CMake/Modules/CMakeFindDependencyMacro.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names and years are hard to maintain and often out-of-date or plain wrong.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

76 lines
2.4 KiB
CMake

# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#.rst:
# CMakeFindDependencyMacro
# -------------------------
#
# ::
#
# find_dependency(<dep> [<version> [EXACT]])
#
#
# ``find_dependency()`` wraps a :command:`find_package` call for a package
# dependency. It is designed to be used in a <package>Config.cmake file, and it
# forwards the correct parameters for EXACT, QUIET and REQUIRED which were
# passed to the original :command:`find_package` call. It also sets an
# informative diagnostic message if the dependency could not be found.
#
macro(find_dependency dep)
if (NOT ${dep}_FOUND)
set(cmake_fd_version)
if (${ARGC} GREATER 1)
if ("${ARGV1}" STREQUAL "")
message(FATAL_ERROR "Invalid arguments to find_dependency. VERSION is empty")
endif()
if ("${ARGV1}" STREQUAL EXACT)
message(FATAL_ERROR "Invalid arguments to find_dependency. EXACT may only be specified if a VERSION is specified")
endif()
set(cmake_fd_version ${ARGV1})
endif()
set(cmake_fd_exact_arg)
if(${ARGC} GREATER 2)
if (NOT "${ARGV2}" STREQUAL EXACT)
message(FATAL_ERROR "Invalid arguments to find_dependency")
endif()
set(cmake_fd_exact_arg EXACT)
endif()
if(${ARGC} GREATER 3)
message(FATAL_ERROR "Invalid arguments to find_dependency")
endif()
set(cmake_fd_quiet_arg)
if(${CMAKE_FIND_PACKAGE_NAME}_FIND_QUIETLY)
set(cmake_fd_quiet_arg QUIET)
endif()
set(cmake_fd_required_arg)
if(${CMAKE_FIND_PACKAGE_NAME}_FIND_REQUIRED)
set(cmake_fd_required_arg REQUIRED)
endif()
get_property(cmake_fd_alreadyTransitive GLOBAL PROPERTY
_CMAKE_${dep}_TRANSITIVE_DEPENDENCY
)
find_package(${dep} ${cmake_fd_version}
${cmake_fd_exact_arg}
${cmake_fd_quiet_arg}
${cmake_fd_required_arg}
)
if(NOT DEFINED cmake_fd_alreadyTransitive OR cmake_fd_alreadyTransitive)
set_property(GLOBAL PROPERTY _CMAKE_${dep}_TRANSITIVE_DEPENDENCY TRUE)
endif()
if (NOT ${dep}_FOUND)
set(${CMAKE_FIND_PACKAGE_NAME}_NOT_FOUND_MESSAGE "${CMAKE_FIND_PACKAGE_NAME} could not be found because dependency ${dep} could not be found.")
set(${CMAKE_FIND_PACKAGE_NAME}_FOUND False)
return()
endif()
set(cmake_fd_version)
set(cmake_fd_required_arg)
set(cmake_fd_quiet_arg)
set(cmake_fd_exact_arg)
endif()
endmacro()