aboutsummaryrefslogtreecommitdiff
path: root/engines/sci/engine/seg_manager.cpp
blob: 905cba9d94bca5e8a56da87a386c0beb4a97ffc6 (plain)
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
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program 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
 * of the License, or (at your option) any later version.

 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $URL$
 * $Id$
 *
 */

#include "sci/sci.h"
#include "sci/engine/seg_manager.h"
#include "sci/engine/state.h"
#include "sci/engine/intmap.h"

namespace Sci {


/**
 * Verify the the given condition is true, output the message if condition is false, and exit.
 * @param cond	condition to be verified
 * @param msg	the message to be printed if condition fails
 */
#define VERIFY( cond, msg ) if (!(cond)) {\
		error("%s, line, %d, %s", __FILE__, __LINE__, msg); \
	}


#define DEFAULT_SCRIPTS 32
#define DEFAULT_OBJECTS 8	    // default # of objects per script
#define DEFAULT_OBJECTS_INCREMENT 4 // Number of additional objects to instantiate if we're running out of them

//#define GC_DEBUG // Debug garbage collection
//#define GC_DEBUG_VERBOSE // Debug garbage verbosely

#undef DEBUG_SEG_MANAGER // Define to turn on debugging

#define INVALID_SCRIPT_ID -1

SegManager::SegManager(bool sci1_1) {
	id_seg_map = new IntMapper();
	reserved_id = INVALID_SCRIPT_ID;
	id_seg_map->checkKey(reserved_id, true);	// reserve entry 0 for INVALID_SCRIPT_ID
	reserved_id--; // reserved_id runs in the reversed direction to make sure no one will use it.

	_heap.push_back(0);

	Clones_seg_id = 0;
	Lists_seg_id = 0;
	Nodes_seg_id = 0;
	Hunks_seg_id = 0;

	exports_wide = 0;
	isSci1_1 = sci1_1;
}

// Destroy the object, free the memorys if allocated before
SegManager::~SegManager() {
	// Free memory
	for (uint i = 0; i < _heap.size(); i++) {
		if (_heap[i])
			deallocate(i, false);
	}

	delete id_seg_map;
}

int SegManager::findFreeId(int *id) {
	bool was_added = false;
	int retval = 0;

	while (!was_added) {
		retval = id_seg_map->checkKey(reserved_id, true, &was_added);
		*id = reserved_id--;
		if (reserved_id < -1000000)
			reserved_id = -10;
		// Make sure we don't underflow
	}

	return retval;
}

MemObject *SegManager::allocNonscriptSegment(MemObjectType type, SegmentId *segid) {
	// Allocates a non-script segment
	int id;

	*segid = findFreeId(&id);
	return memObjAllocate(*segid, id, type);
}

// allocate a memory for script from heap
// Parameters: (EngineState *) s: The state to operate on
//             (int) script_nr: The script number to load
// Returns   : 0 - allocation failure
//             1 - allocated successfully
//             seg_id - allocated segment id
Script *SegManager::allocateScript(EngineState *s, int script_nr, SegmentId *seg_id) {
	bool was_added;
	MemObject *mem;

	*seg_id = id_seg_map->checkKey(script_nr, true, &was_added);
	if (!was_added) {
		return (Script *)_heap[*seg_id];
	}

	// allocate the MemObject
	mem = memObjAllocate(*seg_id, script_nr, MEM_OBJ_SCRIPT);
	if (!mem) {
		error("allocateScript: Not enough memory");
		return NULL;
	}

	return (Script *)mem;
}

void SegManager::setScriptSize(Script &scr, EngineState *s, int script_nr) {
	Resource *script = s->resmgr->findResource(ResourceId(kResourceTypeScript, script_nr), 0);
	Resource *heap = s->resmgr->findResource(ResourceId(kResourceTypeHeap, script_nr), 0);

	scr.script_size = script->size;
	scr.heap_size = 0; // Set later

	if (!script || (s->_version >= SCI_VERSION_1_1 && !heap)) {
		error("SegManager::setScriptSize: failed to load %s", !script ? "script" : "heap");
	}
	if (((SciEngine*)g_engine)->getKernel()->hasOldScriptHeader()) {
		scr.buf_size = script->size + READ_LE_UINT16(script->data) * 2;
		//locals_size = READ_LE_UINT16(script->data) * 2;
	} else if (s->_version < SCI_VERSION_1_1) {
		scr.buf_size = script->size;
	} else {
		scr.buf_size = script->size + heap->size;
		scr.heap_size = heap->size;

