# CMake configuration file of gflags project
#
# This CMakeLists.txt defines some gflags specific configuration variables using
# the "gflags_define" utility macro. The default values of these variables can
# be overridden either on the CMake command-line using the -D option of the
# cmake command or in a super-project which includes the gflags source tree by
# setting the GFLAGS_<varname> CMake variables before adding the gflags source
# directory via CMake's "add_subdirectory" command. Only when the non-cached
# variable GFLAGS_IS_SUBPROJECT has a value equivalent to FALSE, these
# configuration variables are added to the CMake cache so they can be edited in
# the CMake GUI. By default, GFLAGS_IS_SUBPROJECT is set to TRUE when the
# CMAKE_SOURCE_DIR is not identical to the directory of this CMakeLists.txt
# file, i.e., the top-level directory of the gflags project source tree.
#
# When this project is a subproject (GFLAGS_IS_SUBPROJECT is TRUE), the default
# settings are such that only the static single-threaded library is built
# without installation of the gflags files. The "gflags::gflags" target is in
# this case an ALIAS library target for the "gflags_nothreads_static" library
# target. Targets which depend on the gflags library should link to the
# "gflags::gflags" library target.
#
# Example CMakeLists.txt of user project which requires separate gflags
# installation: cmake_minimum_required(VERSION 2.8.12 FATAL_ERROR)
#
# project(Foo)
#
# find_package(gflags REQUIRED)
#
# add_executable(foo src/foo.cc) target_link_libraries(foo gflags::gflags)
#
# Example CMakeLists.txt of user project which requires separate single-threaded
# static gflags installation: cmake_minimum_required(VERSION 2.8.12 FATAL_ERROR)
#
# project(Foo)
#
# find_package(gflags COMPONENTS nothreads_static)
#
# add_executable(foo src/foo.cc) target_link_libraries(foo gflags::gflags)
#
# Example CMakeLists.txt of super-project which contains gflags source tree:
# cmake_minimum_required(VERSION 2.8.12 FATAL_ERROR)
#
# project(Foo)
#
# add_subdirectory(gflags)
#
# add_executable(foo src/foo.cc) target_link_libraries(foo gflags::gflags)
#
# Variables to configure the source files: - GFLAGS_IS_A_DLL - GFLAGS_NAMESPACE
# - GFLAGS_ATTRIBUTE_UNUSED - GFLAGS_INTTYPES_FORMAT
#
# Variables to configure the build: - GFLAGS_SOVERSION -
# GFLAGS_BUILD_SHARED_LIBS - GFLAGS_BUILD_STATIC_LIBS - GFLAGS_BUILD_gflags_LIB
# - GFLAGS_BUILD_gflags_nothreads_LIB - GFLAGS_BUILD_TESTING -
# GFLAGS_BUILD_PACKAGING
#
# Variables to configure the installation: - GFLAGS_INCLUDE_DIR -
# GFLAGS_LIBRARY_INSTALL_DIR or LIB_INSTALL_DIR or LIB_SUFFIX -
# GFLAGS_INSTALL_HEADERS - GFLAGS_INSTALL_SHARED_LIBS -
# GFLAGS_INSTALL_STATIC_LIBS

cmake_minimum_required(VERSION 3.0.2 FATAL_ERROR)

if(POLICY CMP0042)
  cmake_policy(SET CMP0042 NEW)
endif()

if(POLICY CMP0048)
  cmake_policy(SET CMP0048 NEW)
endif()

# ----------------------------------------------------------------------------
# includes
include("${CMAKE_CURRENT_SOURCE_DIR}/cmake/utils.cmake")

# ----------------------------------------------------------------------------
# package information
set(PACKAGE_NAME "gflags")
set(PACKAGE_VERSION "2.2.2")
set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
set(PACKAGE_TARNAME "${PACKAGE_NAME}-${PACKAGE_VERSION}")
set(PACKAGE_BUGREPORT "https://github.com/gflags/gflags/issues")
set(PACKAGE_DESCRIPTION
    "A commandline flags library that allows for distributed flags.")
set(PACKAGE_URL "http://gflags.github.io/gflags")

project(
  ${PACKAGE_NAME}
  VERSION ${PACKAGE_VERSION}
  LANGUAGES CXX)
if(CMAKE_VERSION VERSION_LESS 3.4)
  # C language still needed because the following required CMake modules (or
  # their dependencies, respectively) are not correctly handling the case where
  # only CXX is enabled - CheckTypeSize.cmake (fixed in CMake 3.1, cf.
  # https://cmake.org/Bug/view.php?id=14056) - FindThreads.cmake   (fixed in
  # CMake 3.4, cf. https://cmake.org/Bug/view.php?id=14905)
  enable_language(C)
endif()

version_numbers(${PACKAGE_VERSION} PACKAGE_VERSION_MAJOR PACKAGE_VERSION_MINOR
                PACKAGE_VERSION_PATCH)

# shared library ABI version number, can be overridden by package maintainers
# using -DGFLAGS_SOVERSION=XXX on the command-line
if(GFLAGS_SOVERSION)
  set(PACKAGE_SOVERSION "${GFLAGS_SOVERSION}")
else()
  # TODO: Change default SOVERSION back to PACKAGE_VERSION_MAJOR with the next
  # increase of major version number (i.e., 3.0.0 -> SOVERSION 3) The
  # <major>.<minor> SOVERSION should be used for the 2.x releases versions only
  # which temporarily broke the API by changing the default namespace from
  # "google" to "gflags".
  set(PACKAGE_SOVERSION "${PACKAGE_VERSION_MAJOR}.${PACKAGE_VERSION_MINOR}")
endif()

# when gflags is included as subproject (e.g., as Git submodule/subtree) in the
# source tree of a project that uses it, no variables should be added to the
# CMake cache; users may set the non-cached variable GFLAGS_IS_SUBPROJECT before
# add_subdirectory(gflags)
if(NOT DEFINED GFLAGS_IS_SUBPROJECT)
  if("^${CMAKE_SOURCE_DIR}$" STREQUAL "^${PROJECT_SOURCE_DIR}$")
    set(GFLAGS_IS_SUBPROJECT FALSE)
  else()
    set(GFLAGS_IS_SUBPROJECT TRUE)
  endif()
endif()

# prefix for package variables in CMake configuration file
string(TOUPPER "${PACKAGE_NAME}" PACKAGE_PREFIX)

# convert file path on Windows with back slashes to path with forward slashes
# otherwise this causes an issue with the cmake_install.cmake script
file(TO_CMAKE_PATH "${CMAKE_INSTALL_PREFIX}" CMAKE_INSTALL_PREFIX)

# ----------------------------------------------------------------------------
# options

# maintain binary backwards compatibility with gflags library version <= 2.0,
# but at the same time enable the use of the preferred new "gflags" namespace
gflags_define(
  STRING NAMESPACE
  "Name(s) of library namespace (separate multiple options by semicolon)"
  "google;${PACKAGE_NAME}" "${PACKAGE_NAME}")
gflags_property(NAMESPACE ADVANCED TRUE)
set(GFLAGS_NAMESPACE_SECONDARY "${NAMESPACE}")
list(REMOVE_DUPLICATES GFLAGS_NAMESPACE_SECONDARY)
if(NOT GFLAGS_NAMESPACE_SECONDARY)
  message(
    FATAL_ERROR
      "GFLAGS_NAMESPACE must be set to one (or more) valid C++ namespace identifier(s separated by semicolon \";\")."
  )
endif()
foreach(ns IN LISTS GFLAGS_NAMESPACE_SECONDARY)
  if(NOT ns MATCHES "^[a-zA-Z][a-zA-Z0-9_]*$")
    message(
      FATAL_ERROR
        "GFLAGS_NAMESPACE contains invalid namespace identifier: ${ns}")
  endif()
endforeach()
list(GET GFLAGS_NAMESPACE_SECONDARY 0 GFLAGS_NAMESPACE)
list(REMOVE_AT GFLAGS_NAMESPACE_SECONDARY 0)

# cached build options when gflags is not a subproject, otherwise non-cached
# CMake variables usage: gflags_define(BOOL <name> <doc> <default> [<subproject
# default>])
gflags_define(BOOL BUILD_SHARED_LIBS "Request build of shared libraries." OFF
              OFF)
gflags_define(
  BOOL BUILD_STATIC_LIBS
  "Request build of static libraries (default if BUILD_SHARED_LIBS is OFF)."
  OFF ON)
gflags_define(BOOL BUILD_gflags_LIB
              "Request build of the multi-threaded gflags library." ON ON)
gflags_define(BOOL BUILD_gflags_nothreads_LIB
              "Request build of the single-threaded gflags library." OFF OFF)
gflags_define(BOOL BUILD_PACKAGING
              "Enable build of distribution packages using CPack." OFF OFF)
gflags_define(
  BOOL BUILD_TESTING
  "Enable build of the unit tests and their execution using CTest." OFF OFF)
gflags_define(
  BOOL INSTALL_HEADERS
  "Request installation of headers and other development files." OFF OFF)
gflags_define(BOOL INSTALL_SHARED_LIBS
              "Request installation of shared libraries." OFF OFF)
gflags_define(BOOL INSTALL_STATIC_LIBS
              "Request installation of static libraries." OFF OFF)
gflags_define(
  BOOL REGISTER_BUILD_DIR
  "Request entry of build directory in CMake's package registry." ON ON)
gflags_define(
  BOOL REGISTER_INSTALL_PREFIX
  "Request entry of installed package in CMake's package registry." ON OFF)

gflags_property(BUILD_STATIC_LIBS ADVANCED TRUE)
gflags_property(INSTALL_HEADERS ADVANCED TRUE)
gflags_property(INSTALL_SHARED_LIBS ADVANCED TRUE)
gflags_property(INSTALL_STATIC_LIBS ADVANCED TRUE)

if(NOT GFLAGS_IS_SUBPROJECT)
  foreach(varname IN ITEMS CMAKE_INSTALL_PREFIX)
    gflags_property(${varname} ADVANCED FALSE)
  endforeach()
  foreach(varname IN ITEMS CMAKE_CONFIGURATION_TYPES CMAKE_OSX_ARCHITECTURES
                           CMAKE_OSX_DEPLOYMENT_TARGET CMAKE_OSX_SYSROOT)
    gflags_property(${varname} ADVANCED TRUE)
  endforeach()
  if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CXX_FLAGS)
    gflags_set(CMAKE_BUILD_TYPE Release)
  endif()
  if(CMAKE_CONFIGURATION_TYPES)
    gflags_property(CMAKE_BUILD_TYPE STRINGS "${CMAKE_CONFIGURATION_TYPES}")
  endif()
endif() # NOT GFLAGS_IS_SUBPROJECT

if(NOT BUILD_SHARED_LIBS AND NOT BUILD_STATIC_LIBS)
  set(BUILD_STATIC_LIBS ON)
endif()
if(NOT BUILD_gflags_LIB AND NOT BUILD_gflags_nothreads_LIB)
  message(
    FATAL_ERROR
      "At least one of [GFLAGS_]BUILD_gflags_LIB and [GFLAGS_]BUILD_gflags_nothreads_LIB must be ON."
  )
endif()

gflags_define(
  STRING
  INCLUDE_DIR
  "Name of include directory of installed header files relative to CMAKE_INSTALL_PREFIX/include/"
  "${PACKAGE_NAME}")
gflags_property(INCLUDE_DIR ADVANCED TRUE)
file(TO_CMAKE_PATH "${INCLUDE_DIR}" INCLUDE_DIR)
if(IS_ABSOLUTE INCLUDE_DIR)
  message(
    FATAL_ERROR
      "[GFLAGS_]INCLUDE_DIR must be a path relative to CMAKE_INSTALL_PREFIX/include/"
  )
endif()
if(INCLUDE_DIR MATCHES "^\\.\\.[/\\]")
  message(
    FATAL_ERROR
      "[GFLAGS_]INCLUDE_DIR must not start with parent directory reference (../)"
  )
endif()
set(GFLAGS_INCLUDE_DIR "${INCLUDE_DIR}")

# ----------------------------------------------------------------------------
# system checks
include(CheckTypeSize)
include(CheckIncludeFileCXX)
include(CheckCXXSymbolExists)

if(WIN32 AND NOT CYGWIN)
  set(OS_WINDOWS 1)
else()
  set(OS_WINDOWS 0)
endif()

if(MSVC)
  set(HAVE_SYS_TYPES_H 1)
  set(HAVE_STDDEF_H 1) # used by CheckTypeSize module
  set(HAVE_UNISTD_H 0)
  set(HAVE_SYS_STAT_H 1)
  set(HAVE_SHLWAPI_H 1)
  if(MSVC_VERSION VERSION_LESS 1600)
    check_include_file_cxx("stdint.h" HAVE_STDINT_H)
    bool_to_int(HAVE_STDINT_H) # used in #if directive
  else()
    set(HAVE_STDINT_H 1)
  endif()
  if(MSVC_VERSION VERSION_LESS 1800)
    check_include_file_cxx("inttypes.h" HAVE_INTTYPES_H)
    bool_to_int(HAVE_INTTYPES_H) # used in #if directive
  else()
    set(HAVE_INTTYPES_H 1)
  endif()
else()
  foreach(fname IN ITEMS unistd stdint inttypes sys/types sys/stat fnmatch)
    string(TOUPPER "${fname}" FNAME)
    string(REPLACE "/" "_" FNAME "${FNAME}")
    if(NOT HAVE_${FNAME}_H)
      check_include_file_cxx("${fname}.h" HAVE_${FNAME}_H)
    endif()
  endforeach()
  if(NOT HAVE_FNMATCH_H AND OS_WINDOWS)
    check_include_file_cxx("shlwapi.h" HAVE_SHLWAPI_H)
  endif()
  # the following are used in #if directives not #ifdef
  bool_to_int(HAVE_STDINT_H)
  bool_to_int(HAVE_SYS_TYPES_H)
  bool_to_int(HAVE_INTTYPES_H)
endif()

gflags_define(
  STRING
  INTTYPES_FORMAT
  "Format of integer types: \"C99\" (uint32_t), \"BSD\" (u_int32_t), \"VC7\" (__int32)"
  "")
gflags_property(INTTYPES_FORMAT STRINGS "C99;BSD;VC7")
gflags_property(INTTYPES_FORMAT ADVANCED TRUE)
if(NOT INTTYPES_FORMAT)
  set(TYPES uint32_t u_int32_t)
  if(MSVC)
    list(INSERT TYPES 0 __int32)
  endif()
  foreach(type IN LISTS TYPES)
    check_type_size(${type} ${type} LANGUAGE CXX)
    if(HAVE_${type})
      break()
    endif()
  endforeach()
  if(HAVE_uint32_t)
    gflags_set(INTTYPES_FORMAT C99)
  elseif(HAVE_u_int32_t)
    gflags_set(INTTYPES_FORMAT BSD)
  elseif(HAVE___int32)
    gflags_set(INTTYPES_FORMAT VC7)
  else()
    gflags_property(INTTYPES_FORMAT ADVANCED FALSE)
    message(
      FATAL_ERROR
        "Do not know how to define a 32-bit integer quantity on your system!"
        " Neither uint32_t, u_int32_t, nor __int32 seem to be available."
        " Set [GFLAGS_]INTTYPES_FORMAT to either C99, BSD, or VC7 and try again."
    )
  endif()
endif()
# use of special characters in strings to circumvent bug #0008226
if("^${INTTYPES_FORMAT}$" STREQUAL "^WIN$")
  gflags_set(INTTYPES_FORMAT VC7)
endif()
if(NOT INTTYPES_FORMAT MATCHES "^(C99|BSD|VC7)$")
  message(
    FATAL_ERROR
      "Invalid value for [GFLAGS_]INTTYPES_FORMAT! Choose one of \"C99\", \"BSD\", or \"VC7\""
  )
endif()
set(GFLAGS_INTTYPES_FORMAT "${INTTYPES_FORMAT}")
set(GFLAGS_INTTYPES_FORMAT_C99 0)
set(GFLAGS_INTTYPES_FORMAT_BSD 0)
set(GFLAGS_INTTYPES_FORMAT_VC7 0)
set("GFLAGS_INTTYPES_FORMAT_${INTTYPES_FORMAT}" 1)

if(MSVC)
  set(HAVE_strtoll 0)
  set(HAVE_strtoq 0)
else()
  check_cxx_symbol_exists(strtoll stdlib.h HAVE_STRTOLL)
  if(NOT HAVE_STRTOLL)
    check_cxx_symbol_exists(strtoq stdlib.h HAVE_STRTOQ)
  endif()
endif()

if(BUILD_gflags_LIB)
  set(CMAKE_THREAD_PREFER_PTHREAD TRUE)
  find_package(Threads)
  if(Threads_FOUND AND CMAKE_USE_PTHREADS_INIT)
    set(HAVE_PTHREAD 1)
    check_type_size(pthread_rwlock_t RWLOCK LANGUAGE CXX)
  else()
    set(HAVE_PTHREAD 0)
  endif()
  if(UNIX AND NOT HAVE_PTHREAD)
    if(CMAKE_HAVE_PTHREAD_H)
      set(what "library")
    else()
      set(what ".h file")
    endif()
    message(
      FATAL_ERROR
        "Could not find pthread${what}. Check the log file"
        "\n\t${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log"
        "\nor disable the build of the multi-threaded gflags library (BUILD_gflags_LIB=OFF)."
    )
  endif()
else()
  set(HAVE_PTHREAD 0)
endif()

# ----------------------------------------------------------------------------
# source files - excluding root subdirectory and/or .in suffix
set(PUBLIC_HDRS "gflags.h" "gflags_declare.h" "gflags_completions.h")

if(GFLAGS_NAMESPACE_SECONDARY)
  set(INCLUDE_GFLAGS_NS_H
      "// Import gflags library symbols into alternative/deprecated namespace(s)"
  )
  foreach(ns IN LISTS GFLAGS_NAMESPACE_SECONDARY)
    string(TOUPPER "${ns}" NS)
    set(gflags_ns_h
        "${PROJECT_BINARY_DIR}/include/${GFLAGS_INCLUDE_DIR}/gflags_${ns}.h")
    configure_file("${PROJECT_SOURCE_DIR}/src/gflags_ns.h.in" "${gflags_ns_h}"
                   @ONLY)
    list(APPEND PUBLIC_HDRS "${gflags_ns_h}")
    set(INCLUDE_GFLAGS_NS_H
        "${INCLUDE_GFLAGS_NS_H}\n#include \"gflags_${ns}.h\"")
  endforeach()
else()
  set(INCLUDE_GFLAGS_NS_H)
endif()

set(PRIVATE_HDRS "defines.h" "config.h" "util.h" "mutex.h")

set(GFLAGS_SRCS "gflags.cc" "gflags_reporting.cc" "gflags_completions.cc")

if(OS_WINDOWS)
  list(APPEND PRIVATE_HDRS "windows_port.h")
  list(APPEND GFLAGS_SRCS "windows_port.cc")
endif()

