cmake_minimum_required(VERSION 3.8...3.28)
include_guard(GLOBAL)

# Fallback for using newer policies on CMake <3.12.
if (${CMAKE_VERSION} VERSION_LESS 3.12)
  cmake_policy(VERSION ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION})
endif ()

# Determine if fmt is built as a subproject (using add_subdirectory) or if it is
# the master project.
if (NOT DEFINED FMT_MASTER_PROJECT)
  set(FMT_MASTER_PROJECT OFF)
  # Checking project name is more reliable than checking source directories.
  if (NOT DEFINED PROJECT_NAME)
    set(FMT_MASTER_PROJECT ON)
    message(STATUS "CMake version: ${CMAKE_VERSION}")
  endif ()
endif ()

# Joins arguments and places the results in ${result_var}.
function (join result_var)
  set(result "")
  foreach (arg ${ARGN})
    set(result "${result}${arg}")
  endforeach ()
  set(${result_var}
      "${result}"
      PARENT_SCOPE)
endfunction ()

# Sets a cache variable with a docstring joined from multiple arguments:
#   set_verbose(<variable> <value> CACHE <type> <docstring>...)
# This allows splitting a long docstring for readability.
function (set_verbose variable value _cache type)
  join(doc ${ARGN})
  set(${variable}
      ${value}
      CACHE ${type} ${doc})
endfunction ()

# Set the default CMAKE_BUILD_TYPE to Release.
# This should be done before the project command since the latter can set
# CMAKE_BUILD_TYPE itself (it does so for nmake).
if (FMT_MASTER_PROJECT AND NOT CMAKE_BUILD_TYPE)
  set_verbose(
    CMAKE_BUILD_TYPE Release CACHE STRING
    "Choose the type of build, options are: None(CMAKE_CXX_FLAGS or "
    "CMAKE_C_FLAGS used) Debug Release RelWithDebInfo MinSizeRel.")
endif ()

project(FMT CXX)

# Determine support for the C++ module scanning and CXX_MODULE File_Sets
# Requires C++20, CMake >= 3.28 and
# Generators(Ninja >= 1.11 OR Visual Studio >= 17.4).
# Compilers GCC>=14, Clang>=16 or MSVC >= 17.4
# Source: https://cmake.org/cmake/help/latest/manual/cmake-cxxmodules.7.html
set(FMT_USE_CMAKE_MODULES FALSE)
if (CMAKE_VERSION VERSION_GREATER_EQUAL 3.28 AND CMAKE_CXX_STANDARD
                                                 GREATER_EQUAL 20)
  if (CMAKE_GENERATOR STREQUAL "Ninja")
    execute_process(COMMAND "${CMAKE_MAKE_PROGRAM}" "--version"
                    OUTPUT_VARIABLE NINJA_VERSION)
    if (NINJA_VERSION VERSION_GREATER_EQUAL 1.11)
      if ((CMAKE_CXX_COMPILER_ID STREQUAL "GNU" AND CMAKE_CXX_COMPILER_VERSION
                                                    GREATER_EQUAL 14)
          OR (CMAKE_CXX_COMPILER_ID STREQUAL "Clang"
              AND CMAKE_CXX_COMPILER_VERSION GREATER_EQUAL 16)
          OR (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC" AND MSVC_VERSION
                                                        GREATER_EQUAL 1934))
        set(FMT_USE_CMAKE_MODULES TRUE)
      endif ()
    endif ()
  elseif (CMAKE_GENERATOR MATCHES "^Visual Studio" AND MSVC_VERSION
                                                       GREATER_EQUAL 1934)
    set(FMT_USE_CMAKE_MODULES TRUE)
  endif ()
endif ()

option(FMT_DOC "Generate the doc target." ${FMT_MASTER_PROJECT})
option(FMT_INSTALL "Generate the install target." ${FMT_MASTER_PROJECT})
option(FMT_TEST "Generate the test target." ${FMT_MASTER_PROJECT})
option(FMT_FUZZ "Generate the fuzz target." OFF)
option(FMT_CUDA_TEST "Generate the cuda-test target." OFF)
option(FMT_OS "Include OS-specific APIs." ON)
option(FMT_MODULE "Build a module library." ${FMT_USE_CMAKE_MODULES})
option(FMT_SYSTEM_HEADERS "Expose headers with marking them as system." OFF)
option(FMT_UNICODE "Enable Unicode support." ON)
option(FMT_PEDANTIC "Enable extra warnings and expensive tests." OFF)
option(FMT_WERROR "Halt the compilation with an error on compiler warnings."
       OFF)

