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Re: #include <stdint.h>

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Andrey Tarasevich <andreytarasevich@hotmail.com> writes:
> On 6/24/2021 11:28 AM, Keith Thompson wrote:
>> My reading of the standard is that that's certainly the intent, but
>> it's not quite stated explicitly.
>
> Yes, it does. The intent of 6.2.5/9 is, among other things, is to
> postulate interchangeability of values of corresponding
> signed-unsigned types as function arguments.
>
> No special remarks of any kind are made about variadic functions,
> which immediately closes the matter. No need to dig deeper and involve 
> `va_arg` or anything else.

N1570 6.2.5p9 says that a value that's within the range of corresponding
signed and unsigned types has the same representation in both types.
That doesn't necessarily imply interchangeability as function arguments.

It's only relevant for variadic arguments or if no prototype is visible;
otherwise an argument will be converted to the required type (and the
conversion will correctly yield the same value).

I can imagine an implementation in which signed integer arguments are
passed on the stack and unsigned integer arguments are passed in
registers, or in which they're passed in different registers.  That
would violate the stated intent given in the non-normative footnote:

    The same representation and alignment requirements are meant to imply
    interchangeability as arguments to functions, return values from
    functions, and members of unions.

but I see no normative wording in the standard that would be violated by
such an admittedly perverse implementation.

Perhaps my phrase "not quite stated explicitly" was imprecise.  It's
stated explicitly in a footnote, but not in normative text.

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips
void Void(void) { Void(); } /* The recursive call of the void */

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#include <stdint.h> SIMON <invalid@invalid.invalid> - 2021-06-13 23:08 +0100
  Re: #include <stdint.h> Bart <bc@freeuk.com> - 2021-06-13 23:27 +0100
    Re: #include <stdint.h> Bart <bc@freeuk.com> - 2021-06-13 23:57 +0100
      Re: #include <stdint.h> Philipp Klaus Krause <pkk@spth.de> - 2021-06-14 09:03 +0200
        Re: #include <stdint.h> Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-14 01:23 -0700
          Re: #include <stdint.h> Philipp Klaus Krause <pkk@spth.de> - 2021-06-14 12:31 +0200
        Re: #include <stdint.h> Bart <bc@freeuk.com> - 2021-06-14 11:54 +0100
  Re: #include <stdint.h> James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-06-13 18:34 -0400
  Re: #include <stdint.h> Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-06-13 23:34 +0100
  Re: #include <stdint.h> Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-13 17:48 -0700
    Re: #include <stdint.h> Philipp Klaus Krause <pkk@spth.de> - 2021-06-14 09:09 +0200
      Re: #include <stdint.h> Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-14 01:24 -0700
        Re: #include <stdint.h> Philipp Klaus Krause <pkk@spth.de> - 2021-06-14 12:30 +0200
    Re: #include <stdint.h> Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-06-24 10:31 -0700
      Re: #include <stdint.h> Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-24 11:28 -0700
        Re: #include <stdint.h> Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-07-11 02:49 -0700
          Re: #include <stdint.h> Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-07-11 15:30 -0700
            Re: #include <stdint.h> Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-07-16 03:33 -0700
              Re: #include <stdint.h> Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-07-16 12:31 -0700
                Re: #include <stdint.h> Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-09-30 07:07 -0700
                Re: #include <stdint.h> Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-30 08:42 -0700
                Re: #include <stdint.h> Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-10-06 03:55 -0700
                Re: #include <stdint.h> Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-10-06 07:06 -0700
                Re: #include <stdint.h> James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-10-06 11:47 -0400
        Re: #include <stdint.h> Andrey Tarasevich <andreytarasevich@hotmail.com> - 2021-10-06 09:35 -0700
          Re: #include <stdint.h> Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-10-06 10:06 -0700
          Re: #include <stdint.h> James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-10-06 17:40 -0400
            Re: #include <stdint.h> Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-06 22:14 +0000
              Re: #include <stdint.h> James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-10-06 20:06 -0400
                Re: #include <stdint.h> Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-07 02:15 +0000
      Re: #include <stdint.h> Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-06-24 22:34 +0100
        Re: #include <stdint.h> Öö Tiib <ootiib@hot.ee> - 2021-06-24 15:01 -0700
          Re: #include <stdint.h> Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-24 15:26 -0700
        Re: #include <stdint.h> Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-07-11 02:14 -0700

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