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Re: unsafe C

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ram@zedat.fu-berlin.de (Stefan Ram) writes:

> Meredith Montgomery <mmontgomery@levado.to> writes:
>>> it is funny that this is a  warning and not an error.
>
>>int scan_ulong(register char *s, register unsigned long *u) 
>>{
>>  register unsigned int pos;
> ...
>>  return pos;
>>}
>
>   It returns the /unsigned/ int "pos", but its return type is
>   declared /signed/ int?
>
>   /u/ is accessed at most once in the function, but declared
>   "register"?

Let's see.  I don't think I would've changed that much, but I might.
Lol.  I did.  I can't even copy properly!  Thanks for spotting that.

Hm, wait!  The check for overflow is not his.  It's mine.  Alas, memory
failing me.  Daniel J. Bernstein, sorry about that.

--8<---------------cut here---------------start------------->8---
/* Public domain. */

#include "scan.h"

unsigned int scan_ulong(register const char *s,register unsigned long *u)
{
  register unsigned int pos = 0;
  register unsigned long result = 0;
  register unsigned long c;
  while ((c = (unsigned long) (unsigned char) (s[pos] - '0')) < 10) {
    result = result * 10 + c;
    ++pos;
  }
  *u = result;
  return pos;
}
--8<---------------cut here---------------end--------------->8---

But, yes, he did qualify u with ``register''.

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unsafe C Thiago Adams <thiago.adams@gmail.com> - 2021-12-17 12:13 -0800
  Re: unsafe C Thiago Adams <thiago.adams@gmail.com> - 2021-12-17 12:16 -0800
    Re: unsafe C Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-12-17 12:25 -0800
    Re: unsafe C Meredith Montgomery <mmontgomery@levado.to> - 2021-12-18 12:40 -0300
      Re: unsafe C Meredith Montgomery <mmontgomery@levado.to> - 2021-12-25 21:41 -0300
        Re: unsafe C Meredith Montgomery <mmontgomery@levado.to> - 2021-12-25 21:42 -0300
    Re: unsafe C Andrey Tarasevich <andreytarasevich@hotmail.com> - 2021-12-18 12:29 -0800
  Re: unsafe C Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-12-17 12:20 -0800
    Re: unsafe C Thiago Adams <thiago.adams@gmail.com> - 2021-12-17 12:29 -0800
    Re: unsafe C Peter 'Shaggy' Haywood <phaywood@alphalink.com.au> - 2021-12-19 17:16 +1100
      Re: unsafe C Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-12-19 13:32 -0800
  Re: unsafe C Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-12-17 20:30 +0000
    Re: unsafe C Thiago Adams <thiago.adams@gmail.com> - 2021-12-17 12:35 -0800

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