set(FMT_SYSTEM_HEADERS_ATTRIBUTE "")
if (FMT_SYSTEM_HEADERS)
  set(FMT_SYSTEM_HEADERS_ATTRIBUTE SYSTEM)
endif ()

include(GNUInstallDirs) # CMAKE_INSTALL_INCLUDEDIR

set_verbose(
  FMT_INC_DIR ${CMAKE_INSTALL_INCLUDEDIR} CACHE STRING
  "Installation directory for include files, a relative path that "
  "will be joined with ${CMAKE_INSTALL_PREFIX} or an absolute path.")

set(FMT_DEBUG_POSTFIX
    d
    CACHE STRING "Debug library postfix.")

# Get version from base.h.
file(READ include/fmt/base.h base_h)
if (NOT base_h MATCHES "FMT_VERSION ([0-9]+)([0-9][0-9])([0-9][0-9])")
  message(FATAL_ERROR "Cannot get FMT_VERSION from base.h.")
endif ()
# Use math to skip leading zeros if any.
math(EXPR CPACK_PACKAGE_VERSION_MAJOR ${CMAKE_MATCH_1})
math(EXPR CPACK_PACKAGE_VERSION_MINOR ${CMAKE_MATCH_2})
math(EXPR CPACK_PACKAGE_VERSION_PATCH ${CMAKE_MATCH_3})
join(FMT_VERSION ${CPACK_PACKAGE_VERSION_MAJOR}.${CPACK_PACKAGE_VERSION_MINOR}.
     ${CPACK_PACKAGE_VERSION_PATCH})
message(STATUS "{fmt} version: ${FMT_VERSION}")

message(STATUS "Build type: ${CMAKE_BUILD_TYPE}")

if (NOT CMAKE_RUNTIME_OUTPUT_DIRECTORY)
  set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/bin)
endif ()

list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/support/cmake")

include(CheckCXXCompilerFlag)
include(JoinPaths)

if (FMT_MASTER_PROJECT AND NOT DEFINED CMAKE_CXX_VISIBILITY_PRESET)
  set_verbose(CMAKE_CXX_VISIBILITY_PRESET hidden CACHE STRING
              "Preset for the export of private symbols.")
  set_property(CACHE CMAKE_CXX_VISIBILITY_PRESET PROPERTY STRINGS hidden
                                                          default)
endif ()

if (FMT_MASTER_PROJECT AND NOT DEFINED CMAKE_VISIBILITY_INLINES_HIDDEN)
  set_verbose(
    CMAKE_VISIBILITY_INLINES_HIDDEN ON CACHE BOOL
    "Whether to add a compile flag to hide symbols of inline " "functions.")
endif ()

if (CMAKE_CXX_COMPILER_ID MATCHES "GNU")
  set(PEDANTIC_COMPILE_FLAGS
      -pedantic-errors
      -Wall
      -Wextra
      -pedantic
      -Wold-style-cast
      -Wundef
      -Wredundant-decls
      -Wwrite-strings
      -Wpointer-arith
      -Wcast-qual
      -Wformat=2
      -Wmissing-include-dirs
      -Wcast-align
      -Wctor-dtor-privacy
      -Wdisabled-optimization
      -Winvalid-pch
      -Woverloaded-virtual
      -Wconversion
      -Wundef
      -Wno-ctor-dtor-privacy
      -Wno-format-nonliteral)
  if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.6)
    set(PEDANTIC_COMPILE_FLAGS ${PEDANTIC_COMPILE_FLAGS} -Wno-dangling-else
                               -Wno-unused-local-typedefs)
  endif ()
  if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5.0)
    set(PEDANTIC_COMPILE_FLAGS
        ${PEDANTIC_COMPILE_FLAGS}
        -Wdouble-promotion
        -Wtrampolines
        -Wzero-as-null-pointer-constant
        -Wuseless-cast
        -Wvector-operation-performance
        -Wsized-deallocation
        -Wshadow)
  endif ()
  if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 6.0)
    set(PEDANTIC_COMPILE_FLAGS ${PEDANTIC_COMPILE_FLAGS} -Wshift-overflow=2
                               -Wduplicated-cond)
    # Workaround for GCC 12-15 regression:
    # a false positive null-dereference in vector.resize
    # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108860.
    if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 12.0)
      set(PEDANTIC_COMPILE_FLAGS ${PEDANTIC_COMPILE_FLAGS} -Wnull-dereference)
    endif ()
  endif ()
  set(WERROR_FLAG -Werror)
endif ()

