RE: Autoglobal CVs without silence -- Summary

Hi Sara, Thank you for detailed description, now I see goal that was hidden from me. I am litle bit afraid about FETCH_DIM/FETCH_OBJ patch, because it probably will slowdown each array operation, and I still don't understand what is wrong with silence. Can you show the whole patch (with FETCH_DIM)? (may be draft) Thanks. Dmitry. > -----Original Message----- > From: Sara Golemon [mailto:pollita@php.net] > Sent: Tuesday, January 23, 2007 10:02 PM > To: internals@lists.php.net; Andrei Zmievski; Andi Gutmans; > Dmitry Stogov > Subject: Autoglobal CVs without silence -- Summary > > > >> OK. Now your patch will work, but I would like to > >> think about more elegant solution. > >> The problem that I am busy with other work. > >> Could you please wait a week and then commit it if > >> I won't return (on the next Tuesday). > >> > > Argh. Can we please accelerate this somehow? > > This patch is necessary for the HTTP request > > decoding work in PHP 6 and we really should > > get it done sooner than later. > > > Okay, rewind and reset time. > > Dmitry, here's a quick summary of what's being done, how, and why. > > Initial Problem: PHP6 needs better http input encoding detection, > preferably with minimal wasted effort in conversion and > limited vectors > for conversion failure based attacks. > > Proposed Solution: Wait until the first time a given input > argument is > requested before actually converting it. This allows scripts > to perform > their own (potentially more relevant) determination of what > the correct > input encoding is. > > Proposed Implementation for this solution: Make JIT be runtime based > and fine-grained enough to signal not just the autoglobal > being fetched, > but what specific dimension/property within that auto global is being > requested. Using runtime-dimension-JIT to decode input arguments as > they are requested. > > Rejected Implementation: Use object/array-access overloading > to JIT the > values instead. While this solution is the simplest and can be done > with relatively few LOCs, it breaks assumptions about the GPC auto > globals (is_array() fails, is_object() succeeds, assignments of the > autoglobals becomes "reference-like"*). In short, this solution > introduces BC issues. > > ---------------------------------------------------------------- > > Next Problem: How to actually make runtime-JIT with dim/prop level > granularity? > > Proposed Solution: Catch fetches during FETCH_DIM/FETCH_OBJ execution > handlers. > > ---------------------------------------------------------------- > > Next Problem: auto_globals aren't processed as CVs, meaning > that during > FETCH_DIM, there's no way to tell if op1 came from an auto > global or not > (since the fetch happened earlier). > > Solution (Implemented last week): Remove restriction on CVing auto > globals by adding a fetch_type field to auto global structure. > > ---------------------------------------------------------------- > > Next Problem: Silence operator forces non-CV even in > situations where a > CV is appropriate since the associated fetch_dim/obj op would > not fall > outside of silence scoping. > > Proposed Solution (patch from prior email): modify the > variable parsing > routines slightly to rewrite simple fetch ops to CV'd > fetch_dim/obj ops > when appropriate. > > ---------------------------------------------------------------- > > I'm not meaning to apply pressure (a week doesn't effect my timetable > any), I can even move-forward with the next (and last) ZE > related patch > (FETCH_DIM/FETCH_OBJ handling) separate from this one. I'm > just trying > to balance Andrei's timetable on one side, with a desired to not > overwhelm you and Andi with ZE patches on the other. Hopefully this > summary helps everyone get on the same page. > > -Sara > > * - Sidenote: I refuse to call object behavior "reference by > default", > I've had too many people notice that it's not actually true > and expect > me to explain why in 2 minutes without the aid of a whiteboard.in >