Training courses

Kernel and Embedded Linux

Bootlin training courses

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

Bootlin logo

Elixir Cross Referencer

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
@node typedef bfd, Error reporting, BFD front end, BFD front end
@section @code{typedef bfd}
A BFD has type @code{bfd}; objects of this type are the
cornerstone of any application using BFD. Using BFD
consists of making references though the BFD and to data in the BFD.

Here is the structure that defines the type @code{bfd}.  It
contains the major data about the file and pointers
to the rest of the data.


@example

enum bfd_direction
  @{
    no_direction = 0,
    read_direction = 1,
    write_direction = 2,
    both_direction = 3
  @};

enum bfd_plugin_format
  @{
    bfd_plugin_unknown = 0,
    bfd_plugin_yes = 1,
    bfd_plugin_no = 2
  @};

struct bfd_build_id
  @{
    bfd_size_type size;
    bfd_byte data[1];
  @};

struct bfd
@{
  /* The filename the application opened the BFD with.  */
  const char *filename;

  /* A pointer to the target jump table.  */
  const struct bfd_target *xvec;

  /* The IOSTREAM, and corresponding IO vector that provide access
     to the file backing the BFD.  */
  void *iostream;
  const struct bfd_iovec *iovec;

  /* The caching routines use these to maintain a
     least-recently-used list of BFDs.  */
  struct bfd *lru_prev, *lru_next;

  /* Track current file position (or current buffer offset for
     in-memory BFDs).  When a file is closed by the caching routines,
     BFD retains state information on the file here.  */
  ufile_ptr where;

  /* File modified time, if mtime_set is TRUE.  */
  long mtime;

  /* A unique identifier of the BFD  */
  unsigned int id;

  /* Format_specific flags.  */
  flagword flags;

  /* Values that may appear in the flags field of a BFD.  These also
     appear in the object_flags field of the bfd_target structure, where
     they indicate the set of flags used by that backend (not all flags
     are meaningful for all object file formats) (FIXME: at the moment,
     the object_flags values have mostly just been copied from backend
     to another, and are not necessarily correct).  */

#define BFD_NO_FLAGS                0x0

  /* BFD contains relocation entries.  */
#define HAS_RELOC                   0x1

  /* BFD is directly executable.  */
#define EXEC_P                      0x2

  /* BFD has line number information (basically used for F_LNNO in a
     COFF header).  */
#define HAS_LINENO                  0x4

  /* BFD has debugging information.  */
#define HAS_DEBUG                  0x08

  /* BFD has symbols.  */
#define HAS_SYMS                   0x10

  /* BFD has local symbols (basically used for F_LSYMS in a COFF
     header).  */
#define HAS_LOCALS                 0x20

  /* BFD is a dynamic object.  */
#define DYNAMIC                    0x40

  /* Text section is write protected (if D_PAGED is not set, this is
     like an a.out NMAGIC file) (the linker sets this by default, but
     clears it for -r or -N).  */
#define WP_TEXT                    0x80

  /* BFD is dynamically paged (this is like an a.out ZMAGIC file) (the
     linker sets this by default, but clears it for -r or -n or -N).  */
#define D_PAGED                   0x100

  /* BFD is relaxable (this means that bfd_relax_section may be able to
     do something) (sometimes bfd_relax_section can do something even if
     this is not set).  */
#define BFD_IS_RELAXABLE          0x200

  /* This may be set before writing out a BFD to request using a
     traditional format.  For example, this is used to request that when
     writing out an a.out object the symbols not be hashed to eliminate
     duplicates.  */
#define BFD_TRADITIONAL_FORMAT    0x400

  /* This flag indicates that the BFD contents are actually cached
     in memory.  If this is set, iostream points to a bfd_in_memory
     struct.  */
#define BFD_IN_MEMORY             0x800

  /* This BFD has been created by the linker and doesn't correspond
     to any input file.  */
#define BFD_LINKER_CREATED       0x1000

  /* This may be set before writing out a BFD to request that it
     be written using values for UIDs, GIDs, timestamps, etc. that
     will be consistent from run to run.  */
#define BFD_DETERMINISTIC_OUTPUT 0x2000

  /* Compress sections in this BFD.  */
#define BFD_COMPRESS             0x4000

  /* Decompress sections in this BFD.  */
#define BFD_DECOMPRESS           0x8000

  /* BFD is a dummy, for plugins.  */
#define BFD_PLUGIN              0x10000

  /* Compress sections in this BFD with SHF_COMPRESSED from gABI.  */
#define BFD_COMPRESS_GABI       0x20000

  /* Convert ELF common symbol type to STT_COMMON or STT_OBJECT in this
     BFD.  */
#define BFD_CONVERT_ELF_COMMON  0x40000

  /* Use the ELF STT_COMMON type in this BFD.  */
#define BFD_USE_ELF_STT_COMMON  0x80000

  /* Put pathnames into archives (non-POSIX).  */
#define BFD_ARCHIVE_FULL_PATH  0x100000

