add_jar: add option GENERATE_NATIVE_HEADERS

1 files changed, 73 insertions, 1 deletions

diff --git a/Modules/UseJava.cmake b/Modules/UseJava.cmake
index b5fc236..939bd7b 100644
--- a/Modules/UseJava.cmake
+++ b/Modules/UseJava.cmake
@@ -20,6 +20,7 @@
 #          [VERSION version]
 #          [OUTPUT_NAME name]
 #          [OUTPUT_DIR dir]
+#          [GENERATE_NATIVE_HEADERS target [DESTINATION dir]]
 #          )
 #
 # This command creates a <target_name>.jar.  It compiles the given
@@ -35,6 +36,14 @@
 # The default OUTPUT_DIR can also be changed by setting the variable
 # CMAKE_JAVA_TARGET_OUTPUT_DIR.
 #
+# Optionaly, using option GENERATE_NATIVE_HEADERS, native header files can be generated
+# for methods declared as native. These files provide the connective glue that allow your
+# Java and C code to interact. An INTERFACE target will be created for an easy usage
+# of generated files. Sub-option DESTINATION can be used to specify output directory for
+# generated header files.
+#
+# GENERATE_NATIVE_HEADERS option requires, at least, version 1.8 of the JDK.
+#
 # Additional instructions:
 #
 # ::
@@ -168,6 +177,22 @@
 #
 #
 #
+# ::
+#
+#     For an optimum usage of option GENERATE_NATIVE_HEADERS, it is recommended to
+#     include module JNI before any call to add_jar. The produced target for native
+#     headers can then be used to compile C/C++ sources with command
+#     target_link_libraries.
+#
+#
+# ::
+#
+#        find_package(JNI)
+#        add_jar(foo foo.java GENERATE_NATIVE_HEADERS foo-native)
+#        add_library(bar bar.cpp)
+#        target_link_libraries(bar PRIVATE foo-native)
+#
+#
 # Target Properties:
 #
 # ::
@@ -359,6 +384,10 @@
 # Create C header files from java classes. These files provide the connective glue
 # that allow your Java and C code to interact.
 #
+# This command will no longer be supported starting with version 1.10 of the JDK due
+# to the `suppression of javah tool <http://openjdk.java.net/jeps/313>`_.
+# Command ``add_jar(GENERATE_NATIVE_HEADERS)`` must be used instead.
+#
 # There are two main signatures for create_javah.  The first signature
 # returns generated files through variable specified by GENERATED_FILES option:
 #
@@ -448,7 +477,7 @@ function(add_jar _TARGET_NAME)
     cmake_parse_arguments(_add_jar
       ""
       "VERSION;OUTPUT_DIR;OUTPUT_NAME;ENTRY_POINT;MANIFEST"
-      "SOURCES;INCLUDE_JARS"
+      "SOURCES;INCLUDE_JARS;GENERATE_NATIVE_HEADERS"
       ${ARGN}
     )
 
@@ -494,6 +523,31 @@ function(add_jar _TARGET_NAME)
         get_filename_component (_MANIFEST_VALUE "${_add_jar_MANIFEST}" ABSOLUTE)
     endif ()
 
