aboutsummaryrefslogtreecommitdiff
path: root/cddl/contrib/opensolaris/tools/ctf/cvt/merge.c
blob: 27966af0cf50c2e3bd6ad85a85a49d6f730b79ad (plain) (blame)
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
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*
 * This file contains routines that merge one tdata_t tree, called the child,
 * into another, called the parent.  Note that these names are used mainly for
 * convenience and to represent the direction of the merge.  They are not meant
 * to imply any relationship between the tdata_t graphs prior to the merge.
 *
 * tdata_t structures contain two main elements - a hash of iidesc_t nodes, and
 * a directed graph of tdesc_t nodes, pointed to by the iidesc_t nodes.  Simply
 * put, we merge the tdesc_t graphs, followed by the iidesc_t nodes, and then we
 * clean up loose ends.
 *
 * The algorithm is as follows:
 *
 * 1. Mapping iidesc_t nodes
 *
 * For each child iidesc_t node, we first try to map its tdesc_t subgraph
 * against the tdesc_t graph in the parent.  For each node in the child subgraph
 * that exists in the parent, a mapping between the two (between their type IDs)
 * is established.  For the child nodes that cannot be mapped onto existing
 * parent nodes, a mapping is established between the child node ID and a
 * newly-allocated ID that the node will use when it is re-created in the
 * parent.  These unmappable nodes are added to the md_tdtba (tdesc_t To Be
 * Added) hash, which tracks nodes that need to be created in the parent.
 *
 * If all of the nodes in the subgraph for an iidesc_t in the child can be
 * mapped to existing nodes in the parent, then we can try to map the child
 * iidesc_t onto an iidesc_t in the parent.  If we cannot find an equivalent
 * iidesc_t, or if we were not able to completely map the tdesc_t subgraph(s),
 * then we add this iidesc_t to the md_iitba (iidesc_t To Be Added) list.  This
 * list tracks iidesc_t nodes that are to be created in the parent.
 *
 * While visiting the tdesc_t nodes, we may discover a forward declaration (a
 * FORWARD tdesc_t) in the parent that is resolved in the child.  That is, there
 * may be a structure or union definition in the child with the same name as the
 * forward declaration in the parent.  If we find such a node, we record an
 * association in the md_fdida (Forward => Definition ID Association) list
 * between the parent ID of the forward declaration and the ID that the
 * definition will use when re-created in the parent.
 *
 * 2. Creating new tdesc_t nodes (the md_tdtba hash)
 *
 * We have now attempted to map all tdesc_t nodes from the child into the
 * parent, and have, in md_tdtba, a hash of all tdesc_t nodes that need to be
 * created (or, as we so wittily call it, conjured) in the parent.  We iterate
 * through this hash, creating the indicated tdesc_t nodes.  For a given tdesc_t
 * node, conjuring requires two steps - the copying of the common tdesc_t data
 * (name, type, etc) from the child node, and the creation of links from the
 * newly-created node to the parent equivalents of other tdesc_t nodes pointed
 * to by node being conjured.  Note that in some cases, the targets of these
 * links will be on the md_tdtba hash themselves, and may not have been created
 * yet.  As such, we can't establish the links from these new nodes into the
 * parent graph.  We therefore conjure them with links to nodes in the *child*
 * graph, and add pointers to the links to be created to the md_tdtbr (tdesc_t
 * To Be Remapped) hash.  For example, a POINTER tdesc_t that could not be
 * resolved would have its &tdesc_t->t_tdesc added to md_tdtbr.
 *
 * 3. Creating new iidesc_t nodes (the md_iitba list)
 *
 * When we have completed step 2, all tdesc_t nodes have been created (or
 * already existed) in the parent.  Some of them may have incorrect links (the
 * members of the md_tdtbr list), but they've all been created.  As such, we can
 * create all of the iidesc_t nodes, as we can attach the tdesc_t subgraph
 * pointers correctly.  We create each node, and attach the pointers to the
 * appropriate parts of the parent tdesc_t graph.
 *
 * 4. Resolving newly-created tdesc_t node links (the md_tdtbr list)
 *
 * As in step 3, we rely on the fact that all of the tdesc_t nodes have been
 * created.  Each entry in the md_tdtbr list is a pointer to where a link into
 * the parent will be established.  As saved in the md_tdtbr list, these
 * pointers point into the child tdesc_t subgraph.  We can thus get the target
 * type ID from the child, look at the ID mapping to determine the desired link
 * target, and redirect the link accordingly.
 *
 * 5. Parent => child forward declaration resolution
 *
 * If entries were made in the md_fdida list in step 1, we have forward
 * declarations in the parent that need to be resolved to their definitions
 * re-created in step 2 from the child.  Using the md_fdida list, we can locate
 * the definition for the forward declaration, and we can redirect all inbound
 * edges to the forward declaration node to the actual definition.
 *
 * A pox on the house of anyone who changes the algorithm without updating
 * this comment.
 */

#include <stdio.h>
#include <strings.h>
#include <assert.h>
#include <pthread.h>

#include "ctf_headers.h"
#include "ctftools.h"
#include "list.h"
#include "alist.h"
#include "memory.h"
#include "traverse.h"

typedef struct equiv_data equiv_data_t;
typedef struct merge_cb_data merge_cb_data_t;

