使用Clang++指令编译dsc_extractor.cpp文件报：
xcrun: error: active developer path ("/Applications/Xcode9.app/Contents/Developer") does not exist Use `sudo xcode-select --switch path/to/Xcode.app` to specify the Xcode that you wish to use for command line developer tools, or use `xcode-select --install` to install the standalone command line developer tools. See `man xcode-select` for more details.
执行命令：$:sudo xcode-select --switch /Applications/Xcode.app
Xcode.app版本注意与/Applications中的一致。例如
$:sudo xcode-select --switch /Applications/Xcode9.app
然后再次执行编译指令$:clang++ -o dsc_extractor dsc_extractor.cpp即可
