Fuchsia之GN与Ninja构建hello world

接上篇：Fuchsia中GN与Ninja构建过程 

1.环境搭建
# cp  -rf out/ ~/home/GN //将编译出来的out目录的gn都拷贝出来
# emacs /etc/profile //添加环境配置
export PATH=$PATH:~/home/GN/out

# cp -rf gn/examples/simple_build/build ~/home/GN/myApp
# cp  gn/examples/simple_build/.gn ~/home/GN/myApp
# mkdir -p ~/home/GN/myApp
# cd ~/home/GN/myApp

2.demo
<1>.emacs hello.cpp
#include <iostream>
using namespace std;
int main(){
  cout << "Hello Fuchsia" <<endl;
} 

<2>.emacs BUILD.gn //编写.gn构建配置文件
executable("hello") {                                                                                                                                                                           sources = [ "hello.cpp" ]
}

# gn gen out/default //Build.gn生成.ninja
# ninja -C out/default -v //编译
# cd out/default
# ./hello
Hello Fuchsia!