Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!iscuva!jimc From: jimc@iscuva.ISCS.COM (Jim Cathey) Newsgroups: comp.sys.mac.programmer Subject: Re: Problem with LSC 4.0 debugger. Message-ID: <2633@iscuva.ISCS.COM> Date: 3 Oct 89 03:02:43 GMT References: <244@dbase.UUCP> <3424@cbnewsc.ATT.COM> Distribution: na Organization: ISC Systems Corporation, Spokane WA Lines: 33 In article <3424@cbnewsc.ATT.COM> fjo@cbnewsc.ATT.COM (frank.j.owen) writes: >Many debuggers allow you to do this. It is a VERY nice feature. However, at least sdb (in Unix-land) _requires_ you to throw a compiler switch that in effect turns off all optimizations in order for the code generated to be regular enough for the debugger to pick apart. You then have to recompile anything you want to be able to look at or set breakpoints in, or trace stack frames through. Not very elegant, and the code you're debugging ends up very different than the code that had the problem (unless you always use the grunge switch). Unfortunately, because things moved around when you threw the switch a common class of bugs (mashed pointers) is usually very hard to find as something different (and usually less visible) is being bashed. I certainly wouldn't want the job of finding variables in stack frames far up the stack, especially when they were put into registers who are now in a different place on the stack. It could probably be done, especially if a comprehensive map file were created by the compiler, but how long are you willing to wait for it? Do you want it to hold up the release? A related problem is the size of the output file when the grunge switch is on. We have a 350K object file whose file size is over 1MB just because of all the symbol and stack frame offset crap in it. Of course, like Mom and apple pie I would sure _like_ the smarter debugger. +----------------+ ! II CCCCCC ! Jim Cathey ! II SSSSCC ! ISC-Bunker Ramo ! II CC ! TAF-C8; Spokane, WA 99220 ! IISSSS CC ! UUCP: uunet!iscuva!jimc (jimc@iscuva.iscs.com) ! II CCCCCC ! (509) 927-5757 +----------------+ "With excitement like this, who is needing enemas?"