@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
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 malloc'd
     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

#define BFD_CLOSED_BY_CACHE    0x200000
  /* Compress sections in this BFD with SHF_COMPRESSED zstd.  */
#define BFD_COMPRESS_ZSTD      0x400000

  /* Don't generate ELF section header.  */
#define BFD_NO_SECTION_HEADER  0x800000

  /* 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 \
   | BFD_NO_SECTION_HEADER)

  /* 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;

  /* POSIX.1-2017 (IEEE Std 1003.1) says of fopen : "When a file is
     opened with update mode ('+' as the second or third character in
     the mode argument), both input and output may be performed on
     the associated stream.  However, the application shall ensure
     that output is not directly followed by input without an
     intervening call to fflush() or to a file positioning function
     (fseek(), fsetpos(), or rewind()), and input is not directly
     followed by output without an intervening call to a file
     positioning function, unless the input operation encounters
     end-of-file."
     This field tracks the last IO operation, so that bfd can insert
     a seek when IO direction changes.  */
  ENUM_BITFIELD (bfd_last_io) last_io : 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;

  /* 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;

  /* LTO object type.  */
  ENUM_BITFIELD (bfd_lto_object_type) lto_type : 3;

  /* Set if this BFD is currently being processed by
     bfd_check_format_matches.  This is checked by the cache to
     avoid closing the BFD in this case.  This should only be
     examined or modified while the BFD lock is held.  */
  unsigned int in_format_matches : 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 object-only section on the section list.  */
  struct bfd_section *object_only_section;

  /* 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 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 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;

  /* For input BFDs, mmapped entries. */
  struct bfd_mmapped *mmapped;
@};

@end example
@node Error reporting, Initialization, 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}.

The BFD error is thread-local.

@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}
@deftypefn {Function} bfd_error_type bfd_get_error (void); 
Return the current BFD error condition.

@end deftypefn
@findex bfd_set_error
@subsubsection @code{bfd_set_error}
@deftypefn {Function} void bfd_set_error (bfd_error_type error_tag); 
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.

@end deftypefn
@findex bfd_set_input_error
@subsubsection @code{bfd_set_input_error}
@deftypefn {Function} void bfd_set_input_error (bfd *input, bfd_error_type error_tag); 
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.

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

@end deftypefn
@findex bfd_perror
@subsubsection @code{bfd_perror}
@deftypefn {Function} void bfd_perror (const char *message); 
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.

@end deftypefn
@findex bfd_asprintf
@subsubsection @code{bfd_asprintf}
@deftypefn {Function} char *bfd_asprintf (const char *fmt, ...); 
Primarily for error reporting, this function is like
libiberty's xasprintf except that it can return NULL on no
memory and the returned string should not be freed.  Uses a
thread-local malloc'd buffer managed by libbfd, _bfd_error_buf.
Be aware that a call to this function frees the result of any
previous call.  bfd_errmsg (bfd_error_on_input) also calls
this function.

@end deftypefn
@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

@example
typedef int (*bfd_print_callback) (void *, const char *, ...);
@end example
@findex bfd_print_error
@subsubsection @code{bfd_print_error}
@deftypefn {Function} void bfd_print_error (bfd_print_callback print_func, void *stream, const char *fmt, va_list ap); 
This formats FMT and AP according to BFD "printf" rules,
sending the output to STREAM by repeated calls to PRINT_FUNC.
PRINT_FUNC is a printf-like function; it does not need to
implement the BFD printf format extensions.  This can be used
in a callback that is set via bfd_set_error_handler to turn
the error into ordinary output.

@end deftypefn
@findex _bfd_error_handler
@subsubsection @code{_bfd_error_handler}
@deftypefn {Function} void _bfd_error_handler (const char *fmt, ...) ATTRIBUTE_PRINTF_1; 
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.

@end deftypefn
@findex bfd_set_error_handler
@subsubsection @code{bfd_set_error_handler}
@deftypefn {Function} bfd_error_handler_type bfd_set_error_handler (bfd_error_handler_type); 
Set the BFD error handler function.  Returns the previous
function.

@end deftypefn
@findex _bfd_set_error_handler_caching
@subsubsection @code{_bfd_set_error_handler_caching}
@deftypefn {Function} struct per_xvec_messages *_bfd_set_error_handler_caching (struct per_xvec_messages *); 
Set the BFD error handler function to one that stores messages
to the per_xvec_messages object.  Returns the previous object
to which messages are stored.  Note that two sequential calls
to this with a non-NULL argument will cause output to be
dropped, rather than gathered.

