Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

   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
/* .eh_frame section optimization.
   Copyright (C) 2001-2018 Free Software Foundation, Inc.
   Written by Jakub Jelinek <jakub@redhat.com>.

   This file is part of BFD, the Binary File Descriptor library.

   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 "sysdep.h"
#include "bfd.h"
#include "libbfd.h"
#include "elf-bfd.h"
#include "dwarf2.h"

#define EH_FRAME_HDR_SIZE 8

struct cie
{
  unsigned int length;
  unsigned int hash;
  unsigned char version;
  unsigned char local_personality;
  char augmentation[20];
  bfd_vma code_align;
  bfd_signed_vma data_align;
  bfd_vma ra_column;
  bfd_vma augmentation_size;
  union {
    struct elf_link_hash_entry *h;
    struct {
      unsigned int bfd_id;
      unsigned int index;
    } sym;
    unsigned int reloc_index;
  } personality;
  struct eh_cie_fde *cie_inf;
  unsigned char per_encoding;
  unsigned char lsda_encoding;
  unsigned char fde_encoding;
  unsigned char initial_insn_length;
  unsigned char can_make_lsda_relative;
  unsigned char initial_instructions[50];
};



/* If *ITER hasn't reached END yet, read the next byte into *RESULT and
   move onto the next byte.  Return true on success.  */

static inline bfd_boolean
read_byte (bfd_byte **iter, bfd_byte *end, unsigned char *result)
{
  if (*iter >= end)
    return FALSE;
  *result = *((*iter)++);
  return TRUE;
}

/* Move *ITER over LENGTH bytes, or up to END, whichever is closer.
   Return true it was possible to move LENGTH bytes.  */

static inline bfd_boolean
skip_bytes (bfd_byte **iter, bfd_byte *end, bfd_size_type length)
{
  if ((bfd_size_type) (end - *iter) < length)
    {
      *iter = end;
      return FALSE;
    }
  *iter += length;
  return TRUE;
}

/* Move *ITER over an leb128, stopping at END.  Return true if the end
   of the leb128 was found.  */

static bfd_boolean
skip_leb128 (bfd_byte **iter, bfd_byte *end)
{
  unsigned char byte;
  do
    if (!read_byte (iter, end, &byte))
      return FALSE;
  while (byte & 0x80);
  return TRUE;
}

/* Like skip_leb128, but treat the leb128 as an unsigned value and
   store it in *VALUE.  */

static bfd_boolean
read_uleb128 (bfd_byte **iter, bfd_byte *end, bfd_vma *value)
{
  bfd_byte *start, *p;

  start = *iter;
  if (!skip_leb128 (iter, end))
    return FALSE;

  p = *iter;
  *value = *--p;
  while (p > start)
    *value = (*value << 7) | (*--p & 0x7f);

  return TRUE;
}

/* Like read_uleb128, but for signed values.  */

static bfd_boolean
read_sleb128 (bfd_byte **iter, bfd_byte *end, bfd_signed_vma *value)
{
  bfd_byte *start, *p;

  start = *iter;
  if (!skip_leb128 (iter, end))
    return FALSE;

  p = *iter;
  *value = ((*--p & 0x7f) ^ 0x40) - 0x40;
  while (p > start)
    *value = (*value << 7) | (*--p & 0x7f);

  return TRUE;
}

/* Return 0 if either encoding is variable width, or not yet known to bfd.  */

static
int get_DW_EH_PE_width (int encoding, int ptr_size)
{
  /* DW_EH_PE_ values of 0x60 and 0x70 weren't defined at the time .eh_frame
     was added to bfd.  */
  if ((encoding & 0x60) == 0x60)
    return 0;

  switch (encoding & 7)
    {
    case DW_EH_PE_udata2: return 2;
    case DW_EH_PE_udata4: return 4;
    case DW_EH_PE_udata8: return 8;
    case DW_EH_PE_absptr: return ptr_size;
    default:
      break;
    }

  return 0;
}

#define get_DW_EH_PE_signed(encoding) (((encoding) & DW_EH_PE_signed) != 0)

/* Read a width sized value from memory.  */

static bfd_vma
read_value (bfd *abfd, bfd_byte *buf, int width, int is_signed)
{
  bfd_vma value;

  switch (width)
    {
    case 2:
      if (is_signed)
	value = bfd_get_signed_16 (abfd, buf);
      else
	value = bfd_get_16 (abfd, buf);
      break;
    case 4:
      if (is_signed)
	value = bfd_get_signed_32 (abfd, buf);
      else
	value = bfd_get_32 (abfd, buf);
      break;
    case 8:
      if (is_signed)
	value = bfd_get_signed_64 (abfd, buf);
      else
	value = bfd_get_64 (abfd, buf);
      break;
    default:
      BFD_FAIL ();
      return 0;
    }

  return value;
}

/* Store a width sized value to memory.  */

static void
write_value (bfd *abfd, bfd_byte *buf, bfd_vma value, int width)
{
  switch (width)
    {
    case 2: bfd_put_16 (abfd, value, buf); break;
    case 4: bfd_put_32 (abfd, value, buf); break;
    case 8: bfd_put_64 (abfd, value, buf); break;
    default: BFD_FAIL ();
    }
}

/* Return one if C1 and C2 CIEs can be merged.  */

static int
cie_eq (const void *e1, const void *e2)
{
  const struct cie *c1 = (const struct cie *) e1;
  const struct cie *c2 = (const struct cie *) e2;

  if (c1->hash == c2->hash
      && c1->length == c2->length
      && c1->version == c2->version
      && c1->local_personality == c2->local_personality
      && strcmp (c1->augmentation, c2->augmentation) == 0
      && strcmp (c1->augmentation, "eh") != 0
      && c1->code_align == c2->code_align
      && c1->data_align == c2->data_align
      && c1->ra_column == c2->ra_column
      && c1->augmentation_size == c2->augmentation_size
      && memcmp (&c1->personality, &c2->personality,
		 sizeof (c1->personality)) == 0
      && (c1->cie_inf->u.cie.u.sec->output_section
	  == c2->cie_inf->u.cie.u.sec->output_section)
      && c1->per_encoding == c2->per_encoding
      && c1->lsda_encoding == c2->lsda_encoding
      && c1->fde_encoding == c2->fde_encoding
      && c1->initial_insn_length == c2->initial_insn_length
      && c1->initial_insn_length <= sizeof (c1->initial_instructions)
      && memcmp (c1->initial_instructions,
		 c2->initial_instructions,
		 c1->initial_insn_length) == 0)
    return 1;

  return 0;
}

static hashval_t
cie_hash (const void *e)
{
  const struct cie *c = (const struct cie *) e;
  return c->hash;
}

static hashval_t
cie_compute_hash (struct cie *c)
{
  hashval_t h = 0;
  size_t len;
  h = iterative_hash_object (c->length, h);
  h = iterative_hash_object (c->version, h);
  h = iterative_hash (c->augmentation, strlen (c->augmentation) + 1, h);
  h = iterative_hash_object (c->code_align, h);
  h = iterative_hash_object (c->data_align, h);
  h = iterative_hash_object (c->ra_column, h);
  h = iterative_hash_object (c->augmentation_size, h);
  h = iterative_hash_object (c->personality, h);
  h = iterative_hash_object (c->cie_inf->u.cie.u.sec->output_section, h);
  h = iterative_hash_object (c->per_encoding, h);
  h = iterative_hash_object (c->lsda_encoding, h);
  h = iterative_hash_object (c->fde_encoding, h);
  h = iterative_hash_object (c->initial_insn_length, h);
  len = c->initial_insn_length;
  if (len > sizeof (c->initial_instructions))
    len = sizeof (c->initial_instructions);
  h = iterative_hash (c->initial_instructions, len, h);
  c->hash = h;
  return h;
}

/* Return the number of extra bytes that we'll be inserting into
   ENTRY's augmentation string.  */

static INLINE unsigned int
extra_augmentation_string_bytes (struct eh_cie_fde *entry)
{
  unsigned int size = 0;
  if (entry->cie)
    {
      if (entry->add_augmentation_size)
	size++;
      if (entry->u.cie.add_fde_encoding)
	size++;
    }
  return size;
}

/* Likewise ENTRY's augmentation data.  */

static INLINE unsigned int
extra_augmentation_data_bytes (struct eh_cie_fde *entry)
{
  unsigned int size = 0;
  if (entry->add_augmentation_size)
    size++;
  if (entry->cie && entry->u.cie.add_fde_encoding)
    size++;
  return size;
}

/* Return the size that ENTRY will have in the output.  */

static unsigned int
size_of_output_cie_fde (struct eh_cie_fde *entry)
{
  if (entry->removed)
    return 0;
  if (entry->size == 4)
    return 4;
  return (entry->size
	  + extra_augmentation_string_bytes (entry)
	  + extra_augmentation_data_bytes (entry));
}

/* Return the offset of the FDE or CIE after ENT.  */

static unsigned int
next_cie_fde_offset (const struct eh_cie_fde *ent,
		     const struct eh_cie_fde *last,
		     const asection *sec)
{
  while (++ent < last)
    {
      if (!ent->removed)
	return ent->new_offset;
    }
  return sec->size;
}

/* Assume that the bytes between *ITER and END are CFA instructions.
   Try to move *ITER past the first instruction and return true on
   success.  ENCODED_PTR_WIDTH gives the width of pointer entries.  */

static bfd_boolean
skip_cfa_op (bfd_byte **iter, bfd_byte *end, unsigned int encoded_ptr_width)
{
  bfd_byte op;
  bfd_vma length;

  if (!read_byte (iter, end, &op))
    return FALSE;

  switch (op & 0xc0 ? op & 0xc0 : op)
    {
    case DW_CFA_nop:
    case DW_CFA_advance_loc:
    case DW_CFA_restore:
    case DW_CFA_remember_state:
    case DW_CFA_restore_state:
    case DW_CFA_GNU_window_save:
      /* No arguments.  */
      return TRUE;

    case DW_CFA_offset:
    case DW_CFA_restore_extended:
    case DW_CFA_undefined:
    case DW_CFA_same_value:
    case DW_CFA_def_cfa_register:
    case DW_CFA_def_cfa_offset:
    case DW_CFA_def_cfa_offset_sf:
    case DW_CFA_GNU_args_size:
      /* One leb128 argument.  */
      return skip_leb128 (iter, end);

    case DW_CFA_val_offset:
    case DW_CFA_val_offset_sf:
    case DW_CFA_offset_extended:
    case DW_CFA_register:
    case DW_CFA_def_cfa:
    case DW_CFA_offset_extended_sf:
    case DW_CFA_GNU_negative_offset_extended:
    case DW_CFA_def_cfa_sf:
      /* Two leb128 arguments.  */
      return (skip_leb128 (iter, end)
	      && skip_leb128 (iter, end));

    case DW_CFA_def_cfa_expression:
      /* A variable-length argument.  */
      return (read_uleb128 (iter, end, &length)
	      && skip_bytes (iter, end, length));

    case DW_CFA_expression:
    case DW_CFA_val_expression:
      /* A leb128 followed by a variable-length argument.  */
      return (skip_leb128 (iter, end)
	      && read_uleb128 (iter, end, &length)
	      && skip_bytes (iter, end, length));

    case DW_CFA_set_loc:
      return skip_bytes (iter, end, encoded_ptr_width);

    case DW_CFA_advance_loc1:
      return skip_bytes (iter, end, 1);

    case DW_CFA_advance_loc2:
      return skip_bytes (iter, end, 2);

    case DW_CFA_advance_loc4:
      return skip_bytes (iter, end, 4);

    case DW_CFA_MIPS_advance_loc8:
      return skip_bytes (iter, end, 8);

    default:
      return FALSE;
    }
}

/* Try to interpret the bytes between BUF and END as CFA instructions.
   If every byte makes sense, return a pointer to the first DW_CFA_nop
   padding byte, or END if there is no padding.  Return null otherwise.
   ENCODED_PTR_WIDTH is as for skip_cfa_op.  */

static bfd_byte *
skip_non_nops (bfd_byte *buf, bfd_byte *end, unsigned int encoded_ptr_width,
	       unsigned int *set_loc_count)
{
  bfd_byte *last;

  last = buf;
  while (buf < end)
    if (*buf == DW_CFA_nop)
      buf++;
    else
      {
	if (*buf == DW_CFA_set_loc)
	  ++*set_loc_count;
	if (!skip_cfa_op (&buf, end, encoded_ptr_width))
	  return 0;
	last = buf;
      }
  return last;
}