		// Ensure that the start of the heap resource can be word-aligned.
		if (script->size & 2) {
			scr.buf_size++;
			scr.script_size++;
		}

		if (scr.buf_size > 65535) {
			error("Script and heap sizes combined exceed 64K.\n"
			          "This means a fundamental design bug was made in SCI\n"
			          "regarding SCI1.1 games.\nPlease report this so it can be"
			          "fixed in the next major version");
			return;
		}
	}
}

int SegManager::initialiseScript(Script &scr, EngineState *s, int script_nr) {
	// allocate the script.buf

	setScriptSize(scr, s, script_nr);
	scr.buf = (byte *)malloc(scr.buf_size);

#ifdef DEBUG_SEG_MANAGER
	printf("scr.buf = %p ", scr.buf);
#endif
	if (!scr.buf) {
		scr.freeScript();
		warning("SegManager: Not enough memory space for script size");
		scr.buf_size = 0;
		return 0;
	}

	// Initialize objects
	scr.locals_offset = 0;
	scr.locals_block = NULL;

	scr._codeBlocks.clear();

	scr.nr = script_nr;
	scr._markedAsDeleted = false;
	scr.relocated = 0;

	scr.obj_indices = new IntMapper();

	if (s->_version >= SCI_VERSION_1_1)
		scr.heap_start = scr.buf + scr.script_size;
	else
		scr.heap_start = scr.buf;

	return 1;
}

int SegManager::deallocate(SegmentId seg, bool recursive) {
	MemObject *mobj;
	VERIFY(check(seg), "invalid seg id");

	mobj = _heap[seg];
	id_seg_map->removeKey(mobj->getSegMgrId());

	if (mobj->getType() == MEM_OBJ_SCRIPT) {
		Script *scr = (Script *)mobj;
		if (recursive && scr->locals_segment)
			deallocate(scr->locals_segment, recursive);
	}

	delete mobj;
	_heap[seg] = NULL;

	return 1;
}

bool SegManager::scriptIsMarkedAsDeleted(SegmentId seg) {
	Script *scr = getScriptIfLoaded(seg);
	if (!scr)
		return false;
	return scr->_markedAsDeleted;
}


int SegManager::deallocateScript(int script_nr) {
	SegmentId seg = segGet(script_nr);

	deallocate(seg, true);

	return 1;
}

MemObject *SegManager::memObjAllocate(SegmentId segid, int hash_id, MemObjectType type) {
	MemObject *mem = MemObject::createMemObject(type);
	if (!mem) {
		warning("SegManager: invalid mobj");
		return NULL;
	}

	if (segid >= (int)_heap.size()) {
		assert(segid == (int)_heap.size());
		_heap.push_back(0);
	}

	mem->_segmgrId = hash_id;

	// hook it to the heap
	_heap[segid] = mem;
	return mem;
}

// return the seg if script_id is valid and in the map, else -1
SegmentId SegManager::segGet(int script_id) const {
	return id_seg_map->lookupKey(script_id);
}

Script *SegManager::getScript(const SegmentId seg) {
	// FIXME: We accept segment 0, but that is actually an invalid segment...
	if (seg < 0 || (uint)seg >= _heap.size()) {
		error("SegManager::getScript(): seg id %x out of bounds", seg);
	}
	if (!_heap[seg]) {
		error("SegManager::getScript(): seg id %x is not in memory", seg);
	}
	if (_heap[seg]->getType() != MEM_OBJ_SCRIPT) {
		error("SegManager::getScript(): seg id %x refers to type %d != MEM_OBJ_SCRIPT", seg, _heap[seg]->getType());
	}
	return (Script *)_heap[seg];
}

Script *SegManager::getScriptIfLoaded(const SegmentId seg) {
	// FIXME: We accept segment 0, but that is actually an invalid segment...
	if (seg < 0 || (uint)seg >= _heap.size() || !_heap[seg] || _heap[seg]->getType() != MEM_OBJ_SCRIPT)
		return 0;
	return (Script *)_heap[seg];
}

