# Debugging function
function(ocv_cmake_dump_vars)
  cmake_parse_arguments(DUMP "" "TOFILE" "" ${ARGN})
  set(regex "${DUMP_UNPARSED_ARGUMENTS}")
  get_cmake_property(_variableNames VARIABLES)
  set(VARS "")
  foreach(_variableName ${_variableNames})
    if(_variableName MATCHES "${regex}")
      set(VARS "${VARS}${_variableName}=${${_variableName}}\n")
    endif()
  endforeach()
  if(DUMP_TOFILE)
    file(WRITE ${CMAKE_BINARY_DIR}/${DUMP_TOFILE} "${VARS}")
  else()
    message(AUTHOR_WARNING "${VARS}")
  endif()
endfunction()


# Search packages for host system instead of packages for target system
# in case of cross compilation thess macro should be defined by toolchain file
if(NOT COMMAND find_host_package)
  macro(find_host_package)
    find_package(${ARGN})
  endmacro()
endif()
if(NOT COMMAND find_host_program)
  macro(find_host_program)
    find_program(${ARGN})
  endmacro()
endif()

# assert macro
# Note: it doesn't support lists in arguments
# Usage samples:
#   ocv_assert(MyLib_FOUND)
#   ocv_assert(DEFINED MyLib_INCLUDE_DIRS)
macro(ocv_assert)
  if(NOT (${ARGN}))
    string(REPLACE ";" " " __assert_msg "${ARGN}")
    message(AUTHOR_WARNING "Assertion failed: ${__assert_msg}")
  endif()
endmacro()

macro(ocv_debug_message)
#  string(REPLACE ";" " " __msg "${ARGN}")
#  message(STATUS "${__msg}")
endmacro()

macro(ocv_check_environment_variables)
  foreach(_var ${ARGN})
    if(NOT DEFINED ${_var} AND DEFINED ENV{${_var}})
      set(__value "$ENV{${_var}}")
      file(TO_CMAKE_PATH "${__value}" __value) # Assume that we receive paths
      set(${_var} "${__value}")
      message(STATUS "Update variable ${_var} from environment: ${${_var}}")
    endif()
  endforeach()
endmacro()

# rename modules target to world if needed
macro(_ocv_fix_target target_var)
  if(BUILD_opencv_world)
    if(OPENCV_MODULE_${${target_var}}_IS_PART_OF_WORLD)
      set(${target_var} opencv_world)
    endif()
  endif()
endmacro()

# adds include directories in such way that directories from the OpenCV source tree go first
function(ocv_include_directories)
  ocv_debug_message("ocv_include_directories( ${ARGN} )")
  set(__add_before "")
  foreach(dir ${ARGN})
    get_filename_component(__abs_dir "${dir}" ABSOLUTE)
    if("${__abs_dir}" MATCHES "^${OpenCV_SOURCE_DIR}" OR "${__abs_dir}" MATCHES "^${OpenCV_BINARY_DIR}")
      list(APPEND __add_before "${dir}")
    else()
      include_directories(AFTER SYSTEM "${dir}")
    endif()
  endforeach()
  include_directories(BEFORE ${__add_before})
endfunction()

# adds include directories in such way that directories from the OpenCV source tree go first
function(ocv_target_include_directories target)
  _ocv_fix_target(target)
  set(__params "")
  foreach(dir ${ARGN})
    get_filename_component(__abs_dir "${dir}" ABSOLUTE)
    if("${__abs_dir}" MATCHES "^${OpenCV_SOURCE_DIR}" OR "${__abs_dir}" MATCHES "^${OpenCV_BINARY_DIR}")
      list(APPEND __params "${__abs_dir}")
    else()
      list(APPEND __params "${dir}")
    endif()
  endforeach()
  if(HAVE_CUDA OR CMAKE_VERSION VERSION_LESS 2.8.11)
    include_directories(${__params})
  else()
    if(TARGET ${target})
      target_include_directories(${target} PRIVATE ${__params})
    else()
      set(__new_inc "${OCV_TARGET_INCLUDE_DIRS_${target}};${__params}")
      set(OCV_TARGET_INCLUDE_DIRS_${target} "${__new_inc}" CACHE INTERNAL "")
    endif()
  endif()
endfunction()

# clears all passed variables
macro(ocv_clear_vars)
  foreach(_var ${ARGN})
    unset(${_var} CACHE)
  endforeach()
endmacro()

set(OCV_COMPILER_FAIL_REGEX
    "command line option .* is valid for .* but not for C\\+\\+" # GNU
    "command line option .* is valid for .* but not for C" # GNU
    "unrecognized .*option"                     # GNU
    "unknown .*option"                          # Clang
    "ignoring unknown option"                   # MSVC
    "warning D9002"                             # MSVC, any lang
    "option .*not supported"                    # Intel
    "[Uu]nknown option"                         # HP
    "[Ww]arning: [Oo]ption"                     # SunPro
    "command option .* is not recognized"       # XL
    "not supported in this configuration; ignored"       # AIX
    "File with unknown suffix passed to linker" # PGI
    "WARNING: unknown flag:"                    # Open64
  )