if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
  set(PEDANTIC_COMPILE_FLAGS
      -Wall
      -Wextra
      -pedantic
      -Wconversion
      -Wundef
      -Wdeprecated
      -Wweak-vtables
      -Wshadow
      -Wno-gnu-zero-variadic-macro-arguments)
  check_cxx_compiler_flag(-Wzero-as-null-pointer-constant HAS_NULLPTR_WARNING)
  if (HAS_NULLPTR_WARNING)
    set(PEDANTIC_COMPILE_FLAGS ${PEDANTIC_COMPILE_FLAGS}
                               -Wzero-as-null-pointer-constant)
  endif ()
  set(WERROR_FLAG -Werror)
endif ()

if (MSVC)
  set(PEDANTIC_COMPILE_FLAGS /W3)
  set(WERROR_FLAG /WX)
endif ()

if (FMT_MASTER_PROJECT AND CMAKE_GENERATOR MATCHES "Visual Studio")
  # If Microsoft SDK is installed create script run-msbuild.bat that
  # calls SetEnv.cmd to set up build environment and runs msbuild.
  # It is useful when building Visual Studio projects with the SDK
  # toolchain rather than Visual Studio.
  include(FindSetEnv)
  if (WINSDK_SETENV)
    set(MSBUILD_SETUP "call \"${WINSDK_SETENV}\"")
  endif ()
  # Set FrameworkPathOverride to get rid of MSB3644 warnings.
  join(netfxpath
       "C:\\Program Files\\Reference Assemblies\\Microsoft\\Framework\\"
       ".NETFramework\\v4.0")
  file(WRITE run-msbuild.bat "${MSBUILD_SETUP}
    ${CMAKE_MAKE_PROGRAM} -p:FrameworkPathOverride=\"${netfxpath}\" %*")
endif ()

# Sets up a top-level fmt target. Targets that depend on other top-level targets
# should call this because they'll automatically get the required properties.
function (setup_target target kind)
  add_library(fmt::${target} ALIAS ${target})

  target_include_directories(
    ${target} ${FMT_SYSTEM_HEADERS_ATTRIBUTE} BEFORE ${kind}
    $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
    $<INSTALL_INTERFACE:${FMT_INC_DIR}>)

  if (NOT MSVC)
    # Unicode is always supported on compilers other than MSVC.
  elseif (FMT_UNICODE)
    # Unicode support requires compiling with /utf-8.
    target_compile_options(
      ${target} ${kind}
      $<$<AND:$<COMPILE_LANGUAGE:CXX>,$<CXX_COMPILER_ID:MSVC>>:/utf-8>)
  else ()
    target_compile_definitions(${target} ${kind} FMT_UNICODE=0)
  endif ()

  set_target_properties(
    ${target}
    PROPERTIES VERSION ${FMT_VERSION}
               SOVERSION ${CPACK_PACKAGE_VERSION_MAJOR}
               DEBUG_POSTFIX "${FMT_DEBUG_POSTFIX}")
endfunction ()

set(FMT_HEADERS)
foreach (
  header
  args.h
  base.h
  chrono.h
  color.h
  compile.h
  core.h
  format.h
  format-inl.h
  os.h
  ostream.h
  printf.h
  ranges.h
  std.h
  xchar.h)
  set(FMT_HEADERS ${FMT_HEADERS} include/fmt/${header})
endforeach ()

