[instrumentation] "Object (...) should not be materialized" errors

[fniephaus]

When using the Chrome debugger via the --inspect option, we see quite a few compiler errors (such as the one below) for our language. It seems that the compiler is unable to optimize a call target due to a Frame#materialize() call. How can this be fixed?

[truffle] opt fail         Heap>>downHeapSingle: <split-463685c6>                      |Reason org.graalvm.compiler.code.SourceStackTraceBailoutException$1: Object of type Lorg/graalvm/compiler/truffle/runtime/FrameWithoutBoxing; shoul
d not be materialized:                                                                                                                                                                                                                     
org.graalvm.compiler.code.SourceStackTraceBailoutException$1: Object of type Lorg/graalvm/compiler/truffle/runtime/FrameWithoutBoxing; should not be materialized:                                                                         
        at com.oracle.truffle.api.debug.DebuggerSession$SteppingNode.onEnter(DebuggerSession.java:1286)                                                                                                                                    
        at com.oracle.truffle.api.debug.DebuggerSession$RootSteppingDepthNode.onEnter(DebuggerSession.java:1378)                                                                                                                           
        at com.oracle.truffle.api.instrumentation.ProbeNode$EventProviderChainNode.innerOnEnter(ProbeNode.java:1449)                                                                                                                       
        at com.oracle.truffle.api.instrumentation.ProbeNode$EventChainNode.onEnter(ProbeNode.java:898)                                                                                                                                     
        at com.oracle.truffle.api.instrumentation.ProbeNode.onEnter(ProbeNode.java:156)                                                                                                                                                    
        at de.hpi.swa.graal.squeak.nodes.EnterCodeNodeWrapper.execute(EnterCodeNodeWrapper.java:44)                                                                                                                                        
        at de.hpi.swa.graal.squeak.nodes.EnterCodeNode$SqueakCodeRootNode.execute(EnterCodeNode.java:61)                                                                                                                                   
        at org.graalvm.compiler.truffle.runtime.OptimizedCallTarget.callProxy(OptimizedCallTarget.java:325)                                                                                                                                
        at org.graalvm.compiler.truffle.runtime.OptimizedCallTarget.callRoot(OptimizedCallTarget.java:315)                                                                                                                                 
Caused by: org.graalvm.compiler.graph.VerificationError: Object of type Lorg/graalvm/compiler/truffle/runtime/FrameWithoutBoxing; should not be materialized:                                                                              
        at org.graalvm.compiler.nodes.virtual.EnsureVirtualizedNode.ensureVirtualFailure(EnsureVirtualizedNode.java:98)                                                                                                                    
        at org.graalvm.compiler.nodes.virtual.EnsureVirtualizedNode.lower(EnsureVirtualizedNode.java:82)                                                                                                                                   
        at org.graalvm.compiler.phases.common.LoweringPhase$Round.process(LoweringPhase.java:476)                                                                                                                                          
        at org.graalvm.compiler.phases.common.LoweringPhase$Round.access$200(LoweringPhase.java:352)                                                                                                                                       
        at org.graalvm.compiler.phases.common.LoweringPhase$Round$ProcessFrame.preprocess(LoweringPhase.java:416)                                                                                                                          
        at org.graalvm.compiler.phases.common.LoweringPhase.processBlock(LoweringPhase.java:575)                                                                                                                                           
        at org.graalvm.compiler.phases.common.LoweringPhase$Round.run(LoweringPhase.java:401)                                                                                                                                              
        at org.graalvm.compiler.phases.Phase.run(Phase.java:49)                                                                                                                                                                            
        at org.graalvm.compiler.phases.BasePhase.apply(BasePhase.java:197)                                                                                                                                                                 
        at org.graalvm.compiler.phases.BasePhase.apply(BasePhase.java:139)                                                                                                                                                                 
        at org.graalvm.compiler.phases.PhaseSuite.run(PhaseSuite.java:212)                                                                                                                                                                 
        at org.graalvm.compiler.phases.common.IncrementalCanonicalizerPhase.run(IncrementalCanonicalizerPhase.java:56)                                                                                                                     
        at org.graalvm.compiler.phases.common.IncrementalCanonicalizerPhase.run(IncrementalCanonicalizerPhase.java:38)                                                                                                                     
        at org.graalvm.compiler.phases.BasePhase.apply(BasePhase.java:197)                                                                                                                                                                 
        at org.graalvm.compiler.phases.BasePhase.apply(BasePhase.java:139)                                                                                                                                                                 
        at org.graalvm.compiler.phases.common.LoweringPhase.lower(LoweringPhase.java:272)                                                                                                                                                  
        at org.graalvm.compiler.phases.common.LoweringPhase.run(LoweringPhase.java:265)                                                                                                                                                    
        at org.graalvm.compiler.phases.common.LoweringPhase.run(LoweringPhase.java:95)                                                                                                                                                     
        at org.graalvm.compiler.phases.BasePhase.apply(BasePhase.java:197)                                                                                                                                                                 
        at org.graalvm.compiler.phases.BasePhase.apply(BasePhase.java:139)                                                                                                                                                                 
        at org.graalvm.compiler.phases.PhaseSuite.run(PhaseSuite.java:212)                                                                                                                                                                 
        at org.graalvm.compiler.phases.BasePhase.apply(BasePhase.java:197)                                                                                                                                                                 
        at org.graalvm.compiler.phases.BasePhase.apply(BasePhase.java:139)                                                                                                                                                                 
        at org.graalvm.compiler.core.GraalCompiler.emitFrontEnd(GraalCompiler.java:220)                                                                                                                                                    
        at org.graalvm.compiler.core.GraalCompiler.compile(GraalCompiler.java:144)                                                                                                                                                         
        at org.graalvm.compiler.core.GraalCompiler.compileGraph(GraalCompiler.java:129)                                                                                                                                                    
        at org.graalvm.compiler.truffle.compiler.TruffleCompilerImpl.compilePEGraph(TruffleCompilerImpl.java:518)                                                                                                                          
        at org.graalvm.compiler.truffle.compiler.TruffleCompilerImpl.compileAST(TruffleCompilerImpl.java:452)                                                                                                                              
        at org.graalvm.compiler.truffle.compiler.TruffleCompilerImpl$TruffleCompilationWrapper.performCompilation(TruffleCompilerImpl.java:621)                                                                                            
        at org.graalvm.compiler.truffle.compiler.TruffleCompilerImpl$TruffleCompilationWrapper.performCompilation(TruffleCompilerImpl.java:568)                                                                                            
        at org.graalvm.compiler.core.CompilationWrapper.run(CompilationWrapper.java:177)                                                                                                                                                   
        at org.graalvm.compiler.truffle.compiler.TruffleCompilerImpl.doCompile(TruffleCompilerImpl.java:280)                                                                                                                               
        at org.graalvm.compiler.truffle.compiler.hotspot.libgraal.HotSpotToSVMEntryPoints.doCompile(HotSpotToSVMEntryPoints.java:251)   

[woess]

Do you have CompilerDirectives.ensureVirtualized somewhere in your code?

[fniephaus]

Good catch, yes I do. Apart from removing it, is there any other way to work around this problem?

[woess]

I'm afraid that's the only way to fix this problem currently, since the SteppingNode materializes the frame.

[fniephaus]

Thanks for the info!

[chumer]

@fniephaus you may still use CompilerDirectives.ensureVirtualized in unit tests, maybe even use instrumentation to insert the check.

[fniephaus]

@chumer I realized that CompilerDirectives.ensureVirtualized is barely used in any of the language implementations. Also, I saw that TCK deploys checks via the instrument API. That's probably a good idea. Thanks for the idea!