summaryrefslogtreecommitdiff
path: root/gcc/godump.c
blob: 81efa2877cba71edfff169c827468ef12d2ff4ae (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
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
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
/* Output Go language descriptions of types.
   Copyright (C) 2008-2013 Free Software Foundation, Inc.
   Written by Ian Lance Taylor <iant@google.com>.

This file is part of GCC.

GCC 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 3, or (at your option) any later
version.

GCC 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 GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

/* This file is used during the build process to emit Go language
   descriptions of declarations from C header files.  It uses the
   debug info hooks to emit the descriptions.  The Go language
   descriptions then become part of the Go runtime support
   library.

   All global names are output with a leading underscore, so that they
   are all hidden in Go.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "diagnostic-core.h"
#include "tree.h"
#include "ggc.h"
#include "pointer-set.h"
#include "obstack.h"
#include "debug.h"

/* We dump this information from the debug hooks.  This gives us a
   stable and maintainable API to hook into.  In order to work
   correctly when -g is used, we build our own hooks structure which
   wraps the hooks we need to change.  */

/* Our debug hooks.  This is initialized by dump_go_spec_init.  */

static struct gcc_debug_hooks go_debug_hooks;

/* The real debug hooks.  */

static const struct gcc_debug_hooks *real_debug_hooks;

/* The file where we should write information.  */

static FILE *go_dump_file;

/* A queue of decls to output.  */

static GTY(()) vec<tree, va_gc> *queue;

/* A hash table of macros we have seen.  */

static htab_t macro_hash;

/* The type of a value in macro_hash.  */

struct macro_hash_value
{
  /* The name stored in the hash table.  */
  char *name;
  /* The value of the macro.  */
  char *value;
};

/* Calculate the hash value for an entry in the macro hash table.  */

static hashval_t
macro_hash_hashval (const void *val)
{
  const struct macro_hash_value *mhval = (const struct macro_hash_value *) val;
  return htab_hash_string (mhval->name);
}

/* Compare values in the macro hash table for equality.  */

static int
macro_hash_eq (const void *v1, const void *v2)
{
  const struct macro_hash_value *mhv1 = (const struct macro_hash_value *) v1;
  const struct macro_hash_value *mhv2 = (const struct macro_hash_value *) v2;
  return strcmp (mhv1->name, mhv2->name) == 0;
}

/* Free values deleted from the macro hash table.  */

static void
macro_hash_del (void *v)
{
  struct macro_hash_value *mhv = (struct macro_hash_value *) v;
  XDELETEVEC (mhv->name);
  XDELETEVEC (mhv->value);
  XDELETE (mhv);
}

/* For the string hash tables.  */

static int
string_hash_eq (const void *y1, const void *y2)
{
  return strcmp ((const char *) y1, (const char *) y2) == 0;
}

/* A macro definition.  */

static void
go_define (unsigned int lineno, const char *buffer)
{
  const char *p;
  const char *name_end;
  size_t out_len;
  char *out_buffer;
  char *q;
  bool saw_operand;
  bool need_operand;
  struct macro_hash_value *mhval;
  char *copy;
  hashval_t hashval;
  void **slot;

  real_debug_hooks->define (lineno, buffer);

  /* Skip macro functions.  */
  for (p = buffer; *p != '\0' && *p != ' '; ++p)
    if (*p == '(')
      return;

  if (*p == '\0')
    return;

  name_end = p;

  ++p;
  if (*p == '\0')
    return;

  copy = XNEWVEC (char, name_end - buffer + 1);
  memcpy (copy, buffer, name_end - buffer);
  copy[name_end - buffer] = '\0';

  mhval = XNEW (struct macro_hash_value);
  mhval->name = copy;
  mhval->value = NULL;

  hashval = htab_hash_string (copy);
  slot = htab_find_slot_with_hash (macro_hash, mhval, hashval, NO_INSERT);

  /* For simplicity, we force all names to be hidden by adding an
     initial underscore, and let the user undo this as needed.  */
  out_len = strlen (p) * 2 + 1;
  out_buffer = XNEWVEC (char, out_len);
  q = out_buffer;
  saw_operand = false;
  need_operand = false;
  while (*p != '\0')
    {
      switch (*p)
	{
	case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
	case 'G': case 'H': case 'I': case 'J': case 'K': case 'L':
	case 'M': case 'N': case 'O': case 'P': case 'Q': case 'R':
	case 'S': case 'T': case 'U': case 'V': case 'W': case 'X':
	case 'Y': case 'Z':
	case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
	case 'g': case 'h': case 'i': case 'j': case 'k': case 'l':
	case 'm': case 'n': case 'o': case 'p': case 'q': case 'r':
	case 's': case 't': case 'u': case 'v': case 'w': case 'x':
	case 'y': case 'z':
	case '_':
	  {
	    /* The start of an identifier.  Technically we should also
	       worry about UTF-8 identifiers, but they are not a
	       problem for practical uses of -fdump-go-spec so we
	       don't worry about them.  */
	    const char *start;
	    char *n;
	    struct macro_hash_value idval;

	    if (saw_operand)
	      goto unknown;

	    start = p;
	    while (ISALNUM (*p) || *p == '_')
	      ++p;
	    n = XALLOCAVEC (char, p - start + 1);
	    memcpy (n, start, p - start);
	    n[p - start] = '\0';
	    idval.name = n;
	    idval.value = NULL;
	    if (htab_find (macro_hash, &idval) == NULL)
	      {
		/* This is a reference to a name which was not defined
		   as a macro.  */
		goto unknown;
	      }

	    *q++ = '_';
	    memcpy (q, start, p - start);
	    q += p - start;

	    saw_operand = true;
	    need_operand = false;
	  }
	  break;

	case '.':
	  if (!ISDIGIT (p[1]))
	    goto unknown;
	  /* Fall through.  */
	case '0': case '1': case '2': case '3': case '4':
	case '5': case '6': case '7': case '8': case '9':
	  {
	    const char *start;
	    bool is_hex;

	    start = p;
	    is_hex = false;
	    if (*p == '0' && (p[1] == 'x' || p[1] == 'X'))
	      {
		p += 2;
		is_hex = true;
	      }
	    while (ISDIGIT (*p) || *p == '.' || *p == 'e' || *p == 'E'
		   || (is_hex
		       && ((*p >= 'a' && *p <= 'f')
			   || (*p >= 'A' && *p <= 'F'))))
	      ++p;
	    memcpy (q, start, p - start);
	    q += p - start;
	    while (*p == 'u' || *p == 'U' || *p == 'l' || *p == 'L'
		   || *p == 'f' || *p == 'F'
		   || *p == 'd' || *p == 'D')
	      {
		/* Go doesn't use any of these trailing type
		   modifiers.  */
		++p;
	      }

	    /* We'll pick up the exponent, if any, as an
	       expression.  */

	    saw_operand = true;
	    need_operand = false;
	  }
	  break;

	case ' ': case '\t':
	  *q++ = *p++;
	  break;

	case '(':
	  /* Always OK, not part of an operand, presumed to start an
	     operand.  */
	  *q++ = *p++;
	  saw_operand = false;
	  need_operand = false;
	  break;

	case ')':
	  /* OK if we don't need an operand, and presumed to indicate
	     an operand.  */
	  if (need_operand)
	    goto unknown;
	  *q++ = *p++;
	  saw_operand = true;
	  break;

	case '+': case '-':
	  /* Always OK, but not part of an operand.  */
	  *q++ = *p++;
	  saw_operand = false;
	  break;

	case '*': case '/': case '%': case '|': case '&': case '^':
	  /* Must be a binary operator.  */
	  if (!saw_operand)
	    goto unknown;
	  *q++ = *p++;
	  saw_operand = false;
	  need_operand = true;
	  break;

	case '=':
	  *q++ = *p++;
	  if (*p != '=')
	    goto unknown;
	  /* Must be a binary operator.  */
	  if (!saw_operand)
	    goto unknown;
	  *q++ = *p++;
	  saw_operand = false;
	  need_operand = true;
	  break;

	case '!':
	  *q++ = *p++;
	  if (*p == '=')
	    {
	      /* Must be a binary operator.  */
	      if (!saw_operand)
		goto unknown;
	      *q++ = *p++;
	      saw_operand = false;
	      need_operand = true;
	    }
	  else
	    {
	      /* Must be a unary operator.  */
	      if (saw_operand)
		goto unknown;
	      need_operand = true;
	    }
	  break;

	case '<': case '>':
	  /* Must be a binary operand, may be << or >> or <= or >=.  */
	  if (!saw_operand)
	    goto unknown;
	  *q++ = *p++;
	  if (*p == *(p - 1) || *p == '=')
	    *q++ = *p++;
	  saw_operand = false;
	  need_operand = true;
	  break;

	case '~':
	  /* Must be a unary operand, must be translated for Go.  */
	  if (saw_operand)
	    goto unknown;
	  *q++ = '^';
	  p++;
	  need_operand = true;
	  break;

	case '"':
	case '\'':
	  {
	    char quote;
	    int count;

	    if (saw_operand)
	      goto unknown;
	    quote = *p;
	    *q++ = *p++;
	    count = 0;
	    while (*p != quote)
	      {
		int c;

		if (*p == '\0')
		  goto unknown;

