Comment 1 Ed Willink 2013-12-11 03:05:15 EST

My message rewriting solution is to provide the following override in a derived LazyLinkingResource

	private static final String NO_VIABLE_ALTERNATIVE_AT_INPUT_EOF = "no viable alternative at input '<EOF>'";
	private static final String NO_VIABLE_ALTERNATIVE_FOLLOWING = "no viable alternative following input ";

	@Override		// FIXME This workaround should be eliminated by a BUG 404438 fix
	protected void addSyntaxErrors() {
		if (isValidationDisabled()) {
			return;
		}
		IParseResult parseResult = getParseResult();
		if (parseResult == null) {
			return;
		}
		List<Diagnostic> errors2 = getErrors();
		for (final INode error : parseResult.getSyntaxErrors()) {
			AbstractDiagnostic diagnostic = null;
			final SyntaxErrorMessage syntaxErrorMessage = error.getSyntaxErrorMessage();
			if (syntaxErrorMessage != null) {
				String message = syntaxErrorMessage.getMessage();
				// BUG 404438 "no viable alternative at input '<EOF>'" message is unhelpful.
				if ((message != null) && message.contains(NO_VIABLE_ALTERNATIVE_AT_INPUT_EOF)){
					int index = message.indexOf(NO_VIABLE_ALTERNATIVE_AT_INPUT_EOF);
					if (index >= 0) {
						String tokenText = NodeModelUtils.getTokenText(error);
						if (tokenText != null) {
							final String newMessage = message.substring(0, index) + NO_VIABLE_ALTERNATIVE_FOLLOWING + "'" + tokenText + "'" + message.substring(index+NO_VIABLE_ALTERNATIVE_AT_INPUT_EOF.length());
							diagnostic = new AbstractDiagnostic()
							{
								public String getMessage() {
									return newMessage;
								}

								@Override
								protected INode getNode() {
									return error;
								}

								@Override
								public String getCode() {
									return syntaxErrorMessage.getIssueCode();
								}

								@Override
								public String[] getData() {
									return syntaxErrorMessage.getIssueData();
								}
							};
						}
					}
				}
			}
			if (diagnostic == null) {
				diagnostic = new XtextSyntaxDiagnostic(error);
			}
			errors2.add(diagnostic);
		}
	}