Robert Suetterlin <[EMAIL PROTECTED]> wrote:
> Unfortunately I'm neither proficient in C++ nor efficient in
> debugging, so I stumble around the problem rather blindfolded. Once
> I blamed the compiler, systemlibraries and operating system, I knew
> I needed some help. The problem appeared on a linux system, but I
> guess the techniques I might need will be the same under Linux,
> FreeBSD or any un*x.
Unfortunately, you'll probably have to debug this the hard way.
Figure out what part of memory is being trashed, and then figure out
what is trashing the memory. If the memory address/data is consistent,
you might be able to use the i386 hardware breakpoint debug registers to
help you.
The "best" -- but horribly expensive -- way is to port the software
to another Unix platform (like Solaris or HP-UX), and use Rational
Software's "Purify" to locate the memory corruption. It's almost a
no-brainer to use, and it works ungodly well. You don't even need
source code to use purify -- object files are enough, as purify works at
*link* time (you don't have to specially compile your code, unless you
want to take advantage of special purify APIs). The downside is that
your program does run 3-10X slower, and Purify is pretty expensive (but
it's such a killer programming app). It's not available for either
FreeBSD or Linux, though.
Purify's nearest (commercial) competitor is ParaSoft's "Insure++".
Perhaps things have improved but, when we last evaluated it a year or
two back, it was a LOT slower than purify (unusably slow for our
applications). I seem to recall 5-10X slower than purify (maybe more).
It can detect a few problems that purify does not, however (e.g., bad
arguments to printf()). Insure++ needs access to source code for best
results. I believe a Linux version is available.
There is no open-source equivalent to purify (and probably won't
be, due to patent issues). The closest thing is "GNU checker", but
that's a pale, feeble dust speck compared to purify (assuming that you
even manage to get checker working).
--
Darryl Okahata
[EMAIL PROTECTED]
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