2 The raw data contained within a BFD is maintained through the
3 section abstraction. A single BFD may have any number of
4 sections. It keeps hold of them by pointing to the first;
5 each one points to the next in the list.
7 Sections are supported in BFD in @code{section.c}.
13 * section prototypes::
16 @node Section Input, Section Output, Sections, Sections
17 @subsection Section input
18 When a BFD is opened for reading, the section structures are
19 created and attached to the BFD.
21 Each section has a name which describes the section in the
22 outside world---for example, @code{a.out} would contain at least
23 three sections, called @code{.text}, @code{.data} and @code{.bss}.
25 Names need not be unique; for example a COFF file may have several
26 sections named @code{.data}.
28 Sometimes a BFD will contain more than the ``natural'' number of
29 sections. A back end may attach other sections containing
30 constructor data, or an application may add a section (using
31 @code{bfd_make_section}) to the sections attached to an already open
32 BFD. For example, the linker creates an extra section
33 @code{COMMON} for each input file's BFD to hold information about
36 The raw data is not necessarily read in when
37 the section descriptor is created. Some targets may leave the
38 data in place until a @code{bfd_get_section_contents} call is
39 made. Other back ends may read in all the data at once. For
40 example, an S-record file has to be read once to determine the
41 size of the data. An IEEE-695 file doesn't contain raw data in
42 sections, but data and relocation expressions intermixed, so
43 the data area has to be parsed to get out the data and
46 @node Section Output, typedef asection, Section Input, Sections
47 @subsection Section output
48 To write a new object style BFD, the various sections to be
49 written have to be created. They are attached to the BFD in
50 the same way as input sections; data is written to the
51 sections using @code{bfd_set_section_contents}.
53 Any program that creates or combines sections (e.g., the assembler
54 and linker) must use the @code{asection} fields @code{output_section} and
55 @code{output_offset} to indicate the file sections to which each
56 section must be written. (If the section is being created from
57 scratch, @code{output_section} should probably point to the section
58 itself and @code{output_offset} should probably be zero.)
60 The data to be written comes from input sections attached
61 (via @code{output_section} pointers) to
62 the output sections. The output section structure can be
63 considered a filter for the input section: the output section
64 determines the vma of the output data and the name, but the
65 input section determines the offset into the output section of
66 the data to be written.
68 E.g., to create a section "O", starting at 0x100, 0x123 long,
69 containing two subsections, "A" at offset 0x0 (i.e., at vma
70 0x100) and "B" at offset 0x20 (i.e., at vma 0x120) the @code{asection}
71 structures would look like:
77 output_section -----------> section name "O"
79 section name "B" | size 0x123
82 output_section --------|
85 @subsection Link orders
86 The data within a section is stored in a @dfn{link_order}.
87 These are much like the fixups in @code{gas}. The link_order
88 abstraction allows a section to grow and shrink within itself.
90 A link_order knows how big it is, and which is the next
91 link_order and where the raw data for it is; it also points to
92 a list of relocations which apply to it.
94 The link_order is used by the linker to perform relaxing on
95 final code. The compiler creates code which is as big as
96 necessary to make it work without relaxing, and the user can
97 select whether to relax. Sometimes relaxing takes a lot of
98 time. The linker runs around the relocations to see if any
99 are attached to data which can be shrunk, if so it does it on
100 a link_order by link_order basis.
103 @node typedef asection, section prototypes, Section Output, Sections
104 @subsection typedef asection
105 Here is the section structure:
110 typedef struct bfd_section
112 /* The name of the section; the name isn't a copy, the pointer is
113 the same as that passed to bfd_make_section. */
116 /* A unique sequence number. */
119 /* Which section in the bfd; 0..n-1 as sections are created in a bfd. */
122 /* The next section in the list belonging to the BFD, or NULL. */
123 struct bfd_section *next;
125 /* The previous section in the list belonging to the BFD, or NULL. */
126 struct bfd_section *prev;
128 /* The field flags contains attributes of the section. Some
129 flags are read in from the object file, and some are
130 synthesized from other information. */
133 #define SEC_NO_FLAGS 0x000
135 /* Tells the OS to allocate space for this section when loading.
136 This is clear for a section containing debug information only. */
137 #define SEC_ALLOC 0x001
139 /* Tells the OS to load the section from the file when loading.
140 This is clear for a .bss section. */
141 #define SEC_LOAD 0x002
143 /* The section contains data still to be relocated, so there is
144 some relocation information too. */
145 #define SEC_RELOC 0x004
147 /* A signal to the OS that the section contains read only data. */
148 #define SEC_READONLY 0x008
150 /* The section contains code only. */
151 #define SEC_CODE 0x010
153 /* The section contains data only. */
154 #define SEC_DATA 0x020
156 /* The section will reside in ROM. */
157 #define SEC_ROM 0x040
159 /* The section contains constructor information. This section
160 type is used by the linker to create lists of constructors and
161 destructors used by @code{g++}. When a back end sees a symbol
162 which should be used in a constructor list, it creates a new
163 section for the type of name (e.g., @code{__CTOR_LIST__}), attaches
164 the symbol to it, and builds a relocation. To build the lists
165 of constructors, all the linker has to do is catenate all the
166 sections called @code{__CTOR_LIST__} and relocate the data
167 contained within - exactly the operations it would peform on
169 #define SEC_CONSTRUCTOR 0x080
171 /* The section has contents - a data section could be
172 @code{SEC_ALLOC} | @code{SEC_HAS_CONTENTS}; a debug section could be
173 @code{SEC_HAS_CONTENTS} */
174 #define SEC_HAS_CONTENTS 0x100
176 /* An instruction to the linker to not output the section
177 even if it has information which would normally be written. */
178 #define SEC_NEVER_LOAD 0x200
180 /* The section contains thread local data. */
181 #define SEC_THREAD_LOCAL 0x400
183 /* The section has GOT references. This flag is only for the
184 linker, and is currently only used by the elf32-hppa back end.
185 It will be set if global offset table references were detected
186 in this section, which indicate to the linker that the section
187 contains PIC code, and must be handled specially when doing a
189 #define SEC_HAS_GOT_REF 0x800
191 /* The section contains common symbols (symbols may be defined
192 multiple times, the value of a symbol is the amount of
193 space it requires, and the largest symbol value is the one
194 used). Most targets have exactly one of these (which we
195 translate to bfd_com_section_ptr), but ECOFF has two. */
196 #define SEC_IS_COMMON 0x1000
198 /* The section contains only debugging information. For
199 example, this is set for ELF .debug and .stab sections.
200 strip tests this flag to see if a section can be
202 #define SEC_DEBUGGING 0x2000
204 /* The contents of this section are held in memory pointed to
205 by the contents field. This is checked by bfd_get_section_contents,
206 and the data is retrieved from memory if appropriate. */
207 #define SEC_IN_MEMORY 0x4000
209 /* The contents of this section are to be excluded by the
210 linker for executable and shared objects unless those
211 objects are to be further relocated. */
212 #define SEC_EXCLUDE 0x8000
214 /* The contents of this section are to be sorted based on the sum of
215 the symbol and addend values specified by the associated relocation
216 entries. Entries without associated relocation entries will be
217 appended to the end of the section in an unspecified order. */
218 #define SEC_SORT_ENTRIES 0x10000
220 /* When linking, duplicate sections of the same name should be
221 discarded, rather than being combined into a single section as
222 is usually done. This is similar to how common symbols are
223 handled. See SEC_LINK_DUPLICATES below. */
224 #define SEC_LINK_ONCE 0x20000
226 /* If SEC_LINK_ONCE is set, this bitfield describes how the linker
227 should handle duplicate sections. */
228 #define SEC_LINK_DUPLICATES 0xc0000
230 /* This value for SEC_LINK_DUPLICATES means that duplicate
231 sections with the same name should simply be discarded. */
232 #define SEC_LINK_DUPLICATES_DISCARD 0x0
234 /* This value for SEC_LINK_DUPLICATES means that the linker
235 should warn if there are any duplicate sections, although
236 it should still only link one copy. */
237 #define SEC_LINK_DUPLICATES_ONE_ONLY 0x40000
239 /* This value for SEC_LINK_DUPLICATES means that the linker
240 should warn if any duplicate sections are a different size. */
241 #define SEC_LINK_DUPLICATES_SAME_SIZE 0x80000
243 /* This value for SEC_LINK_DUPLICATES means that the linker
244 should warn if any duplicate sections contain different
246 #define SEC_LINK_DUPLICATES_SAME_CONTENTS \
247 (SEC_LINK_DUPLICATES_ONE_ONLY | SEC_LINK_DUPLICATES_SAME_SIZE)
249 /* This section was created by the linker as part of dynamic
250 relocation or other arcane processing. It is skipped when
251 going through the first-pass output, trusting that someone
252 else up the line will take care of it later. */
253 #define SEC_LINKER_CREATED 0x100000
255 /* This section should not be subject to garbage collection.
