Objects/object.c

   1 /***********************************************************
   2 Copyright 1991, 1992, 1993, 1994 by Stichting Mathematisch Centrum,
   3 Amsterdam, The Netherlands.
   4
   5                         All Rights Reserved
   6
   7 Permission to use, copy, modify, and distribute this software and its
   8 documentation for any purpose and without fee is hereby granted,
   9 provided that the above copyright notice appear in all copies and that
  10 both that copyright notice and this permission notice appear in
  11 supporting documentation, and that the names of Stichting Mathematisch
  12 Centrum or CWI not be used in advertising or publicity pertaining to
  13 distribution of the software without specific, written prior permission.
  14
  15 STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO
  16 THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
  17 FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE
  18 FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  19 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  20 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  21 OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  22
  23 ******************************************************************/
  24
  25 /* Generic object operations; and implementation of None (NoObject) */
  26
  27 #include "allobjects.h"
  28
  29 #ifdef REF_DEBUG
  30 long ref_total;
  31 #endif
  32
  33 /* Object allocation routines used by NEWOBJ and NEWVAROBJ macros.
  34    These are used by the individual routines for object creation.
  35    Do not call them otherwise, they do not initialize the object! */
  36
  37 #ifdef COUNT_ALLOCS
  38 static typeobject *type_list;
  39 extern int tuple_zero_allocs, fast_tuple_allocs;
  40 extern int quick_int_allocs, quick_neg_int_allocs;
  41 extern int null_strings, one_strings;
  42 void
  43 dump_counts()
  44 {
  45         typeobject *tp;
  46
  47         for (tp = type_list; tp; tp = tp->tp_next)
  48                 fprintf(stderr, "%s alloc'd: %d, freed: %d, max in use: %d\n",
  49                         tp->tp_name, tp->tp_alloc, tp->tp_free,
  50                         tp->tp_maxalloc);
  51         fprintf(stderr, "fast tuple allocs: %d, empty: %d\n",
  52                 fast_tuple_allocs, tuple_zero_allocs);
  53         fprintf(stderr, "fast int allocs: pos: %d, neg: %d\n",
  54                 quick_int_allocs, quick_neg_int_allocs);
  55         fprintf(stderr, "null strings: %d, 1-strings: %d\n",
  56                 null_strings, one_strings);
  57 }
  58
  59 void
  60 inc_count(tp)
  61         typeobject *tp;
  62 {
  63         if (tp->tp_alloc == 0) {
  64                 /* first time; hang in linked list */
  65                 if (tp->tp_next != NULL) /* sanity check */
  66                         abort();
  67                 tp->tp_next = type_list;
  68                 type_list = tp;
  69         }
  70         tp->tp_alloc++;
  71         if (tp->tp_alloc - tp->tp_free > tp->tp_maxalloc)
  72                 tp->tp_maxalloc = tp->tp_alloc - tp->tp_free;
  73 }
  74 #endif
  75
  76 object *
  77 newobject(tp)
  78         typeobject *tp;
  79 {
  80         object *op = (object *) malloc(tp->tp_basicsize);
  81         if (op == NULL)
  82                 return err_nomem();
  83         op->ob_type = tp;
  84         NEWREF(op);
  85         return op;
  86 }
  87
  88 varobject *
  89 newvarobject(tp, size)
  90         typeobject *tp;
  91         unsigned int size;
  92 {
  93         varobject *op = (varobject *)
  94                 malloc(tp->tp_basicsize + size * tp->tp_itemsize);
  95         if (op == NULL)
  96                 return (varobject *)err_nomem();
  97         op->ob_type = tp;
  98         op->ob_size = size;
  99         NEWREF(op);
 100         return op;
 101 }
 102
 103 int
 104 printobject(op, fp, flags)
 105         object *op;
 106         FILE *fp;
 107         int flags;
 108 {
 109         int ret = 0;
 110         if (intrcheck()) {
 111                 err_set(KeyboardInterrupt);
 112                 return -1;
 113         }
 114         if (op == NULL) {
 115                 fprintf(fp, "<nil>");
 116         }
 117         else {
 118                 if (op->ob_refcnt <= 0)
 119                         fprintf(fp, "<refcnt %u at %lx>",
 120                                 op->ob_refcnt, (long)op);
 121                 else if (op->ob_type->tp_print == NULL) {
 122                         if (op->ob_type->tp_repr == NULL) {
 123                                 fprintf(fp, "<%s object at %lx>",
 124                                         op->ob_type->tp_name, (long)op);
 125                         }
 126                         else {
 127                                 object *s;
 128                                 if (flags & PRINT_RAW)
 129                                         s = strobject(op);
 130                                 else
 131                                         s = reprobject(op);
 132                                 if (s == NULL)
 133                                         ret = -1;
 134                                 else if (!is_stringobject(s)) {
 135                                         err_setstr(TypeError,
 136                                                    "repr not string");
 137                                         ret = -1;
