How to link Z3 build, Compiled for Java, from Eclipse Plugin? - eclipse-plugin

Question

I have a perfectly working Z3 Build system for Java. I want to call it from an Eclipse plugin. I tried several approaches, but non of them are working for me. These approaches are:
Adding Z3 build as an external class folder
How to Use External Class Files in an Eclipse Project
Exception in thread "main" java.lang.UnsatisfiedLinkError: no
libz3java in java.library.path at
java.lang.ClassLoader.loadLibrary(ClassLoader.java:1867) at
java.lang.Runtime.loadLibrary0(Runtime.java:870) at
java.lang.System.loadLibrary(System.java:1122) at
com.microsoft.z3.Native.(Native.java:14) at
com.microsoft.z3.Global.ToggleWarningMessages(Global.java:87) at
TestZ3.main(TestZ3.java:9)
Copied Z3 build to the Eclipse plugin, at the root. Then added com.microsoft.z3.jar under the Libraries (Right-mouth click on the project->Build Path->Configure Build Path->Libraries->Add Jars). The error is:
java.lang.UnsatisfiedLinkError: no libz3java in java.library.path at
java.lang.ClassLoader.loadLibrary(ClassLoader.java:1867) at
java.lang.Runtime.loadLibrary0(Runtime.java:870) at
java.lang.System.loadLibrary(System.java:1122) at
com.microsoft.z3.Native.(Native.java:14) at
com.microsoft.z3.Global.ToggleWarningMessages(Global.java:87) at
plugintest.handlers.SampleHandler.execute(SampleHandler.java:37) at
org.eclipse.ui.internal.handlers.HandlerProxy.execute(HandlerProxy.java:295)
at
org.eclipse.ui.internal.handlers.E4HandlerProxy.execute(E4HandlerProxy.java:90)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498) at
org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:56)
at
org.eclipse.e4.core.internal.di.InjectorImpl.invokeUsingClass(InjectorImpl.java:252)
at
org.eclipse.e4.core.internal.di.InjectorImpl.invoke(InjectorImpl.java:234)
at
org.eclipse.e4.core.contexts.ContextInjectionFactory.invoke(ContextInjectionFactory.java:132)
at
org.eclipse.e4.core.commands.internal.HandlerServiceHandler.execute(HandlerServiceHandler.java:152)
at
org.eclipse.core.commands.Command.executeWithChecks(Command.java:493)
at
org.eclipse.core.commands.ParameterizedCommand.executeWithChecks(ParameterizedCommand.java:486)
at
org.eclipse.e4.core.commands.internal.HandlerServiceImpl.executeHandler(HandlerServiceImpl.java:210)
at
org.eclipse.e4.ui.workbench.renderers.swt.HandledContributionItem.executeItem(HandledContributionItem.java:799)
at
org.eclipse.e4.ui.workbench.renderers.swt.HandledContributionItem.handleWidgetSelection(HandledContributionItem.java:675)
at
org.eclipse.e4.ui.workbench.renderers.swt.HandledContributionItem.access$7(HandledContributionItem.java:659)
at
org.eclipse.e4.ui.workbench.renderers.swt.HandledContributionItem$4.handleEvent(HandledContributionItem.java:592)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4362) at
org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1113) at
org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4180)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3769)
at
org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$4.run(PartRenderingEngine.java:1127)
at
org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:337)
at
org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1018)
at
org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:156)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:694) at
org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:337)
at
org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:606)
at
org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:150)
at
org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:139)
at
org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at
org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
at
org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
at
org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:380)
at
org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:235)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498) at
org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:669) at
org.eclipse.equinox.launcher.Main.basicRun(Main.java:608) at
org.eclipse.equinox.launcher.Main.run(Main.java:1515) at
org.eclipse.equinox.launcher.Main.main(Main.java:1488)
With or without the previous step, I added com.microsoft.z3.jar to Classpath, located at the Plugin.xml Runtime tab. In this case, the plugin is not finding the handler that is invoked after button press command.
!MESSAGE plugintest.handlers.SampleHandler cannot be found by
PluginTest_1.0.0.qualifier !STACK 0 java.lang.ClassNotFoundException:
plugintest.handlers.SampleHandler cannot be found by ....more
In fact, this approach worked for me a previous a installation (Dell, Intel, x64, Eclipse Mars (x64), Java 1.8 x64)!
Following the discussion in https://github.com/Z3Prover/z3/issues/1093, I configured Native Library Location of com.microsoft.z3.jar with the Z3 Build directory. Calling the Z3 Build from Eclipse plugin, the error reported is the same as in Approach 2, but calling it from a Java application, the error is more specific:
Exception in thread "main" java.lang.UnsatisfiedLinkError:
C:\Users...TestZ33\build\libz3java.dll: Can't find dependent libraries
at java.lang.ClassLoader$NativeLibrary.load(Native Method)
at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1941)
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1857)
at java.lang.Runtime.loadLibrary0(Runtime.java:870)
at java.lang.System.loadLibrary(System.java:1122)
at com.microsoft.z3.Native.(Native.java:14)
at com.microsoft.z3.Global.ToggleWarningMessages(Global.java:87)
at TestZ3.main(TestZ3.java:9)
Other https://www.chilkatsoft.com/java-loadlibrary-windows.asp
What is working is when you have a Java application under the Z3 build directory. Can anyone help how to use the Z3 build directory from a Java application, or from Eclipse plugin. By the way, I followed approach #2, was working fine until I try to replicate it (because my laptop crashed) and forced to use another laptop, then the same procedure is not working for me (I had luck, before). Right now, the new laptop has the following settings:
HP Laptop (AMD, x64)
C:\Users\nmd02\git\resa_mars_workspace>java -version
java version "1.8.0_144"
Java(TM) SE Runtime Environment (build 1.8.0_144-b01)
Java HotSpot(TM) 64-Bit Server VM (build 25.144-b01, mixed mode)
PATH:
%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;%SYSTEMROOT%\System32\WindowsPowerShell\v1.0\;C:\Program
Files (x86)\QuickTime\QTSystem\;C:\Program
Files\MATLAB\2017a\runtime\win64;C:\Program
Files\Java\jdk1.8.0_144\bin;C:\Program Files\Git\cmd;C:\Program
Files\CMake\bin;C:\MinGW\bin;C:\python36;C:\Users...git\ninja;C:\Program
Files (x86)\Windows Kits\8.1\Windows Performance
Toolkit\;C:\gnuwin32\bin
I really appreciate for your help in advance.
Cheers,
/Nas

Answer 1

At runtime your code needs to find com.microsoft.z3.jar, libz3.dll/.so/.dylib, and libz3java.dll/.so/.dylib. Java takes care of the first one, but the operating system will have to find the other libraries, i.e., whatever environment your code runs in must be set up such that PATH (Windows), LD_LIBRARY_PATH (Linux), or DYLD_LIBRARY_PATH (OSX) point to the libraries. Also, make sure that your version of Z3 and your version of Java are both 32-bit or 64-bit, otherwise the error messages you get may not be very informative.
For some flavors of Java, it may also be necessary or helpful to provide the java.library.path setting to the JVM.