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Re: The variable __func__ in C89 in gcc

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Tim Rentsch <txr@alumni.caltech.edu> writes:
> James Kuyper <jameskuyper@verizon.net> writes:
>> On 05/19/2011 05:03 AM, Sorc Chan wrote:
>>> On 18  <<D0>>  <<BC>>  <<D0>>  <<B0>>  <<D0>>  <<B9>> , 18:08, rouben@shady.(none) (Rouben Rostamian) wrote:
>>>> Consider:
>>>>
>>>> #include <stdio.h>
>>>> int main(void)
>>>> {
>>>>         printf("entering function %s\n", __func__);
>>>>         return 0;
>>>>
>>>> }
[...]
>>>>> What would _prevent_ GCC from providing this for C89 code?
>>> 
>>> Because __func__ in C98 undeclared such as any __ohhelloguys__ thing.
>>
>> C89 imposes no such requirement. In fact, the main reason why the C89
>> standard said that a program using __func__ has undefined behavior is so
>> an implementation can choose to do anything it wishes to do with
>> __func__.
>
> Except the C89 standard doesn't say that (nor does the C99
> standard).  Declaring or defining a reserved identifier
> is undefined behavior, but just using one isn't.
>
>> In particular, the fact that the behavior is undefined gives
>> the compiler permission to treat __func__ as behaving in precisely the
>> fashion it's required to behave, according to the C99 standard.
>
> No, under the C99 standard a diagnostic must be issued.
> No diagnostic, no conformance.

Did you forget that __func__ is predefined in C99 (6.4.2.2)?
Or were you referring to declaring or defining __func__ yourself
(which does cause undefined behavior) as opposed to referring to it?

[...]

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Nokia
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"

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The variable __func__ in C89 in gcc rouben@shady.(none) (Rouben Rostamian) - 2011-05-18 14:08 +0000
  Re: The variable __func__ in C89 in gcc Shao Miller <sha0.miller@gmail.com> - 2011-05-18 10:13 -0400
  Re: The variable __func__ in C89 in gcc Seebs <usenet-nospam@seebs.net> - 2011-05-18 16:03 +0000
    Re: The variable __func__ in C89 in gcc Keith Thompson <kst-u@mib.org> - 2011-05-18 10:32 -0700
      Re: The variable __func__ in C89 in gcc cri@tiac.net (Richard Harter) - 2011-05-18 19:39 +0000
        Re: The variable __func__ in C89 in gcc Seebs <usenet-nospam@seebs.net> - 2011-05-18 19:45 +0000
      Re: The variable __func__ in C89 in gcc William Ahern <william@wilbur.25thandClement.com> - 2011-05-18 19:27 -0700
    Re: The variable __func__ in C89 in gcc Keith Thompson <kst-u@mib.org> - 2011-05-19 08:42 -0700
      Re: The variable __func__ in C89 in gcc Seebs <usenet-nospam@seebs.net> - 2011-05-19 16:34 +0000
        Re: The variable __func__ in C89 in gcc Kenneth Brody <kenbrody@spamcop.net> - 2011-05-19 14:15 -0400
        Re: The variable __func__ in C89 in gcc Shao Miller <sha0.miller@gmail.com> - 2011-05-19 14:45 -0400
        Re: The variable __func__ in C89 in gcc Tim Rentsch <txr@alumni.caltech.edu> - 2011-05-19 14:02 -0700
      Re: The variable __func__ in C89 in gcc Tim Rentsch <txr@alumni.caltech.edu> - 2011-05-19 12:45 -0700
  Re: The variable __func__ in C89 in gcc Sorc Chan <sorcchan@gmail.com> - 2011-05-19 02:03 -0700
    Re: The variable __func__ in C89 in gcc James Kuyper <jameskuyper@verizon.net> - 2011-05-19 06:17 -0400
      Re: The variable __func__ in C89 in gcc Tim Rentsch <txr@alumni.caltech.edu> - 2011-05-19 13:44 -0700
        Re: The variable __func__ in C89 in gcc Keith Thompson <kst-u@mib.org> - 2011-05-19 13:48 -0700
          Re: The variable __func__ in C89 in gcc Tim Rentsch <txr@alumni.caltech.edu> - 2011-05-19 14:12 -0700
            Re: The variable __func__ in C89 in gcc Keith Thompson <kst-u@mib.org> - 2011-05-19 14:29 -0700
              Re: The variable __func__ in C89 in gcc gazelle@shell.xmission.com (Kenny McCormack) - 2011-05-19 21:54 +0000
                Re: The variable __func__ in C89 in gcc Angel <angel+news@spamcop.net> - 2011-05-19 22:27 +0000
              Re: The variable __func__ in C89 in gcc Tim Rentsch <txr@alumni.caltech.edu> - 2011-05-24 02:23 -0700
          Re: The variable __func__ in C89 in gcc gazelle@shell.xmission.com (Kenny McCormack) - 2011-05-19 21:54 +0000
          Re: The variable __func__ in C89 in gcc James Kuyper <jameskuyper@verizon.net> - 2011-05-19 23:26 -0400
            Re: The variable __func__ in C89 in gcc Shao Miller <sha0.miller@gmail.com> - 2011-05-19 22:39 -0500
    Re: The variable __func__ in C89 in gcc Shao Miller <sha0.miller@gmail.com> - 2011-05-19 08:22 -0400
      Re: The variable __func__ in C89 in gcc Tim Rentsch <txr@alumni.caltech.edu> - 2011-05-19 13:47 -0700

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