CMake/Modules/FindDCMTK.cmake

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

#[=======================================================================[.rst:
FindDCMTK
---------

Find DICOM ToolKit (DCMTK) libraries and applications

The module defines the following variables::

 DCMTK_INCLUDE_DIRS  - Directories to include to use DCMTK
 DCMTK_LIBRARIES     - Files to link against to use DCMTK
 DCMTK_FOUND         - If false, don't try to use DCMTK
 DCMTK_DIR           - (optional) Source directory for DCMTK

Compatibility
^^^^^^^^^^^^^

This module is able to find a version of DCMTK that does or does not export
a *DCMTKConfig.cmake* file. It applies a two step process:

* Step 1:  Attempt to find DCMTK version providing a *DCMTKConfig.cmake* file.
* Step 2:  If step 1 failed, rely on *FindDCMTK.cmake* to set `DCMTK_*` variables details below.


`Recent DCMTK
<http://git.dcmtk.org/web?p=dcmtk.git;a=commit;h=662ae187c493c6b9a73dd5e3875372cebd0c11fe>`_
provides a *DCMTKConfig.cmake* :manual:`package configuration file
<cmake-packages(7)>`. To exclusively use the package configuration file
(recommended when possible), pass the `NO_MODULE` option to
:command:`find_package`. For example, `find_package(DCMTK NO_MODULE)`.
This requires official DCMTK snapshot *3.6.1_20140617* or newer.


Until all clients update to the more recent DCMTK, build systems will need
to support different versions of DCMTK.

On any given system, the following combinations of DCMTK versions could be
considered:

+--------+---------------------+-----------------------+-------------------+
|        |   SYSTEM DCMTK      |      LOCAL DCMTK      |     Supported ?   |
+--------+---------------------+-----------------------+-------------------+
| Case A |   NA                |      [ ] DCMTKConfig  |         YES       |
+--------+---------------------+-----------------------+-------------------+
| Case B |   NA                |      [X] DCMTKConfig  |         YES       |
+--------+---------------------+-----------------------+-------------------+
| Case C |   [ ] DCMTKConfig   |      NA               |         YES       |
+--------+---------------------+-----------------------+-------------------+
| Case D |   [X] DCMTKConfig   |      NA               |         YES       |
+--------+---------------------+-----------------------+-------------------+
| Case E |   [ ] DCMTKConfig   |      [ ] DCMTKConfig  |         YES (*)   |
+--------+---------------------+-----------------------+-------------------+
| Case F |   [X] DCMTKConfig   |      [ ] DCMTKConfig  |         NO        |
+--------+---------------------+-----------------------+-------------------+
| Case G |   [ ] DCMTKConfig   |      [X] DCMTKConfig  |         YES       |
+--------+---------------------+-----------------------+-------------------+
| Case H |   [X] DCMTKConfig   |      [X] DCMTKConfig  |         YES       |
+--------+---------------------+-----------------------+-------------------+

 (*) See Troubleshooting section.

Legend:

  NA ...............: Means that no System or Local DCMTK is available

  [ ] DCMTKConfig ..: Means that the version of DCMTK does NOT export a DCMTKConfig.cmake file.

  [X] DCMTKConfig ..: Means that the version of DCMTK exports a DCMTKConfig.cmake file.


Troubleshooting
^^^^^^^^^^^^^^^

What to do if my project finds a different version of DCMTK?

Remove DCMTK entry from the CMake cache per :command:`find_package`
documentation.
#]=======================================================================]

#
# Written for VXL by Amitha Perera.
# Upgraded for GDCM by Mathieu Malaterre.
# Modified for EasyViz by Thomas Sondergaard.
#

set(_dcmtk_dir_description "The directory of DCMTK build or install tree.")

# Ensure that DCMTK_DIR is set to a reasonable default value
# so that DCMTK libraries can be found on a standard Unix distribution.
# It also overwrite the value of DCMTK_DIR after this one has been
# set by a successful discovery of DCMTK by the unpatched FindDCMTK.cmake module
# distributed with CMake (as of 0167cea)
if(NOT DCMTK_DIR OR DCMTK_DIR STREQUAL "/usr/include/dcmtk")
  set(DCMTK_DIR "/usr" CACHE PATH ${_dcmtk_dir_description} FORCE)
endif()

set(_SAVED_DCMTK_DIR ${DCMTK_DIR})

