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[u/mdw/catacomb] / mptypes.c

/* -*-c-*-
 *
 * $Id: mptypes.c,v 1.5 2004/04/08 01:36:15 mdw Exp $
 *
 * Generate `mptypes.h' header file for current architecture
 *
 * (c) 1999 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------* 
 *
 * This file is part of Catacomb.
 *
 * Catacomb is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 * 
 * Catacomb is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Library General Public License for more details.
 * 
 * You should have received a copy of the GNU Library General Public
 * License along with Catacomb; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

/*----- Header files ------------------------------------------------------*/

#define _GNU_SOURCE
#include <stdio.h>
#include <limits.h>
#if __STDC_VERSION__ >= 199900l
#  include <stdint.h>
#endif

/*----- Data types --------------------------------------------------------*/

/* --- Hack for GCC --- *
 *
 * WG14 in their infinite wisdom decided not to use the GCC constant name.
 */

#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 91)
#  define EXT __extension__
#else
#  define EXT
#endif

#if defined(ULONG_LONG_MAX) && !defined(ULLONG_MAX)
#  define ULLONG_MAX ULONG_LONG_MAX
#endif

/* --- Choose the largest integer type --- */

#if defined(UINTMAX_MAX)
  typedef uintmax_t umax;
# define P_UMAX PRIuMAX
#elif defined(ULLONG_MAX)
  __extension__ typedef unsigned long long umax;
# define P_UMAX "%llu"
#else
  typedef unsigned long umax;
# define P_UMAX "%lu"
#endif

/* --- Table of interesting types --- *
 *
 * These are in preference order.
 */

enum {
  f_stdint = 1u,
  f_ext = 2u
};

struct itype {
  const char *name;
  const char *suff;
  umax max;
  unsigned flags;
  unsigned bits;
} tytab[] = {
  { "unsigned int",		"u",	UINT_MAX,		0 },
  { "unsigned short",		"u",	USHRT_MAX,		0 },
  { "unsigned long",		"ul",	ULONG_MAX,		0 },
#ifdef ULLONG_MAX
  { "unsigned long long",	"ull",	EXT ULLONG_MAX,		f_ext },
#endif
#ifdef UINTMAX_MAX
  { "uintmax_t",		"u",	UINTMAX_MAX,		f_stdint },
#endif
  { 0,				0 },
};

typedef struct itype itype;

/*----- Main code ---------------------------------------------------------*/

int main(int argc, char *argv[])
{
  itype *i;
  itype *largest, *mpw, *mpd;
  const static char *extstr = "CATACOMB_MPTYPES_EXTENSION ";

  /* --- Find the bitcounts --- */

  for (i = tytab; i->name; i++) {
    unsigned bits;
    umax u = i->max;
    for (bits = 0; u; bits++)
      u >>= 1;
    i->bits = bits;
  }

  /* --- Now try to find the interesting types --- *
   *
   * The first thing to do is to find the largest type.  Then I find the
   * `best' type which is less than half that size, and then the `best' type
   * which is twice as big as that one.
   */

  largest = tytab;
  for (i = tytab; i->name; i++) {
    if (i->bits > largest->bits)
      largest = i;
  }
  for (mpw = 0, i = tytab; i->name; i++) {
    if (i->bits * 2 <= largest->bits && (!mpw || i->bits > mpw->bits))
      mpw = i;
  }
  if (!mpw)
    mpw = tytab;
  for (mpd = 0, i = tytab; i->name; i++) {
    if (i->bits >= mpw->bits * 2 && (!mpd || i->bits < mpd->bits))
      mpd = i;
  }
  if (!mpd) {
    static itype w, d;
    d = w = *mpw;
    w.bits /= 2; w.max = ~(~((umax)0) << w.bits);
    d.bits = w.bits * 2; d.max = ~(~((umax)0) << d.bits);
    mpw = &w; mpd = &d;
  }    

  /* --- Output time --- */

  puts("\
/* -*-c-*-\n\
 *\n\
 * mptypes.h [generated]\n\
 */\n\
\n\
#ifndef CATACOMB_MPTYPES_H\n\
#define CATACOMB_MPTYPES_H\n\
");
  if ((mpd->flags | mpw->flags) & f_stdint) {
    puts("\
#if __STDC_VERSION__ >= 199900l\n\
#  include <stdint.h>\n\
#endif\n\
");
  }
  if ((mpd->flags | mpw->flags) & f_ext) {
    printf("\
#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 91)\n\
#  define %s __extension__\n\
#else\n\
#  define %s\n\
#endif\n\
", extstr, extstr);
  }
  printf("\
%stypedef %s mpw;\n\
#define MPW_BITS %u\n\
#define MPW_MAX %s" P_UMAX "%s\n\
\n\
%stypedef %s mpd;\n\
#define MPD_BITS %u\n\
#define MPD_MAX %s" P_UMAX "%s\n\
\n\
#endif\n\
",
  mpw->flags & f_ext ? extstr : "", mpw->name,
  mpw->bits,
  mpw->flags & f_ext ? extstr : "", mpw->max, mpw->suff,
  mpd->flags & f_ext ? extstr : "", mpd->name,
  mpd->bits,
  mpd->flags & f_ext ? extstr : "", mpd->max, mpd->suff);

  return (0);
}

/*----- That's all, folks -------------------------------------------------*/