summaryrefslogtreecommitdiff
path: root/gcc/objc/objc-gnu-runtime-abi-01.c
blob: 5cd39ef9307cc0d552f87bc26ca244a2aae98567 (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
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
/* GNU Runtime ABI version 8
   Copyright (C) 2011 Free Software Foundation, Inc.
   Contributed by Iain Sandoe (split from objc-act.c)

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/>.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tree.h"

#ifdef OBJCPLUS
#include "cp/cp-tree.h"
#else
#include "c/c-tree.h"
#include "c/c-lang.h"
#endif

#include "langhooks.h"
#include "c-family/c-objc.h"
#include "objc-act.h"

/* When building Objective-C++, we are not linking against the C front-end
   and so need to replicate the C tree-construction functions in some way.  */
#ifdef OBJCPLUS
#define OBJCP_REMAP_FUNCTIONS
#include "objcp-decl.h"
#endif  /* OBJCPLUS */

#include "toplev.h"
#include "ggc.h"
#include "tree-iterator.h"

#include "objc-runtime-hooks.h"
#include "objc-runtime-shared-support.h"
#include "objc-encoding.h"

/* GNU runtime private definitions.  */
#define DEF_CONSTANT_STRING_CLASS_NAME "NXConstantString"

#define TAG_GETCLASS		"objc_get_class"
#define TAG_GETMETACLASS	"objc_get_meta_class"

#define TAG_MSGSEND		"objc_msg_lookup"
#define TAG_MSGSENDSUPER	"objc_msg_lookup_super"

/* GNU-specific tags.  */

#define TAG_EXECCLASS		"__objc_exec_class"
#define TAG_GNUINIT		"__objc_gnu_init"

/* The version identifies which language generation and runtime
   the module (file) was compiled for, and is recorded in the
   module descriptor.  */
#define OBJC_VERSION		8

#define PROTOCOL_VERSION	2

/* This macro provides a method of removing ambiguity between runtimes
   when LTO is in use on targets supporting multiple runtimes.

   For example, at present, any target that includes an implementation of
   the NeXT runtime needs to place Objective-C meta-data into specific
   named sections.  This should _not_ be done for the GNU runtime, and the
   folowing macro is used to attach Objective-C private attributes that may
   be used to identify the runtime for which the meta-data are intended.  */

#define OBJCMETA(DECL,VERS,KIND)					\
  if (VERS)								\
    DECL_ATTRIBUTES (DECL) = build_tree_list ((VERS), (KIND));

static void gnu_runtime_01_initialize (void);

static void build_selector_template (void);

static tree gnu_runtime_abi_01_super_superclassfield_id (void);

static tree gnu_runtime_abi_01_class_decl (tree);
static tree gnu_runtime_abi_01_metaclass_decl (tree);
static tree gnu_runtime_abi_01_category_decl (tree);
static tree gnu_runtime_abi_01_protocol_decl (tree);
static tree gnu_runtime_abi_01_string_decl (tree, const char *, string_section);

static tree gnu_runtime_abi_01_get_class_reference (tree);
static tree gnu_runtime_abi_01_build_typed_selector_reference (location_t, tree,
								tree);
static tree gnu_runtime_abi_01_get_protocol_reference (location_t, tree);
static tree gnu_runtime_abi_01_build_ivar_ref (location_t, tree, tree);
static tree gnu_runtime_abi_01_get_class_super_ref (location_t, struct imp_entry *, bool);
static tree gnu_runtime_abi_01_get_category_super_ref (location_t, struct imp_entry *, bool);

static tree gnu_runtime_abi_01_receiver_is_class_object (tree);
static void gnu_runtime_abi_01_get_arg_type_list_base (vec<tree, va_gc> **,
						       tree, int, int);
static tree gnu_runtime_abi_01_build_objc_method_call (location_t, tree, tree,
							tree, tree, tree, int);

static bool gnu_runtime_abi_01_setup_const_string_class_decl (void);
static tree gnu_runtime_abi_01_build_const_string_constructor (location_t, tree,int);

static void objc_generate_v1_gnu_metadata (void);

static tree objc_eh_runtime_type (tree type);
static tree objc_eh_personality (void);
static tree objc_build_exc_ptr (struct objc_try_context **);
static tree build_throw_stmt (location_t, tree, bool);
static tree begin_catch (struct objc_try_context **, tree, tree, tree, bool);
static void finish_catch (struct objc_try_context **, tree);
static tree finish_try_stmt (struct objc_try_context **);

bool
objc_gnu_runtime_abi_01_init (objc_runtime_hooks *rthooks)
{
  /* GNU runtime does not need the compiler to change code in order to do GC. */
  if (flag_objc_gc)
    {
      warning_at (0, 0, "%<-fobjc-gc%> is ignored for %<-fgnu-runtime%>");
      flag_objc_gc = 0;
    }

  /* Although I guess we could, we don't currently support SJLJ exceptions for the
     GNU runtime.  */
  if (flag_objc_sjlj_exceptions)
    {
      inform (UNKNOWN_LOCATION, "%<-fobjc-sjlj-exceptions%> is ignored for %<-fgnu-runtime%>");
      flag_objc_sjlj_exceptions = 0;
    }

  /* TODO: Complain if -fobjc-abi-version=N was used.  */

  /* TODO: Complain if -fobj-nilcheck was used.  */

  rthooks->initialize = gnu_runtime_01_initialize;
  rthooks->default_constant_string_class_name = DEF_CONSTANT_STRING_CLASS_NAME;
  rthooks->tag_getclass = TAG_GETCLASS;
  rthooks->super_superclassfield_ident = gnu_runtime_abi_01_super_superclassfield_id;

  rthooks->class_decl = gnu_runtime_abi_01_class_decl;
  rthooks->metaclass_decl = gnu_runtime_abi_01_metaclass_decl;
  rthooks->category_decl = gnu_runtime_abi_01_category_decl;
  rthooks->protocol_decl = gnu_runtime_abi_01_protocol_decl;
  rthooks->string_decl = gnu_runtime_abi_01_string_decl;

  rthooks->get_class_reference = gnu_runtime_abi_01_get_class_reference;
  rthooks->build_selector_reference = gnu_runtime_abi_01_build_typed_selector_reference;
  rthooks->get_protocol_reference = gnu_runtime_abi_01_get_protocol_reference;
  rthooks->build_ivar_reference = gnu_runtime_abi_01_build_ivar_ref;
  rthooks->get_class_super_ref = gnu_runtime_abi_01_get_class_super_ref;
  rthooks->get_category_super_ref = gnu_runtime_abi_01_get_category_super_ref;

  rthooks->receiver_is_class_object = gnu_runtime_abi_01_receiver_is_class_object;
  rthooks->get_arg_type_list_base = gnu_runtime_abi_01_get_arg_type_list_base;
  rthooks->build_objc_method_call = gnu_runtime_abi_01_build_objc_method_call;

  rthooks->setup_const_string_class_decl =
				gnu_runtime_abi_01_setup_const_string_class_decl;
  rthooks->build_const_string_constructor =
				gnu_runtime_abi_01_build_const_string_constructor;

  rthooks->build_throw_stmt = build_throw_stmt;
  rthooks->build_exc_ptr = objc_build_exc_ptr;
  rthooks->begin_catch = begin_catch;
  rthooks->finish_catch = finish_catch;
  rthooks->finish_try_stmt = finish_try_stmt;

  rthooks->generate_metadata = objc_generate_v1_gnu_metadata;
  return true;
}

static void build_selector_table_decl (void);
static void build_class_template (void);
static void build_category_template (void);
static void build_protocol_template (void);

static GTY(()) tree objc_meta;
static GTY(()) tree meta_base;

static void gnu_runtime_01_initialize (void)
{
  tree type, ftype, IMP_type;

  /* We do not need to mark GNU ObjC metadata for different sections,
     however, we do need to make sure that it is not mistaken for NeXT
     metadata.  */
  objc_meta = get_identifier ("OBJC1METG");
  meta_base = get_identifier ("NONE");

  /* Declare type of selector-objects that represent an operation name.  */
  /* `const struct objc_selector *' */
  type = xref_tag (RECORD_TYPE, get_identifier (TAG_SELECTOR));
  type = build_qualified_type (type, TYPE_QUAL_CONST);
  objc_selector_type = build_pointer_type (type);

  /* typedef id (*IMP)(id, SEL, ...); */
  ftype = build_varargs_function_type_list (objc_object_type,
					    objc_object_type,
					    objc_selector_type,
					    NULL_TREE);

  IMP_type = build_pointer_type (ftype);

  build_class_template ();
  build_super_template ();
  build_protocol_template ();
  build_category_template ();

  /* GNU runtime messenger entry points.  */
  /* TREE_NOTHROW is cleared for the message-sending functions,
     because the function that gets called can throw in Obj-C++, or
     could itself call something that can throw even in Obj-C.  */

  /* IMP objc_msg_lookup (id, SEL); */
  type = build_function_type_list (IMP_type,
				   objc_object_type,
				   objc_selector_type,
				   NULL_TREE);

  umsg_decl = add_builtin_function (TAG_MSGSEND,
				    type, 0, NOT_BUILT_IN,
				    NULL, NULL_TREE);
  TREE_NOTHROW (umsg_decl) = 0;

  /* IMP objc_msg_lookup_super (struct objc_super *, SEL); */
  type = build_function_type_list (IMP_type,
				   objc_super_type,
				   objc_selector_type,
				   NULL_TREE);

  umsg_super_decl = add_builtin_function (TAG_MSGSENDSUPER,
					  type, 0, NOT_BUILT_IN,
					  NULL, NULL_TREE);
  TREE_NOTHROW (umsg_super_decl) = 0;

  /* The following GNU runtime entry point is called to initialize
	 each module:

	 __objc_exec_class (void *); */
  type = build_function_type_list (void_type_node,
				   ptr_type_node,
				   NULL_TREE);

  execclass_decl = add_builtin_function (TAG_EXECCLASS,
					 type, 0, NOT_BUILT_IN,
					 NULL, NULL_TREE);

  type = build_function_type_list (objc_object_type,
				   const_string_type_node,
				   NULL_TREE);

