typedef bfd
===========

A BFD is has type bfd; objects of this type are the cornerstone of any application using libbfd. References though the BFD and to data in the BFD give the entire BFD functionality. Here is the struct used to define the type bfd.  This contains he major data about the file, and contains 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.             */
         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. */
         char *iostream;

         	/* Is the file being cached */

         boolean cacheable;

         	/* Marks whether there was a default target specified when the
            BFD was opened. This is used to select what matching algorithm
            to use to chose 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:
          */

         file_ptr where;

         	/* and here:*/

         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.*/

         bfd_format format;

         	/* The direction the BFD was opened with*/

         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.   */

         file_ptr origin;

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

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

         	/* 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*/
         struct symbol_cache_entry  **outsymbols;

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

         	/* Stuff only useful for archives:*/
         PTR arelt_data;
         struct _bfd *my_archive;
         struct _bfd *next;
         struct _bfd *archive_head;
         boolean has_armap;

         	/* 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 ieee_data_struct *ieee_data;
           struct ieee_ar_data_struct *ieee_ar_data;
           struct srec_data_struct *srec_data;
           struct elf_obj_tdata_struct *elf_obj_data;
           struct elf_core_tdata_struct *elf_core_data;
           struct bout_data_struct *bout_data;
           struct sun_core_struct *sun_core_data;
           struct trad_core_struct *trad_core_data;
           PTR any;
           } tdata;

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

         	/* Where all the allocated stuff under this BFD goes */
         struct obstack memory;

         asymbol **ld_symbols;
     };

bfd_get_reloc_upper_bound
.........................

Synopsis

     unsigned int bfd_get_reloc_upper_bound(bfd *abfd, asection *sect);

Description

This function return the number of bytes required to store the relocation information associated with section sect attached to bfd abfd

bfd_canonicalize_reloc
......................

Synopsis

     unsigned int bfd_canonicalize_reloc
        (bfd *abfd,
         asection *sec,
         arelent **loc,
         asymbol	**syms);

Description

This function calls the back end associated with the open abfd and translates the external form of the relocation information attached to sec into the internal canonical form.  The table is placed into memory at loc, which has been preallocated, usually by a call to bfd_get_reloc_upper_bound. The syms table is also needed for horrible internal magic reasons.

bfd_set_file_flags
..................

Synopsis

     boolean bfd_set_file_flags(bfd *abfd, flagword flags);

Description

This function attempts to set the flag word in the referenced BFD structure to the value supplied. Possible errors are:

  * wrong_format - The target bfd was not of object format.invalid_operation - The target bfd was open for reading.invalid_operation - The flag word contained a bit which was not applicable to the type of file. eg, an attempt was made to set the D_PAGED bit on a bfd format which does not support demand paging

bfd_set_reloc
.............

Synopsis

     void bfd_set_reloc
        (bfd *abfd, asection *sec, arelent **rel, unsigned int count)

Description

This function sets the relocation pointer and count within a section to the supplied values.

bfd_set_start_address
.....................

Description

Marks the entry point of an output BFD. Returns

Returns true on success, false otherwise. Synopsis

     boolean bfd_set_start_address(bfd *, bfd_vma);

The bfd_get_mtime function
..........................

Synopsis

     long bfd_get_mtime(bfd *);

Description

Return file modification time (as read from file system, or from archive header for archive members).

stuff
.....

Description

stuff which should be documented

     #define bfd_sizeof_headers(abfd, reloc) \
          BFD_SEND (abfd, _bfd_sizeof_headers, (abfd, reloc))

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

     #define bfd_coff_swap_aux_in(a,e,t,c,i) \
             BFD_SEND (a, _bfd_coff_swap_aux_in, (a,e,t,c,i))

     #define bfd_coff_swap_sym_in(a,e,i) \
             BFD_SEND (a, _bfd_coff_swap_sym_in, (a,e,i))

     #define bfd_coff_swap_lineno_in(a,e,i) \
             BFD_SEND ( a, _bfd_coff_swap_lineno_in, (a,e,i))

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

     #define bfd_coff_swap_reloc_out(abfd, i, o) \
             BFD_SEND (abfd, _bfd_coff_swap_reloc_out, (abfd, i, o))

     #define bfd_coff_swap_lineno_out(abfd, i, o) \
             BFD_SEND (abfd, _bfd_coff_swap_lineno_out, (abfd, i, o))

     #define bfd_coff_swap_aux_out(abfd, i, t,c,o) \
             BFD_SEND (abfd, _bfd_coff_swap_aux_out, (abfd, i,t,c, o))

     #define bfd_coff_swap_sym_out(abfd, i,o) \
             BFD_SEND (abfd, _bfd_coff_swap_sym_out, (abfd, i, o))

     #define bfd_coff_swap_scnhdr_out(abfd, i,o) \
             BFD_SEND (abfd, _bfd_coff_swap_scnhdr_out, (abfd, i, o))

     #define bfd_coff_swap_filehdr_out(abfd, i,o) \
             BFD_SEND (abfd, _bfd_coff_swap_filehdr_out, (abfd, i, o))

     #define bfd_coff_swap_aouthdr_out(abfd, i,o) \
             BFD_SEND (abfd, _bfd_coff_swap_aouthdr_out, (abfd, i, o))

     #define bfd_get_relocated_section_contents(abfd, seclet) \
     	BFD_SEND (abfd, _bfd_get_relocated_section_contents, (abfd, seclet))

     #define bfd_relax_section(abfd, section, symbols) \
            BFD_SEND (abfd, _bfd_relax_section, (abfd, section, symbols))