Add cmake version file

CMakeLists.txt

@@ -313,17 +313,29 @@ if (${CMAKE_VERSION} VERSION_LESS 3.0)
     ${${OPENJPEG_NAMESPACE}_BINARY_DIR}/OpenJPEGConfig.cmake
     @ONLY
   )
+  set(CVF_VERSION ${OPENJPEG_VERSION})
+  set(CVF_ARCH_INDEPENDENT FALSE)
+  configure_file(
+    ${${OPENJPEG_NAMESPACE}_SOURCE_DIR}/cmake/OpenJPEGConfigVersion.cmake.in
+    ${${OPENJPEG_NAMESPACE}_BINARY_DIR}/OpenJPEGConfigVersion.cmake
+    @ONLY)
 else()
   include(CMakePackageConfigHelpers)
   configure_package_config_file(${CMAKE_CURRENT_LIST_DIR}/cmake/OpenJPEGConfig.cmake.in
     ${OPENJPEG_BINARY_DIR}/OpenJPEGConfig.cmake
     INSTALL_DESTINATION ${OPENJPEG_INSTALL_PACKAGE_DIR}
     PATH_VARS CMAKE_INSTALL_INCLUDEDIR)
+  write_basic_package_version_file(
+    ${OPENJPEG_BINARY_DIR}/OpenJPEGConfigVersion.cmake
+    COMPATIBILITY SameMajorVersion
+    VERSION ${OPENJPEG_VERSION})
 endif()
 
-install( FILES ${OPENJPEG_BINARY_DIR}/OpenJPEGConfig.cmake
-  DESTINATION ${OPENJPEG_INSTALL_PACKAGE_DIR}
-)
+install(
+  FILES
+    ${OPENJPEG_BINARY_DIR}/OpenJPEGConfig.cmake
+    ${OPENJPEG_BINARY_DIR}/OpenJPEGConfigVersion.cmake
+  DESTINATION ${OPENJPEG_INSTALL_PACKAGE_DIR})
 
 #-----------------------------------------------------------------------------
 

cmake/OpenJPEGConfigVersion.cmake.in

@@ -0,0 +1,70 @@
+# This is a basic version file for the Config-mode of find_package().
+# It is used by write_basic_package_version_file() as input file for configure_file()
+# to create a version-file which can be installed along a config.cmake file.
+#
+# The created file sets PACKAGE_VERSION_EXACT if the current version string and
+# the requested version string are exactly the same and it sets
+# PACKAGE_VERSION_COMPATIBLE if the current version is >= requested version,
+# but only if the requested major version is the same as the current one.
+# The variable CVF_VERSION must be set before calling configure_file().
+
+
+set(PACKAGE_VERSION "@CVF_VERSION@")
+
+if(PACKAGE_VERSION VERSION_LESS PACKAGE_FIND_VERSION)
+  set(PACKAGE_VERSION_COMPATIBLE FALSE)
+else()
+
+  if("@CVF_VERSION@" MATCHES "^([0-9]+)\\.")
+    set(CVF_VERSION_MAJOR "${CMAKE_MATCH_1}")
+    if(NOT CVF_VERSION_MAJOR VERSION_EQUAL 0)
+      string(REGEX REPLACE "^0+" "" CVF_VERSION_MAJOR "${CVF_VERSION_MAJOR}")
+    endif()
+  else()
+    set(CVF_VERSION_MAJOR "@CVF_VERSION@")
+  endif()
+
+  if(PACKAGE_FIND_VERSION_RANGE)
+    # both endpoints of the range must have the expected major version
+    math (EXPR CVF_VERSION_MAJOR_NEXT "${CVF_VERSION_MAJOR} + 1")
+    if (NOT PACKAGE_FIND_VERSION_MIN_MAJOR STREQUAL CVF_VERSION_MAJOR
+        OR ((PACKAGE_FIND_VERSION_RANGE_MAX STREQUAL "INCLUDE" AND NOT PACKAGE_FIND_VERSION_MAX_MAJOR STREQUAL CVF_VERSION_MAJOR)
+          OR (PACKAGE_FIND_VERSION_RANGE_MAX STREQUAL "EXCLUDE" AND NOT PACKAGE_FIND_VERSION_MAX VERSION_LESS_EQUAL CVF_VERSION_MAJOR_NEXT)))
+      set(PACKAGE_VERSION_COMPATIBLE FALSE)
+    elseif(PACKAGE_FIND_VERSION_MIN_MAJOR STREQUAL CVF_VERSION_MAJOR
+        AND ((PACKAGE_FIND_VERSION_RANGE_MAX STREQUAL "INCLUDE" AND PACKAGE_VERSION VERSION_LESS_EQUAL PACKAGE_FIND_VERSION_MAX)
+        OR (PACKAGE_FIND_VERSION_RANGE_MAX STREQUAL "EXCLUDE" AND PACKAGE_VERSION VERSION_LESS PACKAGE_FIND_VERSION_MAX)))
+      set(PACKAGE_VERSION_COMPATIBLE TRUE)
+    else()
+      set(PACKAGE_VERSION_COMPATIBLE FALSE)
+    endif()
+  else()
+    if(PACKAGE_FIND_VERSION_MAJOR STREQUAL CVF_VERSION_MAJOR)
+      set(PACKAGE_VERSION_COMPATIBLE TRUE)
+    else()
+      set(PACKAGE_VERSION_COMPATIBLE FALSE)
+    endif()
+
+    if(PACKAGE_FIND_VERSION STREQUAL PACKAGE_VERSION)
+      set(PACKAGE_VERSION_EXACT TRUE)
+    endif()
+  endif()
+endif()
+
+
+# if the installed project requested no architecture check, don't perform the check
+if("@CVF_ARCH_INDEPENDENT@")
+  return()
+endif()
+
+# if the installed or the using project don't have CMAKE_SIZEOF_VOID_P set, ignore it:
+if("${CMAKE_SIZEOF_VOID_P}" STREQUAL "" OR "@CMAKE_SIZEOF_VOID_P@" STREQUAL "")
+  return()
+endif()
+
+# check that the installed version has the same 32/64bit-ness as the one which is currently searching:
+if(NOT CMAKE_SIZEOF_VOID_P STREQUAL "@CMAKE_SIZEOF_VOID_P@")
+  math(EXPR installedBits "@CMAKE_SIZEOF_VOID_P@ * 8")
+  set(PACKAGE_VERSION "${PACKAGE_VERSION} (${installedBits}bit)")
+  set(PACKAGE_VERSION_UNSUITABLE TRUE)
+endif()