aboutsummaryrefslogtreecommitdiff
path: root/include/clang/AST/DeclObjC.h
blob: c42764b6f3bf185536122f1b47b4c79af1867e3d (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
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
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
//===--- DeclObjC.h - Classes for representing declarations -----*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file defines the DeclObjC interface and subclasses.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_AST_DECLOBJC_H
#define LLVM_CLANG_AST_DECLOBJC_H

#include "clang/AST/Decl.h"
#include "clang/AST/SelectorLocationsKind.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/Compiler.h"

namespace clang {
class Expr;
class Stmt;
class FunctionDecl;
class RecordDecl;
class ObjCIvarDecl;
class ObjCMethodDecl;
class ObjCProtocolDecl;
class ObjCCategoryDecl;
class ObjCPropertyDecl;
class ObjCPropertyImplDecl;
class CXXCtorInitializer;

class ObjCListBase {
  ObjCListBase(const ObjCListBase &) = delete;
  void operator=(const ObjCListBase &) = delete;
protected:
  /// List is an array of pointers to objects that are not owned by this object.
  void **List;
  unsigned NumElts;

public:
  ObjCListBase() : List(nullptr), NumElts(0) {}
  unsigned size() const { return NumElts; }
  bool empty() const { return NumElts == 0; }

protected:
  void set(void *const* InList, unsigned Elts, ASTContext &Ctx);
};


/// ObjCList - This is a simple template class used to hold various lists of
/// decls etc, which is heavily used by the ObjC front-end.  This only use case
/// this supports is setting the list all at once and then reading elements out
/// of it.
template <typename T>
class ObjCList : public ObjCListBase {
public:
  void set(T* const* InList, unsigned Elts, ASTContext &Ctx) {
    ObjCListBase::set(reinterpret_cast<void*const*>(InList), Elts, Ctx);
  }

  typedef T* const * iterator;
  iterator begin() const { return (iterator)List; }
  iterator end() const { return (iterator)List+NumElts; }

  T* operator[](unsigned Idx) const {
    assert(Idx < NumElts && "Invalid access");
    return (T*)List[Idx];
  }
};

/// \brief A list of Objective-C protocols, along with the source
/// locations at which they were referenced.
class ObjCProtocolList : public ObjCList<ObjCProtocolDecl> {
  SourceLocation *Locations;

  using ObjCList<ObjCProtocolDecl>::set;

public:
  ObjCProtocolList() : ObjCList<ObjCProtocolDecl>(), Locations(nullptr) { }

  typedef const SourceLocation *loc_iterator;
  loc_iterator loc_begin() const { return Locations; }
  loc_iterator loc_end() const { return Locations + size(); }

  void set(ObjCProtocolDecl* const* InList, unsigned Elts,
           const SourceLocation *Locs, ASTContext &Ctx);
};


/// ObjCMethodDecl - Represents an instance or class method declaration.
/// ObjC methods can be declared within 4 contexts: class interfaces,
/// categories, protocols, and class implementations. While C++ member
/// functions leverage C syntax, Objective-C method syntax is modeled after
/// Smalltalk (using colons to specify argument types/expressions).
/// Here are some brief examples:
///
/// Setter/getter instance methods:
/// - (void)setMenu:(NSMenu *)menu;
/// - (NSMenu *)menu;
///
/// Instance method that takes 2 NSView arguments:
/// - (void)replaceSubview:(NSView *)oldView with:(NSView *)newView;
///
/// Getter class method:
/// + (NSMenu *)defaultMenu;
///
/// A selector represents a unique name for a method. The selector names for
/// the above methods are setMenu:, menu, replaceSubview:with:, and defaultMenu.
///
class ObjCMethodDecl : public NamedDecl, public DeclContext {
public:
  enum ImplementationControl { None, Required, Optional };
private:
  // The conventional meaning of this method; an ObjCMethodFamily.
  // This is not serialized; instead, it is computed on demand and
  // cached.
  mutable unsigned Family : ObjCMethodFamilyBitWidth;

  /// instance (true) or class (false) method.
  unsigned IsInstance : 1;
  unsigned IsVariadic : 1;

  /// True if this method is the getter or setter for an explicit property.
  unsigned IsPropertyAccessor : 1;

  // Method has a definition.
  unsigned IsDefined : 1;

  /// \brief Method redeclaration in the same interface.
  unsigned IsRedeclaration : 1;

  /// \brief Is redeclared in the same interface.
  mutable unsigned HasRedeclaration : 1;

  // NOTE: VC++ treats enums as signed, avoid using ImplementationControl enum
  /// \@required/\@optional
  unsigned DeclImplementation : 2;

  // NOTE: VC++ treats enums as signed, avoid using the ObjCDeclQualifier enum
  /// in, inout, etc.
  unsigned objcDeclQualifier : 7;

  /// \brief Indicates whether this method has a related result type.
  unsigned RelatedResultType : 1;

  /// \brief Whether the locations of the selector identifiers are in a
  /// "standard" position, a enum SelectorLocationsKind.
  unsigned SelLocsKind : 2;

  /// \brief Whether this method overrides any other in the class hierarchy.
  ///
  /// A method is said to override any method in the class's
  /// base classes, its protocols, or its categories' protocols, that has
  /// the same selector and is of the same kind (class or instance).
  /// A method in an implementation is not considered as overriding the same
  /// method in the interface or its categories.
  unsigned IsOverriding : 1;

  /// \brief Indicates if the method was a definition but its body was skipped.
  unsigned HasSkippedBody : 1;

  // Return type of this method.
  QualType MethodDeclType;

  // Type source information for the return type.
  TypeSourceInfo *ReturnTInfo;

  /// \brief Array of ParmVarDecls for the formal parameters of this method
  /// and optionally followed by selector locations.
  void *ParamsAndSelLocs;
  unsigned NumParams;

  /// List of attributes for this method declaration.
  SourceLocation DeclEndLoc; // the location of the ';' or '{'.

  // The following are only used for method definitions, null otherwise.
  LazyDeclStmtPtr Body;

  /// SelfDecl - Decl for the implicit self parameter. This is lazily
  /// constructed by createImplicitParams.
  ImplicitParamDecl *SelfDecl;
  /// CmdDecl - Decl for the implicit _cmd parameter. This is lazily
  /// constructed by createImplicitParams.
  ImplicitParamDecl *CmdDecl;

  SelectorLocationsKind getSelLocsKind() const {
    return (SelectorLocationsKind)SelLocsKind;
  }
  bool hasStandardSelLocs() const {
    return getSelLocsKind() != SelLoc_NonStandard;
  }

  /// \brief Get a pointer to the stored selector identifiers locations array.
  /// No locations will be stored if HasStandardSelLocs is true.
  SourceLocation *getStoredSelLocs() {
    return reinterpret_cast<SourceLocation*>(getParams() + NumParams);
  }
  const SourceLocation *getStoredSelLocs() const {
    return reinterpret_cast<const SourceLocation*>(getParams() + NumParams);
  }

  /// \brief Get a pointer to the stored selector identifiers locations array.
  /// No locations will be stored if HasStandardSelLocs is true.
  ParmVarDecl **getParams() {
    return reinterpret_cast<ParmVarDecl **>(ParamsAndSelLocs);
  }
  const ParmVarDecl *const *getParams() const {
    return reinterpret_cast<const ParmVarDecl *const *>(ParamsAndSelLocs);
  }

  /// \brief Get the number of stored selector identifiers locations.
  /// No locations will be stored if HasStandardSelLocs is true.
  unsigned getNumStoredSelLocs() const {
    if (hasStandardSelLocs())
      return 0;
    return getNumSelectorLocs();
  }

  void setParamsAndSelLocs(ASTContext &C,
                           ArrayRef<ParmVarDecl*> Params,
                           ArrayRef<SourceLocation> SelLocs);

  ObjCMethodDecl(SourceLocation beginLoc, SourceLocation endLoc,
                 Selector SelInfo, QualType T, TypeSourceInfo *ReturnTInfo,
                 DeclContext *contextDecl, bool isInstance = true,
                 bool isVariadic = false, bool isPropertyAccessor = false,
                 bool isImplicitlyDeclared = false, bool isDefined = false,
                 ImplementationControl impControl = None,
                 bool HasRelatedResultType = false)
      : NamedDecl(ObjCMethod, contextDecl, beginLoc, SelInfo),
        DeclContext(ObjCMethod), Family(InvalidObjCMethodFamily),
        IsInstance(isInstance), IsVariadic(isVariadic),
        IsPropertyAccessor(isPropertyAccessor), IsDefined(isDefined),
        IsRedeclaration(0), HasRedeclaration(0), DeclImplementation(impControl),
        objcDeclQualifier(OBJC_TQ_None),
        RelatedResultType(HasRelatedResultType),
        SelLocsKind(SelLoc_StandardNoSpace), IsOverriding(0), HasSkippedBody(0),
        MethodDeclType(T), ReturnTInfo(ReturnTInfo), ParamsAndSelLocs(nullptr),
        NumParams(0), DeclEndLoc(endLoc), Body(), SelfDecl(nullptr),
        CmdDecl(nullptr) {
    setImplicit(isImplicitlyDeclared);
  }

  /// \brief A definition will return its interface declaration.
  /// An interface declaration will return its definition.
  /// Otherwise it will return itself.
  ObjCMethodDecl *getNextRedeclarationImpl() override;

public:
  static ObjCMethodDecl *
  Create(ASTContext &C, SourceLocation beginLoc, SourceLocation endLoc,
         Selector SelInfo, QualType T, TypeSourceInfo *ReturnTInfo,
         DeclContext *contextDecl, bool isInstance = true,
         bool isVariadic = false, bool isPropertyAccessor = false,
         bool isImplicitlyDeclared = false, bool isDefined = false,
         ImplementationControl impControl = None,
         bool HasRelatedResultType = false);

  static ObjCMethodDecl *CreateDeserialized(ASTContext &C, unsigned ID);

  ObjCMethodDecl *getCanonicalDecl() override;
  const ObjCMethodDecl *getCanonicalDecl() const {
    return const_cast<ObjCMethodDecl*>(this)->getCanonicalDecl();
  }

  ObjCDeclQualifier getObjCDeclQualifier() const {
    return ObjCDeclQualifier(objcDeclQualifier);
  }
  void setObjCDeclQualifier(ObjCDeclQualifier QV) { objcDeclQualifier = QV; }

  /// \brief Determine whether this method has a result type that is related
  /// to the message receiver's type.
  bool hasRelatedResultType() const { return RelatedResultType; }

  /// \brief Note whether this method has a related result type.
  void SetRelatedResultType(bool RRT = true) { RelatedResultType = RRT; }

  /// \brief True if this is a method redeclaration in the same interface.
  bool isRedeclaration() const { return IsRedeclaration; }
  void setAsRedeclaration(const ObjCMethodDecl *PrevMethod);

  /// \brief Returns the location where the declarator ends. It will be
  /// the location of ';' for a method declaration and the location of '{'
  /// for a method definition.
  SourceLocation getDeclaratorEndLoc() const { return DeclEndLoc; }

  // Location information, modeled after the Stmt API.
  SourceLocation getLocStart() const LLVM_READONLY { return getLocation(); }
  SourceLocation getLocEnd() const LLVM_READONLY;
  SourceRange getSourceRange() const override LLVM_READONLY {
    return SourceRange(getLocation(), getLocEnd());
  }

  SourceLocation getSelectorStartLoc() const {
    if (isImplicit())
      return getLocStart();
    return getSelectorLoc(0);
  }
  SourceLocation getSelectorLoc(unsigned Index) const {
    assert(Index < getNumSelectorLocs() && "Index out of range!");
    if (hasStandardSelLocs())
      return getStandardSelectorLoc(Index, getSelector(),
                                   getSelLocsKind() == SelLoc_StandardWithSpace,
                                    parameters(),
                                   DeclEndLoc);
    return getStoredSelLocs()[Index];
  }

  void getSelectorLocs(SmallVectorImpl<SourceLocation> &SelLocs) const;

  unsigned getNumSelectorLocs() const {
    if (isImplicit())
      return 0;
    Selector Sel = getSelector();
    if (Sel.isUnarySelector())
      return 1;
    return Sel.getNumArgs();
  }

  ObjCInterfaceDecl *getClassInterface();
  const ObjCInterfaceDecl *getClassInterface() const {
    return const_cast<ObjCMethodDecl*>(this)->getClassInterface();
  }

  Selector getSelector() const { return getDeclName().getObjCSelector(); }

  QualType getReturnType() const { return MethodDeclType; }
  void setReturnType(QualType T) { MethodDeclType = T; }
  SourceRange getReturnTypeSourceRange() const;

  /// \brief Determine the type of an expression that sends a message to this
  /// function. This replaces the type parameters with the types they would
  /// get if the receiver was parameterless (e.g. it may replace the type
  /// parameter with 'id').
  QualType getSendResultType() const;

  /// Determine the type of an expression that sends a message to this
  /// function with the given receiver type.
  QualType getSendResultType(QualType receiverType) const;

  TypeSourceInfo *getReturnTypeSourceInfo() const { return ReturnTInfo; }
  void setReturnTypeSourceInfo(TypeSourceInfo *TInfo) { ReturnTInfo = TInfo; }

  // Iterator access to formal parameters.
  unsigned param_size() const { return NumParams; }
  typedef const ParmVarDecl *const *param_const_iterator;
  typedef ParmVarDecl *const *param_iterator;
  typedef llvm::iterator_range<param_iterator> param_range;
  typedef llvm::iterator_range<param_const_iterator> param_const_range;

  param_range params() { return param_range(param_begin(), param_end()); }
  param_const_range params() const {
    return param_const_range(param_begin(), param_end());
  }

  param_const_iterator param_begin() const {
    return param_const_iterator(getParams());
  }
  param_const_iterator param_end() const {
    return param_const_iterator(getParams() + NumParams);
  }
  param_iterator param_begin() { return param_iterator(getParams()); }
  param_iterator param_end() { return param_iterator(getParams() + NumParams); }

  // This method returns and of the parameters which are part of the selector
  // name mangling requirements.
  param_const_iterator sel_param_end() const {
    return param_begin() + getSelector().getNumArgs();
  }

  // ArrayRef access to formal parameters.  This should eventually
  // replace the iterator interface above.
  ArrayRef<ParmVarDecl*> parameters() const {
    return llvm::makeArrayRef(const_cast<ParmVarDecl**>(getParams()),
                              NumParams);
  }

  /// \brief Sets the method's parameters and selector source locations.
  /// If the method is implicit (not coming from source) \p SelLocs is
  /// ignored.
  void setMethodParams(ASTContext &C,
                       ArrayRef<ParmVarDecl*> Params,
                       ArrayRef<SourceLocation> SelLocs = llvm::None);

  // Iterator access to parameter types.
  typedef std::const_mem_fun_t<QualType, ParmVarDecl> deref_fun;
  typedef llvm::mapped_iterator<param_const_iterator, deref_fun>
  param_type_iterator;

  param_type_iterator param_type_begin() const {
    return llvm::map_iterator(param_begin(), deref_fun(&ParmVarDecl::getType));
  }
  param_type_iterator param_type_end() const {
    return llvm::map_iterator(param_end(), deref_fun(&ParmVarDecl::getType));
  }

  /// createImplicitParams - Used to lazily create the self and cmd
  /// implict parameters. This must be called prior to using getSelfDecl()
  /// or getCmdDecl(). The call is ignored if the implicit paramters
  /// have already been created.
  void createImplicitParams(ASTContext &Context, const ObjCInterfaceDecl *ID);

  /// \return the type for \c self and set \arg selfIsPseudoStrong and
  /// \arg selfIsConsumed accordingly.
  QualType getSelfType(ASTContext &Context, const ObjCInterfaceDecl *OID,
                       bool &selfIsPseudoStrong, bool &selfIsConsumed);

  ImplicitParamDecl * getSelfDecl() const { return SelfDecl; }
  void setSelfDecl(ImplicitParamDecl *SD) { SelfDecl = SD; }
  ImplicitParamDecl * getCmdDecl() const { return CmdDecl; }
  void setCmdDecl(ImplicitParamDecl *CD) { CmdDecl = CD; }

  /// Determines the family of this method.
  ObjCMethodFamily getMethodFamily() const;

  bool isInstanceMethod() const { return IsInstance; }
  void setInstanceMethod(bool isInst) { IsInstance = isInst; }
  bool isVariadic() const { return IsVariadic; }
  void setVariadic(bool isVar) { IsVariadic = isVar; }

  bool isClassMethod() const { return !IsInstance; }

  bool isPropertyAccessor() const { return IsPropertyAccessor; }
  void setPropertyAccessor(bool isAccessor) { IsPropertyAccessor = isAccessor; }

  bool isDefined() const { return IsDefined; }
  void setDefined(bool isDefined) { IsDefined = isDefined; }

  /// \brief Whether this method overrides any other in the class hierarchy.
  ///
  /// A method is said to override any method in the class's
  /// base classes, its protocols, or its categories' protocols, that has
  /// the same selector and is of the same kind (class or instance).
  /// A method in an implementation is not considered as overriding the same
  /// method in the interface or its categories.
  bool isOverriding() const { return IsOverriding; }
  void setOverriding(bool isOverriding) { IsOverriding = isOverriding; }

  /// \brief Return overridden methods for the given \p Method.
  ///
  /// An ObjC method is considered to override any method in the class's
  /// base classes (and base's categories), its protocols, or its categories'
  /// protocols, that has
  /// the same selector and is of the same kind (class or instance).
  /// A method in an implementation is not considered as overriding the same
  /// method in the interface or its categories.
  void getOverriddenMethods(
                     SmallVectorImpl<const ObjCMethodDecl *> &Overridden) const;

  /// \brief True if the method was a definition but its body was skipped.
  bool hasSkippedBody() const { return HasSkippedBody; }
  void setHasSkippedBody(bool Skipped = true) { HasSkippedBody = Skipped; }

  /// \brief Returns the property associated with this method's selector.
  ///
  /// Note that even if this particular method is not marked as a property
  /// accessor, it is still possible for it to match a property declared in a
  /// superclass. Pass \c false if you only want to check the current class.
  const ObjCPropertyDecl *findPropertyDecl(bool CheckOverrides = true) const;

  // Related to protocols declared in  \@protocol
  void setDeclImplementation(ImplementationControl ic) {
    DeclImplementation = ic;
  }
  ImplementationControl getImplementationControl() const {
    return ImplementationControl(DeclImplementation);
  }

  /// Returns true if this specific method declaration is marked with the
  /// designated initializer attribute.
  bool isThisDeclarationADesignatedInitializer() const;

  /// Returns true if the method selector resolves to a designated initializer
  /// in the class's interface.
  ///
  /// \param InitMethod if non-null and the function returns true, it receives
  /// the method declaration that was marked with the designated initializer
  /// attribute.
  bool isDesignatedInitializerForTheInterface(
      const ObjCMethodDecl **InitMethod = nullptr) const;

  /// \brief Determine whether this method has a body.
  bool hasBody() const override { return Body.isValid(); }

  /// \brief Retrieve the body of this method, if it has one.
  Stmt *getBody() const override;

  void setLazyBody(uint64_t Offset) { Body = Offset; }

  CompoundStmt *getCompoundBody() { return (CompoundStmt*)getBody(); }
  void setBody(Stmt *B) { Body = B; }

  /// \brief Returns whether this specific method is a definition.
  bool isThisDeclarationADefinition() const { return hasBody(); }

  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
  static bool classofKind(Kind K) { return K == ObjCMethod; }
  static DeclContext *castToDeclContext(const ObjCMethodDecl *D) {
    return static_cast<DeclContext *>(const_cast<ObjCMethodDecl*>(D));
  }
  static ObjCMethodDecl *castFromDeclContext(const DeclContext *DC) {
    return static_cast<ObjCMethodDecl *>(const_cast<DeclContext*>(DC));
  }

  friend class ASTDeclReader;
  friend class ASTDeclWriter;
};

/// Describes the variance of a given generic parameter.
enum class ObjCTypeParamVariance : uint8_t {
  /// The parameter is invariant: must match exactly.
  Invariant,
  /// The parameter is covariant, e.g., X<T> is a subtype of X<U> when
  /// the type parameter is covariant and T is a subtype of U.
  Covariant,
  /// The parameter is contravariant, e.g., X<T> is a subtype of X<U>
  /// when the type parameter is covariant and U is a subtype of T.
  Contravariant,
};

/// Represents the declaration of an Objective-C type parameter.
///
/// \code
/// @interface NSDictionary<Key : id<NSCopying>, Value>
/// @end
/// \endcode
///
/// In the example above, both \c Key and \c Value are represented by
/// \c ObjCTypeParamDecl. \c Key has an explicit bound of \c id<NSCopying>,
/// while \c Value gets an implicit bound of \c id.
///
/// Objective-C type parameters are typedef-names in the grammar,
class ObjCTypeParamDecl : public TypedefNameDecl {
  void anchor() override;

  /// Index of this type parameter in the type parameter list.
  unsigned Index : 14;

  /// The variance of the type parameter.
  unsigned Variance : 2;

  /// The location of the variance, if any.
  SourceLocation VarianceLoc;

  /// The location of the ':', which will be valid when the bound was
  /// explicitly specified.
  SourceLocation ColonLoc;

  ObjCTypeParamDecl(ASTContext &ctx, DeclContext *dc, 
                    ObjCTypeParamVariance variance, SourceLocation varianceLoc,
                    unsigned index,
                    SourceLocation nameLoc, IdentifierInfo *name,
                    SourceLocation colonLoc, TypeSourceInfo *boundInfo)
    : TypedefNameDecl(ObjCTypeParam, ctx, dc, nameLoc, nameLoc, name,
                      boundInfo),
      Index(index), Variance(static_cast<unsigned>(variance)),
      VarianceLoc(varianceLoc), ColonLoc(colonLoc) { }

public:
  static ObjCTypeParamDecl *Create(ASTContext &ctx, DeclContext *dc,
                                   ObjCTypeParamVariance variance,
                                   SourceLocation varianceLoc,
                                   unsigned index,
                                   SourceLocation nameLoc,
                                   IdentifierInfo *name,
                                   SourceLocation colonLoc,
                                   TypeSourceInfo *boundInfo);
  static ObjCTypeParamDecl *CreateDeserialized(ASTContext &ctx, unsigned ID);

  SourceRange getSourceRange() const override LLVM_READONLY;

  /// Determine the variance of this type parameter.
  ObjCTypeParamVariance getVariance() const {
    return static_cast<ObjCTypeParamVariance>(Variance);
  }

  /// Set the variance of this type parameter.
  void setVariance(ObjCTypeParamVariance variance) {
    Variance = static_cast<unsigned>(variance);
  }

  /// Retrieve the location of the variance keyword.
  SourceLocation getVarianceLoc() const { return VarianceLoc; }

  /// Retrieve the index into its type parameter list.
  unsigned getIndex() const { return Index; }

  /// Whether this type parameter has an explicitly-written type bound, e.g.,
  /// "T : NSView".
  bool hasExplicitBound() const { return ColonLoc.isValid(); }

  /// Retrieve the location of the ':' separating the type parameter name
  /// from the explicitly-specified bound.
  SourceLocation getColonLoc() const { return ColonLoc; }

  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
  static bool classofKind(Kind K) { return K == ObjCTypeParam; }

  friend class ASTDeclReader;
  friend class ASTDeclWriter;
};

/// Stores a list of Objective-C type parameters for a parameterized class
/// or a category/extension thereof.
///
/// \code
/// @interface NSArray<T> // stores the <T>
/// @end
/// \endcode
class ObjCTypeParamList {
  /// Stores the components of a SourceRange as a POD.
  struct PODSourceRange {
    unsigned Begin;
    unsigned End;
  };

  union { 
    /// Location of the left and right angle brackets.
    PODSourceRange Brackets;

    // Used only for alignment.
    ObjCTypeParamDecl *AlignmentHack;
  };

  /// The number of parameters in the list, which are tail-allocated.
  unsigned NumParams;

  ObjCTypeParamList(SourceLocation lAngleLoc,
                    ArrayRef<ObjCTypeParamDecl *> typeParams,
                    SourceLocation rAngleLoc);

public:
  /// Create a new Objective-C type parameter list.
  static ObjCTypeParamList *create(ASTContext &ctx,
                                   SourceLocation lAngleLoc,
                                   ArrayRef<ObjCTypeParamDecl *> typeParams,
                                   SourceLocation rAngleLoc);

  /// Iterate through the type parameters in the list.
  typedef ObjCTypeParamDecl **iterator;

  iterator begin() { return reinterpret_cast<ObjCTypeParamDecl **>(this + 1); }

  iterator end() { return begin() + size(); }

  /// Determine the number of type parameters in this list.
  unsigned size() const { return NumParams; }

  // Iterate through the type parameters in the list.
  typedef ObjCTypeParamDecl * const *const_iterator;

  const_iterator begin() const {
    return reinterpret_cast<ObjCTypeParamDecl * const *>(this + 1);
  }

  const_iterator end() const {
    return begin() + size();
  }

  ObjCTypeParamDecl *front() const {
    assert(size() > 0 && "empty Objective-C type parameter list");
    return *begin();
  }

  ObjCTypeParamDecl *back() const {
    assert(size() > 0 && "empty Objective-C type parameter list");
    return *(end() - 1);
  }

  SourceLocation getLAngleLoc() const {
    return SourceLocation::getFromRawEncoding(Brackets.Begin);
  }
  SourceLocation getRAngleLoc() const {
    return SourceLocation::getFromRawEncoding(Brackets.End);
  }
  SourceRange getSourceRange() const {
    return SourceRange(getLAngleLoc(), getRAngleLoc());
  }

