Low-cost extraction of class relationships from C++ classes.

This tool extract class relationships from C++ classes. Only a minimal subset of information is extracted which requires parsing much less of the code than e.g. needed by more powerful tools like kythe.

Required dependencies:

• a compiler able to build llvm-10
• libsqlite with headers (probably in some dev package)

This tool needs to be checked out below the clang-tools-extra folder in a full checkout (llvm-project/clang-tools-extra). After that it can be built as part of a normal LLVM/clang build, see build.sh for an example.

Umler visits the AST from parsing C++ source files. The parameter -c specifies which class to document.

% umler -c ClassToDocument *.cpp

The needed compiler flags are extracted from a json compilation database which can be generated automatically with cmake by specifying at configure time

% cmake -DCMAKE_EXPORT_COMPILE_COMMANDS=ON path/to/source

Bear can be used to extract compilation databases for some other build systems. If no compilation database is used -- can be passed as last command line argument.

The infrastructure will automatically find the compilation database if it is located in the current directory or any of its source directories.

Umler will then dump a plantuml description of the parsed classes to stdout. The information to be dumped can be adjusted

• -document-uses: document uses relationships (default: false)
• -document-owns: document owns relationships (default: false)
• -document-binds: document binds relationships (default: false)
• -document-methods: document class methods (default: true)

To persist the parse result the internal database can be dumped with -d

% umler -c ClassToDocument *.cpp -d db.sqlite

If subsequent invocations are given the same database parses the database will contain results from all parses. This allows to iteratively enhance descriptions.