include_what_you_use_guide.md

Author	刘昊
Date	2022-08-11
Email	[email protected]

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Install

# download the code
$ git clone https://github.com/include-what-you-use/include-what-you-use.git
# according to the clang version, switch to the corresponding branch, such as clang-14
$ cd include-what-you-use
$ git checkout clang_14
# create build directory
$ mkdir build && cd build
# start build
$ cmake -G "Unix Makefiles" -DCMAKE_PREFIX_PATH=/usr/lib/llvm-7 ..
$ make -j8
# copy the generated binary to /usr/bin
$ cp bin/include-what-you-use /usr/bin/include-what-you-use

For more details, please refer to Official Tutorial.

Usage

Take lcr for example:

$ mkdir build && cd build
# 1. use clang as the compiler;
# 2. set CMAKE_C_INCLUDE_WHAT_YOU_USE configuration;
# 3. Set CXX to DCMAKE_CXX_INCLUDE_WHAT_YOU_USE
$ CC="clang" CXX="clang++" cmake -DCMAKE_C_INCLUDE_WHAT_YOU_USE=include-what-you-use ..
# build
$ make > iwyu.log 2>&1

You can view the analysis report through the log file iwyu.log. Also, you can use the keyword should remove to quickly view unnecessary header files and remove them.

Note: After deletion, you need to compile and verify.

Effect

The effect after optimization: lcr. This tool can be used later to optimize unnecessary header files in iSulad.

Reference

• https://github.com/include-what-you-use/include-what-you-use