/*
 * There are two traversals in this file, for equivalency and for tdesc_t
 * re-creation, that do not fit into the tdtraverse() framework.  We have our
 * own traversal mechanism and ops vector here for those two cases.
 */
typedef struct tdesc_ops {
	const char *name;
	int (*equiv)(tdesc_t *, tdesc_t *, equiv_data_t *);
	tdesc_t *(*conjure)(tdesc_t *, int, merge_cb_data_t *);
} tdesc_ops_t;
extern tdesc_ops_t tdesc_ops[];

/*
 * The workhorse structure of tdata_t merging.  Holds all lists of nodes to be
 * processed during various phases of the merge algorithm.
 */
struct merge_cb_data {
	tdata_t *md_parent;
	tdata_t *md_tgt;
	alist_t *md_ta;		/* Type Association */
	alist_t *md_fdida;	/* Forward -> Definition ID Association */
	list_t	**md_iitba;	/* iidesc_t nodes To Be Added to the parent */
	hash_t	*md_tdtba;	/* tdesc_t nodes To Be Added to the parent */
	list_t	**md_tdtbr;	/* tdesc_t nodes To Be Remapped */
	int md_flags;
}; /* merge_cb_data_t */

/*
 * When we first create a tdata_t from stabs data, we will have duplicate nodes.
 * Normal merges, however, assume that the child tdata_t is already self-unique,
 * and for speed reasons do not attempt to self-uniquify.  If this flag is set,
 * the merge algorithm will self-uniquify by avoiding the insertion of
 * duplicates in the md_tdtdba list.
 */
#define	MCD_F_SELFUNIQUIFY	0x1

/*
 * When we merge the CTF data for the modules, we don't want it to contain any
 * data that can be found in the reference module (usually genunix).  If this
 * flag is set, we're doing a merge between the fully merged tdata_t for this
 * module and the tdata_t for the reference module, with the data unique to this
 * module ending up in a third tdata_t.  It is this third tdata_t that will end
 * up in the .SUNW_ctf section for the module.
 */
#define	MCD_F_REFMERGE	0x2

/*
 * Mapping of child type IDs to parent type IDs
 */

static void
add_mapping(alist_t *ta, tid_t srcid, tid_t tgtid)
{
	debug(3, "Adding mapping %u <%x> => %u <%x>\n", srcid, srcid, tgtid, tgtid);

	assert(!alist_find(ta, (void *)(uintptr_t)srcid, NULL));
	assert(srcid != 0 && tgtid != 0);

	alist_add(ta, (void *)(uintptr_t)srcid, (void *)(uintptr_t)tgtid);
}

static tid_t
get_mapping(alist_t *ta, int srcid)
{
	void *ltgtid;

	if (alist_find(ta, (void *)(uintptr_t)srcid, (void **)&ltgtid))
		return ((uintptr_t)ltgtid);
	else
		return (0);
}

/*
 * Determining equivalence of tdesc_t subgraphs
 */

struct equiv_data {
	alist_t *ed_ta;
	tdesc_t *ed_node;
	tdesc_t *ed_tgt;

	int ed_clear_mark;
	int ed_cur_mark;
	int ed_selfuniquify;
}; /* equiv_data_t */

static int equiv_node(tdesc_t *, tdesc_t *, equiv_data_t *);

/*ARGSUSED2*/
static int
equiv_intrinsic(tdesc_t *stdp, tdesc_t *ttdp, equiv_data_t *ed __unused)
{
	intr_t *si = stdp->t_intr;
	intr_t *ti = ttdp->t_intr;

	if (si->intr_type != ti->intr_type ||
	    si->intr_signed != ti->intr_signed ||
	    si->intr_offset != ti->intr_offset ||
	    si->intr_nbits != ti->intr_nbits)
		return (0);

	if (si->intr_type == INTR_INT &&
	    si->intr_iformat != ti->intr_iformat)
		return (0);
	else if (si->intr_type == INTR_REAL &&
	    si->intr_fformat != ti->intr_fformat)
		return (0);

	return (1);
}

static int
equiv_plain(tdesc_t *stdp, tdesc_t *ttdp, equiv_data_t *ed)
{
	return (equiv_node(stdp->t_tdesc, ttdp->t_tdesc, ed));
}

static int
equiv_function(tdesc_t *stdp, tdesc_t *ttdp, equiv_data_t *ed)
{
	fndef_t *fn1 = stdp->t_fndef, *fn2 = ttdp->t_fndef;
	int i;

	if (fn1->fn_nargs != fn2->fn_nargs ||
	    fn1->fn_vargs != fn2->fn_vargs)
		return (0);

	if (!equiv_node(fn1->fn_ret, fn2->fn_ret, ed))
		return (0);

	for (i = 0; i < (int) fn1->fn_nargs; i++) {
		if (!equiv_node(fn1->fn_args[i], fn2->fn_args[i], ed))
			return (0);
	}

