Flutter Engine源码编译

有关编译问题这篇文章讲的很清楚Flutter-Engine-编译指北，本文只是一些自己的简单记录

简要步骤

安装depot_tools

克隆depot_tools仓库，获取gclient命令，执行如下：

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

设置环境变量，编辑 ~/.bashrc或者 ~/.zshrc，添加如下内容：

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

编译选项

Flutter's modes

usage: gn [-h] [--unoptimized] [--runtime-mode {debug,profile,release}]
          [--dynamic] [--interpreter] [--dart-debug]
          [--target-os {android,ios,linux}] [--android]
          [--android-cpu {arm,x64,x86,arm64}] [--ios] [--ios-cpu {arm,arm64}]
          [--simulator] [--linux-cpu {x64,x86,arm64,arm}]
          [--arm-float-abi {hard,soft,softfp}] [--goma] [--no-goma] [--lto]
          [--no-lto] [--clang] [--no-clang] [--target-sysroot TARGET_SYSROOT]
          [--target-toolchain TARGET_TOOLCHAIN]
          [--target-triple TARGET_TRIPLE]
          [--toolchain-prefix TOOLCHAIN_PREFIX] [--enable-vulkan]
          [--embedder-for-target]

实践

我在编译的时候，本地的flutter环境是1.12.13+hotfix.5 使用file命令查看原有flutter.framework的架构,大小是92.8M

Flutter: Mach-O universal binary with 3 architectures: [x86_64:Mach-O 64-bit dynamically linked shared library x86_64] [arm64]
Flutter (for architecture x86_64):	Mach-O 64-bit dynamically linked shared library x86_64
Flutter (for architecture armv7):	Mach-O dynamically linked shared library arm_v7
Flutter (for architecture arm64):	Mach-O 64-bit dynamically linked shared library arm64

使用如下命令自己打包:

$ ./flutter/tools/gn --ios --simulator
$ ninja -C out/ios_debug_sim

查看架构:

$ file Flutter.framework/Flutter

Flutter.framework/Flutter: Mach-O 64-bit dynamically linked shared library x86_64

大小约为31.7M

$ ./flutter/tools/gn --ios --ios-cpu=arm --runtime-mode=profile
Generating GN files in: out/ios_profile_arm
Generating Xcode projects took 911ms
Done. Made 398 targets from 182 files in 32534ms

$ ./flutter/tools/gn --runtime-mode=profile
Generating GN files in: out/host_profile
Generating Xcode projects took 585ms
Done. Made 579 targets from 204 files in 32341ms