Re: Patch to use more safe-ctype macros

[DJ Delorie <dj at redhat dot com>]

> >  hex_digit_value (c)
> >       unsigned int c;
> >  {
> > +  if (ISDIGIT (c))
> > +    return c - '0';
> >    if (c >= 'a' && c <= 'f')
> >      return c - 'a' + 10;
> >    if (c >= 'A' && c <= 'F')
> >      return c - 'A' + 10;
> > -  if (c >= '0' && c <= '9')
> > -    return c - '0';
> >    abort ();
> 
> I would prefer if you left this one alone; I think it's more readable
> to have all three conditions take the same general form.

Libiberty exports a table for that purpose.  This is what's in
libiberty.h, although nobody in gcc uses it (or calls hex_init) yet.

/* hex character manipulation routines */

#define _hex_array_size 256
#define _hex_bad        99
extern char _hex_value[_hex_array_size];
extern void hex_init PARAMS ((void));
#define hex_p(c)        (hex_value (c) != _hex_bad)
/* If you change this, note well: Some code relies on side effects in
   the argument being performed exactly once.  */
#define hex_value(c)    (_hex_value[(unsigned char) (c)])