[BUG] Methods with empty body in imp

[lisa-analyzer]

[BUG] Methods with empty body in imp

[pietroferrara]

For instance, when analyzing the following code:

class A { foo() { } }

with the sign (or other value) domains (e.g., with ModularWorstCaseAnalysisTest) one gets the following exception:

it.unive.lisa.AnalysisException: LiSA has encountered an exception while executing the analysis at it.unive.lisa.LiSA.run(LiSA.java:310) at it.unive.lisa.test.interprocedural.ModularWorstCaseInterproceduralAnalysisTest.testCHACallGraph(ModularWorstCaseInterproceduralAnalysisTest.java:47) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:566) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268) at org.junit.runners.ParentRunner.run(ParentRunner.java:363) at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.runTestClass(JUnitTestClassExecutor.java:110) at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:58) at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:38) at org.gradle.api.internal.tasks.testing.junit.AbstractJUnitTestClassProcessor.processTestClass(AbstractJUnitTestClassProcessor.java:62) at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.processTestClass(SuiteTestClassProcessor.java:51) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:566) at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36) at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24) at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33) at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94) at com.sun.proxy.$Proxy2.processTestClass(Unknown Source) at org.gradle.api.internal.tasks.testing.worker.TestWorker.processTestClass(TestWorker.java:118) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:566) at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36) at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24) at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:182) at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:164) at org.gradle.internal.remote.internal.hub.MessageHub$Handler.run(MessageHub.java:412) at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64) at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:48) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56) at java.base/java.lang.Thread.run(Thread.java:834) Caused by: it.unive.lisa.AnalysisExecutionException: Exception during fixpoint computation at it.unive.lisa.LiSA.lambda$runAux$4(LiSA.java:456) at it.unive.lisa.logging.TimerLogger.execAux(TimerLogger.java:882) at it.unive.lisa.logging.TimerLogger.execAction(TimerLogger.java:55) at it.unive.lisa.logging.TimerLogger.execAction(TimerLogger.java:27) at it.unive.lisa.LiSA.runAux(LiSA.java:450) at it.unive.lisa.logging.TimerLogger.execAux(TimerLogger.java:882) at it.unive.lisa.logging.TimerLogger.execAction(TimerLogger.java:55) at it.unive.lisa.logging.TimerLogger.execAction(TimerLogger.java:27) at it.unive.lisa.LiSA.run(LiSA.java:308) ... 48 more Caused by: it.unive.lisa.util.datastructures.graph.FixpointException: Unexpected exception during fixpoint computation at it.unive.lisa.util.datastructures.graph.FixpointGraph.fixpoint(FixpointGraph.java:276) at it.unive.lisa.program.cfg.CFG.fixpoint(CFG.java:720) at it.unive.lisa.program.cfg.CFG.fixpoint(CFG.java:322) at it.unive.lisa.program.cfg.CFG.fixpoint(CFG.java:178) at it.unive.lisa.interprocedural.impl.ModularWorstCaseAnalysis.fixpoint(ModularWorstCaseAnalysis.java:76) at it.unive.lisa.LiSA.lambda$runAux$4(LiSA.java:453) ... 56 more Caused by: it.unive.lisa.util.datastructures.graph.FixpointException: Unknown node encountered during fixpoint execution in 'untyped A::foo() [at 'imp-testcases/interprocedural/program.imp':2:4]' at it.unive.lisa.util.datastructures.graph.FixpointGraph.fixpoint(FixpointGraph.java:196) ... 61 more

[lucaneg]

This is a wider problem of how empty blocks are parsed. The following programs cause exceptions either while parsing or while executing the fixpoint:

class empty { 
    foo() {
    }
}

class empty { 
    foo() {
        if (true) { 
            this.foo(); 
        } else {
        }
    }
}