// validate the seg
// return:
//	false - invalid seg
//	true  - valid seg
bool SegManager::check(SegmentId seg) {
	// FIXME: We accept segment 0, but that is actually an invalid segment...
	if (seg < 0 || (uint)seg >= _heap.size()) {
		return false;
	}
	if (!_heap[seg]) {
		warning("SegManager: seg %x is removed from memory, but not removed from hash_map", seg);
		return false;
	}
	return true;
}

bool SegManager::scriptIsLoaded(SegmentId seg) {
	return getScriptIfLoaded(seg) != 0;
}

void SegManager::setExportWidth(int flag) {
	exports_wide = flag;
}

int SegManager::relocateBlock(Common::Array<reg_t> &block, int block_location, SegmentId segment, int location) {
	int rel = location - block_location;

	if (rel < 0)
		return 0;

	uint idx = rel >> 1;

	if (idx >= block.size())
		return 0;

	if (rel & 1) {
		warning("Attempt to relocate odd variable #%d.5e (relative to %04x)\n", idx, block_location);
		return 0;
	}
	block[idx].segment = segment; // Perform relocation
	if (isSci1_1)
		block[idx].offset += getScript(segment)->script_size;

	return 1;
}

int SegManager::relocateLocal(Script *scr, SegmentId segment, int location) {
	if (scr->locals_block)
		return relocateBlock(scr->locals_block->_locals, scr->locals_offset, segment, location);
	else
		return 0; // No hands, no cookies
}

int SegManager::relocateObject(Object *obj, SegmentId segment, int location) {
	return relocateBlock(obj->_variables, obj->pos.offset, segment, location);
}

void SegManager::scriptAddCodeBlock(reg_t location) {
	Script *scr = getScript(location.segment);

	CodeBlock cb;
	cb.pos = location;
	cb.size = READ_LE_UINT16(scr->buf + location.offset - 2);
	scr->_codeBlocks.push_back(cb);
}

void SegManager::scriptRelocate(reg_t block) {
	Script *scr = getScript(block.segment);

	VERIFY(block.offset < (uint16)scr->buf_size && READ_LE_UINT16(scr->buf + block.offset) * 2 + block.offset < (uint16)scr->buf_size,
	       "Relocation block outside of script\n");

	int count = READ_LE_UINT16(scr->buf + block.offset);

	for (int i = 0; i <= count; i++) {
		int pos = READ_LE_UINT16(scr->buf + block.offset + 2 + (i * 2));
		if (!pos)
			continue; // FIXME: A hack pending investigation

		if (!relocateLocal(scr, block.segment, pos)) {
			bool done = false;
			uint k;

			for (k = 0; !done && k < scr->_objects.size(); k++) {
				if (relocateObject(&scr->_objects[k], block.segment, pos))
					done = true;
			}

			for (k = 0; !done && k < scr->_codeBlocks.size(); k++) {
				if (pos >= scr->_codeBlocks[k].pos.offset &&
				        pos < scr->_codeBlocks[k].pos.offset + scr->_codeBlocks[k].size)
					done = true;
			}

			if (!done) {
				printf("While processing relocation block %04x:%04x:\n", PRINT_REG(block));
				printf("Relocation failed for index %04x (%d/%d)\n", pos, i + 1, count);
				if (scr->locals_block)
					printf("- locals: %d at %04x\n", scr->locals_block->_locals.size(), scr->locals_offset);
				else
					printf("- No locals\n");
				for (k = 0; k < scr->_objects.size(); k++)
					printf("- obj#%d at %04x w/ %d vars\n", k, scr->_objects[k].pos.offset, scr->_objects[k]._variables.size());
				// SQ3 script 71 has broken relocation entries.
				// Since this is mainstream, we can't break out as we used to do.
				printf("Trying to continue anyway...\n");
			}
		}
	}
}

void SegManager::heapRelocate(reg_t block) {
	Script *scr = getScript(block.segment);

