CMake/Modules/FindPkgConfig.cmake

578 lines
21 KiB
CMake

#.rst:
# FindPkgConfig
# -------------
#
# A `pkg-config` module for CMake.
#
# Finds the ``pkg-config`` executable and add the
# :command:`pkg_check_modules` and :command:`pkg_search_module`
# commands.
#
# In order to find the ``pkg-config`` executable, it uses the
# :variable:`PKG_CONFIG_EXECUTABLE` variable or the ``PKG_CONFIG``
# environment variable first.
#=============================================================================
# Copyright 2006-2014 Kitware, Inc.
# Copyright 2014 Christoph Grüninger <foss@grueninger.de>
# Copyright 2006 Enrico Scholz <enrico.scholz@informatik.tu-chemnitz.de>
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
# License text for the above reference.)
### Common stuff ####
set(PKG_CONFIG_VERSION 1)
# find pkg-config, use PKG_CONFIG if set
if((NOT PKG_CONFIG_EXECUTABLE) AND (NOT "$ENV{PKG_CONFIG}" STREQUAL ""))
set(PKG_CONFIG_EXECUTABLE "$ENV{PKG_CONFIG}" CACHE FILEPATH "pkg-config executable")
endif()
find_program(PKG_CONFIG_EXECUTABLE NAMES pkg-config DOC "pkg-config executable")
mark_as_advanced(PKG_CONFIG_EXECUTABLE)
if (PKG_CONFIG_EXECUTABLE)
execute_process(COMMAND ${PKG_CONFIG_EXECUTABLE} --version
OUTPUT_VARIABLE PKG_CONFIG_VERSION_STRING
ERROR_QUIET
OUTPUT_STRIP_TRAILING_WHITESPACE)
endif ()
include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)
find_package_handle_standard_args(PkgConfig
REQUIRED_VARS PKG_CONFIG_EXECUTABLE
VERSION_VAR PKG_CONFIG_VERSION_STRING)
# This is needed because the module name is "PkgConfig" but the name of
# this variable has always been PKG_CONFIG_FOUND so this isn't automatically
# handled by FPHSA.
set(PKG_CONFIG_FOUND "${PKGCONFIG_FOUND}")
# Unsets the given variables
macro(_pkgconfig_unset var)
set(${var} "" CACHE INTERNAL "")
endmacro()
macro(_pkgconfig_set var value)
set(${var} ${value} CACHE INTERNAL "")
endmacro()
# Invokes pkgconfig, cleans up the result and sets variables
macro(_pkgconfig_invoke _pkglist _prefix _varname _regexp)
set(_pkgconfig_invoke_result)
execute_process(
COMMAND ${PKG_CONFIG_EXECUTABLE} ${ARGN} ${_pkglist}
OUTPUT_VARIABLE _pkgconfig_invoke_result
RESULT_VARIABLE _pkgconfig_failed)
if (_pkgconfig_failed)
set(_pkgconfig_${_varname} "")
_pkgconfig_unset(${_prefix}_${_varname})
else()
string(REGEX REPLACE "[\r\n]" " " _pkgconfig_invoke_result "${_pkgconfig_invoke_result}")
string(REGEX REPLACE " +$" "" _pkgconfig_invoke_result "${_pkgconfig_invoke_result}")
if (NOT ${_regexp} STREQUAL "")
string(REGEX REPLACE "${_regexp}" " " _pkgconfig_invoke_result "${_pkgconfig_invoke_result}")
endif()
separate_arguments(_pkgconfig_invoke_result)
#message(STATUS " ${_varname} ... ${_pkgconfig_invoke_result}")
set(_pkgconfig_${_varname} ${_pkgconfig_invoke_result})
_pkgconfig_set(${_prefix}_${_varname} "${_pkgconfig_invoke_result}")
endif()
endmacro()
# Invokes pkgconfig two times; once without '--static' and once with
# '--static'
macro(_pkgconfig_invoke_dyn _pkglist _prefix _varname cleanup_regexp)
_pkgconfig_invoke("${_pkglist}" ${_prefix} ${_varname} "${cleanup_regexp}" ${ARGN})
_pkgconfig_invoke("${_pkglist}" ${_prefix} STATIC_${_varname} "${cleanup_regexp}" --static ${ARGN})