 138                                 }
 139                                 else {
 140                                         fprintf(fp, "%s", getstringvalue(s));
 141                                 }
 142                                 XDECREF(s);
 143                         }
 144                 }
 145                 else
 146                         ret = (*op->ob_type->tp_print)(op, fp, flags);
 147         }
 148         if (ret == 0) {
 149                 if (ferror(fp)) {
 150                         err_errno(IOError);
 151                         clearerr(fp);
 152                         ret = -1;
 153                 }
 154         }
 155         return ret;
 156 }
 157
 158 object *
 159 reprobject(v)
 160         object *v;
 161 {
 162         if (intrcheck()) {
 163                 err_set(KeyboardInterrupt);
 164                 return NULL;
 165         }
 166         if (v == NULL)
 167                 return newstringobject("<NULL>");
 168         else if (v->ob_type->tp_repr == NULL) {
 169                 char buf[120];
 170                 sprintf(buf, "<%.80s object at %lx>",
 171                         v->ob_type->tp_name, (long)v);
 172                 return newstringobject(buf);
 173         }
 174         else
 175                 return (*v->ob_type->tp_repr)(v);
 176 }
 177
 178 object *
 179 strobject(v)
 180         object *v;
 181 {
 182         if (v == NULL)
 183                 return newstringobject("<NULL>");
 184         if (is_stringobject(v)) {
 185                 INCREF(v);
 186                 return v;
 187         }
 188         else {
 189                 object *func = getattr(v, "__str__");
 190                 object *args;
 191                 object *res;
 192                 if (func == NULL) {
 193                         err_clear();
 194                         return reprobject(v);
 195                 }
 196                 args = newtupleobject(0);
 197                 if (args == NULL)
 198                         res = NULL;
 199                 else {
 200                         res = call_object(func, args);
 201                         DECREF(args);
 202                 }
 203                 DECREF(func);
 204                 return res;
 205         }
 206 }
 207
 208 int
 209 cmpobject(v, w)
 210         object *v, *w;
 211 {
 212         typeobject *tp;
 213         if (v == w)
 214                 return 0;
 215         if (v == NULL)
 216                 return -1;
 217         if (w == NULL)
 218                 return 1;
 219         if ((tp = v->ob_type) != w->ob_type) {
 220                 if (tp->tp_as_number != NULL &&
 221                                 w->ob_type->tp_as_number != NULL) {
 222                         if (coerce(&v, &w) != 0) {
 223                                 err_clear();
 224                                 /* XXX Should report the error,
 225                                    XXX but the interface isn't there... */
 226                         }
 227                         else {
 228                                 int cmp = (*v->ob_type->tp_compare)(v, w);
 229                                 DECREF(v);
 230                                 DECREF(w);
 231                                 return cmp;
 232                         }
 233                 }
 234                 return strcmp(tp->tp_name, w->ob_type->tp_name);
 235         }
 236         if (tp->tp_compare == NULL)
 237                 return (v < w) ? -1 : 1;
 238         return (*tp->tp_compare)(v, w);
 239 }
 240
 241 long
 242 hashobject(v)
 243         object *v;
 244 {
 245         typeobject *tp = v->ob_type;
 246         if (tp->tp_hash != NULL)
 247                 return (*tp->tp_hash)(v);
 248         if (tp->tp_compare == NULL)
 249                 return (long) v; /* Use address as hash value */
 250         /* If there's a cmp but no hash defined, the object can't be hashed */
 251         err_setstr(TypeError, "unhashable type");
 252         return -1;
 253 }
 254
 255 object *
 256 getattr(v, name)
 257         object *v;
 258         char *name;
 259 {
 260         if (v->ob_type->tp_getattr == NULL) {
 261                 err_setstr(TypeError, "attribute-less object");
 262                 return NULL;
 263         }
 264         else {
 265                 return (*v->ob_type->tp_getattr)(v, name);
 266         }
 267 }
 268
 269 int
 270 hasattr(v, name)
 271         object *v;
 272         char *name;
 273 {
 274         object *res = getattr(v, name);
 275         if (res != NULL) {
 276                 DECREF(res);
 277                 return 1;
 278         }
 279         err_clear();
 280         return 0;
 281 }
 282
 283 int
 284 setattr(v, name, w)
 285         object *v;
 286         char *name;
 287         object *w;
 288 {
 289         if (v->ob_type->tp_setattr == NULL) {
 290                 if (v->ob_type->tp_getattr == NULL)
 291                         err_setstr(TypeError,
 292                                    "attribute-less object (assign or del)");
 293                 else
 294                         err_setstr(TypeError,
 295                                    "object has read-only attributes");
 296                 return -1;
 297         }
 298         else {
 299                 return (*v->ob_type->tp_setattr)(v, name, w);
 300         }
 301 }
 302
 303 /* Test a value used as condition, e.g., in a for or if statement.
