conky/cmake/DependentOption.cmake

68 lines
2.6 KiB
CMake

# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#[=======================================================================[.rst:
DependentOption
--------------------
Roughly based on CMakeDependentOption:
https://github.com/Kitware/CMake/blob/master/Modules/CMakeDependentOption.cmake
Modified to so it produces warnings instead of hiding an option completely and
sets a default value.
Difference is that `depends` argument is ALWAYS a semicolon separated list of
<expr> tokens.
Argument meaning and order are the same, and there's an additional (warn)
argument which is the message printed if the end-user enabled a feature which
isn't "possible".
Actual checks are deferred until RUN_DEPENDENCY_CHECKS() is called in order to
allow out of order declaration of dependencies and dependecy graph cycles.
As the checks can affect each other they're run in a loop until the graph settles.
#]=======================================================================]
set(__DEPENDENT_OPTIONS_CHANGE_HAPPENED true)
set(__DEPENDENT_OPTIONS_LATER_INVOKED_CODE "")
macro(DEPENDENT_OPTION option doc default depends else warn)
option(${option} "${doc}" "${default}")
string(APPEND __DEPENDENT_OPTIONS_LATER_INVOKED_CODE "
set(${option}_POSSIBLE 1)
string(REGEX MATCHALL \"[^;]+\" __${option}_TOKENS \"${depends}\")
foreach(it \${__${option}_TOKENS})
cmake_language(EVAL CODE \"
if (\${it})
else()
set(${option}_POSSIBLE 0)
endif()\")
endforeach()
unset(__${option}_TOKENS)
if(NOT ${option}_POSSIBLE)
if(NOT \"\${${option}}\" STREQUAL \"${else}\")
message(NOTICE \"${warn}; setting to '${else}'.\")
set(${option} ${else} CACHE BOOL \"${doc}\" FORCE)
set(__DEPENDENT_OPTIONS_CHANGE_HAPPENED true)
endif()
endif()
unset(${option}_POSSIBLE)")
endmacro()
macro(RUN_DEPENDENCY_CHECKS)
# controls max allowed dependency chain to avoid infinite loops during
# configure phase
set(__DEPENDENT_OPTIONS_LOOP_COUNTER 10)
while(__DEPENDENT_OPTIONS_CHANGE_HAPPENED)
MATH(EXPR __DEPENDENT_OPTIONS_LOOP_COUNTER "${__DEPENDENT_OPTIONS_LOOP_COUNTER}-1")
set(__DEPENDENT_OPTIONS_CHANGE_HAPPENED false)
cmake_language(EVAL CODE "${__DEPENDENT_OPTIONS_LATER_INVOKED_CODE}")
if(__DEPENDENT_OPTIONS_LOOP_COUNTER LESS_EQUAL "0")
break()
endif()
endwhile()
unset(__DEPENDENT_OPTIONS_LOOP_COUNTER)
set(__DEPENDENT_OPTIONS_CHANGE_HAPPENED true)
set(__DEPENDENT_OPTIONS_LATER_INVOKED_CODE "")
endmacro()