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
|
// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/debug/debug.h"
#include <memory>
#include <unordered_set>
#include "src/api/api-inl.h"
#include "src/api/api-natives.h"
#include "src/base/platform/mutex.h"
#include "src/builtins/builtins.h"
#include "src/codegen/assembler-inl.h"
#include "src/codegen/compilation-cache.h"
#include "src/codegen/compiler.h"
#include "src/common/globals.h"
#include "src/common/message-template.h"
#include "src/debug/debug-evaluate.h"
#include "src/debug/liveedit.h"
#include "src/deoptimizer/deoptimizer.h"
#include "src/execution/arguments.h"
#include "src/execution/execution.h"
#include "src/execution/frames-inl.h"
#include "src/execution/isolate-inl.h"
#include "src/execution/v8threads.h"
#include "src/handles/global-handles.h"
#include "src/heap/heap-inl.h" // For NextDebuggingId.
#include "src/init/bootstrapper.h"
#include "src/interpreter/bytecode-array-accessor.h"
#include "src/interpreter/bytecode-array-iterator.h"
#include "src/interpreter/interpreter.h"
#include "src/logging/counters.h"
#include "src/objects/api-callbacks-inl.h"
#include "src/objects/debug-objects-inl.h"
#include "src/objects/js-generator-inl.h"
#include "src/objects/js-promise-inl.h"
#include "src/objects/slots.h"
#include "src/snapshot/snapshot.h"
#include "src/wasm/wasm-debug.h"
#include "src/wasm/wasm-objects-inl.h"
namespace v8 {
namespace internal {
class Debug::TemporaryObjectsTracker : public HeapObjectAllocationTracker {
public:
TemporaryObjectsTracker() = default;
~TemporaryObjectsTracker() override = default;
void AllocationEvent(Address addr, int) override { objects_.insert(addr); }
void MoveEvent(Address from, Address to, int) override {
if (from == to) return;
base::MutexGuard guard(&mutex_);
auto it = objects_.find(from);
if (it == objects_.end()) {
// If temporary object was collected we can get MoveEvent which moves
// existing non temporary object to the address where we had temporary
// object. So we should mark new address as non temporary.
objects_.erase(to);
return;
}
objects_.erase(it);
objects_.insert(to);
}
bool HasObject(Handle<HeapObject> obj) const {
if (obj->IsJSObject() &&
Handle<JSObject>::cast(obj)->GetEmbedderFieldCount()) {
// Embedder may store any pointers using embedder fields and implements
// non trivial logic, e.g. create wrappers lazily and store pointer to
// native object inside embedder field. We should consider all objects
// with embedder fields as non temporary.
return false;
}
return objects_.find(obj->address()) != objects_.end();
}
private:
std::unordered_set<Address> objects_;
base::Mutex mutex_;
DISALLOW_COPY_AND_ASSIGN(TemporaryObjectsTracker);
};
Debug::Debug(Isolate* isolate)
: is_active_(false),
hook_on_function_call_(false),
is_suppressed_(false),
break_disabled_(false),
break_points_active_(true),
break_on_exception_(false),
break_on_uncaught_exception_(false),
side_effect_check_failed_(false),
debug_info_list_(nullptr),
feature_tracker_(isolate),
isolate_(isolate) {
ThreadInit();
}
Debug::~Debug() { DCHECK_NULL(debug_delegate_); }
BreakLocation BreakLocation::FromFrame(Handle<DebugInfo> debug_info,
JavaScriptFrame* frame) {
if (debug_info->CanBreakAtEntry()) {
return BreakLocation(Debug::kBreakAtEntryPosition, DEBUG_BREAK_AT_ENTRY);
}
auto summary = FrameSummary::GetTop(frame).AsJavaScript();
int offset = summary.code_offset();
Handle<AbstractCode> abstract_code = summary.abstract_code();
BreakIterator it(debug_info);
it.SkipTo(BreakIndexFromCodeOffset(debug_info, abstract_code, offset));
return it.GetBreakLocation();
}
void BreakLocation::AllAtCurrentStatement(
Handle<DebugInfo> debug_info, JavaScriptFrame* frame,
std::vector<BreakLocation>* result_out) {
DCHECK(!debug_info->CanBreakAtEntry());
auto summary = FrameSummary::GetTop(frame).AsJavaScript();
int offset = summary.code_offset();
Handle<AbstractCode> abstract_code = summary.abstract_code();
if (abstract_code->IsCode()) offset = offset - 1;
int statement_position;
{
BreakIterator it(debug_info);
it.SkipTo(BreakIndexFromCodeOffset(debug_info, abstract_code, offset));
statement_position = it.statement_position();
}
for (BreakIterator it(debug_info); !it.Done(); it.Next()) {
if (it.statement_position() == statement_position) {
result_out->push_back(it.GetBreakLocation());
}
}
}
JSGeneratorObject BreakLocation::GetGeneratorObjectForSuspendedFrame(
JavaScriptFrame* frame) const {
DCHECK(IsSuspend());
DCHECK_GE(generator_obj_reg_index_, 0);
Object generator_obj = InterpretedFrame::cast(frame)->ReadInterpreterRegister(
generator_obj_reg_index_);
return JSGeneratorObject::cast(generator_obj);
}
int BreakLocation::BreakIndexFromCodeOffset(Handle<DebugInfo> debug_info,
Handle<AbstractCode> abstract_code,
int offset) {
// Run through all break points to locate the one closest to the address.
int closest_break = 0;
int distance = kMaxInt;
DCHECK(0 <= offset && offset < abstract_code->Size());
for (BreakIterator it(debug_info); !it.Done(); it.Next()) {
// Check if this break point is closer that what was previously found.
if (it.code_offset() <= offset && offset - it.code_offset() < distance) {
closest_break = it.break_index();
distance = offset - it.code_offset();
// Check whether we can't get any closer.
if (distance == 0) break;
}
}
return closest_break;
}
bool BreakLocation::HasBreakPoint(Isolate* isolate,
Handle<DebugInfo> debug_info) const {
// First check whether there is a break point with the same source position.
if (!debug_info->HasBreakPoint(isolate, position_)) return false;
if (debug_info->CanBreakAtEntry()) {
DCHECK_EQ(Debug::kBreakAtEntryPosition, position_);
return debug_info->BreakAtEntry();
} else {
// Then check whether a break point at that source position would have
// the same code offset. Otherwise it's just a break location that we can
// step to, but not actually a location where we can put a break point.
DCHECK(abstract_code_->IsBytecodeArray());
BreakIterator it(debug_info);
it.SkipToPosition(position_);
return it.code_offset() == code_offset_;
}
}
debug::BreakLocationType BreakLocation::type() const {
switch (type_) {
case DEBUGGER_STATEMENT:
return debug::kDebuggerStatementBreakLocation;
case DEBUG_BREAK_SLOT_AT_CALL:
return debug::kCallBreakLocation;
case DEBUG_BREAK_SLOT_AT_RETURN:
return debug::kReturnBreakLocation;
// Externally, suspend breaks should look like normal breaks.
case DEBUG_BREAK_SLOT_AT_SUSPEND:
default:
return debug::kCommonBreakLocation;
}
}
BreakIterator::BreakIterator(Handle<DebugInfo> debug_info)
: debug_info_(debug_info),
break_index_(-1),
source_position_iterator_(
debug_info->DebugBytecodeArray().SourcePositionTable()) {
position_ = debug_info->shared().StartPosition();
statement_position_ = position_;
// There is at least one break location.
DCHECK(!Done());
Next();
}
int BreakIterator::BreakIndexFromPosition(int source_position) {
int distance = kMaxInt;
int closest_break = break_index();
while (!Done()) {
int next_position = position();
if (source_position <= next_position &&
next_position - source_position < distance) {
closest_break = break_index();
distance = next_position - source_position;
// Check whether we can't get any closer.
if (distance == 0) break;
}
Next();
}
return closest_break;
}
void BreakIterator::Next() {
DisallowHeapAllocation no_gc;
DCHECK(!Done());
bool first = break_index_ == -1;
while (!Done()) {
if (!first) source_position_iterator_.Advance();
first = false;
if (Done()) return;
position_ = source_position_iterator_.source_position().ScriptOffset();
if (source_position_iterator_.is_statement()) {
statement_position_ = position_;
}
DCHECK_LE(0, position_);
DCHECK_LE(0, statement_position_);
DebugBreakType type = GetDebugBreakType();
if (type != NOT_DEBUG_BREAK) break;
}
break_index_++;
}
DebugBreakType BreakIterator::GetDebugBreakType() {
BytecodeArray bytecode_array = debug_info_->OriginalBytecodeArray();
interpreter::Bytecode bytecode =
interpreter::Bytecodes::FromByte(bytecode_array.get(code_offset()));
// Make sure we read the actual bytecode, not a prefix scaling bytecode.
if (interpreter::Bytecodes::IsPrefixScalingBytecode(bytecode)) {
bytecode =
interpreter::Bytecodes::FromByte(bytecode_array.get(code_offset() + 1));
}
if (bytecode == interpreter::Bytecode::kDebugger) {
return DEBUGGER_STATEMENT;
} else if (bytecode == interpreter::Bytecode::kReturn) {
return DEBUG_BREAK_SLOT_AT_RETURN;
} else if (bytecode == interpreter::Bytecode::kSuspendGenerator) {
return DEBUG_BREAK_SLOT_AT_SUSPEND;
} else if (interpreter::Bytecodes::IsCallOrConstruct(bytecode)) {
return DEBUG_BREAK_SLOT_AT_CALL;
} else if (source_position_iterator_.is_statement()) {
return DEBUG_BREAK_SLOT;
} else {
return NOT_DEBUG_BREAK;
}
}
void BreakIterator::SkipToPosition(int position) {
BreakIterator it(debug_info_);
SkipTo(it.BreakIndexFromPosition(position));
}
void BreakIterator::SetDebugBreak() {
DebugBreakType debug_break_type = GetDebugBreakType();
if (debug_break_type == DEBUGGER_STATEMENT) return;
HandleScope scope(isolate());
DCHECK(debug_break_type >= DEBUG_BREAK_SLOT);
Handle<BytecodeArray> bytecode_array(debug_info_->DebugBytecodeArray(),
isolate());
interpreter::BytecodeArrayAccessor(bytecode_array, code_offset())
.ApplyDebugBreak();
}
void BreakIterator::ClearDebugBreak() {
DebugBreakType debug_break_type = GetDebugBreakType();
if (debug_break_type == DEBUGGER_STATEMENT) return;
DCHECK(debug_break_type >= DEBUG_BREAK_SLOT);
BytecodeArray bytecode_array = debug_info_->DebugBytecodeArray();
BytecodeArray original = debug_info_->OriginalBytecodeArray();
bytecode_array.set(code_offset(), original.get(code_offset()));
}
BreakLocation BreakIterator::GetBreakLocation() {
Handle<AbstractCode> code(
AbstractCode::cast(debug_info_->DebugBytecodeArray()), isolate());
DebugBreakType type = GetDebugBreakType();
int generator_object_reg_index = -1;
if (type == DEBUG_BREAK_SLOT_AT_SUSPEND) {
// For suspend break, we'll need the generator object to be able to step
// over the suspend as if it didn't return. We get the interpreter register
// index that holds the generator object by reading it directly off the
// bytecode array, and we'll read the actual generator object off the
// interpreter stack frame in GetGeneratorObjectForSuspendedFrame.
BytecodeArray bytecode_array = debug_info_->OriginalBytecodeArray();
interpreter::BytecodeArrayAccessor accessor(
handle(bytecode_array, isolate()), code_offset());
DCHECK_EQ(accessor.current_bytecode(),
interpreter::Bytecode::kSuspendGenerator);
interpreter::Register generator_obj_reg = accessor.GetRegisterOperand(0);
generator_object_reg_index = generator_obj_reg.index();
}
return BreakLocation(code, type, code_offset(), position_,
generator_object_reg_index);
}
Isolate* BreakIterator::isolate() { return debug_info_->GetIsolate(); }
void DebugFeatureTracker::Track(DebugFeatureTracker::Feature feature) {
uint32_t mask = 1 << feature;
// Only count one sample per feature and isolate.
if (bitfield_ & mask) return;
isolate_->counters()->debug_feature_usage()->AddSample(feature);
bitfield_ |= mask;
}
// Threading support.
void Debug::ThreadInit() {
thread_local_.break_frame_id_ = StackFrameId::NO_ID;
thread_local_.last_step_action_ = StepNone;
thread_local_.last_statement_position_ = kNoSourcePosition;
thread_local_.last_frame_count_ = -1;
thread_local_.fast_forward_to_return_ = false;
thread_local_.ignore_step_into_function_ = Smi::zero();
thread_local_.target_frame_count_ = -1;
thread_local_.return_value_ = Smi::zero();
thread_local_.last_breakpoint_id_ = 0;
clear_suspended_generator();
thread_local_.restart_fp_ = kNullAddress;
base::Relaxed_Store(&thread_local_.current_debug_scope_,
static_cast<base::AtomicWord>(0));
thread_local_.break_on_next_function_call_ = false;
UpdateHookOnFunctionCall();
}
char* Debug::ArchiveDebug(char* storage) {
MemCopy(storage, reinterpret_cast<char*>(&thread_local_),
ArchiveSpacePerThread());
return storage + ArchiveSpacePerThread();
}
char* Debug::RestoreDebug(char* storage) {
MemCopy(reinterpret_cast<char*>(&thread_local_), storage,
ArchiveSpacePerThread());
// Enter the debugger.
DebugScope debug_scope(this);
// Clear any one-shot breakpoints that may have been set by the other
// thread, and reapply breakpoints for this thread.
ClearOneShot();
if (thread_local_.last_step_action_ != StepNone) {
// Reset the previous step action for this thread.
PrepareStep(thread_local_.last_step_action_);
}
return storage + ArchiveSpacePerThread();
}
int Debug::ArchiveSpacePerThread() { return sizeof(ThreadLocal); }
void Debug::Iterate(RootVisitor* v) {
v->VisitRootPointer(Root::kDebug, nullptr,
FullObjectSlot(&thread_local_.return_value_));
v->VisitRootPointer(Root::kDebug, nullptr,
FullObjectSlot(&thread_local_.suspended_generator_));
v->VisitRootPointer(
Root::kDebug, nullptr,
FullObjectSlot(&thread_local_.ignore_step_into_function_));
}
DebugInfoListNode::DebugInfoListNode(Isolate* isolate, DebugInfo debug_info)
: next_(nullptr) {
// Globalize the request debug info object and make it weak.
GlobalHandles* global_handles = isolate->global_handles();
debug_info_ = global_handles->Create(debug_info).location();
}
DebugInfoListNode::~DebugInfoListNode() {
if (debug_info_ == nullptr) return;
GlobalHandles::Destroy(debug_info_);
debug_info_ = nullptr;
}
void Debug::Unload() {
ClearAllBreakPoints();
ClearStepping();
RemoveAllCoverageInfos();
ClearAllDebuggerHints();
debug_delegate_ = nullptr;
}
void Debug::Break(JavaScriptFrame* frame, Handle<JSFunction> break_target) {
// Initialize LiveEdit.
LiveEdit::InitializeThreadLocal(this);
// Just continue if breaks are disabled or debugger cannot be loaded.
if (break_disabled()) return;
// Enter the debugger.
DebugScope debug_scope(this);
DisableBreak no_recursive_break(this);
// Return if we fail to retrieve debug info.
Handle<SharedFunctionInfo> shared(break_target->shared(), isolate_);
if (!EnsureBreakInfo(shared)) return;
PrepareFunctionForDebugExecution(shared);
Handle<DebugInfo> debug_info(shared->GetDebugInfo(), isolate_);
// Find the break location where execution has stopped.
BreakLocation location = BreakLocation::FromFrame(debug_info, frame);
// Find actual break points, if any, and trigger debug break event.
MaybeHandle<FixedArray> break_points_hit =
CheckBreakPoints(debug_info, &location);
if (!break_points_hit.is_null() || break_on_next_function_call()) {
// Clear all current stepping setup.
ClearStepping();
// Notify the debug event listeners.
OnDebugBreak(!break_points_hit.is_null()
? break_points_hit.ToHandleChecked()
: isolate_->factory()->empty_fixed_array());
return;
}
// Debug break at function entry, do not worry about stepping.
if (location.IsDebugBreakAtEntry()) {
DCHECK(debug_info->BreakAtEntry());
return;
}
DCHECK_NOT_NULL(frame);
// No break point. Check for stepping.
StepAction step_action = last_step_action();
int current_frame_count = CurrentFrameCount();
int target_frame_count = thread_local_.target_frame_count_;
int last_frame_count = thread_local_.last_frame_count_;
// StepOut at not return position was requested and return break locations
// were flooded with one shots.
if (thread_local_.fast_forward_to_return_) {
DCHECK(location.IsReturnOrSuspend());
// We have to ignore recursive calls to function.
if (current_frame_count > target_frame_count) return;
ClearStepping();
PrepareStep(StepOut);
return;
}
bool step_break = false;
switch (step_action) {
case StepNone:
return;
case StepOut:
// Step out should not break in a deeper frame than target frame.
if (current_frame_count > target_frame_count) return;
step_break = true;
break;
case StepNext:
// Step next should not break in a deeper frame than target frame.
if (current_frame_count > target_frame_count) return;
V8_FALLTHROUGH;
case StepIn: {
// Special case "next" and "in" for generators that are about to suspend.
if (location.IsSuspend()) {
DCHECK(!has_suspended_generator());
thread_local_.suspended_generator_ =
location.GetGeneratorObjectForSuspendedFrame(frame);
ClearStepping();
return;
}
FrameSummary summary = FrameSummary::GetTop(frame);
step_break = step_break || location.IsReturn() ||
current_frame_count != last_frame_count ||
thread_local_.last_statement_position_ !=
summary.SourceStatementPosition();
break;
}
}
// Clear all current stepping setup.
ClearStepping();
if (step_break) {
// Notify the debug event listeners.
OnDebugBreak(isolate_->factory()->empty_fixed_array());
} else {
// Re-prepare to continue.
PrepareStep(step_action);
}
}
// Find break point objects for this location, if any, and evaluate them.
// Return an array of break point objects that evaluated true, or an empty
// handle if none evaluated true.
MaybeHandle<FixedArray> Debug::CheckBreakPoints(Handle<DebugInfo> debug_info,
BreakLocation* location,
bool* has_break_points) {
bool has_break_points_to_check =
break_points_active_ && location->HasBreakPoint(isolate_, debug_info);
if (has_break_points) *has_break_points = has_break_points_to_check;
if (!has_break_points_to_check) return {};
return Debug::GetHitBreakPoints(debug_info, location->position());
}
bool Debug::IsMutedAtCurrentLocation(JavaScriptFrame* frame) {
HandleScope scope(isolate_);
// A break location is considered muted if break locations on the current
// statement have at least one break point, and all of these break points
// evaluate to false. Aside from not triggering a debug break event at the
// break location, we also do not trigger one for debugger statements, nor
// an exception event on exception at this location.
FrameSummary summary = FrameSummary::GetTop(frame);
DCHECK(!summary.IsWasm());
Handle<JSFunction> function = summary.AsJavaScript().function();
if (!function->shared().HasBreakInfo()) return false;
Handle<DebugInfo> debug_info(function->shared().GetDebugInfo(), isolate_);
// Enter the debugger.
DebugScope debug_scope(this);
std::vector<BreakLocation> break_locations;
BreakLocation::AllAtCurrentStatement(debug_info, frame, &break_locations);
bool has_break_points_at_all = false;
for (size_t i = 0; i < break_locations.size(); i++) {
bool has_break_points;
MaybeHandle<FixedArray> check_result =
CheckBreakPoints(debug_info, &break_locations[i], &has_break_points);
has_break_points_at_all |= has_break_points;
if (has_break_points && !check_result.is_null()) return false;
}
return has_break_points_at_all;
}
// Check whether a single break point object is triggered.
bool Debug::CheckBreakPoint(Handle<BreakPoint> break_point,
bool is_break_at_entry) {
HandleScope scope(isolate_);
if (!break_point->condition().length()) return true;
Handle<String> condition(break_point->condition(), isolate_);
MaybeHandle<Object> maybe_result;
Handle<Object> result;
if (is_break_at_entry) {
maybe_result = DebugEvaluate::WithTopmostArguments(isolate_, condition);
} else {
// Since we call CheckBreakpoint only for deoptimized frame on top of stack,
// we can use 0 as index of inlined frame.
const int inlined_jsframe_index = 0;
const bool throw_on_side_effect = false;
maybe_result =
DebugEvaluate::Local(isolate_, break_frame_id(), inlined_jsframe_index,
condition, throw_on_side_effect);
}
if (!maybe_result.ToHandle(&result)) {
if (isolate_->has_pending_exception()) {
isolate_->clear_pending_exception();
}
return false;
}
return result->BooleanValue(isolate_);
}
bool Debug::SetBreakpoint(Handle<SharedFunctionInfo> shared,
Handle<BreakPoint> break_point,
int* source_position) {
HandleScope scope(isolate_);
// Make sure the function is compiled and has set up the debug info.
if (!EnsureBreakInfo(shared)) return false;
PrepareFunctionForDebugExecution(shared);
Handle<DebugInfo> debug_info(shared->GetDebugInfo(), isolate_);
// Source positions starts with zero.
DCHECK_LE(0, *source_position);
// Find the break point and change it.
*source_position = FindBreakablePosition(debug_info, *source_position);
DebugInfo::SetBreakPoint(isolate_, debug_info, *source_position, break_point);
// At least one active break point now.
DCHECK_LT(0, debug_info->GetBreakPointCount(isolate_));
ClearBreakPoints(debug_info);
ApplyBreakPoints(debug_info);
feature_tracker()->Track(DebugFeatureTracker::kBreakPoint);
return true;
}
bool Debug::SetBreakPointForScript(Handle<Script> script,
Handle<String> condition,
int* source_position, int* id) {
*id = ++thread_local_.last_breakpoint_id_;
Handle<BreakPoint> break_point =
isolate_->factory()->NewBreakPoint(*id, condition);
if (script->type() == Script::TYPE_WASM) {
RecordWasmScriptWithBreakpoints(script);
return WasmScript::SetBreakPoint(script, source_position, break_point);
}
HandleScope scope(isolate_);
// Obtain shared function info for the function.
Handle<Object> result =
FindSharedFunctionInfoInScript(script, *source_position);
if (result->IsUndefined(isolate_)) return false;
// Make sure the function has set up the debug info.
Handle<SharedFunctionInfo> shared = Handle<SharedFunctionInfo>::cast(result);
if (!EnsureBreakInfo(shared)) return false;
PrepareFunctionForDebugExecution(shared);
// Find position within function. The script position might be before the
// source position of the first function.
if (shared->StartPosition() > *source_position) {
*source_position = shared->StartPosition();
}
Handle<DebugInfo> debug_info(shared->GetDebugInfo(), isolate_);
// Find breakable position returns first breakable position after
// *source_position, it can return 0 if no break location is found after
// *source_position.
int breakable_position = FindBreakablePosition(debug_info, *source_position);
if (breakable_position < *source_position) return false;
*source_position = breakable_position;
DebugInfo::SetBreakPoint(isolate_, debug_info, *source_position, break_point);
// At least one active break point now.
DCHECK_LT(0, debug_info->GetBreakPointCount(isolate_));
ClearBreakPoints(debug_info);
ApplyBreakPoints(debug_info);
feature_tracker()->Track(DebugFeatureTracker::kBreakPoint);
return true;
}
int Debug::FindBreakablePosition(Handle<DebugInfo> debug_info,
int source_position) {
if (debug_info->CanBreakAtEntry()) {
return kBreakAtEntryPosition;
} else {
DCHECK(debug_info->HasInstrumentedBytecodeArray());
BreakIterator it(debug_info);
it.SkipToPosition(source_position);
return it.position();
}
}
void Debug::ApplyBreakPoints(Handle<DebugInfo> debug_info) {
DisallowHeapAllocation no_gc;
if (debug_info->CanBreakAtEntry()) {
debug_info->SetBreakAtEntry();
} else {
if (!debug_info->HasInstrumentedBytecodeArray()) return;
FixedArray break_points = debug_info->break_points();
for (int i = 0; i < break_points.length(); i++) {
if (break_points.get(i).IsUndefined(isolate_)) continue;
BreakPointInfo info = BreakPointInfo::cast(break_points.get(i));
if (info.GetBreakPointCount(isolate_) == 0) continue;
DCHECK(debug_info->HasInstrumentedBytecodeArray());
BreakIterator it(debug_info);
it.SkipToPosition(info.source_position());
it.SetDebugBreak();
}
}
debug_info->SetDebugExecutionMode(DebugInfo::kBreakpoints);
}
void Debug::ClearBreakPoints(Handle<DebugInfo> debug_info) {
if (debug_info->CanBreakAtEntry()) {
debug_info->ClearBreakAtEntry();
} else {
// If we attempt to clear breakpoints but none exist, simply return. This
// can happen e.g. CoverageInfos exist but no breakpoints are set.
if (!debug_info->HasInstrumentedBytecodeArray() ||
!debug_info->HasBreakInfo()) {
return;
}
DisallowHeapAllocation no_gc;
for (BreakIterator it(debug_info); !it.Done(); it.Next()) {
it.ClearDebugBreak();
}
}
}
void Debug::ClearBreakPoint(Handle<BreakPoint> break_point) {
HandleScope scope(isolate_);
for (DebugInfoListNode* node = debug_info_list_; node != nullptr;
node = node->next()) {
if (!node->debug_info()->HasBreakInfo()) continue;
Handle<Object> result = DebugInfo::FindBreakPointInfo(
isolate_, node->debug_info(), break_point);
if (result->IsUndefined(isolate_)) continue;
Handle<DebugInfo> debug_info = node->debug_info();
if (DebugInfo::ClearBreakPoint(isolate_, debug_info, break_point)) {
ClearBreakPoints(debug_info);
if (debug_info->GetBreakPointCount(isolate_) == 0) {
RemoveBreakInfoAndMaybeFree(debug_info);
} else {
ApplyBreakPoints(debug_info);
}
return;
}
}
}
int Debug::GetFunctionDebuggingId(Handle<JSFunction> function) {
Handle<SharedFunctionInfo> shared = handle(function->shared(), isolate_);
Handle<DebugInfo> debug_info = GetOrCreateDebugInfo(shared);
int id = debug_info->debugging_id();
if (id == DebugInfo::kNoDebuggingId) {
id = isolate_->heap()->NextDebuggingId();
debug_info->set_debugging_id(id);
}
return id;
}
bool Debug::SetBreakpointForFunction(Handle<SharedFunctionInfo> shared,
Handle<String> condition, int* id) {
*id = ++thread_local_.last_breakpoint_id_;
Handle<BreakPoint> breakpoint =
isolate_->factory()->NewBreakPoint(*id, condition);
int source_position = 0;
// Handle wasm function.
if (shared->HasWasmExportedFunctionData()) {
int func_index = shared->wasm_exported_function_data().function_index();
Handle<WasmInstanceObject> wasm_instance(
shared->wasm_exported_function_data().instance(), isolate_);
Handle<Script> script(Script::cast(wasm_instance->module_object().script()),
isolate_);
return WasmScript::SetBreakPointOnFirstBreakableForFunction(
script, func_index, breakpoint);
}
return SetBreakpoint(shared, breakpoint, &source_position);
}
void Debug::RemoveBreakpoint(int id) {
Handle<BreakPoint> breakpoint = isolate_->factory()->NewBreakPoint(
id, isolate_->factory()->empty_string());
ClearBreakPoint(breakpoint);
}
void Debug::RemoveBreakpointForWasmScript(Handle<Script> script, int id) {
if (script->type() == Script::TYPE_WASM) {
WasmScript::ClearBreakPointById(script, id);
}
}
void Debug::RecordWasmScriptWithBreakpoints(Handle<Script> script) {
if (wasm_scripts_with_breakpoints_.is_null()) {
Handle<WeakArrayList> new_list = isolate_->factory()->NewWeakArrayList(4);
wasm_scripts_with_breakpoints_ =
isolate_->global_handles()->Create(*new_list);
}
{
DisallowHeapAllocation no_gc;
for (int idx = wasm_scripts_with_breakpoints_->length() - 1; idx >= 0;
--idx) {
HeapObject wasm_script;
if (wasm_scripts_with_breakpoints_->Get(idx).GetHeapObject(
&wasm_script) &&
wasm_script == *script) {
return;
}
}
}
Handle<WeakArrayList> new_list = WeakArrayList::Append(
isolate_, wasm_scripts_with_breakpoints_, MaybeObjectHandle{script});
if (*new_list != *wasm_scripts_with_breakpoints_) {
isolate_->global_handles()->Destroy(
wasm_scripts_with_breakpoints_.location());
wasm_scripts_with_breakpoints_ =
isolate_->global_handles()->Create(*new_list);
}
}
// Clear out all the debug break code.
void Debug::ClearAllBreakPoints() {
ClearAllDebugInfos([=](Handle<DebugInfo> info) {
ClearBreakPoints(info);
info->ClearBreakInfo(isolate_);
});
// Clear all wasm breakpoints.
if (!wasm_scripts_with_breakpoints_.is_null()) {
DisallowHeapAllocation no_gc;
for (int idx = wasm_scripts_with_breakpoints_->length() - 1; idx >= 0;
--idx) {
HeapObject raw_wasm_script;
if (wasm_scripts_with_breakpoints_->Get(idx).GetHeapObject(
&raw_wasm_script)) {
WasmScript::ClearAllBreakpoints(Script::cast(raw_wasm_script));
}
}
wasm_scripts_with_breakpoints_ = Handle<WeakArrayList>{};
}
}
void Debug::FloodWithOneShot(Handle<SharedFunctionInfo> shared,
bool returns_only) {
if (IsBlackboxed(shared)) return;
// Make sure the function is compiled and has set up the debug info.
if (!EnsureBreakInfo(shared)) return;
PrepareFunctionForDebugExecution(shared);
Handle<DebugInfo> debug_info(shared->GetDebugInfo(), isolate_);
// Flood the function with break points.
DCHECK(debug_info->HasInstrumentedBytecodeArray());
for (BreakIterator it(debug_info); !it.Done(); it.Next()) {
if (returns_only && !it.GetBreakLocation().IsReturnOrSuspend()) continue;
it.SetDebugBreak();
}
}
void Debug::ChangeBreakOnException(ExceptionBreakType type, bool enable) {
if (type == BreakUncaughtException) {
break_on_uncaught_exception_ = enable;
} else {
break_on_exception_ = enable;
}
}
bool Debug::IsBreakOnException(ExceptionBreakType type) {
if (type == BreakUncaughtException) {
return break_on_uncaught_exception_;
} else {
return break_on_exception_;
}
}
MaybeHandle<FixedArray> Debug::GetHitBreakPoints(Handle<DebugInfo> debug_info,
int position) {
Handle<Object> break_points = debug_info->GetBreakPoints(isolate_, position);
bool is_break_at_entry = debug_info->BreakAtEntry();
DCHECK(!break_points->IsUndefined(isolate_));
if (!break_points->IsFixedArray()) {
if (!CheckBreakPoint(Handle<BreakPoint>::cast(break_points),
is_break_at_entry)) {
return {};
}
Handle<FixedArray> break_points_hit = isolate_->factory()->NewFixedArray(1);
break_points_hit->set(0, *break_points);
return break_points_hit;
}
Handle<FixedArray> array(FixedArray::cast(*break_points), isolate_);
int num_objects = array->length();
Handle<FixedArray> break_points_hit =
isolate_->factory()->NewFixedArray(num_objects);
int break_points_hit_count = 0;
for (int i = 0; i < num_objects; ++i) {
Handle<Object> break_point(array->get(i), isolate_);
if (CheckBreakPoint(Handle<BreakPoint>::cast(break_point),
is_break_at_entry)) {
break_points_hit->set(break_points_hit_count++, *break_point);
}
}
if (break_points_hit_count == 0) return {};
break_points_hit->Shrink(isolate_, break_points_hit_count);
return break_points_hit;
}
void Debug::SetBreakOnNextFunctionCall() {
// This method forces V8 to break on next function call regardless current
// last_step_action_. If any break happens between SetBreakOnNextFunctionCall
// and ClearBreakOnNextFunctionCall, we will clear this flag and stepping. If
// break does not happen, e.g. all called functions are blackboxed or no
// function is called, then we will clear this flag and let stepping continue
// its normal business.
thread_local_.break_on_next_function_call_ = true;
UpdateHookOnFunctionCall();
}
void Debug::ClearBreakOnNextFunctionCall() {
thread_local_.break_on_next_function_call_ = false;
UpdateHookOnFunctionCall();
}
void Debug::PrepareStepIn(Handle<JSFunction> function) {
CHECK(last_step_action() >= StepIn || break_on_next_function_call());
if (ignore_events()) return;
if (in_debug_scope()) return;
if (break_disabled()) return;
Handle<SharedFunctionInfo> shared(function->shared(), isolate_);
if (IsBlackboxed(shared)) return;
if (*function == thread_local_.ignore_step_into_function_) return;
thread_local_.ignore_step_into_function_ = Smi::zero();
FloodWithOneShot(Handle<SharedFunctionInfo>(function->shared(), isolate_));
}
void Debug::PrepareStepInSuspendedGenerator() {
CHECK(has_suspended_generator());
if (ignore_events()) return;
if (in_debug_scope()) return;
if (break_disabled()) return;
thread_local_.last_step_action_ = StepIn;
UpdateHookOnFunctionCall();
Handle<JSFunction> function(
JSGeneratorObject::cast(thread_local_.suspended_generator_).function(),
isolate_);
FloodWithOneShot(Handle<SharedFunctionInfo>(function->shared(), isolate_));
clear_suspended_generator();
}
void Debug::PrepareStepOnThrow() {
if (last_step_action() == StepNone) return;
if (ignore_events()) return;
if (in_debug_scope()) return;
if (break_disabled()) return;
ClearOneShot();
int current_frame_count = CurrentFrameCount();
// Iterate through the JavaScript stack looking for handlers.
JavaScriptFrameIterator it(isolate_);
while (!it.done()) {
JavaScriptFrame* frame = it.frame();
if (frame->LookupExceptionHandlerInTable(nullptr, nullptr) > 0) break;
std::vector<SharedFunctionInfo> infos;
frame->GetFunctions(&infos);
current_frame_count -= infos.size();
it.Advance();
}
// No handler found. Nothing to instrument.
if (it.done()) return;
bool found_handler = false;
// Iterate frames, including inlined frames. First, find the handler frame.
// Then skip to the frame we want to break in, then instrument for stepping.
for (; !it.done(); it.Advance()) {
JavaScriptFrame* frame = JavaScriptFrame::cast(it.frame());
if (last_step_action() == StepIn) {
// Deoptimize frame to ensure calls are checked for step-in.
Deoptimizer::DeoptimizeFunction(frame->function());
}
std::vector<FrameSummary> summaries;
frame->Summarize(&summaries);
for (size_t i = summaries.size(); i != 0; i--, current_frame_count--) {
const FrameSummary& summary = summaries[i - 1];
if (!found_handler) {
// We have yet to find the handler. If the frame inlines multiple
// functions, we have to check each one for the handler.
// If it only contains one function, we already found the handler.
if (summaries.size() > 1) {
Handle<AbstractCode> code = summary.AsJavaScript().abstract_code();
CHECK_EQ(AbstractCode::INTERPRETED_FUNCTION, code->kind());
HandlerTable table(code->GetBytecodeArray());
int code_offset = summary.code_offset();
HandlerTable::CatchPrediction prediction;
int index = table.LookupRange(code_offset, nullptr, &prediction);
if (index > 0) found_handler = true;
} else {
found_handler = true;
}
}
if (found_handler) {
// We found the handler. If we are stepping next or out, we need to
// iterate until we found the suitable target frame to break in.
if ((last_step_action() == StepNext || last_step_action() == StepOut) &&
current_frame_count > thread_local_.target_frame_count_) {
continue;
}
Handle<SharedFunctionInfo> info(
summary.AsJavaScript().function()->shared(), isolate_);
if (IsBlackboxed(info)) continue;
FloodWithOneShot(info);
return;
}
}
}
}
void Debug::PrepareStep(StepAction step_action) {
HandleScope scope(isolate_);
DCHECK(in_debug_scope());
// Get the frame where the execution has stopped and skip the debug frame if
// any. The debug frame will only be present if execution was stopped due to
// hitting a break point. In other situations (e.g. unhandled exception) the
// debug frame is not present.
StackFrameId frame_id = break_frame_id();
// If there is no JavaScript stack don't do anything.
if (frame_id == StackFrameId::NO_ID) return;
feature_tracker()->Track(DebugFeatureTracker::kStepping);
thread_local_.last_step_action_ = step_action;
StackTraceFrameIterator frames_it(isolate_, frame_id);
StandardFrame* frame = frames_it.frame();
BreakLocation location = BreakLocation::Invalid();
Handle<SharedFunctionInfo> shared;
int current_frame_count = CurrentFrameCount();
if (frame->is_java_script()) {
JavaScriptFrame* js_frame = JavaScriptFrame::cast(frame);
DCHECK(js_frame->function().IsJSFunction());
// Get the debug info (create it if it does not exist).
auto summary = FrameSummary::GetTop(frame).AsJavaScript();
Handle<JSFunction> function(summary.function());
shared = Handle<SharedFunctionInfo>(function->shared(), isolate_);
if (!EnsureBreakInfo(shared)) return;
PrepareFunctionForDebugExecution(shared);
Handle<DebugInfo> debug_info(shared->GetDebugInfo(), isolate_);
location = BreakLocation::FromFrame(debug_info, js_frame);
// Any step at a return is a step-out, and a step-out at a suspend behaves
// like a return.
if (location.IsReturn() ||
(location.IsSuspend() && step_action == StepOut)) {
// On StepOut we'll ignore our further calls to current function in
// PrepareStepIn callback.
if (last_step_action() == StepOut) {
thread_local_.ignore_step_into_function_ = *function;
}
step_action = StepOut;
thread_local_.last_step_action_ = StepIn;
}
// We need to schedule DebugOnFunction call callback
UpdateHookOnFunctionCall();
// A step-next in blackboxed function is a step-out.
if (step_action == StepNext && IsBlackboxed(shared)) step_action = StepOut;
thread_local_.last_statement_position_ =
summary.abstract_code()->SourceStatementPosition(summary.code_offset());
thread_local_.last_frame_count_ = current_frame_count;
// No longer perform the current async step.
clear_suspended_generator();
} else if (frame->is_wasm()) {
// Handle stepping in Liftoff code.
WasmFrame* wasm_frame = WasmFrame::cast(frame);
wasm::WasmCodeRefScope code_ref_scope;
wasm::WasmCode* code = wasm_frame->wasm_code();
if (code->is_liftoff()) {
wasm_frame->native_module()->GetDebugInfo()->PrepareStep(isolate_,
frame_id);
}
// In case the wasm code returns, prepare the next frame (if JS) to break.
step_action = StepOut;
UpdateHookOnFunctionCall();
}
switch (step_action) {
case StepNone:
UNREACHABLE();
case StepOut: {
// Clear last position info. For stepping out it does not matter.
thread_local_.last_statement_position_ = kNoSourcePosition;
thread_local_.last_frame_count_ = -1;
if (!shared.is_null() && !location.IsReturnOrSuspend() &&
!IsBlackboxed(shared)) {
// At not return position we flood return positions with one shots and
// will repeat StepOut automatically at next break.
thread_local_.target_frame_count_ = current_frame_count;
thread_local_.fast_forward_to_return_ = true;
FloodWithOneShot(shared, true);
return;
}
// Skip the current frame, find the first frame we want to step out to
// and deoptimize every frame along the way.
bool in_current_frame = true;
for (; !frames_it.done(); frames_it.Advance()) {
if (frames_it.frame()->is_wasm()) {
in_current_frame = false;
continue;
}
JavaScriptFrame* frame = JavaScriptFrame::cast(frames_it.frame());
if (last_step_action() == StepIn) {
// Deoptimize frame to ensure calls are checked for step-in.
Deoptimizer::DeoptimizeFunction(frame->function());
}
HandleScope scope(isolate_);
std::vector<Handle<SharedFunctionInfo>> infos;
frame->GetFunctions(&infos);
for (; !infos.empty(); current_frame_count--) {
Handle<SharedFunctionInfo> info = infos.back();
infos.pop_back();
if (in_current_frame) {
// We want to skip out, so skip the current frame.
in_current_frame = false;
continue;
}
if (IsBlackboxed(info)) continue;
FloodWithOneShot(info);
thread_local_.target_frame_count_ = current_frame_count;
return;
}
}
break;
}
case StepNext:
thread_local_.target_frame_count_ = current_frame_count;
V8_FALLTHROUGH;
case StepIn:
// TODO(clemensb): Implement stepping from JS into wasm.
FloodWithOneShot(shared);
break;
}
}
// Simple function for returning the source positions for active break points.
Handle<Object> Debug::GetSourceBreakLocations(
Isolate* isolate, Handle<SharedFunctionInfo> shared) {
if (!shared->HasBreakInfo()) {
return isolate->factory()->undefined_value();
}
Handle<DebugInfo> debug_info(shared->GetDebugInfo(), isolate);
if (debug_info->GetBreakPointCount(isolate) == 0) {
return isolate->factory()->undefined_value();
}
Handle<FixedArray> locations = isolate->factory()->NewFixedArray(
debug_info->GetBreakPointCount(isolate));
int count = 0;
for (int i = 0; i < debug_info->break_points().length(); ++i) {
if (!debug_info->break_points().get(i).IsUndefined(isolate)) {
BreakPointInfo break_point_info =
BreakPointInfo::cast(debug_info->break_points().get(i));
int break_points = break_point_info.GetBreakPointCount(isolate);
if (break_points == 0) continue;
for (int j = 0; j < break_points; ++j) {
locations->set(count++,
Smi::FromInt(break_point_info.source_position()));
}
}
}
return locations;
}
void Debug::ClearStepping() {
// Clear the various stepping setup.
ClearOneShot();
thread_local_.last_step_action_ = StepNone;
thread_local_.last_statement_position_ = kNoSourcePosition;
thread_local_.ignore_step_into_function_ = Smi::zero();
thread_local_.fast_forward_to_return_ = false;
thread_local_.last_frame_count_ = -1;
thread_local_.target_frame_count_ = -1;
thread_local_.break_on_next_function_call_ = false;
UpdateHookOnFunctionCall();
}
// Clears all the one-shot break points that are currently set. Normally this
// function is called each time a break point is hit as one shot break points
// are used to support stepping.
void Debug::ClearOneShot() {
// The current implementation just runs through all the breakpoints. When the
// last break point for a function is removed that function is automatically
// removed from the list.
for (DebugInfoListNode* node = debug_info_list_; node != nullptr;
node = node->next()) {
Handle<DebugInfo> debug_info = node->debug_info();
ClearBreakPoints(debug_info);
ApplyBreakPoints(debug_info);
}
}
void Debug::DeoptimizeFunction(Handle<SharedFunctionInfo> shared) {
// Deoptimize all code compiled from this shared function info including
// inlining.
isolate_->AbortConcurrentOptimization(BlockingBehavior::kBlock);
bool found_something = false;
Code::OptimizedCodeIterator iterator(isolate_);
do {
Code code = iterator.Next();
if (code.is_null()) break;
if (code.Inlines(*shared)) {
code.set_marked_for_deoptimization(true);
found_something = true;
}
} while (true);
if (found_something) {
// Only go through with the deoptimization if something was found.
Deoptimizer::DeoptimizeMarkedCode(isolate_);
}
}
void Debug::PrepareFunctionForDebugExecution(
Handle<SharedFunctionInfo> shared) {
// To prepare bytecode for debugging, we already need to have the debug
// info (containing the debug copy) upfront, but since we do not recompile,
// preparing for break points cannot fail.
DCHECK(shared->is_compiled());
DCHECK(shared->HasDebugInfo());
Handle<DebugInfo> debug_info = GetOrCreateDebugInfo(shared);
if (debug_info->flags() & DebugInfo::kPreparedForDebugExecution) return;
// Make a copy of the bytecode array if available.
Handle<HeapObject> maybe_original_bytecode_array =
isolate_->factory()->undefined_value();
if (shared->HasBytecodeArray()) {
Handle<BytecodeArray> original_bytecode_array =
handle(shared->GetBytecodeArray(), isolate_);
Handle<BytecodeArray> debug_bytecode_array =
isolate_->factory()->CopyBytecodeArray(original_bytecode_array);
debug_info->set_debug_bytecode_array(*debug_bytecode_array);
shared->SetDebugBytecodeArray(*debug_bytecode_array);
maybe_original_bytecode_array = original_bytecode_array;
}
debug_info->set_original_bytecode_array(*maybe_original_bytecode_array);
if (debug_info->CanBreakAtEntry()) {
// Deopt everything in case the function is inlined anywhere.
Deoptimizer::DeoptimizeAll(isolate_);
InstallDebugBreakTrampoline();
} else {
DeoptimizeFunction(shared);
// Update PCs on the stack to point to recompiled code.
RedirectActiveFunctions redirect_visitor(
*shared, RedirectActiveFunctions::Mode::kUseDebugBytecode);
redirect_visitor.VisitThread(isolate_, isolate_->thread_local_top());
isolate_->thread_manager()->IterateArchivedThreads(&redirect_visitor);
}
debug_info->set_flags(debug_info->flags() |
DebugInfo::kPreparedForDebugExecution);
}
void Debug::InstallDebugBreakTrampoline() {
// Check the list of debug infos whether the debug break trampoline needs to
// be installed. If that's the case, iterate the heap for functions to rewire
// to the trampoline.
HandleScope scope(isolate_);
// If there is a breakpoint at function entry, we need to install trampoline.
bool needs_to_use_trampoline = false;
// If there we break at entry to an api callback, we need to clear ICs.
bool needs_to_clear_ic = false;
for (DebugInfoListNode* current = debug_info_list_; current != nullptr;
current = current->next()) {
if (current->debug_info()->CanBreakAtEntry()) {
needs_to_use_trampoline = true;
if (current->debug_info()->shared().IsApiFunction()) {
needs_to_clear_ic = true;
break;
}
}
}
if (!needs_to_use_trampoline) return;
Handle<Code> trampoline = BUILTIN_CODE(isolate_, DebugBreakTrampoline);
std::vector<Handle<JSFunction>> needs_compile;
using AccessorPairWithContext =
std::pair<Handle<AccessorPair>, Handle<NativeContext>>;
std::vector<AccessorPairWithContext> needs_instantiate;
{
// Deduplicate {needs_instantiate} by recording all collected AccessorPairs.
std::set<AccessorPair> recorded;
HeapObjectIterator iterator(isolate_->heap());
for (HeapObject obj = iterator.Next(); !obj.is_null();
obj = iterator.Next()) {
if (needs_to_clear_ic && obj.IsFeedbackVector()) {
FeedbackVector::cast(obj).ClearSlots(isolate_);
continue;
} else if (obj.IsJSFunction()) {
JSFunction fun = JSFunction::cast(obj);
SharedFunctionInfo shared = fun.shared();
if (!shared.HasDebugInfo()) continue;
if (!shared.GetDebugInfo().CanBreakAtEntry()) continue;
if (!fun.is_compiled()) {
needs_compile.push_back(handle(fun, isolate_));
} else {
fun.set_code(*trampoline);
}
} else if (obj.IsJSObject()) {
JSObject object = JSObject::cast(obj);
DescriptorArray descriptors = object.map().instance_descriptors();
for (InternalIndex i : object.map().IterateOwnDescriptors()) {
if (descriptors.GetDetails(i).kind() == PropertyKind::kAccessor) {
Object value = descriptors.GetStrongValue(i);
if (!value.IsAccessorPair()) continue;
AccessorPair accessor_pair = AccessorPair::cast(value);
if (!accessor_pair.getter().IsFunctionTemplateInfo() &&
!accessor_pair.setter().IsFunctionTemplateInfo()) {
continue;
}
if (recorded.find(accessor_pair) != recorded.end()) continue;
needs_instantiate.emplace_back(handle(accessor_pair, isolate_),
object.GetCreationContext());
recorded.insert(accessor_pair);
}
}
}
}
}
// Forcibly instantiate all lazy accessor pairs to make sure that they
// properly hit the debug break trampoline.
for (AccessorPairWithContext tuple : needs_instantiate) {
Handle<AccessorPair> accessor_pair = tuple.first;
Handle<NativeContext> native_context = tuple.second;
if (accessor_pair->getter().IsFunctionTemplateInfo()) {
Handle<JSFunction> fun =
ApiNatives::InstantiateFunction(
isolate_, native_context,
handle(FunctionTemplateInfo::cast(accessor_pair->getter()),
isolate_))
.ToHandleChecked();
accessor_pair->set_getter(*fun);
}
if (accessor_pair->setter().IsFunctionTemplateInfo()) {
Handle<JSFunction> fun =
ApiNatives::InstantiateFunction(
isolate_, native_context,
handle(FunctionTemplateInfo::cast(accessor_pair->setter()),
isolate_))
.ToHandleChecked();
accessor_pair->set_setter(*fun);
}
}
// By overwriting the function code with DebugBreakTrampoline, which tailcalls
// to shared code, we bypass CompileLazy. Perform CompileLazy here instead.
for (Handle<JSFunction> fun : needs_compile) {
IsCompiledScope is_compiled_scope;
Compiler::Compile(fun, Compiler::CLEAR_EXCEPTION, &is_compiled_scope);
DCHECK(is_compiled_scope.is_compiled());
fun->set_code(*trampoline);
}
}
namespace {
template <typename Iterator>
void GetBreakablePositions(Iterator* it, int start_position, int end_position,
std::vector<BreakLocation>* locations) {
while (!it->Done()) {
if (it->position() >= start_position && it->position() < end_position) {
locations->push_back(it->GetBreakLocation());
}
it->Next();
}
}
void FindBreakablePositions(Handle<DebugInfo> debug_info, int start_position,
int end_position,
std::vector<BreakLocation>* locations) {
DCHECK(debug_info->HasInstrumentedBytecodeArray());
BreakIterator it(debug_info);
GetBreakablePositions(&it, start_position, end_position, locations);
}
} // namespace
bool Debug::GetPossibleBreakpoints(Handle<Script> script, int start_position,
int end_position, bool restrict_to_function,
std::vector<BreakLocation>* locations) {
if (restrict_to_function) {
Handle<Object> result =
FindSharedFunctionInfoInScript(script, start_position);
if (result->IsUndefined(isolate_)) return false;
// Make sure the function has set up the debug info.
Handle<SharedFunctionInfo> shared =
Handle<SharedFunctionInfo>::cast(result);
if (!EnsureBreakInfo(shared)) return false;
PrepareFunctionForDebugExecution(shared);
Handle<DebugInfo> debug_info(shared->GetDebugInfo(), isolate_);
FindBreakablePositions(debug_info, start_position, end_position, locations);
return true;
}
while (true) {
HandleScope scope(isolate_);
std::vector<Handle<SharedFunctionInfo>> candidates;
std::vector<IsCompiledScope> compiled_scopes;
SharedFunctionInfo::ScriptIterator iterator(isolate_, *script);
for (SharedFunctionInfo info = iterator.Next(); !info.is_null();
info = iterator.Next()) {
if (info.EndPosition() < start_position ||
info.StartPosition() >= end_position) {
continue;
}
if (!info.IsSubjectToDebugging()) continue;
if (!info.is_compiled() && !info.allows_lazy_compilation()) continue;
candidates.push_back(i::handle(info, isolate_));
}
bool was_compiled = false;
for (const auto& candidate : candidates) {
IsCompiledScope is_compiled_scope(candidate->is_compiled_scope());
if (!is_compiled_scope.is_compiled()) {
// Code that cannot be compiled lazily are internal and not debuggable.
DCHECK(candidate->allows_lazy_compilation());
if (!Compiler::Compile(candidate, Compiler::CLEAR_EXCEPTION,
&is_compiled_scope)) {
return false;
} else {
was_compiled = true;
}
}
DCHECK(is_compiled_scope.is_compiled());
compiled_scopes.push_back(is_compiled_scope);
if (!EnsureBreakInfo(candidate)) return false;
PrepareFunctionForDebugExecution(candidate);
}
if (was_compiled) continue;
for (const auto& candidate : candidates) {
CHECK(candidate->HasBreakInfo());
Handle<DebugInfo> debug_info(candidate->GetDebugInfo(), isolate_);
FindBreakablePositions(debug_info, start_position, end_position,
locations);
}
return true;
}
UNREACHABLE();
}
class SharedFunctionInfoFinder {
public:
explicit SharedFunctionInfoFinder(int target_position)
: current_start_position_(kNoSourcePosition),
target_position_(target_position) {}
void NewCandidate(SharedFunctionInfo shared,
JSFunction closure = JSFunction()) {
if (!shared.IsSubjectToDebugging()) return;
int start_position = shared.function_token_position();
if (start_position == kNoSourcePosition) {
start_position = shared.StartPosition();
}
if (start_position > target_position_) return;
if (target_position_ > shared.EndPosition()) return;
if (!current_candidate_.is_null()) {
if (current_start_position_ == start_position &&
shared.EndPosition() == current_candidate_.EndPosition()) {
// If we already have a matching closure, do not throw it away.
if (!current_candidate_closure_.is_null() && closure.is_null()) return;
// If a top-level function contains only one function
// declaration the source for the top-level and the function
// is the same. In that case prefer the non top-level function.
if (!current_candidate_.is_toplevel() && shared.is_toplevel()) return;
} else if (start_position < current_start_position_ ||
current_candidate_.EndPosition() < shared.EndPosition()) {
return;
}
}
current_start_position_ = start_position;
current_candidate_ = shared;
current_candidate_closure_ = closure;
}
SharedFunctionInfo Result() { return current_candidate_; }
JSFunction ResultClosure() { return current_candidate_closure_; }
private:
SharedFunctionInfo current_candidate_;
JSFunction current_candidate_closure_;
int current_start_position_;
int target_position_;
DisallowHeapAllocation no_gc_;
};
// We need to find a SFI for a literal that may not yet have been compiled yet,
// and there may not be a JSFunction referencing it. Find the SFI closest to
// the given position, compile it to reveal possible inner SFIs and repeat.
// While we are at this, also ensure code with debug break slots so that we do
// not have to compile a SFI without JSFunction, which is paifu for those that
// cannot be compiled without context (need to find outer compilable SFI etc.)
Handle<Object> Debug::FindSharedFunctionInfoInScript(Handle<Script> script,
int position) {
for (int iteration = 0;; iteration++) {
// Go through all shared function infos associated with this script to
// find the inner most function containing this position.
// If there is no shared function info for this script at all, there is
// no point in looking for it by walking the heap.
SharedFunctionInfo shared;
IsCompiledScope is_compiled_scope;
{
SharedFunctionInfoFinder finder(position);
SharedFunctionInfo::ScriptIterator iterator(isolate_, *script);
for (SharedFunctionInfo info = iterator.Next(); !info.is_null();
info = iterator.Next()) {
finder.NewCandidate(info);
}
shared = finder.Result();
if (shared.is_null()) break;
// We found it if it's already compiled.
is_compiled_scope = shared.is_compiled_scope();
if (is_compiled_scope.is_compiled()) {
Handle<SharedFunctionInfo> shared_handle(shared, isolate_);
// If the iteration count is larger than 1, we had to compile the outer
// function in order to create this shared function info. So there can
// be no JSFunction referencing it. We can anticipate creating a debug
// info while bypassing PrepareFunctionForDebugExecution.
if (iteration > 1) {
AllowHeapAllocation allow_before_return;
CreateBreakInfo(shared_handle);
}
return shared_handle;
}
}
// If not, compile to reveal inner functions.
HandleScope scope(isolate_);
// Code that cannot be compiled lazily are internal and not debuggable.
DCHECK(shared.allows_lazy_compilation());
if (!Compiler::Compile(handle(shared, isolate_), Compiler::CLEAR_EXCEPTION,
&is_compiled_scope)) {
break;
}
}
return isolate_->factory()->undefined_value();
}
// Ensures the debug information is present for shared.
bool Debug::EnsureBreakInfo(Handle<SharedFunctionInfo> shared) {
// Return if we already have the break info for shared.
if (shared->HasBreakInfo()) return true;
if (!shared->IsSubjectToDebugging() && !CanBreakAtEntry(shared)) {
return false;
}
IsCompiledScope is_compiled_scope = shared->is_compiled_scope();
if (!is_compiled_scope.is_compiled() &&
!Compiler::Compile(shared, Compiler::CLEAR_EXCEPTION,
&is_compiled_scope)) {
return false;
}
CreateBreakInfo(shared);
return true;
}
void Debug::CreateBreakInfo(Handle<SharedFunctionInfo> shared) {
HandleScope scope(isolate_);
Handle<DebugInfo> debug_info = GetOrCreateDebugInfo(shared);
// Initialize with break information.
DCHECK(!debug_info->HasBreakInfo());
Factory* factory = isolate_->factory();
Handle<FixedArray> break_points(
factory->NewFixedArray(DebugInfo::kEstimatedNofBreakPointsInFunction));
int flags = debug_info->flags();
flags |= DebugInfo::kHasBreakInfo;
if (CanBreakAtEntry(shared)) flags |= DebugInfo::kCanBreakAtEntry;
debug_info->set_flags(flags);
debug_info->set_break_points(*break_points);
SharedFunctionInfo::EnsureSourcePositionsAvailable(isolate_, shared);
}
Handle<DebugInfo> Debug::GetOrCreateDebugInfo(
Handle<SharedFunctionInfo> shared) {
if (shared->HasDebugInfo()) return handle(shared->GetDebugInfo(), isolate_);
// Create debug info and add it to the list.
Handle<DebugInfo> debug_info = isolate_->factory()->NewDebugInfo(shared);
DebugInfoListNode* node = new DebugInfoListNode(isolate_, *debug_info);
node->set_next(debug_info_list_);
debug_info_list_ = node;
return debug_info;
}
void Debug::InstallCoverageInfo(Handle<SharedFunctionInfo> shared,
Handle<CoverageInfo> coverage_info) {
DCHECK(!coverage_info.is_null());
Handle<DebugInfo> debug_info = GetOrCreateDebugInfo(shared);
DCHECK(!debug_info->HasCoverageInfo());
debug_info->set_flags(debug_info->flags() | DebugInfo::kHasCoverageInfo);
debug_info->set_coverage_info(*coverage_info);
}
void Debug::RemoveAllCoverageInfos() {
ClearAllDebugInfos(
[=](Handle<DebugInfo> info) { info->ClearCoverageInfo(isolate_); });
}
void Debug::ClearAllDebuggerHints() {
ClearAllDebugInfos(
[=](Handle<DebugInfo> info) { info->set_debugger_hints(0); });
}
void Debug::FindDebugInfo(Handle<DebugInfo> debug_info,
DebugInfoListNode** prev, DebugInfoListNode** curr) {
HandleScope scope(isolate_);
*prev = nullptr;
*curr = debug_info_list_;
while (*curr != nullptr) {
if ((*curr)->debug_info().is_identical_to(debug_info)) return;
*prev = *curr;
*curr = (*curr)->next();
}
UNREACHABLE();
}
void Debug::ClearAllDebugInfos(const DebugInfoClearFunction& clear_function) {
DebugInfoListNode* prev = nullptr;
DebugInfoListNode* current = debug_info_list_;
while (current != nullptr) {
DebugInfoListNode* next = current->next();
Handle<DebugInfo> debug_info = current->debug_info();
clear_function(debug_info);
if (debug_info->IsEmpty()) {
FreeDebugInfoListNode(prev, current);
current = next;
} else {
prev = current;
current = next;
}
}
}
void Debug::RemoveBreakInfoAndMaybeFree(Handle<DebugInfo> debug_info) {
debug_info->ClearBreakInfo(isolate_);
if (debug_info->IsEmpty()) {
DebugInfoListNode* prev;
DebugInfoListNode* node;
FindDebugInfo(debug_info, &prev, &node);
FreeDebugInfoListNode(prev, node);
}
}
void Debug::FreeDebugInfoListNode(DebugInfoListNode* prev,
DebugInfoListNode* node) {
DCHECK(node->debug_info()->IsEmpty());
// Unlink from list. If prev is nullptr we are looking at the first element.
if (prev == nullptr) {
debug_info_list_ = node->next();
} else {
prev->set_next(node->next());
}
// Pack script back into the
// SFI::script_or_debug_info field.
Handle<DebugInfo> debug_info(node->debug_info());
debug_info->shared().set_script_or_debug_info(debug_info->script());
delete node;
}
bool Debug::IsBreakAtReturn(JavaScriptFrame* frame) {
HandleScope scope(isolate_);
// Get the executing function in which the debug break occurred.
Handle<SharedFunctionInfo> shared(frame->function().shared(), isolate_);
// With no debug info there are no break points, so we can't be at a return.
if (!shared->HasBreakInfo()) return false;
DCHECK(!frame->is_optimized());
Handle<DebugInfo> debug_info(shared->GetDebugInfo(), isolate_);
BreakLocation location = BreakLocation::FromFrame(debug_info, frame);
return location.IsReturn();
}
void Debug::ScheduleFrameRestart(StackFrame* frame) {
// Set a target FP for the FrameDropperTrampoline builtin to drop to once
// we return from the debugger.
DCHECK(frame->is_java_script());
// Only reschedule to a frame further below a frame we already scheduled for.
if (frame->fp() <= thread_local_.restart_fp_) return;
// If the frame is optimized, trigger a deopt and jump into the
// FrameDropperTrampoline in the deoptimizer.
thread_local_.restart_fp_ = frame->fp();
// Reset break frame ID to the frame below the restarted frame.
StackTraceFrameIterator it(isolate_);
thread_local_.break_frame_id_ = StackFrameId::NO_ID;
for (StackTraceFrameIterator it(isolate_); !it.done(); it.Advance()) {
if (it.frame()->fp() > thread_local_.restart_fp_) {
thread_local_.break_frame_id_ = it.frame()->id();
return;
}
}
}
Handle<FixedArray> Debug::GetLoadedScripts() {
isolate_->heap()->CollectAllGarbage(Heap::kNoGCFlags,
GarbageCollectionReason::kDebugger);
Factory* factory = isolate_->factory();
if (!factory->script_list()->IsWeakArrayList()) {
return factory->empty_fixed_array();
}
Handle<WeakArrayList> array =
Handle<WeakArrayList>::cast(factory->script_list());
Handle<FixedArray> results = factory->NewFixedArray(array->length());
int length = 0;
{
Script::Iterator iterator(isolate_);
for (Script script = iterator.Next(); !script.is_null();
script = iterator.Next()) {
if (script.HasValidSource()) results->set(length++, script);
}
}
return FixedArray::ShrinkOrEmpty(isolate_, results, length);
}
base::Optional<Object> Debug::OnThrow(Handle<Object> exception) {
if (in_debug_scope() || ignore_events()) return {};
// Temporarily clear any scheduled_exception to allow evaluating
// JavaScript from the debug event handler.
HandleScope scope(isolate_);
Handle<Object> scheduled_exception;
if (isolate_->has_scheduled_exception()) {
scheduled_exception = handle(isolate_->scheduled_exception(), isolate_);
isolate_->clear_scheduled_exception();
}
Handle<Object> maybe_promise = isolate_->GetPromiseOnStackOnThrow();
OnException(exception, maybe_promise,
maybe_promise->IsJSPromise() ? v8::debug::kPromiseRejection
: v8::debug::kException);
if (!scheduled_exception.is_null()) {
isolate_->thread_local_top()->scheduled_exception_ = *scheduled_exception;
}
PrepareStepOnThrow();
// If the OnException handler requested termination, then indicated this to
// our caller Isolate::Throw so it can deal with it immediatelly instead of
// throwing the original exception.
if (isolate_->stack_guard()->CheckTerminateExecution()) {
isolate_->stack_guard()->ClearTerminateExecution();
return isolate_->TerminateExecution();
}
return {};
}
void Debug::OnPromiseReject(Handle<Object> promise, Handle<Object> value) {
if (in_debug_scope() || ignore_events()) return;
HandleScope scope(isolate_);
// Check whether the promise has been marked as having triggered a message.
Handle<Symbol> key = isolate_->factory()->promise_debug_marker_symbol();
if (!promise->IsJSObject() ||
JSReceiver::GetDataProperty(Handle<JSObject>::cast(promise), key)
->IsUndefined(isolate_)) {
OnException(value, promise, v8::debug::kPromiseRejection);
}
}
bool Debug::IsExceptionBlackboxed(bool uncaught) {
// Uncaught exception is blackboxed if all current frames are blackboxed,
// caught exception if top frame is blackboxed.
StackTraceFrameIterator it(isolate_);
while (!it.done() && it.is_wasm()) it.Advance();
bool is_top_frame_blackboxed =
!it.done() ? IsFrameBlackboxed(it.javascript_frame()) : true;
if (!uncaught || !is_top_frame_blackboxed) return is_top_frame_blackboxed;
return AllFramesOnStackAreBlackboxed();
}
bool Debug::IsFrameBlackboxed(JavaScriptFrame* frame) {
HandleScope scope(isolate_);
std::vector<Handle<SharedFunctionInfo>> infos;
frame->GetFunctions(&infos);
for (const auto& info : infos) {
if (!IsBlackboxed(info)) return false;
}
return true;
}
void Debug::OnException(Handle<Object> exception, Handle<Object> promise,
v8::debug::ExceptionType exception_type) {
Isolate::CatchType catch_type = isolate_->PredictExceptionCatcher();
// Don't notify listener of exceptions that are internal to a desugaring.
if (catch_type == Isolate::CAUGHT_BY_DESUGARING) return;
bool uncaught = catch_type == Isolate::NOT_CAUGHT;
if (promise->IsJSObject()) {
Handle<JSObject> jspromise = Handle<JSObject>::cast(promise);
// Mark the promise as already having triggered a message.
Handle<Symbol> key = isolate_->factory()->promise_debug_marker_symbol();
Object::SetProperty(isolate_, jspromise, key, key, StoreOrigin::kMaybeKeyed,
Just(ShouldThrow::kThrowOnError))
.Assert();
// Check whether the promise reject is considered an uncaught exception.
uncaught = !isolate_->PromiseHasUserDefinedRejectHandler(jspromise);
}
if (!debug_delegate_) return;
// Bail out if exception breaks are not active
if (uncaught) {
// Uncaught exceptions are reported by either flags.
if (!(break_on_uncaught_exception_ || break_on_exception_)) return;
} else {
// Caught exceptions are reported is activated.
if (!break_on_exception_) return;
}
{
JavaScriptFrameIterator it(isolate_);
// Check whether the top frame is blackboxed or the break location is muted.
if (!it.done() && (IsMutedAtCurrentLocation(it.frame()) ||
IsExceptionBlackboxed(uncaught))) {
return;
}
if (it.done()) return; // Do not trigger an event with an empty stack.
}
// Do not trigger exception event on stack overflow. We cannot perform
// anything useful for debugging in that situation.
StackLimitCheck stack_limit_check(isolate_);
if (stack_limit_check.JsHasOverflowed()) return;
DebugScope debug_scope(this);
HandleScope scope(isolate_);
DisableBreak no_recursive_break(this);
Handle<Context> native_context(isolate_->native_context());
debug_delegate_->ExceptionThrown(
v8::Utils::ToLocal(native_context), v8::Utils::ToLocal(exception),
v8::Utils::ToLocal(promise), uncaught, exception_type);
}
void Debug::OnDebugBreak(Handle<FixedArray> break_points_hit) {
DCHECK(!break_points_hit.is_null());
// The caller provided for DebugScope.
AssertDebugContext();
// Bail out if there is no listener for this event
if (ignore_events()) return;
#ifdef DEBUG
PrintBreakLocation();
#endif // DEBUG
if (!debug_delegate_) return;
DCHECK(in_debug_scope());
HandleScope scope(isolate_);
DisableBreak no_recursive_break(this);
std::vector<int> inspector_break_points_hit;
int inspector_break_points_count = 0;
// This array contains breakpoints installed using JS debug API.
for (int i = 0; i < break_points_hit->length(); ++i) {
BreakPoint break_point = BreakPoint::cast(break_points_hit->get(i));
inspector_break_points_hit.push_back(break_point.id());
++inspector_break_points_count;
}
Handle<Context> native_context(isolate_->native_context());
debug_delegate_->BreakProgramRequested(v8::Utils::ToLocal(native_context),
inspector_break_points_hit);
}
namespace {
debug::Location GetDebugLocation(Handle<Script> script, int source_position) {
Script::PositionInfo info;
Script::GetPositionInfo(script, source_position, &info, Script::WITH_OFFSET);
// V8 provides ScriptCompiler::CompileFunctionInContext method which takes
// expression and compile it as anonymous function like (function() ..
// expression ..). To produce correct locations for stmts inside of this
// expression V8 compile this function with negative offset. Instead of stmt
// position blackboxing use function start position which is negative in
// described case.
return debug::Location(std::max(info.line, 0), std::max(info.column, 0));
}
} // namespace
bool Debug::IsBlackboxed(Handle<SharedFunctionInfo> shared) {
if (!debug_delegate_) return !shared->IsSubjectToDebugging();
Handle<DebugInfo> debug_info = GetOrCreateDebugInfo(shared);
if (!debug_info->computed_debug_is_blackboxed()) {
bool is_blackboxed =
!shared->IsSubjectToDebugging() || !shared->script().IsScript();
if (!is_blackboxed) {
SuppressDebug while_processing(this);
HandleScope handle_scope(isolate_);
PostponeInterruptsScope no_interrupts(isolate_);
DisableBreak no_recursive_break(this);
DCHECK(shared->script().IsScript());
Handle<Script> script(Script::cast(shared->script()), isolate_);
DCHECK(script->IsUserJavaScript());
debug::Location start = GetDebugLocation(script, shared->StartPosition());
debug::Location end = GetDebugLocation(script, shared->EndPosition());
is_blackboxed = debug_delegate_->IsFunctionBlackboxed(
ToApiHandle<debug::Script>(script), start, end);
}
debug_info->set_debug_is_blackboxed(is_blackboxed);
debug_info->set_computed_debug_is_blackboxed(true);
}
return debug_info->debug_is_blackboxed();
}
bool Debug::AllFramesOnStackAreBlackboxed() {
HandleScope scope(isolate_);
for (StackTraceFrameIterator it(isolate_); !it.done(); it.Advance()) {
if (!it.is_javascript()) continue;
if (!IsFrameBlackboxed(it.javascript_frame())) return false;
}
return true;
}
bool Debug::CanBreakAtEntry(Handle<SharedFunctionInfo> shared) {
// Allow break at entry for builtin functions.
if (shared->native() || shared->IsApiFunction()) {
// Functions that are subject to debugging can have regular breakpoints.
DCHECK(!shared->IsSubjectToDebugging());
return true;
}
return false;
}
bool Debug::SetScriptSource(Handle<Script> script, Handle<String> source,
bool preview, debug::LiveEditResult* result) {
DebugScope debug_scope(this);
feature_tracker()->Track(DebugFeatureTracker::kLiveEdit);
running_live_edit_ = true;
LiveEdit::PatchScript(isolate_, script, source, preview, result);
running_live_edit_ = false;
return result->status == debug::LiveEditResult::OK;
}
void Debug::OnCompileError(Handle<Script> script) {
ProcessCompileEvent(true, script);
}
void Debug::OnAfterCompile(Handle<Script> script) {
ProcessCompileEvent(false, script);
}
void Debug::ProcessCompileEvent(bool has_compile_error, Handle<Script> script) {
// TODO(kozyatinskiy): teach devtools to work with liveedit scripts better
// first and then remove this fast return.
if (running_live_edit_) return;
// Attach the correct debug id to the script. The debug id is used by the
// inspector to filter scripts by native context.
script->set_context_data(isolate_->native_context()->debug_context_id());
if (ignore_events()) return;
if (!script->IsUserJavaScript() && script->type() != i::Script::TYPE_WASM) {
return;
}
if (!debug_delegate_) return;
SuppressDebug while_processing(this);
DebugScope debug_scope(this);
HandleScope scope(isolate_);
DisableBreak no_recursive_break(this);
AllowJavascriptExecution allow_script(isolate_);
debug_delegate_->ScriptCompiled(ToApiHandle<debug::Script>(script),
running_live_edit_, has_compile_error);
}
int Debug::CurrentFrameCount() {
StackTraceFrameIterator it(isolate_);
if (break_frame_id() != StackFrameId::NO_ID) {
// Skip to break frame.
DCHECK(in_debug_scope());
while (!it.done() && it.frame()->id() != break_frame_id()) it.Advance();
}
int counter = 0;
while (!it.done()) {
if (it.frame()->is_optimized()) {
std::vector<SharedFunctionInfo> infos;
OptimizedFrame::cast(it.frame())->GetFunctions(&infos);
counter += infos.size();
} else {
counter++;
}
it.Advance();
}
return counter;
}
void Debug::SetDebugDelegate(debug::DebugDelegate* delegate) {
debug_delegate_ = delegate;
UpdateState();
}
void Debug::UpdateState() {
bool is_active = debug_delegate_ != nullptr;
if (is_active == is_active_) return;
if (is_active) {
// Note that the debug context could have already been loaded to
// bootstrap test cases.
isolate_->compilation_cache()->DisableScriptAndEval();
is_active = true;
feature_tracker()->Track(DebugFeatureTracker::kActive);
} else {
isolate_->compilation_cache()->EnableScriptAndEval();
Unload();
}
is_active_ = is_active;
isolate_->PromiseHookStateUpdated();
}
void Debug::UpdateHookOnFunctionCall() {
STATIC_ASSERT(LastStepAction == StepIn);
hook_on_function_call_ =
thread_local_.last_step_action_ == StepIn ||
isolate_->debug_execution_mode() == DebugInfo::kSideEffects ||
thread_local_.break_on_next_function_call_;
}
void Debug::HandleDebugBreak(IgnoreBreakMode ignore_break_mode) {
// Initialize LiveEdit.
LiveEdit::InitializeThreadLocal(this);
// Ignore debug break during bootstrapping.
if (isolate_->bootstrapper()->IsActive()) return;
// Just continue if breaks are disabled.
if (break_disabled()) return;
// Ignore debug break if debugger is not active.
if (!is_active()) return;
StackLimitCheck check(isolate_);
if (check.HasOverflowed()) return;
{ JavaScriptFrameIterator it(isolate_);
DCHECK(!it.done());
Object fun = it.frame()->function();
if (fun.IsJSFunction()) {
HandleScope scope(isolate_);
Handle<JSFunction> function(JSFunction::cast(fun), isolate_);
// Don't stop in builtin and blackboxed functions.
Handle<SharedFunctionInfo> shared(function->shared(), isolate_);
bool ignore_break = ignore_break_mode == kIgnoreIfTopFrameBlackboxed
? IsBlackboxed(shared)
: AllFramesOnStackAreBlackboxed();
if (ignore_break) return;
// Don't stop if the break location is muted.
if (IsMutedAtCurrentLocation(it.frame())) return;
}
}
// Clear stepping to avoid duplicate breaks.
ClearStepping();
HandleScope scope(isolate_);
DebugScope debug_scope(this);
OnDebugBreak(isolate_->factory()->empty_fixed_array());
}
#ifdef DEBUG
void Debug::PrintBreakLocation() {
if (!FLAG_print_break_location) return;
HandleScope scope(isolate_);
StackTraceFrameIterator iterator(isolate_);
if (iterator.done()) return;
StandardFrame* frame = iterator.frame();
FrameSummary summary = FrameSummary::GetTop(frame);
summary.EnsureSourcePositionsAvailable();
int source_position = summary.SourcePosition();
Handle<Object> script_obj = summary.script();
PrintF("[debug] break in function '");
summary.FunctionName()->PrintOn(stdout);
PrintF("'.\n");
if (script_obj->IsScript()) {
Handle<Script> script = Handle<Script>::cast(script_obj);
Handle<String> source(String::cast(script->source()), isolate_);
Script::InitLineEnds(isolate_, script);
int line =
Script::GetLineNumber(script, source_position) - script->line_offset();
int column = Script::GetColumnNumber(script, source_position) -
(line == 0 ? script->column_offset() : 0);
Handle<FixedArray> line_ends(FixedArray::cast(script->line_ends()),
isolate_);
int line_start = line == 0 ? 0 : Smi::ToInt(line_ends->get(line - 1)) + 1;
int line_end = Smi::ToInt(line_ends->get(line));
DisallowHeapAllocation no_gc;
String::FlatContent content = source->GetFlatContent(no_gc);
if (content.IsOneByte()) {
PrintF("[debug] %.*s\n", line_end - line_start,
content.ToOneByteVector().begin() + line_start);
PrintF("[debug] ");
for (int i = 0; i < column; i++) PrintF(" ");
PrintF("^\n");
} else {
PrintF("[debug] at line %d column %d\n", line, column);
}
}
}
#endif // DEBUG
DebugScope::DebugScope(Debug* debug)
: debug_(debug),
prev_(reinterpret_cast<DebugScope*>(
base::Relaxed_Load(&debug->thread_local_.current_debug_scope_))),
no_interrupts_(debug_->isolate_) {
// Link recursive debugger entry.
base::Relaxed_Store(&debug_->thread_local_.current_debug_scope_,
reinterpret_cast<base::AtomicWord>(this));
// Store the previous frame id and return value.
break_frame_id_ = debug_->break_frame_id();
// Create the new break info. If there is no proper frames there is no break
// frame id.
StackTraceFrameIterator it(isolate());
bool has_frames = !it.done();
debug_->thread_local_.break_frame_id_ =
has_frames ? it.frame()->id() : StackFrameId::NO_ID;
debug_->UpdateState();
}
void DebugScope::set_terminate_on_resume() { terminate_on_resume_ = true; }
DebugScope::~DebugScope() {
// Terminate on resume must have been handled by retrieving it, if this is
// the outer scope.
if (terminate_on_resume_) {
if (!prev_) {
debug_->isolate_->stack_guard()->RequestTerminateExecution();
} else {
prev_->set_terminate_on_resume();
}
}
// Leaving this debugger entry.
base::Relaxed_Store(&debug_->thread_local_.current_debug_scope_,
reinterpret_cast<base::AtomicWord>(prev_));
// Restore to the previous break state.
debug_->thread_local_.break_frame_id_ = break_frame_id_;
debug_->UpdateState();
}
ReturnValueScope::ReturnValueScope(Debug* debug) : debug_(debug) {
return_value_ = debug_->return_value_handle();
}
ReturnValueScope::~ReturnValueScope() {
debug_->set_return_value(*return_value_);
}
void Debug::UpdateDebugInfosForExecutionMode() {
// Walk all debug infos and update their execution mode if it is different
// from the isolate execution mode.
DebugInfoListNode* current = debug_info_list_;
while (current != nullptr) {
Handle<DebugInfo> debug_info = current->debug_info();
if (debug_info->HasInstrumentedBytecodeArray() &&
debug_info->DebugExecutionMode() != isolate_->debug_execution_mode()) {
DCHECK(debug_info->shared().HasBytecodeArray());
if (isolate_->debug_execution_mode() == DebugInfo::kBreakpoints) {
ClearSideEffectChecks(debug_info);
ApplyBreakPoints(debug_info);
} else {
ClearBreakPoints(debug_info);
ApplySideEffectChecks(debug_info);
}
}
current = current->next();
}
}
void Debug::SetTerminateOnResume() {
DebugScope* scope = reinterpret_cast<DebugScope*>(
base::Acquire_Load(&thread_local_.current_debug_scope_));
CHECK_NOT_NULL(scope);
scope->set_terminate_on_resume();
}
void Debug::StartSideEffectCheckMode() {
DCHECK(isolate_->debug_execution_mode() != DebugInfo::kSideEffects);
isolate_->set_debug_execution_mode(DebugInfo::kSideEffects);
UpdateHookOnFunctionCall();
side_effect_check_failed_ = false;
DCHECK(!temporary_objects_);
temporary_objects_.reset(new TemporaryObjectsTracker());
isolate_->heap()->AddHeapObjectAllocationTracker(temporary_objects_.get());
Handle<FixedArray> array(isolate_->native_context()->regexp_last_match_info(),
isolate_);
regexp_match_info_ =
Handle<RegExpMatchInfo>::cast(isolate_->factory()->CopyFixedArray(array));
// Update debug infos to have correct execution mode.
UpdateDebugInfosForExecutionMode();
}
void Debug::StopSideEffectCheckMode() {
DCHECK(isolate_->debug_execution_mode() == DebugInfo::kSideEffects);
if (side_effect_check_failed_) {
DCHECK(isolate_->has_pending_exception());
DCHECK_EQ(ReadOnlyRoots(isolate_).termination_exception(),
isolate_->pending_exception());
// Convert the termination exception into a regular exception.
isolate_->CancelTerminateExecution();
isolate_->Throw(*isolate_->factory()->NewEvalError(
MessageTemplate::kNoSideEffectDebugEvaluate));
}
isolate_->set_debug_execution_mode(DebugInfo::kBreakpoints);
UpdateHookOnFunctionCall();
side_effect_check_failed_ = false;
DCHECK(temporary_objects_);
isolate_->heap()->RemoveHeapObjectAllocationTracker(temporary_objects_.get());
temporary_objects_.reset();
isolate_->native_context()->set_regexp_last_match_info(*regexp_match_info_);
regexp_match_info_ = Handle<RegExpMatchInfo>::null();
// Update debug infos to have correct execution mode.
UpdateDebugInfosForExecutionMode();
}
void Debug::ApplySideEffectChecks(Handle<DebugInfo> debug_info) {
DCHECK(debug_info->HasInstrumentedBytecodeArray());
Handle<BytecodeArray> debug_bytecode(debug_info->DebugBytecodeArray(),
isolate_);
DebugEvaluate::ApplySideEffectChecks(debug_bytecode);
debug_info->SetDebugExecutionMode(DebugInfo::kSideEffects);
}
void Debug::ClearSideEffectChecks(Handle<DebugInfo> debug_info) {
DCHECK(debug_info->HasInstrumentedBytecodeArray());
Handle<BytecodeArray> debug_bytecode(debug_info->DebugBytecodeArray(),
isolate_);
Handle<BytecodeArray> original(debug_info->OriginalBytecodeArray(), isolate_);
for (interpreter::BytecodeArrayIterator it(debug_bytecode); !it.done();
it.Advance()) {
// Restore from original. This may copy only the scaling prefix, which is
// correct, since we patch scaling prefixes to debug breaks if exists.
debug_bytecode->set(it.current_offset(),
original->get(it.current_offset()));
}
}
bool Debug::PerformSideEffectCheck(Handle<JSFunction> function,
Handle<Object> receiver) {
DCHECK_EQ(isolate_->debug_execution_mode(), DebugInfo::kSideEffects);
DisallowJavascriptExecution no_js(isolate_);
IsCompiledScope is_compiled_scope(function->shared().is_compiled_scope());
if (!function->is_compiled() &&
!Compiler::Compile(function, Compiler::KEEP_EXCEPTION,
&is_compiled_scope)) {
return false;
}
DCHECK(is_compiled_scope.is_compiled());
Handle<SharedFunctionInfo> shared(function->shared(), isolate_);
Handle<DebugInfo> debug_info = GetOrCreateDebugInfo(shared);
DebugInfo::SideEffectState side_effect_state =
debug_info->GetSideEffectState(isolate_);
switch (side_effect_state) {
case DebugInfo::kHasSideEffects:
if (FLAG_trace_side_effect_free_debug_evaluate) {
PrintF("[debug-evaluate] Function %s failed side effect check.\n",
function->shared().DebugName().ToCString().get());
}
side_effect_check_failed_ = true;
// Throw an uncatchable termination exception.
isolate_->TerminateExecution();
return false;
case DebugInfo::kRequiresRuntimeChecks: {
if (!shared->HasBytecodeArray()) {
return PerformSideEffectCheckForObject(receiver);
}
// If function has bytecode array then prepare function for debug
// execution to perform runtime side effect checks.
DCHECK(shared->is_compiled());
PrepareFunctionForDebugExecution(shared);
ApplySideEffectChecks(debug_info);
return true;
}
case DebugInfo::kHasNoSideEffect:
return true;
case DebugInfo::kNotComputed:
UNREACHABLE();
return false;
}
UNREACHABLE();
return false;
}
Handle<Object> Debug::return_value_handle() {
return handle(thread_local_.return_value_, isolate_);
}
bool Debug::PerformSideEffectCheckForCallback(
Handle<Object> callback_info, Handle<Object> receiver,
Debug::AccessorKind accessor_kind) {
DCHECK_EQ(!receiver.is_null(), callback_info->IsAccessorInfo());
DCHECK_EQ(isolate_->debug_execution_mode(), DebugInfo::kSideEffects);
if (!callback_info.is_null() && callback_info->IsCallHandlerInfo() &&
i::CallHandlerInfo::cast(*callback_info).NextCallHasNoSideEffect()) {
return true;
}
// TODO(7515): always pass a valid callback info object.
if (!callback_info.is_null()) {
if (callback_info->IsAccessorInfo()) {
// List of whitelisted internal accessors can be found in accessors.h.
AccessorInfo info = AccessorInfo::cast(*callback_info);
DCHECK_NE(kNotAccessor, accessor_kind);
switch (accessor_kind == kSetter ? info.setter_side_effect_type()
: info.getter_side_effect_type()) {
case SideEffectType::kHasNoSideEffect:
// We do not support setter accessors with no side effects, since
// calling set accessors go through a store bytecode. Store bytecodes
// are considered to cause side effects (to non-temporary objects).
DCHECK_NE(kSetter, accessor_kind);
return true;
case SideEffectType::kHasSideEffectToReceiver:
DCHECK(!receiver.is_null());
if (PerformSideEffectCheckForObject(receiver)) return true;
isolate_->OptionalRescheduleException(false);
return false;
case SideEffectType::kHasSideEffect:
break;
}
if (FLAG_trace_side_effect_free_debug_evaluate) {
PrintF("[debug-evaluate] API Callback '");
info.name().ShortPrint();
PrintF("' may cause side effect.\n");
}
} else if (callback_info->IsInterceptorInfo()) {
InterceptorInfo info = InterceptorInfo::cast(*callback_info);
if (info.has_no_side_effect()) return true;
if (FLAG_trace_side_effect_free_debug_evaluate) {
PrintF("[debug-evaluate] API Interceptor may cause side effect.\n");
}
} else if (callback_info->IsCallHandlerInfo()) {
CallHandlerInfo info = CallHandlerInfo::cast(*callback_info);
if (info.IsSideEffectFreeCallHandlerInfo()) return true;
if (FLAG_trace_side_effect_free_debug_evaluate) {
PrintF("[debug-evaluate] API CallHandlerInfo may cause side effect.\n");
}
}
}
side_effect_check_failed_ = true;
// Throw an uncatchable termination exception.
isolate_->TerminateExecution();
isolate_->OptionalRescheduleException(false);
return false;
}
bool Debug::PerformSideEffectCheckAtBytecode(InterpretedFrame* frame) {
using interpreter::Bytecode;
DCHECK_EQ(isolate_->debug_execution_mode(), DebugInfo::kSideEffects);
SharedFunctionInfo shared = frame->function().shared();
BytecodeArray bytecode_array = shared.GetBytecodeArray();
int offset = frame->GetBytecodeOffset();
interpreter::BytecodeArrayAccessor bytecode_accessor(
handle(bytecode_array, isolate_), offset);
Bytecode bytecode = bytecode_accessor.current_bytecode();
interpreter::Register reg;
switch (bytecode) {
case Bytecode::kStaCurrentContextSlot:
reg = interpreter::Register::current_context();
break;
default:
reg = bytecode_accessor.GetRegisterOperand(0);
break;
}
Handle<Object> object =
handle(frame->ReadInterpreterRegister(reg.index()), isolate_);
return PerformSideEffectCheckForObject(object);
}
bool Debug::PerformSideEffectCheckForObject(Handle<Object> object) {
DCHECK_EQ(isolate_->debug_execution_mode(), DebugInfo::kSideEffects);
// We expect no side-effects for primitives.
if (object->IsNumber()) return true;
if (object->IsName()) return true;
if (temporary_objects_->HasObject(Handle<HeapObject>::cast(object))) {
return true;
}
if (FLAG_trace_side_effect_free_debug_evaluate) {
PrintF("[debug-evaluate] failed runtime side effect check.\n");
}
side_effect_check_failed_ = true;
// Throw an uncatchable termination exception.
isolate_->TerminateExecution();
return false;
}
} // namespace internal
} // namespace v8
|