summaryrefslogtreecommitdiffstats
path: root/libobjc/encoding.c
blob: bd8b67e0e8b70314b6ac55e7619f661c122594a4 (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
/* Encoding of types for Objective C.
   Copyright (C) 1993, 1995, 1996, 1997, 1998, 2000, 2002, 2004, 2009, 2010
   Free Software Foundation, Inc.
   Contributed by Kresten Krab Thorup
   Bitfield support by Ovidiu Predescu

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.

Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.

You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
<http://www.gnu.org/licenses/>.  */

/* FIXME: This file has no business including tm.h.  */

/* FIXME: This file contains functions that will abort the entire
   program if they fail.  Is that really needed ?  */

#include "objc-private/common.h"
#include "objc-private/error.h"
#include "tconfig.h"
#include "coretypes.h"
#include "tm.h"
#include "objc/runtime.h"
#include "objc-private/module-abi-8.h" /* For struct objc_method */
#include <stdlib.h>
#include <ctype.h>
#include <string.h>                    /* For memcpy.  */

#undef  MAX
#define MAX(X, Y)                    \
  ({ typeof (X) __x = (X), __y = (Y); \
     (__x > __y ? __x : __y); })

#undef  MIN
#define MIN(X, Y)                    \
  ({ typeof (X) __x = (X), __y = (Y); \
     (__x < __y ? __x : __y); })

#undef  ROUND
#define ROUND(V, A) \
  ({ typeof (V) __v = (V); typeof (A) __a = (A); \
     __a * ((__v+__a - 1)/__a); })


/* Various hacks for objc_layout_record. These are used by the target
   macros. */

#define TREE_CODE(TYPE) *(TYPE)
#define TREE_TYPE(TREE) (TREE)

#define RECORD_TYPE     _C_STRUCT_B
#define UNION_TYPE      _C_UNION_B
#define QUAL_UNION_TYPE _C_UNION_B
#define ARRAY_TYPE      _C_ARY_B

#define REAL_TYPE       _C_DBL

#define VECTOR_TYPE	_C_VECTOR

#define TYPE_FIELDS(TYPE)           ({const char *_field = (TYPE)+1; \
    while (*_field != _C_STRUCT_E && *_field != _C_STRUCT_B \
           && *_field != _C_UNION_B && *_field++ != '=') \
    /* do nothing */; \
    _field;})

#define DECL_MODE(TYPE) *(TYPE)
#define TYPE_MODE(TYPE) *(TYPE)

#define DFmode          _C_DBL

#define strip_array_types(TYPE)      ({const char *_field = (TYPE); \
  while (*_field == _C_ARY_B)\
    {\
      while (isdigit ((unsigned char)*++_field))\
	;\
    }\
    _field;})

/* Some ports (eg ARM) allow the structure size boundary to be
   selected at compile-time.  We override the normal definition with
   one that has a constant value for this compilation.  */
#ifndef BITS_PER_UNIT
#define BITS_PER_UNIT 8
#endif
#undef  STRUCTURE_SIZE_BOUNDARY
#define STRUCTURE_SIZE_BOUNDARY (BITS_PER_UNIT * sizeof (struct{char a;}))

/* Some ROUND_TYPE_ALIGN macros use TARGET_foo, and consequently
   target_flags.  Define a dummy entry here to so we don't die.
   We have to rename it because target_flags may already have been
   declared extern.  */
#define target_flags not_target_flags
static int __attribute__ ((__unused__)) not_target_flags = 0;

/* Some ROUND_TYPE_ALIGN use ALTIVEC_VECTOR_MODE (rs6000 darwin).
   Define a dummy ALTIVEC_VECTOR_MODE so it will not die.  */
#undef ALTIVEC_VECTOR_MODE
#define ALTIVEC_VECTOR_MODE(MODE) (0)

/* Furthermore, some (powerpc) targets also use TARGET_ALIGN_NATURAL
 in their alignment macros. Currently[4.5/6], rs6000.h points this
 to a static variable, initialized by target overrides. This is reset
 in linux64.h but not in darwin64.h.  The macro is not used by *86*.  */

#if __MACH__ 
# if __LP64__
#  undef TARGET_ALIGN_NATURAL
#  define TARGET_ALIGN_NATURAL 1
# endif

/* On Darwin32, we need to recurse until we find the starting stuct type.  */
static int 
_darwin_rs6000_special_round_type_align (const char *struc, int comp, int spec)
{
  const char *_stp , *_fields = TYPE_FIELDS (struc);
  if (!_fields)
    return MAX (comp, spec);
  _stp = strip_array_types (_fields);
  if (TYPE_MODE(_stp) == _C_COMPLEX)
   _stp++;
  switch (TYPE_MODE(_stp))
    {
      case RECORD_TYPE:
      case UNION_TYPE:
	return MAX (MAX (comp, spec), objc_alignof_type (_stp) * BITS_PER_UNIT);
	break;
      case DFmode:
      case _C_LNG_LNG:
      case _C_ULNG_LNG:
	return MAX (MAX (comp, spec), 64);
	break;

      default:
	return MAX (comp, spec);
	break;
    }
}

/* See comment below.  */
#define darwin_rs6000_special_round_type_align(S,C,S2)			\
  (_darwin_rs6000_special_round_type_align ((char*)(S), (int)(C), (int)(S2)))
#endif

/*  FIXME: while this file has no business including tm.h, this
    definitely has no business defining this macro but it
    is only way around without really rewritting this file,
    should look after the branch of 3.4 to fix this.   */
#define rs6000_special_round_type_align(STRUCT, COMPUTED, SPECIFIED)	\
  ({ const char *_fields = TYPE_FIELDS (STRUCT);			\
  ((_fields != 0							\
    && TYPE_MODE (strip_array_types (TREE_TYPE (_fields))) == DFmode)	\
   ? MAX (MAX (COMPUTED, SPECIFIED), 64)				\
   : MAX (COMPUTED, SPECIFIED));})


/* Skip a variable name, enclosed in quotes (").  */
static inline
const char *
objc_skip_variable_name (const char *type)
{
  /* Skip the variable name if any.  */
  if (*type == '"')
    {
      /* FIXME: How do we know we won't read beyond the end of the
	 string.  Here and in the rest of the file!  */
      /* Skip '"'.  */
      type++;
      /* Skip to the next '"'.  */
      while (*type != '"')
	type++;
      /* Skip '"'.  */
      type++;
    }

  return type;
}

int
objc_sizeof_type (const char *type)
{
  type = objc_skip_variable_name (type);

  switch (*type) {
  case _C_BOOL:
    return sizeof (_Bool);
    break;

  case _C_ID:
    return sizeof (id);
    break;

  case _C_CLASS:
    return sizeof (Class);
    break;

  case _C_SEL:
    return sizeof (SEL);
    break;

  case _C_CHR:
    return sizeof (char);
    break;

  case _C_UCHR:
    return sizeof (unsigned char);
    break;

  case _C_SHT:
    return sizeof (short);
    break;

  case _C_USHT:
    return sizeof (unsigned short);
    break;

  case _C_INT:
    return sizeof (int);
    break;

  case _C_UINT:
    return sizeof (unsigned int);
    break;

  case _C_LNG:
    return sizeof (long);
    break;

  case _C_ULNG:
    return sizeof (unsigned long);
    break;

  case _C_LNG_LNG:
    return sizeof (long long);
    break;

  case _C_ULNG_LNG:
    return sizeof (unsigned long long);
    break;

  case _C_FLT:
    return sizeof (float);
    break;

  case _C_DBL:
    return sizeof (double);
    break;

  case _C_LNG_DBL:
    return sizeof (long double);
    break;

  case _C_VOID:
    return sizeof (void);
    break;

  case _C_PTR:
  case _C_ATOM:
  case _C_CHARPTR:
    return sizeof (char *);
    break;

  case _C_ARY_B:
    {
      int len = atoi (type + 1);
      while (isdigit ((unsigned char)*++type))
	;
      return len * objc_aligned_size (type);
    }
    break;

  case _C_VECTOR:
    {
      /* Skip the '!'.  */
      type++;
      /* Skip the '['.  */
      type++;

      /* The size in bytes is the following number.  */
      int size = atoi (type);
      return size;
    }
    break;

  case _C_BFLD:
    {
      /* The GNU encoding of bitfields is: b 'position' 'type'
	 'size'.  */
      int position, size;
      int startByte, endByte;

      position = atoi (type + 1);
      while (isdigit ((unsigned char)*++type))
	;
      size = atoi (type + 1);

      startByte = position / BITS_PER_UNIT;
      endByte = (position + size) / BITS_PER_UNIT;
      return endByte - startByte;
    }

  case _C_UNION_B:
  case _C_STRUCT_B:
    {
      struct objc_struct_layout layout;
      unsigned int size;

      objc_layout_structure (type, &layout);
      while (objc_layout_structure_next_member (&layout))
        /* do nothing */ ;
      objc_layout_finish_structure (&layout, &size, NULL);

      return size;
    }
    
  case _C_COMPLEX:
    {
      type++; /* Skip after the 'j'. */
      switch (*type)
        {
	    case _C_CHR:
	      return sizeof (_Complex char);
	      break;

	    case _C_UCHR:
	      return sizeof (_Complex unsigned char);
	      break;

	    case _C_SHT:
	      return sizeof (_Complex short);
	      break;

	    case _C_USHT:
	      return sizeof (_Complex unsigned short);
	      break;

	    case _C_INT:
	      return sizeof (_Complex int);
	      break;

	    case _C_UINT:
	      return sizeof (_Complex unsigned int);
	      break;

	    case _C_LNG:
	      return sizeof (_Complex long);
	      break;

	    case _C_ULNG:
	      return sizeof (_Complex unsigned long);
	      break;

	    case _C_LNG_LNG:
	      return sizeof (_Complex long long);
	      break;

	    case _C_ULNG_LNG:
	      return sizeof (_Complex unsigned long long);
	      break;

	    case _C_FLT:
	      return sizeof (_Complex float);
	      break;

	    case _C_DBL:
	      return sizeof (_Complex double);
	      break;

	    case _C_LNG_DBL:
	      return sizeof (_Complex long double);
	      break;
	    
	    default:
	      {
		/* FIXME: Is this so bad that we have to abort the
		   entire program ?  (it applies to all the other
		   _objc_abort calls in this file).
		*/
		_objc_abort ("unknown complex type %s\n", type);
		return 0;
	      }
	}
    }

  default:
    {
      _objc_abort ("unknown type %s\n", type);
      return 0;
    }
  }
}

int
objc_alignof_type (const char *type)
{
  type = objc_skip_variable_name (type);

  switch (*type) {
  case _C_BOOL:
    return __alignof__ (_Bool);
    break;

  case _C_ID:
    return __alignof__ (id);
    break;

  case _C_CLASS:
    return __alignof__ (Class);
    break;

  case _C_SEL:
    return __alignof__ (SEL);
    break;

  case _C_CHR:
    return __alignof__ (char);
    break;

  case _C_UCHR:
    return __alignof__ (unsigned char);
    break;

  case _C_SHT:
    return __alignof__ (short);
    break;

  case _C_USHT:
    return __alignof__ (unsigned short);
    break;

  case _C_INT:
    return __alignof__ (int);
    break;

  case _C_UINT:
    return __alignof__ (unsigned int);
    break;

  case _C_LNG:
    return __alignof__ (long);
    break;

  case _C_ULNG:
    return __alignof__ (unsigned long);
    break;

  case _C_LNG_LNG:
    return __alignof__ (long long);
    break;

  case _C_ULNG_LNG:
    return __alignof__ (unsigned long long);
    break;

  case _C_FLT:
    return __alignof__ (float);
    break;

  case _C_DBL:
    return __alignof__ (double);
    break;

  case _C_LNG_DBL:
    return __alignof__ (long double);
    break;

  case _C_PTR:
  case _C_ATOM:
  case _C_CHARPTR:
    return __alignof__ (char *);
    break;

  case _C_ARY_B:
    while (isdigit ((unsigned char)*++type))
      /* do nothing */;
    return objc_alignof_type (type);

  case _C_VECTOR:
    {   
      /* Skip the '!'.  */
      type++;
      /* Skip the '['.  */
      type++;
      
