Flutter Engine 编译与调试

一、环境搭建

1.1 GitHub帐户添加SSH密钥

https://docs.github.com/en/github/authenticating-to-github/checking-for-existing-ssh-keys

1.2 配置ninja

1. 下载和编译

git clone git://github.com/ninja-build/ninja.git && cd ninja
git checkout release
./configure.py --bootstrap

2. 配置环境变量

$ vi ~/.bashrc
export PATH=$PATH:/home/wangzhen/WorkSpace/ninja
$ source ~/.bashrc

1.3 配置depot_tools

Clone the depot_tools repository:

git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git

在 ~/.bashrc添加depot_tools路径：

export PATH=/path/to/depot_tools:$PATH

1.4 配置Engine环境

1. 下载Engine代码：https://github.com/flutter/engine

2. 在engine目录下创建.gclient文件，文件中填充以下内容

   solutions = [
     {
       "managed": False,
       "name": "src/flutter",
       "url": "[email protected]:/engine.git",
       "custom_deps": {},
       "deps_file": "DEPS",
       "safesync_url": "",
     },
   ]
   

3. 在engine目录下执行gclient sync命令，它会下载所有依赖并同步最新代码

4. 执行以下命令：

   sudo ./build/install-build-deps-android.sh
   sudo ./build/install-build-deps.sh
   sudo ./flutter/build/install-build-deps-linux-desktop.sh
   

二、编译Engine

1. 在engine目录下，创建compile.sh脚本，填充以下内容：

   set -ex
   
   cd ~/dev/engine/src/flutter #换成你的代码路径
   git fetch upstream
   git rebase upstream/master
   gclient sync
   cd ..
   
   flutter/tools/gn --unoptimized --runtime-mode=debug
   flutter/tools/gn --android --unoptimized --android-cpu=arm64
   flutter/tools/gn --android --unoptimized --runtime-mode=debug
   flutter/tools/gn --android --runtime-mode=profile
   flutter/tools/gn --android --runtime-mode=release
   
   cd out
   find . -mindepth 1 -maxdepth 1 -type d | xargs -n 1 sh -c 'ninja -C $0 || exit 255'
   

2. 授予运行权限：

   chmod a+x compile.sh
   

3. 执行compile.sh进行编译

单独编译指定可执行文件的方法:

1. 准备编译文件
   • ./flutter/tools/gn --android --unoptimized for device-side executables.
   • ./flutter/tools/gn --android --unoptimized --android-cpu=arm64 for newer 64-bit Android devices.
   • ./flutter/tools/gn --android --android-cpu x86 --unoptimized for x86 emulators.
   • ./flutter/tools/gn --android --android-cpu x64 --unoptimized for x64 emulators.
   • ./flutter/tools/gn --unoptimized for host-side executables, needed to compile the code.
2. 使用ninja编译
   • ninja -C out/android_debug_unopt for device-side executables.
   • ninja -C out/android_debug_unopt_arm64 for newer 64-bit Android devices.
   • ninja -C out/android_debug_unopt_x86 for x86 emulators.
   • ninja -C out/android_debug_unopt_x64 for x64 emulators.
   • ninja -C out/host_debug_unopt for host-side executables.

三、运行与调试

修改engine代码后，需要在flutter app目录下执行：

flutter run --local-engine-src-path <your_path>/engine/src/ --local-engine=android_debug_unopt_arm64

--local-engine-src-path指定engine路径，--local-engine指定在什么设备上运行。