		++count;

		if (*p != '\\')
		  {
		    *q++ = *p++;
		    continue;
		  }

		*q++ = *p++;
		switch (*p)
		  {
		  case '0': case '1': case '2': case '3':
		  case '4': case '5': case '6': case '7':
		    c = 0;
		    while (*p >= '0' && *p <= '7')
		      {
			*q++ = *p++;
			++c;
		      }
		    /* Go octal characters are always 3
		       digits.  */
		    if (c != 3)
		      goto unknown;
		    break;

		  case 'x':
		    *q++ = *p++;
		    c = 0;
		    while (ISXDIGIT (*p))
		      {
			*q++ = *p++;
			++c;
		      }
		    /* Go hex characters are always 2 digits.  */
		    if (c != 2)
		      goto unknown;
		    break;

		  case 'a': case 'b': case 'f': case 'n': case 'r':
		  case 't': case 'v': case '\\': case '\'': case '"':
		    *q++ = *p++;
		    break;

		  default:
		    goto unknown;
		  }
	      }

	    *q++ = *p++;

	    if (quote == '\'' && count != 1)
	      goto unknown;

	    saw_operand = true;
	    need_operand = false;

	    break;
	  }

	default:
	  goto unknown;
	}
    }

  if (need_operand)
    goto unknown;

  gcc_assert ((size_t) (q - out_buffer) < out_len);
  *q = '\0';

  mhval->value = out_buffer;

  if (slot == NULL)
    {
      slot = htab_find_slot_with_hash (macro_hash, mhval, hashval, INSERT);
      gcc_assert (slot != NULL && *slot == NULL);
    }
  else
    {
      if (*slot != NULL)
	macro_hash_del (*slot);
    }

  *slot = mhval;

  return;

 unknown:
  fprintf (go_dump_file, "// unknowndefine %s\n", buffer);
  if (slot != NULL)
    htab_clear_slot (macro_hash, slot);
  XDELETEVEC (out_buffer);
  XDELETEVEC (copy);
}

/* A macro undef.  */

static void
go_undef (unsigned int lineno, const char *buffer)
{
  struct macro_hash_value mhval;
  void **slot;

  real_debug_hooks->undef (lineno, buffer);

  mhval.name = CONST_CAST (char *, buffer);
  mhval.value = NULL;
  slot = htab_find_slot (macro_hash, &mhval, NO_INSERT);
  if (slot != NULL)
    htab_clear_slot (macro_hash, slot);
}

/* A function or variable decl.  */

static void
go_decl (tree decl)
{
  if (!TREE_PUBLIC (decl)
      || DECL_IS_BUILTIN (decl)
      || DECL_NAME (decl) == NULL_TREE)
    return;
  vec_safe_push (queue, decl);
}

/* A function decl.  */

static void
go_function_decl (tree decl)
{
  real_debug_hooks->function_decl (decl);
  go_decl (decl);
}

/* A global variable decl.  */

static void
go_global_decl (tree decl)
{
  real_debug_hooks->global_decl (decl);
  go_decl (decl);
}

/* A type declaration.  */

static void
go_type_decl (tree decl, int local)
{
  real_debug_hooks->type_decl (decl, local);

  if (local || DECL_IS_BUILTIN (decl))
    return;
  if (DECL_NAME (decl) == NULL_TREE
      && (TYPE_NAME (TREE_TYPE (decl)) == NULL_TREE
	  || TREE_CODE (TYPE_NAME (TREE_TYPE (decl))) != IDENTIFIER_NODE)
      && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE)
    return;
  vec_safe_push (queue, decl);
}

/* A container for the data we pass around when generating information
   at the end of the compilation.  */

struct godump_container
{
  /* DECLs that we have already seen.  */
  struct pointer_set_t *decls_seen;

  /* Types which may potentially have to be defined as dummy
     types.  */
  struct pointer_set_t *pot_dummy_types;

  /* Go keywords.  */
  htab_t keyword_hash;

  /* Global type definitions.  */
  htab_t type_hash;

  /* Invalid types.  */
  htab_t invalid_hash;

  /* Obstack used to write out a type definition.  */
  struct obstack type_obstack;
};

/* Append an IDENTIFIER_NODE to OB.  */

static void
go_append_string (struct obstack *ob, tree id)
{
  obstack_grow (ob, IDENTIFIER_POINTER (id), IDENTIFIER_LENGTH (id));
}

/* Write the Go version of TYPE to CONTAINER->TYPE_OBSTACK.
   USE_TYPE_NAME is true if we can simply use a type name here without
   needing to define it.  IS_FUNC_OK is true if we can output a func
   type here; the "func" keyword will already have been added.  Return
   true if the type can be represented in Go, false otherwise.  */

static bool
go_format_type (struct godump_container *container, tree type,
		bool use_type_name, bool is_func_ok)
{
  bool ret;
  struct obstack *ob;

  ret = true;
  ob = &container->type_obstack;

  if (TYPE_NAME (type) != NULL_TREE
      && (pointer_set_contains (container->decls_seen, type)
	  || pointer_set_contains (container->decls_seen, TYPE_NAME (type)))
      && (AGGREGATE_TYPE_P (type)
	  || POINTER_TYPE_P (type)
	  || TREE_CODE (type) == FUNCTION_TYPE))
    {
      tree name;
      void **slot;

      name = TYPE_NAME (type);
      if (TREE_CODE (name) == TYPE_DECL)
	name = DECL_NAME (name);

      slot = htab_find_slot (container->invalid_hash, IDENTIFIER_POINTER (name),
			     NO_INSERT);
      if (slot != NULL)
	ret = false;

      obstack_1grow (ob, '_');
      go_append_string (ob, name);
      return ret;
    }

  pointer_set_insert (container->decls_seen, type);

  switch (TREE_CODE (type))
    {
    case ENUMERAL_TYPE:
      obstack_grow (ob, "int", 3);
      break;

    case TYPE_DECL:
      {
	void **slot;

	slot = htab_find_slot (container->invalid_hash,
			       IDENTIFIER_POINTER (DECL_NAME (type)),
			       NO_INSERT);
	if (slot != NULL)
	  ret = false;

	obstack_1grow (ob, '_');
	go_append_string (ob, DECL_NAME (type));
      }
      break;

    case INTEGER_TYPE:
      {
	const char *s;
	char buf[100];

	switch (TYPE_PRECISION (type))
	  {
	  case 8:
	    s = TYPE_UNSIGNED (type) ? "uint8" : "int8";
	    break;
	  case 16:
	    s = TYPE_UNSIGNED (type) ? "uint16" : "int16";
	    break;
	  case 32:
	    s = TYPE_UNSIGNED (type) ? "uint32" : "int32";
	    break;
	  case 64:
	    s = TYPE_UNSIGNED (type) ? "uint64" : "int64";
	    break;
	  default:
	    snprintf (buf, sizeof buf, "INVALID-int-%u%s",
		      TYPE_PRECISION (type),
		      TYPE_UNSIGNED (type) ? "u" : "");
	    s = buf;
	    ret = false;
	    break;
	  }
	obstack_grow (ob, s, strlen (s));
      }
      break;

    case REAL_TYPE:
      {
	const char *s;
	char buf[100];

	switch (TYPE_PRECISION (type))
	  {
	  case 32:
	    s = "float32";
	    break;
	  case 64:
	    s = "float64";
	    break;
	  default:
	    snprintf (buf, sizeof buf, "INVALID-float-%u",
		      TYPE_PRECISION (type));
	    s = buf;
	    ret = false;
	    break;
	  }
	obstack_grow (ob, s, strlen (s));
      }
      break;

    case BOOLEAN_TYPE:
      obstack_grow (ob, "bool", 4);
      break;

    case POINTER_TYPE:
      if (use_type_name
          && TYPE_NAME (TREE_TYPE (type)) != NULL_TREE
          && (RECORD_OR_UNION_TYPE_P (TREE_TYPE (type))
	      || (POINTER_TYPE_P (TREE_TYPE (type))
                  && (TREE_CODE (TREE_TYPE (TREE_TYPE (type)))
		      == FUNCTION_TYPE))))
        {
	  tree name;
	  void **slot;

	  name = TYPE_NAME (TREE_TYPE (type));
	  if (TREE_CODE (name) == TYPE_DECL)
	    name = DECL_NAME (name);

	  slot = htab_find_slot (container->invalid_hash,
				 IDENTIFIER_POINTER (name), NO_INSERT);
	  if (slot != NULL)
	    ret = false;

	  obstack_grow (ob, "*_", 2);
	  go_append_string (ob, name);

	  /* The pointer here can be used without the struct or union
	     definition.  So this struct or union is a potential dummy
	     type.  */
	  if (RECORD_OR_UNION_TYPE_P (TREE_TYPE (type)))
	    pointer_set_insert (container->pot_dummy_types,
				IDENTIFIER_POINTER (name));

	  return ret;
        }
      if (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
	obstack_grow (ob, "func", 4);
      else
	obstack_1grow (ob, '*');
      if (VOID_TYPE_P (TREE_TYPE (type)))
	obstack_grow (ob, "byte", 4);
      else
	{
	  if (!go_format_type (container, TREE_TYPE (type), use_type_name,
			       true))
	    ret = false;
	}
      break;

    case ARRAY_TYPE:
      obstack_1grow (ob, '[');
      if (TYPE_DOMAIN (type) != NULL_TREE
	  && TREE_CODE (TYPE_DOMAIN (type)) == INTEGER_TYPE
	  && TYPE_MIN_VALUE (TYPE_DOMAIN (type)) != NULL_TREE
	  && TREE_CODE (TYPE_MIN_VALUE (TYPE_DOMAIN (type))) == INTEGER_CST
	  && tree_int_cst_sgn (TYPE_MIN_VALUE (TYPE_DOMAIN (type))) == 0
	  && TYPE_MAX_VALUE (TYPE_DOMAIN (type)) != NULL_TREE
	  && TREE_CODE (TYPE_MAX_VALUE (TYPE_DOMAIN (type))) == INTEGER_CST
	  && host_integerp (TYPE_MAX_VALUE (TYPE_DOMAIN (type)), 0))
	{
	  char buf[100];

	  snprintf (buf, sizeof buf, HOST_WIDE_INT_PRINT_DEC "+1",
		    tree_low_cst (TYPE_MAX_VALUE (TYPE_DOMAIN (type)), 0));
	  obstack_grow (ob, buf, strlen (buf));
	}
      obstack_1grow (ob, ']');
      if (!go_format_type (container, TREE_TYPE (type), use_type_name, false))
	ret = false;
      break;

    case UNION_TYPE:
    case RECORD_TYPE:
      {
	tree field;
	int i;

	obstack_grow (ob, "struct { ", 9);
	i = 0;
	for (field = TYPE_FIELDS (type);
	     field != NULL_TREE;
	     field = TREE_CHAIN (field))
	  {
	    struct obstack hold_type_obstack;
	    bool field_ok;

	    if (TREE_CODE (type) == UNION_TYPE)
	      {
		hold_type_obstack = container->type_obstack;
		obstack_init (&container->type_obstack);
	      }

	    field_ok = true;

	    if (DECL_NAME (field) == NULL)
	      {
		char buf[100];

		obstack_grow (ob, "Godump_", 7);
		snprintf (buf, sizeof buf, "%d", i);
		obstack_grow (ob, buf, strlen (buf));
		i++;
	      }
	    else
              {
		const char *var_name;
		void **slot;

		/* Start variable name with an underscore if a keyword.  */
		var_name = IDENTIFIER_POINTER (DECL_NAME (field));
		slot = htab_find_slot (container->keyword_hash, var_name,
				       NO_INSERT);
		if (slot != NULL)
		  obstack_1grow (ob, '_');
		go_append_string (ob, DECL_NAME (field));
	      }
	    obstack_1grow (ob, ' ');
	    if (DECL_BIT_FIELD (field))
	      {
		obstack_grow (ob, "INVALID-bit-field", 17);
		field_ok = false;
	      }
	    else
              {
		/* Do not expand type if a record or union type or a
		   function pointer.  */
		if (TYPE_NAME (TREE_TYPE (field)) != NULL_TREE
		    && (RECORD_OR_UNION_TYPE_P (TREE_TYPE (field))
			|| (POINTER_TYPE_P (TREE_TYPE (field))
			    && (TREE_CODE (TREE_TYPE (TREE_TYPE (field)))
                                == FUNCTION_TYPE))))
		  {
		    tree name;
		    void **slot;

		    name = TYPE_NAME (TREE_TYPE (field));
		    if (TREE_CODE (name) == TYPE_DECL)
		      name = DECL_NAME (name);

		    slot = htab_find_slot (container->invalid_hash,
					   IDENTIFIER_POINTER (name),
					   NO_INSERT);
		    if (slot != NULL)
		      field_ok = false;

		    obstack_1grow (ob, '_');
		    go_append_string (ob, name);
		  }
		else
		  {
		    if (!go_format_type (container, TREE_TYPE (field), true,
					 false))
		      field_ok = false;
		  }
              }
	    obstack_grow (ob, "; ", 2);

	    /* Only output the first successful field of a union, and
	       hope for the best.  */
	    if (TREE_CODE (type) == UNION_TYPE)
	      {
		if (!field_ok && TREE_CHAIN (field) == NULL_TREE)
		  {
		    field_ok = true;
		    ret = false;
		  }
		if (field_ok)
		  {
		    unsigned int sz;

		    sz = obstack_object_size (&container->type_obstack);
		    obstack_grow (&hold_type_obstack,
				  obstack_base (&container->type_obstack),
				  sz);
		  }
		obstack_free (&container->type_obstack, NULL);
		container->type_obstack = hold_type_obstack;
		if (field_ok)
		  break;
	      }
	    else
	      {
		if (!field_ok)
		  ret = false;
	      }
	  }
	obstack_1grow (ob, '}');
      }
      break;

    case FUNCTION_TYPE:
      {
	tree arg_type;
	bool is_varargs;
	tree result;
	function_args_iterator iter;
	bool seen_arg;

	/* Go has no way to write a type which is a function but not a
	   pointer to a function.  */
	if (!is_func_ok)
	  {
	    obstack_grow (ob, "func*", 5);
	    ret = false;
	  }

	obstack_1grow (ob, '(');
	is_varargs = stdarg_p (type);
	seen_arg = false;
	FOREACH_FUNCTION_ARGS (type, arg_type, iter)
	  {
	    if (VOID_TYPE_P (arg_type))
	      break;
	    if (seen_arg)
	      obstack_grow (ob, ", ", 2);
	    if (!go_format_type (container, arg_type, true, false))
	      ret = false;
	    seen_arg = true;
	  }
	if (is_varargs)
	  {
	    if (prototype_p (type))
	      obstack_grow (ob, ", ", 2);
	    obstack_grow (ob, "...interface{}", 14);
	  }
	obstack_1grow (ob, ')');

	result = TREE_TYPE (type);
	if (!VOID_TYPE_P (result))
	  {
	    obstack_1grow (ob, ' ');
	    if (!go_format_type (container, result, use_type_name, false))
	      ret = false;
	  }
      }
      break;

    default:
      obstack_grow (ob, "INVALID-type", 12);
      ret = false;
      break;
    }

  return ret;
}

/* Output the type which was built on the type obstack, and then free
   it.  */

static void
go_output_type (struct godump_container *container)
{
  struct obstack *ob;

  ob = &container->type_obstack;
  obstack_1grow (ob, '\0');
  fputs (obstack_base (ob), go_dump_file);
  obstack_free (ob, obstack_base (ob));
}

/* Output a function declaration.  */

static void
go_output_fndecl (struct godump_container *container, tree decl)
{
  if (!go_format_type (container, TREE_TYPE (decl), false, true))
    fprintf (go_dump_file, "// ");
  fprintf (go_dump_file, "func _%s ",
	   IDENTIFIER_POINTER (DECL_NAME (decl)));
  go_output_type (container);
  fprintf (go_dump_file, " __asm__(\"%s\")\n",
	   IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)));
}

/* Output a typedef or something like a struct definition.  */

static void
go_output_typedef (struct godump_container *container, tree decl)
{
  /* If we have an enum type, output the enum constants
     separately.  */
  if (TREE_CODE (TREE_TYPE (decl)) == ENUMERAL_TYPE
      && TYPE_SIZE (TREE_TYPE (decl)) != 0
      && !pointer_set_contains (container->decls_seen, TREE_TYPE (decl))
      && (TYPE_CANONICAL (TREE_TYPE (decl)) == NULL_TREE
	  || !pointer_set_contains (container->decls_seen,
				    TYPE_CANONICAL (TREE_TYPE (decl)))))
    {
      tree element;

      for (element = TYPE_VALUES (TREE_TYPE (decl));
	   element != NULL_TREE;
	   element = TREE_CHAIN (element))
	{
	  const char *name;
	  struct macro_hash_value *mhval;
	  void **slot;
	  char buf[100];

	  name = IDENTIFIER_POINTER (TREE_PURPOSE (element));

	  /* Sometimes a name will be defined as both an enum constant
	     and a macro.  Avoid duplicate definition errors by
	     treating enum constants as macros.  */
	  mhval = XNEW (struct macro_hash_value);
	  mhval->name = xstrdup (name);
	  mhval->value = NULL;
	  slot = htab_find_slot (macro_hash, mhval, INSERT);
	  if (*slot != NULL)
	    macro_hash_del (*slot);

	  if (host_integerp (TREE_VALUE (element), 0))
	    snprintf (buf, sizeof buf, HOST_WIDE_INT_PRINT_DEC,
		     tree_low_cst (TREE_VALUE (element), 0));
	  else if (host_integerp (TREE_VALUE (element), 1))
	    snprintf (buf, sizeof buf, HOST_WIDE_INT_PRINT_UNSIGNED,
		     ((unsigned HOST_WIDE_INT)
		      tree_low_cst (TREE_VALUE (element), 1)));
	  else
	    snprintf (buf, sizeof buf, HOST_WIDE_INT_PRINT_DOUBLE_HEX,
		     ((unsigned HOST_WIDE_INT)
		      TREE_INT_CST_HIGH (TREE_VALUE (element))),
		     TREE_INT_CST_LOW (TREE_VALUE (element)));

	  mhval->value = xstrdup (buf);
	  *slot = mhval;
	}
      pointer_set_insert (container->decls_seen, TREE_TYPE (decl));
      if (TYPE_CANONICAL (TREE_TYPE (decl)) != NULL_TREE)
	pointer_set_insert (container->decls_seen,
			    TYPE_CANONICAL (TREE_TYPE (decl)));
    }

  if (DECL_NAME (decl) != NULL_TREE)
    {
      void **slot;
      const char *type;

      type = IDENTIFIER_POINTER (DECL_NAME (decl));
      /* If type defined already, skip.  */
      slot = htab_find_slot (container->type_hash, type, INSERT);
      if (*slot != NULL)
	return;
      *slot = CONST_CAST (void *, (const void *) type);

      if (!go_format_type (container, TREE_TYPE (decl), false, false))
	{
	  fprintf (go_dump_file, "// ");
	  slot = htab_find_slot (container->invalid_hash, type, INSERT);
	  *slot = CONST_CAST (void *, (const void *) type);
	}
      fprintf (go_dump_file, "type _%s ",
	       IDENTIFIER_POINTER (DECL_NAME (decl)));
      go_output_type (container);

      if (RECORD_OR_UNION_TYPE_P (TREE_TYPE (decl)))
	{
	  HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (decl));

	  if (size > 0)
	    fprintf (go_dump_file,
		     "\nconst _sizeof_%s = " HOST_WIDE_INT_PRINT_DEC,
		     IDENTIFIER_POINTER (DECL_NAME (decl)),
		     size);
	}

      pointer_set_insert (container->decls_seen, decl);
    }
  else if (RECORD_OR_UNION_TYPE_P (TREE_TYPE (decl)))
    {
       void **slot;
       const char *type;
       HOST_WIDE_INT size;

       type = IDENTIFIER_POINTER (TYPE_NAME (TREE_TYPE ((decl))));
       /* If type defined already, skip.  */
       slot = htab_find_slot (container->type_hash, type, INSERT);
       if (*slot != NULL)
         return;
       *slot = CONST_CAST (void *, (const void *) type);

       if (!go_format_type (container, TREE_TYPE (decl), false, false))
	 {
	   fprintf (go_dump_file, "// ");
	   slot = htab_find_slot (container->invalid_hash, type, INSERT);
	   *slot = CONST_CAST (void *, (const void *) type);
	 }
       fprintf (go_dump_file, "type _%s ",
	       IDENTIFIER_POINTER (TYPE_NAME (TREE_TYPE (decl))));
       go_output_type (container);

       size = int_size_in_bytes (TREE_TYPE (decl));
       if (size > 0)
	 fprintf (go_dump_file,
		  "\nconst _sizeof_%s = " HOST_WIDE_INT_PRINT_DEC,
		  IDENTIFIER_POINTER (TYPE_NAME (TREE_TYPE (decl))),
		  size);
    }
  else
    return;

  fprintf (go_dump_file, "\n");
}

/* Output a variable.  */

static void
go_output_var (struct godump_container *container, tree decl)
{
  bool is_valid;

  if (pointer_set_contains (container->decls_seen, decl)
      || pointer_set_contains (container->decls_seen, DECL_NAME (decl)))
    return;
  pointer_set_insert (container->decls_seen, decl);
  pointer_set_insert (container->decls_seen, DECL_NAME (decl));

  is_valid = go_format_type (container, TREE_TYPE (decl), true, false);
  if (is_valid
      && htab_find_slot (container->type_hash,
			 IDENTIFIER_POINTER (DECL_NAME (decl)),
			 NO_INSERT) != NULL)
    {
      /* There is already a type with this name, probably from a
	 struct tag.  Prefer the type to the variable.  */
      is_valid = false;
    }
  if (!is_valid)
    fprintf (go_dump_file, "// ");

  fprintf (go_dump_file, "var _%s ",
	   IDENTIFIER_POINTER (DECL_NAME (decl)));
  go_output_type (container);
  fprintf (go_dump_file, "\n");

  /* Sometimes an extern variable is declared with an unknown struct
     type.  */
  if (TYPE_NAME (TREE_TYPE (decl)) != NULL_TREE
      && RECORD_OR_UNION_TYPE_P (TREE_TYPE (decl)))
    {
      tree type_name = TYPE_NAME (TREE_TYPE (decl));
      if (TREE_CODE (type_name) == IDENTIFIER_NODE)
	pointer_set_insert (container->pot_dummy_types,
			    IDENTIFIER_POINTER (type_name));
      else if (TREE_CODE (type_name) == TYPE_DECL)
	pointer_set_insert (container->pot_dummy_types,
			    IDENTIFIER_POINTER (DECL_NAME (type_name)));
    }
}