      /* Skip the size.  */
      while (isdigit ((unsigned char)*type))
	type++;
      
      /* Skip the ','.  */
      type++;
      
      /* The alignment in bytes is the following number.  */
      return atoi (type);
    }
  case _C_STRUCT_B:
  case _C_UNION_B:
    {
      struct objc_struct_layout layout;
      unsigned int align;

      objc_layout_structure (type, &layout);
      while (objc_layout_structure_next_member (&layout))
        /* do nothing */;
      objc_layout_finish_structure (&layout, NULL, &align);

      return align;
    }
    
    
  case _C_COMPLEX:
    {
      type++; /* Skip after the 'j'. */
      switch (*type)
        {
	    case _C_CHR:
	      return __alignof__ (_Complex char);
	      break;

	    case _C_UCHR:
	      return __alignof__ (_Complex unsigned char);
	      break;

	    case _C_SHT:
	      return __alignof__ (_Complex short);
	      break;

	    case _C_USHT:
	      return __alignof__ (_Complex unsigned short);
	      break;

	    case _C_INT:
	      return __alignof__ (_Complex int);
	      break;

	    case _C_UINT:
	      return __alignof__ (_Complex unsigned int);
	      break;

	    case _C_LNG:
	      return __alignof__ (_Complex long);
	      break;

	    case _C_ULNG:
	      return __alignof__ (_Complex unsigned long);
	      break;

	    case _C_LNG_LNG:
	      return __alignof__ (_Complex long long);
	      break;

	    case _C_ULNG_LNG:
	      return __alignof__ (_Complex unsigned long long);
	      break;

	    case _C_FLT:
	      return __alignof__ (_Complex float);
	      break;

	    case _C_DBL:
	      return __alignof__ (_Complex double);
	      break;

	    case _C_LNG_DBL:
	      return __alignof__ (_Complex long double);
	      break;
	    
	    default:
	      {
		_objc_abort ("unknown complex type %s\n", type);
		return 0;
	      }
	}
    }

  default:
    {
      _objc_abort ("unknown type %s\n", type);
      return 0;
    }
  }
}

int
objc_aligned_size (const char *type)
{
  int size, align;

  type = objc_skip_variable_name (type);
  size = objc_sizeof_type (type);
  align = objc_alignof_type (type);

  return ROUND (size, align);
}

int
objc_promoted_size (const char *type)
{
  int size, wordsize;

  type = objc_skip_variable_name (type);
  size = objc_sizeof_type (type);
  wordsize = sizeof (void *);

  return ROUND (size, wordsize);
}

inline
const char *
objc_skip_type_qualifiers (const char *type)
{
  while (*type == _C_CONST
	 || *type == _C_IN
	 || *type == _C_INOUT
	 || *type == _C_OUT
	 || *type == _C_BYCOPY
         || *type == _C_BYREF
	 || *type == _C_ONEWAY
	 || *type == _C_GCINVISIBLE)
    {
      type += 1;
    }
  return type;
}

inline
const char *
objc_skip_typespec (const char *type)
{
  type = objc_skip_variable_name (type);
  type = objc_skip_type_qualifiers (type);

  switch (*type) {

  case _C_ID:
    /* An id may be annotated by the actual type if it is known
       with the @"ClassName" syntax */

    if (*++type != '"')
      return type;
    else
      {
	while (*++type != '"')
	  /* do nothing */;
	return type + 1;
      }

