oracle/graal · error · NullPointerException

receiver

Error message

receiver

What it means

Error "receiver" thrown in oracle/graal.

Source

Thrown at espresso-compiler-stub/src/com.oracle.truffle.espresso.vmaccess/src/com/oracle/truffle/espresso/vmaccess/EspressoExternalResolvedJavaField.java:126

    public Value readValue(Value receiver) {
        return vmFieldMirror.invokeMember("read", receiver);
    }

    void writeValue(JavaConstant receiver, JavaConstant value) {
        if (value == null) {
            throw new NullPointerException("value");
        }

        final Value receiverValue;
        if (isStatic()) {
            if (receiver != null) {
                throw new IllegalArgumentException("Static field write requires null receiver");
            }
            receiverValue = null;
        } else {
            if (receiver == null) {
                throw new NullPointerException("receiver");
            }
            if (receiver.isNull()) {
                throw new IllegalArgumentException("Receiver is null");
            }
            if (!(receiver instanceof EspressoExternalObjectConstant espressoReceiver)) {
                throw new IllegalArgumentException("Expected an espresso object receiver, got " + receiver.getClass().getName());
            }
            receiverValue = espressoReceiver.getValue();
        }

        JavaKind kind = getJavaKind();
        final Object boxed;
        if (kind == JavaKind.Object) {
            if (value.isNull()) {
                boxed = null;
            } else if (value instanceof EspressoExternalObjectConstant objConst) {
                boxed = objConst.getValue();
            } else {

View on GitHub (pinned to a66e9ccd1d)

Solutions

1. Fix the condition reported by the error: receiver
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: receiver

When it happens

Trigger: Thrown at espresso-compiler-stub/src/com.oracle.truffle.espresso.vmaccess/src/com/oracle/truffle/espresso/vmaccess/EspressoExternalResolvedJavaField.java:126 when the library encounters an invalid state.

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

AI-assisted analysis of oracle/graal@a66e9ccd1d (2026-08-14). Data as JSON: /api/errors/b5efe3d7ae8cc391. Report an issue: GitHub.