  /* id objc_getClass (const char *); */
  objc_get_class_decl
    = add_builtin_function (TAG_GETCLASS, type, 0, NOT_BUILT_IN,
			    NULL, NULL_TREE);

  /* id objc_getMetaClass (const char *); */
  objc_get_meta_class_decl = add_builtin_function (TAG_GETMETACLASS, type,
						   0, NOT_BUILT_IN, NULL,
						   NULL_TREE);

  /* static SEL _OBJC_SELECTOR_TABLE[]; */
  build_selector_table_decl ();

  /* Stuff for properties.
     The codegen relies on this being NULL for GNU.  */
  objc_copyStruct_decl = NULL_TREE;

  /* This is the type of all of the following functions
     bjc_getPropertyStruct() and objc_setPropertyStruct().  */
  type = build_function_type_list (void_type_node,
				   ptr_type_node,
				   const_ptr_type_node,
				   ptrdiff_type_node,
				   boolean_type_node,
				   boolean_type_node,
				   NULL_TREE);

  /* Declare the following function:
	 void
	 objc_getPropertyStruct (void *destination, const void *source,
                                 ptrdiff_t size, BOOL is_atomic, BOOL has_strong);  */
  objc_getPropertyStruct_decl = add_builtin_function ("objc_getPropertyStruct",
							  type, 0, NOT_BUILT_IN,
							  NULL, NULL_TREE);
  TREE_NOTHROW (objc_getPropertyStruct_decl) = 0;
  /* Declare the following function:
	 void
	 objc_setPropertyStruct (void *destination, const void *source,
	                         ptrdiff_t size, BOOL is_atomic, BOOL has_strong);  */
  objc_setPropertyStruct_decl = add_builtin_function ("objc_setPropertyStruct",
							  type, 0, NOT_BUILT_IN,
							  NULL, NULL_TREE);
  TREE_NOTHROW (objc_setPropertyStruct_decl) = 0;

  using_eh_for_cleanups ();
  lang_hooks.eh_runtime_type = objc_eh_runtime_type;
  lang_hooks.eh_personality = objc_eh_personality;
}

/* --- templates --- */
/* struct _objc_selector {
     SEL sel_id;
     char *sel_type;
   }; */

static void
build_selector_template (void)
{
  tree decls, *chain = NULL;

  objc_selector_template = objc_start_struct (get_identifier (UTAG_SELECTOR));

  /* SEL sel_id; */
  decls = add_field_decl (objc_selector_type, "sel_id", &chain);

  /* char *sel_type; */
  add_field_decl (string_type_node, "sel_type", &chain);

  objc_finish_struct (objc_selector_template, decls);
}

/* struct _objc_class {
     struct _objc_class *isa;
     struct _objc_class *super_class;
     char *name;
     long version;
     long info;
     long instance_size;
     struct _objc_ivar_list *ivars;
     struct _objc_method_list *methods;
     struct sarray *dtable;
     struct _objc_class *subclass_list;
     struct _objc_class *sibling_class;
     struct _objc_protocol_list *protocols;
     void *gc_object_type;
   };  */

static void
build_class_template (void)
{
  tree ptype, decls, *chain = NULL;

  objc_class_template = objc_start_struct (get_identifier (UTAG_CLASS));

  /* struct _objc_class *isa; */
  decls = add_field_decl (build_pointer_type (objc_class_template),
			  "isa", &chain);

  /* struct _objc_class *super_class; */
  add_field_decl (build_pointer_type (objc_class_template),
		  "super_class", &chain);

  /* char *name; */
  add_field_decl (string_type_node, "name", &chain);

  /* long version; */
  add_field_decl (long_integer_type_node, "version", &chain);

  /* long info; */
  add_field_decl (long_integer_type_node, "info", &chain);

  /* long instance_size; */
  add_field_decl (long_integer_type_node, "instance_size", &chain);

  /* struct _objc_ivar_list *ivars; */
  add_field_decl (objc_ivar_list_ptr,"ivars", &chain);

  /* struct _objc_method_list *methods; */
  add_field_decl (objc_method_list_ptr, "methods", &chain);

  /* struct sarray *dtable; */
  ptype = build_pointer_type(xref_tag (RECORD_TYPE,
					   get_identifier ("sarray")));
  add_field_decl (ptype, "dtable", &chain);

  /* struct objc_class *subclass_list; */
  ptype = build_pointer_type (objc_class_template);
  add_field_decl (ptype, "subclass_list", &chain);

  /* struct objc_class *sibling_class; */
  ptype = build_pointer_type (objc_class_template);
  add_field_decl (ptype, "sibling_class", &chain);

  /* struct _objc_protocol **protocol_list; */
  ptype = build_pointer_type (build_pointer_type
			      (xref_tag (RECORD_TYPE,
					 get_identifier (UTAG_PROTOCOL))));
  add_field_decl (ptype, "protocol_list", &chain);

  /* void *gc_object_type; */
  add_field_decl (build_pointer_type (void_type_node),
		    "gc_object_type", &chain);

  objc_finish_struct (objc_class_template, decls);
}

/* struct _objc_category {
     char *category_name;
     char *class_name;
     struct _objc_method_list *instance_methods;
     struct _objc_method_list *class_methods;
     struct _objc_protocol_list *protocols;
   };   */

static void
build_category_template (void)
{
  tree ptype, decls, *chain = NULL;

  objc_category_template = objc_start_struct (get_identifier (UTAG_CATEGORY));

  /* char *category_name; */
  decls = add_field_decl (string_type_node, "category_name", &chain);

  /* char *class_name; */
  add_field_decl (string_type_node, "class_name", &chain);

  /* struct _objc_method_list *instance_methods; */
  add_field_decl (objc_method_list_ptr, "instance_methods", &chain);

  /* struct _objc_method_list *class_methods; */
  add_field_decl (objc_method_list_ptr, "class_methods", &chain);

  /* struct _objc_protocol **protocol_list; */
  ptype = build_pointer_type (build_pointer_type (objc_protocol_template));
  add_field_decl (ptype, "protocol_list", &chain);

  objc_finish_struct (objc_category_template, decls);
}

/* struct _objc_protocol {
     struct _objc_class *isa;
     char *protocol_name;
     struct _objc_protocol **protocol_list;
     struct _objc__method_prototype_list *instance_methods;
     struct _objc__method_prototype_list *class_methods;
   };  */

static void
build_protocol_template (void)
{
  tree ptype, decls, *chain = NULL;

  objc_protocol_template = objc_start_struct (get_identifier (UTAG_PROTOCOL));

  /* struct _objc_class *isa; */
  ptype = build_pointer_type (xref_tag (RECORD_TYPE,
					get_identifier (UTAG_CLASS)));
  decls = add_field_decl (ptype, "isa", &chain);

  /* char *protocol_name; */
  add_field_decl (string_type_node, "protocol_name", &chain);

  /* struct _objc_protocol **protocol_list; */
  ptype = build_pointer_type (build_pointer_type (objc_protocol_template));
  add_field_decl (ptype, "protocol_list", &chain);

  /* struct _objc__method_prototype_list *instance_methods; */
  add_field_decl (objc_method_proto_list_ptr, "instance_methods", &chain);

  /* struct _objc__method_prototype_list *class_methods; */
  add_field_decl (objc_method_proto_list_ptr, "class_methods", &chain);

  objc_finish_struct (objc_protocol_template, decls);
}

/* --- names, decls + identifers --- */

static void
build_selector_table_decl (void)
{
  tree temp;

  build_selector_template ();
  temp = build_array_type (objc_selector_template, NULL_TREE);

  UOBJC_SELECTOR_TABLE_decl = start_var_decl (temp, "_OBJC_SELECTOR_TABLE");
  OBJCMETA (UOBJC_SELECTOR_TABLE_decl, objc_meta, meta_base);
}


static tree
gnu_runtime_abi_01_super_superclassfield_id (void)
{
  if (!super_superclassfield_id)
    super_superclassfield_id = get_identifier ("super_class");
  return super_superclassfield_id;
}


static tree
gnu_runtime_abi_01_class_decl (tree klass)
{
  tree decl;
  char buf[BUFSIZE];
  snprintf (buf, BUFSIZE, "_OBJC_Class_%s",
	    IDENTIFIER_POINTER (CLASS_NAME (klass)));
  decl = start_var_decl (objc_class_template, buf);
  OBJCMETA (decl, objc_meta, meta_base);
  return decl;
}

static tree
gnu_runtime_abi_01_metaclass_decl (tree klass)
{
  tree decl;
  char buf[BUFSIZE];
  snprintf (buf, BUFSIZE, "_OBJC_MetaClass_%s",
	    IDENTIFIER_POINTER (CLASS_NAME (klass)));
  decl = start_var_decl (objc_class_template, buf);
  OBJCMETA (decl, objc_meta, meta_base);
  return decl;
}

static tree
gnu_runtime_abi_01_category_decl (tree klass)
{
  tree decl;
  char buf[BUFSIZE];
  snprintf (buf, BUFSIZE, "_OBJC_Category_%s_on_%s",
	    IDENTIFIER_POINTER (CLASS_SUPER_NAME (klass)),
	    IDENTIFIER_POINTER (CLASS_NAME (klass)));
  decl = start_var_decl (objc_category_template, buf);
  OBJCMETA (decl, objc_meta, meta_base);
  return decl;
}

static tree
gnu_runtime_abi_01_protocol_decl (tree p)
{
  tree decl;
  char buf[BUFSIZE];

  /* static struct _objc_protocol _OBJC_Protocol_<mumble>; */
  snprintf (buf, BUFSIZE, "_OBJC_Protocol_%s",
	    IDENTIFIER_POINTER (PROTOCOL_NAME (p)));
  decl = start_var_decl (objc_protocol_template, buf);
  OBJCMETA (decl, objc_meta, meta_base);
  return decl;
}

static tree
gnu_runtime_abi_01_string_decl (tree type, const char *name,
				string_section where ATTRIBUTE_UNUSED)
{
  tree decl = start_var_decl (type, name);
  OBJCMETA (decl, objc_meta, meta_base);
  return decl;
}

/* --- entry --- */

static tree
gnu_runtime_abi_01_get_class_reference (tree ident)
{
  tree params;

  add_class_reference (ident);

  params = build_tree_list (NULL_TREE, my_build_string_pointer
						(IDENTIFIER_LENGTH (ident) + 1,
						 IDENTIFIER_POINTER (ident)));

  return build_function_call (input_location, objc_get_class_decl, params);
}

/* Used by build_function_type_for_method.  Append the types for
   receiver & _cmd at the start of a method argument list to ARGTYPES.
   CONTEXT is either METHOD_DEF or METHOD_REF, saying whether we are
   trying to define a method or call one.  SUPERFLAG says this is for a
   send to super.  METH may be NULL, in the case that there is no
   prototype.  */

static void
gnu_runtime_abi_01_get_arg_type_list_base (vec<tree, va_gc> **argtypes,
					   tree meth, int context,
					   int superflag ATTRIBUTE_UNUSED)
{
  tree receiver_type;

  if (context == METHOD_DEF && TREE_CODE (meth) == INSTANCE_METHOD_DECL)
    receiver_type = objc_instance_type;
  else
    receiver_type = objc_object_type;

  vec_safe_push (*argtypes, receiver_type);
  /* Selector type - will eventually change to `int'.  */
  vec_safe_push (*argtypes, objc_selector_type);
}

/* Unused for GNU runtime.  */
static tree
gnu_runtime_abi_01_receiver_is_class_object (tree a ATTRIBUTE_UNUSED)
{
  return NULL_TREE;
}

/* sel_ref_chain is a list whose "value" fields will be instances of
   identifier_node that represent the selector.  LOC is the location of
   the @selector.  */

static tree
gnu_runtime_abi_01_build_typed_selector_reference (location_t loc, tree ident,
						   tree prototype)
{
  tree *chain = &sel_ref_chain;
  tree expr;
  int index = 0;

  while (*chain)
    {
      /* When we do a lookup for @selector () we have no idea of the
         prototype - so match the first we find.  */
      if (TREE_VALUE (*chain) == ident
          && (!prototype || TREE_PURPOSE (*chain) == prototype))
	goto return_at_index;

      index++;
      chain = &TREE_CHAIN (*chain);
    }

  *chain = tree_cons (prototype, ident, NULL_TREE);

  /* TODO: Use a vec and keep this in it to (a) avoid re-creating and
     (b) provide better diagnostics for the first time an undefined
     selector is used.  */
 return_at_index:
  expr = build_unary_op (loc, ADDR_EXPR,
			 build_array_ref (loc, UOBJC_SELECTOR_TABLE_decl,
					  build_int_cst (NULL_TREE, index)),
			 1);
  return convert (objc_selector_type, expr);
}

/* Build a tree expression to send OBJECT the operation SELECTOR,
   looking up the method on object LOOKUP_OBJECT (often same as OBJECT),
   assuming the method has prototype METHOD_PROTOTYPE.
   (That is an INSTANCE_METHOD_DECL or CLASS_METHOD_DECL.)
   LOC is the location of the expression to build.
   Use METHOD_PARAMS as list of args to pass to the method.
   If SUPER_FLAG is nonzero, we look up the superclass's method.  */

static tree
build_objc_method_call (location_t loc, int super_flag, tree method_prototype,
			tree lookup_object, tree selector,
			tree method_params)
{
  tree sender = (super_flag ? umsg_super_decl
			    : (flag_objc_direct_dispatch ? umsg_fast_decl
							 : umsg_decl));
  tree rcv_p = (super_flag ? objc_super_type : objc_object_type);
  vec<tree, va_gc> *parms;
  vec<tree, va_gc> *tv;
  unsigned nparm = (method_params ? list_length (method_params) : 0);

  /* If a prototype for the method to be called exists, then cast
     the sender's return type and arguments to match that of the method.
     Otherwise, leave sender as is.  */
  tree ret_type
    = (method_prototype
       ? TREE_VALUE (TREE_TYPE (method_prototype))
       : objc_object_type);
  tree ftype
    = build_function_type_for_method (ret_type, method_prototype,
				      METHOD_REF, super_flag);
  tree sender_cast;
  tree method, t;

  if (method_prototype && METHOD_TYPE_ATTRIBUTES (method_prototype))
    ftype = build_type_attribute_variant (ftype,
					  METHOD_TYPE_ATTRIBUTES
					  (method_prototype));

  sender_cast = build_pointer_type (ftype);

  lookup_object = build_c_cast (loc, rcv_p, lookup_object);

  /* Use SAVE_EXPR to avoid evaluating the receiver twice.  */
  lookup_object = save_expr (lookup_object);

  /* Param list + 2 slots for object and selector.  */
  vec_alloc (parms, nparm + 2);
  vec_alloc (tv, 2);

  /* First, call the lookup function to get a pointer to the method,
     then cast the pointer, then call it with the method arguments.  */
  tv->quick_push (lookup_object);
  tv->quick_push (selector);
  method = build_function_call_vec (loc, sender, tv, NULL);
  vec_free (tv);

  /* Pass the appropriate object to the method.  */
  parms->quick_push ((super_flag ? self_decl : lookup_object));

  /* Pass the selector to the method.  */
  parms->quick_push (selector);
  /* Now append the remainder of the parms.  */
  if (nparm)
    for (; method_params; method_params = TREE_CHAIN (method_params))
      parms->quick_push (TREE_VALUE (method_params));

  /* Build an obj_type_ref, with the correct cast for the method call.  */
  t = build3 (OBJ_TYPE_REF, sender_cast, method, lookup_object, size_zero_node);
  t = build_function_call_vec (loc, t, parms, NULL);
  vec_free (parms);
  return t;
}

static tree
gnu_runtime_abi_01_build_objc_method_call (location_t loc,
					   tree method_prototype,
					   tree receiver,
					   tree rtype ATTRIBUTE_UNUSED,
					   tree sel_name,
					   tree method_params,
					   int super ATTRIBUTE_UNUSED)
{
  tree selector =
	gnu_runtime_abi_01_build_typed_selector_reference (loc,
							  sel_name,
							  method_prototype);

  return build_objc_method_call (loc, super, method_prototype, receiver,
				 selector, method_params);
}

static tree
gnu_runtime_abi_01_get_protocol_reference (location_t loc, tree p)
{
  tree expr, protocol_struct_type, *chain;
  if (!PROTOCOL_FORWARD_DECL (p))
    PROTOCOL_FORWARD_DECL (p) = gnu_runtime_abi_01_protocol_decl (p);

  expr = build_unary_op (loc, ADDR_EXPR, PROTOCOL_FORWARD_DECL (p), 0);

  /* ??? Ideally we'd build the reference with objc_protocol_type directly,
     if we have it, rather than converting it here.  */
  expr = convert (objc_protocol_type, expr);

  /* The @protocol() expression is being compiled into a pointer to a
     statically allocated instance of the Protocol class.  To become
     usable at runtime, the 'isa' pointer of the instance need to be
     fixed up at runtime by the runtime library, to point to the
     actual 'Protocol' class.  */

  /* For the GNU runtime, put the static Protocol instance in the list
     of statically allocated instances, so that we make sure that its
     'isa' pointer is fixed up at runtime by the GNU runtime library
     to point to the Protocol class (at runtime, when loading the
     module, the GNU runtime library loops on the statically allocated
     instances (as found in the defs field in objc_symtab) and fixups
     all the 'isa' pointers of those objects).  */

  /* This type is a struct containing the fields of a Protocol
     object.  (Cfr. objc_protocol_type instead is the type of a pointer
     to such a struct).  */
  protocol_struct_type = xref_tag (RECORD_TYPE,
				   get_identifier (PROTOCOL_OBJECT_CLASS_NAME));

  /* Look for the list of Protocol statically allocated instances
     to fixup at runtime.  Create a new list to hold Protocol
     statically allocated instances, if the list is not found.  At
     present there is only another list, holding NSConstantString
     static instances to be fixed up at runtime.  */

  for (chain = &objc_static_instances;
	*chain && TREE_VALUE (*chain) != protocol_struct_type;
	chain = &TREE_CHAIN (*chain));

  if (!*chain)
    {
       *chain = tree_cons (NULL_TREE, protocol_struct_type, NULL_TREE);
       add_objc_string (OBJC_TYPE_NAME (protocol_struct_type),
                          class_names);
    }

  /* Add this statically allocated instance to the Protocol list.  */
  TREE_PURPOSE (*chain) = tree_cons (NULL_TREE,
				     PROTOCOL_FORWARD_DECL (p),
				     TREE_PURPOSE (*chain));
  return expr;
}

/* For ABI 8 an IVAR is just a fixed offset in the class struct.  */

static tree
gnu_runtime_abi_01_build_ivar_ref (location_t loc ATTRIBUTE_UNUSED,
				   tree base, tree id)
{
  return objc_build_component_ref (base, id);
}

/* We build super class references as we need them (but keep them once
   built for the sake of efficiency).  */

static tree
gnu_runtime_abi_01_get_class_super_ref (location_t loc ATTRIBUTE_UNUSED,
					struct imp_entry *imp, bool inst_meth)
{
  if (inst_meth)
    {
      if (!ucls_super_ref)
	ucls_super_ref =
		objc_build_component_ref (imp->class_decl,
					  get_identifier ("super_class"));
	return ucls_super_ref;
    }
  else
    {
      if (!uucls_super_ref)
	uucls_super_ref =
		objc_build_component_ref (imp->meta_decl,
					  get_identifier ("super_class"));
	return uucls_super_ref;
    }
}

static tree
gnu_runtime_abi_01_get_category_super_ref (location_t loc ATTRIBUTE_UNUSED,
					   struct imp_entry *imp, bool inst_meth)
{
  tree super_name = CLASS_SUPER_NAME (imp->imp_template);
  tree super_class;

  add_class_reference (super_name);
  super_class = (inst_meth ? objc_get_class_decl : objc_get_meta_class_decl);
  super_name = my_build_string_pointer (IDENTIFIER_LENGTH (super_name) + 1,
					IDENTIFIER_POINTER (super_name));
  /* super_class = get_{meta_}class("CLASS_SUPER_NAME");  */
  return build_function_call (input_location,
			      super_class,
			      build_tree_list (NULL_TREE, super_name));
}

static bool
gnu_runtime_abi_01_setup_const_string_class_decl (void)
{
  /* Do nothing, and create no error.  */
  return true;
}

/* Declare a static instance of CLASS_DECL initialized by CONSTRUCTOR.  */

static GTY(()) int num_static_inst;

static tree
objc_add_static_instance (tree constructor, tree class_decl)
{
  tree *chain, decl;
  char buf[BUFSIZE];

  /* Find the list of static instances for the CLASS_DECL.  Create one if
     not found.  */
  for (chain = &objc_static_instances;
       *chain && TREE_VALUE (*chain) != class_decl;
       chain = &TREE_CHAIN (*chain));
  if (!*chain)
    {
      *chain = tree_cons (NULL_TREE, class_decl, NULL_TREE);
      add_objc_string (OBJC_TYPE_NAME (class_decl), class_names);
    }

  snprintf (buf, BUFSIZE, "_OBJC_INSTANCE_%d", num_static_inst++);
  decl = build_decl (input_location,
		     VAR_DECL, get_identifier (buf), class_decl);
  TREE_STATIC (decl) = 1;
  DECL_ARTIFICIAL (decl) = 1;
  TREE_USED (decl) = 1;
  DECL_INITIAL (decl) = constructor;
  DECL_CONTEXT (decl) = NULL;
  OBJCMETA (decl, objc_meta, meta_base);

  /* We may be writing something else just now.
     Postpone till end of input. */
  DECL_DEFER_OUTPUT (decl) = 1;
  pushdecl_top_level (decl);
  rest_of_decl_compilation (decl, 1, 0);

  /* Add the DECL to the head of this CLASS' list.  */
  TREE_PURPOSE (*chain) = tree_cons (NULL_TREE, decl, TREE_PURPOSE (*chain));

  return decl;
}

static tree
gnu_runtime_abi_01_build_const_string_constructor (location_t loc, tree string,
						   int length)
{
  tree constructor, fields;
  vec<constructor_elt, va_gc> *v = NULL;

  /* GNU:    (NXConstantString *) & ((__builtin_ObjCString) { NULL, string, length })  */
  fields = TYPE_FIELDS (internal_const_str_type);
  CONSTRUCTOR_APPEND_ELT (v, fields, build_int_cst (NULL_TREE, 0));

  fields = DECL_CHAIN (fields);
  CONSTRUCTOR_APPEND_ELT (v, fields, build_unary_op (loc,
						     ADDR_EXPR, string, 1));

  fields = DECL_CHAIN (fields);
  CONSTRUCTOR_APPEND_ELT (v, fields, build_int_cst (NULL_TREE, length));
  constructor = objc_build_constructor (internal_const_str_type, v);

  constructor = objc_add_static_instance (constructor, constant_string_type);
  return constructor;
}

/* --- metadata - module initializer --- */

/* The GNU runtime requires us to provide a static initializer function
   for each module:

   static void __objc_gnu_init (void) {
     __objc_exec_class (&L_OBJC_MODULES);
   }  */


static void
build_module_initializer_routine (void)
{
  tree body;

#ifdef OBJCPLUS
  push_lang_context (lang_name_c); /* extern "C" */
#endif

  objc_push_parm (build_decl (input_location,
			      PARM_DECL, NULL_TREE, void_type_node));
#ifdef OBJCPLUS
  objc_start_function (get_identifier (TAG_GNUINIT),
		       build_function_type_list (void_type_node, NULL_TREE),
		       NULL_TREE, NULL_TREE);
#else
  objc_start_function (get_identifier (TAG_GNUINIT),
		       build_function_type_list (void_type_node, NULL_TREE),
		       NULL_TREE, objc_get_parm_info (0, NULL_TREE));
#endif
  body = c_begin_compound_stmt (true);
  add_stmt (build_function_call
	    (input_location,
	     execclass_decl,
	     build_tree_list
	     (NULL_TREE,
	      build_unary_op (input_location, ADDR_EXPR,
			      UOBJC_MODULES_decl, 0))));
  add_stmt (c_end_compound_stmt (input_location, body, true));

  TREE_PUBLIC (current_function_decl) = 0;

#ifndef OBJCPLUS
  /* For Objective-C++, we will need to call __objc_gnu_init
     from objc_generate_static_init_call() below.  */
  DECL_STATIC_CONSTRUCTOR (current_function_decl) = 1;
#endif

  GNU_INIT_decl = current_function_decl;
  finish_function ();

#ifdef OBJCPLUS
    pop_lang_context ();
#endif
}

#ifdef OBJCPLUS
/* Return 1 if the __objc_gnu_init function has been synthesized and needs
   to be called by the module initializer routine.  */

int
objc_static_init_needed_p (void)
{
  return (GNU_INIT_decl != NULL_TREE);
}

/* Generate a call to the __objc_gnu_init initializer function.  */

tree
objc_generate_static_init_call (tree ctors ATTRIBUTE_UNUSED)
{
  add_stmt (build_stmt (input_location, EXPR_STMT,
			build_function_call (input_location,
					     GNU_INIT_decl, NULL_TREE)));

  return ctors;
}
#endif /* OBJCPLUS */

/* --- Output GNU Meta-data --- */

static void
generate_classref_translation_entry (tree chain)
{
  tree expr, decl, type;

  decl = TREE_PURPOSE (chain);
  type = TREE_TYPE (decl);

  expr = add_objc_string (TREE_VALUE (chain), class_names);
  expr = convert (type, expr); /* cast! */

  /* This is a class reference.  It is re-written by the runtime,
     but will be optimized away unless we force it.  */
  DECL_PRESERVE_P (decl) = 1;
  OBJCMETA (decl, objc_meta, meta_base);
  finish_var_decl (decl, expr);
  return;
}


static void
handle_impent (struct imp_entry *impent)
{
  char *string;

/*  objc_implementation_context = impent->imp_context;
  implementation_template = impent->imp_template;*/

  switch (TREE_CODE (impent->imp_context))
    {
    case CLASS_IMPLEMENTATION_TYPE:
      {
	const char *const class_name =
	  IDENTIFIER_POINTER (CLASS_NAME (impent->imp_context));

	string = (char *) alloca (strlen (class_name) + 30);

	sprintf (string, "__objc_class_name_%s", class_name);
	break;
      }
    case CATEGORY_IMPLEMENTATION_TYPE:
      {
	const char *const class_name =
	  IDENTIFIER_POINTER (CLASS_NAME (impent->imp_context));
	const char *const class_super_name =
	  IDENTIFIER_POINTER (CLASS_SUPER_NAME (impent->imp_context));

	string = (char *) alloca (strlen (class_name)
				  + strlen (class_super_name) + 30);

	/* Do the same for categories.  Even though no references to
	   these symbols are generated automatically by the compiler,
	   it gives you a handle to pull them into an archive by
	   hand.  */
	sprintf (string, "*__objc_category_name_%s_%s", class_name, class_super_name);
	break;
      }
    default:
      return;
    }

    {
      tree decl, init;

      init = integer_zero_node;
      decl = build_decl (input_location,
			 VAR_DECL, get_identifier (string), TREE_TYPE (init));
      TREE_PUBLIC (decl) = 1;
      TREE_READONLY (decl) = 1;
      TREE_USED (decl) = 1;
      TREE_CONSTANT (decl) = 1;
      DECL_CONTEXT (decl) = NULL_TREE;
      DECL_ARTIFICIAL (decl) = 1;
      TREE_STATIC (decl) = 1;
      DECL_INITIAL (decl) = error_mark_node; /* A real initializer is coming... */
      /* We must force the reference.  */
      DECL_PRESERVE_P (decl) = 1;

      finish_var_decl(decl, init) ;
    }
}

tree
build_protocol_initializer (tree type, tree protocol_name, tree protocol_list,
			    tree inst_methods, tree class_methods)
{
  tree expr, ttyp;
  location_t loc;
  vec<constructor_elt, va_gc> *inits = NULL;

  /* TODO: pass the loc in or find it from args.  */
  loc = input_location;
  ttyp = build_pointer_type (xref_tag (RECORD_TYPE,
				       get_identifier (UTAG_CLASS)));
  /* Filling the "isa" in with a version allows the runtime system to
     detect this ...   */
  expr = build_int_cst (ttyp, PROTOCOL_VERSION);

  CONSTRUCTOR_APPEND_ELT (inits, NULL_TREE, expr);

  CONSTRUCTOR_APPEND_ELT (inits, NULL_TREE, protocol_name);
  CONSTRUCTOR_APPEND_ELT (inits, NULL_TREE, protocol_list);

  ttyp = objc_method_proto_list_ptr;
  if (inst_methods)
    expr = convert (ttyp, build_unary_op (loc, ADDR_EXPR, inst_methods, 0));
  else
    expr = convert (ttyp, null_pointer_node);
  CONSTRUCTOR_APPEND_ELT (inits, NULL_TREE, expr);

  if (class_methods)
    expr = convert (ttyp, build_unary_op (loc, ADDR_EXPR, class_methods, 0));
  else
    expr = convert (ttyp, null_pointer_node);
  CONSTRUCTOR_APPEND_ELT (inits, NULL_TREE, expr);

  return objc_build_constructor (type, inits);
}

static tree
generate_protocol_list (tree i_or_p, tree klass_ctxt)
{
  tree array_type, ptype, refs_decl, lproto, e, plist;
  vec<constructor_elt, va_gc> *v = NULL;
  char buf[BUFSIZE];
  int size = 0;

  switch (TREE_CODE (i_or_p))
    {
    case CLASS_INTERFACE_TYPE:
    case CATEGORY_INTERFACE_TYPE:
      plist = CLASS_PROTOCOL_LIST (i_or_p);
      break;
    case PROTOCOL_INTERFACE_TYPE:
      plist = PROTOCOL_LIST (i_or_p);
      break;
    default:
      gcc_unreachable ();
    }

  /* Compute size.  */
  for (lproto = plist; lproto; lproto = TREE_CHAIN (lproto))
    if (TREE_CODE (TREE_VALUE (lproto)) == PROTOCOL_INTERFACE_TYPE
	&& PROTOCOL_FORWARD_DECL (TREE_VALUE (lproto)))
      size++;

  /* Build initializer.  */
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, build_int_cst (NULL_TREE, 0));
  e = build_int_cst (build_pointer_type (objc_protocol_template), size);
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, e);

  for (lproto = plist; lproto; lproto = TREE_CHAIN (lproto))
    {
      tree pval = TREE_VALUE (lproto);

      if (TREE_CODE (pval) == PROTOCOL_INTERFACE_TYPE
	  && PROTOCOL_FORWARD_DECL (pval))
	{
	  tree fwref = PROTOCOL_FORWARD_DECL (pval);
	  location_t loc = DECL_SOURCE_LOCATION (fwref) ;
	  e = build_unary_op (loc, ADDR_EXPR, fwref, 0);
          CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, e);
	}
    }

  /* static struct objc_protocol *refs[n]; */

  switch (TREE_CODE (i_or_p))
    {
    case PROTOCOL_INTERFACE_TYPE:
      snprintf (buf, BUFSIZE, "_OBJC_ProtocolRefs_%s",
		IDENTIFIER_POINTER (PROTOCOL_NAME (i_or_p)));
      break;
    case CLASS_INTERFACE_TYPE:
      snprintf (buf, BUFSIZE, "_OBJC_ClassProtocols_%s",
		IDENTIFIER_POINTER (CLASS_NAME (i_or_p)));
      break;
    case CATEGORY_INTERFACE_TYPE:
      snprintf (buf, BUFSIZE, "_OBJC_CategoryProtocols_%s_%s",
		IDENTIFIER_POINTER (CLASS_NAME (klass_ctxt)),
		IDENTIFIER_POINTER (CLASS_SUPER_NAME (klass_ctxt)));
      break;
    default:
      gcc_unreachable ();
    }

  ptype = build_pointer_type (objc_protocol_template);
  array_type = build_sized_array_type (ptype, size + 3);
  refs_decl = start_var_decl (array_type, buf);
  OBJCMETA (refs_decl, objc_meta, meta_base);
  finish_var_decl (refs_decl,
                   objc_build_constructor (TREE_TYPE (refs_decl), v));

  return refs_decl;
}

static tree
generate_v1_meth_descriptor_table (tree chain, tree protocol, const char *prefix)
{
  tree method_list_template, initlist, decl;
  int size;
  vec<constructor_elt, va_gc> *v = NULL;
  char buf[BUFSIZE];

  if (!chain || !prefix)
    return NULL_TREE;

  if (!objc_method_prototype_template)
    objc_method_prototype_template = build_method_prototype_template ();

  size = list_length (chain);
  method_list_template =
	build_method_prototype_list_template (objc_method_prototype_template,
					      size);
  snprintf (buf, BUFSIZE, "%s_%s", prefix,
	    IDENTIFIER_POINTER (PROTOCOL_NAME (protocol)));

  decl = start_var_decl (method_list_template, buf);

  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, build_int_cst (NULL_TREE, size));
  initlist =
	build_descriptor_table_initializer (objc_method_prototype_template,
					    chain);
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, initlist);
  OBJCMETA (decl, objc_meta, meta_base);
  finish_var_decl (decl, objc_build_constructor (method_list_template, v));
  return decl;
}

/* For each protocol which was referenced either from a @protocol()
   expression, or because a class/category implements it (then a
   pointer to the protocol is stored in the struct describing the
   class/category), we create a statically allocated instance of the
   Protocol class.  The code is written in such a way as to generate
   as few Protocol objects as possible; we generate a unique Protocol
   instance for each protocol, and we don't generate a Protocol
   instance if the protocol is never referenced (either from a
   @protocol() or from a class/category implementation).  These
   statically allocated objects can be referred to via the static
   (that is, private to this module) symbols _OBJC_PROTOCOL_n.

   The statically allocated Protocol objects that we generate here
   need to be fixed up at runtime in order to be used: the 'isa'
   pointer of the objects need to be set up to point to the 'Protocol'
   class, as known at runtime.

   The GNU runtime fixes up all protocols before user code from the module
   is executed; it requires pointers to those symbols
   to be put in the objc_symtab (which is then passed as argument to
   the function __objc_exec_class() which the compiler sets up to be
   executed automatically when the module is loaded); setup of those
   Protocol objects happen in two ways in the GNU runtime: all
   Protocol objects referred to by a class or category implementation
   are fixed up when the class/category is loaded; all Protocol
   objects referred to by a @protocol() expression are added by the
   compiler to the list of statically allocated instances to fixup
   (the same list holding the statically allocated constant string
   objects).  Because, as explained above, the compiler generates as
   few Protocol objects as possible, some Protocol object might end up
   being referenced multiple times when compiled with the GNU runtime,
   and end up being fixed up multiple times at runtime initialization.
   But that doesn't hurt, it's just a little inefficient.  */

static void
generate_protocols (void)
{
  tree p, encoding;
  tree decl;
  tree initlist, protocol_name_expr, refs_decl, refs_expr;

  /* If a protocol was directly referenced, pull in indirect references.  */
  for (p = protocol_chain; p; p = TREE_CHAIN (p))
    if (PROTOCOL_FORWARD_DECL (p) && PROTOCOL_LIST (p))
      generate_protocol_references (PROTOCOL_LIST (p));

  for (p = protocol_chain; p; p = TREE_CHAIN (p))
    {
      tree nst_methods = PROTOCOL_NST_METHODS (p);
      tree cls_methods = PROTOCOL_CLS_METHODS (p);

      /* If protocol wasn't referenced, don't generate any code.  */
      decl = PROTOCOL_FORWARD_DECL (p);

      if (!decl)
	continue;

      /* Make sure we link in the Protocol class.  */
      add_class_reference (get_identifier (PROTOCOL_OBJECT_CLASS_NAME));

      while (nst_methods)
	{
	  if (! METHOD_ENCODING (nst_methods))
	    {
	      encoding = encode_method_prototype (nst_methods);
	      METHOD_ENCODING (nst_methods) = encoding;
	    }
	  nst_methods = DECL_CHAIN (nst_methods);
	}

      UOBJC_INSTANCE_METHODS_decl =
	generate_v1_meth_descriptor_table (PROTOCOL_NST_METHODS (p), p,
					   "_OBJC_PROTOCOL_INSTANCE_METHODS");

      while (cls_methods)
	{
	  if (! METHOD_ENCODING (cls_methods))
	    {
	      encoding = encode_method_prototype (cls_methods);
	      METHOD_ENCODING (cls_methods) = encoding;
	    }

	  cls_methods = DECL_CHAIN (cls_methods);
	}

      UOBJC_CLASS_METHODS_decl =
	generate_v1_meth_descriptor_table (PROTOCOL_CLS_METHODS (p), p,
					   "_OBJC_PROTOCOL_CLASS_METHODS");
/*      generate_method_descriptors (p);*/

      if (PROTOCOL_LIST (p))
	refs_decl = generate_protocol_list (p, NULL_TREE);
      else
	refs_decl = 0;

      /* static struct objc_protocol _OBJC_PROTOCOL_<mumble>; */
      protocol_name_expr = add_objc_string (PROTOCOL_NAME (p), class_names);

      if (refs_decl)
	refs_expr = convert (build_pointer_type (build_pointer_type
						 (objc_protocol_template)),
			     build_unary_op (input_location,
					     ADDR_EXPR, refs_decl, 0));
      else
	refs_expr = build_int_cst (NULL_TREE, 0);

      /* UOBJC_INSTANCE_METHODS_decl/UOBJC_CLASS_METHODS_decl are set
	 by generate_method_descriptors, which is called above.  */
      initlist = build_protocol_initializer (TREE_TYPE (decl),
					     protocol_name_expr, refs_expr,
					     UOBJC_INSTANCE_METHODS_decl,
					     UOBJC_CLASS_METHODS_decl);
      finish_var_decl (decl, initlist);
    }
}

static tree
generate_dispatch_table (tree chain, const char *name)
{
  tree decl, method_list_template, initlist;
  vec<constructor_elt, va_gc> *v = NULL;
  int size = list_length (chain);

  if (!objc_method_template)
    objc_method_template = build_method_template ();

  method_list_template = build_method_list_template (objc_method_template,
						     size);
  initlist = build_dispatch_table_initializer (objc_method_template, chain);

  decl = start_var_decl (method_list_template, name);

  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, integer_zero_node);
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE,
			  build_int_cst (integer_type_node, size));
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, initlist);

  OBJCMETA (decl, objc_meta, meta_base);
  finish_var_decl (decl,
		   objc_build_constructor (TREE_TYPE (decl), v));

  return decl;
}

/* Init a category.  */
static tree
build_category_initializer (tree type, tree cat_name, tree class_name,
			    tree inst_methods, tree class_methods,
			    tree protocol_list)
{
  tree expr, ltyp;
  location_t loc;
  vec<constructor_elt, va_gc> *v = NULL;