# ----------------------------------------------------------------------------
# configure source files
if(NOT DEFINED GFLAGS_ATTRIBUTE_UNUSED)
  if(CMAKE_COMPILER_IS_GNUCXX)
    set(GFLAGS_ATTRIBUTE_UNUSED "__attribute((unused))")
  else()
    set(GFLAGS_ATTRIBUTE_UNUSED)
  endif()
endif()

# whenever we build a shared library (DLL on Windows), configure the public
# headers of the API for use of this shared library rather than the optionally
# also build statically linked library; users can override GFLAGS_DLL_DECL in
# particular, this done by setting the INTERFACE_COMPILE_DEFINITIONS of static
# libraries to include an empty definition for GFLAGS_DLL_DECL
if(NOT DEFINED GFLAGS_IS_A_DLL)
  if(BUILD_SHARED_LIBS)
    set(GFLAGS_IS_A_DLL 1)
  else()
    set(GFLAGS_IS_A_DLL 0)
  endif()
endif()

configure_headers(PUBLIC_HDRS ${PUBLIC_HDRS})
configure_sources(PRIVATE_HDRS ${PRIVATE_HDRS})
configure_sources(GFLAGS_SRCS ${GFLAGS_SRCS})

# ----------------------------------------------------------------------------
# output directories
if(NOT GFLAGS_IS_SUBPROJECT)
  set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "bin")
  set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "lib")
  set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "lib")
endif()
# Set postfixes for generated libraries based on buildtype.
set(CMAKE_RELEASE_POSTFIX "")
set(CMAKE_DEBUG_POSTFIX "_debug")

# ----------------------------------------------------------------------------
# installation directories
if(OS_WINDOWS)
  set(RUNTIME_INSTALL_DIR "bin")
  set(LIBRARY_INSTALL_DIR "lib")
  set(INCLUDE_INSTALL_DIR "include")
  set(CONFIG_INSTALL_DIR "lib/cmake/${PACKAGE_NAME}")
  set(PKGCONFIG_INSTALL_DIR)
else()
  set(RUNTIME_INSTALL_DIR bin)
  # The LIB_INSTALL_DIR and LIB_SUFFIX variables are used by the Fedora package
  # maintainers. Also package maintainers of other distribution packages need to
  # be able to specify the name of the library directory.
  if(NOT GFLAGS_LIBRARY_INSTALL_DIR AND LIB_INSTALL_DIR)
    set(GFLAGS_LIBRARY_INSTALL_DIR "${LIB_INSTALL_DIR}")
  endif()
  gflags_define(
    PATH LIBRARY_INSTALL_DIR
    "Directory of installed libraries, e.g., \"lib64\"" "lib${LIB_SUFFIX}")
  gflags_property(LIBRARY_INSTALL_DIR ADVANCED TRUE)
  set(INCLUDE_INSTALL_DIR include)
  set(CONFIG_INSTALL_DIR ${LIBRARY_INSTALL_DIR}/cmake/${PACKAGE_NAME})
  set(PKGCONFIG_INSTALL_DIR ${LIBRARY_INSTALL_DIR}/pkgconfig)
endif()

# ----------------------------------------------------------------------------
# add library targets
set(TARGETS)
# static vs. shared
foreach(TYPE IN ITEMS STATIC SHARED)
  if(BUILD_${TYPE}_LIBS)
    string(TOLOWER "${TYPE}" type)
    # whether or not targets are a DLL
    if(OS_WINDOWS AND "^${TYPE}$" STREQUAL "^SHARED$")
      set(GFLAGS_IS_A_DLL 1)
    else()
      set(GFLAGS_IS_A_DLL 0)
    endif()
    # filename suffix for static libraries on Windows
    if(OS_WINDOWS AND "^${TYPE}$" STREQUAL "^STATIC$")
      set(type_suffix "_${type}")
    else()
      set(type_suffix "")
    endif()
    # multi-threaded vs. single-threaded
    foreach(opts IN ITEMS "" _nothreads)
      if(BUILD_gflags${opts}_LIB)
        set(target_name "gflags${opts}_${type}")
        add_library(${target_name} ${TYPE} ${GFLAGS_SRCS} ${PRIVATE_HDRS}
                                   ${PUBLIC_HDRS})
        set_target_properties(
          ${target_name}
          PROPERTIES OUTPUT_NAME "gflags${opts}${type_suffix}"
                     VERSION "${PACKAGE_VERSION}"
                     SOVERSION "${PACKAGE_SOVERSION}")
        set(include_dirs "$<BUILD_INTERFACE:${PROJECT_BINARY_DIR}/include>")
        if(INSTALL_HEADERS)
          list(APPEND include_dirs
               "$<INSTALL_INTERFACE:${INCLUDE_INSTALL_DIR}>")
        endif()
        target_include_directories(
          ${target_name}
          PUBLIC "${include_dirs}"
          PRIVATE
            "${PROJECT_SOURCE_DIR}/src;${PROJECT_BINARY_DIR}/include/${GFLAGS_INCLUDE_DIR}"
        )
        target_compile_definitions(${target_name}
                                   PUBLIC GFLAGS_IS_A_DLL=${GFLAGS_IS_A_DLL})
        if(opts MATCHES "nothreads")
          target_compile_definitions(${target_name} PRIVATE NO_THREADS)
        elseif(CMAKE_USE_PTHREADS_INIT)
          target_link_libraries(${target_name} ${CMAKE_THREAD_LIBS_INIT})
        endif()
        if(HAVE_SHLWAPI_H)
          target_link_libraries(${target_name} shlwapi.lib)
        endif()
        list(APPEND TARGETS ${target_name})
        # add convenience make target for build of both shared and static
        # libraries
        if(NOT GFLAGS_IS_SUBPROJECT)
          if(NOT TARGET gflags${opts})
            add_custom_target(gflags${opts})
          endif()
          add_dependencies(gflags${opts} ${target_name})
        endif()
      endif()
    endforeach()
  endif()
endforeach()

