[MPlayer-dev-eng] [PATCH] mplayer.c

[Oded Shimon]

On Sun, Mar 27, 2005 at 10:17:54PM -0500, D Richard Felker III wrote:
> On Sun, Mar 27, 2005 at 07:23:06PM -0600, Joey Parrish wrote:
> > On Sun, Mar 27, 2005 at 09:10:39PM +0200, Bj?rn Sandell wrote:
> > > Avoid some missing sentinel warnings.
> > 
> > > -          if (execlp("gdb", "gdb", prog_path, spid, NULL) == -1)
> > > +          if (execlp("gdb", "gdb", prog_path, spid, (void *)NULL) == -1)
> > 
> > > -          execl("/bin/sh","sh","-c",cmd->args[0].v.s,NULL);
> > > +          execl("/bin/sh","sh","-c",cmd->args[0].v.s,(void *)NULL);
> > 
> > This is silly.  There should be no need to cast compatible constants.
> > 
> > 1) NULL should always be assumed to be a pointer (common sense)
> > 2) even treating NULL as int, C doesn't care about such stupid
> >     casting, only C++ would complain
> > 
> > What good is this patch?  What is sentinel?
> 
> Actually with functions which take a variable number of arguments, it
> _does_ matter, since there is no profile to force the right promotion
> of 0 to a pointer type. However, NULL is already (void*)0, so this is
> nonsense (strictly speaking C allows it to be defined as 0 I think,
> but no sane implementation does that..).

If you want to be really anal, the "correct" thing to put is '(char *)0', but 
I don't think there is any modern architecture where this matters. This patch 
is totally useless, because NULL already is '(void *)0'.

- ods15