RUNTIME_LIBRARY="MultiThreaded$<$<CONFIG:Debug>:Debug>DLL" ^
 -Dprotobuf_BUILD_TESTS=false -Dprotobuf_WITH_ZLIB=false ^
 -Dprotobuf_DEBUG_POSTFIX="" ^
 -DCMAKE_INSTALL_LIBDIR="lib/win64/$<$<CONFIG:Debug>:Debug>$<$<CONFIG:Release>:Release>" ^
 -DCMAKE_INSTALL_CMAKEDIR=lib/win64/cmake ^
 -Dprotobuf_MSVC_STATIC_RUNTIME=false ^
 -DCMAKE_POLICY_DEFAULT_CMP0091=NEW -DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreadedDLL ^
 %PB_LIBRARY_PATH%/protobuf-source/cmake
cmake --build . --target INSTALL --config Debug
cmake --build . --target INSTALL --config Release

2. Linux(Cross Compiling)

Clang cross-compile toolchain, Ninja and Unreal Engine Source Code are required, and make sure the following environment variables are set correctly

• UE_THIRD_PARTY_PATH UE third party source directory, This directory is located in a subdirectory Engine/Source/ThirdParty of the UE source directory
• LINUX_MULTIARCH_ROOT The directory where you installed Clang cross-compile toolchain for Linux
• NINJA_EXE_PATH The file path of ninja.exe, Ninja is a small build system with a focus on speed.

mkdir %PB_LIBRARY_PATH%\build\_linux & cd %PB_LIBRARY_PATH%\build\_linux
cmake -G "Ninja Multi-Config" -DCMAKE_MAKE_PROGRAM=%NINJA_EXE_PATH% ^
 -DCMAKE_TOOLCHAIN_FILE="%PB_LIBRARY_PATH%\build\linux\ue4-linux-cross-compile.cmake" ^
 -DUE_THIRD_PARTY_PATH=%UE_THIRD_PARTY_PATH% -Dprotobuf_DEBUG_POSTFIX="" ^
 -DCMAKE_INSTALL_PREFIX=%PB_LIBRARY_PATH%/libprotobuf ^
 -DCMAKE_INSTALL_LIBDIR="lib/linux/$<$<CONFIG:Debug>:Debug>$<$<CONFIG:Release>:Release>" ^
 -DCMAKE_INSTALL_CMAKEDIR=lib/linux/cmake ^
 -Dprotobuf_BUILD_TESTS=false -Dprotobuf_WITH_ZLIB=false ^
 -Dprotobuf_BUILD_EXAMPLES=false ^
 -Dprotobuf_BUILD_PROTOC_BINARIES=false -Dprotobuf_BUILD_LIBPROTOC=false ^
 %PB_LIBRARY_PATH%/protobuf-source/cmake
cmake --build . --target install --config Debug
cmake --build . --target install --config Release

3. Android

Android Studio is required. And you need install other additional sdk and tools through SDK Manager.

• Android NDK
• Android SDK Build-Tools
• Android SDK Command-line Tools
• CMake make sure the following environment variables are set correctly
• ANDROID_HOME The directory where you installed the Android SDK, It must contain a directory called platform-tools.
• NDKROOT The directory where you unzipped the Android NDK, It must contain a file called ndk-build.cmd
• NDK_CMAKE_VERSION The version number of cmake that comes with the Android NDK, like 3.22.1(Must later than 3.18)

mkdir %PB_LIBRARY_PATH%\build\_android & cd %PB_LIBRARY_PATH%\build\_android
for /d %a in (armeabi-v7a arm64-v8a x86_64) do (
mkdir %a & pushd %a ^
 & "%ANDROID_HOME%\cmake\%NDK_CMAKE_VERSION%\bin\cmake.exe" -G "Ninja Multi-Config" ^
 -DCMAKE_TOOLCHAIN_FILE="%NDKROOT%\build\cmake\android.toolchain.cmake" ^
 -DCMAKE_MAKE_PROGRAM=%ANDROID_HOME%\cmake\%NDK_CMAKE_VERSION%\bin\ninja.exe ^
 -DANDROID_ABI=%a -Dprotobuf_DEBUG_POSTFIX="" ^
 -DCMAKE_INSTALL_PREFIX=%PB_LIBRARY_PATH%/libprotobuf ^
 -DCMAKE_INSTALL_LIBDIR="lib/android/%a/$<$<CONFIG:Debug>:Debug>$<$<CONFIG:Release>:Release>" ^
 -DCMAKE_INSTALL_CMAKEDIR=lib/android/%a/cmake ^
 -Dprotobuf_BUILD_TESTS=false -Dprotobuf_WITH_ZLIB=false ^
 -Dprotobuf_BUILD_PROTOC_BINARIES=false -Dprotobuf_BUILD_LIBPROTOC=false ^
 %PB_LIBRARY_PATH%/protobuf-source/cmake ^
 & "%ANDROID_HOME%\cmake\%NDK_CMAKE_VERSION%\bin\cmake.exe" --build . --target install --config Debug ^
 & "%ANDROID_HOME%\cmake\%NDK_CMAKE_VERSION%\bin\cmake.exe" --build . --target install --config Release ^
 & popd
)