  /* Flags bits to be saved in bfd_preserve_save.  */
#define BFD_FLAGS_SAVED \
  (BFD_IN_MEMORY | BFD_COMPRESS | BFD_DECOMPRESS | BFD_LINKER_CREATED \
   | BFD_PLUGIN | BFD_COMPRESS_GABI | BFD_CONVERT_ELF_COMMON \
   | BFD_USE_ELF_STT_COMMON)

  /* Flags bits which are for BFD use only.  */
#define BFD_FLAGS_FOR_BFD_USE_MASK \
  (BFD_IN_MEMORY | BFD_COMPRESS | BFD_DECOMPRESS | BFD_LINKER_CREATED \
   | BFD_PLUGIN | BFD_TRADITIONAL_FORMAT | BFD_DETERMINISTIC_OUTPUT \
   | BFD_COMPRESS_GABI | BFD_CONVERT_ELF_COMMON | BFD_USE_ELF_STT_COMMON)

  /* The format which belongs to the BFD. (object, core, etc.)  */
  ENUM_BITFIELD (bfd_format) format : 3;

  /* The direction with which the BFD was opened.  */
  ENUM_BITFIELD (bfd_direction) direction : 2;

  /* Is the file descriptor being cached?  That is, can it be closed as
     needed, and re-opened when accessed later?  */
  unsigned int cacheable : 1;

  /* Marks whether there was a default target specified when the
     BFD was opened. This is used to select which matching algorithm
     to use to choose the back end.  */
  unsigned int target_defaulted : 1;

  /* ... and here: (``once'' means at least once).  */
  unsigned int opened_once : 1;

  /* Set if we have a locally maintained mtime value, rather than
     getting it from the file each time.  */
  unsigned int mtime_set : 1;

  /* Flag set if symbols from this BFD should not be exported.  */
  unsigned int no_export : 1;

  /* Remember when output has begun, to stop strange things
     from happening.  */
  unsigned int output_has_begun : 1;

  /* Have archive map.  */
  unsigned int has_armap : 1;

  /* Set if this is a thin archive.  */
  unsigned int is_thin_archive : 1;

  /* Set if this archive should not cache element positions.  */
  unsigned int no_element_cache : 1;

  /* Set if only required symbols should be added in the link hash table for
     this object.  Used by VMS linkers.  */
  unsigned int selective_search : 1;

  /* Set if this is the linker output BFD.  */
  unsigned int is_linker_output : 1;

  /* Set if this is the linker input BFD.  */
  unsigned int is_linker_input : 1;

  /* If this is an input for a compiler plug-in library.  */
  ENUM_BITFIELD (bfd_plugin_format) plugin_format : 2;

  /* Set if this is a plugin output file.  */
  unsigned int lto_output : 1;

  /* Set if this is a slim LTO object not loaded with a compiler plugin.  */
  unsigned int lto_slim_object : 1;

  /* Do not attempt to modify this file.  Set when detecting errors
     that BFD is not prepared to handle for objcopy/strip.  */
  unsigned int read_only : 1;

  /* Set to dummy BFD created when claimed by a compiler plug-in
     library.  */
  bfd *plugin_dummy_bfd;

  /* The offset of this bfd in the file, typically 0 if it is not
     contained in an archive.  */
  ufile_ptr origin;

  /* The origin in the archive of the proxy entry.  This will
     normally be the same as origin, except for thin archives,
     when it will contain the current offset of the proxy in the
     thin archive rather than the offset of the bfd in its actual
     container.  */
  ufile_ptr proxy_origin;

  /* A hash table for section names.  */
  struct bfd_hash_table section_htab;

  /* Pointer to linked list of sections.  */
  struct bfd_section *sections;

  /* The last section on the section list.  */
  struct bfd_section *section_last;

  /* The number of sections.  */
  unsigned int section_count;

  /* The archive plugin file descriptor.  */
  int archive_plugin_fd;

  /* The number of opens on the archive plugin file descriptor.  */
  unsigned int archive_plugin_fd_open_count;

  /* A field used by _bfd_generic_link_add_archive_symbols.  This will
     be used only for archive elements.  */
  int archive_pass;

  /* The total size of memory from bfd_alloc.  */
  bfd_size_type alloc_size;

  /* Stuff only useful for object files:
     The start address.  */
  bfd_vma start_address;

  /* Symbol table for output BFD (with symcount entries).
     Also used by the linker to cache input BFD symbols.  */
  struct bfd_symbol **outsymbols;

  /* Used for input and output.  */
  unsigned int symcount;

  /* Used for slurped dynamic symbol tables.  */
  unsigned int dynsymcount;

  /* Pointer to structure which contains architecture information.  */
  const struct bfd_arch_info *arch_info;

  /* Cached length of file for bfd_get_size.  0 until bfd_get_size is
     called, 1 if stat returns an error or the file size is too large to
     return in ufile_ptr.  Both 0 and 1 should be treated as "unknown".  */
  ufile_ptr size;