	VERIFY(block.offset < (uint16)scr->heap_size && READ_LE_UINT16(scr->heap_start + block.offset) * 2 + block.offset < (uint16)scr->buf_size,
	       "Relocation block outside of script\n");

	if (scr->relocated)
		return;
	scr->relocated = 1;
	int count = READ_LE_UINT16(scr->heap_start + block.offset);

	for (int i = 0; i < count; i++) {
		int pos = READ_LE_UINT16(scr->heap_start + block.offset + 2 + (i * 2)) + scr->script_size;

		if (!relocateLocal(scr, block.segment, pos)) {
			bool done = false;
			uint k;

			for (k = 0; !done && k < scr->_objects.size(); k++) {
				if (relocateObject(&scr->_objects[k], block.segment, pos))
					done = true;
			}

			if (!done) {
				printf("While processing relocation block %04x:%04x:\n", PRINT_REG(block));
				printf("Relocation failed for index %04x (%d/%d)\n", pos, i + 1, count);
				if (scr->locals_block)
					printf("- locals: %d at %04x\n", scr->locals_block->_locals.size(), scr->locals_offset);
				else
					printf("- No locals\n");
				for (k = 0; k < scr->_objects.size(); k++)
					printf("- obj#%d at %04x w/ %d vars\n", k, scr->_objects[k].pos.offset, scr->_objects[k]._variables.size());
				printf("Triggering breakpoint...\n");
				error("Breakpoint in %s, line %d", __FILE__, __LINE__);
			}
		}
	}
}

#define INST_LOOKUP_CLASS(id) ((id == 0xffff) ? NULL_REG : get_class_address(s, id, SCRIPT_GET_LOCK, NULL_REG))

reg_t get_class_address(EngineState *s, int classnr, SCRIPT_GET lock, reg_t caller);

Object *SegManager::scriptObjInit0(EngineState *s, reg_t obj_pos) {
	Object *obj;
	int id;
	unsigned int base = obj_pos.offset - SCRIPT_OBJECT_MAGIC_OFFSET;
	reg_t temp;

	Script *scr = getScript(obj_pos.segment);

	VERIFY(base < scr->buf_size, "Attempt to initialize object beyond end of script\n");

	temp = make_reg(obj_pos.segment, base);

	id = scr->obj_indices->checkKey(base, true);
	if ((uint)id == scr->_objects.size())
		scr->_objects.push_back(Object());

	obj = &scr->_objects[id];

	VERIFY(base + SCRIPT_FUNCTAREAPTR_OFFSET  < scr->buf_size, "Function area pointer stored beyond end of script\n");

	{
		byte *data = (byte *)(scr->buf + base);
		int funct_area = READ_LE_UINT16(data + SCRIPT_FUNCTAREAPTR_OFFSET);
		int variables_nr;
		int functions_nr;
		int is_class;
		int i;

		obj->flags = 0;
		obj->pos = temp;

		VERIFY(base + funct_area < scr->buf_size, "Function area pointer references beyond end of script");

		variables_nr = READ_LE_UINT16(data + SCRIPT_SELECTORCTR_OFFSET);
		functions_nr = READ_LE_UINT16(data + funct_area - 2);
		is_class = READ_LE_UINT16(data + SCRIPT_INFO_OFFSET) & SCRIPT_INFO_CLASS;

		VERIFY(base + funct_area + functions_nr * 2
		       // add again for classes, since those also store selectors
		       + (is_class ? functions_nr * 2 : 0) < scr->buf_size, "Function area extends beyond end of script");

		obj->_variables.resize(variables_nr);

		obj->methods_nr = functions_nr;
		obj->base = scr->buf;
		obj->base_obj = data;
		obj->base_method = (uint16 *)(data + funct_area);
		obj->base_vars = NULL;

		for (i = 0; i < variables_nr; i++)
			obj->_variables[i] = make_reg(0, READ_LE_UINT16(data + (i * 2)));
	}

	return obj;
}

Object *SegManager::scriptObjInit11(EngineState *s, reg_t obj_pos) {
	Object *obj;
	int id;
	int base = obj_pos.offset;

	Script *scr = getScript(obj_pos.segment);

	VERIFY(base < (uint16)scr->buf_size, "Attempt to initialize object beyond end of script\n");

	id = scr->obj_indices->checkKey(obj_pos.offset, true);
	if ((uint)id == scr->_objects.size())
		scr->_objects.push_back(Object());

	obj = &scr->_objects[id];

	VERIFY(base + SCRIPT_FUNCTAREAPTR_OFFSET < (uint16)scr->buf_size, "Function area pointer stored beyond end of script\n");