/* Output the final value of a preprocessor macro or enum constant.
   This is called via htab_traverse_noresize.  */

static int
go_print_macro (void **slot, void *arg ATTRIBUTE_UNUSED)
{
  struct macro_hash_value *mhval = (struct macro_hash_value *) *slot;
  fprintf (go_dump_file, "const _%s = %s\n", mhval->name, mhval->value);
  return 1;
}

/* Build a hash table with the Go keywords.  */

static const char * const keywords[] = {
  "__asm__", "break", "case", "chan", "const", "continue", "default",
  "defer", "else", "fallthrough", "for", "func", "go", "goto", "if",
  "import", "interface", "map", "package", "range", "return", "select",
  "struct", "switch", "type", "var"
};

static void
keyword_hash_init (struct godump_container *container)
{
  size_t i;
  size_t count = sizeof (keywords) / sizeof (keywords[0]);
  void **slot;

  for (i = 0; i < count; i++)
    {
      slot = htab_find_slot (container->keyword_hash, keywords[i], INSERT);
      *slot = CONST_CAST (void *, (const void *) keywords[i]);
    }
}

/* Traversing the pot_dummy_types and seeing which types are present
   in the global types hash table and creating dummy definitions if
   not found.  This function is invoked by pointer_set_traverse.  */

static bool
find_dummy_types (const void *ptr, void *adata)
{
  struct godump_container *data = (struct godump_container *) adata;
  const char *type = (const char *) ptr;
  void **slot;
  void **islot;

  slot = htab_find_slot (data->type_hash, type, NO_INSERT);
  islot = htab_find_slot (data->invalid_hash, type, NO_INSERT);
  if (slot == NULL || islot != NULL)
    fprintf (go_dump_file, "type _%s struct {}\n", type);
  return true;
}

/* Output symbols.  */

static void
go_finish (const char *filename)
{
  struct godump_container container;
  unsigned int ix;
  tree decl;

  real_debug_hooks->finish (filename);

  container.decls_seen = pointer_set_create ();
  container.pot_dummy_types = pointer_set_create ();
  container.type_hash = htab_create (100, htab_hash_string,
                                     string_hash_eq, NULL);
  container.invalid_hash = htab_create (10, htab_hash_string,
					string_hash_eq, NULL);
  container.keyword_hash = htab_create (50, htab_hash_string,
                                        string_hash_eq, NULL);
  obstack_init (&container.type_obstack);

  keyword_hash_init (&container);

  FOR_EACH_VEC_SAFE_ELT (queue, ix, decl)
    {
      switch (TREE_CODE (decl))
	{
	case FUNCTION_DECL:
	  go_output_fndecl (&container, decl);
	  break;

	case TYPE_DECL:
	  go_output_typedef (&container, decl);
	  break;

	case VAR_DECL:
	  go_output_var (&container, decl);
	  break;

	default:
	  gcc_unreachable();
	}
    }

  htab_traverse_noresize (macro_hash, go_print_macro, NULL);

  /* To emit dummy definitions.  */
  pointer_set_traverse (container.pot_dummy_types, find_dummy_types,
                        (void *) &container);

  pointer_set_destroy (container.decls_seen);
  pointer_set_destroy (container.pot_dummy_types);
  htab_delete (container.type_hash);
  htab_delete (container.invalid_hash);
  htab_delete (container.keyword_hash);
  obstack_free (&container.type_obstack, NULL);

  vec_free (queue);

  if (fclose (go_dump_file) != 0)
    error ("could not close Go dump file: %m");
  go_dump_file = NULL;
}

/* Set up our hooks.  */

const struct gcc_debug_hooks *
dump_go_spec_init (const char *filename, const struct gcc_debug_hooks *hooks)
{
  go_dump_file = fopen (filename, "w");
  if (go_dump_file == NULL)
    {
      error ("could not open Go dump file %qs: %m", filename);
      return hooks;
    }

  go_debug_hooks = *hooks;
  real_debug_hooks = hooks;

  go_debug_hooks.finish = go_finish;
  go_debug_hooks.define = go_define;
  go_debug_hooks.undef = go_undef;
  go_debug_hooks.function_decl = go_function_decl;
  go_debug_hooks.global_decl = go_global_decl;
  go_debug_hooks.type_decl = go_type_decl;

  macro_hash = htab_create (100, macro_hash_hashval, macro_hash_eq,
			    macro_hash_del);

  return &go_debug_hooks;
}

#include "gt-godump.h"