NationalSecurityAgency/ghidra · error · IllegalArgumentException

TracePlatform must use a Sleigh language

Error message

TracePlatform must use a Sleigh language

What it means

buildByteExecutor constructs a byte-array p-code executor over a trace platform by compiling/using Sleigh-specific machinery. It requires platform.getLanguage() to be a SleighLanguage; any other Language implementation is rejected because Sleigh expression compilation and the bytes arithmetic depend on it.

Source

Thrown at Ghidra/Debug/Framework-TraceModeling/src/main/java/ghidra/pcode/exec/trace/TraceSleighUtils.java:62

	/**
	 * Build a p-code executor that operates directly on bytes of the given trace
	 * 
	 * <p>
	 * This executor is most suitable for evaluating Sleigh expression on a given trace snapshot,
	 * and for manipulating or initializing variables using Sleigh code. It is generally not
	 * suitable for use in an emulator. For that, use {@link PcodeEmulator} with
	 * {@link TraceEmulationIntegration}.
	 * 
	 * @param platform the platform
	 * @param snap the snap
	 * @param thread the thread, required if register space is used
	 * @param frame the frame, for when register space is used
	 * @return the executor
	 */
	public static PcodeExecutor<byte[]> buildByteExecutor(TracePlatform platform, long snap,
			TraceThread thread, int frame) {
		if (!(platform.getLanguage() instanceof SleighLanguage language)) {
			throw new IllegalArgumentException("TracePlatform must use a Sleigh language");
		}
		DefaultPcodeTraceAccess access = new DefaultPcodeTraceAccess(platform, snap);
		PcodeStateCallbacks cb =
			TraceEmulationIntegration.bytesImmediateWrite(access, thread, frame);
		BytesPcodeExecutorState state = new BytesPcodeExecutorState(language, cb);
		return new PcodeExecutor<>(language, BytesPcodeArithmetic.forLanguage(language), state,
			Reason.INSPECT);
	}

	/**
	 * @see #buildByteExecutor(TracePlatform, long, TraceThread, int)
	 * @param trace the trace whose host platform to use
	 * @param snap the snap
	 * @param thread the thread, required if register space is used
	 * @param frame the frame, for when register space is used
	 * @return the executor
	 */
	public static PcodeExecutor<byte[]> buildByteExecutor(Trace trace, long snap,

View on GitHub (pinned to d5f144c24d)

Solutions

1. Verify platform.getLanguage() instanceof SleighLanguage before calling buildByteExecutor; if not, use the host platform or a Sleigh-backed guest.
2. Ensure the trace's language provider resolves to a SleighLanguage (proper language ID / .ldefs entry).
3. If you must evaluate on a non-Sleigh language, implement the byte arithmetic/executor yourself instead of using this helper.

Example fix

// before
PcodeExecutor<byte[]> exec = TraceSleighUtils.buildByteExecutor(platform, snap, thread, frame);

// after
if (!(platform.getLanguage() instanceof SleighLanguage)) {
    throw new IllegalStateException("platform not Sleigh-based: " + platform.getLanguage());
}
PcodeExecutor<byte[]> exec = TraceSleighUtils.buildByteExecutor(platform, snap, thread, frame);

if (!(platform.getLanguage() instanceof SleighLanguage)) {
    throw new IllegalStateException(
        "platform language is not Sleigh: " + platform.getLanguage());
}
PcodeExecutor<byte[]> exec = TraceSleighUtils.buildByteExecutor(platform, snap, thread, frame);

static boolean isSleighPlatform(TracePlatform platform) {
    return platform.getLanguage() instanceof SleighLanguage;
}

try {
    PcodeExecutor<byte[]> exec = TraceSleighUtils.buildByteExecutor(platform, snap, thread, frame);
} catch (IllegalArgumentException e) {
    if (e.getMessage().contains("Sleigh language")) {
        // switch to a Sleigh-backed platform or host platform
    } else throw e;
}

When it happens

Trigger: Calling TraceSleighUtils.buildByteExecutor(platform, snap, thread, frame) where platform is a guest platform whose language is not a SleighLanguage subclass (a custom or non-Sleigh Language).

Common situations: Defining a guest platform backed by a hand-rolled Language. Loading a trace whose base language provider returned a non-Sleigh language. Mixed-language traces where a guest language lacks a Sleigh implementation.

Related errors

• Sleigh language required
• Emulation requires a Sleigh language
• Trace must use a sleigh-based language
• Current trace does not use Sleigh
• Unknown register or label: '{nm}'

AI-assisted analysis of NationalSecurityAgency/ghidra@d5f144c24d (2026-08-14). Data as JSON: /api/errors/b61dc983076a5a63. Report an issue: GitHub.