oracle/graal · error · IllegalArgumentException

Expected an object constant

Error message

Expected an object constant

What it means

Error "Expected an object constant" thrown in oracle/graal.

Source

Thrown at espresso-compiler-stub/src/com.oracle.truffle.espresso.vmaccess/src/com/oracle/truffle/espresso/vmaccess/EspressoExternalMethodHandleAccessProvider.java:68

    @Override
    public ResolvedJavaMethod resolveInvokeBasicTarget(JavaConstant methodHandle, boolean forceBytecodeGeneration) {
        if (!(Objects.requireNonNull(methodHandle) instanceof EspressoExternalObjectConstant objectConstant)) {
            return null;
        }
        Value result = access.invokeJVMCIHelper("resolveInvokeBasicTarget", objectConstant.getValue(), forceBytecodeGeneration);
        if (result.isNull()) {
            return null;
        }
        return new EspressoExternalResolvedJavaMethod(result, access);
    }

    @Override
    public ResolvedJavaMethod resolveLinkToTarget(JavaConstant memberName) {
        if (Objects.requireNonNull(memberName).isNull()) {
            return null;
        }
        if (!(memberName instanceof EspressoExternalObjectConstant objectConstant)) {
            throw new IllegalArgumentException("Expected an object constant");
        }
        Value result = access.invokeJVMCIHelper("resolveLinkToTarget", objectConstant.getValue());
        if (result.isNull()) {
            return null;
        }
        if (result.isString()) {
            throw new IllegalArgumentException(result.asString());
        }
        return new EspressoExternalResolvedJavaMethod(result, access);
    }
}

View on GitHub (pinned to a66e9ccd1d)

Solutions

1. Fix the condition reported by the error: Expected an object constant
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: Expected an object constant

When it happens

Trigger: Thrown at espresso-compiler-stub/src/com.oracle.truffle.espresso.vmaccess/src/com/oracle/truffle/espresso/vmaccess/EspressoExternalMethodHandleAccessProvider.java:68 when the library encounters an invalid state.

Common situations: Occurs when a caller violates the contract guarded by this check: Expected an object constant

AI-assisted analysis of oracle/graal@a66e9ccd1d (2026-08-14). Data as JSON: /api/errors/f92fd2deb09ff409. Report an issue: GitHub.