@end deftypefn
@findex _bfd_restore_error_handler_caching
@subsubsection @code{_bfd_restore_error_handler_caching}
@deftypefn {Function} void _bfd_restore_error_handler_caching (struct per_xvec_messages *); 
Reset the BFD error handler object to an earlier value.

@end deftypefn
@findex bfd_set_error_program_name
@subsubsection @code{bfd_set_error_program_name}
@deftypefn {Function} void bfd_set_error_program_name (const char *); 
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.

@end deftypefn
@findex _bfd_get_error_program_name
@subsubsection @code{_bfd_get_error_program_name}
@deftypefn {Function} const char *_bfd_get_error_program_name (void); 
Get the program name used when printing a BFD error.

@end deftypefn
@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}
@deftypefn {Function} bfd_assert_handler_type bfd_set_assert_handler (bfd_assert_handler_type); 
Set the BFD assert handler function.  Returns the previous
function.

@end deftypefn
@node Initialization, Threading, Error reporting, BFD front end
@findex bfd_init
@subsubsection @code{bfd_init}
@deftypefn {Function} unsigned int bfd_init (void); 
This routine must be called before any other BFD function to
initialize magical internal data structures.
Returns a magic number, which may be used to check
that the bfd library is configured as expected by users.
@example
/* Value returned by bfd_init.  */
#define BFD_INIT_MAGIC (sizeof (struct bfd_section))

@end example

@end deftypefn
@node Threading, Miscellaneous, Initialization, BFD front end
@section Threading
BFD has limited support for thread-safety.  Most BFD globals
are protected by locks, while the error-related globals are
thread-local.  A given BFD cannot safely be used from two
threads at the same time; it is up to the application to do
any needed locking.  However, it is ok for different threads
to work on different BFD objects at the same time.

@subsection Thread functions.



@example
typedef bool (*bfd_lock_unlock_fn_type) (void *);
@end example
@findex _bfd_threading_enabled
@subsubsection @code{_bfd_threading_enabled}
@deftypefn {Function} bool _bfd_threading_enabled (void); 
Return true if threading is enabled, false if not.

@end deftypefn
@findex bfd_thread_init
@subsubsection @code{bfd_thread_init}
@deftypefn {Function} bool bfd_thread_init (bfd_lock_unlock_fn_type lock, bfd_lock_unlock_fn_type unlock, void *data); 
Initialize BFD threading.  The functions passed in will be
used to lock and unlock global data structures.  This may only
be called a single time in a given process.  Returns true on
success and false on error.  On error, the caller should
assume that BFD cannot be used by multiple threads.  DATA is
passed verbatim to the lock and unlock functions.  The lock
and unlock functions should return true on success, or set the
BFD error and return false on failure.  Note also that the
lock must be a recursive lock: BFD may attempt to acquire the
lock when it is already held by the current thread.

@end deftypefn
@findex bfd_thread_cleanup
@subsubsection @code{bfd_thread_cleanup}
@deftypefn {Function} void bfd_thread_cleanup (void); 
Clean up any thread-local state.  This should be called by a
thread that uses any BFD functions, before the thread exits.
It is fine to call this multiple times, or to call it and then
later call BFD functions on the same thread again.

@end deftypefn
@findex bfd_lock
@subsubsection @code{bfd_lock}
@deftypefn {Function} bool bfd_lock (void); 
Acquire the global BFD lock, if needed.  Returns true on
success, false on error.

@end deftypefn
@findex bfd_unlock
@subsubsection @code{bfd_unlock}
@deftypefn {Function} bool bfd_unlock (void); 
Release the global BFD lock, if needed.  Returns true on
success, false on error.

@end deftypefn
@node Miscellaneous, Memory Usage, Threading, BFD front end
@section Miscellaneous


@subsection Miscellaneous functions


@findex bfd_get_reloc_upper_bound
@subsubsection @code{bfd_get_reloc_upper_bound}
@deftypefn {Function} long bfd_get_reloc_upper_bound (bfd *abfd, asection *sect); 
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.

@end deftypefn
@findex bfd_canonicalize_reloc
@subsubsection @code{bfd_canonicalize_reloc}
@deftypefn {Function} long bfd_canonicalize_reloc (bfd *abfd, asection *sec, arelent **loc, asymbol **syms); 
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.

