Issues with JNI .so for FRC

[AustinSchuh]

Originally Posted by connor.worley

and running into an error resolving _ZN5nFPGA16nFRC_2016_16_1_020g_currentTargetClassE . Does anyone know what static library provides this? We are already using all static libraries available in wpilib/cpp/current/lib.

austin[23463] iron ~/local/robotics/971-Robot-Code/bazel-971-Robot-Code/external/allwpilib_ni_libraries_repo
$ grep -R "_ZN5nFPGA16nFRC_2016_16_1_020g_currentTargetClassE" ./
Binary file ./libFRC_NetworkCommunicationLV.so.16.0.0 matches
Binary file ./libRoboRIO_FRC_ChipObject.so.16.0.0 matches
austin[23464] iron ~/local/robotics/971-Robot-Code/bazel-971-Robot-Code/external/allwpilib_ni_libraries_repo
$ c++filt 
_ZN5nFPGA16nFRC_2016_16_1_020g_currentTargetClassE
nFPGA::nFRC_2016_16_1_0::g_currentTargetClass
austin[23461] iron (master) ~/local/robotics/971-Robot-Code
$ git grep g_currentTargetClass
third_party/allwpilib_2016/hal/lib/Athena/FRC_FPGA_ChipObject/nInvariantFPGANamespace/nInterfaceGlobals.h:   extern unsigned int g_currentTargetClass;
third_party/allwpilib_2016/hal/lib/Athena/FRC_FPGA_ChipObject/nRoboRIO_FPGANamespace/nInterfaceGlobals.h:   extern unsigned int g_currentTargetClass;
third_party/allwpilib_2016/hal/lib/Athena/FRC_FPGA_ChipObject/nRuntimeFPGANamespace/nInterfaceGlobals.h:   extern unsigned int g_currentTargetClass;

Looks like part of libRoboRIO_FRC_ChipObject.so

[Peter Johnson]

Note that libRoboRIO_FRC_ChipObject requires other libraries, so you'll probably need to link to nearly every .so in cpp/current/lib. There's two ways to do this: the standard JNI .so (which is built using gradle) explicitly links every .so except libwpi.so and libwpi_2015.so. When building C++ via eclipse, libwpi.so is referenced, which is actually a text file which references libwpi_2015.so, which is also a text file which references a bunch of .so's as well as a couple of .a's.

[connor.worley]

Got it - we later found that libHALAthena.so was missing from the roboRIO and copied over all libs to /usr/lib. Finally worked.