1 @section @code{typedef bfd}
2 A BFD has type @code{bfd}; objects of this type are the
3 cornerstone of any application using BFD. Using BFD
4 consists of making references though the BFD and to data in the BFD.
6 Here is the structure that defines the type @code{bfd}. It
7 contains the major data about the file and pointers
8 to the rest of the data.
15 /* The filename the application opened the BFD with. */
18 /* A pointer to the target jump table. */
19 const struct bfd_target *xvec;
21 /* To avoid dragging too many header files into every file that
22 includes `@code{bfd.h}', IOSTREAM has been declared as a "char *",
23 and MTIME as a "long". Their correct types, to which they
24 are cast when used, are "FILE *" and "time_t". The iostream
25 is the result of an fopen on the filename. However, if the
26 BFD_IN_MEMORY flag is set, then iostream is actually a pointer
27 to a bfd_in_memory struct. */
30 /* Is the file descriptor being cached? That is, can it be closed as
31 needed, and re-opened when accessed later? */
34 /* Marks whether there was a default target specified when the
35 BFD was opened. This is used to select which matching algorithm
36 to use to choose the back end. */
37 boolean target_defaulted;
39 /* The caching routines use these to maintain a
40 least-recently-used list of BFDs. */
41 struct _bfd *lru_prev, *lru_next;
43 /* When a file is closed by the caching routines, BFD retains
44 state information on the file here... */
47 /* ... and here: (``once'' means at least once). */
50 /* Set if we have a locally maintained mtime value, rather than
51 getting it from the file each time. */
54 /* File modified time, if mtime_set is true. */
57 /* Reserved for an unimplemented file locking extension. */
60 /* The format which belongs to the BFD. (object, core, etc.) */
63 /* The direction with which the BFD was opened. */
73 /* Format_specific flags. */
76 /* Currently my_archive is tested before adding origin to
77 anything. I believe that this can become always an add of
78 origin, with origin set to 0 for non archive files. */
81 /* Remember when output has begun, to stop strange things
83 boolean output_has_begun;
85 /* A hash table for section names. */
86 struct bfd_hash_table section_htab;
88 /* Pointer to linked list of sections. */
91 /* The place where we add to the section list. */
92 struct sec **section_tail;
94 /* The number of sections. */
95 unsigned int section_count;
97 /* Stuff only useful for object files:
99 bfd_vma start_address;
101 /* Used for input and output. */
102 unsigned int symcount;
104 /* Symbol table for output BFD (with symcount entries). */
105 struct symbol_cache_entry **outsymbols;
107 /* Pointer to structure which contains architecture information. */
108 const struct bfd_arch_info *arch_info;
110 /* Stuff only useful for archives. */
112 struct _bfd *my_archive; /* The containing archive BFD. */
113 struct _bfd *next; /* The next BFD in the archive. */
114 struct _bfd *archive_head; /* The first BFD in the archive. */
117 /* A chain of BFD structures involved in a link. */
118 struct _bfd *link_next;
120 /* A field used by _bfd_generic_link_add_archive_symbols. This will
121 be used only for archive elements. */
124 /* Used by the back end to hold private data. */
127 struct aout_data_struct *aout_data;
128 struct artdata *aout_ar_data;
129 struct _oasys_data *oasys_obj_data;
130 struct _oasys_ar_data *oasys_ar_data;
131 struct coff_tdata *coff_obj_data;
132 struct pe_tdata *pe_obj_data;
133 struct xcoff_tdata *xcoff_obj_data;
134 struct ecoff_tdata *ecoff_obj_data;
135 struct ieee_data_struct *ieee_data;
136 struct ieee_ar_data_struct *ieee_ar_data;
137 struct srec_data_struct *srec_data;
138 struct ihex_data_struct *ihex_data;
139 struct tekhex_data_struct *tekhex_data;
140 struct elf_obj_tdata *elf_obj_data;
141 struct nlm_obj_tdata *nlm_obj_data;
142 struct bout_data_struct *bout_data;
143 struct mmo_data_struct *mmo_data;
144 struct sun_core_struct *sun_core_data;
145 struct sco5_core_struct *sco5_core_data;
146 struct trad_core_struct *trad_core_data;
147 struct som_data_struct *som_data;
148 struct hpux_core_struct *hpux_core_data;
149 struct hppabsd_core_struct *hppabsd_core_data;
150 struct sgi_core_struct *sgi_core_data;
151 struct lynx_core_struct *lynx_core_data;
152 struct osf_core_struct *osf_core_data;
153 struct cisco_core_struct *cisco_core_data;
154 struct versados_data_struct *versados_data;
155 struct netbsd_core_struct *netbsd_core_data;
160 /* Used by the application to hold private data. */
163 /* Where all the allocated stuff under this BFD goes. This is a
164 struct objalloc *, but we use PTR to avoid requiring the inclusion of
170 @section Error reporting
171 Most BFD functions return nonzero on success (check their
172 individual documentation for precise semantics). On an error,
173 they call @code{bfd_set_error} to set an error condition that callers
174 can check by calling @code{bfd_get_error}.