256 Also set to inform the linker that this section should not be
257 listed in the link map as discarded. */
258 #define SEC_KEEP 0x200000
260 /* This section contains "short" data, and should be placed
262 #define SEC_SMALL_DATA 0x400000
264 /* Attempt to merge identical entities in the section.
265 Entity size is given in the entsize field. */
266 #define SEC_MERGE 0x800000
268 /* If given with SEC_MERGE, entities to merge are zero terminated
269 strings where entsize specifies character size instead of fixed
271 #define SEC_STRINGS 0x1000000
273 /* This section contains data about section groups. */
274 #define SEC_GROUP 0x2000000
276 /* The section is a COFF shared library section. This flag is
277 only for the linker. If this type of section appears in
278 the input file, the linker must copy it to the output file
279 without changing the vma or size. FIXME: Although this
280 was originally intended to be general, it really is COFF
281 specific (and the flag was renamed to indicate this). It
282 might be cleaner to have some more general mechanism to
283 allow the back end to control what the linker does with
285 #define SEC_COFF_SHARED_LIBRARY 0x4000000
287 /* This input section should be copied to output in reverse order
288 as an array of pointers. This is for ELF linker internal use
290 #define SEC_ELF_REVERSE_COPY 0x4000000
292 /* This section contains data which may be shared with other
293 executables or shared objects. This is for COFF only. */
294 #define SEC_COFF_SHARED 0x8000000
296 /* When a section with this flag is being linked, then if the size of
297 the input section is less than a page, it should not cross a page
298 boundary. If the size of the input section is one page or more,
299 it should be aligned on a page boundary. This is for TI
301 #define SEC_TIC54X_BLOCK 0x10000000
303 /* Conditionally link this section; do not link if there are no
304 references found to any symbol in the section. This is for TI
306 #define SEC_TIC54X_CLINK 0x20000000
308 /* Indicate that section has the no read flag set. This happens
309 when memory read flag isn't set. */
310 #define SEC_COFF_NOREAD 0x40000000
312 /* End of section flags. */
314 /* Some internal packed boolean fields. */
316 /* See the vma field. */
317 unsigned int user_set_vma : 1;
319 /* A mark flag used by some of the linker backends. */
320 unsigned int linker_mark : 1;
322 /* Another mark flag used by some of the linker backends. Set for
323 output sections that have an input section. */
324 unsigned int linker_has_input : 1;
326 /* Mark flag used by some linker backends for garbage collection. */
327 unsigned int gc_mark : 1;
329 /* Section compression status. */
330 unsigned int compress_status : 2;
331 #define COMPRESS_SECTION_NONE 0
332 #define COMPRESS_SECTION_DONE 1
333 #define DECOMPRESS_SECTION_SIZED 2
335 /* The following flags are used by the ELF linker. */
337 /* Mark sections which have been allocated to segments. */
338 unsigned int segment_mark : 1;
340 /* Type of sec_info information. */
341 unsigned int sec_info_type:3;
342 #define SEC_INFO_TYPE_NONE 0
343 #define SEC_INFO_TYPE_STABS 1
344 #define SEC_INFO_TYPE_MERGE 2
345 #define SEC_INFO_TYPE_EH_FRAME 3
346 #define SEC_INFO_TYPE_JUST_SYMS 4
347 #define SEC_INFO_TYPE_TARGET 5
349 /* Nonzero if this section uses RELA relocations, rather than REL. */
350 unsigned int use_rela_p:1;
352 /* Bits used by various backends. The generic code doesn't touch
355 unsigned int sec_flg0:1;
356 unsigned int sec_flg1:1;
357 unsigned int sec_flg2:1;
358 unsigned int sec_flg3:1;
359 unsigned int sec_flg4:1;
360 unsigned int sec_flg5:1;
362 /* End of internal packed boolean fields. */
364 /* The virtual memory address of the section - where it will be
365 at run time. The symbols are relocated against this. The
366 user_set_vma flag is maintained by bfd; if it's not set, the
367 backend can assign addresses (for example, in @code{a.out}, where
368 the default address for @code{.data} is dependent on the specific
369 target and various flags). */
372 /* The load address of the section - where it would be in a
373 rom image; really only used for writing section header
377 /* The size of the section in octets, as it will be output.
378 Contains a value even if the section has no contents (e.g., the
379 size of @code{.bss}). */
382 /* For input sections, the original size on disk of the section, in
383 octets. This field should be set for any section whose size is
384 changed by linker relaxation. It is required for sections where
385 the linker relaxation scheme doesn't cache altered section and
386 reloc contents (stabs, eh_frame, SEC_MERGE, some coff relaxing
387 targets), and thus the original size needs to be kept to read the
388 section multiple times. For output sections, rawsize holds the
389 section size calculated on a previous linker relaxation pass. */
390 bfd_size_type rawsize;
392 /* The compressed size of the section in octets. */
393 bfd_size_type compressed_size;
395 /* Relaxation table. */
396 struct relax_table *relax;
398 /* Count of used relaxation table entries. */
402 /* If this section is going to be output, then this value is the
403 offset in *bytes* into the output section of the first byte in the
404 input section (byte ==> smallest addressable unit on the
405 target). In most cases, if this was going to start at the
406 100th octet (8-bit quantity) in the output section, this value
407 would be 100. However, if the target byte size is 16 bits
408 (bfd_octets_per_byte is "2"), this value would be 50. */
409 bfd_vma output_offset;
411 /* The output section through which to map on output. */
412 struct bfd_section *output_section;
414 /* The alignment requirement of the section, as an exponent of 2 -
415 e.g., 3 aligns to 2^3 (or 8). */
416 unsigned int alignment_power;
418 /* If an input section, a pointer to a vector of relocation
419 records for the data in this section. */
420 struct reloc_cache_entry *relocation;
422 /* If an output section, a pointer to a vector of pointers to
423 relocation records for the data in this section. */
424 struct reloc_cache_entry **orelocation;
426 /* The number of relocation records in one of the above. */
427 unsigned reloc_count;
429 /* Information below is back end specific - and not always used
432 /* File position of section data. */
435 /* File position of relocation info. */
436 file_ptr rel_filepos;
438 /* File position of line data. */
439 file_ptr line_filepos;
441 /* Pointer to data for applications. */
444 /* If the SEC_IN_MEMORY flag is set, this points to the actual
446 unsigned char *contents;
448 /* Attached line number information. */
451 /* Number of line number records. */
452 unsigned int lineno_count;
454 /* Entity size for merging purposes. */
455 unsigned int entsize;
457 /* Points to the kept section if this section is a link-once section,
459 struct bfd_section *kept_section;
461 /* When a section is being output, this value changes as more
462 linenumbers are written out. */
463 file_ptr moving_line_filepos;
465 /* What the section number is in the target world. */
470 /* If this is a constructor section then here is a list of the
471 relocations created to relocate items within it. */
472 struct relent_chain *constructor_chain;
474 /* The BFD which owns the section. */
477 /* A symbol which points at this section only. */
478 struct bfd_symbol *symbol;
479 struct bfd_symbol **symbol_ptr_ptr;
481 /* Early in the link process, map_head and map_tail are used to build
482 a list of input sections attached to an output section. Later,
483 output sections use these fields for a list of bfd_link_order
486 struct bfd_link_order *link_order;
487 struct bfd_section *s;
488 @} map_head, map_tail;
491 /* Relax table contains information about instructions which can
