On Thursday 05 July 2007 19:58:50 Patrick R. Michaud wrote: > I also get segfaults after applying this patch. > > However, if I change the patch such that the "size_t sentinel;" > line goes at the end of the struct PMC instead of the beginning, > then everything appears to compile and run. > > In fact, if "size_t sentinel;" is placed as the second or third > line in the struct (i.e., after "pobj_t obj;" or "VTABLE *vtable;") > then things still appear to compile and run. It's only when the > sentinel is given as the first line that I get errors. > > So, I'm guessing there's some code somewhere that assumes that > "obj" is always the first component of PMC.
Right, and the clue was also in parrot/pobj.h. Because buffers, strings, and PMCs all are PObjs, their structs must be isomorphic. Hoisting the sentinel into the pobj_t struct gets past that segfault. Structural subtyping hates me. -- c
