skylot/jadx · error · JadxRuntimeException

Unexpected end of signature

Error message

Unexpected end of signature

What it means

Thrown by consumeExtendsTypesList() while parsing the bound(s) of a generic type parameter (the part after ':' in '<T:Ljava/lang/Exception;:Ljava/lang/Object;>'). If consumeType() returns null — meaning the signature ended where a type was expected — the method aborts. This indicates the bound list is truncated.

Source

Thrown at jadx-core/src/main/java/jadx/core/dex/nodes/parser/SignatureParser.java:311

			List<ArgType> types = consumeExtendsTypesList();
			list.add(ArgType.genericType(id, types));
		}
		consume('>');
		return list;
	}

	/**
	 * List of types separated by ':' last type is 'java.lang.Object'.
	 * <p/>
	 * Example: "Ljava/lang/Exception;:Ljava/lang/Object;"
	 */
	private List<ArgType> consumeExtendsTypesList() {
		List<ArgType> types = Collections.emptyList();
		boolean next;
		do {
			ArgType argType = consumeType();
			if (argType == null) {
				throw new JadxRuntimeException("Unexpected end of signature");
			}
			if (!argType.equals(ArgType.OBJECT)) {
				if (types.isEmpty()) {
					types = new ArrayList<>();
				}
				types.add(argType);
			}
			next = lookAhead(':');
			if (next) {
				consume(':');
			}
		} while (next);
		return types;
	}

	public List<ArgType> consumeMethodArgs(int argsCount) {
		consume('(');
		if (lookAhead(')')) {

View on GitHub (pinned to e738a26571)

Solutions

1. Upgrade jadx for improved parser resilience.
2. Catch JadxRuntimeException per class and skip the failing one.
3. Report with the signature debug string from the error.
4. Remove the malformed Signature attribute before decompiling.

try {
    javaClass.decompile();
} catch (JadxRuntimeException e) {
    LOG.warn("Type-bound parse failed in {}: {}", javaClass.getName(), e.getMessage());
}

When it happens

Trigger: Inside consumeExtendsTypesList(), the do-while loop calls consumeType() which returns null (STOP_CHAR reached). This happens when a generic bound like ':Lcom/Foo;' is missing its type, e.g. '<T:' with nothing after the colon.

Common situations: Truncated or malformed type-parameter bounds in Signature attributes from obfuscators, hand-edited bytecode, or buggy DEX processing tools.

Related errors

• Bad name for type variable: {}
• No inner type found: {}
• Unexpected inner type found: {}
• Failed to parse generic types map
• Can't parse type: {}, unexpected: {}

AI-assisted analysis of skylot/jadx@e738a26571 (2026-08-14). Data as JSON: /api/errors/d9e7f9685b3d50cf. Report an issue: GitHub.