libguile/smob.c

   1 /*      Copyright (C) 1995, 1996, 1998, 1999, 2000 Free Software Foundation, Inc.
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2, or (at your option)
   6  * any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this software; see the file COPYING.  If not, write to
  15  * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  16  * Boston, MA 02111-1307 USA
  17  *
  18  * As a special exception, the Free Software Foundation gives permission
  19  * for additional uses of the text contained in its release of GUILE.
  20  *
  21  * The exception is that, if you link the GUILE library with other files
  22  * to produce an executable, this does not by itself cause the
  23  * resulting executable to be covered by the GNU General Public License.
  24  * Your use of that executable is in no way restricted on account of
  25  * linking the GUILE library code into it.
  26  *
  27  * This exception does not however invalidate any other reasons why
  28  * the executable file might be covered by the GNU General Public License.
  29  *
  30  * This exception applies only to the code released by the
  31  * Free Software Foundation under the name GUILE.  If you copy
  32  * code from other Free Software Foundation releases into a copy of
  33  * GUILE, as the General Public License permits, the exception does
  34  * not apply to the code that you add in this way.  To avoid misleading
  35  * anyone as to the status of such modified files, you must delete
  36  * this exception notice from them.
  37  *
  38  * If you write modifications of your own for GUILE, it is your choice
  39  * whether to permit this exception to apply to your modifications.
  40  * If you do not wish that, delete this exception notice.  */
  41
  42 /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
  43    gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
  44
  45 \f
  46
  47 #include <stdio.h>
  48 #include "libguile/_scm.h"
  49
  50 #include "libguile/objects.h"
  51 #include "libguile/ports.h"
  52
  53 #ifdef HAVE_MALLOC_H
  54 #include <malloc.h>
  55 #endif
  56
  57 #include "libguile/smob.h"
  58
  59 \f
  60
  61 /* scm_smobs scm_numsmob
  62  * implement a dynamicly resized array of smob records.
  63  * Indexes into this table are used when generating type
  64  * tags for smobjects (if you know a tag you can get an index and conversely).
  65  */
  66 int scm_numsmob;
  67 scm_smob_descriptor *scm_smobs;
  68
  69 /* {Mark}
  70  */
  71
  72 /* This function is vestigial.  It used to be the mark function's
  73    responsibility to set the mark bit on the smob or port, but now the
  74    generic marking routine in gc.c takes care of that, and a zero
  75    pointer for a mark function means "don't bother".  So you never
  76    need scm_mark0.
  77
  78    However, we leave it here because it's harmless to call it, and
  79    people out there have smob code that uses it, and there's no reason
  80    to make their links fail.  */
  81
  82 SCM
  83 scm_mark0 (SCM ptr)
  84 {
  85   return SCM_BOOL_F;
  86 }
  87
  88 SCM
  89 scm_markcdr (SCM ptr)
  90 {
  91   return SCM_CDR (ptr);
  92 }
  93
  94 /* {Free}
  95  */
  96
  97 scm_sizet
  98 scm_free0 (SCM ptr)
  99 {
 100   return 0;
 101 }
 102
 103 scm_sizet
 104 scm_smob_free (SCM obj)
 105 {
 106   scm_must_free ((char *) SCM_CELL_WORD_1 (obj));
 107   return scm_smobs[SCM_SMOBNUM (obj)].size;
 108 }
 109
 110 /* {Print}
 111  */
 112
 113 int
 114 scm_smob_print (SCM exp, SCM port, scm_print_state *pstate)
 115 {
 116   int n = SCM_SMOBNUM (exp);
 117   scm_puts ("#<", port);
 118   scm_puts (SCM_SMOBNAME (n) ? SCM_SMOBNAME (n) : "smob", port);
 119   scm_putc (' ', port);
 120   scm_intprint (SCM_UNPACK (scm_smobs[n].size ? SCM_CDR (exp) : exp), 16, port);
 121   scm_putc ('>', port);
 122   return 1;
 123 }
 124
 125 long
 126 scm_make_smob_type (char *name, scm_sizet size)
 127 {
 128   char *tmp;
 129   if (255 <= scm_numsmob)
 130     goto smoberr;
 131   SCM_DEFER_INTS;
 132   SCM_SYSCALL (tmp = (char *) realloc ((char *) scm_smobs,
 133                                        (1 + scm_numsmob)
 134                                        * sizeof (scm_smob_descriptor)));
 135   if (tmp)
 136     {
 137       scm_smobs = (scm_smob_descriptor *) tmp;
 138       scm_smobs[scm_numsmob].name = name;
 139       scm_smobs[scm_numsmob].size = size;
 140       scm_smobs[scm_numsmob].mark = 0;
