1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
|
/* GNU Objective C Runtime message lookup
Copyright (C) 1993, 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
Contributed by Kresten Krab Thorup
This file is part of GNU CC.
GNU CC is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 2, or (at your option) any later version.
GNU CC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
details.
You should have received a copy of the GNU General Public License along with
GNU CC; see the file COPYING. If not, write to the Free Software
Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/* As a special exception, if you link this library with files compiled with
GCC to produce an executable, this does not cause the resulting executable
to be covered by the GNU General Public License. This exception does not
however invalidate any other reasons why the executable file might be
covered by the GNU General Public License. */
/* $FreeBSD$ */
#include "../tconfig.h"
#include "runtime.h"
#include "sarray.h"
#include "encoding.h"
#include "runtime-info.h"
/* this is how we hack STRUCT_VALUE to be 1 or 0 */
#define gen_rtx(args...) 1
#define gen_rtx_MEM(args...) 1
#define rtx int
#if !defined(STRUCT_VALUE) || STRUCT_VALUE == 0
#define INVISIBLE_STRUCT_RETURN 1
#else
#define INVISIBLE_STRUCT_RETURN 0
#endif
/* The uninstalled dispatch table */
struct sarray* __objc_uninstalled_dtable = 0; /* !T:MUTEX */
/* Send +initialize to class */
static void __objc_send_initialize(Class);
static void __objc_install_dispatch_table_for_class (Class);
/* Forward declare some functions */
static void __objc_init_install_dtable(id, SEL);
/* Various forwarding functions that are used based upon the
return type for the selector.
__objc_block_forward for structures.
__objc_double_forward for floats/doubles.
__objc_word_forward for pointers or types that fit in registers.
*/
static double __objc_double_forward(id, SEL, ...);
static id __objc_word_forward(id, SEL, ...);
typedef struct { id many[8]; } __big;
#if INVISIBLE_STRUCT_RETURN
static __big
#else
static id
#endif
__objc_block_forward(id, SEL, ...);
static Method_t search_for_method_in_hierarchy (Class class, SEL sel);
Method_t search_for_method_in_list(MethodList_t list, SEL op);
id nil_method(id, SEL, ...);
/* Given a selector, return the proper forwarding implementation. */
__inline__
IMP
__objc_get_forward_imp (SEL sel)
{
const char *t = sel->sel_types;
if (t && (*t == '[' || *t == '(' || *t == '{')
#ifdef OBJC_MAX_STRUCT_BY_VALUE
&& objc_sizeof_type(t) > OBJC_MAX_STRUCT_BY_VALUE
#endif
)
return (IMP)__objc_block_forward;
else if (t && (*t == 'f' || *t == 'd'))
return (IMP)__objc_double_forward;
else
return (IMP)__objc_word_forward;
}
/* Given a class and selector, return the selector's implementation. */
__inline__
IMP
get_imp (Class class, SEL sel)
{
void* res = sarray_get_safe (class->dtable, (size_t) sel->sel_id);
if (res == 0)
{
/* Not a valid method */
if(class->dtable == __objc_uninstalled_dtable)
{
/* The dispatch table needs to be installed. */
objc_mutex_lock(__objc_runtime_mutex);
__objc_install_dispatch_table_for_class (class);
objc_mutex_unlock(__objc_runtime_mutex);
/* Call ourselves with the installed dispatch table
and get the real method */
res = get_imp(class, sel);
}
else
{
/* The dispatch table has been installed so the
method just doesn't exist for the class.
Return the forwarding implementation. */
res = __objc_get_forward_imp(sel);
}
}
return res;
}
/* Query if an object can respond to a selector, returns YES if the
object implements the selector otherwise NO. Does not check if the
method can be forwarded. */
__inline__
BOOL
__objc_responds_to (id object, SEL sel)
{
void* res;
/* Install dispatch table if need be */
if (object->class_pointer->dtable == __objc_uninstalled_dtable)
{
objc_mutex_lock(__objc_runtime_mutex);
__objc_install_dispatch_table_for_class (object->class_pointer);
objc_mutex_unlock(__objc_runtime_mutex);
}
/* Get the method from the dispatch table */
res = sarray_get_safe (object->class_pointer->dtable, (size_t) sel->sel_id);
return (res != 0);
}
/* This is the lookup function. All entries in the table are either a
valid method *or* zero. If zero then either the dispatch table
needs to be installed or it doesn't exist and forwarding is attempted. */
__inline__
IMP
objc_msg_lookup(id receiver, SEL op)
{
IMP result;
if(receiver)
{
result = sarray_get_safe (receiver->class_pointer->dtable,
(sidx)op->sel_id);
if (result == 0)
{
/* Not a valid method */
if(receiver->class_pointer->dtable == __objc_uninstalled_dtable)
{
/* The dispatch table needs to be installed.
This happens on the very first method call to the class. */
__objc_init_install_dtable(receiver, op);
/* Get real method for this in newly installed dtable */
result = get_imp(receiver->class_pointer, op);
}
else
{
/* The dispatch table has been installed so the
method just doesn't exist for the class.
Attempt to forward the method. */
result = __objc_get_forward_imp(op);
}
}
return result;
}
else
return nil_method;
}
IMP
objc_msg_lookup_super (Super_t super, SEL sel)
{
if (super->self)
return get_imp (super->class, sel);
else
return nil_method;
}
int method_get_sizeof_arguments (Method*);
retval_t
objc_msg_sendv(id object, SEL op, arglist_t arg_frame)
{
Method* m = class_get_instance_method(object->class_pointer, op);
const char *type;
*((id*)method_get_first_argument (m, arg_frame, &type)) = object;
*((SEL*)method_get_next_argument (arg_frame, &type)) = op;
return __builtin_apply((apply_t)m->method_imp,
arg_frame,
method_get_sizeof_arguments (m));
}
void
__objc_init_dispatch_tables()
{
__objc_uninstalled_dtable
= sarray_new(200, 0);
}
/* This function is called by objc_msg_lookup when the
dispatch table needs to be installed; thus it is called once
for each class, namely when the very first message is sent to it. */
static void
__objc_init_install_dtable(id receiver, SEL op)
{
/* This may happen, if the programmer has taken the address of a
method before the dtable was initialized... too bad for him! */
if(receiver->class_pointer->dtable != __objc_uninstalled_dtable)
return;
objc_mutex_lock(__objc_runtime_mutex);
if(CLS_ISCLASS(receiver->class_pointer))
{
/* receiver is an ordinary object */
assert(CLS_ISCLASS(receiver->class_pointer));
/* install instance methods table */
__objc_install_dispatch_table_for_class (receiver->class_pointer);
/* call +initialize -- this will in turn install the factory
dispatch table if not already done :-) */
__objc_send_initialize(receiver->class_pointer);
}
else
{
/* receiver is a class object */
assert(CLS_ISCLASS((Class)receiver));
assert(CLS_ISMETA(receiver->class_pointer));
/* Install real dtable for factory methods */
__objc_install_dispatch_table_for_class (receiver->class_pointer);
if (strcmp (sel_get_name (op), "initialize"))
__objc_send_initialize((Class)receiver);
else
CLS_SETINITIALIZED((Class)receiver);
}
objc_mutex_unlock(__objc_runtime_mutex);
}
/* Install dummy table for class which causes the first message to
that class (or instances hereof) to be initialized properly */
void
__objc_install_premature_dtable(Class class)
{
assert(__objc_uninstalled_dtable);
class->dtable = __objc_uninstalled_dtable;
}
/* Send +initialize to class if not already done */
static void
__objc_send_initialize(Class class)
{
/* This *must* be a class object */
assert(CLS_ISCLASS(class));
assert(!CLS_ISMETA(class));
if (!CLS_ISINITIALIZED(class))
{
CLS_SETINITIALIZED(class);
CLS_SETINITIALIZED(class->class_pointer);
if(class->super_class)
__objc_send_initialize(class->super_class);
{
SEL op = sel_register_name ("initialize");
Class tmpclass = class;
IMP imp = 0;
while (!imp && tmpclass) {
MethodList_t method_list = tmpclass->class_pointer->methods;
while(!imp && method_list) {
int i;
Method_t method;
for (i=0;i<method_list->method_count;i++) {
method = &(method_list->method_list[i]);
if (method->method_name
&& method->method_name->sel_id == op->sel_id) {
imp = method->method_imp;
break;
}
}
method_list = method_list->method_next;
}
tmpclass = tmpclass->super_class;
}
if (imp)
(*imp)((id)class, op);
}
}
}
/* Walk on the methods list of class and install the methods in the reverse
order of the lists. Since methods added by categories are before the methods
of class in the methods list, this allows categories to substitute methods
declared in class. However if more than one category replaces the same
method nothing is guaranteed about what method will be used.
Assumes that __objc_runtime_mutex is locked down. */
static void
__objc_install_methods_in_dtable (Class class, MethodList_t method_list)
{
int i;
if (!method_list)
return;
if (method_list->method_next)
__objc_install_methods_in_dtable (class, method_list->method_next);
for (i = 0; i < method_list->method_count; i++)
{
Method_t method = &(method_list->method_list[i]);
sarray_at_put_safe (class->dtable,
(sidx) method->method_name->sel_id,
method->method_imp);
}
}
/* Assumes that __objc_runtime_mutex is locked down. */
static void
__objc_install_dispatch_table_for_class (Class class)
{
Class super;
/* If the class has not yet had its class links resolved, we must
re-compute all class links */
if(!CLS_ISRESOLV(class))
__objc_resolve_class_links();
super = class->super_class;
if (super != 0 && (super->dtable == __objc_uninstalled_dtable))
__objc_install_dispatch_table_for_class (super);
/* Allocate dtable if necessary */
if (super == 0)
{
objc_mutex_lock(__objc_runtime_mutex);
class->dtable = sarray_new (__objc_selector_max_index, 0);
objc_mutex_unlock(__objc_runtime_mutex);
}
else
class->dtable = sarray_lazy_copy (super->dtable);
__objc_install_methods_in_dtable (class, class->methods);
}
void
__objc_update_dispatch_table_for_class (Class class)
{
Class next;
struct sarray *arr;
/* not yet installed -- skip it */
if (class->dtable == __objc_uninstalled_dtable)
return;
objc_mutex_lock(__objc_runtime_mutex);
arr = class->dtable;
__objc_install_premature_dtable (class); /* someone might require it... */
sarray_free (arr); /* release memory */
/* could have been lazy... */
__objc_install_dispatch_table_for_class (class);
if (class->subclass_list) /* Traverse subclasses */
for (next = class->subclass_list; next; next = next->sibling_class)
__objc_update_dispatch_table_for_class (next);
objc_mutex_unlock(__objc_runtime_mutex);
}
/* This function adds a method list to a class. This function is
typically called by another function specific to the run-time. As
such this function does not worry about thread safe issues.
This one is only called for categories. Class objects have their
methods installed right away, and their selectors are made into
SEL's by the function __objc_register_selectors_from_class. */
void
class_add_method_list (Class class, MethodList_t list)
{
int i;
/* Passing of a linked list is not allowed. Do multiple calls. */
assert (!list->method_next);
/* Check for duplicates. */
for (i = 0; i < list->method_count; ++i)
{
Method_t method = &list->method_list[i];
if (method->method_name) /* Sometimes these are NULL */
{
/* This is where selector names are transmogrified to SEL's */
method->method_name =
sel_register_typed_name ((const char*)method->method_name,
method->method_types);
}
}
/* Add the methods to the class's method list. */
list->method_next = class->methods;
class->methods = list;
/* Update the dispatch table of class */
__objc_update_dispatch_table_for_class (class);
}
Method_t
class_get_instance_method(Class class, SEL op)
{
return search_for_method_in_hierarchy(class, op);
}
Method_t
class_get_class_method(MetaClass class, SEL op)
{
return search_for_method_in_hierarchy(class, op);
}
/* Search for a method starting from the current class up its hierarchy.
Return a pointer to the method's method structure if found. NULL
otherwise. */
static Method_t
search_for_method_in_hierarchy (Class cls, SEL sel)
{
Method_t method = NULL;
Class class;
if (! sel_is_mapped (sel))
return NULL;
/* Scan the method list of the class. If the method isn't found in the
list then step to its super class. */
for (class = cls; ((! method) && class); class = class->super_class)
method = search_for_method_in_list (class->methods, sel);
return method;
}
/* Given a linked list of method and a method's name. Search for the named
method's method structure. Return a pointer to the method's method
structure if found. NULL otherwise. */
Method_t
search_for_method_in_list (MethodList_t list, SEL op)
{
MethodList_t method_list = list;
if (! sel_is_mapped (op))
return NULL;
/* If not found then we'll search the list. */
while (method_list)
{
int i;
/* Search the method list. */
for (i = 0; i < method_list->method_count; ++i)
{
Method_t method = &method_list->method_list[i];
if (method->method_name)
if (method->method_name->sel_id == op->sel_id)
return method;
}
/* The method wasn't found. Follow the link to the next list of
methods. */
method_list = method_list->method_next;
}
return NULL;
}
static retval_t __objc_forward (id object, SEL sel, arglist_t args);
/* Forwarding pointers/integers through the normal registers */
static id
__objc_word_forward (id rcv, SEL op, ...)
{
void *args, *res;
args = __builtin_apply_args ();
res = __objc_forward (rcv, op, args);
if (res)
__builtin_return (res);
else
return res;
}
/* Specific routine for forwarding floats/double because of
architectural differences on some processors. i386s for
example which uses a floating point stack versus general
registers for floating point numbers. This forward routine
makes sure that GCC restores the proper return values */
static double
__objc_double_forward (id rcv, SEL op, ...)
{
void *args, *res;
args = __builtin_apply_args ();
res = __objc_forward (rcv, op, args);
__builtin_return (res);
}
#if INVISIBLE_STRUCT_RETURN
static __big
#else
static id
#endif
__objc_block_forward (id rcv, SEL op, ...)
{
void *args, *res;
args = __builtin_apply_args ();
res = __objc_forward (rcv, op, args);
if (res)
__builtin_return (res);
else
#if INVISIBLE_STRUCT_RETURN
return (__big) {{0, 0, 0, 0, 0, 0, 0, 0}};
#else
return nil;
#endif
}
/* This function is installed in the dispatch table for all methods which are
not implemented. Thus, it is called when a selector is not recognized. */
static retval_t
__objc_forward (id object, SEL sel, arglist_t args)
{
IMP imp;
static SEL frwd_sel = 0; /* !T:SAFE2 */
SEL err_sel;
/* first try if the object understands forward:: */
if (!frwd_sel)
frwd_sel = sel_get_any_uid("forward::");
if (__objc_responds_to (object, frwd_sel))
{
imp = get_imp(object->class_pointer, frwd_sel);
return (*imp)(object, frwd_sel, sel, args);
}
/* If the object recognizes the doesNotRecognize: method then we're going
to send it. */
err_sel = sel_get_any_uid ("doesNotRecognize:");
if (__objc_responds_to (object, err_sel))
{
imp = get_imp (object->class_pointer, err_sel);
return (*imp) (object, err_sel, sel);
}
/* The object doesn't recognize the method. Check for responding to
error:. If it does then sent it. */
{
size_t strlen (const char*);
char msg[256 + strlen ((const char*)sel_get_name (sel))
+ strlen ((const char*)object->class_pointer->name)];
sprintf (msg, "(%s) %s does not recognize %s",
(CLS_ISMETA(object->class_pointer)
? "class"
: "instance" ),
object->class_pointer->name, sel_get_name (sel));
err_sel = sel_get_any_uid ("error:");
if (__objc_responds_to (object, err_sel))
{
imp = get_imp (object->class_pointer, err_sel);
return (*imp) (object, sel_get_any_uid ("error:"), msg);
}
/* The object doesn't respond to doesNotRecognize: or error:; Therefore,
a default action is taken. */
objc_error (object, OBJC_ERR_UNIMPLEMENTED, "%s\n", msg);
return 0;
}
}
void
__objc_print_dtable_stats()
{
int total = 0;
objc_mutex_lock(__objc_runtime_mutex);
printf("memory usage: (%s)\n",
#ifdef OBJC_SPARSE2
"2-level sparse arrays"
#else
"3-level sparse arrays"
#endif
);
printf("arrays: %d = %ld bytes\n", narrays,
(long)narrays*sizeof(struct sarray));
total += narrays*sizeof(struct sarray);
printf("buckets: %d = %ld bytes\n", nbuckets,
(long)nbuckets*sizeof(struct sbucket));
total += nbuckets*sizeof(struct sbucket);
printf("idxtables: %d = %ld bytes\n", idxsize, (long)idxsize*sizeof(void*));
total += idxsize*sizeof(void*);
printf("-----------------------------------\n");
printf("total: %d bytes\n", total);
printf("===================================\n");
objc_mutex_unlock(__objc_runtime_mutex);
}
/* Returns the uninstalled dispatch table indicator.
If a class' dispatch table points to __objc_uninstalled_dtable
then that means it needs its dispatch table to be installed. */
__inline__
struct sarray*
objc_get_uninstalled_dtable()
{
return __objc_uninstalled_dtable;
}
|