	return (1);
}

static int
equiv_array(tdesc_t *stdp, tdesc_t *ttdp, equiv_data_t *ed)
{
	ardef_t *ar1 = stdp->t_ardef, *ar2 = ttdp->t_ardef;

	if (!equiv_node(ar1->ad_contents, ar2->ad_contents, ed) ||
	    !equiv_node(ar1->ad_idxtype, ar2->ad_idxtype, ed))
		return (0);

	if (ar1->ad_nelems != ar2->ad_nelems)
		return (0);

	return (1);
}

static int
equiv_su(tdesc_t *stdp, tdesc_t *ttdp, equiv_data_t *ed)
{
	mlist_t *ml1 = stdp->t_members, *ml2 = ttdp->t_members;
	mlist_t *olm1 = NULL;

	while (ml1 && ml2) {
		if (ml1->ml_offset != ml2->ml_offset ||
		    strcmp(ml1->ml_name, ml2->ml_name) != 0 ||
		    ml1->ml_size != ml2->ml_size ||
		    !equiv_node(ml1->ml_type, ml2->ml_type, ed))
			return (0);

		olm1 = ml1;
		ml1 = ml1->ml_next;
		ml2 = ml2->ml_next;
	}

	if (ml1 || ml2)
		return (0);

	return (1);
}

/*ARGSUSED2*/
static int
equiv_enum(tdesc_t *stdp, tdesc_t *ttdp, equiv_data_t *ed __unused)
{
	elist_t *el1 = stdp->t_emem;
	elist_t *el2 = ttdp->t_emem;

	while (el1 && el2) {
		if (el1->el_number != el2->el_number ||
		    strcmp(el1->el_name, el2->el_name) != 0)
			return (0);

		el1 = el1->el_next;
		el2 = el2->el_next;
	}

	if (el1 || el2)
		return (0);

	return (1);
}

/*ARGSUSED*/
static int
equiv_assert(tdesc_t *stdp __unused, tdesc_t *ttdp __unused, equiv_data_t *ed __unused)
{
	/* foul, evil, and very bad - this is a "shouldn't happen" */
	assert(1 == 0);

	return (0);
}

static int
fwd_equiv(tdesc_t *ctdp, tdesc_t *mtdp)
{
	tdesc_t *defn = (ctdp->t_type == FORWARD ? mtdp : ctdp);

	return (defn->t_type == STRUCT || defn->t_type == UNION);
}

static int
equiv_node(tdesc_t *ctdp, tdesc_t *mtdp, equiv_data_t *ed)
{
	int (*equiv)(tdesc_t *, tdesc_t *, equiv_data_t *);
	int mapping;

	if (ctdp->t_emark > ed->ed_clear_mark ||
	    mtdp->t_emark > ed->ed_clear_mark)
		return (ctdp->t_emark == mtdp->t_emark);

	/*
	 * In normal (non-self-uniquify) mode, we don't want to do equivalency
	 * checking on a subgraph that has already been checked.  If a mapping
	 * has already been established for a given child node, we can simply
	 * compare the mapping for the child node with the ID of the parent
	 * node.  If we are in self-uniquify mode, then we're comparing two
	 * subgraphs within the child graph, and thus need to ignore any
	 * type mappings that have been created, as they are only valid into the
	 * parent.
	 */
	if ((mapping = get_mapping(ed->ed_ta, ctdp->t_id)) > 0 &&
	    mapping == mtdp->t_id && !ed->ed_selfuniquify)
		return (1);

	if (!streq(ctdp->t_name, mtdp->t_name))
		return (0);

	if (ctdp->t_type != mtdp->t_type) {
		if (ctdp->t_type == FORWARD || mtdp->t_type == FORWARD)
			return (fwd_equiv(ctdp, mtdp));
		else
			return (0);
	}

	ctdp->t_emark = ed->ed_cur_mark;
	mtdp->t_emark = ed->ed_cur_mark;
	ed->ed_cur_mark++;

	if ((equiv = tdesc_ops[ctdp->t_type].equiv) != NULL)
		return (equiv(ctdp, mtdp, ed));

	return (1);
}

/*
 * We perform an equivalency check on two subgraphs by traversing through them
 * in lockstep.  If a given node is equivalent in both the parent and the child,
 * we mark it in both subgraphs, using the t_emark field, with a monotonically
 * increasing number.  If, in the course of the traversal, we reach a node that
 * we have visited and numbered during this equivalency check, we have a cycle.
 * If the previously-visited nodes don't have the same emark, then the edges
 * that brought us to these nodes are not equivalent, and so the check ends.
 * If the emarks are the same, the edges are equivalent.  We then backtrack and
 * continue the traversal.  If we have exhausted all edges in the subgraph, and
 * have not found any inequivalent nodes, then the subgraphs are equivalent.
 */
static int
equiv_cb(void *bucket, void *arg)
{
	equiv_data_t *ed = arg;
	tdesc_t *mtdp = bucket;
	tdesc_t *ctdp = ed->ed_node;

	ed->ed_clear_mark = ed->ed_cur_mark + 1;
	ed->ed_cur_mark = ed->ed_clear_mark + 1;