 141       scm_smobs[scm_numsmob].free = (size == 0 ? scm_free0 : scm_smob_free);
 142       scm_smobs[scm_numsmob].print = scm_smob_print;
 143       scm_smobs[scm_numsmob].equalp = 0;
 144       scm_numsmob++;
 145     }
 146   SCM_ALLOW_INTS;
 147   if (!tmp)
 148   smoberr:scm_wta (SCM_MAKINUM ((long) scm_numsmob),
 149                    (char *) SCM_NALLOC, "scm_make_smob_type");
 150   /* Make a class object if Goops is present. */
 151   if (scm_smob_class)
 152     scm_smob_class[scm_numsmob - 1]
 153       = scm_make_extended_class (SCM_SMOBNAME (scm_numsmob - 1));
 154   return scm_tc7_smob + (scm_numsmob - 1) * 256;
 155 }
 156
 157 long
 158 scm_make_smob_type_mfpe (char *name, scm_sizet size,
 159                         SCM (*mark) (SCM),
 160                         scm_sizet (*free) (SCM),
 161                         int (*print) (SCM, SCM, scm_print_state *),
 162                         SCM (*equalp) (SCM, SCM))
 163 {
 164   long answer = scm_make_smob_type (name, size);
 165   scm_set_smob_mfpe (answer, mark, free, print, equalp);
 166   return answer;
 167 }
 168
 169 void
 170 scm_set_smob_mark (long tc, SCM (*mark) (SCM))
 171 {
 172   scm_smobs[SCM_TC2SMOBNUM (tc)].mark = mark;
 173 }
 174
 175 void
 176 scm_set_smob_free (long tc, scm_sizet (*free) (SCM))
 177 {
 178   scm_smobs[SCM_TC2SMOBNUM (tc)].free = free;
 179 }
 180
 181 void
 182 scm_set_smob_print (long tc, int (*print) (SCM, SCM, scm_print_state*))
 183 {
 184   scm_smobs[SCM_TC2SMOBNUM (tc)].print = print;
 185 }
 186
 187 void
 188 scm_set_smob_equalp (long tc, SCM (*equalp) (SCM, SCM))
 189 {
 190   scm_smobs[SCM_TC2SMOBNUM (tc)].equalp = equalp;
 191 }
 192
 193 void
 194 scm_set_smob_mfpe (long tc,
 195                    SCM (*mark) (SCM),
 196                    scm_sizet (*free) (SCM),
 197                    int (*print) (SCM, SCM, scm_print_state *),
 198                    SCM (*equalp) (SCM, SCM))
 199 {
 200   if (mark) scm_set_smob_mark (tc, mark);
 201   if (free) scm_set_smob_free (tc, free);
 202   if (print) scm_set_smob_print (tc, print);
 203   if (equalp) scm_set_smob_equalp (tc, equalp);
 204 }
 205
 206 /* Deprecated function - use scm_make_smob_type, or scm_make_smob_type_mfpe
 207    instead. */
 208 long
 209 scm_newsmob (const scm_smobfuns *smob)
 210 {
 211   long tc = scm_make_smob_type (0, 0);
 212   scm_set_smob_mark (tc, smob->mark);
 213   scm_set_smob_free (tc, smob->free);
 214   scm_set_smob_print (tc, smob->print);
 215   scm_set_smob_equalp (tc, smob->equalp);
 216   return tc;
 217 }
 218
 219
 220 SCM
 221 scm_make_smob (long tc)
 222 {
 223   int n = SCM_TC2SMOBNUM (tc);
 224   scm_sizet size = scm_smobs[n].size;
 225   SCM z;
 226   SCM_NEWCELL (z);
 227   if (size != 0)
 228     {
 229 #if 0
 230       SCM_ASSERT (scm_smobs[n].mark == 0,
 231                   0,
 232                   "forbidden operation for smobs with GC data, use SCM_NEWSMOB",
 233                   SCM_SMOBNAME (n));
 234 #endif
 235       SCM_SET_SMOB_DATA (z, scm_must_malloc (size, SCM_SMOBNAME (n)));
 236     }
 237   SCM_SET_CELL_TYPE (z, tc);
 238   return z;
 239 }
 240
 241 \f
 242 /* {Initialization for i/o types, float, bignum, the type of free cells}
 243  */
 244
 245 static int
 246 freeprint (SCM exp,
 247            SCM port,
 248            scm_print_state *pstate)
 249 {
 250   char buf[100];
 251
 252   sprintf (buf, "#<freed cell %p; GC missed a reference>", (void *) SCM_UNPACK (exp));
 253   scm_puts (buf, port);
 254
 255   return 1;
 256 }
 257
 258
 259 void
 260 scm_smob_prehistory ()
 261 {
 262   scm_numsmob = 0;
 263   scm_smobs = ((scm_smob_descriptor *)
 264                malloc (7 * sizeof (scm_smob_descriptor)));
 265
 266   /* WARNING: These scm_make_smob_type calls must be done in this order */
 267   scm_make_smob_type_mfpe ("free", 0,
 268                           NULL, NULL, freeprint, NULL);
 269
 270   scm_make_smob_type_mfpe ("big", 0,     /* freed in gc */
 271                           NULL, NULL, scm_bigprint, scm_bigequal);
 272
 273   scm_make_smob_type_mfpe ("real", 0,    /* freed in gc */
 274                            NULL, NULL, scm_print_real, scm_real_equalp);
 275
 276   scm_make_smob_type_mfpe ("complex", 0,    /* freed in gc */
 277                            NULL, NULL, scm_print_complex, scm_complex_equalp);
 278
 279   scm_make_smob_type ("allocated", 0);
 280 }
 281
 282 /*
 283   Local Variables:
 284   c-file-style: "gnu"
 285   End:
 286 */