Bug#215260: /usr/include/math.h: No prototype for roundf()

[Daniel Jacobowitz <dan@debian.org>]

On Sat, Oct 11, 2003 at 04:56:34PM +0200, Johan Walles wrote:
> Package: libc6-dev
> Version: 2.3.2-7
> Severity: normal
> File: /usr/include/math.h
> 
> libm.so.6 has a roundf() function:
> 
> johan@foo:~$ nm -D /lib/libm.so.6|grep roundf
> 00013180 W llroundf
> 000130e0 W lroundf
> 00011630 W roundf
> 
> It is documented on the roundf(3) man page:
> 
> johan@foo:~$ dpkg -S /usr/share/man/man3/roundf.3.gz
> manpages-dev: /usr/share/man/man3/roundf.3.gz
> 
> But it has no prototype:
> 
> johan@foo:~$ grep roundf /usr/include/ -r
> grep: warning: /usr/include/gnome-xml/libxml: recursive directory loop
> johan@foo:~$ echo $?
> 1
> 
> This goes for truncf() and probably some other functions as well, but
> roundf() and truncf() are the ones I care about.

Grep's not a good way to check.  Glibc uses a lot of preprocessor
macros.

<bits/mathcalls.h>:

#ifdef __USE_ISOC99
...
/* Round X to nearest integral value, rounding halfway cases away from
   zero.  */
__MATHCALLX (round,, (_Mdouble_ __x), (__const__));

Try using -D_GNU_SOURCE and then see if it's there.  Or
-D_ISOC99_SOURCE, or gcc -std=c99.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer