Method returnOrYield

rhino/src/main/java/org/mozilla/javascript/Parser.java:2263–2338

(int tt, boolean exprContext)

    }

    private AstNode returnOrYield(int tt, boolean exprContext) throws IOException {
        if (!insideFunctionBody()) {
            reportError(tt == Token.RETURN ? "msg.bad.return" : "msg.bad.yield");
        }
        consumeToken();
        int lineno = lineNumber(), column = columnNumber(), pos = ts.tokenBeg, end = ts.tokenEnd;

        boolean yieldStar = false;
        if ((tt == Token.YIELD)
                && (compilerEnv.getLanguageVersion() >= Context.VERSION_ES6)
                && (peekToken() == Token.MUL)) {
            yieldStar = true;
            consumeToken();
        }

        AstNode e = null;
        // This is ugly, but we don't want to require a semicolon.
        switch (peekTokenOrEOL()) {
            case Token.SEMI:
            case Token.RC:
            case Token.RB:
            case Token.RP:
            case Token.EOF:
            case Token.EOL:
            case Token.ERROR:
                break;
            case Token.YIELD:
                if (compilerEnv.getLanguageVersion() < Context.VERSION_ES6) {
                    // Take extra care to preserve language compatibility
                    break;
                }
            // fallthrough
            default:
                e = expr(false);
                end = getNodeEnd(e);
        }

        int before = endFlags;
        AstNode ret;

        if (tt == Token.RETURN) {
            endFlags |= e == null ? Node.END_RETURNS : Node.END_RETURNS_VALUE;
            ret = new ReturnStatement(pos, end - pos, e);

            // see if we need a strict mode warning
            if (nowAllSet(before, endFlags, Node.END_RETURNS | Node.END_RETURNS_VALUE))
                addStrictWarning("msg.return.inconsistent", "", pos, end - pos);
        } else {
            if (!insideFunctionBody()) reportError("msg.bad.yield");
            endFlags |= Node.END_YIELDS;
            ret = new Yield(pos, end - pos, e, yieldStar);
            setRequiresActivation();
            setIsGenerator();
            if (!exprContext) {
                ret.setLineColumnNumber(lineno, column);
                ret = new ExpressionStatement(ret);
            }
        }