  /* TODO: pass the loc in or find it from args.  */
  /* TODO: pass the loc in or find it from args.  */
  loc = UNKNOWN_LOCATION;
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, cat_name);
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, class_name);

  ltyp = objc_method_list_ptr;
  if (inst_methods)
    expr = convert (ltyp, build_unary_op (loc, ADDR_EXPR, inst_methods, 0));
  else
    expr = convert (ltyp, null_pointer_node);
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, expr);

  if (class_methods)
    expr = convert (ltyp, build_unary_op (loc, ADDR_EXPR, class_methods, 0));
  else
    expr = convert (ltyp, null_pointer_node);
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, expr);

  /* protocol_list = */
  ltyp = build_pointer_type (build_pointer_type (objc_protocol_template));
  if (protocol_list)
    expr = convert (ltyp, build_unary_op (loc, ADDR_EXPR, protocol_list, 0));
  else
    expr = convert (ltyp, null_pointer_node);
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, expr);

  return objc_build_constructor (type, v);
}

/* static struct objc_category _OBJC_CATEGORY_<name> = { ... };  */

static void
generate_category (struct imp_entry *impent)
{
  tree initlist, cat_name_expr, class_name_expr;
  tree protocol_decl, category, cat_decl;
  tree inst_methods = NULL_TREE, class_methods = NULL_TREE;
  tree cat = impent->imp_context;
  char buf[BUFSIZE];

  cat_decl = impent->class_decl;

  add_class_reference (CLASS_NAME (cat));
  cat_name_expr = add_objc_string (CLASS_SUPER_NAME (cat), class_names);

  class_name_expr = add_objc_string (CLASS_NAME (cat), class_names);

  category = lookup_category (impent->imp_template, CLASS_SUPER_NAME (cat));

  if (category && CLASS_PROTOCOL_LIST (category))
    {
      generate_protocol_references (CLASS_PROTOCOL_LIST (category));
      protocol_decl = generate_protocol_list (category, cat);
    }
  else
    protocol_decl = 0;

  if (CLASS_NST_METHODS (cat))
    {
      snprintf (buf, BUFSIZE, "_OBJC_CategoryInstanceMethods_%s_%s",
		IDENTIFIER_POINTER (CLASS_NAME (cat)),
		IDENTIFIER_POINTER (CLASS_SUPER_NAME (cat)));
      inst_methods = generate_dispatch_table (CLASS_NST_METHODS (cat), buf);
    }

  if (CLASS_CLS_METHODS (cat))
    {
      snprintf (buf, BUFSIZE, "_OBJC_CategoryClassMethods_%s_%s",
		IDENTIFIER_POINTER (CLASS_NAME (cat)),
		IDENTIFIER_POINTER (CLASS_SUPER_NAME (cat)));
      class_methods = generate_dispatch_table (CLASS_CLS_METHODS (cat), buf);
    }

  initlist = build_category_initializer (TREE_TYPE (cat_decl),
					 cat_name_expr, class_name_expr,
					 inst_methods, class_methods,
					 protocol_decl);
  /* Finish and initialize the forward decl.  */
  finish_var_decl (cat_decl, initlist);
  impent->class_decl = cat_decl;
}

/* struct _objc_class {
     struct objc_class *isa;
     struct objc_class *super_class;
     char *name;
     long version;
     long info;
     long instance_size;
     struct objc_ivar_list *ivars;
     struct objc_method_list *methods;
     struct sarray *dtable;
     struct objc_class *subclass_list;
     struct objc_class *sibling_class;
     struct objc_protocol_list *protocols;
     void *gc_object_type;
   };  */

static tree
build_shared_structure_initializer (tree type, tree isa, tree super,
				    tree name, tree size, int status,
				    tree dispatch_table, tree ivar_list,
				    tree protocol_list)
{
  tree expr, ltyp;
  vec<constructor_elt, va_gc> *v = NULL;

  /* isa = */
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, isa);

  /* super_class = */
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, super);

  /* name = */
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, default_conversion (name));

  /* version = */
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE,
                          build_int_cst (long_integer_type_node, 0));

  /* info = */
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE,
                          build_int_cst (long_integer_type_node, status));

  /* instance_size = */
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE,
                          convert (long_integer_type_node, size));

  /* objc_ivar_list = */
  if (!ivar_list)
    CONSTRUCTOR_APPEND_ELT (v, NULL_TREE,
			    build_int_cst (objc_ivar_list_ptr, 0));
  else
    {
      expr = convert (objc_ivar_list_ptr,
		      build_unary_op (input_location, ADDR_EXPR,
				      ivar_list, 0));
      CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, expr);
    }

  /* objc_method_list = */
  if (!dispatch_table)
    CONSTRUCTOR_APPEND_ELT (v, NULL_TREE,
			   convert (objc_method_list_ptr, null_pointer_node));
  else
    {
      expr = convert (objc_method_list_ptr,
		      build_unary_op (input_location, ADDR_EXPR,
				      dispatch_table, 0));
      CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, expr);
    }

  /* FIXME: Remove NeXT runtime code.  */
  if (flag_next_runtime)
    {
      ltyp = build_pointer_type (xref_tag (RECORD_TYPE,
					   get_identifier ("objc_cache")));
      /* method_cache = */
      CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, convert (ltyp, null_pointer_node));
    }
  else
    {
      /* dtable = */
      CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, build_int_cst (NULL_TREE, 0));

      /* subclass_list = */
      CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, build_int_cst (NULL_TREE, 0));

      /* sibling_class = */
      CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, build_int_cst (NULL_TREE, 0));
    }

  /* protocol_list = */
  ltyp = build_pointer_type (build_pointer_type (objc_protocol_template));
  if (! protocol_list)
    CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, build_int_cst (ltyp, 0));
  else
    {
      expr = convert (ltyp,
		      build_unary_op (input_location, ADDR_EXPR,
				      protocol_list, 0));
      CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, expr);
    }

  /* FIXME: Remove NeXT runtime code.  */
  if (flag_next_runtime)
    /* sel_id = NULL */
    CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, build_int_cst (NULL_TREE, 0));

  /* gc_object_type = NULL */
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, build_int_cst (NULL_TREE, 0));

  return objc_build_constructor (type, v);
}


static tree
generate_ivars_list (tree chain, const char *name)
{
  tree initlist, ivar_list_template, decl;
  int size;
  vec<constructor_elt, va_gc> *inits = NULL;

  if (!chain)
    return NULL_TREE;

  if (!objc_ivar_template)
    objc_ivar_template = build_ivar_template ();

  size = ivar_list_length (chain);

  generating_instance_variables = 1;
  ivar_list_template = build_ivar_list_template (objc_ivar_template, size);
  initlist = build_ivar_list_initializer (objc_ivar_template, chain);
  generating_instance_variables = 0;

  decl = start_var_decl (ivar_list_template, name);

  CONSTRUCTOR_APPEND_ELT (inits, NULL_TREE, build_int_cst (NULL_TREE, size));
  CONSTRUCTOR_APPEND_ELT (inits, NULL_TREE, initlist);

  OBJCMETA (decl, objc_meta, meta_base);
  finish_var_decl (decl,
		   objc_build_constructor (TREE_TYPE (decl), inits));

  return decl;
}

/* static struct objc_class _OBJC_METACLASS_Foo={ ... };
   static struct objc_class _OBJC_CLASS_Foo={ ... };  */

static void
generate_class_structures (struct imp_entry *impent)
{
  tree name_expr, super_expr, root_expr, class_decl, meta_decl;
  tree my_root_id, my_super_id;
  tree cast_type, initlist, protocol_decl;
  tree inst_methods = NULL_TREE, class_methods = NULL_TREE;
  tree chain, inst_ivars = NULL_TREE, class_ivars = NULL_TREE;
  location_t loc;
  char buf[BUFSIZE];
  int cls_flags = 0 ;

/*  objc_implementation_context = impent->imp_context;
  implementation_template = impent->imp_template;*/
  class_decl = impent->class_decl;
  meta_decl = impent->meta_decl;
/*  UOBJC_CLASS_decl = impent->class_decl;
  UOBJC_METACLASS_decl = impent->meta_decl;*/

  loc = DECL_SOURCE_LOCATION (impent->class_decl);

  my_super_id = CLASS_SUPER_NAME (impent->imp_template);
  if (my_super_id)
    {
      add_class_reference (my_super_id);

      /* Compute "my_root_id" - this is required for code generation.
         the "isa" for all meta class structures points to the root of
         the inheritance hierarchy (e.g. "__Object")...  */
      my_root_id = my_super_id;
      do
	{
	  tree my_root_int = lookup_interface (my_root_id);

	  if (my_root_int && CLASS_SUPER_NAME (my_root_int))
	    my_root_id = CLASS_SUPER_NAME (my_root_int);
	  else
	    break;
	}
      while (1);
    }
  else
    /* No super class.  */
    my_root_id = CLASS_NAME (impent->imp_template);

  cast_type = build_pointer_type (objc_class_template);
  name_expr = add_objc_string (CLASS_NAME (impent->imp_template),
			       class_names);

  /* Install class `isa' and `super' pointers at runtime.  */
  if (my_super_id)
    super_expr = add_objc_string (my_super_id, class_names);
  else
    super_expr = null_pointer_node;

  super_expr = build_c_cast (loc, cast_type, super_expr);

  root_expr = add_objc_string (my_root_id, class_names);
  root_expr = build_c_cast (loc, cast_type, root_expr);

  if (CLASS_PROTOCOL_LIST (impent->imp_template))
    {
      generate_protocol_references (CLASS_PROTOCOL_LIST (impent->imp_template));
      protocol_decl = generate_protocol_list (impent->imp_template,
					      impent->imp_context);
    }
  else
    protocol_decl = NULL_TREE;

  if (CLASS_CLS_METHODS (impent->imp_context))
    {
      snprintf (buf, BUFSIZE, "_OBJC_ClassMethods_%s",
		IDENTIFIER_POINTER (CLASS_NAME (impent->imp_context)));
      class_methods = generate_dispatch_table (CLASS_CLS_METHODS (impent->imp_context),
					       buf);
    }

  if (CLASS_SUPER_NAME (impent->imp_template) == NULL_TREE
      && (chain = TYPE_FIELDS (objc_class_template)))
    {
      snprintf (buf, BUFSIZE, "_OBJC_ClassIvars_%s",
		IDENTIFIER_POINTER (CLASS_NAME (impent->imp_context)));
      class_ivars = generate_ivars_list (chain, buf);
    }

  /* static struct objc_class _OBJC_METACLASS_Foo = { ... }; */

  initlist =
	build_shared_structure_initializer
			(TREE_TYPE (meta_decl),
			root_expr, super_expr, name_expr,
			convert (integer_type_node,
				TYPE_SIZE_UNIT (objc_class_template)),
			CLS_META, class_methods, class_ivars,
			protocol_decl);

  finish_var_decl (meta_decl, initlist);
  impent->meta_decl = meta_decl;

  /* static struct objc_class _OBJC_CLASS_Foo={ ... }; */
  if (CLASS_NST_METHODS (impent->imp_context))
    {
      snprintf (buf, BUFSIZE, "_OBJC_InstanceMethods_%s",
		IDENTIFIER_POINTER (CLASS_NAME (impent->imp_context)));
      inst_methods = generate_dispatch_table (CLASS_NST_METHODS (impent->imp_context),
					      buf);
    }

  if ((chain = CLASS_IVARS (impent->imp_template)))
    {
      snprintf (buf, BUFSIZE, "_OBJC_InstanceIvars_%s",
		IDENTIFIER_POINTER (CLASS_NAME (impent->imp_context)));
      inst_ivars = generate_ivars_list (chain, buf);
    }

  initlist =
	build_shared_structure_initializer
		(TREE_TYPE (class_decl),
		build_unary_op (loc, ADDR_EXPR, meta_decl, 0),
		super_expr, name_expr,
		convert (integer_type_node,
			 TYPE_SIZE_UNIT (CLASS_STATIC_TEMPLATE
					(impent->imp_template))),
		CLS_FACTORY | cls_flags, inst_methods, inst_ivars,
		protocol_decl);

  finish_var_decl (class_decl, initlist);
  impent->class_decl = class_decl;
}

/* --- Output GNU Metadata --- */

/* TODO: Make this into an array of refs.  */
static void
handle_class_ref (tree chain)
{
  const char *name = IDENTIFIER_POINTER (TREE_VALUE (chain));
  char *string = (char *) alloca (strlen (name) + 30);
  tree decl;
  tree exp;

  sprintf (string, "__objc_class_name_%s", name);

  /* Make a decl for this name, so we can use its address in a tree.  */
  decl = build_decl (input_location,
		     VAR_DECL, get_identifier (string), TREE_TYPE (integer_zero_node));
  DECL_EXTERNAL (decl) = 1;
  TREE_PUBLIC (decl) = 1;
  DECL_CONTEXT (decl) = NULL_TREE;
  finish_var_decl (decl, 0);

  /* Make a decl for the address.  */
  sprintf (string, "__objc_class_ref_%s", name);
  exp = build1 (ADDR_EXPR, string_type_node, decl);
  decl = build_decl (input_location,
		     VAR_DECL, get_identifier (string), string_type_node);
  TREE_STATIC (decl) = 1;
  TREE_USED (decl) = 1;
  DECL_READ_P (decl) = 1;
  DECL_ARTIFICIAL (decl) = 1;
  DECL_INITIAL (decl) = error_mark_node;

  /* We must force the reference.  */
  DECL_PRESERVE_P (decl) = 1;

  DECL_CONTEXT (decl) = NULL_TREE;
  finish_var_decl (decl, exp);
}

static tree
get_proto_encoding (tree proto)
{
  tree encoding;
  if (proto)
    {
      if (! METHOD_ENCODING (proto))
	{
	  encoding = encode_method_prototype (proto);
	  METHOD_ENCODING (proto) = encoding;
	}
      else
	encoding = METHOD_ENCODING (proto);

      return add_objc_string (encoding, meth_var_types);
    }
  else
    return build_int_cst (NULL_TREE, 0);
}

static void
build_gnu_selector_translation_table (void)
{
  tree chain, expr;
  vec<constructor_elt, va_gc> *inits = NULL;
  vec<constructor_elt, va_gc> *v ;

  /* Cause the selector table (previously forward-declared)
     to be actually output.  */

  for (chain = sel_ref_chain; chain; chain = TREE_CHAIN (chain))
    {
      tree encoding;
      if (warn_selector)
	{
	  /* TODO: improve on the location for the diagnostic.  */
	  location_t loc = input_location;
	  diagnose_missing_method (TREE_VALUE (chain), loc);
	}

      v = NULL;
      expr = build_selector (TREE_VALUE (chain));
      encoding = get_proto_encoding (TREE_PURPOSE (chain));
      CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, expr);
      CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, encoding);
      expr = objc_build_constructor (objc_selector_template, v);

      CONSTRUCTOR_APPEND_ELT (inits, NULL_TREE, expr);
    } /* each element in the chain */

  /* List terminator.  */
  v = NULL;
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, integer_zero_node);
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, integer_zero_node);
  expr = objc_build_constructor (objc_selector_template, v);

  CONSTRUCTOR_APPEND_ELT (inits, NULL_TREE, expr);
  expr = objc_build_constructor (TREE_TYPE (UOBJC_SELECTOR_TABLE_decl),
				     inits);
  finish_var_decl (UOBJC_SELECTOR_TABLE_decl, expr);
}

/* Output references to all statically allocated objects.  Return the DECL
   for the array built.  */

static void
generate_static_references (void)
{
  tree expr = NULL_TREE;
  tree class_name, klass, decl;
  tree cl_chain, in_chain, type
    = build_array_type (build_pointer_type (void_type_node), NULL_TREE);
  int num_inst, num_class;
  char buf[BUFSIZE];
  vec<constructor_elt, va_gc> *decls = NULL;

  /* FIXME: Remove NeXT runtime code.  */
  if (flag_next_runtime)
    gcc_unreachable ();

  for (cl_chain = objc_static_instances, num_class = 0;
       cl_chain; cl_chain = TREE_CHAIN (cl_chain), num_class++)
    {
      vec<constructor_elt, va_gc> *v = NULL;

      for (num_inst = 0, in_chain = TREE_PURPOSE (cl_chain);
	   in_chain; num_inst++, in_chain = TREE_CHAIN (in_chain));

      snprintf (buf, BUFSIZE, "_OBJC_STATIC_INSTANCES_%d", num_class);
      decl = start_var_decl (type, buf);

      /* Output {class_name, ...}.  */
      klass = TREE_VALUE (cl_chain);
      class_name = get_objc_string_decl (OBJC_TYPE_NAME (klass), class_names);
      CONSTRUCTOR_APPEND_ELT (v, NULL_TREE,
			      build_unary_op (input_location,
					      ADDR_EXPR, class_name, 1));

      /* Output {..., instance, ...}.  */
      for (in_chain = TREE_PURPOSE (cl_chain);
	   in_chain; in_chain = TREE_CHAIN (in_chain))
	{
	  expr = build_unary_op (input_location,
				 ADDR_EXPR, TREE_VALUE (in_chain), 1);
	  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, expr);
	}

      /* Output {..., NULL}.  */
      CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, build_int_cst (NULL_TREE, 0));

      expr = objc_build_constructor (TREE_TYPE (decl), v);
      OBJCMETA (decl, objc_meta, meta_base);
      finish_var_decl (decl, expr);
      CONSTRUCTOR_APPEND_ELT (decls, NULL_TREE,
			      build_unary_op (input_location,
					      ADDR_EXPR, decl, 1));
    }

  CONSTRUCTOR_APPEND_ELT (decls, NULL_TREE, build_int_cst (NULL_TREE, 0));
  expr = objc_build_constructor (type, decls);
  static_instances_decl = start_var_decl (type, "_OBJC_STATIC_INSTANCES");
  OBJCMETA (static_instances_decl, objc_meta, meta_base);
  finish_var_decl (static_instances_decl, expr);
}

/* Create the initial value for the `defs' field of _objc_symtab.
   This is a CONSTRUCTOR.  */

static tree
init_def_list (tree type)
{
  tree expr;
  struct imp_entry *impent;
  location_t loc;
  vec<constructor_elt, va_gc> *v = NULL;

  if (imp_count)
    for (impent = imp_list; impent; impent = impent->next)
      {
	if (TREE_CODE (impent->imp_context) == CLASS_IMPLEMENTATION_TYPE)
	  {
	    loc = DECL_SOURCE_LOCATION (impent->class_decl);
	    expr = build_unary_op (loc,
				   ADDR_EXPR, impent->class_decl, 0);
	    CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, expr);
	  }
      }

  if (cat_count)
    for (impent = imp_list; impent; impent = impent->next)
      {
	if (TREE_CODE (impent->imp_context) == CATEGORY_IMPLEMENTATION_TYPE)
	  {
	    loc = DECL_SOURCE_LOCATION (impent->class_decl);
	    expr = build_unary_op (loc,
				   ADDR_EXPR, impent->class_decl, 0);
	    CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, expr);
	  }
      }

  loc = UNKNOWN_LOCATION;
  /* statics = { ..., _OBJC_STATIC_INSTANCES, ... }  */
  if (static_instances_decl)
    expr = build_unary_op (loc, ADDR_EXPR, static_instances_decl, 0);
  else
    expr = integer_zero_node;
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, expr);

  return objc_build_constructor (type, v);
}

/* Take care of defining and initializing _OBJC_SYMBOLS.  */

/* Predefine the following data type:

   struct _objc_symtab
   {
     long sel_ref_cnt;
     SEL *refs;
     short cls_def_cnt;
     short cat_def_cnt;
     void *defs[cls_def_cnt + cat_def_cnt];
   }; */

static void
build_objc_symtab_template (void)
{
  tree fields, array_type, *chain = NULL;
  int index;

  objc_symtab_template = objc_start_struct (get_identifier (UTAG_SYMTAB));