  /* Stuff only useful for archives.  */
  void *arelt_data;
  struct bfd *my_archive;      /* The containing archive BFD.  */
  struct bfd *archive_next;    /* The next BFD in the archive.  */
  struct bfd *archive_head;    /* The first BFD in the archive.  */
  struct bfd *nested_archives; /* List of nested archive in a flattened
                                  thin archive.  */

  union @{
    /* For input BFDs, a chain of BFDs involved in a link.  */
    struct bfd *next;
    /* For output BFD, the linker hash table.  */
    struct bfd_link_hash_table *hash;
  @} link;

  /* Used by the back end to hold private data.  */
  union
    @{
      struct aout_data_struct *aout_data;
      struct artdata *aout_ar_data;
      struct coff_tdata *coff_obj_data;
      struct pe_tdata *pe_obj_data;
      struct xcoff_tdata *xcoff_obj_data;
      struct ecoff_tdata *ecoff_obj_data;
      struct srec_data_struct *srec_data;
      struct verilog_data_struct *verilog_data;
      struct ihex_data_struct *ihex_data;
      struct tekhex_data_struct *tekhex_data;
      struct elf_obj_tdata *elf_obj_data;
      struct mmo_data_struct *mmo_data;
      struct sun_core_struct *sun_core_data;
      struct sco5_core_struct *sco5_core_data;
      struct trad_core_struct *trad_core_data;
      struct som_data_struct *som_data;
      struct hpux_core_struct *hpux_core_data;
      struct hppabsd_core_struct *hppabsd_core_data;
      struct sgi_core_struct *sgi_core_data;
      struct lynx_core_struct *lynx_core_data;
      struct osf_core_struct *osf_core_data;
      struct cisco_core_struct *cisco_core_data;
      struct versados_data_struct *versados_data;
      struct netbsd_core_struct *netbsd_core_data;
      struct mach_o_data_struct *mach_o_data;
      struct mach_o_fat_data_struct *mach_o_fat_data;
      struct plugin_data_struct *plugin_data;
      struct bfd_pef_data_struct *pef_data;
      struct bfd_pef_xlib_data_struct *pef_xlib_data;
      struct bfd_sym_data_struct *sym_data;
      void *any;
    @}
  tdata;

  /* Used by the application to hold private data.  */
  void *usrdata;

  /* Where all the allocated stuff under this BFD goes.  This is a
     struct objalloc *, but we use void * to avoid requiring the inclusion
     of objalloc.h.  */
  void *memory;

  /* For input BFDs, the build ID, if the object has one. */
  const struct bfd_build_id *build_id;
@};

static inline const char *
bfd_get_filename (const bfd *abfd)
@{
  return abfd->filename;
@}

static inline bool
bfd_get_cacheable (const bfd *abfd)
@{
  return abfd->cacheable;
@}

static inline enum bfd_format
bfd_get_format (const bfd *abfd)
@{
  return abfd->format;
@}

static inline flagword
bfd_get_file_flags (const bfd *abfd)
@{
  return abfd->flags;
@}

static inline bfd_vma
bfd_get_start_address (const bfd *abfd)
@{
  return abfd->start_address;
@}

static inline unsigned int
bfd_get_symcount (const bfd *abfd)
@{
  return abfd->symcount;
@}

static inline unsigned int
bfd_get_dynamic_symcount (const bfd *abfd)
@{
  return abfd->dynsymcount;
@}

static inline struct bfd_symbol **
bfd_get_outsymbols (const bfd *abfd)
@{
  return abfd->outsymbols;
@}

static inline unsigned int
bfd_count_sections (const bfd *abfd)
@{
  return abfd->section_count;
@}

static inline bool
bfd_has_map (const bfd *abfd)
@{
  return abfd->has_armap;
@}

static inline bool
bfd_is_thin_archive (const bfd *abfd)
@{
  return abfd->is_thin_archive;
@}

static inline void *
bfd_usrdata (const bfd *abfd)
@{
  return abfd->usrdata;
@}

/* See note beside bfd_set_section_userdata.  */
static inline bool
bfd_set_cacheable (bfd * abfd, bool val)
@{
  abfd->cacheable = val;
  return true;
@}

static inline void
bfd_set_thin_archive (bfd *abfd, bool val)
@{
  abfd->is_thin_archive = val;
@}

static inline void
bfd_set_usrdata (bfd *abfd, void *val)
@{
  abfd->usrdata = val;
@}

static inline asection *
bfd_asymbol_section (const asymbol *sy)
@{
  return sy->section;
@}

static inline bfd_vma
bfd_asymbol_value (const asymbol *sy)
@{
  return sy->section->vma + sy->value;
@}

static inline const char *
bfd_asymbol_name (const asymbol *sy)
@{
  return sy->name;
@}

static inline struct bfd *
bfd_asymbol_bfd (const asymbol *sy)
@{
  return sy->the_bfd;
@}

static inline void
bfd_set_asymbol_name (asymbol *sy, const char *name)
@{
  sy->name = name;
@}

static inline bfd_size_type
bfd_get_section_limit_octets (const bfd *abfd, const asection *sec)
@{
  if (abfd->direction != write_direction && sec->rawsize != 0)
    return sec->rawsize;
  return sec->size;
@}

/* Find the address one past the end of SEC.  */
static inline bfd_size_type
bfd_get_section_limit (const bfd *abfd, const asection *sec)
@{
  return (bfd_get_section_limit_octets (abfd, sec)
          / bfd_octets_per_byte (abfd, sec));
@}

/* Functions to handle insertion and deletion of a bfd's sections.  These
   only handle the list pointers, ie. do not adjust section_count,
   target_index etc.  */
static inline void
bfd_section_list_remove (bfd *abfd, asection *s)
@{
  asection *next = s->next;
  asection *prev = s->prev;
  if (prev)
    prev->next = next;
  else
    abfd->sections = next;
  if (next)
    next->prev = prev;
  else
    abfd->section_last = prev;
@}

static inline void
bfd_section_list_append (bfd *abfd, asection *s)
@{
  s->next = 0;
  if (abfd->section_last)
    @{
      s->prev = abfd->section_last;
      abfd->section_last->next = s;
    @}
  else
    @{
      s->prev = 0;
      abfd->sections = s;
    @}
  abfd->section_last = s;
@}

static inline void
bfd_section_list_prepend (bfd *abfd, asection *s)
@{
  s->prev = 0;
  if (abfd->sections)
    @{
      s->next = abfd->sections;
      abfd->sections->prev = s;
    @}
  else
    @{
      s->next = 0;
      abfd->section_last = s;
    @}
  abfd->sections = s;
@}

static inline void
bfd_section_list_insert_after (bfd *abfd, asection *a, asection *s)
@{
  asection *next = a->next;
  s->next = next;
  s->prev = a;
  a->next = s;
  if (next)
    next->prev = s;
  else
    abfd->section_last = s;
@}

static inline void
bfd_section_list_insert_before (bfd *abfd, asection *b, asection *s)
@{
  asection *prev = b->prev;
  s->prev = prev;
  s->next = b;
  b->prev = s;
  if (prev)
    prev->next = s;
  else
    abfd->sections = s;
@}

static inline bool
bfd_section_removed_from_list (const bfd *abfd, const asection *s)
@{
  return s->next ? s->next->prev != s : abfd->section_last != s;
@}

@end example
@node Error reporting, Miscellaneous, typedef bfd, BFD front end
@section Error reporting
Most BFD functions return nonzero on success (check their
individual documentation for precise semantics).  On an error,
they call @code{bfd_set_error} to set an error condition that callers
can check by calling @code{bfd_get_error}.
If that returns @code{bfd_error_system_call}, then check
@code{errno}.

The easiest way to report a BFD error to the user is to
use @code{bfd_perror}.

@subsection Type @code{bfd_error_type}
The values returned by @code{bfd_get_error} are defined by the
enumerated type @code{bfd_error_type}.


@example

typedef enum bfd_error
@{
  bfd_error_no_error = 0,
  bfd_error_system_call,
  bfd_error_invalid_target,
  bfd_error_wrong_format,
  bfd_error_wrong_object_format,
  bfd_error_invalid_operation,
  bfd_error_no_memory,
  bfd_error_no_symbols,
  bfd_error_no_armap,
  bfd_error_no_more_archived_files,
  bfd_error_malformed_archive,
  bfd_error_missing_dso,
  bfd_error_file_not_recognized,
  bfd_error_file_ambiguously_recognized,
  bfd_error_no_contents,
  bfd_error_nonrepresentable_section,
  bfd_error_no_debug_section,
  bfd_error_bad_value,
  bfd_error_file_truncated,
  bfd_error_file_too_big,
  bfd_error_sorry,
  bfd_error_on_input,
  bfd_error_invalid_error_code
@}
bfd_error_type;

@end example
@findex bfd_get_error
@subsubsection @code{bfd_get_error}
@strong{Synopsis}
@example
bfd_error_type bfd_get_error (void);
@end example
@strong{Description}@*
Return the current BFD error condition.

@findex bfd_set_error
@subsubsection @code{bfd_set_error}
@strong{Synopsis}
@example
void bfd_set_error (bfd_error_type error_tag);
@end example
@strong{Description}@*
Set the BFD error condition to be @var{error_tag}.

@var{error_tag} must not be bfd_error_on_input.  Use
bfd_set_input_error for input errors instead.

@findex bfd_set_input_error
@subsubsection @code{bfd_set_input_error}
@strong{Synopsis}
@example
void bfd_set_input_error (bfd *input, bfd_error_type error_tag);
@end example
@strong{Description}@*
Set the BFD error condition to be bfd_error_on_input.
@var{input} is the input bfd where the error occurred, and
@var{error_tag} the bfd_error_type error.

@findex bfd_errmsg
@subsubsection @code{bfd_errmsg}
@strong{Synopsis}
@example
const char *bfd_errmsg (bfd_error_type error_tag);
@end example
@strong{Description}@*
Return a string describing the error @var{error_tag}, or
the system error if @var{error_tag} is @code{bfd_error_system_call}.

@findex bfd_perror
@subsubsection @code{bfd_perror}
@strong{Synopsis}
@example
void bfd_perror (const char *message);
@end example
@strong{Description}@*
Print to the standard error stream a string describing the
last BFD error that occurred, or the last system error if
the last BFD error was a system call failure.  If @var{message}
is non-NULL and non-empty, the error string printed is preceded
by @var{message}, a colon, and a space.  It is followed by a newline.

@subsection BFD error handler
Some BFD functions want to print messages describing the
problem.  They call a BFD error handler function.  This
function may be overridden by the program.

The BFD error handler acts like vprintf.


@example

typedef void (*bfd_error_handler_type) (const char *, va_list);

@end example
@findex _bfd_error_handler
@subsubsection @code{_bfd_error_handler}
@strong{Synopsis}
@example
void _bfd_error_handler (const char *fmt, ...) ATTRIBUTE_PRINTF_1;
@end example
@strong{Description}@*
This is the default routine to handle BFD error messages.
Like fprintf (stderr, ...), but also handles some extra format
specifiers.

%pA section name from section.  For group components, prints
group name too.
%pB file name from bfd.  For archive components, prints
archive too.

Beware: Only supports a maximum of 9 format arguments.

@findex bfd_set_error_handler
@subsubsection @code{bfd_set_error_handler}
@strong{Synopsis}
@example
bfd_error_handler_type bfd_set_error_handler (bfd_error_handler_type);
@end example
@strong{Description}@*
Set the BFD error handler function.  Returns the previous
function.

@findex bfd_set_error_program_name
@subsubsection @code{bfd_set_error_program_name}
@strong{Synopsis}
@example
void bfd_set_error_program_name (const char *);
@end example
@strong{Description}@*
Set the program name to use when printing a BFD error.  This
is printed before the error message followed by a colon and
space.  The string must not be changed after it is passed to
this function.

@subsection BFD assert handler
If BFD finds an internal inconsistency, the bfd assert
handler is called with information on the BFD version, BFD
source file and line.  If this happens, most programs linked
against BFD are expected to want to exit with an error, or mark
the current BFD operation as failed, so it is recommended to
override the default handler, which just calls
_bfd_error_handler and continues.


@example

typedef void (*bfd_assert_handler_type) (const char *bfd_formatmsg,
                                         const char *bfd_version,
                                         const char *bfd_file,
                                         int bfd_line);

@end example
@findex bfd_set_assert_handler
@subsubsection @code{bfd_set_assert_handler}
@strong{Synopsis}
@example
bfd_assert_handler_type bfd_set_assert_handler (bfd_assert_handler_type);
@end example
@strong{Description}@*
Set the BFD assert handler function.  Returns the previous
function.

@node Miscellaneous, Memory Usage, Error reporting, BFD front end
@section Miscellaneous


@subsection Miscellaneous functions


@findex bfd_get_reloc_upper_bound
@subsubsection @code{bfd_get_reloc_upper_bound}
@strong{Synopsis}
@example
long bfd_get_reloc_upper_bound (bfd *abfd, asection *sect);
@end example
@strong{Description}@*
Return the number of bytes required to store the
relocation information associated with section @var{sect}
attached to bfd @var{abfd}.  If an error occurs, return -1.

@findex bfd_canonicalize_reloc
@subsubsection @code{bfd_canonicalize_reloc}
@strong{Synopsis}
@example
long bfd_canonicalize_reloc
   (bfd *abfd, asection *sec, arelent **loc, asymbol **syms);
@end example
@strong{Description}@*
Call the back end associated with the open BFD
@var{abfd} and translate the external form of the relocation
information attached to @var{sec} into the internal canonical
form.  Place the table into memory at @var{loc}, which has
been preallocated, usually by a call to
@code{bfd_get_reloc_upper_bound}.  Returns the number of relocs, or
-1 on error.

The @var{syms} table is also needed for horrible internal magic
reasons.

@findex bfd_set_reloc
@subsubsection @code{bfd_set_reloc}
@strong{Synopsis}
@example
void bfd_set_reloc
   (bfd *abfd, asection *sec, arelent **rel, unsigned int count);
@end example
@strong{Description}@*
Set the relocation pointer and count within
section @var{sec} to the values @var{rel} and @var{count}.
The argument @var{abfd} is ignored.
@example
#define bfd_set_reloc(abfd, asect, location, count) \
       BFD_SEND (abfd, _bfd_set_reloc, (abfd, asect, location, count))
@end example

@findex bfd_set_file_flags
@subsubsection @code{bfd_set_file_flags}
@strong{Synopsis}
@example
bool bfd_set_file_flags (bfd *abfd, flagword flags);
@end example
@strong{Description}@*
Set the flag word in the BFD @var{abfd} to the value @var{flags}.