/* Convert absolute encoding ENCODING into PC-relative form.
   SIZE is the size of a pointer.  */

static unsigned char
make_pc_relative (unsigned char encoding, unsigned int ptr_size)
{
  if ((encoding & 0x7f) == DW_EH_PE_absptr)
    switch (ptr_size)
      {
      case 2:
	encoding |= DW_EH_PE_sdata2;
	break;
      case 4:
	encoding |= DW_EH_PE_sdata4;
	break;
      case 8:
	encoding |= DW_EH_PE_sdata8;
	break;
      }
  return encoding | DW_EH_PE_pcrel;
}

/*  Examine each .eh_frame_entry section and discard those
    those that are marked SEC_EXCLUDE.  */

static void
bfd_elf_discard_eh_frame_entry (struct eh_frame_hdr_info *hdr_info)
{
  unsigned int i;
  for (i = 0; i < hdr_info->array_count; i++)
    {
      if (hdr_info->u.compact.entries[i]->flags & SEC_EXCLUDE)
	{
	  unsigned int j;
	  for (j = i + 1; j < hdr_info->array_count; j++)
	    hdr_info->u.compact.entries[j-1] = hdr_info->u.compact.entries[j];

	  hdr_info->array_count--;
	  hdr_info->u.compact.entries[hdr_info->array_count] = NULL;
	  i--;
	}
    }
}

/* Add a .eh_frame_entry section.  */

static void
bfd_elf_record_eh_frame_entry (struct eh_frame_hdr_info *hdr_info,
				 asection *sec)
{
  if (hdr_info->array_count == hdr_info->u.compact.allocated_entries)
    {
      if (hdr_info->u.compact.allocated_entries == 0)
	{
	  hdr_info->frame_hdr_is_compact = TRUE;
	  hdr_info->u.compact.allocated_entries = 2;
	  hdr_info->u.compact.entries =
	    bfd_malloc (hdr_info->u.compact.allocated_entries
			* sizeof (hdr_info->u.compact.entries[0]));
	}
      else
	{
	  hdr_info->u.compact.allocated_entries *= 2;
	  hdr_info->u.compact.entries =
	    bfd_realloc (hdr_info->u.compact.entries,
			 hdr_info->u.compact.allocated_entries
			   * sizeof (hdr_info->u.compact.entries[0]));
	}

      BFD_ASSERT (hdr_info->u.compact.entries);
    }

  hdr_info->u.compact.entries[hdr_info->array_count++] = sec;
}

/* Parse a .eh_frame_entry section.  Figure out which text section it
   references.  */

bfd_boolean
_bfd_elf_parse_eh_frame_entry (struct bfd_link_info *info,
			       asection *sec, struct elf_reloc_cookie *cookie)
{
  struct elf_link_hash_table *htab;
  struct eh_frame_hdr_info *hdr_info;
  unsigned long r_symndx;
  asection *text_sec;

  htab = elf_hash_table (info);
  hdr_info = &htab->eh_info;

  if (sec->size == 0
      || sec->sec_info_type != SEC_INFO_TYPE_NONE)
    {
      return TRUE;
    }

  if (sec->output_section && bfd_is_abs_section (sec->output_section))
    {
      /* At least one of the sections is being discarded from the
	 link, so we should just ignore them.  */
      return TRUE;
    }

  if (cookie->rel == cookie->relend)
    return FALSE;

  /* The first relocation is the function start.  */
  r_symndx = cookie->rel->r_info >> cookie->r_sym_shift;
  if (r_symndx == STN_UNDEF)
    return FALSE;

  text_sec = _bfd_elf_section_for_symbol (cookie, r_symndx, FALSE);

  if (text_sec == NULL)
    return FALSE;

  elf_section_eh_frame_entry (text_sec) = sec;
  if (text_sec->output_section
      && bfd_is_abs_section (text_sec->output_section))
    sec->flags |= SEC_EXCLUDE;

  sec->sec_info_type = SEC_INFO_TYPE_EH_FRAME_ENTRY;
  elf_section_data (sec)->sec_info = text_sec;
  bfd_elf_record_eh_frame_entry (hdr_info, sec);
  return TRUE;
}

/* Try to parse .eh_frame section SEC, which belongs to ABFD.  Store the
   information in the section's sec_info field on success.  COOKIE
   describes the relocations in SEC.  */

void
_bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info,
			 asection *sec, struct elf_reloc_cookie *cookie)
{
#define REQUIRE(COND)					\
  do							\
    if (!(COND))					\
      goto free_no_table;				\
  while (0)

  bfd_byte *ehbuf = NULL, *buf, *end;
  bfd_byte *last_fde;
  struct eh_cie_fde *this_inf;
  unsigned int hdr_length, hdr_id;
  unsigned int cie_count;
  struct cie *cie, *local_cies = NULL;
  struct elf_link_hash_table *htab;
  struct eh_frame_hdr_info *hdr_info;
  struct eh_frame_sec_info *sec_info = NULL;
  unsigned int ptr_size;
  unsigned int num_cies;
  unsigned int num_entries;
  elf_gc_mark_hook_fn gc_mark_hook;

  htab = elf_hash_table (info);
  hdr_info = &htab->eh_info;

  if (sec->size == 0
      || sec->sec_info_type != SEC_INFO_TYPE_NONE)
    {
      /* This file does not contain .eh_frame information.  */
      return;
    }

  if (bfd_is_abs_section (sec->output_section))
    {
      /* At least one of the sections is being discarded from the
	 link, so we should just ignore them.  */
      return;
    }

  /* Read the frame unwind information from abfd.  */

  REQUIRE (bfd_malloc_and_get_section (abfd, sec, &ehbuf));

  /* If .eh_frame section size doesn't fit into int, we cannot handle
     it (it would need to use 64-bit .eh_frame format anyway).  */
  REQUIRE (sec->size == (unsigned int) sec->size);

  ptr_size = (get_elf_backend_data (abfd)
	      ->elf_backend_eh_frame_address_size (abfd, sec));
  REQUIRE (ptr_size != 0);

  /* Go through the section contents and work out how many FDEs and
     CIEs there are.  */
  buf = ehbuf;
  end = ehbuf + sec->size;
  num_cies = 0;
  num_entries = 0;
  while (buf != end)
    {
      num_entries++;

      /* Read the length of the entry.  */
      REQUIRE (skip_bytes (&buf, end, 4));
      hdr_length = bfd_get_32 (abfd, buf - 4);

      /* 64-bit .eh_frame is not supported.  */
      REQUIRE (hdr_length != 0xffffffff);
      if (hdr_length == 0)
	break;

      REQUIRE (skip_bytes (&buf, end, 4));
      hdr_id = bfd_get_32 (abfd, buf - 4);
      if (hdr_id == 0)
	num_cies++;

      REQUIRE (skip_bytes (&buf, end, hdr_length - 4));
    }

  sec_info = (struct eh_frame_sec_info *)
      bfd_zmalloc (sizeof (struct eh_frame_sec_info)
		   + (num_entries - 1) * sizeof (struct eh_cie_fde));
  REQUIRE (sec_info);

  /* We need to have a "struct cie" for each CIE in this section.  */
  if (num_cies)
    {
      local_cies = (struct cie *) bfd_zmalloc (num_cies * sizeof (*local_cies));
      REQUIRE (local_cies);
    }

  /* FIXME: octets_per_byte.  */
#define ENSURE_NO_RELOCS(buf)				\
  while (cookie->rel < cookie->relend			\
	 && (cookie->rel->r_offset			\
	     < (bfd_size_type) ((buf) - ehbuf)))	\
    {							\
      REQUIRE (cookie->rel->r_info == 0);		\
      cookie->rel++;					\
    }

  /* FIXME: octets_per_byte.  */
#define SKIP_RELOCS(buf)				\
  while (cookie->rel < cookie->relend			\
	 && (cookie->rel->r_offset			\
	     < (bfd_size_type) ((buf) - ehbuf)))	\
    cookie->rel++

  /* FIXME: octets_per_byte.  */
#define GET_RELOC(buf)					\
  ((cookie->rel < cookie->relend			\
    && (cookie->rel->r_offset				\
	== (bfd_size_type) ((buf) - ehbuf)))		\
   ? cookie->rel : NULL)

  buf = ehbuf;
  cie_count = 0;
  gc_mark_hook = get_elf_backend_data (abfd)->gc_mark_hook;
  while ((bfd_size_type) (buf - ehbuf) != sec->size)
    {
      char *aug;
      bfd_byte *start, *insns, *insns_end;
      bfd_size_type length;
      unsigned int set_loc_count;

      this_inf = sec_info->entry + sec_info->count;
      last_fde = buf;

      /* Read the length of the entry.  */
      REQUIRE (skip_bytes (&buf, ehbuf + sec->size, 4));
      hdr_length = bfd_get_32 (abfd, buf - 4);

      /* The CIE/FDE must be fully contained in this input section.  */
      REQUIRE ((bfd_size_type) (buf - ehbuf) + hdr_length <= sec->size);
      end = buf + hdr_length;

      this_inf->offset = last_fde - ehbuf;
      this_inf->size = 4 + hdr_length;
      this_inf->reloc_index = cookie->rel - cookie->rels;

      if (hdr_length == 0)
	{
	  /* A zero-length CIE should only be found at the end of
	     the section, but allow multiple terminators.  */
	  while (skip_bytes (&buf, ehbuf + sec->size, 4))
	    REQUIRE (bfd_get_32 (abfd, buf - 4) == 0);
	  REQUIRE ((bfd_size_type) (buf - ehbuf) == sec->size);
	  ENSURE_NO_RELOCS (buf);
	  sec_info->count++;
	  break;
	}