    /* The following are one character type codes */
  case _C_CLASS:
  case _C_SEL:
  case _C_CHR:
  case _C_UCHR:
  case _C_CHARPTR:
  case _C_ATOM:
  case _C_SHT:
  case _C_USHT:
  case _C_INT:
  case _C_UINT:
  case _C_LNG:
  case _C_BOOL:
  case _C_ULNG:
  case _C_LNG_LNG:
  case _C_ULNG_LNG:
  case _C_FLT:
  case _C_DBL:
  case _C_LNG_DBL:
  case _C_VOID:
  case _C_UNDEF:
    return ++type;
    break;
    
  case _C_COMPLEX:
    return type + 2;
    break;

  case _C_ARY_B:
    /* skip digits, typespec and closing ']' */
    while (isdigit ((unsigned char)*++type))
      ;
    type = objc_skip_typespec (type);
    if (*type == _C_ARY_E)
      return ++type;
    else
      {
	_objc_abort ("bad array type %s\n", type);
	return 0;
      }

  case _C_VECTOR:
    /* Skip '!' */
    type++;
    /* Skip '[' */
    type++;
    /* Skip digits (size) */
    while (isdigit ((unsigned char)*type))
      type++;
    /* Skip ',' */
    type++;
    /* Skip digits (alignment) */
    while (isdigit ((unsigned char)*type))
      type++;
    /* Skip typespec.  */
    type = objc_skip_typespec (type);
    /* Skip closing ']'.  */
    if (*type == _C_ARY_E)
      return ++type;
    else
      {
	_objc_abort ("bad vector type %s\n", type);
	return 0;
      }

  case _C_BFLD:
    /* The GNU encoding of bitfields is: b 'position' 'type'
       'size'.  */
    while (isdigit ((unsigned char)*++type))
      ;	/* skip position */
    while (isdigit ((unsigned char)*++type))
      ;	/* skip type and size */
    return type;

  case _C_STRUCT_B:
    /* skip name, and elements until closing '}'  */

    while (*type != _C_STRUCT_E && *type++ != '=')
      ;
    while (*type != _C_STRUCT_E)
      {
	type = objc_skip_typespec (type);
      }
    return ++type;

  case _C_UNION_B:
    /* skip name, and elements until closing ')'  */

    while (*type != _C_UNION_E && *type++ != '=')
      ;
    while (*type != _C_UNION_E)
      {
	type = objc_skip_typespec (type);
      }
    return ++type;

  case _C_PTR:
    /* Just skip the following typespec */

    return objc_skip_typespec (++type);

  default:
    {
      _objc_abort ("unknown type %s\n", type);
      return 0;
    }
  }
}

inline
const char *
objc_skip_offset (const char *type)
{
  /* The offset is prepended by a '+' if the argument is passed in
     registers.  PS: The compiler stopped generating this '+' in
     version 3.4.  */
  if (*type == '+')
    type++;

  /* Some people claim that on some platforms, where the stack grows
     backwards, the compiler generates negative offsets (??).  Skip a
     '-' for such a negative offset.  */
  if (*type == '-')
    type++;

  /* Skip the digits that represent the offset.  */
  while (isdigit ((unsigned char) *type))
    type++;

  return type;
}

const char *
objc_skip_argspec (const char *type)
{
  type = objc_skip_typespec (type);
  type = objc_skip_offset (type);
  return type;
}

char *
method_copyReturnType (struct objc_method *method)
{
  if (method == NULL)
    return 0;
  else
    {
      char *returnValue;
      size_t returnValueSize;

      /* Determine returnValueSize.  */
      {
	/* Find the end of the first argument.  We want to return the
	   first argument spec, plus 1 byte for the \0 at the end.  */
	const char *type = method->method_types;
	if (*type == '\0')
	  return NULL;
	type = objc_skip_argspec (type);
	returnValueSize = type - method->method_types + 1;
      }

      /* Copy the first argument into returnValue.  */
      returnValue = malloc (sizeof (char) * returnValueSize);
      memcpy (returnValue, method->method_types, returnValueSize);
      returnValue[returnValueSize - 1] = '\0';

      return returnValue;
    }
}

char *
method_copyArgumentType (struct objc_method * method, unsigned int argumentNumber)
{
  if (method == NULL)
    return 0;
  else
    {
      char *returnValue;
      const char *returnValueStart;
      size_t returnValueSize;

      /* Determine returnValueStart and returnValueSize.  */
      {
	const char *type = method->method_types;

	/* Skip the first argument (return type).  */
	type = objc_skip_argspec (type);

	/* Now keep skipping arguments until we get to
	   argumentNumber.  */
	while (argumentNumber > 0)
	  {
	    /* We are supposed to skip an argument, but the string is
	       finished.  This means we were asked for a non-existing
	       argument.  */
	    if (*type == '\0')
	      return NULL;

	    type = objc_skip_argspec (type);
	    argumentNumber--;
	  }

	/* If the argument does not exist, return NULL.  */
	if (*type == '\0')
	  return NULL;

	returnValueStart = type;
	type = objc_skip_argspec (type);
	returnValueSize = type - returnValueStart + 1;
      }
      
      /* Copy the argument into returnValue.  */
      returnValue = malloc (sizeof (char) * returnValueSize);
      memcpy (returnValue, returnValueStart, returnValueSize);
      returnValue[returnValueSize - 1] = '\0';

      return returnValue;
    }
}

void method_getReturnType (struct objc_method * method, char *returnValue, 
			   size_t returnValueSize)
{
  if (returnValue == NULL  ||  returnValueSize == 0)
    return;

  /* Zero the string; we'll then write the argument type at the
     beginning of it, if needed.  */
  memset (returnValue, 0, returnValueSize);

  if (method == NULL)
    return;
  else
    {
      size_t argumentTypeSize;

      /* Determine argumentTypeSize.  */
      {
	/* Find the end of the first argument.  We want to return the
	   first argument spec.  */
	const char *type = method->method_types;
	if (*type == '\0')
	  return;
	type = objc_skip_argspec (type);
	argumentTypeSize = type - method->method_types;
	if (argumentTypeSize > returnValueSize)
	  argumentTypeSize = returnValueSize;
      }
      /* Copy the argument at the beginning of the string.  */
      memcpy (returnValue, method->method_types, argumentTypeSize);
    }
}

void method_getArgumentType (struct objc_method * method, unsigned int argumentNumber,
			     char *returnValue, size_t returnValueSize)
{
  if (returnValue == NULL  ||  returnValueSize == 0)
    return;

  /* Zero the string; we'll then write the argument type at the
     beginning of it, if needed.  */
  memset (returnValue, 0, returnValueSize);

  if (method == NULL)
    return;
  else
    {
      const char *returnValueStart;
      size_t argumentTypeSize;

      /* Determine returnValueStart and argumentTypeSize.  */
      {
	const char *type = method->method_types;

	/* Skip the first argument (return type).  */
	type = objc_skip_argspec (type);

	/* Now keep skipping arguments until we get to
	   argumentNumber.  */
	while (argumentNumber > 0)
	  {
	    /* We are supposed to skip an argument, but the string is
	       finished.  This means we were asked for a non-existing
	       argument.  */
	    if (*type == '\0')
	      return;

	    type = objc_skip_argspec (type);
	    argumentNumber--;
	  }

	/* If the argument does not exist, it's game over.  */
	if (*type == '\0')
	  return;

	returnValueStart = type;
	type = objc_skip_argspec (type);
	argumentTypeSize = type - returnValueStart;
	if (argumentTypeSize > returnValueSize)
	  argumentTypeSize = returnValueSize;
      }
      /* Copy the argument at the beginning of the string.  */
      memcpy (returnValue, returnValueStart, argumentTypeSize);
    }
}

unsigned int
method_getNumberOfArguments (struct objc_method *method)
{
  if (method == NULL)
    return 0;
  else
    {
      unsigned int i = 0;
      const char *type = method->method_types;
      while (*type)
	{
	  type = objc_skip_argspec (type);
	  i += 1;
	}

      if (i == 0)
	{
	  /* This could only happen if method_types is invalid; in
	     that case, return 0.  */
	  return 0;
	}
      else
	{
	  /* Remove the return type.  */
	  return (i - 1);
	}
    }
}

unsigned
objc_get_type_qualifiers (const char *type)
{
  unsigned res = 0;
  BOOL flag = YES;

  while (flag)
    switch (*type++)
      {
      case _C_CONST:       res |= _F_CONST; break;
      case _C_IN:          res |= _F_IN; break;
      case _C_INOUT:       res |= _F_INOUT; break;
      case _C_OUT:         res |= _F_OUT; break;
      case _C_BYCOPY:      res |= _F_BYCOPY; break;
      case _C_BYREF:       res |= _F_BYREF; break;
      case _C_ONEWAY:      res |= _F_ONEWAY; break;
      case _C_GCINVISIBLE: res |= _F_GCINVISIBLE; break;
      default: flag = NO;
    }

  return res;
}

/* The following three functions can be used to determine how a
   structure is laid out by the compiler. For example:

  struct objc_struct_layout layout;
  int i;

  objc_layout_structure (type, &layout);
  while (objc_layout_structure_next_member (&layout))
    {
      int position, align;
      const char *type;

      objc_layout_structure_get_info (&layout, &position, &align, &type);
      printf ("element %d has offset %d, alignment %d\n",
              i++, position, align);
    }

  These functions are used by objc_sizeof_type and objc_alignof_type
  functions to compute the size and alignment of structures. The
  previous method of computing the size and alignment of a structure
  was not working on some architectures, particulary on AIX, and in
  the presence of bitfields inside the structure.  */
void
objc_layout_structure (const char *type,
		       struct objc_struct_layout *layout)
{
  const char *ntype;

  if (*type != _C_UNION_B && *type != _C_STRUCT_B)
    {
      _objc_abort ("record (or union) type expected in objc_layout_structure, got %s\n",
		   type);
    }

  type ++;
  layout->original_type = type;

  /* Skip "<name>=" if any. Avoid embedded structures and unions. */
  ntype = type;
  while (*ntype != _C_STRUCT_E && *ntype != _C_STRUCT_B && *ntype != _C_UNION_B
         && *ntype++ != '=')
    /* do nothing */;

  /* If there's a "<name>=", ntype - 1 points to '='; skip the the name */
  if (*(ntype - 1) == '=')
    type = ntype;

  layout->type = type;
  layout->prev_type = NULL;
  layout->record_size = 0;
  layout->record_align = BITS_PER_UNIT;

  layout->record_align = MAX (layout->record_align, STRUCTURE_SIZE_BOUNDARY);
}

BOOL
objc_layout_structure_next_member (struct objc_struct_layout *layout)
{
  register int desired_align = 0;

  /* The following are used only if the field is a bitfield */
  register const char *bfld_type = 0;
  register int bfld_type_align = 0, bfld_field_size = 0;

  /* The current type without the type qualifiers */
  const char *type;
  BOOL unionp = layout->original_type[-1] == _C_UNION_B;

  /* Add the size of the previous field to the size of the record.  */
  if (layout->prev_type)
    {
      type = objc_skip_type_qualifiers (layout->prev_type);
      if (unionp)
        layout->record_size = MAX (layout->record_size,
				   objc_sizeof_type (type) * BITS_PER_UNIT);

      else if (*type != _C_BFLD)
        layout->record_size += objc_sizeof_type (type) * BITS_PER_UNIT;
      else {
        /* Get the bitfield's type */
        for (bfld_type = type + 1;
             isdigit ((unsigned char)*bfld_type);
             bfld_type++)
          /* do nothing */;

        bfld_type_align = objc_alignof_type (bfld_type) * BITS_PER_UNIT;
        bfld_field_size = atoi (objc_skip_typespec (bfld_type));
        layout->record_size += bfld_field_size;
      }
    }

  if ((unionp && *layout->type == _C_UNION_E)
      || (!unionp && *layout->type == _C_STRUCT_E))
    return NO;

  /* Skip the variable name if any */
  layout->type = objc_skip_variable_name (layout->type);
  type = objc_skip_type_qualifiers (layout->type);

  if (*type != _C_BFLD)
    desired_align = objc_alignof_type (type) * BITS_PER_UNIT;
  else
    {
      desired_align = 1;
      /* Skip the bitfield's offset */
      for (bfld_type = type + 1;
           isdigit ((unsigned char) *bfld_type);
           bfld_type++)
        /* do nothing */;

      bfld_type_align = objc_alignof_type (bfld_type) * BITS_PER_UNIT;
      bfld_field_size = atoi (objc_skip_typespec (bfld_type));
    }

  /* The following won't work for vectors.  */
#ifdef BIGGEST_FIELD_ALIGNMENT
  desired_align = MIN (desired_align, BIGGEST_FIELD_ALIGNMENT);
#endif
#ifdef ADJUST_FIELD_ALIGN
  desired_align = ADJUST_FIELD_ALIGN (type, desired_align);
#endif

  /* Record must have at least as much alignment as any field.
     Otherwise, the alignment of the field within the record
     is meaningless.  */
#ifndef PCC_BITFIELD_TYPE_MATTERS
  layout->record_align = MAX (layout->record_align, desired_align);
#else	/* PCC_BITFIELD_TYPE_MATTERS */
  if (*type == _C_BFLD)
    {
      /* For these machines, a zero-length field does not
         affect the alignment of the structure as a whole.
         It does, however, affect the alignment of the next field
         within the structure.  */
      if (bfld_field_size)
        layout->record_align = MAX (layout->record_align, desired_align);
      else
        desired_align = objc_alignof_type (bfld_type) * BITS_PER_UNIT;

      /* A named bit field of declared type `int'
         forces the entire structure to have `int' alignment.
         Q1: How is encoded this thing and how to check for it?
         Q2: How to determine maximum_field_alignment at runtime? */

/*	  if (DECL_NAME (field) != 0) */
      {
        int type_align = bfld_type_align;
#if 0
        if (maximum_field_alignment != 0)
          type_align = MIN (type_align, maximum_field_alignment);
        else if (DECL_PACKED (field))
          type_align = MIN (type_align, BITS_PER_UNIT);
#endif

        layout->record_align = MAX (layout->record_align, type_align);
      }
    }
  else
    layout->record_align = MAX (layout->record_align, desired_align);
#endif	/* PCC_BITFIELD_TYPE_MATTERS */

  /* Does this field automatically have alignment it needs
     by virtue of the fields that precede it and the record's
     own alignment?  */

  if (*type == _C_BFLD)
    layout->record_size = atoi (type + 1);
  else if (layout->record_size % desired_align != 0)
    {
      /* No, we need to skip space before this field.
         Bump the cumulative size to multiple of field alignment.  */
      layout->record_size = ROUND (layout->record_size, desired_align);
    }

  /* Jump to the next field in record. */

  layout->prev_type = layout->type;
  layout->type = objc_skip_typespec (layout->type);      /* skip component */

  return YES;
}

void objc_layout_finish_structure (struct objc_struct_layout *layout,
                                   unsigned int *size,
                                   unsigned int *align)
{
  BOOL unionp = layout->original_type[-1] == _C_UNION_B;
  if (layout->type
      && ((!unionp && *layout->type == _C_STRUCT_E)
       	  || (unionp && *layout->type == _C_UNION_E)))
    {
      /* Work out the alignment of the record as one expression and store
         in the record type.  Round it up to a multiple of the record's
         alignment. */
#if defined (ROUND_TYPE_ALIGN) && ! defined (__sparc__)
      layout->record_align = ROUND_TYPE_ALIGN (layout->original_type-1,
                                               1,
                                               layout->record_align);
#else
      layout->record_align = MAX (1, layout->record_align);
#endif

#ifdef ROUND_TYPE_SIZE
      layout->record_size = ROUND_TYPE_SIZE (layout->original_type,
                                             layout->record_size,
                                             layout->record_align);
#else
      /* Round the size up to be a multiple of the required alignment */
      layout->record_size = ROUND (layout->record_size, layout->record_align);
#endif

      layout->type = NULL;
    }
  if (size)
    *size = layout->record_size / BITS_PER_UNIT;
  if (align)
    *align = layout->record_align / BITS_PER_UNIT;
}

void objc_layout_structure_get_info (struct objc_struct_layout *layout,
                                     unsigned int *offset,
                                     unsigned int *align,
                                     const char **type)
{
  if (offset)
    *offset = layout->record_size / BITS_PER_UNIT;
  if (align)
    *align = layout->record_align / BITS_PER_UNIT;
  if (type)
    *type = layout->prev_type;
}
OpenPOWER on IntegriCloud