cmake/Modules/FindZLIB.cmake

# - Find zlib
# Find the native ZLIB includes and library
#
#  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_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 distributed this file outside of CMake, substitute the full
#  License text for the above reference.)

FIND_PATH(ZLIB_INCLUDE_DIR zlib.h
    "[HKEY_LOCAL_MACHINE\\SOFTWARE\\GnuWin32\\Zlib;InstallPath]/include"
)

SET(ZLIB_NAMES z zlib zdll)
FIND_LIBRARY(ZLIB_LIBRARY
    NAMES
        ${ZLIB_NAMES}
    PATHS
        "[HKEY_LOCAL_MACHINE\\SOFTWARE\\GnuWin32\\Zlib;InstallPath]/lib"
)
MARK_AS_ADVANCED(ZLIB_LIBRARY ZLIB_INCLUDE_DIR)

IF (ZLIB_INCLUDE_DIR AND EXISTS "${ZLIB_INCLUDE_DIR}/zlib.h")
    FILE(READ "${ZLIB_INCLUDE_DIR}/zlib.h" ZLIB_H)
    STRING(REGEX REPLACE ".*#define ZLIB_VERSION \"([0-9]+)\\.([0-9]+)\\.([0-9]+)\".*" "\\1.\\2.\\3" ZLIB_VERSION_STRING "${ZLIB_H}")
ENDIF()

# 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 DEFAULT_MSG ZLIB_INCLUDE_DIR ZLIB_LIBRARY)

IF (ZLIB_FOUND)
    SET(ZLIB_INCLUDE_DIRS ${ZLIB_INCLUDE_DIR})
    SET(ZLIB_LIBRARIES    ${ZLIB_LIBRARY})
ENDIF()