http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51731
--- Comment #2 from M.L. Hekkelman <m.hekkelman at cmbi dot ru.nl> 2012-01-02 17:03:46 UTC --- Beste paolo.carlini, maandag 2 januari 2012, 17:23:42, schreef je: > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51731 > --- Comment #1 from Paolo Carlini <paolo.carlini at oracle dot com> > 2012-01-02 16:23:42 UTC --- > Maybe I'm just tired (sorry in case) but I really don't see how this can > possibly work: *negative* index?!? Can you explain? It is a technique that dates back to, who knows when. It is even common practice to have a zero sized array in the struct, like this: struct page { char keys[1024]; int offsets[0]; }; This way you have a fixed size page you can write to disk containing non terminated strings in keys and the direct offsets to the keys in the offsets arrays. Fill the page until the keys and offsets would collide with the addition of a new key. E.g. the B-Tree implementation of the HFS file system in MacOS Classic uses this. I have used code like this for many years now, and this code works with all compilers I'm aware off but not with gcc 4.5 and 4.6.