MACRO(ocv_check_compiler_flag LANG FLAG RESULT)
  if(NOT DEFINED ${RESULT})
    if("_${LANG}_" MATCHES "_CXX_")
      set(_fname "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.cxx")
      if("${CMAKE_CXX_FLAGS} ${FLAG} " MATCHES "-Werror " OR "${CMAKE_CXX_FLAGS} ${FLAG} " MATCHES "-Werror=unknown-pragmas ")
        FILE(WRITE "${_fname}" "int main() { return 0; }\n")
      else()
        FILE(WRITE "${_fname}" "#pragma\nint main() { return 0; }\n")
      endif()
    elseif("_${LANG}_" MATCHES "_C_")
      set(_fname "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.c")
      if("${CMAKE_C_FLAGS} ${FLAG} " MATCHES "-Werror " OR "${CMAKE_C_FLAGS} ${FLAG} " MATCHES "-Werror=unknown-pragmas ")
        FILE(WRITE "${_fname}" "int main(void) { return 0; }\n")
      else()
        FILE(WRITE "${_fname}" "#pragma\nint main(void) { return 0; }\n")
      endif()
    elseif("_${LANG}_" MATCHES "_OBJCXX_")
      set(_fname "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.mm")
      if("${CMAKE_CXX_FLAGS} ${FLAG} " MATCHES "-Werror " OR "${CMAKE_CXX_FLAGS} ${FLAG} " MATCHES "-Werror=unknown-pragmas ")
        FILE(WRITE "${_fname}" "int main() { return 0; }\n")
      else()
        FILE(WRITE "${_fname}" "#pragma\nint main() { return 0; }\n")
      endif()
    else()
      unset(_fname)
    endif()
    if(_fname)
      MESSAGE(STATUS "Performing Test ${RESULT}")
      TRY_COMPILE(${RESULT}
        "${CMAKE_BINARY_DIR}"
        "${_fname}"
        COMPILE_DEFINITIONS "${FLAG}"
        OUTPUT_VARIABLE OUTPUT)

      FOREACH(_regex ${OCV_COMPILER_FAIL_REGEX})
        IF("${OUTPUT}" MATCHES "${_regex}")
          SET(${RESULT} 0)
          break()
        ENDIF()
      ENDFOREACH()

      IF(${RESULT})
        SET(${RESULT} 1 CACHE INTERNAL "Test ${RESULT}")
        MESSAGE(STATUS "Performing Test ${RESULT} - Success")
      ELSE(${RESULT})
        MESSAGE(STATUS "Performing Test ${RESULT} - Failed")
        SET(${RESULT} "" CACHE INTERNAL "Test ${RESULT}")
      ENDIF(${RESULT})
    else()
      SET(${RESULT} 0)
    endif()
  endif()
ENDMACRO()

macro(ocv_check_flag_support lang flag varname)
  if("_${lang}_" MATCHES "_CXX_")
    set(_lang CXX)
  elseif("_${lang}_" MATCHES "_C_")
    set(_lang C)
  elseif("_${lang}_" MATCHES "_OBJCXX_")
    set(_lang OBJCXX)
  else()
    set(_lang ${lang})
  endif()

  string(TOUPPER "${flag}" ${varname})
  string(REGEX REPLACE "^(/|-)" "HAVE_${_lang}_" ${varname} "${${varname}}")
  string(REGEX REPLACE " -|-|=| |\\." "_" ${varname} "${${varname}}")

  ocv_check_compiler_flag("${_lang}" "${ARGN} ${flag}" ${${varname}})
endmacro()

# turns off warnings
macro(ocv_warnings_disable)
  if(NOT ENABLE_NOISY_WARNINGS)
    set(_flag_vars "")
    set(_msvc_warnings "")
    set(_gxx_warnings "")
    foreach(arg ${ARGN})
      if(arg MATCHES "^CMAKE_")
        list(APPEND _flag_vars ${arg})
      elseif(arg MATCHES "^/wd")
        list(APPEND _msvc_warnings ${arg})
      elseif(arg MATCHES "^-W")
        list(APPEND _gxx_warnings ${arg})
      endif()
    endforeach()
    if(MSVC AND _msvc_warnings AND _flag_vars)
      foreach(var ${_flag_vars})
        foreach(warning ${_msvc_warnings})
          set(${var} "${${var}} ${warning}")
        endforeach()
      endforeach()
    elseif((CMAKE_COMPILER_IS_GNUCXX OR (UNIX AND CV_ICC)) AND _gxx_warnings AND _flag_vars)
      foreach(var ${_flag_vars})
        foreach(warning ${_gxx_warnings})
          if(NOT warning MATCHES "^-Wno-")
            string(REPLACE "${warning}" "" ${var} "${${var}}")
            string(REPLACE "-W" "-Wno-" warning "${warning}")
          endif()
          ocv_check_flag_support(${var} "${warning}" _varname)
          if(${_varname})
            set(${var} "${${var}} ${warning}")
          endif()
        endforeach()
      endforeach()
    endif()
    unset(_flag_vars)
    unset(_msvc_warnings)
    unset(_gxx_warnings)
  endif(NOT ENABLE_NOISY_WARNINGS)
endmacro()

