oracle/graal · error · IllegalArgumentException

Unexpected architecture ${architecture}

Error message

Unexpected architecture ${architecture}

What it means

architectureKind maps a live Architecture instance to an architecture kind constant for encoding; the switch covers only AMD64, RISCV64 and AArch64, and anything else throws IllegalArgumentException 'Unexpected architecture <architecture>'. This is a write-path capability check: the codec can only record replays for those three supported architectures.

Source

Thrown at compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/hotspot/replaycomp/BinaryReplayCodec.java:1137

    private static Throwable createThrowable(String className, String message) {
        if (className.equals(JVMCIError.class.getName())) {
            return new JVMCIError(message);
        } else if (className.equals(GraalError.class.getName())) {
            return new GraalError(message);
        } else if (className.equals(IllegalArgumentException.class.getName())) {
            return new IllegalArgumentException(message);
        } else {
            return new Throwable(message);
        }
    }

    private static int architectureKind(Architecture architecture) {
        return switch (architecture) {
            case AMD64 ignored -> AMD64_ARCHITECTURE;
            case RISCV64 ignored -> RISCV64_ARCHITECTURE;
            case AArch64 ignored -> AARCH64_ARCHITECTURE;
            default -> throw new IllegalArgumentException("Unexpected architecture " + architecture);
        };
    }

    private static void writeArchitectureFeatures(ObjectCopierOutputStream out, Architecture architecture) throws IOException {
        switch (architecture) {
            case AMD64 amd64 -> writeEnumOrdinals(out, amd64.getFeatures());
            case RISCV64 riscv64 -> writeEnumOrdinals(out, riscv64.getFeatures());
            case AArch64 aarch64 -> writeEnumOrdinals(out, aarch64.getFeatures());
            default -> throw new IllegalArgumentException("Unexpected architecture " + architecture);
        }
    }

    private Architecture createFallbackArchitecture(String archName) {
        if (!Platform.KNOWN_ARCHITECTURES.contains(archName)) {
            throw new IllegalArgumentException("Unexpected architecture name " + archName);
        }
        return hostTarget.arch;
    }

View on GitHub (pinned to a66e9ccd1d)

Solutions

1. Record the replay on a supported architecture (amd64, riscv64, aarch64)
2. If porting, add the architecture to architectureKind, writeArchitectureFeatures and readArchitecture before enabling replay recording
3. Guard before recording: only enable replay output when the host architecture is one of the three supported kinds

Example fix

// before
int kind = architectureKind(arch); // throws on unsupported arch

// after
if (!(arch instanceof AMD64 || arch instanceof RISCV64 || arch instanceof AArch64)) {
    // skip replay recording on this platform
    return;
}
int kind = architectureKind(arch);

static boolean architectureSupported(Architecture a) {
    return a instanceof AMD64 || a instanceof RISCV64 || a instanceof AArch64;
}

static boolean isReplaySupportedArchitecture(Architecture arch) {
    return arch instanceof AMD64 || arch instanceof RISCV64 || arch instanceof AArch64;
}

try {
    codec.writeReplay(out);
} catch (IllegalArgumentException e) {
    if (e.getMessage() != null && e.getMessage().startsWith("Unexpected architecture")) {
        // disable replay recording on this platform
    } else throw e;
}

When it happens

Trigger: Attempting to record a replay compilation while running on any architecture outside AMD64/RISCV64/AArch64 (e.g. a port in progress or an exotic platform).

Common situations: Running GraalVM replay recording on an unsupported or in-development architecture port; unit tests constructing custom Architecture subclasses.

Related errors

• Unexpected register config ${registerConfig}
• Unexpected marker
• No serializer for :
• Unknown registration
• Unexpected architecture name ${archName}

AI-assisted analysis of oracle/graal@a66e9ccd1d (2026-08-14). Data as JSON: /api/errors/ee3b6257c7b61882. Report an issue: GitHub.