oracle/graal · error · IllegalArgumentException

Receiver is null

Error message

Receiver is null

What it means

Error "Receiver is null" thrown in oracle/graal.

Source

Thrown at espresso-compiler-stub/src/com.oracle.truffle.espresso.vmaccess/src/com/oracle/truffle/espresso/vmaccess/EspressoExternalResolvedJavaField.java:129

    }

    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 {
                throw new IllegalArgumentException("Expected an espresso object constant, got " + value.getClass().getName());
            }
        } else {

View on GitHub (pinned to a66e9ccd1d)

Solutions

1. Fix the condition reported by the error: Receiver is null
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 is null

When it happens

Trigger: Thrown at espresso-compiler-stub/src/com.oracle.truffle.espresso.vmaccess/src/com/oracle/truffle/espresso/vmaccess/EspressoExternalResolvedJavaField.java:129 when the library encounters an invalid state.

Common situations: Occurs when a caller violates the contract guarded by this check: Receiver is null

AI-assisted analysis of oracle/graal@a66e9ccd1d (2026-08-14). Data as JSON: /api/errors/a1a8ad00aa156f62. Report an issue: GitHub.