endmacro()
# Splits given arguments into options and a package list
macro(_pkgconfig_parse_options _result _is_req _is_silent _no_cmake_path _no_cmake_environment_path)
set(${_is_req} 0)
set(${_is_silent} 0)
set(${_no_cmake_path} 0)
set(${_no_cmake_environment_path} 0)
if(DEFINED PKG_CONFIG_USE_CMAKE_PREFIX_PATH)
if(NOT PKG_CONFIG_USE_CMAKE_PREFIX_PATH)
set(${_no_cmake_path} 1)
set(${_no_cmake_environment_path} 1)
endif()
elseif(${CMAKE_MINIMUM_REQUIRED_VERSION} VERSION_LESS 3.1)
set(${_no_cmake_path} 1)
set(${_no_cmake_environment_path} 1)
endif()
foreach(_pkg ${ARGN})
if (_pkg STREQUAL "REQUIRED")
set(${_is_req} 1)
endif ()
if (_pkg STREQUAL "QUIET")
set(${_is_silent} 1)
endif ()
if (_pkg STREQUAL "NO_CMAKE_PATH")
set(${_no_cmake_path} 1)
endif()
if (_pkg STREQUAL "NO_CMAKE_ENVIRONMENT_PATH")
set(${_no_cmake_environment_path} 1)
endif()
endforeach()
set(${_result} ${ARGN})
list(REMOVE_ITEM ${_result} "REQUIRED")
list(REMOVE_ITEM ${_result} "QUIET")
list(REMOVE_ITEM ${_result} "NO_CMAKE_PATH")
list(REMOVE_ITEM ${_result} "NO_CMAKE_ENVIRONMENT_PATH")
endmacro()
# Add the content of a variable or an environment variable to a list of
# paths
# Usage:
# - _pkgconfig_add_extra_path(_extra_paths VAR)
# - _pkgconfig_add_extra_path(_extra_paths ENV VAR)
function(_pkgconfig_add_extra_path _extra_paths_var _var)
set(_is_env 0)
if(_var STREQUAL "ENV")
set(_var ${ARGV2})
set(_is_env 1)
endif()
if(NOT _is_env)
if(NOT "${${_var}}" STREQUAL "")
list(APPEND ${_extra_paths_var} ${CMAKE_PREFIX_PATH})
endif()
else()
if(NOT "$ENV{${_var}}" STREQUAL "")
file(TO_CMAKE_PATH "$ENV{${_var}}" _path)
list(APPEND ${_extra_paths_var} ${_path})
unset(_path)
endif()
endif()
set(${_extra_paths_var} ${${_extra_paths_var}} PARENT_SCOPE)
endfunction()
###
macro(_pkg_check_modules_internal _is_required _is_silent _no_cmake_path _no_cmake_environment_path _prefix)
_pkgconfig_unset(${_prefix}_FOUND)
_pkgconfig_unset(${_prefix}_VERSION)
_pkgconfig_unset(${_prefix}_PREFIX)
_pkgconfig_unset(${_prefix}_INCLUDEDIR)
_pkgconfig_unset(${_prefix}_LIBDIR)
_pkgconfig_unset(${_prefix}_LIBS)
_pkgconfig_unset(${_prefix}_LIBS_L)
_pkgconfig_unset(${_prefix}_LIBS_PATHS)
_pkgconfig_unset(${_prefix}_LIBS_OTHER)
_pkgconfig_unset(${_prefix}_CFLAGS)
_pkgconfig_unset(${_prefix}_CFLAGS_I)
_pkgconfig_unset(${_prefix}_CFLAGS_OTHER)
_pkgconfig_unset(${_prefix}_STATIC_LIBDIR)
_pkgconfig_unset(${_prefix}_STATIC_LIBS)
_pkgconfig_unset(${_prefix}_STATIC_LIBS_L)
_pkgconfig_unset(${_prefix}_STATIC_LIBS_PATHS)
_pkgconfig_unset(${_prefix}_STATIC_LIBS_OTHER)
_pkgconfig_unset(${_prefix}_STATIC_CFLAGS)
_pkgconfig_unset(${_prefix}_STATIC_CFLAGS_I)
_pkgconfig_unset(${_prefix}_STATIC_CFLAGS_OTHER)
# create a better addressable variable of the modules and calculate its size
set(_pkg_check_modules_list ${ARGN})
list(LENGTH _pkg_check_modules_list _pkg_check_modules_cnt)
if(PKG_CONFIG_EXECUTABLE)
# give out status message telling checked module
if (NOT ${_is_silent})
if (_pkg_check_modules_cnt EQUAL 1)
message(STATUS "checking for module '${_pkg_check_modules_list}'")
else()
message(STATUS "checking for modules '${_pkg_check_modules_list}'")
endif()
