BZ #13908 Fix mktemp attribute and comment

[Andreas Jaeger]

On 04/04/2012 06:16 PM, Paul Eggert wrote:
> On 04/04/2012 08:58 AM, Carlos O'Donell wrote:
>
>> Is there some common idiom that is used by developers which triggers a
>> warning when it shouldn't?
>
> It's the typical way mktemp should be used.  Here's an example, from
> <http://stuff.mit.edu/afs/athena/astaff/project/opssrc/cups/foomatic-filters-4.0.3/pdf.c>:
>
>      snprintf(filename, PATH_MAX, "%s/foomatic-XXXXXX", temp_dir());
>      mktemp(filename);
>      if (!filename[0])
>          return 0;
>
>> Is this with a recent GCC?
>
> It should be with any gcc that supports __wur, no?

Yep, with gcc 4.6:

  gcc -Wall t.c -O2 -D_FORTIFY_SOURCE=2
t.c: In function ‘main’:
t.c:12:10: warning: ignoring return value of ‘mktemp’, declared with 
attribute warn_unused_result [-Wunused-result]
/tmp/ccm8JfIk.o: In function `main':
t.c:(.text.startup+0x1f): warning: the use of `mktemp' is dangerous, 
better use `mkstemp'

Ok, with the change to use "Always returns"?

Andreas

Testprogram:
#include <sys/param.h>
#include <stdlib.h>
#include <stdio.h>

int
main (void)
{
   char filename [PATH_MAX];

    snprintf(filename, PATH_MAX, "/tmp/foomatic-XXXXXX");
    mktemp(filename);
    if (!filename[0])
      return 1;
    return 0;
}

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  Andreas Jaeger aj@{suse.com,opensuse.org} Twitter/Identica: jaegerandi
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