Re: Compiler Warnings

[Miroslaw Dobrzanski-Neumann <mne mosaic-ag com>]

On Sat, Feb 16, 2002 at 07:01:49PM -0500, David L. Cooper II wrote:
> I generally compile glib/gtk+ on Solaris using Sun's compiler. I also have
> gcc loaded and use it on occasion. I've noticed that the sun compiler
> generates warnings in areas that gcc does not. Is anyone other than me
> interested in resolving these? If not, I won't bother. The code does compile
> but all the warnings make me nervous. Maybe it's just a personal problem ;>
> 
> If there IS interest, I'll start working on resolving some of these.

Generally I would turn on all warnings and the stop on warning option for each
compiler used. In many cases a warning reported by the compiler is indeed an
error.

for gcc one get many extra warnings with -W option and -Werror stops the
compilation at first warning

for xlc setting -qhalt=W behaves like gcc's -Werror



And other question

Why is the type gsize not just size_t?

   Here the current procedure taken from configure

   on AIX size_t is a unsigned long (a typedef in system header)
   sizeof(size_t) evaluates to 4


glib_size_t=$glib_cv_sizeof_size_t

   case x$glib_size_t in
   x2) echo "typedef gint16  gssize;" >> $outfile
       echo "typedef guint16 gsize;"  >> $outfile
       ;;
   x4) echo "typedef gint32  gssize;" >> $outfile
       echo "typedef guint32 gsize;"  >> $outfile
       ;;
   x8) echo "typedef gint64  gssize;" >> $outfile
       echo "typedef guint64 gsize;"  >> $outfile
       ;;
   *)  echo "#error size of size_t is unknown" >> $outfile
       ;;
   esac

===> gsize evaluates to guint32;
   
 case 4 in
 $ac_cv_sizeof_short)
   gint32=short
   gint32_format='"hi"'
   guint32_format='"hu"'
   ;;
 $ac_cv_sizeof_int)
   gint32=int
   gint32_format='"i"'
   guint32_format='"u"'
   ;; 
 $ac_cv_sizeof_long)
   gint32=long
   gint32_format='"li"'
   guint32_format='"lu"'
   ;;
 esac

===> guint32 evaluates to unsigned int

===> gsize is unsigned int and not unsigned long as declared in the system header
The xlc complains at many places about the use gsize where size_t was expected.
(unsigned int vs. unsigned long) especially for iconv call where two (size_t *)
parameter are expected and (gsize *) are suplied in gconvert.c.

extern  size_t  iconv(iconv_t, const char**, size_t*, char**, size_t*);

size_t 
g_iconv (GIConv   converter,
         gchar  **inbuf,
         gsize   *inbytes_left,
         gchar  **outbuf,
         gsize   *outbytes_left)
{
  iconv_t cd = (iconv_t)converter;

  return iconv (cd, inbuf, inbytes_left, outbuf, outbytes_left);
}

-- 
Miroslaw Dobrzanski-Neumann

MOSAIC SOFTWARE AG
Base Development and Research
Tel +49-2225-882-291
Fax +49-2225-882-201
E-mail: mne mosaic-ag com