NationalSecurityAgency/ghidra · warning · IllegalArgumentException

Register {regName} not found for program {programName}

Error message

Register {regName} not found for program {programName}

What it means

Thrown by FunctionStartRFParams.setRegistersAndValues(csv) when a register name parsed from the CSV is not present in the training source program — trainingSource.getRegister(regName) returned null. The register must be a real context register defined in the program's language for it to be constrainable. State is cleared before throwing.

Source

Thrown at Ghidra/Extensions/MachineLearning/src/main/java/ghidra/machinelearning/functionfinding/FunctionStartRFParams.java:199

	 * @param csv the list to parse
	 * @throws IllegalArgumentException if there are any parsing errors
	 */
	public void setRegistersAndValues(String csv) {
		contextRegisterNames = new ArrayList<>();
		contextRegisterVals = new ArrayList<>();
		String[] parts = csv.split(",");
		for (String part : parts) {
			String[] regValPair = part.split("=");
			if (regValPair.length != 2) {
				contextRegisterNames.clear();
				contextRegisterVals.clear();
				throw new IllegalArgumentException("Error parsing register=value string " + part);
			}
			String regName = regValPair[0].trim();
			if (trainingSource.getRegister(regName) == null) {
				contextRegisterNames.clear();
				contextRegisterVals.clear();
				throw new IllegalArgumentException(
					"Register " + regName + " not found for program " + trainingSource.getName());
			}
			contextRegisterNames.add(regName);
			BigInteger bigInt = new BigInteger(regValPair[1].trim());
			contextRegisterVals.add(bigInt);
		}
	}

	/**
	 * Parses a CSV into a sorted list of distinct integer values (duplicates are ignored).  Returns
	 * an empty list of a parse error is encountered.
	 * @param csv csv string to parse
	 * @return sorted list  
	 */
	public static List<Integer> parseIntegerCSV(String csv) {
		if (StringUtils.isBlank(csv)) {
			throw new IllegalArgumentException("Entry cannot be blank");
		}

View on GitHub (pinned to d5f144c24d)

Solutions

1. Use program.getLanguage().getRegisters() (or getRegister(name)) to enumerate valid register names for the training program and pass only those.
2. Correct the spelling/architecture of the register name in the CSV.
3. If the register should exist, verify the correct language/program is the trainingSource.

Example fix

// before
params.setRegistersAndValues("rax=0"); // ARM program

// after
Register r = trainingSource.getRegister("r0");
params.setRegistersAndValues(r == null ? "" : "r0=0");

import ghidra.program.model.listing.Program;
String csv = "cs=0x33,ds=0x2b";
StringBuilder ok = new StringBuilder();
for (String part : csv.split(",")) {
    String[] kv = part.split("=", -1);
    String reg = kv[0].trim();
    if (trainingSource.getRegister(reg) != null) {
        if (ok.length() > 0) ok.append(",");
        ok.append(part);
    } // else skip unknown register
}
params.setRegistersAndValues(ok.toString());

null

try {
    params.setRegistersAndValues(csv);
} catch (IllegalArgumentException e) {
    if (e.getMessage().contains("not found for program")) {
        // fetch valid registers from trainingSource and re-prompt
    } else throw e;
}

When it happens

Trigger: Passing a register name that does not exist for the program's language (e.g. 'rax' for an ARM program, or a typo), or a context register that the Sleigh language does not expose.

Common situations: Copying register constraints from a different architecture; mistyping a register; using a processor context register that the language marks as hidden/unnamed.

Related errors

• Error parsing register=value string {part}
• Entry cannot be blank
• String must not begin or end with a comma
• Invalid element {part} - must be non-negative
• Maximum size of test sets must be positive!

AI-assisted analysis of NationalSecurityAgency/ghidra@d5f144c24d (2026-08-14). Data as JSON: /api/errors/7d7f7aab4ac6dcdb. Report an issue: GitHub.