#
# Step1: Attempt to find a version of DCMTK providing a DCMTKConfig.cmake file.
#
if(NOT DCMTK_FIND_QUIETLY)
  message(CHECK_START "Trying to find DCMTK expecting DCMTKConfig.cmake")
endif()
find_package(DCMTK QUIET NO_MODULE)
if(DCMTK_FOUND
    AND NOT "x" STREQUAL "x${DCMTK_LIBRARIES}"
    AND NOT "x" STREQUAL "x${DCMTK_INCLUDE_DIRS}")

  if(NOT DCMTK_FIND_QUIETLY)
    message(CHECK_PASS "ok")
  endif()
  return()
else()
  if(NOT DCMTK_FIND_QUIETLY)
    message(CHECK_FAIL "failed")
  endif()
endif()

if(NOT DCMTK_FIND_QUIETLY)
  message(STATUS "Trying to find DCMTK relying on FindDCMTK.cmake")
endif()

# Restore the value reset by the previous call to 'find_package(DCMTK QUIET NO_MODULE)'
set(DCMTK_DIR ${_SAVED_DCMTK_DIR} CACHE PATH ${_dcmtk_dir_description} FORCE)


#
# Step2: Attempt to find a version of DCMTK that does NOT provide a DCMTKConfig.cmake file.
#

# prefer DCMTK_DIR over default system paths like /usr/lib
if(DCMTK_DIR)
  set(CMAKE_PREFIX_PATH ${DCMTK_DIR}/lib ${CMAKE_PREFIX_PATH}) # this is given to FIND_LIBRARY or FIND_PATH
endif()

# Find all libraries, store debug and release separately
foreach(lib
    dcmpstat
    dcmsr
    dcmsign
    dcmtls
    dcmqrdb
    dcmnet
    dcmjpeg
    dcmimage
    dcmimgle
    dcmdata
    oflog
    ofstd
    ijg12
    ijg16
    ijg8
    )

  # Find Release libraries
  find_library(DCMTK_${lib}_LIBRARY_RELEASE
    ${lib}
    PATHS
    ${DCMTK_DIR}/${lib}/libsrc
    ${DCMTK_DIR}/${lib}/libsrc/Release
    ${DCMTK_DIR}/${lib}/Release
    ${DCMTK_DIR}/lib
    ${DCMTK_DIR}/lib/Release
    ${DCMTK_DIR}/dcmjpeg/lib${lib}/Release
    NO_DEFAULT_PATH
    )

  # Find Debug libraries
  find_library(DCMTK_${lib}_LIBRARY_DEBUG
    ${lib}${DCMTK_CMAKE_DEBUG_POSTFIX}
    PATHS
    ${DCMTK_DIR}/${lib}/libsrc
    ${DCMTK_DIR}/${lib}/libsrc/Debug
    ${DCMTK_DIR}/${lib}/Debug
    ${DCMTK_DIR}/lib
    ${DCMTK_DIR}/lib/Debug
    ${DCMTK_DIR}/dcmjpeg/lib${lib}/Debug
    NO_DEFAULT_PATH
    )

  mark_as_advanced(DCMTK_${lib}_LIBRARY_RELEASE)
  mark_as_advanced(DCMTK_${lib}_LIBRARY_DEBUG)

  # Add libraries to variable according to build type
  if(DCMTK_${lib}_LIBRARY_RELEASE)
    list(APPEND DCMTK_LIBRARIES optimized ${DCMTK_${lib}_LIBRARY_RELEASE})
  endif()

  if(DCMTK_${lib}_LIBRARY_DEBUG)
    list(APPEND DCMTK_LIBRARIES debug ${DCMTK_${lib}_LIBRARY_DEBUG})
  endif()

endforeach()

set(CMAKE_THREAD_LIBS_INIT)
if(DCMTK_oflog_LIBRARY_RELEASE OR DCMTK_oflog_LIBRARY_DEBUG)
  # Hack - Not having a DCMTKConfig.cmake file to read the settings from, we will attempt to
  # find the library in all cases.
  # Ideally, pthread library should be discovered only if DCMTK_WITH_THREADS is enabled.
  find_package(Threads)
endif()

if(CMAKE_THREAD_LIBS_INIT)
  list(APPEND DCMTK_LIBRARIES ${CMAKE_THREAD_LIBS_INIT})
endif()

#
# SPECIFIC CASE FOR DCMTK BUILD DIR as DCMTK_DIR
# (as opposed to a DCMTK install dir)
# Have to find the source directory.
if(EXISTS ${DCMTK_DIR}/CMakeCache.txt)
          load_cache(${DCMTK_DIR} READ_WITH_PREFIX "EXT"
          DCMTK_SOURCE_DIR)
  if(NOT EXISTS ${EXTDCMTK_SOURCE_DIR})
    message(FATAL_ERROR
      "DCMTK build directory references
nonexistent DCMTK source directory ${EXTDCMTK_SOURCE_DIR}")
  endif()
endif()

