oracle/graal · error · ElementException

NodeInputList field must be annotated with @${Input.getSimpl

Error message

NodeInputList field must be annotated with @${Input.getSimpleName()} or @${OptionalInput.getSimpleName()}

What it means

NodeInputList fields must carry @Input or @OptionalInput. An unannotated input list would be a collection of Node references the graph does not know about: no usage tracking, no visiting, no replacement handling, which breaks graph integrity. GraphNodeVerifier throws this during annotation processing whenever it finds a NodeInputList-typed field without an input annotation (there is no 'Null' exemption here).

Source

Thrown at compiler/src/jdk.graal.compiler.processor/src/jdk/graal/compiler/nodeinfo/processor/GraphNodeVerifier.java:169

                        }
                    } else {
                        if (!isAssignableWithErasure(field, Node)) {
                            throw new ElementException(field, "Successor field must be a Node type");
                        }
                        if (modifiers.contains(FINAL)) {
                            throw new ElementException(field, "Successor field must not be final");
                        }
                        if (modifiers.contains(PUBLIC)) {
                            throw new ElementException(field, "Successor field must not be public");
                        }
                    }

                } else {
                    if (isAssignableWithErasure(field, Node) && !field.getSimpleName().contentEquals("Null")) {
                        throw new ElementException(field, "Node field must be annotated with @" + Input.getSimpleName() + ", @" + OptionalInput.getSimpleName() + " or @" + Successor.getSimpleName());
                    }
                    if (isAssignableWithErasure(field, NodeInputList)) {
                        throw new ElementException(field, "NodeInputList field must be annotated with @" + Input.getSimpleName() + " or @" + OptionalInput.getSimpleName());
                    }
                    if (isAssignableWithErasure(field, NodeSuccessorList)) {
                        throw new ElementException(field, "NodeSuccessorList field must be annotated with @" + Successor.getSimpleName());
                    }
                    if (modifiers.contains(PUBLIC) && !modifiers.contains(FINAL)) {
                        throw new ElementException(field, "Data field must be final if public");
                    }
                }
            }
            currentClazz = getSuperType(currentClazz);
        } while (!isObject(getSuperType(currentClazz).asType()));
    }

    private AnnotationMirror findAnnotationMirror(List<? extends AnnotationMirror> mirrors, TypeElement expectedAnnotationType) {
        for (AnnotationMirror mirror : mirrors) {
            if (sameType(mirror.getAnnotationType(), expectedAnnotationType.asType())) {
                return mirror;
            }

View on GitHub (pinned to a66e9ccd1d)

Solutions

1. Add @Input (or @OptionalInput if entries may be absent/null) to the NodeInputList field.
2. If the list is not part of the graph, use a plain List type instead of NodeInputList, or mark the field transient/static so the verifier skips it.
3. Rebuild to confirm.

Example fix

// before
protected NodeInputList<ValueNode> arguments;

// after
@Input
protected NodeInputList<ValueNode> arguments;

When it happens

Trigger: isAssignableWithErasure(field, NodeInputList) is true and neither @Input nor @OptionalInput (nor @Successor) is present on the field (GraphNodeVerifier.java:168-170). Example: 'protected NodeInputList<ValueNode> args;' with no annotation.

Common situations: Adding an argument list to a node and forgetting the annotation; copy-pasting a list field from a non-node class; renaming annotations during import fixes so the annotation resolves to the wrong type.

Related errors

• Node field must be annotated with @${Input.getSimpleName()},
• NodeSuccessorList field must be annotated with @${Successor.
• Input list field must not be final
• Input list field must not be public
• Input field type must be an interface or assignable to Node

AI-assisted analysis of oracle/graal@a66e9ccd1d (2026-08-14). Data as JSON: /api/errors/04d52ee282b6c7f6. Report an issue: GitHub.