492 be removed by relaxation -- replacing a long address with a
494 struct relax_table @{
495 /* Address where bytes may be deleted. */
498 /* Number of bytes to be deleted. */
502 /* Note: the following are provided as inline functions rather than macros
503 because not all callers use the return value. A macro implementation
504 would use a comma expression, eg: "((ptr)->foo = val, TRUE)" and some
505 compilers will complain about comma expressions that have no effect. */
506 static inline bfd_boolean
507 bfd_set_section_userdata (bfd * abfd ATTRIBUTE_UNUSED, asection * ptr, void * val)
513 static inline bfd_boolean
514 bfd_set_section_vma (bfd * abfd ATTRIBUTE_UNUSED, asection * ptr, bfd_vma val)
516 ptr->vma = ptr->lma = val;
517 ptr->user_set_vma = TRUE;
521 static inline bfd_boolean
522 bfd_set_section_alignment (bfd * abfd ATTRIBUTE_UNUSED, asection * ptr, unsigned int val)
524 ptr->alignment_power = val;
528 /* These sections are global, and are managed by BFD. The application
529 and target back end are not permitted to change the values in
531 extern asection _bfd_std_section[4];
533 #define BFD_ABS_SECTION_NAME "*ABS*"
534 #define BFD_UND_SECTION_NAME "*UND*"
535 #define BFD_COM_SECTION_NAME "*COM*"
536 #define BFD_IND_SECTION_NAME "*IND*"
538 /* Pointer to the common section. */
539 #define bfd_com_section_ptr (&_bfd_std_section[0])
540 /* Pointer to the undefined section. */
541 #define bfd_und_section_ptr (&_bfd_std_section[1])
542 /* Pointer to the absolute section. */
543 #define bfd_abs_section_ptr (&_bfd_std_section[2])
544 /* Pointer to the indirect section. */
545 #define bfd_ind_section_ptr (&_bfd_std_section[3])
547 #define bfd_is_und_section(sec) ((sec) == bfd_und_section_ptr)
548 #define bfd_is_abs_section(sec) ((sec) == bfd_abs_section_ptr)
549 #define bfd_is_ind_section(sec) ((sec) == bfd_ind_section_ptr)
551 #define bfd_is_const_section(SEC) \
552 ( ((SEC) == bfd_abs_section_ptr) \
553 || ((SEC) == bfd_und_section_ptr) \
554 || ((SEC) == bfd_com_section_ptr) \
555 || ((SEC) == bfd_ind_section_ptr))
557 /* Macros to handle insertion and deletion of a bfd's sections. These
558 only handle the list pointers, ie. do not adjust section_count,
560 #define bfd_section_list_remove(ABFD, S) \
564 asection *_next = _s->next; \
565 asection *_prev = _s->prev; \
567 _prev->next = _next; \
569 (ABFD)->sections = _next; \
571 _next->prev = _prev; \
573 (ABFD)->section_last = _prev; \
576 #define bfd_section_list_append(ABFD, S) \
582 if (_abfd->section_last) \
584 _s->prev = _abfd->section_last; \
585 _abfd->section_last->next = _s; \
590 _abfd->sections = _s; \
592 _abfd->section_last = _s; \
595 #define bfd_section_list_prepend(ABFD, S) \
601 if (_abfd->sections) \
603 _s->next = _abfd->sections; \
604 _abfd->sections->prev = _s; \
609 _abfd->section_last = _s; \
611 _abfd->sections = _s; \
614 #define bfd_section_list_insert_after(ABFD, A, S) \
619 asection *_next = _a->next; \
626 (ABFD)->section_last = _s; \
629 #define bfd_section_list_insert_before(ABFD, B, S) \
634 asection *_prev = _b->prev; \
641 (ABFD)->sections = _s; \
644 #define bfd_section_removed_from_list(ABFD, S) \
645 ((S)->next == NULL ? (ABFD)->section_last != (S) : (S)->next->prev != (S))
647 #define BFD_FAKE_SECTION(SEC, FLAGS, SYM, NAME, IDX) \
648 /* name, id, index, next, prev, flags, user_set_vma, */ \
649 @{ NAME, IDX, 0, NULL, NULL, FLAGS, 0, \
651 /* linker_mark, linker_has_input, gc_mark, decompress_status, */ \
654 /* segment_mark, sec_info_type, use_rela_p, */ \
657 /* sec_flg0, sec_flg1, sec_flg2, sec_flg3, sec_flg4, sec_flg5, */ \
660 /* vma, lma, size, rawsize, compressed_size, relax, relax_count, */ \
661 0, 0, 0, 0, 0, 0, 0, \
663 /* output_offset, output_section, alignment_power, */ \
666 /* relocation, orelocation, reloc_count, filepos, rel_filepos, */ \
667 NULL, NULL, 0, 0, 0, \
669 /* line_filepos, userdata, contents, lineno, lineno_count, */ \
670 0, NULL, NULL, NULL, 0, \
672 /* entsize, kept_section, moving_line_filepos, */ \
675 /* target_index, used_by_bfd, constructor_chain, owner, */ \
676 0, NULL, NULL, NULL, \
678 /* symbol, symbol_ptr_ptr, */ \
679 (struct bfd_symbol *) SYM, &SEC.symbol, \
681 /* map_head, map_tail */ \
682 @{ NULL @}, @{ NULL @} \
687 @node section prototypes, , typedef asection, Sections
688 @subsection Section prototypes
689 These are the functions exported by the section handling part of BFD.
691 @findex bfd_section_list_clear
692 @subsubsection @code{bfd_section_list_clear}
695 void bfd_section_list_clear (bfd *);
697 @strong{Description}@*
698 Clears the section list, and also resets the section count and
701 @findex bfd_get_section_by_name
702 @subsubsection @code{bfd_get_section_by_name}
705 asection *bfd_get_section_by_name (bfd *abfd, const char *name);
707 @strong{Description}@*
708 Return the most recently created section attached to @var{abfd}
709 named @var{name}. Return NULL if no such section exists.
711 @findex bfd_get_next_section_by_name
712 @subsubsection @code{bfd_get_next_section_by_name}
715 asection *bfd_get_next_section_by_name (asection *sec);
717 @strong{Description}@*
718 Given @var{sec} is a section returned by @code{bfd_get_section_by_name},
719 return the next most recently created section attached to the same
720 BFD with the same name. Return NULL if no such section exists.
722 @findex bfd_get_linker_section
723 @subsubsection @code{bfd_get_linker_section}
726 asection *bfd_get_linker_section (bfd *abfd, const char *name);
728 @strong{Description}@*
729 Return the linker created section attached to @var{abfd}
730 named @var{name}. Return NULL if no such section exists.
732 @findex bfd_get_section_by_name_if
733 @subsubsection @code{bfd_get_section_by_name_if}
736 asection *bfd_get_section_by_name_if
739 bfd_boolean (*func) (bfd *abfd, asection *sect, void *obj),
742 @strong{Description}@*
743 Call the provided function @var{func} for each section
744 attached to the BFD @var{abfd} whose name matches @var{name},
745 passing @var{obj} as an argument. The function will be called
749 func (abfd, the_section, obj);
752 It returns the first section for which @var{func} returns true,
753 otherwise @code{NULL}.
755 @findex bfd_get_unique_section_name
756 @subsubsection @code{bfd_get_unique_section_name}
759 char *bfd_get_unique_section_name
760 (bfd *abfd, const char *templat, int *count);
762 @strong{Description}@*
763 Invent a section name that is unique in @var{abfd} by tacking
764 a dot and a digit suffix onto the original @var{templat}. If
765 @var{count} is non-NULL, then it specifies the first number
766 tried as a suffix to generate a unique name. The value
767 pointed to by @var{count} will be incremented in this case.
769 @findex bfd_make_section_old_way
770 @subsubsection @code{bfd_make_section_old_way}
773 asection *bfd_make_section_old_way (bfd *abfd, const char *name);
775 @strong{Description}@*
776 Create a new empty section called @var{name}
777 and attach it to the end of the chain of sections for the
778 BFD @var{abfd}. An attempt to create a section with a name which
779 is already in use returns its pointer without changing the
782 It has the funny name since this is the way it used to be
783 before it was rewritten....
789 @code{bfd_error_invalid_operation} -
790 If output has already started for this BFD.
792 @code{bfd_error_no_memory} -
793 If memory allocation fails.
796 @findex bfd_make_section_anyway_with_flags
797 @subsubsection @code{bfd_make_section_anyway_with_flags}
800 asection *bfd_make_section_anyway_with_flags
801 (bfd *abfd, const char *name, flagword flags);
803 @strong{Description}@*
804 Create a new empty section called @var{name} and attach it to the end of
805 the chain of sections for @var{abfd}. Create a new section even if there
806 is already a section with that name. Also set the attributes of the
807 new section to the value @var{flags}.
809 Return @code{NULL} and set @code{bfd_error} on error; possible errors are:
813 @code{bfd_error_invalid_operation} - If output has already started for @var{abfd}.
815 @code{bfd_error_no_memory} - If memory allocation fails.
818 @findex bfd_make_section_anyway
819 @subsubsection @code{bfd_make_section_anyway}
822 asection *bfd_make_section_anyway (bfd *abfd, const char *name);
824 @strong{Description}@*
825 Create a new empty section called @var{name} and attach it to the end of
826 the chain of sections for @var{abfd}. Create a new section even if there
827 is already a section with that name.
829 Return @code{NULL} and set @code{bfd_error} on error; possible errors are:
833 @code{bfd_error_invalid_operation} - If output has already started for @var{abfd}.
835 @code{bfd_error_no_memory} - If memory allocation fails.
838 @findex bfd_make_section_with_flags
839 @subsubsection @code{bfd_make_section_with_flags}
842 asection *bfd_make_section_with_flags
843 (bfd *, const char *name, flagword flags);
845 @strong{Description}@*
846 Like @code{bfd_make_section_anyway}, but return @code{NULL} (without calling
847 bfd_set_error ()) without changing the section chain if there is already a
848 section named @var{name}. Also set the attributes of the new section to
849 the value @var{flags}. If there is an error, return @code{NULL} and set
852 @findex bfd_make_section
853 @subsubsection @code{bfd_make_section}
856 asection *bfd_make_section (bfd *, const char *name);
858 @strong{Description}@*
859 Like @code{bfd_make_section_anyway}, but return @code{NULL} (without calling
860 bfd_set_error ()) without changing the section chain if there is already a
861 section named @var{name}. If there is an error, return @code{NULL} and set
864 @findex bfd_set_section_flags
865 @subsubsection @code{bfd_set_section_flags}
868 bfd_boolean bfd_set_section_flags
869 (bfd *abfd, asection *sec, flagword flags);
871 @strong{Description}@*
872 Set the attributes of the section @var{sec} in the BFD
873 @var{abfd} to the value @var{flags}. Return @code{TRUE} on success,
874 @code{FALSE} on error. Possible error returns are:
879 @code{bfd_error_invalid_operation} -
880 The section cannot have one or more of the attributes
881 requested. For example, a .bss section in @code{a.out} may not
882 have the @code{SEC_HAS_CONTENTS} field set.
885 @findex bfd_rename_section
886 @subsubsection @code{bfd_rename_section}
889 void bfd_rename_section
890 (bfd *abfd, asection *sec, const char *newname);
892 @strong{Description}@*
893 Rename section @var{sec} in @var{abfd} to @var{newname}.
895 @findex bfd_map_over_sections
896 @subsubsection @code{bfd_map_over_sections}
899 void bfd_map_over_sections
901 void (*func) (bfd *abfd, asection *sect, void *obj),
904 @strong{Description}@*
905 Call the provided function @var{func} for each section
906 attached to the BFD @var{abfd}, passing @var{obj} as an
907 argument. The function will be called as if by
910 func (abfd, the_section, obj);
913 This is the preferred method for iterating over sections; an
914 alternative would be to use a loop:
918 for (p = abfd->sections; p != NULL; p = p->next)
922 @findex bfd_sections_find_if
923 @subsubsection @code{bfd_sections_find_if}
926 asection *bfd_sections_find_if
928 bfd_boolean (*operation) (bfd *abfd, asection *sect, void *obj),
931 @strong{Description}@*
932 Call the provided function @var{operation} for each section
933 attached to the BFD @var{abfd}, passing @var{obj} as an
934 argument. The function will be called as if by
937 operation (abfd, the_section, obj);
