cmake: use javac -h for creating JNI native headers

JDK 1.10 does not offer javah anymore, so we need to use "javac -h" or
add_jar(... GENERATE_NATIVE_HEADERS) instead.

Fixes: http://tracker.ceph.com/issues/24012
Signed-off-by: Kefu Chai <kchai@redhat.com>
(cherry picked from commit edc504b9d446cc1739f3e8e087914cfe66d6cac3)

Conflicts:
	src/java/CMakeLists.txt: in master, we dropped the support for
trusty, but luminous still supports trusty. while trusty ships JDK-7,
where javac does not support "-h" option yet. so we need to handle this
case. "-h" was introduced in Java SE 8, see
https://docs.oracle.com/javase/8/docs/technotes/guides/javac/index.html
.

diff --git a/src/java/CMakeLists.txt b/src/java/CMakeLists.txt
index fe365501de9e4736f9a584a0c67e4e1944e5fcc7..70ed8e6d839309ac9fffda33be80c529d2a8afee 100644 (file)
--- a/src/java/CMakeLists.txt
+++ b/src/java/CMakeLists.txt
@@ -22,18 +22,34 @@ set(java_srcs
 # as per
 #   https://blogs.oracle.com/darcy/entry/bootclasspath_older_source
 set(CMAKE_JAVA_COMPILE_FLAGS "-source" "1.7" "-target" "1.7" "-Xlint:-options")
-add_jar(libcephfs ${java_srcs})
+set(jni_header_dir "${CMAKE_CURRENT_BINARY_DIR}/native")
+if(Java_VERSION VERSION_LESS 1.8)
+  add_jar(libcephfs ${java_srcs})
+  get_property(libcephfs_jar TARGET libcephfs PROPERTY JAR_FILE)
+  set(java_h native/com_ceph_fs_CephMount.h)
+  add_custom_command(
+    OUTPUT ${java_h}
+    COMMAND ${Java_JAVAH_EXECUTABLE} -classpath ${libcephfs_jar} -jni -o ${java_h} com.ceph.fs.CephMount
+    COMMENT "Building C header files from classes...")
+  add_custom_target(jni-header
+    DEPENDS ${java_h})
+  add_dependencies(jni-header libcephfs)
+else()
+  if(CMAKE_VERSION VERSION_LESS 3.11)
+    set(CMAKE_JAVA_COMPILE_FLAGS ${CMAKE_JAVA_COMPILE_FLAGS} "-h" ${jni_header_dir})
+    add_jar(libcephfs ${java_srcs})
+    add_custom_target(
+      jni-header
+      DEPENDS libcephfs)
+    add_dependencies(jni-header libcephfs)
+  else()
+    add_jar(libcephfs ${java_srcs}
+      GENERATE_NATIVE_HEADERS jni-header
+      DESTINATION ${jni_header_dir})
+  endif()
+  get_property(libcephfs_jar TARGET libcephfs PROPERTY JAR_FILE)
+endif()
 install_jar(libcephfs share/java)
-get_property(libcephfs_jar TARGET libcephfs PROPERTY JAR_FILE)
-
-set(java_h native/com_ceph_fs_CephMount.h)
-add_custom_command(
-  OUTPUT ${java_h}
-  COMMAND ${Java_JAVAH_EXECUTABLE} -classpath ${libcephfs_jar} -jni -o ${CMAKE_CURRENT_BINARY_DIR}/${java_h} com.ceph.fs.CephMount)
-add_custom_target(
-  jni-header
-  DEPENDS ${java_h})
-add_dependencies(jni-header libcephfs)
 
 find_jar(JUNIT_JAR
   NAMES junit4 junit