# pkg_check_variable() - a function to retrieve pkg-config variables in CMake

#

# source: http://bloerg.net/2015/03/06/pkg-config-variables-in-cmake.html

find_package(PkgConfig REQUIRED)

function(pkg_check_variable _pkg _name)

string(TOUPPER ${_pkg} _pkg_upper)

string(TOUPPER ${_name} _name_upper)

string(REPLACE "-" "_" _pkg_upper ${_pkg_upper})

string(REPLACE "-" "_" _name_upper ${_name_upper})

set(_output_name "${_pkg_upper}_${_name_upper}")

execute_process(COMMAND ${PKG_CONFIG_EXECUTABLE} --variable=${_name} ${_pkg}

OUTPUT_VARIABLE _pkg_result

OUTPUT_STRIP_TRAILING_WHITESPACE)

set("${_output_name}" "${_pkg_result}" CACHE STRING "pkg-config variable ${_name} of ${_pkg}")

endfunction()

# Join a cmake list of strings with a given glue character/string

# E.g. join(MY_RESULT, ",", "1; 2; 3;") returns "1, 2, 3"

function(join OUTPUT GLUE)

set(_TMP_RESULT "")

set(_GLUE "") # effective glue is empty at the beginning

foreach(arg ${ARGN})

# Skip empty lines

if(NOT arg STREQUAL "\n")

set(_TMP_RESULT "${_TMP_RESULT}${_GLUE}${arg}")

set(_GLUE "${GLUE}")

endif()

endforeach()

set(${OUTPUT} "${_TMP_RESULT}" PARENT_SCOPE)

endfunction()