940 It returns the first section for which @var{operation} returns true.
942 @findex bfd_set_section_size
943 @subsubsection @code{bfd_set_section_size}
946 bfd_boolean bfd_set_section_size
947 (bfd *abfd, asection *sec, bfd_size_type val);
949 @strong{Description}@*
950 Set @var{sec} to the size @var{val}. If the operation is
951 ok, then @code{TRUE} is returned, else @code{FALSE}.
953 Possible error returns:
957 @code{bfd_error_invalid_operation} -
958 Writing has started to the BFD, so setting the size is invalid.
961 @findex bfd_set_section_contents
962 @subsubsection @code{bfd_set_section_contents}
965 bfd_boolean bfd_set_section_contents
966 (bfd *abfd, asection *section, const void *data,
967 file_ptr offset, bfd_size_type count);
969 @strong{Description}@*
970 Sets the contents of the section @var{section} in BFD
971 @var{abfd} to the data starting in memory at @var{data}. The
972 data is written to the output section starting at offset
973 @var{offset} for @var{count} octets.
975 Normally @code{TRUE} is returned, else @code{FALSE}. Possible error
980 @code{bfd_error_no_contents} -
981 The output section does not have the @code{SEC_HAS_CONTENTS}
982 attribute, so nothing can be written to it.
986 This routine is front end to the back end function
987 @code{_bfd_set_section_contents}.
989 @findex bfd_get_section_contents
990 @subsubsection @code{bfd_get_section_contents}
993 bfd_boolean bfd_get_section_contents
994 (bfd *abfd, asection *section, void *location, file_ptr offset,
995 bfd_size_type count);
997 @strong{Description}@*
998 Read data from @var{section} in BFD @var{abfd}
999 into memory starting at @var{location}. The data is read at an
1000 offset of @var{offset} from the start of the input section,
1001 and is read for @var{count} bytes.
1003 If the contents of a constructor with the @code{SEC_CONSTRUCTOR}
1004 flag set are requested or if the section does not have the
1005 @code{SEC_HAS_CONTENTS} flag set, then the @var{location} is filled
1006 with zeroes. If no errors occur, @code{TRUE} is returned, else
1009 @findex bfd_malloc_and_get_section
1010 @subsubsection @code{bfd_malloc_and_get_section}
1013 bfd_boolean bfd_malloc_and_get_section
1014 (bfd *abfd, asection *section, bfd_byte **buf);
1016 @strong{Description}@*
1017 Read all data from @var{section} in BFD @var{abfd}
1018 into a buffer, *@var{buf}, malloc'd by this function.
1020 @findex bfd_copy_private_section_data
1021 @subsubsection @code{bfd_copy_private_section_data}
1024 bfd_boolean bfd_copy_private_section_data
1025 (bfd *ibfd, asection *isec, bfd *obfd, asection *osec);
1027 @strong{Description}@*
1028 Copy private section information from @var{isec} in the BFD
1029 @var{ibfd} to the section @var{osec} in the BFD @var{obfd}.
1030 Return @code{TRUE} on success, @code{FALSE} on error. Possible error
1036 @code{bfd_error_no_memory} -
1037 Not enough memory exists to create private data for @var{osec}.
1040 #define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \
1041 BFD_SEND (obfd, _bfd_copy_private_section_data, \
1042 (ibfd, isection, obfd, osection))
1045 @findex bfd_generic_is_group_section
1046 @subsubsection @code{bfd_generic_is_group_section}
1049 bfd_boolean bfd_generic_is_group_section (bfd *, const asection *sec);
1051 @strong{Description}@*
1052 Returns TRUE if @var{sec} is a member of a group.
1054 @findex bfd_generic_discard_group
1055 @subsubsection @code{bfd_generic_discard_group}
1058 bfd_boolean bfd_generic_discard_group (bfd *abfd, asection *group);
1060 @strong{Description}@*
1061 Remove all members of @var{group} from the output.