macro(add_apple_compiler_options the_module)
  ocv_check_flag_support(OBJCXX "-fobjc-exceptions" HAVE_OBJC_EXCEPTIONS)
  if(HAVE_OBJC_EXCEPTIONS)
    foreach(source ${OPENCV_MODULE_${the_module}_SOURCES})
      if("${source}" MATCHES "\\.mm$")
        get_source_file_property(flags "${source}" COMPILE_FLAGS)
        if(flags)
          set(flags "${_flags} -fobjc-exceptions")
        else()
          set(flags "-fobjc-exceptions")
        endif()

        set_source_files_properties("${source}" PROPERTIES COMPILE_FLAGS "${flags}")
      endif()
    endforeach()
  endif()
endmacro()

# Provides an option that the user can optionally select.
# Can accept condition to control when option is available for user.
# Usage:
#   option(<option_variable> "help string describing the option" <initial value or boolean expression> [IF <condition>])
macro(OCV_OPTION variable description value)
  set(__value ${value})
  set(__condition "")
  set(__varname "__value")
  foreach(arg ${ARGN})
    if(arg STREQUAL "IF" OR arg STREQUAL "if")
      set(__varname "__condition")
    else()
      list(APPEND ${__varname} ${arg})
    endif()
  endforeach()
  unset(__varname)
  if(__condition STREQUAL "")
    set(__condition 2 GREATER 1)
  endif()

  if(${__condition})
    if(__value MATCHES ";")
      if(${__value})
        option(${variable} "${description}" ON)
      else()
        option(${variable} "${description}" OFF)
      endif()
    elseif(DEFINED ${__value})
      if(${__value})
        option(${variable} "${description}" ON)
      else()
        option(${variable} "${description}" OFF)
      endif()
    else()
      option(${variable} "${description}" ${__value})
    endif()
  else()
    unset(${variable} CACHE)
  endif()
  unset(__condition)
  unset(__value)
endmacro()


# Macros that checks if module have been installed.
# After it adds module to build and define
# constants passed as second arg
macro(CHECK_MODULE module_name define)
  set(${define} 0)
  if(PKG_CONFIG_FOUND)
    set(ALIAS               ALIASOF_${module_name})
    set(ALIAS_FOUND                 ${ALIAS}_FOUND)
    set(ALIAS_INCLUDE_DIRS   ${ALIAS}_INCLUDE_DIRS)
    set(ALIAS_LIBRARY_DIRS   ${ALIAS}_LIBRARY_DIRS)
    set(ALIAS_LIBRARIES         ${ALIAS}_LIBRARIES)

    PKG_CHECK_MODULES(${ALIAS} ${module_name})

    if(${ALIAS_FOUND})
      set(${define} 1)
      foreach(P "${ALIAS_INCLUDE_DIRS}")
        if(${P})
          list(APPEND VIDEOIO_INCLUDE_DIRS ${${P}})
          list(APPEND HIGHGUI_INCLUDE_DIRS ${${P}})
        endif()
      endforeach()

      foreach(P "${ALIAS_LIBRARY_DIRS}")
        if(${P})
          list(APPEND VIDEOIO_LIBRARY_DIRS ${${P}})
          list(APPEND HIGHGUI_LIBRARY_DIRS ${${P}})
        endif()
      endforeach()

      list(APPEND VIDEOIO_LIBRARIES ${${ALIAS_LIBRARIES}})
      list(APPEND HIGHGUI_LIBRARIES ${${ALIAS_LIBRARIES}})
    endif()
  endif()
endmacro()


set(OPENCV_BUILD_INFO_FILE "${OpenCV_BINARY_DIR}/version_string.tmp")
file(REMOVE "${OPENCV_BUILD_INFO_FILE}")
function(ocv_output_status msg)
  message(STATUS "${msg}")
  string(REPLACE "\\" "\\\\" msg "${msg}")
  string(REPLACE "\"" "\\\"" msg "${msg}")
  file(APPEND "${OPENCV_BUILD_INFO_FILE}" "\"${msg}\\n\"\n")
endfunction()

macro(ocv_finalize_status)
  if(NOT OPENCV_SKIP_STATUS_FINALIZATION)
    if(DEFINED OPENCV_MODULE_opencv_core_BINARY_DIR)
      execute_process(COMMAND ${CMAKE_COMMAND} -E copy_if_different "${OPENCV_BUILD_INFO_FILE}" "${OPENCV_MODULE_opencv_core_BINARY_DIR}/version_string.inc" OUTPUT_QUIET)
    endif()
  endif()
endmacro()