+    unset (_GENERATE_NATIVE_HEADERS)
+    if (_add_jar_GENERATE_NATIVE_HEADERS)
+      # Raise an error if JDK version is less than 1.8 because javac -h is not supported
+      # by earlier versions.
+      if ("${Java_VERSION}" VERSION_LESS 1.8)
+        message (FATAL_ERROR "ADD_JAR: GENERATE_NATIVE_HEADERS is not supported with this version of Java.")
+      endif()
+      cmake_parse_arguments (_add_jar_GENERATE_NATIVE_HEADERS "" "DESTINATION" "" ${_add_jar_GENERATE_NATIVE_HEADERS})
+      if (NOT _add_jar_GENERATE_NATIVE_HEADERS_UNPARSED_ARGUMENTS)
+        message (FATAL_ERROR "ADD_JAR: GENERATE_NATIVE_HEADERS: missing required argument.")
+      endif()
+      list (LENGTH _add_jar_GENERATE_NATIVE_HEADERS_UNPARSED_ARGUMENTS length)
+      if (length GREATER 1)
+        list (REMOVE_AT _add_jar_GENERATE_NATIVE_HEADERS_UNPARSED_ARGUMENTS 0)
+        message (FATAL_ERROR "ADD_JAR: GENERATE_NATIVE_HEADERS: ${_add_jar_GENERATE_NATIVE_HEADERS_UNPARSED_ARGUMENTS}: unexpected argument(s).")
+      endif()
+      if (NOT _add_jar_GENERATE_NATIVE_HEADERS_DESTINATION)
+        set (_add_jar_GENERATE_NATIVE_HEADERS_DESTINATION "${CMAKE_CURRENT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/${_TARGET_NAME}.dir/native_headers")
+      endif()
+
+      set (_GENERATE_NATIVE_HEADERS_TARGET ${_add_jar_GENERATE_NATIVE_HEADERS_UNPARSED_ARGUMENTS})
+      set (_GENERATE_NATIVE_HEADERS_OUTPUT_DIR "${_add_jar_GENERATE_NATIVE_HEADERS_DESTINATION}")
+      set (_GENERATE_NATIVE_HEADERS -h "${_GENERATE_NATIVE_HEADERS_OUTPUT_DIR}")
+    endif()
+
     if (LIBRARY_OUTPUT_PATH)
         set(CMAKE_JAVA_LIBRARY_OUTPUT_PATH ${LIBRARY_OUTPUT_PATH})
     else ()
@@ -625,6 +679,7 @@ function(add_jar _TARGET_NAME)
                 ${CMAKE_JAVA_COMPILE_FLAGS}
                 -classpath "${CMAKE_JAVA_INCLUDE_PATH_FINAL}"
                 -d ${CMAKE_JAVA_CLASS_OUTPUT_PATH}
+                ${_GENERATE_NATIVE_HEADERS}
                 ${_JAVA_SOURCES_FILELISTS}
             COMMAND ${CMAKE_COMMAND} -E touch ${CMAKE_JAVA_CLASS_OUTPUT_PATH}/java_compiled_${_TARGET_NAME}
             DEPENDS ${_JAVA_COMPILE_FILES} ${_JAVA_COMPILE_FILELISTS} ${_JAVA_COMPILE_DEPENDS}
@@ -735,6 +790,17 @@ function(add_jar _TARGET_NAME)
                 ${CMAKE_JAVA_CLASS_OUTPUT_PATH}
     )
 
+  if (_GENERATE_NATIVE_HEADERS)
+    # create an INTERFACE library encapsulating include directory for generated headers
+    add_library (${_GENERATE_NATIVE_HEADERS_TARGET} INTERFACE)
+    target_include_directories (${_GENERATE_NATIVE_HEADERS_TARGET} INTERFACE
+      "${_GENERATE_NATIVE_HEADERS_OUTPUT_DIR}"
+      ${JNI_INCLUDE_DIRS})
+    # this INTERFACE library depends on jar generation
+    add_dependencies (${_GENERATE_NATIVE_HEADERS_TARGET} ${_TARGET_NAME})
+
+    set_property (DIRECTORY PROPERTY ADDITIONAL_MAKE_CLEAN_FILES "${_GENERATE_NATIVE_HEADERS_OUTPUT_DIR}")
+  endif()
 endfunction()
 
 function(INSTALL_JAR _TARGET_NAME)
@@ -1246,6 +1312,12 @@ function(create_javadoc _target)
 endfunction()
 
 function (create_javah)
+  if ("${Java_VERSION}" VERSION_GREATER_EQUAL 1.10)
+    message (FATAL_ERROR "create_javah: not supported with this Java version. Use add_jar(GENERATE_NATIVE_HEADERS) instead.")
+  elseif ("${Java_VERSION}" VERSION_GREATER_EQUAL 1.8)
+    message (DEPRECATION "create_javah: this command will no longer be supported starting with version 1.10 of JDK. Update your project by using command add_jar(GENERATE_NATIVE_HEADERS) instead.")
+  endif()
+
     cmake_parse_arguments(_create_javah
       ""
       "TARGET;GENERATED_FILES;OUTPUT_NAME;OUTPUT_DIR"