  /* long sel_ref_cnt; */
  fields = add_field_decl (long_integer_type_node, "sel_ref_cnt", &chain);

  /* SEL *refs; */
  add_field_decl (build_pointer_type (objc_selector_type), "refs", &chain);

  /* short cls_def_cnt; */
  add_field_decl (short_integer_type_node, "cls_def_cnt", &chain);

  /* short cat_def_cnt; */
  add_field_decl (short_integer_type_node, "cat_def_cnt", &chain);

  /* Note that padding will be added here on LP64.  */

  /* void *defs[imp_count + cat_count (+ 1)]; */
  /* NB: The index is one less than the size of the array.  */
  index = imp_count + cat_count;
  array_type = build_sized_array_type (ptr_type_node, index + 1);
  add_field_decl (array_type, "defs", &chain);

  objc_finish_struct (objc_symtab_template, fields);
}
/* Construct the initial value for all of _objc_symtab.  */

static tree
init_objc_symtab (tree type)
{
  tree field, expr, ltyp;
  location_t loc;
  vec<constructor_elt, va_gc> *v = NULL;

  loc = UNKNOWN_LOCATION;

  /* sel_ref_cnt = { ..., 5, ... } */

  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE,
			  build_int_cst (long_integer_type_node, 0));

  /* refs = { ..., _OBJC_SELECTOR_TABLE, ... } */

  ltyp = build_pointer_type (objc_selector_type);
  if (sel_ref_chain)
    expr = convert (ltyp, build_unary_op (loc, ADDR_EXPR,
					  UOBJC_SELECTOR_TABLE_decl, 1));
  else
    expr = convert (ltyp, null_pointer_node);
  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, expr);

  /* cls_def_cnt = { ..., 5, ... } */

  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE,
			  build_int_cst (short_integer_type_node, imp_count));

  /* cat_def_cnt = { ..., 5, ... } */

  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE,
			  build_int_cst (short_integer_type_node, cat_count));

  /* cls_def = { ..., { &Foo, &Bar, ...}, ... } */

  field = TYPE_FIELDS (type);
  field = DECL_CHAIN (DECL_CHAIN (DECL_CHAIN (DECL_CHAIN (field))));

  CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, init_def_list (TREE_TYPE (field)));

  return objc_build_constructor (type, v);
}

/* Create the declaration of _OBJC_SYMBOLS, with type `struct _objc_symtab'
   and initialized appropriately.  */

static void
generate_objc_symtab_decl (void)
{
  build_objc_symtab_template ();
  UOBJC_SYMBOLS_decl = start_var_decl (objc_symtab_template, "_OBJC_SYMBOLS");
  OBJCMETA (UOBJC_SYMBOLS_decl, objc_meta, meta_base);
  finish_var_decl (UOBJC_SYMBOLS_decl,
		   init_objc_symtab (TREE_TYPE (UOBJC_SYMBOLS_decl)));
}

static void
objc_generate_v1_gnu_metadata (void)
{
  struct imp_entry *impent;
  tree chain;

  /* Process the static instances here because initialization of objc_symtab
     depends on them.  */
  if (objc_static_instances)
    generate_static_references ();

  objc_implementation_context =
  implementation_template =
  UOBJC_CLASS_decl =
  UOBJC_METACLASS_decl = NULL_TREE;

  for (impent = imp_list; impent; impent = impent->next)
    {
      /* If -gen-decls is present, Dump the @interface of each class.
	 TODO: Dump the classes in the  order they were found, rather than in
	 reverse order as we are doing now.  */
      if (flag_gen_declaration)
	dump_interface (gen_declaration_file, impent->imp_context);

      /* all of the following reference the string pool...  */
      if (TREE_CODE (impent->imp_context) == CLASS_IMPLEMENTATION_TYPE)
	generate_class_structures (impent);
      else
	generate_category (impent);
    }

  /* If we are using an array of selectors, we must always
     finish up the array decl even if no selectors were used.  */
  build_gnu_selector_translation_table ();

  if (protocol_chain)
    generate_protocols ();

  /* Arrange for ObjC data structures to be initialized at run time.  */
  /* FIXME: Have some more elegant way to determine if we need to
     generate objc_symtab_decl or not, instead of checking these
     global symbols.  */
  if (imp_list || class_names_chain
      || meth_var_names_chain || meth_var_types_chain || sel_ref_chain
      || prop_names_attr_chain)
    generate_objc_symtab_decl ();

  if (imp_list || class_names_chain || objc_static_instances
      || meth_var_names_chain || meth_var_types_chain || sel_ref_chain)
    {
      /* Make sure that the meta-data are identified as being
	 GNU-runtime.  */
      build_module_descriptor (OBJC_VERSION,
			       build_tree_list (objc_meta, meta_base));
      build_module_initializer_routine ();
    }

  /* Dump the class references.  This forces the appropriate classes
     to be linked into the executable image, preserving unix archive
     semantics.  This can be removed when we move to a more dynamically
     linked environment.  */

  for (chain = cls_ref_chain; chain; chain = TREE_CHAIN (chain))
    {
      handle_class_ref (chain);
      if (TREE_PURPOSE (chain))
	generate_classref_translation_entry (chain);
    }

  for (impent = imp_list; impent; impent = impent->next)
    handle_impent (impent);

  generate_strings ();
}

/* --- exceptions --- */

static GTY(()) tree objc_eh_personality_decl;

static tree
objc_eh_runtime_type (tree type)
{
  tree ident, eh_id, decl, str;

  if (type == error_mark_node
      || errorcount || sorrycount)
    {
      /* Use 'ErrorMarkNode' as class name when error_mark_node is found
	 to prevent an ICE.  Note that we know that the compiler will
	 terminate with an error and this 'ErrorMarkNode' class name will
	 never be actually used.  */
      ident = get_identifier ("ErrorMarkNode");
      goto make_err_class;
    }

  if (POINTER_TYPE_P (type) && objc_is_object_id (TREE_TYPE (type)))
    /* We don't want to identify 'id' for GNU. Instead, build a 0
       entry in the exceptions table.  */
    return null_pointer_node;

  if (!POINTER_TYPE_P (type) || !TYPED_OBJECT (TREE_TYPE (type)))
    {
#ifdef OBJCPLUS
      /* This routine is also called for c++ catch clauses; in which case,
	 we use the c++ typeinfo decl. */
      return build_eh_type_type (type);
#else
      error ("non-objective-c type '%T' cannot be caught", type);
      ident = get_identifier ("ErrorMarkNode");
      goto make_err_class;
#endif
    }
  else
    ident = OBJC_TYPE_NAME (TREE_TYPE (type));

make_err_class:
  /* If this class was already referenced, then it will be output during
     meta-data emission, so we don't need to do it here.  */
  decl = get_objc_string_decl (ident, class_names);
  eh_id = add_objc_string (ident, class_names);
  if (!decl)
    {
      /* Not found ... so we need to build it - from the freshly-entered id.  */
      decl = get_objc_string_decl (ident, class_names);
      str = my_build_string (IDENTIFIER_LENGTH (ident) + 1,
			     IDENTIFIER_POINTER (ident));
      /* We have to finalize this var here, because this might be called after
	 all the other metadata strings have been emitted.  */
      finish_var_decl (decl, str);
    }
  return eh_id;
}

static tree
objc_eh_personality (void)
{
  if (!objc_eh_personality_decl)
#ifndef OBJCPLUS
    objc_eh_personality_decl = build_personality_function  ("gnu_objc");
#else
    objc_eh_personality_decl = build_personality_function  ("gxx");
#endif
  return objc_eh_personality_decl;
}

/* -- interfaces --- */

static tree
build_throw_stmt (location_t loc, tree throw_expr, bool rethrown ATTRIBUTE_UNUSED)
{
  tree t;
  vec<tree, va_gc> *parms;
  vec_alloc (parms, 1);
  /* A throw is just a call to the runtime throw function with the
     object as a parameter.  */
  parms->quick_push (throw_expr);
  t = build_function_call_vec (loc, objc_exception_throw_decl, parms, NULL);
  vec_free (parms);
  return add_stmt (t);
}

/* Build __builtin_eh_pointer.  */

static tree
objc_build_exc_ptr (struct objc_try_context **x ATTRIBUTE_UNUSED)
{
  tree t;
  t = builtin_decl_explicit (BUILT_IN_EH_POINTER);
  t = build_call_expr (t, 1, integer_zero_node);
  return fold_convert (objc_object_type, t);
}

static tree
begin_catch (struct objc_try_context **cur_try_context, tree type,
	     tree decl, tree compound, bool ellipsis ATTRIBUTE_UNUSED)
{
  tree t;
  /* Record the data for the catch in the try context so that we can
     finalize it later.  */
  if (ellipsis)
    t = build_stmt (input_location, CATCH_EXPR, NULL, compound);
  else
    t = build_stmt (input_location, CATCH_EXPR, type, compound);
  (*cur_try_context)->current_catch = t;

  /* Initialize the decl from the EXC_PTR_EXPR we get from the runtime.  */
  t = objc_build_exc_ptr (cur_try_context);
  t = convert (TREE_TYPE (decl), t);
  return build2 (MODIFY_EXPR, void_type_node, decl, t);
}

static void
finish_catch (struct objc_try_context **cur_try_context, tree current_catch)
{
  append_to_statement_list (current_catch, &((*cur_try_context)->catch_list));
}

static tree
finish_try_stmt (struct objc_try_context **cur_try_context)
{
  struct objc_try_context *c = *cur_try_context;
  tree stmt = c->try_body;
  if (c->catch_list)
    stmt = build_stmt (c->try_locus, TRY_CATCH_EXPR, stmt, c->catch_list);
  if (c->finally_body)
    stmt = build_stmt (c->try_locus, TRY_FINALLY_EXPR, stmt, c->finally_body);
  return stmt;
}

#include "gt-objc-objc-gnu-runtime-abi-01.h"