aboutsummaryrefslogtreecommitdiff
path: root/libbacktrace/elf.c
blob: 3cd87020b031530b46a5eff79ef51598562554c8 (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
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
5198
5199
5200
5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5274
5275
5276
5277
5278
5279
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
5302
5303
5304
5305
5306
5307
5308
5309
5310
5311
5312
5313
5314
5315
5316
5317
5318
5319
5320
5321
5322
5323
5324
5325
5326
5327
5328
5329
5330
5331
5332
5333
5334
5335
5336
5337
5338
5339
5340
5341
5342
5343
5344
5345
5346
5347
5348
5349
5350
5351
5352
5353
5354
5355
5356
5357
5358
5359
5360
5361
5362
5363
5364
5365
5366
5367
5368
5369
5370
5371
5372
5373
5374
5375
5376
5377
5378
5379
5380
5381
5382
5383
5384
5385
5386
5387
5388
5389
5390
5391
5392
5393
5394
5395
5396
5397
5398
5399
5400
5401
5402
5403
5404
5405
5406
5407
5408
5409
5410
5411
5412
5413
5414
5415
5416
5417
5418
5419
5420
5421
5422
5423
5424
5425
5426
5427
5428
5429
5430
5431
5432
5433
5434
5435
5436
5437
5438
5439
5440
5441
5442
5443
5444
5445
5446
5447
5448
5449
5450
5451
5452
5453
5454
5455
5456
5457
5458
5459
5460
5461
5462
5463
5464
5465
5466
5467
5468
5469
5470
5471
5472
5473
5474
5475
5476
5477
5478
5479
5480
5481
5482
5483
5484
5485
5486
5487
5488
5489
5490
5491
5492
5493
5494
5495
5496
5497
5498
5499
5500
5501
5502
5503
5504
5505
5506
5507
5508
5509
5510
5511
5512
5513
5514
5515
5516
5517
5518
5519
5520
5521
5522
5523
5524
5525
5526
5527
5528
5529
5530
5531
5532
5533
5534
5535
5536
5537
5538
5539
5540
5541
5542
5543
5544
5545
5546
5547
5548
5549
5550
5551
5552
5553
5554
5555
5556
5557
5558
5559
5560
5561
5562
5563
5564
5565
5566
5567
5568
5569
5570
5571
5572
5573
5574
5575
5576
5577
5578
5579
5580
5581
5582
5583
5584
5585
5586
5587
5588
5589
5590
5591
5592
5593
5594
5595
5596
5597
5598
5599
5600
5601
5602
5603
5604
5605
5606
5607
5608
5609
5610
5611
5612
5613
5614
5615
5616
5617
5618
5619
5620
5621
5622
5623
5624
5625
5626
5627
5628
5629
5630
5631
5632
5633
5634
5635
5636
5637
5638
5639
5640
5641
5642
5643
5644
5645
5646
5647
5648
5649
5650
5651
5652
5653
5654
5655
5656
5657
5658
5659
5660
5661
5662
5663
5664
5665
5666
5667
5668
5669
5670
5671
5672
5673
5674
5675
5676
5677
5678
5679
5680
5681
5682
5683
5684
5685
5686
5687
5688
5689
5690
5691
5692
5693
5694
5695
5696
5697
5698
5699
5700
5701
5702
5703
5704
5705
5706
5707
5708
5709
5710
5711
5712
5713
5714
5715
5716
5717
5718
5719
5720
5721
5722
5723
5724
5725
5726
5727
5728
5729
5730
5731
5732
5733
5734
5735
5736
5737
5738
5739
5740
5741
5742
5743
5744
5745
5746
5747
5748
5749
5750
5751
5752
5753
5754
5755
5756
5757
5758
5759
5760
5761
5762
5763
5764
5765
5766
5767
5768
5769
5770
5771
5772
5773
5774
5775
5776
5777
5778
5779
5780
5781
5782
5783
5784
5785
5786
5787
5788
5789
5790
5791
5792
5793
5794
5795
5796
5797
5798
5799
5800
5801
5802
5803
5804
5805
5806
5807
5808
5809
5810
5811
5812
5813
5814
5815
5816
5817
5818
5819
5820
5821
5822
5823
5824
5825
5826
5827
5828
5829
5830
5831
5832
5833
5834
5835
5836
5837
5838
5839
5840
5841
5842
5843
5844
5845
5846
5847
5848
5849
5850
5851
5852
5853
5854
5855
5856
5857
5858
5859
5860
5861
5862
5863
5864
5865
5866
5867
5868
5869
5870
5871
5872
5873
5874
5875
5876
5877
5878
5879
5880
5881
5882
5883
5884
5885
5886
5887
5888
5889
5890
5891
5892
5893
5894
5895
5896
5897
5898
5899
5900
5901
5902
5903
5904
5905
5906
5907
5908
5909
5910
5911
5912
5913
5914
5915
5916
5917
5918
5919
5920
5921
5922
5923
5924
5925
5926
5927
5928
5929
5930
5931
5932
5933
5934
5935
5936
5937
5938
5939
5940
5941
5942
5943
5944
5945
5946
5947
5948
5949
5950
5951
5952
5953
5954
5955
5956
5957
5958
5959
5960
5961
5962
5963
5964
5965
5966
5967
5968
5969
5970
5971
5972
5973
5974
5975
5976
5977
5978
5979
5980
5981
5982
5983
5984
5985
5986
5987
5988
5989
5990
5991
5992
5993
5994
5995
5996
5997
5998
5999
6000
6001
6002
6003
6004
6005
6006
6007
6008
6009
6010
6011
6012
6013
6014
6015
6016
6017
6018
6019
6020
6021
6022
6023
6024
6025
6026
6027
6028
6029
6030
6031
6032
6033
6034
6035
6036
6037
6038
6039
6040
6041
6042
6043
6044
6045
6046
6047
6048
6049
6050
6051
6052
6053
6054
6055
6056
6057
6058
6059
6060
6061
6062
6063
6064
6065
6066
6067
6068
6069
6070
6071
6072
6073
6074
6075
6076
6077
6078
6079
6080
6081
6082
6083
6084
6085
6086
6087
6088
6089
6090
6091
6092
6093
6094
6095
6096
6097
6098
6099
6100
6101
6102
6103
6104
6105
6106
6107
6108
6109
6110
6111
6112
6113
6114
6115
6116
6117
6118
6119
6120
6121
6122
6123
6124
6125
6126
6127
6128
6129
6130
6131
6132
6133
6134
6135
6136
6137
6138
6139
6140
6141
6142
6143
6144
6145
6146
6147
6148
6149
6150
6151
6152
6153
6154
6155
6156
6157
6158
6159
6160
6161
6162
6163
6164
6165
6166
6167
6168
6169
6170
6171
6172
6173
6174
6175
6176
6177
6178
6179
6180
6181
6182
6183
6184
6185
6186
6187
6188
6189
6190
6191
6192
6193
6194
6195
6196
6197
6198
6199
6200
6201
6202
6203
6204
6205
6206
6207
6208
6209
6210
6211
6212
6213
6214
6215
6216
6217
6218
6219
6220
6221
6222
6223
6224
6225
6226
6227
6228
6229
6230
6231
6232
6233
6234
6235
6236
6237
6238
6239
6240
6241
6242
6243
6244
6245
6246
6247
6248
6249
6250
6251
6252
6253
6254
6255
6256
6257
6258
6259
6260
6261
6262
6263
6264
6265
6266
6267
6268
6269
6270
6271
6272
6273
6274
6275
6276
6277
6278
6279
6280
6281
6282
6283
6284
6285
6286
6287
6288
6289
6290
6291
6292
6293
6294
6295
6296
6297
6298
6299
6300
6301
6302
6303
6304
6305
6306
6307
6308
6309
6310
6311
6312
6313
6314
6315
6316
6317
6318
6319
6320
6321
6322
6323
6324
6325
6326
6327
6328
6329
6330
6331
6332
6333
6334
6335
6336
6337
6338
6339
6340
6341
6342
6343
6344
6345
6346
6347
6348
6349
6350
6351
6352
6353
6354
6355
6356
6357
6358
6359
6360
6361
6362
6363
6364
6365
6366
6367
6368
6369
6370
6371
6372
6373
6374
6375
6376
6377
6378
6379
6380
6381
6382
6383
6384
6385
6386
6387
6388
6389
6390
6391
6392
6393
6394
6395
6396
6397
6398
6399
6400
6401
6402
6403
6404
6405
6406
6407
6408
6409
6410
6411
6412
6413
6414
6415
6416
6417
6418
6419
6420
6421
6422
6423
6424
6425
6426
6427
6428
6429
6430
6431
6432
6433
6434
6435
6436
6437
6438
6439
6440
6441
6442
6443
6444
6445
6446
6447
6448
6449
6450
6451
6452
6453
6454
6455
6456
6457
6458
6459
6460
6461
6462
6463
6464
6465
6466
6467
6468
6469
6470
6471
6472
6473
6474
6475
6476
6477
6478
6479
6480
6481
6482
6483
6484
6485
6486
6487
6488
6489
6490
6491
6492
6493
6494
6495
6496
6497
6498
6499
6500
6501
6502
6503
6504
6505
6506
6507
6508
6509
6510
6511
6512
6513
6514
6515
6516
6517
6518
6519
6520
6521
6522
6523
6524
6525
6526
6527
6528
6529
6530
6531
6532
6533
6534
6535
6536
6537
6538
6539
6540
6541
6542
6543
6544
6545
6546
6547
6548
6549
6550
6551
6552
6553
6554
6555
6556
6557
6558
6559
6560
6561
6562
6563
6564
6565
6566
6567
6568
6569
6570
6571
6572
6573
6574
6575
6576
6577
6578
6579
6580
6581
6582
6583
6584
6585
6586
6587
6588
6589
6590
6591
6592
6593
6594
6595
6596
6597
6598
6599
6600
6601
6602
6603
6604
6605
6606
6607
6608
6609
6610
6611
6612
6613
6614
6615
6616
6617
6618
6619
6620
6621
6622
6623
6624
6625
6626
6627
6628
6629
6630
6631
6632
6633
6634
6635
6636
6637
6638
6639
6640
6641
6642
6643
6644
6645
6646
6647
6648
6649
6650
6651
6652
6653
6654
6655
6656
6657
6658
6659
6660
6661
6662
6663
6664
6665
6666
6667
6668
6669
6670
6671
6672
6673
6674
6675
6676
6677
6678
6679
6680
6681
6682
6683
6684
6685
6686
6687
6688
6689
6690
6691
6692
6693
6694
6695
6696
6697
6698
6699
6700
6701
6702
6703
6704
6705
6706
6707
6708
6709
6710
6711
6712
6713
6714
6715
6716
6717
6718
6719
6720
6721
6722
6723
6724
6725
6726
6727
6728
6729
6730
6731
6732
6733
6734
6735
6736
6737
6738
6739
6740
6741
6742
6743
6744
6745
6746
6747
6748
6749
6750
6751
6752
6753
6754
6755
6756
6757
6758
6759
6760
6761
6762
6763
6764
6765
6766
6767
6768
6769
6770
6771
6772
6773
6774
6775
6776
6777
6778
6779
6780
6781
6782
6783
6784
6785
6786
6787
6788
6789
6790
6791
6792
6793
6794
6795
6796
6797
6798
6799
6800
6801
6802
6803
6804
6805
6806
6807
6808
6809
6810
6811
6812
6813
6814
6815
6816
6817
6818
6819
6820
6821
6822
6823
6824
6825
6826
6827
6828
6829
6830
6831
6832
6833
6834
6835
6836
6837
6838
6839
6840
6841
6842
6843
6844
6845
6846
6847
6848
6849
6850
6851
6852
6853
6854
6855
6856
6857
6858
6859
6860
6861
6862
6863
6864
6865
6866
6867
6868
6869
6870
6871
6872
6873
6874
6875
6876
6877
6878
6879
6880
6881
6882
6883
6884
6885
6886
6887
6888
6889
6890
6891
6892
6893
6894
6895
6896
6897
6898
6899
6900
6901
6902
6903
6904
6905
6906
6907
6908
6909
6910
6911
6912
6913
6914
6915
6916
6917
6918
6919
6920
6921
6922
6923
6924
6925
6926
6927
6928
6929
6930
6931
6932
6933
6934
6935
6936
6937
6938
6939
6940
6941
6942
6943
6944
6945
6946
6947
6948
6949
6950
6951
6952
6953
6954
6955
6956
6957
6958
6959
6960
6961
6962
6963
6964
6965
6966
6967
6968
6969
6970
6971
6972
6973
6974
6975
6976
6977
6978
6979
6980
6981
6982
6983
6984
6985
6986
6987
6988
6989
6990
6991
6992
6993
6994
6995
6996
6997
6998
6999
7000
7001
7002
7003
7004
7005
7006
7007
7008
7009
7010
7011
7012
7013
7014
7015
7016
7017
7018
7019
7020
7021
7022
7023
7024
7025
7026
7027
7028
7029
7030
7031
7032
7033
7034
7035
7036
7037
7038
7039
7040
7041
7042
7043
7044
7045
7046
7047
7048
7049
7050
7051
7052
7053
7054
7055
7056
7057
7058
7059
7060
7061
7062
7063
7064
7065
7066
7067
7068
7069
7070
7071
7072
7073
7074
7075
7076
7077
7078
7079
7080
7081
7082
7083
7084
7085
7086
7087
7088
7089
7090
7091
7092
7093
7094
7095
7096
7097
7098
7099
7100
7101
7102
7103
7104
7105
7106
7107
7108
7109
7110
7111
7112
7113
7114
7115
7116
7117
7118
7119
7120
7121
7122
7123
7124
7125
7126
7127
7128
7129
7130
7131
7132
7133
7134
7135
7136
7137
7138
7139
7140
7141
7142
7143
7144
7145
7146
7147
7148
7149
7150
7151
7152
7153
7154
7155
7156
7157
7158
7159
7160
7161
7162
7163
7164
7165
7166
7167
7168
7169
7170
7171
7172
7173
7174
7175
7176
7177
7178
7179
7180
7181
7182
7183
7184
7185
7186
7187
7188
7189
7190
7191
7192
7193
7194
7195
7196
7197
7198
7199
7200
7201
7202
7203
7204
7205
7206
7207
7208
7209
7210
7211
7212
7213
7214
7215
7216
7217
7218
7219
7220
7221
7222
7223
7224
7225
7226
7227
7228
7229
7230
7231
7232
7233
7234
7235
7236
7237
7238
7239
7240
7241
7242
7243
7244
7245
7246
7247
7248
7249
7250
7251
7252
7253
7254
7255
7256
7257
7258
7259
7260
7261
7262
7263
7264
7265
7266
7267
7268
7269
7270
7271
7272
7273
7274
7275
7276
7277
7278
7279
7280
7281
7282
7283
7284
7285
7286
7287
7288
7289
7290
7291
7292
7293
7294
7295
7296
7297
7298
7299
7300
7301
7302
7303
7304
7305
7306
7307
7308
7309
7310
7311
7312
7313
7314
7315
7316
7317
7318
7319
7320
7321
7322
7323
7324
7325
7326
7327
7328
7329
7330
7331
7332
7333
7334
7335
7336
7337
7338
7339
7340
7341
7342
7343
7344
7345
7346
7347
7348
7349
7350
7351
7352
7353
7354
7355
7356
7357
7358
7359
7360
7361
7362
7363
7364
7365
7366
7367
7368
7369
7370
7371
7372
7373
7374
7375
7376
7377
7378
7379
7380
7381
7382
7383
7384
7385
7386
7387
7388
7389
7390
7391
7392
7393
7394
7395
7396
7397
7398
7399
7400
7401
7402
7403
7404
7405
7406
7407
7408
7409
7410
7411
7412
7413
7414
7415
7416
7417
7418
7419
7420
7421
7422
7423
7424
7425
7426
7427
7428
7429
7430
7431
7432
7433
7434
7435
7436
7437
7438
7439
7440
7441
7442
7443
7444
7445
7446
7447
7448
7449
7450
7451
7452
7453
7454
7455
7456
7457
7458
/* elf.c -- Get debug data from an ELF file for backtraces.
   Copyright (C) 2012-2024 Free Software Foundation, Inc.
   Written by Ian Lance Taylor, Google.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

    (1) Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.

    (2) Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in
    the documentation and/or other materials provided with the
    distribution.

    (3) The name of the author may not be used to
    endorse or promote products derived from this software without
    specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.  */

#include "config.h"

#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

#ifdef HAVE_DL_ITERATE_PHDR
 #ifdef HAVE_LINK_H
  #include <link.h>
 #endif
 #ifdef HAVE_SYS_LINK_H
  #include <sys/link.h>
 #endif
#endif

#include "backtrace.h"
#include "internal.h"

#ifndef S_ISLNK
 #ifndef S_IFLNK
  #define S_IFLNK 0120000
 #endif
 #ifndef S_IFMT
  #define S_IFMT 0170000
 #endif
 #define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK)
#endif

#ifndef __GNUC__
#define __builtin_prefetch(p, r, l)
#define unlikely(x) (x)
#else
#define unlikely(x) __builtin_expect(!!(x), 0)
#endif

#if !defined(HAVE_DECL_STRNLEN) || !HAVE_DECL_STRNLEN

/* If strnlen is not declared, provide our own version.  */

static size_t
xstrnlen (const char *s, size_t maxlen)
{
  size_t i;

  for (i = 0; i < maxlen; ++i)
    if (s[i] == '\0')
      break;
  return i;
}

#define strnlen xstrnlen

#endif

#ifndef HAVE_LSTAT

/* Dummy version of lstat for systems that don't have it.  */

static int
xlstat (const char *path ATTRIBUTE_UNUSED, struct stat *st ATTRIBUTE_UNUSED)
{
  return -1;
}

#define lstat xlstat

#endif

#ifndef HAVE_READLINK

/* Dummy version of readlink for systems that don't have it.  */

static ssize_t
xreadlink (const char *path ATTRIBUTE_UNUSED, char *buf ATTRIBUTE_UNUSED,
	   size_t bufsz ATTRIBUTE_UNUSED)
{
  return -1;
}

#define readlink xreadlink

#endif

#ifndef HAVE_DL_ITERATE_PHDR

/* Dummy version of dl_iterate_phdr for systems that don't have it.  */

#define dl_phdr_info x_dl_phdr_info
#define dl_iterate_phdr x_dl_iterate_phdr

struct dl_phdr_info
{
  uintptr_t dlpi_addr;
  const char *dlpi_name;
};

static int
dl_iterate_phdr (int (*callback) (struct dl_phdr_info *,
				  size_t, void *) ATTRIBUTE_UNUSED,
		 void *data ATTRIBUTE_UNUSED)
{
  return 0;
}

#endif /* ! defined (HAVE_DL_ITERATE_PHDR) */

/* The configure script must tell us whether we are 32-bit or 64-bit
   ELF.  We could make this code test and support either possibility,
   but there is no point.  This code only works for the currently
   running executable, which means that we know the ELF mode at
   configure time.  */

#if BACKTRACE_ELF_SIZE != 32 && BACKTRACE_ELF_SIZE != 64
#error "Unknown BACKTRACE_ELF_SIZE"
#endif

/* <link.h> might #include <elf.h> which might define our constants
   with slightly different values.  Undefine them to be safe.  */

#undef EI_NIDENT
#undef EI_MAG0
#undef EI_MAG1
#undef EI_MAG2
#undef EI_MAG3
#undef EI_CLASS
#undef EI_DATA
#undef EI_VERSION
#undef ELF_MAG0
#undef ELF_MAG1
#undef ELF_MAG2
#undef ELF_MAG3
#undef ELFCLASS32
#undef ELFCLASS64
#undef ELFDATA2LSB
#undef ELFDATA2MSB
#undef EV_CURRENT
#undef ET_DYN
#undef EM_PPC64
#undef EF_PPC64_ABI
#undef SHN_LORESERVE
#undef SHN_XINDEX
#undef SHN_UNDEF
#undef SHT_PROGBITS
#undef SHT_SYMTAB
#undef SHT_STRTAB
#undef SHT_DYNSYM
#undef SHF_COMPRESSED
#undef STT_OBJECT
#undef STT_FUNC
#undef NT_GNU_BUILD_ID
#undef ELFCOMPRESS_ZLIB
#undef ELFCOMPRESS_ZSTD

/* Basic types.  */

typedef uint16_t b_elf_half;    /* Elf_Half.  */
typedef uint32_t b_elf_word;    /* Elf_Word.  */
typedef int32_t  b_elf_sword;   /* Elf_Sword.  */

#if BACKTRACE_ELF_SIZE == 32

typedef uint32_t b_elf_addr;    /* Elf_Addr.  */
typedef uint32_t b_elf_off;     /* Elf_Off.  */

typedef uint32_t b_elf_wxword;  /* 32-bit Elf_Word, 64-bit ELF_Xword.  */

#else

typedef uint64_t b_elf_addr;    /* Elf_Addr.  */
typedef uint64_t b_elf_off;     /* Elf_Off.  */
typedef uint64_t b_elf_xword;   /* Elf_Xword.  */
typedef int64_t  b_elf_sxword;  /* Elf_Sxword.  */

typedef uint64_t b_elf_wxword;  /* 32-bit Elf_Word, 64-bit ELF_Xword.  */

#endif

/* Data structures and associated constants.  */

#define EI_NIDENT 16

typedef struct {
  unsigned char	e_ident[EI_NIDENT];	/* ELF "magic number" */
  b_elf_half	e_type;			/* Identifies object file type */
  b_elf_half	e_machine;		/* Specifies required architecture */
  b_elf_word	e_version;		/* Identifies object file version */
  b_elf_addr	e_entry;		/* Entry point virtual address */
  b_elf_off	e_phoff;		/* Program header table file offset */
  b_elf_off	e_shoff;		/* Section header table file offset */
  b_elf_word	e_flags;		/* Processor-specific flags */
  b_elf_half	e_ehsize;		/* ELF header size in bytes */
  b_elf_half	e_phentsize;		/* Program header table entry size */
  b_elf_half	e_phnum;		/* Program header table entry count */
  b_elf_half	e_shentsize;		/* Section header table entry size */
  b_elf_half	e_shnum;		/* Section header table entry count */
  b_elf_half	e_shstrndx;		/* Section header string table index */
} b_elf_ehdr;  /* Elf_Ehdr.  */

#define EI_MAG0 0
#define EI_MAG1 1
#define EI_MAG2 2
#define EI_MAG3 3
#define EI_CLASS 4
#define EI_DATA 5
#define EI_VERSION 6

#define ELFMAG0 0x7f
#define ELFMAG1 'E'
#define ELFMAG2 'L'
#define ELFMAG3 'F'

#define ELFCLASS32 1
#define ELFCLASS64 2

#define ELFDATA2LSB 1
#define ELFDATA2MSB 2

#define EV_CURRENT 1

#define ET_DYN 3

#define EM_PPC64 21
#define EF_PPC64_ABI 3

typedef struct {
  b_elf_word	sh_name;		/* Section name, index in string tbl */
  b_elf_word	sh_type;		/* Type of section */
  b_elf_wxword	sh_flags;		/* Miscellaneous section attributes */
  b_elf_addr	sh_addr;		/* Section virtual addr at execution */
  b_elf_off	sh_offset;		/* Section file offset */
  b_elf_wxword	sh_size;		/* Size of section in bytes */
  b_elf_word	sh_link;		/* Index of another section */
  b_elf_word	sh_info;		/* Additional section information */
  b_elf_wxword	sh_addralign;		/* Section alignment */
  b_elf_wxword	sh_entsize;		/* Entry size if section holds table */
} b_elf_shdr;  /* Elf_Shdr.  */

#define SHN_UNDEF	0x0000		/* Undefined section */
#define SHN_LORESERVE	0xFF00		/* Begin range of reserved indices */
#define SHN_XINDEX	0xFFFF		/* Section index is held elsewhere */

#define SHT_PROGBITS 1
#define SHT_SYMTAB 2
#define SHT_STRTAB 3
#define SHT_DYNSYM 11

#define SHF_COMPRESSED 0x800

#if BACKTRACE_ELF_SIZE == 32

typedef struct
{
  b_elf_word	st_name;		/* Symbol name, index in string tbl */
  b_elf_addr	st_value;		/* Symbol value */
  b_elf_word	st_size;		/* Symbol size */
  unsigned char	st_info;		/* Symbol binding and type */
  unsigned char	st_other;		/* Visibility and other data */
  b_elf_half	st_shndx;		/* Symbol section index */
} b_elf_sym;  /* Elf_Sym.  */

#else /* BACKTRACE_ELF_SIZE != 32 */

typedef struct
{
  b_elf_word	st_name;		/* Symbol name, index in string tbl */
  unsigned char	st_info;		/* Symbol binding and type */
  unsigned char	st_other;		/* Visibility and other data */
  b_elf_half	st_shndx;		/* Symbol section index */
  b_elf_addr	st_value;		/* Symbol value */
  b_elf_xword	st_size;		/* Symbol size */
} b_elf_sym;  /* Elf_Sym.  */

#endif /* BACKTRACE_ELF_SIZE != 32 */

#define STT_OBJECT 1
#define STT_FUNC 2

typedef struct
{
  uint32_t namesz;
  uint32_t descsz;
  uint32_t type;
  char name[1];
} b_elf_note;

#define NT_GNU_BUILD_ID 3

#if BACKTRACE_ELF_SIZE == 32

typedef struct
{
  b_elf_word	ch_type;		/* Compresstion algorithm */
  b_elf_word	ch_size;		/* Uncompressed size */
  b_elf_word	ch_addralign;		/* Alignment for uncompressed data */
} b_elf_chdr;  /* Elf_Chdr */

#else /* BACKTRACE_ELF_SIZE != 32 */

typedef struct
{
  b_elf_word	ch_type;		/* Compression algorithm */
  b_elf_word	ch_reserved;		/* Reserved */
  b_elf_xword	ch_size;		/* Uncompressed size */
  b_elf_xword	ch_addralign;		/* Alignment for uncompressed data */
} b_elf_chdr;  /* Elf_Chdr */

#endif /* BACKTRACE_ELF_SIZE != 32 */

#define ELFCOMPRESS_ZLIB 1
#define ELFCOMPRESS_ZSTD 2

/* Names of sections, indexed by enum dwarf_section in internal.h.  */

static const char * const dwarf_section_names[DEBUG_MAX] =
{
  ".debug_info",
  ".debug_line",
  ".debug_abbrev",
  ".debug_ranges",
  ".debug_str",
  ".debug_addr",
  ".debug_str_offsets",
  ".debug_line_str",
  ".debug_rnglists"
};

/* Information we gather for the sections we care about.  */

struct debug_section_info
{
  /* Section file offset.  */
  off_t offset;
  /* Section size.  */
  size_t size;
  /* Section contents, after read from file.  */
  const unsigned char *data;
  /* Whether the SHF_COMPRESSED flag is set for the section.  */
  int compressed;
};

/* Information we keep for an ELF symbol.  */

struct elf_symbol
{
  /* The name of the symbol.  */
  const char *name;
  /* The address of the symbol.  */
  uintptr_t address;
  /* The size of the symbol.  */
  size_t size;
};

/* Information to pass to elf_syminfo.  */

struct elf_syminfo_data
{
  /* Symbols for the next module.  */
  struct elf_syminfo_data *next;
  /* The ELF symbols, sorted by address.  */
  struct elf_symbol *symbols;
  /* The number of symbols.  */
  size_t count;
};

/* A view that works for either a file or memory.  */

struct elf_view
{
  struct backtrace_view view;
  int release; /* If non-zero, must call backtrace_release_view.  */
};

/* Information about PowerPC64 ELFv1 .opd section.  */

struct elf_ppc64_opd_data
{
  /* Address of the .opd section.  */
  b_elf_addr addr;
  /* Section data.  */
  const char *data;
  /* Size of the .opd section.  */
  size_t size;
  /* Corresponding section view.  */
  struct elf_view view;
};

/* Create a view of SIZE bytes from DESCRIPTOR/MEMORY at OFFSET.  */

static int
elf_get_view (struct backtrace_state *state, int descriptor,
	      const unsigned char *memory, size_t memory_size, off_t offset,
	      uint64_t size, backtrace_error_callback error_callback,
	      void *data, struct elf_view *view)
{
  if (memory == NULL)
    {
      view->release = 1;
      return backtrace_get_view (state, descriptor, offset, size,
				 error_callback, data, &view->view);
    }
  else
    {
      if ((uint64_t) offset + size > (uint64_t) memory_size)
	{
	  error_callback (data, "out of range for in-memory file", 0);
	  return 0;
	}
      view->view.data = (const void *) (memory + offset);
      view->view.base = NULL;
      view->view.len = size;
      view->release = 0;
      return 1;
    }
}

/* Release a view read by elf_get_view.  */

static void
elf_release_view (struct backtrace_state *state, struct elf_view *view,
		  backtrace_error_callback error_callback, void *data)
{
  if (view->release)
    backtrace_release_view (state, &view->view, error_callback, data);
}

/* Compute the CRC-32 of BUF/LEN.  This uses the CRC used for
   .gnu_debuglink files.  */

static uint32_t
elf_crc32 (uint32_t crc, const unsigned char *buf, size_t len)
{
  static const uint32_t crc32_table[256] =
    {
      0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419,
      0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,
      0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07,
      0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
      0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856,
      0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
      0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,
      0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
      0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3,
      0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a,
      0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599,
      0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
      0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190,
      0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,
      0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e,
      0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
      0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed,
      0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
      0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3,
      0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
      0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a,
      0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5,
      0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010,
      0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
      0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17,
      0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6,
      0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615,
      0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
      0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344,
      0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
      0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a,
      0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
      0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1,
      0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c,
      0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef,
      0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
      0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe,
      0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31,
      0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c,
      0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
      0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b,
      0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
      0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1,
      0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
      0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278,
      0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7,
      0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66,
      0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
      0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605,
      0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8,
      0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b,
      0x2d02ef8d
    };
  const unsigned char *end;

  crc = ~crc;
  for (end = buf + len; buf < end; ++ buf)
    crc = crc32_table[(crc ^ *buf) & 0xff] ^ (crc >> 8);
  return ~crc;
}

/* Return the CRC-32 of the entire file open at DESCRIPTOR.  */

static uint32_t
elf_crc32_file (struct backtrace_state *state, int descriptor,
		backtrace_error_callback error_callback, void *data)
{
  struct stat st;
  struct backtrace_view file_view;
  uint32_t ret;

  if (fstat (descriptor, &st) < 0)
    {
      error_callback (data, "fstat", errno);
      return 0;
    }

  if (!backtrace_get_view (state, descriptor, 0, st.st_size, error_callback,
			   data, &file_view))
    return 0;

  ret = elf_crc32 (0, (const unsigned char *) file_view.data, st.st_size);

  backtrace_release_view (state, &file_view, error_callback, data);

  return ret;
}

/* A dummy callback function used when we can't find a symbol
   table.  */

static void
elf_nosyms (struct backtrace_state *state ATTRIBUTE_UNUSED,
	    uintptr_t addr ATTRIBUTE_UNUSED,
	    backtrace_syminfo_callback callback ATTRIBUTE_UNUSED,
	    backtrace_error_callback error_callback, void *data)
{
  error_callback (data, "no symbol table in ELF executable", -1);
}

/* A callback function used when we can't find any debug info.  */

static int
elf_nodebug (struct backtrace_state *state, uintptr_t pc,
	     backtrace_full_callback callback,
	     backtrace_error_callback error_callback, void *data)
{
  if (state->syminfo_fn != NULL && state->syminfo_fn != elf_nosyms)
    {
      struct backtrace_call_full bdata;

      /* Fetch symbol information so that we can least get the
	 function name.  */

      bdata.full_callback = callback;
      bdata.full_error_callback = error_callback;
      bdata.full_data = data;
      bdata.ret = 0;
      state->syminfo_fn (state, pc, backtrace_syminfo_to_full_callback,
			 backtrace_syminfo_to_full_error_callback, &bdata);
      return bdata.ret;
    }

  error_callback (data, "no debug info in ELF executable", -1);
  return 0;
}

/* Compare struct elf_symbol for qsort.  */

static int
elf_symbol_compare (const void *v1, const void *v2)
{
  const struct elf_symbol *e1 = (const struct elf_symbol *) v1;
  const struct elf_symbol *e2 = (const struct elf_symbol *) v2;

  if (e1->address < e2->address)
    return -1;
  else if (e1->address > e2->address)
    return 1;
  else
    return 0;
}

/* Compare an ADDR against an elf_symbol for bsearch.  We allocate one
   extra entry in the array so that this can look safely at the next
   entry.  */

static int
elf_symbol_search (const void *vkey, const void *ventry)
{
  const uintptr_t *key = (const uintptr_t *) vkey;
  const struct elf_symbol *entry = (const struct elf_symbol *) ventry;
  uintptr_t addr;

  addr = *key;
  if (addr < entry->address)
    return -1;
  else if (addr >= entry->address + entry->size)
    return 1;
  else
    return 0;
}

/* Initialize the symbol table info for elf_syminfo.  */

static int
elf_initialize_syminfo (struct backtrace_state *state,
			uintptr_t base_address,
			const unsigned char *symtab_data, size_t symtab_size,
			const unsigned char *strtab, size_t strtab_size,
			backtrace_error_callback error_callback,
			void *data, struct elf_syminfo_data *sdata,
			struct elf_ppc64_opd_data *opd)
{
  size_t sym_count;
  const b_elf_sym *sym;
  size_t elf_symbol_count;
  size_t elf_symbol_size;
  struct elf_symbol *elf_symbols;
  size_t i;
  unsigned int j;

  sym_count = symtab_size / sizeof (b_elf_sym);

  /* We only care about function symbols.  Count them.  */
  sym = (const b_elf_sym *) symtab_data;
  elf_symbol_count = 0;
  for (i = 0; i < sym_count; ++i, ++sym)
    {
      int info;

      info = sym->st_info & 0xf;
      if ((info == STT_FUNC || info == STT_OBJECT)
	  && sym->st_shndx != SHN_UNDEF)
	++elf_symbol_count;
    }

  elf_symbol_size = elf_symbol_count * sizeof (struct elf_symbol);
  elf_symbols = ((struct elf_symbol *)
		 backtrace_alloc (state, elf_symbol_size, error_callback,
				  data));
  if (elf_symbols == NULL)
    return 0;

  sym = (const b_elf_sym *) symtab_data;
  j = 0;
  for (i = 0; i < sym_count; ++i, ++sym)
    {
      int info;

      info = sym->st_info & 0xf;
      if (info != STT_FUNC && info != STT_OBJECT)
	continue;
      if (sym->st_shndx == SHN_UNDEF)
	continue;
      if (sym->st_name >= strtab_size)
	{
	  error_callback (data, "symbol string index out of range", 0);
	  backtrace_free (state, elf_symbols, elf_symbol_size, error_callback,
			  data);
	  return 0;
	}
      elf_symbols[j].name = (const char *) strtab + sym->st_name;
      /* Special case PowerPC64 ELFv1 symbols in .opd section, if the symbol
	 is a function descriptor, read the actual code address from the
	 descriptor.  */
      if (opd
	  && sym->st_value >= opd->addr
	  && sym->st_value < opd->addr + opd->size)
	elf_symbols[j].address
	  = *(const b_elf_addr *) (opd->data + (sym->st_value - opd->addr));
      else
	elf_symbols[j].address = sym->st_value;
      elf_symbols[j].address += base_address;
      elf_symbols[j].size = sym->st_size;
      ++j;
    }

  backtrace_qsort (elf_symbols, elf_symbol_count, sizeof (struct elf_symbol),
		   elf_symbol_compare);

  sdata->next = NULL;
  sdata->symbols = elf_symbols;
  sdata->count = elf_symbol_count;

  return 1;
}

/* Add EDATA to the list in STATE.  */

static void
elf_add_syminfo_data (struct backtrace_state *state,
		      struct elf_syminfo_data *edata)
{
  if (!state->threaded)
    {
      struct elf_syminfo_data **pp;

      for (pp = (struct elf_syminfo_data **) (void *) &state->syminfo_data;
	   *pp != NULL;
	   pp = &(*pp)->next)
	;
      *pp = edata;
    }
  else
    {
      while (1)
	{
	  struct elf_syminfo_data **pp;

	  pp = (struct elf_syminfo_data **) (void *) &state->syminfo_data;

	  while (1)
	    {
	      struct elf_syminfo_data *p;

	      p = backtrace_atomic_load_pointer (pp);

	      if (p == NULL)
		break;

	      pp = &p->next;
	    }

	  if (__sync_bool_compare_and_swap (pp, NULL, edata))
	    break;
	}
    }
}

/* Return the symbol name and value for an ADDR.  */

static void
elf_syminfo (struct backtrace_state *state, uintptr_t addr,
	     backtrace_syminfo_callback callback,
	     backtrace_error_callback error_callback ATTRIBUTE_UNUSED,
	     void *data)
{
  struct elf_syminfo_data *edata;
  struct elf_symbol *sym = NULL;

  if (!state->threaded)
    {
      for (edata = (struct elf_syminfo_data *) state->syminfo_data;
	   edata != NULL;
	   edata = edata->next)
	{
	  sym = ((struct elf_symbol *)
		 bsearch (&addr, edata->symbols, edata->count,
			  sizeof (struct elf_symbol), elf_symbol_search));
	  if (sym != NULL)
	    break;
	}
    }
  else
    {
      struct elf_syminfo_data **pp;

      pp = (struct elf_syminfo_data **) (void *) &state->syminfo_data;
      while (1)
	{
	  edata = backtrace_atomic_load_pointer (pp);
	  if (edata == NULL)
	    break;

	  sym = ((struct elf_symbol *)
		 bsearch (&addr, edata->symbols, edata->count,
			  sizeof (struct elf_symbol), elf_symbol_search));
	  if (sym != NULL)
	    break;

	  pp = &edata->next;
	}
    }

  if (sym == NULL)
    callback (data, addr, NULL, 0, 0);
  else
    callback (data, addr, sym->name, sym->address, sym->size);
}

/* Return whether FILENAME is a symlink.  */

static int
elf_is_symlink (const char *filename)
{
  struct stat st;

  if (lstat (filename, &st) < 0)
    return 0;
  return S_ISLNK (st.st_mode);
}

/* Return the results of reading the symlink FILENAME in a buffer
   allocated by backtrace_alloc.  Return the length of the buffer in
   *LEN.  */

static char *
elf_readlink (struct backtrace_state *state, const char *filename,
	      backtrace_error_callback error_callback, void *data,
	      size_t *plen)
{
  size_t len;
  char *buf;

  len = 128;
  while (1)
    {
      ssize_t rl;

      buf = backtrace_alloc (state, len, error_callback, data);
      if (buf == NULL)
	return NULL;
      rl = readlink (filename, buf, len);
      if (rl < 0)
	{
	  backtrace_free (state, buf, len, error_callback, data);
	  return NULL;
	}
      if ((size_t) rl < len - 1)
	{
	  buf[rl] = '\0';
	  *plen = len;
	  return buf;
	}
      backtrace_free (state, buf, len, error_callback, data);
      len *= 2;
    }
}

#define SYSTEM_BUILD_ID_DIR "/usr/lib/debug/.build-id/"

/* Open a separate debug info file, using the build ID to find it.
   Returns an open file descriptor, or -1.

   The GDB manual says that the only place gdb looks for a debug file
   when the build ID is known is in /usr/lib/debug/.build-id.  */

static int
elf_open_debugfile_by_buildid (struct backtrace_state *state,
			       const char *buildid_data, size_t buildid_size,
			       backtrace_error_callback error_callback,
			       void *data)
{
  const char * const prefix = SYSTEM_BUILD_ID_DIR;
  const size_t prefix_len = strlen (prefix);
  const char * const suffix = ".debug";
  const size_t suffix_len = strlen (suffix);
  size_t len;
  char *bd_filename;
  char *t;
  size_t i;
  int ret;
  int does_not_exist;

  len = prefix_len + buildid_size * 2 + suffix_len + 2;
  bd_filename = backtrace_alloc (state, len, error_callback, data);
  if (bd_filename == NULL)
    return -1;

  t = bd_filename;
  memcpy (t, prefix, prefix_len);
  t += prefix_len;
  for (i = 0; i < buildid_size; i++)
    {
      unsigned char b;
      unsigned char nib;

      b = (unsigned char) buildid_data[i];
      nib = (b & 0xf0) >> 4;
      *t++ = nib < 10 ? '0' + nib : 'a' + nib - 10;
      nib = b & 0x0f;
      *t++ = nib < 10 ? '0' + nib : 'a' + nib - 10;
      if (i == 0)
	*t++ = '/';
    }
  memcpy (t, suffix, suffix_len);
  t[suffix_len] = '\0';

  ret = backtrace_open (bd_filename, error_callback, data, &does_not_exist);

  backtrace_free (state, bd_filename, len, error_callback, data);

  /* gdb checks that the debuginfo file has the same build ID note.
     That seems kind of pointless to me--why would it have the right
     name but not the right build ID?--so skipping the check.  */

  return ret;
}

/* Try to open a file whose name is PREFIX (length PREFIX_LEN)
   concatenated with PREFIX2 (length PREFIX2_LEN) concatenated with
   DEBUGLINK_NAME.  Returns an open file descriptor, or -1.  */

static int
elf_try_debugfile (struct backtrace_state *state, const char *prefix,
		   size_t prefix_len, const char *prefix2, size_t prefix2_len,
		   const char *debuglink_name,
		   backtrace_error_callback error_callback, void *data)
{
  size_t debuglink_len;
  size_t try_len;
  char *try;
  int does_not_exist;
  int ret;

  debuglink_len = strlen (debuglink_name);
  try_len = prefix_len + prefix2_len + debuglink_len + 1;
  try = backtrace_alloc (state, try_len, error_callback, data);
  if (try == NULL)
    return -1;

  memcpy (try, prefix, prefix_len);
  memcpy (try + prefix_len, prefix2, prefix2_len);
  memcpy (try + prefix_len + prefix2_len, debuglink_name, debuglink_len);
  try[prefix_len + prefix2_len + debuglink_len] = '\0';

  ret = backtrace_open (try, error_callback, data, &does_not_exist);

  backtrace_free (state, try, try_len, error_callback, data);

  return ret;
}

/* Find a separate debug info file, using the debuglink section data
   to find it.  Returns an open file descriptor, or -1.  */

static int
elf_find_debugfile_by_debuglink (struct backtrace_state *state,
				 const char *filename,
				 const char *debuglink_name,
				 backtrace_error_callback error_callback,
				 void *data)
{
  int ret;
  char *alc;
  size_t alc_len;
  const char *slash;
  int ddescriptor;
  const char *prefix;
  size_t prefix_len;

  /* Resolve symlinks in FILENAME.  Since FILENAME is fairly likely to
     be /proc/self/exe, symlinks are common.  We don't try to resolve
     the whole path name, just the base name.  */
  ret = -1;
  alc = NULL;
  alc_len = 0;
  while (elf_is_symlink (filename))
    {
      char *new_buf;
      size_t new_len;

      new_buf = elf_readlink (state, filename, error_callback, data, &new_len);
      if (new_buf == NULL)
	break;

      if (new_buf[0] == '/')
	filename = new_buf;
      else
	{
	  slash = strrchr (filename, '/');
	  if (slash == NULL)
	    filename = new_buf;
	  else
	    {
	      size_t clen;
	      char *c;

	      slash++;
	      clen = slash - filename + strlen (new_buf) + 1;
	      c = backtrace_alloc (state, clen, error_callback, data);
	      if (c == NULL)
		goto done;

	      memcpy (c, filename, slash - filename);
	      memcpy (c + (slash - filename), new_buf, strlen (new_buf));
	      c[slash - filename + strlen (new_buf)] = '\0';
	      backtrace_free (state, new_buf, new_len, error_callback, data);
	      filename = c;
	      new_buf = c;
	      new_len = clen;
	    }
	}

      if (alc != NULL)
	backtrace_free (state, alc, alc_len, error_callback, data);
      alc = new_buf;
      alc_len = new_len;
    }

  /* Look for DEBUGLINK_NAME in the same directory as FILENAME.  */

  slash = strrchr (filename, '/');
  if (slash == NULL)
    {
      prefix = "";
      prefix_len = 0;
    }
  else
    {
      slash++;
      prefix = filename;
      prefix_len = slash - filename;
    }

  ddescriptor = elf_try_debugfile (state, prefix, prefix_len, "", 0,
				   debuglink_name, error_callback, data);
  if (ddescriptor >= 0)
    {
      ret = ddescriptor;
      goto done;
    }

  /* Look for DEBUGLINK_NAME in a .debug subdirectory of FILENAME.  */

  ddescriptor = elf_try_debugfile (state, prefix, prefix_len, ".debug/",
				   strlen (".debug/"), debuglink_name,
				   error_callback, data);
  if (ddescriptor >= 0)
    {
      ret = ddescriptor;
      goto done;
    }

  /* Look for DEBUGLINK_NAME in /usr/lib/debug.  */

  ddescriptor = elf_try_debugfile (state, "/usr/lib/debug/",
				   strlen ("/usr/lib/debug/"), prefix,
				   prefix_len, debuglink_name,
				   error_callback, data);
  if (ddescriptor >= 0)
    ret = ddescriptor;

 done:
  if (alc != NULL && alc_len > 0)
    backtrace_free (state, alc, alc_len, error_callback, data);
  return ret;
}

/* Open a separate debug info file, using the debuglink section data
   to find it.  Returns an open file descriptor, or -1.  */

static int
elf_open_debugfile_by_debuglink (struct backtrace_state *state,
				 const char *filename,
				 const char *debuglink_name,
				 uint32_t debuglink_crc,
				 backtrace_error_callback error_callback,
				 void *data)
{
  int ddescriptor;

  ddescriptor = elf_find_debugfile_by_debuglink (state, filename,
						 debuglink_name,
						 error_callback, data);
  if (ddescriptor < 0)
    return -1;

  if (debuglink_crc != 0)
    {
      uint32_t got_crc;

      got_crc = elf_crc32_file (state, ddescriptor, error_callback, data);
      if (got_crc != debuglink_crc)
	{
	  backtrace_close (ddescriptor, error_callback, data);
	  return -1;
	}
    }

  return ddescriptor;
}

/* A function useful for setting a breakpoint for an inflation failure
   when this code is compiled with -g.  */

static void
elf_uncompress_failed(void)
{
}

/* *PVAL is the current value being read from the stream, and *PBITS
   is the number of valid bits.  Ensure that *PVAL holds at least 15
   bits by reading additional bits from *PPIN, up to PINEND, as
   needed.  Updates *PPIN, *PVAL and *PBITS.  Returns 1 on success, 0
   on error.  */

static int
elf_fetch_bits (const unsigned char **ppin, const unsigned char *pinend,
		uint64_t *pval, unsigned int *pbits)
{
  unsigned int bits;
  const unsigned char *pin;
  uint64_t val;
  uint32_t next;

  bits = *pbits;
  if (bits >= 15)
    return 1;
  pin = *ppin;
  val = *pval;

  if (unlikely (pinend - pin < 4))
    {
      elf_uncompress_failed ();
      return 0;
    }

#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) \
    && defined(__ORDER_BIG_ENDIAN__) \
    && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ \
        || __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
  /* We've ensured that PIN is aligned.  */
  next = *(const uint32_t *)pin;

#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
  next = __builtin_bswap32 (next);
#endif
#else
  next = pin[0] | (pin[1] << 8) | (pin[2] << 16) | (pin[3] << 24);
#endif

  val |= (uint64_t)next << bits;
  bits += 32;
  pin += 4;

  /* We will need the next four bytes soon.  */
  __builtin_prefetch (pin, 0, 0);

  *ppin = pin;
  *pval = val;
  *pbits = bits;
  return 1;
}

/* This is like elf_fetch_bits, but it fetchs the bits backward, and ensures at
   least 16 bits.  This is for zstd.  */

static int
elf_fetch_bits_backward (const unsigned char **ppin,
			 const unsigned char *pinend,
			 uint64_t *pval, unsigned int *pbits)
{
  unsigned int bits;
  const unsigned char *pin;
  uint64_t val;
  uint32_t next;

  bits = *pbits;
  if (bits >= 16)
    return 1;
  pin = *ppin;
  val = *pval;

  if (unlikely (pin <= pinend))
    {
      if (bits == 0)
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      return 1;
    }

  pin -= 4;

#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) \
  && defined(__ORDER_BIG_ENDIAN__)				\
  && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__			\
      || __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
  /* We've ensured that PIN is aligned.  */
  next = *(const uint32_t *)pin;

#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
  next = __builtin_bswap32 (next);
#endif
#else
  next = pin[0] | (pin[1] << 8) | (pin[2] << 16) | (pin[3] << 24);
#endif

  val <<= 32;
  val |= next;
  bits += 32;

  if (unlikely (pin < pinend))
    {
      val >>= (pinend - pin) * 8;
      bits -= (pinend - pin) * 8;
    }

  *ppin = pin;
  *pval = val;
  *pbits = bits;
  return 1;
}

/* Initialize backward fetching when the bitstream starts with a 1 bit in the
   last byte in memory (which is the first one that we read).  This is used by
   zstd decompression.  Returns 1 on success, 0 on error.  */

static int
elf_fetch_backward_init (const unsigned char **ppin,
			 const unsigned char *pinend,
			 uint64_t *pval, unsigned int *pbits)
{
  const unsigned char *pin;
  unsigned int stream_start;
  uint64_t val;
  unsigned int bits;

  pin = *ppin;
  stream_start = (unsigned int)*pin;
  if (unlikely (stream_start == 0))
    {
      elf_uncompress_failed ();
      return 0;
    }
  val = 0;
  bits = 0;

  /* Align to a 32-bit boundary.  */
  while ((((uintptr_t)pin) & 3) != 0)
    {
      val <<= 8;
      val |= (uint64_t)*pin;
      bits += 8;
      --pin;
    }

  val <<= 8;
  val |= (uint64_t)*pin;
  bits += 8;

  *ppin = pin;
  *pval = val;
  *pbits = bits;
  if (!elf_fetch_bits_backward (ppin, pinend, pval, pbits))
    return 0;

  *pbits -= __builtin_clz (stream_start) - (sizeof (unsigned int) - 1) * 8 + 1;

  if (!elf_fetch_bits_backward (ppin, pinend, pval, pbits))
    return 0;

  return 1;
}

/* Huffman code tables, like the rest of the zlib format, are defined
   by RFC 1951.  We store a Huffman code table as a series of tables
   stored sequentially in memory.  Each entry in a table is 16 bits.
   The first, main, table has 256 entries.  It is followed by a set of
   secondary tables of length 2 to 128 entries.  The maximum length of
   a code sequence in the deflate format is 15 bits, so that is all we
   need.  Each secondary table has an index, which is the offset of
   the table in the overall memory storage.

   The deflate format says that all codes of a given bit length are
   lexicographically consecutive.  Perhaps we could have 130 values
   that require a 15-bit code, perhaps requiring three secondary
   tables of size 128.  I don't know if this is actually possible, but
   it suggests that the maximum size required for secondary tables is
   3 * 128 + 3 * 64 ... == 768.  The zlib enough program reports 660
   as the maximum.  We permit 768, since in addition to the 256 for
   the primary table, with two bytes per entry, and with the two
   tables we need, that gives us a page.

   A single table entry needs to store a value or (for the main table
   only) the index and size of a secondary table.  Values range from 0
   to 285, inclusive.  Secondary table indexes, per above, range from
   0 to 510.  For a value we need to store the number of bits we need
   to determine that value (one value may appear multiple times in the
   table), which is 1 to 8.  For a secondary table we need to store
   the number of bits used to index into the table, which is 1 to 7.
   And of course we need 1 bit to decide whether we have a value or a
   secondary table index.  So each entry needs 9 bits for value/table
   index, 3 bits for size, 1 bit what it is.  For simplicity we use 16
   bits per entry.  */

/* Number of entries we allocate to for one code table.  We get a page
   for the two code tables we need.  */

#define ZLIB_HUFFMAN_TABLE_SIZE (1024)

/* Bit masks and shifts for the values in the table.  */

#define ZLIB_HUFFMAN_VALUE_MASK 0x01ff
#define ZLIB_HUFFMAN_BITS_SHIFT 9
#define ZLIB_HUFFMAN_BITS_MASK 0x7
#define ZLIB_HUFFMAN_SECONDARY_SHIFT 12

/* For working memory while inflating we need two code tables, we need
   an array of code lengths (max value 15, so we use unsigned char),
   and an array of unsigned shorts used while building a table.  The
   latter two arrays must be large enough to hold the maximum number
   of code lengths, which RFC 1951 defines as 286 + 30.  */

#define ZLIB_TABLE_SIZE \
  (2 * ZLIB_HUFFMAN_TABLE_SIZE * sizeof (uint16_t) \
   + (286 + 30) * sizeof (uint16_t)	      \
   + (286 + 30) * sizeof (unsigned char))

#define ZLIB_TABLE_CODELEN_OFFSET \
  (2 * ZLIB_HUFFMAN_TABLE_SIZE * sizeof (uint16_t) \
   + (286 + 30) * sizeof (uint16_t))

#define ZLIB_TABLE_WORK_OFFSET \
  (2 * ZLIB_HUFFMAN_TABLE_SIZE * sizeof (uint16_t))

#ifdef BACKTRACE_GENERATE_FIXED_HUFFMAN_TABLE

/* Used by the main function that generates the fixed table to learn
   the table size.  */
static size_t final_next_secondary;

#endif

/* Build a Huffman code table from an array of lengths in CODES of
   length CODES_LEN.  The table is stored into *TABLE.  ZDEBUG_TABLE
   is the same as for elf_zlib_inflate, used to find some work space.
   Returns 1 on success, 0 on error.  */

static int
elf_zlib_inflate_table (unsigned char *codes, size_t codes_len,
			uint16_t *zdebug_table, uint16_t *table)
{
  uint16_t count[16];
  uint16_t start[16];
  uint16_t prev[16];
  uint16_t firstcode[7];
  uint16_t *next;
  size_t i;
  size_t j;
  unsigned int code;
  size_t next_secondary;

  /* Count the number of code of each length.  Set NEXT[val] to be the
     next value after VAL with the same bit length.  */

  next = (uint16_t *) (((unsigned char *) zdebug_table)
		       + ZLIB_TABLE_WORK_OFFSET);

  memset (&count[0], 0, 16 * sizeof (uint16_t));
  for (i = 0; i < codes_len; ++i)
    {
      if (unlikely (codes[i] >= 16))
	{
	  elf_uncompress_failed ();
	  return 0;
	}

      if (count[codes[i]] == 0)
	{
	  start[codes[i]] = i;
	  prev[codes[i]] = i;
	}
      else
	{
	  next[prev[codes[i]]] = i;
	  prev[codes[i]] = i;
	}

      ++count[codes[i]];
    }

  /* For each length, fill in the table for the codes of that
     length.  */

  memset (table, 0, ZLIB_HUFFMAN_TABLE_SIZE * sizeof (uint16_t));

  /* Handle the values that do not require a secondary table.  */

  code = 0;
  for (j = 1; j <= 8; ++j)
    {
      unsigned int jcnt;
      unsigned int val;

      jcnt = count[j];
      if (jcnt == 0)
	continue;

      if (unlikely (jcnt > (1U << j)))
	{
	  elf_uncompress_failed ();
	  return 0;
	}

      /* There are JCNT values that have this length, the values
	 starting from START[j] continuing through NEXT[VAL].  Those
	 values are assigned consecutive values starting at CODE.  */

      val = start[j];
      for (i = 0; i < jcnt; ++i)
	{
	  uint16_t tval;
	  size_t ind;
	  unsigned int incr;

	  /* In the compressed bit stream, the value VAL is encoded as
	     J bits with the value C.  */

	  if (unlikely ((val & ~ZLIB_HUFFMAN_VALUE_MASK) != 0))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }

	  tval = val | ((j - 1) << ZLIB_HUFFMAN_BITS_SHIFT);

	  /* The table lookup uses 8 bits.  If J is less than 8, we
	     don't know what the other bits will be.  We need to fill
	     in all possibilities in the table.  Since the Huffman
	     code is unambiguous, those entries can't be used for any
	     other code.  */

	  for (ind = code; ind < 0x100; ind += 1 << j)
	    {
	      if (unlikely (table[ind] != 0))
		{
		  elf_uncompress_failed ();
		  return 0;
		}
	      table[ind] = tval;
	    }

	  /* Advance to the next value with this length.  */
	  if (i + 1 < jcnt)
	    val = next[val];

	  /* The Huffman codes are stored in the bitstream with the
	     most significant bit first, as is required to make them
	     unambiguous.  The effect is that when we read them from
	     the bitstream we see the bit sequence in reverse order:
	     the most significant bit of the Huffman code is the least
	     significant bit of the value we read from the bitstream.
	     That means that to make our table lookups work, we need
	     to reverse the bits of CODE.  Since reversing bits is
	     tedious and in general requires using a table, we instead
	     increment CODE in reverse order.  That is, if the number
	     of bits we are currently using, here named J, is 3, we
	     count as 000, 100, 010, 110, 001, 101, 011, 111, which is
	     to say the numbers from 0 to 7 but with the bits
	     reversed.  Going to more bits, aka incrementing J,
	     effectively just adds more zero bits as the beginning,
	     and as such does not change the numeric value of CODE.

	     To increment CODE of length J in reverse order, find the
	     most significant zero bit and set it to one while
	     clearing all higher bits.  In other words, add 1 modulo
	     2^J, only reversed.  */

	  incr = 1U << (j - 1);
	  while ((code & incr) != 0)
	    incr >>= 1;
	  if (incr == 0)
	    code = 0;
	  else
	    {
	      code &= incr - 1;
	      code += incr;
	    }
	}
    }

  /* Handle the values that require a secondary table.  */

  /* Set FIRSTCODE, the number at which the codes start, for each
     length.  */

  for (j = 9; j < 16; j++)
    {
      unsigned int jcnt;
      unsigned int k;

      jcnt = count[j];
      if (jcnt == 0)
	continue;

      /* There are JCNT values that have this length, the values
	 starting from START[j].  Those values are assigned
	 consecutive values starting at CODE.  */

      firstcode[j - 9] = code;

      /* Reverse add JCNT to CODE modulo 2^J.  */
      for (k = 0; k < j; ++k)
	{
	  if ((jcnt & (1U << k)) != 0)
	    {
	      unsigned int m;
	      unsigned int bit;

	      bit = 1U << (j - k - 1);
	      for (m = 0; m < j - k; ++m, bit >>= 1)
		{
		  if ((code & bit) == 0)
		    {
		      code += bit;
		      break;
		    }
		  code &= ~bit;
		}
	      jcnt &= ~(1U << k);
	    }
	}
      if (unlikely (jcnt != 0))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
    }

  /* For J from 9 to 15, inclusive, we store COUNT[J] consecutive
     values starting at START[J] with consecutive codes starting at
     FIRSTCODE[J - 9].  In the primary table we need to point to the
     secondary table, and the secondary table will be indexed by J - 9
     bits.  We count down from 15 so that we install the larger
     secondary tables first, as the smaller ones may be embedded in
     the larger ones.  */

  next_secondary = 0; /* Index of next secondary table (after primary).  */
  for (j = 15; j >= 9; j--)
    {
      unsigned int jcnt;
      unsigned int val;
      size_t primary; /* Current primary index.  */
      size_t secondary; /* Offset to current secondary table.  */
      size_t secondary_bits; /* Bit size of current secondary table.  */

      jcnt = count[j];
      if (jcnt == 0)
	continue;

      val = start[j];
      code = firstcode[j - 9];
      primary = 0x100;
      secondary = 0;
      secondary_bits = 0;
      for (i = 0; i < jcnt; ++i)
	{
	  uint16_t tval;
	  size_t ind;
	  unsigned int incr;

	  if ((code & 0xff) != primary)
	    {
	      uint16_t tprimary;

	      /* Fill in a new primary table entry.  */

	      primary = code & 0xff;

	      tprimary = table[primary];
	      if (tprimary == 0)
		{
		  /* Start a new secondary table.  */

		  if (unlikely ((next_secondary & ZLIB_HUFFMAN_VALUE_MASK)
				!= next_secondary))
		    {
		      elf_uncompress_failed ();
		      return 0;
		    }

		  secondary = next_secondary;
		  secondary_bits = j - 8;
		  next_secondary += 1 << secondary_bits;
		  table[primary] = (secondary
				    + ((j - 8) << ZLIB_HUFFMAN_BITS_SHIFT)
				    + (1U << ZLIB_HUFFMAN_SECONDARY_SHIFT));
		}
	      else
		{
		  /* There is an existing entry.  It had better be a
		     secondary table with enough bits.  */
		  if (unlikely ((tprimary
				 & (1U << ZLIB_HUFFMAN_SECONDARY_SHIFT))
				== 0))
		    {
		      elf_uncompress_failed ();
		      return 0;
		    }
		  secondary = tprimary & ZLIB_HUFFMAN_VALUE_MASK;
		  secondary_bits = ((tprimary >> ZLIB_HUFFMAN_BITS_SHIFT)
				    & ZLIB_HUFFMAN_BITS_MASK);
		  if (unlikely (secondary_bits < j - 8))
		    {
		      elf_uncompress_failed ();
		      return 0;
		    }
		}
	    }

	  /* Fill in secondary table entries.  */

	  tval = val | ((j - 8) << ZLIB_HUFFMAN_BITS_SHIFT);

	  for (ind = code >> 8;
	       ind < (1U << secondary_bits);
	       ind += 1U << (j - 8))
	    {
	      if (unlikely (table[secondary + 0x100 + ind] != 0))
		{
		  elf_uncompress_failed ();
		  return 0;
		}
	      table[secondary + 0x100 + ind] = tval;
	    }

	  if (i + 1 < jcnt)
	    val = next[val];

	  incr = 1U << (j - 1);
	  while ((code & incr) != 0)
	    incr >>= 1;
	  if (incr == 0)
	    code = 0;
	  else
	    {
	      code &= incr - 1;
	      code += incr;
	    }
	}
    }

#ifdef BACKTRACE_GENERATE_FIXED_HUFFMAN_TABLE
  final_next_secondary = next_secondary;
#endif

  return 1;
}

#ifdef BACKTRACE_GENERATE_FIXED_HUFFMAN_TABLE

/* Used to generate the fixed Huffman table for block type 1.  */

#include <stdio.h>

static uint16_t table[ZLIB_TABLE_SIZE];
static unsigned char codes[288];

int
main ()
{
  size_t i;

  for (i = 0; i <= 143; ++i)
    codes[i] = 8;
  for (i = 144; i <= 255; ++i)
    codes[i] = 9;
  for (i = 256; i <= 279; ++i)
    codes[i] = 7;
  for (i = 280; i <= 287; ++i)
    codes[i] = 8;
  if (!elf_zlib_inflate_table (&codes[0], 288, &table[0], &table[0]))
    {
      fprintf (stderr, "elf_zlib_inflate_table failed\n");
      exit (EXIT_FAILURE);
    }

  printf ("static const uint16_t elf_zlib_default_table[%#zx] =\n",
	  final_next_secondary + 0x100);
  printf ("{\n");
  for (i = 0; i < final_next_secondary + 0x100; i += 8)
    {
      size_t j;

      printf (" ");
      for (j = i; j < final_next_secondary + 0x100 && j < i + 8; ++j)
	printf (" %#x,", table[j]);
      printf ("\n");
    }
  printf ("};\n");
  printf ("\n");

  for (i = 0; i < 32; ++i)
    codes[i] = 5;
  if (!elf_zlib_inflate_table (&codes[0], 32, &table[0], &table[0]))
    {
      fprintf (stderr, "elf_zlib_inflate_table failed\n");
      exit (EXIT_FAILURE);
    }

  printf ("static const uint16_t elf_zlib_default_dist_table[%#zx] =\n",
	  final_next_secondary + 0x100);
  printf ("{\n");
  for (i = 0; i < final_next_secondary + 0x100; i += 8)
    {
      size_t j;

      printf (" ");
      for (j = i; j < final_next_secondary + 0x100 && j < i + 8; ++j)
	printf (" %#x,", table[j]);
      printf ("\n");
    }
  printf ("};\n");

  return 0;
}

#endif

/* The fixed tables generated by the #ifdef'ed out main function
   above.  */

static const uint16_t elf_zlib_default_table[0x170] =
{
  0xd00, 0xe50, 0xe10, 0xf18, 0xd10, 0xe70, 0xe30, 0x1230,
  0xd08, 0xe60, 0xe20, 0x1210, 0xe00, 0xe80, 0xe40, 0x1250,
  0xd04, 0xe58, 0xe18, 0x1200, 0xd14, 0xe78, 0xe38, 0x1240,
  0xd0c, 0xe68, 0xe28, 0x1220, 0xe08, 0xe88, 0xe48, 0x1260,
  0xd02, 0xe54, 0xe14, 0xf1c, 0xd12, 0xe74, 0xe34, 0x1238,
  0xd0a, 0xe64, 0xe24, 0x1218, 0xe04, 0xe84, 0xe44, 0x1258,
  0xd06, 0xe5c, 0xe1c, 0x1208, 0xd16, 0xe7c, 0xe3c, 0x1248,
  0xd0e, 0xe6c, 0xe2c, 0x1228, 0xe0c, 0xe8c, 0xe4c, 0x1268,
  0xd01, 0xe52, 0xe12, 0xf1a, 0xd11, 0xe72, 0xe32, 0x1234,
  0xd09, 0xe62, 0xe22, 0x1214, 0xe02, 0xe82, 0xe42, 0x1254,
  0xd05, 0xe5a, 0xe1a, 0x1204, 0xd15, 0xe7a, 0xe3a, 0x1244,
  0xd0d, 0xe6a, 0xe2a, 0x1224, 0xe0a, 0xe8a, 0xe4a, 0x1264,
  0xd03, 0xe56, 0xe16, 0xf1e, 0xd13, 0xe76, 0xe36, 0x123c,
  0xd0b, 0xe66, 0xe26, 0x121c, 0xe06, 0xe86, 0xe46, 0x125c,
  0xd07, 0xe5e, 0xe1e, 0x120c, 0xd17, 0xe7e, 0xe3e, 0x124c,
  0xd0f, 0xe6e, 0xe2e, 0x122c, 0xe0e, 0xe8e, 0xe4e, 0x126c,
  0xd00, 0xe51, 0xe11, 0xf19, 0xd10, 0xe71, 0xe31, 0x1232,
  0xd08, 0xe61, 0xe21, 0x1212, 0xe01, 0xe81, 0xe41, 0x1252,
  0xd04, 0xe59, 0xe19, 0x1202, 0xd14, 0xe79, 0xe39, 0x1242,
  0xd0c, 0xe69, 0xe29, 0x1222, 0xe09, 0xe89, 0xe49, 0x1262,
  0xd02, 0xe55, 0xe15, 0xf1d, 0xd12, 0xe75, 0xe35, 0x123a,
  0xd0a, 0xe65, 0xe25, 0x121a, 0xe05, 0xe85, 0xe45, 0x125a,
  0xd06, 0xe5d, 0xe1d, 0x120a, 0xd16, 0xe7d, 0xe3d, 0x124a,
  0xd0e, 0xe6d, 0xe2d, 0x122a, 0xe0d, 0xe8d, 0xe4d, 0x126a,
  0xd01, 0xe53, 0xe13, 0xf1b, 0xd11, 0xe73, 0xe33, 0x1236,
  0xd09, 0xe63, 0xe23, 0x1216, 0xe03, 0xe83, 0xe43, 0x1256,
  0xd05, 0xe5b, 0xe1b, 0x1206, 0xd15, 0xe7b, 0xe3b, 0x1246,
  0xd0d, 0xe6b, 0xe2b, 0x1226, 0xe0b, 0xe8b, 0xe4b, 0x1266,
  0xd03, 0xe57, 0xe17, 0xf1f, 0xd13, 0xe77, 0xe37, 0x123e,
  0xd0b, 0xe67, 0xe27, 0x121e, 0xe07, 0xe87, 0xe47, 0x125e,
  0xd07, 0xe5f, 0xe1f, 0x120e, 0xd17, 0xe7f, 0xe3f, 0x124e,
  0xd0f, 0xe6f, 0xe2f, 0x122e, 0xe0f, 0xe8f, 0xe4f, 0x126e,
  0x290, 0x291, 0x292, 0x293, 0x294, 0x295, 0x296, 0x297,
  0x298, 0x299, 0x29a, 0x29b, 0x29c, 0x29d, 0x29e, 0x29f,
  0x2a0, 0x2a1, 0x2a2, 0x2a3, 0x2a4, 0x2a5, 0x2a6, 0x2a7,
  0x2a8, 0x2a9, 0x2aa, 0x2ab, 0x2ac, 0x2ad, 0x2ae, 0x2af,
  0x2b0, 0x2b1, 0x2b2, 0x2b3, 0x2b4, 0x2b5, 0x2b6, 0x2b7,
  0x2b8, 0x2b9, 0x2ba, 0x2bb, 0x2bc, 0x2bd, 0x2be, 0x2bf,
  0x2c0, 0x2c1, 0x2c2, 0x2c3, 0x2c4, 0x2c5, 0x2c6, 0x2c7,
  0x2c8, 0x2c9, 0x2ca, 0x2cb, 0x2cc, 0x2cd, 0x2ce, 0x2cf,
  0x2d0, 0x2d1, 0x2d2, 0x2d3, 0x2d4, 0x2d5, 0x2d6, 0x2d7,
  0x2d8, 0x2d9, 0x2da, 0x2db, 0x2dc, 0x2dd, 0x2de, 0x2df,
  0x2e0, 0x2e1, 0x2e2, 0x2e3, 0x2e4, 0x2e5, 0x2e6, 0x2e7,
  0x2e8, 0x2e9, 0x2ea, 0x2eb, 0x2ec, 0x2ed, 0x2ee, 0x2ef,
  0x2f0, 0x2f1, 0x2f2, 0x2f3, 0x2f4, 0x2f5, 0x2f6, 0x2f7,
  0x2f8, 0x2f9, 0x2fa, 0x2fb, 0x2fc, 0x2fd, 0x2fe, 0x2ff,
};

static const uint16_t elf_zlib_default_dist_table[0x100] =
{
  0x800, 0x810, 0x808, 0x818, 0x804, 0x814, 0x80c, 0x81c,
  0x802, 0x812, 0x80a, 0x81a, 0x806, 0x816, 0x80e, 0x81e,
  0x801, 0x811, 0x809, 0x819, 0x805, 0x815, 0x80d, 0x81d,
  0x803, 0x813, 0x80b, 0x81b, 0x807, 0x817, 0x80f, 0x81f,
  0x800, 0x810, 0x808, 0x818, 0x804, 0x814, 0x80c, 0x81c,
  0x802, 0x812, 0x80a, 0x81a, 0x806, 0x816, 0x80e, 0x81e,
  0x801, 0x811, 0x809, 0x819, 0x805, 0x815, 0x80d, 0x81d,
  0x803, 0x813, 0x80b, 0x81b, 0x807, 0x817, 0x80f, 0x81f,
  0x800, 0x810, 0x808, 0x818, 0x804, 0x814, 0x80c, 0x81c,
  0x802, 0x812, 0x80a, 0x81a, 0x806, 0x816, 0x80e, 0x81e,
  0x801, 0x811, 0x809, 0x819, 0x805, 0x815, 0x80d, 0x81d,
  0x803, 0x813, 0x80b, 0x81b, 0x807, 0x817, 0x80f, 0x81f,
  0x800, 0x810, 0x808, 0x818, 0x804, 0x814, 0x80c, 0x81c,
  0x802, 0x812, 0x80a, 0x81a, 0x806, 0x816, 0x80e, 0x81e,
  0x801, 0x811, 0x809, 0x819, 0x805, 0x815, 0x80d, 0x81d,
  0x803, 0x813, 0x80b, 0x81b, 0x807, 0x817, 0x80f, 0x81f,
  0x800, 0x810, 0x808, 0x818, 0x804, 0x814, 0x80c, 0x81c,
  0x802, 0x812, 0x80a, 0x81a, 0x806, 0x816, 0x80e, 0x81e,
  0x801, 0x811, 0x809, 0x819, 0x805, 0x815, 0x80d, 0x81d,
  0x803, 0x813, 0x80b, 0x81b, 0x807, 0x817, 0x80f, 0x81f,
  0x800, 0x810, 0x808, 0x818, 0x804, 0x814, 0x80c, 0x81c,
  0x802, 0x812, 0x80a, 0x81a, 0x806, 0x816, 0x80e, 0x81e,
  0x801, 0x811, 0x809, 0x819, 0x805, 0x815, 0x80d, 0x81d,
  0x803, 0x813, 0x80b, 0x81b, 0x807, 0x817, 0x80f, 0x81f,
  0x800, 0x810, 0x808, 0x818, 0x804, 0x814, 0x80c, 0x81c,
  0x802, 0x812, 0x80a, 0x81a, 0x806, 0x816, 0x80e, 0x81e,
  0x801, 0x811, 0x809, 0x819, 0x805, 0x815, 0x80d, 0x81d,
  0x803, 0x813, 0x80b, 0x81b, 0x807, 0x817, 0x80f, 0x81f,
  0x800, 0x810, 0x808, 0x818, 0x804, 0x814, 0x80c, 0x81c,
  0x802, 0x812, 0x80a, 0x81a, 0x806, 0x816, 0x80e, 0x81e,
  0x801, 0x811, 0x809, 0x819, 0x805, 0x815, 0x80d, 0x81d,
  0x803, 0x813, 0x80b, 0x81b, 0x807, 0x817, 0x80f, 0x81f,
};

/* Inflate a zlib stream from PIN/SIN to POUT/SOUT.  Return 1 on
   success, 0 on some error parsing the stream.  */

static int
elf_zlib_inflate (const unsigned char *pin, size_t sin, uint16_t *zdebug_table,
		  unsigned char *pout, size_t sout)
{
  unsigned char *porigout;
  const unsigned char *pinend;
  unsigned char *poutend;

  /* We can apparently see multiple zlib streams concatenated
     together, so keep going as long as there is something to read.
     The last 4 bytes are the checksum.  */
  porigout = pout;
  pinend = pin + sin;
  poutend = pout + sout;
  while ((pinend - pin) > 4)
    {
      uint64_t val;
      unsigned int bits;
      int last;

      /* Read the two byte zlib header.  */

      if (unlikely ((pin[0] & 0xf) != 8)) /* 8 is zlib encoding.  */
	{
	  /* Unknown compression method.  */
	  elf_uncompress_failed ();
	  return 0;
	}
      if (unlikely ((pin[0] >> 4) > 7))
	{
	  /* Window size too large.  Other than this check, we don't
	     care about the window size.  */
	  elf_uncompress_failed ();
	  return 0;
	}
      if (unlikely ((pin[1] & 0x20) != 0))
	{
	  /* Stream expects a predefined dictionary, but we have no
	     dictionary.  */
	  elf_uncompress_failed ();
	  return 0;
	}
      val = (pin[0] << 8) | pin[1];
      if (unlikely (val % 31 != 0))
	{
	  /* Header check failure.  */
	  elf_uncompress_failed ();
	  return 0;
	}
      pin += 2;

      /* Align PIN to a 32-bit boundary.  */

      val = 0;
      bits = 0;
      while ((((uintptr_t) pin) & 3) != 0)
	{
	  val |= (uint64_t)*pin << bits;
	  bits += 8;
	  ++pin;
	}

      /* Read blocks until one is marked last.  */

      last = 0;

      while (!last)
	{
	  unsigned int type;
	  const uint16_t *tlit;
	  const uint16_t *tdist;

	  if (!elf_fetch_bits (&pin, pinend, &val, &bits))
	    return 0;

	  last = val & 1;
	  type = (val >> 1) & 3;
	  val >>= 3;
	  bits -= 3;

	  if (unlikely (type == 3))
	    {
	      /* Invalid block type.  */
	      elf_uncompress_failed ();
	      return 0;
	    }

	  if (type == 0)
	    {
	      uint16_t len;
	      uint16_t lenc;

	      /* An uncompressed block.  */

	      /* If we've read ahead more than a byte, back up.  */
	      while (bits >= 8)
		{
		  --pin;
		  bits -= 8;
		}

	      val = 0;
	      bits = 0;
	      if (unlikely ((pinend - pin) < 4))
		{
		  /* Missing length.  */
		  elf_uncompress_failed ();
		  return 0;
		}
	      len = pin[0] | (pin[1] << 8);
	      lenc = pin[2] | (pin[3] << 8);
	      pin += 4;
	      lenc = ~lenc;
	      if (unlikely (len != lenc))
		{
		  /* Corrupt data.  */
		  elf_uncompress_failed ();
		  return 0;
		}
	      if (unlikely (len > (unsigned int) (pinend - pin)
			    || len > (unsigned int) (poutend - pout)))
		{
		  /* Not enough space in buffers.  */
		  elf_uncompress_failed ();
		  return 0;
		}
	      memcpy (pout, pin, len);
	      pout += len;
	      pin += len;

	      /* Align PIN.  */
	      while ((((uintptr_t) pin) & 3) != 0)
		{
		  val |= (uint64_t)*pin << bits;
		  bits += 8;
		  ++pin;
		}

	      /* Go around to read the next block.  */
	      continue;
	    }

	  if (type == 1)
	    {
	      tlit = elf_zlib_default_table;
	      tdist = elf_zlib_default_dist_table;
	    }
	  else
	    {
	      unsigned int nlit;
	      unsigned int ndist;
	      unsigned int nclen;
	      unsigned char codebits[19];
	      unsigned char *plenbase;
	      unsigned char *plen;
	      unsigned char *plenend;

	      /* Read a Huffman encoding table.  The various magic
		 numbers here are from RFC 1951.  */

	      if (!elf_fetch_bits (&pin, pinend, &val, &bits))
		return 0;

	      nlit = (val & 0x1f) + 257;
	      val >>= 5;
	      ndist = (val & 0x1f) + 1;
	      val >>= 5;
	      nclen = (val & 0xf) + 4;
	      val >>= 4;
	      bits -= 14;
	      if (unlikely (nlit > 286 || ndist > 30))
		{
		  /* Values out of range.  */
		  elf_uncompress_failed ();
		  return 0;
		}

	      /* Read and build the table used to compress the
		 literal, length, and distance codes.  */

	      memset(&codebits[0], 0, 19);

	      /* There are always at least 4 elements in the
		 table.  */

	      if (!elf_fetch_bits (&pin, pinend, &val, &bits))
		return 0;

	      codebits[16] = val & 7;
	      codebits[17] = (val >> 3) & 7;
	      codebits[18] = (val >> 6) & 7;
	      codebits[0] = (val >> 9) & 7;
	      val >>= 12;
	      bits -= 12;

	      if (nclen == 4)
		goto codebitsdone;

	      codebits[8] = val & 7;
	      val >>= 3;
	      bits -= 3;

	      if (nclen == 5)
		goto codebitsdone;

	      if (!elf_fetch_bits (&pin, pinend, &val, &bits))
		return 0;

	      codebits[7] = val & 7;
	      val >>= 3;
	      bits -= 3;

	      if (nclen == 6)
		goto codebitsdone;

	      codebits[9] = val & 7;
	      val >>= 3;
	      bits -= 3;

	      if (nclen == 7)
		goto codebitsdone;

	      codebits[6] = val & 7;
	      val >>= 3;
	      bits -= 3;

	      if (nclen == 8)
		goto codebitsdone;

	      codebits[10] = val & 7;
	      val >>= 3;
	      bits -= 3;

	      if (nclen == 9)
		goto codebitsdone;

	      codebits[5] = val & 7;
	      val >>= 3;
	      bits -= 3;

	      if (nclen == 10)
		goto codebitsdone;

	      if (!elf_fetch_bits (&pin, pinend, &val, &bits))
		return 0;

	      codebits[11] = val & 7;
	      val >>= 3;
	      bits -= 3;

	      if (nclen == 11)
		goto codebitsdone;

	      codebits[4] = val & 7;
	      val >>= 3;
	      bits -= 3;

	      if (nclen == 12)
		goto codebitsdone;

	      codebits[12] = val & 7;
	      val >>= 3;
	      bits -= 3;

	      if (nclen == 13)
		goto codebitsdone;

	      codebits[3] = val & 7;
	      val >>= 3;
	      bits -= 3;

	      if (nclen == 14)
		goto codebitsdone;

	      codebits[13] = val & 7;
	      val >>= 3;
	      bits -= 3;

	      if (nclen == 15)
		goto codebitsdone;

	      if (!elf_fetch_bits (&pin, pinend, &val, &bits))
		return 0;

	      codebits[2] = val & 7;
	      val >>= 3;
	      bits -= 3;

	      if (nclen == 16)
		goto codebitsdone;

	      codebits[14] = val & 7;
	      val >>= 3;
	      bits -= 3;

	      if (nclen == 17)
		goto codebitsdone;

	      codebits[1] = val & 7;
	      val >>= 3;
	      bits -= 3;

	      if (nclen == 18)
		goto codebitsdone;

	      codebits[15] = val & 7;
	      val >>= 3;
	      bits -= 3;

	    codebitsdone:

	      if (!elf_zlib_inflate_table (codebits, 19, zdebug_table,
					   zdebug_table))
		return 0;

	      /* Read the compressed bit lengths of the literal,
		 length, and distance codes.  We have allocated space
		 at the end of zdebug_table to hold them.  */

	      plenbase = (((unsigned char *) zdebug_table)
			  + ZLIB_TABLE_CODELEN_OFFSET);
	      plen = plenbase;
	      plenend = plen + nlit + ndist;
	      while (plen < plenend)
		{
		  uint16_t t;
		  unsigned int b;
		  uint16_t v;

		  if (!elf_fetch_bits (&pin, pinend, &val, &bits))
		    return 0;

		  t = zdebug_table[val & 0xff];

		  /* The compression here uses bit lengths up to 7, so
		     a secondary table is never necessary.  */
		  if (unlikely ((t & (1U << ZLIB_HUFFMAN_SECONDARY_SHIFT))
				!= 0))
		    {
		      elf_uncompress_failed ();
		      return 0;
		    }

		  b = (t >> ZLIB_HUFFMAN_BITS_SHIFT) & ZLIB_HUFFMAN_BITS_MASK;
		  val >>= b + 1;
		  bits -= b + 1;

		  v = t & ZLIB_HUFFMAN_VALUE_MASK;
		  if (v < 16)
		    *plen++ = v;
		  else if (v == 16)
		    {
		      unsigned int c;
		      unsigned int prev;

		      /* Copy previous entry 3 to 6 times.  */

		      if (unlikely (plen == plenbase))
			{
			  elf_uncompress_failed ();
			  return 0;
			}

		      /* We used up to 7 bits since the last
			 elf_fetch_bits, so we have at least 8 bits
			 available here.  */

		      c = 3 + (val & 0x3);
		      val >>= 2;
		      bits -= 2;
		      if (unlikely ((unsigned int) (plenend - plen) < c))
			{
			  elf_uncompress_failed ();
			  return 0;
			}

		      prev = plen[-1];
		      switch (c)
			{
			case 6:
			  *plen++ = prev;
			  ATTRIBUTE_FALLTHROUGH;
			case 5:
			  *plen++ = prev;
			  ATTRIBUTE_FALLTHROUGH;
			case 4:
			  *plen++ = prev;
			}
		      *plen++ = prev;
		      *plen++ = prev;
		      *plen++ = prev;
		    }
		  else if (v == 17)
		    {
		      unsigned int c;

		      /* Store zero 3 to 10 times.  */

		      /* We used up to 7 bits since the last
			 elf_fetch_bits, so we have at least 8 bits
			 available here.  */

		      c = 3 + (val & 0x7);
		      val >>= 3;
		      bits -= 3;
		      if (unlikely ((unsigned int) (plenend - plen) < c))
			{
			  elf_uncompress_failed ();
			  return 0;
			}

		      switch (c)
			{
			case 10:
			  *plen++ = 0;
			  ATTRIBUTE_FALLTHROUGH;
			case 9:
			  *plen++ = 0;
			  ATTRIBUTE_FALLTHROUGH;
			case 8:
			  *plen++ = 0;
			  ATTRIBUTE_FALLTHROUGH;
			case 7:
			  *plen++ = 0;
			  ATTRIBUTE_FALLTHROUGH;
			case 6:
			  *plen++ = 0;
			  ATTRIBUTE_FALLTHROUGH;
			case 5:
			  *plen++ = 0;
			  ATTRIBUTE_FALLTHROUGH;
			case 4:
			  *plen++ = 0;
			}
		      *plen++ = 0;
		      *plen++ = 0;
		      *plen++ = 0;
		    }
		  else if (v == 18)
		    {
		      unsigned int c;

		      /* Store zero 11 to 138 times.  */

		      /* We used up to 7 bits since the last
			 elf_fetch_bits, so we have at least 8 bits
			 available here.  */

		      c = 11 + (val & 0x7f);
		      val >>= 7;
		      bits -= 7;
		      if (unlikely ((unsigned int) (plenend - plen) < c))
			{
			  elf_uncompress_failed ();
			  return 0;
			}

		      memset (plen, 0, c);
		      plen += c;
		    }
		  else
		    {
		      elf_uncompress_failed ();
		      return 0;
		    }
		}

	      /* Make sure that the stop code can appear.  */

	      plen = plenbase;
	      if (unlikely (plen[256] == 0))
		{
		  elf_uncompress_failed ();
		  return 0;
		}

	      /* Build the decompression tables.  */

	      if (!elf_zlib_inflate_table (plen, nlit, zdebug_table,
					   zdebug_table))
		return 0;
	      if (!elf_zlib_inflate_table (plen + nlit, ndist, zdebug_table,
					   (zdebug_table
					    + ZLIB_HUFFMAN_TABLE_SIZE)))
		return 0;
	      tlit = zdebug_table;
	      tdist = zdebug_table + ZLIB_HUFFMAN_TABLE_SIZE;
	    }

	  /* Inflate values until the end of the block.  This is the
	     main loop of the inflation code.  */

	  while (1)
	    {
	      uint16_t t;
	      unsigned int b;
	      uint16_t v;
	      unsigned int lit;

	      if (!elf_fetch_bits (&pin, pinend, &val, &bits))
		return 0;

	      t = tlit[val & 0xff];
	      b = (t >> ZLIB_HUFFMAN_BITS_SHIFT) & ZLIB_HUFFMAN_BITS_MASK;
	      v = t & ZLIB_HUFFMAN_VALUE_MASK;

	      if ((t & (1U << ZLIB_HUFFMAN_SECONDARY_SHIFT)) == 0)
		{
		  lit = v;
		  val >>= b + 1;
		  bits -= b + 1;
		}
	      else
		{
		  t = tlit[v + 0x100 + ((val >> 8) & ((1U << b) - 1))];
		  b = (t >> ZLIB_HUFFMAN_BITS_SHIFT) & ZLIB_HUFFMAN_BITS_MASK;
		  lit = t & ZLIB_HUFFMAN_VALUE_MASK;
		  val >>= b + 8;
		  bits -= b + 8;
		}

	      if (lit < 256)
		{
		  if (unlikely (pout == poutend))
		    {
		      elf_uncompress_failed ();
		      return 0;
		    }

		  *pout++ = lit;

		  /* We will need to write the next byte soon.  We ask
		     for high temporal locality because we will write
		     to the whole cache line soon.  */
		  __builtin_prefetch (pout, 1, 3);
		}
	      else if (lit == 256)
		{
		  /* The end of the block.  */
		  break;
		}
	      else
		{
		  unsigned int dist;
		  unsigned int len;

		  /* Convert lit into a length.  */

		  if (lit < 265)
		    len = lit - 257 + 3;
		  else if (lit == 285)
		    len = 258;
		  else if (unlikely (lit > 285))
		    {
		      elf_uncompress_failed ();
		      return 0;
		    }
		  else
		    {
		      unsigned int extra;

		      if (!elf_fetch_bits (&pin, pinend, &val, &bits))
			return 0;

		      /* This is an expression for the table of length
			 codes in RFC 1951 3.2.5.  */
		      lit -= 265;
		      extra = (lit >> 2) + 1;
		      len = (lit & 3) << extra;
		      len += 11;
		      len += ((1U << (extra - 1)) - 1) << 3;
		      len += val & ((1U << extra) - 1);
		      val >>= extra;
		      bits -= extra;
		    }

		  if (!elf_fetch_bits (&pin, pinend, &val, &bits))
		    return 0;

		  t = tdist[val & 0xff];
		  b = (t >> ZLIB_HUFFMAN_BITS_SHIFT) & ZLIB_HUFFMAN_BITS_MASK;
		  v = t & ZLIB_HUFFMAN_VALUE_MASK;

		  if ((t & (1U << ZLIB_HUFFMAN_SECONDARY_SHIFT)) == 0)
		    {
		      dist = v;
		      val >>= b + 1;
		      bits -= b + 1;
		    }
		  else
		    {
		      t = tdist[v + 0x100 + ((val >> 8) & ((1U << b) - 1))];
		      b = ((t >> ZLIB_HUFFMAN_BITS_SHIFT)
			   & ZLIB_HUFFMAN_BITS_MASK);
		      dist = t & ZLIB_HUFFMAN_VALUE_MASK;
		      val >>= b + 8;
		      bits -= b + 8;
		    }

		  /* Convert dist to a distance.  */

		  if (dist == 0)
		    {
		      /* A distance of 1.  A common case, meaning
			 repeat the last character LEN times.  */

		      if (unlikely (pout == porigout))
			{
			  elf_uncompress_failed ();
			  return 0;
			}

		      if (unlikely ((unsigned int) (poutend - pout) < len))
			{
			  elf_uncompress_failed ();
			  return 0;
			}

		      memset (pout, pout[-1], len);
		      pout += len;
		    }
		  else if (unlikely (dist > 29))
		    {
		      elf_uncompress_failed ();
		      return 0;
		    }
		  else
		    {
		      if (dist < 4)
			dist = dist + 1;
		      else
			{
			  unsigned int extra;

			  if (!elf_fetch_bits (&pin, pinend, &val, &bits))
			    return 0;

			  /* This is an expression for the table of
			     distance codes in RFC 1951 3.2.5.  */
			  dist -= 4;
			  extra = (dist >> 1) + 1;
			  dist = (dist & 1) << extra;
			  dist += 5;
			  dist += ((1U << (extra - 1)) - 1) << 2;
			  dist += val & ((1U << extra) - 1);
			  val >>= extra;
			  bits -= extra;
			}

		      /* Go back dist bytes, and copy len bytes from
			 there.  */

		      if (unlikely ((unsigned int) (pout - porigout) < dist))
			{
			  elf_uncompress_failed ();
			  return 0;
			}

		      if (unlikely ((unsigned int) (poutend - pout) < len))
			{
			  elf_uncompress_failed ();
			  return 0;
			}

		      if (dist >= len)
			{
			  memcpy (pout, pout - dist, len);
			  pout += len;
			}
		      else
			{
			  while (len > 0)
			    {
			      unsigned int copy;

			      copy = len < dist ? len : dist;
			      memcpy (pout, pout - dist, copy);
			      len -= copy;
			      pout += copy;
			    }
			}
		    }
		}
	    }
	}
    }

  /* We should have filled the output buffer.  */
  if (unlikely (pout != poutend))
    {
      elf_uncompress_failed ();
      return 0;
    }

  return 1;
}

/* Verify the zlib checksum.  The checksum is in the 4 bytes at
   CHECKBYTES, and the uncompressed data is at UNCOMPRESSED /
   UNCOMPRESSED_SIZE.  Returns 1 on success, 0 on failure.  */

static int
elf_zlib_verify_checksum (const unsigned char *checkbytes,
			  const unsigned char *uncompressed,
			  size_t uncompressed_size)
{
  unsigned int i;
  unsigned int cksum;
  const unsigned char *p;
  uint32_t s1;
  uint32_t s2;
  size_t hsz;

  cksum = 0;
  for (i = 0; i < 4; i++)
    cksum = (cksum << 8) | checkbytes[i];

  s1 = 1;
  s2 = 0;

  /* Minimize modulo operations.  */

  p = uncompressed;
  hsz = uncompressed_size;
  while (hsz >= 5552)
    {
      for (i = 0; i < 5552; i += 16)
	{
	  /* Manually unroll loop 16 times.  */
	  s1 = s1 + *p++;
	  s2 = s2 + s1;
	  s1 = s1 + *p++;
	  s2 = s2 + s1;
	  s1 = s1 + *p++;
	  s2 = s2 + s1;
	  s1 = s1 + *p++;
	  s2 = s2 + s1;
	  s1 = s1 + *p++;
	  s2 = s2 + s1;
	  s1 = s1 + *p++;
	  s2 = s2 + s1;
	  s1 = s1 + *p++;
	  s2 = s2 + s1;
	  s1 = s1 + *p++;
	  s2 = s2 + s1;
	  s1 = s1 + *p++;
	  s2 = s2 + s1;
	  s1 = s1 + *p++;
	  s2 = s2 + s1;
	  s1 = s1 + *p++;
	  s2 = s2 + s1;
	  s1 = s1 + *p++;
	  s2 = s2 + s1;
	  s1 = s1 + *p++;
	  s2 = s2 + s1;
	  s1 = s1 + *p++;
	  s2 = s2 + s1;
	  s1 = s1 + *p++;
	  s2 = s2 + s1;
	  s1 = s1 + *p++;
	  s2 = s2 + s1;
	}
      hsz -= 5552;
      s1 %= 65521;
      s2 %= 65521;
    }

  while (hsz >= 16)
    {
      /* Manually unroll loop 16 times.  */
      s1 = s1 + *p++;
      s2 = s2 + s1;
      s1 = s1 + *p++;
      s2 = s2 + s1;
      s1 = s1 + *p++;
      s2 = s2 + s1;
      s1 = s1 + *p++;
      s2 = s2 + s1;
      s1 = s1 + *p++;
      s2 = s2 + s1;
      s1 = s1 + *p++;
      s2 = s2 + s1;
      s1 = s1 + *p++;
      s2 = s2 + s1;
      s1 = s1 + *p++;
      s2 = s2 + s1;
      s1 = s1 + *p++;
      s2 = s2 + s1;
      s1 = s1 + *p++;
      s2 = s2 + s1;
      s1 = s1 + *p++;
      s2 = s2 + s1;
      s1 = s1 + *p++;
      s2 = s2 + s1;
      s1 = s1 + *p++;
      s2 = s2 + s1;
      s1 = s1 + *p++;
      s2 = s2 + s1;
      s1 = s1 + *p++;
      s2 = s2 + s1;
      s1 = s1 + *p++;
      s2 = s2 + s1;

      hsz -= 16;
    }

  for (i = 0; i < hsz; ++i)
    {
      s1 = s1 + *p++;
      s2 = s2 + s1;
    }

  s1 %= 65521;
  s2 %= 65521;

  if (unlikely ((s2 << 16) + s1 != cksum))
    {
      elf_uncompress_failed ();
      return 0;
    }

  return 1;
}

/* Inflate a zlib stream from PIN/SIN to POUT/SOUT, and verify the
   checksum.  Return 1 on success, 0 on error.  */

static int
elf_zlib_inflate_and_verify (const unsigned char *pin, size_t sin,
			     uint16_t *zdebug_table, unsigned char *pout,
			     size_t sout)
{
  if (!elf_zlib_inflate (pin, sin, zdebug_table, pout, sout))
    return 0;
  if (!elf_zlib_verify_checksum (pin + sin - 4, pout, sout))
    return 0;
  return 1;
}

/* For working memory during zstd compression, we need
   - a literal length FSE table: 512 64-bit values == 4096 bytes
   - a match length FSE table: 512 64-bit values == 4096 bytes
   - a offset FSE table: 256 64-bit values == 2048 bytes
   - a Huffman tree: 2048 uint16_t values == 4096 bytes
   - scratch space, one of
     - to build an FSE table: 512 uint16_t values == 1024 bytes
     - to build a Huffman tree: 512 uint16_t + 256 uint32_t == 2048 bytes
*/

#define ZSTD_TABLE_SIZE					\
  (2 * 512 * sizeof (struct elf_zstd_fse_baseline_entry)	\
   + 256 * sizeof (struct elf_zstd_fse_baseline_entry)		\
   + 2048 * sizeof (uint16_t)					\
   + 512 * sizeof (uint16_t) + 256 * sizeof (uint32_t))

#define ZSTD_TABLE_LITERAL_FSE_OFFSET (0)

#define ZSTD_TABLE_MATCH_FSE_OFFSET			\
  (512 * sizeof (struct elf_zstd_fse_baseline_entry))

#define ZSTD_TABLE_OFFSET_FSE_OFFSET			\
  (ZSTD_TABLE_MATCH_FSE_OFFSET				\
   + 512 * sizeof (struct elf_zstd_fse_baseline_entry))

#define ZSTD_TABLE_HUFFMAN_OFFSET					\
  (ZSTD_TABLE_OFFSET_FSE_OFFSET						\
   + 256 * sizeof (struct elf_zstd_fse_baseline_entry))

#define ZSTD_TABLE_WORK_OFFSET \
  (ZSTD_TABLE_HUFFMAN_OFFSET + 2048 * sizeof (uint16_t))

/* An entry in a zstd FSE table.  */

struct elf_zstd_fse_entry
{
  /* The value that this FSE entry represents.  */
  unsigned char symbol;
  /* The number of bits to read to determine the next state.  */
  unsigned char bits;
  /* Add the bits to this base to get the next state.  */
  uint16_t base;
};

static int
elf_zstd_build_fse (const int16_t *, int, uint16_t *, int,
		    struct elf_zstd_fse_entry *);

/* Read a zstd FSE table and build the decoding table in *TABLE, updating *PPIN
   as it reads.  ZDEBUG_TABLE is scratch space; it must be enough for 512
   uint16_t values (1024 bytes).  MAXIDX is the maximum number of symbols
   permitted. *TABLE_BITS is the maximum number of bits for symbols in the
   table: the size of *TABLE is at least 1 << *TABLE_BITS.  This updates
   *TABLE_BITS to the actual number of bits.  Returns 1 on success, 0 on
   error.  */

static int
elf_zstd_read_fse (const unsigned char **ppin, const unsigned char *pinend,
		   uint16_t *zdebug_table, int maxidx,
		   struct elf_zstd_fse_entry *table, int *table_bits)
{
  const unsigned char *pin;
  int16_t *norm;
  uint16_t *next;
  uint64_t val;
  unsigned int bits;
  int accuracy_log;
  uint32_t remaining;
  uint32_t threshold;
  int bits_needed;
  int idx;
  int prev0;

  pin = *ppin;

  norm = (int16_t *) zdebug_table;
  next = zdebug_table + 256;

  if (unlikely (pin + 3 >= pinend))
    {
      elf_uncompress_failed ();
      return 0;
    }

  /* Align PIN to a 32-bit boundary.  */

  val = 0;
  bits = 0;
  while ((((uintptr_t) pin) & 3) != 0)
    {
      val |= (uint64_t)*pin << bits;
      bits += 8;
      ++pin;
    }

  if (!elf_fetch_bits (&pin, pinend, &val, &bits))
    return 0;

  accuracy_log = (val & 0xf) + 5;
  if (accuracy_log > *table_bits)
    {
      elf_uncompress_failed ();
      return 0;
    }
  *table_bits = accuracy_log;
  val >>= 4;
  bits -= 4;

  /* This code is mostly copied from the reference implementation.  */

  /* The number of remaining probabilities, plus 1.  This sets the number of
     bits that need to be read for the next value.  */
  remaining = (1 << accuracy_log) + 1;

  /* The current difference between small and large values, which depends on
     the number of remaining values.  Small values use one less bit.  */
  threshold = 1 << accuracy_log;

  /* The number of bits used to compute threshold.  */
  bits_needed = accuracy_log + 1;

  /* The next character value.  */
  idx = 0;

  /* Whether the last count was 0.  */
  prev0 = 0;

  while (remaining > 1 && idx <= maxidx)
    {
      uint32_t max;
      int32_t count;

      if (!elf_fetch_bits (&pin, pinend, &val, &bits))
	return 0;

      if (prev0)
	{
	  int zidx;

	  /* Previous count was 0, so there is a 2-bit repeat flag.  If the
	     2-bit flag is 0b11, it adds 3 and then there is another repeat
	     flag.  */
	  zidx = idx;
	  while ((val & 0xfff) == 0xfff)
	    {
	      zidx += 3 * 6;
	      val >>= 12;
	      bits -= 12;
	      if  (!elf_fetch_bits (&pin, pinend, &val, &bits))
		return 0;
	    }
	  while ((val & 3) == 3)
	    {
	      zidx += 3;
	      val >>= 2;
	      bits -= 2;
	      if (!elf_fetch_bits (&pin, pinend, &val, &bits))
		return 0;
	    }
	  /* We have at least 13 bits here, don't need to fetch.  */
	  zidx += val & 3;
	  val >>= 2;
	  bits -= 2;

	  if (unlikely (zidx > maxidx))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }

	  for (; idx < zidx; idx++)
	    norm[idx] = 0;

	  prev0 = 0;
	  continue;
	}

      max = (2 * threshold - 1) - remaining;
      if ((val & (threshold - 1)) < max)
	{
	  /* A small value.  */
	  count = (int32_t) ((uint32_t) val & (threshold - 1));
	  val >>= bits_needed - 1;
	  bits -= bits_needed - 1;
	}
      else
	{
	  /* A large value.  */
	  count = (int32_t) ((uint32_t) val & (2 * threshold - 1));
	  if (count >= (int32_t) threshold)
	    count -= (int32_t) max;
	  val >>= bits_needed;
	  bits -= bits_needed;
	}

      count--;
      if (count >= 0)
	remaining -= count;
      else
	remaining--;
      if (unlikely (idx >= 256))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      norm[idx] = (int16_t) count;
      ++idx;

      prev0 = count == 0;

      while (remaining < threshold)
	{
	  bits_needed--;
	  threshold >>= 1;
	}
    }

  if (unlikely (remaining != 1))
    {
      elf_uncompress_failed ();
      return 0;
    }

  /* If we've read ahead more than a byte, back up.  */
  while (bits >= 8)
    {
      --pin;
      bits -= 8;
    }

  *ppin = pin;

  for (; idx <= maxidx; idx++)
    norm[idx] = 0;

  return elf_zstd_build_fse (norm, idx, next, *table_bits, table);
}

/* Build the FSE decoding table from a list of probabilities.  This reads from
   NORM of length IDX, uses NEXT as scratch space, and writes to *TABLE, whose
   size is TABLE_BITS.  */

static int
elf_zstd_build_fse (const int16_t *norm, int idx, uint16_t *next,
		    int table_bits, struct elf_zstd_fse_entry *table)
{
  int table_size;
  int high_threshold;
  int i;
  int pos;
  int step;
  int mask;

  table_size = 1 << table_bits;
  high_threshold = table_size - 1;
  for (i = 0; i < idx; i++)
    {
      int16_t n;

      n = norm[i];
      if (n >= 0)
	next[i] = (uint16_t) n;
      else
	{
	  table[high_threshold].symbol = (unsigned char) i;
	  high_threshold--;
	  next[i] = 1;
	}
    }

  pos = 0;
  step = (table_size >> 1) + (table_size >> 3) + 3;
  mask = table_size - 1;
  for (i = 0; i < idx; i++)
    {
      int n;
      int j;

      n = (int) norm[i];
      for (j = 0; j < n; j++)
	{
	  table[pos].symbol = (unsigned char) i;
	  pos = (pos + step) & mask;
	  while (unlikely (pos > high_threshold))
	    pos = (pos + step) & mask;
	}
    }
  if (unlikely (pos != 0))
    {
      elf_uncompress_failed ();
      return 0;
    }

  for (i = 0; i < table_size; i++)
    {
      unsigned char sym;
      uint16_t next_state;
      int high_bit;
      int bits;

      sym = table[i].symbol;
      next_state = next[sym];
      ++next[sym];

      if (next_state == 0)
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      high_bit = 31 - __builtin_clz (next_state);

      bits = table_bits - high_bit;
      table[i].bits = (unsigned char) bits;
      table[i].base = (uint16_t) ((next_state << bits) - table_size);
    }

  return 1;
}

/* Encode the baseline and bits into a single 32-bit value.  */

#define ZSTD_ENCODE_BASELINE_BITS(baseline, basebits)	\
  ((uint32_t)(baseline) | ((uint32_t)(basebits) << 24))

#define ZSTD_DECODE_BASELINE(baseline_basebits)	\
  ((uint32_t)(baseline_basebits) & 0xffffff)

#define ZSTD_DECODE_BASEBITS(baseline_basebits)	\
  ((uint32_t)(baseline_basebits) >> 24)

/* Given a literal length code, we need to read a number of bits and add that
   to a baseline.  For states 0 to 15 the baseline is the state and the number
   of bits is zero.  */

#define ZSTD_LITERAL_LENGTH_BASELINE_OFFSET (16)

static const uint32_t elf_zstd_literal_length_base[] =
{
  ZSTD_ENCODE_BASELINE_BITS(16, 1),
  ZSTD_ENCODE_BASELINE_BITS(18, 1),
  ZSTD_ENCODE_BASELINE_BITS(20, 1),
  ZSTD_ENCODE_BASELINE_BITS(22, 1),
  ZSTD_ENCODE_BASELINE_BITS(24, 2),
  ZSTD_ENCODE_BASELINE_BITS(28, 2),
  ZSTD_ENCODE_BASELINE_BITS(32, 3),
  ZSTD_ENCODE_BASELINE_BITS(40, 3),
  ZSTD_ENCODE_BASELINE_BITS(48, 4),
  ZSTD_ENCODE_BASELINE_BITS(64, 6),
  ZSTD_ENCODE_BASELINE_BITS(128, 7),
  ZSTD_ENCODE_BASELINE_BITS(256, 8),
  ZSTD_ENCODE_BASELINE_BITS(512, 9),
  ZSTD_ENCODE_BASELINE_BITS(1024, 10),
  ZSTD_ENCODE_BASELINE_BITS(2048, 11),
  ZSTD_ENCODE_BASELINE_BITS(4096, 12),
  ZSTD_ENCODE_BASELINE_BITS(8192, 13),
  ZSTD_ENCODE_BASELINE_BITS(16384, 14),
  ZSTD_ENCODE_BASELINE_BITS(32768, 15),
  ZSTD_ENCODE_BASELINE_BITS(65536, 16)
};

/* The same applies to match length codes.  For states 0 to 31 the baseline is
   the state + 3 and the number of bits is zero.  */

#define ZSTD_MATCH_LENGTH_BASELINE_OFFSET (32)

static const uint32_t elf_zstd_match_length_base[] =
{
  ZSTD_ENCODE_BASELINE_BITS(35, 1),
  ZSTD_ENCODE_BASELINE_BITS(37, 1),
  ZSTD_ENCODE_BASELINE_BITS(39, 1),
  ZSTD_ENCODE_BASELINE_BITS(41, 1),
  ZSTD_ENCODE_BASELINE_BITS(43, 2),
  ZSTD_ENCODE_BASELINE_BITS(47, 2),
  ZSTD_ENCODE_BASELINE_BITS(51, 3),
  ZSTD_ENCODE_BASELINE_BITS(59, 3),
  ZSTD_ENCODE_BASELINE_BITS(67, 4),
  ZSTD_ENCODE_BASELINE_BITS(83, 4),
  ZSTD_ENCODE_BASELINE_BITS(99, 5),
  ZSTD_ENCODE_BASELINE_BITS(131, 7),
  ZSTD_ENCODE_BASELINE_BITS(259, 8),
  ZSTD_ENCODE_BASELINE_BITS(515, 9),
  ZSTD_ENCODE_BASELINE_BITS(1027, 10),
  ZSTD_ENCODE_BASELINE_BITS(2051, 11),
  ZSTD_ENCODE_BASELINE_BITS(4099, 12),
  ZSTD_ENCODE_BASELINE_BITS(8195, 13),
  ZSTD_ENCODE_BASELINE_BITS(16387, 14),
  ZSTD_ENCODE_BASELINE_BITS(32771, 15),
  ZSTD_ENCODE_BASELINE_BITS(65539, 16)
};

/* An entry in an FSE table used for literal/match/length values.  For these we
   have to map the symbol to a baseline value, and we have to read zero or more
   bits and add that value to the baseline value.  Rather than look the values
   up in a separate table, we grow the FSE table so that we get better memory
   caching.  */

struct elf_zstd_fse_baseline_entry
{
  /* The baseline for the value that this FSE entry represents..  */
  uint32_t baseline;
  /* The number of bits to read to add to the baseline.  */
  unsigned char basebits;
  /* The number of bits to read to determine the next state.  */
  unsigned char bits;
  /* Add the bits to this base to get the next state.  */
  uint16_t base;
};

/* Convert the literal length FSE table FSE_TABLE to an FSE baseline table at
   BASELINE_TABLE.  Note that FSE_TABLE and BASELINE_TABLE will overlap.  */

static int
elf_zstd_make_literal_baseline_fse (
    const struct elf_zstd_fse_entry *fse_table,
    int table_bits,
    struct elf_zstd_fse_baseline_entry *baseline_table)
{
  size_t count;
  const struct elf_zstd_fse_entry *pfse;
  struct elf_zstd_fse_baseline_entry *pbaseline;

  /* Convert backward to avoid overlap.  */

  count = 1U << table_bits;
  pfse = fse_table + count;
  pbaseline = baseline_table + count;
  while (pfse > fse_table)
    {
      unsigned char symbol;
      unsigned char bits;
      uint16_t base;

      --pfse;
      --pbaseline;
      symbol = pfse->symbol;
      bits = pfse->bits;
      base = pfse->base;
      if (symbol < ZSTD_LITERAL_LENGTH_BASELINE_OFFSET)
	{
	  pbaseline->baseline = (uint32_t)symbol;
	  pbaseline->basebits = 0;
	}
      else
	{
	  unsigned int idx;
	  uint32_t basebits;

	  if (unlikely (symbol > 35))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }
	  idx = symbol - ZSTD_LITERAL_LENGTH_BASELINE_OFFSET;
	  basebits = elf_zstd_literal_length_base[idx];
	  pbaseline->baseline = ZSTD_DECODE_BASELINE(basebits);
	  pbaseline->basebits = ZSTD_DECODE_BASEBITS(basebits);
	}
      pbaseline->bits = bits;
      pbaseline->base = base;
    }

  return 1;
}

/* Convert the offset length FSE table FSE_TABLE to an FSE baseline table at
   BASELINE_TABLE.  Note that FSE_TABLE and BASELINE_TABLE will overlap.  */

static int
elf_zstd_make_offset_baseline_fse (
    const struct elf_zstd_fse_entry *fse_table,
    int table_bits,
    struct elf_zstd_fse_baseline_entry *baseline_table)
{
  size_t count;
  const struct elf_zstd_fse_entry *pfse;
  struct elf_zstd_fse_baseline_entry *pbaseline;

  /* Convert backward to avoid overlap.  */

  count = 1U << table_bits;
  pfse = fse_table + count;
  pbaseline = baseline_table + count;
  while (pfse > fse_table)
    {
      unsigned char symbol;
      unsigned char bits;
      uint16_t base;

      --pfse;
      --pbaseline;
      symbol = pfse->symbol;
      bits = pfse->bits;
      base = pfse->base;
      if (unlikely (symbol > 31))
	{
	  elf_uncompress_failed ();
	  return 0;
	}

      /* The simple way to write this is

	   pbaseline->baseline = (uint32_t)1 << symbol;
	   pbaseline->basebits = symbol;

	 That will give us an offset value that corresponds to the one
	 described in the RFC.  However, for offset values > 3, we have to
	 subtract 3.  And for offset values 1, 2, 3 we use a repeated offset.
	 The baseline is always a power of 2, and is never 0, so for these low
	 values we will see one entry that is baseline 1, basebits 0, and one
	 entry that is baseline 2, basebits 1.  All other entries will have
	 baseline >= 4 and basebits >= 2.

	 So we can check for RFC offset <= 3 by checking for basebits <= 1.
	 And that means that we can subtract 3 here and not worry about doing
	 it in the hot loop.  */

      pbaseline->baseline = (uint32_t)1 << symbol;
      if (symbol >= 2)
	pbaseline->baseline -= 3;
      pbaseline->basebits = symbol;
      pbaseline->bits = bits;
      pbaseline->base = base;
    }

  return 1;
}

/* Convert the match length FSE table FSE_TABLE to an FSE baseline table at
   BASELINE_TABLE.  Note that FSE_TABLE and BASELINE_TABLE will overlap.  */

static int
elf_zstd_make_match_baseline_fse (
    const struct elf_zstd_fse_entry *fse_table,
    int table_bits,
    struct elf_zstd_fse_baseline_entry *baseline_table)
{
  size_t count;
  const struct elf_zstd_fse_entry *pfse;
  struct elf_zstd_fse_baseline_entry *pbaseline;

  /* Convert backward to avoid overlap.  */

  count = 1U << table_bits;
  pfse = fse_table + count;
  pbaseline = baseline_table + count;
  while (pfse > fse_table)
    {
      unsigned char symbol;
      unsigned char bits;
      uint16_t base;

      --pfse;
      --pbaseline;
      symbol = pfse->symbol;
      bits = pfse->bits;
      base = pfse->base;
      if (symbol < ZSTD_MATCH_LENGTH_BASELINE_OFFSET)
	{
	  pbaseline->baseline = (uint32_t)symbol + 3;
	  pbaseline->basebits = 0;
	}
      else
	{
	  unsigned int idx;
	  uint32_t basebits;

	  if (unlikely (symbol > 52))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }
	  idx = symbol - ZSTD_MATCH_LENGTH_BASELINE_OFFSET;
	  basebits = elf_zstd_match_length_base[idx];
	  pbaseline->baseline = ZSTD_DECODE_BASELINE(basebits);
	  pbaseline->basebits = ZSTD_DECODE_BASEBITS(basebits);
	}
      pbaseline->bits = bits;
      pbaseline->base = base;
    }

  return 1;
}

#ifdef BACKTRACE_GENERATE_ZSTD_FSE_TABLES

/* Used to generate the predefined FSE decoding tables for zstd.  */

#include <stdio.h>

/* These values are straight from RFC 8878.  */

static int16_t lit[36] =
{
   4, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1,
   2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 1, 1, 1, 1, 1,
  -1,-1,-1,-1
};

static int16_t match[53] =
{
   1, 4, 3, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1,
   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,-1,-1,
  -1,-1,-1,-1,-1
};

static int16_t offset[29] =
{
  1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,-1,-1,-1,-1,-1
};

static uint16_t next[256];

static void
print_table (const struct elf_zstd_fse_baseline_entry *table, size_t size)
{
  size_t i;

  printf ("{\n");
  for (i = 0; i < size; i += 3)
    {
      int j;

      printf (" ");
      for (j = 0; j < 3 && i + j < size; ++j)
	printf (" { %u, %d, %d, %d },", table[i + j].baseline,
		table[i + j].basebits, table[i + j].bits,
		table[i + j].base);
      printf ("\n");
    }
  printf ("};\n");
}

int
main ()
{
  struct elf_zstd_fse_entry lit_table[64];
  struct elf_zstd_fse_baseline_entry lit_baseline[64];
  struct elf_zstd_fse_entry match_table[64];
  struct elf_zstd_fse_baseline_entry match_baseline[64];
  struct elf_zstd_fse_entry offset_table[32];
  struct elf_zstd_fse_baseline_entry offset_baseline[32];

  if (!elf_zstd_build_fse (lit, sizeof lit / sizeof lit[0], next,
			   6, lit_table))
    {
      fprintf (stderr, "elf_zstd_build_fse failed\n");
      exit (EXIT_FAILURE);
    }

  if (!elf_zstd_make_literal_baseline_fse (lit_table, 6, lit_baseline))
    {
      fprintf (stderr, "elf_zstd_make_literal_baseline_fse failed\n");
      exit (EXIT_FAILURE);
    }

  printf ("static const struct elf_zstd_fse_baseline_entry "
	  "elf_zstd_lit_table[64] =\n");
  print_table (lit_baseline,
	       sizeof lit_baseline / sizeof lit_baseline[0]);
  printf ("\n");

  if (!elf_zstd_build_fse (match, sizeof match / sizeof match[0], next,
			   6, match_table))
    {
      fprintf (stderr, "elf_zstd_build_fse failed\n");
      exit (EXIT_FAILURE);
    }

  if (!elf_zstd_make_match_baseline_fse (match_table, 6, match_baseline))
    {
      fprintf (stderr, "elf_zstd_make_match_baseline_fse failed\n");
      exit (EXIT_FAILURE);
    }

  printf ("static const struct elf_zstd_fse_baseline_entry "
	  "elf_zstd_match_table[64] =\n");
  print_table (match_baseline,
	       sizeof match_baseline / sizeof match_baseline[0]);
  printf ("\n");

  if (!elf_zstd_build_fse (offset, sizeof offset / sizeof offset[0], next,
			   5, offset_table))
    {
      fprintf (stderr, "elf_zstd_build_fse failed\n");
      exit (EXIT_FAILURE);
    }

  if (!elf_zstd_make_offset_baseline_fse (offset_table, 5, offset_baseline))
    {
      fprintf (stderr, "elf_zstd_make_offset_baseline_fse failed\n");
      exit (EXIT_FAILURE);
    }

  printf ("static const struct elf_zstd_fse_baseline_entry "
	  "elf_zstd_offset_table[32] =\n");
  print_table (offset_baseline,
	       sizeof offset_baseline / sizeof offset_baseline[0]);
  printf ("\n");

  return 0;
}

#endif

/* The fixed tables generated by the #ifdef'ed out main function
   above.  */

static const struct elf_zstd_fse_baseline_entry elf_zstd_lit_table[64] =
{
  { 0, 0, 4, 0 }, { 0, 0, 4, 16 }, { 1, 0, 5, 32 },
  { 3, 0, 5, 0 }, { 4, 0, 5, 0 }, { 6, 0, 5, 0 },
  { 7, 0, 5, 0 }, { 9, 0, 5, 0 }, { 10, 0, 5, 0 },
  { 12, 0, 5, 0 }, { 14, 0, 6, 0 }, { 16, 1, 5, 0 },
  { 20, 1, 5, 0 }, { 22, 1, 5, 0 }, { 28, 2, 5, 0 },
  { 32, 3, 5, 0 }, { 48, 4, 5, 0 }, { 64, 6, 5, 32 },
  { 128, 7, 5, 0 }, { 256, 8, 6, 0 }, { 1024, 10, 6, 0 },
  { 4096, 12, 6, 0 }, { 0, 0, 4, 32 }, { 1, 0, 4, 0 },
  { 2, 0, 5, 0 }, { 4, 0, 5, 32 }, { 5, 0, 5, 0 },
  { 7, 0, 5, 32 }, { 8, 0, 5, 0 }, { 10, 0, 5, 32 },
  { 11, 0, 5, 0 }, { 13, 0, 6, 0 }, { 16, 1, 5, 32 },
  { 18, 1, 5, 0 }, { 22, 1, 5, 32 }, { 24, 2, 5, 0 },
  { 32, 3, 5, 32 }, { 40, 3, 5, 0 }, { 64, 6, 4, 0 },
  { 64, 6, 4, 16 }, { 128, 7, 5, 32 }, { 512, 9, 6, 0 },
  { 2048, 11, 6, 0 }, { 0, 0, 4, 48 }, { 1, 0, 4, 16 },
  { 2, 0, 5, 32 }, { 3, 0, 5, 32 }, { 5, 0, 5, 32 },
  { 6, 0, 5, 32 }, { 8, 0, 5, 32 }, { 9, 0, 5, 32 },
  { 11, 0, 5, 32 }, { 12, 0, 5, 32 }, { 15, 0, 6, 0 },
  { 18, 1, 5, 32 }, { 20, 1, 5, 32 }, { 24, 2, 5, 32 },
  { 28, 2, 5, 32 }, { 40, 3, 5, 32 }, { 48, 4, 5, 32 },
  { 65536, 16, 6, 0 }, { 32768, 15, 6, 0 }, { 16384, 14, 6, 0 },
  { 8192, 13, 6, 0 },
};

static const struct elf_zstd_fse_baseline_entry elf_zstd_match_table[64] =
{
  { 3, 0, 6, 0 }, { 4, 0, 4, 0 }, { 5, 0, 5, 32 },
  { 6, 0, 5, 0 }, { 8, 0, 5, 0 }, { 9, 0, 5, 0 },
  { 11, 0, 5, 0 }, { 13, 0, 6, 0 }, { 16, 0, 6, 0 },
  { 19, 0, 6, 0 }, { 22, 0, 6, 0 }, { 25, 0, 6, 0 },
  { 28, 0, 6, 0 }, { 31, 0, 6, 0 }, { 34, 0, 6, 0 },
  { 37, 1, 6, 0 }, { 41, 1, 6, 0 }, { 47, 2, 6, 0 },
  { 59, 3, 6, 0 }, { 83, 4, 6, 0 }, { 131, 7, 6, 0 },
  { 515, 9, 6, 0 }, { 4, 0, 4, 16 }, { 5, 0, 4, 0 },
  { 6, 0, 5, 32 }, { 7, 0, 5, 0 }, { 9, 0, 5, 32 },
  { 10, 0, 5, 0 }, { 12, 0, 6, 0 }, { 15, 0, 6, 0 },
  { 18, 0, 6, 0 }, { 21, 0, 6, 0 }, { 24, 0, 6, 0 },
  { 27, 0, 6, 0 }, { 30, 0, 6, 0 }, { 33, 0, 6, 0 },
  { 35, 1, 6, 0 }, { 39, 1, 6, 0 }, { 43, 2, 6, 0 },
  { 51, 3, 6, 0 }, { 67, 4, 6, 0 }, { 99, 5, 6, 0 },
  { 259, 8, 6, 0 }, { 4, 0, 4, 32 }, { 4, 0, 4, 48 },
  { 5, 0, 4, 16 }, { 7, 0, 5, 32 }, { 8, 0, 5, 32 },
  { 10, 0, 5, 32 }, { 11, 0, 5, 32 }, { 14, 0, 6, 0 },
  { 17, 0, 6, 0 }, { 20, 0, 6, 0 }, { 23, 0, 6, 0 },
  { 26, 0, 6, 0 }, { 29, 0, 6, 0 }, { 32, 0, 6, 0 },
  { 65539, 16, 6, 0 }, { 32771, 15, 6, 0 }, { 16387, 14, 6, 0 },
  { 8195, 13, 6, 0 }, { 4099, 12, 6, 0 }, { 2051, 11, 6, 0 },
  { 1027, 10, 6, 0 },
};

static const struct elf_zstd_fse_baseline_entry elf_zstd_offset_table[32] =
{
  { 1, 0, 5, 0 }, { 61, 6, 4, 0 }, { 509, 9, 5, 0 },
  { 32765, 15, 5, 0 }, { 2097149, 21, 5, 0 }, { 5, 3, 5, 0 },
  { 125, 7, 4, 0 }, { 4093, 12, 5, 0 }, { 262141, 18, 5, 0 },
  { 8388605, 23, 5, 0 }, { 29, 5, 5, 0 }, { 253, 8, 4, 0 },
  { 16381, 14, 5, 0 }, { 1048573, 20, 5, 0 }, { 1, 2, 5, 0 },
  { 125, 7, 4, 16 }, { 2045, 11, 5, 0 }, { 131069, 17, 5, 0 },
  { 4194301, 22, 5, 0 }, { 13, 4, 5, 0 }, { 253, 8, 4, 16 },
  { 8189, 13, 5, 0 }, { 524285, 19, 5, 0 }, { 2, 1, 5, 0 },
  { 61, 6, 4, 16 }, { 1021, 10, 5, 0 }, { 65533, 16, 5, 0 },
  { 268435453, 28, 5, 0 }, { 134217725, 27, 5, 0 }, { 67108861, 26, 5, 0 },
  { 33554429, 25, 5, 0 }, { 16777213, 24, 5, 0 },
};