 304    Return -1 if an error occurred */
 305
 306 int
 307 testbool(v)
 308         object *v;
 309 {
 310         int res;
 311         if (v == None)
 312                 res = 0;
 313         else if (v->ob_type->tp_as_number != NULL)
 314                 res = (*v->ob_type->tp_as_number->nb_nonzero)(v);
 315         else if (v->ob_type->tp_as_mapping != NULL)
 316                 res = (*v->ob_type->tp_as_mapping->mp_length)(v);
 317         else if (v->ob_type->tp_as_sequence != NULL)
 318                 res = (*v->ob_type->tp_as_sequence->sq_length)(v);
 319         else
 320                 res = 1;
 321         if (res > 0)
 322                 res = 1;
 323         return res;
 324 }
 325
 326
 327 /*
 328 NoObject is usable as a non-NULL undefined value, used by the macro None.
 329 There is (and should be!) no way to create other objects of this type,
 330 so there is exactly one (which is indestructible, by the way).
 331 */
 332
 333 /* ARGSUSED */
 334 static object *
 335 none_repr(op)
 336         object *op;
 337 {
 338         return newstringobject("None");
 339 }
 340
 341 static typeobject Notype = {
 342         OB_HEAD_INIT(&Typetype)
 343         0,
 344         "None",
 345         0,
 346         0,
 347         0,              /*tp_dealloc*/ /*never called*/
 348         0,              /*tp_print*/
 349         0,              /*tp_getattr*/
 350         0,              /*tp_setattr*/
 351         0,              /*tp_compare*/
 352         (reprfunc)none_repr, /*tp_repr*/
 353         0,              /*tp_as_number*/
 354         0,              /*tp_as_sequence*/
 355         0,              /*tp_as_mapping*/
 356         0,              /*tp_hash */
 357 };
 358
 359 object NoObject = {
 360         OB_HEAD_INIT(&Notype)
 361 };
 362
 363
 364 #ifdef TRACE_REFS
 365
 366 static object refchain = {&refchain, &refchain};
 367
 368 NEWREF(op)
 369         object *op;
 370 {
 371         ref_total++;
 372         op->ob_refcnt = 1;
 373         op->_ob_next = refchain._ob_next;
 374         op->_ob_prev = &refchain;
 375         refchain._ob_next->_ob_prev = op;
 376         refchain._ob_next = op;
 377 #ifdef COUNT_ALLOCS
 378         inc_count(op->ob_type);
 379 #endif
 380 }
 381
 382 UNREF(op)
 383         register object *op;
 384 {
 385         register object *p;
 386         if (op->ob_refcnt < 0) {
 387                 fprintf(stderr, "UNREF negative refcnt\n");
 388                 abort();
 389         }
 390         if (op == &refchain ||
 391             op->_ob_prev->_ob_next != op || op->_ob_next->_ob_prev != op) {
 392                 fprintf(stderr, "UNREF invalid object\n");
 393                 abort();
 394         }
 395 #ifdef SLOW_UNREF_CHECK
 396         for (p = refchain._ob_next; p != &refchain; p = p->_ob_next) {
 397                 if (p == op)
 398                         break;
 399         }
 400         if (p == &refchain) { /* Not found */
 401                 fprintf(stderr, "UNREF unknown object\n");
 402                 abort();
 403         }
 404 #endif
 405         op->_ob_next->_ob_prev = op->_ob_prev;
 406         op->_ob_prev->_ob_next = op->_ob_next;
 407         op->_ob_next = op->_ob_prev = NULL;
 408 }
 409
 410 DELREF(op)
 411         object *op;
 412 {
 413         UNREF(op);
 414 #ifdef COUNT_ALLOCS
 415         op->ob_type->tp_free++;
 416 #endif
 417         (*(op)->ob_type->tp_dealloc)(op);
 418         op->ob_type = NULL;
 419 }
 420
 421 printrefs(fp)
 422         FILE *fp;
 423 {
 424         object *op;
 425         fprintf(fp, "Remaining objects (except strings referenced once):\n");
 426         for (op = refchain._ob_next; op != &refchain; op = op->_ob_next) {
 427                 if (op->ob_refcnt == 1 && is_stringobject(op))
 428                         continue; /* Will be printed elsewhere */
 429                 fprintf(fp, "[%d] ", op->ob_refcnt);
 430                 if (printobject(op, fp, 0) != 0)
 431                         err_clear();
 432                 putc('\n', fp);
 433         }
 434 }
 435
 436 #endif