InteropLibrary with execute message cannot AOT

[tisonkun]

The class:

package io.korandoru.trufflebf.language;

import com.oracle.truffle.api.CompilerDirectives;
import com.oracle.truffle.api.TruffleLanguage;
import com.oracle.truffle.api.interop.InteropLibrary;
import com.oracle.truffle.api.interop.InvalidArrayIndexException;
import com.oracle.truffle.api.interop.TruffleObject;
import com.oracle.truffle.api.interop.UnsupportedMessageException;
import com.oracle.truffle.api.library.ExportLibrary;
import com.oracle.truffle.api.library.ExportMessage;

@ExportLibrary(InteropLibrary.class)
@SuppressWarnings("unused")
public class BFState implements TruffleObject {

    // code segment
    private final CharSequence instructions;
    private final int end;
    private int ip;

    // data segment
    private long[] data;
    private int dp;

    public BFState(CharSequence instructions) {
        this.instructions = instructions;
        this.end = instructions.length();
    }

    @ExportMessage
    boolean hasLanguage() {
        return true;
    }

    @ExportMessage
    Class<? extends TruffleLanguage<?>> getLanguage() {
        return BFLanguage.class;
    }

    @ExportMessage
    @CompilerDirectives.TruffleBoundary
    Object toDisplayString(boolean allowSideEffects) {
        return "State";
    }

    @ExportMessage
    boolean isExecutable() {
        return true;
    }

    @ExportMessage
    Object execute(Object[] arguments) throws UnsupportedMessageException {
        // reset instructions pointer
        this.ip = 0;

        boolean initialized = false;
        switch (arguments.length) {
            case 0 -> {
                this.data = new long[1024];
                this.dp = 0;
                initialized = true;
            }
            case 2 -> {
                if (arguments[0] instanceof TruffleObject object) {
                    InteropLibrary library = InteropLibrary.getFactory().getUncached();
                    int size = (int) library.getArraySize(object);
                    this.data = new long[size];
                    for (int i = 0; i < size; i++) {
                        try {
                            this.data[i] = ((Number) library.readArrayElement(object, i)).longValue();
                        } catch (InvalidArrayIndexException e) {
                            throw UnsupportedMessageException.create(e);
                        }
                    }
                    if (arguments[1] instanceof Number pointer) {
                        this.dp = pointer.intValue();
                        initialized = true;
                    }
                }
            }
        }

        if (!initialized) {
            throw UnsupportedMessageException.create();
        }

        return this.instructions;
    }
}

The output:

[3/7] Building universe...                                                                               (1.4s @ 1.08GB)

=== Found 2 compilation blocklist violations ===

Blocklisted method
  java.math.BigDecimal.intValue()
called from
  io.korandoru.trufflebf.language.BFState.execute(BFState.java:76)
  io.korandoru.trufflebf.language.BFStateGen$InteropLibraryExports$Cached.execute(BFStateGen.java:92)
  com.oracle.truffle.polyglot.PolyglotValueDispatch$InteropValue$AbstractExecuteNode.executeShared(PolyglotValueDispatch.java:4268)
  com.oracle.truffle.polyglot.PolyglotValueDispatch$InteropValue$ExecuteNoArgsNode.executeImpl(PolyglotValueDispatch.java:4375)
  com.oracle.truffle.polyglot.HostToGuestRootNode.execute(HostToGuestRootNode.java:124)
  org.graalvm.compiler.truffle.runtime.OptimizedCallTarget.executeRootNode(OptimizedCallTarget.java:709)
  org.graalvm.compiler.truffle.runtime.OptimizedCallTarget.profiledPERoot(OptimizedCallTarget.java:632)
  
Blocklisted method
  java.math.BigDecimal.longValue()
called from
  io.korandoru.trufflebf.language.BFState.execute(BFState.java:70)
  io.korandoru.trufflebf.language.BFStateGen$InteropLibraryExports$Cached.execute(BFStateGen.java:92)
  com.oracle.truffle.polyglot.PolyglotValueDispatch$InteropValue$AbstractExecuteNode.executeShared(PolyglotValueDispatch.java:4268)
  com.oracle.truffle.polyglot.PolyglotValueDispatch$InteropValue$ExecuteNoArgsNode.executeImpl(PolyglotValueDispatch.java:4375)
  com.oracle.truffle.polyglot.HostToGuestRootNode.execute(HostToGuestRootNode.java:124)
  org.graalvm.compiler.truffle.runtime.OptimizedCallTarget.executeRootNode(OptimizedCallTarget.java:709)
  org.graalvm.compiler.truffle.runtime.OptimizedCallTarget.profiledPERoot(OptimizedCallTarget.java:632)
  

Fatal error: com.oracle.svm.core.util.VMError$HostedError: Blocklisted methods are reachable for runtime compilation
	at com.oracle.svm.core.util.VMError.shouldNotReachHere(VMError.java:68)
	at com.oracle.svm.truffle.TruffleFeature.beforeCompilation(TruffleFeature.java:738)
	at com.oracle.svm.hosted.NativeImageGenerator.lambda$doRun$4(NativeImageGenerator.java:644)
	at com.oracle.svm.hosted.FeatureHandler.forEachFeature(FeatureHandler.java:85)
	at com.oracle.svm.hosted.NativeImageGenerator.doRun(NativeImageGenerator.java:644)
	at com.oracle.svm.hosted.NativeImageGenerator.run(NativeImageGenerator.java:535)
	at com.oracle.svm.hosted.NativeImageGeneratorRunner.buildImage(NativeImageGeneratorRunner.java:403)
	at com.oracle.svm.hosted.NativeImageGeneratorRunner.build(NativeImageGeneratorRunner.java:580)
	at com.oracle.svm.hosted.NativeImageGeneratorRunner.main(NativeImageGeneratorRunner.java:128)
	at com.oracle.svm.hosted.NativeImageGeneratorRunner$JDK9Plus.main(NativeImageGeneratorRunner.java:610)------------------------------------------------------------------------------------------------------------------------

                        0.5s (2.7% of total time) in 17 GCs | Peak RSS: 3.41GB | CPU load: 4.19
========================================================================================================================

The build command:

#!/usr/bin/env bash

if [[ $SL_BUILD_NATIVE == "false" ]]; then
    echo "Skipping the native image build because SL_BUILD_NATIVE is set to false."
    exit 0
fi
"$JAVA_HOME"/bin/native-image \
    --macro:truffle --no-fallback --initialize-at-build-time \
    -cp ../trufflebf-language/target/bf-language.jar:../trufflebf-launcher/target/bf-launcher.jar \
    io.korandoru.trufflebf.launcher.BFMain \
    bfnative

[tisonkun]

The general question can be: how do I write code as I wish in an export message context?

[tisonkun]

It seems adding a @CompilerDirectives.TruffleBoundary annotation to the execute method helps.