Top-level cyclic imports fail

[Matt Giuca]

If the top-level module of a Mars program is involved in a cyclic import, its functions are duplicated and a compiler error occurs.

This is demonstrated in test case compiler/import2b.mar and import2c.mar.

import2b.mar:

import import2c

def b(...):
    ...

import2c.mar:

def c(...):
    ...

import import2b

$ mars -i import2b.mar
import2b.mar:25: Duplicate function name: b.

This only happens at the top level. (import2a.mar imports import2b which has a cyclic import, and that is handled correctly).

(The "top level" refers to the module being directly opened in the mars interpreter).

[Matt Giuca (mgiuca)]

This happens since this file is not imported, but loaded directly. It doesn't have a "module name", so it isn't caught - this causes "duplicate function defined" errors.

First, fix bug #439168 ("add :l command to load a module"). Then, replace top-level loading with an invocation of :l, which does a proper import of a module.

[Matt Giuca (mgiuca)]

Fixed in trunk r922.