aboutsummaryrefslogtreecommitdiffstats
path: root/lib/StaticAnalyzer/Core/RegionStore.cpp
blob: 15ca2c14f9440b6fd13c6a47ab1c0d13b5f6780b (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
//== RegionStore.cpp - Field-sensitive store model --------------*- 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 a basic region store model. In this model, we do have field
// sensitivity. But we assume nothing about the heap shape. So recursive data
// structures are largely ignored. Basically we do 1-limiting analysis.
// Parameter pointers are assumed with no aliasing. Pointee objects of
// parameters are created lazily.
//
//===----------------------------------------------------------------------===//

#include "clang/AST/Attr.h"
#include "clang/AST/CharUnits.h"
#include "clang/Analysis/Analyses/LiveVariables.h"
#include "clang/Analysis/AnalysisContext.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SubEngine.h"
#include "llvm/ADT/ImmutableMap.h"
#include "llvm/ADT/Optional.h"
#include "llvm/Support/raw_ostream.h"
#include <utility>

using namespace clang;
using namespace ento;

//===----------------------------------------------------------------------===//
// Representation of binding keys.
//===----------------------------------------------------------------------===//

namespace {
class BindingKey {
public:
  enum Kind { Default = 0x0, Direct = 0x1 };
private:
  enum { Symbolic = 0x2 };

  llvm::PointerIntPair<const MemRegion *, 2> P;
  uint64_t Data;

  /// Create a key for a binding to region \p r, which has a symbolic offset
  /// from region \p Base.
  explicit BindingKey(const SubRegion *r, const SubRegion *Base, Kind k)
    : P(r, k | Symbolic), Data(reinterpret_cast<uintptr_t>(Base)) {
    assert(r && Base && "Must have known regions.");
    assert(getConcreteOffsetRegion() == Base && "Failed to store base region");
  }

  /// Create a key for a binding at \p offset from base region \p r.
  explicit BindingKey(const MemRegion *r, uint64_t offset, Kind k)
    : P(r, k), Data(offset) {
    assert(r && "Must have known regions.");
    assert(getOffset() == offset && "Failed to store offset");
    assert((r == r->getBaseRegion() || isa<ObjCIvarRegion>(r)) && "Not a base");
  }
public:

  bool isDirect() const { return P.getInt() & Direct; }
  bool hasSymbolicOffset() const { return P.getInt() & Symbolic; }

  const MemRegion *getRegion() const { return P.getPointer(); }
  uint64_t getOffset() const {
    assert(!hasSymbolicOffset());
    return Data;
  }

  const SubRegion *getConcreteOffsetRegion() const {
    assert(hasSymbolicOffset());
    return reinterpret_cast<const SubRegion *>(static_cast<uintptr_t>(Data));
  }

  const MemRegion *getBaseRegion() const {
    if (hasSymbolicOffset())
      return getConcreteOffsetRegion()->getBaseRegion();
    return getRegion()->getBaseRegion();
  }

  void Profile(llvm::FoldingSetNodeID& ID) const {
    ID.AddPointer(P.getOpaqueValue());
    ID.AddInteger(Data);
  }

  static BindingKey Make(const MemRegion *R, Kind k);

  bool operator<(const BindingKey &X) const {
    if (P.getOpaqueValue() < X.P.getOpaqueValue())
      return true;
    if (P.getOpaqueValue() > X.P.getOpaqueValue())
      return false;
    return Data < X.Data;
  }

  bool operator==(const BindingKey &X) const {
    return P.getOpaqueValue() == X.P.getOpaqueValue() &&
           Data == X.Data;
  }

  void dump() const;
};
} // end anonymous namespace

BindingKey BindingKey::Make(const MemRegion *R, Kind k) {
  const RegionOffset &RO = R->getAsOffset();
  if (RO.hasSymbolicOffset())
    return BindingKey(cast<SubRegion>(R), cast<SubRegion>(RO.getRegion()), k);

  return BindingKey(RO.getRegion(), RO.getOffset(), k);
}

namespace llvm {
  static inline
  raw_ostream &operator<<(raw_ostream &os, BindingKey K) {
    os << '(' << K.getRegion();
    if (!K.hasSymbolicOffset())
      os << ',' << K.getOffset();
    os << ',' << (K.isDirect() ? "direct" : "default")
       << ')';
    return os;
  }

  template <typename T> struct isPodLike;
  template <> struct isPodLike<BindingKey> {
    static const bool value = true;
  };
} // end llvm namespace

LLVM_DUMP_METHOD void BindingKey::dump() const { llvm::errs() << *this; }

//===----------------------------------------------------------------------===//
// Actual Store type.
//===----------------------------------------------------------------------===//

typedef llvm::ImmutableMap<BindingKey, SVal>    ClusterBindings;
typedef llvm::ImmutableMapRef<BindingKey, SVal> ClusterBindingsRef;
typedef std::pair<BindingKey, SVal> BindingPair;

typedef llvm::ImmutableMap<const MemRegion *, ClusterBindings>
        RegionBindings;

namespace {
class RegionBindingsRef : public llvm::ImmutableMapRef<const MemRegion *,
                                 ClusterBindings> {
  ClusterBindings::Factory *CBFactory;

public:
  typedef llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>
          ParentTy;

  RegionBindingsRef(ClusterBindings::Factory &CBFactory,
                    const RegionBindings::TreeTy *T,
                    RegionBindings::TreeTy::Factory *F)
      : llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>(T, F),
        CBFactory(&CBFactory) {}

  RegionBindingsRef(const ParentTy &P, ClusterBindings::Factory &CBFactory)
      : llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>(P),
        CBFactory(&CBFactory) {}

  RegionBindingsRef add(key_type_ref K, data_type_ref D) const {
    return RegionBindingsRef(static_cast<const ParentTy *>(this)->add(K, D),
                             *CBFactory);
  }

  RegionBindingsRef remove(key_type_ref K) const {
    return RegionBindingsRef(static_cast<const ParentTy *>(this)->remove(K),
                             *CBFactory);
  }

  RegionBindingsRef addBinding(BindingKey K, SVal V) const;

  RegionBindingsRef addBinding(const MemRegion *R,
                               BindingKey::Kind k, SVal V) const;

  const SVal *lookup(BindingKey K) const;
  const SVal *lookup(const MemRegion *R, BindingKey::Kind k) const;
  using llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>::lookup;

  RegionBindingsRef removeBinding(BindingKey K);

  RegionBindingsRef removeBinding(const MemRegion *R,
                                  BindingKey::Kind k);

  RegionBindingsRef removeBinding(const MemRegion *R) {
    return removeBinding(R, BindingKey::Direct).
           removeBinding(R, BindingKey::Default);
  }

  Optional<SVal> getDirectBinding(const MemRegion *R) const;

  /// getDefaultBinding - Returns an SVal* representing an optional default
  ///  binding associated with a region and its subregions.
  Optional<SVal> getDefaultBinding(const MemRegion *R) const;

  /// Return the internal tree as a Store.
  Store asStore() const {
    return asImmutableMap().getRootWithoutRetain();
  }

  void dump(raw_ostream &OS, const char *nl) const {
   for (iterator I = begin(), E = end(); I != E; ++I) {
     const ClusterBindings &Cluster = I.getData();
     for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
          CI != CE; ++CI) {
       OS << ' ' << CI.getKey() << " : " << CI.getData() << nl;
     }
     OS << nl;
   }
  }

  LLVM_DUMP_METHOD void dump() const { dump(llvm::errs(), "\n"); }
};
} // end anonymous namespace

typedef const RegionBindingsRef& RegionBindingsConstRef;

Optional<SVal> RegionBindingsRef::getDirectBinding(const MemRegion *R) const {
  return Optional<SVal>::create(lookup(R, BindingKey::Direct));
}

Optional<SVal> RegionBindingsRef::getDefaultBinding(const MemRegion *R) const {
  if (R->isBoundable())
    if (const TypedValueRegion *TR = dyn_cast<TypedValueRegion>(R))
      if (TR->getValueType()->isUnionType())
        return UnknownVal();

  return Optional<SVal>::create(lookup(R, BindingKey::Default));
}

RegionBindingsRef RegionBindingsRef::addBinding(BindingKey K, SVal V) const {
  const MemRegion *Base = K.getBaseRegion();

  const ClusterBindings *ExistingCluster = lookup(Base);
  ClusterBindings Cluster =
      (ExistingCluster ? *ExistingCluster : CBFactory->getEmptyMap());

  ClusterBindings NewCluster = CBFactory->add(Cluster, K, V);
  return add(Base, NewCluster);
}


RegionBindingsRef RegionBindingsRef::addBinding(const MemRegion *R,
                                                BindingKey::Kind k,
                                                SVal V) const {
  return addBinding(BindingKey::Make(R, k), V);
}

const SVal *RegionBindingsRef::lookup(BindingKey K) const {
  const ClusterBindings *Cluster = lookup(K.getBaseRegion());
  if (!Cluster)
    return nullptr;
  return Cluster->lookup(K);
}

const SVal *RegionBindingsRef::lookup(const MemRegion *R,
                                      BindingKey::Kind k) const {
  return lookup(BindingKey::Make(R, k));
}

RegionBindingsRef RegionBindingsRef::removeBinding(BindingKey K) {
  const MemRegion *Base = K.getBaseRegion();
  const ClusterBindings *Cluster = lookup(Base);
  if (!Cluster)
    return *this;

  ClusterBindings NewCluster = CBFactory->remove(*Cluster, K);
  if (NewCluster.isEmpty())
    return remove(Base);
  return add(Base, NewCluster);
}

RegionBindingsRef RegionBindingsRef::removeBinding(const MemRegion *R,
                                                BindingKey::Kind k){
  return removeBinding(BindingKey::Make(R, k));
}

//===----------------------------------------------------------------------===//
// Fine-grained control of RegionStoreManager.
//===----------------------------------------------------------------------===//

namespace {
struct minimal_features_tag {};
struct maximal_features_tag {};

class RegionStoreFeatures {
  bool SupportsFields;
public:
  RegionStoreFeatures(minimal_features_tag) :
    SupportsFields(false) {}

  RegionStoreFeatures(maximal_features_tag) :
    SupportsFields(true) {}

  void enableFields(bool t) { SupportsFields = t; }

  bool supportsFields() const { return SupportsFields; }
};
}

//===----------------------------------------------------------------------===//
// Main RegionStore logic.
//===----------------------------------------------------------------------===//

namespace {
class invalidateRegionsWorker;

class RegionStoreManager : public StoreManager {
public:
  const RegionStoreFeatures Features;

  RegionBindings::Factory RBFactory;
  mutable ClusterBindings::Factory CBFactory;

  typedef std::vector<SVal> SValListTy;
private:
  typedef llvm::DenseMap<const LazyCompoundValData *,
                         SValListTy> LazyBindingsMapTy;
  LazyBindingsMapTy LazyBindingsMap;

  /// The largest number of fields a struct can have and still be
  /// considered "small".
  ///
  /// This is currently used to decide whether or not it is worth "forcing" a
  /// LazyCompoundVal on bind.
  ///
  /// This is controlled by 'region-store-small-struct-limit' option.
  /// To disable all small-struct-dependent behavior, set the option to "0".
  unsigned SmallStructLimit;

  /// \brief A helper used to populate the work list with the given set of
  /// regions.
  void populateWorkList(invalidateRegionsWorker &W,
                        ArrayRef<SVal> Values,
                        InvalidatedRegions *TopLevelRegions);

public:
  RegionStoreManager(ProgramStateManager& mgr, const RegionStoreFeatures &f)
    : StoreManager(mgr), Features(f),
      RBFactory(mgr.getAllocator()), CBFactory(mgr.getAllocator()),
      SmallStructLimit(0) {
    if (SubEngine *Eng = StateMgr.getOwningEngine()) {
      AnalyzerOptions &Options = Eng->getAnalysisManager().options;
      SmallStructLimit =
        Options.getOptionAsInteger("region-store-small-struct-limit", 2);
    }
  }


  /// setImplicitDefaultValue - Set the default binding for the provided
  ///  MemRegion to the value implicitly defined for compound literals when
  ///  the value is not specified.
  RegionBindingsRef setImplicitDefaultValue(RegionBindingsConstRef B,
                                            const MemRegion *R, QualType T);

  /// ArrayToPointer - Emulates the "decay" of an array to a pointer
  ///  type.  'Array' represents the lvalue of the array being decayed
  ///  to a pointer, and the returned SVal represents the decayed
  ///  version of that lvalue (i.e., a pointer to the first element of
  ///  the array).  This is called by ExprEngine when evaluating
  ///  casts from arrays to pointers.
  SVal ArrayToPointer(Loc Array, QualType ElementTy) override;

  StoreRef getInitialStore(const LocationContext *InitLoc) override {
    return StoreRef(RBFactory.getEmptyMap().getRootWithoutRetain(), *this);
  }

  //===-------------------------------------------------------------------===//
  // Binding values to regions.
  //===-------------------------------------------------------------------===//
  RegionBindingsRef invalidateGlobalRegion(MemRegion::Kind K,
                                           const Expr *Ex,
                                           unsigned Count,
                                           const LocationContext *LCtx,
                                           RegionBindingsRef B,
                                           InvalidatedRegions *Invalidated);

  StoreRef invalidateRegions(Store store,
                             ArrayRef<SVal> Values,
                             const Expr *E, unsigned Count,
                             const LocationContext *LCtx,
                             const CallEvent *Call,
                             InvalidatedSymbols &IS,
                             RegionAndSymbolInvalidationTraits &ITraits,
                             InvalidatedRegions *Invalidated,
                             InvalidatedRegions *InvalidatedTopLevel) override;

  bool scanReachableSymbols(Store S, const MemRegion *R,
                            ScanReachableSymbols &Callbacks) override;

  RegionBindingsRef removeSubRegionBindings(RegionBindingsConstRef B,
                                            const SubRegion *R);

public: // Part of public interface to class.

  StoreRef Bind(Store store, Loc LV, SVal V) override {
    return StoreRef(bind(getRegionBindings(store), LV, V).asStore(), *this);
  }

  RegionBindingsRef bind(RegionBindingsConstRef B, Loc LV, SVal V);

  // BindDefault is only used to initialize a region with a default value.
  StoreRef BindDefault(Store store, const MemRegion *R, SVal V) override {
    RegionBindingsRef B = getRegionBindings(store);
    assert(!B.lookup(R, BindingKey::Direct));

    BindingKey Key = BindingKey::Make(R, BindingKey::Default);
    if (B.lookup(Key)) {
      const SubRegion *SR = cast<SubRegion>(R);
      assert(SR->getAsOffset().getOffset() ==
             SR->getSuperRegion()->getAsOffset().getOffset() &&
             "A default value must come from a super-region");
      B = removeSubRegionBindings(B, SR);
    } else {
      B = B.addBinding(Key, V);
    }

    return StoreRef(B.asImmutableMap().getRootWithoutRetain(), *this);
  }

  /// Attempt to extract the fields of \p LCV and bind them to the struct region
  /// \p R.
  ///
  /// This path is used when it seems advantageous to "force" loading the values
  /// within a LazyCompoundVal to bind memberwise to the struct region, rather
  /// than using a Default binding at the base of the entire region. This is a
  /// heuristic attempting to avoid building long chains of LazyCompoundVals.
  ///
  /// \returns The updated store bindings, or \c None if binding non-lazily
  ///          would be too expensive.
  Optional<RegionBindingsRef> tryBindSmallStruct(RegionBindingsConstRef B,
                                                 const TypedValueRegion *R,
                                                 const RecordDecl *RD,
                                                 nonloc::LazyCompoundVal LCV);

  /// BindStruct - Bind a compound value to a structure.
  RegionBindingsRef bindStruct(RegionBindingsConstRef B,
                               const TypedValueRegion* R, SVal V);

  /// BindVector - Bind a compound value to a vector.
  RegionBindingsRef bindVector(RegionBindingsConstRef B,
                               const TypedValueRegion* R, SVal V);

  RegionBindingsRef bindArray(RegionBindingsConstRef B,
                              const TypedValueRegion* R,
                              SVal V);

  /// Clears out all bindings in the given region and assigns a new value
  /// as a Default binding.
  RegionBindingsRef bindAggregate(RegionBindingsConstRef B,
                                  const TypedRegion *R,
                                  SVal DefaultVal);

  /// \brief Create a new store with the specified binding removed.
  /// \param ST the original store, that is the basis for the new store.
  /// \param L the location whose binding should be removed.
  StoreRef killBinding(Store ST, Loc L) override;

  void incrementReferenceCount(Store store) override {
    getRegionBindings(store).manualRetain();
  }

  /// If the StoreManager supports it, decrement the reference count of
  /// the specified Store object.  If the reference count hits 0, the memory
  /// associated with the object is recycled.
  void decrementReferenceCount(Store store) override {
    getRegionBindings(store).manualRelease();
  }

  bool includedInBindings(Store store, const MemRegion *region) const override;

  /// \brief Return the value bound to specified location in a given state.
  ///
  /// The high level logic for this method is this:
  /// getBinding (L)
  ///   if L has binding
  ///     return L's binding
  ///   else if L is in killset
  ///     return unknown
  ///   else
  ///     if L is on stack or heap
  ///       return undefined
  ///     else
  ///       return symbolic
  SVal getBinding(Store S, Loc L, QualType T) override {
    return getBinding(getRegionBindings(S), L, T);
  }

  SVal getBinding(RegionBindingsConstRef B, Loc L, QualType T = QualType());

  SVal getBindingForElement(RegionBindingsConstRef B, const ElementRegion *R);

  SVal getBindingForField(RegionBindingsConstRef B, const FieldRegion *R);

  SVal getBindingForObjCIvar(RegionBindingsConstRef B, const ObjCIvarRegion *R);

  SVal getBindingForVar(RegionBindingsConstRef B, const VarRegion *R);

  SVal getBindingForLazySymbol(const TypedValueRegion *R);

  SVal getBindingForFieldOrElementCommon(RegionBindingsConstRef B,
                                         const TypedValueRegion *R,
                                         QualType Ty);

  SVal getLazyBinding(const SubRegion *LazyBindingRegion,
                      RegionBindingsRef LazyBinding);

  /// Get bindings for the values in a struct and return a CompoundVal, used
  /// when doing struct copy:
  /// struct s x, y;
  /// x = y;
  /// y's value is retrieved by this method.
  SVal getBindingForStruct(RegionBindingsConstRef B, const TypedValueRegion *R);
  SVal getBindingForArray(RegionBindingsConstRef B, const TypedValueRegion *R);
  NonLoc createLazyBinding(RegionBindingsConstRef B, const TypedValueRegion *R);

  /// Used to lazily generate derived symbols for bindings that are defined
  /// implicitly by default bindings in a super region.
  ///
  /// Note that callers may need to specially handle LazyCompoundVals, which
  /// are returned as is in case the caller needs to treat them differently.
  Optional<SVal> getBindingForDerivedDefaultValue(RegionBindingsConstRef B,
                                                  const MemRegion *superR,
                                                  const TypedValueRegion *R,
                                                  QualType Ty);

  /// Get the state and region whose binding this region \p R corresponds to.
  ///
  /// If there is no lazy binding for \p R, the returned value will have a null
  /// \c second. Note that a null pointer can represents a valid Store.
  std::pair<Store, const SubRegion *>
  findLazyBinding(RegionBindingsConstRef B, const SubRegion *R,
                  const SubRegion *originalRegion);

  /// Returns the cached set of interesting SVals contained within a lazy
  /// binding.
  ///
  /// The precise value of "interesting" is determined for the purposes of
  /// RegionStore's internal analysis. It must always contain all regions and
  /// symbols, but may omit constants and other kinds of SVal.
  const SValListTy &getInterestingValues(nonloc::LazyCompoundVal LCV);

  //===------------------------------------------------------------------===//
  // State pruning.
  //===------------------------------------------------------------------===//

  /// removeDeadBindings - Scans the RegionStore of 'state' for dead values.
  ///  It returns a new Store with these values removed.
  StoreRef removeDeadBindings(Store store, const StackFrameContext *LCtx,
                              SymbolReaper& SymReaper) override;

  //===------------------------------------------------------------------===//
  // Region "extents".
  //===------------------------------------------------------------------===//

  // FIXME: This method will soon be eliminated; see the note in Store.h.
  DefinedOrUnknownSVal getSizeInElements(ProgramStateRef state,
                                         const MemRegion* R,
                                         QualType EleTy) override;

  //===------------------------------------------------------------------===//
  // Utility methods.
  //===------------------------------------------------------------------===//

  RegionBindingsRef getRegionBindings(Store store) const {
    return RegionBindingsRef(CBFactory,
                             static_cast<const RegionBindings::TreeTy*>(store),
                             RBFactory.getTreeFactory());
  }

  void print(Store store, raw_ostream &Out, const char* nl,
             const char *sep) override;

  void iterBindings(Store store, BindingsHandler& f) override {
    RegionBindingsRef B = getRegionBindings(store);
    for (RegionBindingsRef::iterator I = B.begin(), E = B.end(); I != E; ++I) {
      const ClusterBindings &Cluster = I.getData();
      for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
           CI != CE; ++CI) {
        const BindingKey &K = CI.getKey();
        if (!K.isDirect())
          continue;
        if (const SubRegion *R = dyn_cast<SubRegion>(K.getRegion())) {
          // FIXME: Possibly incorporate the offset?
          if (!f.HandleBinding(*this, store, R, CI.getData()))
            return;
        }
      }
    }
  }
};

} // end anonymous namespace

//===----------------------------------------------------------------------===//
// RegionStore creation.
//===----------------------------------------------------------------------===//

std::unique_ptr<StoreManager>
ento::CreateRegionStoreManager(ProgramStateManager &StMgr) {
  RegionStoreFeatures F = maximal_features_tag();
  return llvm::make_unique<RegionStoreManager>(StMgr, F);
}

std::unique_ptr<StoreManager>
ento::CreateFieldsOnlyRegionStoreManager(ProgramStateManager &StMgr) {
  RegionStoreFeatures F = minimal_features_tag();
  F.enableFields(true);
  return llvm::make_unique<RegionStoreManager>(StMgr, F);
}


//===----------------------------------------------------------------------===//
// Region Cluster analysis.
//===----------------------------------------------------------------------===//

namespace {
/// Used to determine which global regions are automatically included in the
/// initial worklist of a ClusterAnalysis.
enum GlobalsFilterKind {
  /// Don't include any global regions.
  GFK_None,
  /// Only include system globals.
  GFK_SystemOnly,
  /// Include all global regions.
  GFK_All
};

template <typename DERIVED>
class ClusterAnalysis  {
protected:
  typedef llvm::DenseMap<const MemRegion *, const ClusterBindings *> ClusterMap;
  typedef const MemRegion * WorkListElement;
  typedef SmallVector<WorkListElement, 10> WorkList;

  llvm::SmallPtrSet<const ClusterBindings *, 16> Visited;

  WorkList WL;

  RegionStoreManager &RM;
  ASTContext &Ctx;
  SValBuilder &svalBuilder;

  RegionBindingsRef B;


protected:
  const ClusterBindings *getCluster(const MemRegion *R) {
    return B.lookup(R);
  }

  /// Returns true if all clusters in the given memspace should be initially
  /// included in the cluster analysis. Subclasses may provide their
  /// own implementation.
  bool includeEntireMemorySpace(const MemRegion *Base) {
    return false;
  }

public:
  ClusterAnalysis(RegionStoreManager &rm, ProgramStateManager &StateMgr,
                  RegionBindingsRef b)
      : RM(rm), Ctx(StateMgr.getContext()),
        svalBuilder(StateMgr.getSValBuilder()), B(std::move(b)) {}

  RegionBindingsRef getRegionBindings() const { return B; }

  bool isVisited(const MemRegion *R) {
    return Visited.count(getCluster(R));
  }

  void GenerateClusters() {
    // Scan the entire set of bindings and record the region clusters.
    for (RegionBindingsRef::iterator RI = B.begin(), RE = B.end();
         RI != RE; ++RI){
      const MemRegion *Base = RI.getKey();

      const ClusterBindings &Cluster = RI.getData();
      assert(!Cluster.isEmpty() && "Empty clusters should be removed");
      static_cast<DERIVED*>(this)->VisitAddedToCluster(Base, Cluster);

      // If the base's memspace should be entirely invalidated, add the cluster
      // to the workspace up front.
      if (static_cast<DERIVED*>(this)->includeEntireMemorySpace(Base))
        AddToWorkList(WorkListElement(Base), &Cluster);
    }
  }

  bool AddToWorkList(WorkListElement E, const ClusterBindings *C) {
    if (C && !Visited.insert(C).second)
      return false;
    WL.push_back(E);
    return true;
  }

  bool AddToWorkList(const MemRegion *R) {
    return static_cast<DERIVED*>(this)->AddToWorkList(R);
  }

  void RunWorkList() {
    while (!WL.empty()) {
      WorkListElement E = WL.pop_back_val();
      const MemRegion *BaseR = E;

      static_cast<DERIVED*>(this)->VisitCluster(BaseR, getCluster(BaseR));
    }
  }

  void VisitAddedToCluster(const MemRegion *baseR, const ClusterBindings &C) {}
  void VisitCluster(const MemRegion *baseR, const ClusterBindings *C) {}

  void VisitCluster(const MemRegion *BaseR, const ClusterBindings *C,
                    bool Flag) {
    static_cast<DERIVED*>(this)->VisitCluster(BaseR, C);
  }
};
}

//===----------------------------------------------------------------------===//
// Binding invalidation.
//===----------------------------------------------------------------------===//

bool RegionStoreManager::scanReachableSymbols(Store S, const MemRegion *R,
                                              ScanReachableSymbols &Callbacks) {
  assert(R == R->getBaseRegion() && "Should only be called for base regions");
  RegionBindingsRef B = getRegionBindings(S);
  const ClusterBindings *Cluster = B.lookup(R);

  if (!Cluster)
    return true;

  for (ClusterBindings::iterator RI = Cluster->begin(), RE = Cluster->end();
       RI != RE; ++RI) {
    if (!Callbacks.scan(RI.getData()))
      return false;
  }

  return true;
}

static inline bool isUnionField(const FieldRegion *FR) {
  return FR->getDecl()->getParent()->isUnion();
}

typedef SmallVector<const FieldDecl *, 8> FieldVector;

static void getSymbolicOffsetFields(BindingKey K, FieldVector &Fields) {
  assert(K.hasSymbolicOffset() && "Not implemented for concrete offset keys");

  const MemRegion *Base = K.getConcreteOffsetRegion();
  const MemRegion *R = K.getRegion();

  while (R != Base) {
    if (const FieldRegion *FR = dyn_cast<FieldRegion>(R))
      if (!isUnionField(FR))
        Fields.push_back(FR->getDecl());

    R = cast<SubRegion>(R)->getSuperRegion();
  }
}

static bool isCompatibleWithFields(BindingKey K, const FieldVector &Fields) {
  assert(K.hasSymbolicOffset() && "Not implemented for concrete offset keys");

  if (Fields.empty())
    return true;

  FieldVector FieldsInBindingKey;
  getSymbolicOffsetFields(K, FieldsInBindingKey);

  ptrdiff_t Delta = FieldsInBindingKey.size() - Fields.size();
  if (Delta >= 0)
    return std::equal(FieldsInBindingKey.begin() + Delta,
                      FieldsInBindingKey.end(),
                      Fields.begin());
  else
    return std::equal(FieldsInBindingKey.begin(), FieldsInBindingKey.end(),
                      Fields.begin() - Delta);
}

/// Collects all bindings in \p Cluster that may refer to bindings within
/// \p Top.
///
/// Each binding is a pair whose \c first is the key (a BindingKey) and whose
/// \c second is the value (an SVal).
///
/// The \p IncludeAllDefaultBindings parameter specifies whether to include
/// default bindings that may extend beyond \p Top itself, e.g. if \p Top is
/// an aggregate within a larger aggregate with a default binding.
static void
collectSubRegionBindings(SmallVectorImpl<BindingPair> &Bindings,
                         SValBuilder &SVB, const ClusterBindings &Cluster,
                         const SubRegion *Top, BindingKey TopKey,
                         bool IncludeAllDefaultBindings) {
  FieldVector FieldsInSymbolicSubregions;
  if (TopKey.hasSymbolicOffset()) {
    getSymbolicOffsetFields(TopKey, FieldsInSymbolicSubregions);
    Top = cast<SubRegion>(TopKey.getConcreteOffsetRegion());
    TopKey = BindingKey::Make(Top, BindingKey::Default);
  }

  // Find the length (in bits) of the region being invalidated.
  uint64_t Length = UINT64_MAX;
  SVal Extent = Top->getExtent(SVB);
  if (Optional<nonloc::ConcreteInt> ExtentCI =
          Extent.getAs<nonloc::ConcreteInt>()) {
    const llvm::APSInt &ExtentInt = ExtentCI->getValue();
    assert(ExtentInt.isNonNegative() || ExtentInt.isUnsigned());
    // Extents are in bytes but region offsets are in bits. Be careful!
    Length = ExtentInt.getLimitedValue() * SVB.getContext().getCharWidth();
  } else if (const FieldRegion *FR = dyn_cast<FieldRegion>(Top)) {
    if (FR->getDecl()->isBitField())
      Length = FR->getDecl()->getBitWidthValue(SVB.getContext());
  }

  for (ClusterBindings::iterator I = Cluster.begin(), E = Cluster.end();
       I != E; ++I) {
    BindingKey NextKey = I.getKey();
    if (NextKey.getRegion() == TopKey.getRegion()) {
      // FIXME: This doesn't catch the case where we're really invalidating a
      // region with a symbolic offset. Example:
      //      R: points[i].y
      //   Next: points[0].x

      if (NextKey.getOffset() > TopKey.getOffset() &&
          NextKey.getOffset() - TopKey.getOffset() < Length) {
        // Case 1: The next binding is inside the region we're invalidating.
        // Include it.
        Bindings.push_back(*I);

      } else if (NextKey.getOffset() == TopKey.getOffset()) {
        // Case 2: The next binding is at the same offset as the region we're
        // invalidating. In this case, we need to leave default bindings alone,
        // since they may be providing a default value for a regions beyond what
        // we're invalidating.
        // FIXME: This is probably incorrect; consider invalidating an outer
        // struct whose first field is bound to a LazyCompoundVal.
        if (IncludeAllDefaultBindings || NextKey.isDirect())
          Bindings.push_back(*I);
      }

    } else if (NextKey.hasSymbolicOffset()) {
      const MemRegion *Base = NextKey.getConcreteOffsetRegion();
      if (Top->isSubRegionOf(Base)) {
        // Case 3: The next key is symbolic and we just changed something within
        // its concrete region. We don't know if the binding is still valid, so
        // we'll be conservative and include it.
        if (IncludeAllDefaultBindings || NextKey.isDirect())
          if (isCompatibleWithFields(NextKey, FieldsInSymbolicSubregions))
            Bindings.push_back(*I);
      } else if (const SubRegion *BaseSR = dyn_cast<SubRegion>(Base)) {
        // Case 4: The next key is symbolic, but we changed a known
        // super-region. In this case the binding is certainly included.
        if (Top == Base || BaseSR->isSubRegionOf(Top))
          if (isCompatibleWithFields(NextKey, FieldsInSymbolicSubregions))
            Bindings.push_back(*I);
      }
    }
  }
}

static void
collectSubRegionBindings(SmallVectorImpl<BindingPair> &Bindings,
                         SValBuilder &SVB, const ClusterBindings &Cluster,
                         const SubRegion *Top, bool IncludeAllDefaultBindings) {
  collectSubRegionBindings(Bindings, SVB, Cluster, Top,
                           BindingKey::Make(Top, BindingKey::Default),
                           IncludeAllDefaultBindings);
}

RegionBindingsRef
RegionStoreManager::removeSubRegionBindings(RegionBindingsConstRef B,
                                            const SubRegion *Top) {
  BindingKey TopKey = BindingKey::Make(Top, BindingKey::Default);
  const MemRegion *ClusterHead = TopKey.getBaseRegion();

  if (Top == ClusterHead) {
    // We can remove an entire cluster's bindings all in one go.
    return B.remove(Top);
  }

  const ClusterBindings *Cluster = B.lookup(ClusterHead);
  if (!Cluster) {
    // If we're invalidating a region with a symbolic offset, we need to make
    // sure we don't treat the base region as uninitialized anymore.
    if (TopKey.hasSymbolicOffset()) {
      const SubRegion *Concrete = TopKey.getConcreteOffsetRegion();
      return B.addBinding(Concrete, BindingKey::Default, UnknownVal());
    }
    return B;
  }

  SmallVector<BindingPair, 32> Bindings;
  collectSubRegionBindings(Bindings, svalBuilder, *Cluster, Top, TopKey,
                           /*IncludeAllDefaultBindings=*/false);

  ClusterBindingsRef Result(*Cluster, CBFactory);
  for (SmallVectorImpl<BindingPair>::const_iterator I = Bindings.begin(),
                                                    E = Bindings.end();
       I != E; ++I)
    Result = Result.remove(I->first);

  // If we're invalidating a region with a symbolic offset, we need to make sure
  // we don't treat the base region as uninitialized anymore.
  // FIXME: This isn't very precise; see the example in
  // collectSubRegionBindings.
  if (TopKey.hasSymbolicOffset()) {
    const SubRegion *Concrete = TopKey.getConcreteOffsetRegion();
    Result = Result.add(BindingKey::Make(Concrete, BindingKey::Default),
                        UnknownVal());
  }

  if (Result.isEmpty())
    return B.remove(ClusterHead);
  return B.add(ClusterHead, Result.asImmutableMap());
}

namespace {
class invalidateRegionsWorker : public ClusterAnalysis<invalidateRegionsWorker>
{
  const Expr *Ex;
  unsigned Count;
  const LocationContext *LCtx;
  InvalidatedSymbols &IS;
  RegionAndSymbolInvalidationTraits &ITraits;
  StoreManager::InvalidatedRegions *Regions;
  GlobalsFilterKind GlobalsFilter;
public:
  invalidateRegionsWorker(RegionStoreManager &rm,
                          ProgramStateManager &stateMgr,
                          RegionBindingsRef b,
                          const Expr *ex, unsigned count,
                          const LocationContext *lctx,
                          InvalidatedSymbols &is,
                          RegionAndSymbolInvalidationTraits &ITraitsIn,
                          StoreManager::InvalidatedRegions *r,
                          GlobalsFilterKind GFK)
     : ClusterAnalysis<invalidateRegionsWorker>(rm, stateMgr, b),
       Ex(ex), Count(count), LCtx(lctx), IS(is), ITraits(ITraitsIn), Regions(r),
       GlobalsFilter(GFK) {}

  void VisitCluster(const MemRegion *baseR, const ClusterBindings *C);
  void VisitBinding(SVal V);

  using ClusterAnalysis::AddToWorkList;

  bool AddToWorkList(const MemRegion *R);

  /// Returns true if all clusters in the memory space for \p Base should be
  /// be invalidated.
  bool includeEntireMemorySpace(const MemRegion *Base);

  /// Returns true if the memory space of the given region is one of the global
  /// regions specially included at the start of invalidation.
  bool isInitiallyIncludedGlobalRegion(const MemRegion *R);
};
}

bool invalidateRegionsWorker::AddToWorkList(const MemRegion *R) {
  bool doNotInvalidateSuperRegion = ITraits.hasTrait(
      R, RegionAndSymbolInvalidationTraits::TK_DoNotInvalidateSuperRegion);
  const MemRegion *BaseR = doNotInvalidateSuperRegion ? R : R->getBaseRegion();
  return AddToWorkList(WorkListElement(BaseR), getCluster(BaseR));
}

void invalidateRegionsWorker::VisitBinding(SVal V) {
  // A symbol?  Mark it touched by the invalidation.
  if (SymbolRef Sym = V.getAsSymbol())
    IS.insert(Sym);

  if (const MemRegion *R = V.getAsRegion()) {
    AddToWorkList(R);
    return;
  }

  // Is it a LazyCompoundVal?  All references get invalidated as well.
  if (Optional<nonloc::LazyCompoundVal> LCS =
          V.getAs<nonloc::LazyCompoundVal>()) {

    const RegionStoreManager::SValListTy &Vals = RM.getInterestingValues(*LCS);

    for (RegionStoreManager::SValListTy::const_iterator I = Vals.begin(),
                                                        E = Vals.end();
         I != E; ++I)
      VisitBinding(*I);

    return;
  }
}

void invalidateRegionsWorker::VisitCluster(const MemRegion *baseR,
                                           const ClusterBindings *C) {

  bool PreserveRegionsContents =
      ITraits.hasTrait(baseR,
                       RegionAndSymbolInvalidationTraits::TK_PreserveContents);

  if (C) {
    for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E; ++I)
      VisitBinding(I.getData());

    // Invalidate regions contents.
    if (!PreserveRegionsContents)
      B = B.remove(baseR);
  }

  // BlockDataRegion?  If so, invalidate captured variables that are passed
  // by reference.
  if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(baseR)) {
    for (BlockDataRegion::referenced_vars_iterator
         BI = BR->referenced_vars_begin(), BE = BR->referenced_vars_end() ;
         BI != BE; ++BI) {
      const VarRegion *VR = BI.getCapturedRegion();
      const VarDecl *VD = VR->getDecl();
      if (VD->hasAttr<BlocksAttr>() || !VD->hasLocalStorage()) {
        AddToWorkList(VR);
      }
      else if (Loc::isLocType(VR->getValueType())) {
        // Map the current bindings to a Store to retrieve the value
        // of the binding.  If that binding itself is a region, we should
        // invalidate that region.  This is because a block may capture
        // a pointer value, but the thing pointed by that pointer may
        // get invalidated.
        SVal V = RM.getBinding(B, loc::MemRegionVal(VR));
        if (Optional<Loc> L = V.getAs<Loc>()) {
          if (const MemRegion *LR = L->getAsRegion())
            AddToWorkList(LR);
        }
      }
    }
    return;
  }

  // Symbolic region?
  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR))
    IS.insert(SR->getSymbol());

  // Nothing else should be done in the case when we preserve regions context.
  if (PreserveRegionsContents)
    return;

  // Otherwise, we have a normal data region. Record that we touched the region.
  if (Regions)
    Regions->push_back(baseR);

  if (isa<AllocaRegion>(baseR) || isa<SymbolicRegion>(baseR)) {
    // Invalidate the region by setting its default value to
    // conjured symbol. The type of the symbol is irrelevant.
    DefinedOrUnknownSVal V =
      svalBuilder.conjureSymbolVal(baseR, Ex, LCtx, Ctx.IntTy, Count);
    B = B.addBinding(baseR, BindingKey::Default, V);
    return;
  }

  if (!baseR->isBoundable())
    return;

  const TypedValueRegion *TR = cast<TypedValueRegion>(baseR);
  QualType T = TR->getValueType();

  if (isInitiallyIncludedGlobalRegion(baseR)) {
    // If the region is a global and we are invalidating all globals,
    // erasing the entry is good enough.  This causes all globals to be lazily
    // symbolicated from the same base symbol.
    return;
  }

  if (T->isStructureOrClassType()) {
    // Invalidate the region by setting its default value to
    // conjured symbol. The type of the symbol is irrelevant.
    DefinedOrUnknownSVal V = svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
                                                          Ctx.IntTy, Count);
    B = B.addBinding(baseR, BindingKey::Default, V);
    return;
  }

  if (const ArrayType *AT = Ctx.getAsArrayType(T)) {
    bool doNotInvalidateSuperRegion = ITraits.hasTrait(
        baseR,
        RegionAndSymbolInvalidationTraits::TK_DoNotInvalidateSuperRegion);

    if (doNotInvalidateSuperRegion) {
      // We are not doing blank invalidation of the whole array region so we
      // have to manually invalidate each elements.
      Optional<uint64_t> NumElements;

      // Compute lower and upper offsets for region within array.
      if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(AT))
        NumElements = CAT->getSize().getZExtValue();
      if (!NumElements) // We are not dealing with a constant size array
        goto conjure_default;
      QualType ElementTy = AT->getElementType();
      uint64_t ElemSize = Ctx.getTypeSize(ElementTy);
      const RegionOffset &RO = baseR->getAsOffset();
      const MemRegion *SuperR = baseR->getBaseRegion();
      if (RO.hasSymbolicOffset()) {
        // If base region has a symbolic offset,
        // we revert to invalidating the super region.
        if (SuperR)
          AddToWorkList(SuperR);
        goto conjure_default;
      }

      uint64_t LowerOffset = RO.getOffset();
      uint64_t UpperOffset = LowerOffset + *NumElements * ElemSize;
      bool UpperOverflow = UpperOffset < LowerOffset;

      // Invalidate regions which are within array boundaries,
      // or have a symbolic offset.
      if (!SuperR)
        goto conjure_default;

      const ClusterBindings *C = B.lookup(SuperR);
      if (!C)
        goto conjure_default;

      for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E;
           ++I) {
        const BindingKey &BK = I.getKey();
        Optional<uint64_t> ROffset =
            BK.hasSymbolicOffset() ? Optional<uint64_t>() : BK.getOffset();

        // Check offset is not symbolic and within array's boundaries.
        // Handles arrays of 0 elements and of 0-sized elements as well.
        if (!ROffset ||
            ((*ROffset >= LowerOffset && *ROffset < UpperOffset) ||
             (UpperOverflow &&
              (*ROffset >= LowerOffset || *ROffset < UpperOffset)) ||
             (LowerOffset == UpperOffset && *ROffset == LowerOffset))) {
          B = B.removeBinding(I.getKey());
          // Bound symbolic regions need to be invalidated for dead symbol
          // detection.
          SVal V = I.getData();
          const MemRegion *R = V.getAsRegion();
          if (R && isa<SymbolicRegion>(R))
            VisitBinding(V);
        }
      }
    }
  conjure_default:
      // Set the default value of the array to conjured symbol.
    DefinedOrUnknownSVal V =
    svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
                                     AT->getElementType(), Count);
    B = B.addBinding(baseR, BindingKey::Default, V);
    return;
  }

  DefinedOrUnknownSVal V = svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
                                                        T,Count);
  assert(SymbolManager::canSymbolicate(T) || V.isUnknown());
  B = B.addBinding(baseR, BindingKey::Direct, V);
}

bool invalidateRegionsWorker::isInitiallyIncludedGlobalRegion(
    const MemRegion *R) {
  switch (GlobalsFilter) {
  case GFK_None:
    return false;
  case GFK_SystemOnly:
    return isa<GlobalSystemSpaceRegion>(R->getMemorySpace());
  case GFK_All:
    return isa<NonStaticGlobalSpaceRegion>(R->getMemorySpace());
  }

  llvm_unreachable("unknown globals filter");
}

bool invalidateRegionsWorker::includeEntireMemorySpace(const MemRegion *Base) {
  if (isInitiallyIncludedGlobalRegion(Base))
    return true;

  const MemSpaceRegion *MemSpace = Base->getMemorySpace();
  return ITraits.hasTrait(MemSpace,
                          RegionAndSymbolInvalidationTraits::TK_EntireMemSpace);
}

RegionBindingsRef
RegionStoreManager::invalidateGlobalRegion(MemRegion::Kind K,
                                           const Expr *Ex,
                                           unsigned Count,
                                           const LocationContext *LCtx,
                                           RegionBindingsRef B,
                                           InvalidatedRegions *Invalidated) {
  // Bind the globals memory space to a new symbol that we will use to derive
  // the bindings for all globals.
  const GlobalsSpaceRegion *GS = MRMgr.getGlobalsRegion(K);
  SVal V = svalBuilder.conjureSymbolVal(/* SymbolTag = */ (const void*) GS, Ex, LCtx,
                                        /* type does not matter */ Ctx.IntTy,
                                        Count);

  B = B.removeBinding(GS)
       .addBinding(BindingKey::Make(GS, BindingKey::Default), V);

  // Even if there are no bindings in the global scope, we still need to
  // record that we touched it.
  if (Invalidated)
    Invalidated->push_back(GS);

  return B;
}

void RegionStoreManager::populateWorkList(invalidateRegionsWorker &W,
                                          ArrayRef<SVal> Values,
                                          InvalidatedRegions *TopLevelRegions) {
  for (ArrayRef<SVal>::iterator I = Values.begin(),
                                E = Values.end(); I != E; ++I) {
    SVal V = *I;
    if (Optional<nonloc::LazyCompoundVal> LCS =
        V.getAs<nonloc::LazyCompoundVal>()) {

      const SValListTy &Vals = getInterestingValues(*LCS);

      for (SValListTy::const_iterator I = Vals.begin(),
                                      E = Vals.end(); I != E; ++I) {
        // Note: the last argument is false here because these are
        // non-top-level regions.
        if (const MemRegion *R = (*I).getAsRegion())
          W.AddToWorkList(R);
      }
      continue;
    }

    if (const MemRegion *R = V.getAsRegion()) {
      if (TopLevelRegions)
        TopLevelRegions->push_back(R);
      W.AddToWorkList(R);
      continue;
    }
  }
}

StoreRef
RegionStoreManager::invalidateRegions(Store store,
                                     ArrayRef<SVal> Values,
                                     const Expr *Ex, unsigned Count,
                                     const LocationContext *LCtx,
                                     const CallEvent *Call,
                                     InvalidatedSymbols &IS,
                                     RegionAndSymbolInvalidationTraits &ITraits,
                                     InvalidatedRegions *TopLevelRegions,
                                     InvalidatedRegions *Invalidated) {
  GlobalsFilterKind GlobalsFilter;
  if (Call) {
    if (Call->isInSystemHeader())
      GlobalsFilter = GFK_SystemOnly;
    else
      GlobalsFilter = GFK_All;
  } else {
    GlobalsFilter = GFK_None;
  }

  RegionBindingsRef B = getRegionBindings(store);
  invalidateRegionsWorker W(*this, StateMgr, B, Ex, Count, LCtx, IS, ITraits,
                            Invalidated, GlobalsFilter);

  // Scan the bindings and generate the clusters.
  W.GenerateClusters();

  // Add the regions to the worklist.
  populateWorkList(W, Values, TopLevelRegions);

  W.RunWorkList();

  // Return the new bindings.
  B = W.getRegionBindings();

  // For calls, determine which global regions should be invalidated and
  // invalidate them. (Note that function-static and immutable globals are never
  // invalidated by this.)
  // TODO: This could possibly be more precise with modules.
  switch (GlobalsFilter) {
  case GFK_All:
    B = invalidateGlobalRegion(MemRegion::GlobalInternalSpaceRegionKind,
                               Ex, Count, LCtx, B, Invalidated);
    // FALLTHROUGH
  case GFK_SystemOnly:
    B = invalidateGlobalRegion(MemRegion::GlobalSystemSpaceRegionKind,
                               Ex, Count, LCtx, B, Invalidated);
    // FALLTHROUGH
  case GFK_None:
    break;
  }

  return StoreRef(B.asStore(), *this);
}

//===----------------------------------------------------------------------===//
// Extents for regions.
//===----------------------------------------------------------------------===//

DefinedOrUnknownSVal
RegionStoreManager::getSizeInElements(ProgramStateRef state,
                                      const MemRegion *R,
                                      QualType EleTy) {
  SVal Size = cast<SubRegion>(R)->getExtent(svalBuilder);
  const llvm::APSInt *SizeInt = svalBuilder.getKnownValue(state, Size);
  if (!SizeInt)
    return UnknownVal();

  CharUnits RegionSize = CharUnits::fromQuantity(SizeInt->getSExtValue());

  if (Ctx.getAsVariableArrayType(EleTy)) {
    // FIXME: We need to track extra state to properly record the size
    // of VLAs.  Returning UnknownVal here, however, is a stop-gap so that
    // we don't have a divide-by-zero below.
    return UnknownVal();
  }

  CharUnits EleSize = Ctx.getTypeSizeInChars(EleTy);

  // If a variable is reinterpreted as a type that doesn't fit into a larger
  // type evenly, round it down.
  // This is a signed value, since it's used in arithmetic with signed indices.
  return svalBuilder.makeIntVal(RegionSize / EleSize, false);
}

//===----------------------------------------------------------------------===//
// Location and region casting.
//===----------------------------------------------------------------------===//

/// ArrayToPointer - Emulates the "decay" of an array to a pointer
///  type.  'Array' represents the lvalue of the array being decayed
///  to a pointer, and the returned SVal represents the decayed
///  version of that lvalue (i.e., a pointer to the first element of
///  the array).  This is called by ExprEngine when evaluating casts
///  from arrays to pointers.
SVal RegionStoreManager::ArrayToPointer(Loc Array, QualType T) {
  if (!Array.getAs<loc::MemRegionVal>())
    return UnknownVal();

  const MemRegion* R = Array.castAs<loc::MemRegionVal>().getRegion();
  NonLoc ZeroIdx = svalBuilder.makeZeroArrayIndex();
  return loc::MemRegionVal(MRMgr.getElementRegion(T, ZeroIdx, R, Ctx));
}

//===----------------------------------------------------------------------===//
// Loading values from regions.
//===----------------------------------------------------------------------===//

SVal RegionStoreManager::getBinding(RegionBindingsConstRef B, Loc L, QualType T) {
  assert(!L.getAs<UnknownVal>() && "location unknown");
  assert(!L.getAs<UndefinedVal>() && "location undefined");

  // For access to concrete addresses, return UnknownVal.  Checks
  // for null dereferences (and similar errors) are done by checkers, not
  // the Store.
  // FIXME: We can consider lazily symbolicating such memory, but we really
  // should defer this when we can reason easily about symbolicating arrays
  // of bytes.
  if (L.getAs<loc::ConcreteInt>()) {
    return UnknownVal();
  }
  if (!L.getAs<loc::MemRegionVal>()) {
    return UnknownVal();
  }

  const MemRegion *MR = L.castAs<loc::MemRegionVal>().getRegion();

  if (isa<BlockDataRegion>(MR)) {
    return UnknownVal();
  }

  if (isa<AllocaRegion>(MR) ||
      isa<SymbolicRegion>(MR) ||
      isa<CodeTextRegion>(MR)) {
    if (T.isNull()) {
      if (const TypedRegion *TR = dyn_cast<TypedRegion>(MR))
        T = TR->getLocationType();
      else {
        const SymbolicRegion *SR = cast<SymbolicRegion>(MR);
        T = SR->getSymbol()->getType();
      }
    }
    MR = GetElementZeroRegion(MR, T);
  }

  // FIXME: Perhaps this method should just take a 'const MemRegion*' argument
  //  instead of 'Loc', and have the other Loc cases handled at a higher level.
  const TypedValueRegion *R = cast<TypedValueRegion>(MR);
  QualType RTy = R->getValueType();

  // FIXME: we do not yet model the parts of a complex type, so treat the
  // whole thing as "unknown".
  if (RTy->isAnyComplexType())
    return UnknownVal();

  // FIXME: We should eventually handle funny addressing.  e.g.:
  //
  //   int x = ...;
  //   int *p = &x;
  //   char *q = (char*) p;
  //   char c = *q;  // returns the first byte of 'x'.
  //
  // Such funny addressing will occur due to layering of regions.
  if (RTy->isStructureOrClassType())
    return getBindingForStruct(B, R);

  // FIXME: Handle unions.
  if (RTy->isUnionType())
    return createLazyBinding(B, R);

  if (RTy->isArrayType()) {
    if (RTy->isConstantArrayType())
      return getBindingForArray(B, R);
    else
      return UnknownVal();
  }

  // FIXME: handle Vector types.
  if (RTy->isVectorType())
    return UnknownVal();

  if (const FieldRegion* FR = dyn_cast<FieldRegion>(R))
    return CastRetrievedVal(getBindingForField(B, FR), FR, T, false);

  if (const ElementRegion* ER = dyn_cast<ElementRegion>(R)) {
    // FIXME: Here we actually perform an implicit conversion from the loaded
    // value to the element type.  Eventually we want to compose these values
    // more intelligently.  For example, an 'element' can encompass multiple
    // bound regions (e.g., several bound bytes), or could be a subset of
    // a larger value.
    return CastRetrievedVal(getBindingForElement(B, ER), ER, T, false);
  }

  if (const ObjCIvarRegion *IVR = dyn_cast<ObjCIvarRegion>(R)) {
    // FIXME: Here we actually perform an implicit conversion from the loaded
    // value to the ivar type.  What we should model is stores to ivars
    // that blow past the extent of the ivar.  If the address of the ivar is
    // reinterpretted, it is possible we stored a different value that could
    // fit within the ivar.  Either we need to cast these when storing them
    // or reinterpret them lazily (as we do here).
    return CastRetrievedVal(getBindingForObjCIvar(B, IVR), IVR, T, false);
  }

  if (const VarRegion *VR = dyn_cast<VarRegion>(R)) {
    // FIXME: Here we actually perform an implicit conversion from the loaded
    // value to the variable type.  What we should model is stores to variables
    // that blow past the extent of the variable.  If the address of the
    // variable is reinterpretted, it is possible we stored a different value
    // that could fit within the variable.  Either we need to cast these when
    // storing them or reinterpret them lazily (as we do here).
    return CastRetrievedVal(getBindingForVar(B, VR), VR, T, false);
  }

  const SVal *V = B.lookup(R, BindingKey::Direct);

  // Check if the region has a binding.
  if (V)
    return *V;

  // The location does not have a bound value.  This means that it has
  // the value it had upon its creation and/or entry to the analyzed
  // function/method.  These are either symbolic values or 'undefined'.
  if (R->hasStackNonParametersStorage()) {
    // All stack variables are considered to have undefined values
    // upon creation.  All heap allocated blocks are considered to
    // have undefined values as well unless they are explicitly bound
    // to specific values.
    return UndefinedVal();
  }

  // All other values are symbolic.
  return svalBuilder.getRegionValueSymbolVal(R);
}

static QualType getUnderlyingType(const SubRegion *R) {
  QualType RegionTy;
  if (const TypedValueRegion *TVR = dyn_cast<TypedValueRegion>(R))
    RegionTy = TVR->getValueType();

  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R))
    RegionTy = SR->getSymbol()->getType();

  return RegionTy;
}

/// Checks to see if store \p B has a lazy binding for region \p R.
///
/// If \p AllowSubregionBindings is \c false, a lazy binding will be rejected
/// if there are additional bindings within \p R.
///
/// Note that unlike RegionStoreManager::findLazyBinding, this will not search
/// for lazy bindings for super-regions of \p R.
static Optional<nonloc::LazyCompoundVal>
getExistingLazyBinding(SValBuilder &SVB, RegionBindingsConstRef B,
                       const SubRegion *R, bool AllowSubregionBindings) {
  Optional<SVal> V = B.getDefaultBinding(R);
  if (!V)
    return None;

  Optional<nonloc::LazyCompoundVal> LCV = V->getAs<nonloc::LazyCompoundVal>();
  if (!LCV)
    return None;

  // If the LCV is for a subregion, the types might not match, and we shouldn't
  // reuse the binding.
  QualType RegionTy = getUnderlyingType(R);
  if (!RegionTy.isNull() &&
      !RegionTy->isVoidPointerType()) {
    QualType SourceRegionTy = LCV->getRegion()->getValueType();
    if (!SVB.getContext().hasSameUnqualifiedType(RegionTy, SourceRegionTy))
      return None;
  }

  if (!AllowSubregionBindings) {
    // If there are any other bindings within this region, we shouldn't reuse
    // the top-level binding.
    SmallVector<BindingPair, 16> Bindings;
    collectSubRegionBindings(Bindings, SVB, *B.lookup(R->getBaseRegion()), R,
                             /*IncludeAllDefaultBindings=*/true);
    if (Bindings.size() > 1)
      return None;
  }

  return *LCV;
}


std::pair<Store, const SubRegion *>
RegionStoreManager::findLazyBinding(RegionBindingsConstRef B,
                                   const SubRegion *R,
                                   const SubRegion *originalRegion) {
  if (originalRegion != R) {
    if (Optional<nonloc::LazyCompoundVal> V =
          getExistingLazyBinding(svalBuilder, B, R, true))
      return std::make_pair(V->getStore(), V->getRegion());
  }

  typedef std::pair<Store, const SubRegion *> StoreRegionPair;
  StoreRegionPair Result = StoreRegionPair();

  if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
    Result = findLazyBinding(B, cast<SubRegion>(ER->getSuperRegion()),
                             originalRegion);

    if (Result.second)
      Result.second = MRMgr.getElementRegionWithSuper(ER, Result.second);

  } else if (const FieldRegion *FR = dyn_cast<FieldRegion>(R)) {
    Result = findLazyBinding(B, cast<SubRegion>(FR->getSuperRegion()),
                                       originalRegion);

    if (Result.second)
      Result.second = MRMgr.getFieldRegionWithSuper(FR, Result.second);

  } else if (const CXXBaseObjectRegion *BaseReg =
               dyn_cast<CXXBaseObjectRegion>(R)) {
    // C++ base object region is another kind of region that we should blast
    // through to look for lazy compound value. It is like a field region.
    Result = findLazyBinding(B, cast<SubRegion>(BaseReg->getSuperRegion()),
                             originalRegion);

    if (Result.second)
      Result.second = MRMgr.getCXXBaseObjectRegionWithSuper(BaseReg,
                                                            Result.second);
  }

  return Result;
}

SVal RegionStoreManager::getBindingForElement(RegionBindingsConstRef B,
                                              const ElementRegion* R) {
  // We do not currently model bindings of the CompoundLiteralregion.
  if (isa<CompoundLiteralRegion>(R->getBaseRegion()))
    return UnknownVal();

  // Check if the region has a binding.
  if (const Optional<SVal> &V = B.getDirectBinding(R))
    return *V;

  const MemRegion* superR = R->getSuperRegion();

  // Check if the region is an element region of a string literal.
  if (const StringRegion *StrR=dyn_cast<StringRegion>(superR)) {
    // FIXME: Handle loads from strings where the literal is treated as
    // an integer, e.g., *((unsigned int*)"hello")
    QualType T = Ctx.getAsArrayType(StrR->getValueType())->getElementType();
    if (!Ctx.hasSameUnqualifiedType(T, R->getElementType()))
      return UnknownVal();

    const StringLiteral *Str = StrR->getStringLiteral();
    SVal Idx = R->getIndex();
    if (Optional<nonloc::ConcreteInt> CI = Idx.getAs<nonloc::ConcreteInt>()) {
      int64_t i = CI->getValue().getSExtValue();
      // Abort on string underrun.  This can be possible by arbitrary
      // clients of getBindingForElement().
      if (i < 0)
        return UndefinedVal();
      int64_t length = Str->getLength();
      // Technically, only i == length is guaranteed to be null.
      // However, such overflows should be caught before reaching this point;
      // the only time such an access would be made is if a string literal was
      // used to initialize a larger array.
      char c = (i >= length) ? '\0' : Str->getCodeUnit(i);
      return svalBuilder.makeIntVal(c, T);
    }
  }

  // Check for loads from a code text region.  For such loads, just give up.
  if (isa<CodeTextRegion>(superR))
    return UnknownVal();

  // Handle the case where we are indexing into a larger scalar object.
  // For example, this handles:
  //   int x = ...
  //   char *y = &x;
  //   return *y;
  // FIXME: This is a hack, and doesn't do anything really intelligent yet.
  const RegionRawOffset &O = R->getAsArrayOffset();

  // If we cannot reason about the offset, return an unknown value.
  if (!O.getRegion())
    return UnknownVal();

  if (const TypedValueRegion *baseR =
        dyn_cast_or_null<TypedValueRegion>(O.getRegion())) {
    QualType baseT = baseR->getValueType();
    if (baseT->isScalarType()) {
      QualType elemT = R->getElementType();
      if (elemT->isScalarType()) {
        if (Ctx.getTypeSizeInChars(baseT) >= Ctx.getTypeSizeInChars(elemT)) {
          if (const Optional<SVal> &V = B.getDirectBinding(superR)) {
            if (SymbolRef parentSym = V->getAsSymbol())
              return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);

            if (V->isUnknownOrUndef())
              return *V;
            // Other cases: give up.  We are indexing into a larger object
            // that has some value, but we don't know how to handle that yet.
            return UnknownVal();
          }
        }
      }
    }
  }
  return getBindingForFieldOrElementCommon(B, R, R->getElementType());
}

SVal RegionStoreManager::getBindingForField(RegionBindingsConstRef B,
                                            const FieldRegion* R) {

  // Check if the region has a binding.
  if (const Optional<SVal> &V = B.getDirectBinding(R))
    return *V;

  QualType Ty = R->getValueType();
  return getBindingForFieldOrElementCommon(B, R, Ty);
}

Optional<SVal>
RegionStoreManager::getBindingForDerivedDefaultValue(RegionBindingsConstRef B,
                                                     const MemRegion *superR,
                                                     const TypedValueRegion *R,
                                                     QualType Ty) {

  if (const Optional<SVal> &D = B.getDefaultBinding(superR)) {
    const SVal &val = D.getValue();
    if (SymbolRef parentSym = val.getAsSymbol())
      return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);

    if (val.isZeroConstant())
      return svalBuilder.makeZeroVal(Ty);

    if (val.isUnknownOrUndef())
      return val;

    // Lazy bindings are usually handled through getExistingLazyBinding().
    // We should unify these two code paths at some point.
    if (val.getAs<nonloc::LazyCompoundVal>() ||
        val.getAs<nonloc::CompoundVal>())
      return val;

    llvm_unreachable("Unknown default value");
  }

  return None;
}

SVal RegionStoreManager::getLazyBinding(const SubRegion *LazyBindingRegion,
                                        RegionBindingsRef LazyBinding) {
  SVal Result;
  if (const ElementRegion *ER = dyn_cast<ElementRegion>(LazyBindingRegion))
    Result = getBindingForElement(LazyBinding, ER);
  else
    Result = getBindingForField(LazyBinding,
                                cast<FieldRegion>(LazyBindingRegion));

  // FIXME: This is a hack to deal with RegionStore's inability to distinguish a
  // default value for /part/ of an aggregate from a default value for the
  // /entire/ aggregate. The most common case of this is when struct Outer
  // has as its first member a struct Inner, which is copied in from a stack
  // variable. In this case, even if the Outer's default value is symbolic, 0,
  // or unknown, it gets overridden by the Inner's default value of undefined.
  //
  // This is a general problem -- if the Inner is zero-initialized, the Outer
  // will now look zero-initialized. The proper way to solve this is with a
  // new version of RegionStore that tracks the extent of a binding as well
  // as the offset.
  //
  // This hack only takes care of the undefined case because that can very
  // quickly result in a warning.
  if (Result.isUndef())
    Result = UnknownVal();

  return Result;
}

SVal
RegionStoreManager::getBindingForFieldOrElementCommon(RegionBindingsConstRef B,
                                                      const TypedValueRegion *R,
                                                      QualType Ty) {

  // At this point we have already checked in either getBindingForElement or
  // getBindingForField if 'R' has a direct binding.

  // Lazy binding?
  Store lazyBindingStore = nullptr;
  const SubRegion *lazyBindingRegion = nullptr;
  std::tie(lazyBindingStore, lazyBindingRegion) = findLazyBinding(B, R, R);
  if (lazyBindingRegion)
    return getLazyBinding(lazyBindingRegion,
                          getRegionBindings(lazyBindingStore));

  // Record whether or not we see a symbolic index.  That can completely
  // be out of scope of our lookup.
  bool hasSymbolicIndex = false;

  // FIXME: This is a hack to deal with RegionStore's inability to distinguish a
  // default value for /part/ of an aggregate from a default value for the
  // /entire/ aggregate. The most common case of this is when struct Outer
  // has as its first member a struct Inner, which is copied in from a stack
  // variable. In this case, even if the Outer's default value is symbolic, 0,
  // or unknown, it gets overridden by the Inner's default value of undefined.
  //
  // This is a general problem -- if the Inner is zero-initialized, the Outer
  // will now look zero-initialized. The proper way to solve this is with a
  // new version of RegionStore that tracks the extent of a binding as well
  // as the offset.
  //
  // This hack only takes care of the undefined case because that can very
  // quickly result in a warning.
  bool hasPartialLazyBinding = false;

  const SubRegion *SR = dyn_cast<SubRegion>(R);
  while (SR) {
    const MemRegion *Base = SR->getSuperRegion();
    if (Optional<SVal> D = getBindingForDerivedDefaultValue(B, Base, R, Ty)) {
      if (D->getAs<nonloc::LazyCompoundVal>()) {
        hasPartialLazyBinding = true;
        break;
      }

      return *D;
    }

    if (const ElementRegion *ER = dyn_cast<ElementRegion>(Base)) {
      NonLoc index = ER->getIndex();
      if (!index.isConstant())
        hasSymbolicIndex = true;
    }

    // If our super region is a field or element itself, walk up the region
    // hierarchy to see if there is a default value installed in an ancestor.
    SR = dyn_cast<SubRegion>(Base);
  }

  if (R->hasStackNonParametersStorage()) {
    if (isa<ElementRegion>(R)) {
      // Currently we don't reason specially about Clang-style vectors.  Check
      // if superR is a vector and if so return Unknown.
      if (const TypedValueRegion *typedSuperR =
            dyn_cast<TypedValueRegion>(R->getSuperRegion())) {
        if (typedSuperR->getValueType()->isVectorType())
          return UnknownVal();
      }
    }

    // FIXME: We also need to take ElementRegions with symbolic indexes into
    // account.  This case handles both directly accessing an ElementRegion
    // with a symbolic offset, but also fields within an element with
    // a symbolic offset.
    if (hasSymbolicIndex)
      return UnknownVal();

    if (!hasPartialLazyBinding)
      return UndefinedVal();
  }

  // All other values are symbolic.
  return svalBuilder.getRegionValueSymbolVal(R);
}

SVal RegionStoreManager::getBindingForObjCIvar(RegionBindingsConstRef B,
                                               const ObjCIvarRegion* R) {
  // Check if the region has a binding.
  if (const Optional<SVal> &V = B.getDirectBinding(R))
    return *V;

  const MemRegion *superR = R->getSuperRegion();

  // Check if the super region has a default binding.
  if (const Optional<SVal> &V = B.getDefaultBinding(superR)) {
    if (SymbolRef parentSym = V->getAsSymbol())
      return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);

    // Other cases: give up.
    return UnknownVal();
  }

  return getBindingForLazySymbol(R);
}

SVal RegionStoreManager::getBindingForVar(RegionBindingsConstRef B,
                                          const VarRegion *R) {

  // Check if the region has a binding.
  if (const Optional<SVal> &V = B.getDirectBinding(R))
    return *V;

  // Lazily derive a value for the VarRegion.
  const VarDecl *VD = R->getDecl();
  const MemSpaceRegion *MS = R->getMemorySpace();

  // Arguments are always symbolic.
  if (isa<StackArgumentsSpaceRegion>(MS))
    return svalBuilder.getRegionValueSymbolVal(R);

  // Is 'VD' declared constant?  If so, retrieve the constant value.
  if (VD->getType().isConstQualified())
    if (const Expr *Init = VD->getInit())
      if (Optional<SVal> V = svalBuilder.getConstantVal(Init))
        return *V;

  // This must come after the check for constants because closure-captured
  // constant variables may appear in UnknownSpaceRegion.
  if (isa<UnknownSpaceRegion>(MS))
    return svalBuilder.getRegionValueSymbolVal(R);

  if (isa<GlobalsSpaceRegion>(MS)) {
    QualType T = VD->getType();

    // Function-scoped static variables are default-initialized to 0; if they
    // have an initializer, it would have been processed by now.
    if (isa<StaticGlobalSpaceRegion>(MS))
      return svalBuilder.makeZeroVal(T);

    if (Optional<SVal> V = getBindingForDerivedDefaultValue(B, MS, R, T)) {
      assert(!V->getAs<nonloc::LazyCompoundVal>());
      return V.getValue();
    }

    return svalBuilder.getRegionValueSymbolVal(R);
  }

  return UndefinedVal();
}

SVal RegionStoreManager::getBindingForLazySymbol(const TypedValueRegion *R) {
  // All other values are symbolic.
  return svalBuilder.getRegionValueSymbolVal(R);
}

const RegionStoreManager::SValListTy &
RegionStoreManager::getInterestingValues(nonloc::LazyCompoundVal LCV) {
  // First, check the cache.
  LazyBindingsMapTy::iterator I = LazyBindingsMap.find(LCV.getCVData());
  if (I != LazyBindingsMap.end())
    return I->second;

  // If we don't have a list of values cached, start constructing it.
  SValListTy List;

  const SubRegion *LazyR = LCV.getRegion();
  RegionBindingsRef B = getRegionBindings(LCV.getStore());

  // If this region had /no/ bindings at the time, there are no interesting
  // values to return.
  const ClusterBindings *Cluster = B.lookup(LazyR->getBaseRegion());
  if (!Cluster)
    return (LazyBindingsMap[LCV.getCVData()] = std::move(List));

  SmallVector<BindingPair, 32> Bindings;
  collectSubRegionBindings(Bindings, svalBuilder, *Cluster, LazyR,
                           /*IncludeAllDefaultBindings=*/true);
  for (SmallVectorImpl<BindingPair>::const_iterator I = Bindings.begin(),
                                                    E = Bindings.end();
       I != E; ++I) {
    SVal V = I->second;
    if (V.isUnknownOrUndef() || V.isConstant())
      continue;

    if (Optional<nonloc::LazyCompoundVal> InnerLCV =
            V.getAs<nonloc::LazyCompoundVal>()) {
      const SValListTy &InnerList = getInterestingValues(*InnerLCV);
      List.insert(List.end(), InnerList.begin(), InnerList.end());
      continue;
    }

    List.push_back(V);
  }

  return (LazyBindingsMap[LCV.getCVData()] = std::move(List));
}

NonLoc RegionStoreManager::createLazyBinding(RegionBindingsConstRef B,
                                             const TypedValueRegion *R) {
  if (Optional<nonloc::LazyCompoundVal> V =
        getExistingLazyBinding(svalBuilder, B, R, false))
    return *V;

  return svalBuilder.makeLazyCompoundVal(StoreRef(B.asStore(), *this), R);
}

static bool isRecordEmpty(const RecordDecl *RD) {
  if (!RD->field_empty())
    return false;
  if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD))
    return CRD->getNumBases() == 0;
  return true;
}

SVal RegionStoreManager::getBindingForStruct(RegionBindingsConstRef B,
                                             const TypedValueRegion *R) {
  const RecordDecl *RD = R->getValueType()->castAs<RecordType>()->getDecl();
  if (!RD->getDefinition() || isRecordEmpty(RD))
    return UnknownVal();

  return createLazyBinding(B, R);
}

SVal RegionStoreManager::getBindingForArray(RegionBindingsConstRef B,
                                            const TypedValueRegion *R) {
  assert(Ctx.getAsConstantArrayType(R->getValueType()) &&
         "Only constant array types can have compound bindings.");

  return createLazyBinding(B, R);
}

bool RegionStoreManager::includedInBindings(Store store,
                                            const MemRegion *region) const {
  RegionBindingsRef B = getRegionBindings(store);
  region = region->getBaseRegion();

  // Quick path: if the base is the head of a cluster, the region is live.
  if (B.lookup(region))
    return true;

  // Slow path: if the region is the VALUE of any binding, it is live.
  for (RegionBindingsRef::iterator RI = B.begin(), RE = B.end(); RI != RE; ++RI) {
    const ClusterBindings &Cluster = RI.getData();
    for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
         CI != CE; ++CI) {
      const SVal &D = CI.getData();
      if (const MemRegion *R = D.getAsRegion())
        if (R->getBaseRegion() == region)
          return true;
    }
  }

  return false;
}

//===----------------------------------------------------------------------===//
// Binding values to regions.
//===----------------------------------------------------------------------===//

StoreRef RegionStoreManager::killBinding(Store ST, Loc L) {
  if (Optional<loc::MemRegionVal> LV = L.getAs<loc::MemRegionVal>())
    if (const MemRegion* R = LV->getRegion())
      return StoreRef(getRegionBindings(ST).removeBinding(R)
                                           .asImmutableMap()
                                           .getRootWithoutRetain(),
                      *this);

  return StoreRef(ST, *this);
}

RegionBindingsRef
RegionStoreManager::bind(RegionBindingsConstRef B, Loc L, SVal V) {
  if (L.getAs<loc::ConcreteInt>())
    return B;

  // If we get here, the location should be a region.
  const MemRegion *R = L.castAs<loc::MemRegionVal>().getRegion();

  // Check if the region is a struct region.
  if (const TypedValueRegion* TR = dyn_cast<TypedValueRegion>(R)) {
    QualType Ty = TR->getValueType();
    if (Ty->isArrayType())
      return bindArray(B, TR, V);
    if (Ty->isStructureOrClassType())
      return bindStruct(B, TR, V);
    if (Ty->isVectorType())
      return bindVector(B, TR, V);
    if (Ty->isUnionType())
      return bindAggregate(B, TR, V);
  }

  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) {
    // Binding directly to a symbolic region should be treated as binding
    // to element 0.
    QualType T = SR->getSymbol()->getType();
    if (T->isAnyPointerType() || T->isReferenceType())
      T = T->getPointeeType();

    R = GetElementZeroRegion(SR, T);
  }

  // Clear out bindings that may overlap with this binding.
  RegionBindingsRef NewB = removeSubRegionBindings(B, cast<SubRegion>(R));
  return NewB.addBinding(BindingKey::Make(R, BindingKey::Direct), V);
}

RegionBindingsRef
RegionStoreManager::setImplicitDefaultValue(RegionBindingsConstRef B,
                                            const MemRegion *R,
                                            QualType T) {
  SVal V;

  if (Loc::isLocType(T))
    V = svalBuilder.makeNull();
  else if (T->isIntegralOrEnumerationType())
    V = svalBuilder.makeZeroVal(T);
  else if (T->isStructureOrClassType() || T->isArrayType()) {
    // Set the default value to a zero constant when it is a structure
    // or array.  The type doesn't really matter.
    V = svalBuilder.makeZeroVal(Ctx.IntTy);
  }
  else {
    // We can't represent values of this type, but we still need to set a value
    // to record that the region has been initialized.
    // If this assertion ever fires, a new case should be added above -- we
    // should know how to default-initialize any value we can symbolicate.
    assert(!SymbolManager::canSymbolicate(T) && "This type is representable");
    V = UnknownVal();
  }

  return B.addBinding(R, BindingKey::Default, V);
}

RegionBindingsRef
RegionStoreManager::bindArray(RegionBindingsConstRef B,
                              const TypedValueRegion* R,
                              SVal Init) {

  const ArrayType *AT =cast<ArrayType>(Ctx.getCanonicalType(R->getValueType()));
  QualType ElementTy = AT->getElementType();
  Optional<uint64_t> Size;

  if (const ConstantArrayType* CAT = dyn_cast<ConstantArrayType>(AT))
    Size = CAT->getSize().getZExtValue();

  // Check if the init expr is a string literal.
  if (Optional<loc::MemRegionVal> MRV = Init.getAs<loc::MemRegionVal>()) {
    const StringRegion *S = cast<StringRegion>(MRV->getRegion());

    // Treat the string as a lazy compound value.
    StoreRef store(B.asStore(), *this);
    nonloc::LazyCompoundVal LCV = svalBuilder.makeLazyCompoundVal(store, S)
        .castAs<nonloc::LazyCompoundVal>();
    return bindAggregate(B, R, LCV);
  }

  // Handle lazy compound values.
  if (Init.getAs<nonloc::LazyCompoundVal>())
    return bindAggregate(B, R, Init);

  if (Init.isUnknown())
    return bindAggregate(B, R, UnknownVal());

  // Remaining case: explicit compound values.
  const nonloc::CompoundVal& CV = Init.castAs<nonloc::CompoundVal>();
  nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
  uint64_t i = 0;

  RegionBindingsRef NewB(B);

  for (; Size.hasValue() ? i < Size.getValue() : true ; ++i, ++VI) {
    // The init list might be shorter than the array length.
    if (VI == VE)
      break;

    const NonLoc &Idx = svalBuilder.makeArrayIndex(i);
    const ElementRegion *ER = MRMgr.getElementRegion(ElementTy, Idx, R, Ctx);

    if (ElementTy->isStructureOrClassType())
      NewB = bindStruct(NewB, ER, *VI);
    else if (ElementTy->isArrayType())
      NewB = bindArray(NewB, ER, *VI);
    else
      NewB = bind(NewB, loc::MemRegionVal(ER), *VI);
  }

  // If the init list is shorter than the array length, set the
  // array default value.
  if (Size.hasValue() && i < Size.getValue())
    NewB = setImplicitDefaultValue(NewB, R, ElementTy);

  return NewB;
}

RegionBindingsRef RegionStoreManager::bindVector(RegionBindingsConstRef B,
                                                 const TypedValueRegion* R,
                                                 SVal V) {
  QualType T = R->getValueType();
  assert(T->isVectorType());
  const VectorType *VT = T->getAs<VectorType>(); // Use getAs for typedefs.

  // Handle lazy compound values and symbolic values.
  if (V.getAs<nonloc::LazyCompoundVal>() || V.getAs<nonloc::SymbolVal>())
    return bindAggregate(B, R, V);

  // We may get non-CompoundVal accidentally due to imprecise cast logic or
  // that we are binding symbolic struct value. Kill the field values, and if
  // the value is symbolic go and bind it as a "default" binding.
  if (!V.getAs<nonloc::CompoundVal>()) {
    return bindAggregate(B, R, UnknownVal());
  }

  QualType ElemType = VT->getElementType();
  nonloc::CompoundVal CV = V.castAs<nonloc::CompoundVal>();
  nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
  unsigned index = 0, numElements = VT->getNumElements();
  RegionBindingsRef NewB(B);

  for ( ; index != numElements ; ++index) {
    if (VI == VE)
      break;

    NonLoc Idx = svalBuilder.makeArrayIndex(index);
    const ElementRegion *ER = MRMgr.getElementRegion(ElemType, Idx, R, Ctx);

    if (ElemType->isArrayType())
      NewB = bindArray(NewB, ER, *VI);
    else if (ElemType->isStructureOrClassType())
      NewB = bindStruct(NewB, ER, *VI);
    else
      NewB = bind(NewB, loc::MemRegionVal(ER), *VI);
  }
  return NewB;
}

Optional<RegionBindingsRef>
RegionStoreManager::tryBindSmallStruct(RegionBindingsConstRef B,
                                       const TypedValueRegion *R,
                                       const RecordDecl *RD,
                                       nonloc::LazyCompoundVal LCV) {
  FieldVector Fields;

  if (const CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(RD))
    if (Class->getNumBases() != 0 || Class->getNumVBases() != 0)
      return None;

  for (const auto *FD : RD->fields()) {
    if (FD->isUnnamedBitfield())
      continue;

    // If there are too many fields, or if any of the fields are aggregates,
    // just use the LCV as a default binding.
    if (Fields.size() == SmallStructLimit)
      return None;

    QualType Ty = FD->getType();
    if (!(Ty->isScalarType() || Ty->isReferenceType()))
      return None;

    Fields.push_back(FD);
  }

  RegionBindingsRef NewB = B;

  for (FieldVector::iterator I = Fields.begin(), E = Fields.end(); I != E; ++I){
    const FieldRegion *SourceFR = MRMgr.getFieldRegion(*I, LCV.getRegion());
    SVal V = getBindingForField(getRegionBindings(LCV.getStore()), SourceFR);

    const FieldRegion *DestFR = MRMgr.getFieldRegion(*I, R);
    NewB = bind(NewB, loc::MemRegionVal(DestFR), V);
  }

  return NewB;
}

RegionBindingsRef RegionStoreManager::bindStruct(RegionBindingsConstRef B,
                                                 const TypedValueRegion* R,
                                                 SVal V) {
  if (!Features.supportsFields())
    return B;

  QualType T = R->getValueType();
  assert(T->isStructureOrClassType());

  const RecordType* RT = T->getAs<RecordType>();
  const RecordDecl *RD = RT->getDecl();

  if (!RD->isCompleteDefinition())
    return B;

  // Handle lazy compound values and symbolic values.
  if (Optional<nonloc::LazyCompoundVal> LCV =
        V.getAs<nonloc::LazyCompoundVal>()) {
    if (Optional<RegionBindingsRef> NewB = tryBindSmallStruct(B, R, RD, *LCV))
      return *NewB;
    return bindAggregate(B, R, V);
  }
  if (V.getAs<nonloc::SymbolVal>())
    return bindAggregate(B, R, V);

  // We may get non-CompoundVal accidentally due to imprecise cast logic or
  // that we are binding symbolic struct value. Kill the field values, and if
  // the value is symbolic go and bind it as a "default" binding.
  if (V.isUnknown() || !V.getAs<nonloc::CompoundVal>())
    return bindAggregate(B, R, UnknownVal());

  const nonloc::CompoundVal& CV = V.castAs<nonloc::CompoundVal>();
  nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();

  RecordDecl::field_iterator FI, FE;
  RegionBindingsRef NewB(B);

  for (FI = RD->field_begin(), FE = RD->field_end(); FI != FE; ++FI) {

    if (VI == VE)
      break;

    // Skip any unnamed bitfields to stay in sync with the initializers.
    if (FI->isUnnamedBitfield())
      continue;

    QualType FTy = FI->getType();
    const FieldRegion* FR = MRMgr.getFieldRegion(*FI, R);

    if (FTy->isArrayType())
      NewB = bindArray(NewB, FR, *VI);
    else if (FTy->isStructureOrClassType())
      NewB = bindStruct(NewB, FR, *VI);
    else
      NewB = bind(NewB, loc::MemRegionVal(FR), *VI);
    ++VI;
  }

  // There may be fewer values in the initialize list than the fields of struct.
  if (FI != FE) {
    NewB = NewB.addBinding(R, BindingKey::Default,
                           svalBuilder.makeIntVal(0, false));
  }

  return NewB;
}

RegionBindingsRef
RegionStoreManager::bindAggregate(RegionBindingsConstRef B,
                                  const TypedRegion *R,
                                  SVal Val) {
  // Remove the old bindings, using 'R' as the root of all regions
  // we will invalidate. Then add the new binding.
  return removeSubRegionBindings(B, R).addBinding(R, BindingKey::Default, Val);
}

//===----------------------------------------------------------------------===//
// State pruning.
//===----------------------------------------------------------------------===//

namespace {
class removeDeadBindingsWorker :
  public ClusterAnalysis<removeDeadBindingsWorker> {
  SmallVector<const SymbolicRegion*, 12> Postponed;
  SymbolReaper &SymReaper;
  const StackFrameContext *CurrentLCtx;

public:
  removeDeadBindingsWorker(RegionStoreManager &rm,
                           ProgramStateManager &stateMgr,
                           RegionBindingsRef b, SymbolReaper &symReaper,
                           const StackFrameContext *LCtx)
    : ClusterAnalysis<removeDeadBindingsWorker>(rm, stateMgr, b),
      SymReaper(symReaper), CurrentLCtx(LCtx) {}

  // Called by ClusterAnalysis.
  void VisitAddedToCluster(const MemRegion *baseR, const ClusterBindings &C);
  void VisitCluster(const MemRegion *baseR, const ClusterBindings *C);
  using ClusterAnalysis<removeDeadBindingsWorker>::VisitCluster;

  using ClusterAnalysis::AddToWorkList;

  bool AddToWorkList(const MemRegion *R);

  bool UpdatePostponed();
  void VisitBinding(SVal V);
};
}

bool removeDeadBindingsWorker::AddToWorkList(const MemRegion *R) {
  const MemRegion *BaseR = R->getBaseRegion();
  return AddToWorkList(WorkListElement(BaseR), getCluster(BaseR));
}

void removeDeadBindingsWorker::VisitAddedToCluster(const MemRegion *baseR,
                                                   const ClusterBindings &C) {

  if (const VarRegion *VR = dyn_cast<VarRegion>(baseR)) {
    if (SymReaper.isLive(VR))
      AddToWorkList(baseR, &C);

    return;
  }

  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR)) {
    if (SymReaper.isLive(SR->getSymbol()))
      AddToWorkList(SR, &C);
    else
      Postponed.push_back(SR);

    return;
  }

  if (isa<NonStaticGlobalSpaceRegion>(baseR)) {
    AddToWorkList(baseR, &C);
    return;
  }

  // CXXThisRegion in the current or parent location context is live.
  if (const CXXThisRegion *TR = dyn_cast<CXXThisRegion>(baseR)) {
    const StackArgumentsSpaceRegion *StackReg =
      cast<StackArgumentsSpaceRegion>(TR->getSuperRegion());
    const StackFrameContext *RegCtx = StackReg->getStackFrame();
    if (CurrentLCtx &&
        (RegCtx == CurrentLCtx || RegCtx->isParentOf(CurrentLCtx)))
      AddToWorkList(TR, &C);
  }
}

void removeDeadBindingsWorker::VisitCluster(const MemRegion *baseR,
                                            const ClusterBindings *C) {
  if (!C)
    return;

  // Mark the symbol for any SymbolicRegion with live bindings as live itself.
  // This means we should continue to track that symbol.
  if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(baseR))
    SymReaper.markLive(SymR->getSymbol());

  for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E; ++I) {
    // Element index of a binding key is live.
    SymReaper.markElementIndicesLive(I.getKey().getRegion());

    VisitBinding(I.getData());
  }
}

void removeDeadBindingsWorker::VisitBinding(SVal V) {
  // Is it a LazyCompoundVal?  All referenced regions are live as well.
  if (Optional<nonloc::LazyCompoundVal> LCS =
          V.getAs<nonloc::LazyCompoundVal>()) {

    const RegionStoreManager::SValListTy &Vals = RM.getInterestingValues(*LCS);

    for (RegionStoreManager::SValListTy::const_iterator I = Vals.begin(),
                                                        E = Vals.end();
         I != E; ++I)
      VisitBinding(*I);

    return;
  }

  // If V is a region, then add it to the worklist.
  if (const MemRegion *R = V.getAsRegion()) {
    AddToWorkList(R);
    SymReaper.markLive(R);

    // All regions captured by a block are also live.
    if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(R)) {
      BlockDataRegion::referenced_vars_iterator I = BR->referenced_vars_begin(),
                                                E = BR->referenced_vars_end();
      for ( ; I != E; ++I)
        AddToWorkList(I.getCapturedRegion());
    }
  }


  // Update the set of live symbols.
  for (SymExpr::symbol_iterator SI = V.symbol_begin(), SE = V.symbol_end();
       SI!=SE; ++SI)
    SymReaper.markLive(*SI);
}

bool removeDeadBindingsWorker::UpdatePostponed() {
  // See if any postponed SymbolicRegions are actually live now, after
  // having done a scan.
  bool changed = false;

  for (SmallVectorImpl<const SymbolicRegion*>::iterator
        I = Postponed.begin(), E = Postponed.end() ; I != E ; ++I) {
    if (const SymbolicRegion *SR = *I) {
      if (SymReaper.isLive(SR->getSymbol())) {
        changed |= AddToWorkList(SR);
        *I = nullptr;
      }
    }
  }

  return changed;
}

StoreRef RegionStoreManager::removeDeadBindings(Store store,
                                                const StackFrameContext *LCtx,
                                                SymbolReaper& SymReaper) {
  RegionBindingsRef B = getRegionBindings(store);
  removeDeadBindingsWorker W(*this, StateMgr, B, SymReaper, LCtx);
  W.GenerateClusters();

  // Enqueue the region roots onto the worklist.
  for (SymbolReaper::region_iterator I = SymReaper.region_begin(),
       E = SymReaper.region_end(); I != E; ++I) {
    W.AddToWorkList(*I);
  }

  do W.RunWorkList(); while (W.UpdatePostponed());

  // We have now scanned the store, marking reachable regions and symbols
  // as live.  We now remove all the regions that are dead from the store
  // as well as update DSymbols with the set symbols that are now dead.
  for (RegionBindingsRef::iterator I = B.begin(), E = B.end(); I != E; ++I) {
    const MemRegion *Base = I.getKey();

    // If the cluster has been visited, we know the region has been marked.
    if (W.isVisited(Base))
      continue;

    // Remove the dead entry.
    B = B.remove(Base);

    if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(Base))
      SymReaper.maybeDead(SymR->getSymbol());

    // Mark all non-live symbols that this binding references as dead.
    const ClusterBindings &Cluster = I.getData();
    for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
         CI != CE; ++CI) {
      SVal X = CI.getData();
      SymExpr::symbol_iterator SI = X.symbol_begin(), SE = X.symbol_end();
      for (; SI != SE; ++SI)
        SymReaper.maybeDead(*SI);
    }
  }

  return StoreRef(B.asStore(), *this);
}

//===----------------------------------------------------------------------===//
// Utility methods.
//===----------------------------------------------------------------------===//

void RegionStoreManager::print(Store store, raw_ostream &OS,
                               const char* nl, const char *sep) {
  RegionBindingsRef B = getRegionBindings(store);
  OS << "Store (direct and default bindings), "
     << B.asStore()
     << " :" << nl;
  B.dump(OS, nl);
}