Howto CMakeExports¶

CMake permits to write files that describe the DCMTK build configuration (DCMTConfig.cmake) as well as all targets (executables and libraries) that have been produced (DCMTKTargets.cmake). Those files can be utilized by external projects by using CMake' find_package() mechanism in “CONFIG” mode in order to adapt their own build configuration, and directly make use of all available target libraries and executables.

Kitware provides tutorials how to deal with the XXXTargets.cmake exports, and how the XXXConfig.cmake files work in general.

On systems using CMake versions equal or greater than 2.8.8, these files are written during installation to the installation directory's subfolder /cmake on Windows systems, and /lib/cmake/dcmtk on Unix-like systems. Additionally, these files are already written to the main directory of CMake's build tree during the build, with all content (e.g. the include paths within DCMTConfig.cmake) pointing to the correct values for the build tree. Thus even a DCMTK build tree can be used by external projects that process these two files.

On systems using CMake versions lower than 2.8.8, only a simplified DCMTKConfig.cmake is created which is only available in the install tree. DCMTKTargets.cmake is not created at all.

Examples¶

Here is a typical example of how a DCMTKConfig.cmake file usually looks and what kind of information it provides (created 2014-03-07 on Debian 7.4 using CMake 2.8.9):

#
# DCMTKConfig.cmake - DCMTK CMake configuration file for external projects
#

####### Expanded from @PACKAGE_INIT@ by configure_package_config_file() #######
get_filename_component(PACKAGE_PREFIX_DIR "${CMAKE_CURRENT_LIST_DIR}/../../../" ABSOLUTE)

macro(set_and_check _var _file)
  set(${_var} "${_file}")
  if(NOT EXISTS "${_file}")
    message(FATAL_ERROR "File or directory ${_file} referenced by variable ${_var} does not exist !")
  endif()
endmacro()

####################################################################################

# Basic version information
SET(DCMTK_MAJOR_VERSION 3)
SET(DCMTK_MINOR_VERSION 6)
SET(DCMTK_BUILD_VERSION 1)

# DCMTK libraries and modules
SET(DCMTK_MODULES "ofstd;oflog;dcmdata;dcmimgle;dcmimage;dcmjpeg;dcmjpls;dcmtls;dcmnet;dcmsr;dcmsign;dcmwlm;dcmqrdb;dcmpstat;dcmrt")
SET(DCMTK_LIBRARIES "ofstd;oflog;dcmdata;i2d;dcmimgle;dcmimage;dcmjpeg;ijg8;ijg12;ijg16;dcmjpls;charls;dcmtls;dcmnet;dcmsr;dcmdsig;dcmwlm;dcmqrdb;dcmpstat;dcmrt")

# DCMTK build options
SET(DCMTK_WITH_TIFF OFF)
SET(DCMTK_WITH_PNG OFF)
SET(DCMTK_WITH_XML OFF)
SET(DCMTK_WITH_ZLIB ON)
SET(DCMTK_WITH_OPENSSL ON)
SET(DCMTK_WITH_SNDFILE OFF)
SET(DCMTK_WITH_ICONV ON)
SET(DCMTK_WITH_PRIVATE_TAGS OFF)
SET(DCMTK_WITH_THREADS ON)

# DCMTK shared libraries
SET(DCMTK_SHARED_LIBRARIES OFF)
SET(DCMTK_SINGLE_SHARED_LIBRARY OFF)

# DCMTK additional options
SET(DCMTK_OVERWRITE_WIN32_COMPILER_FLAGS OFF)
SET(DCMTK_WIDE_CHAR_FILE_IO_FUNCTIONS OFF)
SET(DCMTK_WIDE_CHAR_MAIN_FUNCTION OFF)

SET_AND_CHECK(DCMTK_config_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include/dcmtk/config")
SET_AND_CHECK(DCMTK_ofstd_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include/dcmtk/ofstd")
SET_AND_CHECK(DCMTK_oflog_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include/dcmtk/oflog")
SET_AND_CHECK(DCMTK_dcmdata_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include/dcmtk/dcmdata")
SET_AND_CHECK(DCMTK_dcmimgle_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include/dcmtk/dcmimgle")
SET_AND_CHECK(DCMTK_dcmimage_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include/dcmtk/dcmimage")
SET_AND_CHECK(DCMTK_dcmjpeg_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include/dcmtk/dcmjpeg")
SET_AND_CHECK(DCMTK_dcmjpls_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include/dcmtk/dcmjpls")
SET_AND_CHECK(DCMTK_dcmtls_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include/dcmtk/dcmtls")
SET_AND_CHECK(DCMTK_dcmnet_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include/dcmtk/dcmnet")
SET_AND_CHECK(DCMTK_dcmsr_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include/dcmtk/dcmsr")
SET_AND_CHECK(DCMTK_dcmsign_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include/dcmtk/dcmsign")
SET_AND_CHECK(DCMTK_dcmwlm_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include/dcmtk/dcmwlm")
SET_AND_CHECK(DCMTK_dcmqrdb_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include/dcmtk/dcmqrdb")
SET_AND_CHECK(DCMTK_dcmpstat_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include/dcmtk/dcmpstat")
SET_AND_CHECK(DCMTK_dcmrt_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include/dcmtk/dcmrt")

SET_AND_CHECK(DCMTK_TARGETS "${PACKAGE_PREFIX_DIR}/lib/cmake/dcmtk/DCMTKTargets.cmake")

SET(DCMTK_INCLUDE_DIRS "")
FOREACH(module config ${DCMTK_MODULES})
  LIST(APPEND DCMTK_INCLUDE_DIRS ${DCMTK_${module}_INCLUDE_DIR})
ENDFOREACH(module)

####### Expanded from @DCMTK_CONFIG_CODE@ #######
list(APPEND DCMTK_INCLUDE_DIRS "${PACKAGE_PREFIX_DIR}/include")
##################################################

# Compatibility: This variable is deprecated
SET(DCMTK_INCLUDE_DIR ${DCMTK_INCLUDE_DIRS})

IF(NOT DCMTK_TARGETS_IMPORTED)
  SET(DCMTK_TARGETS_IMPORTED 1)
  INCLUDE(${DCMTK_TARGETS})
ENDIF(NOT DCMTK_TARGETS_IMPORTED)