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2.1 typedef bfd

A BFD has type 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 bfd. It contains the major data about the file and pointers to the rest of the data.

 
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;

  /* To avoid dragging too many header files into every file that
     includes `bfd.h', IOSTREAM has been declared as a "char *",
     and MTIME as a "long".  Their correct types, to which they
     are cast when used, are "FILE *" and "time_t".    The iostream
     is the result of an fopen on the filename.  However, if the
     BFD_IN_MEMORY flag is set, then iostream is actually a pointer
     to a bfd_in_memory struct.  */
  PTR iostream;

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

  /* 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.  */
  boolean target_defaulted;

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

  /* When a file is closed by the caching routines, BFD retains
     state information on the file here...  */
  ufile_ptr where;

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

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

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

  /* Reserved for an unimplemented file locking extension.  */
  int ifd;

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

  /* The direction with which the BFD was opened.  */
  enum bfd_direction
    {
      no_direction = 0,
      read_direction = 1,
      write_direction = 2,
      both_direction = 3
    }
  direction;

  /* Format_specific flags.  */
  flagword flags;

  /* Currently my_archive is tested before adding origin to
     anything. I believe that this can become always an add of
     origin, with origin set to 0 for non archive files.  */
  ufile_ptr origin;

  /* Remember when output has begun, to stop strange things
     from happening.  */
  boolean output_has_begun;

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

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

  /* The place where we add to the section list.  */
  struct sec **section_tail;

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

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

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

  /* Symbol table for output BFD (with symcount entries).  */
  struct symbol_cache_entry  **outsymbols;

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

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

  /* Stuff only useful for archives.  */
  PTR arelt_data;
  struct _bfd *my_archive;     /* The containing archive BFD.  */
  struct _bfd *next;           /* The next BFD in the archive.  */
  struct _bfd *archive_head;   /* The first BFD in the archive.  */
  boolean has_armap;

  /* A chain of BFD structures involved in a link.  */
  struct _bfd *link_next;

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

  /* Used by the back end to hold private data.  */
  union
    {
      struct aout_data_struct *aout_data;
      struct artdata *aout_ar_data;
      struct _oasys_data *oasys_obj_data;
      struct _oasys_ar_data *oasys_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 ieee_data_struct *ieee_data;
      struct ieee_ar_data_struct *ieee_ar_data;
      struct srec_data_struct *srec_data;
      struct ihex_data_struct *ihex_data;
      struct tekhex_data_struct *tekhex_data;
      struct elf_obj_tdata *elf_obj_data;
      struct nlm_obj_tdata *nlm_obj_data;
      struct bout_data_struct *bout_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;
      PTR any;
    }
  tdata;

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

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


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