# Add the main fmt library.
add_library(fmt src/format.cc ${FMT_HEADERS} README.md ChangeLog.md)
setup_target(fmt PUBLIC)
set_target_properties(fmt PROPERTIES PUBLIC_HEADER "${FMT_HEADERS}")

if (FMT_OS)
  target_sources(fmt PRIVATE src/os.cc)
else ()
  target_compile_definitions(fmt PRIVATE FMT_OS=0)
endif ()

if (FMT_WERROR)
  target_compile_options(fmt PRIVATE ${WERROR_FLAG})
endif ()
if (FMT_PEDANTIC)
  target_compile_options(fmt PRIVATE ${PEDANTIC_COMPILE_FLAGS})
endif ()

if (cxx_std_11 IN_LIST CMAKE_CXX_COMPILE_FEATURES)
  target_compile_features(fmt PUBLIC cxx_std_11)
else ()
  message(WARNING "Feature cxx_std_11 is unknown for the CXX compiler")
endif ()

# Set FMT_LIB_NAME for pkg-config fmt.pc. We cannot use the OUTPUT_NAME target
# property because it's not set by default.
set(FMT_LIB_NAME fmt)
if (CMAKE_BUILD_TYPE STREQUAL "Debug")
  set(FMT_LIB_NAME ${FMT_LIB_NAME}${FMT_DEBUG_POSTFIX})
endif ()

if (BUILD_SHARED_LIBS)
  target_compile_definitions(
    fmt
    PRIVATE FMT_LIB_EXPORT
    INTERFACE FMT_SHARED)
endif ()
if (FMT_SAFE_DURATION_CAST)
  target_compile_definitions(fmt PUBLIC FMT_SAFE_DURATION_CAST)
endif ()

# Adds a library compiled with C++20 module support.
#
# Usage:
#   add_module_library(<name> [sources...] [USE_CMAKE_MODULES TRUE])
function (add_module_library name)
  cmake_parse_arguments(AML "" "USE_CMAKE_MODULES" "" ${ARGN})
  set(sources ${AML_UNPARSED_ARGUMENTS})

  add_library(${name})
  set_target_properties(${name} PROPERTIES LINKER_LANGUAGE CXX)

  # Modules require C++20.
  target_compile_features(${name} PUBLIC cxx_std_20)

  if (MSVC)
    if (NOT CMAKE_GENERATOR STREQUAL "Ninja")
      set(BMI_DIR "${CMAKE_CURRENT_BINARY_DIR}")
      file(TO_NATIVE_PATH "${BMI_DIR}/${name}.ifc" BMI)
      target_compile_options(
        ${name}
        PRIVATE /interface /ifcOutput ${BMI}
        INTERFACE /reference fmt=${BMI})
      set_target_properties(${name} PROPERTIES ADDITIONAL_CLEAN_FILES ${BMI})
      set_source_files_properties(${BMI} PROPERTIES GENERATED ON)
    endif ()
  endif ()

  if (${AML_USE_CMAKE_MODULES})
    target_sources(${name} PUBLIC FILE_SET fmt TYPE CXX_MODULES FILES
                                  ${sources})
    return()
  endif ()

  if (CMAKE_COMPILER_IS_GNUCXX)
    target_compile_options(${name} PUBLIC -fmodules-ts)
  endif ()

  # `std` is affected by CMake options and may be higher than C++20.
  get_target_property(std ${name} CXX_STANDARD)

  if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
    set(pcms)
    foreach (src ${sources})
      get_filename_component(pcm ${src} NAME_WE)
      set(pcm ${pcm}.pcm)

      # Propagate -fmodule-file=*.pcm to targets that link with this library.
      target_compile_options(
        ${name} PUBLIC -fmodule-file=${CMAKE_CURRENT_BINARY_DIR}/${pcm})

      # Use an absolute path to prevent target_link_libraries prepending -l
      # to it.
      set(pcms ${pcms} ${CMAKE_CURRENT_BINARY_DIR}/${pcm})
      add_custom_command(
        OUTPUT ${pcm}
        COMMAND
          ${CMAKE_CXX_COMPILER} -std=c++${std} -x c++-module --precompile -c -o
          ${pcm} ${CMAKE_CURRENT_SOURCE_DIR}/${src}
          "-I$<JOIN:$<TARGET_PROPERTY:${name},INCLUDE_DIRECTORIES>,;-I>"
        # Required by the -I generator expression above.
        COMMAND_EXPAND_LISTS
        DEPENDS ${src})
    endforeach ()