# add ALIAS target for use in super-project, prefer static over shared,
# single-threaded over multi-threaded
if(GFLAGS_IS_SUBPROJECT)
  foreach(type IN ITEMS static shared)
    foreach(opts IN ITEMS "_nothreads" "")
      if(TARGET gflags${opts}_${type})
        # Define "gflags" alias for super-projects treating targets of this
        # library as part of their own project (also for backwards compatibility
        # with gflags 2.2.1 which only defined this alias)
        add_library(gflags ALIAS gflags${opts}_${type})
        # Define "gflags::gflags" alias for projects that support both
        # find_package(gflags) and add_subdirectory(gflags)
        add_library(gflags::gflags ALIAS gflags${opts}_${type})
        break()
      endif()
    endforeach()
    if(TARGET gflags::gflags)
      break()
    endif()
  endforeach()
endif()

# ----------------------------------------------------------------------------
# installation rules
set(EXPORT_NAME ${PACKAGE_NAME}-targets)
file(RELATIVE_PATH INSTALL_PREFIX_REL2CONFIG_DIR
     "${CMAKE_INSTALL_PREFIX}/${CONFIG_INSTALL_DIR}" "${CMAKE_INSTALL_PREFIX}")
configure_file(
  cmake/config.cmake.in
  "${PROJECT_BINARY_DIR}/${PACKAGE_NAME}-config-install.cmake" @ONLY)
configure_file(
  cmake/version.cmake.in
  "${PROJECT_BINARY_DIR}/${PACKAGE_NAME}-config-version.cmake" @ONLY)

if(BUILD_SHARED_LIBS AND INSTALL_SHARED_LIBS)
  foreach(opts IN ITEMS "" _nothreads)
    if(BUILD_gflags${opts}_LIB)
      install(
        TARGETS gflags${opts}_shared
        EXPORT ${EXPORT_NAME}
        RUNTIME DESTINATION ${RUNTIME_INSTALL_DIR}
        LIBRARY DESTINATION ${LIBRARY_INSTALL_DIR}
        ARCHIVE DESTINATION ${LIBRARY_INSTALL_DIR})
    endif()
  endforeach()
endif()
if(BUILD_STATIC_LIBS AND INSTALL_STATIC_LIBS)
  foreach(opts IN ITEMS "" _nothreads)
    if(BUILD_gflags${opts}_LIB)
      install(
        TARGETS gflags${opts}_static
        EXPORT ${EXPORT_NAME}
        RUNTIME DESTINATION ${RUNTIME_INSTALL_DIR}
        LIBRARY DESTINATION ${LIBRARY_INSTALL_DIR}
        ARCHIVE DESTINATION ${LIBRARY_INSTALL_DIR})
    endif()
  endforeach()
endif()

if(INSTALL_HEADERS)
  install(FILES ${PUBLIC_HDRS}
          DESTINATION ${INCLUDE_INSTALL_DIR}/${GFLAGS_INCLUDE_DIR})
  install(
    FILES "${PROJECT_BINARY_DIR}/${PACKAGE_NAME}-config-install.cmake"
    RENAME ${PACKAGE_NAME}-config.cmake
    DESTINATION ${CONFIG_INSTALL_DIR})
  install(FILES "${PROJECT_BINARY_DIR}/${PACKAGE_NAME}-config-version.cmake"
          DESTINATION ${CONFIG_INSTALL_DIR})
  install(
    EXPORT ${EXPORT_NAME}
    NAMESPACE ${PACKAGE_NAME}::
    DESTINATION ${CONFIG_INSTALL_DIR})
  install(
    EXPORT ${EXPORT_NAME}
    FILE ${PACKAGE_NAME}-nonamespace-targets.cmake
    DESTINATION ${CONFIG_INSTALL_DIR})
  if(UNIX)
    install(PROGRAMS src/gflags_completions.sh
            DESTINATION ${RUNTIME_INSTALL_DIR})
  endif()
endif()

if(PKGCONFIG_INSTALL_DIR)
  configure_file("cmake/package.pc.in"
                 "${PROJECT_BINARY_DIR}/${PACKAGE_NAME}.pc" @ONLY)
  install(FILES "${PROJECT_BINARY_DIR}/${PACKAGE_NAME}.pc"
          DESTINATION "${PKGCONFIG_INSTALL_DIR}")
endif()