175 If that returns @code{bfd_error_system_call}, then check
178 The easiest way to report a BFD error to the user is to
179 use @code{bfd_perror}.
181 @subsection Type @code{bfd_error_type}
182 The values returned by @code{bfd_get_error} are defined by the
183 enumerated type @code{bfd_error_type}.
188 typedef enum bfd_error
190 bfd_error_no_error = 0,
191 bfd_error_system_call,
192 bfd_error_invalid_target,
193 bfd_error_wrong_format,
194 bfd_error_wrong_object_format,
195 bfd_error_invalid_operation,
197 bfd_error_no_symbols,
199 bfd_error_no_more_archived_files,
200 bfd_error_malformed_archive,
201 bfd_error_file_not_recognized,
202 bfd_error_file_ambiguously_recognized,
203 bfd_error_no_contents,
204 bfd_error_nonrepresentable_section,
205 bfd_error_no_debug_section,
207 bfd_error_file_truncated,
208 bfd_error_file_too_big,
209 bfd_error_invalid_error_code
214 @findex bfd_get_error
215 @subsubsection @code{bfd_get_error}
218 bfd_error_type bfd_get_error (void);
220 @strong{Description}@*
221 Return the current BFD error condition.
223 @findex bfd_set_error
224 @subsubsection @code{bfd_set_error}
227 void bfd_set_error (bfd_error_type error_tag);
229 @strong{Description}@*
230 Set the BFD error condition to be @var{error_tag}.
233 @subsubsection @code{bfd_errmsg}
236 const char *bfd_errmsg (bfd_error_type error_tag);
238 @strong{Description}@*
239 Return a string describing the error @var{error_tag}, or
240 the system error if @var{error_tag} is @code{bfd_error_system_call}.
243 @subsubsection @code{bfd_perror}
246 void bfd_perror (const char *message);
248 @strong{Description}@*
249 Print to the standard error stream a string describing the
250 last BFD error that occurred, or the last system error if
251 the last BFD error was a system call failure. If @var{message}
252 is non-NULL and non-empty, the error string printed is preceded
253 by @var{message}, a colon, and a space. It is followed by a newline.
255 @subsection BFD error handler
256 Some BFD functions want to print messages describing the
257 problem. They call a BFD error handler function. This
258 function may be overriden by the program.
260 The BFD error handler acts like printf.
265 typedef void (*bfd_error_handler_type) PARAMS ((const char *, ...));
268 @findex bfd_set_error_handler
269 @subsubsection @code{bfd_set_error_handler}
272 bfd_error_handler_type bfd_set_error_handler (bfd_error_handler_type);
274 @strong{Description}@*
275 Set the BFD error handler function. Returns the previous
278 @findex bfd_set_error_program_name
279 @subsubsection @code{bfd_set_error_program_name}
282 void bfd_set_error_program_name (const char *);
284 @strong{Description}@*
285 Set the program name to use when printing a BFD error. This
286 is printed before the error message followed by a colon and
287 space. The string must not be changed after it is passed to
290 @findex bfd_get_error_handler
291 @subsubsection @code{bfd_get_error_handler}
294 bfd_error_handler_type bfd_get_error_handler (void);
296 @strong{Description}@*
297 Return the BFD error handler function.
299 @findex bfd_archive_filename
300 @subsubsection @code{bfd_archive_filename}
303 const char *bfd_archive_filename (bfd *);
305 @strong{Description}@*
306 For a BFD that is a component of an archive, returns a string
307 with both the archive name and file name. For other BFDs, just
308 returns the file name.
313 @findex bfd_get_reloc_upper_bound
314 @subsubsection @code{bfd_get_reloc_upper_bound}
317 long bfd_get_reloc_upper_bound(bfd *abfd, asection *sect);
319 @strong{Description}@*
320 Return the number of bytes required to store the
321 relocation information associated with section @var{sect}
322 attached to bfd @var{abfd}. If an error occurs, return -1.
324 @findex bfd_canonicalize_reloc
325 @subsubsection @code{bfd_canonicalize_reloc}
328 long bfd_canonicalize_reloc
334 @strong{Description}@*
335 Call the back end associated with the open BFD
336 @var{abfd} and translate the external form of the relocation
337 information attached to @var{sec} into the internal canonical
338 form. Place the table into memory at @var{loc}, which has
339 been preallocated, usually by a call to
340 @code{bfd_get_reloc_upper_bound}. Returns the number of relocs, or
343 The @var{syms} table is also needed for horrible internal magic
346 @findex bfd_set_reloc
347 @subsubsection @code{bfd_set_reloc}
351 (bfd *abfd, asection *sec, arelent **rel, unsigned int count);
353 @strong{Description}@*
354 Set the relocation pointer and count within
355 section @var{sec} to the values @var{rel} and @var{count}.
356 The argument @var{abfd} is ignored.
358 @findex bfd_set_file_flags
359 @subsubsection @code{bfd_set_file_flags}
362 boolean bfd_set_file_flags(bfd *abfd, flagword flags);
364 @strong{Description}@*
365 Set the flag word in the BFD @var{abfd} to the value @var{flags}.
371 @code{bfd_error_wrong_format} - The target bfd was not of object format.
373 @code{bfd_error_invalid_operation} - The target bfd was open for reading.
375 @code{bfd_error_invalid_operation} -
376 The flag word contained a bit which was not applicable to the
377 type of file. E.g., an attempt was made to set the @code{D_PAGED} bit
378 on a BFD format which does not support demand paging.
381 @findex bfd_get_arch_size
382 @subsubsection @code{bfd_get_arch_size}
385 int bfd_get_arch_size (bfd *abfd);
387 @strong{Description}@*
388 Returns the architecture address size, in bits, as determined
389 by the object file's format. For ELF, this information is
390 included in the header.
393 Returns the arch size in bits if known, @code{-1} otherwise.
395 @findex bfd_get_sign_extend_vma
396 @subsubsection @code{bfd_get_sign_extend_vma}
399 int bfd_get_sign_extend_vma (bfd *abfd);
401 @strong{Description}@*
402 Indicates if the target architecture "naturally" sign extends
403 an address. Some architectures implicitly sign extend address
404 values when they are converted to types larger than the size
405 of an address. For instance, bfd_get_start_address() will
406 return an address sign extended to fill a bfd_vma when this is
410 Returns @code{1} if the target architecture is known to sign
411 extend addresses, @code{0} if the target architecture is known to
412 not sign extend addresses, and @code{-1} otherwise.
414 @findex bfd_set_start_address
415 @subsubsection @code{bfd_set_start_address}
418 boolean bfd_set_start_address(bfd *abfd, bfd_vma vma);
420 @strong{Description}@*
421 Make @var{vma} the entry point of output BFD @var{abfd}.
424 Returns @code{true} on success, @code{false} otherwise.
426 @findex bfd_get_mtime
427 @subsubsection @code{bfd_get_mtime}
430 long bfd_get_mtime(bfd *abfd);
432 @strong{Description}@*
433 Return the file modification time (as read from the file system, or
434 from the archive header for archive members).
437 @subsubsection @code{bfd_get_size}
440 long bfd_get_size(bfd *abfd);
442 @strong{Description}@*
443 Return the file size (as read from file system) for the file
444 associated with BFD @var{abfd}.
446 The initial motivation for, and use of, this routine is not
447 so we can get the exact size of the object the BFD applies to, since
448 that might not be generally possible (archive members for example).
449 It would be ideal if someone could eventually modify
450 it so that such results were guaranteed.
452 Instead, we want to ask questions like "is this NNN byte sized
453 object I'm about to try read from file offset YYY reasonable?"
454 As as example of where we might do this, some object formats
455 use string tables for which the first @code{sizeof (long)} bytes of the
456 table contain the size of the table itself, including the size bytes.
457 If an application tries to read what it thinks is one of these
458 string tables, without some way to validate the size, and for
459 some reason the size is wrong (byte swapping error, wrong location
460 for the string table, etc.), the only clue is likely to be a read
461 error when it tries to read the table, or a "virtual memory
462 exhausted" error when it tries to allocate 15 bazillon bytes
463 of space for the 15 bazillon byte table it is about to read.
464 This function at least allows us to answer the quesion, "is the
467 @findex bfd_get_gp_size
468 @subsubsection @code{bfd_get_gp_size}
471 unsigned int bfd_get_gp_size(bfd *abfd);
473 @strong{Description}@*
474 Return the maximum size of objects to be optimized using the GP
475 register under MIPS ECOFF. This is typically set by the @code{-G}
476 argument to the compiler, assembler or linker.
478 @findex bfd_set_gp_size
479 @subsubsection @code{bfd_set_gp_size}
482 void bfd_set_gp_size(bfd *abfd, unsigned int i);
484 @strong{Description}@*
485 Set the maximum size of objects to be optimized using the GP
486 register under ECOFF or MIPS ELF. This is typically set by
487 the @code{-G} argument to the compiler, assembler or linker.
490 @subsubsection @code{bfd_scan_vma}
493 bfd_vma bfd_scan_vma(const char *string, const char **end, int base);
495 @strong{Description}@*
496 Convert, like @code{strtoul}, a numerical expression
497 @var{string} into a @code{bfd_vma} integer, and return that integer.
498 (Though without as many bells and whistles as @code{strtoul}.)
499 The expression is assumed to be unsigned (i.e., positive).
500 If given a @var{base}, it is used as the base for conversion.
501 A base of 0 causes the function to interpret the string
502 in hex if a leading "0x" or "0X" is found, otherwise
503 in octal if a leading zero is found, otherwise in decimal.
505 Overflow is not detected.
507 @findex bfd_copy_private_bfd_data
508 @subsubsection @code{bfd_copy_private_bfd_data}
511 boolean bfd_copy_private_bfd_data(bfd *ibfd, bfd *obfd);
513 @strong{Description}@*
514 Copy private BFD information from the BFD @var{ibfd} to the
515 the BFD @var{obfd}. Return @code{true} on success, @code{false} on error.
516 Possible error returns are:
521 @code{bfd_error_no_memory} -
522 Not enough memory exists to create private data for @var{obfd}.
525 #define bfd_copy_private_bfd_data(ibfd, obfd) \
526 BFD_SEND (obfd, _bfd_copy_private_bfd_data, \
530 @findex bfd_merge_private_bfd_data
531 @subsubsection @code{bfd_merge_private_bfd_data}
534 boolean bfd_merge_private_bfd_data(bfd *ibfd, bfd *obfd);
536 @strong{Description}@*
537 Merge private BFD information from the BFD @var{ibfd} to the
538 the output file BFD @var{obfd} when linking. Return @code{true}
539 on success, @code{false} on error. Possible error returns are:
544 @code{bfd_error_no_memory} -
545 Not enough memory exists to create private data for @var{obfd}.
548 #define bfd_merge_private_bfd_data(ibfd, obfd) \
549 BFD_SEND (obfd, _bfd_merge_private_bfd_data, \
553 @findex bfd_set_private_flags
554 @subsubsection @code{bfd_set_private_flags}
557 boolean bfd_set_private_flags(bfd *abfd, flagword flags);
559 @strong{Description}@*
560 Set private BFD flag information in the BFD @var{abfd}.
561 Return @code{true} on success, @code{false} on error. Possible error
567 @code{bfd_error_no_memory} -
568 Not enough memory exists to create private data for @var{obfd}.
571 #define bfd_set_private_flags(abfd, flags) \
572 BFD_SEND (abfd, _bfd_set_private_flags, \
577 @subsubsection @code{stuff}
578 @strong{Description}@*
579 Stuff which should be documented:
581 #define bfd_sizeof_headers(abfd, reloc) \
582 BFD_SEND (abfd, _bfd_sizeof_headers, (abfd, reloc))
584 #define bfd_find_nearest_line(abfd, sec, syms, off, file, func, line) \
585 BFD_SEND (abfd, _bfd_find_nearest_line, (abfd, sec, syms, off, file, func, line))
587 /* Do these three do anything useful at all, for any back end? */
588 #define bfd_debug_info_start(abfd) \
589 BFD_SEND (abfd, _bfd_debug_info_start, (abfd))
591 #define bfd_debug_info_end(abfd) \
592 BFD_SEND (abfd, _bfd_debug_info_end, (abfd))
594 #define bfd_debug_info_accumulate(abfd, section) \
595 BFD_SEND (abfd, _bfd_debug_info_accumulate, (abfd, section))
598 #define bfd_stat_arch_elt(abfd, stat) \
599 BFD_SEND (abfd, _bfd_stat_arch_elt,(abfd, stat))
601 #define bfd_update_armap_timestamp(abfd) \
602 BFD_SEND (abfd, _bfd_update_armap_timestamp, (abfd))
604 #define bfd_set_arch_mach(abfd, arch, mach)\
605 BFD_SEND ( abfd, _bfd_set_arch_mach, (abfd, arch, mach))
607 #define bfd_relax_section(abfd, section, link_info, again) \
608 BFD_SEND (abfd, _bfd_relax_section, (abfd, section, link_info, again))
610 #define bfd_gc_sections(abfd, link_info) \
611 BFD_SEND (abfd, _bfd_gc_sections, (abfd, link_info))
613 #define bfd_merge_sections(abfd, link_info) \
614 BFD_SEND (abfd, _bfd_merge_sections, (abfd, link_info))
616 #define bfd_link_hash_table_create(abfd) \
617 BFD_SEND (abfd, _bfd_link_hash_table_create, (abfd))
619 #define bfd_link_add_symbols(abfd, info) \
620 BFD_SEND (abfd, _bfd_link_add_symbols, (abfd, info))
622 #define bfd_final_link(abfd, info) \
623 BFD_SEND (abfd, _bfd_final_link, (abfd, info))
625 #define bfd_free_cached_info(abfd) \
626 BFD_SEND (abfd, _bfd_free_cached_info, (abfd))
628 #define bfd_get_dynamic_symtab_upper_bound(abfd) \
629 BFD_SEND (abfd, _bfd_get_dynamic_symtab_upper_bound, (abfd))
631 #define bfd_print_private_bfd_data(abfd, file)\
632 BFD_SEND (abfd, _bfd_print_private_bfd_data, (abfd, file))
634 #define bfd_canonicalize_dynamic_symtab(abfd, asymbols) \
635 BFD_SEND (abfd, _bfd_canonicalize_dynamic_symtab, (abfd, asymbols))
637 #define bfd_get_dynamic_reloc_upper_bound(abfd) \
638 BFD_SEND (abfd, _bfd_get_dynamic_reloc_upper_bound, (abfd))
640 #define bfd_canonicalize_dynamic_reloc(abfd, arels, asyms) \
641 BFD_SEND (abfd, _bfd_canonicalize_dynamic_reloc, (abfd, arels, asyms))
643 extern bfd_byte *bfd_get_relocated_section_contents
644 PARAMS ((bfd *, struct bfd_link_info *,
645 struct bfd_link_order *, bfd_byte *,
646 boolean, asymbol **));
650 @findex bfd_alt_mach_code
651 @subsubsection @code{bfd_alt_mach_code}
654 boolean bfd_alt_mach_code(bfd *abfd, int index);
656 @strong{Description}@*
657 When more than one machine code number is available for the
658 same machine type, this function can be used to switch between
659 the preferred one (index == 0) and any others. Currently,
660 only ELF supports this feature, with up to two alternate