git.distorted.org.uk Git - u/mdw/catacomb/blob - mptypes.c

   1 /* -*-c-*-
   2  *
   3  * $Id: mptypes.c,v 1.2 1999/11/13 01:54:32 mdw Exp $
   4  *
   5  * Generate `mptypes.h' header file for current architecture
   6  *
   7  * (c) 1999 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Catacomb.
  13  *
  14  * Catacomb is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU Library General Public License as
  16  * published by the Free Software Foundation; either version 2 of the
  17  * License, or (at your option) any later version.
  18  *
  19  * Catacomb is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU Library General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU Library General Public
  25  * License along with Catacomb; if not, write to the Free
  26  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  27  * MA 02111-1307, USA.
  28  */
  29
  30 /*----- Revision history --------------------------------------------------*
  31  *
  32  * $Log: mptypes.c,v $
  33  * Revision 1.2  1999/11/13 01:54:32  mdw
  34  * Format source code properly ;-).  Attach suffixes to the `max'
  35  * constants.
  36  *
  37  */
  38
  39 /*----- Header files ------------------------------------------------------*/
  40
  41 #define _GNU_SOURCE
  42 #include <stdio.h>
  43 #include <limits.h>
  44 #if __STDC_VERSION__ >= 199900l
  45 #  include <stdint.h>
  46 #endif
  47
  48 /*----- Data types --------------------------------------------------------*/
  49
  50 /* --- Hack for GCC --- *
  51  *
  52  * WG14 in their infinite wisdom decided not to use the GCC constant name.
  53  */
  54
  55 #if defined(ULONG_LONG_MAX) && !defined(ULLONG_MAX)
  56 #  define ULLONG_MAX ULONG_LONG_MAX
  57 #endif
  58
  59 /* --- Choose the largest integer type --- */
  60
  61 #if defined(UINTMAX_MAX)
  62   typedef uintmax_t umax;
  63 # define P_UMAX PRIuMAX
  64 #elif defined(ULLONG_MAX)
  65   typedef unsigned long long umax;
  66 # define P_UMAX "%llu"
  67 #else
  68   typedef unsigned long umax;
  69 # define P_UMAX "%lu"
  70 #endif
  71
  72 /* --- Table of interesting types --- *
  73  *
  74  * These are in preference order.
  75  */
  76
  77 enum {
  78   f_stdint
  79 };
  80
  81 struct itype {
  82   const char *name;
  83   const char *suff;
  84   umax max;
  85   unsigned flags;
  86   unsigned bits;
  87 } tytab[] = {
  88   { "unsigned int", "u",        UINT_MAX,       0 },
  89   { "unsigned short", "u",      USHRT_MAX,      0 },
  90   { "unsigned long", "ul",      ULONG_MAX,      0 },
  91 #ifdef ULLONG_MAX
  92   { "unsigned long long", "ull", ULLONG_MAX,    0 },
  93 #endif
  94 #ifdef UINTMAX_MAX
  95   { "uintmax_t", "u",           UINTMAX_MAX,    f_stdint },
  96 #endif
  97   { 0,                          0 },
  98 };
  99
 100 typedef struct itype itype;
 101
 102 /*----- Main code ---------------------------------------------------------*/
 103
 104 int main(int argc, char *argv[])
 105 {
 106   itype *i;
 107   itype *largest, *mpw, *mpd;
 108
 109   /* --- Find the bitcounts --- */
 110
 111   for (i = tytab; i->name; i++) {
 112     unsigned bits;
 113     umax u = i->max;
 114     for (bits = 0; u; bits++)
 115       u >>= 1;
 116     i->bits = bits;
 117   }
 118
 119   /* --- Now try to find the interesting types --- *
 120    *
 121    * The first thing to do is to find the largest type.  Then I find the
 122    * `best' type which is less than half that size, and then the `best' type
 123    * which is twice as big as that one.
 124    */
 125
 126   largest = tytab;
 127   for (i = tytab; i->name; i++) {
 128     if (i->bits > largest->bits)
 129       largest = i;
 130   }
 131   for (mpw = 0, i = tytab; i->name; i++) {
 132     if (i->bits * 2 <= largest->bits && (!mpw || i->bits > mpw->bits))
 133       mpw = i;
 134   }
 135   if (!mpw)
 136     mpw = tytab;
 137   for (mpd = 0, i = tytab; i->name; i++) {
 138     if (i->bits >= mpw->bits * 2 && (!mpd || i->bits < mpd->bits))
 139       mpd = i;
 140   }
 141   if (!mpd) {
 142     static itype w, d;
 143     d = w = *mpw;
 144     w.bits /= 2; w.max = ~(~((umax)0) << w.bits);
 145     d.bits = w.bits * 2; d.max = ~(~((umax)0) << d.bits);
 146     mpw = &w; mpd = &d;
 147   }
 148
 149   /* --- Output time --- */
 150
 151   puts("\
 152 /* -*-c-*-\n\
 153  *\n\
 154  * mptypes.h [generated]\n\
 155  */\n\
 156 \n\
 157 #ifndef MPTYPES_H\n\
 158 #define MPTYPES_H\n\
 159 ");
 160   if ((mpd->flags | mpw->flags) & f_stdint) {
 161     puts("\
 162 #if __STDC_VERSION__ >= 199900l\n\
 163 #  include <stdint.h>\n\
 164 #endif\n\
 165 ");
 166   }
 167   printf("\
 168 typedef %s mpw;\n\
 169 #define MPW_BITS %u\n\
 170 #define MPW_MAX " P_UMAX "%s\n\
 171 \n\
 172 typedef %s mpd;\n\
 173 #define MPD_BITS %u\n\
 174 #define MPD_MAX " P_UMAX "%s\n\
 175 \n\
 176 #endif\n\
 177 ",
 178   mpw->name, mpw->bits, mpw->max, mpw->suff,
 179   mpd->name, mpd->bits, mpd->max, mpd->suff);
 180
 181   return (0);
 182 }
 183 /*----- That's all, folks -------------------------------------------------*/