The tool does the following:

1. Extracts input packages
2. Searches for *.debuginfo, *.so and header files
3. Creates ABI dumps of all found shared objects
4. Filters out private part of the ABI using info from header files
5. Matches shared objects in old and new packages
6. Compares ABI dumps of corresponding objects
7. Creates backward binary/source compatibility reports
The pkg-abidiff tool is based on the ABI Compliance Checker tool. It is executed on every shared object found in the RPM. You can find reports of the ABI Compliance Checker by following the links in the "Shared Objects" section of the output report: https://abi-laboratory.pro/examples/compat_report/x86_64/libssh4/0.5.3-2.1.1/0.6.3-8.1/

The ABI Compliance Checker tool is designed to compare particular shared objects (or debug info ABI dumps). The pkg-abidiff is designed to compare sets of shared objects in RPM packages. Also it searches for all necessary data in RPMs and provides all necessary options to ABI Compliance Checker.