	if (equiv_node(ctdp, mtdp, ed)) {
		debug(3, "equiv_node matched %d <%x> %d <%x>\n",
		    ctdp->t_id, ctdp->t_id, mtdp->t_id, mtdp->t_id);
		ed->ed_tgt = mtdp;
		/* matched.  stop looking */
		return (-1);
	}

	return (0);
}

/*ARGSUSED1*/
static int
map_td_tree_pre(tdesc_t *ctdp, tdesc_t **ctdpp __unused, void *private)
{
	merge_cb_data_t *mcd = private;

	if (get_mapping(mcd->md_ta, ctdp->t_id) > 0)
		return (0);

	return (1);
}

/*ARGSUSED1*/
static int
map_td_tree_post(tdesc_t *ctdp, tdesc_t **ctdpp __unused, void *private)
{
	merge_cb_data_t *mcd = private;
	equiv_data_t ed;

	ed.ed_ta = mcd->md_ta;
	ed.ed_clear_mark = mcd->md_parent->td_curemark;
	ed.ed_cur_mark = mcd->md_parent->td_curemark + 1;
	ed.ed_node = ctdp;
	ed.ed_selfuniquify = 0;

	debug(3, "map_td_tree_post on %d <%x> %s\n", ctdp->t_id, ctdp->t_id,tdesc_name(ctdp));

	if (hash_find_iter(mcd->md_parent->td_layouthash, ctdp,
	    equiv_cb, &ed) < 0) {
		/* We found an equivalent node */
		if (ed.ed_tgt->t_type == FORWARD && ctdp->t_type != FORWARD) {
			int id = mcd->md_tgt->td_nextid++;

			debug(3, "Creating new defn type %d <%x>\n", id, id);
			add_mapping(mcd->md_ta, ctdp->t_id, id);
			alist_add(mcd->md_fdida, (void *)(ulong_t)ed.ed_tgt,
			    (void *)(ulong_t)id);
			hash_add(mcd->md_tdtba, ctdp);
		} else
			add_mapping(mcd->md_ta, ctdp->t_id, ed.ed_tgt->t_id);

	} else if (debug_level > 1 && hash_iter(mcd->md_parent->td_idhash,
	    equiv_cb, &ed) < 0) {
		/*
		 * We didn't find an equivalent node by looking through the
		 * layout hash, but we somehow found it by performing an
		 * exhaustive search through the entire graph.  This usually
		 * means that the "name" hash function is broken.
		 */
		aborterr("Second pass for %d (%s) == %d\n", ctdp->t_id,
		    tdesc_name(ctdp), ed.ed_tgt->t_id);
	} else {
		int id = mcd->md_tgt->td_nextid++;

		debug(3, "Creating new type %d <%x>\n", id, id);
		add_mapping(mcd->md_ta, ctdp->t_id, id);
		hash_add(mcd->md_tdtba, ctdp);
	}

	mcd->md_parent->td_curemark = ed.ed_cur_mark + 1;

	return (1);
}

/*ARGSUSED1*/
static int
map_td_tree_self_post(tdesc_t *ctdp, tdesc_t **ctdpp __unused, void *private)
{
	merge_cb_data_t *mcd = private;
	equiv_data_t ed;

	ed.ed_ta = mcd->md_ta;
	ed.ed_clear_mark = mcd->md_parent->td_curemark;
	ed.ed_cur_mark = mcd->md_parent->td_curemark + 1;
	ed.ed_node = ctdp;
	ed.ed_selfuniquify = 1;
	ed.ed_tgt = NULL;

	if (hash_find_iter(mcd->md_tdtba, ctdp, equiv_cb, &ed) < 0) {
		debug(3, "Self check found %d <%x> in %d <%x>\n", ctdp->t_id,
		    ctdp->t_id, ed.ed_tgt->t_id, ed.ed_tgt->t_id);
		add_mapping(mcd->md_ta, ctdp->t_id,
		    get_mapping(mcd->md_ta, ed.ed_tgt->t_id));
	} else if (debug_level > 1 && hash_iter(mcd->md_tdtba,
	    equiv_cb, &ed) < 0) {
		/*
		 * We didn't find an equivalent node using the quick way (going
		 * through the hash normally), but we did find it by iterating
		 * through the entire hash.  This usually means that the hash
		 * function is broken.
		 */
		aborterr("Self-unique second pass for %d <%x> (%s) == %d <%x>\n",
		    ctdp->t_id, ctdp->t_id, tdesc_name(ctdp), ed.ed_tgt->t_id,
		    ed.ed_tgt->t_id);
	} else {
		int id = mcd->md_tgt->td_nextid++;

		debug(3, "Creating new type %d <%x>\n", id, id);
		add_mapping(mcd->md_ta, ctdp->t_id, id);
		hash_add(mcd->md_tdtba, ctdp);
	}

	mcd->md_parent->td_curemark = ed.ed_cur_mark + 1;