# Status report function.
# Automatically align right column and selects text based on condition.
# Usage:
#   status(<text>)
#   status(<heading> <value1> [<value2> ...])
#   status(<heading> <condition> THEN <text for TRUE> ELSE <text for FALSE> )
function(status text)
  set(status_cond)
  set(status_then)
  set(status_else)

  set(status_current_name "cond")
  foreach(arg ${ARGN})
    if(arg STREQUAL "THEN")
      set(status_current_name "then")
    elseif(arg STREQUAL "ELSE")
      set(status_current_name "else")
    else()
      list(APPEND status_${status_current_name} ${arg})
    endif()
  endforeach()

  if(DEFINED status_cond)
    set(status_placeholder_length 32)
    string(RANDOM LENGTH ${status_placeholder_length} ALPHABET " " status_placeholder)
    string(LENGTH "${text}" status_text_length)
    if(status_text_length LESS status_placeholder_length)
      string(SUBSTRING "${text}${status_placeholder}" 0 ${status_placeholder_length} status_text)
    elseif(DEFINED status_then OR DEFINED status_else)
      ocv_output_status("${text}")
      set(status_text "${status_placeholder}")
    else()
      set(status_text "${text}")
    endif()

    if(DEFINED status_then OR DEFINED status_else)
      if(${status_cond})
        string(REPLACE ";" " " status_then "${status_then}")
        string(REGEX REPLACE "^[ \t]+" "" status_then "${status_then}")
        ocv_output_status("${status_text} ${status_then}")
      else()
        string(REPLACE ";" " " status_else "${status_else}")
        string(REGEX REPLACE "^[ \t]+" "" status_else "${status_else}")
        ocv_output_status("${status_text} ${status_else}")
      endif()
    else()
      string(REPLACE ";" " " status_cond "${status_cond}")
      string(REGEX REPLACE "^[ \t]+" "" status_cond "${status_cond}")
      ocv_output_status("${status_text} ${status_cond}")
    endif()
  else()
    ocv_output_status("${text}")
  endif()
endfunction()


# remove all matching elements from the list
macro(ocv_list_filterout lst regex)
  foreach(item ${${lst}})
    if(item MATCHES "${regex}")
      list(REMOVE_ITEM ${lst} "${item}")
    endif()
  endforeach()
endmacro()


# stable & safe duplicates removal macro
macro(ocv_list_unique __lst)
  if(${__lst})
    list(REMOVE_DUPLICATES ${__lst})
  endif()
endmacro()


# safe list reversal macro
macro(ocv_list_reverse __lst)
  if(${__lst})
    list(REVERSE ${__lst})
  endif()
endmacro()


# safe list sorting macro
macro(ocv_list_sort __lst)
  if(${__lst})
    list(SORT ${__lst})
  endif()
endmacro()


# add prefix to each item in the list
macro(ocv_list_add_prefix LST PREFIX)
  set(__tmp "")
  foreach(item ${${LST}})
    list(APPEND __tmp "${PREFIX}${item}")
  endforeach()
  set(${LST} ${__tmp})
  unset(__tmp)
endmacro()


# add suffix to each item in the list
macro(ocv_list_add_suffix LST SUFFIX)
  set(__tmp "")
  foreach(item ${${LST}})
    list(APPEND __tmp "${item}${SUFFIX}")
  endforeach()
  set(${LST} ${__tmp})
  unset(__tmp)
endmacro()


# gets and removes the first element from list
macro(ocv_list_pop_front LST VAR)
  if(${LST})
    list(GET ${LST} 0 ${VAR})
    list(REMOVE_AT ${LST} 0)
  else()
    set(${VAR} "")
  endif()
endmacro()


# simple regex escaping routine (does not cover all cases!!!)
macro(ocv_regex_escape var regex)
  string(REGEX REPLACE "([+.*^$])" "\\\\1" ${var} "${regex}")
endmacro()


# convert list of paths to full paths
macro(ocv_convert_to_full_paths VAR)
  if(${VAR})
    set(__tmp "")
    foreach(path ${${VAR}})
      get_filename_component(${VAR} "${path}" ABSOLUTE)
      list(APPEND __tmp "${${VAR}}")
    endforeach()
    set(${VAR} ${__tmp})
    unset(__tmp)
  endif()
endmacro()


# convert list of paths to libraries names without lib prefix
macro(ocv_convert_to_lib_name var)
  set(__tmp "")
  foreach(path ${ARGN})
    get_filename_component(__tmp_name "${path}" NAME_WE)
    string(REGEX REPLACE "^lib" "" __tmp_name ${__tmp_name})
    list(APPEND __tmp "${__tmp_name}")
  endforeach()
  set(${var} ${__tmp})
  unset(__tmp)
  unset(__tmp_name)
endmacro()


# add install command
function(ocv_install_target)
  install(TARGETS ${ARGN})

  set(isPackage 0)
  unset(__package)
  unset(__target)
  foreach(e ${ARGN})
    if(NOT DEFINED __target)
      set(__target "${e}")
    endif()
    if(isPackage EQUAL 1)
      set(__package "${e}")
      break()
    endif()
    if(e STREQUAL "EXPORT")
      set(isPackage 1)
    endif()
  endforeach()

  if(DEFINED __package)
    list(APPEND ${__package}_TARGETS ${__target})
    set(${__package}_TARGETS "${${__package}_TARGETS}" CACHE INTERNAL "List of ${__package} targets")
  endif()

  if(INSTALL_CREATE_DISTRIB)
    if(MSVC AND NOT BUILD_SHARED_LIBS)
      set(__target "${ARGV0}")

      set(isArchive 0)
      set(isDst 0)
      unset(__dst)
      foreach(e ${ARGN})
        if(isDst EQUAL 1)
          set(__dst "${e}")
          break()
        endif()
        if(isArchive EQUAL 1 AND e STREQUAL "DESTINATION")
          set(isDst 1)
        endif()
        if(e STREQUAL "ARCHIVE")
          set(isArchive 1)
        else()
          set(isArchive 0)
        endif()
      endforeach()

#      message(STATUS "Process ${__target} dst=${__dst}...")
      if(DEFINED __dst)
        # If CMake version is >=3.1.0 or <2.8.12.
        if(NOT CMAKE_VERSION VERSION_LESS 3.1.0 OR CMAKE_VERSION VERSION_LESS 2.8.12)
          get_target_property(fname ${__target} LOCATION_DEBUG)
          if(fname MATCHES "\\.lib$")
            string(REGEX REPLACE "\\.lib$" ".pdb" fname "${fname}")
            install(FILES "${fname}" DESTINATION "${__dst}" CONFIGURATIONS Debug)
          endif()

          get_target_property(fname ${__target} LOCATION_RELEASE)
          if(fname MATCHES "\\.lib$")
            string(REGEX REPLACE "\\.lib$" ".pdb" fname "${fname}")
            install(FILES "${fname}" DESTINATION "${__dst}" CONFIGURATIONS Release)
          endif()
        else()
          # CMake 2.8.12 broke PDB support for STATIC libraries from MSVS, fix was introduced in CMake 3.1.0.
          message(WARNING "PDB's are not supported from this version of CMake, use CMake version later then 3.1.0 or before 2.8.12.")
        endif()
      endif()
    endif()
  endif()
endfunction()


# read set of version defines from the header file
macro(ocv_parse_header FILENAME FILE_VAR)
  set(vars_regex "")
  set(__parnet_scope OFF)
  set(__add_cache OFF)
  foreach(name ${ARGN})
    if("${name}" STREQUAL "PARENT_SCOPE")
      set(__parnet_scope ON)
    elseif("${name}" STREQUAL "CACHE")
      set(__add_cache ON)
    elseif(vars_regex)
      set(vars_regex "${vars_regex}|${name}")
    else()
      set(vars_regex "${name}")
    endif()
  endforeach()
  if(EXISTS "${FILENAME}")
    file(STRINGS "${FILENAME}" ${FILE_VAR} REGEX "#define[ \t]+(${vars_regex})[ \t]+[0-9]+" )
  else()
    unset(${FILE_VAR})
  endif()
  foreach(name ${ARGN})
    if(NOT "${name}" STREQUAL "PARENT_SCOPE" AND NOT "${name}" STREQUAL "CACHE")
      if(${FILE_VAR})
        if(${FILE_VAR} MATCHES ".+[ \t]${name}[ \t]+([0-9]+).*")
          string(REGEX REPLACE ".+[ \t]${name}[ \t]+([0-9]+).*" "\\1" ${name} "${${FILE_VAR}}")
        else()
          set(${name} "")
        endif()
        if(__add_cache)
          set(${name} ${${name}} CACHE INTERNAL "${name} parsed from ${FILENAME}" FORCE)
        elseif(__parnet_scope)
          set(${name} "${${name}}" PARENT_SCOPE)
        endif()
      else()
        unset(${name} CACHE)
      endif()
    endif()
  endforeach()
endmacro()

# read single version define from the header file
macro(ocv_parse_header2 LIBNAME HDR_PATH VARNAME)
  ocv_clear_vars(${LIBNAME}_VERSION_MAJOR
                 ${LIBNAME}_VERSION_MAJOR
                 ${LIBNAME}_VERSION_MINOR
                 ${LIBNAME}_VERSION_PATCH
                 ${LIBNAME}_VERSION_TWEAK
                 ${LIBNAME}_VERSION_STRING)
  set(${LIBNAME}_H "")
  if(EXISTS "${HDR_PATH}")
    file(STRINGS "${HDR_PATH}" ${LIBNAME}_H REGEX "^#define[ \t]+${VARNAME}[ \t]+\"[^\"]*\".*$" LIMIT_COUNT 1)
  endif()

  if(${LIBNAME}_H)
    string(REGEX REPLACE "^.*[ \t]${VARNAME}[ \t]+\"([0-9]+).*$" "\\1" ${LIBNAME}_VERSION_MAJOR "${${LIBNAME}_H}")
    string(REGEX REPLACE "^.*[ \t]${VARNAME}[ \t]+\"[0-9]+\\.([0-9]+).*$" "\\1" ${LIBNAME}_VERSION_MINOR  "${${LIBNAME}_H}")
    string(REGEX REPLACE "^.*[ \t]${VARNAME}[ \t]+\"[0-9]+\\.[0-9]+\\.([0-9]+).*$" "\\1" ${LIBNAME}_VERSION_PATCH "${${LIBNAME}_H}")
    set(${LIBNAME}_VERSION_MAJOR ${${LIBNAME}_VERSION_MAJOR} ${ARGN})
    set(${LIBNAME}_VERSION_MINOR ${${LIBNAME}_VERSION_MINOR} ${ARGN})
    set(${LIBNAME}_VERSION_PATCH ${${LIBNAME}_VERSION_PATCH} ${ARGN})
    set(${LIBNAME}_VERSION_STRING "${${LIBNAME}_VERSION_MAJOR}.${${LIBNAME}_VERSION_MINOR}.${${LIBNAME}_VERSION_PATCH}")

    # append a TWEAK version if it exists:
    set(${LIBNAME}_VERSION_TWEAK "")
    if("${${LIBNAME}_H}" MATCHES "^.*[ \t]${VARNAME}[ \t]+\"[0-9]+\\.[0-9]+\\.[0-9]+\\.([0-9]+).*$")
      set(${LIBNAME}_VERSION_TWEAK "${CMAKE_MATCH_1}" ${ARGN})
    endif()
    if(${LIBNAME}_VERSION_TWEAK)
      set(${LIBNAME}_VERSION_STRING "${${LIBNAME}_VERSION_STRING}.${${LIBNAME}_VERSION_TWEAK}" ${ARGN})
    else()
      set(${LIBNAME}_VERSION_STRING "${${LIBNAME}_VERSION_STRING}" ${ARGN})
    endif()
  endif()
endmacro()

# read single version info from the pkg file
macro(ocv_parse_pkg LIBNAME PKG_PATH SCOPE)
  if(EXISTS "${PKG_PATH}/${LIBNAME}.pc")
    file(STRINGS "${PKG_PATH}/${LIBNAME}.pc" line_to_parse REGEX "^Version:[ \t]+[0-9.]*.*$" LIMIT_COUNT 1)
    STRING(REGEX REPLACE ".*Version: ([^ ]+).*" "\\1" ALIASOF_${LIBNAME}_VERSION "${line_to_parse}" )
  endif()
endmacro()

################################################################################################
# short command to setup source group
function(ocv_source_group group)
  if(BUILD_opencv_world AND OPENCV_MODULE_${the_module}_IS_PART_OF_WORLD)
    set(group "${the_module}\\${group}")
  endif()
  cmake_parse_arguments(SG "" "DIRBASE" "GLOB;GLOB_RECURSE;FILES" ${ARGN})
  set(files "")
  if(SG_FILES)
    list(APPEND files ${SG_FILES})
  endif()
  if(SG_GLOB)
    file(GLOB srcs ${SG_GLOB})
    list(APPEND files ${srcs})
  endif()
  if(SG_GLOB_RECURSE)
    file(GLOB_RECURSE srcs ${SG_GLOB_RECURSE})
    list(APPEND files ${srcs})
  endif()
  if(SG_DIRBASE)
    foreach(f ${files})
      file(RELATIVE_PATH fpart "${SG_DIRBASE}" "${f}")
      if(fpart MATCHES "^\\.\\.")
        message(AUTHOR_WARNING "Can't detect subpath for source_group command: Group=${group} FILE=${f} DIRBASE=${SG_DIRBASE}")
        set(fpart "")
      else()
        get_filename_component(fpart "${fpart}" PATH)
        if(fpart)
          set(fpart "/${fpart}") # add '/'
          string(REPLACE "/" "\\" fpart "${fpart}")
        endif()
      endif()
      source_group("${group}${fpart}" FILES ${f})
    endforeach()
  else()
    source_group(${group} FILES ${files})
  endif()
endfunction()

function(ocv_target_link_libraries target)
  _ocv_fix_target(target)
  set(LINK_DEPS ${ARGN})
  # process world
  if(BUILD_opencv_world)
    foreach(m ${OPENCV_MODULES_BUILD})
      if(OPENCV_MODULE_${m}_IS_PART_OF_WORLD)
        if(";${LINK_DEPS};" MATCHES ";${m};")
          list(REMOVE_ITEM LINK_DEPS ${m})
          if(NOT (";${LINK_DEPS};" MATCHES ";opencv_world;"))
            list(APPEND LINK_DEPS opencv_world)
          endif()
        endif()
      endif()
    endforeach()
  endif()
  target_link_libraries(${target} ${LINK_DEPS})
endfunction()

function(_ocv_append_target_includes target)
  if(DEFINED OCV_TARGET_INCLUDE_DIRS_${target})
    target_include_directories(${target} PRIVATE ${OCV_TARGET_INCLUDE_DIRS_${target}})
    if (TARGET ${target}_object)
      target_include_directories(${target}_object PRIVATE ${OCV_TARGET_INCLUDE_DIRS_${target}})
    endif()
    unset(OCV_TARGET_INCLUDE_DIRS_${target} CACHE)
  endif()
endfunction()

function(ocv_add_executable target)
  add_executable(${target} ${ARGN})
  _ocv_append_target_includes(${target})
endfunction()

function(ocv_add_library target)
  set(cuda_objs "")
  if(HAVE_CUDA)
    set(cuda_srcs "")

    foreach(var ${ARGN})
      if(var MATCHES ".cu")
        list(APPEND cuda_srcs ${var})
      endif()
    endforeach()

    if(cuda_srcs)
      ocv_include_directories(${CUDA_INCLUDE_DIRS})
      ocv_cuda_compile(cuda_objs ${lib_cuda_srcs} ${lib_cuda_hdrs})
    endif()
    set(OPENCV_MODULE_${target}_CUDA_OBJECTS ${cuda_objs} CACHE INTERNAL "Compiled CUDA object files")
  endif()

  add_library(${target} ${ARGN} ${cuda_objs})

  # Add OBJECT library (added in cmake 2.8.8) to use in compound modules
  if (NOT CMAKE_VERSION VERSION_LESS "2.8.8"
      AND NOT OPENCV_MODULE_${target}_CHILDREN
      AND NOT OPENCV_MODULE_${target}_CLASS STREQUAL "BINDINGS"
      AND NOT ${target} STREQUAL "opencv_ts"
    )
    set(sources ${ARGN})
    ocv_list_filterout(sources "\\\\.(cl|inc)$")
    add_library(${target}_object OBJECT ${sources})
    set_target_properties(${target}_object PROPERTIES
      EXCLUDE_FROM_ALL True
      EXCLUDE_FROM_DEFAULT_BUILD True
      POSITION_INDEPENDENT_CODE True
      )
    if (ENABLE_SOLUTION_FOLDERS)
      set_target_properties(${target}_object PROPERTIES FOLDER "object_libraries")
    endif()
    unset(sources)
  endif()

  _ocv_append_target_includes(${target})
endfunction()

# build the list of opencv libs and dependencies for all modules
#  _modules - variable to hold list of all modules
#  _extra - variable to hold list of extra dependencies
#  _3rdparty - variable to hold list of prebuilt 3rdparty libraries
macro(ocv_get_all_libs _modules _extra _3rdparty)
  set(${_modules} "")
  set(${_extra} "")
  set(${_3rdparty} "")
  foreach(m ${OPENCV_MODULES_PUBLIC})
    if(TARGET ${m})
      get_target_property(deps ${m} INTERFACE_LINK_LIBRARIES)
      if(NOT deps)
        set(deps "")
      endif()
    else()
      set(deps "")
    endif()
    list(INSERT ${_modules} 0 ${deps} ${m})
    foreach (dep ${deps} ${OPENCV_LINKER_LIBS})
      if (NOT DEFINED OPENCV_MODULE_${dep}_LOCATION)
        if (TARGET ${dep})
          get_target_property(_output ${dep} ARCHIVE_OUTPUT_DIRECTORY)
          if ("${_output}" STREQUAL "${3P_LIBRARY_OUTPUT_PATH}")
            list(INSERT ${_3rdparty} 0 ${dep})
          else()
            list(INSERT ${_extra} 0 ${dep})
          endif()
        else()
          list(INSERT ${_extra} 0 ${dep})
        endif()
      endif()
    endforeach()
  endforeach()

  # ippicv specific handling
  list(FIND ${_extra} "ippicv" ippicv_idx)
  if (${ippicv_idx} GREATER -1)
    list(REMOVE_ITEM ${_extra} "ippicv")
    list(INSERT ${_3rdparty} 0 "ippicv")
  endif()

  # split 3rdparty libs and modules
  list(REMOVE_ITEM ${_modules} ${${_3rdparty}} ${${_extra}} non_empty_list)

  # convert CMake lists to makefile literals
  foreach(lst ${_modules} ${_3rdparty} ${_extra})
    ocv_list_unique(${lst})
    ocv_list_reverse(${lst})
  endforeach()
endmacro()