      REQUIRE (skip_bytes (&buf, end, 4));
      hdr_id = bfd_get_32 (abfd, buf - 4);

      if (hdr_id == 0)
	{
	  unsigned int initial_insn_length;

	  /* CIE  */
	  this_inf->cie = 1;

	  /* Point CIE to one of the section-local cie structures.  */
	  cie = local_cies + cie_count++;

	  cie->cie_inf = this_inf;
	  cie->length = hdr_length;
	  start = buf;
	  REQUIRE (read_byte (&buf, end, &cie->version));

	  /* Cannot handle unknown versions.  */
	  REQUIRE (cie->version == 1
		   || cie->version == 3
		   || cie->version == 4);
	  REQUIRE (strlen ((char *) buf) < sizeof (cie->augmentation));

	  strcpy (cie->augmentation, (char *) buf);
	  buf = (bfd_byte *) strchr ((char *) buf, '\0') + 1;
	  this_inf->u.cie.aug_str_len = buf - start - 1;
	  ENSURE_NO_RELOCS (buf);
	  if (buf[0] == 'e' && buf[1] == 'h')
	    {
	      /* GCC < 3.0 .eh_frame CIE */
	      /* We cannot merge "eh" CIEs because __EXCEPTION_TABLE__
		 is private to each CIE, so we don't need it for anything.
		 Just skip it.  */
	      REQUIRE (skip_bytes (&buf, end, ptr_size));
	      SKIP_RELOCS (buf);
	    }
	  if (cie->version >= 4)
	    {
	      REQUIRE (buf + 1 < end);
	      REQUIRE (buf[0] == ptr_size);
	      REQUIRE (buf[1] == 0);
	      buf += 2;
	    }
	  REQUIRE (read_uleb128 (&buf, end, &cie->code_align));
	  REQUIRE (read_sleb128 (&buf, end, &cie->data_align));
	  if (cie->version == 1)
	    {
	      REQUIRE (buf < end);
	      cie->ra_column = *buf++;
	    }
	  else
	    REQUIRE (read_uleb128 (&buf, end, &cie->ra_column));
	  ENSURE_NO_RELOCS (buf);
	  cie->lsda_encoding = DW_EH_PE_omit;
	  cie->fde_encoding = DW_EH_PE_omit;
	  cie->per_encoding = DW_EH_PE_omit;
	  aug = cie->augmentation;
	  if (aug[0] != 'e' || aug[1] != 'h')
	    {
	      if (*aug == 'z')
		{
		  aug++;
		  REQUIRE (read_uleb128 (&buf, end, &cie->augmentation_size));
		  ENSURE_NO_RELOCS (buf);
		}

	      while (*aug != '\0')
		switch (*aug++)
		  {
		  case 'L':
		    REQUIRE (read_byte (&buf, end, &cie->lsda_encoding));
		    ENSURE_NO_RELOCS (buf);
		    REQUIRE (get_DW_EH_PE_width (cie->lsda_encoding, ptr_size));
		    break;
		  case 'R':
		    REQUIRE (read_byte (&buf, end, &cie->fde_encoding));
		    ENSURE_NO_RELOCS (buf);
		    REQUIRE (get_DW_EH_PE_width (cie->fde_encoding, ptr_size));
		    break;
		  case 'S':
		    break;
		  case 'P':
		    {
		      int per_width;

		      REQUIRE (read_byte (&buf, end, &cie->per_encoding));
		      per_width = get_DW_EH_PE_width (cie->per_encoding,
						      ptr_size);
		      REQUIRE (per_width);
		      if ((cie->per_encoding & 0x70) == DW_EH_PE_aligned)
			{
			  length = -(buf - ehbuf) & (per_width - 1);
			  REQUIRE (skip_bytes (&buf, end, length));
			  if (per_width == 8)
			    this_inf->u.cie.per_encoding_aligned8 = 1;
			}
		      this_inf->u.cie.personality_offset = buf - start;
		      ENSURE_NO_RELOCS (buf);
		      /* Ensure we have a reloc here.  */
		      REQUIRE (GET_RELOC (buf));
		      cie->personality.reloc_index
			= cookie->rel - cookie->rels;
		      /* Cope with MIPS-style composite relocations.  */
		      do
			cookie->rel++;
		      while (GET_RELOC (buf) != NULL);
		      REQUIRE (skip_bytes (&buf, end, per_width));
		    }
		    break;
		  default:
		    /* Unrecognized augmentation. Better bail out.  */
		    goto free_no_table;
		  }
	    }
	  this_inf->u.cie.aug_data_len
	    = buf - start - 1 - this_inf->u.cie.aug_str_len;

	  /* For shared libraries, try to get rid of as many RELATIVE relocs
	     as possible.  */
	  if (bfd_link_pic (info)
	      && (get_elf_backend_data (abfd)
		  ->elf_backend_can_make_relative_eh_frame
		  (abfd, info, sec)))
	    {
	      if ((cie->fde_encoding & 0x70) == DW_EH_PE_absptr)
		this_inf->make_relative = 1;
	      /* If the CIE doesn't already have an 'R' entry, it's fairly
		 easy to add one, provided that there's no aligned data
		 after the augmentation string.  */
	      else if (cie->fde_encoding == DW_EH_PE_omit
		       && (cie->per_encoding & 0x70) != DW_EH_PE_aligned)
		{
		  if (*cie->augmentation == 0)
		    this_inf->add_augmentation_size = 1;
		  this_inf->u.cie.add_fde_encoding = 1;
		  this_inf->make_relative = 1;
		}

	      if ((cie->lsda_encoding & 0x70) == DW_EH_PE_absptr)
		cie->can_make_lsda_relative = 1;
	    }

	  /* If FDE encoding was not specified, it defaults to
	     DW_EH_absptr.  */
	  if (cie->fde_encoding == DW_EH_PE_omit)
	    cie->fde_encoding = DW_EH_PE_absptr;

	  initial_insn_length = end - buf;
	  cie->initial_insn_length = initial_insn_length;
	  memcpy (cie->initial_instructions, buf,
		  initial_insn_length <= sizeof (cie->initial_instructions)
		  ? initial_insn_length : sizeof (cie->initial_instructions));
	  insns = buf;
	  buf += initial_insn_length;
	  ENSURE_NO_RELOCS (buf);

	  if (!bfd_link_relocatable (info))
	    {
	      /* Keep info for merging cies.  */
	      this_inf->u.cie.u.full_cie = cie;
	      this_inf->u.cie.per_encoding_relative
		= (cie->per_encoding & 0x70) == DW_EH_PE_pcrel;
	    }
	}
      else
	{
	  /* Find the corresponding CIE.  */
	  unsigned int cie_offset = this_inf->offset + 4 - hdr_id;
	  for (cie = local_cies; cie < local_cies + cie_count; cie++)
	    if (cie_offset == cie->cie_inf->offset)
	      break;

	  /* Ensure this FDE references one of the CIEs in this input
	     section.  */
	  REQUIRE (cie != local_cies + cie_count);
	  this_inf->u.fde.cie_inf = cie->cie_inf;
	  this_inf->make_relative = cie->cie_inf->make_relative;
	  this_inf->add_augmentation_size
	    = cie->cie_inf->add_augmentation_size;

	  ENSURE_NO_RELOCS (buf);
	  if ((sec->flags & SEC_LINKER_CREATED) == 0 || cookie->rels != NULL)
	    {
	      asection *rsec;

	      REQUIRE (GET_RELOC (buf));

	      /* Chain together the FDEs for each section.  */
	      rsec = _bfd_elf_gc_mark_rsec (info, sec, gc_mark_hook,
					    cookie, NULL);
	      /* RSEC will be NULL if FDE was cleared out as it was belonging to
		 a discarded SHT_GROUP.  */
	      if (rsec)
		{
		  REQUIRE (rsec->owner == abfd);
		  this_inf->u.fde.next_for_section = elf_fde_list (rsec);
		  elf_fde_list (rsec) = this_inf;
		}
	    }

	  /* Skip the initial location and address range.  */
	  start = buf;
	  length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size);
	  REQUIRE (skip_bytes (&buf, end, 2 * length));

	  SKIP_RELOCS (buf - length);
	  if (!GET_RELOC (buf - length)
	      && read_value (abfd, buf - length, length, FALSE) == 0)
	    {
	      (*info->callbacks->minfo)
		/* xgettext:c-format */
		(_("discarding zero address range FDE in %pB(%pA).\n"),
		 abfd, sec);
	      this_inf->u.fde.cie_inf = NULL;
	    }

	  /* Skip the augmentation size, if present.  */
	  if (cie->augmentation[0] == 'z')
	    REQUIRE (read_uleb128 (&buf, end, &length));
	  else
	    length = 0;

	  /* Of the supported augmentation characters above, only 'L'
	     adds augmentation data to the FDE.  This code would need to
	     be adjusted if any future augmentations do the same thing.  */
	  if (cie->lsda_encoding != DW_EH_PE_omit)
	    {
	      SKIP_RELOCS (buf);
	      if (cie->can_make_lsda_relative && GET_RELOC (buf))
		cie->cie_inf->u.cie.make_lsda_relative = 1;
	      this_inf->lsda_offset = buf - start;
	      /* If there's no 'z' augmentation, we don't know where the
		 CFA insns begin.  Assume no padding.  */
	      if (cie->augmentation[0] != 'z')
		length = end - buf;
	    }

	  /* Skip over the augmentation data.  */
	  REQUIRE (skip_bytes (&buf, end, length));
	  insns = buf;

	  buf = last_fde + 4 + hdr_length;

	  /* For NULL RSEC (cleared FDE belonging to a discarded section)
	     the relocations are commonly cleared.  We do not sanity check if
	     all these relocations are cleared as (1) relocations to
	     .gcc_except_table will remain uncleared (they will get dropped
	     with the drop of this unused FDE) and (2) BFD already safely drops
	     relocations of any type to .eh_frame by
	     elf_section_ignore_discarded_relocs.
	     TODO: The .gcc_except_table entries should be also filtered as
	     .eh_frame entries; or GCC could rather use COMDAT for them.  */
	  SKIP_RELOCS (buf);
	}

      /* Try to interpret the CFA instructions and find the first
	 padding nop.  Shrink this_inf's size so that it doesn't
	 include the padding.  */
      length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size);
      set_loc_count = 0;
      insns_end = skip_non_nops (insns, end, length, &set_loc_count);
      /* If we don't understand the CFA instructions, we can't know
	 what needs to be adjusted there.  */
      if (insns_end == NULL
	  /* For the time being we don't support DW_CFA_set_loc in
	     CIE instructions.  */
	  || (set_loc_count && this_inf->cie))
	goto free_no_table;
      this_inf->size -= end - insns_end;
      if (insns_end != end && this_inf->cie)
	{
	  cie->initial_insn_length -= end - insns_end;
	  cie->length -= end - insns_end;
	}
      if (set_loc_count
	  && ((cie->fde_encoding & 0x70) == DW_EH_PE_pcrel
	      || this_inf->make_relative))
	{
	  unsigned int cnt;
	  bfd_byte *p;

	  this_inf->set_loc = (unsigned int *)
	      bfd_malloc ((set_loc_count + 1) * sizeof (unsigned int));
	  REQUIRE (this_inf->set_loc);
	  this_inf->set_loc[0] = set_loc_count;
	  p = insns;
	  cnt = 0;
	  while (p < end)
	    {
	      if (*p == DW_CFA_set_loc)
		this_inf->set_loc[++cnt] = p + 1 - start;
	      REQUIRE (skip_cfa_op (&p, end, length));
	    }
	}

      this_inf->removed = 1;
      this_inf->fde_encoding = cie->fde_encoding;
      this_inf->lsda_encoding = cie->lsda_encoding;
      sec_info->count++;
    }
  BFD_ASSERT (sec_info->count == num_entries);
  BFD_ASSERT (cie_count == num_cies);

  elf_section_data (sec)->sec_info = sec_info;
  sec->sec_info_type = SEC_INFO_TYPE_EH_FRAME;
  if (!bfd_link_relocatable (info))
    {
      /* Keep info for merging cies.  */
      sec_info->cies = local_cies;
      local_cies = NULL;
    }
  goto success;

 free_no_table:
  _bfd_error_handler
    /* xgettext:c-format */
    (_("error in %pB(%pA); no .eh_frame_hdr table will be created"),
     abfd, sec);
  hdr_info->u.dwarf.table = FALSE;
  if (sec_info)
    free (sec_info);
 success:
  if (ehbuf)
    free (ehbuf);
  if (local_cies)
    free (local_cies);
#undef REQUIRE
}

/* Order eh_frame_hdr entries by the VMA of their text section.  */

static int
cmp_eh_frame_hdr (const void *a, const void *b)
{
  bfd_vma text_a;
  bfd_vma text_b;
  asection *sec;

  sec = *(asection *const *)a;
  sec = (asection *) elf_section_data (sec)->sec_info;
  text_a = sec->output_section->vma + sec->output_offset;
  sec = *(asection *const *)b;
  sec = (asection *) elf_section_data (sec)->sec_info;
  text_b = sec->output_section->vma + sec->output_offset;

  if (text_a < text_b)
    return -1;
  return text_a > text_b;

}

/* Add space for a CANTUNWIND terminator to SEC if the text sections
   referenced by it and NEXT are not contiguous, or NEXT is NULL.  */

static void
add_eh_frame_hdr_terminator (asection *sec,
			     asection *next)
{
  bfd_vma end;
  bfd_vma next_start;
  asection *text_sec;

  if (next)
    {
      /* See if there is a gap (presumably a text section without unwind info)
	 between these two entries.  */
      text_sec = (asection *) elf_section_data (sec)->sec_info;
      end = text_sec->output_section->vma + text_sec->output_offset
	    + text_sec->size;
      text_sec = (asection *) elf_section_data (next)->sec_info;
      next_start = text_sec->output_section->vma + text_sec->output_offset;
      if (end == next_start)
	return;
    }

  /* Add space for a CANTUNWIND terminator.  */
  if (!sec->rawsize)
    sec->rawsize = sec->size;

  bfd_set_section_size (sec->owner, sec, sec->size + 8);
}

/* Finish a pass over all .eh_frame_entry sections.  */

bfd_boolean
_bfd_elf_end_eh_frame_parsing (struct bfd_link_info *info)
{
  struct eh_frame_hdr_info *hdr_info;
  unsigned int i;

  hdr_info = &elf_hash_table (info)->eh_info;

  if (info->eh_frame_hdr_type != COMPACT_EH_HDR
      || hdr_info->array_count == 0)
    return FALSE;

  bfd_elf_discard_eh_frame_entry (hdr_info);

  qsort (hdr_info->u.compact.entries, hdr_info->array_count,
	 sizeof (asection *), cmp_eh_frame_hdr);

  for (i = 0; i < hdr_info->array_count - 1; i++)
    {
      add_eh_frame_hdr_terminator (hdr_info->u.compact.entries[i],
				   hdr_info->u.compact.entries[i + 1]);
    }

  /* Add a CANTUNWIND terminator after the last entry.  */
  add_eh_frame_hdr_terminator (hdr_info->u.compact.entries[i], NULL);
  return TRUE;
}

/* Mark all relocations against CIE or FDE ENT, which occurs in
   .eh_frame section SEC.  COOKIE describes the relocations in SEC;
   its "rel" field can be changed freely.  */

static bfd_boolean
mark_entry (struct bfd_link_info *info, asection *sec,
	    struct eh_cie_fde *ent, elf_gc_mark_hook_fn gc_mark_hook,
	    struct elf_reloc_cookie *cookie)
{
  /* FIXME: octets_per_byte.  */
  for (cookie->rel = cookie->rels + ent->reloc_index;
       cookie->rel < cookie->relend
	 && cookie->rel->r_offset < ent->offset + ent->size;
       cookie->rel++)
    if (!_bfd_elf_gc_mark_reloc (info, sec, gc_mark_hook, cookie))
      return FALSE;

  return TRUE;
}

/* Mark all the relocations against FDEs that relate to code in input
   section SEC.  The FDEs belong to .eh_frame section EH_FRAME, whose
   relocations are described by COOKIE.  */

bfd_boolean
_bfd_elf_gc_mark_fdes (struct bfd_link_info *info, asection *sec,
		       asection *eh_frame, elf_gc_mark_hook_fn gc_mark_hook,
		       struct elf_reloc_cookie *cookie)
{
  struct eh_cie_fde *fde, *cie;

  for (fde = elf_fde_list (sec); fde; fde = fde->u.fde.next_for_section)
    {
      if (!mark_entry (info, eh_frame, fde, gc_mark_hook, cookie))
	return FALSE;

      /* At this stage, all cie_inf fields point to local CIEs, so we
	 can use the same cookie to refer to them.  */
      cie = fde->u.fde.cie_inf;
      if (cie != NULL && !cie->u.cie.gc_mark)
	{
	  cie->u.cie.gc_mark = 1;
	  if (!mark_entry (info, eh_frame, cie, gc_mark_hook, cookie))
	    return FALSE;
	}
    }
  return TRUE;
}

/* Input section SEC of ABFD is an .eh_frame section that contains the
   CIE described by CIE_INF.  Return a version of CIE_INF that is going
   to be kept in the output, adding CIE_INF to the output if necessary.

   HDR_INFO is the .eh_frame_hdr information and COOKIE describes the
   relocations in REL.  */

static struct eh_cie_fde *
find_merged_cie (bfd *abfd, struct bfd_link_info *info, asection *sec,
		 struct eh_frame_hdr_info *hdr_info,
		 struct elf_reloc_cookie *cookie,
		 struct eh_cie_fde *cie_inf)
{
  unsigned long r_symndx;
  struct cie *cie, *new_cie;
  Elf_Internal_Rela *rel;
  void **loc;

  /* Use CIE_INF if we have already decided to keep it.  */
  if (!cie_inf->removed)
    return cie_inf;

  /* If we have merged CIE_INF with another CIE, use that CIE instead.  */
  if (cie_inf->u.cie.merged)
    return cie_inf->u.cie.u.merged_with;

  cie = cie_inf->u.cie.u.full_cie;

  /* Assume we will need to keep CIE_INF.  */
  cie_inf->removed = 0;
  cie_inf->u.cie.u.sec = sec;

  /* If we are not merging CIEs, use CIE_INF.  */
  if (cie == NULL)
    return cie_inf;

  if (cie->per_encoding != DW_EH_PE_omit)
    {
      bfd_boolean per_binds_local;

      /* Work out the address of personality routine, or at least
	 enough info that we could calculate the address had we made a
	 final section layout.  The symbol on the reloc is enough,
	 either the hash for a global, or (bfd id, index) pair for a
	 local.  The assumption here is that no one uses addends on
	 the reloc.  */
      rel = cookie->rels + cie->personality.reloc_index;
      memset (&cie->personality, 0, sizeof (cie->personality));
#ifdef BFD64
      if (elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64)
	r_symndx = ELF64_R_SYM (rel->r_info);
      else
#endif
	r_symndx = ELF32_R_SYM (rel->r_info);
      if (r_symndx >= cookie->locsymcount
	  || ELF_ST_BIND (cookie->locsyms[r_symndx].st_info) != STB_LOCAL)
	{
	  struct elf_link_hash_entry *h;

	  r_symndx -= cookie->extsymoff;
	  h = cookie->sym_hashes[r_symndx];

	  while (h->root.type == bfd_link_hash_indirect
		 || h->root.type == bfd_link_hash_warning)
	    h = (struct elf_link_hash_entry *) h->root.u.i.link;

	  cie->personality.h = h;
	  per_binds_local = SYMBOL_REFERENCES_LOCAL (info, h);
	}
      else
	{
	  Elf_Internal_Sym *sym;
	  asection *sym_sec;

	  sym = &cookie->locsyms[r_symndx];
	  sym_sec = bfd_section_from_elf_index (abfd, sym->st_shndx);
	  if (sym_sec == NULL)
	    return cie_inf;

	  if (sym_sec->kept_section != NULL)
	    sym_sec = sym_sec->kept_section;
	  if (sym_sec->output_section == NULL)
	    return cie_inf;

	  cie->local_personality = 1;
	  cie->personality.sym.bfd_id = abfd->id;
	  cie->personality.sym.index = r_symndx;
	  per_binds_local = TRUE;
	}

      if (per_binds_local
	  && bfd_link_pic (info)
	  && (cie->per_encoding & 0x70) == DW_EH_PE_absptr
	  && (get_elf_backend_data (abfd)
	      ->elf_backend_can_make_relative_eh_frame (abfd, info, sec)))
	{
	  cie_inf->u.cie.make_per_encoding_relative = 1;
	  cie_inf->u.cie.per_encoding_relative = 1;
	}
    }

