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
348
/* Nonzero if this section uses RELA relocations, rather than REL. */
349
unsigned int use_rela_p:1;
351
/* Bits used by various backends. The generic code doesn't touch
354
unsigned int sec_flg0:1;
355
unsigned int sec_flg1:1;
356
unsigned int sec_flg2:1;
357
unsigned int sec_flg3:1;
358
unsigned int sec_flg4:1;
359
unsigned int sec_flg5:1;
361
/* End of internal packed boolean fields. */
363
/* The virtual memory address of the section - where it will be
364
at run time. The symbols are relocated against this. The
365
user_set_vma flag is maintained by bfd; if it's not set, the
366
backend can assign addresses (for example, in @code{a.out}, where
367
the default address for @code{.data} is dependent on the specific
368
target and various flags). */
371
/* The load address of the section - where it would be in a
372
rom image; really only used for writing section header
376
/* The size of the section in octets, as it will be output.
377
Contains a value even if the section has no contents (e.g., the
378
size of @code{.bss}). */
381
/* For input sections, the original size on disk of the section, in
382
octets. This field should be set for any section whose size is
383
changed by linker relaxation. It is required for sections where
384
the linker relaxation scheme doesn't cache altered section and
385
reloc contents (stabs, eh_frame, SEC_MERGE, some coff relaxing
386
targets), and thus the original size needs to be kept to read the
387
section multiple times. For output sections, rawsize holds the
388
section size calculated on a previous linker relaxation pass. */
389
bfd_size_type rawsize;
391
/* The compressed size of the section in octets. */
392
bfd_size_type compressed_size;
394
/* Relaxation table. */
395
struct relax_table *relax;
397
/* Count of used relaxation table entries. */
401
/* If this section is going to be output, then this value is the
402
offset in *bytes* into the output section of the first byte in the
403
input section (byte ==> smallest addressable unit on the
404
target). In most cases, if this was going to start at the
405
100th octet (8-bit quantity) in the output section, this value
406
would be 100. However, if the target byte size is 16 bits
407
(bfd_octets_per_byte is "2"), this value would be 50. */
408
bfd_vma output_offset;
410
/* The output section through which to map on output. */
411
struct bfd_section *output_section;
413
/* The alignment requirement of the section, as an exponent of 2 -
414
e.g., 3 aligns to 2^3 (or 8). */
415
unsigned int alignment_power;
417
/* If an input section, a pointer to a vector of relocation
418
records for the data in this section. */
419
struct reloc_cache_entry *relocation;
421
/* If an output section, a pointer to a vector of pointers to
422
relocation records for the data in this section. */
423
struct reloc_cache_entry **orelocation;
425
/* The number of relocation records in one of the above. */
426
unsigned reloc_count;
428
/* Information below is back end specific - and not always used
431
/* File position of section data. */
434
/* File position of relocation info. */
435
file_ptr rel_filepos;
437
/* File position of line data. */
438
file_ptr line_filepos;
440
/* Pointer to data for applications. */
443
/* If the SEC_IN_MEMORY flag is set, this points to the actual
445
unsigned char *contents;
447
/* Attached line number information. */
450
/* Number of line number records. */
451
unsigned int lineno_count;
453
/* Entity size for merging purposes. */
454
unsigned int entsize;
456
/* Points to the kept section if this section is a link-once section,
458
struct bfd_section *kept_section;
460
/* When a section is being output, this value changes as more
461
linenumbers are written out. */
462
file_ptr moving_line_filepos;
464
/* What the section number is in the target world. */