/* Read a zstd Huffman table and build the decoding table in *TABLE, reading
   and updating *PPIN.  This sets *PTABLE_BITS to the number of bits of the
   table, such that the table length is 1 << *TABLE_BITS.  ZDEBUG_TABLE is
   scratch space; it must be enough for 512 uint16_t values + 256 32-bit values
   (2048 bytes).  Returns 1 on success, 0 on error.  */

static int
elf_zstd_read_huff (const unsigned char **ppin, const unsigned char *pinend,
		    uint16_t *zdebug_table, uint16_t *table, int *ptable_bits)
{
  const unsigned char *pin;
  unsigned char hdr;
  unsigned char *weights;
  size_t count;
  uint32_t *weight_mark;
  size_t i;
  uint32_t weight_mask;
  size_t table_bits;

  pin = *ppin;
  if (unlikely (pin >= pinend))
    {
      elf_uncompress_failed ();
      return 0;
    }
  hdr = *pin;
  ++pin;

  weights = (unsigned char *) zdebug_table;

  if (hdr < 128)
    {
      /* Table is compressed using FSE.  */

      struct elf_zstd_fse_entry *fse_table;
      int fse_table_bits;
      uint16_t *scratch;
      const unsigned char *pfse;
      const unsigned char *pback;
      uint64_t val;
      unsigned int bits;
      unsigned int state1, state2;

      /* SCRATCH is used temporarily by elf_zstd_read_fse.  It overlaps
	 WEIGHTS.  */
      scratch = zdebug_table;
      fse_table = (struct elf_zstd_fse_entry *) (scratch + 512);
      fse_table_bits = 6;

      pfse = pin;
      if (!elf_zstd_read_fse (&pfse, pinend, scratch, 255, fse_table,
			      &fse_table_bits))
	return 0;

      if (unlikely (pin + hdr > pinend))
	{
	  elf_uncompress_failed ();
	  return 0;
	}

      /* We no longer need SCRATCH.  Start recording weights.  We need up to
	 256 bytes of weights and 64 bytes of rank counts, so it won't overlap
	 FSE_TABLE.  */

      pback = pin + hdr - 1;

      if (!elf_fetch_backward_init (&pback, pfse, &val, &bits))
	return 0;

      bits -= fse_table_bits;
      state1 = (val >> bits) & ((1U << fse_table_bits) - 1);
      bits -= fse_table_bits;
      state2 = (val >> bits) & ((1U << fse_table_bits) - 1);

      /* There are two independent FSE streams, tracked by STATE1 and STATE2.
	 We decode them alternately.  */

      count = 0;
      while (1)
	{
	  struct elf_zstd_fse_entry *pt;
	  uint64_t v;

	  pt = &fse_table[state1];

	  if (unlikely (pin < pinend) && bits < pt->bits)
	    {
	      if (unlikely (count >= 254))
		{
		  elf_uncompress_failed ();
		  return 0;
		}
	      weights[count] = (unsigned char) pt->symbol;
	      weights[count + 1] = (unsigned char) fse_table[state2].symbol;
	      count += 2;
	      break;
	    }

	  if (unlikely (pt->bits == 0))
	    v = 0;
	  else
	    {
	      if (!elf_fetch_bits_backward (&pback, pfse, &val, &bits))
		return 0;

	      bits -= pt->bits;
	      v = (val >> bits) & (((uint64_t)1 << pt->bits) - 1);
	    }

	  state1 = pt->base + v;

	  if (unlikely (count >= 255))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }

	  weights[count] = pt->symbol;
	  ++count;

	  pt = &fse_table[state2];

	  if (unlikely (pin < pinend && bits < pt->bits))
	    {
	      if (unlikely (count >= 254))
		{
		  elf_uncompress_failed ();
		  return 0;
		}
	      weights[count] = (unsigned char) pt->symbol;
	      weights[count + 1] = (unsigned char) fse_table[state1].symbol;
	      count += 2;
	      break;
	    }

	  if (unlikely (pt->bits == 0))
	    v = 0;
	  else
	    {
	      if (!elf_fetch_bits_backward (&pback, pfse, &val, &bits))
		return 0;

	      bits -= pt->bits;
	      v = (val >> bits) & (((uint64_t)1 << pt->bits) - 1);
	    }

	  state2 = pt->base + v;

	  if (unlikely (count >= 255))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }

	  weights[count] = pt->symbol;
	  ++count;
	}

      pin += hdr;
    }
  else
    {
      /* Table is not compressed.  Each weight is 4 bits.  */

      count = hdr - 127;
      if (unlikely (pin + ((count + 1) / 2) >= pinend))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      for (i = 0; i < count; i += 2)
	{
	  unsigned char b;

	  b = *pin;
	  ++pin;
	  weights[i] = b >> 4;
	  weights[i + 1] = b & 0xf;
	}
    }

  weight_mark = (uint32_t *) (weights + 256);
  memset (weight_mark, 0, 13 * sizeof (uint32_t));
  weight_mask = 0;
  for (i = 0; i < count; ++i)
    {
      unsigned char w;

      w = weights[i];
      if (unlikely (w > 12))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      ++weight_mark[w];
      if (w > 0)
	weight_mask += 1U << (w - 1);
    }
  if (unlikely (weight_mask == 0))
    {
      elf_uncompress_failed ();
      return 0;
    }

  table_bits = 32 - __builtin_clz (weight_mask);
  if (unlikely (table_bits > 11))
    {
      elf_uncompress_failed ();
      return 0;
    }

  /* Work out the last weight value, which is omitted because the weights must
     sum to a power of two.  */
  {
    uint32_t left;
    uint32_t high_bit;

    left = ((uint32_t)1 << table_bits) - weight_mask;
    if (left == 0)
      {
	elf_uncompress_failed ();
	return 0;
      }
    high_bit = 31 - __builtin_clz (left);
    if (((uint32_t)1 << high_bit) != left)
      {
	elf_uncompress_failed ();
	return 0;
      }

    if (unlikely (count >= 256))
      {
	elf_uncompress_failed ();
	return 0;
      }

    weights[count] = high_bit + 1;
    ++count;
    ++weight_mark[high_bit + 1];
  }

  if (weight_mark[1] < 2 || (weight_mark[1] & 1) != 0)
    {
      elf_uncompress_failed ();
      return 0;
    }

  /* Change WEIGHT_MARK from a count of weights to the index of the first
     symbol for that weight.  We shift the indexes to also store how many we
     have seen so far, below.  */
  {
    uint32_t next;

    next = 0;
    for (i = 0; i < table_bits; ++i)
      {
	uint32_t cur;

	cur = next;
	next += weight_mark[i + 1] << i;
	weight_mark[i + 1] = cur;
      }
  }

  for (i = 0; i < count; ++i)
    {
      unsigned char weight;
      uint32_t length;
      uint16_t tval;
      size_t start;
      uint32_t j;

      weight = weights[i];
      if (weight == 0)
	continue;

      length = 1U << (weight - 1);
      tval = (i << 8) | (table_bits + 1 - weight);
      start = weight_mark[weight];
      for (j = 0; j < length; ++j)
	table[start + j] = tval;
      weight_mark[weight] += length;
    }

  *ppin = pin;
  *ptable_bits = (int)table_bits;

  return 1;
}

/* Read and decompress the literals and store them ending at POUTEND.  This
   works because we are going to use all the literals in the output, so they
   must fit into the output buffer.  HUFFMAN_TABLE, and PHUFFMAN_TABLE_BITS
   store the Huffman table across calls.  SCRATCH is used to read a Huffman
   table.  Store the start of the decompressed literals in *PPLIT.  Update
   *PPIN.  Return 1 on success, 0 on error.  */

static int
elf_zstd_read_literals (const unsigned char **ppin,
			const unsigned char *pinend,
			unsigned char *pout,
			unsigned char *poutend,
			uint16_t *scratch,
			uint16_t *huffman_table,
			int *phuffman_table_bits,
			unsigned char **pplit)
{
  const unsigned char *pin;
  unsigned char *plit;
  unsigned char hdr;
  uint32_t regenerated_size;
  uint32_t compressed_size;
  int streams;
  uint32_t total_streams_size;
  unsigned int huffman_table_bits;
  uint64_t huffman_mask;

  pin = *ppin;
  if (unlikely (pin >= pinend))
    {
      elf_uncompress_failed ();
      return 0;
    }
  hdr = *pin;
  ++pin;

  if ((hdr & 3) == 0 || (hdr & 3) == 1)
    {
      int raw;

      /* Raw_Literals_Block or RLE_Literals_Block */

      raw = (hdr & 3) == 0;

      switch ((hdr >> 2) & 3)
	{
	case 0: case 2:
	  regenerated_size = hdr >> 3;
	  break;
	case 1:
	  if (unlikely (pin >= pinend))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }
	  regenerated_size = (hdr >> 4) + ((uint32_t)(*pin) << 4);
	  ++pin;
	  break;
	case 3:
	  if (unlikely (pin + 1 >= pinend))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }
	  regenerated_size = ((hdr >> 4)
			      + ((uint32_t)*pin << 4)
			      + ((uint32_t)pin[1] << 12));
	  pin += 2;
	  break;
	default:
	  elf_uncompress_failed ();
	  return 0;
	}

      if (unlikely ((size_t)(poutend - pout) < regenerated_size))
	{
	  elf_uncompress_failed ();
	  return 0;
	}

      plit = poutend - regenerated_size;

      if (raw)
	{
	  if (unlikely (pin + regenerated_size >= pinend))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }
	  memcpy (plit, pin, regenerated_size);
	  pin += regenerated_size;
	}
      else
	{
	  if (pin >= pinend)
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }
	  memset (plit, *pin, regenerated_size);
	  ++pin;
	}

      *ppin = pin;
      *pplit = plit;

      return 1;
    }

  /* Compressed_Literals_Block or Treeless_Literals_Block */

  switch ((hdr >> 2) & 3)
    {
    case 0: case 1:
      if (unlikely (pin + 1 >= pinend))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      regenerated_size = (hdr >> 4) | ((uint32_t)(*pin & 0x3f) << 4);
      compressed_size = (uint32_t)*pin >> 6 | ((uint32_t)pin[1] << 2);
      pin += 2;
      streams = ((hdr >> 2) & 3) == 0 ? 1 : 4;
      break;
    case 2:
      if (unlikely (pin + 2 >= pinend))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      regenerated_size = (((uint32_t)hdr >> 4)
			  | ((uint32_t)*pin << 4)
			  | (((uint32_t)pin[1] & 3) << 12));
      compressed_size = (((uint32_t)pin[1] >> 2)
			 | ((uint32_t)pin[2] << 6));
      pin += 3;
      streams = 4;
      break;
    case 3:
      if (unlikely (pin + 3 >= pinend))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      regenerated_size = (((uint32_t)hdr >> 4)
			  | ((uint32_t)*pin << 4)
			  | (((uint32_t)pin[1] & 0x3f) << 12));
      compressed_size = (((uint32_t)pin[1] >> 6)
			 | ((uint32_t)pin[2] << 2)
			 | ((uint32_t)pin[3] << 10));
      pin += 4;
      streams = 4;
      break;
    default:
      elf_uncompress_failed ();
      return 0;
    }

  if (unlikely (pin + compressed_size > pinend))
    {
      elf_uncompress_failed ();
      return 0;
    }

  pinend = pin + compressed_size;
  *ppin = pinend;

  if (unlikely ((size_t)(poutend - pout) < regenerated_size))
    {
      elf_uncompress_failed ();
      return 0;
    }

  plit = poutend - regenerated_size;

  *pplit = plit;

  total_streams_size = compressed_size;
  if ((hdr & 3) == 2)
    {
      const unsigned char *ptable;

      /* Compressed_Literals_Block.  Read Huffman tree.  */

      ptable = pin;
      if (!elf_zstd_read_huff (&ptable, pinend, scratch, huffman_table,
			       phuffman_table_bits))
	return 0;

      if (unlikely (total_streams_size < (size_t)(ptable - pin)))
	{
	  elf_uncompress_failed ();
	  return 0;
	}

      total_streams_size -= ptable - pin;
      pin = ptable;
    }
  else
    {
      /* Treeless_Literals_Block.  Reuse previous Huffman tree.  */
      if (unlikely (*phuffman_table_bits == 0))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
    }

  /* Decompress COMPRESSED_SIZE bytes of data at PIN using the huffman table,
     storing REGENERATED_SIZE bytes of decompressed data at PLIT.  */

  huffman_table_bits = (unsigned int)*phuffman_table_bits;
  huffman_mask = ((uint64_t)1 << huffman_table_bits) - 1;

  if (streams == 1)
    {
      const unsigned char *pback;
      const unsigned char *pbackend;
      uint64_t val;
      unsigned int bits;
      uint32_t i;

      pback = pin + total_streams_size - 1;
      pbackend = pin;
      if (!elf_fetch_backward_init (&pback, pbackend, &val, &bits))
	return 0;

      /* This is one of the inner loops of the decompression algorithm, so we
	 put some effort into optimization.  We can't get more than 64 bytes
	 from a single call to elf_fetch_bits_backward, and we can't subtract
	 more than 11 bits at a time.  */

      if (regenerated_size >= 64)
	{
	  unsigned char *plitstart;
	  unsigned char *plitstop;

	  plitstart = plit;
	  plitstop = plit + regenerated_size - 64;
	  while (plit < plitstop)
	    {
	      uint16_t t;

	      if (!elf_fetch_bits_backward (&pback, pbackend, &val, &bits))
		return 0;

	      if (bits < 16)
		break;

	      while (bits >= 33)
		{
		  t = huffman_table[(val >> (bits - huffman_table_bits))
				    & huffman_mask];
		  *plit = t >> 8;
		  ++plit;
		  bits -= t & 0xff;

		  t = huffman_table[(val >> (bits - huffman_table_bits))
				    & huffman_mask];
		  *plit = t >> 8;
		  ++plit;
		  bits -= t & 0xff;

		  t = huffman_table[(val >> (bits - huffman_table_bits))
				    & huffman_mask];
		  *plit = t >> 8;
		  ++plit;
		  bits -= t & 0xff;
		}

	      while (bits > 11)
		{
		  t = huffman_table[(val >> (bits - huffman_table_bits))
				    & huffman_mask];
		  *plit = t >> 8;
		  ++plit;
		  bits -= t & 0xff;
		}
	    }

	  regenerated_size -= plit - plitstart;
	}

      for (i = 0; i < regenerated_size; ++i)
	{
	  uint16_t t;

	  if (!elf_fetch_bits_backward (&pback, pbackend, &val, &bits))
	    return 0;

	  if (unlikely (bits < huffman_table_bits))
	    {
	      t = huffman_table[(val << (huffman_table_bits - bits))
				& huffman_mask];
	      if (unlikely (bits < (t & 0xff)))
		{
		  elf_uncompress_failed ();
		  return 0;
		}
	    }
	  else
	    t = huffman_table[(val >> (bits - huffman_table_bits))
			      & huffman_mask];

	  *plit = t >> 8;
	  ++plit;
	  bits -= t & 0xff;
	}

      return 1;
    }

  {
    uint32_t stream_size1, stream_size2, stream_size3, stream_size4;
    uint32_t tot;
    const unsigned char *pback1, *pback2, *pback3, *pback4;
    const unsigned char *pbackend1, *pbackend2, *pbackend3, *pbackend4;
    uint64_t val1, val2, val3, val4;
    unsigned int bits1, bits2, bits3, bits4;
    unsigned char *plit1, *plit2, *plit3, *plit4;
    uint32_t regenerated_stream_size;
    uint32_t regenerated_stream_size4;
    uint16_t t1, t2, t3, t4;
    uint32_t i;
    uint32_t limit;

    /* Read jump table.  */
    if (unlikely (pin + 5 >= pinend))
      {
	elf_uncompress_failed ();
	return 0;
      }
    stream_size1 = (uint32_t)*pin | ((uint32_t)pin[1] << 8);
    pin += 2;
    stream_size2 = (uint32_t)*pin | ((uint32_t)pin[1] << 8);
    pin += 2;
    stream_size3 = (uint32_t)*pin | ((uint32_t)pin[1] << 8);
    pin += 2;
    tot = stream_size1 + stream_size2 + stream_size3;
    if (unlikely (tot > total_streams_size - 6))
      {
	elf_uncompress_failed ();
	return 0;
      }
    stream_size4 = total_streams_size - 6 - tot;

    pback1 = pin + stream_size1 - 1;
    pbackend1 = pin;

    pback2 = pback1 + stream_size2;
    pbackend2 = pback1 + 1;

    pback3 = pback2 + stream_size3;
    pbackend3 = pback2 + 1;

    pback4 = pback3 + stream_size4;
    pbackend4 = pback3 + 1;

    if (!elf_fetch_backward_init (&pback1, pbackend1, &val1, &bits1))
      return 0;
    if (!elf_fetch_backward_init (&pback2, pbackend2, &val2, &bits2))
      return 0;
    if (!elf_fetch_backward_init (&pback3, pbackend3, &val3, &bits3))
      return 0;
    if (!elf_fetch_backward_init (&pback4, pbackend4, &val4, &bits4))
      return 0;

    regenerated_stream_size = (regenerated_size + 3) / 4;

    plit1 = plit;
    plit2 = plit1 + regenerated_stream_size;
    plit3 = plit2 + regenerated_stream_size;
    plit4 = plit3 + regenerated_stream_size;

    regenerated_stream_size4 = regenerated_size - regenerated_stream_size * 3;

    /* We can't get more than 64 literal bytes from a single call to
       elf_fetch_bits_backward.  The fourth stream can be up to 3 bytes less,
       so use as the limit.  */

    limit = regenerated_stream_size4 <= 64 ? 0 : regenerated_stream_size4 - 64;
    i = 0;
    while (i < limit)
      {
	if (!elf_fetch_bits_backward (&pback1, pbackend1, &val1, &bits1))
	  return 0;
	if (!elf_fetch_bits_backward (&pback2, pbackend2, &val2, &bits2))
	  return 0;
	if (!elf_fetch_bits_backward (&pback3, pbackend3, &val3, &bits3))
	  return 0;
	if (!elf_fetch_bits_backward (&pback4, pbackend4, &val4, &bits4))
	  return 0;

	/* We can't subtract more than 11 bits at a time.  */

	do
	  {
	    t1 = huffman_table[(val1 >> (bits1 - huffman_table_bits))
			       & huffman_mask];
	    t2 = huffman_table[(val2 >> (bits2 - huffman_table_bits))
			       & huffman_mask];
	    t3 = huffman_table[(val3 >> (bits3 - huffman_table_bits))
			       & huffman_mask];
	    t4 = huffman_table[(val4 >> (bits4 - huffman_table_bits))
			       & huffman_mask];

	    *plit1 = t1 >> 8;
	    ++plit1;
	    bits1 -= t1 & 0xff;

	    *plit2 = t2 >> 8;
	    ++plit2;
	    bits2 -= t2 & 0xff;

	    *plit3 = t3 >> 8;
	    ++plit3;
	    bits3 -= t3 & 0xff;

	    *plit4 = t4 >> 8;
	    ++plit4;
	    bits4 -= t4 & 0xff;

	    ++i;
	  }
	while (bits1 > 11 && bits2 > 11 && bits3 > 11 && bits4 > 11);
      }

    while (i < regenerated_stream_size)
      {
	int use4;

	use4 = i < regenerated_stream_size4;

	if (!elf_fetch_bits_backward (&pback1, pbackend1, &val1, &bits1))
	  return 0;
	if (!elf_fetch_bits_backward (&pback2, pbackend2, &val2, &bits2))
	  return 0;
	if (!elf_fetch_bits_backward (&pback3, pbackend3, &val3, &bits3))
	  return 0;
	if (use4)
	  {
	    if (!elf_fetch_bits_backward (&pback4, pbackend4, &val4, &bits4))
	      return 0;
	  }

	if (unlikely (bits1 < huffman_table_bits))
	  {
	    t1 = huffman_table[(val1 << (huffman_table_bits - bits1))
			       & huffman_mask];
	    if (unlikely (bits1 < (t1 & 0xff)))
	      {
		elf_uncompress_failed ();
		return 0;
	      }
	  }
	else
	  t1 = huffman_table[(val1 >> (bits1 - huffman_table_bits))
			     & huffman_mask];

	if (unlikely (bits2 < huffman_table_bits))
	  {
	    t2 = huffman_table[(val2 << (huffman_table_bits - bits2))
			       & huffman_mask];
	    if (unlikely (bits2 < (t2 & 0xff)))
	      {
		elf_uncompress_failed ();
		return 0;
	      }
	  }
	else
	  t2 = huffman_table[(val2 >> (bits2 - huffman_table_bits))
			     & huffman_mask];

	if (unlikely (bits3 < huffman_table_bits))
	  {
	    t3 = huffman_table[(val3 << (huffman_table_bits - bits3))
			       & huffman_mask];
	    if (unlikely (bits3 < (t3 & 0xff)))
	      {
		elf_uncompress_failed ();
		return 0;
	      }
	  }
	else
	  t3 = huffman_table[(val3 >> (bits3 - huffman_table_bits))
			     & huffman_mask];

	if (use4)
	  {
	    if (unlikely (bits4 < huffman_table_bits))
	      {
		t4 = huffman_table[(val4 << (huffman_table_bits - bits4))
				   & huffman_mask];
		if (unlikely (bits4 < (t4 & 0xff)))
		  {
		    elf_uncompress_failed ();
		    return 0;
		  }
	      }
	    else
	      t4 = huffman_table[(val4 >> (bits4 - huffman_table_bits))
				 & huffman_mask];

	    *plit4 = t4 >> 8;
	    ++plit4;
	    bits4 -= t4 & 0xff;
	  }

	*plit1 = t1 >> 8;
	++plit1;
	bits1 -= t1 & 0xff;

	*plit2 = t2 >> 8;
	++plit2;
	bits2 -= t2 & 0xff;

	*plit3 = t3 >> 8;
	++plit3;
	bits3 -= t3 & 0xff;

	++i;
      }
  }

  return 1;
}

/* The information used to decompress a sequence code, which can be a literal
   length, an offset, or a match length.  */

struct elf_zstd_seq_decode
{
  const struct elf_zstd_fse_baseline_entry *table;
  int table_bits;
};

/* Unpack a sequence code compression mode.  */

static int
elf_zstd_unpack_seq_decode (int mode,
			    const unsigned char **ppin,
			    const unsigned char *pinend,
			    const struct elf_zstd_fse_baseline_entry *predef,
			    int predef_bits,
			    uint16_t *scratch,
			    int maxidx,
			    struct elf_zstd_fse_baseline_entry *table,
			    int table_bits,
			    int (*conv)(const struct elf_zstd_fse_entry *,
					int,
					struct elf_zstd_fse_baseline_entry *),
			    struct elf_zstd_seq_decode *decode)
{
  switch (mode)
    {
    case 0:
      decode->table = predef;
      decode->table_bits = predef_bits;
      break;

    case 1:
      {
	struct elf_zstd_fse_entry entry;

	if (unlikely (*ppin >= pinend))
	  {
	    elf_uncompress_failed ();
	    return 0;
	  }
	entry.symbol = **ppin;
	++*ppin;
	entry.bits = 0;
	entry.base = 0;
	decode->table_bits = 0;
	if (!conv (&entry, 0, table))
	  return 0;
      }
      break;

    case 2:
      {
	struct elf_zstd_fse_entry *fse_table;

	/* We use the same space for the simple FSE table and the baseline
	   table.  */
	fse_table = (struct elf_zstd_fse_entry *)table;
	decode->table_bits = table_bits;
	if (!elf_zstd_read_fse (ppin, pinend, scratch, maxidx, fse_table,
				&decode->table_bits))
	  return 0;
	if (!conv (fse_table, decode->table_bits, table))
	  return 0;
	decode->table = table;
      }
      break;

    case 3:
      if (unlikely (decode->table_bits == -1))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      break;

    default:
      elf_uncompress_failed ();
      return 0;
    }

  return 1;
}

/* Decompress a zstd stream from PIN/SIN to POUT/SOUT.  Code based on RFC 8878.
   Return 1 on success, 0 on error.  */

static int
elf_zstd_decompress (const unsigned char *pin, size_t sin,
		     unsigned char *zdebug_table, unsigned char *pout,
		     size_t sout)
{
  const unsigned char *pinend;
  unsigned char *poutstart;
  unsigned char *poutend;
  struct elf_zstd_seq_decode literal_decode;
  struct elf_zstd_fse_baseline_entry *literal_fse_table;
  struct elf_zstd_seq_decode match_decode;
  struct elf_zstd_fse_baseline_entry *match_fse_table;
  struct elf_zstd_seq_decode offset_decode;
  struct elf_zstd_fse_baseline_entry *offset_fse_table;
  uint16_t *huffman_table;
  int huffman_table_bits;
  uint32_t repeated_offset1;
  uint32_t repeated_offset2;
  uint32_t repeated_offset3;
  uint16_t *scratch;
  unsigned char hdr;
  int has_checksum;
  uint64_t content_size;
  int last_block;

  pinend = pin + sin;
  poutstart = pout;
  poutend = pout + sout;

  literal_decode.table = NULL;
  literal_decode.table_bits = -1;
  literal_fse_table = ((struct elf_zstd_fse_baseline_entry *)
		       (zdebug_table + ZSTD_TABLE_LITERAL_FSE_OFFSET));

  match_decode.table = NULL;
  match_decode.table_bits = -1;
  match_fse_table = ((struct elf_zstd_fse_baseline_entry *)
		     (zdebug_table + ZSTD_TABLE_MATCH_FSE_OFFSET));

  offset_decode.table = NULL;
  offset_decode.table_bits = -1;
  offset_fse_table = ((struct elf_zstd_fse_baseline_entry *)
		      (zdebug_table + ZSTD_TABLE_OFFSET_FSE_OFFSET));
  huffman_table = ((uint16_t *)
		   (zdebug_table + ZSTD_TABLE_HUFFMAN_OFFSET));
  huffman_table_bits = 0;
  scratch = ((uint16_t *)
	     (zdebug_table + ZSTD_TABLE_WORK_OFFSET));

  repeated_offset1 = 1;
  repeated_offset2 = 4;
  repeated_offset3 = 8;

  if (unlikely (sin < 4))
    {
      elf_uncompress_failed ();
      return 0;
    }

  /* These values are the zstd magic number.  */
  if (unlikely (pin[0] != 0x28
		|| pin[1] != 0xb5
		|| pin[2] != 0x2f
		|| pin[3] != 0xfd))
    {
      elf_uncompress_failed ();
      return 0;
    }

  pin += 4;

  if (unlikely (pin >= pinend))
    {
      elf_uncompress_failed ();
      return 0;
    }

  hdr = *pin++;

  /* We expect a single frame.  */
  if (unlikely ((hdr & (1 << 5)) == 0))
    {
      elf_uncompress_failed ();
      return 0;
    }
  /* Reserved bit must be zero.  */
  if (unlikely ((hdr & (1 << 3)) != 0))
    {
      elf_uncompress_failed ();
      return 0;
    }
  /* We do not expect a dictionary.  */
  if (unlikely ((hdr & 3) != 0))
    {
      elf_uncompress_failed ();
      return 0;
    }
  has_checksum = (hdr & (1 << 2)) != 0;
  switch (hdr >> 6)
    {
    case 0:
      if (unlikely (pin >= pinend))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      content_size = (uint64_t) *pin++;
      break;
    case 1:
      if (unlikely (pin + 1 >= pinend))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      content_size = (((uint64_t) pin[0]) | (((uint64_t) pin[1]) << 8)) + 256;
      pin += 2;
      break;
    case 2:
      if (unlikely (pin + 3 >= pinend))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      content_size = ((uint64_t) pin[0]
		      | (((uint64_t) pin[1]) << 8)
		      | (((uint64_t) pin[2]) << 16)
		      | (((uint64_t) pin[3]) << 24));
      pin += 4;
      break;
    case 3:
      if (unlikely (pin + 7 >= pinend))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      content_size = ((uint64_t) pin[0]
		      | (((uint64_t) pin[1]) << 8)
		      | (((uint64_t) pin[2]) << 16)
		      | (((uint64_t) pin[3]) << 24)
		      | (((uint64_t) pin[4]) << 32)
		      | (((uint64_t) pin[5]) << 40)
		      | (((uint64_t) pin[6]) << 48)
		      | (((uint64_t) pin[7]) << 56));
      pin += 8;
      break;
    default:
      elf_uncompress_failed ();
      return 0;
    }

  if (unlikely (content_size != (size_t) content_size
		|| (size_t) content_size != sout))
    {
      elf_uncompress_failed ();
      return 0;
    }

  last_block = 0;
  while (!last_block)
    {
      uint32_t block_hdr;
      int block_type;
      uint32_t block_size;

      if (unlikely (pin + 2 >= pinend))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      block_hdr = ((uint32_t) pin[0]
		   | (((uint32_t) pin[1]) << 8)
		   | (((uint32_t) pin[2]) << 16));
      pin += 3;

      last_block = block_hdr & 1;
      block_type = (block_hdr >> 1) & 3;
      block_size = block_hdr >> 3;

      switch (block_type)
	{
	case 0:
	  /* Raw_Block */
	  if (unlikely ((size_t) block_size > (size_t) (pinend - pin)))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }
	  if (unlikely ((size_t) block_size > (size_t) (poutend - pout)))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }
	  memcpy (pout, pin, block_size);
	  pout += block_size;
	  pin += block_size;
	  break;

	case 1:
	  /* RLE_Block */
	  if (unlikely (pin >= pinend))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }
	  if (unlikely ((size_t) block_size > (size_t) (poutend - pout)))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }
	  memset (pout, *pin, block_size);
	  pout += block_size;
	  pin++;
	  break;

	case 2:
	  {
	    const unsigned char *pblockend;
	    unsigned char *plitstack;
	    unsigned char *plit;
	    uint32_t literal_count;
	    unsigned char seq_hdr;
	    size_t seq_count;
	    size_t seq;
	    const unsigned char *pback;
	    uint64_t val;
	    unsigned int bits;
	    unsigned int literal_state;
	    unsigned int offset_state;
	    unsigned int match_state;

	    /* Compressed_Block */
	    if (unlikely ((size_t) block_size > (size_t) (pinend - pin)))
	      {
		elf_uncompress_failed ();
		return 0;
	      }

	    pblockend = pin + block_size;

	    /* Read the literals into the end of the output space, and leave
	       PLIT pointing at them.  */

	    if (!elf_zstd_read_literals (&pin, pblockend, pout, poutend,
					 scratch, huffman_table,
					 &huffman_table_bits,
					 &plitstack))
	      return 0;
	    plit = plitstack;
	    literal_count = poutend - plit;

	    seq_hdr = *pin;
	    pin++;
	    if (seq_hdr < 128)
	      seq_count = seq_hdr;
	    else if (seq_hdr < 255)
	      {
		if (unlikely (pin >= pinend))
		  {
		    elf_uncompress_failed ();
		    return 0;
		  }
		seq_count = ((seq_hdr - 128) << 8) + *pin;
		pin++;
	      }
	    else
	      {
		if (unlikely (pin + 1 >= pinend))
		  {
		    elf_uncompress_failed ();
		    return 0;
		  }
		seq_count = *pin + (pin[1] << 8) + 0x7f00;
		pin += 2;
	      }

	    if (seq_count > 0)
	      {
		int (*pfn)(const struct elf_zstd_fse_entry *,
			   int, struct elf_zstd_fse_baseline_entry *);

		if (unlikely (pin >= pinend))
		  {
		    elf_uncompress_failed ();
		    return 0;
		  }
		seq_hdr = *pin;
		++pin;

		pfn = elf_zstd_make_literal_baseline_fse;
		if (!elf_zstd_unpack_seq_decode ((seq_hdr >> 6) & 3,
						 &pin, pinend,
						 &elf_zstd_lit_table[0], 6,
						 scratch, 35,
						 literal_fse_table, 9, pfn,
						 &literal_decode))
		  return 0;

		pfn = elf_zstd_make_offset_baseline_fse;
		if (!elf_zstd_unpack_seq_decode ((seq_hdr >> 4) & 3,
						 &pin, pinend,
						 &elf_zstd_offset_table[0], 5,
						 scratch, 31,
						 offset_fse_table, 8, pfn,
						 &offset_decode))
		  return 0;

		pfn = elf_zstd_make_match_baseline_fse;
		if (!elf_zstd_unpack_seq_decode ((seq_hdr >> 2) & 3,
						 &pin, pinend,
						 &elf_zstd_match_table[0], 6,
						 scratch, 52,
						 match_fse_table, 9, pfn,
						 &match_decode))
		  return 0;
	      }

	    pback = pblockend - 1;
	    if (!elf_fetch_backward_init (&pback, pin, &val, &bits))
	      return 0;

	    bits -= literal_decode.table_bits;
	    literal_state = ((val >> bits)
			     & ((1U << literal_decode.table_bits) - 1));

	    if (!elf_fetch_bits_backward (&pback, pin, &val, &bits))
	      return 0;
	    bits -= offset_decode.table_bits;
	    offset_state = ((val >> bits)
			    & ((1U << offset_decode.table_bits) - 1));

	    if (!elf_fetch_bits_backward (&pback, pin, &val, &bits))
	      return 0;
	    bits -= match_decode.table_bits;
	    match_state = ((val >> bits)
			   & ((1U << match_decode.table_bits) - 1));

	    seq = 0;
	    while (1)
	      {
		const struct elf_zstd_fse_baseline_entry *pt;
		uint32_t offset_basebits;
		uint32_t offset_baseline;
		uint32_t offset_bits;
		uint32_t offset_base;
		uint32_t offset;
		uint32_t match_baseline;
		uint32_t match_bits;
		uint32_t match_base;
		uint32_t match;
		uint32_t literal_baseline;
		uint32_t literal_bits;
		uint32_t literal_base;
		uint32_t literal;
		uint32_t need;
		uint32_t add;

		pt = &offset_decode.table[offset_state];
		offset_basebits = pt->basebits;
		offset_baseline = pt->baseline;
		offset_bits = pt->bits;
		offset_base = pt->base;

		/* This case can be more than 16 bits, which is all that
		   elf_fetch_bits_backward promises.  */
		need = offset_basebits;
		add = 0;
		if (unlikely (need > 16))
		  {
		    if (!elf_fetch_bits_backward (&pback, pin, &val, &bits))
		      return 0;
		    bits -= 16;
		    add = (val >> bits) & ((1U << 16) - 1);
		    need -= 16;
		    add <<= need;
		  }
		if (need > 0)
		  {
		    if (!elf_fetch_bits_backward (&pback, pin, &val, &bits))
		      return 0;
		    bits -= need;
		    add += (val >> bits) & ((1U << need) - 1);
		  }

		offset = offset_baseline + add;

		pt = &match_decode.table[match_state];
		need = pt->basebits;
		match_baseline = pt->baseline;
		match_bits = pt->bits;
		match_base = pt->base;

		add = 0;
		if (need > 0)
		  {
		    if (!elf_fetch_bits_backward (&pback, pin, &val, &bits))
		      return 0;
		    bits -= need;
		    add = (val >> bits) & ((1U << need) - 1);
		  }

		match = match_baseline + add;

		pt = &literal_decode.table[literal_state];
		need = pt->basebits;
		literal_baseline = pt->baseline;
		literal_bits = pt->bits;
		literal_base = pt->base;

		add = 0;
		if (need > 0)
		  {
		    if (!elf_fetch_bits_backward (&pback, pin, &val, &bits))
		      return 0;
		    bits -= need;
		    add = (val >> bits) & ((1U << need) - 1);
		  }

		literal = literal_baseline + add;

		/* See the comment in elf_zstd_make_offset_baseline_fse.  */
		if (offset_basebits > 1)
		  {
		    repeated_offset3 = repeated_offset2;
		    repeated_offset2 = repeated_offset1;
		    repeated_offset1 = offset;
		  }
		else
		  {
		    if (unlikely (literal == 0))
		      ++offset;
		    switch (offset)
		      {
		      case 1:
			offset = repeated_offset1;
			break;
		      case 2:
			offset = repeated_offset2;
			repeated_offset2 = repeated_offset1;
			repeated_offset1 = offset;
			break;
		      case 3:
			offset = repeated_offset3;
			repeated_offset3 = repeated_offset2;
			repeated_offset2 = repeated_offset1;
			repeated_offset1 = offset;
			break;
		      case 4:
			offset = repeated_offset1 - 1;
			repeated_offset3 = repeated_offset2;
			repeated_offset2 = repeated_offset1;
			repeated_offset1 = offset;
			break;
		      }
		  }

		++seq;
		if (seq < seq_count)
		  {
		    uint32_t v;

		    /* Update the three states.  */

		    if (!elf_fetch_bits_backward (&pback, pin, &val, &bits))
		      return 0;

		    need = literal_bits;
		    bits -= need;
		    v = (val >> bits) & (((uint32_t)1 << need) - 1);

		    literal_state = literal_base + v;

		    if (!elf_fetch_bits_backward (&pback, pin, &val, &bits))
		      return 0;

		    need = match_bits;
		    bits -= need;
		    v = (val >> bits) & (((uint32_t)1 << need) - 1);

		    match_state = match_base + v;

		    if (!elf_fetch_bits_backward (&pback, pin, &val, &bits))
		      return 0;

		    need = offset_bits;
		    bits -= need;
		    v = (val >> bits) & (((uint32_t)1 << need) - 1);

		    offset_state = offset_base + v;
		  }

		/* The next sequence is now in LITERAL, OFFSET, MATCH.  */

		/* Copy LITERAL bytes from the literals.  */

		if (unlikely ((size_t)(poutend - pout) < literal))
		  {
		    elf_uncompress_failed ();
		    return 0;
		  }

		if (unlikely (literal_count < literal))
		  {
		    elf_uncompress_failed ();
		    return 0;
		  }

		literal_count -= literal;

		/* Often LITERAL is small, so handle small cases quickly.  */
		switch (literal)
		  {
		  case 8:
		    *pout++ = *plit++;
		    /* FALLTHROUGH */
		  case 7:
		    *pout++ = *plit++;
		    /* FALLTHROUGH */
		  case 6:
		    *pout++ = *plit++;
		    /* FALLTHROUGH */
		  case 5:
		    *pout++ = *plit++;
		    /* FALLTHROUGH */
		  case 4:
		    *pout++ = *plit++;
		    /* FALLTHROUGH */
		  case 3:
		    *pout++ = *plit++;
		    /* FALLTHROUGH */
		  case 2:
		    *pout++ = *plit++;
		    /* FALLTHROUGH */
		  case 1:
		    *pout++ = *plit++;
		    break;

		  case 0:
		    break;

		  default:
		    if (unlikely ((size_t)(plit - pout) < literal))
		      {
			uint32_t move;

			move = plit - pout;
			while (literal > move)
			  {
			    memcpy (pout, plit, move);
			    pout += move;
			    plit += move;
			    literal -= move;
			  }
		      }

		    memcpy (pout, plit, literal);
		    pout += literal;
		    plit += literal;
		  }

		if (match > 0)
		  {
		    /* Copy MATCH bytes from the decoded output at OFFSET.  */

		    if (unlikely ((size_t)(poutend - pout) < match))
		      {
			elf_uncompress_failed ();
			return 0;
		      }

		    if (unlikely ((size_t)(pout - poutstart) < offset))
		      {
			elf_uncompress_failed ();
			return 0;
		      }

		    if (offset >= match)
		      {
			memcpy (pout, pout - offset, match);
			pout += match;
		      }
		    else
		      {
			while (match > 0)
			  {
			    uint32_t copy;

			    copy = match < offset ? match : offset;
			    memcpy (pout, pout - offset, copy);
			    match -= copy;
			    pout += copy;
			  }
		      }
		  }

		if (unlikely (seq >= seq_count))
		  {
		    /* Copy remaining literals.  */
		    if (literal_count > 0 && plit != pout)
		      {
			if (unlikely ((size_t)(poutend - pout)
				      < literal_count))
			  {
			    elf_uncompress_failed ();
			    return 0;
			  }

			if ((size_t)(plit - pout) < literal_count)
			  {
			    uint32_t move;

			    move = plit - pout;
			    while (literal_count > move)
			      {
				memcpy (pout, plit, move);
				pout += move;
				plit += move;
				literal_count -= move;
			      }
			  }

			memcpy (pout, plit, literal_count);
		      }

		    pout += literal_count;

		    break;
		  }
	      }

	    pin = pblockend;
	  }
	  break;

	case 3:
	default:
	  elf_uncompress_failed ();
	  return 0;
	}
    }

  if (has_checksum)
    {
      if (unlikely (pin + 4 > pinend))
	{
	  elf_uncompress_failed ();
	  return 0;
	}

      /* We don't currently verify the checksum.  Currently running GNU ld with
	 --compress-debug-sections=zstd does not seem to generate a
	 checksum.  */

      pin += 4;
    }

  if (pin != pinend)
    {
      elf_uncompress_failed ();
      return 0;
    }

  return 1;
}

#define ZDEBUG_TABLE_SIZE \
  (ZLIB_TABLE_SIZE > ZSTD_TABLE_SIZE ? ZLIB_TABLE_SIZE : ZSTD_TABLE_SIZE)

/* Uncompress the old compressed debug format, the one emitted by
   --compress-debug-sections=zlib-gnu.  The compressed data is in
   COMPRESSED / COMPRESSED_SIZE, and the function writes to
   *UNCOMPRESSED / *UNCOMPRESSED_SIZE.  ZDEBUG_TABLE is work space to
   hold Huffman tables.  Returns 0 on error, 1 on successful
   decompression or if something goes wrong.  In general we try to
   carry on, by returning 1, even if we can't decompress.  */

static int
elf_uncompress_zdebug (struct backtrace_state *state,
		       const unsigned char *compressed, size_t compressed_size,
		       uint16_t *zdebug_table,
		       backtrace_error_callback error_callback, void *data,
		       unsigned char **uncompressed, size_t *uncompressed_size)
{
  size_t sz;
  size_t i;
  unsigned char *po;

  *uncompressed = NULL;
  *uncompressed_size = 0;

  /* The format starts with the four bytes ZLIB, followed by the 8
     byte length of the uncompressed data in big-endian order,
     followed by a zlib stream.  */

  if (compressed_size < 12 || memcmp (compressed, "ZLIB", 4) != 0)
    return 1;

  sz = 0;
  for (i = 0; i < 8; i++)
    sz = (sz << 8) | compressed[i + 4];

  if (*uncompressed != NULL && *uncompressed_size >= sz)
    po = *uncompressed;
  else
    {
      po = (unsigned char *) backtrace_alloc (state, sz, error_callback, data);
      if (po == NULL)
	return 0;
    }

  if (!elf_zlib_inflate_and_verify (compressed + 12, compressed_size - 12,
				    zdebug_table, po, sz))
    return 1;

  *uncompressed = po;
  *uncompressed_size = sz;

  return 1;
}

/* Uncompress the new compressed debug format, the official standard
   ELF approach emitted by --compress-debug-sections=zlib-gabi.  The
   compressed data is in COMPRESSED / COMPRESSED_SIZE, and the
   function writes to *UNCOMPRESSED / *UNCOMPRESSED_SIZE.
   ZDEBUG_TABLE is work space as for elf_uncompress_zdebug.  Returns 0
   on error, 1 on successful decompression or if something goes wrong.
   In general we try to carry on, by returning 1, even if we can't
   decompress.  */

static int
elf_uncompress_chdr (struct backtrace_state *state,
		     const unsigned char *compressed, size_t compressed_size,
		     uint16_t *zdebug_table,
		     backtrace_error_callback error_callback, void *data,
		     unsigned char **uncompressed, size_t *uncompressed_size)
{
  b_elf_chdr chdr;
  char *alc;
  size_t alc_len;
  unsigned char *po;

  *uncompressed = NULL;
  *uncompressed_size = 0;

  /* The format starts with an ELF compression header.  */
  if (compressed_size < sizeof (b_elf_chdr))
    return 1;

  /* The lld linker can misalign a compressed section, so we can't safely read
     the fields directly as we can for other ELF sections.  See
     https://github.com/ianlancetaylor/libbacktrace/pull/120.  */
  memcpy (&chdr, compressed, sizeof (b_elf_chdr));

  alc = NULL;
  alc_len = 0;
  if (*uncompressed != NULL && *uncompressed_size >= chdr.ch_size)
    po = *uncompressed;
  else
    {
      alc_len = chdr.ch_size;
      alc = backtrace_alloc (state, alc_len, error_callback, data);
      if (alc == NULL)
	return 0;
      po = (unsigned char *) alc;
    }

  switch (chdr.ch_type)
    {
    case ELFCOMPRESS_ZLIB:
      if (!elf_zlib_inflate_and_verify (compressed + sizeof (b_elf_chdr),
					compressed_size - sizeof (b_elf_chdr),
					zdebug_table, po, chdr.ch_size))
	goto skip;
      break;

    case ELFCOMPRESS_ZSTD:
      if (!elf_zstd_decompress (compressed + sizeof (b_elf_chdr),
				compressed_size - sizeof (b_elf_chdr),
				(unsigned char *)zdebug_table, po,
				chdr.ch_size))
	goto skip;
      break;

    default:
      /* Unsupported compression algorithm.  */
      goto skip;
    }

  *uncompressed = po;
  *uncompressed_size = chdr.ch_size;

  return 1;

 skip:
  if (alc != NULL && alc_len > 0)
    backtrace_free (state, alc, alc_len, error_callback, data);
  return 1;
}

/* This function is a hook for testing the zlib support.  It is only
   used by tests.  */

int
backtrace_uncompress_zdebug (struct backtrace_state *state,
			     const unsigned char *compressed,
			     size_t compressed_size,
			     backtrace_error_callback error_callback,
			     void *data, unsigned char **uncompressed,
			     size_t *uncompressed_size)
{
  uint16_t *zdebug_table;
  int ret;

  zdebug_table = ((uint16_t *) backtrace_alloc (state, ZDEBUG_TABLE_SIZE,
						error_callback, data));
  if (zdebug_table == NULL)
    return 0;
  ret = elf_uncompress_zdebug (state, compressed, compressed_size,
			       zdebug_table, error_callback, data,
			       uncompressed, uncompressed_size);
  backtrace_free (state, zdebug_table, ZDEBUG_TABLE_SIZE,
		  error_callback, data);
  return ret;
}

/* This function is a hook for testing the zstd support.  It is only used by
   tests.  */

int
backtrace_uncompress_zstd (struct backtrace_state *state,
			   const unsigned char *compressed,
			   size_t compressed_size,
			   backtrace_error_callback error_callback,
			   void *data, unsigned char *uncompressed,
			   size_t uncompressed_size)
{
  unsigned char *zdebug_table;
  int ret;

  zdebug_table = ((unsigned char *) backtrace_alloc (state, ZDEBUG_TABLE_SIZE,
						     error_callback, data));
  if (zdebug_table == NULL)
    return 0;
  ret = elf_zstd_decompress (compressed, compressed_size,
			     zdebug_table, uncompressed, uncompressed_size);
  backtrace_free (state, zdebug_table, ZDEBUG_TABLE_SIZE,
		  error_callback, data);
  return ret;
}

/* Number of LZMA states.  */
#define LZMA_STATES (12)

/* Number of LZMA position states.  The pb value of the property byte
   is the number of bits to include in these states, and the maximum
   value of pb is 4.  */
#define LZMA_POS_STATES (16)

/* Number of LZMA distance states.  These are used match distances
   with a short match length: up to 4 bytes.  */
#define LZMA_DIST_STATES (4)

/* Number of LZMA distance slots.  LZMA uses six bits to encode larger
   match lengths, so 1 << 6 possible probabilities.  */
#define LZMA_DIST_SLOTS (64)

/* LZMA distances 0 to 3 are encoded directly, larger values use a
   probability model.  */
#define LZMA_DIST_MODEL_START (4)

/* The LZMA probability model ends at 14.  */
#define LZMA_DIST_MODEL_END (14)

/* LZMA distance slots for distances less than 127.  */
#define LZMA_FULL_DISTANCES (128)

/* LZMA uses four alignment bits.  */
#define LZMA_ALIGN_SIZE (16)

/* LZMA match length is encoded with 4, 5, or 10 bits, some of which
   are already known.  */
#define LZMA_LEN_LOW_SYMBOLS (8)
#define LZMA_LEN_MID_SYMBOLS (8)
#define LZMA_LEN_HIGH_SYMBOLS (256)

/* LZMA literal encoding.  */
#define LZMA_LITERAL_CODERS_MAX (16)
#define LZMA_LITERAL_CODER_SIZE (0x300)

/* LZMA is based on a large set of probabilities, each managed
   independently.  Each probability is an 11 bit number that we store
   in a uint16_t.  We use a single large array of probabilities.  */

/* Lengths of entries in the LZMA probabilities array.  The names used
   here are copied from the Linux kernel implementation.  */

#define LZMA_PROB_IS_MATCH_LEN (LZMA_STATES * LZMA_POS_STATES)
#define LZMA_PROB_IS_REP_LEN LZMA_STATES
#define LZMA_PROB_IS_REP0_LEN LZMA_STATES
#define LZMA_PROB_IS_REP1_LEN LZMA_STATES
#define LZMA_PROB_IS_REP2_LEN LZMA_STATES
#define LZMA_PROB_IS_REP0_LONG_LEN (LZMA_STATES * LZMA_POS_STATES)
#define LZMA_PROB_DIST_SLOT_LEN (LZMA_DIST_STATES * LZMA_DIST_SLOTS)
#define LZMA_PROB_DIST_SPECIAL_LEN (LZMA_FULL_DISTANCES - LZMA_DIST_MODEL_END)
#define LZMA_PROB_DIST_ALIGN_LEN LZMA_ALIGN_SIZE
#define LZMA_PROB_MATCH_LEN_CHOICE_LEN 1
#define LZMA_PROB_MATCH_LEN_CHOICE2_LEN 1
#define LZMA_PROB_MATCH_LEN_LOW_LEN (LZMA_POS_STATES * LZMA_LEN_LOW_SYMBOLS)
#define LZMA_PROB_MATCH_LEN_MID_LEN (LZMA_POS_STATES * LZMA_LEN_MID_SYMBOLS)
#define LZMA_PROB_MATCH_LEN_HIGH_LEN LZMA_LEN_HIGH_SYMBOLS
#define LZMA_PROB_REP_LEN_CHOICE_LEN 1
#define LZMA_PROB_REP_LEN_CHOICE2_LEN 1
#define LZMA_PROB_REP_LEN_LOW_LEN (LZMA_POS_STATES * LZMA_LEN_LOW_SYMBOLS)
#define LZMA_PROB_REP_LEN_MID_LEN (LZMA_POS_STATES * LZMA_LEN_MID_SYMBOLS)
#define LZMA_PROB_REP_LEN_HIGH_LEN LZMA_LEN_HIGH_SYMBOLS
#define LZMA_PROB_LITERAL_LEN \
  (LZMA_LITERAL_CODERS_MAX * LZMA_LITERAL_CODER_SIZE)

/* Offsets into the LZMA probabilities array.  This is mechanically
   generated from the above lengths.  */

#define LZMA_PROB_IS_MATCH_OFFSET 0
#define LZMA_PROB_IS_REP_OFFSET \
  (LZMA_PROB_IS_MATCH_OFFSET + LZMA_PROB_IS_MATCH_LEN)
#define LZMA_PROB_IS_REP0_OFFSET \
  (LZMA_PROB_IS_REP_OFFSET + LZMA_PROB_IS_REP_LEN)
#define LZMA_PROB_IS_REP1_OFFSET \
  (LZMA_PROB_IS_REP0_OFFSET + LZMA_PROB_IS_REP0_LEN)
#define LZMA_PROB_IS_REP2_OFFSET \
  (LZMA_PROB_IS_REP1_OFFSET + LZMA_PROB_IS_REP1_LEN)
#define LZMA_PROB_IS_REP0_LONG_OFFSET \
  (LZMA_PROB_IS_REP2_OFFSET + LZMA_PROB_IS_REP2_LEN)
#define LZMA_PROB_DIST_SLOT_OFFSET \
  (LZMA_PROB_IS_REP0_LONG_OFFSET + LZMA_PROB_IS_REP0_LONG_LEN)
#define LZMA_PROB_DIST_SPECIAL_OFFSET \
  (LZMA_PROB_DIST_SLOT_OFFSET + LZMA_PROB_DIST_SLOT_LEN)
#define LZMA_PROB_DIST_ALIGN_OFFSET \
  (LZMA_PROB_DIST_SPECIAL_OFFSET + LZMA_PROB_DIST_SPECIAL_LEN)
#define LZMA_PROB_MATCH_LEN_CHOICE_OFFSET \
  (LZMA_PROB_DIST_ALIGN_OFFSET + LZMA_PROB_DIST_ALIGN_LEN)
#define LZMA_PROB_MATCH_LEN_CHOICE2_OFFSET \
  (LZMA_PROB_MATCH_LEN_CHOICE_OFFSET + LZMA_PROB_MATCH_LEN_CHOICE_LEN)
#define LZMA_PROB_MATCH_LEN_LOW_OFFSET \
  (LZMA_PROB_MATCH_LEN_CHOICE2_OFFSET + LZMA_PROB_MATCH_LEN_CHOICE2_LEN)
#define LZMA_PROB_MATCH_LEN_MID_OFFSET \
  (LZMA_PROB_MATCH_LEN_LOW_OFFSET + LZMA_PROB_MATCH_LEN_LOW_LEN)
#define LZMA_PROB_MATCH_LEN_HIGH_OFFSET \
  (LZMA_PROB_MATCH_LEN_MID_OFFSET + LZMA_PROB_MATCH_LEN_MID_LEN)
#define LZMA_PROB_REP_LEN_CHOICE_OFFSET \
  (LZMA_PROB_MATCH_LEN_HIGH_OFFSET + LZMA_PROB_MATCH_LEN_HIGH_LEN)
#define LZMA_PROB_REP_LEN_CHOICE2_OFFSET \
  (LZMA_PROB_REP_LEN_CHOICE_OFFSET + LZMA_PROB_REP_LEN_CHOICE_LEN)
#define LZMA_PROB_REP_LEN_LOW_OFFSET \
  (LZMA_PROB_REP_LEN_CHOICE2_OFFSET + LZMA_PROB_REP_LEN_CHOICE2_LEN)
#define LZMA_PROB_REP_LEN_MID_OFFSET \
  (LZMA_PROB_REP_LEN_LOW_OFFSET + LZMA_PROB_REP_LEN_LOW_LEN)
#define LZMA_PROB_REP_LEN_HIGH_OFFSET \
  (LZMA_PROB_REP_LEN_MID_OFFSET + LZMA_PROB_REP_LEN_MID_LEN)
#define LZMA_PROB_LITERAL_OFFSET \
  (LZMA_PROB_REP_LEN_HIGH_OFFSET + LZMA_PROB_REP_LEN_HIGH_LEN)

#define LZMA_PROB_TOTAL_COUNT \
  (LZMA_PROB_LITERAL_OFFSET + LZMA_PROB_LITERAL_LEN)

/* Check that the number of LZMA probabilities is the same as the
   Linux kernel implementation.  */

#if LZMA_PROB_TOTAL_COUNT != 1846 + (1 << 4) * 0x300
 #error Wrong number of LZMA probabilities
#endif

/* Expressions for the offset in the LZMA probabilities array of a
   specific probability.  */

#define LZMA_IS_MATCH(state, pos) \
  (LZMA_PROB_IS_MATCH_OFFSET + (state) * LZMA_POS_STATES + (pos))
#define LZMA_IS_REP(state) \
  (LZMA_PROB_IS_REP_OFFSET + (state))
#define LZMA_IS_REP0(state) \
  (LZMA_PROB_IS_REP0_OFFSET + (state))
#define LZMA_IS_REP1(state) \
  (LZMA_PROB_IS_REP1_OFFSET + (state))
#define LZMA_IS_REP2(state) \
  (LZMA_PROB_IS_REP2_OFFSET + (state))
#define LZMA_IS_REP0_LONG(state, pos) \
  (LZMA_PROB_IS_REP0_LONG_OFFSET + (state) * LZMA_POS_STATES + (pos))
#define LZMA_DIST_SLOT(dist, slot) \
  (LZMA_PROB_DIST_SLOT_OFFSET + (dist) * LZMA_DIST_SLOTS + (slot))
#define LZMA_DIST_SPECIAL(dist) \
  (LZMA_PROB_DIST_SPECIAL_OFFSET + (dist))
#define LZMA_DIST_ALIGN(dist) \
  (LZMA_PROB_DIST_ALIGN_OFFSET + (dist))
#define LZMA_MATCH_LEN_CHOICE \
  LZMA_PROB_MATCH_LEN_CHOICE_OFFSET
#define LZMA_MATCH_LEN_CHOICE2 \
  LZMA_PROB_MATCH_LEN_CHOICE2_OFFSET
#define LZMA_MATCH_LEN_LOW(pos, sym) \
  (LZMA_PROB_MATCH_LEN_LOW_OFFSET + (pos) * LZMA_LEN_LOW_SYMBOLS + (sym))
#define LZMA_MATCH_LEN_MID(pos, sym) \
  (LZMA_PROB_MATCH_LEN_MID_OFFSET + (pos) * LZMA_LEN_MID_SYMBOLS + (sym))
#define LZMA_MATCH_LEN_HIGH(sym) \
  (LZMA_PROB_MATCH_LEN_HIGH_OFFSET + (sym))
#define LZMA_REP_LEN_CHOICE \
  LZMA_PROB_REP_LEN_CHOICE_OFFSET
#define LZMA_REP_LEN_CHOICE2 \
  LZMA_PROB_REP_LEN_CHOICE2_OFFSET
#define LZMA_REP_LEN_LOW(pos, sym) \
  (LZMA_PROB_REP_LEN_LOW_OFFSET + (pos) * LZMA_LEN_LOW_SYMBOLS + (sym))
#define LZMA_REP_LEN_MID(pos, sym) \
  (LZMA_PROB_REP_LEN_MID_OFFSET + (pos) * LZMA_LEN_MID_SYMBOLS + (sym))
#define LZMA_REP_LEN_HIGH(sym) \
  (LZMA_PROB_REP_LEN_HIGH_OFFSET + (sym))
#define LZMA_LITERAL(code, size) \
  (LZMA_PROB_LITERAL_OFFSET + (code) * LZMA_LITERAL_CODER_SIZE + (size))

/* Read an LZMA varint from BUF, reading and updating *POFFSET,
   setting *VAL.  Returns 0 on error, 1 on success.  */

static int
elf_lzma_varint (const unsigned char *compressed, size_t compressed_size,
		 size_t *poffset, uint64_t *val)
{
  size_t off;
  int i;
  uint64_t v;
  unsigned char b;

  off = *poffset;
  i = 0;
  v = 0;
  while (1)
    {
      if (unlikely (off >= compressed_size))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      b = compressed[off];
      v |= (b & 0x7f) << (i * 7);
      ++off;
      if ((b & 0x80) == 0)
	{
	  *poffset = off;
	  *val = v;
	  return 1;
	}
      ++i;
      if (unlikely (i >= 9))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
    }
}

/* Normalize the LZMA range decoder, pulling in an extra input byte if
   needed.  */

static void
elf_lzma_range_normalize (const unsigned char *compressed,
			  size_t compressed_size, size_t *poffset,
			  uint32_t *prange, uint32_t *pcode)
{
  if (*prange < (1U << 24))
    {
      if (unlikely (*poffset >= compressed_size))
	{
	  /* We assume this will be caught elsewhere.  */
	  elf_uncompress_failed ();
	  return;
	}
      *prange <<= 8;
      *pcode <<= 8;
      *pcode += compressed[*poffset];
      ++*poffset;
    }
}

/* Read and return a single bit from the LZMA stream, reading and
   updating *PROB.  Each bit comes from the range coder.  */

static int
elf_lzma_bit (const unsigned char *compressed, size_t compressed_size,
	      uint16_t *prob, size_t *poffset, uint32_t *prange,
	      uint32_t *pcode)
{
  uint32_t bound;

  elf_lzma_range_normalize (compressed, compressed_size, poffset,
			    prange, pcode);
  bound = (*prange >> 11) * (uint32_t) *prob;
  if (*pcode < bound)
    {
      *prange = bound;
      *prob += ((1U << 11) - *prob) >> 5;
      return 0;
    }
  else
    {
      *prange -= bound;
      *pcode -= bound;
      *prob -= *prob >> 5;
      return 1;
    }
}

/* Read an integer of size BITS from the LZMA stream, most significant
   bit first.  The bits are predicted using PROBS.  */

static uint32_t
elf_lzma_integer (const unsigned char *compressed, size_t compressed_size,
		  uint16_t *probs, uint32_t bits, size_t *poffset,
		  uint32_t *prange, uint32_t *pcode)
{
  uint32_t sym;
  uint32_t i;

  sym = 1;
  for (i = 0; i < bits; i++)
    {
      int bit;

      bit = elf_lzma_bit (compressed, compressed_size, probs + sym, poffset,
			  prange, pcode);
      sym <<= 1;
      sym += bit;
    }
  return sym - (1 << bits);
}

/* Read an integer of size BITS from the LZMA stream, least
   significant bit first.  The bits are predicted using PROBS.  */

static uint32_t
elf_lzma_reverse_integer (const unsigned char *compressed,
			  size_t compressed_size, uint16_t *probs,
			  uint32_t bits, size_t *poffset, uint32_t *prange,
			  uint32_t *pcode)
{
  uint32_t sym;
  uint32_t val;
  uint32_t i;

  sym = 1;
  val = 0;
  for (i = 0; i < bits; i++)
    {
      int bit;

      bit = elf_lzma_bit (compressed, compressed_size, probs + sym, poffset,
			  prange, pcode);
      sym <<= 1;
      sym += bit;
      val += bit << i;
    }
  return val;
}

/* Read a length from the LZMA stream.  IS_REP picks either LZMA_MATCH
   or LZMA_REP probabilities.  */

static uint32_t
elf_lzma_len (const unsigned char *compressed, size_t compressed_size,
	      uint16_t *probs, int is_rep, unsigned int pos_state,
	      size_t *poffset, uint32_t *prange, uint32_t *pcode)
{
  uint16_t *probs_choice;
  uint16_t *probs_sym;
  uint32_t bits;
  uint32_t len;

  probs_choice = probs + (is_rep
			  ? LZMA_REP_LEN_CHOICE
			  : LZMA_MATCH_LEN_CHOICE);
  if (elf_lzma_bit (compressed, compressed_size, probs_choice, poffset,
		    prange, pcode))
    {
      probs_choice = probs + (is_rep
			      ? LZMA_REP_LEN_CHOICE2
			      : LZMA_MATCH_LEN_CHOICE2);
      if (elf_lzma_bit (compressed, compressed_size, probs_choice,
			poffset, prange, pcode))
	{
	  probs_sym = probs + (is_rep
			       ? LZMA_REP_LEN_HIGH (0)
			       : LZMA_MATCH_LEN_HIGH (0));
	  bits = 8;
	  len = 2 + 8 + 8;
	}
      else
	{
	  probs_sym = probs + (is_rep
			       ? LZMA_REP_LEN_MID (pos_state, 0)
			       : LZMA_MATCH_LEN_MID (pos_state, 0));
	  bits = 3;
	  len = 2 + 8;
	}
    }
  else
    {
      probs_sym = probs + (is_rep
			   ? LZMA_REP_LEN_LOW (pos_state, 0)
			   : LZMA_MATCH_LEN_LOW (pos_state, 0));
      bits = 3;
      len = 2;
    }

  len += elf_lzma_integer (compressed, compressed_size, probs_sym, bits,
			   poffset, prange, pcode);
  return len;
}

/* Uncompress one LZMA block from a minidebug file.  The compressed
   data is at COMPRESSED + *POFFSET.  Update *POFFSET.  Store the data
   into the memory at UNCOMPRESSED, size UNCOMPRESSED_SIZE.  CHECK is
   the stream flag from the xz header.  Return 1 on successful
   decompression.  */

static int
elf_uncompress_lzma_block (const unsigned char *compressed,
			   size_t compressed_size, unsigned char check,
			   uint16_t *probs, unsigned char *uncompressed,
			   size_t uncompressed_size, size_t *poffset)
{
  size_t off;
  size_t block_header_offset;
  size_t block_header_size;
  unsigned char block_flags;
  uint64_t header_compressed_size;
  uint64_t header_uncompressed_size;
  unsigned char lzma2_properties;
  size_t crc_offset;
  uint32_t computed_crc;
  uint32_t stream_crc;
  size_t uncompressed_offset;
  size_t dict_start_offset;
  unsigned int lc;
  unsigned int lp;
  unsigned int pb;
  uint32_t range;
  uint32_t code;
  uint32_t lstate;
  uint32_t dist[4];

  off = *poffset;
  block_header_offset = off;

  /* Block header size is a single byte.  */
  if (unlikely (off >= compressed_size))
    {
      elf_uncompress_failed ();
      return 0;
    }
  block_header_size = (compressed[off] + 1) * 4;
  if (unlikely (off + block_header_size > compressed_size))
    {
      elf_uncompress_failed ();
      return 0;
    }

  /* Block flags.  */
  block_flags = compressed[off + 1];
  if (unlikely ((block_flags & 0x3c) != 0))
    {
      elf_uncompress_failed ();
      return 0;
    }

  off += 2;

  /* Optional compressed size.  */
  header_compressed_size = 0;
  if ((block_flags & 0x40) != 0)
    {
      *poffset = off;
      if (!elf_lzma_varint (compressed, compressed_size, poffset,
			    &header_compressed_size))
	return 0;
      off = *poffset;
    }

  /* Optional uncompressed size.  */
  header_uncompressed_size = 0;
  if ((block_flags & 0x80) != 0)
    {
      *poffset = off;
      if (!elf_lzma_varint (compressed, compressed_size, poffset,
			    &header_uncompressed_size))
	return 0;
      off = *poffset;
    }

  /* The recipe for creating a minidebug file is to run the xz program
     with no arguments, so we expect exactly one filter: lzma2.  */

  if (unlikely ((block_flags & 0x3) != 0))
    {
      elf_uncompress_failed ();
      return 0;
    }

  if (unlikely (off + 2 >= block_header_offset + block_header_size))
    {
      elf_uncompress_failed ();
      return 0;
    }

  /* The filter ID for LZMA2 is 0x21.  */
  if (unlikely (compressed[off] != 0x21))
    {
      elf_uncompress_failed ();
      return 0;
    }
  ++off;

  /* The size of the filter properties for LZMA2 is 1.  */
  if (unlikely (compressed[off] != 1))
    {
      elf_uncompress_failed ();
      return 0;
    }
  ++off;

  lzma2_properties = compressed[off];
  ++off;

  if (unlikely (lzma2_properties > 40))
    {
      elf_uncompress_failed ();
      return 0;
    }

  /* The properties describe the dictionary size, but we don't care
     what that is.  */

  /* Skip to just before CRC, verifying zero bytes in between.  */
  crc_offset = block_header_offset + block_header_size - 4;
  if (unlikely (crc_offset + 4 > compressed_size))
    {
      elf_uncompress_failed ();
      return 0;
    }
  for (; off < crc_offset; off++)
    {
      if (compressed[off] != 0)
	{
	  elf_uncompress_failed ();
	  return 0;
	}
    }

  /* Block header CRC.  */
  computed_crc = elf_crc32 (0, compressed + block_header_offset,
			    block_header_size - 4);
  stream_crc = ((uint32_t)compressed[off]
		| ((uint32_t)compressed[off + 1] << 8)
		| ((uint32_t)compressed[off + 2] << 16)
		| ((uint32_t)compressed[off + 3] << 24));
  if (unlikely (computed_crc != stream_crc))
    {
      elf_uncompress_failed ();
      return 0;
    }
  off += 4;

  /* Read a sequence of LZMA2 packets.  */

  uncompressed_offset = 0;
  dict_start_offset = 0;
  lc = 0;
  lp = 0;
  pb = 0;
  lstate = 0;
  while (off < compressed_size)
    {
      unsigned char control;

      range = 0xffffffff;
      code = 0;

      control = compressed[off];
      ++off;
      if (unlikely (control == 0))
	{
	  /* End of packets.  */
	  break;
	}

      if (control == 1 || control >= 0xe0)
	{
	  /* Reset dictionary to empty.  */
	  dict_start_offset = uncompressed_offset;
	}

      if (control < 0x80)
	{
	  size_t chunk_size;

	  /* The only valid values here are 1 or 2.  A 1 means to
	     reset the dictionary (done above).  Then we see an
	     uncompressed chunk.  */

	  if (unlikely (control > 2))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }

	  /* An uncompressed chunk is a two byte size followed by
	     data.  */

	  if (unlikely (off + 2 > compressed_size))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }

	  chunk_size = compressed[off] << 8;
	  chunk_size += compressed[off + 1];
	  ++chunk_size;

	  off += 2;

	  if (unlikely (off + chunk_size > compressed_size))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }
	  if (unlikely (uncompressed_offset + chunk_size > uncompressed_size))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }

	  memcpy (uncompressed + uncompressed_offset, compressed + off,
		  chunk_size);
	  uncompressed_offset += chunk_size;
	  off += chunk_size;
	}
      else
	{
	  size_t uncompressed_chunk_start;
	  size_t uncompressed_chunk_size;
	  size_t compressed_chunk_size;
	  size_t limit;

	  /* An LZMA chunk.  This starts with an uncompressed size and
	     a compressed size.  */

	  if (unlikely (off + 4 >= compressed_size))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }

	  uncompressed_chunk_start = uncompressed_offset;

	  uncompressed_chunk_size = (control & 0x1f) << 16;
	  uncompressed_chunk_size += compressed[off] << 8;
	  uncompressed_chunk_size += compressed[off + 1];
	  ++uncompressed_chunk_size;

	  compressed_chunk_size = compressed[off + 2] << 8;
	  compressed_chunk_size += compressed[off + 3];
	  ++compressed_chunk_size;

	  off += 4;

	  /* Bit 7 (0x80) is set.
	     Bits 6 and 5 (0x40 and 0x20) are as follows:
	     0: don't reset anything
	     1: reset state
	     2: reset state, read properties
	     3: reset state, read properties, reset dictionary (done above) */

	  if (control >= 0xc0)
	    {
	      unsigned char props;

	      /* Bit 6 is set, read properties.  */

	      if (unlikely (off >= compressed_size))
		{
		  elf_uncompress_failed ();
		  return 0;
		}
	      props = compressed[off];
	      ++off;
	      if (unlikely (props > (4 * 5 + 4) * 9 + 8))
		{
		  elf_uncompress_failed ();
		  return 0;
		}
	      pb = 0;
	      while (props >= 9 * 5)
		{
		  props -= 9 * 5;
		  ++pb;
		}
	      lp = 0;
	      while (props > 9)
		{
		  props -= 9;
		  ++lp;
		}
	      lc = props;
	      if (unlikely (lc + lp > 4))
		{
		  elf_uncompress_failed ();
		  return 0;
		}
	    }

	  if (control >= 0xa0)
	    {
	      size_t i;

	      /* Bit 5 or 6 is set, reset LZMA state.  */

	      lstate = 0;
	      memset (&dist, 0, sizeof dist);
	      for (i = 0; i < LZMA_PROB_TOTAL_COUNT; i++)
		probs[i] = 1 << 10;
	      range = 0xffffffff;
	      code = 0;
	    }

	  /* Read the range code.  */

	  if (unlikely (off + 5 > compressed_size))
	    {
	      elf_uncompress_failed ();
	      return 0;
	    }

	  /* The byte at compressed[off] is ignored for some
	     reason.  */

	  code = ((compressed[off + 1] << 24)
		  + (compressed[off + 2] << 16)
		  + (compressed[off + 3] << 8)
		  + compressed[off + 4]);
	  off += 5;

	  /* This is the main LZMA decode loop.  */

	  limit = off + compressed_chunk_size;
	  *poffset = off;
	  while (*poffset < limit)
	    {
	      unsigned int pos_state;

	      if (unlikely (uncompressed_offset
			    == (uncompressed_chunk_start
				+ uncompressed_chunk_size)))
		{
		  /* We've decompressed all the expected bytes.  */
		  break;
		}

	      pos_state = ((uncompressed_offset - dict_start_offset)
			   & ((1 << pb) - 1));

	      if (elf_lzma_bit (compressed, compressed_size,
				probs + LZMA_IS_MATCH (lstate, pos_state),
				poffset, &range, &code))
		{
		  uint32_t len;

		  if (elf_lzma_bit (compressed, compressed_size,
				    probs + LZMA_IS_REP (lstate),
				    poffset, &range, &code))
		    {
		      int short_rep;
		      uint32_t next_dist;

		      /* Repeated match.  */

		      short_rep = 0;
		      if (elf_lzma_bit (compressed, compressed_size,
					probs + LZMA_IS_REP0 (lstate),
					poffset, &range, &code))
			{
			  if (elf_lzma_bit (compressed, compressed_size,
					    probs + LZMA_IS_REP1 (lstate),
					    poffset, &range, &code))
			    {
			      if (elf_lzma_bit (compressed, compressed_size,
						probs + LZMA_IS_REP2 (lstate),
						poffset, &range, &code))
				{
				  next_dist = dist[3];
				  dist[3] = dist[2];
				}
			      else
				{
				  next_dist = dist[2];
				}
			      dist[2] = dist[1];
			    }
			  else
			    {
			      next_dist = dist[1];
			    }

			  dist[1] = dist[0];
			  dist[0] = next_dist;
			}
		      else
			{
			  if (!elf_lzma_bit (compressed, compressed_size,
					    (probs
					     + LZMA_IS_REP0_LONG (lstate,
								  pos_state)),
					    poffset, &range, &code))
			    short_rep = 1;
			}

		      if (lstate < 7)
			lstate = short_rep ? 9 : 8;
		      else
			lstate = 11;

		      if (short_rep)
			len = 1;
		      else
			len = elf_lzma_len (compressed, compressed_size,
					    probs, 1, pos_state, poffset,
					    &range, &code);
		    }
		  else
		    {
		      uint32_t dist_state;
		      uint32_t dist_slot;
		      uint16_t *probs_dist;

		      /* Match.  */

		      if (lstate < 7)
			lstate = 7;
		      else
			lstate = 10;
		      dist[3] = dist[2];
		      dist[2] = dist[1];
		      dist[1] = dist[0];
		      len = elf_lzma_len (compressed, compressed_size,
					  probs, 0, pos_state, poffset,
					  &range, &code);

		      if (len < 4 + 2)
			dist_state = len - 2;
		      else
			dist_state = 3;
		      probs_dist = probs + LZMA_DIST_SLOT (dist_state, 0);
		      dist_slot = elf_lzma_integer (compressed,
						    compressed_size,
						    probs_dist, 6,
						    poffset, &range,
						    &code);
		      if (dist_slot < LZMA_DIST_MODEL_START)
			dist[0] = dist_slot;
		      else
			{
			  uint32_t limit;

			  limit = (dist_slot >> 1) - 1;
			  dist[0] = 2 + (dist_slot & 1);
			  if (dist_slot < LZMA_DIST_MODEL_END)
			    {
			      dist[0] <<= limit;
			      probs_dist = (probs
					    + LZMA_DIST_SPECIAL(dist[0]
								- dist_slot
								- 1));
			      dist[0] +=
				elf_lzma_reverse_integer (compressed,
							  compressed_size,
							  probs_dist,
							  limit, poffset,
							  &range, &code);
			    }
			  else
			    {
			      uint32_t dist0;
			      uint32_t i;

			      dist0 = dist[0];
			      for (i = 0; i < limit - 4; i++)
				{
				  uint32_t mask;

				  elf_lzma_range_normalize (compressed,
							    compressed_size,
							    poffset,
							    &range, &code);
				  range >>= 1;
				  code -= range;
				  mask = -(code >> 31);
				  code += range & mask;
				  dist0 <<= 1;
				  dist0 += mask + 1;
				}
			      dist0 <<= 4;
			      probs_dist = probs + LZMA_DIST_ALIGN (0);
			      dist0 +=
				elf_lzma_reverse_integer (compressed,
							  compressed_size,
							  probs_dist, 4,
							  poffset,
							  &range, &code);
			      dist[0] = dist0;
			    }
			}
		    }

		  if (unlikely (uncompressed_offset
				- dict_start_offset < dist[0] + 1))
		    {
		      elf_uncompress_failed ();
		      return 0;
		    }
		  if (unlikely (uncompressed_offset + len > uncompressed_size))
		    {
		      elf_uncompress_failed ();
		      return 0;
		    }

		  if (dist[0] == 0)
		    {
		      /* A common case, meaning repeat the last
			 character LEN times.  */
		      memset (uncompressed + uncompressed_offset,
			      uncompressed[uncompressed_offset - 1],
			      len);
		      uncompressed_offset += len;
		    }
		  else if (dist[0] + 1 >= len)
		    {
		      memcpy (uncompressed + uncompressed_offset,
			      uncompressed + uncompressed_offset - dist[0] - 1,
			      len);
		      uncompressed_offset += len;
		    }
		  else
		    {
		      while (len > 0)
			{
			  uint32_t copy;

			  copy = len < dist[0] + 1 ? len : dist[0] + 1;
			  memcpy (uncompressed + uncompressed_offset,
				  (uncompressed + uncompressed_offset
				   - dist[0] - 1),
				  copy);
			  len -= copy;
			  uncompressed_offset += copy;
			}
		    }
		}
	      else
		{
		  unsigned char prev;
		  unsigned char low;
		  size_t high;
		  uint16_t *lit_probs;
		  unsigned int sym;

		  /* Literal value.  */

		  if (uncompressed_offset > 0)
		    prev = uncompressed[uncompressed_offset - 1];
		  else
		    prev = 0;
		  low = prev >> (8 - lc);
		  high = (((uncompressed_offset - dict_start_offset)
			   & ((1 << lp) - 1))
			  << lc);
		  lit_probs = probs + LZMA_LITERAL (low + high, 0);
		  if (lstate < 7)
		    sym = elf_lzma_integer (compressed, compressed_size,
					    lit_probs, 8, poffset, &range,
					    &code);
		  else
		    {
		      unsigned int match;
		      unsigned int bit;
		      unsigned int match_bit;
		      unsigned int idx;

		      sym = 1;
		      if (uncompressed_offset >= dist[0] + 1)
			match = uncompressed[uncompressed_offset - dist[0] - 1];
		      else
			match = 0;
		      match <<= 1;
		      bit = 0x100;
		      do
			{
			  match_bit = match & bit;
			  match <<= 1;
			  idx = bit + match_bit + sym;
			  sym <<= 1;
			  if (elf_lzma_bit (compressed, compressed_size,
					    lit_probs + idx, poffset,
					    &range, &code))
			    {
			      ++sym;
			      bit &= match_bit;
			    }
			  else
			    {
			      bit &= ~ match_bit;
			    }
			}
		      while (sym < 0x100);
		    }

		  if (unlikely (uncompressed_offset >= uncompressed_size))
		    {
		      elf_uncompress_failed ();
		      return 0;
		    }

		  uncompressed[uncompressed_offset] = (unsigned char) sym;
		  ++uncompressed_offset;
		  if (lstate <= 3)
		    lstate = 0;
		  else if (lstate <= 9)
		    lstate -= 3;
		  else
		    lstate -= 6;
		}
	    }

	  elf_lzma_range_normalize (compressed, compressed_size, poffset,
				    &range, &code);

	  off = *poffset;
	}
    }

  /* We have reached the end of the block.  Pad to four byte
     boundary.  */
  off = (off + 3) &~ (size_t) 3;
  if (unlikely (off > compressed_size))
    {
      elf_uncompress_failed ();
      return 0;
    }

  switch (check)
    {
    case 0:
      /* No check.  */
      break;

    case 1:
      /* CRC32 */
      if (unlikely (off + 4 > compressed_size))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      computed_crc = elf_crc32 (0, uncompressed, uncompressed_offset);
      stream_crc = (compressed[off]
		    | (compressed[off + 1] << 8)
		    | (compressed[off + 2] << 16)
		    | (compressed[off + 3] << 24));
      if (computed_crc != stream_crc)
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      off += 4;
      break;

    case 4:
      /* CRC64.  We don't bother computing a CRC64 checksum.  */
      if (unlikely (off + 8 > compressed_size))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      off += 8;
      break;

    case 10:
      /* SHA.  We don't bother computing a SHA checksum.  */
      if (unlikely (off + 32 > compressed_size))
	{
	  elf_uncompress_failed ();
	  return 0;
	}
      off += 32;
      break;

    default:
      elf_uncompress_failed ();
      return 0;
    }

  *poffset = off;

  return 1;
}

/* Uncompress LZMA data found in a minidebug file.  The minidebug
   format is described at
   https://sourceware.org/gdb/current/onlinedocs/gdb/MiniDebugInfo.html.
   Returns 0 on error, 1 on successful decompression.  For this
   function we return 0 on failure to decompress, as the calling code
   will carry on in that case.  */

static int
elf_uncompress_lzma (struct backtrace_state *state,
		     const unsigned char *compressed, size_t compressed_size,
		     backtrace_error_callback error_callback, void *data,
		     unsigned char **uncompressed, size_t *uncompressed_size)
{
  size_t header_size;
  size_t footer_size;
  unsigned char check;
  uint32_t computed_crc;
  uint32_t stream_crc;
  size_t offset;
  size_t index_size;
  size_t footer_offset;
  size_t index_offset;
  uint64_t index_compressed_size;
  uint64_t index_uncompressed_size;
  unsigned char *mem;
  uint16_t *probs;
  size_t compressed_block_size;

  /* The format starts with a stream header and ends with a stream
     footer.  */
  header_size = 12;
  footer_size = 12;
  if (unlikely (compressed_size < header_size + footer_size))
    {
      elf_uncompress_failed ();
      return 0;
    }

  /* The stream header starts with a magic string.  */
  if (unlikely (memcmp (compressed, "\375" "7zXZ\0", 6) != 0))
    {
      elf_uncompress_failed ();
      return 0;
    }

  /* Next come stream flags.  The first byte is zero, the second byte
     is the check.  */
  if (unlikely (compressed[6] != 0))
    {
      elf_uncompress_failed ();
      return 0;
    }
  check = compressed[7];
  if (unlikely ((check & 0xf8) != 0))
    {
      elf_uncompress_failed ();
      return 0;
    }

  /* Next comes a CRC of the stream flags.  */
  computed_crc = elf_crc32 (0, compressed + 6, 2);
  stream_crc = ((uint32_t)compressed[8]
		| ((uint32_t)compressed[9] << 8)
		| ((uint32_t)compressed[10] << 16)
		| ((uint32_t)compressed[11] << 24));
  if (unlikely (computed_crc != stream_crc))
    {
      elf_uncompress_failed ();
      return 0;
    }

  /* Now that we've parsed the header, parse the footer, so that we
     can get the uncompressed size.  */

  /* The footer ends with two magic bytes.  */

  offset = compressed_size;
  if (unlikely (memcmp (compressed + offset - 2, "YZ", 2) != 0))
    {
      elf_uncompress_failed ();
      return 0;
    }
  offset -= 2;

  /* Before that are the stream flags, which should be the same as the
     flags in the header.  */
  if (unlikely (compressed[offset - 2] != 0
		|| compressed[offset - 1] != check))
    {
      elf_uncompress_failed ();
      return 0;
    }
  offset -= 2;

  /* Before that is the size of the index field, which precedes the
     footer.  */
  index_size = (compressed[offset - 4]
		| (compressed[offset - 3] << 8)
		| (compressed[offset - 2] << 16)
		| (compressed[offset - 1] << 24));
  index_size = (index_size + 1) * 4;
  offset -= 4;

  /* Before that is a footer CRC.  */
  computed_crc = elf_crc32 (0, compressed + offset, 6);
  stream_crc = ((uint32_t)compressed[offset - 4]
		| ((uint32_t)compressed[offset - 3] << 8)
		| ((uint32_t)compressed[offset - 2] << 16)
		| ((uint32_t)compressed[offset - 1] << 24));
  if (unlikely (computed_crc != stream_crc))
    {
      elf_uncompress_failed ();
      return 0;
    }
  offset -= 4;

  /* The index comes just before the footer.  */
  if (unlikely (offset < index_size + header_size))
    {
      elf_uncompress_failed ();
      return 0;
    }

  footer_offset = offset;
  offset -= index_size;
  index_offset = offset;

  /* The index starts with a zero byte.  */
  if (unlikely (compressed[offset] != 0))
    {
      elf_uncompress_failed ();
      return 0;
    }
  ++offset;

  /* Next is the number of blocks.  We expect zero blocks for an empty
     stream, and otherwise a single block.  */
  if (unlikely (compressed[offset] == 0))
    {
      *uncompressed = NULL;
      *uncompressed_size = 0;
      return 1;
    }
  if (unlikely (compressed[offset] != 1))
    {
      elf_uncompress_failed ();
      return 0;
    }
  ++offset;

  /* Next is the compressed size and the uncompressed size.  */
  if (!elf_lzma_varint (compressed, compressed_size, &offset,
			&index_compressed_size))
    return 0;
  if (!elf_lzma_varint (compressed, compressed_size, &offset,
			&index_uncompressed_size))
    return 0;

  /* Pad to a four byte boundary.  */
  offset = (offset + 3) &~ (size_t) 3;

  /* Next is a CRC of the index.  */
  computed_crc = elf_crc32 (0, compressed + index_offset,
			    offset - index_offset);
  stream_crc = ((uint32_t)compressed[offset]
		| ((uint32_t)compressed[offset + 1] << 8)
		| ((uint32_t)compressed[offset + 2] << 16)
		| ((uint32_t)compressed[offset + 3] << 24));
  if (unlikely (computed_crc != stream_crc))
    {
      elf_uncompress_failed ();
      return 0;
    }
  offset += 4;

  /* We should now be back at the footer.  */
  if (unlikely (offset != footer_offset))
    {
      elf_uncompress_failed ();
      return 0;
    }

  /* Allocate space to hold the uncompressed data.  If we succeed in
     uncompressing the LZMA data, we never free this memory.  */
  mem = (unsigned char *) backtrace_alloc (state, index_uncompressed_size,
					   error_callback, data);
  if (unlikely (mem == NULL))
    return 0;
  *uncompressed = mem;
  *uncompressed_size = index_uncompressed_size;

  /* Allocate space for probabilities.  */
  probs = ((uint16_t *)
	   backtrace_alloc (state,
			    LZMA_PROB_TOTAL_COUNT * sizeof (uint16_t),
			    error_callback, data));
  if (unlikely (probs == NULL))
    {
      backtrace_free (state, mem, index_uncompressed_size, error_callback,
		      data);
      return 0;
    }

  /* Uncompress the block, which follows the header.  */
  offset = 12;
  if (!elf_uncompress_lzma_block (compressed, compressed_size, check, probs,
				  mem, index_uncompressed_size, &offset))
    {
      backtrace_free (state, mem, index_uncompressed_size, error_callback,
		      data);
      return 0;
    }

  compressed_block_size = offset - 12;
  if (unlikely (compressed_block_size
		!= ((index_compressed_size + 3) &~ (size_t) 3)))
    {
      elf_uncompress_failed ();
      backtrace_free (state, mem, index_uncompressed_size, error_callback,
		      data);
      return 0;
    }

  offset = (offset + 3) &~ (size_t) 3;
  if (unlikely (offset != index_offset))
    {
      elf_uncompress_failed ();
      backtrace_free (state, mem, index_uncompressed_size, error_callback,
		      data);
      return 0;
    }

  return 1;
}

/* This function is a hook for testing the LZMA support.  It is only
   used by tests.  */

int
backtrace_uncompress_lzma (struct backtrace_state *state,
			   const unsigned char *compressed,
			   size_t compressed_size,
			   backtrace_error_callback error_callback,
			   void *data, unsigned char **uncompressed,
			   size_t *uncompressed_size)
{
  return elf_uncompress_lzma (state, compressed, compressed_size,
			      error_callback, data, uncompressed,
			      uncompressed_size);
}

/* Add the backtrace data for one ELF file.  Returns 1 on success,
   0 on failure (in both cases descriptor is closed) or -1 if exe
   is non-zero and the ELF file is ET_DYN, which tells the caller that
   elf_add will need to be called on the descriptor again after
   base_address is determined.  */

static int
elf_add (struct backtrace_state *state, const char *filename, int descriptor,
	 const unsigned char *memory, size_t memory_size,
	 uintptr_t base_address, struct elf_ppc64_opd_data *caller_opd,
	 backtrace_error_callback error_callback, void *data,
	 fileline *fileline_fn, int *found_sym, int *found_dwarf,
	 struct dwarf_data **fileline_entry, int exe, int debuginfo,
	 const char *with_buildid_data, uint32_t with_buildid_size)
{
  struct elf_view ehdr_view;
  b_elf_ehdr ehdr;
  off_t shoff;
  unsigned int shnum;
  unsigned int shstrndx;
  struct elf_view shdrs_view;
  int shdrs_view_valid;
  const b_elf_shdr *shdrs;
  const b_elf_shdr *shstrhdr;
  size_t shstr_size;
  off_t shstr_off;
  struct elf_view names_view;
  int names_view_valid;
  const char *names;
  unsigned int symtab_shndx;
  unsigned int dynsym_shndx;
  unsigned int i;
  struct debug_section_info sections[DEBUG_MAX];
  struct debug_section_info zsections[DEBUG_MAX];
  struct elf_view symtab_view;
  int symtab_view_valid;
  struct elf_view strtab_view;
  int strtab_view_valid;
  struct elf_view buildid_view;
  int buildid_view_valid;
  const char *buildid_data;
  uint32_t buildid_size;
  struct elf_view debuglink_view;
  int debuglink_view_valid;
  const char *debuglink_name;
  uint32_t debuglink_crc;
  struct elf_view debugaltlink_view;
  int debugaltlink_view_valid;
  const char *debugaltlink_name;
  const char *debugaltlink_buildid_data;
  uint32_t debugaltlink_buildid_size;
  struct elf_view gnu_debugdata_view;
  int gnu_debugdata_view_valid;
  size_t gnu_debugdata_size;
  unsigned char *gnu_debugdata_uncompressed;
  size_t gnu_debugdata_uncompressed_size;
  off_t min_offset;
  off_t max_offset;
  off_t debug_size;
  struct elf_view debug_view;
  int debug_view_valid;
  unsigned int using_debug_view;
  uint16_t *zdebug_table;
  struct elf_view split_debug_view[DEBUG_MAX];
  unsigned char split_debug_view_valid[DEBUG_MAX];
  struct elf_ppc64_opd_data opd_data, *opd;
  int opd_view_valid;
  struct dwarf_sections dwarf_sections;

  if (!debuginfo)
    {
      *found_sym = 0;
      *found_dwarf = 0;
    }

  shdrs_view_valid = 0;
  names_view_valid = 0;
  symtab_view_valid = 0;
  strtab_view_valid = 0;
  buildid_view_valid = 0;
  buildid_data = NULL;
  buildid_size = 0;
  debuglink_view_valid = 0;
  debuglink_name = NULL;
  debuglink_crc = 0;
  debugaltlink_view_valid = 0;
  debugaltlink_name = NULL;
  debugaltlink_buildid_data = NULL;
  debugaltlink_buildid_size = 0;
  gnu_debugdata_view_valid = 0;
  gnu_debugdata_size = 0;
  debug_view_valid = 0;
  memset (&split_debug_view_valid[0], 0, sizeof split_debug_view_valid);
  opd = NULL;
  opd_view_valid = 0;

  if (!elf_get_view (state, descriptor, memory, memory_size, 0, sizeof ehdr,
		     error_callback, data, &ehdr_view))
    goto fail;

  memcpy (&ehdr, ehdr_view.view.data, sizeof ehdr);

  elf_release_view (state, &ehdr_view, error_callback, data);

  if (ehdr.e_ident[EI_MAG0] != ELFMAG0
      || ehdr.e_ident[EI_MAG1] != ELFMAG1
      || ehdr.e_ident[EI_MAG2] != ELFMAG2
      || ehdr.e_ident[EI_MAG3] != ELFMAG3)
    {
      error_callback (data, "executable file is not ELF", 0);
      goto fail;
    }
  if (ehdr.e_ident[EI_VERSION] != EV_CURRENT)
    {
      error_callback (data, "executable file is unrecognized ELF version", 0);
      goto fail;
    }

#if BACKTRACE_ELF_SIZE == 32
#define BACKTRACE_ELFCLASS ELFCLASS32
#else
#define BACKTRACE_ELFCLASS ELFCLASS64
#endif

  if (ehdr.e_ident[EI_CLASS] != BACKTRACE_ELFCLASS)
    {
      error_callback (data, "executable file is unexpected ELF class", 0);
      goto fail;
    }

  if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB
      && ehdr.e_ident[EI_DATA] != ELFDATA2MSB)
    {
      error_callback (data, "executable file has unknown endianness", 0);
      goto fail;
    }

  /* If the executable is ET_DYN, it is either a PIE, or we are running
     directly a shared library with .interp.  We need to wait for
     dl_iterate_phdr in that case to determine the actual base_address.  */
  if (exe && ehdr.e_type == ET_DYN)
    return -1;

  shoff = ehdr.e_shoff;
  shnum = ehdr.e_shnum;
  shstrndx = ehdr.e_shstrndx;

  if ((shnum == 0 || shstrndx == SHN_XINDEX)
      && shoff != 0)
    {
      struct elf_view shdr_view;
      const b_elf_shdr *shdr;

      if (!elf_get_view (state, descriptor, memory, memory_size, shoff,
			 sizeof shdr, error_callback, data, &shdr_view))
	goto fail;

      shdr = (const b_elf_shdr *) shdr_view.view.data;

      if (shnum == 0)
	shnum = shdr->sh_size;

      if (shstrndx == SHN_XINDEX)
	{
	  shstrndx = shdr->sh_link;

	  /* Versions of the GNU binutils between 2.12 and 2.18 did
	     not handle objects with more than SHN_LORESERVE sections
	     correctly.  All large section indexes were offset by
	     0x100.  There is more information at
	     http://sourceware.org/bugzilla/show_bug.cgi?id-5900 .
	     Fortunately these object files are easy to detect, as the
	     GNU binutils always put the section header string table
	     near the end of the list of sections.  Thus if the
	     section header string table index is larger than the
	     number of sections, then we know we have to subtract
	     0x100 to get the real section index.  */
	  if (shstrndx >= shnum && shstrndx >= SHN_LORESERVE + 0x100)
	    shstrndx -= 0x100;
	}

      elf_release_view (state, &shdr_view, error_callback, data);
    }

  if (shnum == 0 || shstrndx == 0)
    goto fail;

  /* To translate PC to file/line when using DWARF, we need to find
     the .debug_info and .debug_line sections.  */

  /* Read the section headers, skipping the first one.  */

  if (!elf_get_view (state, descriptor, memory, memory_size,
		     shoff + sizeof (b_elf_shdr),
		     (shnum - 1) * sizeof (b_elf_shdr),
		     error_callback, data, &shdrs_view))
    goto fail;
  shdrs_view_valid = 1;
  shdrs = (const b_elf_shdr *) shdrs_view.view.data;

  /* Read the section names.  */

  shstrhdr = &shdrs[shstrndx - 1];
  shstr_size = shstrhdr->sh_size;
  shstr_off = shstrhdr->sh_offset;

  if (!elf_get_view (state, descriptor, memory, memory_size, shstr_off,
		     shstrhdr->sh_size, error_callback, data, &names_view))
    goto fail;
  names_view_valid = 1;
  names = (const char *) names_view.view.data;

  symtab_shndx = 0;
  dynsym_shndx = 0;

  memset (sections, 0, sizeof sections);
  memset (zsections, 0, sizeof zsections);

  /* Look for the symbol table.  */
  for (i = 1; i < shnum; ++i)
    {
      const b_elf_shdr *shdr;
      unsigned int sh_name;
      const char *name;
      int j;

      shdr = &shdrs[i - 1];

      if (shdr->sh_type == SHT_SYMTAB)
	symtab_shndx = i;
      else if (shdr->sh_type == SHT_DYNSYM)
	dynsym_shndx = i;

      sh_name = shdr->sh_name;
      if (sh_name >= shstr_size)
	{
	  error_callback (data, "ELF section name out of range", 0);
	  goto fail;
	}

      name = names + sh_name;

      for (j = 0; j < (int) DEBUG_MAX; ++j)
	{
	  if (strcmp (name, dwarf_section_names[j]) == 0)
	    {
	      sections[j].offset = shdr->sh_offset;
	      sections[j].size = shdr->sh_size;
	      sections[j].compressed = (shdr->sh_flags & SHF_COMPRESSED) != 0;
	      break;
	    }
	}

      if (name[0] == '.' && name[1] == 'z')
	{
	  for (j = 0; j < (int) DEBUG_MAX; ++j)
	    {
	      if (strcmp (name + 2, dwarf_section_names[j] + 1) == 0)
		{
		  zsections[j].offset = shdr->sh_offset;
		  zsections[j].size = shdr->sh_size;
		  break;
		}
	    }
	}

      /* Read the build ID if present.  This could check for any
	 SHT_NOTE section with the right note name and type, but gdb
	 looks for a specific section name.  */
      if ((!debuginfo || with_buildid_data != NULL)
	  && !buildid_view_valid
	  && strcmp (name, ".note.gnu.build-id") == 0)
	{
	  const b_elf_note *note;

	  if (!elf_get_view (state, descriptor, memory, memory_size,
			     shdr->sh_offset, shdr->sh_size, error_callback,
			     data, &buildid_view))
	    goto fail;

	  buildid_view_valid = 1;
	  note = (const b_elf_note *) buildid_view.view.data;
	  if (note->type == NT_GNU_BUILD_ID
	      && note->namesz == 4
	      && strncmp (note->name, "GNU", 4) == 0
	      && shdr->sh_size <= 12 + ((note->namesz + 3) & ~ 3) + note->descsz)
	    {
	      buildid_data = &note->name[0] + ((note->namesz + 3) & ~ 3);
	      buildid_size = note->descsz;
	    }

	  if (with_buildid_size != 0)
	    {
	      if (buildid_size != with_buildid_size)
		goto fail;

	      if (memcmp (buildid_data, with_buildid_data, buildid_size) != 0)
		goto fail;
	    }
	}

      /* Read the debuglink file if present.  */
      if (!debuginfo
	  && !debuglink_view_valid
	  && strcmp (name, ".gnu_debuglink") == 0)
	{
	  const char *debuglink_data;
	  size_t crc_offset;

	  if (!elf_get_view (state, descriptor, memory, memory_size,
			     shdr->sh_offset, shdr->sh_size, error_callback,
			     data, &debuglink_view))
	    goto fail;

	  debuglink_view_valid = 1;
	  debuglink_data = (const char *) debuglink_view.view.data;
	  crc_offset = strnlen (debuglink_data, shdr->sh_size);
	  crc_offset = (crc_offset + 3) & ~3;
	  if (crc_offset + 4 <= shdr->sh_size)
	    {
	      debuglink_name = debuglink_data;
	      debuglink_crc = *(const uint32_t*)(debuglink_data + crc_offset);
	    }
	}

      if (!debugaltlink_view_valid
	  && strcmp (name, ".gnu_debugaltlink") == 0)
	{
	  const char *debugaltlink_data;
	  size_t debugaltlink_name_len;

	  if (!elf_get_view (state, descriptor, memory, memory_size,
			     shdr->sh_offset, shdr->sh_size, error_callback,
			     data, &debugaltlink_view))
	    goto fail;

	  debugaltlink_view_valid = 1;
	  debugaltlink_data = (const char *) debugaltlink_view.view.data;
	  debugaltlink_name = debugaltlink_data;
	  debugaltlink_name_len = strnlen (debugaltlink_data, shdr->sh_size);
	  if (debugaltlink_name_len < shdr->sh_size)
	    {
	      /* Include terminating zero.  */
	      debugaltlink_name_len += 1;

	      debugaltlink_buildid_data
		= debugaltlink_data + debugaltlink_name_len;
	      debugaltlink_buildid_size = shdr->sh_size - debugaltlink_name_len;
	    }
	}

      if (!gnu_debugdata_view_valid
	  && strcmp (name, ".gnu_debugdata") == 0)
	{
	  if (!elf_get_view (state, descriptor, memory, memory_size,
			     shdr->sh_offset, shdr->sh_size, error_callback,
			     data, &gnu_debugdata_view))
	    goto fail;

	  gnu_debugdata_size = shdr->sh_size;
	  gnu_debugdata_view_valid = 1;
	}

      /* Read the .opd section on PowerPC64 ELFv1.  */
      if (ehdr.e_machine == EM_PPC64
	  && (ehdr.e_flags & EF_PPC64_ABI) < 2
	  && shdr->sh_type == SHT_PROGBITS
	  && strcmp (name, ".opd") == 0)
	{
	  if (!elf_get_view (state, descriptor, memory, memory_size,
			     shdr->sh_offset, shdr->sh_size, error_callback,
			     data, &opd_data.view))
	    goto fail;

	  opd = &opd_data;
	  opd->addr = shdr->sh_addr;
	  opd->data = (const char *) opd_data.view.view.data;
	  opd->size = shdr->sh_size;
	  opd_view_valid = 1;
	}
    }

  /* A debuginfo file may not have a useful .opd section, but we can use the
     one from the original executable.  */
  if (opd == NULL)
    opd = caller_opd;

  if (symtab_shndx == 0)
    symtab_shndx = dynsym_shndx;
  if (symtab_shndx != 0)
    {
      const b_elf_shdr *symtab_shdr;
      unsigned int strtab_shndx;
      const b_elf_shdr *strtab_shdr;
      struct elf_syminfo_data *sdata;

      symtab_shdr = &shdrs[symtab_shndx - 1];
      strtab_shndx = symtab_shdr->sh_link;
      if (strtab_shndx >= shnum)
	{
	  error_callback (data,
			  "ELF symbol table strtab link out of range", 0);
	  goto fail;
	}
      strtab_shdr = &shdrs[strtab_shndx - 1];

      if (!elf_get_view (state, descriptor, memory, memory_size,
			 symtab_shdr->sh_offset, symtab_shdr->sh_size,
			 error_callback, data, &symtab_view))
	goto fail;
      symtab_view_valid = 1;

      if (!elf_get_view (state, descriptor, memory, memory_size,
			 strtab_shdr->sh_offset, strtab_shdr->sh_size,
			 error_callback, data, &strtab_view))
	goto fail;
      strtab_view_valid = 1;

      sdata = ((struct elf_syminfo_data *)
	       backtrace_alloc (state, sizeof *sdata, error_callback, data));
      if (sdata == NULL)
	goto fail;

      if (!elf_initialize_syminfo (state, base_address,
				   symtab_view.view.data, symtab_shdr->sh_size,
				   strtab_view.view.data, strtab_shdr->sh_size,
				   error_callback, data, sdata, opd))
	{
	  backtrace_free (state, sdata, sizeof *sdata, error_callback, data);
	  goto fail;
	}

      /* We no longer need the symbol table, but we hold on to the
	 string table permanently.  */
      elf_release_view (state, &symtab_view, error_callback, data);
      symtab_view_valid = 0;
      strtab_view_valid = 0;

      *found_sym = 1;

      elf_add_syminfo_data (state, sdata);
    }

  elf_release_view (state, &shdrs_view, error_callback, data);
  shdrs_view_valid = 0;
  elf_release_view (state, &names_view, error_callback, data);
  names_view_valid = 0;

  /* If the debug info is in a separate file, read that one instead.  */

  if (buildid_data != NULL)
    {
      int d;

      d = elf_open_debugfile_by_buildid (state, buildid_data, buildid_size,
					 error_callback, data);
      if (d >= 0)
	{
	  int ret;

	  elf_release_view (state, &buildid_view, error_callback, data);
	  if (debuglink_view_valid)
	    elf_release_view (state, &debuglink_view, error_callback, data);
	  if (debugaltlink_view_valid)
	    elf_release_view (state, &debugaltlink_view, error_callback, data);
	  ret = elf_add (state, "", d, NULL, 0, base_address, opd,
			 error_callback, data, fileline_fn, found_sym,
			 found_dwarf, NULL, 0, 1, NULL, 0);
	  if (ret < 0)
	    backtrace_close (d, error_callback, data);
	  else if (descriptor >= 0)
	    backtrace_close (descriptor, error_callback, data);
	  return ret;
	}
    }

  if (buildid_view_valid)
    {
      elf_release_view (state, &buildid_view, error_callback, data);
      buildid_view_valid = 0;
    }

  if (debuglink_name != NULL)
    {
      int d;

      d = elf_open_debugfile_by_debuglink (state, filename, debuglink_name,
					   debuglink_crc, error_callback,
					   data);
      if (d >= 0)
	{
	  int ret;

	  elf_release_view (state, &debuglink_view, error_callback, data);
	  if (debugaltlink_view_valid)
	    elf_release_view (state, &debugaltlink_view, error_callback, data);
	  ret = elf_add (state, "", d, NULL, 0, base_address, opd,
			 error_callback, data, fileline_fn, found_sym,
			 found_dwarf, NULL, 0, 1, NULL, 0);
	  if (ret < 0)
	    backtrace_close (d, error_callback, data);
	  else if (descriptor >= 0)
	    backtrace_close(descriptor, error_callback, data);
	  return ret;
	}
    }

  if (debuglink_view_valid)
    {
      elf_release_view (state, &debuglink_view, error_callback, data);
      debuglink_view_valid = 0;
    }

  struct dwarf_data *fileline_altlink = NULL;
  if (debugaltlink_name != NULL)
    {
      int d;

      d = elf_open_debugfile_by_debuglink (state, filename, debugaltlink_name,
					   0, error_callback, data);
      if (d >= 0)
	{
	  int ret;

	  ret = elf_add (state, filename, d, NULL, 0, base_address, opd,
			 error_callback, data, fileline_fn, found_sym,
			 found_dwarf, &fileline_altlink, 0, 1,
			 debugaltlink_buildid_data, debugaltlink_buildid_size);
	  elf_release_view (state, &debugaltlink_view, error_callback, data);
	  debugaltlink_view_valid = 0;
	  if (ret < 0)
	    {
	      backtrace_close (d, error_callback, data);
	      return ret;
	    }
	}
    }

  if (debugaltlink_view_valid)
    {
      elf_release_view (state, &debugaltlink_view, error_callback, data);
      debugaltlink_view_valid = 0;
    }

  if (gnu_debugdata_view_valid)
    {
      int ret;

      ret = elf_uncompress_lzma (state,
				 ((const unsigned char *)
				  gnu_debugdata_view.view.data),
				 gnu_debugdata_size, error_callback, data,
				 &gnu_debugdata_uncompressed,
				 &gnu_debugdata_uncompressed_size);

      elf_release_view (state, &gnu_debugdata_view, error_callback, data);
      gnu_debugdata_view_valid = 0;

      if (ret)
	{
	  ret = elf_add (state, filename, -1, gnu_debugdata_uncompressed,
			 gnu_debugdata_uncompressed_size, base_address, opd,
			 error_callback, data, fileline_fn, found_sym,
			 found_dwarf, NULL, 0, 0, NULL, 0);
	  if (ret >= 0 && descriptor >= 0)
	    backtrace_close(descriptor, error_callback, data);
	  return ret;
	}
    }

  if (opd_view_valid)
    {
      elf_release_view (state, &opd->view, error_callback, data);
      opd_view_valid = 0;
      opd = NULL;
    }

  /* Read all the debug sections in a single view, since they are
     probably adjacent in the file.  If any of sections are
     uncompressed, we never release this view.  */

  min_offset = 0;
  max_offset = 0;
  debug_size = 0;
  for (i = 0; i < (int) DEBUG_MAX; ++i)
    {
      off_t end;

      if (sections[i].size != 0)
	{
	  if (min_offset == 0 || sections[i].offset < min_offset)
	    min_offset = sections[i].offset;
	  end = sections[i].offset + sections[i].size;
	  if (end > max_offset)
	    max_offset = end;
	  debug_size += sections[i].size;
	}
      if (zsections[i].size != 0)
	{
	  if (min_offset == 0 || zsections[i].offset < min_offset)
	    min_offset = zsections[i].offset;
	  end = zsections[i].offset + zsections[i].size;
	  if (end > max_offset)
	    max_offset = end;
	  debug_size += zsections[i].size;
	}
    }
  if (min_offset == 0 || max_offset == 0)
    {
      if (descriptor >= 0)
	{
	  if (!backtrace_close (descriptor, error_callback, data))
	    goto fail;
	}
      return 1;
    }

  /* If the total debug section size is large, assume that there are
     gaps between the sections, and read them individually.  */

  if (max_offset - min_offset < 0x20000000
      || max_offset - min_offset < debug_size + 0x10000)
    {
      if (!elf_get_view (state, descriptor, memory, memory_size, min_offset,
			 max_offset - min_offset, error_callback, data,
			 &debug_view))
	goto fail;
      debug_view_valid = 1;
    }
  else
    {
      memset (&split_debug_view[0], 0, sizeof split_debug_view);
      for (i = 0; i < (int) DEBUG_MAX; ++i)
	{
	  struct debug_section_info *dsec;

	  if (sections[i].size != 0)
	    dsec = &sections[i];
	  else if (zsections[i].size != 0)
	    dsec = &zsections[i];
	  else
	    continue;

	  if (!elf_get_view (state, descriptor, memory, memory_size,
			     dsec->offset, dsec->size, error_callback, data,
			     &split_debug_view[i]))
	    goto fail;
	  split_debug_view_valid[i] = 1;

	  if (sections[i].size != 0)
	    sections[i].data = ((const unsigned char *)
				split_debug_view[i].view.data);
	  else
	    zsections[i].data = ((const unsigned char *)
				 split_debug_view[i].view.data);
	}
    }

  /* We've read all we need from the executable.  */
  if (descriptor >= 0)
    {
      if (!backtrace_close (descriptor, error_callback, data))
	goto fail;
      descriptor = -1;
    }

  using_debug_view = 0;
  if (debug_view_valid)
    {
      for (i = 0; i < (int) DEBUG_MAX; ++i)
	{
	  if (sections[i].size == 0)
	    sections[i].data = NULL;
	  else
	    {
	      sections[i].data = ((const unsigned char *) debug_view.view.data
				  + (sections[i].offset - min_offset));
	      ++using_debug_view;
	    }

	  if (zsections[i].size == 0)
	    zsections[i].data = NULL;
	  else
	    zsections[i].data = ((const unsigned char *) debug_view.view.data
				 + (zsections[i].offset - min_offset));
	}
    }

  /* Uncompress the old format (--compress-debug-sections=zlib-gnu).  */

  zdebug_table = NULL;
  for (i = 0; i < (int) DEBUG_MAX; ++i)
    {
      if (sections[i].size == 0 && zsections[i].size > 0)
	{
	  unsigned char *uncompressed_data;
	  size_t uncompressed_size;

	  if (zdebug_table == NULL)
	    {
	      zdebug_table = ((uint16_t *)
			      backtrace_alloc (state, ZLIB_TABLE_SIZE,
					       error_callback, data));
	      if (zdebug_table == NULL)
		goto fail;
	    }

	  uncompressed_data = NULL;
	  uncompressed_size = 0;
	  if (!elf_uncompress_zdebug (state, zsections[i].data,
				      zsections[i].size, zdebug_table,
				      error_callback, data,
				      &uncompressed_data, &uncompressed_size))
	    goto fail;
	  sections[i].data = uncompressed_data;
	  sections[i].size = uncompressed_size;
	  sections[i].compressed = 0;

	  if (split_debug_view_valid[i])
	    {
	      elf_release_view (state, &split_debug_view[i],
				error_callback, data);
	      split_debug_view_valid[i] = 0;
	    }
	}
    }

  if (zdebug_table != NULL)
    {
      backtrace_free (state, zdebug_table, ZLIB_TABLE_SIZE,
		      error_callback, data);
      zdebug_table = NULL;
    }

  /* Uncompress the official ELF format
     (--compress-debug-sections=zlib-gabi, --compress-debug-sections=zstd).  */
  for (i = 0; i < (int) DEBUG_MAX; ++i)
    {
      unsigned char *uncompressed_data;
      size_t uncompressed_size;

      if (sections[i].size == 0 || !sections[i].compressed)
	continue;

      if (zdebug_table == NULL)
	{
	  zdebug_table = ((uint16_t *)
			  backtrace_alloc (state, ZDEBUG_TABLE_SIZE,
					   error_callback, data));
	  if (zdebug_table == NULL)
	    goto fail;
	}

      uncompressed_data = NULL;
      uncompressed_size = 0;
      if (!elf_uncompress_chdr (state, sections[i].data, sections[i].size,
				zdebug_table, error_callback, data,
				&uncompressed_data, &uncompressed_size))
	goto fail;
      sections[i].data = uncompressed_data;
      sections[i].size = uncompressed_size;
      sections[i].compressed = 0;

      if (debug_view_valid)
	--using_debug_view;
      else if (split_debug_view_valid[i])
	{
	  elf_release_view (state, &split_debug_view[i], error_callback, data);
	  split_debug_view_valid[i] = 0;
	}
    }

  if (zdebug_table != NULL)
    backtrace_free (state, zdebug_table, ZDEBUG_TABLE_SIZE,
		    error_callback, data);

  if (debug_view_valid && using_debug_view == 0)
    {
      elf_release_view (state, &debug_view, error_callback, data);
      debug_view_valid = 0;
    }

  for (i = 0; i < (int) DEBUG_MAX; ++i)
    {
      dwarf_sections.data[i] = sections[i].data;
      dwarf_sections.size[i] = sections[i].size;
    }

  if (!backtrace_dwarf_add (state, base_address, &dwarf_sections,
			    ehdr.e_ident[EI_DATA] == ELFDATA2MSB,
			    fileline_altlink,
			    error_callback, data, fileline_fn,
			    fileline_entry))
    goto fail;

  *found_dwarf = 1;

  return 1;

 fail:
  if (shdrs_view_valid)
    elf_release_view (state, &shdrs_view, error_callback, data);
  if (names_view_valid)
    elf_release_view (state, &names_view, error_callback, data);
  if (symtab_view_valid)
    elf_release_view (state, &symtab_view, error_callback, data);
  if (strtab_view_valid)
    elf_release_view (state, &strtab_view, error_callback, data);
  if (debuglink_view_valid)
    elf_release_view (state, &debuglink_view, error_callback, data);
  if (debugaltlink_view_valid)
    elf_release_view (state, &debugaltlink_view, error_callback, data);
  if (gnu_debugdata_view_valid)
    elf_release_view (state, &gnu_debugdata_view, error_callback, data);
  if (buildid_view_valid)
    elf_release_view (state, &buildid_view, error_callback, data);
  if (debug_view_valid)
    elf_release_view (state, &debug_view, error_callback, data);
  for (i = 0; i < (int) DEBUG_MAX; ++i)
    {
      if (split_debug_view_valid[i])
	elf_release_view (state, &split_debug_view[i], error_callback, data);
    }
  if (opd_view_valid)
    elf_release_view (state, &opd->view, error_callback, data);
  if (descriptor >= 0)
    backtrace_close (descriptor, error_callback, data);
  return 0;
}

/* Data passed to phdr_callback.  */

struct phdr_data
{
  struct backtrace_state *state;
  backtrace_error_callback error_callback;
  void *data;
  fileline *fileline_fn;
  int *found_sym;
  int *found_dwarf;
  const char *exe_filename;
  int exe_descriptor;
};

/* Callback passed to dl_iterate_phdr.  Load debug info from shared
   libraries.  */

static int
#ifdef __i386__
__attribute__ ((__force_align_arg_pointer__))
#endif
phdr_callback (struct dl_phdr_info *info, size_t size ATTRIBUTE_UNUSED,
	       void *pdata)
{
  struct phdr_data *pd = (struct phdr_data *) pdata;
  const char *filename;
  int descriptor;
  int does_not_exist;
  fileline elf_fileline_fn;
  int found_dwarf;

  /* There is not much we can do if we don't have the module name,
     unless executable is ET_DYN, where we expect the very first
     phdr_callback to be for the PIE.  */
  if (info->dlpi_name == NULL || info->dlpi_name[0] == '\0')
    {
      if (pd->exe_descriptor == -1)
	return 0;
      filename = pd->exe_filename;
      descriptor = pd->exe_descriptor;
      pd->exe_descriptor = -1;
    }
  else
    {
      if (pd->exe_descriptor != -1)
	{
	  backtrace_close (pd->exe_descriptor, pd->error_callback, pd->data);
	  pd->exe_descriptor = -1;
	}

      filename = info->dlpi_name;
      descriptor = backtrace_open (info->dlpi_name, pd->error_callback,
				   pd->data, &does_not_exist);
      if (descriptor < 0)
	return 0;
    }

  if (elf_add (pd->state, filename, descriptor, NULL, 0, info->dlpi_addr, NULL,
	       pd->error_callback, pd->data, &elf_fileline_fn, pd->found_sym,
	       &found_dwarf, NULL, 0, 0, NULL, 0))
    {
      if (found_dwarf)
	{
	  *pd->found_dwarf = 1;
	  *pd->fileline_fn = elf_fileline_fn;
	}
    }

  return 0;
}

/* Initialize the backtrace data we need from an ELF executable.  At
   the ELF level, all we need to do is find the debug info
   sections.  */

int
backtrace_initialize (struct backtrace_state *state, const char *filename,
		      int descriptor, backtrace_error_callback error_callback,
		      void *data, fileline *fileline_fn)
{
  int ret;
  int found_sym;
  int found_dwarf;
  fileline elf_fileline_fn = elf_nodebug;
  struct phdr_data pd;

  ret = elf_add (state, filename, descriptor, NULL, 0, 0, NULL, error_callback,
		 data, &elf_fileline_fn, &found_sym, &found_dwarf, NULL, 1, 0,
		 NULL, 0);
  if (!ret)
    return 0;

  pd.state = state;
  pd.error_callback = error_callback;
  pd.data = data;
  pd.fileline_fn = &elf_fileline_fn;
  pd.found_sym = &found_sym;
  pd.found_dwarf = &found_dwarf;
  pd.exe_filename = filename;
  pd.exe_descriptor = ret < 0 ? descriptor : -1;

  dl_iterate_phdr (phdr_callback, (void *) &pd);

  if (!state->threaded)
    {
      if (found_sym)
	state->syminfo_fn = elf_syminfo;
      else if (state->syminfo_fn == NULL)
	state->syminfo_fn = elf_nosyms;
    }
  else
    {
      if (found_sym)
	backtrace_atomic_store_pointer (&state->syminfo_fn, elf_syminfo);
      else
	(void) __sync_bool_compare_and_swap (&state->syminfo_fn, NULL,
					     elf_nosyms);
    }

  if (!state->threaded)
    *fileline_fn = state->fileline_fn;
  else
    *fileline_fn = backtrace_atomic_load_pointer (&state->fileline_fn);

  if (*fileline_fn == NULL || *fileline_fn == elf_nodebug)
    *fileline_fn = elf_fileline_fn;

  return 1;
}