cmake_host_system_information: Can run fallback scripts

This commit is contained in:
Alex Turbov
2021-08-03 16:49:02 +03:00
committed by Brad King
parent 1e65e4a6e5
commit efe139d1b8
16 changed files with 308 additions and 2 deletions
@@ -176,8 +176,75 @@ system identification as described in the `man 5 os-release`_.
-- DISTRO_VERSION_CODENAME=`focal`
-- DISTRO_VERSION_ID=`20.04`
If :file:`/etc/os-release` file is not found, the command tries to gather OS
identification via fallback scripts. The fallback script can use `various
distribution-specific files`_ to collect OS identification data and map it
into `man 5 os-release`_ variables.
Fallback Interface Variables
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. variable:: CMAKE_GET_OS_RELEASE_FALLBACK_SCRIPTS
In addition to the scripts shipped with CMake, a user may append full
paths to his script(s) to the this list. The script filename has the
following format: ``NNN-<name>.cmake``, where ``NNN`` is three digits
used to apply collected scripts in a specific order.
.. variable:: CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_<varname>
Variables collected by the user provided fallback script
ought to be assigned to CMake variables using this naming
convention. Example, the ``ID`` variable from the manual becomes
``CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_ID``.
.. variable:: CMAKE_GET_OS_RELEASE_FALLBACK_RESULT
The fallback script ought to store names of all assigned
``CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_<varname>`` variables in this list.
Example:
.. code-block:: cmake
# Try to detect some old distribution
# See also
# - http://linuxmafia.com/faq/Admin/release-files.html
#
if(NOT EXISTS "${CMAKE_SYSROOT}/etc/foobar-release")
return()
endif()
# Get the first string only
file(
STRINGS "${CMAKE_SYSROOT}/etc/foobar-release" CMAKE_GET_OS_RELEASE_FALLBACK_CONTENT
LIMIT_COUNT 1
)
#
# Example:
#
# Foobar distribution release 1.2.3 (server)
#
if(CMAKE_GET_OS_RELEASE_FALLBACK_CONTENT MATCHES "Foobar distribution release ([0-9\.]+) .*")
set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_NAME Foobar)
set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_PRETTY_NAME "${CMAKE_GET_OS_RELEASE_FALLBACK_CONTENT}")
set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_ID foobar)
set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_VERSION ${CMAKE_MATCH_1})
set(CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_VERSION_ID ${CMAKE_MATCH_1})
list(
APPEND CMAKE_GET_OS_RELEASE_FALLBACK_RESULT
CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_NAME
CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_PRETTY_NAME
CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_ID
CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_VERSION
CMAKE_GET_OS_RELEASE_FALLBACK_RESULT_VERSION_ID
)
endif()
unset(CMAKE_GET_OS_RELEASE_FALLBACK_CONTENT)
.. rubric:: Footnotes
.. [#mebibytes] One MiB (mebibyte) is equal to 1024x1024 bytes.
.. _man 5 os-release: https://www.freedesktop.org/software/systemd/man/os-release.html
.. _various distribution-specific files: http://linuxmafia.com/faq/Admin/release-files.html