	{
		byte *data = (byte *)(scr->buf + base);
		uint16 *funct_area = (uint16 *)(scr->buf + READ_LE_UINT16(data + 6));
		uint16 *prop_area = (uint16 *)(scr->buf + READ_LE_UINT16(data + 4));
		int variables_nr;
		int functions_nr;
		int is_class;
		int i;

		obj->flags = 0;
		obj->pos = obj_pos;

		VERIFY((byte *) funct_area < scr->buf + scr->buf_size, "Function area pointer references beyond end of script");

		variables_nr = READ_LE_UINT16(data + 2);
		functions_nr = READ_LE_UINT16(funct_area);
		is_class = READ_LE_UINT16(data + 14) & SCRIPT_INFO_CLASS;

		obj->base_method = funct_area;
		obj->base_vars = prop_area;

		VERIFY(((byte *) funct_area + functions_nr) < scr->buf + scr->buf_size, "Function area extends beyond end of script");

		obj->variable_names_nr = variables_nr;
		obj->_variables.resize(variables_nr);

		obj->methods_nr = functions_nr;
		obj->base = scr->buf;
		obj->base_obj = data;

		for (i = 0; i < variables_nr; i++)
			obj->_variables[i] = make_reg(0, READ_LE_UINT16(data + (i * 2)));
	}

	return obj;
}

Object *SegManager::scriptObjInit(EngineState *s, reg_t obj_pos) {
	if (!isSci1_1)
		return scriptObjInit0(s, obj_pos);
	else
		return scriptObjInit11(s, obj_pos);
}

LocalVariables *SegManager::allocLocalsSegment(Script *scr, int count) {
	if (!count) { // No locals
		scr->locals_segment = 0;
		scr->locals_block = NULL;
		return NULL;
	} else {
		LocalVariables *locals;

		if (scr->locals_segment) {
			locals = (LocalVariables *)_heap[scr->locals_segment];
			VERIFY(locals != NULL, "Re-used locals segment was NULL'd out");
			VERIFY(locals->getType() == MEM_OBJ_LOCALS, "Re-used locals segment did not consist of local variables");
			VERIFY(locals->script_id == scr->nr, "Re-used locals segment belonged to other script");
		} else
			locals = (LocalVariables *)allocNonscriptSegment(MEM_OBJ_LOCALS, &scr->locals_segment);

		scr->locals_block = locals;
		locals->script_id = scr->nr;
		locals->_locals.resize(count);

		return locals;
	}
}

void SegManager::scriptInitialiseLocalsZero(SegmentId seg, int count) {
	Script *scr = getScript(seg);

	scr->locals_offset = -count * 2; // Make sure it's invalid

	allocLocalsSegment(scr, count);
}

void SegManager::scriptInitialiseLocals(reg_t location) {
	Script *scr = getScript(location.segment);
	unsigned int count;

	VERIFY(location.offset + 1 < (uint16)scr->buf_size, "Locals beyond end of script\n");

	if (isSci1_1)
		count = READ_LE_UINT16(scr->buf + location.offset - 2);
	else
		count = (READ_LE_UINT16(scr->buf + location.offset - 2) - 4) >> 1;
	// half block size

	scr->locals_offset = location.offset;

	if (!(location.offset + count * 2 + 1 < scr->buf_size)) {
		warning("Locals extend beyond end of script: offset %04x, count %x vs size %x", location.offset, count, (uint)scr->buf_size);
		count = (scr->buf_size - location.offset) >> 1;
	}

	LocalVariables *locals = allocLocalsSegment(scr, count);
	if (locals) {
		uint i;
		byte *base = (byte *)(scr->buf + location.offset);

		for (i = 0; i < count; i++)
			locals->_locals[i].offset = READ_LE_UINT16(base + i * 2);
	}
}

void SegManager::scriptRelocateExportsSci11(SegmentId seg) {
	Script *scr = getScript(seg);
	for (int i = 0; i < scr->exports_nr; i++) {
		/* We are forced to use an ugly heuristic here to distinguish function
		   exports from object/class exports. The former kind points into the
		   script resource, the latter into the heap resource.  */
		uint16 location = READ_LE_UINT16((byte *)(scr->export_table + i));
		if ((location < scr->heap_size - 1) && (READ_LE_UINT16(scr->heap_start + location) == SCRIPT_OBJECT_MAGIC_NUMBER)) {
			WRITE_LE_UINT16((byte *)(scr->export_table + i), location + scr->heap_start - scr->buf);
		} else {
			// Otherwise it's probably a function export,
			// and we don't need to do anything.
		}
	}
}

