Build protoc files for Unreal Engine 4 using cmake.

Env:

• protobuf version is 3.12.2
• Native build command is nmake
• cmake version is 3.10
• Unreal Engine 4 version is 4.18

Windows

1. build protobuf-lite library ( or run build-windows.bat)

1. open Native Tools Command Prompt command, e.g. x64 Native Tools Command Prompt for VS 2017.

2. Address to directory build_protobuf-lite/ (address to directory build_protobuf/ if you want to build libprotobuf).

    cd build_protobuf-lite
   

3. Create directory build and navigate in it.

    mkdir build & cd build
   

4. Create directory release and navigate in it.

    mkdir release & cd release
   

5. Generate configuration using CMakeList.txt.

    cmake -G "NMake Makefiles" -DCMAKE_BUILD_TYPE=Release -DPROTOBUF_VERSION=3.12.2 ../..
   

   If the version is lower then 3.12.x, you need to append -Dprotobuf_MSVC_STATIC_RUNTIME=OFF -Dprotobuf_BUILD_TESTS=OFF -Dprotobuf_BUILD_EXAMPLES=OFF.

6. Build libprotobuf.

    nmake
   

then libprotobuf-lite.lib would output to directory install/Release/.

protobuf source has been modified. The build from original protobuf source with UE4 would fail if protobuf version is lower than 3.12.
Source modification details:
version 3.5.x: https://github.com/jashking/UE4Protobuf
version 3.9.x: https://github.com/kingsoftgames/protobuf-ue4/blob/master/Fix-3.9.2.bat

2. generate protoc files

1. Address to directory test/:

    cd test
   

2. execute protoc_gen.bat.

then test.pb.h and test.pb.cc would be outputed in directory test/

3. build protoc C++ files ( or run test/build-windows.bat)

1. Address to directory test/cmake/:

    cd test/cmake/
   

2. Create directory build and navigate in it.

    mkdir build & cd build
   

3. Create directory release and navigate in it.

    mkdir release & cd release
   

4. Generate configuration using CMakeList.txt.

    cmake -G "NMake Makefiles" -DCMAKE_BUILD_TYPE=Release -DPROTOBUF_VERSION=3.12.2 ../..
   

5. Build your own library.

    nmake
   

then libtest.lib would output to directory test/install/Release/

4. Extract includes

Execute extract_includes.bat, then protobuf headers would be saved in directory include.

5. Configure UE4 Build.cs

1. copy ue4/MyProj.Build.cs into your UE4 project: MyProj/Source/MyProj/

2. copy libtest.lib and libprotobuf-lite.lib into your UE4 project: MyProj/ThirdParty/Protobuf/Library/

3. copy google protobuf headers into your UE4 project: MyProj/ThirdParty/Protobuf/Include/

4. copy test.pb.h into your UE4 project: MyProj/ThirdParty/Protobuf/Include/

5. Add bEnableExceptions = true; inside the {ProjectName}.Build.cs constructor.

then your can build your UE4 project with protoc C++ files.

More details can be saw in example: MyProj.Build.cs.

Attention

If want to build other version, modify parameter PROTOBUF_VERSION to specified version (e.g. -DPROTOBUF_VERSION=3.5.1), and also modify version in extract_includes.bat, and replace protoc.exe with matched version (3.12.2 in current repository).

Android NDK

Steps

1. execute \ndk_build\build.bat

2. execute test\ndk_build\build.bat

3. copy ndk_build\obj\local\armeabi-v7a\libprotobuf-lite-ndk.a and test\ndk_build\obj\local\armeabi-v7a\libtest-ndk.a into your UE4 project: MyProj/ThirdParty/Protobuf/Library/

4. copy headers which are in test\src\ into your UE4 project: MyProj/ThirdParty/Protobuf/Include/

5. build your UE4 project.

Reference

Offical CMakeList.txt (cpp files & included heads)

libprotobuf-lite:
https://github.com/protocolbuffers/protobuf/blob/master/cmake/libprotobuf-lite.cmake

libprotobuf:
https://github.com/protocolbuffers/protobuf/blob/master/cmake/libprotobuf.cmake

Source

Build Protobuf for Unreal Engine 4 with Jenkins Pipeline.
https://github.com/kingsoftgames/protobuf-ue4