endif()
set(_pkg_check_modules_packages)
set(_pkg_check_modules_failed)
set(_extra_paths)
if(NOT _no_cmake_path)
_pkgconfig_add_extra_path(_extra_paths CMAKE_PREFIX_PATH)
_pkgconfig_add_extra_path(_extra_paths CMAKE_FRAMEWORK_PATH)
_pkgconfig_add_extra_path(_extra_paths CMAKE_APPBUNDLE_PATH)
endif()
if(NOT _no_cmake_environment_path)
_pkgconfig_add_extra_path(_extra_paths ENV CMAKE_PREFIX_PATH)
_pkgconfig_add_extra_path(_extra_paths ENV CMAKE_FRAMEWORK_PATH)
_pkgconfig_add_extra_path(_extra_paths ENV CMAKE_APPBUNDLE_PATH)
endif()
if(NOT "${_extra_paths}" STREQUAL "")
# Save the PKG_CONFIG_PATH environment variable, and add paths
# from the CMAKE_PREFIX_PATH variables
set(_pkgconfig_path_old $ENV{PKG_CONFIG_PATH})
set(_pkgconfig_path ${_pkgconfig_path_old})
if(NOT "${_pkgconfig_path}" STREQUAL "")
file(TO_CMAKE_PATH "${_pkgconfig_path}" _pkgconfig_path)
endif()
# Create a list of the possible pkgconfig subfolder (depending on
# the system
set(_lib_dirs)
if(NOT DEFINED CMAKE_SYSTEM_NAME
OR (CMAKE_SYSTEM_NAME MATCHES "^(Linux|kFreeBSD|GNU)$"
AND NOT CMAKE_CROSSCOMPILING))
if(EXISTS "/etc/debian_version") # is this a debian system ?
if(CMAKE_LIBRARY_ARCHITECTURE)
list(APPEND _lib_dirs "lib/${CMAKE_LIBRARY_ARCHITECTURE}/pkgconfig")
endif()
else()
# not debian, chech the FIND_LIBRARY_USE_LIB64_PATHS property
get_property(uselib64 GLOBAL PROPERTY FIND_LIBRARY_USE_LIB64_PATHS)
if(uselib64)
list(APPEND _lib_dirs "lib64/pkgconfig")
endif()
endif()
endif()
list(APPEND _lib_dirs "lib/pkgconfig")
# Check if directories exist and eventually append them to the
# pkgconfig path list
foreach(_prefix_dir ${_extra_paths})
foreach(_lib_dir ${_lib_dirs})
if(EXISTS "${_prefix_dir}/${_lib_dir}")
list(APPEND _pkgconfig_path "${_prefix_dir}/${_lib_dir}")
list(REMOVE_DUPLICATES _pkgconfig_path)
endif()
endforeach()
endforeach()
# Prepare and set the environment variable
if(NOT "${_pkgconfig_path}" STREQUAL "")
# remove empty values from the list
list(REMOVE_ITEM _pkgconfig_path "")
file(TO_NATIVE_PATH "${_pkgconfig_path}" _pkgconfig_path)
if(UNIX)
string(REPLACE ";" ":" _pkgconfig_path "${_pkgconfig_path}")
string(REPLACE "\\ " " " _pkgconfig_path "${_pkgconfig_path}")
endif()
set(ENV{PKG_CONFIG_PATH} ${_pkgconfig_path})
endif()
# Unset variables
unset(_lib_dirs)
unset(_pkgconfig_path)
endif()
# iterate through module list and check whether they exist and match the required version
foreach (_pkg_check_modules_pkg ${_pkg_check_modules_list})
set(_pkg_check_modules_exist_query)
# check whether version is given
if (_pkg_check_modules_pkg MATCHES "(.*[^><])(>=|=|<=)(.*)")
set(_pkg_check_modules_pkg_name "${CMAKE_MATCH_1}")
set(_pkg_check_modules_pkg_op "${CMAKE_MATCH_2}")
set(_pkg_check_modules_pkg_ver "${CMAKE_MATCH_3}")
else()
set(_pkg_check_modules_pkg_name "${_pkg_check_modules_pkg}")
set(_pkg_check_modules_pkg_op)
set(_pkg_check_modules_pkg_ver)
endif()
# handle the operands
if (_pkg_check_modules_pkg_op STREQUAL ">=")
list(APPEND _pkg_check_modules_exist_query --atleast-version)
endif()
if (_pkg_check_modules_pkg_op STREQUAL "=")
list(APPEND _pkg_check_modules_exist_query --exact-version)
endif()
if (_pkg_check_modules_pkg_op STREQUAL "<=")
