[GRASS5] r.flow: strange compile error M_PI

[Daniel Calvelo Aros]

From: Markus Neteler <neteler at itc.it>
Sent: Thu, 23 Jun 2005 04:25:54 +0200
>
> On Wed, Jun 22, 2005 at 07:04:55PM -0700, Brad Douglas wrote:
> > On Thu, 2005-06-23 at 00:12 +0200, Markus Neteler wrote:
> > > Hi,
> > > 
> > > after an update of the Linux OS, I am no longer able to
> > > compile r.flow:
> > > 
> > > thuille:r.flow[281.25] make
> > > gcc -I/hardmnt/thuille0/ssi/software/cvsgrass61/include
-I/hardmnt/thuille0/ssi/software/cvsgrass61/dist.i686-pc-linux-gnu/include/grass
 -g -Wall -ansi  -Wall -Wconversion -Wno-implicit-int   -I/usr/local/include 
   -DPACKAGE=\""grassmods"\" 
-I/hardmnt/thuille0/ssi/software/cvsgrass61/include
-I/hardmnt/thuille0/ssi/software/cvsgrass61/dist.i686-pc-linux-gnu/include/grass \
> > >         -o OBJ.i686-pc-linux-gnu/aspect.o -c aspect.c
> > > aspect.c: In function `aspect_fly':
> > > aspect.c:50: error: `M_PI' undeclared (first use in this function)
> > > aspect.c:50: error: (Each undeclared identifier is reported only once
> > > aspect.c:50: error: for each function it appears in.)
> > > make: *** [OBJ.i686-pc-linux-gnu/aspect.o] Error 1
>
> Sorry, forgot to post that. Yes, it is defined:
> 
> grep M_PI /usr/include/math.h
> # define M_PI           3.14159265358979323846  /* pi */
> # define M_PI_2         1.57079632679489661923  /* pi/2 */
> # define M_PI_4         0.78539816339744830962  /* pi/4 */
> # define M_PIl          3.1415926535897932384626433832795029L  /* pi */
> # define M_PI_2l        1.5707963267948966192313216916397514L  /* pi/2 */
> # define M_PI_4l        0.7853981633974483096156608458198757L  /* pi/4 */

Try to launch a "gcc -E apect.c" (with the appropriate -I's) and grep for M_PI
in the resulting file. That will tell if it ends up being visible. Now, I
wonder wether "#define" and "# define" are the same...

Daniel.