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Date: Mon, 10 Oct 2011 11:21:12 +0200
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: stdio.h: broken standard compliance.
Message-ID: <20111010092112.GA28134@calimero.vinschen.de>
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On Oct  9 11:23, Kaz Kylheku wrote:
> 
> On Sun, 09 Oct 2011 11:08:58 -0700, Kaz Kylheku <kaz AT kylheku DOT com>
> wrote:
> > reason, I cannot get a warning about fileno from this test case if
> > I add a reference to it. I will try to produce a minimal repro test
> > case for that.
> 
> In my real program I have -Wall, and I'm not taking the function
> pointers.
> 
> With -Wall we get warnings about implicit declarations.
> 
> So, here is a better test case which shows that these identifiers are
> not declared when they should be. Of course the two errors occur
> without -Wall.
> 
> $ cat posix-ansi.c
> #include <stdio.h>
> 
> void foo(void)
> {
>   int (*f1)(FILE *) = fileno;
>   int (*f2)(FILE *) = pclose;
> }
> 
> int main(void)
> {
>   int x = fileno(stdin);
>   pclose(NULL);
>   return 0;
> }
> 
> $ gcc -Wall -ansi -D_POSIX_C_SOURCE=2 posix-ansi.c
              ^^^^^
fileno and pclose are *not* ANSI functions.  Therefore, if you define
-ansi, you get the below errors.  The newlib headers have explicit
#ifndef __STRICT_ANSI__ guards around the non-ANSI definitions.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

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