1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
|
// object.cc -- support for an object file for linking in gold
// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
// MA 02110-1301, USA.
#include "gold.h"
#include <cerrno>
#include <cstring>
#include <cstdarg>
#include "demangle.h"
#include "libiberty.h"
#include "gc.h"
#include "target-select.h"
#include "dwarf_reader.h"
#include "layout.h"
#include "output.h"
#include "symtab.h"
#include "cref.h"
#include "reloc.h"
#include "object.h"
#include "dynobj.h"
#include "plugin.h"
namespace gold
{
// Class Xindex.
// Initialize the symtab_xindex_ array. Find the SHT_SYMTAB_SHNDX
// section and read it in. SYMTAB_SHNDX is the index of the symbol
// table we care about.
template<int size, bool big_endian>
void
Xindex::initialize_symtab_xindex(Object* object, unsigned int symtab_shndx)
{
if (!this->symtab_xindex_.empty())
return;
gold_assert(symtab_shndx != 0);
// Look through the sections in reverse order, on the theory that it
// is more likely to be near the end than the beginning.
unsigned int i = object->shnum();
while (i > 0)
{
--i;
if (object->section_type(i) == elfcpp::SHT_SYMTAB_SHNDX
&& this->adjust_shndx(object->section_link(i)) == symtab_shndx)
{
this->read_symtab_xindex<size, big_endian>(object, i, NULL);
return;
}
}
object->error(_("missing SHT_SYMTAB_SHNDX section"));
}
// Read in the symtab_xindex_ array, given the section index of the
// SHT_SYMTAB_SHNDX section. If PSHDRS is not NULL, it points at the
// section headers.
template<int size, bool big_endian>
void
Xindex::read_symtab_xindex(Object* object, unsigned int xindex_shndx,
const unsigned char* pshdrs)
{
section_size_type bytecount;
const unsigned char* contents;
if (pshdrs == NULL)
contents = object->section_contents(xindex_shndx, &bytecount, false);
else
{
const unsigned char* p = (pshdrs
+ (xindex_shndx
* elfcpp::Elf_sizes<size>::shdr_size));
typename elfcpp::Shdr<size, big_endian> shdr(p);
bytecount = convert_to_section_size_type(shdr.get_sh_size());
contents = object->get_view(shdr.get_sh_offset(), bytecount, true, false);
}
gold_assert(this->symtab_xindex_.empty());
this->symtab_xindex_.reserve(bytecount / 4);
for (section_size_type i = 0; i < bytecount; i += 4)
{
unsigned int shndx = elfcpp::Swap<32, big_endian>::readval(contents + i);
// We preadjust the section indexes we save.
this->symtab_xindex_.push_back(this->adjust_shndx(shndx));
}
}
// Symbol symndx has a section of SHN_XINDEX; return the real section
// index.
unsigned int
Xindex::sym_xindex_to_shndx(Object* object, unsigned int symndx)
{
if (symndx >= this->symtab_xindex_.size())
{
object->error(_("symbol %u out of range for SHT_SYMTAB_SHNDX section"),
symndx);
return elfcpp::SHN_UNDEF;
}
unsigned int shndx = this->symtab_xindex_[symndx];
if (shndx < elfcpp::SHN_LORESERVE || shndx >= object->shnum())
{
object->error(_("extended index for symbol %u out of range: %u"),
symndx, shndx);
return elfcpp::SHN_UNDEF;
}
return shndx;
}
// Class Object.
// Report an error for this object file. This is used by the
// elfcpp::Elf_file interface, and also called by the Object code
// itself.
void
Object::error(const char* format, ...) const
{
va_list args;
va_start(args, format);
char* buf = NULL;
if (vasprintf(&buf, format, args) < 0)
gold_nomem();
va_end(args);
gold_error(_("%s: %s"), this->name().c_str(), buf);
free(buf);
}
// Return a view of the contents of a section.
const unsigned char*
Object::section_contents(unsigned int shndx, section_size_type* plen,
bool cache)
{
Location loc(this->do_section_contents(shndx));
*plen = convert_to_section_size_type(loc.data_size);
if (*plen == 0)
{
static const unsigned char empty[1] = { '\0' };
return empty;
}
return this->get_view(loc.file_offset, *plen, true, cache);
}
// Read the section data into SD. This is code common to Sized_relobj
// and Sized_dynobj, so we put it into Object.
template<int size, bool big_endian>
void
Object::read_section_data(elfcpp::Elf_file<size, big_endian, Object>* elf_file,
Read_symbols_data* sd)
{
const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
// Read the section headers.
const off_t shoff = elf_file->shoff();
const unsigned int shnum = this->shnum();
sd->section_headers = this->get_lasting_view(shoff, shnum * shdr_size,
true, true);
// Read the section names.
const unsigned char* pshdrs = sd->section_headers->data();
const unsigned char* pshdrnames = pshdrs + elf_file->shstrndx() * shdr_size;
typename elfcpp::Shdr<size, big_endian> shdrnames(pshdrnames);
if (shdrnames.get_sh_type() != elfcpp::SHT_STRTAB)
this->error(_("section name section has wrong type: %u"),
static_cast<unsigned int>(shdrnames.get_sh_type()));
sd->section_names_size =
convert_to_section_size_type(shdrnames.get_sh_size());
sd->section_names = this->get_lasting_view(shdrnames.get_sh_offset(),
sd->section_names_size, false,
false);
}
// If NAME is the name of a special .gnu.warning section, arrange for
// the warning to be issued. SHNDX is the section index. Return
// whether it is a warning section.
bool
Object::handle_gnu_warning_section(const char* name, unsigned int shndx,
Symbol_table* symtab)
{
const char warn_prefix[] = ".gnu.warning.";
const int warn_prefix_len = sizeof warn_prefix - 1;
if (strncmp(name, warn_prefix, warn_prefix_len) == 0)
{
// Read the section contents to get the warning text. It would
// be nicer if we only did this if we have to actually issue a
// warning. Unfortunately, warnings are issued as we relocate
// sections. That means that we can not lock the object then,
// as we might try to issue the same warning multiple times
// simultaneously.
section_size_type len;
const unsigned char* contents = this->section_contents(shndx, &len,
false);
if (len == 0)
{
const char* warning = name + warn_prefix_len;
contents = reinterpret_cast<const unsigned char*>(warning);
len = strlen(warning);
}
std::string warning(reinterpret_cast<const char*>(contents), len);
symtab->add_warning(name + warn_prefix_len, this, warning);
return true;
}
return false;
}
// If NAME is the name of the special section which indicates that
// this object was compiled with -fstack-split, mark it accordingly.
bool
Object::handle_split_stack_section(const char* name)
{
if (strcmp(name, ".note.GNU-split-stack") == 0)
{
this->uses_split_stack_ = true;
return true;
}
if (strcmp(name, ".note.GNU-no-split-stack") == 0)
{
this->has_no_split_stack_ = true;
return true;
}
return false;
}
// Class Relobj
// To copy the symbols data read from the file to a local data structure.
// This function is called from do_layout only while doing garbage
// collection.
void
Relobj::copy_symbols_data(Symbols_data* gc_sd, Read_symbols_data* sd,
unsigned int section_header_size)
{
gc_sd->section_headers_data =
new unsigned char[(section_header_size)];
memcpy(gc_sd->section_headers_data, sd->section_headers->data(),
section_header_size);
gc_sd->section_names_data =
new unsigned char[sd->section_names_size];
memcpy(gc_sd->section_names_data, sd->section_names->data(),
sd->section_names_size);
gc_sd->section_names_size = sd->section_names_size;
if (sd->symbols != NULL)
{
gc_sd->symbols_data =
new unsigned char[sd->symbols_size];
memcpy(gc_sd->symbols_data, sd->symbols->data(),
sd->symbols_size);
}
else
{
gc_sd->symbols_data = NULL;
}
gc_sd->symbols_size = sd->symbols_size;
gc_sd->external_symbols_offset = sd->external_symbols_offset;
if (sd->symbol_names != NULL)
{
gc_sd->symbol_names_data =
new unsigned char[sd->symbol_names_size];
memcpy(gc_sd->symbol_names_data, sd->symbol_names->data(),
sd->symbol_names_size);
}
else
{
gc_sd->symbol_names_data = NULL;
}
gc_sd->symbol_names_size = sd->symbol_names_size;
}
// This function determines if a particular section name must be included
// in the link. This is used during garbage collection to determine the
// roots of the worklist.
bool
Relobj::is_section_name_included(const char* name)
{
if (is_prefix_of(".ctors", name)
|| is_prefix_of(".dtors", name)
|| is_prefix_of(".note", name)
|| is_prefix_of(".init", name)
|| is_prefix_of(".fini", name)
|| is_prefix_of(".gcc_except_table", name)
|| is_prefix_of(".jcr", name)
|| is_prefix_of(".preinit_array", name)
|| (is_prefix_of(".text", name)
&& strstr(name, "personality"))
|| (is_prefix_of(".data", name)
&& strstr(name, "personality"))
|| (is_prefix_of(".gnu.linkonce.d", name)
&& strstr(name, "personality")))
{
return true;
}
return false;
}
// Class Sized_relobj.