void SegManager::scriptInitialiseObjectsSci11(EngineState *s, SegmentId seg) {
	Script *scr = getScript(seg);
	byte *seeker = scr->heap_start + 4 + READ_LE_UINT16(scr->heap_start + 2) * 2;

	while (READ_LE_UINT16(seeker) == SCRIPT_OBJECT_MAGIC_NUMBER) {
		if (READ_LE_UINT16(seeker + 14) & SCRIPT_INFO_CLASS) {
			int classpos = seeker - scr->buf;
			int species = READ_LE_UINT16(seeker + 10);

			if (species < 0 || species >= (int)s->_classtable.size()) {
				error("Invalid species %d(0x%x) not in interval [0,%d) while instantiating script %d\n",
				          species, species, s->_classtable.size(), scr->nr);
				return;
			}

			s->_classtable[species].script = scr->nr;
			s->_classtable[species].reg.segment = seg;
			s->_classtable[species].reg.offset = classpos;
		}
		seeker += READ_LE_UINT16(seeker + 2) * 2;
	}

	seeker = scr->heap_start + 4 + READ_LE_UINT16(scr->heap_start + 2) * 2;
	while (READ_LE_UINT16(seeker) == SCRIPT_OBJECT_MAGIC_NUMBER) {
		reg_t reg;
		Object *obj;

		reg.segment = seg;
		reg.offset = seeker - scr->buf;
		obj = scriptObjInit(s, reg);

#if 0
		if (obj->_variables[5].offset != 0xffff) {
			obj->_variables[5] = INST_LOOKUP_CLASS(obj->_variables[5].offset);
			base_obj = obj_get(s, obj->_variables[5]);
			obj->variable_names_nr = base_obj->variables_nr;
			obj->base_obj = base_obj->base_obj;
		}
#endif

		// Copy base from species class, as we need its selector IDs
		obj->_variables[SCRIPT_SUPERCLASS_SELECTOR] = INST_LOOKUP_CLASS(obj->_variables[SCRIPT_SUPERCLASS_SELECTOR].offset);

		// Set the -classScript- selector to the script number.
		// FIXME: As this selector is filled in at run-time, it is likely
		// that it is supposed to hold a pointer. The Obj::isKindOf method
		// uses this selector together with -propDict- to compare classes.
		// For the purpose of Obj::isKindOf, using the script number appears
		// to be sufficient.
		obj->_variables[SCRIPT_CLASSSCRIPT_SELECTOR] = make_reg(0, scr->nr);

		seeker += READ_LE_UINT16(seeker + 2) * 2;
	}
}

/*
static char *SegManager::dynprintf(char *msg, ...) {
	va_list argp;
	char *buf = (char *)malloc(strlen(msg) + 100);

	va_start(argp, msg);
	vsprintf(buf, msg, argp);
	va_end(argp);

	return buf;
}
*/

DataStack *SegManager::allocateStack(int size, SegmentId *segid) {
	MemObject *mobj = allocNonscriptSegment(MEM_OBJ_STACK, segid);
	DataStack *retval = (DataStack *)mobj;

	retval->entries = (reg_t *)calloc(size, sizeof(reg_t));
	retval->nr = size;

	return retval;
}

SystemStrings *SegManager::allocateSysStrings(SegmentId *segid) {
	return (SystemStrings *)allocNonscriptSegment(MEM_OBJ_SYS_STRINGS, segid);
}

SegmentId SegManager::allocateStringFrags() {
	SegmentId segid;

	allocNonscriptSegment(MEM_OBJ_STRING_FRAG, &segid);

	return segid;
}

uint16 SegManager::validateExportFunc(int pubfunct, SegmentId seg) {
	Script *scr = getScript(seg);
	if (scr->exports_nr <= pubfunct) {
		warning("validateExportFunc(): pubfunct is invalid");
		return 0;
	}

	if (exports_wide)
		pubfunct *= 2;
	uint16 offset = READ_LE_UINT16((byte *)(scr->export_table + pubfunct));
	VERIFY(offset < scr->buf_size, "invalid export function pointer");

	return offset;
}

void SegManager::free_hunk_entry(reg_t addr) {
	HunkTable *ht = (HunkTable *)GET_SEGMENT(*this, addr.segment, MEM_OBJ_HUNK);

	if (!ht) {
		warning("Attempt to free Hunk from address %04x:%04x: Invalid segment type", PRINT_REG(addr));
		return;
	}

	ht->freeEntry(addr.offset);
}

Hunk *SegManager::alloc_hunk_entry(const char *hunk_type, int size, reg_t *reg) {
	Hunk *h = alloc_Hunk(reg);

	if (!h)
		return NULL;

	h->mem = malloc(size);
	h->size = size;
	h->type = hunk_type;

	return h;
}

Clone *SegManager::alloc_Clone(reg_t *addr) {
	CloneTable *table;
	int offset;

	if (!Clones_seg_id) {
		table = (CloneTable *)allocNonscriptSegment(MEM_OBJ_CLONES, &(Clones_seg_id));
	} else
		table = (CloneTable *)_heap[Clones_seg_id];

	offset = table->allocEntry();

	*addr = make_reg(Clones_seg_id, offset);
	return &(table->_table[offset]);
}

List *SegManager::alloc_List(reg_t *addr) {
	ListTable *table;
	int offset;

	if (!Lists_seg_id)
		allocNonscriptSegment(MEM_OBJ_LISTS, &(Lists_seg_id));
	table = (ListTable *)_heap[Lists_seg_id];

	offset = table->allocEntry();

	*addr = make_reg(Lists_seg_id, offset);
	return &(table->_table[offset]);
}

Node *SegManager::alloc_Node(reg_t *addr) {
	NodeTable *table;
	int offset;

	if (!Nodes_seg_id)
		allocNonscriptSegment(MEM_OBJ_NODES, &(Nodes_seg_id));
	table = (NodeTable *)_heap[Nodes_seg_id];

	offset = table->allocEntry();

	*addr = make_reg(Nodes_seg_id, offset);
	return &(table->_table[offset]);
}

Hunk *SegManager::alloc_Hunk(reg_t *addr) {
	HunkTable *table;
	int offset;

	if (!Hunks_seg_id)
		allocNonscriptSegment(MEM_OBJ_HUNK, &(Hunks_seg_id));
	table = (HunkTable *)_heap[Hunks_seg_id];

	offset = table->allocEntry();

	*addr = make_reg(Hunks_seg_id, offset);
	return &(table->_table[offset]);
}

byte *SegManager::dereference(reg_t pointer, int *size) {
	if (!pointer.segment || (pointer.segment >= _heap.size()) || !_heap[pointer.segment]) {
		// This occurs in KQ5CD when interacting with certain objects
		warning("Attempt to dereference invalid pointer %04x:%04x", PRINT_REG(pointer));
		return NULL; /* Invalid */
	}

	MemObject *mobj = _heap[pointer.segment];
	return mobj->dereference(pointer, size);
}

unsigned char *SegManager::allocDynmem(int size, const char *descr, reg_t *addr) {
	SegmentId seg;
	MemObject *mobj = allocNonscriptSegment(MEM_OBJ_DYNMEM, &seg);
	*addr = make_reg(seg, 0);

	DynMem &d = *(DynMem *)mobj;

	d._size = size;

	if (size == 0)
		d._buf = NULL;
	else
		d._buf = (byte *)malloc(size);

	d._description = strdup(descr);

	return (unsigned char *)(d._buf);
}

const char *SegManager::getDescription(reg_t addr) {
	if (addr.segment >= _heap.size())
		return "";

	MemObject *mobj = _heap[addr.segment];

	switch (mobj->getType()) {
	case MEM_OBJ_DYNMEM:
		return (*(DynMem *)mobj)._description;
	default:
		return "";
	}
}

int SegManager::freeDynmem(reg_t addr) {
	if (addr.segment <= 0 || addr.segment >= _heap.size() || !_heap[addr.segment] || _heap[addr.segment]->getType() != MEM_OBJ_DYNMEM)
		return 1; // error

	deallocate(addr.segment, true);

	return 0; // OK
}


} // End of namespace Sci