I've been using the HiTech PICC-18 compiler for a recent project, and have
been experiencing some extremely odd behavior.  I'm reluctant to point the
finger at the compiler, but I can't figure out what else is going wrong.

I have a function that seemed to be trashing a global variable.  The
variable value is reported back via an I2C link.  I stripped the function
down to the absolute bare bones and there was no change.  In desperation, I
"commented" out the original function using #ifdef QWERTY and #endif, where
QWERTY is obviously an undefined symbol.  Underneath the original function,
I made a copy that I could tweak.  However, when I re-compiled, the problem
had gone.  To check, I deleted the copy, and uncommented the original and
the problem returned.  This is totally repeatable.  To summarise:

The following gives problems with global variable corruption

void myfunc(void)
{
// my code here
}

The following works correctly.

#ifdef QWERTY
void myfunc(void)
{
// my code here
}
#endif

void myfunc(void)
{
// my code here
}

My question is, how likely is this a compiler bug, and whats the best way of
proving it one way or the other?  Finding this problem has taken the best
part of a week, and I'm worried that other parts of the code are going to be
similarly affected.  The code is  more or less a direct port from a product
that used the 16F877 compiled with HiTech PICC, and this problem was never
seen.

Regards

Mike

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu