1@section Targets
2
3
4@strong{Description}@*
5Each port of BFD to a different machine requires the creation
6of a target back end. All the back end provides to the root
7part of BFD is a structure containing pointers to functions
8which perform certain low level operations on files. BFD
9translates the applications's requests through a pointer into
10calls to the back end routines.
11
12When a file is opened with @code{bfd_openr}, its format and
13target are unknown. BFD uses various mechanisms to determine
14how to interpret the file. The operations performed are:
15
16@itemize @bullet
17
18@item
19Create a BFD by calling the internal routine
20@code{_bfd_new_bfd}, then call @code{bfd_find_target} with the
21target string supplied to @code{bfd_openr} and the new BFD pointer.
22
23@item
24If a null target string was provided to @code{bfd_find_target},
25look up the environment variable @code{GNUTARGET} and use
26that as the target string.
27
28@item
29If the target string is still @code{NULL}, or the target string is
30@code{default}, then use the first item in the target vector
31as the target type, and set @code{target_defaulted} in the BFD to
32cause @code{bfd_check_format} to loop through all the targets.
33@xref{bfd_target}.  @xref{Formats}.
34
35@item
36Otherwise, inspect the elements in the target vector
37one by one, until a match on target name is found. When found,
38use it.
39
40@item
41Otherwise return the error @code{bfd_error_invalid_target} to
42@code{bfd_openr}.
43
44@item
45@code{bfd_openr} attempts to open the file using
46@code{bfd_open_file}, and returns the BFD.
47@end itemize
48Once the BFD has been opened and the target selected, the file
49format may be determined. This is done by calling
50@code{bfd_check_format} on the BFD with a suggested format.
51If @code{target_defaulted} has been set, each possible target
52type is tried to see if it recognizes the specified format.
53@code{bfd_check_format} returns @code{TRUE} when the caller guesses right.
54@menu
55* bfd_target::
56@end menu
57
58@node bfd_target,  , Targets, Targets
59
60@subsection bfd_target
61
62
63@strong{Description}@*
64This structure contains everything that BFD knows about a
65target. It includes things like its byte order, name, and which
66routines to call to do various operations.
67
68Every BFD points to a target structure with its @code{xvec}
69member.
70
71The macros below are used to dispatch to functions through the
72@code{bfd_target} vector. They are used in a number of macros further
73down in @file{bfd.h}, and are also used when calling various
74routines by hand inside the BFD implementation.  The @var{arglist}
75argument must be parenthesized; it contains all the arguments
76to the called function.
77
78They make the documentation (more) unpleasant to read, so if
79someone wants to fix this and not break the above, please do.
80@example
81#define BFD_SEND(bfd, message, arglist) \
82  ((*((bfd)->xvec->message)) arglist)
83
84#ifdef DEBUG_BFD_SEND
85#undef BFD_SEND
86#define BFD_SEND(bfd, message, arglist) \
87  (((bfd) && (bfd)->xvec && (bfd)->xvec->message) ? \
88    ((*((bfd)->xvec->message)) arglist) : \
89    (bfd_assert (__FILE__,__LINE__), NULL))
90#endif
91@end example
92For operations which index on the BFD format:
93@example
94#define BFD_SEND_FMT(bfd, message, arglist) \
95  (((bfd)->xvec->message[(int) ((bfd)->format)]) arglist)
96
97#ifdef DEBUG_BFD_SEND
98#undef BFD_SEND_FMT
99#define BFD_SEND_FMT(bfd, message, arglist) \
100  (((bfd) && (bfd)->xvec && (bfd)->xvec->message) ? \
101   (((bfd)->xvec->message[(int) ((bfd)->format)]) arglist) : \
102   (bfd_assert (__FILE__,__LINE__), NULL))
103#endif
104
105@end example
106This is the structure which defines the type of BFD this is.  The
107@code{xvec} member of the struct @code{bfd} itself points here.  Each
108module that implements access to a different target under BFD,
109defines one of these.
110
111FIXME, these names should be rationalised with the names of
112the entry points which call them. Too bad we can't have one
113macro to define them both!
114@example
115enum bfd_flavour
116@{
117  bfd_target_unknown_flavour,
118  bfd_target_aout_flavour,
119  bfd_target_coff_flavour,
120  bfd_target_ecoff_flavour,
121  bfd_target_xcoff_flavour,
122  bfd_target_elf_flavour,
123  bfd_target_ieee_flavour,
124  bfd_target_nlm_flavour,
125  bfd_target_oasys_flavour,
126  bfd_target_tekhex_flavour,
127  bfd_target_srec_flavour,
128  bfd_target_verilog_flavour,
129  bfd_target_ihex_flavour,
130  bfd_target_som_flavour,
131  bfd_target_os9k_flavour,
132  bfd_target_versados_flavour,
133  bfd_target_msdos_flavour,
134  bfd_target_ovax_flavour,
135  bfd_target_evax_flavour,
136  bfd_target_mmo_flavour,
137  bfd_target_mach_o_flavour,
138  bfd_target_pef_flavour,
139  bfd_target_pef_xlib_flavour,
140  bfd_target_sym_flavour
141@};
142
143enum bfd_endian @{ BFD_ENDIAN_BIG, BFD_ENDIAN_LITTLE, BFD_ENDIAN_UNKNOWN @};
144
145/* Forward declaration.  */
146typedef struct bfd_link_info _bfd_link_info;
147
148/* Forward declaration.  */
149typedef struct flag_info flag_info;
150
151typedef struct bfd_target
152@{
153  /* Identifies the kind of target, e.g., SunOS4, Ultrix, etc.  */
154  char *name;
155
156 /* The "flavour" of a back end is a general indication about
157    the contents of a file.  */
158  enum bfd_flavour flavour;
159
160  /* The order of bytes within the data area of a file.  */
161  enum bfd_endian byteorder;
162
163 /* The order of bytes within the header parts of a file.  */
164  enum bfd_endian header_byteorder;
165
166  /* A mask of all the flags which an executable may have set -
167     from the set @code{BFD_NO_FLAGS}, @code{HAS_RELOC}, ...@code{D_PAGED}.  */
168  flagword object_flags;
169
170 /* A mask of all the flags which a section may have set - from
171    the set @code{SEC_NO_FLAGS}, @code{SEC_ALLOC}, ...@code{SET_NEVER_LOAD}.  */
172  flagword section_flags;
173
174 /* The character normally found at the front of a symbol.
175    (if any), perhaps `_'.  */
176  char symbol_leading_char;
177
178 /* The pad character for file names within an archive header.  */
179  char ar_pad_char;
180
181  /* The maximum number of characters in an archive header.  */
182  unsigned char ar_max_namelen;
183
184  /* How well this target matches, used to select between various
185     possible targets when more than one target matches.  */
186  unsigned char match_priority;
187
188  /* Entries for byte swapping for data. These are different from the
189     other entry points, since they don't take a BFD as the first argument.
190     Certain other handlers could do the same.  */
191  bfd_uint64_t   (*bfd_getx64) (const void *);
192  bfd_int64_t    (*bfd_getx_signed_64) (const void *);
193  void           (*bfd_putx64) (bfd_uint64_t, void *);
194  bfd_vma        (*bfd_getx32) (const void *);
195  bfd_signed_vma (*bfd_getx_signed_32) (const void *);
196  void           (*bfd_putx32) (bfd_vma, void *);
197  bfd_vma        (*bfd_getx16) (const void *);
198  bfd_signed_vma (*bfd_getx_signed_16) (const void *);
199  void           (*bfd_putx16) (bfd_vma, void *);
200
201  /* Byte swapping for the headers.  */
202  bfd_uint64_t   (*bfd_h_getx64) (const void *);
203  bfd_int64_t    (*bfd_h_getx_signed_64) (const void *);
204  void           (*bfd_h_putx64) (bfd_uint64_t, void *);
205  bfd_vma        (*bfd_h_getx32) (const void *);
206  bfd_signed_vma (*bfd_h_getx_signed_32) (const void *);
207  void           (*bfd_h_putx32) (bfd_vma, void *);
208  bfd_vma        (*bfd_h_getx16) (const void *);
209  bfd_signed_vma (*bfd_h_getx_signed_16) (const void *);
210  void           (*bfd_h_putx16) (bfd_vma, void *);
211
212  /* Format dependent routines: these are vectors of entry points
213     within the target vector structure, one for each format to check.  */
214
215  /* Check the format of a file being read.  Return a @code{bfd_target *} or zero.  */
216  const struct bfd_target *(*_bfd_check_format[bfd_type_end]) (bfd *);
217
218  /* Set the format of a file being written.  */
219  bfd_boolean (*_bfd_set_format[bfd_type_end]) (bfd *);
220
221  /* Write cached information into a file being written, at @code{bfd_close}.  */
222  bfd_boolean (*_bfd_write_contents[bfd_type_end]) (bfd *);
223
224@end example
225The general target vector.  These vectors are initialized using the
226BFD_JUMP_TABLE macros.
227@example
228
229  /* Generic entry points.  */
230#define BFD_JUMP_TABLE_GENERIC(NAME) \
231  NAME##_close_and_cleanup, \
232  NAME##_bfd_free_cached_info, \
233  NAME##_new_section_hook, \
234  NAME##_get_section_contents, \
235  NAME##_get_section_contents_in_window
236
237  /* Called when the BFD is being closed to do any necessary cleanup.  */
238  bfd_boolean (*_close_and_cleanup) (bfd *);
239  /* Ask the BFD to free all cached information.  */
240  bfd_boolean (*_bfd_free_cached_info) (bfd *);
241  /* Called when a new section is created.  */
242  bfd_boolean (*_new_section_hook) (bfd *, sec_ptr);
243  /* Read the contents of a section.  */
244  bfd_boolean (*_bfd_get_section_contents)
245    (bfd *, sec_ptr, void *, file_ptr, bfd_size_type);
246  bfd_boolean (*_bfd_get_section_contents_in_window)
247    (bfd *, sec_ptr, bfd_window *, file_ptr, bfd_size_type);
248
249  /* Entry points to copy private data.  */
250#define BFD_JUMP_TABLE_COPY(NAME) \
251  NAME##_bfd_copy_private_bfd_data, \
252  NAME##_bfd_merge_private_bfd_data, \
253  _bfd_generic_init_private_section_data, \
254  NAME##_bfd_copy_private_section_data, \
255  NAME##_bfd_copy_private_symbol_data, \
256  NAME##_bfd_copy_private_header_data, \
257  NAME##_bfd_set_private_flags, \
258  NAME##_bfd_print_private_bfd_data
259
260  /* Called to copy BFD general private data from one object file
261     to another.  */
262  bfd_boolean (*_bfd_copy_private_bfd_data) (bfd *, bfd *);
263  /* Called to merge BFD general private data from one object file
264     to a common output file when linking.  */
265  bfd_boolean (*_bfd_merge_private_bfd_data) (bfd *, bfd *);
266  /* Called to initialize BFD private section data from one object file
267     to another.  */
268#define bfd_init_private_section_data(ibfd, isec, obfd, osec, link_info) \
269  BFD_SEND (obfd, _bfd_init_private_section_data, (ibfd, isec, obfd, osec, link_info))
270  bfd_boolean (*_bfd_init_private_section_data)
271    (bfd *, sec_ptr, bfd *, sec_ptr, struct bfd_link_info *);
272  /* Called to copy BFD private section data from one object file
273     to another.  */
274  bfd_boolean (*_bfd_copy_private_section_data)
275    (bfd *, sec_ptr, bfd *, sec_ptr);
276  /* Called to copy BFD private symbol data from one symbol
277     to another.  */
278  bfd_boolean (*_bfd_copy_private_symbol_data)
279    (bfd *, asymbol *, bfd *, asymbol *);
280  /* Called to copy BFD private header data from one object file
281     to another.  */
282  bfd_boolean (*_bfd_copy_private_header_data)
283    (bfd *, bfd *);
284  /* Called to set private backend flags.  */
285  bfd_boolean (*_bfd_set_private_flags) (bfd *, flagword);
286
287  /* Called to print private BFD data.  */
288  bfd_boolean (*_bfd_print_private_bfd_data) (bfd *, void *);
289
290  /* Core file entry points.  */
291#define BFD_JUMP_TABLE_CORE(NAME) \
292  NAME##_core_file_failing_command, \
293  NAME##_core_file_failing_signal, \
294  NAME##_core_file_matches_executable_p, \
295  NAME##_core_file_pid
296
297  char *      (*_core_file_failing_command) (bfd *);
298  int         (*_core_file_failing_signal) (bfd *);
299  bfd_boolean (*_core_file_matches_executable_p) (bfd *, bfd *);
300  int         (*_core_file_pid) (bfd *);
301
302  /* Archive entry points.  */
303#define BFD_JUMP_TABLE_ARCHIVE(NAME) \
304  NAME##_slurp_armap, \
305  NAME##_slurp_extended_name_table, \
306  NAME##_construct_extended_name_table, \
307  NAME##_truncate_arname, \
308  NAME##_write_armap, \
309  NAME##_read_ar_hdr, \
310  NAME##_write_ar_hdr, \
311  NAME##_openr_next_archived_file, \
312  NAME##_get_elt_at_index, \
313  NAME##_generic_stat_arch_elt, \
314  NAME##_update_armap_timestamp
315
316  bfd_boolean (*_bfd_slurp_armap) (bfd *);
317  bfd_boolean (*_bfd_slurp_extended_name_table) (bfd *);
318  bfd_boolean (*_bfd_construct_extended_name_table)
319    (bfd *, char **, bfd_size_type *, const char **);
320  void        (*_bfd_truncate_arname) (bfd *, const char *, char *);
321  bfd_boolean (*write_armap)
322    (bfd *, unsigned int, struct orl *, unsigned int, int);
323  void *      (*_bfd_read_ar_hdr_fn) (bfd *);
324  bfd_boolean (*_bfd_write_ar_hdr_fn) (bfd *, bfd *);
325  bfd *       (*openr_next_archived_file) (bfd *, bfd *);
326#define bfd_get_elt_at_index(b,i) BFD_SEND (b, _bfd_get_elt_at_index, (b,i))
327  bfd *       (*_bfd_get_elt_at_index) (bfd *, symindex);
328  int         (*_bfd_stat_arch_elt) (bfd *, struct stat *);
329  bfd_boolean (*_bfd_update_armap_timestamp) (bfd *);
330
331  /* Entry points used for symbols.  */
332#define BFD_JUMP_TABLE_SYMBOLS(NAME) \
333  NAME##_get_symtab_upper_bound, \
334  NAME##_canonicalize_symtab, \
335  NAME##_make_empty_symbol, \
336  NAME##_print_symbol, \
337  NAME##_get_symbol_info, \
338  NAME##_bfd_is_local_label_name, \
339  NAME##_bfd_is_target_special_symbol, \
340  NAME##_get_lineno, \
341  NAME##_find_nearest_line, \
342  _bfd_generic_find_nearest_line_discriminator, \
343  _bfd_generic_find_line, \
344  NAME##_find_inliner_info, \
345  NAME##_bfd_make_debug_symbol, \
346  NAME##_read_minisymbols, \
347  NAME##_minisymbol_to_symbol
348
349  long        (*_bfd_get_symtab_upper_bound) (bfd *);
350  long        (*_bfd_canonicalize_symtab)
351    (bfd *, struct bfd_symbol **);
352  struct bfd_symbol *
353              (*_bfd_make_empty_symbol) (bfd *);
354  void        (*_bfd_print_symbol)
355    (bfd *, void *, struct bfd_symbol *, bfd_print_symbol_type);
356#define bfd_print_symbol(b,p,s,e) BFD_SEND (b, _bfd_print_symbol, (b,p,s,e))
357  void        (*_bfd_get_symbol_info)
358    (bfd *, struct bfd_symbol *, symbol_info *);
359#define bfd_get_symbol_info(b,p,e) BFD_SEND (b, _bfd_get_symbol_info, (b,p,e))
360  bfd_boolean (*_bfd_is_local_label_name) (bfd *, const char *);
361  bfd_boolean (*_bfd_is_target_special_symbol) (bfd *, asymbol *);
362  alent *     (*_get_lineno) (bfd *, struct bfd_symbol *);
363  bfd_boolean (*_bfd_find_nearest_line)
364    (bfd *, struct bfd_section *, struct bfd_symbol **, bfd_vma,
365     const char **, const char **, unsigned int *);
366  bfd_boolean (*_bfd_find_nearest_line_discriminator)
367    (bfd *, struct bfd_section *, struct bfd_symbol **, bfd_vma,
368     const char **, const char **, unsigned int *, unsigned int *);
369  bfd_boolean (*_bfd_find_line)
370    (bfd *, struct bfd_symbol **, struct bfd_symbol *,
371     const char **, unsigned int *);
372  bfd_boolean (*_bfd_find_inliner_info)
373    (bfd *, const char **, const char **, unsigned int *);
374 /* Back-door to allow format-aware applications to create debug symbols
375    while using BFD for everything else.  Currently used by the assembler
376    when creating COFF files.  */
377  asymbol *   (*_bfd_make_debug_symbol)
378    (bfd *, void *, unsigned long size);
379#define bfd_read_minisymbols(b, d, m, s) \
380  BFD_SEND (b, _read_minisymbols, (b, d, m, s))
381  long        (*_read_minisymbols)
382    (bfd *, bfd_boolean, void **, unsigned int *);
383#define bfd_minisymbol_to_symbol(b, d, m, f) \
384  BFD_SEND (b, _minisymbol_to_symbol, (b, d, m, f))
385  asymbol *   (*_minisymbol_to_symbol)
386    (bfd *, bfd_boolean, const void *, asymbol *);
387
388  /* Routines for relocs.  */
389#define BFD_JUMP_TABLE_RELOCS(NAME) \
390  NAME##_get_reloc_upper_bound, \
391  NAME##_canonicalize_reloc, \
392  NAME##_bfd_reloc_type_lookup, \
393  NAME##_bfd_reloc_name_lookup
394
395  long        (*_get_reloc_upper_bound) (bfd *, sec_ptr);
396  long        (*_bfd_canonicalize_reloc)
397    (bfd *, sec_ptr, arelent **, struct bfd_symbol **);
398  /* See documentation on reloc types.  */
399  reloc_howto_type *
400              (*reloc_type_lookup) (bfd *, bfd_reloc_code_real_type);
401  reloc_howto_type *
402              (*reloc_name_lookup) (bfd *, const char *);
403
404
405  /* Routines used when writing an object file.  */
406#define BFD_JUMP_TABLE_WRITE(NAME) \
407  NAME##_set_arch_mach, \
408  NAME##_set_section_contents
409
410  bfd_boolean (*_bfd_set_arch_mach)
411    (bfd *, enum bfd_architecture, unsigned long);
412  bfd_boolean (*_bfd_set_section_contents)
413    (bfd *, sec_ptr, const void *, file_ptr, bfd_size_type);
414
415  /* Routines used by the linker.  */
416#define BFD_JUMP_TABLE_LINK(NAME) \
417  NAME##_sizeof_headers, \
418  NAME##_bfd_get_relocated_section_contents, \
419  NAME##_bfd_relax_section, \
420  NAME##_bfd_link_hash_table_create, \
421  NAME##_bfd_link_hash_table_free, \
422  NAME##_bfd_link_add_symbols, \
423  NAME##_bfd_link_just_syms, \
424  NAME##_bfd_copy_link_hash_symbol_type, \
425  NAME##_bfd_final_link, \
426  NAME##_bfd_link_split_section, \
427  NAME##_bfd_gc_sections, \
428  NAME##_bfd_lookup_section_flags, \
429  NAME##_bfd_merge_sections, \
430  NAME##_bfd_is_group_section, \
431  NAME##_bfd_discard_group, \
432  NAME##_section_already_linked, \
433  NAME##_bfd_define_common_symbol
434
435  int         (*_bfd_sizeof_headers) (bfd *, struct bfd_link_info *);
436  bfd_byte *  (*_bfd_get_relocated_section_contents)
437    (bfd *, struct bfd_link_info *, struct bfd_link_order *,
438     bfd_byte *, bfd_boolean, struct bfd_symbol **);
439
440  bfd_boolean (*_bfd_relax_section)
441    (bfd *, struct bfd_section *, struct bfd_link_info *, bfd_boolean *);
442
443  /* Create a hash table for the linker.  Different backends store
444     different information in this table.  */
445  struct bfd_link_hash_table *
446              (*_bfd_link_hash_table_create) (bfd *);
447
448  /* Release the memory associated with the linker hash table.  */
449  void        (*_bfd_link_hash_table_free) (struct bfd_link_hash_table *);
450
451  /* Add symbols from this object file into the hash table.  */
452  bfd_boolean (*_bfd_link_add_symbols) (bfd *, struct bfd_link_info *);
453
454  /* Indicate that we are only retrieving symbol values from this section.  */
455  void        (*_bfd_link_just_syms) (asection *, struct bfd_link_info *);
456
457  /* Copy the symbol type of a linker hash table entry.  */
458#define bfd_copy_link_hash_symbol_type(b, t, f) \
459  BFD_SEND (b, _bfd_copy_link_hash_symbol_type, (b, t, f))
460  void (*_bfd_copy_link_hash_symbol_type)
461    (bfd *, struct bfd_link_hash_entry *, struct bfd_link_hash_entry *);
462
463  /* Do a link based on the link_order structures attached to each
464     section of the BFD.  */
465  bfd_boolean (*_bfd_final_link) (bfd *, struct bfd_link_info *);
466
467  /* Should this section be split up into smaller pieces during linking.  */
468  bfd_boolean (*_bfd_link_split_section) (bfd *, struct bfd_section *);
469
470  /* Remove sections that are not referenced from the output.  */
471  bfd_boolean (*_bfd_gc_sections) (bfd *, struct bfd_link_info *);
472
473  /* Sets the bitmask of allowed and disallowed section flags.  */
474  bfd_boolean (*_bfd_lookup_section_flags) (struct bfd_link_info *,
475                                            struct flag_info *,
476                                            asection *);
477
478  /* Attempt to merge SEC_MERGE sections.  */
479  bfd_boolean (*_bfd_merge_sections) (bfd *, struct bfd_link_info *);
480
481  /* Is this section a member of a group?  */
482  bfd_boolean (*_bfd_is_group_section) (bfd *, const struct bfd_section *);
483
484  /* Discard members of a group.  */
485  bfd_boolean (*_bfd_discard_group) (bfd *, struct bfd_section *);
486
487  /* Check if SEC has been already linked during a reloceatable or
488     final link.  */
489  bfd_boolean (*_section_already_linked) (bfd *, asection *,
490                                          struct bfd_link_info *);
491
492  /* Define a common symbol.  */
493  bfd_boolean (*_bfd_define_common_symbol) (bfd *, struct bfd_link_info *,
494                                            struct bfd_link_hash_entry *);
495
496  /* Routines to handle dynamic symbols and relocs.  */
497#define BFD_JUMP_TABLE_DYNAMIC(NAME) \
498  NAME##_get_dynamic_symtab_upper_bound, \
499  NAME##_canonicalize_dynamic_symtab, \
500  NAME##_get_synthetic_symtab, \
501  NAME##_get_dynamic_reloc_upper_bound, \
502  NAME##_canonicalize_dynamic_reloc
503
504  /* Get the amount of memory required to hold the dynamic symbols.  */
505  long        (*_bfd_get_dynamic_symtab_upper_bound) (bfd *);
506  /* Read in the dynamic symbols.  */
507  long        (*_bfd_canonicalize_dynamic_symtab)
508    (bfd *, struct bfd_symbol **);
509  /* Create synthetized symbols.  */
510  long        (*_bfd_get_synthetic_symtab)
511    (bfd *, long, struct bfd_symbol **, long, struct bfd_symbol **,
512     struct bfd_symbol **);
513  /* Get the amount of memory required to hold the dynamic relocs.  */
514  long        (*_bfd_get_dynamic_reloc_upper_bound) (bfd *);
515  /* Read in the dynamic relocs.  */
516  long        (*_bfd_canonicalize_dynamic_reloc)
517    (bfd *, arelent **, struct bfd_symbol **);
518
519@end example
520A pointer to an alternative bfd_target in case the current one is not
521satisfactory.  This can happen when the target cpu supports both big
522and little endian code, and target chosen by the linker has the wrong
523endianness.  The function open_output() in ld/ldlang.c uses this field
524to find an alternative output format that is suitable.
525@example
526  /* Opposite endian version of this target.  */
527  const struct bfd_target * alternative_target;
528
529  /* Data for use by back-end routines, which isn't
530     generic enough to belong in this structure.  */
531  const void *backend_data;
532
533@} bfd_target;
534
535@end example
536
537@findex bfd_set_default_target
538@subsubsection @code{bfd_set_default_target}
539@strong{Synopsis}
540@example
541bfd_boolean bfd_set_default_target (const char *name);
542@end example
543@strong{Description}@*
544Set the default target vector to use when recognizing a BFD.
545This takes the name of the target, which may be a BFD target
546name or a configuration triplet.
547
548@findex bfd_find_target
549@subsubsection @code{bfd_find_target}
550@strong{Synopsis}
551@example
552const bfd_target *bfd_find_target (const char *target_name, bfd *abfd);
553@end example
554@strong{Description}@*
555Return a pointer to the transfer vector for the object target
556named @var{target_name}.  If @var{target_name} is @code{NULL},
557choose the one in the environment variable @code{GNUTARGET}; if
558that is null or not defined, then choose the first entry in the
559target list.  Passing in the string "default" or setting the
560environment variable to "default" will cause the first entry in
561the target list to be returned, and "target_defaulted" will be
562set in the BFD if @var{abfd} isn't @code{NULL}.  This causes
563@code{bfd_check_format} to loop over all the targets to find the
564one that matches the file being read.
565
566@findex bfd_get_target_info
567@subsubsection @code{bfd_get_target_info}
568@strong{Synopsis}
569@example
570const bfd_target *bfd_get_target_info (const char *target_name,
571    bfd *abfd,
572    bfd_boolean *is_bigendian,
573    int *underscoring,
574    const char **def_target_arch);
575@end example
576@strong{Description}@*
577Return a pointer to the transfer vector for the object target
578named @var{target_name}.  If @var{target_name} is @code{NULL},
579choose the one in the environment variable @code{GNUTARGET}; if
580that is null or not defined, then choose the first entry in the
581target list.  Passing in the string "default" or setting the
582environment variable to "default" will cause the first entry in
583the target list to be returned, and "target_defaulted" will be
584set in the BFD if @var{abfd} isn't @code{NULL}.  This causes
585@code{bfd_check_format} to loop over all the targets to find the
586one that matches the file being read.
587If @var{is_bigendian} is not @code{NULL}, then set this value to target's
588endian mode. True for big-endian, FALSE for little-endian or for
589invalid target.
590If @var{underscoring} is not @code{NULL}, then set this value to target's
591underscoring mode. Zero for none-underscoring, -1 for invalid target,
592else the value of target vector's symbol underscoring.
593If @var{def_target_arch} is not @code{NULL}, then set it to the architecture
594string specified by the target_name.
595
596@findex bfd_target_list
597@subsubsection @code{bfd_target_list}
598@strong{Synopsis}
599@example
600const char ** bfd_target_list (void);
601@end example
602@strong{Description}@*
603Return a freshly malloced NULL-terminated
604vector of the names of all the valid BFD targets. Do not
605modify the names.
606
607@findex bfd_seach_for_target
608@subsubsection @code{bfd_seach_for_target}
609@strong{Synopsis}
610@example
611const bfd_target *bfd_search_for_target
612   (int (*search_func) (const bfd_target *, void *),
613    void *);
614@end example
615@strong{Description}@*
616Return a pointer to the first transfer vector in the list of
617transfer vectors maintained by BFD that produces a non-zero
618result when passed to the function @var{search_func}.  The
619parameter @var{data} is passed, unexamined, to the search
620function.
621
622