    # Add .pcm files as sources to make sure they are built before the library.
    set(sources)
    foreach (pcm ${pcms})
      get_filename_component(pcm_we ${pcm} NAME_WE)
      set(obj ${pcm_we}.o)
      # Use an absolute path to prevent target_link_libraries prepending -l.
      set(sources ${sources} ${pcm} ${CMAKE_CURRENT_BINARY_DIR}/${obj})
      add_custom_command(
        OUTPUT ${obj}
        COMMAND ${CMAKE_CXX_COMPILER} $<TARGET_PROPERTY:${name},COMPILE_OPTIONS>
                -c -o ${obj} ${pcm}
        DEPENDS ${pcm})
    endforeach ()
  endif ()
  target_sources(${name} PRIVATE ${sources})
endfunction ()

if (FMT_MODULE)
  add_module_library(fmt-module src/fmt.cc USE_CMAKE_MODULES
                     ${FMT_USE_CMAKE_MODULES})
  setup_target(fmt-module PUBLIC)
endif ()

add_library(fmt-header-only INTERFACE)

target_compile_definitions(fmt-header-only INTERFACE FMT_HEADER_ONLY=1)
target_compile_features(fmt-header-only INTERFACE cxx_std_11)
setup_target(fmt-header-only INTERFACE)

add_library(fmt-c STATIC src/fmt-c.cc)
target_compile_features(fmt-c INTERFACE c_std_11)
if (MSVC)
  target_compile_options(fmt-c PUBLIC /Zc:preprocessor)
endif ()
target_link_libraries(fmt-c PUBLIC fmt::fmt)
add_library(fmt::fmt-c ALIAS fmt-c)

set_target_properties(fmt-c PROPERTIES PUBLIC_HEADER include/fmt/fmt-c.h)

# Install targets.
if (FMT_INSTALL)
  include(CMakePackageConfigHelpers)
  set_verbose(
    FMT_CMAKE_DIR
    ${CMAKE_INSTALL_LIBDIR}/cmake/fmt
    CACHE
    STRING
    "Installation directory for cmake files, a relative path that "
    "will be joined with ${CMAKE_INSTALL_PREFIX} or an absolute "
    "path.")
  set(version_config ${PROJECT_BINARY_DIR}/fmt-config-version.cmake)
  set(project_config ${PROJECT_BINARY_DIR}/fmt-config.cmake)
  set(pkgconfig ${PROJECT_BINARY_DIR}/fmt.pc)
  set(targets_export_name fmt-targets)

  set_verbose(
    FMT_LIB_DIR ${CMAKE_INSTALL_LIBDIR} CACHE STRING
    "Installation directory for libraries, a relative path that "
    "will be joined to ${CMAKE_INSTALL_PREFIX} or an absolute path.")

  set_verbose(
    FMT_PKGCONFIG_DIR
    ${CMAKE_INSTALL_LIBDIR}/pkgconfig
    CACHE
    STRING
    "Installation directory for pkgconfig (.pc) files, a relative "
    "path that will be joined with ${CMAKE_INSTALL_PREFIX} or an "
    "absolute path.")

  # Generate the version, config and target files into the build directory.
  write_basic_package_version_file(
    ${version_config}
    VERSION ${FMT_VERSION}
    COMPATIBILITY AnyNewerVersion)

  join_paths(libdir_for_pc_file "\${exec_prefix}" "${FMT_LIB_DIR}")
  join_paths(includedir_for_pc_file "\${prefix}" "${FMT_INC_DIR}")

  configure_file("${PROJECT_SOURCE_DIR}/support/cmake/fmt.pc.in" "${pkgconfig}"
                 @ONLY)
  configure_package_config_file(
    ${PROJECT_SOURCE_DIR}/support/cmake/fmt-config.cmake.in ${project_config}
    INSTALL_DESTINATION ${FMT_CMAKE_DIR})

  set(INSTALL_TARGETS fmt fmt-header-only fmt-c)

  if (FMT_MODULE)
    list(APPEND INSTALL_TARGETS fmt-module)
    if (FMT_USE_CMAKE_MODULES)
      set(INSTALL_FILE_SET FILE_SET fmt DESTINATION ${FMT_INC_DIR}/fmt)
    endif ()
  endif ()

