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

   1 /* -*-c-*-
   2  *
   3  * $Id: mptypes.c,v 1.5 2004/04/08 01:36:15 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 /*----- 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 #endif
  38
  39 /*----- Data types --------------------------------------------------------*/
  40
  41 /* --- Hack for GCC --- *
  42  *
  43  * WG14 in their infinite wisdom decided not to use the GCC constant name.
  44  */
  45
  46 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 91)
  47 #  define EXT __extension__
  48 #else
  49 #  define EXT
  50 #endif
  51
  52 #if defined(ULONG_LONG_MAX) && !defined(ULLONG_MAX)
  53 #  define ULLONG_MAX ULONG_LONG_MAX
  54 #endif
  55
  56 /* --- Choose the largest integer type --- */
  57
  58 #if defined(UINTMAX_MAX)
  59   typedef uintmax_t umax;
  60 # define P_UMAX PRIuMAX
  61 #elif defined(ULLONG_MAX)
  62   __extension__ typedef unsigned long long umax;
  63 # define P_UMAX "%llu"
  64 #else
  65   typedef unsigned long umax;
  66 # define P_UMAX "%lu"
  67 #endif
  68
  69 /* --- Table of interesting types --- *
  70  *
  71  * These are in preference order.
  72  */
  73
  74 enum {
  75   f_stdint = 1u,
  76   f_ext = 2u
  77 };
  78
  79 struct itype {
  80   const char *name;
  81   const char *suff;
  82   umax max;
  83   unsigned flags;
  84   unsigned bits;
  85 } tytab[] = {
  86   { "unsigned int",             "u",    UINT_MAX,               0 },
  87   { "unsigned short",           "u",    USHRT_MAX,              0 },
  88   { "unsigned long",            "ul",   ULONG_MAX,              0 },
  89 #ifdef ULLONG_MAX
  90   { "unsigned long long",       "ull",  EXT ULLONG_MAX,         f_ext },
  91 #endif
  92 #ifdef UINTMAX_MAX
  93   { "uintmax_t",                "u",    UINTMAX_MAX,            f_stdint },
  94 #endif
  95   { 0,                          0 },
  96 };
  97
  98 typedef struct itype itype;
  99
 100 /*----- Main code ---------------------------------------------------------*/
 101
 102 int main(int argc, char *argv[])
 103 {
 104   itype *i;
 105   itype *largest, *mpw, *mpd;
 106   const static char *extstr = "CATACOMB_MPTYPES_EXTENSION ";
 107
 108   /* --- Find the bitcounts --- */
 109
 110   for (i = tytab; i->name; i++) {
 111     unsigned bits;
 112     umax u = i->max;
 113     for (bits = 0; u; bits++)
 114       u >>= 1;
 115     i->bits = bits;
 116   }
 117
 118   /* --- Now try to find the interesting types --- *
 119    *
 120    * The first thing to do is to find the largest type.  Then I find the
 121    * `best' type which is less than half that size, and then the `best' type
 122    * which is twice as big as that one.
 123    */
 124
 125   largest = tytab;
 126   for (i = tytab; i->name; i++) {
 127     if (i->bits > largest->bits)
 128       largest = i;
 129   }
 130   for (mpw = 0, i = tytab; i->name; i++) {
 131     if (i->bits * 2 <= largest->bits && (!mpw || i->bits > mpw->bits))
 132       mpw = i;
 133   }
 134   if (!mpw)
 135     mpw = tytab;
 136   for (mpd = 0, i = tytab; i->name; i++) {
 137     if (i->bits >= mpw->bits * 2 && (!mpd || i->bits < mpd->bits))
 138       mpd = i;
 139   }
 140   if (!mpd) {
 141     static itype w, d;
 142     d = w = *mpw;
 143     w.bits /= 2; w.max = ~(~((umax)0) << w.bits);
 144     d.bits = w.bits * 2; d.max = ~(~((umax)0) << d.bits);
 145     mpw = &w; mpd = &d;
 146   }
 147
 148   /* --- Output time --- */
 149
 150   puts("\
 151 /* -*-c-*-\n\
 152  *\n\
 153  * mptypes.h [generated]\n\
 154  */\n\
 155 \n\
 156 #ifndef CATACOMB_MPTYPES_H\n\
 157 #define CATACOMB_MPTYPES_H\n\
 158 ");
 159   if ((mpd->flags | mpw->flags) & f_stdint) {
 160     puts("\
 161 #if __STDC_VERSION__ >= 199900l\n\
 162 #  include <stdint.h>\n\
 163 #endif\n\
 164 ");
 165   }
 166   if ((mpd->flags | mpw->flags) & f_ext) {
 167     printf("\
 168 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 91)\n\
 169 #  define %s __extension__\n\
 170 #else\n\
 171 #  define %s\n\
 172 #endif\n\
 173 ", extstr, extstr);
 174   }
 175   printf("\
 176 %stypedef %s mpw;\n\
 177 #define MPW_BITS %u\n\
 178 #define MPW_MAX %s" P_UMAX "%s\n\
 179 \n\
 180 %stypedef %s mpd;\n\
 181 #define MPD_BITS %u\n\
 182 #define MPD_MAX %s" P_UMAX "%s\n\
 183 \n\
 184 #endif\n\
 185 ",
 186   mpw->flags & f_ext ? extstr : "", mpw->name,
 187   mpw->bits,
 188   mpw->flags & f_ext ? extstr : "", mpw->max, mpw->suff,
 189   mpd->flags & f_ext ? extstr : "", mpd->name,
 190   mpd->bits,
 191   mpd->flags & f_ext ? extstr : "", mpd->max, mpd->suff);
 192
 193   return (0);
 194 }
 195
 196 /*----- That's all, folks -------------------------------------------------*/