template<int size, bool big_endian>
Sized_relobj<size, big_endian>::Sized_relobj(
const std::string& name,
Input_file* input_file,
off_t offset,
const elfcpp::Ehdr<size, big_endian>& ehdr)
: Relobj(name, input_file, offset),
elf_file_(this, ehdr),
symtab_shndx_(-1U),
local_symbol_count_(0),
output_local_symbol_count_(0),
output_local_dynsym_count_(0),
symbols_(),
defined_count_(0),
local_symbol_offset_(0),
local_dynsym_offset_(0),
local_values_(),
local_got_offsets_(),
kept_comdat_sections_(),
has_eh_frame_(false),
discarded_eh_frame_shndx_(-1U)
{
}
template<int size, bool big_endian>
Sized_relobj<size, big_endian>::~Sized_relobj()
{
}
// Set up an object file based on the file header. This sets up the
// section information.
template<int size, bool big_endian>
void
Sized_relobj<size, big_endian>::do_setup()
{
const unsigned int shnum = this->elf_file_.shnum();
this->set_shnum(shnum);
}
// Find the SHT_SYMTAB section, given the section headers. The ELF
// standard says that maybe in the future there can be more than one
// SHT_SYMTAB section. Until somebody figures out how that could
// work, we assume there is only one.
template<int size, bool big_endian>
void
Sized_relobj<size, big_endian>::find_symtab(const unsigned char* pshdrs)
{
const unsigned int shnum = this->shnum();
this->symtab_shndx_ = 0;
if (shnum > 0)
{
// Look through the sections in reverse order, since gas tends
// to put the symbol table at the end.
const unsigned char* p = pshdrs + shnum * This::shdr_size;
unsigned int i = shnum;
unsigned int xindex_shndx = 0;
unsigned int xindex_link = 0;
while (i > 0)
{
--i;
p -= This::shdr_size;
typename This::Shdr shdr(p);
if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
{
this->symtab_shndx_ = i;
if (xindex_shndx > 0 && xindex_link == i)
{
Xindex* xindex =
new Xindex(this->elf_file_.large_shndx_offset());
xindex->read_symtab_xindex<size, big_endian>(this,
xindex_shndx,
pshdrs);
this->set_xindex(xindex);
}
break;
}
// Try to pick up the SHT_SYMTAB_SHNDX section, if there is
// one. This will work if it follows the SHT_SYMTAB
// section.
if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB_SHNDX)
{
xindex_shndx = i;
xindex_link = this->adjust_shndx(shdr.get_sh_link());
}
}
}
}
// Return the Xindex structure to use for object with lots of
// sections.
template<int size, bool big_endian>
Xindex*
Sized_relobj<size, big_endian>::do_initialize_xindex()
{
gold_assert(this->symtab_shndx_ != -1U);
Xindex* xindex = new Xindex(this->elf_file_.large_shndx_offset());
xindex->initialize_symtab_xindex<size, big_endian>(this, this->symtab_shndx_);
return xindex;
}
// Return whether SHDR has the right type and flags to be a GNU
// .eh_frame section.
template<int size, bool big_endian>
bool
Sized_relobj<size, big_endian>::check_eh_frame_flags(
const elfcpp::Shdr<size, big_endian>* shdr) const
{
return (shdr->get_sh_type() == elfcpp::SHT_PROGBITS
&& (shdr->get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
}
// Return whether there is a GNU .eh_frame section, given the section
// headers and the section names.
template<int size, bool big_endian>
bool
Sized_relobj<size, big_endian>::find_eh_frame(
const unsigned char* pshdrs,
const char* names,
section_size_type names_size) const
{
const unsigned int shnum = this->shnum();
const unsigned char* p = pshdrs + This::shdr_size;
for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
{
typename This::Shdr shdr(p);
if (this->check_eh_frame_flags(&shdr))
{
if (shdr.get_sh_name() >= names_size)
{
this->error(_("bad section name offset for section %u: %lu"),
i, static_cast<unsigned long>(shdr.get_sh_name()));
continue;
}
const char* name = names + shdr.get_sh_name();
if (strcmp(name, ".eh_frame") == 0)
return true;
}
}
return false;
}
// Read the sections and symbols from an object file.
template<int size, bool big_endian>
void
Sized_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
{
this->read_section_data(&this->elf_file_, sd);
const unsigned char* const pshdrs = sd->section_headers->data();
this->find_symtab(pshdrs);
const unsigned char* namesu = sd->section_names->data();
const char* names = reinterpret_cast<const char*>(namesu);
if (memmem(names, sd->section_names_size, ".eh_frame", 10) != NULL)
{
if (this->find_eh_frame(pshdrs, names, sd->section_names_size))
this->has_eh_frame_ = true;
}
sd->symbols = NULL;
sd->symbols_size = 0;
sd->external_symbols_offset = 0;
sd->symbol_names = NULL;
sd->symbol_names_size = 0;
if (this->symtab_shndx_ == 0)
{
// No symbol table. Weird but legal.
return;
}
// Get the symbol table section header.
typename This::Shdr symtabshdr(pshdrs
+ this->symtab_shndx_ * This::shdr_size);
gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
// If this object has a .eh_frame section, we need all the symbols.
// Otherwise we only need the external symbols. While it would be
// simpler to just always read all the symbols, I've seen object
// files with well over 2000 local symbols, which for a 64-bit
// object file format is over 5 pages that we don't need to read
// now.
const int sym_size = This::sym_size;
const unsigned int loccount = symtabshdr.get_sh_info();
this->local_symbol_count_ = loccount;
this->local_values_.resize(loccount);
section_offset_type locsize = loccount * sym_size;
off_t dataoff = symtabshdr.get_sh_offset();
section_size_type datasize =
convert_to_section_size_type(symtabshdr.get_sh_size());
off_t extoff = dataoff + locsize;
section_size_type extsize = datasize - locsize;
off_t readoff = this->has_eh_frame_ ? dataoff : extoff;
section_size_type readsize = this->has_eh_frame_ ? datasize : extsize;
if (readsize == 0)
{
// No external symbols. Also weird but also legal.
return;
}
File_view* fvsymtab = this->get_lasting_view(readoff, readsize, true, false);
// Read the section header for the symbol names.
unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
if (strtab_shndx >= this->shnum())
{
this->error(_("invalid symbol table name index: %u"), strtab_shndx);
return;
}
typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size);
if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
{
this->error(_("symbol table name section has wrong type: %u"),
static_cast<unsigned int>(strtabshdr.get_sh_type()));
return;
}
// Read the symbol names.
File_view* fvstrtab = this->get_lasting_view(strtabshdr.get_sh_offset(),
strtabshdr.get_sh_size(),
false, true);
sd->symbols = fvsymtab;
sd->symbols_size = readsize;
sd->external_symbols_offset = this->has_eh_frame_ ? locsize : 0;
sd->symbol_names = fvstrtab;
sd->symbol_names_size =
convert_to_section_size_type(strtabshdr.get_sh_size());
}
// Return the section index of symbol SYM. Set *VALUE to its value in
// the object file. Set *IS_ORDINARY if this is an ordinary section
// index. not a special cod between SHN_LORESERVE and SHN_HIRESERVE.
// Note that for a symbol which is not defined in this object file,
// this will set *VALUE to 0 and return SHN_UNDEF; it will not return
// the final value of the symbol in the link.
template<int size, bool big_endian>
unsigned int
Sized_relobj<size, big_endian>::symbol_section_and_value(unsigned int sym,
Address* value,
bool* is_ordinary)
{
section_size_type symbols_size;
const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
&symbols_size,
false);
const size_t count = symbols_size / This::sym_size;
gold_assert(sym < count);
elfcpp::Sym<size, big_endian> elfsym(symbols + sym * This::sym_size);
*value = elfsym.get_st_value();
return this->adjust_sym_shndx(sym, elfsym.get_st_shndx(), is_ordinary);
}
// Return whether to include a section group in the link. LAYOUT is
// used to keep track of which section groups we have already seen.
// INDEX is the index of the section group and SHDR is the section
// header. If we do not want to include this group, we set bits in
// OMIT for each section which should be discarded.
template<int size, bool big_endian>
bool
Sized_relobj<size, big_endian>::include_section_group(
Symbol_table* symtab,
Layout* layout,
unsigned int index,
const char* name,
const unsigned char* shdrs,
const char* section_names,
section_size_type section_names_size,
std::vector<bool>* omit)
{
// Read the section contents.
typename This::Shdr shdr(shdrs + index * This::shdr_size);
const unsigned char* pcon = this->get_view(shdr.get_sh_offset(),
shdr.get_sh_size(), true, false);
const elfcpp::Elf_Word* pword =
reinterpret_cast<const elfcpp::Elf_Word*>(pcon);
// The first word contains flags. We only care about COMDAT section
// groups. Other section groups are always included in the link
// just like ordinary sections.
elfcpp::Elf_Word flags = elfcpp::Swap<32, big_endian>::readval(pword);
// Look up the group signature, which is the name of a symbol. This
// is a lot of effort to go to to read a string. Why didn't they
// just have the group signature point into the string table, rather
// than indirect through a symbol?
// Get the appropriate symbol table header (this will normally be
// the single SHT_SYMTAB section, but in principle it need not be).
const unsigned int link = this->adjust_shndx(shdr.get_sh_link());
typename This::Shdr symshdr(this, this->elf_file_.section_header(link));
// Read the symbol table entry.
unsigned int symndx = shdr.get_sh_info();
if (symndx >= symshdr.get_sh_size() / This::sym_size)
{
this->error(_("section group %u info %u out of range"),
index, symndx);
return false;
}
off_t symoff = symshdr.get_sh_offset() + symndx * This::sym_size;
const unsigned char* psym = this->get_view(symoff, This::sym_size, true,
false);
elfcpp::Sym<size, big_endian> sym(psym);
// Read the symbol table names.
section_size_type symnamelen;
const unsigned char* psymnamesu;
psymnamesu = this->section_contents(this->adjust_shndx(symshdr.get_sh_link()),
&symnamelen, true);
const char* psymnames = reinterpret_cast<const char*>(psymnamesu);
// Get the section group signature.
if (sym.get_st_name() >= symnamelen)
{
this->error(_("symbol %u name offset %u out of range"),
symndx, sym.get_st_name());
return false;
}
std::string signature(psymnames + sym.get_st_name());
// It seems that some versions of gas will create a section group
// associated with a section symbol, and then fail to give a name to
// the section symbol. In such a case, use the name of the section.
if (signature[0] == '\0' && sym.get_st_type() == elfcpp::STT_SECTION)
{
bool is_ordinary;
unsigned int sym_shndx = this->adjust_sym_shndx(symndx,
sym.get_st_shndx(),
&is_ordinary);
if (!is_ordinary || sym_shndx >= this->shnum())
{
this->error(_("symbol %u invalid section index %u"),
symndx, sym_shndx);
return false;
}
typename This::Shdr member_shdr(shdrs + sym_shndx * This::shdr_size);
if (member_shdr.get_sh_name() < section_names_size)
signature = section_names + member_shdr.get_sh_name();
}
// Record this section group in the layout, and see whether we've already
// seen one with the same signature.
bool include_group;
bool is_comdat;
Kept_section* kept_section = NULL;
if ((flags & elfcpp::GRP_COMDAT) == 0)
{
include_group = true;
is_comdat = false;
}
else
{
include_group = layout->find_or_add_kept_section(signature,
this, index, true,
true, &kept_section);
is_comdat = true;
}
size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word);
std::vector<unsigned int> shndxes;
bool relocate_group = include_group && parameters->options().relocatable();
if (relocate_group)
shndxes.reserve(count - 1);
for (size_t i = 1; i < count; ++i)
{
elfcpp::Elf_Word shndx =
this->adjust_shndx(elfcpp::Swap<32, big_endian>::readval(pword + i));
if (relocate_group)
shndxes.push_back(shndx);
if (shndx >= this->shnum())
{
this->error(_("section %u in section group %u out of range"),
shndx, index);
continue;
}
// Check for an earlier section number, since we're going to get
// it wrong--we may have already decided to include the section.
if (shndx < index)
this->error(_("invalid section group %u refers to earlier section %u"),
index, shndx);
// Get the name of the member section.
typename This::Shdr member_shdr(shdrs + shndx * This::shdr_size);
if (member_shdr.get_sh_name() >= section_names_size)
{
// This is an error, but it will be diagnosed eventually
// in do_layout, so we don't need to do anything here but
// ignore it.
continue;
}
std::string mname(section_names + member_shdr.get_sh_name());
if (include_group)
{
if (is_comdat)
kept_section->add_comdat_section(mname, shndx,
member_shdr.get_sh_size());
}
else
{
(*omit)[shndx] = true;
if (is_comdat)
{
Relobj* kept_object = kept_section->object();
if (kept_section->is_comdat())
{
// Find the corresponding kept section, and store
// that info in the discarded section table.
unsigned int kept_shndx;
uint64_t kept_size;
if (kept_section->find_comdat_section(mname, &kept_shndx,
&kept_size))
{
// We don't keep a mapping for this section if
// it has a different size. The mapping is only
// used for relocation processing, and we don't
// want to treat the sections as similar if the
// sizes are different. Checking the section
// size is the approach used by the GNU linker.
if (kept_size == member_shdr.get_sh_size())
this->set_kept_comdat_section(shndx, kept_object,
kept_shndx);
}
}
else
{
// The existing section is a linkonce section. Add
// a mapping if there is exactly one section in the
// group (which is true when COUNT == 2) and if it
// is the same size.
if (count == 2
&& (kept_section->linkonce_size()
== member_shdr.get_sh_size()))
this->set_kept_comdat_section(shndx, kept_object,
kept_section->shndx());
}
}
}
}
if (relocate_group)
layout->layout_group(symtab, this, index, name, signature.c_str(),
shdr, flags, &shndxes);
return include_group;
}
// Whether to include a linkonce section in the link. NAME is the
// name of the section and SHDR is the section header.
// Linkonce sections are a GNU extension implemented in the original
// GNU linker before section groups were defined. The semantics are
// that we only include one linkonce section with a given name. The
// name of a linkonce section is normally .gnu.linkonce.T.SYMNAME,
// where T is the type of section and SYMNAME is the name of a symbol.
// In an attempt to make linkonce sections interact well with section
// groups, we try to identify SYMNAME and use it like a section group
// signature. We want to block section groups with that signature,
// but not other linkonce sections with that signature. We also use
// the full name of the linkonce section as a normal section group
// signature.
template<int size, bool big_endian>
bool
Sized_relobj<size, big_endian>::include_linkonce_section(
Layout* layout,
unsigned int index,
const char* name,
const elfcpp::Shdr<size, big_endian>& shdr)
{
typename elfcpp::Elf_types<size>::Elf_WXword sh_size = shdr.get_sh_size();
// In general the symbol name we want will be the string following
// the last '.'. However, we have to handle the case of
// .gnu.linkonce.t.__i686.get_pc_thunk.bx, which was generated by
// some versions of gcc. So we use a heuristic: if the name starts
// with ".gnu.linkonce.t.", we use everything after that. Otherwise
// we look for the last '.'. We can't always simply skip
// ".gnu.linkonce.X", because we have to deal with cases like
// ".gnu.linkonce.d.rel.ro.local".
const char* const linkonce_t = ".gnu.linkonce.t.";
const char* symname;
if (strncmp(name, linkonce_t, strlen(linkonce_t)) == 0)
symname = name + strlen(linkonce_t);
else
symname = strrchr(name, '.') + 1;
std::string sig1(symname);
std::string sig2(name);
Kept_section* kept1;
Kept_section* kept2;
bool include1 = layout->find_or_add_kept_section(sig1, this, index, false,
false, &kept1);
bool include2 = layout->find_or_add_kept_section(sig2, this, index, false,
true, &kept2);
if (!include2)
{
// We are not including this section because we already saw the
// name of the section as a signature. This normally implies
// that the kept section is another linkonce section. If it is
// the same size, record it as the section which corresponds to
// this one.
if (kept2->object() != NULL
&& !kept2->is_comdat()
&& kept2->linkonce_size() == sh_size)
this->set_kept_comdat_section(index, kept2->object(), kept2->shndx());
}
else if (!include1)
{
// The section is being discarded on the basis of its symbol
// name. This means that the corresponding kept section was
// part of a comdat group, and it will be difficult to identify
// the specific section within that group that corresponds to
// this linkonce section. We'll handle the simple case where
// the group has only one member section. Otherwise, it's not
// worth the effort.
unsigned int kept_shndx;
uint64_t kept_size;
if (kept1->object() != NULL
&& kept1->is_comdat()
&& kept1->find_single_comdat_section(&kept_shndx, &kept_size)
&& kept_size == sh_size)
this->set_kept_comdat_section(index, kept1->object(), kept_shndx);
}
else
{
kept1->set_linkonce_size(sh_size);
kept2->set_linkonce_size(sh_size);
}
return include1 && include2;
}
// Layout an input section.
template<int size, bool big_endian>
inline void
Sized_relobj<size, big_endian>::layout_section(Layout* layout,
unsigned int shndx,
const char* name,
typename This::Shdr& shdr,
unsigned int reloc_shndx,
unsigned int reloc_type)
{
off_t offset;
Output_section* os = layout->layout(this, shndx, name, shdr,
reloc_shndx, reloc_type, &offset);
this->output_sections()[shndx] = os;
if (offset == -1)
this->section_offsets_[shndx] = invalid_address;
else
this->section_offsets_[shndx] = convert_types<Address, off_t>(offset);
// If this section requires special handling, and if there are
// relocs that apply to it, then we must do the special handling
// before we apply the relocs.
if (offset == -1 && reloc_shndx != 0)
this->set_relocs_must_follow_section_writes();
}
// Lay out the input sections. We walk through the sections and check
// whether they should be included in the link. If they should, we
// pass them to the Layout object, which will return an output section
// and an offset.
// During garbage collection (--gc-sections) and identical code folding
// (--icf), this function is called twice. When it is called the first
// time, it is for setting up some sections as roots to a work-list for
// --gc-sections and to do comdat processing. Actual layout happens the
// second time around after all the relevant sections have been determined.
// The first time, is_worklist_ready or is_icf_ready is false. It is then
// set to true after the garbage collection worklist or identical code
// folding is processed and the relevant sections to be kept are
// determined. Then, this function is called again to layout the sections.
template<int size, bool big_endian>
void
Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
Layout* layout,
Read_symbols_data* sd)
{
const unsigned int shnum = this->shnum();
bool is_gc_pass_one = ((parameters->options().gc_sections()
&& !symtab->gc()->is_worklist_ready())
|| (parameters->options().icf_enabled()
&& !symtab->icf()->is_icf_ready()));
bool is_gc_pass_two = ((parameters->options().gc_sections()
&& symtab->gc()->is_worklist_ready())
|| (parameters->options().icf_enabled()
&& symtab->icf()->is_icf_ready()));
bool is_gc_or_icf = (parameters->options().gc_sections()
|| parameters->options().icf_enabled());
// Both is_gc_pass_one and is_gc_pass_two should not be true.
gold_assert(!(is_gc_pass_one && is_gc_pass_two));
if (shnum == 0)
return;
Symbols_data* gc_sd = NULL;
if (is_gc_pass_one)
{
// During garbage collection save the symbols data to use it when
// re-entering this function.
gc_sd = new Symbols_data;
this->copy_symbols_data(gc_sd, sd, This::shdr_size * shnum);
this->set_symbols_data(gc_sd);
}
else if (is_gc_pass_two)
{
gc_sd = this->get_symbols_data();
}
const unsigned char* section_headers_data = NULL;
section_size_type section_names_size;
const unsigned char* symbols_data = NULL;
section_size_type symbols_size;
section_offset_type external_symbols_offset;
const unsigned char* symbol_names_data = NULL;
section_size_type symbol_names_size;
if (is_gc_or_icf)
{
section_headers_data = gc_sd->section_headers_data;
section_names_size = gc_sd->section_names_size;
symbols_data = gc_sd->symbols_data;
symbols_size = gc_sd->symbols_size;
external_symbols_offset = gc_sd->external_symbols_offset;
symbol_names_data = gc_sd->symbol_names_data;
symbol_names_size = gc_sd->symbol_names_size;
}
else
{
section_headers_data = sd->section_headers->data();
section_names_size = sd->section_names_size;
if (sd->symbols != NULL)
symbols_data = sd->symbols->data();
symbols_size = sd->symbols_size;
external_symbols_offset = sd->external_symbols_offset;
if (sd->symbol_names != NULL)
symbol_names_data = sd->symbol_names->data();
symbol_names_size = sd->symbol_names_size;
}
// Get the section headers.
const unsigned char* shdrs = section_headers_data;
const unsigned char* pshdrs;
// Get the section names.
const unsigned char* pnamesu = (is_gc_or_icf)
? gc_sd->section_names_data
: sd->section_names->data();
const char* pnames = reinterpret_cast<const char*>(pnamesu);
// If any input files have been claimed by plugins, we need to defer
// actual layout until the replacement files have arrived.
const bool should_defer_layout =
(parameters->options().has_plugins()
&& parameters->options().plugins()->should_defer_layout());
unsigned int num_sections_to_defer = 0;
// For each section, record the index of the reloc section if any.
// Use 0 to mean that there is no reloc section, -1U to mean that
// there is more than one.
std::vector<unsigned int> reloc_shndx(shnum, 0);
std::vector<unsigned int> reloc_type(shnum, elfcpp::SHT_NULL);
// Skip the first, dummy, section.
pshdrs = shdrs + This::shdr_size;
for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
{
typename This::Shdr shdr(pshdrs);
// Count the number of sections whose layout will be deferred.
if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
++num_sections_to_defer;
unsigned int sh_type = shdr.get_sh_type();
if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
{
unsigned int target_shndx = this->adjust_shndx(shdr.get_sh_info());
if (target_shndx == 0 || target_shndx >= shnum)
{
this->error(_("relocation section %u has bad info %u"),
i, target_shndx);
continue;
}
if (reloc_shndx[target_shndx] != 0)
reloc_shndx[target_shndx] = -1U;
else
{
reloc_shndx[target_shndx] = i;
reloc_type[target_shndx] = sh_type;
}
}
}
Output_sections& out_sections(this->output_sections());
std::vector<Address>& out_section_offsets(this->section_offsets_);
if (!is_gc_pass_two)
{
out_sections.resize(shnum);
out_section_offsets.resize(shnum);
}
// If we are only linking for symbols, then there is nothing else to
// do here.
if (this->input_file()->just_symbols())
{
if (!is_gc_pass_two)
{
delete sd->section_headers;
sd->section_headers = NULL;
delete sd->section_names;
sd->section_names = NULL;
}
return;
}
if (num_sections_to_defer > 0)
{
parameters->options().plugins()->add_deferred_layout_object(this);
this->deferred_layout_.reserve(num_sections_to_defer);
}
// Whether we've seen a .note.GNU-stack section.
bool seen_gnu_stack = false;
// The flags of a .note.GNU-stack section.
uint64_t gnu_stack_flags = 0;
// Keep track of which sections to omit.
std::vector<bool> omit(shnum, false);
// Keep track of reloc sections when emitting relocations.
const bool relocatable = parameters->options().relocatable();
const bool emit_relocs = (relocatable
|| parameters->options().emit_relocs());
std::vector<unsigned int> reloc_sections;
// Keep track of .eh_frame sections.
std::vector<unsigned int> eh_frame_sections;
// Skip the first, dummy, section.
pshdrs = shdrs + This::shdr_size;
for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
{
typename This::Shdr shdr(pshdrs);
if (shdr.get_sh_name() >= section_names_size)
{
this->error(_("bad section name offset for section %u: %lu"),
i, static_cast<unsigned long>(shdr.get_sh_name()));
return;
}
const char* name = pnames + shdr.get_sh_name();
if (!is_gc_pass_two)
{
if (this->handle_gnu_warning_section(name, i, symtab))
{
if (!relocatable)
omit[i] = true;
}
// The .note.GNU-stack section is special. It gives the
// protection flags that this object file requires for the stack
// in memory.
if (strcmp(name, ".note.GNU-stack") == 0)
{
seen_gnu_stack = true;
gnu_stack_flags |= shdr.get_sh_flags();
omit[i] = true;
}
// The .note.GNU-split-stack section is also special. It
// indicates that the object was compiled with
// -fsplit-stack.
if (this->handle_split_stack_section(name))
{
if (!parameters->options().relocatable()
&& !parameters->options().shared())
omit[i] = true;
}
// Skip attributes section.
if (parameters->target().is_attributes_section(name))
{
omit[i] = true;
}
bool discard = omit[i];
if (!discard)
{
if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
{
if (!this->include_section_group(symtab, layout, i, name,
shdrs, pnames,
section_names_size,
&omit))
discard = true;
}
else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0
&& Layout::is_linkonce(name))
{
if (!this->include_linkonce_section(layout, i, name, shdr))
discard = true;
}
}
if (discard)
{
// Do not include this section in the link.
out_sections[i] = NULL;
out_section_offsets[i] = invalid_address;
continue;
}
}
if (is_gc_pass_one && parameters->options().gc_sections())
{
if (is_section_name_included(name)
|| shdr.get_sh_type() == elfcpp::SHT_INIT_ARRAY
|| shdr.get_sh_type() == elfcpp::SHT_FINI_ARRAY)
{
symtab->gc()->worklist().push(Section_id(this, i));
}
// If the section name XXX can be represented as a C identifier
// it cannot be discarded if there are references to
// __start_XXX and __stop_XXX symbols. These need to be
// specially handled.
if (is_cident(name))
{
symtab->gc()->add_cident_section(name, Section_id(this, i));
}
}
// When doing a relocatable link we are going to copy input
// reloc sections into the output. We only want to copy the
// ones associated with sections which are not being discarded.
// However, we don't know that yet for all sections. So save
// reloc sections and process them later. Garbage collection is
// not triggered when relocatable code is desired.
if (emit_relocs
&& (shdr.get_sh_type() == elfcpp::SHT_REL
|| shdr.get_sh_type() == elfcpp::SHT_RELA))
{
reloc_sections.push_back(i);
continue;
}
if (relocatable && shdr.get_sh_type() == elfcpp::SHT_GROUP)
continue;
// The .eh_frame section is special. It holds exception frame
// information that we need to read in order to generate the
// exception frame header. We process these after all the other
// sections so that the exception frame reader can reliably
// determine which sections are being discarded, and discard the
// corresponding information.
if (!relocatable
&& strcmp(name, ".eh_frame") == 0
&& this->check_eh_frame_flags(&shdr))
{
if (is_gc_pass_one)
{
out_sections[i] = reinterpret_cast<Output_section*>(1);
out_section_offsets[i] = invalid_address;
}
else
eh_frame_sections.push_back(i);
continue;
}
if (is_gc_pass_two && parameters->options().gc_sections())
{
// This is executed during the second pass of garbage
// collection. do_layout has been called before and some
// sections have been already discarded. Simply ignore
// such sections this time around.
if (out_sections[i] == NULL)
{
gold_assert(out_section_offsets[i] == invalid_address);
continue;
}
if (((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0)
&& symtab->gc()->is_section_garbage(this, i))
{
if (parameters->options().print_gc_sections())
gold_info(_("%s: removing unused section from '%s'"
" in file '%s'"),
program_name, this->section_name(i).c_str(),
this->name().c_str());
out_sections[i] = NULL;
out_section_offsets[i] = invalid_address;
continue;
}
}
if (is_gc_pass_two && parameters->options().icf_enabled())
{
if (out_sections[i] == NULL)
{
gold_assert(out_section_offsets[i] == invalid_address);
continue;
}
if (((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0)
&& symtab->icf()->is_section_folded(this, i))
{
if (parameters->options().print_icf_sections())
{
Section_id folded =
symtab->icf()->get_folded_section(this, i);
Relobj* folded_obj =
reinterpret_cast<Relobj*>(folded.first);
gold_info(_("%s: ICF folding section '%s' in file '%s'"
"into '%s' in file '%s'"),
program_name, this->section_name(i).c_str(),
this->name().c_str(),
folded_obj->section_name(folded.second).c_str(),
folded_obj->name().c_str());
}
out_sections[i] = NULL;
out_section_offsets[i] = invalid_address;
continue;
}
}
// Defer layout here if input files are claimed by plugins. When gc
// is turned on this function is called twice. For the second call
// should_defer_layout should be false.
if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
{
gold_assert(!is_gc_pass_two);
this->deferred_layout_.push_back(Deferred_layout(i, name,
pshdrs,
reloc_shndx[i],
reloc_type[i]));
// Put dummy values here; real values will be supplied by
// do_layout_deferred_sections.
out_sections[i] = reinterpret_cast<Output_section*>(2);
out_section_offsets[i] = invalid_address;
continue;
}
// During gc_pass_two if a section that was previously deferred is
// found, do not layout the section as layout_deferred_sections will
// do it later from gold.cc.
if (is_gc_pass_two
&& (out_sections[i] == reinterpret_cast<Output_section*>(2)))
continue;
if (is_gc_pass_one)
{
// This is during garbage collection. The out_sections are
// assigned in the second call to this function.
out_sections[i] = reinterpret_cast<Output_section*>(1);
out_section_offsets[i] = invalid_address;
}
else
{
// When garbage collection is switched on the actual layout
// only happens in the second call.
this->layout_section(layout, i, name, shdr, reloc_shndx[i],
reloc_type[i]);
}
}
if (!is_gc_pass_two)
layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags);
// When doing a relocatable link handle the reloc sections at the
// end. Garbage collection and Identical Code Folding is not
// turned on for relocatable code.
if (emit_relocs)
this->size_relocatable_relocs();
gold_assert(!(is_gc_or_icf) || reloc_sections.empty());
for (std::vector<unsigned int>::const_iterator p = reloc_sections.begin();
p != reloc_sections.end();
++p)
{
unsigned int i = *p;
const unsigned char* pshdr;
pshdr = section_headers_data + i * This::shdr_size;
typename This::Shdr shdr(pshdr);
unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info());
if (data_shndx >= shnum)
{
// We already warned about this above.
continue;
}
Output_section* data_section = out_sections[data_shndx];
if (data_section == NULL)
{
out_sections[i] = NULL;
out_section_offsets[i] = invalid_address;
continue;
}
Relocatable_relocs* rr = new Relocatable_relocs();
this->set_relocatable_relocs(i, rr);
Output_section* os = layout->layout_reloc(this, i, shdr, data_section,
rr);
out_sections[i] = os;
out_section_offsets[i] = invalid_address;
}
// Handle the .eh_frame sections at the end.
gold_assert(!is_gc_pass_one || eh_frame_sections.empty());
for (std::vector<unsigned int>::const_iterator p = eh_frame_sections.begin();
p != eh_frame_sections.end();
++p)
{
gold_assert(this->has_eh_frame_);
gold_assert(external_symbols_offset != 0);
unsigned int i = *p;
const unsigned char *pshdr;
pshdr = section_headers_data + i * This::shdr_size;
typename This::Shdr shdr(pshdr);
off_t offset;
Output_section* os = layout->layout_eh_frame(this,
symbols_data,
symbols_size,
symbol_names_data,
symbol_names_size,
i, shdr,
reloc_shndx[i],
reloc_type[i],
&offset);
out_sections[i] = os;
if (os == NULL || offset == -1)
{
// An object can contain at most one section holding exception
// frame information.
gold_assert(this->discarded_eh_frame_shndx_ == -1U);
this->discarded_eh_frame_shndx_ = i;
out_section_offsets[i] = invalid_address;
}
else
out_section_offsets[i] = convert_types<Address, off_t>(offset);
// If this section requires special handling, and if there are
// relocs that apply to it, then we must do the special handling
// before we apply the relocs.
if (os != NULL && offset == -1 && reloc_shndx[i] != 0)
this->set_relocs_must_follow_section_writes();
}
if (is_gc_pass_two)
{
delete[] gc_sd->section_headers_data;
delete[] gc_sd->section_names_data;
delete[] gc_sd->symbols_data;
delete[] gc_sd->symbol_names_data;
this->set_symbols_data(NULL);
}
else
{
delete sd->section_headers;
sd->section_headers = NULL;
delete sd->section_names;
sd->section_names = NULL;
}
}
// Layout sections whose layout was deferred while waiting for
// input files from a plugin.
template<int size, bool big_endian>
void
Sized_relobj<size, big_endian>::do_layout_deferred_sections(Layout* layout)
{
typename std::vector<Deferred_layout>::iterator deferred;
for (deferred = this->deferred_layout_.begin();
deferred != this->deferred_layout_.end();
++deferred)
{
typename This::Shdr shdr(deferred->shdr_data_);
this->layout_section(layout, deferred->shndx_, deferred->name_.c_str(),
shdr, deferred->reloc_shndx_, deferred->reloc_type_);
}
this->deferred_layout_.clear();
}
// Add the symbols to the symbol table.
template<int size, bool big_endian>
void
Sized_relobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
Read_symbols_data* sd,
Layout*)
{
if (sd->symbols == NULL)
{
gold_assert(sd->symbol_names == NULL);
return;
}
const int sym_size = This::sym_size;
size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
/ sym_size);
if (symcount * sym_size != sd->symbols_size - sd->external_symbols_offset)
{
this->error(_("size of symbols is not multiple of symbol size"));
return;
}
this->symbols_.resize(symcount);
const char* sym_names =
reinterpret_cast<const char*>(sd->symbol_names->data());
symtab->add_from_relobj(this,
sd->symbols->data() + sd->external_symbols_offset,
symcount, this->local_symbol_count_,
sym_names, sd->symbol_names_size,
&this->symbols_,
&this->defined_count_);
delete sd->symbols;
sd->symbols = NULL;
delete sd->symbol_names;
sd->symbol_names = NULL;
}
// First pass over the local symbols. Here we add their names to
// *POOL and *DYNPOOL, and we store the symbol value in
// THIS->LOCAL_VALUES_. This function is always called from a
// singleton thread. This is followed by a call to
// finalize_local_symbols.
template<int size, bool big_endian>
void
Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool,
Stringpool* dynpool)
{
gold_assert(this->symtab_shndx_ != -1U);
if (this->symtab_shndx_ == 0)
{
// This object has no symbols. Weird but legal.
return;
}
// Read the symbol table section header.
const unsigned int symtab_shndx = this->symtab_shndx_;
typename This::Shdr symtabshdr(this,
this->elf_file_.section_header(symtab_shndx));
gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
// Read the local symbols.
const int sym_size = This::sym_size;
const unsigned int loccount = this->local_symbol_count_;
gold_assert(loccount == symtabshdr.get_sh_info());
off_t locsize = loccount * sym_size;
const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
locsize, true, true);
// Read the symbol names.
const unsigned int strtab_shndx =
this->adjust_shndx(symtabshdr.get_sh_link());
section_size_type strtab_size;
const unsigned char* pnamesu = this->section_contents(strtab_shndx,
&strtab_size,
true);
const char* pnames = reinterpret_cast<const char*>(pnamesu);
// Loop over the local symbols.
const Output_sections& out_sections(this->output_sections());
unsigned int shnum = this->shnum();
unsigned int count = 0;
unsigned int dyncount = 0;
// Skip the first, dummy, symbol.
psyms += sym_size;
bool discard_all = parameters->options().discard_all();
bool discard_locals = parameters->options().discard_locals();
for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
{
elfcpp::Sym<size, big_endian> sym(psyms);
Symbol_value<size>& lv(this->local_values_[i]);
bool is_ordinary;
unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
&is_ordinary);
lv.set_input_shndx(shndx, is_ordinary);
if (sym.get_st_type() == elfcpp::STT_SECTION)
lv.set_is_section_symbol();
else if (sym.get_st_type() == elfcpp::STT_TLS)
lv.set_is_tls_symbol();
// Save the input symbol value for use in do_finalize_local_symbols().
lv.set_input_value(sym.get_st_value());
// Decide whether this symbol should go into the output file.
if ((shndx < shnum && out_sections[shndx] == NULL)
|| shndx == this->discarded_eh_frame_shndx_)
{
lv.set_no_output_symtab_entry();
gold_assert(!lv.needs_output_dynsym_entry());
continue;
}
if (sym.get_st_type() == elfcpp::STT_SECTION)
{
lv.set_no_output_symtab_entry();
gold_assert(!lv.needs_output_dynsym_entry());
continue;
}
if (sym.get_st_name() >= strtab_size)
{
this->error(_("local symbol %u section name out of range: %u >= %u"),
i, sym.get_st_name(),
static_cast<unsigned int>(strtab_size));
lv.set_no_output_symtab_entry();
continue;
}
const char* name = pnames + sym.get_st_name();
// If needed, add the symbol to the dynamic symbol table string pool.
if (lv.needs_output_dynsym_entry())
{
dynpool->add(name, true, NULL);
++dyncount;
}
if (discard_all && lv.may_be_discarded_from_output_symtab())
{
lv.set_no_output_symtab_entry();
continue;
}
// If --discard-locals option is used, discard all temporary local
// symbols. These symbols start with system-specific local label
// prefixes, typically .L for ELF system. We want to be compatible
// with GNU ld so here we essentially use the same check in
// bfd_is_local_label(). The code is different because we already
// know that:
//
// - the symbol is local and thus cannot have global or weak binding.
// - the symbol is not a section symbol.
// - the symbol has a name.
//
// We do not discard a symbol if it needs a dynamic symbol entry.
if (discard_locals
&& sym.get_st_type() != elfcpp::STT_FILE
&& !lv.needs_output_dynsym_entry()
&& lv.may_be_discarded_from_output_symtab()
&& parameters->target().is_local_label_name(name))
{
lv.set_no_output_symtab_entry();
continue;
}
// Discard the local symbol if -retain_symbols_file is specified
// and the local symbol is not in that file.
if (!parameters->options().should_retain_symbol(name))
{
lv.set_no_output_symtab_entry();
continue;
}
// Add the symbol to the symbol table string pool.
pool->add(name, true, NULL);
++count;
}
this->output_local_symbol_count_ = count;
this->output_local_dynsym_count_ = dyncount;
}
// Finalize the local symbols. Here we set the final value in
// THIS->LOCAL_VALUES_ and set their output symbol table indexes.
// This function is always called from a singleton thread. The actual
// output of the local symbols will occur in a separate task.
template<int size, bool big_endian>
unsigned int
Sized_relobj<size, big_endian>::do_finalize_local_symbols(unsigned int index,
off_t off,
Symbol_table* symtab)
{
gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
const unsigned int loccount = this->local_symbol_count_;
this->local_symbol_offset_ = off;
const bool relocatable = parameters->options().relocatable();
const Output_sections& out_sections(this->output_sections());
const std::vector<Address>& out_offsets(this->section_offsets_);
unsigned int shnum = this->shnum();
for (unsigned int i = 1; i < loccount; ++i)
{
Symbol_value<size>& lv(this->local_values_[i]);
bool is_ordinary;
unsigned int shndx = lv.input_shndx(&is_ordinary);
// Set the output symbol value.
if (!is_ordinary)
{
if (shndx == elfcpp::SHN_ABS || Symbol::is_common_shndx(shndx))
lv.set_output_value(lv.input_value());
else
{
this->error(_("unknown section index %u for local symbol %u"),
shndx, i);
lv.set_output_value(0);
}
}
else
{
if (shndx >= shnum)
{
this->error(_("local symbol %u section index %u out of range"),
i, shndx);
shndx = 0;
}
Output_section* os = out_sections[shndx];
Address secoffset = out_offsets[shndx];
if (symtab->is_section_folded(this, shndx))
{
gold_assert (os == NULL && secoffset == invalid_address);
// Get the os of the section it is folded onto.
Section_id folded = symtab->icf()->get_folded_section(this,
shndx);
gold_assert(folded.first != NULL);
Sized_relobj<size, big_endian>* folded_obj = reinterpret_cast
<Sized_relobj<size, big_endian>*>(folded.first);
os = folded_obj->output_section(folded.second);
gold_assert(os != NULL);
secoffset = folded_obj->get_output_section_offset(folded.second);
// This could be a relaxed input section.
if (secoffset == invalid_address)
{
const Output_relaxed_input_section* relaxed_section =
os->find_relaxed_input_section(folded_obj, folded.second);
gold_assert(relaxed_section != NULL);
secoffset = relaxed_section->address() - os->address();
}
}
if (os == NULL)
{
// This local symbol belongs to a section we are discarding.
// In some cases when applying relocations later, we will
// attempt to match it to the corresponding kept section,
// so we leave the input value unchanged here.
continue;
}
else if (secoffset == invalid_address)
{
uint64_t start;
// This is a SHF_MERGE section or one which otherwise
// requires special handling.
if (shndx == this->discarded_eh_frame_shndx_)
{
// This local symbol belongs to a discarded .eh_frame
// section. Just treat it like the case in which
// os == NULL above.
gold_assert(this->has_eh_frame_);
continue;
}
else if (!lv.is_section_symbol())
{
// This is not a section symbol. We can determine
// the final value now.
lv.set_output_value(os->output_address(this, shndx,
lv.input_value()));
}
else if (!os->find_starting_output_address(this, shndx, &start))
{
// This is a section symbol, but apparently not one in a
// merged section. First check to see if this is a relaxed
// input section. If so, use its address. Otherwise just
// use the start of the output section. This happens with
// relocatable links when the input object has section
// symbols for arbitrary non-merge sections.
const Output_section_data* posd =
os->find_relaxed_input_section(this, shndx);
if (posd != NULL)
{
Address relocatable_link_adjustment =
relocatable ? os->address() : 0;
lv.set_output_value(posd->address()
- relocatable_link_adjustment);
}
else
lv.set_output_value(os->address());
}
else
{
// We have to consider the addend to determine the
// value to use in a relocation. START is the start
// of this input section. If we are doing a relocatable
// link, use offset from start output section instead of
// address.
Address adjusted_start =
relocatable ? start - os->address() : start;
Merged_symbol_value<size>* msv =
new Merged_symbol_value<size>(lv.input_value(),
adjusted_start);
lv.set_merged_symbol_value(msv);
}
}
else if (lv.is_tls_symbol())
lv.set_output_value(os->tls_offset()
+ secoffset
+ lv.input_value());
else
lv.set_output_value((relocatable ? 0 : os->address())
+ secoffset
+ lv.input_value());
}
if (!lv.is_output_symtab_index_set())
{
lv.set_output_symtab_index(index);
++index;
}
}
return index;
}
// Set the output dynamic symbol table indexes for the local variables.
template<int size, bool big_endian>
unsigned int
Sized_relobj<size, big_endian>::do_set_local_dynsym_indexes(unsigned int index)
{
const unsigned int loccount = this->local_symbol_count_;
for (unsigned int i = 1; i < loccount; ++i)
{
Symbol_value<size>& lv(this->local_values_[i]);
if (lv.needs_output_dynsym_entry())
{
lv.set_output_dynsym_index(index);
++index;
}
}
return index;
}
// Set the offset where local dynamic symbol information will be stored.
// Returns the count of local symbols contributed to the symbol table by
// this object.
template<int size, bool big_endian>
unsigned int
Sized_relobj<size, big_endian>::do_set_local_dynsym_offset(off_t off)
{
gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
this->local_dynsym_offset_ = off;
return this->output_local_dynsym_count_;
}
// If Symbols_data is not NULL get the section flags from here otherwise
// get it from the file.
template<int size, bool big_endian>
uint64_t
Sized_relobj<size, big_endian>::do_section_flags(unsigned int shndx)
{
Symbols_data* sd = this->get_symbols_data();
if (sd != NULL)
{
const unsigned char* pshdrs = sd->section_headers_data
+ This::shdr_size * shndx;
typename This::Shdr shdr(pshdrs);
return shdr.get_sh_flags();
}
// If sd is NULL, read the section header from the file.
return this->elf_file_.section_flags(shndx);
}
// Get the section's ent size from Symbols_data. Called by get_section_contents
// in icf.cc
template<int size, bool big_endian>
uint64_t
Sized_relobj<size, big_endian>::do_section_entsize(unsigned int shndx)
{
Symbols_data* sd = this->get_symbols_data();
gold_assert (sd != NULL);
const unsigned char* pshdrs = sd->section_headers_data
+ This::shdr_size * shndx;
typename This::Shdr shdr(pshdrs);
return shdr.get_sh_entsize();
}
// Write out the local symbols.
template<int size, bool big_endian>
void
Sized_relobj<size, big_endian>::write_local_symbols(
Output_file* of,
const Stringpool* sympool,
const Stringpool* dynpool,
Output_symtab_xindex* symtab_xindex,
Output_symtab_xindex* dynsym_xindex)
{
const bool strip_all = parameters->options().strip_all();
if (strip_all)
{
if (this->output_local_dynsym_count_ == 0)
return;
this->output_local_symbol_count_ = 0;
}
gold_assert(this->symtab_shndx_ != -1U);
if (this->symtab_shndx_ == 0)
{
// This object has no symbols. Weird but legal.
return;
}
// Read the symbol table section header.
const unsigned int symtab_shndx = this->symtab_shndx_;
typename This::Shdr symtabshdr(this,
this->elf_file_.section_header(symtab_shndx));
gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
const unsigned int loccount = this->local_symbol_count_;
gold_assert(loccount == symtabshdr.get_sh_info());
// Read the local symbols.
const int sym_size = This::sym_size;
off_t locsize = loccount * sym_size;
const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
locsize, true, false);
// Read the symbol names.
const unsigned int strtab_shndx =
this->adjust_shndx(symtabshdr.get_sh_link());
section_size_type strtab_size;
const unsigned char* pnamesu = this->section_contents(strtab_shndx,
&strtab_size,
false);
const char* pnames = reinterpret_cast<const char*>(pnamesu);
// Get views into the output file for the portions of the symbol table
// and the dynamic symbol table that we will be writing.
off_t output_size = this->output_local_symbol_count_ * sym_size;
unsigned char* oview = NULL;
if (output_size > 0)
oview = of->get_output_view(this->local_symbol_offset_, output_size);
off_t dyn_output_size = this->output_local_dynsym_count_ * sym_size;
unsigned char* dyn_oview = NULL;
if (dyn_output_size > 0)
dyn_oview = of->get_output_view(this->local_dynsym_offset_,
dyn_output_size);
const Output_sections out_sections(this->output_sections());
gold_assert(this->local_values_.size() == loccount);
unsigned char* ov = oview;
unsigned char* dyn_ov = dyn_oview;
psyms += sym_size;
for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
{
elfcpp::Sym<size, big_endian> isym(psyms);
Symbol_value<size>& lv(this->local_values_[i]);
bool is_ordinary;
unsigned int st_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(),
&is_ordinary);
if (is_ordinary)
{
gold_assert(st_shndx < out_sections.size());
if (out_sections[st_shndx] == NULL)
continue;
st_shndx = out_sections[st_shndx]->out_shndx();
if (st_shndx >= elfcpp::SHN_LORESERVE)
{
if (lv.has_output_symtab_entry())
symtab_xindex->add(lv.output_symtab_index(), st_shndx);
if (lv.has_output_dynsym_entry())
dynsym_xindex->add(lv.output_dynsym_index(), st_shndx);
st_shndx = elfcpp::SHN_XINDEX;
}
}
// Write the symbol to the output symbol table.
if (lv.has_output_symtab_entry())
{
elfcpp::Sym_write<size, big_endian> osym(ov);
gold_assert(isym.get_st_name() < strtab_size);
const char* name = pnames + isym.get_st_name();
osym.put_st_name(sympool->get_offset(name));
osym.put_st_value(this->local_values_[i].value(this, 0));
osym.put_st_size(isym.get_st_size());
osym.put_st_info(isym.get_st_info());
osym.put_st_other(isym.get_st_other());
osym.put_st_shndx(st_shndx);
ov += sym_size;
}
// Write the symbol to the output dynamic symbol table.
if (lv.has_output_dynsym_entry())
{
gold_assert(dyn_ov < dyn_oview + dyn_output_size);
elfcpp::Sym_write<size, big_endian> osym(dyn_ov);
gold_assert(isym.get_st_name() < strtab_size);
const char* name = pnames + isym.get_st_name();
osym.put_st_name(dynpool->get_offset(name));
osym.put_st_value(this->local_values_[i].value(this, 0));
osym.put_st_size(isym.get_st_size());
osym.put_st_info(isym.get_st_info());
osym.put_st_other(isym.get_st_other());
osym.put_st_shndx(st_shndx);
dyn_ov += sym_size;
}
}
if (output_size > 0)
{
gold_assert(ov - oview == output_size);
of->write_output_view(this->local_symbol_offset_, output_size, oview);
}
if (dyn_output_size > 0)
{
gold_assert(dyn_ov - dyn_oview == dyn_output_size);
of->write_output_view(this->local_dynsym_offset_, dyn_output_size,
dyn_oview);
}
}
// Set *INFO to symbolic information about the offset OFFSET in the
// section SHNDX. Return true if we found something, false if we
// found nothing.
template<int size, bool big_endian>
bool
Sized_relobj<size, big_endian>::get_symbol_location_info(
unsigned int shndx,
off_t offset,
Symbol_location_info* info)
{
if (this->symtab_shndx_ == 0)
return false;
section_size_type symbols_size;
const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
&symbols_size,
false);
unsigned int symbol_names_shndx =
this->adjust_shndx(this->section_link(this->symtab_shndx_));
section_size_type names_size;
const unsigned char* symbol_names_u =
this->section_contents(symbol_names_shndx, &names_size, false);
const char* symbol_names = reinterpret_cast<const char*>(symbol_names_u);
const int sym_size = This::sym_size;
const size_t count = symbols_size / sym_size;
const unsigned char* p = symbols;
for (size_t i = 0; i < count; ++i, p += sym_size)
{
elfcpp::Sym<size, big_endian> sym(p);
if (sym.get_st_type() == elfcpp::STT_FILE)
{
if (sym.get_st_name() >= names_size)
info->source_file = "(invalid)";
else
info->source_file = symbol_names + sym.get_st_name();
continue;
}
bool is_ordinary;
unsigned int st_shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
&is_ordinary);
if (is_ordinary
&& st_shndx == shndx
&& static_cast<off_t>(sym.get_st_value()) <= offset
&& (static_cast<off_t>(sym.get_st_value() + sym.get_st_size())
> offset))
{
if (sym.get_st_name() > names_size)
info->enclosing_symbol_name = "(invalid)";
else
{
info->enclosing_symbol_name = symbol_names + sym.get_st_name();
if (parameters->options().do_demangle())
{
char* demangled_name = cplus_demangle(
info->enclosing_symbol_name.c_str(),
DMGL_ANSI | DMGL_PARAMS);
if (demangled_name != NULL)
{
info->enclosing_symbol_name.assign(demangled_name);
free(demangled_name);
}
}
}
return true;
}
}
return false;
}
// Look for a kept section corresponding to the given discarded section,
// and return its output address. This is used only for relocations in
// debugging sections. If we can't find the kept section, return 0.
template<int size, bool big_endian>
typename Sized_relobj<size, big_endian>::Address
Sized_relobj<size, big_endian>::map_to_kept_section(
unsigned int shndx,
bool* found) const
{
Relobj* kept_object;
unsigned int kept_shndx;
if (this->get_kept_comdat_section(shndx, &kept_object, &kept_shndx))
{
Sized_relobj<size, big_endian>* kept_relobj =
static_cast<Sized_relobj<size, big_endian>*>(kept_object);
Output_section* os = kept_relobj->output_section(kept_shndx);
Address offset = kept_relobj->get_output_section_offset(kept_shndx);
if (os != NULL && offset != invalid_address)
{
*found = true;
return os->address() + offset;
}
}
*found = false;
return 0;
}
// Get symbol counts.
template<int size, bool big_endian>
void
Sized_relobj<size, big_endian>::do_get_global_symbol_counts(
const Symbol_table*,
size_t* defined,
size_t* used) const
{
*defined = this->defined_count_;
size_t count = 0;
for (Symbols::const_iterator p = this->symbols_.begin();
p != this->symbols_.end();
++p)
if (*p != NULL
&& (*p)->source() == Symbol::FROM_OBJECT
&& (*p)->object() == this
&& (*p)->is_defined())
++count;
*used = count;
}
// Input_objects methods.
// Add a regular relocatable object to the list. Return false if this
// object should be ignored.
bool
Input_objects::add_object(Object* obj)
{
// Print the filename if the -t/--trace option is selected.
if (parameters->options().trace())
gold_info("%s", obj->name().c_str());
if (!obj->is_dynamic())
this->relobj_list_.push_back(static_cast<Relobj*>(obj));
else
{
// See if this is a duplicate SONAME.
Dynobj* dynobj = static_cast<Dynobj*>(obj);
const char* soname = dynobj->soname();
std::pair<Unordered_set<std::string>::iterator, bool> ins =
this->sonames_.insert(soname);
if (!ins.second)
{
// We have already seen a dynamic object with this soname.
return false;
}
this->dynobj_list_.push_back(dynobj);
}
// Add this object to the cross-referencer if requested.
if (parameters->options().user_set_print_symbol_counts()
|| parameters->options().cref())
{
if (this->cref_ == NULL)
this->cref_ = new Cref();
this->cref_->add_object(obj);
}
return true;
}
// For each dynamic object, record whether we've seen all of its
// explicit dependencies.
void
Input_objects::check_dynamic_dependencies() const
{
bool issued_copy_dt_needed_error = false;
for (Dynobj_list::const_iterator p = this->dynobj_list_.begin();
p != this->dynobj_list_.end();
++p)
{
const Dynobj::Needed& needed((*p)->needed());
bool found_all = true;
Dynobj::Needed::const_iterator pneeded;
for (pneeded = needed.begin(); pneeded != needed.end(); ++pneeded)
{
if (this->sonames_.find(*pneeded) == this->sonames_.end())
{
found_all = false;
break;
}
}
(*p)->set_has_unknown_needed_entries(!found_all);
// --copy-dt-needed-entries aka --add-needed is a GNU ld option
// that gold does not support. However, they cause no trouble
// unless there is a DT_NEEDED entry that we don't know about;
// warn only in that case.
if (!found_all
&& !issued_copy_dt_needed_error
&& (parameters->options().copy_dt_needed_entries()
|| parameters->options().add_needed()))
{
const char* optname;
if (parameters->options().copy_dt_needed_entries())
optname = "--copy-dt-needed-entries";
else
optname = "--add-needed";
gold_error(_("%s is not supported but is required for %s in %s"),
optname, (*pneeded).c_str(), (*p)->name().c_str());
issued_copy_dt_needed_error = true;
}
}
}
// Start processing an archive.
void
Input_objects::archive_start(Archive* archive)
{
if (parameters->options().user_set_print_symbol_counts()
|| parameters->options().cref())
{
if (this->cref_ == NULL)
this->cref_ = new Cref();
this->cref_->add_archive_start(archive);
}
}
// Stop processing an archive.
void
Input_objects::archive_stop(Archive* archive)
{
if (parameters->options().user_set_print_symbol_counts()
|| parameters->options().cref())
this->cref_->add_archive_stop(archive);
}
// Print symbol counts
void
Input_objects::print_symbol_counts(const Symbol_table* symtab) const
{
if (parameters->options().user_set_print_symbol_counts()
&& this->cref_ != NULL)
this->cref_->print_symbol_counts(symtab);
}
// Print a cross reference table.
void
Input_objects::print_cref(const Symbol_table* symtab, FILE* f) const
{
if (parameters->options().cref() && this->cref_ != NULL)
this->cref_->print_cref(symtab, f);
}
// Relocate_info methods.
// Return a string describing the location of a relocation. This is
// only used in error messages.
template<int size, bool big_endian>
std::string
Relocate_info<size, big_endian>::location(size_t, off_t offset) const
{
// See if we can get line-number information from debugging sections.
std::string filename;
std::string file_and_lineno; // Better than filename-only, if available.
Sized_dwarf_line_info<size, big_endian> line_info(this->object);
// This will be "" if we failed to parse the debug info for any reason.
file_and_lineno = line_info.addr2line(this->data_shndx, offset);
std::string ret(this->object->name());
ret += ':';
Symbol_location_info info;
if (this->object->get_symbol_location_info(this->data_shndx, offset, &info))
{
ret += " in function ";
ret += info.enclosing_symbol_name;
ret += ":";
filename = info.source_file;
}
if (!file_and_lineno.empty())
ret += file_and_lineno;
else
{
if (!filename.empty())
ret += filename;
ret += "(";
ret += this->object->section_name(this->data_shndx);
char buf[100];
// Offsets into sections have to be positive.
snprintf(buf, sizeof(buf), "+0x%lx", static_cast<long>(offset));
ret += buf;
ret += ")";
}
return ret;
}
} // End namespace gold.
namespace
{
using namespace gold;
// Read an ELF file with the header and return the appropriate
// instance of Object.
template<int size, bool big_endian>
Object*
make_elf_sized_object(const std::string& name, Input_file* input_file,
off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr,
bool* punconfigured)
{
Target* target = select_target(ehdr.get_e_machine(), size, big_endian,
ehdr.get_e_ident()[elfcpp::EI_OSABI],
ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
if (target == NULL)
gold_fatal(_("%s: unsupported ELF machine number %d"),
name.c_str(), ehdr.get_e_machine());
if (!parameters->target_valid())
set_parameters_target(target);
else if (target != ¶meters->target())
{
if (punconfigured != NULL)
*punconfigured = true;
else
gold_error(_("%s: incompatible target"), name.c_str());
return NULL;
}
return target->make_elf_object<size, big_endian>(name, input_file, offset,
ehdr);
}
} // End anonymous namespace.
namespace gold
{
// Return whether INPUT_FILE is an ELF object.
bool
is_elf_object(Input_file* input_file, off_t offset,
const unsigned char** start, int *read_size)
{
off_t filesize = input_file->file().filesize();
int want = elfcpp::Elf_recognizer::max_header_size;
if (filesize - offset < want)
want = filesize - offset;
const unsigned char* p = input_file->file().get_view(offset, 0, want,
true, false);
*start = p;
*read_size = want;
return elfcpp::Elf_recognizer::is_elf_file(p, want);
}
// Read an ELF file and return the appropriate instance of Object.
Object*
make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
const unsigned char* p, section_offset_type bytes,
bool* punconfigured)
{
if (punconfigured != NULL)
*punconfigured = false;
std::string error;
bool big_endian = false;
int size = 0;
if (!elfcpp::Elf_recognizer::is_valid_header(p, bytes, &size,
&big_endian, &error))
{
gold_error(_("%s: %s"), name.c_str(), error.c_str());
return NULL;
}
if (size == 32)
{
if (big_endian)
{
#ifdef HAVE_TARGET_32_BIG
elfcpp::Ehdr<32, true> ehdr(p);
return make_elf_sized_object<32, true>(name, input_file,
offset, ehdr, punconfigured);
#else
if (punconfigured != NULL)
*punconfigured = true;
else
gold_error(_("%s: not configured to support "
"32-bit big-endian object"),
name.c_str());
return NULL;
#endif
}
else
{
#ifdef HAVE_TARGET_32_LITTLE
elfcpp::Ehdr<32, false> ehdr(p);
return make_elf_sized_object<32, false>(name, input_file,
offset, ehdr, punconfigured);
#else
if (punconfigured != NULL)
*punconfigured = true;
else
gold_error(_("%s: not configured to support "
"32-bit little-endian object"),
name.c_str());
return NULL;
#endif
}
}
else if (size == 64)
{
if (big_endian)
{
#ifdef HAVE_TARGET_64_BIG
elfcpp::Ehdr<64, true> ehdr(p);
return make_elf_sized_object<64, true>(name, input_file,
offset, ehdr, punconfigured);
#else
if (punconfigured != NULL)
*punconfigured = true;
else
gold_error(_("%s: not configured to support "
"64-bit big-endian object"),
name.c_str());
return NULL;
#endif
}
else
{
#ifdef HAVE_TARGET_64_LITTLE
elfcpp::Ehdr<64, false> ehdr(p);
return make_elf_sized_object<64, false>(name, input_file,
offset, ehdr, punconfigured);
#else
if (punconfigured != NULL)
*punconfigured = true;
else
gold_error(_("%s: not configured to support "
"64-bit little-endian object"),
name.c_str());
return NULL;
#endif
}
}
else
gold_unreachable();
}
// Instantiate the templates we need.
#ifdef HAVE_TARGET_32_LITTLE
template
void
Object::read_section_data<32, false>(elfcpp::Elf_file<32, false, Object>*,
Read_symbols_data*);
#endif
#ifdef HAVE_TARGET_32_BIG
template
void
Object::read_section_data<32, true>(elfcpp::Elf_file<32, true, Object>*,
Read_symbols_data*);
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
void
Object::read_section_data<64, false>(elfcpp::Elf_file<64, false, Object>*,
Read_symbols_data*);
#endif
#ifdef HAVE_TARGET_64_BIG
template
void
Object::read_section_data<64, true>(elfcpp::Elf_file<64, true, Object>*,
Read_symbols_data*);
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
class Sized_relobj<32, false>;
#endif
#ifdef HAVE_TARGET_32_BIG
template
class Sized_relobj<32, true>;
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
class Sized_relobj<64, false>;
#endif
#ifdef HAVE_TARGET_64_BIG
template
class Sized_relobj<64, true>;
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
struct Relocate_info<32, false>;
#endif
#ifdef HAVE_TARGET_32_BIG
template
struct Relocate_info<32, true>;
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
struct Relocate_info<64, false>;
#endif
#ifdef HAVE_TARGET_64_BIG
template
struct Relocate_info<64, true>;
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
void
Xindex::initialize_symtab_xindex<32, false>(Object*, unsigned int);
template
void
Xindex::read_symtab_xindex<32, false>(Object*, unsigned int,
const unsigned char*);
#endif
#ifdef HAVE_TARGET_32_BIG
template
void
Xindex::initialize_symtab_xindex<32, true>(Object*, unsigned int);
template
void
Xindex::read_symtab_xindex<32, true>(Object*, unsigned int,
const unsigned char*);
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
void
Xindex::initialize_symtab_xindex<64, false>(Object*, unsigned int);
template
void
Xindex::read_symtab_xindex<64, false>(Object*, unsigned int,
const unsigned char*);
#endif
#ifdef HAVE_TARGET_64_BIG
template
void
Xindex::initialize_symtab_xindex<64, true>(Object*, unsigned int);
template
void
Xindex::read_symtab_xindex<64, true>(Object*, unsigned int,
const unsigned char*);
#endif
} // End namespace gold.
|