Re: [PATCH 1/4] localename: -Wtautological-pointer-compare

[Paul Eggert]

On 2023-01-15 14:03, Bruno Haible wrote:

> > My confusion arose partly because I am accustomed to languages where the
> > distinction between null and non-null pointers is checked statically ...
>
> Oh, now I understand. May I guess the language: Haskell, OCaml, TypeScript,
> Rust?

These days OCaml and maybe Rust, though the language that first comes to 
my mind is one I designed in the 1970s and never got off the ground: B 
Pascal.


> Unfortunately, this is an excellent example for a portability problem:
> The division yields a SIGFPE on x86, x86_64, alpha, m68k, and s390/s390x
> CPU, but not on other architectures.

I suppose I should have written that my assumption was that the code is 
executed in a context where the divisor must be positive. (This is 
pretty common when calculating indexes from sizes.)

In other contexts the extra checking may be necessary, or at least helpful.