	return (1);
}

static tdtrav_cb_f map_pre[] = {
	NULL,
	map_td_tree_pre,	/* intrinsic */
	map_td_tree_pre,	/* pointer */
	map_td_tree_pre,	/* array */
	map_td_tree_pre,	/* function */
	map_td_tree_pre,	/* struct */
	map_td_tree_pre,	/* union */
	map_td_tree_pre,	/* enum */
	map_td_tree_pre,	/* forward */
	map_td_tree_pre,	/* typedef */
	tdtrav_assert,		/* typedef_unres */
	map_td_tree_pre,	/* volatile */
	map_td_tree_pre,	/* const */
	map_td_tree_pre		/* restrict */
};

static tdtrav_cb_f map_post[] = {
	NULL,
	map_td_tree_post,	/* intrinsic */
	map_td_tree_post,	/* pointer */
	map_td_tree_post,	/* array */
	map_td_tree_post,	/* function */
	map_td_tree_post,	/* struct */
	map_td_tree_post,	/* union */
	map_td_tree_post,	/* enum */
	map_td_tree_post,	/* forward */
	map_td_tree_post,	/* typedef */
	tdtrav_assert,		/* typedef_unres */
	map_td_tree_post,	/* volatile */
	map_td_tree_post,	/* const */
	map_td_tree_post	/* restrict */
};

static tdtrav_cb_f map_self_post[] = {
	NULL,
	map_td_tree_self_post,	/* intrinsic */
	map_td_tree_self_post,	/* pointer */
	map_td_tree_self_post,	/* array */
	map_td_tree_self_post,	/* function */
	map_td_tree_self_post,	/* struct */
	map_td_tree_self_post,	/* union */
	map_td_tree_self_post,	/* enum */
	map_td_tree_self_post,	/* forward */
	map_td_tree_self_post,	/* typedef */
	tdtrav_assert,		/* typedef_unres */
	map_td_tree_self_post,	/* volatile */
	map_td_tree_self_post,	/* const */
	map_td_tree_self_post	/* restrict */
};

/*
 * Determining equivalence of iidesc_t nodes
 */

typedef struct iifind_data {
	iidesc_t *iif_template;
	alist_t *iif_ta;
	int iif_newidx;
	int iif_refmerge;
} iifind_data_t;

/*
 * Check to see if this iidesc_t (node) - the current one on the list we're
 * iterating through - matches the target one (iif->iif_template).  Return -1
 * if it matches, to stop the iteration.
 */
static int
iidesc_match(void *data, void *arg)
{
	iidesc_t *node = data;
	iifind_data_t *iif = arg;
	int i;

	if (node->ii_type != iif->iif_template->ii_type ||
	    !streq(node->ii_name, iif->iif_template->ii_name) ||
	    node->ii_dtype->t_id != iif->iif_newidx)
		return (0);

	if ((node->ii_type == II_SVAR || node->ii_type == II_SFUN) &&
	    !streq(node->ii_owner, iif->iif_template->ii_owner))
		return (0);

	if (node->ii_nargs != iif->iif_template->ii_nargs)
		return (0);

	for (i = 0; i < node->ii_nargs; i++) {
		if (get_mapping(iif->iif_ta,
		    iif->iif_template->ii_args[i]->t_id) !=
		    node->ii_args[i]->t_id)
			return (0);
	}

	if (iif->iif_refmerge) {
		switch (iif->iif_template->ii_type) {
		case II_GFUN:
		case II_SFUN:
		case II_GVAR:
		case II_SVAR:
			debug(3, "suppressing duping of %d %s from %s\n",
			    iif->iif_template->ii_type,
			    iif->iif_template->ii_name,
			    (iif->iif_template->ii_owner ?
			    iif->iif_template->ii_owner : "NULL"));
			return (0);
		case II_NOT:
		case II_PSYM:
		case II_SOU:
		case II_TYPE:
			break;
		}
	}

	return (-1);
}

static int
merge_type_cb(void *data, void *arg)
{
	iidesc_t *sii = data;
	merge_cb_data_t *mcd = arg;
	iifind_data_t iif;
	tdtrav_cb_f *post;

	post = (mcd->md_flags & MCD_F_SELFUNIQUIFY ? map_self_post : map_post);

	/* Map the tdesc nodes */
	(void) iitraverse(sii, &mcd->md_parent->td_curvgen, NULL, map_pre, post,
	    mcd);

	/* Map the iidesc nodes */
	iif.iif_template = sii;
	iif.iif_ta = mcd->md_ta;
	iif.iif_newidx = get_mapping(mcd->md_ta, sii->ii_dtype->t_id);
	iif.iif_refmerge = (mcd->md_flags & MCD_F_REFMERGE);

	if (hash_match(mcd->md_parent->td_iihash, sii, iidesc_match,
	    &iif) == 1)
		/* successfully mapped */
		return (1);

	debug(3, "tba %s (%d)\n", (sii->ii_name ? sii->ii_name : "(anon)"),
	    sii->ii_type);

	list_add(mcd->md_iitba, sii);

	return (0);
}

static int
remap_node(tdesc_t **tgtp, tdesc_t *oldtgt, int selftid, tdesc_t *newself,
    merge_cb_data_t *mcd)
{
	tdesc_t *tgt = NULL;
	tdesc_t template;
	int oldid = oldtgt->t_id;

	if (oldid == selftid) {
		*tgtp = newself;
		return (1);
	}

	if ((template.t_id = get_mapping(mcd->md_ta, oldid)) == 0)
		aborterr("failed to get mapping for tid %d <%x>\n", oldid, oldid);

	if (!hash_find(mcd->md_parent->td_idhash, (void *)&template,
	    (void *)&tgt) && (!(mcd->md_flags & MCD_F_REFMERGE) ||
	    !hash_find(mcd->md_tgt->td_idhash, (void *)&template,
	    (void *)&tgt))) {
		debug(3, "Remap couldn't find %d <%x> (from %d <%x>)\n", template.t_id,
		    template.t_id, oldid, oldid);
		*tgtp = oldtgt;
		list_add(mcd->md_tdtbr, tgtp);
		return (0);
	}

	*tgtp = tgt;
	return (1);
}

static tdesc_t *
conjure_template(tdesc_t *old, int newselfid)
{
	tdesc_t *new = xcalloc(sizeof (tdesc_t));

	new->t_name = old->t_name ? xstrdup(old->t_name) : NULL;
	new->t_type = old->t_type;
	new->t_size = old->t_size;
	new->t_id = newselfid;
	new->t_flags = old->t_flags;

	return (new);
}

/*ARGSUSED2*/
static tdesc_t *
conjure_intrinsic(tdesc_t *old, int newselfid, merge_cb_data_t *mcd __unused)
{
	tdesc_t *new = conjure_template(old, newselfid);

	new->t_intr = xmalloc(sizeof (intr_t));
	bcopy(old->t_intr, new->t_intr, sizeof (intr_t));

	return (new);
}

static tdesc_t *
conjure_plain(tdesc_t *old, int newselfid, merge_cb_data_t *mcd)
{
	tdesc_t *new = conjure_template(old, newselfid);

	(void) remap_node(&new->t_tdesc, old->t_tdesc, old->t_id, new, mcd);

	return (new);
}

static tdesc_t *
conjure_function(tdesc_t *old, int newselfid, merge_cb_data_t *mcd)
{
	tdesc_t *new = conjure_template(old, newselfid);
	fndef_t *nfn = xmalloc(sizeof (fndef_t));
	fndef_t *ofn = old->t_fndef;
	int i;

	(void) remap_node(&nfn->fn_ret, ofn->fn_ret, old->t_id, new, mcd);

	nfn->fn_nargs = ofn->fn_nargs;
	nfn->fn_vargs = ofn->fn_vargs;

	if (nfn->fn_nargs > 0)
		nfn->fn_args = xcalloc(sizeof (tdesc_t *) * ofn->fn_nargs);

	for (i = 0; i < (int) ofn->fn_nargs; i++) {
		(void) remap_node(&nfn->fn_args[i], ofn->fn_args[i], old->t_id,
		    new, mcd);
	}

	new->t_fndef = nfn;

	return (new);
}

static tdesc_t *
conjure_array(tdesc_t *old, int newselfid, merge_cb_data_t *mcd)
{
	tdesc_t *new = conjure_template(old, newselfid);
	ardef_t *nar = xmalloc(sizeof (ardef_t));
	ardef_t *oar = old->t_ardef;

	(void) remap_node(&nar->ad_contents, oar->ad_contents, old->t_id, new,
	    mcd);
	(void) remap_node(&nar->ad_idxtype, oar->ad_idxtype, old->t_id, new,
	    mcd);

	nar->ad_nelems = oar->ad_nelems;

	new->t_ardef = nar;

	return (new);
}

static tdesc_t *
conjure_su(tdesc_t *old, int newselfid, merge_cb_data_t *mcd)
{
	tdesc_t *new = conjure_template(old, newselfid);
	mlist_t *omem, **nmemp;

	for (omem = old->t_members, nmemp = &new->t_members;
	    omem; omem = omem->ml_next, nmemp = &((*nmemp)->ml_next)) {
		*nmemp = xmalloc(sizeof (mlist_t));
		(*nmemp)->ml_offset = omem->ml_offset;
		(*nmemp)->ml_size = omem->ml_size;
		(*nmemp)->ml_name = xstrdup(omem->ml_name ? omem->ml_name : "empty omem->ml_name");
		(void) remap_node(&((*nmemp)->ml_type), omem->ml_type,
		    old->t_id, new, mcd);
	}
	*nmemp = NULL;

	return (new);
}

/*ARGSUSED2*/
static tdesc_t *
conjure_enum(tdesc_t *old, int newselfid, merge_cb_data_t *mcd __unused)
{
	tdesc_t *new = conjure_template(old, newselfid);
	elist_t *oel, **nelp;

	for (oel = old->t_emem, nelp = &new->t_emem;
	    oel; oel = oel->el_next, nelp = &((*nelp)->el_next)) {
		*nelp = xmalloc(sizeof (elist_t));
		(*nelp)->el_name = xstrdup(oel->el_name);
		(*nelp)->el_number = oel->el_number;
	}
	*nelp = NULL;

	return (new);
}

/*ARGSUSED2*/
static tdesc_t *
conjure_forward(tdesc_t *old, int newselfid, merge_cb_data_t *mcd)
{
	tdesc_t *new = conjure_template(old, newselfid);

	list_add(&mcd->md_tgt->td_fwdlist, new);

	return (new);
}

/*ARGSUSED*/
static tdesc_t *
conjure_assert(tdesc_t *old __unused, int newselfid __unused, merge_cb_data_t *mcd __unused)
{
	assert(1 == 0);
	return (NULL);
}

static iidesc_t *
conjure_iidesc(iidesc_t *old, merge_cb_data_t *mcd)
{
	iidesc_t *new = iidesc_dup(old);
	int i;

	(void) remap_node(&new->ii_dtype, old->ii_dtype, -1, NULL, mcd);
	for (i = 0; i < new->ii_nargs; i++) {
		(void) remap_node(&new->ii_args[i], old->ii_args[i], -1, NULL,
		    mcd);
	}

	return (new);
}

static int
fwd_redir(tdesc_t *fwd, tdesc_t **fwdp, void *private)
{
	alist_t *map = private;
	void *defn;

	if (!alist_find(map, (void *)fwd, (void **)&defn))
		return (0);

	debug(3, "Redirecting an edge to %s\n", tdesc_name(defn));

	*fwdp = defn;

	return (1);
}

static tdtrav_cb_f fwd_redir_cbs[] = {
	NULL,
	NULL,			/* intrinsic */
	NULL,			/* pointer */
	NULL,			/* array */
	NULL,			/* function */
	NULL,			/* struct */
	NULL,			/* union */
	NULL,			/* enum */
	fwd_redir,		/* forward */
	NULL,			/* typedef */
	tdtrav_assert,		/* typedef_unres */
	NULL,			/* volatile */
	NULL,			/* const */
	NULL			/* restrict */
};

typedef struct redir_mstr_data {
	tdata_t *rmd_tgt;
	alist_t *rmd_map;
} redir_mstr_data_t;

static int
redir_mstr_fwd_cb(void *name, void *value, void *arg)
{
	tdesc_t *fwd = name;
	int defnid = (uintptr_t)value;
	redir_mstr_data_t *rmd = arg;
	tdesc_t template;
	tdesc_t *defn;

	template.t_id = defnid;

	if (!hash_find(rmd->rmd_tgt->td_idhash, (void *)&template,
	    (void *)&defn)) {
		aborterr("Couldn't unforward %d (%s)\n", defnid,
		    tdesc_name(defn));
	}

	debug(3, "Forward map: resolved %d to %s\n", defnid, tdesc_name(defn));

	alist_add(rmd->rmd_map, (void *)fwd, (void *)defn);

	return (1);
}

static void
redir_mstr_fwds(merge_cb_data_t *mcd)
{
	redir_mstr_data_t rmd;
	alist_t *map = alist_new(NULL, NULL);

	rmd.rmd_tgt = mcd->md_tgt;
	rmd.rmd_map = map;

	if (alist_iter(mcd->md_fdida, redir_mstr_fwd_cb, &rmd)) {
		(void) iitraverse_hash(mcd->md_tgt->td_iihash,
		    &mcd->md_tgt->td_curvgen, fwd_redir_cbs, NULL, NULL, map);
	}

	alist_free(map);
}

static int
add_iitba_cb(void *data, void *private)
{
	merge_cb_data_t *mcd = private;
	iidesc_t *tba = data;
	iidesc_t *new;
	iifind_data_t iif;
	int newidx;

	newidx = get_mapping(mcd->md_ta, tba->ii_dtype->t_id);
	assert(newidx != -1);

	(void) list_remove(mcd->md_iitba, data, NULL, NULL);

	iif.iif_template = tba;
	iif.iif_ta = mcd->md_ta;
	iif.iif_newidx = newidx;
	iif.iif_refmerge = (mcd->md_flags & MCD_F_REFMERGE);

	if (hash_match(mcd->md_parent->td_iihash, tba, iidesc_match,
	    &iif) == 1) {
		debug(3, "iidesc_t %s already exists\n",
		    (tba->ii_name ? tba->ii_name : "(anon)"));
		return (1);
	}

	new = conjure_iidesc(tba, mcd);
	hash_add(mcd->md_tgt->td_iihash, new);

	return (1);
}

static int
add_tdesc(tdesc_t *oldtdp, int newid, merge_cb_data_t *mcd)
{
	tdesc_t *newtdp;
	tdesc_t template;

	template.t_id = newid;
	assert(hash_find(mcd->md_parent->td_idhash,
	    (void *)&template, NULL) == 0);

	debug(3, "trying to conjure %d %s (%d, <%x>) as %d, <%x>\n",
	    oldtdp->t_type, tdesc_name(oldtdp), oldtdp->t_id,
	    oldtdp->t_id, newid, newid);

	if ((newtdp = tdesc_ops[oldtdp->t_type].conjure(oldtdp, newid,
	    mcd)) == NULL)
		/* couldn't map everything */
		return (0);

	debug(3, "succeeded\n");

	hash_add(mcd->md_tgt->td_idhash, newtdp);
	hash_add(mcd->md_tgt->td_layouthash, newtdp);

	return (1);
}

static int
add_tdtba_cb(void *data, void *arg)
{
	tdesc_t *tdp = data;
	merge_cb_data_t *mcd = arg;
	int newid;
	int rc;

	newid = get_mapping(mcd->md_ta, tdp->t_id);
	assert(newid != -1);

	if ((rc = add_tdesc(tdp, newid, mcd)))
		hash_remove(mcd->md_tdtba, (void *)tdp);

	return (rc);
}

static int
add_tdtbr_cb(void *data, void *arg)
{
	tdesc_t **tdpp = data;
	merge_cb_data_t *mcd = arg;

	debug(3, "Remapping %s (%d)\n", tdesc_name(*tdpp), (*tdpp)->t_id);

	if (!remap_node(tdpp, *tdpp, -1, NULL, mcd))
		return (0);

	(void) list_remove(mcd->md_tdtbr, (void *)tdpp, NULL, NULL);
	return (1);
}

static void
merge_types(hash_t *src, merge_cb_data_t *mcd)
{
	list_t *iitba = NULL;
	list_t *tdtbr = NULL;
	int iirc, tdrc;

	mcd->md_iitba = &iitba;
	mcd->md_tdtba = hash_new(TDATA_LAYOUT_HASH_SIZE, tdesc_layouthash,
	    tdesc_layoutcmp);
	mcd->md_tdtbr = &tdtbr;

	(void) hash_iter(src, merge_type_cb, mcd);

	tdrc = hash_iter(mcd->md_tdtba, add_tdtba_cb, mcd);
	debug(3, "add_tdtba_cb added %d items\n", tdrc);

	iirc = list_iter(*mcd->md_iitba, add_iitba_cb, mcd);
	debug(3, "add_iitba_cb added %d items\n", iirc);

	assert(list_count(*mcd->md_iitba) == 0 &&
	    hash_count(mcd->md_tdtba) == 0);

	tdrc = list_iter(*mcd->md_tdtbr, add_tdtbr_cb, mcd);
	debug(3, "add_tdtbr_cb added %d items\n", tdrc);

	if (list_count(*mcd->md_tdtbr) != 0)
		aborterr("Couldn't remap all nodes\n");

	/*
	 * We now have an alist of master forwards and the ids of the new master
	 * definitions for those forwards in mcd->md_fdida.  By this point,
	 * we're guaranteed that all of the master definitions referenced in
	 * fdida have been added to the master tree.  We now traverse through
	 * the master tree, redirecting all edges inbound to forwards that have
	 * definitions to those definitions.
	 */
	if (mcd->md_parent == mcd->md_tgt) {
		redir_mstr_fwds(mcd);
	}
}

void
merge_into_master(tdata_t *cur, tdata_t *mstr, tdata_t *tgt, int selfuniquify)
{
	merge_cb_data_t mcd;

	cur->td_ref++;
	mstr->td_ref++;
	if (tgt)
		tgt->td_ref++;

	assert(cur->td_ref == 1 && mstr->td_ref == 1 &&
	    (tgt == NULL || tgt->td_ref == 1));

	mcd.md_parent = mstr;
	mcd.md_tgt = (tgt ? tgt : mstr);
	mcd.md_ta = alist_new(NULL, NULL);
	mcd.md_fdida = alist_new(NULL, NULL);
	mcd.md_flags = 0;

	if (selfuniquify)
		mcd.md_flags |= MCD_F_SELFUNIQUIFY;
	if (tgt)
		mcd.md_flags |= MCD_F_REFMERGE;

	mstr->td_curvgen = MAX(mstr->td_curvgen, cur->td_curvgen);
	mstr->td_curemark = MAX(mstr->td_curemark, cur->td_curemark);

	merge_types(cur->td_iihash, &mcd);

	if (debug_level >= 3) {
		debug(3, "Type association stats\n");
		alist_stats(mcd.md_ta, 0);
		debug(3, "Layout hash stats\n");
		hash_stats(mcd.md_tgt->td_layouthash, 1);
	}

	alist_free(mcd.md_fdida);
	alist_free(mcd.md_ta);

	cur->td_ref--;
	mstr->td_ref--;
	if (tgt)
		tgt->td_ref--;
}

tdesc_ops_t tdesc_ops[] = {
	{ "ERROR! BAD tdesc TYPE", NULL, NULL },
	{ "intrinsic",		equiv_intrinsic,	conjure_intrinsic },
	{ "pointer", 		equiv_plain,		conjure_plain },
	{ "array", 		equiv_array,		conjure_array },
	{ "function", 		equiv_function,		conjure_function },
	{ "struct",		equiv_su,		conjure_su },
	{ "union",		equiv_su,		conjure_su },
	{ "enum",		equiv_enum,		conjure_enum },
	{ "forward",		NULL,			conjure_forward },
	{ "typedef",		equiv_plain,		conjure_plain },
	{ "typedef_unres",	equiv_assert,		conjure_assert },
	{ "volatile",		equiv_plain,		conjure_plain },
	{ "const", 		equiv_plain,		conjure_plain },
	{ "restrict",		equiv_plain,		conjure_plain }
};