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

   1 /* -*-c-*-
   2  *
   3  * $Id$
   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 /*----- Header files ------------------------------------------------------*/
  31
  32 #define _GNU_SOURCE
  33 #include <stdio.h>
  34 #include <limits.h>
  35 #if __STDC_VERSION__ >= 199900l
  36 #  include <stdint.h>
  37 #  include <inttypes.h>
  38 #endif
  39
  40 /*----- Data types --------------------------------------------------------*/
  41
  42 /* --- Hack for GCC --- *
  43  *
  44  * WG14 in their infinite wisdom decided not to use the GCC constant name.
  45  */
  46
  47 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 91)
  48 #  define EXT __extension__
  49 #else
  50 #  define EXT
  51 #endif
  52
  53 #if defined(ULONG_LONG_MAX) && !defined(ULLONG_MAX)
  54 #  define ULLONG_MAX ULONG_LONG_MAX
  55 #endif
  56
  57 /* --- Choose the largest integer type --- */
  58
  59 #if defined(UINTMAX_MAX) && defined(PRIuMAX)
  60   typedef uintmax_t umax;
  61 # define P_UMAX PRIuMAX
  62 #elif defined(ULLONG_MAX)
  63   __extension__ typedef unsigned long long umax;
  64 # define P_UMAX "llu"
  65 #else
  66   typedef unsigned long umax;
  67 # define P_UMAX "lu"
  68 #endif
  69
  70 /* --- Table of interesting types --- *
  71  *
  72  * These are in preference order.
  73  */
  74
  75 enum {
  76   f_stdint = 1u,
  77   f_ext = 2u
  78 };
  79
  80 struct itype {
  81   const char *name;
  82   const char *suff;
  83   umax max;
  84   unsigned flags;
  85   unsigned bits;
  86 } tytab[] = {
  87   { "unsigned int",             "u",    UINT_MAX,               0 },
  88   { "unsigned short",           "u",    USHRT_MAX,              0 },
  89   { "unsigned long",            "ul",   ULONG_MAX,              0 },
  90 #ifdef ULLONG_MAX
  91   { "unsigned long long",       "ull",  EXT ULLONG_MAX,         f_ext },
  92 #endif
  93 #ifdef UINTMAX_MAX
  94   { "uintmax_t",                "u",    UINTMAX_MAX,            f_stdint },
  95 #endif
  96   { 0,                          0 },
  97 };
  98
  99 typedef struct itype itype;
 100
 101 /*----- Main code ---------------------------------------------------------*/
 102
 103 int main(int argc, char *argv[])
 104 {
 105   itype *i;
 106   itype *largest, *mpw, *mpd;
 107   const static char *extstr = "CATACOMB_MPTYPES_EXTENSION ";
 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 CATACOMB_MPTYPES_H\n\
 158 #define CATACOMB_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   if ((mpd->flags | mpw->flags) & f_ext) {
 168     printf("\
 169 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 91)\n\
 170 #  define %s __extension__\n\
 171 #else\n\
 172 #  define %s\n\
 173 #endif\n\
 174 ", extstr, extstr);
 175   }
 176   printf("\
 177 %stypedef %s mpw;\n\
 178 #define MPW_BITS %u\n\
 179 #define MPW_MAX %s%" P_UMAX "%s\n\
 180 \n\
 181 %stypedef %s mpd;\n\
 182 #define MPD_BITS %u\n\
 183 #define MPD_MAX %s%" P_UMAX "%s\n\
 184 \n\
 185 #endif\n\
 186 ",
 187   mpw->flags & f_ext ? extstr : "", mpw->name,
 188   mpw->bits,
 189   mpw->flags & f_ext ? extstr : "", mpw->max, mpw->suff,
 190   mpd->flags & f_ext ? extstr : "", mpd->name,
 191   mpd->bits,
 192   mpd->flags & f_ext ? extstr : "", mpd->max, mpd->suff);
 193
 194   return (0);
 195 }
 196
 197 /*----- That's all, folks -------------------------------------------------*/