list(APPEND _pkg_check_modules_exist_query --max-version)
endif()
# create the final query which is of the format:
# * --atleast-version <version> <pkg-name>
# * --exact-version <version> <pkg-name>
# * --max-version <version> <pkg-name>
# * --exists <pkg-name>
if (_pkg_check_modules_pkg_op)
list(APPEND _pkg_check_modules_exist_query "${_pkg_check_modules_pkg_ver}")
else()
list(APPEND _pkg_check_modules_exist_query --exists)
endif()
_pkgconfig_unset(${_prefix}_${_pkg_check_modules_pkg_name}_VERSION)
_pkgconfig_unset(${_prefix}_${_pkg_check_modules_pkg_name}_PREFIX)
_pkgconfig_unset(${_prefix}_${_pkg_check_modules_pkg_name}_INCLUDEDIR)
_pkgconfig_unset(${_prefix}_${_pkg_check_modules_pkg_name}_LIBDIR)
list(APPEND _pkg_check_modules_exist_query "${_pkg_check_modules_pkg_name}")
list(APPEND _pkg_check_modules_packages "${_pkg_check_modules_pkg_name}")
# execute the query
execute_process(
COMMAND ${PKG_CONFIG_EXECUTABLE} ${_pkg_check_modules_exist_query}
RESULT_VARIABLE _pkgconfig_retval)
# evaluate result and tell failures
if (_pkgconfig_retval)
if(NOT ${_is_silent})
message(STATUS " package '${_pkg_check_modules_pkg}' not found")
endif()
set(_pkg_check_modules_failed 1)
endif()
endforeach()
if(_pkg_check_modules_failed)
# fail when requested
if (${_is_required})
message(FATAL_ERROR "A required package was not found")
endif ()
else()
# when we are here, we checked whether requested modules
# exist. Now, go through them and set variables
_pkgconfig_set(${_prefix}_FOUND 1)
list(LENGTH _pkg_check_modules_packages pkg_count)
# iterate through all modules again and set individual variables
foreach (_pkg_check_modules_pkg ${_pkg_check_modules_packages})
# handle case when there is only one package required
if (pkg_count EQUAL 1)
set(_pkg_check_prefix "${_prefix}")
else()
set(_pkg_check_prefix "${_prefix}_${_pkg_check_modules_pkg}")
endif()
_pkgconfig_invoke(${_pkg_check_modules_pkg} "${_pkg_check_prefix}" VERSION "" --modversion )
_pkgconfig_invoke(${_pkg_check_modules_pkg} "${_pkg_check_prefix}" PREFIX "" --variable=prefix )
_pkgconfig_invoke(${_pkg_check_modules_pkg} "${_pkg_check_prefix}" INCLUDEDIR "" --variable=includedir )
_pkgconfig_invoke(${_pkg_check_modules_pkg} "${_pkg_check_prefix}" LIBDIR "" --variable=libdir )
if (NOT ${_is_silent})
message(STATUS " found ${_pkg_check_modules_pkg}, version ${_pkgconfig_VERSION}")
endif ()
endforeach()
# set variables which are combined for multiple modules
_pkgconfig_invoke_dyn("${_pkg_check_modules_packages}" "${_prefix}" LIBRARIES "(^| )-l" --libs-only-l )
_pkgconfig_invoke_dyn("${_pkg_check_modules_packages}" "${_prefix}" LIBRARY_DIRS "(^| )-L" --libs-only-L )
_pkgconfig_invoke_dyn("${_pkg_check_modules_packages}" "${_prefix}" LDFLAGS "" --libs )
_pkgconfig_invoke_dyn("${_pkg_check_modules_packages}" "${_prefix}" LDFLAGS_OTHER "" --libs-only-other )
_pkgconfig_invoke_dyn("${_pkg_check_modules_packages}" "${_prefix}" INCLUDE_DIRS "(^| )-I" --cflags-only-I )
_pkgconfig_invoke_dyn("${_pkg_check_modules_packages}" "${_prefix}" CFLAGS "" --cflags )
_pkgconfig_invoke_dyn("${_pkg_check_modules_packages}" "${_prefix}" CFLAGS_OTHER "" --cflags-only-other )
endif()
