aboutsummaryrefslogtreecommitdiff
path: root/bfd/elf-eh-frame.c
blob: 902d7c16334ea725b0caac8033d05422316bb4c5 (plain)
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
/* .eh_frame section optimization.
   Copyright (C) 2001-2024 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 bool
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 bool
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 bool
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 bool
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 bool
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 bool
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.  */

bool
_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->flags & SEC_HAS_CONTENTS) == 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_elf_mmap_section_contents (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 'B':
		    break;
		  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;
  free (sec_info);
 success:
  _bfd_elf_munmap_section_contents (sec, ehbuf);
  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, sec->size + 8);
}

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

bool
_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 bool
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.  */

bool
_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)
    {
      bool 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.  */

bool
_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)
{
  int adjusted = 0;

  if (cookie->locsymcount > 1)
    {
      unsigned int shndx = elf_section_data (sec)->this_idx;
      Elf_Internal_Sym *end_sym = cookie->locsyms + cookie->locsymcount;
      Elf_Internal_Sym *sym;

      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.  */

bool
_bfd_elf_discard_section_eh_frame
   (bfd *abfd, struct bfd_link_info *info, asection *sec,
    bool (*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)
      {
	bool 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;
		/* Only warn if --eh-frame-hdr was specified.  */
		if (info->eh_frame_hdr_type != 0)
		  {
		    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);
	  }
      }

  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.  */

bool
_bfd_elf_discard_section_eh_frame_hdr (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;
    }

  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.  */

bool
_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.  */

bool
_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_section_name (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.  */

bool
_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.  */

bool
_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.  */

bool
_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 version, 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.  */
	      buf += 8;
	      version = *buf++;
	      aug = (char *) buf;
	      buf += strlen (aug) + 1;
	      skip_leb128 (&buf, end);
	      skip_leb128 (&buf, end);
	      if (version == 1)
		skip_bytes (&buf, end, 1);
	      else
		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:
		      case bfd_arch_nios2:
			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.  */

bool
_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 bool
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 bool
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;
  bool 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;
      bool 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);

  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.  */

bool
_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.  */

bool
_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;
}