CMP0159ΒΆ
New in version 3.29.
file(STRINGS) with REGEX updates CMAKE_MATCH_<n>.
In CMake 3.28 and below the file(STRINGS) command's REGEX
option does not affect CMAKE_MATCH_<n> variables. CMake 3.29
and above prefer to update the CMAKE_MATCH_<n> variables using
captures from the last match in the file, similar to the
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 file(STRINGS) with
REGEX to not store capture groups in CMAKE_MATCH_<n>
variables. The NEW behavior is to store the capture groups.
This policy was introduced in CMake version 3.29.
It may be set by cmake_policy() or cmake_minimum_required().
If it is not set, CMake does not warn, and uses OLD behavior.
Note
The OLD behavior of a policy is
deprecated by definition
and may be removed in a future version of CMake.