yoga/java/BUILD_JAVA.md

Building Yoga native lib for Java

Instruction how to build Yoga native lib on local MacOs/Linux machine.

Prerequisites

Required tools:

• ninja
• cmake
• g++

Steps

1. Modify cmake/project-defaults.cmake file by commenting out -Werror:

   diff --git a/cmake/project-defaults.cmake b/cmake/project-defaults.cmake
   index 987529c..c28d542 100644
   --- a/cmake/project-defaults.cmake
   +++ b/cmake/project-defaults.cmake
   @@ -33,7 +33,7 @@ add_compile_options(
        -fexceptions
        # Enable warnings and warnings as errors
        -Wall
   -    -Werror
   +    #-Werror
        # Disable RTTI
        $<$<COMPILE_LANGUAGE:CXX>:-fno-rtti>
        # Use -O2 (prioritize speed)
   

2. Modify java/CMakeLists.txt file:

   diff --git a/java/CMakeLists.txt b/java/CMakeLists.txt
   index d8afd67..185a6fb 100644
   --- a/java/CMakeLists.txt
   +++ b/java/CMakeLists.txt
   @@ -5,8 +5,13 @@
   
    cmake_minimum_required(VERSION 3.13...3.26)
    project(yogajni)
   +find_package(JNI REQUIRED)
   +include_directories(${JNI_INCLUDE_DIRS})
    set(CMAKE_VERBOSE_MAKEFILE on)
   
   +set(CMAKE_CURRENT_SOURCE_DIR ${CMAKE_SOURCE_DIR})
   +message(CMAKE_CURRENT_SOURCE_DIR="${CMAKE_CURRENT_SOURCE_DIR}")
   +
    set(YOGA_ROOT ${CMAKE_CURRENT_SOURCE_DIR}/..)
    include(${YOGA_ROOT}/cmake/project-defaults.cmake)
   
   @@ -18,5 +23,9 @@ file(GLOB VERSION_SCRIPT CONFIGURE_DEPENDS
        ${CMAKE_CURRENT_SOURCE_DIR}/yogajni.version)
   
    add_library(yoga SHARED ${SOURCES})
   +
   +# TODO export lib with .so extension on MacOS with Apple Silicon
   +#set_target_properties(yoga PROPERTIES SUFFIX ".so")
   +
    target_link_libraries(yoga yogacore)
   -target_link_options(yoga PRIVATE -Wl,--version-script=${VERSION_SCRIPT})
   +target_link_options(yoga PRIVATE "-Wl")
   

3. Create a ./build_java build file.

   #!/bin/sh
   # Copyright (c) Meta Platforms, Inc. and affiliates.
   #
   # This source code is licensed under the MIT license found in the
   # LICENSE file in the root directory of this source tree.
   
   cd "$(dirname "$0")/java"
   rm -rf build
   
   if [ "$#" -eq 0 ]; then
     build_type="Debug"
   else
     build_type="$1"
   fi
   
   if which ninja; then
     set -e
     cmake -B build -S . -D CMAKE_OSX_ARCHITECTURES=arm64 -D CMAKE_BUILD_TYPE="$build_type" -G Ninja
   else
     set -e
     cmake -B build -S . -D CMAKE_BUILD_TYPE="$build_type"
   fi
   
   cmake --build build
   
   find . \( -name "*.so" -o -name "*.dylib" \)
   
   

4. Run ./build_java from the terminal.

   MacOS systems will create a .dylib, whereas Linux an .so version of the library. There's possiblity to build yoga lib for two architectures (only for MacOs), just update CMAKE_OSX_ARCHITECTURES flag to: CMAKE_OSX_ARCHITECTURES:STRING="x86_64;arm64".

5. Artifact location will be printed in output. Output may contain several warnings - which are a non-issue. If there's a library location printed out at the end, the build was successful.