CMake/Modules/CMakeDependentOption.cmake
Brad King 86578eccf2 Simplify CMake per-source license notices
Per-source copyright/license notice headers that spell out copyright holder
names and years are hard to maintain and often out-of-date or plain wrong.
Precise contributor information is already maintained automatically by the
version control tool.  Ultimately it is the receiver of a file who is
responsible for determining its licensing status, and per-source notices are
merely a convenience.  Therefore it is simpler and more accurate for
each source to have a generic notice of the license name and references to
more detailed information on copyright holders and full license terms.

Our `Copyright.txt` file now contains a list of Contributors whose names
appeared source-level copyright notices.  It also references version control
history for more precise information.  Therefore we no longer need to spell
out the list of Contributors in each source file notice.

Replace CMake per-source copyright/license notice headers with a short
description of the license and links to `Copyright.txt` and online information
available from "https://cmake.org/licensing".  The online URL also handles
cases of modules being copied out of our source into other projects, so we
can drop our notices about replacing links with full license text.

Run the `Utilities/Scripts/filter-notices.bash` script to perform the majority
of the replacements mechanically.  Manually fix up shebang lines and trailing
newlines in a few files.  Manually update the notices in a few files that the
script does not handle.
2016-09-27 15:14:44 -04:00

50 lines
1.6 KiB
CMake

# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#.rst:
# CMakeDependentOption
# --------------------
#
# Macro to provide an option dependent on other options.
#
# This macro presents an option to the user only if a set of other
# conditions are true. When the option is not presented a default value
# is used, but any value set by the user is preserved for when the
# option is presented again. Example invocation:
#
# ::
#
# CMAKE_DEPENDENT_OPTION(USE_FOO "Use Foo" ON
# "USE_BAR;NOT USE_ZOT" OFF)
#
# If USE_BAR is true and USE_ZOT is false, this provides an option
# called USE_FOO that defaults to ON. Otherwise, it sets USE_FOO to
# OFF. If the status of USE_BAR or USE_ZOT ever changes, any value for
# the USE_FOO option is saved so that when the option is re-enabled it
# retains its old value.
macro(CMAKE_DEPENDENT_OPTION option doc default depends force)
if(${option}_ISSET MATCHES "^${option}_ISSET$")
set(${option}_AVAILABLE 1)
foreach(d ${depends})
string(REGEX REPLACE " +" ";" CMAKE_DEPENDENT_OPTION_DEP "${d}")
if(${CMAKE_DEPENDENT_OPTION_DEP})
else()
set(${option}_AVAILABLE 0)
endif()
endforeach()
if(${option}_AVAILABLE)
option(${option} "${doc}" "${default}")
set(${option} "${${option}}" CACHE BOOL "${doc}" FORCE)
else()
if(${option} MATCHES "^${option}$")
else()
set(${option} "${${option}}" CACHE INTERNAL "${doc}")
endif()
set(${option} ${force})
endif()
else()
set(${option} "${${option}_ISSET}")
endif()
endmacro()