cmake/Modules/FindZLIB.cmake

# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.

#.rst:
# FindZLIB
# --------
#
# Find the native ZLIB includes and library.
#
# IMPORTED Targets
# ^^^^^^^^^^^^^^^^
#
# This module defines :prop_tgt:`IMPORTED` target ``ZLIB::ZLIB``, if
# ZLIB has been found.
#
# Result Variables
# ^^^^^^^^^^^^^^^^
#
# This module defines the following variables:
#
# ::
#
#   ZLIB_INCLUDE_DIRS   - where to find zlib.h, etc.
#   ZLIB_LIBRARIES      - List of libraries when using zlib.
#   ZLIB_FOUND          - True if zlib found.
#
# ::
#
#   ZLIB_VERSION_STRING - The version of zlib found (x.y.z)
#   ZLIB_VERSION_MAJOR  - The major version of zlib
#   ZLIB_VERSION_MINOR  - The minor version of zlib
#   ZLIB_VERSION_PATCH  - The patch version of zlib
#   ZLIB_VERSION_TWEAK  - The tweak version of zlib
#
# Backward Compatibility
# ^^^^^^^^^^^^^^^^^^^^^^
#
# The following variable are provided for backward compatibility
#
# ::
#
#   ZLIB_MAJOR_VERSION  - The major version of zlib
#   ZLIB_MINOR_VERSION  - The minor version of zlib
#   ZLIB_PATCH_VERSION  - The patch version of zlib
#
# Hints
# ^^^^^
#
# A user may set ``ZLIB_ROOT`` to a zlib installation root to tell this
# module where to look.

set(_ZLIB_SEARCHES)

# Search ZLIB_ROOT first if it is set.
if(ZLIB_ROOT)
  set(_ZLIB_SEARCH_ROOT PATHS ${ZLIB_ROOT} NO_DEFAULT_PATH)
  list(APPEND _ZLIB_SEARCHES _ZLIB_SEARCH_ROOT)
endif()

# Normal search.
set(_ZLIB_SEARCH_NORMAL
  PATHS "[HKEY_LOCAL_MACHINE\\SOFTWARE\\GnuWin32\\Zlib;InstallPath]"
        "$ENV{PROGRAMFILES}/zlib"
  )
list(APPEND _ZLIB_SEARCHES _ZLIB_SEARCH_NORMAL)

set(ZLIB_NAMES z zlib zdll zlib1)
set(ZLIB_NAMES_DEBUG zlibd zlibd1)

# Try each search configuration.
foreach(search ${_ZLIB_SEARCHES})
  find_path(ZLIB_INCLUDE_DIR NAMES zlib.h ${${search}} PATH_SUFFIXES include)
endforeach()

# Allow ZLIB_LIBRARY to be set manually, as the location of the zlib library
if(NOT ZLIB_LIBRARY)
  foreach(search ${_ZLIB_SEARCHES})
    find_library(ZLIB_LIBRARY_RELEASE NAMES ${ZLIB_NAMES} NAMES_PER_DIR ${${search}} PATH_SUFFIXES lib)
    find_library(ZLIB_LIBRARY_DEBUG NAMES ${ZLIB_NAMES_DEBUG} NAMES_PER_DIR ${${search}} PATH_SUFFIXES lib)
  endforeach()

  include(${CMAKE_CURRENT_LIST_DIR}/SelectLibraryConfigurations.cmake)
  select_library_configurations(ZLIB)
endif()

unset(ZLIB_NAMES)
unset(ZLIB_NAMES_DEBUG)

mark_as_advanced(ZLIB_INCLUDE_DIR)

if(ZLIB_INCLUDE_DIR AND EXISTS "${ZLIB_INCLUDE_DIR}/zlib.h")
    file(STRINGS "${ZLIB_INCLUDE_DIR}/zlib.h" ZLIB_H REGEX "^#define ZLIB_VERSION \"[^\"]*\"$")

    string(REGEX REPLACE "^.*ZLIB_VERSION \"([0-9]+).*$" "\\1" ZLIB_VERSION_MAJOR "${ZLIB_H}")
    string(REGEX REPLACE "^.*ZLIB_VERSION \"[0-9]+\\.([0-9]+).*$" "\\1" ZLIB_VERSION_MINOR  "${ZLIB_H}")
    string(REGEX REPLACE "^.*ZLIB_VERSION \"[0-9]+\\.[0-9]+\\.([0-9]+).*$" "\\1" ZLIB_VERSION_PATCH "${ZLIB_H}")
    set(ZLIB_VERSION_STRING "${ZLIB_VERSION_MAJOR}.${ZLIB_VERSION_MINOR}.${ZLIB_VERSION_PATCH}")

    # only append a TWEAK version if it exists:
    set(ZLIB_VERSION_TWEAK "")
    if( "${ZLIB_H}" MATCHES "ZLIB_VERSION \"[0-9]+\\.[0-9]+\\.[0-9]+\\.([0-9]+)")
        set(ZLIB_VERSION_TWEAK "${CMAKE_MATCH_1}")
        string(APPEND ZLIB_VERSION_STRING ".${ZLIB_VERSION_TWEAK}")
    endif()

    set(ZLIB_MAJOR_VERSION "${ZLIB_VERSION_MAJOR}")
    set(ZLIB_MINOR_VERSION "${ZLIB_VERSION_MINOR}")
    set(ZLIB_PATCH_VERSION "${ZLIB_VERSION_PATCH}")
endif()

include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(ZLIB REQUIRED_VARS ZLIB_LIBRARY ZLIB_INCLUDE_DIR
                                       VERSION_VAR ZLIB_VERSION_STRING)

if(ZLIB_FOUND)
    set(ZLIB_INCLUDE_DIRS ${ZLIB_INCLUDE_DIR})

    if(NOT ZLIB_LIBRARIES)
      set(ZLIB_LIBRARIES ${ZLIB_LIBRARY})
    endif()

    if(NOT TARGET ZLIB::ZLIB)
      add_library(ZLIB::ZLIB UNKNOWN IMPORTED)
      set_target_properties(ZLIB::ZLIB PROPERTIES
        INTERFACE_INCLUDE_DIRECTORIES "${ZLIB_INCLUDE_DIRS}")

      if(ZLIB_LIBRARY_RELEASE)
        set_property(TARGET ZLIB::ZLIB APPEND PROPERTY
          IMPORTED_CONFIGURATIONS RELEASE)
        set_target_properties(ZLIB::ZLIB PROPERTIES
          IMPORTED_LOCATION_RELEASE "${ZLIB_LIBRARY_RELEASE}")
      endif()

      if(ZLIB_LIBRARY_DEBUG)
        set_property(TARGET ZLIB::ZLIB APPEND PROPERTY
          IMPORTED_CONFIGURATIONS DEBUG)
        set_target_properties(ZLIB::ZLIB PROPERTIES
          IMPORTED_LOCATION_DEBUG "${ZLIB_LIBRARY_DEBUG}")
      endif()

      if(NOT ZLIB_LIBRARY_RELEASE AND NOT ZLIB_LIBRARY_DEBUG)
        set_property(TARGET ZLIB::ZLIB APPEND PROPERTY
          IMPORTED_LOCATION "${ZLIB_LIBRARY}")
      endif()
    endif()
endif()