oracle/graal · error · IllegalArgumentException

Unsupported kind:

Error message

Unsupported kind: 

What it means

Error "Unsupported kind: " thrown in oracle/graal.

Source

Thrown at espresso-compiler-stub/src/com.oracle.truffle.espresso.vmaccess/src/com/oracle/truffle/espresso/vmaccess/EspressoExternalVMAccess.java:1067

        if (!(arrayType.isArray() && arrayType.getComponentType().isPrimitive())) {
            throw new IllegalArgumentException("Source should be a primitive array, got " + arrayType);
        }
        Value value = objectConstant.getValue();
        long byteLength = value.getBufferSize();
        int bytesToRead = kind.getByteCount();
        if (offset < 0 || (long) offset + bytesToRead > byteLength) {
            throw new IllegalArgumentException("Invalid input range: " + offset + ".." + (offset + bytesToRead) + " for buffer size " + byteLength);
        }
        return switch (kind) {
            case Boolean -> JavaConstant.forBoolean(value.readBufferByte(offset) != 0);
            case Byte -> JavaConstant.forByte(value.readBufferByte(offset));
            case Short -> JavaConstant.forShort(value.readBufferShort(ByteOrder.nativeOrder(), offset));
            case Char -> JavaConstant.forChar((char) value.readBufferShort(ByteOrder.nativeOrder(), offset));
            case Int -> JavaConstant.forInt(value.readBufferInt(ByteOrder.nativeOrder(), offset));
            case Long -> JavaConstant.forLong(value.readBufferLong(ByteOrder.nativeOrder(), offset));
            case Float -> JavaConstant.forFloat(value.readBufferFloat(ByteOrder.nativeOrder(), offset));
            case Double -> JavaConstant.forDouble(value.readBufferDouble(ByteOrder.nativeOrder(), offset));
            default -> throw new IllegalArgumentException("Unsupported kind: " + kind);
        };
    }

    @Override
    public JavaConstant createHostProxy(Object hostTarget, ResolvedJavaType guestType) {
        Objects.requireNonNull(hostTarget);
        if (!(Objects.requireNonNull(guestType) instanceof EspressoExternalResolvedInstanceType espressoGuestType) || !espressoGuestType.isInterface()) {
            throw new IllegalArgumentException("Invalid guest type");
        }
        Value hostProxy = hostProxies.createHostProxy(hostTarget, espressoGuestType);
        return new EspressoExternalObjectConstant(this, hostProxy);
    }

    @Override
    public Throwable unwrapHostProxyException(JavaConstant guestWrapper) {
        Objects.requireNonNull(guestWrapper);
        if (!(guestWrapper instanceof EspressoExternalObjectConstant espressoWrapper)) {
            return null;

View on GitHub (pinned to a66e9ccd1d)

Solutions

1. Fix the condition reported by the error: Unsupported kind:
2. Check the throwing call site and ensure its documented preconditions (argument values, types, environment, or configuration) are satisfied before the call.

Example fix

Validate inputs and environment so that the failing condition does not occur: Unsupported kind:

When it happens

Trigger: Thrown at espresso-compiler-stub/src/com.oracle.truffle.espresso.vmaccess/src/com/oracle/truffle/espresso/vmaccess/EspressoExternalVMAccess.java:1067 when the library encounters an invalid state.

Common situations: Occurs when a caller violates the contract guarded by this check: Unsupported kind:

AI-assisted analysis of oracle/graal@a66e9ccd1d (2026-08-14). Data as JSON: /api/errors/cf19445d1b7989d7. Report an issue: GitHub.