drop dependencies of unused linked libraries

libjavatinyb.so currently links against libraries that are not necessary
at runtime anymore.
For example the "libjawt.so" and "libjvm.so" needs to be found by the
dynamic linker at runtime without any need.

Here the output of ldd for libjavatinyb.so before:
  linux-vdso.so.1 (0x00007ffed2fdf000)
  libjawt.so => not found
  libjvm.so => not found
  libtinyb.so.0.5.0-18-g6fb269f => /tmp/tinyb/build/install/lib64/libtinyb.so.0.5.0-18-g6fb269f (0x00007f68c50c6000)
  libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f68c4ea6000)
  libglib-2.0.so.0 => /usr/lib64/libglib-2.0.so.0 (0x00007f68c4b8f000)
  libgio-2.0.so.0 => /usr/lib64/libgio-2.0.so.0 (0x00007f68c47f9000)
  libgobject-2.0.so.0 => /usr/lib64/libgobject-2.0.so.0 (0x00007f68c45a5000)
  libstdc++.so.6 => /usr/lib/gcc/x86_64-pc-linux-gnu/6.4.0/libstdc++.so.6 (0x00007f68c41a3000)
  libm.so.6 => /lib64/libm.so.6 (0x00007f68c3e9a000)
  libgcc_s.so.1 => /usr/lib/gcc/x86_64-pc-linux-gnu/6.4.0/libgcc_s.so.1 (0x00007f68c3c83000)
  libc.so.6 => /lib64/libc.so.6 (0x00007f68c38d0000)
  /lib64/ld-linux-x86-64.so.2 (0x00005569851cc000)
  libpcre.so.1 => /lib64/libpcre.so.1 (0x00007f68c365f000)
  libgmodule-2.0.so.0 => /usr/lib64/libgmodule-2.0.so.0 (0x00007f68c345b000)
  libz.so.1 => /lib64/libz.so.1 (0x00007f68c3244000)
  libresolv.so.2 => /lib64/libresolv.so.2 (0x00007f68c302d000)
  libmount.so.1 => /lib64/libmount.so.1 (0x00007f68c2dd8000)
  libffi.so.6 => /usr/lib64/libffi.so.6 (0x00007f68c2bcd000)
  libdl.so.2 => /lib64/libdl.so.2 (0x00007f68c29c9000)
  libblkid.so.1 => /lib64/libblkid.so.1 (0x00007f68c277e000)
  librt.so.1 => /lib64/librt.so.1 (0x00007f68c2576000)
  libuuid.so.1 => /lib64/libuuid.so.1 (0x00007f68c2371000)

Here the output of ldd for libjavatinyb.so after:
  linux-vdso.so.1 (0x00007fff037ce000)
  libtinyb.so.0.5.0-18-g6fb269f => /tmp/tinyb/build/install/lib64/libtinyb.so.0.5.0-18-g6fb269f (0x00007fd9f60d7000)
  libstdc++.so.6 => /usr/lib/gcc/x86_64-pc-linux-gnu/6.4.0/libstdc++.so.6 (0x00007fd9f5c99000)
  libgcc_s.so.1 => /usr/lib/gcc/x86_64-pc-linux-gnu/6.4.0/libgcc_s.so.1 (0x00007fd9f5a82000)
  libc.so.6 => /lib64/libc.so.6 (0x00007fd9f56d1000)
  /lib64/ld-linux-x86-64.so.2 (0x00005607dae4e000)
  libpthread.so.0 => /lib64/libpthread.so.0 (0x00007fd9f54af000)
  libglib-2.0.so.0 => /usr/lib64/libglib-2.0.so.0 (0x00007fd9f519a000)
  libgio-2.0.so.0 => /usr/lib64/libgio-2.0.so.0 (0x00007fd9f4e04000)
  libgobject-2.0.so.0 => /usr/lib64/libgobject-2.0.so.0 (0x00007fd9f4bb0000)
  libm.so.6 => /lib64/libm.so.6 (0x00007fd9f48a7000)
  libpcre.so.1 => /lib64/libpcre.so.1 (0x00007fd9f4636000)
  libgmodule-2.0.so.0 => /usr/lib64/libgmodule-2.0.so.0 (0x00007fd9f4430000)
  libz.so.1 => /lib64/libz.so.1 (0x00007fd9f4219000)
  libresolv.so.2 => /lib64/libresolv.so.2 (0x00007fd9f4002000)
  libmount.so.1 => /lib64/libmount.so.1 (0x00007fd9f3dad000)
  libffi.so.6 => /usr/lib64/libffi.so.6 (0x00007fd9f3ba4000)
  libdl.so.2 => /lib64/libdl.so.2 (0x00007fd9f39a0000)
  libblkid.so.1 => /lib64/libblkid.so.1 (0x00007fd9f3753000)
  librt.so.1 => /lib64/librt.so.1 (0x00007fd9f354b000)
  libuuid.so.1 => /lib64/libuuid.so.1 (0x00007fd9f3346000)

Signed-off-by: Markus Rathgeb <[email protected]>

Author: Markus Rathgeb

java/jni/CMakeLists.txt

@@ -19,6 +19,8 @@ include_directories(
 
 file(GLOB JNI_SOURCES "*.cxx")
 
+set (CMAKE_SHARED_LINKER_FLAGS "-Wl,--as-needed")
+
 add_library (javatinyb SHARED ${JNI_SOURCES})
 target_link_libraries(javatinyb ${JNI_LIBRARIES} tinyb)