Method endCheckLoop

rhino/src/main/java/org/mozilla/javascript/Node.java:799–823

Return statement in the loop body must be consistent. The default assumption for any kind of a loop is that it will eventually terminate. The only exception is a loop with a constant true condition. Code that follows such a loop is examined only if one can statically determine that there is a break

()

     * @return logical OR of END_* flags
     */
    private int endCheckLoop() {
        Node n;
        int rv = END_UNREACHED;

        // To find the loop body, we look at the second to last node of the
        // loop node, which should be the predicate that the loop should
        // satisfy.
        // The target of the predicate is the loop-body for all 4 kinds of
        // loops.
        for (n = first; n.next != last; n = n.next) {
            /* skip */
        }
        if (n.type != Token.IFEQ) return END_DROPS_OFF;

        // The target's next is the loop body block
        rv = ((Jump) n).target.next.endCheck();

        // check to see if the loop condition is true
        if (n.first.type == Token.TRUE) rv &= ~END_DROPS_OFF;

        // look for effect of breaks
        rv |= getIntProp(CONTROL_BLOCK_PROP, END_UNREACHED);

        return rv;
    }

    /**
     * A general block of code is examined statement by statement. If any statement (even compound