cmake/Help/prop_tgt/SOVERSION.rst

SOVERSION
---------

ABI version number of a shared library target.

For shared libraries :prop_tgt:`VERSION` and ``SOVERSION`` can be used to
specify the build version and ABI version respectively.  When building or
installing appropriate symlinks are created if the platform supports
symlinks and the linker supports so-names.  If only one of both is
specified the missing is assumed to have the same version number.
``SOVERSION`` is ignored if :prop_tgt:`NO_SONAME` property is set.

.. include:: VERSION_SOVERSION_EXAMPLE.txt

Windows Versions
^^^^^^^^^^^^^^^^

For shared libraries and executables on Windows the :prop_tgt:`VERSION`
attribute is parsed to extract a ``<major>.<minor>`` version number.
These numbers are used as the image version of the binary.

Mach-O Versions
^^^^^^^^^^^^^^^

For shared libraries and executables on Mach-O systems (e.g. macOS, iOS),
the ``SOVERSION`` property corresponds to the *compatibility version* and
:prop_tgt:`VERSION` corresponds to the *current version* (unless Mach-O
specific overrides are provided, as discussed below).
See the :prop_tgt:`FRAMEWORK` target property for an example.

For shared libraries, the :prop_tgt:`MACHO_COMPATIBILITY_VERSION` and
:prop_tgt:`MACHO_CURRENT_VERSION` properties can be used to
override the *compatibility version* and *current version* respectively.
Note that ``SOVERSION`` will still be used to form the ``install_name``
and both ``SOVERSION`` and :prop_tgt:`VERSION` may also affect the file
and symlink names.

Versions of Mach-O binaries may be checked with the ``otool -L <binary>``
command.