NationalSecurityAgency/ghidra · warning · IllegalArgumentException

String must not begin or end with a comma

Error message

String must not begin or end with a comma

What it means

Thrown by parseIntegerCSV(csv) after trimming, when the string starts or ends with a comma (e.g. ',1,2' or '1,2,'). split(",") on such input would yield an empty leading/trailing element and a confusing NumberFormatException later, so this is caught early with a clear message.

Source

Thrown at Ghidra/Extensions/MachineLearning/src/main/java/ghidra/machinelearning/functionfinding/FunctionStartRFParams.java:220

			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");
		}
		String trimmed = csv.trim();
		if (trimmed.startsWith(",") || trimmed.endsWith(",")) {
			throw new IllegalArgumentException("String must not begin or end with a comma");
		}
		Set<Integer> results = new HashSet<>();
		String[] parts = trimmed.split(",");
		for (String part : parts) {
			Integer i = Integer.decode(part.trim());
			if (i < 0) {
				throw new IllegalArgumentException(
					"Invalid element " + part + " - must be non-negative");
			}
			results.add(i);
		}
		return results.stream().sorted().collect(Collectors.toList());
	}

	/**
	 * Returns the {@link AddressSet} of function entries in the source program.
	 * <P>
	 * NB: Invoke {@link FunctionStartRFParams#computeFuncEntriesAndInteriors} before

View on GitHub (pinned to d5f144c24d)

Solutions

1. Remove leading/trailing commas before submitting: csv.replaceAll("^[,\\s]+|[,\\s]+$", "").
2. Build the CSV from non-empty tokens only (filter blanks before joining).
3. Validate in the UI that the field does not begin or end with ','.

Example fix

// before
parseIntegerCSV("1,2,"); // trailing comma -> throws

// after
parseIntegerCSV("1,2");

String safe = csv == null ? "" : csv.trim().replaceAll("^[,\\s]+|[,\\s]+$", "");
if (!safe.isEmpty()) {
    List<Integer> r = FunctionStartRFParams.parseIntegerCSV(safe);
}

null

try {
    List<Integer> r = FunctionStartRFParams.parseIntegerCSV(csv);
} catch (IllegalArgumentException e) {
    if (e.getMessage().contains("begin or end with a comma")) {
        List<Integer> r = FunctionStartRFParams.parseIntegerCSV(csv.trim().replaceAll("^[,]+|[,]+$", ""));
    } else throw e;
}

When it happens

Trigger: parseIntegerCSV(",1,2,3"); parseIntegerCSV("1,2,"); a CSV built by joining a list that included an empty/null tail element.

Common situations: Trailing comma from manual entry or from String.join on a list containing an empty string; copy-paste artifacts; UI text field with a stray comma at the cursor.

Related errors

• Error parsing register=value string {part}
• Entry cannot be blank
• Invalid element {part} - must be non-negative
• Register {regName} not found for program {programName}
• Maximum size of test sets must be positive!

AI-assisted analysis of NationalSecurityAgency/ghidra@d5f144c24d (2026-08-14). Data as JSON: /api/errors/a7438d69c2b8af65. Report an issue: GitHub.