Possible errors are:
@itemize @bullet

@item
@code{bfd_error_wrong_format} - The target bfd was not of object format.
@item
@code{bfd_error_invalid_operation} - The target bfd was open for reading.
@item
@code{bfd_error_invalid_operation} -
The flag word contained a bit which was not applicable to the
type of file.  E.g., an attempt was made to set the @code{D_PAGED} bit
on a BFD format which does not support demand paging.
@end itemize

@findex bfd_get_arch_size
@subsubsection @code{bfd_get_arch_size}
@strong{Synopsis}
@example
int bfd_get_arch_size (bfd *abfd);
@end example
@strong{Description}@*
Returns the normalized architecture address size, in bits, as
determined by the object file's format.  By normalized, we mean
either 32 or 64.  For ELF, this information is included in the
header.  Use bfd_arch_bits_per_address for number of bits in
the architecture address.

@strong{Returns}@*
Returns the arch size in bits if known, @code{-1} otherwise.

@findex bfd_get_sign_extend_vma
@subsubsection @code{bfd_get_sign_extend_vma}
@strong{Synopsis}
@example
int bfd_get_sign_extend_vma (bfd *abfd);
@end example
@strong{Description}@*
Indicates if the target architecture "naturally" sign extends
an address.  Some architectures implicitly sign extend address
values when they are converted to types larger than the size
of an address.  For instance, bfd_get_start_address() will
return an address sign extended to fill a bfd_vma when this is
the case.

@strong{Returns}@*
Returns @code{1} if the target architecture is known to sign
extend addresses, @code{0} if the target architecture is known to
not sign extend addresses, and @code{-1} otherwise.

@findex bfd_set_start_address
@subsubsection @code{bfd_set_start_address}
@strong{Synopsis}
@example
bool bfd_set_start_address (bfd *abfd, bfd_vma vma);
@end example
@strong{Description}@*
Make @var{vma} the entry point of output BFD @var{abfd}.

@strong{Returns}@*
Returns @code{TRUE} on success, @code{FALSE} otherwise.

@findex bfd_get_gp_size
@subsubsection @code{bfd_get_gp_size}
@strong{Synopsis}
@example
unsigned int bfd_get_gp_size (bfd *abfd);
@end example
@strong{Description}@*
Return the maximum size of objects to be optimized using the GP
register under MIPS ECOFF.  This is typically set by the @code{-G}
argument to the compiler, assembler or linker.

@findex bfd_set_gp_size
@subsubsection @code{bfd_set_gp_size}
@strong{Synopsis}
@example
void bfd_set_gp_size (bfd *abfd, unsigned int i);
@end example
@strong{Description}@*
Set the maximum size of objects to be optimized using the GP
register under ECOFF or MIPS ELF.  This is typically set by
the @code{-G} argument to the compiler, assembler or linker.

@findex bfd_set_gp_value
@subsubsection @code{bfd_set_gp_value}
@strong{Synopsis}
@example
void bfd_set_gp_value (bfd *abfd, bfd_vma v);
@end example
@strong{Description}@*
Allow external access to the fucntion to set the GP value.
This is specifically added for gdb-compile support.

@findex bfd_scan_vma
@subsubsection @code{bfd_scan_vma}
@strong{Synopsis}
@example
bfd_vma bfd_scan_vma (const char *string, const char **end, int base);
@end example
@strong{Description}@*
Convert, like @code{strtoul}, a numerical expression
@var{string} into a @code{bfd_vma} integer, and return that integer.
(Though without as many bells and whistles as @code{strtoul}.)
The expression is assumed to be unsigned (i.e., positive).
If given a @var{base}, it is used as the base for conversion.
A base of 0 causes the function to interpret the string
in hex if a leading "0x" or "0X" is found, otherwise
in octal if a leading zero is found, otherwise in decimal.

If the value would overflow, the maximum @code{bfd_vma} value is
returned.

@findex bfd_copy_private_header_data
@subsubsection @code{bfd_copy_private_header_data}
@strong{Synopsis}
@example
bool bfd_copy_private_header_data (bfd *ibfd, bfd *obfd);
@end example
@strong{Description}@*
Copy private BFD header information from the BFD @var{ibfd} to the
the BFD @var{obfd}.  This copies information that may require
sections to exist, but does not require symbol tables.  Return
@code{true} on success, @code{false} on error.
Possible error returns are:

@itemize @bullet

@item
@code{bfd_error_no_memory} -
Not enough memory exists to create private data for @var{obfd}.
@end itemize
@example
#define bfd_copy_private_header_data(ibfd, obfd) \
       BFD_SEND (obfd, _bfd_copy_private_header_data, \
                 (ibfd, obfd))
@end example

@findex bfd_copy_private_bfd_data
@subsubsection @code{bfd_copy_private_bfd_data}
@strong{Synopsis}
@example
bool bfd_copy_private_bfd_data (bfd *ibfd, bfd *obfd);
@end example
@strong{Description}@*
Copy private BFD information from the BFD @var{ibfd} to the
the BFD @var{obfd}.  Return @code{TRUE} on success, @code{FALSE} on error.
Possible error returns are:

@itemize @bullet

@item
@code{bfd_error_no_memory} -
Not enough memory exists to create private data for @var{obfd}.
@end itemize
@example
#define bfd_copy_private_bfd_data(ibfd, obfd) \
       BFD_SEND (obfd, _bfd_copy_private_bfd_data, \
                 (ibfd, obfd))
@end example

@findex bfd_set_private_flags
@subsubsection @code{bfd_set_private_flags}
@strong{Synopsis}
@example
bool bfd_set_private_flags (bfd *abfd, flagword flags);
@end example
@strong{Description}@*
Set private BFD flag information in the BFD @var{abfd}.
Return @code{TRUE} on success, @code{FALSE} on error.  Possible error
returns are:

@itemize @bullet

@item
@code{bfd_error_no_memory} -
Not enough memory exists to create private data for @var{obfd}.
@end itemize
@example
#define bfd_set_private_flags(abfd, flags) \
       BFD_SEND (abfd, _bfd_set_private_flags, (abfd, flags))
@end example

@findex Other functions
@subsubsection @code{Other functions}
@strong{Description}@*
The following functions exist but have not yet been documented.
@example
#define bfd_sizeof_headers(abfd, info) \
       BFD_SEND (abfd, _bfd_sizeof_headers, (abfd, info))

#define bfd_find_nearest_line(abfd, sec, syms, off, file, func, line) \
       BFD_SEND (abfd, _bfd_find_nearest_line, \
                 (abfd, syms, sec, off, file, func, line, NULL))

#define bfd_find_nearest_line_discriminator(abfd, sec, syms, off, file, func, \
                                           line, disc) \
       BFD_SEND (abfd, _bfd_find_nearest_line, \
                 (abfd, syms, sec, off, file, func, line, disc))

#define bfd_find_line(abfd, syms, sym, file, line) \
       BFD_SEND (abfd, _bfd_find_line, \
                 (abfd, syms, sym, file, line))

#define bfd_find_inliner_info(abfd, file, func, line) \
       BFD_SEND (abfd, _bfd_find_inliner_info, \
                 (abfd, file, func, line))

#define bfd_debug_info_start(abfd) \
       BFD_SEND (abfd, _bfd_debug_info_start, (abfd))

#define bfd_debug_info_end(abfd) \
       BFD_SEND (abfd, _bfd_debug_info_end, (abfd))

#define bfd_debug_info_accumulate(abfd, section) \
       BFD_SEND (abfd, _bfd_debug_info_accumulate, (abfd, section))

#define bfd_stat_arch_elt(abfd, stat) \
       BFD_SEND (abfd->my_archive ? abfd->my_archive : abfd, \
                 _bfd_stat_arch_elt, (abfd, stat))

#define bfd_update_armap_timestamp(abfd) \
       BFD_SEND (abfd, _bfd_update_armap_timestamp, (abfd))

#define bfd_set_arch_mach(abfd, arch, mach)\
       BFD_SEND ( abfd, _bfd_set_arch_mach, (abfd, arch, mach))

#define bfd_relax_section(abfd, section, link_info, again) \
       BFD_SEND (abfd, _bfd_relax_section, (abfd, section, link_info, again))

#define bfd_gc_sections(abfd, link_info) \
       BFD_SEND (abfd, _bfd_gc_sections, (abfd, link_info))

#define bfd_lookup_section_flags(link_info, flag_info, section) \
       BFD_SEND (abfd, _bfd_lookup_section_flags, (link_info, flag_info, section))

#define bfd_merge_sections(abfd, link_info) \
       BFD_SEND (abfd, _bfd_merge_sections, (abfd, link_info))

#define bfd_is_group_section(abfd, sec) \
       BFD_SEND (abfd, _bfd_is_group_section, (abfd, sec))

#define bfd_group_name(abfd, sec) \
       BFD_SEND (abfd, _bfd_group_name, (abfd, sec))

#define bfd_discard_group(abfd, sec) \
       BFD_SEND (abfd, _bfd_discard_group, (abfd, sec))

#define bfd_link_hash_table_create(abfd) \
       BFD_SEND (abfd, _bfd_link_hash_table_create, (abfd))

#define bfd_link_add_symbols(abfd, info) \
       BFD_SEND (abfd, _bfd_link_add_symbols, (abfd, info))

#define bfd_link_just_syms(abfd, sec, info) \
       BFD_SEND (abfd, _bfd_link_just_syms, (sec, info))

#define bfd_final_link(abfd, info) \
       BFD_SEND (abfd, _bfd_final_link, (abfd, info))

#define bfd_free_cached_info(abfd) \
       BFD_SEND (abfd, _bfd_free_cached_info, (abfd))

#define bfd_get_dynamic_symtab_upper_bound(abfd) \
       BFD_SEND (abfd, _bfd_get_dynamic_symtab_upper_bound, (abfd))

#define bfd_print_private_bfd_data(abfd, file)\
       BFD_SEND (abfd, _bfd_print_private_bfd_data, (abfd, file))

#define bfd_canonicalize_dynamic_symtab(abfd, asymbols) \
       BFD_SEND (abfd, _bfd_canonicalize_dynamic_symtab, (abfd, asymbols))

#define bfd_get_synthetic_symtab(abfd, count, syms, dyncount, dynsyms, ret) \
       BFD_SEND (abfd, _bfd_get_synthetic_symtab, (abfd, count, syms, \
                                                   dyncount, dynsyms, ret))

#define bfd_get_dynamic_reloc_upper_bound(abfd) \
       BFD_SEND (abfd, _bfd_get_dynamic_reloc_upper_bound, (abfd))

#define bfd_canonicalize_dynamic_reloc(abfd, arels, asyms) \
       BFD_SEND (abfd, _bfd_canonicalize_dynamic_reloc, (abfd, arels, asyms))

extern bfd_byte *bfd_get_relocated_section_contents
  (bfd *, struct bfd_link_info *, struct bfd_link_order *, bfd_byte *,
   bool, asymbol **);

@end example

@findex bfd_alt_mach_code
@subsubsection @code{bfd_alt_mach_code}
@strong{Synopsis}
@example
bool bfd_alt_mach_code (bfd *abfd, int alternative);
@end example
@strong{Description}@*
When more than one machine code number is available for the
same machine type, this function can be used to switch between
the preferred one (alternative == 0) and any others.  Currently,
only ELF supports this feature, with up to two alternate
machine codes.

@findex bfd_emul_get_maxpagesize
@subsubsection @code{bfd_emul_get_maxpagesize}
@strong{Synopsis}
@example
bfd_vma bfd_emul_get_maxpagesize (const char *);
@end example
@strong{Description}@*
Returns the maximum page size, in bytes, as determined by
emulation.

@strong{Returns}@*
Returns the maximum page size in bytes for ELF, 0 otherwise.

@findex bfd_emul_get_commonpagesize
@subsubsection @code{bfd_emul_get_commonpagesize}
@strong{Synopsis}
@example
bfd_vma bfd_emul_get_commonpagesize (const char *);
@end example
@strong{Description}@*
Returns the common page size, in bytes, as determined by
emulation.

@strong{Returns}@*
Returns the common page size in bytes for ELF, 0 otherwise.

@findex bfd_demangle
@subsubsection @code{bfd_demangle}
@strong{Synopsis}
@example
char *bfd_demangle (bfd *, const char *, int);
@end example
@strong{Description}@*
Wrapper around cplus_demangle.  Strips leading underscores and
other such chars that would otherwise confuse the demangler.
If passed a g++ v3 ABI mangled name, returns a buffer allocated
with malloc holding the demangled name.  Returns NULL otherwise
and on memory alloc failure.

@findex bfd_update_compression_header
@subsubsection @code{bfd_update_compression_header}
@strong{Synopsis}
@example
void bfd_update_compression_header
   (bfd *abfd, bfd_byte *contents, asection *sec);
@end example
@strong{Description}@*
Set the compression header at CONTENTS of SEC in ABFD and update
elf_section_flags for compression.

@findex bfd_check_compression_header
@subsubsection @code{bfd_check_compression_header}
@strong{Synopsis}
@example
bool bfd_check_compression_header
   (bfd *abfd, bfd_byte *contents, asection *sec,
    bfd_size_type *uncompressed_size,
    unsigned int *uncompressed_alignment_power);
@end example
@strong{Description}@*
Check the compression header at CONTENTS of SEC in ABFD and
store the uncompressed size in UNCOMPRESSED_SIZE and the
uncompressed data alignment in UNCOMPRESSED_ALIGNMENT_POWER
if the compression header is valid.

@strong{Returns}@*
Return TRUE if the compression header is valid.

@findex bfd_get_compression_header_size
@subsubsection @code{bfd_get_compression_header_size}
@strong{Synopsis}
@example
int bfd_get_compression_header_size (bfd *abfd, asection *sec);
@end example
@strong{Description}@*
Return the size of the compression header of SEC in ABFD.

@strong{Returns}@*
Return the size of the compression header in bytes.

@findex bfd_convert_section_size
@subsubsection @code{bfd_convert_section_size}
@strong{Synopsis}
@example
bfd_size_type bfd_convert_section_size
   (bfd *ibfd, asection *isec, bfd *obfd, bfd_size_type size);
@end example
@strong{Description}@*
Convert the size @var{size} of the section @var{isec} in input
BFD @var{ibfd} to the section size in output BFD @var{obfd}.

@findex bfd_convert_section_contents
@subsubsection @code{bfd_convert_section_contents}
@strong{Synopsis}
@example
bool bfd_convert_section_contents
   (bfd *ibfd, asection *isec, bfd *obfd,
    bfd_byte **ptr, bfd_size_type *ptr_size);
@end example
@strong{Description}@*
Convert the contents, stored in @var{*ptr}, of the section
@var{isec} in input BFD @var{ibfd} to output BFD @var{obfd}
if needed.  The original buffer pointed to by @var{*ptr} may
be freed and @var{*ptr} is returned with memory malloc'd by this
function, and the new size written to @var{ptr_size}.