4. PlayStation 4

PS4 SDK(Orbis) is required.

mkdir %PB_LIBRARY_PATH%\build\_ps4 & cd %PB_LIBRARY_PATH%\build\_ps4
"%SCE_ROOT_DIR%\ORBIS\Tools\CMake\PS4CMake.bat" ^
 -DCMAKE_INSTALL_PREFIX=%PB_LIBRARY_PATH%/libprotobuf ^
 -DCMAKE_INSTALL_LIBDIR="lib/ps4/$<$<CONFIG:Debug>:Debug>$<$<CONFIG:Release>:Release>" ^
 -DCMAKE_INSTALL_CMAKEDIR=lib/ps4/cmake -DCMAKE_CXX_STANDARD=14 ^
 -Dprotobuf_BUILD_TESTS=false -Dprotobuf_WITH_ZLIB=false ^
 -Dprotobuf_BUILD_EXAMPLES=false ^
 -Dprotobuf_BUILD_PROTOC_BINARIES=false -Dprotobuf_BUILD_LIBPROTOC=false ^
 -Dprotobuf_DISABLE_RTTI=true ^
 %PB_LIBRARY_PATH%/protobuf-source/cmake
cmake --build . --target INSTALL --config Debug
cmake --build . --target INSTALL --config Release

5. PlayStation 5

PS5 SDK(Prospero) is required.

mkdir %PB_LIBRARY_PATH%\build\_ps5 & cd %PB_LIBRARY_PATH%\build\_ps5
"%SCE_ROOT_DIR%\Prospero\Tools\CMake\PS5CMake.bat" ^
 -DCMAKE_INSTALL_PREFIX=%PB_LIBRARY_PATH%/libprotobuf ^
 -DCMAKE_INSTALL_LIBDIR="lib/ps5/$<$<CONFIG:Debug>:Debug>$<$<CONFIG:Release>:Release>" ^
 -DCMAKE_INSTALL_CMAKEDIR=lib/ps5/cmake -DCMAKE_CXX_STANDARD=14 ^
 -Dprotobuf_BUILD_TESTS=false -Dprotobuf_WITH_ZLIB=false ^
 -Dprotobuf_BUILD_EXAMPLES=false ^
 -Dprotobuf_BUILD_PROTOC_BINARIES=false -Dprotobuf_BUILD_LIBPROTOC=false ^
 -Dprotobuf_DISABLE_RTTI=true ^
 %PB_LIBRARY_PATH%/protobuf-source/cmake
cmake --build . --target INSTALL --config Debug
cmake --build . --target INSTALL --config Release

6. Mac

Xcode and CMake are required.

mkdir -p $PB_LIBRARY_PATH/build/_mac && cd $PB_LIBRARY_PATH/build/_mac
cmake -G "Unix Makefiles" \
 -DCMAKE_INSTALL_PREFIX=$PB_LIBRARY_PATH/libprotobuf \
 -DCMAKE_INSTALL_LIBDIR=lib/mac -DCMAKE_OSX_DEPLOYMENT_TARGET=10.14 \
 -DCMAKE_INSTALL_CMAKEDIR=lib/mac/cmake -DCMAKE_CXX_STANDARD=14 \
 -Dprotobuf_BUILD_TESTS=false -Dprotobuf_WITH_ZLIB=false \
 -Dprotobuf_BUILD_EXAMPLES=false \
 -Dprotobuf_BUILD_PROTOC_BINARIES=false -Dprotobuf_BUILD_LIBPROTOC=false \
 $PB_LIBRARY_PATH/protobuf-source/cmake
cmake --build . --target install --config Release

7. iOS

Xcode and CMake are required.

mkdir -p $PB_LIBRARY_PATH/build/_ios && cd $PB_LIBRARY_PATH/build/_ios
cmake -G "Unix Makefiles" \
 -DCMAKE_INSTALL_PREFIX=$PB_LIBRARY_PATH/libprotobuf \
 -DCMAKE_TOOLCHAIN_FILE=$PB_LIBRARY_PATH/build/ios/ios.toolchain.cmake \
 -DCMAKE_INSTALL_LIBDIR=lib/ios -DPLATFORM=OS64 \
 -DCMAKE_INSTALL_CMAKEDIR=lib/ios/cmake -DCMAKE_CXX_STANDARD=17 \
 -Dprotobuf_BUILD_TESTS=false -Dprotobuf_WITH_ZLIB=false \
 -Dprotobuf_BUILD_EXAMPLES=false \
 -Dprotobuf_BUILD_PROTOC_BINARIES=false -Dprotobuf_BUILD_LIBPROTOC=false \
 $PB_LIBRARY_PATH/protobuf-source/cmake
cmake --build . --target install --config Release

License

Use The MIT License.

Reference

1. https://github.com/code4game/libprotobuf
2. https://unrealcommunity.wiki/standalone-dedicated-server-i5qjfc27
3. https://unrealcommunity.wiki/linking-static-libraries-using-the-build-system-1ahhe4vt
4. https://unrealcommunity.wiki/compiling-for-linux-nutp04d0
5. https://docs.unrealengine.com/4.27/en-US/SharingAndReleasing/Linux/