混合来源

-vala langCopyproject('Mixed sources Project', 'vala')

glib_dep = dependency('glib-2.0')
gobject_dep = dependency('gobject-2.0')

executable('foo', 'foo.vala', 'bar.c', dependencies: [glib_dep, gobject_dep])

In foo.vala:

-vala langCopynamespace Foo {
    public extern int bar ();

    public int main (string[] args) {
        return bar ();
    }
}

In bar.c:

-c langCopyint 
bar () 
{
    return 0;
}