if(NOT "${_extra_paths}" STREQUAL "")
# Restore the environment variable
set(ENV{PKG_CONFIG_PATH} ${_pkgconfig_path})
endif()
unset(_extra_paths)
unset(_pkgconfig_path_old)
else()
if (${_is_required})
message(SEND_ERROR "pkg-config tool not found")
endif ()
endif()
endmacro()
###
### User visible macros start here
###
#[========================================[.rst:
.. command:: pkg_check_modules
Checks for all the given modules. ::
pkg_check_modules(<PREFIX> [REQUIRED] [QUIET]
[NO_CMAKE_PATH] [NO_CMAKE_ENVIRONMENT_PATH]
<MODULE> [<MODULE>]*)
When the ``REQUIRED`` argument was set, macros will fail with an error
when module(s) could not be found.
When the ``QUIET`` argument is set, no status messages will be printed.
By default, if :variable:`CMAKE_MINIMUM_REQUIRED_VERSION` is 3.1 or
later, or if :variable:`PKG_CONFIG_USE_CMAKE_PREFIX_PATH` is set, the
:variable:`CMAKE_PREFIX_PATH`, :variable:`CMAKE_FRAMEWORK_PATH`, and
:variable:`CMAKE_APPBUNDLE_PATH` cache and environment variables will
be added to ``pkg-config`` search path.
The ``NO_CMAKE_PATH`` and ``NO_CMAKE_ENVIRONMENT_PATH`` arguments
disable this behavior for the cache variables and the environment
variables, respectively.
It sets the following variables: ::
PKG_CONFIG_FOUND ... if pkg-config executable was found
PKG_CONFIG_EXECUTABLE ... pathname of the pkg-config program
PKG_CONFIG_VERSION_STRING ... the version of the pkg-config program found
(since CMake 2.8.8)
For the following variables two sets of values exist; first one is the
common one and has the given PREFIX. The second set contains flags
which are given out when ``pkg-config`` was called with the ``--static``
option. ::
<XPREFIX>_FOUND ... set to 1 if module(s) exist
<XPREFIX>_LIBRARIES ... only the libraries (w/o the '-l')
<XPREFIX>_LIBRARY_DIRS ... the paths of the libraries (w/o the '-L')
<XPREFIX>_LDFLAGS ... all required linker flags
<XPREFIX>_LDFLAGS_OTHER ... all other linker flags
<XPREFIX>_INCLUDE_DIRS ... the '-I' preprocessor flags (w/o the '-I')
<XPREFIX>_CFLAGS ... all required cflags
<XPREFIX>_CFLAGS_OTHER ... the other compiler flags
::
<XPREFIX> = <PREFIX> for common case
<XPREFIX> = <PREFIX>_STATIC for static linking
There are some special variables whose prefix depends on the count of
given modules. When there is only one module, <PREFIX> stays
unchanged. When there are multiple modules, the prefix will be
changed to <PREFIX>_<MODNAME>: ::
<XPREFIX>_VERSION ... version of the module
<XPREFIX>_PREFIX ... prefix-directory of the module
<XPREFIX>_INCLUDEDIR ... include-dir of the module
<XPREFIX>_LIBDIR ... lib-dir of the module
::
<XPREFIX> = <PREFIX> when |MODULES| == 1, else
<XPREFIX> = <PREFIX>_<MODNAME>
A <MODULE> parameter can have the following formats: ::
{MODNAME} ... matches any version
{MODNAME}>={VERSION} ... at least version <VERSION> is required
{MODNAME}={VERSION} ... exactly version <VERSION> is required
{MODNAME}<={VERSION} ... modules must not be newer than <VERSION>
Examples
.. code-block:: cmake
pkg_check_modules (GLIB2 glib-2.0)
.. code-block:: cmake
pkg_check_modules (GLIB2 glib-2.0>=2.10)
Requires at least version 2.10 of glib2 and defines e.g.