  /// Gather the default set of type arguments to be substituted for
  /// these type parameters when dealing with an unspecialized type.
  void gatherDefaultTypeArgs(SmallVectorImpl<QualType> &typeArgs) const;
};

/// ObjCContainerDecl - Represents a container for method declarations.
/// Current sub-classes are ObjCInterfaceDecl, ObjCCategoryDecl,
/// ObjCProtocolDecl, and ObjCImplDecl.
///
class ObjCContainerDecl : public NamedDecl, public DeclContext {
  void anchor() override;

  SourceLocation AtStart;

  // These two locations in the range mark the end of the method container.
  // The first points to the '@' token, and the second to the 'end' token.
  SourceRange AtEnd;
public:

  ObjCContainerDecl(Kind DK, DeclContext *DC,
                    IdentifierInfo *Id, SourceLocation nameLoc,
                    SourceLocation atStartLoc)
    : NamedDecl(DK, DC, nameLoc, Id), DeclContext(DK), AtStart(atStartLoc) {}

  // Iterator access to properties.
  typedef specific_decl_iterator<ObjCPropertyDecl> prop_iterator;
  typedef llvm::iterator_range<specific_decl_iterator<ObjCPropertyDecl>>
    prop_range;

  prop_range properties() const { return prop_range(prop_begin(), prop_end()); }
  prop_iterator prop_begin() const {
    return prop_iterator(decls_begin());
  }
  prop_iterator prop_end() const {
    return prop_iterator(decls_end());
  }

  // Iterator access to instance/class methods.
  typedef specific_decl_iterator<ObjCMethodDecl> method_iterator;
  typedef llvm::iterator_range<specific_decl_iterator<ObjCMethodDecl>>
    method_range;

  method_range methods() const {
    return method_range(meth_begin(), meth_end());
  }
  method_iterator meth_begin() const {
    return method_iterator(decls_begin());
  }
  method_iterator meth_end() const {
    return method_iterator(decls_end());
  }

  typedef filtered_decl_iterator<ObjCMethodDecl,
                                 &ObjCMethodDecl::isInstanceMethod>
    instmeth_iterator;
  typedef llvm::iterator_range<instmeth_iterator> instmeth_range;

  instmeth_range instance_methods() const {
    return instmeth_range(instmeth_begin(), instmeth_end());
  }
  instmeth_iterator instmeth_begin() const {
    return instmeth_iterator(decls_begin());
  }
  instmeth_iterator instmeth_end() const {
    return instmeth_iterator(decls_end());
  }

  typedef filtered_decl_iterator<ObjCMethodDecl,
                                 &ObjCMethodDecl::isClassMethod>
    classmeth_iterator;
  typedef llvm::iterator_range<classmeth_iterator> classmeth_range;

  classmeth_range class_methods() const {
    return classmeth_range(classmeth_begin(), classmeth_end());
  }
  classmeth_iterator classmeth_begin() const {
    return classmeth_iterator(decls_begin());
  }
  classmeth_iterator classmeth_end() const {
    return classmeth_iterator(decls_end());
  }

  // Get the local instance/class method declared in this interface.
  ObjCMethodDecl *getMethod(Selector Sel, bool isInstance,
                            bool AllowHidden = false) const;
  ObjCMethodDecl *getInstanceMethod(Selector Sel,
                                    bool AllowHidden = false) const {
    return getMethod(Sel, true/*isInstance*/, AllowHidden);
  }
  ObjCMethodDecl *getClassMethod(Selector Sel, bool AllowHidden = false) const {
    return getMethod(Sel, false/*isInstance*/, AllowHidden);
  }
  bool HasUserDeclaredSetterMethod(const ObjCPropertyDecl *P) const;
  ObjCIvarDecl *getIvarDecl(IdentifierInfo *Id) const;

  ObjCPropertyDecl *
  FindPropertyDeclaration(const IdentifierInfo *PropertyId) const;

  typedef llvm::DenseMap<IdentifierInfo*, ObjCPropertyDecl*> PropertyMap;
  
  typedef llvm::DenseMap<const ObjCProtocolDecl *, ObjCPropertyDecl*>
            ProtocolPropertyMap;
  
  typedef llvm::SmallVector<ObjCPropertyDecl*, 8> PropertyDeclOrder;
  
  /// This routine collects list of properties to be implemented in the class.
  /// This includes, class's and its conforming protocols' properties.
  /// Note, the superclass's properties are not included in the list.
  virtual void collectPropertiesToImplement(PropertyMap &PM,
                                            PropertyDeclOrder &PO) const {}

  SourceLocation getAtStartLoc() const { return AtStart; }
  void setAtStartLoc(SourceLocation Loc) { AtStart = Loc; }

  // Marks the end of the container.
  SourceRange getAtEndRange() const {
    return AtEnd;
  }
  void setAtEndRange(SourceRange atEnd) {
    AtEnd = atEnd;
  }

  SourceRange getSourceRange() const override LLVM_READONLY {
    return SourceRange(AtStart, getAtEndRange().getEnd());
  }

  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
  static bool classofKind(Kind K) {
    return K >= firstObjCContainer &&
           K <= lastObjCContainer;
  }

  static DeclContext *castToDeclContext(const ObjCContainerDecl *D) {
    return static_cast<DeclContext *>(const_cast<ObjCContainerDecl*>(D));
  }
  static ObjCContainerDecl *castFromDeclContext(const DeclContext *DC) {
    return static_cast<ObjCContainerDecl *>(const_cast<DeclContext*>(DC));
  }
};

/// \brief Represents an ObjC class declaration.
///
/// For example:
///
/// \code
///   // MostPrimitive declares no super class (not particularly useful).
///   \@interface MostPrimitive
///     // no instance variables or methods.
///   \@end
///
///   // NSResponder inherits from NSObject & implements NSCoding (a protocol).
///   \@interface NSResponder : NSObject \<NSCoding>
///   { // instance variables are represented by ObjCIvarDecl.
///     id nextResponder; // nextResponder instance variable.
///   }
///   - (NSResponder *)nextResponder; // return a pointer to NSResponder.
///   - (void)mouseMoved:(NSEvent *)theEvent; // return void, takes a pointer
///   \@end                                    // to an NSEvent.
/// \endcode
///
///   Unlike C/C++, forward class declarations are accomplished with \@class.
///   Unlike C/C++, \@class allows for a list of classes to be forward declared.
///   Unlike C++, ObjC is a single-rooted class model. In Cocoa, classes
///   typically inherit from NSObject (an exception is NSProxy).
///
class ObjCInterfaceDecl : public ObjCContainerDecl
                        , public Redeclarable<ObjCInterfaceDecl> {
  void anchor() override;

  /// TypeForDecl - This indicates the Type object that represents this
  /// TypeDecl.  It is a cache maintained by ASTContext::getObjCInterfaceType
  mutable const Type *TypeForDecl;
  friend class ASTContext;
  
  struct DefinitionData {
    /// \brief The definition of this class, for quick access from any 
    /// declaration.
    ObjCInterfaceDecl *Definition;
    
    /// When non-null, this is always an ObjCObjectType.
    TypeSourceInfo *SuperClassTInfo;
    
    /// Protocols referenced in the \@interface  declaration
    ObjCProtocolList ReferencedProtocols;

    /// Protocols reference in both the \@interface and class extensions.
    ObjCList<ObjCProtocolDecl> AllReferencedProtocols;

    /// \brief List of categories and class extensions defined for this class.
    ///
    /// Categories are stored as a linked list in the AST, since the categories
    /// and class extensions come long after the initial interface declaration,
    /// and we avoid dynamically-resized arrays in the AST wherever possible.
    ObjCCategoryDecl *CategoryList;

    /// IvarList - List of all ivars defined by this class; including class
    /// extensions and implementation. This list is built lazily.
    ObjCIvarDecl *IvarList;

    /// \brief Indicates that the contents of this Objective-C class will be
    /// completed by the external AST source when required.
    mutable bool ExternallyCompleted : 1;

    /// \brief Indicates that the ivar cache does not yet include ivars
    /// declared in the implementation.
    mutable bool IvarListMissingImplementation : 1;

    /// Indicates that this interface decl contains at least one initializer
    /// marked with the 'objc_designated_initializer' attribute.
    bool HasDesignatedInitializers : 1;

    enum InheritedDesignatedInitializersState {
      /// We didn't calculate whether the designated initializers should be
      /// inherited or not.
      IDI_Unknown = 0,
      /// Designated initializers are inherited for the super class.
      IDI_Inherited = 1,
      /// The class does not inherit designated initializers.
      IDI_NotInherited = 2
    };
    /// One of the \c InheritedDesignatedInitializersState enumeratos.
    mutable unsigned InheritedDesignatedInitializers : 2;
    
    /// \brief The location of the last location in this declaration, before
    /// the properties/methods. For example, this will be the '>', '}', or 
    /// identifier, 
    SourceLocation EndLoc; 

    DefinitionData() : Definition(), SuperClassTInfo(), CategoryList(), IvarList(), 
                       ExternallyCompleted(),
                       IvarListMissingImplementation(true),
                       HasDesignatedInitializers(),
                       InheritedDesignatedInitializers(IDI_Unknown) { }
  };

  ObjCInterfaceDecl(const ASTContext &C, DeclContext *DC, SourceLocation AtLoc,
                    IdentifierInfo *Id, ObjCTypeParamList *typeParamList,
                    SourceLocation CLoc, ObjCInterfaceDecl *PrevDecl,
                    bool IsInternal);

  void LoadExternalDefinition() const;

  /// The type parameters associated with this class, if any.
  ObjCTypeParamList *TypeParamList;

  /// \brief Contains a pointer to the data associated with this class,
  /// which will be NULL if this class has not yet been defined.
  ///
  /// The bit indicates when we don't need to check for out-of-date
  /// declarations. It will be set unless modules are enabled.
  llvm::PointerIntPair<DefinitionData *, 1, bool> Data;

  DefinitionData &data() const {
    assert(Data.getPointer() && "Declaration has no definition!");
    return *Data.getPointer();
  }

  /// \brief Allocate the definition data for this class.
  void allocateDefinitionData();
  
  typedef Redeclarable<ObjCInterfaceDecl> redeclarable_base;
  ObjCInterfaceDecl *getNextRedeclarationImpl() override {
    return getNextRedeclaration();
  }
  ObjCInterfaceDecl *getPreviousDeclImpl() override {
    return getPreviousDecl();
  }
  ObjCInterfaceDecl *getMostRecentDeclImpl() override {
    return getMostRecentDecl();
  }

public:
  static ObjCInterfaceDecl *Create(const ASTContext &C, DeclContext *DC,
                                   SourceLocation atLoc,
                                   IdentifierInfo *Id,
                                   ObjCTypeParamList *typeParamList,
                                   ObjCInterfaceDecl *PrevDecl,
                                   SourceLocation ClassLoc = SourceLocation(),
                                   bool isInternal = false);

  static ObjCInterfaceDecl *CreateDeserialized(const ASTContext &C, unsigned ID);

  /// Retrieve the type parameters of this class.
  ///
  /// This function looks for a type parameter list for the given
  /// class; if the class has been declared (with \c \@class) but not
  /// defined (with \c \@interface), it will search for a declaration that
  /// has type parameters, skipping any declarations that do not.
  ObjCTypeParamList *getTypeParamList() const;

  /// Set the type parameters of this class.
  ///
  /// This function is used by the AST importer, which must import the type
  /// parameters after creating their DeclContext to avoid loops.
  void setTypeParamList(ObjCTypeParamList *TPL);

  /// Retrieve the type parameters written on this particular declaration of
  /// the class.
  ObjCTypeParamList *getTypeParamListAsWritten() const {
    return TypeParamList;
  }

  SourceRange getSourceRange() const override LLVM_READONLY {
    if (isThisDeclarationADefinition())
      return ObjCContainerDecl::getSourceRange();
    
    return SourceRange(getAtStartLoc(), getLocation());
  }

  /// \brief Indicate that this Objective-C class is complete, but that
  /// the external AST source will be responsible for filling in its contents
  /// when a complete class is required.
  void setExternallyCompleted();

  /// Indicate that this interface decl contains at least one initializer
  /// marked with the 'objc_designated_initializer' attribute.
  void setHasDesignatedInitializers();

  /// Returns true if this interface decl contains at least one initializer
  /// marked with the 'objc_designated_initializer' attribute.
  bool hasDesignatedInitializers() const;

  /// Returns true if this interface decl declares a designated initializer
  /// or it inherites one from its super class.
  bool declaresOrInheritsDesignatedInitializers() const {
    return hasDesignatedInitializers() || inheritsDesignatedInitializers();
  }

  const ObjCProtocolList &getReferencedProtocols() const {
    assert(hasDefinition() && "Caller did not check for forward reference!");
    if (data().ExternallyCompleted)
      LoadExternalDefinition();

    return data().ReferencedProtocols;
  }

  ObjCImplementationDecl *getImplementation() const;
  void setImplementation(ObjCImplementationDecl *ImplD);

  ObjCCategoryDecl *FindCategoryDeclaration(IdentifierInfo *CategoryId) const;

  // Get the local instance/class method declared in a category.
  ObjCMethodDecl *getCategoryInstanceMethod(Selector Sel) const;
  ObjCMethodDecl *getCategoryClassMethod(Selector Sel) const;
  ObjCMethodDecl *getCategoryMethod(Selector Sel, bool isInstance) const {
    return isInstance ? getCategoryInstanceMethod(Sel)
                      : getCategoryClassMethod(Sel);
  }

  typedef ObjCProtocolList::iterator protocol_iterator;
  typedef llvm::iterator_range<protocol_iterator> protocol_range;

  protocol_range protocols() const {
    return protocol_range(protocol_begin(), protocol_end());
  }
  protocol_iterator protocol_begin() const {
    // FIXME: Should make sure no callers ever do this.
    if (!hasDefinition())
      return protocol_iterator();
    
    if (data().ExternallyCompleted)
      LoadExternalDefinition();

    return data().ReferencedProtocols.begin();
  }
  protocol_iterator protocol_end() const {
    // FIXME: Should make sure no callers ever do this.
    if (!hasDefinition())
      return protocol_iterator();

    if (data().ExternallyCompleted)
      LoadExternalDefinition();

    return data().ReferencedProtocols.end();
  }

  typedef ObjCProtocolList::loc_iterator protocol_loc_iterator;
  typedef llvm::iterator_range<protocol_loc_iterator> protocol_loc_range;

  protocol_loc_range protocol_locs() const {
    return protocol_loc_range(protocol_loc_begin(), protocol_loc_end());
  }
  protocol_loc_iterator protocol_loc_begin() const {
    // FIXME: Should make sure no callers ever do this.
    if (!hasDefinition())
      return protocol_loc_iterator();

    if (data().ExternallyCompleted)
      LoadExternalDefinition();

    return data().ReferencedProtocols.loc_begin();
  }

  protocol_loc_iterator protocol_loc_end() const {
    // FIXME: Should make sure no callers ever do this.
    if (!hasDefinition())
      return protocol_loc_iterator();

    if (data().ExternallyCompleted)
      LoadExternalDefinition();

    return data().ReferencedProtocols.loc_end();
  }

  typedef ObjCList<ObjCProtocolDecl>::iterator all_protocol_iterator;
  typedef llvm::iterator_range<all_protocol_iterator> all_protocol_range;

  all_protocol_range all_referenced_protocols() const {
    return all_protocol_range(all_referenced_protocol_begin(),
                              all_referenced_protocol_end());
  }
  all_protocol_iterator all_referenced_protocol_begin() const {
    // FIXME: Should make sure no callers ever do this.
    if (!hasDefinition())
      return all_protocol_iterator();

    if (data().ExternallyCompleted)
      LoadExternalDefinition();

    return data().AllReferencedProtocols.empty()  
             ? protocol_begin()
             : data().AllReferencedProtocols.begin();
  }
  all_protocol_iterator all_referenced_protocol_end() const {
    // FIXME: Should make sure no callers ever do this.
    if (!hasDefinition())
      return all_protocol_iterator();
    
    if (data().ExternallyCompleted)
      LoadExternalDefinition();

    return data().AllReferencedProtocols.empty() 
             ? protocol_end()
             : data().AllReferencedProtocols.end();
  }

  typedef specific_decl_iterator<ObjCIvarDecl> ivar_iterator;
  typedef llvm::iterator_range<specific_decl_iterator<ObjCIvarDecl>> ivar_range;

  ivar_range ivars() const { return ivar_range(ivar_begin(), ivar_end()); }
  ivar_iterator ivar_begin() const { 
    if (const ObjCInterfaceDecl *Def = getDefinition())
      return ivar_iterator(Def->decls_begin()); 
    
    // FIXME: Should make sure no callers ever do this.
    return ivar_iterator();
  }
  ivar_iterator ivar_end() const { 
    if (const ObjCInterfaceDecl *Def = getDefinition())
      return ivar_iterator(Def->decls_end()); 

    // FIXME: Should make sure no callers ever do this.
    return ivar_iterator();
  }

  unsigned ivar_size() const {
    return std::distance(ivar_begin(), ivar_end());
  }

  bool ivar_empty() const { return ivar_begin() == ivar_end(); }

  ObjCIvarDecl *all_declared_ivar_begin();
  const ObjCIvarDecl *all_declared_ivar_begin() const {
    // Even though this modifies IvarList, it's conceptually const:
    // the ivar chain is essentially a cached property of ObjCInterfaceDecl.
    return const_cast<ObjCInterfaceDecl *>(this)->all_declared_ivar_begin();
  }
  void setIvarList(ObjCIvarDecl *ivar) { data().IvarList = ivar; }

  /// setProtocolList - Set the list of protocols that this interface
  /// implements.
  void setProtocolList(ObjCProtocolDecl *const* List, unsigned Num,
                       const SourceLocation *Locs, ASTContext &C) {
    data().ReferencedProtocols.set(List, Num, Locs, C);
  }

  /// mergeClassExtensionProtocolList - Merge class extension's protocol list
  /// into the protocol list for this class.
  void mergeClassExtensionProtocolList(ObjCProtocolDecl *const* List,
                                       unsigned Num,
                                       ASTContext &C);

  /// Produce a name to be used for class's metadata. It comes either via
  /// objc_runtime_name attribute or class name.
  StringRef getObjCRuntimeNameAsString() const;

  /// Returns the designated initializers for the interface.
  ///
  /// If this declaration does not have methods marked as designated
  /// initializers then the interface inherits the designated initializers of
  /// its super class.
  void getDesignatedInitializers(
                  llvm::SmallVectorImpl<const ObjCMethodDecl *> &Methods) const;

  /// Returns true if the given selector is a designated initializer for the
  /// interface.
  ///
  /// If this declaration does not have methods marked as designated
  /// initializers then the interface inherits the designated initializers of
  /// its super class.
  ///
  /// \param InitMethod if non-null and the function returns true, it receives
  /// the method that was marked as a designated initializer.
  bool
  isDesignatedInitializer(Selector Sel,
                          const ObjCMethodDecl **InitMethod = nullptr) const;

  /// \brief Determine whether this particular declaration of this class is
  /// actually also a definition.
  bool isThisDeclarationADefinition() const { 
    return getDefinition() == this;
  }
                          
  /// \brief Determine whether this class has been defined.
  bool hasDefinition() const {
    // If the name of this class is out-of-date, bring it up-to-date, which
    // might bring in a definition.
    // Note: a null value indicates that we don't have a definition and that
    // modules are enabled.
    if (!Data.getOpaqueValue()) {
      if (IdentifierInfo *II = getIdentifier()) {
        if (II->isOutOfDate()) {
          updateOutOfDate(*II);
        }
      }
    }

    return Data.getPointer();
  }
                        
  /// \brief Retrieve the definition of this class, or NULL if this class 
  /// has been forward-declared (with \@class) but not yet defined (with 
  /// \@interface).
  ObjCInterfaceDecl *getDefinition() {
    return hasDefinition()? Data.getPointer()->Definition : nullptr;
  }

  /// \brief Retrieve the definition of this class, or NULL if this class 
  /// has been forward-declared (with \@class) but not yet defined (with 
  /// \@interface).
  const ObjCInterfaceDecl *getDefinition() const {
    return hasDefinition()? Data.getPointer()->Definition : nullptr;
  }

  /// \brief Starts the definition of this Objective-C class, taking it from
  /// a forward declaration (\@class) to a definition (\@interface).
  void startDefinition();
  
  /// Retrieve the superclass type.
  const ObjCObjectType *getSuperClassType() const {
    if (TypeSourceInfo *TInfo = getSuperClassTInfo())
      return TInfo->getType()->castAs<ObjCObjectType>();

    return nullptr;
  }

  // Retrieve the type source information for the superclass.
  TypeSourceInfo *getSuperClassTInfo() const {
    // FIXME: Should make sure no callers ever do this.
    if (!hasDefinition())
      return nullptr;
    
    if (data().ExternallyCompleted)
      LoadExternalDefinition();

    return data().SuperClassTInfo;
  }

  // Retrieve the declaration for the superclass of this class, which
  // does not include any type arguments that apply to the superclass.
  ObjCInterfaceDecl *getSuperClass() const;

  void setSuperClass(TypeSourceInfo *superClass) { 
    data().SuperClassTInfo = superClass;
  }

  /// \brief Iterator that walks over the list of categories, filtering out
  /// those that do not meet specific criteria.
  ///
  /// This class template is used for the various permutations of category
  /// and extension iterators.
  template<bool (*Filter)(ObjCCategoryDecl *)>
  class filtered_category_iterator {
    ObjCCategoryDecl *Current;

    void findAcceptableCategory();
    
  public:
    typedef ObjCCategoryDecl *      value_type;
    typedef value_type              reference;
    typedef value_type              pointer;
    typedef std::ptrdiff_t          difference_type;
    typedef std::input_iterator_tag iterator_category;

    filtered_category_iterator() : Current(nullptr) { }
    explicit filtered_category_iterator(ObjCCategoryDecl *Current)
      : Current(Current)
    {
      findAcceptableCategory();
    }

    reference operator*() const { return Current; }
    pointer operator->() const { return Current; }

    filtered_category_iterator &operator++();

    filtered_category_iterator operator++(int) {
      filtered_category_iterator Tmp = *this;
      ++(*this);
      return Tmp;
    }

    friend bool operator==(filtered_category_iterator X,
                           filtered_category_iterator Y) {
      return X.Current == Y.Current;
    }

    friend bool operator!=(filtered_category_iterator X,
                           filtered_category_iterator Y) {
      return X.Current != Y.Current;
    }
  };

private:
  /// \brief Test whether the given category is visible.
  ///
  /// Used in the \c visible_categories_iterator.
  static bool isVisibleCategory(ObjCCategoryDecl *Cat);
                        
public:
  /// \brief Iterator that walks over the list of categories and extensions
  /// that are visible, i.e., not hidden in a non-imported submodule.
  typedef filtered_category_iterator<isVisibleCategory>
    visible_categories_iterator;

  typedef llvm::iterator_range<visible_categories_iterator>
    visible_categories_range;

  visible_categories_range visible_categories() const {
    return visible_categories_range(visible_categories_begin(),
                                    visible_categories_end());
  }

  /// \brief Retrieve an iterator to the beginning of the visible-categories
  /// list.
  visible_categories_iterator visible_categories_begin() const {
    return visible_categories_iterator(getCategoryListRaw());
  }

  /// \brief Retrieve an iterator to the end of the visible-categories list.
  visible_categories_iterator visible_categories_end() const {
    return visible_categories_iterator();
  }

  /// \brief Determine whether the visible-categories list is empty.
  bool visible_categories_empty() const {
    return visible_categories_begin() == visible_categories_end();
  }

private:
  /// \brief Test whether the given category... is a category.
  ///
  /// Used in the \c known_categories_iterator.
  static bool isKnownCategory(ObjCCategoryDecl *) { return true; }

public:
  /// \brief Iterator that walks over all of the known categories and
  /// extensions, including those that are hidden.
  typedef filtered_category_iterator<isKnownCategory> known_categories_iterator;
  typedef llvm::iterator_range<known_categories_iterator>
    known_categories_range;

  known_categories_range known_categories() const {
    return known_categories_range(known_categories_begin(),
                                  known_categories_end());
  }

  /// \brief Retrieve an iterator to the beginning of the known-categories
  /// list.
  known_categories_iterator known_categories_begin() const {
    return known_categories_iterator(getCategoryListRaw());
  }

  /// \brief Retrieve an iterator to the end of the known-categories list.
  known_categories_iterator known_categories_end() const {
    return known_categories_iterator();
  }

  /// \brief Determine whether the known-categories list is empty.
  bool known_categories_empty() const {
    return known_categories_begin() == known_categories_end();
  }

private:
  /// \brief Test whether the given category is a visible extension.
  ///
  /// Used in the \c visible_extensions_iterator.
  static bool isVisibleExtension(ObjCCategoryDecl *Cat);

public:
  /// \brief Iterator that walks over all of the visible extensions, skipping
  /// any that are known but hidden.
  typedef filtered_category_iterator<isVisibleExtension>
    visible_extensions_iterator;

  typedef llvm::iterator_range<visible_extensions_iterator>
    visible_extensions_range;

  visible_extensions_range visible_extensions() const {
    return visible_extensions_range(visible_extensions_begin(),
                                    visible_extensions_end());
  }

  /// \brief Retrieve an iterator to the beginning of the visible-extensions
  /// list.
  visible_extensions_iterator visible_extensions_begin() const {
    return visible_extensions_iterator(getCategoryListRaw());
  }

  /// \brief Retrieve an iterator to the end of the visible-extensions list.
  visible_extensions_iterator visible_extensions_end() const {
    return visible_extensions_iterator();
  }

  /// \brief Determine whether the visible-extensions list is empty.
  bool visible_extensions_empty() const {
    return visible_extensions_begin() == visible_extensions_end();
  }

private:
  /// \brief Test whether the given category is an extension.
  ///
  /// Used in the \c known_extensions_iterator.
  static bool isKnownExtension(ObjCCategoryDecl *Cat);
  
public:
  /// \brief Iterator that walks over all of the known extensions.
  typedef filtered_category_iterator<isKnownExtension>
    known_extensions_iterator;
  typedef llvm::iterator_range<known_extensions_iterator>
    known_extensions_range;

  known_extensions_range known_extensions() const {
    return known_extensions_range(known_extensions_begin(),
                                  known_extensions_end());
  }

  /// \brief Retrieve an iterator to the beginning of the known-extensions
  /// list.
  known_extensions_iterator known_extensions_begin() const {
    return known_extensions_iterator(getCategoryListRaw());
  }
  
  /// \brief Retrieve an iterator to the end of the known-extensions list.
  known_extensions_iterator known_extensions_end() const {
    return known_extensions_iterator();
  }

  /// \brief Determine whether the known-extensions list is empty.
  bool known_extensions_empty() const {
    return known_extensions_begin() == known_extensions_end();
  }

  /// \brief Retrieve the raw pointer to the start of the category/extension
  /// list.
  ObjCCategoryDecl* getCategoryListRaw() const {
    // FIXME: Should make sure no callers ever do this.
    if (!hasDefinition())
      return nullptr;
    
    if (data().ExternallyCompleted)
      LoadExternalDefinition();

    return data().CategoryList;
  }

  /// \brief Set the raw pointer to the start of the category/extension
  /// list.
  void setCategoryListRaw(ObjCCategoryDecl *category) {
    data().CategoryList = category;
  }

  ObjCPropertyDecl
    *FindPropertyVisibleInPrimaryClass(IdentifierInfo *PropertyId) const;

  void collectPropertiesToImplement(PropertyMap &PM,
                                    PropertyDeclOrder &PO) const override;

  /// isSuperClassOf - Return true if this class is the specified class or is a
  /// super class of the specified interface class.
  bool isSuperClassOf(const ObjCInterfaceDecl *I) const {
    // If RHS is derived from LHS it is OK; else it is not OK.
    while (I != nullptr) {
      if (declaresSameEntity(this, I))
        return true;
      
      I = I->getSuperClass();
    }
    return false;
  }

  /// isArcWeakrefUnavailable - Checks for a class or one of its super classes
  /// to be incompatible with __weak references. Returns true if it is.
  bool isArcWeakrefUnavailable() const;

  /// isObjCRequiresPropertyDefs - Checks that a class or one of its super 
  /// classes must not be auto-synthesized. Returns class decl. if it must not
  /// be; 0, otherwise.
  const ObjCInterfaceDecl *isObjCRequiresPropertyDefs() const;

  ObjCIvarDecl *lookupInstanceVariable(IdentifierInfo *IVarName,
                                       ObjCInterfaceDecl *&ClassDeclared);
  ObjCIvarDecl *lookupInstanceVariable(IdentifierInfo *IVarName) {
    ObjCInterfaceDecl *ClassDeclared;
    return lookupInstanceVariable(IVarName, ClassDeclared);
  }

  ObjCProtocolDecl *lookupNestedProtocol(IdentifierInfo *Name);
                          
  // Lookup a method. First, we search locally. If a method isn't
  // found, we search referenced protocols and class categories.
  ObjCMethodDecl *lookupMethod(Selector Sel, bool isInstance,
                               bool shallowCategoryLookup = false,
                               bool followSuper = true,
                               const ObjCCategoryDecl *C = nullptr) const;

  /// Lookup an instance method for a given selector.
  ObjCMethodDecl *lookupInstanceMethod(Selector Sel) const {
    return lookupMethod(Sel, true/*isInstance*/);
  }

  /// Lookup a class method for a given selector.
  ObjCMethodDecl *lookupClassMethod(Selector Sel) const {
    return lookupMethod(Sel, false/*isInstance*/);
  }
  ObjCInterfaceDecl *lookupInheritedClass(const IdentifierInfo *ICName);

  /// \brief Lookup a method in the classes implementation hierarchy.
  ObjCMethodDecl *lookupPrivateMethod(const Selector &Sel,
                                      bool Instance=true) const;

  ObjCMethodDecl *lookupPrivateClassMethod(const Selector &Sel) {
    return lookupPrivateMethod(Sel, false);
  }

  /// \brief Lookup a setter or getter in the class hierarchy,
  /// including in all categories except for category passed
  /// as argument.
  ObjCMethodDecl *lookupPropertyAccessor(const Selector Sel,
                                         const ObjCCategoryDecl *Cat) const {
    return lookupMethod(Sel, true/*isInstance*/,
                        false/*shallowCategoryLookup*/,
                        true /* followsSuper */,
                        Cat);
  }
                          
  SourceLocation getEndOfDefinitionLoc() const { 
    if (!hasDefinition())
      return getLocation();
    
    return data().EndLoc; 
  }
                          
  void setEndOfDefinitionLoc(SourceLocation LE) { data().EndLoc = LE; }

  /// Retrieve the starting location of the superclass.
  SourceLocation getSuperClassLoc() const;

  /// isImplicitInterfaceDecl - check that this is an implicitly declared
  /// ObjCInterfaceDecl node. This is for legacy objective-c \@implementation
  /// declaration without an \@interface declaration.
  bool isImplicitInterfaceDecl() const { 
    return hasDefinition() ? data().Definition->isImplicit() : isImplicit();
  }

  /// ClassImplementsProtocol - Checks that 'lProto' protocol
  /// has been implemented in IDecl class, its super class or categories (if
  /// lookupCategory is true).
  bool ClassImplementsProtocol(ObjCProtocolDecl *lProto,
                               bool lookupCategory,
                               bool RHSIsQualifiedID = false);

  typedef redeclarable_base::redecl_range redecl_range;
  typedef redeclarable_base::redecl_iterator redecl_iterator;
  using redeclarable_base::redecls_begin;
  using redeclarable_base::redecls_end;
  using redeclarable_base::redecls;
  using redeclarable_base::getPreviousDecl;
  using redeclarable_base::getMostRecentDecl;
  using redeclarable_base::isFirstDecl;

  /// Retrieves the canonical declaration of this Objective-C class.
  ObjCInterfaceDecl *getCanonicalDecl() override { return getFirstDecl(); }
  const ObjCInterfaceDecl *getCanonicalDecl() const { return getFirstDecl(); }

  // Low-level accessor
  const Type *getTypeForDecl() const { return TypeForDecl; }
  void setTypeForDecl(const Type *TD) const { TypeForDecl = TD; }

  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
  static bool classofKind(Kind K) { return K == ObjCInterface; }

  friend class ASTReader;
  friend class ASTDeclReader;
  friend class ASTDeclWriter;

private:
  const ObjCInterfaceDecl *findInterfaceWithDesignatedInitializers() const;
  bool inheritsDesignatedInitializers() const;
};

/// ObjCIvarDecl - Represents an ObjC instance variable. In general, ObjC
/// instance variables are identical to C. The only exception is Objective-C
/// supports C++ style access control. For example:
///
///   \@interface IvarExample : NSObject
///   {
///     id defaultToProtected;
///   \@public:
///     id canBePublic; // same as C++.
///   \@protected:
///     id canBeProtected; // same as C++.
///   \@package:
///     id canBePackage; // framework visibility (not available in C++).
///   }
///
class ObjCIvarDecl : public FieldDecl {
  void anchor() override;

public:
  enum AccessControl {
    None, Private, Protected, Public, Package
  };

private:
  ObjCIvarDecl(ObjCContainerDecl *DC, SourceLocation StartLoc,
               SourceLocation IdLoc, IdentifierInfo *Id,
               QualType T, TypeSourceInfo *TInfo, AccessControl ac, Expr *BW,
               bool synthesized)
    : FieldDecl(ObjCIvar, DC, StartLoc, IdLoc, Id, T, TInfo, BW,
                /*Mutable=*/false, /*HasInit=*/ICIS_NoInit),
      NextIvar(nullptr), DeclAccess(ac), Synthesized(synthesized) {}

public:
  static ObjCIvarDecl *Create(ASTContext &C, ObjCContainerDecl *DC,
                              SourceLocation StartLoc, SourceLocation IdLoc,
                              IdentifierInfo *Id, QualType T,
                              TypeSourceInfo *TInfo,
                              AccessControl ac, Expr *BW = nullptr,
                              bool synthesized=false);

  static ObjCIvarDecl *CreateDeserialized(ASTContext &C, unsigned ID);
  
  /// \brief Return the class interface that this ivar is logically contained
  /// in; this is either the interface where the ivar was declared, or the
  /// interface the ivar is conceptually a part of in the case of synthesized
  /// ivars.
  const ObjCInterfaceDecl *getContainingInterface() const;

  ObjCIvarDecl *getNextIvar() { return NextIvar; }
  const ObjCIvarDecl *getNextIvar() const { return NextIvar; }
  void setNextIvar(ObjCIvarDecl *ivar) { NextIvar = ivar; }

  void setAccessControl(AccessControl ac) { DeclAccess = ac; }

  AccessControl getAccessControl() const { return AccessControl(DeclAccess); }

  AccessControl getCanonicalAccessControl() const {
    return DeclAccess == None ? Protected : AccessControl(DeclAccess);
  }

  void setSynthesize(bool synth) { Synthesized = synth; }
  bool getSynthesize() const { return Synthesized; }

  /// Retrieve the type of this instance variable when viewed as a member of a
  /// specific object type.
  QualType getUsageType(QualType objectType) const;

  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
  static bool classofKind(Kind K) { return K == ObjCIvar; }
private:
  /// NextIvar - Next Ivar in the list of ivars declared in class; class's
  /// extensions and class's implementation
  ObjCIvarDecl *NextIvar;

  // NOTE: VC++ treats enums as signed, avoid using the AccessControl enum
  unsigned DeclAccess : 3;
  unsigned Synthesized : 1;
};


/// \brief Represents a field declaration created by an \@defs(...).
class ObjCAtDefsFieldDecl : public FieldDecl {
  void anchor() override;
  ObjCAtDefsFieldDecl(DeclContext *DC, SourceLocation StartLoc,
                      SourceLocation IdLoc, IdentifierInfo *Id,
                      QualType T, Expr *BW)
    : FieldDecl(ObjCAtDefsField, DC, StartLoc, IdLoc, Id, T,
                /*TInfo=*/nullptr, // FIXME: Do ObjCAtDefs have declarators ?
                BW, /*Mutable=*/false, /*HasInit=*/ICIS_NoInit) {}

public:
  static ObjCAtDefsFieldDecl *Create(ASTContext &C, DeclContext *DC,
                                     SourceLocation StartLoc,
                                     SourceLocation IdLoc, IdentifierInfo *Id,
                                     QualType T, Expr *BW);

  static ObjCAtDefsFieldDecl *CreateDeserialized(ASTContext &C, unsigned ID);
  
  // Implement isa/cast/dyncast/etc.
  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
  static bool classofKind(Kind K) { return K == ObjCAtDefsField; }
};

/// \brief Represents an Objective-C protocol declaration.
///
/// Objective-C protocols declare a pure abstract type (i.e., no instance
/// variables are permitted).  Protocols originally drew inspiration from
/// C++ pure virtual functions (a C++ feature with nice semantics and lousy
/// syntax:-). Here is an example:
///
/// \code
/// \@protocol NSDraggingInfo <refproto1, refproto2>
/// - (NSWindow *)draggingDestinationWindow;
/// - (NSImage *)draggedImage;
/// \@end
/// \endcode
///
/// This says that NSDraggingInfo requires two methods and requires everything
/// that the two "referenced protocols" 'refproto1' and 'refproto2' require as
/// well.
///
/// \code
/// \@interface ImplementsNSDraggingInfo : NSObject \<NSDraggingInfo>
/// \@end
/// \endcode
///
/// ObjC protocols inspired Java interfaces. Unlike Java, ObjC classes and
/// protocols are in distinct namespaces. For example, Cocoa defines both
/// an NSObject protocol and class (which isn't allowed in Java). As a result,
/// protocols are referenced using angle brackets as follows:
///
/// id \<NSDraggingInfo> anyObjectThatImplementsNSDraggingInfo;
///
class ObjCProtocolDecl : public ObjCContainerDecl,
                         public Redeclarable<ObjCProtocolDecl> {
  void anchor() override;

  struct DefinitionData {
    // \brief The declaration that defines this protocol.
    ObjCProtocolDecl *Definition;

    /// \brief Referenced protocols
    ObjCProtocolList ReferencedProtocols;    
  };

  /// \brief Contains a pointer to the data associated with this class,
  /// which will be NULL if this class has not yet been defined.
  ///
  /// The bit indicates when we don't need to check for out-of-date
  /// declarations. It will be set unless modules are enabled.
  llvm::PointerIntPair<DefinitionData *, 1, bool> Data;

  DefinitionData &data() const {
    assert(Data.getPointer() && "Objective-C protocol has no definition!");
    return *Data.getPointer();
  }
  
  ObjCProtocolDecl(ASTContext &C, DeclContext *DC, IdentifierInfo *Id,
                   SourceLocation nameLoc, SourceLocation atStartLoc,
                   ObjCProtocolDecl *PrevDecl);

  void allocateDefinitionData();

  typedef Redeclarable<ObjCProtocolDecl> redeclarable_base;
  ObjCProtocolDecl *getNextRedeclarationImpl() override {
    return getNextRedeclaration();
  }
  ObjCProtocolDecl *getPreviousDeclImpl() override {
    return getPreviousDecl();
  }
  ObjCProtocolDecl *getMostRecentDeclImpl() override {
    return getMostRecentDecl();
  }

public:
  static ObjCProtocolDecl *Create(ASTContext &C, DeclContext *DC,
                                  IdentifierInfo *Id,
                                  SourceLocation nameLoc,
                                  SourceLocation atStartLoc,
                                  ObjCProtocolDecl *PrevDecl);

  static ObjCProtocolDecl *CreateDeserialized(ASTContext &C, unsigned ID);

  const ObjCProtocolList &getReferencedProtocols() const {
    assert(hasDefinition() && "No definition available!");
    return data().ReferencedProtocols;
  }
  typedef ObjCProtocolList::iterator protocol_iterator;
  typedef llvm::iterator_range<protocol_iterator> protocol_range;

  protocol_range protocols() const {
    return protocol_range(protocol_begin(), protocol_end());
  }
  protocol_iterator protocol_begin() const {
    if (!hasDefinition())
      return protocol_iterator();
    
    return data().ReferencedProtocols.begin();
  }
  protocol_iterator protocol_end() const { 
    if (!hasDefinition())
      return protocol_iterator();
    
    return data().ReferencedProtocols.end(); 
  }
  typedef ObjCProtocolList::loc_iterator protocol_loc_iterator;
  typedef llvm::iterator_range<protocol_loc_iterator> protocol_loc_range;

  protocol_loc_range protocol_locs() const {
    return protocol_loc_range(protocol_loc_begin(), protocol_loc_end());
  }
  protocol_loc_iterator protocol_loc_begin() const {
    if (!hasDefinition())
      return protocol_loc_iterator();
    
    return data().ReferencedProtocols.loc_begin();
  }
  protocol_loc_iterator protocol_loc_end() const {
    if (!hasDefinition())
      return protocol_loc_iterator();
    
    return data().ReferencedProtocols.loc_end();
  }
  unsigned protocol_size() const { 
    if (!hasDefinition())
      return 0;
    
    return data().ReferencedProtocols.size(); 
  }

  /// setProtocolList - Set the list of protocols that this interface
  /// implements.
  void setProtocolList(ObjCProtocolDecl *const*List, unsigned Num,
                       const SourceLocation *Locs, ASTContext &C) {
    assert(hasDefinition() && "Protocol is not defined");
    data().ReferencedProtocols.set(List, Num, Locs, C);
  }

  ObjCProtocolDecl *lookupProtocolNamed(IdentifierInfo *PName);

  // Lookup a method. First, we search locally. If a method isn't
  // found, we search referenced protocols and class categories.
  ObjCMethodDecl *lookupMethod(Selector Sel, bool isInstance) const;
  ObjCMethodDecl *lookupInstanceMethod(Selector Sel) const {
    return lookupMethod(Sel, true/*isInstance*/);
  }
  ObjCMethodDecl *lookupClassMethod(Selector Sel) const {
    return lookupMethod(Sel, false/*isInstance*/);
  }

  /// \brief Determine whether this protocol has a definition.
  bool hasDefinition() const {
    // If the name of this protocol is out-of-date, bring it up-to-date, which
    // might bring in a definition.
    // Note: a null value indicates that we don't have a definition and that
    // modules are enabled.
    if (!Data.getOpaqueValue()) {
      if (IdentifierInfo *II = getIdentifier()) {
        if (II->isOutOfDate()) {
          updateOutOfDate(*II);
        }
      }
    }

    return Data.getPointer();
  }

  /// \brief Retrieve the definition of this protocol, if any.
  ObjCProtocolDecl *getDefinition() {
    return hasDefinition()? Data.getPointer()->Definition : nullptr;
  }

  /// \brief Retrieve the definition of this protocol, if any.
  const ObjCProtocolDecl *getDefinition() const {
    return hasDefinition()? Data.getPointer()->Definition : nullptr;
  }

  /// \brief Determine whether this particular declaration is also the 
  /// definition.
  bool isThisDeclarationADefinition() const {
    return getDefinition() == this;
  }
  
  /// \brief Starts the definition of this Objective-C protocol.
  void startDefinition();

  /// Produce a name to be used for protocol's metadata. It comes either via
  /// objc_runtime_name attribute or protocol name.
  StringRef getObjCRuntimeNameAsString() const;

  SourceRange getSourceRange() const override LLVM_READONLY {
    if (isThisDeclarationADefinition())
      return ObjCContainerDecl::getSourceRange();
   
    return SourceRange(getAtStartLoc(), getLocation());
  }
   
  typedef redeclarable_base::redecl_range redecl_range;
  typedef redeclarable_base::redecl_iterator redecl_iterator;
  using redeclarable_base::redecls_begin;
  using redeclarable_base::redecls_end;
  using redeclarable_base::redecls;
  using redeclarable_base::getPreviousDecl;
  using redeclarable_base::getMostRecentDecl;
  using redeclarable_base::isFirstDecl;

  /// Retrieves the canonical declaration of this Objective-C protocol.
  ObjCProtocolDecl *getCanonicalDecl() override { return getFirstDecl(); }
  const ObjCProtocolDecl *getCanonicalDecl() const { return getFirstDecl(); }

  void collectPropertiesToImplement(PropertyMap &PM,
                                    PropertyDeclOrder &PO) const override;

  void collectInheritedProtocolProperties(const ObjCPropertyDecl *Property,
                                          ProtocolPropertyMap &PM) const;

  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
  static bool classofKind(Kind K) { return K == ObjCProtocol; }

  friend class ASTReader;
  friend class ASTDeclReader;
  friend class ASTDeclWriter;
};

/// ObjCCategoryDecl - Represents a category declaration. A category allows
/// you to add methods to an existing class (without subclassing or modifying
/// the original class interface or implementation:-). Categories don't allow
/// you to add instance data. The following example adds "myMethod" to all
/// NSView's within a process:
///
/// \@interface NSView (MyViewMethods)
/// - myMethod;
/// \@end
///
/// Categories also allow you to split the implementation of a class across
/// several files (a feature more naturally supported in C++).
///
/// Categories were originally inspired by dynamic languages such as Common
/// Lisp and Smalltalk.  More traditional class-based languages (C++, Java)
/// don't support this level of dynamism, which is both powerful and dangerous.
///
class ObjCCategoryDecl : public ObjCContainerDecl {
  void anchor() override;

  /// Interface belonging to this category
  ObjCInterfaceDecl *ClassInterface;

  /// The type parameters associated with this category, if any.
  ObjCTypeParamList *TypeParamList;

  /// referenced protocols in this category.
  ObjCProtocolList ReferencedProtocols;

  /// Next category belonging to this class.
  /// FIXME: this should not be a singly-linked list.  Move storage elsewhere.
  ObjCCategoryDecl *NextClassCategory;

  /// \brief The location of the category name in this declaration.
  SourceLocation CategoryNameLoc;

  /// class extension may have private ivars.
  SourceLocation IvarLBraceLoc;
  SourceLocation IvarRBraceLoc;
  
  ObjCCategoryDecl(DeclContext *DC, SourceLocation AtLoc,
                   SourceLocation ClassNameLoc, SourceLocation CategoryNameLoc,
                   IdentifierInfo *Id, ObjCInterfaceDecl *IDecl,
                   ObjCTypeParamList *typeParamList,
                   SourceLocation IvarLBraceLoc=SourceLocation(),
                   SourceLocation IvarRBraceLoc=SourceLocation());

public:

  static ObjCCategoryDecl *Create(ASTContext &C, DeclContext *DC,
                                  SourceLocation AtLoc,
                                  SourceLocation ClassNameLoc,
                                  SourceLocation CategoryNameLoc,
                                  IdentifierInfo *Id,
                                  ObjCInterfaceDecl *IDecl,
                                  ObjCTypeParamList *typeParamList,
                                  SourceLocation IvarLBraceLoc=SourceLocation(),
                                  SourceLocation IvarRBraceLoc=SourceLocation());
  static ObjCCategoryDecl *CreateDeserialized(ASTContext &C, unsigned ID);

  ObjCInterfaceDecl *getClassInterface() { return ClassInterface; }
  const ObjCInterfaceDecl *getClassInterface() const { return ClassInterface; }

  /// Retrieve the type parameter list associated with this category or
  /// extension.
  ObjCTypeParamList *getTypeParamList() const { return TypeParamList; }

  /// Set the type parameters of this category.
  ///
  /// This function is used by the AST importer, which must import the type
  /// parameters after creating their DeclContext to avoid loops.
  void setTypeParamList(ObjCTypeParamList *TPL);


  ObjCCategoryImplDecl *getImplementation() const;
  void setImplementation(ObjCCategoryImplDecl *ImplD);

  /// setProtocolList - Set the list of protocols that this interface
  /// implements.
  void setProtocolList(ObjCProtocolDecl *const*List, unsigned Num,
                       const SourceLocation *Locs, ASTContext &C) {
    ReferencedProtocols.set(List, Num, Locs, C);
  }

  const ObjCProtocolList &getReferencedProtocols() const {
    return ReferencedProtocols;
  }

  typedef ObjCProtocolList::iterator protocol_iterator;
  typedef llvm::iterator_range<protocol_iterator> protocol_range;

  protocol_range protocols() const {
    return protocol_range(protocol_begin(), protocol_end());
  }
  protocol_iterator protocol_begin() const {
    return ReferencedProtocols.begin();
  }
  protocol_iterator protocol_end() const { return ReferencedProtocols.end(); }
  unsigned protocol_size() const { return ReferencedProtocols.size(); }
  typedef ObjCProtocolList::loc_iterator protocol_loc_iterator;
  typedef llvm::iterator_range<protocol_loc_iterator> protocol_loc_range;

  protocol_loc_range protocol_locs() const {
    return protocol_loc_range(protocol_loc_begin(), protocol_loc_end());
  }
  protocol_loc_iterator protocol_loc_begin() const {
    return ReferencedProtocols.loc_begin();
  }
  protocol_loc_iterator protocol_loc_end() const {
    return ReferencedProtocols.loc_end();
  }

  ObjCCategoryDecl *getNextClassCategory() const { return NextClassCategory; }

  /// \brief Retrieve the pointer to the next stored category (or extension),
  /// which may be hidden.
  ObjCCategoryDecl *getNextClassCategoryRaw() const {
    return NextClassCategory;
  }

  bool IsClassExtension() const { return getIdentifier() == nullptr; }

  typedef specific_decl_iterator<ObjCIvarDecl> ivar_iterator;
  typedef llvm::iterator_range<specific_decl_iterator<ObjCIvarDecl>> ivar_range;

  ivar_range ivars() const { return ivar_range(ivar_begin(), ivar_end()); }
  ivar_iterator ivar_begin() const {
    return ivar_iterator(decls_begin());
  }
  ivar_iterator ivar_end() const {
    return ivar_iterator(decls_end());
  }
  unsigned ivar_size() const {
    return std::distance(ivar_begin(), ivar_end());
  }
  bool ivar_empty() const {
    return ivar_begin() == ivar_end();
  }

  SourceLocation getCategoryNameLoc() const { return CategoryNameLoc; }
  void setCategoryNameLoc(SourceLocation Loc) { CategoryNameLoc = Loc; }
  
  void setIvarLBraceLoc(SourceLocation Loc) { IvarLBraceLoc = Loc; }
  SourceLocation getIvarLBraceLoc() const { return IvarLBraceLoc; }
  void setIvarRBraceLoc(SourceLocation Loc) { IvarRBraceLoc = Loc; }
  SourceLocation getIvarRBraceLoc() const { return IvarRBraceLoc; }

  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
  static bool classofKind(Kind K) { return K == ObjCCategory; }

  friend class ASTDeclReader;
  friend class ASTDeclWriter;
};

class ObjCImplDecl : public ObjCContainerDecl {
  void anchor() override;

  /// Class interface for this class/category implementation
  ObjCInterfaceDecl *ClassInterface;

protected:
  ObjCImplDecl(Kind DK, DeclContext *DC,
               ObjCInterfaceDecl *classInterface,
               SourceLocation nameLoc, SourceLocation atStartLoc)
    : ObjCContainerDecl(DK, DC,
                        classInterface? classInterface->getIdentifier()
                                      : nullptr,
                        nameLoc, atStartLoc),
      ClassInterface(classInterface) {}

public:
  const ObjCInterfaceDecl *getClassInterface() const { return ClassInterface; }
  ObjCInterfaceDecl *getClassInterface() { return ClassInterface; }
  void setClassInterface(ObjCInterfaceDecl *IFace);

  void addInstanceMethod(ObjCMethodDecl *method) {
    // FIXME: Context should be set correctly before we get here.
    method->setLexicalDeclContext(this);
    addDecl(method);
  }
  void addClassMethod(ObjCMethodDecl *method) {
    // FIXME: Context should be set correctly before we get here.
    method->setLexicalDeclContext(this);
    addDecl(method);
  }

  void addPropertyImplementation(ObjCPropertyImplDecl *property);

  ObjCPropertyImplDecl *FindPropertyImplDecl(IdentifierInfo *propertyId) const;
  ObjCPropertyImplDecl *FindPropertyImplIvarDecl(IdentifierInfo *ivarId) const;

  // Iterator access to properties.
  typedef specific_decl_iterator<ObjCPropertyImplDecl> propimpl_iterator;
  typedef llvm::iterator_range<specific_decl_iterator<ObjCPropertyImplDecl>>
    propimpl_range;

  propimpl_range property_impls() const {
    return propimpl_range(propimpl_begin(), propimpl_end());
  }
  propimpl_iterator propimpl_begin() const {
    return propimpl_iterator(decls_begin());
  }
  propimpl_iterator propimpl_end() const {
    return propimpl_iterator(decls_end());
  }

  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
  static bool classofKind(Kind K) {
    return K >= firstObjCImpl && K <= lastObjCImpl;
  }
};

/// ObjCCategoryImplDecl - An object of this class encapsulates a category
/// \@implementation declaration. If a category class has declaration of a
/// property, its implementation must be specified in the category's
/// \@implementation declaration. Example:
/// \@interface I \@end
/// \@interface I(CATEGORY)
///    \@property int p1, d1;
/// \@end
/// \@implementation I(CATEGORY)
///  \@dynamic p1,d1;
/// \@end
///
/// ObjCCategoryImplDecl
class ObjCCategoryImplDecl : public ObjCImplDecl {
  void anchor() override;

  // Category name
  IdentifierInfo *Id;

  // Category name location
  SourceLocation CategoryNameLoc;

  ObjCCategoryImplDecl(DeclContext *DC, IdentifierInfo *Id,
                       ObjCInterfaceDecl *classInterface,
                       SourceLocation nameLoc, SourceLocation atStartLoc,
                       SourceLocation CategoryNameLoc)
    : ObjCImplDecl(ObjCCategoryImpl, DC, classInterface, nameLoc, atStartLoc),
      Id(Id), CategoryNameLoc(CategoryNameLoc) {}
public:
  static ObjCCategoryImplDecl *Create(ASTContext &C, DeclContext *DC,
                                      IdentifierInfo *Id,
                                      ObjCInterfaceDecl *classInterface,
                                      SourceLocation nameLoc,
                                      SourceLocation atStartLoc,
                                      SourceLocation CategoryNameLoc);
  static ObjCCategoryImplDecl *CreateDeserialized(ASTContext &C, unsigned ID);

  /// getIdentifier - Get the identifier that names the category
  /// interface associated with this implementation.
  /// FIXME: This is a bad API, we are hiding NamedDecl::getIdentifier()
  /// with a different meaning. For example:
  /// ((NamedDecl *)SomeCategoryImplDecl)->getIdentifier()
  /// returns the class interface name, whereas
  /// ((ObjCCategoryImplDecl *)SomeCategoryImplDecl)->getIdentifier()
  /// returns the category name.
  IdentifierInfo *getIdentifier() const {
    return Id;
  }
  void setIdentifier(IdentifierInfo *II) { Id = II; }

  ObjCCategoryDecl *getCategoryDecl() const;

  SourceLocation getCategoryNameLoc() const { return CategoryNameLoc; }

  /// getName - Get the name of identifier for the class interface associated
  /// with this implementation as a StringRef.
  //
  // FIXME: This is a bad API, we are hiding NamedDecl::getName with a different
  // meaning.
  StringRef getName() const { return Id ? Id->getName() : StringRef(); }

  /// @brief Get the name of the class associated with this interface.
  //
  // FIXME: Deprecated, move clients to getName().
  std::string getNameAsString() const {
    return getName();
  }

  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
  static bool classofKind(Kind K) { return K == ObjCCategoryImpl;}

  friend class ASTDeclReader;
  friend class ASTDeclWriter;
};

raw_ostream &operator<<(raw_ostream &OS, const ObjCCategoryImplDecl &CID);

/// ObjCImplementationDecl - Represents a class definition - this is where
/// method definitions are specified. For example:
///
/// @code
/// \@implementation MyClass
/// - (void)myMethod { /* do something */ }
/// \@end
/// @endcode
///
/// In a non-fragile runtime, instance variables can appear in the class
/// interface, class extensions (nameless categories), and in the implementation
/// itself, as well as being synthesized as backing storage for properties.
///
/// In a fragile runtime, instance variables are specified in the class
/// interface, \em not in the implementation. Nevertheless (for legacy reasons),
/// we allow instance variables to be specified in the implementation. When
/// specified, they need to be \em identical to the interface.
class ObjCImplementationDecl : public ObjCImplDecl {
  void anchor() override;
  /// Implementation Class's super class.
  ObjCInterfaceDecl *SuperClass;
  SourceLocation SuperLoc;

  /// \@implementation may have private ivars.
  SourceLocation IvarLBraceLoc;
  SourceLocation IvarRBraceLoc;
  
  /// Support for ivar initialization.
  /// \brief The arguments used to initialize the ivars
  LazyCXXCtorInitializersPtr IvarInitializers;
  unsigned NumIvarInitializers;

  /// Do the ivars of this class require initialization other than
  /// zero-initialization?
  bool HasNonZeroConstructors : 1;

  /// Do the ivars of this class require non-trivial destruction?
  bool HasDestructors : 1;

  ObjCImplementationDecl(DeclContext *DC,
                         ObjCInterfaceDecl *classInterface,
                         ObjCInterfaceDecl *superDecl,
                         SourceLocation nameLoc, SourceLocation atStartLoc,
                         SourceLocation superLoc = SourceLocation(),
                         SourceLocation IvarLBraceLoc=SourceLocation(), 
                         SourceLocation IvarRBraceLoc=SourceLocation())
    : ObjCImplDecl(ObjCImplementation, DC, classInterface, nameLoc, atStartLoc),
       SuperClass(superDecl), SuperLoc(superLoc), IvarLBraceLoc(IvarLBraceLoc),
       IvarRBraceLoc(IvarRBraceLoc),
       IvarInitializers(nullptr), NumIvarInitializers(0),
       HasNonZeroConstructors(false), HasDestructors(false) {}
public:
  static ObjCImplementationDecl *Create(ASTContext &C, DeclContext *DC,
                                        ObjCInterfaceDecl *classInterface,
                                        ObjCInterfaceDecl *superDecl,
                                        SourceLocation nameLoc,
                                        SourceLocation atStartLoc,
                                     SourceLocation superLoc = SourceLocation(),
                                        SourceLocation IvarLBraceLoc=SourceLocation(), 
                                        SourceLocation IvarRBraceLoc=SourceLocation());

  static ObjCImplementationDecl *CreateDeserialized(ASTContext &C, unsigned ID);

  /// init_iterator - Iterates through the ivar initializer list.
  typedef CXXCtorInitializer **init_iterator;

  /// init_const_iterator - Iterates through the ivar initializer list.
  typedef CXXCtorInitializer * const * init_const_iterator;

  typedef llvm::iterator_range<init_iterator> init_range;
  typedef llvm::iterator_range<init_const_iterator> init_const_range;

  init_range inits() { return init_range(init_begin(), init_end()); }
  init_const_range inits() const {
    return init_const_range(init_begin(), init_end());
  }

  /// init_begin() - Retrieve an iterator to the first initializer.
  init_iterator init_begin() {
    const auto *ConstThis = this;
    return const_cast<init_iterator>(ConstThis->init_begin());
  }
  /// begin() - Retrieve an iterator to the first initializer.
  init_const_iterator init_begin() const;

  /// init_end() - Retrieve an iterator past the last initializer.
  init_iterator       init_end()       {
    return init_begin() + NumIvarInitializers;
  }
  /// end() - Retrieve an iterator past the last initializer.
  init_const_iterator init_end() const {
    return init_begin() + NumIvarInitializers;
  }
  /// getNumArgs - Number of ivars which must be initialized.
  unsigned getNumIvarInitializers() const {
    return NumIvarInitializers;
  }

  void setNumIvarInitializers(unsigned numNumIvarInitializers) {
    NumIvarInitializers = numNumIvarInitializers;
  }

  void setIvarInitializers(ASTContext &C,
                           CXXCtorInitializer ** initializers,
                           unsigned numInitializers);

  /// Do any of the ivars of this class (not counting its base classes)
  /// require construction other than zero-initialization?
  bool hasNonZeroConstructors() const { return HasNonZeroConstructors; }
  void setHasNonZeroConstructors(bool val) { HasNonZeroConstructors = val; }

  /// Do any of the ivars of this class (not counting its base classes)
  /// require non-trivial destruction?
  bool hasDestructors() const { return HasDestructors; }
  void setHasDestructors(bool val) { HasDestructors = val; }

  /// getIdentifier - Get the identifier that names the class
  /// interface associated with this implementation.
  IdentifierInfo *getIdentifier() const {
    return getClassInterface()->getIdentifier();
  }

  /// getName - Get the name of identifier for the class interface associated
  /// with this implementation as a StringRef.
  //
  // FIXME: This is a bad API, we are hiding NamedDecl::getName with a different
  // meaning.
  StringRef getName() const {
    assert(getIdentifier() && "Name is not a simple identifier");
    return getIdentifier()->getName();
  }

  /// @brief Get the name of the class associated with this interface.
  //
  // FIXME: Move to StringRef API.
  std::string getNameAsString() const {
    return getName();
  }
    
  /// Produce a name to be used for class's metadata. It comes either via
  /// class's objc_runtime_name attribute or class name.
  StringRef getObjCRuntimeNameAsString() const;

  const ObjCInterfaceDecl *getSuperClass() const { return SuperClass; }
  ObjCInterfaceDecl *getSuperClass() { return SuperClass; }
  SourceLocation getSuperClassLoc() const { return SuperLoc; }

  void setSuperClass(ObjCInterfaceDecl * superCls) { SuperClass = superCls; }

  void setIvarLBraceLoc(SourceLocation Loc) { IvarLBraceLoc = Loc; }
  SourceLocation getIvarLBraceLoc() const { return IvarLBraceLoc; }
  void setIvarRBraceLoc(SourceLocation Loc) { IvarRBraceLoc = Loc; }
  SourceLocation getIvarRBraceLoc() const { return IvarRBraceLoc; }
  
  typedef specific_decl_iterator<ObjCIvarDecl> ivar_iterator;
  typedef llvm::iterator_range<specific_decl_iterator<ObjCIvarDecl>> ivar_range;

  ivar_range ivars() const { return ivar_range(ivar_begin(), ivar_end()); }
  ivar_iterator ivar_begin() const {
    return ivar_iterator(decls_begin());
  }
  ivar_iterator ivar_end() const {
    return ivar_iterator(decls_end());
  }
  unsigned ivar_size() const {
    return std::distance(ivar_begin(), ivar_end());
  }
  bool ivar_empty() const {
    return ivar_begin() == ivar_end();
  }

  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
  static bool classofKind(Kind K) { return K == ObjCImplementation; }

  friend class ASTDeclReader;
  friend class ASTDeclWriter;
};

raw_ostream &operator<<(raw_ostream &OS, const ObjCImplementationDecl &ID);

/// ObjCCompatibleAliasDecl - Represents alias of a class. This alias is
/// declared as \@compatibility_alias alias class.
class ObjCCompatibleAliasDecl : public NamedDecl {
  void anchor() override;
  /// Class that this is an alias of.
  ObjCInterfaceDecl *AliasedClass;

  ObjCCompatibleAliasDecl(DeclContext *DC, SourceLocation L, IdentifierInfo *Id,
                          ObjCInterfaceDecl* aliasedClass)
    : NamedDecl(ObjCCompatibleAlias, DC, L, Id), AliasedClass(aliasedClass) {}
public:
  static ObjCCompatibleAliasDecl *Create(ASTContext &C, DeclContext *DC,
                                         SourceLocation L, IdentifierInfo *Id,
                                         ObjCInterfaceDecl* aliasedClass);

  static ObjCCompatibleAliasDecl *CreateDeserialized(ASTContext &C, 
                                                     unsigned ID);
  
  const ObjCInterfaceDecl *getClassInterface() const { return AliasedClass; }
  ObjCInterfaceDecl *getClassInterface() { return AliasedClass; }
  void setClassInterface(ObjCInterfaceDecl *D) { AliasedClass = D; }

  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
  static bool classofKind(Kind K) { return K == ObjCCompatibleAlias; }

};

/// \brief Represents one property declaration in an Objective-C interface.
///
/// For example:
/// \code{.mm}
/// \@property (assign, readwrite) int MyProperty;
/// \endcode
class ObjCPropertyDecl : public NamedDecl {
  void anchor() override;
public:
  enum PropertyAttributeKind {
    OBJC_PR_noattr    = 0x00,
    OBJC_PR_readonly  = 0x01,
    OBJC_PR_getter    = 0x02,
    OBJC_PR_assign    = 0x04,
    OBJC_PR_readwrite = 0x08,
    OBJC_PR_retain    = 0x10,
    OBJC_PR_copy      = 0x20,
    OBJC_PR_nonatomic = 0x40,
    OBJC_PR_setter    = 0x80,
    OBJC_PR_atomic    = 0x100,
    OBJC_PR_weak      = 0x200,
    OBJC_PR_strong    = 0x400,
    OBJC_PR_unsafe_unretained = 0x800,
    /// Indicates that the nullability of the type was spelled with a
    /// property attribute rather than a type qualifier.
    OBJC_PR_nullability = 0x1000,
    OBJC_PR_null_resettable = 0x2000
    // Adding a property should change NumPropertyAttrsBits
  };

  enum {
    /// \brief Number of bits fitting all the property attributes.
    NumPropertyAttrsBits = 14
  };

  enum SetterKind { Assign, Retain, Copy, Weak };
  enum PropertyControl { None, Required, Optional };
private:
  SourceLocation AtLoc;   // location of \@property
  SourceLocation LParenLoc; // location of '(' starting attribute list or null.
  QualType DeclType;
  TypeSourceInfo *DeclTypeSourceInfo;
  unsigned PropertyAttributes : NumPropertyAttrsBits;
  unsigned PropertyAttributesAsWritten : NumPropertyAttrsBits;
  // \@required/\@optional
  unsigned PropertyImplementation : 2;

  Selector GetterName;    // getter name of NULL if no getter
  Selector SetterName;    // setter name of NULL if no setter

  ObjCMethodDecl *GetterMethodDecl; // Declaration of getter instance method
  ObjCMethodDecl *SetterMethodDecl; // Declaration of setter instance method
  ObjCIvarDecl *PropertyIvarDecl;   // Synthesize ivar for this property

  ObjCPropertyDecl(DeclContext *DC, SourceLocation L, IdentifierInfo *Id,
                   SourceLocation AtLocation,  SourceLocation LParenLocation,
                   QualType T, TypeSourceInfo *TSI,
                   PropertyControl propControl)
    : NamedDecl(ObjCProperty, DC, L, Id), AtLoc(AtLocation), 
      LParenLoc(LParenLocation), DeclType(T), DeclTypeSourceInfo(TSI),
      PropertyAttributes(OBJC_PR_noattr),
      PropertyAttributesAsWritten(OBJC_PR_noattr),
      PropertyImplementation(propControl),
      GetterName(Selector()),
      SetterName(Selector()),
      GetterMethodDecl(nullptr), SetterMethodDecl(nullptr),
      PropertyIvarDecl(nullptr) {}

public:
  static ObjCPropertyDecl *Create(ASTContext &C, DeclContext *DC,
                                  SourceLocation L,
                                  IdentifierInfo *Id, SourceLocation AtLocation,
                                  SourceLocation LParenLocation,
                                  QualType T,
                                  TypeSourceInfo *TSI,
                                  PropertyControl propControl = None);
  
  static ObjCPropertyDecl *CreateDeserialized(ASTContext &C, unsigned ID);
  
  SourceLocation getAtLoc() const { return AtLoc; }
  void setAtLoc(SourceLocation L) { AtLoc = L; }
  
  SourceLocation getLParenLoc() const { return LParenLoc; }
  void setLParenLoc(SourceLocation L) { LParenLoc = L; }

  TypeSourceInfo *getTypeSourceInfo() const { return DeclTypeSourceInfo; }

  QualType getType() const { return DeclType; }

  void setType(QualType T, TypeSourceInfo *TSI) { 
    DeclType = T;
    DeclTypeSourceInfo = TSI; 
  }

  /// Retrieve the type when this property is used with a specific base object
  /// type.
  QualType getUsageType(QualType objectType) const;

  PropertyAttributeKind getPropertyAttributes() const {
    return PropertyAttributeKind(PropertyAttributes);
  }
  void setPropertyAttributes(PropertyAttributeKind PRVal) {
    PropertyAttributes |= PRVal;
  }

  PropertyAttributeKind getPropertyAttributesAsWritten() const {
    return PropertyAttributeKind(PropertyAttributesAsWritten);
  }

  bool hasWrittenStorageAttribute() const {
    return PropertyAttributesAsWritten & (OBJC_PR_assign | OBJC_PR_copy |
        OBJC_PR_unsafe_unretained | OBJC_PR_retain | OBJC_PR_strong |
        OBJC_PR_weak);
  }

  void setPropertyAttributesAsWritten(PropertyAttributeKind PRVal) {
    PropertyAttributesAsWritten = PRVal;
  }

 void makeitReadWriteAttribute() {
    PropertyAttributes &= ~OBJC_PR_readonly;
    PropertyAttributes |= OBJC_PR_readwrite;
 }

  // Helper methods for accessing attributes.

  /// isReadOnly - Return true iff the property has a setter.
  bool isReadOnly() const {
    return (PropertyAttributes & OBJC_PR_readonly);
  }

  /// isAtomic - Return true if the property is atomic.
  bool isAtomic() const {
    return (PropertyAttributes & OBJC_PR_atomic);
  }

  /// isRetaining - Return true if the property retains its value.
  bool isRetaining() const {
    return (PropertyAttributes &
            (OBJC_PR_retain | OBJC_PR_strong | OBJC_PR_copy));
  }

  /// getSetterKind - Return the method used for doing assignment in
  /// the property setter. This is only valid if the property has been
  /// defined to have a setter.
  SetterKind getSetterKind() const {
    if (PropertyAttributes & OBJC_PR_strong)
      return getType()->isBlockPointerType() ? Copy : Retain;
    if (PropertyAttributes & OBJC_PR_retain)
      return Retain;
    if (PropertyAttributes & OBJC_PR_copy)
      return Copy;
    if (PropertyAttributes & OBJC_PR_weak)
      return Weak;
    return Assign;
  }

  Selector getGetterName() const { return GetterName; }
  void setGetterName(Selector Sel) { GetterName = Sel; }

  Selector getSetterName() const { return SetterName; }
  void setSetterName(Selector Sel) { SetterName = Sel; }

  ObjCMethodDecl *getGetterMethodDecl() const { return GetterMethodDecl; }
  void setGetterMethodDecl(ObjCMethodDecl *gDecl) { GetterMethodDecl = gDecl; }

  ObjCMethodDecl *getSetterMethodDecl() const { return SetterMethodDecl; }
  void setSetterMethodDecl(ObjCMethodDecl *gDecl) { SetterMethodDecl = gDecl; }

  // Related to \@optional/\@required declared in \@protocol
  void setPropertyImplementation(PropertyControl pc) {
    PropertyImplementation = pc;
  }
  PropertyControl getPropertyImplementation() const {
    return PropertyControl(PropertyImplementation);
  }

  void setPropertyIvarDecl(ObjCIvarDecl *Ivar) {
    PropertyIvarDecl = Ivar;
  }
  ObjCIvarDecl *getPropertyIvarDecl() const {
    return PropertyIvarDecl;
  }

  SourceRange getSourceRange() const override LLVM_READONLY {
    return SourceRange(AtLoc, getLocation());
  }
  
  /// Get the default name of the synthesized ivar.
  IdentifierInfo *getDefaultSynthIvarName(ASTContext &Ctx) const;

  /// Lookup a property by name in the specified DeclContext.
  static ObjCPropertyDecl *findPropertyDecl(const DeclContext *DC,
                                            const IdentifierInfo *propertyID);

  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
  static bool classofKind(Kind K) { return K == ObjCProperty; }
};

/// ObjCPropertyImplDecl - Represents implementation declaration of a property
/// in a class or category implementation block. For example:
/// \@synthesize prop1 = ivar1;
///
class ObjCPropertyImplDecl : public Decl {
public:
  enum Kind {
    Synthesize,
    Dynamic
  };
private:
  SourceLocation AtLoc;   // location of \@synthesize or \@dynamic

  /// \brief For \@synthesize, the location of the ivar, if it was written in
  /// the source code.
  ///
  /// \code
  /// \@synthesize int a = b
  /// \endcode
  SourceLocation IvarLoc;

  /// Property declaration being implemented
  ObjCPropertyDecl *PropertyDecl;

  /// Null for \@dynamic. Required for \@synthesize.
  ObjCIvarDecl *PropertyIvarDecl;

  /// Null for \@dynamic. Non-null if property must be copy-constructed in
  /// getter.
  Expr *GetterCXXConstructor;

  /// Null for \@dynamic. Non-null if property has assignment operator to call
  /// in Setter synthesis.
  Expr *SetterCXXAssignment;

  ObjCPropertyImplDecl(DeclContext *DC, SourceLocation atLoc, SourceLocation L,
                       ObjCPropertyDecl *property,
                       Kind PK,
                       ObjCIvarDecl *ivarDecl,
                       SourceLocation ivarLoc)
    : Decl(ObjCPropertyImpl, DC, L), AtLoc(atLoc),
      IvarLoc(ivarLoc), PropertyDecl(property), PropertyIvarDecl(ivarDecl),
      GetterCXXConstructor(nullptr), SetterCXXAssignment(nullptr) {
    assert (PK == Dynamic || PropertyIvarDecl);
  }

public:
  static ObjCPropertyImplDecl *Create(ASTContext &C, DeclContext *DC,
                                      SourceLocation atLoc, SourceLocation L,
                                      ObjCPropertyDecl *property,
                                      Kind PK,
                                      ObjCIvarDecl *ivarDecl,
                                      SourceLocation ivarLoc);

  static ObjCPropertyImplDecl *CreateDeserialized(ASTContext &C, unsigned ID);

  SourceRange getSourceRange() const override LLVM_READONLY;

  SourceLocation getLocStart() const LLVM_READONLY { return AtLoc; }
  void setAtLoc(SourceLocation Loc) { AtLoc = Loc; }

  ObjCPropertyDecl *getPropertyDecl() const {
    return PropertyDecl;
  }
  void setPropertyDecl(ObjCPropertyDecl *Prop) { PropertyDecl = Prop; }

  Kind getPropertyImplementation() const {
    return PropertyIvarDecl ? Synthesize : Dynamic;
  }

  ObjCIvarDecl *getPropertyIvarDecl() const {
    return PropertyIvarDecl;
  }
  SourceLocation getPropertyIvarDeclLoc() const { return IvarLoc; }

  void setPropertyIvarDecl(ObjCIvarDecl *Ivar,
                           SourceLocation IvarLoc) {
    PropertyIvarDecl = Ivar;
    this->IvarLoc = IvarLoc;
  }

  /// \brief For \@synthesize, returns true if an ivar name was explicitly
  /// specified.
  ///
  /// \code
  /// \@synthesize int a = b; // true
  /// \@synthesize int a; // false
  /// \endcode
  bool isIvarNameSpecified() const {
    return IvarLoc.isValid() && IvarLoc != getLocation();
  }

  Expr *getGetterCXXConstructor() const {
    return GetterCXXConstructor;
  }
  void setGetterCXXConstructor(Expr *getterCXXConstructor) {
    GetterCXXConstructor = getterCXXConstructor;
  }

  Expr *getSetterCXXAssignment() const {
    return SetterCXXAssignment;
  }
  void setSetterCXXAssignment(Expr *setterCXXAssignment) {
    SetterCXXAssignment = setterCXXAssignment;
  }

  static bool classof(const Decl *D) { return classofKind(D->getKind()); }
  static bool classofKind(Decl::Kind K) { return K == ObjCPropertyImpl; }

  friend class ASTDeclReader;
};

template<bool (*Filter)(ObjCCategoryDecl *)>
void
ObjCInterfaceDecl::filtered_category_iterator<Filter>::
findAcceptableCategory() {
  while (Current && !Filter(Current))
    Current = Current->getNextClassCategoryRaw();
}

template<bool (*Filter)(ObjCCategoryDecl *)>
inline ObjCInterfaceDecl::filtered_category_iterator<Filter> &
ObjCInterfaceDecl::filtered_category_iterator<Filter>::operator++() {
  Current = Current->getNextClassCategoryRaw();
  findAcceptableCategory();
  return *this;
}

inline bool ObjCInterfaceDecl::isVisibleCategory(ObjCCategoryDecl *Cat) {
  return !Cat->isHidden();
}

inline bool ObjCInterfaceDecl::isVisibleExtension(ObjCCategoryDecl *Cat) {
  return Cat->IsClassExtension() && !Cat->isHidden();
}

inline bool ObjCInterfaceDecl::isKnownExtension(ObjCCategoryDecl *Cat) {
  return Cat->IsClassExtension();
}

}  // end namespace clang
#endif