# 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 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 brokes PDB support in STATIC libraries for MSVS
        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()