``GLIB2_VERSION=2.10.3``
.. code-block:: cmake
pkg_check_modules (FOO glib-2.0>=2.10 gtk+-2.0)
Requires both glib2 and gtk2, and defines e.g.
``FOO_glib-2.0_VERSION=2.10.3`` and ``FOO_gtk+-2.0_VERSION=2.8.20``
.. code-block:: cmake
pkg_check_modules (XRENDER REQUIRED xrender)
Defines e.g.:
``XRENDER_LIBRARIES=Xrender;X11`` and
``XRENDER_STATIC_LIBRARIES=Xrender;X11;pthread;Xau;Xdmcp``
#]========================================]
macro(pkg_check_modules _prefix _module0)
# check cached value
if (NOT DEFINED __pkg_config_checked_${_prefix} OR __pkg_config_checked_${_prefix} LESS ${PKG_CONFIG_VERSION} OR NOT ${_prefix}_FOUND)
_pkgconfig_parse_options (_pkg_modules _pkg_is_required _pkg_is_silent _no_cmake_path _no_cmake_environment_path "${_module0}" ${ARGN})
_pkg_check_modules_internal("${_pkg_is_required}" "${_pkg_is_silent}" ${_no_cmake_path} ${_no_cmake_environment_path} "${_prefix}" ${_pkg_modules})
_pkgconfig_set(__pkg_config_checked_${_prefix} ${PKG_CONFIG_VERSION})
endif()
endmacro()
#[========================================[.rst:
.. command:: pkg_search_module
Same as :command:`pkg_check_modules`, but instead it checks for given
modules and uses the first working one. ::
pkg_search_module(<PREFIX> [REQUIRED] [QUIET]
[NO_CMAKE_PATH] [NO_CMAKE_ENVIRONMENT_PATH]
<MODULE> [<MODULE>]*)
Examples
.. code-block:: cmake
pkg_search_module (BAR libxml-2.0 libxml2 libxml>=2)
#]========================================]
macro(pkg_search_module _prefix _module0)
# check cached value
if (NOT DEFINED __pkg_config_checked_${_prefix} OR __pkg_config_checked_${_prefix} LESS ${PKG_CONFIG_VERSION} OR NOT ${_prefix}_FOUND)
set(_pkg_modules_found 0)
_pkgconfig_parse_options(_pkg_modules_alt _pkg_is_required _pkg_is_silent _no_cmake_path _no_cmake_environment_path "${_module0}" ${ARGN})
if (NOT ${_pkg_is_silent})
message(STATUS "checking for one of the modules '${_pkg_modules_alt}'")
endif ()
# iterate through all modules and stop at the first working one.
foreach(_pkg_alt ${_pkg_modules_alt})
if(NOT _pkg_modules_found)
_pkg_check_modules_internal(0 1 ${_no_cmake_path} ${_no_cmake_environment_path} "${_prefix}" "${_pkg_alt}")
endif()
if (${_prefix}_FOUND)
set(_pkg_modules_found 1)
endif()
endforeach()
if (NOT ${_prefix}_FOUND)
if(${_pkg_is_required})
message(SEND_ERROR "None of the required '${_pkg_modules_alt}' found")
endif()
endif()
_pkgconfig_set(__pkg_config_checked_${_prefix} ${PKG_CONFIG_VERSION})
endif()
endmacro()
#[========================================[.rst:
.. variable:: PKG_CONFIG_EXECUTABLE
Path to the pkg-config executable.
.. variable:: PKG_CONFIG_USE_CMAKE_PREFIX_PATH
Whether :command:`pkg_check_modules` and :command:`pkg_search_module`
should add the paths in :variable:`CMAKE_PREFIX_PATH`,
:variable:`CMAKE_FRAMEWORK_PATH`, and :variable:`CMAKE_APPBUNDLE_PATH`
cache and environment variables to ``pkg-config`` search path.
If this variable is not set, this behavior is enabled by default if
:variable:`CMAKE_MINIMUM_REQUIRED_VERSION` is 3.1 or later, disabled
otherwise.
#]========================================]
### Local Variables:
### mode: cmake
### End: