David Darby wrote:
| My Windows programmer has provided me with jni compatible .c and .h
| files which compile just fine on his system. It creates a HiResTimer
| dll returning microsecond elapsed times. He wishes me to compile this
| into a shared library (called libHiResTimer.jnilib) to place into the
| same folder to allow the java byte code to work on both platforms.
| (I've used Microseconds() as a first attempt at this).
|
| I've followed the instructions in the XCode documentation on JNI using
| gcc and the command line. The calls are:
|
| cc -c -I/System/Library/Frameworks/JavaVM.framework/Headers
| com_cogstate_utils_HiResTimer.c
|
| which successfully creates the object file:
| com_cogstate_utils_HiResTimer.o
|
| Then:
|
| cc -dynamiclib -o libHiResTimer.jnilib com_cogstate_utils_HiResTimer.o
| -framework JavaVM
|
| This fails to link with the following error:
|
| internal link edit command failed
| ld: com_cogstate_utils_HiResTimer.o illegal reference to symbol:
| _Microseconds defined in indirectly referenced dynamic library
| /System/Library/Frameworks/CoreServices.framework/Versions/A/
| Frameworks/CarbonCore.framework/Versions/A/CarbonCore
This says that Microseconds is defined in CoreServices.framework, not JavaVM.framework, but you haven't sais that your code requires the CoreServices framework to run. (In other words, the linker knows where to find "Microseconds" only because Java uses it. Your code won't have that advantage.)
| So, how do I include the correct extra shared library that contains the
| Microseconds()?
Since the missing library is a framework (CoreServices.framework), the same way you included the JavaVM.framework: "-framework CoreServices".
| (I apologize if it's trivially simple and I need to include a lib from
| somewhere, but I tried without success to find and include all sorts
| of libs.)
The missing item isn't a library; it's a framework. Frameworks have libraries at their core, but include a bunch of other stuff, too. I suggest that you read the OS X overviews and learn how OS X handles object code. JNI is tricky enough without doing it blind.
Glen Fisher
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Java-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/java-dev/email@hidden
This email sent to email@hidden