# ----------------------------------------------------------------------------
# support direct use of build tree
set(INSTALL_PREFIX_REL2CONFIG_DIR .)
export(
  TARGETS ${TARGETS}
  NAMESPACE ${PACKAGE_NAME}::
  FILE "${PROJECT_BINARY_DIR}/${EXPORT_NAME}.cmake")
export(TARGETS ${TARGETS}
       FILE "${PROJECT_BINARY_DIR}/${PACKAGE_NAME}-nonamespace-targets.cmake")
if(REGISTER_BUILD_DIR)
  export(PACKAGE ${PACKAGE_NAME})
endif()
if(REGISTER_INSTALL_PREFIX)
  register_gflags_package(${CONFIG_INSTALL_DIR})
endif()
# configure_file(cmake/config.cmake.in
# "${PROJECT_BINARY_DIR}/${PACKAGE_NAME}-config.cmake" @ONLY)

# ----------------------------------------------------------------------------
# testing - MUST follow the generation of the build tree config file
# if(BUILD_TESTING) include(CTest) add_subdirectory(test) endif()

# ----------------------------------------------------------------------------
# packaging
if(BUILD_PACKAGING)

  if(NOT BUILD_SHARED_LIBS AND NOT INSTALL_HEADERS)
    message(
      WARNING "Package will contain static libraries without headers!"
              "\nRecommended options for generation of runtime package:"
              "\n  BUILD_SHARED_LIBS=ON"
              "\n  BUILD_STATIC_LIBS=OFF"
              "\n  INSTALL_HEADERS=OFF"
              "\n  INSTALL_SHARED_LIBS=ON"
              "\nRecommended options for generation of development package:"
              "\n  BUILD_SHARED_LIBS=ON"
              "\n  BUILD_STATIC_LIBS=ON"
              "\n  INSTALL_HEADERS=ON"
              "\n  INSTALL_SHARED_LIBS=ON"
              "\n  INSTALL_STATIC_LIBS=ON")
  endif()

  # default package generators
  if(APPLE)
    set(PACKAGE_GENERATOR "PackageMaker")
    set(PACKAGE_SOURCE_GENERATOR "TGZ;ZIP")
  elseif(UNIX)
    set(PACKAGE_GENERATOR "DEB;RPM")
    set(PACKAGE_SOURCE_GENERATOR "TGZ;ZIP")
  else()
    set(PACKAGE_GENERATOR "ZIP")
    set(PACKAGE_SOURCE_GENERATOR "ZIP")
  endif()

  # used package generators
  set(CPACK_GENERATOR
      "${PACKAGE_GENERATOR}"
      CACHE STRING "List of binary package generators (CPack).")
  set(CPACK_SOURCE_GENERATOR
      "${PACKAGE_SOURCE_GENERATOR}"
      CACHE STRING "List of source package generators (CPack).")
  mark_as_advanced(CPACK_GENERATOR CPACK_SOURCE_GENERATOR)

  # some package generators (e.g., PackageMaker) do not allow .md extension
  configure_file("${CMAKE_CURRENT_LIST_DIR}/README.md"
                 "${CMAKE_CURRENT_BINARY_DIR}/README.txt" COPYONLY)

  # common package information
  set(CPACK_PACKAGE_VENDOR "Andreas Schuh")
  set(CPACK_PACKAGE_CONTACT "google-gflags@googlegroups.com")
  set(CPACK_PACKAGE_NAME "${PACKAGE_NAME}")
  set(CPACK_PACKAGE_VERSION "${PACKAGE_VERSION}")
  set(CPACK_PACKAGE_VERSION_MAJOR "${PACKAGE_VERSION_MAJOR}")
  set(CPACK_PACKAGE_VERSION_MINOR "${PACKAGE_VERSION_MINOR}")
  set(CPACK_PACKAGE_VERSION_PATCH "${PACKAGE_VERSION_PATCH}")
  set(CPACK_PACKAGE_DESCRIPTION_SUMMARY "${PACKAGE_DESCRIPTION}")
  set(CPACK_RESOURCE_FILE_WELCOME "${CMAKE_CURRENT_BINARY_DIR}/README.txt")
  set(CPACK_RESOURCE_FILE_LICENSE "${CMAKE_CURRENT_LIST_DIR}/COPYING.txt")
  set(CPACK_PACKAGE_DESCRIPTION_FILE "${CMAKE_CURRENT_BINARY_DIR}/README.txt")
  set(CPACK_INSTALL_PREFIX "${CMAKE_INSTALL_PREFIX}")
  set(CPACK_OUTPUT_FILE_PREFIX packages)
  set(CPACK_PACKAGE_RELOCATABLE TRUE)
  set(CPACK_MONOLITHIC_INSTALL TRUE)