  # Install the library and headers.
  install(
    TARGETS ${INSTALL_TARGETS}
    COMPONENT fmt_core
    EXPORT ${targets_export_name}
    LIBRARY DESTINATION ${FMT_LIB_DIR}
    ARCHIVE DESTINATION ${FMT_LIB_DIR}
    PUBLIC_HEADER DESTINATION ${FMT_INC_DIR}/fmt
    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} ${INSTALL_FILE_SET})

  # Use a namespace because CMake provides better diagnostics for namespaced
  # imported targets.
  export(
    TARGETS ${INSTALL_TARGETS}
    NAMESPACE fmt::
    FILE ${PROJECT_BINARY_DIR}/${targets_export_name}.cmake)

  # Install version, config and target files.
  install(
    FILES ${project_config} ${version_config}
    DESTINATION ${FMT_CMAKE_DIR}
    COMPONENT fmt_core)
  install(
    EXPORT ${targets_export_name}
    DESTINATION ${FMT_CMAKE_DIR}
    NAMESPACE fmt::
    COMPONENT fmt_core)

  install(
    FILES "${pkgconfig}"
    DESTINATION "${FMT_PKGCONFIG_DIR}"
    COMPONENT fmt_core)
endif ()

function (add_doc_target)
  find_program(DOXYGEN doxygen PATHS "$ENV{ProgramFiles}/doxygen/bin"
                                     "$ENV{ProgramFiles\(x86\)}/doxygen/bin")
  if (NOT DOXYGEN)
    message(STATUS "Target 'doc' disabled because doxygen not found")
    return()
  endif ()

  find_program(MKDOCS mkdocs)
  if (NOT MKDOCS)
    message(STATUS "Target 'doc' disabled because mkdocs not found")
    return()
  endif ()

  set(sources)
  foreach (source api.md index.md syntax.md get-started.md fmt.css fmt.js)
    set(sources ${sources} doc/${source})
  endforeach ()

  add_custom_target(
    doc
    COMMAND
      ${CMAKE_COMMAND} -E env
      PYTHONPATH=${CMAKE_CURRENT_SOURCE_DIR}/support/python ${MKDOCS} build -f
      ${CMAKE_CURRENT_SOURCE_DIR}/support/mkdocs.yml
      # MkDocs requires the site dir to be outside of the doc dir.
      --site-dir ${CMAKE_CURRENT_BINARY_DIR}/doc-html --no-directory-urls
    SOURCES ${sources})

  install(
    DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/doc-html/
    DESTINATION ${CMAKE_INSTALL_DATAROOTDIR}/doc/fmt
    COMPONENT fmt_doc
    OPTIONAL)
endfunction ()

if (FMT_DOC)
  add_doc_target()
endif ()

if (FMT_TEST)
  enable_testing()
  add_subdirectory(test)
endif ()

# Control fuzzing independent of the unit tests.
if (FMT_FUZZ)
  add_subdirectory(test/fuzzing)

  # The FMT_FUZZ macro is used to prevent resource exhaustion in fuzzing
  # mode and make fuzzing practically possible. It is similar to
  # FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION but uses a different name to
  # avoid interfering with fuzzing of projects that use {fmt}.
  # See also https://llvm.org/docs/LibFuzzer.html#fuzzer-friendly-build-mode.
  target_compile_definitions(fmt PUBLIC FMT_FUZZ)
endif ()

set(gitignore ${PROJECT_SOURCE_DIR}/.gitignore)
if (FMT_MASTER_PROJECT AND EXISTS ${gitignore})
  # Get the list of ignored files from .gitignore.
  file(STRINGS ${gitignore} lines)
  list(REMOVE_ITEM lines /doc/html)
  foreach (line ${lines})
    string(REPLACE "." "[.]" line "${line}")
    string(REPLACE "*" ".*" line "${line}")
    set(ignored_files ${ignored_files} "${line}$" "${line}/")
  endforeach ()
  set(ignored_files ${ignored_files} /.git /build/doxyxml .vagrant)

  set(CPACK_SOURCE_GENERATOR ZIP)
  set(CPACK_SOURCE_IGNORE_FILES ${ignored_files})
  set(CPACK_SOURCE_PACKAGE_FILE_NAME fmt-${FMT_VERSION})
  set(CPACK_PACKAGE_NAME fmt)
  set(CPACK_RESOURCE_FILE_README ${PROJECT_SOURCE_DIR}/README.md)
  include(CPack)
endif ()