file: `STRINGS` + `REGEX` store match results

Signed-off-by: Cristian Le <cristian.le@mpsd.mpg.de>

1 files changed, 24 insertions, 0 deletions

diff --git a/Help/policy/CMP0159.rst b/Help/policy/CMP0159.rst
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+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