@end deftypefn
@findex bfd_set_reloc
@subsubsection @code{bfd_set_reloc}
@deftypefn {Function} void bfd_set_reloc (bfd *abfd, asection *sec, arelent **rel, unsigned int count); 
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

@end deftypefn
@findex bfd_set_file_flags
@subsubsection @code{bfd_set_file_flags}
@deftypefn {Function} bool bfd_set_file_flags (bfd *abfd, flagword flags); 
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

@end deftypefn
@findex bfd_get_arch_size
@subsubsection @code{bfd_get_arch_size}
@deftypefn {Function} int bfd_get_arch_size (bfd *abfd); 
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.

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

@end deftypefn
@findex bfd_get_sign_extend_vma
@subsubsection @code{bfd_get_sign_extend_vma}
@deftypefn {Function} int bfd_get_sign_extend_vma (bfd *abfd); 
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.

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.

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

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

@end deftypefn
@findex bfd_get_gp_size
@subsubsection @code{bfd_get_gp_size}
@deftypefn {Function} unsigned int bfd_get_gp_size (bfd *abfd); 
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.

@end deftypefn
@findex bfd_set_gp_size
@subsubsection @code{bfd_set_gp_size}
@deftypefn {Function} void bfd_set_gp_size (bfd *abfd, unsigned int i); 
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.

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

@end deftypefn
@findex bfd_scan_vma
@subsubsection @code{bfd_scan_vma}
@deftypefn {Function} bfd_vma bfd_scan_vma (const char *string, const char **end, int base); 
Convert, like @code{strtoul} or @code{stdtoull}depending on the size
of a @code{bfd_vma}, a numerical expression @var{string} into a
@code{bfd_vma} integer, and return that integer.

@end deftypefn
@findex bfd_copy_private_header_data
@subsubsection @code{bfd_copy_private_header_data}
@deftypefn {Function} bool bfd_copy_private_header_data (bfd *ibfd, bfd *obfd); 
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

@end deftypefn
@findex bfd_copy_private_bfd_data
@subsubsection @code{bfd_copy_private_bfd_data}
@deftypefn {Function} bool bfd_copy_private_bfd_data (bfd *ibfd, bfd *obfd); 
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

@end deftypefn
@findex bfd_set_private_flags
@subsubsection @code{bfd_set_private_flags}
@deftypefn {Function} bool bfd_set_private_flags (bfd *abfd, flagword flags); 
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

@end deftypefn
@findex Other functions
@subsubsection @code{Other functions}
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_with_alt(abfd, alt_filename, sec, syms, off, \
                                       file, func, line, disc) \
       BFD_SEND (abfd, _bfd_find_nearest_line_with_alt, \
                 (abfd, alt_filename, syms, sec, off, file, func, line, disc))

#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))

@end example

@findex bfd_get_relocated_section_contents
@subsubsection @code{bfd_get_relocated_section_contents}
@deftypefn {Function} bfd_byte *bfd_get_relocated_section_contents (bfd *, struct bfd_link_info *, struct bfd_link_order *, bfd_byte *, bool, asymbol **); 
Read and relocate the indirect link_order section, into DATA
(if non-NULL) or to a malloc'd buffer.  Return the buffer, or
NULL on errors.

@end deftypefn
@findex bfd_record_phdr
@subsubsection @code{bfd_record_phdr}
@deftypefn {Function} bool bfd_record_phdr (bfd *, unsigned long, bool, flagword, bool, bfd_vma, bool, bool, unsigned int, struct bfd_section **); 
Record information about an ELF program header.

@end deftypefn
@findex bfd_sprintf_vma
@subsubsection @code{bfd_sprintf_vma}
@deftypefn {Function} void bfd_sprintf_vma (bfd *, char *, bfd_vma); void bfd_fprintf_vma (bfd *, void *, bfd_vma); 
bfd_sprintf_vma and bfd_fprintf_vma display an address in the
target's address size.

@end deftypefn
@findex bfd_alt_mach_code
@subsubsection @code{bfd_alt_mach_code}
@deftypefn {Function} bool bfd_alt_mach_code (bfd *abfd, int alternative); 
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.

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

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

@end deftypefn
@findex bfd_demangle
@subsubsection @code{bfd_demangle}
@deftypefn {Function} char *bfd_demangle (bfd *, const char *, int); 
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.

@end deftypefn
@findex bfd_group_signature
@subsubsection @code{bfd_group_signature}
@deftypefn {Function} asymbol *bfd_group_signature (asection *group, asymbol **isympp); 
Return a pointer to the symbol used as a signature for GROUP.

@end deftypefn
