dmikushin/xunused

xunused is a tool to find unused C/C++ functions and methods across source files in the whole project.

Find unused C/C++ functions with xunused

xunused is a tool to find unused C/C++ functions and methods across source files in the whole project. It is built upon clang to parse the source code (in parallel). It then shows all functions that had a definition but no use. Templates, virtual functions, constructors, functions with static linkage are all taken into account.

xunused is compatible with LLVM and Clang version 12.

Prerequisites

sudo apt install llvm-12-dev clang-12 libclang-12-dev libtbb-dev

Building

mkdir build
cd build
cmake ..
make

Testing

To run the tool, provide a compilation database. By default, it will analyze all files that are mentioned in it.

In order to generate compile_commands.json for a CMake project, add the following line into CMakeLists.txt:

set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

An example compile_commands.json file is create in the build folder:

cd build
./xunused ./compile_commands.json

You can specify the option -filter together with a regular expressions. Only files who's path is matching the regular expression will be analyzed. You might want to exclude your test's source code to find functions that are only used by tests but not any other code.

If xunused complains about missing include files such as stddef.h, try adding -extra-arg=-I/usr/include/clang/10/include (or similar) to the arguments.