Date:	Tue, 1 Nov 94 12:05:32 JST
From:	Stephen Turnbull <turnbull AT shako DOT sk DOT tsukuba DOT ac DOT jp>
To:	dj AT stealth DOT ctron DOT com
Cc:	babcock AT cfa DOT harvard DOT edu, djgpp AT sun DOT soe DOT clarkson DOT edu
Subject:	NULL pointers in (ANSI) string functions [was: strcat() ?]

   Date: Mon, 31 Oct 94 16:36:43 -0500
   From: dj AT stealth DOT ctron DOT com (DJ Delorie)

   > It might be nice to have a _debugging_ library which checked for
   > things like null pointers passed to strxxx() routines.  A related
   > item: Borland compilers tend to print "(null)" when you pass null
   > to printf rather than crashing or printing garbage.

   I think a stack trace (or gdb exception) is the best kind of debugging
   - "It broke - HERE"

Well, yes, except that early releases of v 1.10 didn't always point to
the rigth place; symify would often give a line too late or early, I
forget which, and I had a devil of a time figuring it out.  Nowadays I
awk out the 5 lines surrounding the place pointed to by symify, and if
I see a strxxx() I look for a NULL pointer.  :-)  But I didn't know
that *then*, and other newbies don't know that *now*.  If this
(admittedly teensy weensy) bug has been fixed, then I don't see a lot
of need for a debugging library.
    Oh, yeah, didn't you say that under DPMI you don't get a GPF and
stack dump in this situation?  (I have no idea what I'm talking about,
I don't use DPMI, I just recall a bunch of words that were sort of in
that order---a reply to Tony Helm's original question about
"strcat()?")  If this is so, then there is a need for a debugging
library.

    --Steve

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