Path: utzoo!attcan!uunet!lll-winken!xanth!ames!oliveb!apple!Apple.COM!lsr
From: lsr@Apple.COM (Larry Rosenstein)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Re: Legal Tail Patches
Message-ID: <785@internal.Apple.COM>
Date: 27 Feb 89 02:35:05 GMT
Sender: usenet@Apple.COM
Organization: Apple Computer, Inc.
Lines: 20
References:<1285@ccnysci.UUCP> <10050076@accuvax.nwu.edu> <19886@santra.UUCP> <26341@apple.Apple.COM> <19971@santra.UUCP>

In article <19971@santra.UUCP> jmunkki@kampi.hut.fi (Juri Munkki) writes:
> 3.  Change GetTrapAddress so that it first checks if the trap does 
>come-from patching. If it does, return the address that is contained in
>the jump table. If the routine only has the apple patch, the ROM address 
>will be returned.

No good.  A program may do a GetTrapAddress, and JSR directly to that as a
way to save time (although I doubt that you save much time at all).
GetTrapAddress must therefore return the same address you would jump to by
executing the trap.

Your approach tries to keep the come-from patch as the "last" patch for 
the particular trap (ie, the code that gets control first).  I don't think 
you can change the way Get/SetTrapAddress works and still maintain 
compatibility.

Larry Rosenstein, Apple Computer, Inc.

Internet: lsr@Apple.com   UUCP: {nsc, sun}!apple!lsr
AppleLink: Rosenstein1