  # RPM package information -- used in cmake/package.cmake.in also for DEB
  set(CPACK_RPM_PACKAGE_GROUP "Development/Libraries")
  set(CPACK_RPM_PACKAGE_LICENSE "BSD")
  set(CPACK_RPM_PACKAGE_URL "${PACKAGE_URL}")
  set(CPACK_RPM_CHANGELOG_FILE "${CMAKE_CURRENT_LIST_DIR}/ChangeLog.txt")

  if(INSTALL_HEADERS)
    set(CPACK_RESOURCE_FILE_README "${CMAKE_CURRENT_LIST_DIR}/doc/index.html")
  else()
    set(CPACK_RESOURCE_FILE_README
        "${CMAKE_CURRENT_LIST_DIR}/cmake/README_runtime.txt")
  endif()

  # system/architecture
  if(WINDOWS)
    if(CMAKE_CL_64)
      set(CPACK_SYSTEM_NAME "win64")
    else()
      set(CPACK_SYSTEM_NAME "win32")
    endif()
    set(CPACK_PACKAGE_ARCHITECTURE)
  elseif(APPLE)
    set(CPACK_PACKAGE_ARCHITECTURE darwin)
  else()
    string(TOLOWER "${CMAKE_SYSTEM_NAME}" CPACK_SYSTEM_NAME)
    if(CMAKE_CXX_FLAGS MATCHES "-m32")
      set(CPACK_PACKAGE_ARCHITECTURE i386)
    else()
      execute_process(
        COMMAND dpkg --print-architecture
        RESULT_VARIABLE RV
        OUTPUT_VARIABLE CPACK_PACKAGE_ARCHITECTURE)
      if(RV EQUAL 0)
        string(STRIP "${CPACK_PACKAGE_ARCHITECTURE}" CPACK_PACKAGE_ARCHITECTURE)
      else()
        execute_process(COMMAND uname -m
                        OUTPUT_VARIABLE CPACK_PACKAGE_ARCHITECTURE)
        if(CPACK_PACKAGE_ARCHITECTURE MATCHES "x86_64")
          set(CPACK_PACKAGE_ARCHITECTURE amd64)
        else()
          set(CPACK_PACKAGE_ARCHITECTURE i386)
        endif()
      endif()
    endif()
  endif()

  # source package settings
  set(CPACK_SOURCE_TOPLEVEL_TAG "source")
  set(CPACK_SOURCE_PACKAGE_FILE_NAME
      "${CPACK_PACKAGE_NAME}-${CPACK_PACKAGE_VERSION}")
  set(CPACK_SOURCE_IGNORE_FILES
      "/\\\\.git/;\\\\.swp$;\\\\.#;/#;\\\\.*~;cscope\\\\.*;/[Bb]uild[.+-_a-zA-Z0-9]*/"
  )

  # default binary package settings
  set(CPACK_INCLUDE_TOPLEVEL_DIRECTORY TRUE)
  set(CPACK_PACKAGE_FILE_NAME
      "${CPACK_PACKAGE_NAME}-${CPACK_PACKAGE_VERSION}-${CPACK_SYSTEM_NAME}")
  if(CPACK_PACKAGE_ARCHITECTURE)
    set(CPACK_PACKAGE_FILE_NAME
        "${CPACK_PACKAGE_FILE_NAME}-${CPACK_PACKAGE_ARCHITECTURE}")
  endif()

  # generator specific configuration file
  #
  # allow package maintainers to use their own configuration file $ cmake
  # -DCPACK_PROJECT_CONFIG_FILE:FILE=/path/to/package/config
  if(NOT CPACK_PROJECT_CONFIG_FILE)
    configure_file("${CMAKE_CURRENT_LIST_DIR}/cmake/package.cmake.in"
                   "${PROJECT_BINARY_DIR}/${PACKAGE_NAME}-package.cmake" @ONLY)
    set(CPACK_PROJECT_CONFIG_FILE
        "${PROJECT_BINARY_DIR}/${PACKAGE_NAME}-package.cmake")
  endif()

  include(CPack)

endif() # BUILD_PACKAGING

if(NOT GFLAGS_IS_SUBPROJECT AND NOT TARGET uninstall)
  configure_file("${CMAKE_CURRENT_SOURCE_DIR}/cmake/cmake_uninstall.cmake.in"
                 "${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake" @ONLY)
  add_custom_target(
    uninstall COMMAND ${CMAKE_COMMAND} -P
                      "${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake")
endif()