wireshark/cmake/modules/FindZLIB.cmake

# - Find zlib
#
# Find the native ZLIB includes and library.
# Once done this will define
#
#  ZLIB_INCLUDE_DIRS   - where to find zlib.h, etc.
#  ZLIB_LIBRARIES      - List of libraries when using zlib.
#  ZLIB_FOUND          - True if zlib found.
#  ZLIB_DLL_DIR        - (Windows) Path to the zlib DLL.
#  ZLIB_DLL            - (Windows) Name of the zlib DLL.
#  ZLIB_PDB            - (Windows) Name of the zlib PDB.
#
#  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
#
# 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

#=============================================================================
# Copyright 2001-2009 Kitware, Inc.
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
#  License text for the above reference.)

include( FindWSWinLibs )
# Zlib is included with GLib2
FindWSWinLibs( "vcpkg-export-*" "ZLIB_HINTS" )

if(MSVC)
    # else we'll find Strawberry Perl's version
    set (_zlib_sys_env_option NO_SYSTEM_ENVIRONMENT_PATH)
endif()

if (NOT ZLIB_INCLUDE_DIR OR NOT ZLIB_LIBRARY)
    if (NOT WIN32) # else we'll find Strawberry Perl's pkgconfig
        find_package(PkgConfig)
        pkg_search_module(ZLIB zlib)
    endif()

    FIND_PATH(ZLIB_INCLUDE_DIR
        NAMES
            zlib.h
        HINTS
            "${ZLIB_INCLUDEDIR}"
            ${ZLIB_HINTS}/include
            ${ZLIB_HINTS}
        PATHS
            "[HKEY_LOCAL_MACHINE\\SOFTWARE\\GnuWin32\\Zlib;InstallPath]/include"
	${_zlib_sys_env_option}
    )

    SET(ZLIB_NAMES z zlib zdll zlib1 zlibd zlibd1)
    FIND_LIBRARY(ZLIB_LIBRARY
        NAMES
            ${ZLIB_NAMES}
        HINTS
            "${ZLIB_LIBDIR}"
            ${ZLIB_HINTS}/lib
            ${ZLIB_HINTS}
        PATHS
            "[HKEY_LOCAL_MACHINE\\SOFTWARE\\GnuWin32\\Zlib;InstallPath]/lib"
	${_zlib_sys_env_option}
    )
endif()
unset(_zlib_sys_env_option)
MARK_AS_ADVANCED(ZLIB_LIBRARY ZLIB_INCLUDE_DIR)

# handle the QUIETLY and REQUIRED arguments and set ZLIB_FOUND to TRUE if
# all listed variables are TRUE
INCLUDE(FindPackageHandleStandardArgs)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(ZLIB REQUIRED_VARS ZLIB_LIBRARY ZLIB_INCLUDE_DIR
                                       VERSION_VAR ZLIB_VERSION_STRING)

if(ZLIB_FOUND)
    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 "${CMAKE_MATCH_1}")
            SET(ZLIB_VERSION_STRING "${ZLIB_VERSION_STRING}.${ZLIB_VERSION_TWEAK}")
        ENDIF( "${ZLIB_H}" MATCHES "^.*ZLIB_VERSION \"[0-9]+\\.[0-9]+\\.[0-9]+\\.([0-9]+).*$")

        SET(ZLIB_MAJOR_VERSION "${ZLIB_VERSION_MAJOR}")
        SET(ZLIB_MINOR_VERSION "${ZLIB_VERSION_MINOR}")
        SET(ZLIB_PATCH_VERSION "${ZLIB_VERSION_PATCH}")
    ENDIF()

    #
    # inflatePrime was added in zlib 1.2.2.4 in 2005. We're guaranteed
    # to have it on Windows.
    #
    IF(WIN32)
        SET(HAVE_INFLATEPRIME ON)
    ELSE()
        INCLUDE(CMakePushCheckState)
        INCLUDE(CheckFunctionExists)
        CMAKE_PUSH_CHECK_STATE()
        set(CMAKE_REQUIRED_INCLUDES ${ZLIB_INCLUDE_DIR})
        set(CMAKE_REQUIRED_LIBRARIES ${ZLIB_LIBRARY})
        #
        # Check for inflate() in zlib, to make sure the zlib library is
        # usable.
        #
        # For example, on at least some versions of Fedora, if you have a
        # 64-bit machine, have both the 32-bit and 64-bit versions of the
        # run-time zlib package installed, and have only the *32-bit*
        # version of the zlib development package installed, it'll find the
        # header, and think it can use zlib, and will use it in subsequent
        # tests, but it'll try and link 64-bit test programs with the 32-bit
        # library, causing those tests to falsely fail.  Hilarity ensues.
        #
        CHECK_FUNCTION_EXISTS("inflate" HAVE_INFLATE)
        IF(NOT HAVE_INFLATE)
            MESSAGE(FATAL_ERROR "zlib.h found but linking with -lz failed to find inflate(); do you have the right developer package installed (32-bit vs. 64-bit)?")
        ENDIF()
        CHECK_FUNCTION_EXISTS("inflatePrime" HAVE_INFLATEPRIME)
        # reset
        CMAKE_POP_CHECK_STATE()
    ENDIF()

    AddWSWinDLL(ZLIB ZLIB_HINTS "zlib*")
    SET(ZLIB_INCLUDE_DIRS ${ZLIB_INCLUDE_DIR})
    SET(ZLIB_LIBRARIES ${ZLIB_LIBRARY})
ELSE()
    SET(ZLIB_INCLUDE_DIRS )
    SET(ZLIB_LIBRARIES )
    SET(ZLIB_DLL_DIR )
    SET(ZLIB_DLL )
    SET(ZLIB_PDB )
ENDIF()