Using rand_r and -std=c99 with gcc

Larry Hall (Cygwin) reply-to-list-only-lh@cygwin.com
Fri Sep 7 05:55:00 GMT 2012


On 9/6/2012 10:37 PM, Jason Gross wrote:
> Hi,
> If I try to compile a C program which uses rand_r with gcc 4.5.3, with
> -std=c99, I get
>
> warning: implicit declaration of function 'rand_r'.
>
> Google gave me http://cygwin.com/ml/cygwin/2009-05/msg00417.html and
> http://sourceware.org/ml/newlib/2007/msg00800.html, which explains why
> this happens, but these messages are 3 years old.  Additionally,
> http://linux.die.net/man/3/rand_r suggests that rand_r is c99.  Are
> there plans to update stdlib.h to account for c99?  If I look through
> the http://linux.die.net/man pages and figure out which things are c99
> and submit a patch, will it get checked in?

The Linux man page you point to has this to say about rand_r's conformance:

   The function rand_r() is from POSIX.1-2001. POSIX.1-2008 marks rand_r() 
as obsolete.

The fact that rand_r doesn't list c99 and is obsoleted in POSIX.1-2008
makes me dubious that newlib folks are going to jump at a patch to add
it to c99.

-- 
Larry

_____________________________________________________________________

A: Yes.
 > Q: Are you sure?
 >> A: Because it reverses the logical flow of conversation.
 >>> Q: Why is top posting annoying in email?

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