oracle/graal · error · IllegalStateException

Unexpected kind of register config: ${name}

Error message

Unexpected kind of register config: ${name}

What it means

Deserialization counterpart of 151: the registerConfig entry's 'name' must be 'AMD64', 'RISCV64', or 'AArch64'; anything else throws IllegalStateException('Unexpected kind of register config: ...'). Note the casing differs from the Architecture names ('AMD64' vs 'riscv64'/'aarch64' lowercase), a common trip-up when editing files by hand.

Source

Thrown at compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/hotspot/replaycomp/JsonReplayCodec.java:1702

        @Override
        @SuppressWarnings("unchecked")
        public Object deserialize(EconomicMap<String, Object> json, RecursiveDeserializer deserializer, CompilationProxies.ProxyFactory proxyFactory) throws DeserializationException {
            String name = (String) json.get("name");
            TargetDescription targetDescription = (TargetDescription) deserializer.deserialize(json.get("target"), proxyFactory);
            List<Register> allocatable = (List<Register>) deserializer.deserialize(json.get("allocatable"), proxyFactory);
            switch (name) {
                case "AMD64" -> {
                    boolean windowsOS = (boolean) json.get("windowsOS");
                    return new AMD64HotSpotRegisterConfig(targetDescription, allocatable, windowsOS);
                }
                case "RISCV64" -> {
                    return new RISCV64HotSpotRegisterConfig(targetDescription, allocatable);
                }
                case "AArch64" -> {
                    return new AArch64HotSpotRegisterConfig(targetDescription, allocatable);
                }
                default -> throw new IllegalStateException("Unexpected kind of register config: " + name);
            }
        }
    }

    private static final class ThrowableSerializer implements ObjectSerializer {

        @Override
        public boolean serializesSubclasses() {
            return true;
        }

        @Override
        public Class<?> clazz() {
            return Throwable.class;
        }

        @Override
        public String tag() {

View on GitHub (pinned to a66e9ccd1d)

Solutions

1. Fix the name casing/values: AMD64, RISCV64, AArch64 (note uppercase here, lowercase in the architecture name)
2. Re-record the file on the same build and architecture
3. For new backends, extend both this switch and the serializer in error 151

Example fix

// before (hand-edited file): { "tag": "registerConfig", "name": "aarch64", ... }
// after: { "tag": "registerConfig", "name": "AArch64", ... }

static final Set<String> VALID_REGISTER_CONFIG_KINDS = Set.of("AMD64", "RISCV64", "AArch64");

if (!VALID_REGISTER_CONFIG_KINDS.contains(name)) {
    throw new IllegalArgumentException("Unsupported register config kind in replay file: " + name);
}

When it happens

Trigger: Replaying a JSON replay file whose registerConfig.name is unknown or wrongly cased — e.g. hand-edited from 'aarch64' (architecture spelling) instead of 'AArch64' (register-config spelling), or written by a codec with additional backends.

Common situations: Manual JSON edits with case mismatch; cross-version replay; fork architectures not upstreamed.

Related errors

• No singleton found for ${registration}
• Unknown class ${className} for constant${value}
• Invalid marker type.
• Invalid constant.
• Unexpected value: ${name}

AI-assisted analysis of oracle/graal@a66e9ccd1d (2026-08-14). Data as JSON: /api/errors/088e90d408b0ec01. Report an issue: GitHub.