function(ocv_download)
  cmake_parse_arguments(DL "" "PACKAGE;HASH;URL;DESTINATION_DIR;DOWNLOAD_DIR" "" ${ARGN})
  if(NOT DL_DOWNLOAD_DIR)
    set(DL_DOWNLOAD_DIR "${DL_DESTINATION_DIR}/downloads")
  endif()
  if(DEFINED DL_DESTINATION_DIR)
    set(DESTINATION_TARGET "${DL_DESTINATION_DIR}/${DL_PACKAGE}")
    if(EXISTS "${DESTINATION_TARGET}")
      file(MD5 "${DESTINATION_TARGET}" target_md5)
      if(NOT target_md5 STREQUAL DL_HASH)
        file(REMOVE "${DESTINATION_TARGET}")
      else()
        set(DOWNLOAD_PACKAGE_LOCATION "" PARENT_SCOPE)
        unset(DOWNLOAD_PACKAGE_LOCATION)
        return()
      endif()
    endif()
  endif()
  set(DOWNLOAD_TARGET "${DL_DOWNLOAD_DIR}/${DL_HASH}/${DL_PACKAGE}")
  get_filename_component(DOWNLOAD_TARGET_DIR "${DOWNLOAD_TARGET}" PATH)
  if(EXISTS "${DOWNLOAD_TARGET}")
    file(MD5 "${DOWNLOAD_TARGET}" target_md5)
    if(NOT target_md5 STREQUAL DL_HASH)
      message(WARNING "Download: Local copy of ${DL_PACKAGE} has invalid MD5 hash: ${target_md5} (expected: ${DL_HASH})")
      file(REMOVE "${DOWNLOAD_TARGET}")
      file(REMOVE_RECURSE "${DOWNLOAD_TARGET_DIR}")
    endif()
  endif()

  if(NOT EXISTS "${DOWNLOAD_TARGET}")
    set(__url "")
    foreach(__url_i ${DL_URL})
      if(NOT ("${__url_i}" STREQUAL ""))
        set(__url "${__url_i}")
        break()
      endif()
    endforeach()
    if("${__url}" STREQUAL "")
      message(FATAL_ERROR "Download URL is not specified for package ${DL_PACKAGE}")
    endif()

    if(NOT EXISTS "${DOWNLOAD_TARGET_DIR}")
      file(MAKE_DIRECTORY ${DOWNLOAD_TARGET_DIR})
    endif()
    message(STATUS "Downloading ${DL_PACKAGE}...")
    #message(STATUS "    ${__url}${DL_PACKAGE}")
    file(DOWNLOAD "${__url}${DL_PACKAGE}" "${DOWNLOAD_TARGET}"
         TIMEOUT 600 STATUS __status
         EXPECTED_MD5 ${DL_HASH})
    if(NOT __status EQUAL 0)
      message(FATAL_ERROR "Failed to download ${DL_PACKAGE}. Status=${__status}")
    else()
      # Don't remove this code, because EXPECTED_MD5 parameter doesn't fail "file(DOWNLOAD)" step on wrong hash
      file(MD5 "${DOWNLOAD_TARGET}" target_md5)
      if(NOT target_md5 STREQUAL DL_HASH)
        message(FATAL_ERROR "Downloaded copy of ${DL_PACKAGE} has invalid MD5 hash: ${target_md5} (expected: ${DL_HASH})")
      endif()
    endif()
    message(STATUS "Downloading ${DL_PACKAGE}... Done")
  endif()

  if(DEFINED DL_DESTINATION_DIR)
    execute_process(COMMAND ${CMAKE_COMMAND} -E copy_if_different "${DOWNLOAD_TARGET}" "${DL_DESTINATION_DIR}/"
                    RESULT_VARIABLE __result)

    if(NOT __result EQUAL 0)
      message(FATAL_ERROR "Downloader: Failed to copy package from ${DOWNLOAD_TARGET} to ${DL_DESTINATION_DIR} with error ${__result}")
    endif()
  endif()

  set(DOWNLOAD_PACKAGE_LOCATION ${DOWNLOAD_TARGET} PARENT_SCOPE)
endfunction()

function(ocv_add_test_from_target test_name test_kind the_target)
  if(CMAKE_VERSION VERSION_GREATER "2.8" AND NOT CMAKE_CROSSCOMPILING)
    if(NOT "${test_kind}" MATCHES "^(Accuracy|Performance|Sanity)$")
      message(FATAL_ERROR "Unknown test kind : ${test_kind}")
    endif()
    if(NOT TARGET "${the_target}")
      message(FATAL_ERROR "${the_target} is not a CMake target")
    endif()

    string(TOLOWER "${test_kind}" test_kind_lower)
    set(test_report_dir "${CMAKE_BINARY_DIR}/test-reports/${test_kind_lower}")
    file(MAKE_DIRECTORY "${test_report_dir}")

    add_test(NAME "${test_name}"
      COMMAND "${the_target}"
              "--gtest_output=xml:${the_target}.xml"
              ${ARGN})

    set_tests_properties("${test_name}" PROPERTIES
      LABELS "${OPENCV_MODULE_${the_module}_LABEL};${test_kind}"
      WORKING_DIRECTORY "${test_report_dir}")

    if(OPENCV_TEST_DATA_PATH)
      set_tests_properties("${test_name}" PROPERTIES
        ENVIRONMENT "OPENCV_TEST_DATA_PATH=${OPENCV_TEST_DATA_PATH}")
    endif()
  endif()
endfunction()