  /* See if we can merge this CIE with an earlier one.  */
  cie_compute_hash (cie);
  if (hdr_info->u.dwarf.cies == NULL)
    {
      hdr_info->u.dwarf.cies = htab_try_create (1, cie_hash, cie_eq, free);
      if (hdr_info->u.dwarf.cies == NULL)
	return cie_inf;
    }
  loc = htab_find_slot_with_hash (hdr_info->u.dwarf.cies, cie,
				  cie->hash, INSERT);
  if (loc == NULL)
    return cie_inf;

  new_cie = (struct cie *) *loc;
  if (new_cie == NULL)
    {
      /* Keep CIE_INF and record it in the hash table.  */
      new_cie = (struct cie *) malloc (sizeof (struct cie));
      if (new_cie == NULL)
	return cie_inf;

      memcpy (new_cie, cie, sizeof (struct cie));
      *loc = new_cie;
    }
  else
    {
      /* Merge CIE_INF with NEW_CIE->CIE_INF.  */
      cie_inf->removed = 1;
      cie_inf->u.cie.merged = 1;
      cie_inf->u.cie.u.merged_with = new_cie->cie_inf;
      if (cie_inf->u.cie.make_lsda_relative)
	new_cie->cie_inf->u.cie.make_lsda_relative = 1;
    }
  return new_cie->cie_inf;
}

/* For a given OFFSET in SEC, return the delta to the new location
   after .eh_frame editing.  */

static bfd_signed_vma
offset_adjust (bfd_vma offset, const asection *sec)
{
  struct eh_frame_sec_info *sec_info
    = (struct eh_frame_sec_info *) elf_section_data (sec)->sec_info;
  unsigned int lo, hi, mid;
  struct eh_cie_fde *ent = NULL;
  bfd_signed_vma delta;

  lo = 0;
  hi = sec_info->count;
  if (hi == 0)
    return 0;

  while (lo < hi)
    {
      mid = (lo + hi) / 2;
      ent = &sec_info->entry[mid];
      if (offset < ent->offset)
	hi = mid;
      else if (mid + 1 >= hi)
	break;
      else if (offset >= ent[1].offset)
	lo = mid + 1;
      else
	break;
    }

  if (!ent->removed)
    delta = (bfd_vma) ent->new_offset - (bfd_vma) ent->offset;
  else if (ent->cie && ent->u.cie.merged)
    {
      struct eh_cie_fde *cie = ent->u.cie.u.merged_with;
      delta = ((bfd_vma) cie->new_offset + cie->u.cie.u.sec->output_offset
	       - (bfd_vma) ent->offset - sec->output_offset);
    }
  else
    {
      /* Is putting the symbol on the next entry best for a deleted
	 CIE/FDE?  */
      struct eh_cie_fde *last = sec_info->entry + sec_info->count;
      delta = ((bfd_vma) next_cie_fde_offset (ent, last, sec)
	       - (bfd_vma) ent->offset);
      return delta;
    }

  /* Account for editing within this CIE/FDE.  */
  offset -= ent->offset;
  if (ent->cie)
    {
      unsigned int extra
	= ent->add_augmentation_size + ent->u.cie.add_fde_encoding;
      if (extra == 0
	  || offset <= 9u + ent->u.cie.aug_str_len)
	return delta;
      delta += extra;
      if (offset <= 9u + ent->u.cie.aug_str_len + ent->u.cie.aug_data_len)
	return delta;
      delta += extra;
    }
  else
    {
      unsigned int ptr_size, width, extra = ent->add_augmentation_size;
      if (offset <= 12 || extra == 0)
	return delta;
      ptr_size = (get_elf_backend_data (sec->owner)
		  ->elf_backend_eh_frame_address_size (sec->owner, sec));
      width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size);
      if (offset <= 8 + 2 * width)
	return delta;
      delta += extra;
    }

  return delta;
}

/* Adjust a global symbol defined in .eh_frame, so that it stays
   relative to its original CIE/FDE.  It is assumed that a symbol
   defined at the beginning of a CIE/FDE belongs to that CIE/FDE
   rather than marking the end of the previous CIE/FDE.  This matters
   when a CIE is merged with a previous CIE, since the symbol is
   moved to the merged CIE.  */

bfd_boolean
_bfd_elf_adjust_eh_frame_global_symbol (struct elf_link_hash_entry *h,
					void *arg ATTRIBUTE_UNUSED)
{
  asection *sym_sec;
  bfd_signed_vma delta;

  if (h->root.type != bfd_link_hash_defined
      && h->root.type != bfd_link_hash_defweak)
    return TRUE;

  sym_sec = h->root.u.def.section;
  if (sym_sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME
      || elf_section_data (sym_sec)->sec_info == NULL)
    return TRUE;

  delta = offset_adjust (h->root.u.def.value, sym_sec);
  h->root.u.def.value += delta;

  return TRUE;
}

/* The same for all local symbols defined in .eh_frame.  Returns true
   if any symbol was changed.  */

static int
adjust_eh_frame_local_symbols (const asection *sec,
			       struct elf_reloc_cookie *cookie)
{
  unsigned int shndx;
  Elf_Internal_Sym *sym;
  Elf_Internal_Sym *end_sym;
  int adjusted = 0;

  shndx = elf_section_data (sec)->this_idx;
  end_sym = cookie->locsyms + cookie->locsymcount;
  for (sym = cookie->locsyms + 1; sym < end_sym; ++sym)
    if (sym->st_info <= ELF_ST_INFO (STB_LOCAL, STT_OBJECT)
	&& sym->st_shndx == shndx)
      {
	bfd_signed_vma delta = offset_adjust (sym->st_value, sec);

	if (delta != 0)
	  {
	    adjusted = 1;
	    sym->st_value += delta;
	  }
      }
  return adjusted;
}

/* This function is called for each input file before the .eh_frame
   section is relocated.  It discards duplicate CIEs and FDEs for discarded
   functions.  The function returns TRUE iff any entries have been
   deleted.  */

bfd_boolean
_bfd_elf_discard_section_eh_frame
   (bfd *abfd, struct bfd_link_info *info, asection *sec,
    bfd_boolean (*reloc_symbol_deleted_p) (bfd_vma, void *),
    struct elf_reloc_cookie *cookie)
{
  struct eh_cie_fde *ent;
  struct eh_frame_sec_info *sec_info;
  struct eh_frame_hdr_info *hdr_info;
  unsigned int ptr_size, offset, eh_alignment;
  int changed;

  if (sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME)
    return FALSE;

  sec_info = (struct eh_frame_sec_info *) elf_section_data (sec)->sec_info;
  if (sec_info == NULL)
    return FALSE;

  ptr_size = (get_elf_backend_data (sec->owner)
	      ->elf_backend_eh_frame_address_size (sec->owner, sec));

  hdr_info = &elf_hash_table (info)->eh_info;
  for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent)
    if (ent->size == 4)
      /* There should only be one zero terminator, on the last input
	 file supplying .eh_frame (crtend.o).  Remove any others.  */
      ent->removed = sec->map_head.s != NULL;
    else if (!ent->cie && ent->u.fde.cie_inf != NULL)
      {
	bfd_boolean keep;
	if ((sec->flags & SEC_LINKER_CREATED) != 0 && cookie->rels == NULL)
	  {
	    unsigned int width
	      = get_DW_EH_PE_width (ent->fde_encoding, ptr_size);
	    bfd_vma value
	      = read_value (abfd, sec->contents + ent->offset + 8 + width,
			    width, get_DW_EH_PE_signed (ent->fde_encoding));
	    keep = value != 0;
	  }
	else
	  {
	    cookie->rel = cookie->rels + ent->reloc_index;
	    /* FIXME: octets_per_byte.  */
	    BFD_ASSERT (cookie->rel < cookie->relend
			&& cookie->rel->r_offset == ent->offset + 8);
	    keep = !(*reloc_symbol_deleted_p) (ent->offset + 8, cookie);
	  }
	if (keep)
	  {
	    if (bfd_link_pic (info)
		&& (((ent->fde_encoding & 0x70) == DW_EH_PE_absptr
		     && ent->make_relative == 0)
		    || (ent->fde_encoding & 0x70) == DW_EH_PE_aligned))
	      {
		static int num_warnings_issued = 0;

		/* If a shared library uses absolute pointers
		   which we cannot turn into PC relative,
		   don't create the binary search table,
		   since it is affected by runtime relocations.  */
		hdr_info->u.dwarf.table = FALSE;
		if (num_warnings_issued < 10)
		  {
		    _bfd_error_handler
		      /* xgettext:c-format */
		      (_("FDE encoding in %pB(%pA) prevents .eh_frame_hdr"
			 " table being created"), abfd, sec);
		    num_warnings_issued ++;
		  }
		else if (num_warnings_issued == 10)
		  {
		    _bfd_error_handler
		      (_("further warnings about FDE encoding preventing .eh_frame_hdr generation dropped"));
		    num_warnings_issued ++;
		  }
	      }
	    ent->removed = 0;
	    hdr_info->u.dwarf.fde_count++;
	    ent->u.fde.cie_inf = find_merged_cie (abfd, info, sec, hdr_info,
						  cookie, ent->u.fde.cie_inf);
	  }
      }

  if (sec_info->cies)
    {
      free (sec_info->cies);
      sec_info->cies = NULL;
    }

  /* It may be that some .eh_frame input section has greater alignment
     than other .eh_frame sections.  In that case we run the risk of
     padding with zeros before that section, which would be seen as a
     zero terminator.  Alignment padding must be added *inside* the
     last FDE instead.  For other FDEs we align according to their
     encoding, in order to align FDE address range entries naturally.  */
  offset = 0;
  changed = 0;
  for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent)
    if (!ent->removed)
      {
	eh_alignment = 4;
	if (ent->size == 4)
	  ;
	else if (ent->cie)
	  {
	    if (ent->u.cie.per_encoding_aligned8)
	      eh_alignment = 8;
	  }
	else
	  {
	    eh_alignment = get_DW_EH_PE_width (ent->fde_encoding, ptr_size);
	    if (eh_alignment < 4)
	      eh_alignment = 4;
	  }
	offset = (offset + eh_alignment - 1) & -eh_alignment;
	ent->new_offset = offset;
	if (ent->new_offset != ent->offset)
	  changed = 1;
	offset += size_of_output_cie_fde (ent);
      }

  eh_alignment = 4;
  offset = (offset + eh_alignment - 1) & -eh_alignment;
  sec->rawsize = sec->size;
  sec->size = offset;
  if (sec->size != sec->rawsize)
    changed = 1;

  if (changed && adjust_eh_frame_local_symbols (sec, cookie))
    {
      Elf_Internal_Shdr *symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
      symtab_hdr->contents = (unsigned char *) cookie->locsyms;
    }
  return changed;
}

/* This function is called for .eh_frame_hdr section after
   _bfd_elf_discard_section_eh_frame has been called on all .eh_frame
   input sections.  It finalizes the size of .eh_frame_hdr section.  */

bfd_boolean
_bfd_elf_discard_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info)
{
  struct elf_link_hash_table *htab;
  struct eh_frame_hdr_info *hdr_info;
  asection *sec;

  htab = elf_hash_table (info);
  hdr_info = &htab->eh_info;

  if (!hdr_info->frame_hdr_is_compact && hdr_info->u.dwarf.cies != NULL)
    {
      htab_delete (hdr_info->u.dwarf.cies);
      hdr_info->u.dwarf.cies = NULL;
    }

  sec = hdr_info->hdr_sec;
  if (sec == NULL)
    return FALSE;

  if (info->eh_frame_hdr_type == COMPACT_EH_HDR)
    {
      /* For compact frames we only add the header.  The actual table comes
	 from the .eh_frame_entry sections.  */
      sec->size = 8;
    }
  else
    {
      sec->size = EH_FRAME_HDR_SIZE;
      if (hdr_info->u.dwarf.table)
	sec->size += 4 + hdr_info->u.dwarf.fde_count * 8;
    }

  elf_eh_frame_hdr (abfd) = sec;
  return TRUE;
}

/* Return true if there is at least one non-empty .eh_frame section in
   input files.  Can only be called after ld has mapped input to
   output sections, and before sections are stripped.  */

bfd_boolean
_bfd_elf_eh_frame_present (struct bfd_link_info *info)
{
  asection *eh = bfd_get_section_by_name (info->output_bfd, ".eh_frame");

  if (eh == NULL)
    return FALSE;

  /* Count only sections which have at least a single CIE or FDE.
     There cannot be any CIE or FDE <= 8 bytes.  */
  for (eh = eh->map_head.s; eh != NULL; eh = eh->map_head.s)
    if (eh->size > 8)
      return TRUE;

  return FALSE;
}

/* Return true if there is at least one .eh_frame_entry section in
   input files.  */

bfd_boolean
_bfd_elf_eh_frame_entry_present (struct bfd_link_info *info)
{
  asection *o;
  bfd *abfd;

  for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
    {
      for (o = abfd->sections; o; o = o->next)
	{
	  const char *name = bfd_get_section_name (abfd, o);

	  if (strcmp (name, ".eh_frame_entry")
	      && !bfd_is_abs_section (o->output_section))
	    return TRUE;
	}
    }
  return FALSE;
}

/* This function is called from size_dynamic_sections.
   It needs to decide whether .eh_frame_hdr should be output or not,
   because when the dynamic symbol table has been sized it is too late
   to strip sections.  */

bfd_boolean
_bfd_elf_maybe_strip_eh_frame_hdr (struct bfd_link_info *info)
{
  struct elf_link_hash_table *htab;
  struct eh_frame_hdr_info *hdr_info;
  struct bfd_link_hash_entry *bh = NULL;
  struct elf_link_hash_entry *h;

  htab = elf_hash_table (info);
  hdr_info = &htab->eh_info;
  if (hdr_info->hdr_sec == NULL)
    return TRUE;

  if (bfd_is_abs_section (hdr_info->hdr_sec->output_section)
      || info->eh_frame_hdr_type == 0
      || (info->eh_frame_hdr_type == DWARF2_EH_HDR
	  && !_bfd_elf_eh_frame_present (info))
      || (info->eh_frame_hdr_type == COMPACT_EH_HDR
	  && !_bfd_elf_eh_frame_entry_present (info)))
    {
      hdr_info->hdr_sec->flags |= SEC_EXCLUDE;
      hdr_info->hdr_sec = NULL;
      return TRUE;
    }

  /* Add a hidden symbol so that systems without access to PHDRs can
     find the table.  */
  if (! (_bfd_generic_link_add_one_symbol
	 (info, info->output_bfd, "__GNU_EH_FRAME_HDR", BSF_LOCAL,
	  hdr_info->hdr_sec, 0, NULL, FALSE, FALSE, &bh)))
    return FALSE;

  h = (struct elf_link_hash_entry *) bh;
  h->def_regular = 1;
  h->other = STV_HIDDEN;
  get_elf_backend_data
    (info->output_bfd)->elf_backend_hide_symbol (info, h, TRUE);

  if (!hdr_info->frame_hdr_is_compact)
    hdr_info->u.dwarf.table = TRUE;
  return TRUE;
}

/* Adjust an address in the .eh_frame section.  Given OFFSET within
   SEC, this returns the new offset in the adjusted .eh_frame section,
   or -1 if the address refers to a CIE/FDE which has been removed
   or to offset with dynamic relocation which is no longer needed.  */

bfd_vma
_bfd_elf_eh_frame_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED,
				  struct bfd_link_info *info ATTRIBUTE_UNUSED,
				  asection *sec,
				  bfd_vma offset)
{
  struct eh_frame_sec_info *sec_info;
  unsigned int lo, hi, mid;

  if (sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME)
    return offset;
  sec_info = (struct eh_frame_sec_info *) elf_section_data (sec)->sec_info;

  if (offset >= sec->rawsize)
    return offset - sec->rawsize + sec->size;

  lo = 0;
  hi = sec_info->count;
  mid = 0;
  while (lo < hi)
    {
      mid = (lo + hi) / 2;
      if (offset < sec_info->entry[mid].offset)
	hi = mid;
      else if (offset
	       >= sec_info->entry[mid].offset + sec_info->entry[mid].size)
	lo = mid + 1;
      else
	break;
    }

  BFD_ASSERT (lo < hi);

  /* FDE or CIE was removed.  */
  if (sec_info->entry[mid].removed)
    return (bfd_vma) -1;

  /* If converting personality pointers to DW_EH_PE_pcrel, there will be
     no need for run-time relocation against the personality field.  */
  if (sec_info->entry[mid].cie
      && sec_info->entry[mid].u.cie.make_per_encoding_relative
      && offset == (sec_info->entry[mid].offset + 8
		    + sec_info->entry[mid].u.cie.personality_offset))
    return (bfd_vma) -2;

  /* If converting to DW_EH_PE_pcrel, there will be no need for run-time
     relocation against FDE's initial_location field.  */
  if (!sec_info->entry[mid].cie
      && sec_info->entry[mid].make_relative
      && offset == sec_info->entry[mid].offset + 8)
    return (bfd_vma) -2;

  /* If converting LSDA pointers to DW_EH_PE_pcrel, there will be no need
     for run-time relocation against LSDA field.  */
  if (!sec_info->entry[mid].cie
      && sec_info->entry[mid].u.fde.cie_inf->u.cie.make_lsda_relative
      && offset == (sec_info->entry[mid].offset + 8
		    + sec_info->entry[mid].lsda_offset))
    return (bfd_vma) -2;

  /* If converting to DW_EH_PE_pcrel, there will be no need for run-time
     relocation against DW_CFA_set_loc's arguments.  */
  if (sec_info->entry[mid].set_loc
      && sec_info->entry[mid].make_relative
      && (offset >= sec_info->entry[mid].offset + 8
		    + sec_info->entry[mid].set_loc[1]))
    {
      unsigned int cnt;

      for (cnt = 1; cnt <= sec_info->entry[mid].set_loc[0]; cnt++)
	if (offset == sec_info->entry[mid].offset + 8
		      + sec_info->entry[mid].set_loc[cnt])
	  return (bfd_vma) -2;
    }

  /* Any new augmentation bytes go before the first relocation.  */
  return (offset + sec_info->entry[mid].new_offset
	  - sec_info->entry[mid].offset
	  + extra_augmentation_string_bytes (sec_info->entry + mid)
	  + extra_augmentation_data_bytes (sec_info->entry + mid));
}

/* Write out .eh_frame_entry section.  Add CANTUNWIND terminator if needed.
   Also check that the contents look sane.  */

bfd_boolean
_bfd_elf_write_section_eh_frame_entry (bfd *abfd, struct bfd_link_info *info,
				       asection *sec, bfd_byte *contents)
{
  const struct elf_backend_data *bed;
  bfd_byte cantunwind[8];
  bfd_vma addr;
  bfd_vma last_addr;
  bfd_vma offset;
  asection *text_sec = (asection *) elf_section_data (sec)->sec_info;

  if (!sec->rawsize)
    sec->rawsize = sec->size;

  BFD_ASSERT (sec->sec_info_type == SEC_INFO_TYPE_EH_FRAME_ENTRY);

  /* Check to make sure that the text section corresponding to this eh_frame_entry
     section has not been excluded.  In particular, mips16 stub entries will be
     excluded outside of the normal process.  */
  if (sec->flags & SEC_EXCLUDE
      || text_sec->flags & SEC_EXCLUDE)
    return TRUE;

  if (!bfd_set_section_contents (abfd, sec->output_section, contents,
				 sec->output_offset, sec->rawsize))
      return FALSE;

  last_addr = bfd_get_signed_32 (abfd, contents);
  /* Check that all the entries are in order.  */
  for (offset = 8; offset < sec->rawsize; offset += 8)
    {
      addr = bfd_get_signed_32 (abfd, contents + offset) + offset;
      if (addr <= last_addr)
	{
	  /* xgettext:c-format */
	  _bfd_error_handler (_("%pB: %pA not in order"), sec->owner, sec);
	  return FALSE;
	}

      last_addr = addr;
    }

  addr = text_sec->output_section->vma + text_sec->output_offset
	 + text_sec->size;
  addr &= ~1;
  addr -= (sec->output_section->vma + sec->output_offset + sec->rawsize);
  if (addr & 1)
    {
      /* xgettext:c-format */
      _bfd_error_handler (_("%pB: %pA invalid input section size"),
			  sec->owner, sec);
      bfd_set_error (bfd_error_bad_value);
      return FALSE;
    }
  if (last_addr >= addr + sec->rawsize)
    {
      /* xgettext:c-format */
      _bfd_error_handler (_("%pB: %pA points past end of text section"),
			  sec->owner, sec);
      bfd_set_error (bfd_error_bad_value);
      return FALSE;
    }

  if (sec->size == sec->rawsize)
    return TRUE;

  bed = get_elf_backend_data (abfd);
  BFD_ASSERT (sec->size == sec->rawsize + 8);
  BFD_ASSERT ((addr & 1) == 0);
  BFD_ASSERT (bed->cant_unwind_opcode);

  bfd_put_32 (abfd, addr, cantunwind);
  bfd_put_32 (abfd, (*bed->cant_unwind_opcode) (info), cantunwind + 4);
  return bfd_set_section_contents (abfd, sec->output_section, cantunwind,
				   sec->output_offset + sec->rawsize, 8);
}

/* Write out .eh_frame section.  This is called with the relocated
   contents.  */

bfd_boolean
_bfd_elf_write_section_eh_frame (bfd *abfd,
				 struct bfd_link_info *info,
				 asection *sec,
				 bfd_byte *contents)
{
  struct eh_frame_sec_info *sec_info;
  struct elf_link_hash_table *htab;
  struct eh_frame_hdr_info *hdr_info;
  unsigned int ptr_size;
  struct eh_cie_fde *ent, *last_ent;

  if (sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME)
    /* FIXME: octets_per_byte.  */
    return bfd_set_section_contents (abfd, sec->output_section, contents,
				     sec->output_offset, sec->size);

  ptr_size = (get_elf_backend_data (abfd)
	      ->elf_backend_eh_frame_address_size (abfd, sec));
  BFD_ASSERT (ptr_size != 0);

  sec_info = (struct eh_frame_sec_info *) elf_section_data (sec)->sec_info;
  htab = elf_hash_table (info);
  hdr_info = &htab->eh_info;

  if (hdr_info->u.dwarf.table && hdr_info->u.dwarf.array == NULL)
    {
      hdr_info->frame_hdr_is_compact = FALSE;
      hdr_info->u.dwarf.array = (struct eh_frame_array_ent *)
	bfd_malloc (hdr_info->u.dwarf.fde_count
		    * sizeof (*hdr_info->u.dwarf.array));
    }
  if (hdr_info->u.dwarf.array == NULL)
    hdr_info = NULL;

  /* The new offsets can be bigger or smaller than the original offsets.
     We therefore need to make two passes over the section: one backward
     pass to move entries up and one forward pass to move entries down.
     The two passes won't interfere with each other because entries are
     not reordered  */
  for (ent = sec_info->entry + sec_info->count; ent-- != sec_info->entry;)
    if (!ent->removed && ent->new_offset > ent->offset)
      memmove (contents + ent->new_offset, contents + ent->offset, ent->size);

  for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent)
    if (!ent->removed && ent->new_offset < ent->offset)
      memmove (contents + ent->new_offset, contents + ent->offset, ent->size);

  last_ent = sec_info->entry + sec_info->count;
  for (ent = sec_info->entry; ent < last_ent; ++ent)
    {
      unsigned char *buf, *end;
      unsigned int new_size;

      if (ent->removed)
	continue;

      if (ent->size == 4)
	{
	  /* Any terminating FDE must be at the end of the section.  */
	  BFD_ASSERT (ent == last_ent - 1);
	  continue;
	}

      buf = contents + ent->new_offset;
      end = buf + ent->size;
      new_size = next_cie_fde_offset (ent, last_ent, sec) - ent->new_offset;

      /* Update the size.  It may be shrinked.  */
      bfd_put_32 (abfd, new_size - 4, buf);

      /* Filling the extra bytes with DW_CFA_nops.  */
      if (new_size != ent->size)
	memset (end, 0, new_size - ent->size);

      if (ent->cie)
	{
	  /* CIE */
	  if (ent->make_relative
	      || ent->u.cie.make_lsda_relative
	      || ent->u.cie.per_encoding_relative)
	    {
	      char *aug;
	      unsigned int action, extra_string, extra_data;
	      unsigned int per_width, per_encoding;

	      /* Need to find 'R' or 'L' augmentation's argument and modify
		 DW_EH_PE_* value.  */
	      action = ((ent->make_relative ? 1 : 0)
			| (ent->u.cie.make_lsda_relative ? 2 : 0)
			| (ent->u.cie.per_encoding_relative ? 4 : 0));
	      extra_string = extra_augmentation_string_bytes (ent);
	      extra_data = extra_augmentation_data_bytes (ent);

	      /* Skip length, id and version.  */
	      buf += 9;
	      aug = (char *) buf;
	      buf += strlen (aug) + 1;
	      skip_leb128 (&buf, end);
	      skip_leb128 (&buf, end);
	      skip_leb128 (&buf, end);
	      if (*aug == 'z')
		{
		  /* The uleb128 will always be a single byte for the kind
		     of augmentation strings that we're prepared to handle.  */
		  *buf++ += extra_data;
		  aug++;
		}

	      /* Make room for the new augmentation string and data bytes.  */
	      memmove (buf + extra_string + extra_data, buf, end - buf);
	      memmove (aug + extra_string, aug, buf - (bfd_byte *) aug);
	      buf += extra_string;
	      end += extra_string + extra_data;

	      if (ent->add_augmentation_size)
		{
		  *aug++ = 'z';
		  *buf++ = extra_data - 1;
		}
	      if (ent->u.cie.add_fde_encoding)
		{
		  BFD_ASSERT (action & 1);
		  *aug++ = 'R';
		  *buf++ = make_pc_relative (DW_EH_PE_absptr, ptr_size);
		  action &= ~1;
		}

	      while (action)
		switch (*aug++)
		  {
		  case 'L':
		    if (action & 2)
		      {
			BFD_ASSERT (*buf == ent->lsda_encoding);
			*buf = make_pc_relative (*buf, ptr_size);
			action &= ~2;
		      }
		    buf++;
		    break;
		  case 'P':
		    if (ent->u.cie.make_per_encoding_relative)
		      *buf = make_pc_relative (*buf, ptr_size);
		    per_encoding = *buf++;
		    per_width = get_DW_EH_PE_width (per_encoding, ptr_size);
		    BFD_ASSERT (per_width != 0);
		    BFD_ASSERT (((per_encoding & 0x70) == DW_EH_PE_pcrel)
				== ent->u.cie.per_encoding_relative);
		    if ((per_encoding & 0x70) == DW_EH_PE_aligned)
		      buf = (contents
			     + ((buf - contents + per_width - 1)
				& ~((bfd_size_type) per_width - 1)));
		    if (action & 4)
		      {
			bfd_vma val;

			val = read_value (abfd, buf, per_width,
					  get_DW_EH_PE_signed (per_encoding));
			if (ent->u.cie.make_per_encoding_relative)
			  val -= (sec->output_section->vma
				  + sec->output_offset
				  + (buf - contents));
			else
			  {
			    val += (bfd_vma) ent->offset - ent->new_offset;
			    val -= extra_string + extra_data;
			  }
			write_value (abfd, buf, val, per_width);
			action &= ~4;
		      }
		    buf += per_width;
		    break;
		  case 'R':
		    if (action & 1)
		      {
			BFD_ASSERT (*buf == ent->fde_encoding);
			*buf = make_pc_relative (*buf, ptr_size);
			action &= ~1;
		      }
		    buf++;
		    break;
		  case 'S':
		    break;
		  default:
		    BFD_FAIL ();
		  }
	    }
	}
      else
	{
	  /* FDE */
	  bfd_vma value, address;
	  unsigned int width;
	  bfd_byte *start;
	  struct eh_cie_fde *cie;

	  /* Skip length.  */
	  cie = ent->u.fde.cie_inf;
	  buf += 4;
	  value = ((ent->new_offset + sec->output_offset + 4)
		   - (cie->new_offset + cie->u.cie.u.sec->output_offset));
	  bfd_put_32 (abfd, value, buf);
	  if (bfd_link_relocatable (info))
	    continue;
	  buf += 4;
	  width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size);
	  value = read_value (abfd, buf, width,
			      get_DW_EH_PE_signed (ent->fde_encoding));
	  address = value;
	  if (value)
	    {
	      switch (ent->fde_encoding & 0x70)
		{
		case DW_EH_PE_textrel:
		  BFD_ASSERT (hdr_info == NULL);
		  break;
		case DW_EH_PE_datarel:
		  {
		    switch (abfd->arch_info->arch)
		      {
		      case bfd_arch_ia64:
			BFD_ASSERT (elf_gp (abfd) != 0);
			address += elf_gp (abfd);
			break;
		      default:
			_bfd_error_handler
			  (_("DW_EH_PE_datarel unspecified"
			     " for this architecture"));
			/* Fall thru */
		      case bfd_arch_frv:
		      case bfd_arch_i386:
			BFD_ASSERT (htab->hgot != NULL
				    && ((htab->hgot->root.type
					 == bfd_link_hash_defined)
					|| (htab->hgot->root.type
					    == bfd_link_hash_defweak)));
			address
			  += (htab->hgot->root.u.def.value
			      + htab->hgot->root.u.def.section->output_offset
			      + (htab->hgot->root.u.def.section->output_section
				 ->vma));
			break;
		      }
		  }
		  break;
		case DW_EH_PE_pcrel:
		  value += (bfd_vma) ent->offset - ent->new_offset;
		  address += (sec->output_section->vma
			      + sec->output_offset
			      + ent->offset + 8);
		  break;
		}
	      if (ent->make_relative)
		value -= (sec->output_section->vma
			  + sec->output_offset
			  + ent->new_offset + 8);
	      write_value (abfd, buf, value, width);
	    }

	  start = buf;

	  if (hdr_info)
	    {
	      /* The address calculation may overflow, giving us a
		 value greater than 4G on a 32-bit target when
		 dwarf_vma is 64-bit.  */
	      if (sizeof (address) > 4 && ptr_size == 4)
		address &= 0xffffffff;
	      hdr_info->u.dwarf.array[hdr_info->array_count].initial_loc
		= address;
	      hdr_info->u.dwarf.array[hdr_info->array_count].range
		= read_value (abfd, buf + width, width, FALSE);
	      hdr_info->u.dwarf.array[hdr_info->array_count++].fde
		= (sec->output_section->vma
		   + sec->output_offset
		   + ent->new_offset);
	    }

	  if ((ent->lsda_encoding & 0x70) == DW_EH_PE_pcrel
	      || cie->u.cie.make_lsda_relative)
	    {
	      buf += ent->lsda_offset;
	      width = get_DW_EH_PE_width (ent->lsda_encoding, ptr_size);
	      value = read_value (abfd, buf, width,
				  get_DW_EH_PE_signed (ent->lsda_encoding));
	      if (value)
		{
		  if ((ent->lsda_encoding & 0x70) == DW_EH_PE_pcrel)
		    value += (bfd_vma) ent->offset - ent->new_offset;
		  else if (cie->u.cie.make_lsda_relative)
		    value -= (sec->output_section->vma
			      + sec->output_offset
			      + ent->new_offset + 8 + ent->lsda_offset);
		  write_value (abfd, buf, value, width);
		}
	    }
	  else if (ent->add_augmentation_size)
	    {
	      /* Skip the PC and length and insert a zero byte for the
		 augmentation size.  */
	      buf += width * 2;
	      memmove (buf + 1, buf, end - buf);
	      *buf = 0;
	    }

	  if (ent->set_loc)
	    {
	      /* Adjust DW_CFA_set_loc.  */
	      unsigned int cnt;
	      bfd_vma new_offset;

	      width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size);
	      new_offset = ent->new_offset + 8
			   + extra_augmentation_string_bytes (ent)
			   + extra_augmentation_data_bytes (ent);

	      for (cnt = 1; cnt <= ent->set_loc[0]; cnt++)
		{
		  buf = start + ent->set_loc[cnt];

		  value = read_value (abfd, buf, width,
				      get_DW_EH_PE_signed (ent->fde_encoding));
		  if (!value)
		    continue;

		  if ((ent->fde_encoding & 0x70) == DW_EH_PE_pcrel)
		    value += (bfd_vma) ent->offset + 8 - new_offset;
		  if (ent->make_relative)
		    value -= (sec->output_section->vma
			      + sec->output_offset
			      + new_offset + ent->set_loc[cnt]);
		  write_value (abfd, buf, value, width);
		}
	    }
	}
    }

  /* FIXME: octets_per_byte.  */
  return bfd_set_section_contents (abfd, sec->output_section,
				   contents, (file_ptr) sec->output_offset,
				   sec->size);
}

/* Helper function used to sort .eh_frame_hdr search table by increasing
   VMA of FDE initial location.  */

static int
vma_compare (const void *a, const void *b)
{
  const struct eh_frame_array_ent *p = (const struct eh_frame_array_ent *) a;
  const struct eh_frame_array_ent *q = (const struct eh_frame_array_ent *) b;
  if (p->initial_loc > q->initial_loc)
    return 1;
  if (p->initial_loc < q->initial_loc)
    return -1;
  if (p->range > q->range)
    return 1;
  if (p->range < q->range)
    return -1;
  return 0;
}

/* Reorder .eh_frame_entry sections to match the associated text sections.
   This routine is called during the final linking step, just before writing
   the contents.  At this stage, sections in the eh_frame_hdr_info are already
   sorted in order of increasing text section address and so we simply need
   to make the .eh_frame_entrys follow that same order.  Note that it is
   invalid for a linker script to try to force a particular order of
   .eh_frame_entry sections.  */

bfd_boolean
_bfd_elf_fixup_eh_frame_hdr (struct bfd_link_info *info)
{
  asection *sec = NULL;
  asection *osec;
  struct eh_frame_hdr_info *hdr_info;
  unsigned int i;
  bfd_vma offset;
  struct bfd_link_order *p;

  hdr_info = &elf_hash_table (info)->eh_info;

  if (hdr_info->hdr_sec == NULL
      || info->eh_frame_hdr_type != COMPACT_EH_HDR
      || hdr_info->array_count == 0)
    return TRUE;

  /* Change section output offsets to be in text section order.  */
  offset = 8;
  osec = hdr_info->u.compact.entries[0]->output_section;
  for (i = 0; i < hdr_info->array_count; i++)
    {
      sec = hdr_info->u.compact.entries[i];
      if (sec->output_section != osec)
	{
	  _bfd_error_handler
	    (_("invalid output section for .eh_frame_entry: %pA"),
	     sec->output_section);
	  return FALSE;
	}
      sec->output_offset = offset;
      offset += sec->size;
    }


  /* Fix the link_order to match.  */
  for (p = sec->output_section->map_head.link_order; p != NULL; p = p->next)
    {
      if (p->type != bfd_indirect_link_order)
	abort();

      p->offset = p->u.indirect.section->output_offset;
      if (p->next != NULL)
	i--;
    }

  if (i != 0)
    {
      _bfd_error_handler
	(_("invalid contents in %pA section"), osec);
      return FALSE;
    }

  return TRUE;
}

/* The .eh_frame_hdr format for Compact EH frames:
   ubyte version		(2)
   ubyte eh_ref_enc		(DW_EH_PE_* encoding of typinfo references)
   uint32_t count		(Number of entries in table)
   [array from .eh_frame_entry sections]  */

static bfd_boolean
write_compact_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info)
{
  struct elf_link_hash_table *htab;
  struct eh_frame_hdr_info *hdr_info;
  asection *sec;
  const struct elf_backend_data *bed;
  bfd_vma count;
  bfd_byte contents[8];
  unsigned int i;

  htab = elf_hash_table (info);
  hdr_info = &htab->eh_info;
  sec = hdr_info->hdr_sec;

  if (sec->size != 8)
    abort();

  for (i = 0; i < sizeof (contents); i++)
    contents[i] = 0;

  contents[0] = COMPACT_EH_HDR;
  bed = get_elf_backend_data (abfd);

  BFD_ASSERT (bed->compact_eh_encoding);
  contents[1] = (*bed->compact_eh_encoding) (info);

  count = (sec->output_section->size - 8) / 8;
  bfd_put_32 (abfd, count, contents + 4);
  return bfd_set_section_contents (abfd, sec->output_section, contents,
				   (file_ptr) sec->output_offset, sec->size);
}

/* The .eh_frame_hdr format for DWARF frames:

   ubyte version		(currently 1)
   ubyte eh_frame_ptr_enc	(DW_EH_PE_* encoding of pointer to start of
				 .eh_frame section)
   ubyte fde_count_enc		(DW_EH_PE_* encoding of total FDE count
				 number (or DW_EH_PE_omit if there is no
				 binary search table computed))
   ubyte table_enc		(DW_EH_PE_* encoding of binary search table,
				 or DW_EH_PE_omit if not present.
				 DW_EH_PE_datarel is using address of
				 .eh_frame_hdr section start as base)
   [encoded] eh_frame_ptr	(pointer to start of .eh_frame section)
   optionally followed by:
   [encoded] fde_count		(total number of FDEs in .eh_frame section)
   fde_count x [encoded] initial_loc, fde
				(array of encoded pairs containing
				 FDE initial_location field and FDE address,
				 sorted by increasing initial_loc).  */

static bfd_boolean
write_dwarf_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info)
{
  struct elf_link_hash_table *htab;
  struct eh_frame_hdr_info *hdr_info;
  asection *sec;
  bfd_boolean retval = TRUE;

  htab = elf_hash_table (info);
  hdr_info = &htab->eh_info;
  sec = hdr_info->hdr_sec;
  bfd_byte *contents;
  asection *eh_frame_sec;
  bfd_size_type size;
  bfd_vma encoded_eh_frame;

  size = EH_FRAME_HDR_SIZE;
  if (hdr_info->u.dwarf.array
      && hdr_info->array_count == hdr_info->u.dwarf.fde_count)
    size += 4 + hdr_info->u.dwarf.fde_count * 8;
  contents = (bfd_byte *) bfd_malloc (size);
  if (contents == NULL)
    return FALSE;

  eh_frame_sec = bfd_get_section_by_name (abfd, ".eh_frame");
  if (eh_frame_sec == NULL)
    {
      free (contents);
      return FALSE;
    }

  memset (contents, 0, EH_FRAME_HDR_SIZE);
  /* Version.  */
  contents[0] = 1;
  /* .eh_frame offset.  */
  contents[1] = get_elf_backend_data (abfd)->elf_backend_encode_eh_address
    (abfd, info, eh_frame_sec, 0, sec, 4, &encoded_eh_frame);

  if (hdr_info->u.dwarf.array
      && hdr_info->array_count == hdr_info->u.dwarf.fde_count)
    {
      /* FDE count encoding.  */
      contents[2] = DW_EH_PE_udata4;
      /* Search table encoding.  */
      contents[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4;
    }
  else
    {
      contents[2] = DW_EH_PE_omit;
      contents[3] = DW_EH_PE_omit;
    }
  bfd_put_32 (abfd, encoded_eh_frame, contents + 4);

  if (contents[2] != DW_EH_PE_omit)
    {
      unsigned int i;
      bfd_boolean overlap, overflow;

      bfd_put_32 (abfd, hdr_info->u.dwarf.fde_count,
		  contents + EH_FRAME_HDR_SIZE);
      qsort (hdr_info->u.dwarf.array, hdr_info->u.dwarf.fde_count,
	     sizeof (*hdr_info->u.dwarf.array), vma_compare);
      overlap = FALSE;
      overflow = FALSE;
      for (i = 0; i < hdr_info->u.dwarf.fde_count; i++)
	{
	  bfd_vma val;

	  val = hdr_info->u.dwarf.array[i].initial_loc
	    - sec->output_section->vma;
	  val = ((val & 0xffffffff) ^ 0x80000000) - 0x80000000;
	  if (elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64
	      && (hdr_info->u.dwarf.array[i].initial_loc
		  != sec->output_section->vma + val))
	    overflow = TRUE;
	  bfd_put_32 (abfd, val, contents + EH_FRAME_HDR_SIZE + i * 8 + 4);
	  val = hdr_info->u.dwarf.array[i].fde - sec->output_section->vma;
	  val = ((val & 0xffffffff) ^ 0x80000000) - 0x80000000;
	  if (elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64
	      && (hdr_info->u.dwarf.array[i].fde
		  != sec->output_section->vma + val))
	    overflow = TRUE;
	  bfd_put_32 (abfd, val, contents + EH_FRAME_HDR_SIZE + i * 8 + 8);
	  if (i != 0
	      && (hdr_info->u.dwarf.array[i].initial_loc
		  < (hdr_info->u.dwarf.array[i - 1].initial_loc
		     + hdr_info->u.dwarf.array[i - 1].range)))
	    overlap = TRUE;
	}
      if (overflow)
	_bfd_error_handler (_(".eh_frame_hdr entry overflow"));
      if (overlap)
	_bfd_error_handler (_(".eh_frame_hdr refers to overlapping FDEs"));
      if (overflow || overlap)
	{
	  bfd_set_error (bfd_error_bad_value);
	  retval = FALSE;
	}
    }

  /* FIXME: octets_per_byte.  */
  if (!bfd_set_section_contents (abfd, sec->output_section, contents,
				 (file_ptr) sec->output_offset,
				 sec->size))
    retval = FALSE;
  free (contents);

  if (hdr_info->u.dwarf.array != NULL)
    free (hdr_info->u.dwarf.array);
  return retval;
}

/* Write out .eh_frame_hdr section.  This must be called after
   _bfd_elf_write_section_eh_frame has been called on all input
   .eh_frame sections.  */

bfd_boolean
_bfd_elf_write_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info)
{
  struct elf_link_hash_table *htab;
  struct eh_frame_hdr_info *hdr_info;
  asection *sec;

  htab = elf_hash_table (info);
  hdr_info = &htab->eh_info;
  sec = hdr_info->hdr_sec;

  if (info->eh_frame_hdr_type == 0 || sec == NULL)
    return TRUE;

  if (info->eh_frame_hdr_type == COMPACT_EH_HDR)
    return write_compact_eh_frame_hdr (abfd, info);
  else
    return write_dwarf_eh_frame_hdr (abfd, info);
}

/* Return the width of FDE addresses.  This is the default implementation.  */

unsigned int
_bfd_elf_eh_frame_address_size (bfd *abfd, const asection *sec ATTRIBUTE_UNUSED)
{
  return elf_elfheader (abfd)->e_ident[EI_CLASS] == ELFCLASS64 ? 8 : 4;
}

/* Decide whether we can use a PC-relative encoding within the given
   EH frame section.  This is the default implementation.  */

bfd_boolean
_bfd_elf_can_make_relative (bfd *input_bfd ATTRIBUTE_UNUSED,
			    struct bfd_link_info *info ATTRIBUTE_UNUSED,
			    asection *eh_frame_section ATTRIBUTE_UNUSED)
{
  return TRUE;
}

/* Select an encoding for the given address.  Preference is given to
   PC-relative addressing modes.  */

bfd_byte
_bfd_elf_encode_eh_address (bfd *abfd ATTRIBUTE_UNUSED,
			    struct bfd_link_info *info ATTRIBUTE_UNUSED,
			    asection *osec, bfd_vma offset,
			    asection *loc_sec, bfd_vma loc_offset,
			    bfd_vma *encoded)
{
  *encoded = osec->vma + offset -
    (loc_sec->output_section->vma + loc_sec->output_offset + loc_offset);
  return DW_EH_PE_pcrel | DW_EH_PE_sdata4;
}