CMake/Help/policy/CMP0159.rst

CMP0159
-------

.. versionadded:: 3.29

:command:`file(STRINGS)` with ``REGEX`` updates :variable:`CMAKE_MATCH_<n>`.

In CMake 3.28 and below the :command:`file(STRINGS)` command's ``REGEX``
option does not affect :variable:`CMAKE_MATCH_<n>` variables.  CMake 3.29
and above prefer to update the :variable:`CMAKE_MATCH_<n>` variables using
captures from the last match in the file, similar to the
:command:`string(REGEX MATCHALL)` command.  This policy provides
compatibility for projects that have not been updated to expect the behavior.

The ``OLD`` behavior for this policy is for :command:`file(STRINGS)` with
``REGEX`` to not store capture groups in :variable:`CMAKE_MATCH_<n>`
variables.  The ``NEW`` behavior is to store the capture groups.

This policy was introduced in CMake version 3.29. Use the
:command:`cmake_policy` command to set it to ``OLD`` or ``NEW`` explicitly.
Unlike many policies, CMake version |release| does *not* warn
when this policy is not set and simply uses ``OLD`` behavior.

.. include:: DEPRECATED.txt