Re: Memory protection between compilation units?

On Thu, 12 Jun 2025 06:05 Tim Rentsch wrote:

The code in question shows several classic error patterns.  In no
particular order:
 
  * buffer overflow
  * off-by-one error

I'd consider that one item, since one leads to another.

  * bitwise operator with signed operand

My mistake. Real code is acting on something else than an int, I wasn't
paying enough attention when writing the illustrative example.

  * using & to effect what is really a modulo operation

You think of it as modulo, I think of it as "bits trimming".
Essentially same operation, but different viewpoints I guess.

I acknowledge that this response isn't exactly an answer to the
original question.  It does illustrate though a kind of thinking
that can be useful when trying to track down hard-to-find bugs.

Thank you for your insightful remarks. I completely agree - the best
way to debug a program is to avoid the need for debugging in the first
place. :-) But working with a large, 15-year-old codebase that has
seen contributions from dozens of programmers makes things a bit
non-ideal sometimes.

Mateusz