set(DCMTK_config_TEST_HEADER osconfig.h)
set(DCMTK_dcmdata_TEST_HEADER dctypes.h)
set(DCMTK_dcmimage_TEST_HEADER dicoimg.h)
set(DCMTK_dcmimgle_TEST_HEADER dcmimage.h)
set(DCMTK_dcmjpeg_TEST_HEADER djdecode.h)
set(DCMTK_dcmnet_TEST_HEADER assoc.h)
set(DCMTK_dcmpstat_TEST_HEADER dcmpstat.h)
set(DCMTK_dcmqrdb_TEST_HEADER dcmqrdba.h)
set(DCMTK_dcmsign_TEST_HEADER sicert.h)
set(DCMTK_dcmsr_TEST_HEADER dsrtree.h)
set(DCMTK_dcmtls_TEST_HEADER tlslayer.h)
set(DCMTK_ofstd_TEST_HEADER ofstdinc.h)
set(DCMTK_oflog_TEST_HEADER oflog.h)
set(DCMTK_dcmjpls_TEST_HEADER djlsutil.h)

set(DCMTK_INCLUDE_DIR_NAMES)

foreach(dir
    config
    dcmdata
    dcmimage
    dcmimgle
    dcmjpeg
    dcmjpls
    dcmnet
    dcmpstat
    dcmqrdb
    dcmsign
    dcmsr
    dcmtls
    ofstd
    oflog)
  if(EXTDCMTK_SOURCE_DIR)
    set(SOURCE_DIR_PATH
      ${EXTDCMTK_SOURCE_DIR}/${dir}/include/dcmtk/${dir})
  endif()
  find_path(DCMTK_${dir}_INCLUDE_DIR
    ${DCMTK_${dir}_TEST_HEADER}
    PATHS
    ${DCMTK_DIR}/${dir}/include
    ${DCMTK_DIR}/${dir}
    ${DCMTK_DIR}/include/dcmtk/${dir}
    ${DCMTK_DIR}/${dir}/include/dcmtk/${dir}
    ${DCMTK_DIR}/include/${dir}
    ${SOURCE_DIR_PATH}
    )
  mark_as_advanced(DCMTK_${dir}_INCLUDE_DIR)
  list(APPEND DCMTK_INCLUDE_DIR_NAMES DCMTK_${dir}_INCLUDE_DIR)

  if(DCMTK_${dir}_INCLUDE_DIR)
    # add the 'include' path so eg
    #include "dcmtk/dcmimgle/dcmimage.h"
    # works
    get_filename_component(_include ${DCMTK_${dir}_INCLUDE_DIR} PATH)
    get_filename_component(_include ${_include} PATH)
    list(APPEND
      DCMTK_INCLUDE_DIRS
      ${DCMTK_${dir}_INCLUDE_DIR}
      ${_include})
  endif()
endforeach()

list(APPEND DCMTK_INCLUDE_DIRS ${DCMTK_DIR}/include)

if(WIN32)
  list(APPEND DCMTK_LIBRARIES netapi32 wsock32)
endif()

if(DCMTK_ofstd_INCLUDE_DIR)
  get_filename_component(DCMTK_dcmtk_INCLUDE_DIR
    ${DCMTK_ofstd_INCLUDE_DIR}
    PATH
    CACHE)
  list(APPEND DCMTK_INCLUDE_DIRS ${DCMTK_dcmtk_INCLUDE_DIR})
  mark_as_advanced(DCMTK_dcmtk_INCLUDE_DIR)
endif()

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

include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)
find_package_handle_standard_args(DCMTK
  REQUIRED_VARS ${DCMTK_INCLUDE_DIR_NAMES} DCMTK_LIBRARIES
  FAIL_MESSAGE "Please set DCMTK_DIR and re-run configure")

# Workaround bug in packaging of DCMTK 3.6.0 on Debian.
# See http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=637687
if(DCMTK_FOUND AND UNIX AND NOT APPLE)
  include(${CMAKE_CURRENT_LIST_DIR}/CheckIncludeFiles.cmake)
  set(CMAKE_REQUIRED_FLAGS )
  set(CMAKE_REQUIRED_DEFINITIONS )
  set(CMAKE_REQUIRED_INCLUDES ${DCMTK_INCLUDE_DIRS})
  set(CMAKE_REQUIRED_LIBRARIES ${DCMTK_LIBRARIES})
  set(CMAKE_REQUIRED_QUIET ${DCMTK_FIND_QUIETLY})
  check_include_files("dcmtk/config/osconfig.h;dcmtk/ofstd/ofstream.h" DCMTK_HAVE_CONFIG_H_OPTIONAL LANGUAGE CXX)
  if(NOT DCMTK_HAVE_CONFIG_H_OPTIONAL)
    set(DCMTK_DEFINITIONS "HAVE_CONFIG_H")
  endif()
endif()