469
/* If this is a constructor section then here is a list of the
470
relocations created to relocate items within it. */
471
struct relent_chain *constructor_chain;
473
/* The BFD which owns the section. */
476
/* A symbol which points at this section only. */
477
struct bfd_symbol *symbol;
478
struct bfd_symbol **symbol_ptr_ptr;
480
/* Early in the link process, map_head and map_tail are used to build
481
a list of input sections attached to an output section. Later,
482
output sections use these fields for a list of bfd_link_order
485
struct bfd_link_order *link_order;
486
struct bfd_section *s;
487
@} map_head, map_tail;
490
/* Relax table contains information about instructions which can
491
be removed by relaxation -- replacing a long address with a
493
struct relax_table @{
494
/* Address where bytes may be deleted. */
497
/* Number of bytes to be deleted. */
501
/* These sections are global, and are managed by BFD. The application
502
and target back end are not permitted to change the values in
504
extern asection _bfd_std_section[4];
506
#define BFD_ABS_SECTION_NAME "*ABS*"
507
#define BFD_UND_SECTION_NAME "*UND*"
508
#define BFD_COM_SECTION_NAME "*COM*"
509
#define BFD_IND_SECTION_NAME "*IND*"
511
/* Pointer to the common section. */
512
#define bfd_com_section_ptr (&_bfd_std_section[0])
513
/* Pointer to the undefined section. */
514
#define bfd_und_section_ptr (&_bfd_std_section[1])
515
/* Pointer to the absolute section. */
516
#define bfd_abs_section_ptr (&_bfd_std_section[2])
517
/* Pointer to the indirect section. */
518
#define bfd_ind_section_ptr (&_bfd_std_section[3])
520
#define bfd_is_und_section(sec) ((sec) == bfd_und_section_ptr)
521
#define bfd_is_abs_section(sec) ((sec) == bfd_abs_section_ptr)
522
#define bfd_is_ind_section(sec) ((sec) == bfd_ind_section_ptr)
524
#define bfd_is_const_section(SEC) \
525
( ((SEC) == bfd_abs_section_ptr) \
526
|| ((SEC) == bfd_und_section_ptr) \
527
|| ((SEC) == bfd_com_section_ptr) \
528
|| ((SEC) == bfd_ind_section_ptr))
530
/* Macros to handle insertion and deletion of a bfd's sections. These
531
only handle the list pointers, ie. do not adjust section_count,
533
#define bfd_section_list_remove(ABFD, S) \
537
asection *_next = _s->next; \
538
asection *_prev = _s->prev; \
540
_prev->next = _next; \
542
(ABFD)->sections = _next; \
544
_next->prev = _prev; \
546
(ABFD)->section_last = _prev; \
549
#define bfd_section_list_append(ABFD, S) \
555
if (_abfd->section_last) \
557
_s->prev = _abfd->section_last; \
558
_abfd->section_last->next = _s; \
563
_abfd->sections = _s; \
565
_abfd->section_last = _s; \
568
#define bfd_section_list_prepend(ABFD, S) \
574
if (_abfd->sections) \
576
_s->next = _abfd->sections; \
577
_abfd->sections->prev = _s; \
582
_abfd->section_last = _s; \
584
_abfd->sections = _s; \
587
#define bfd_section_list_insert_after(ABFD, A, S) \
592
asection *_next = _a->next; \
599
(ABFD)->section_last = _s; \
602
#define bfd_section_list_insert_before(ABFD, B, S) \
607
asection *_prev = _b->prev; \
614
(ABFD)->sections = _s; \
617
#define bfd_section_removed_from_list(ABFD, S) \
618
((S)->next == NULL ? (ABFD)->section_last != (S) : (S)->next->prev != (S))
620
#define BFD_FAKE_SECTION(SEC, FLAGS, SYM, NAME, IDX) \
621
/* name, id, index, next, prev, flags, user_set_vma, */ \
622
@{ NAME, IDX, 0, NULL, NULL, FLAGS, 0, \
624
/* linker_mark, linker_has_input, gc_mark, decompress_status, */ \
627
/* segment_mark, sec_info_type, use_rela_p, */ \
630
/* sec_flg0, sec_flg1, sec_flg2, sec_flg3, sec_flg4, sec_flg5, */ \
633
/* vma, lma, size, rawsize, compressed_size, relax, relax_count, */ \
634
0, 0, 0, 0, 0, 0, 0, \
636
/* output_offset, output_section, alignment_power, */ \
639
/* relocation, orelocation, reloc_count, filepos, rel_filepos, */ \
640
NULL, NULL, 0, 0, 0, \
642
/* line_filepos, userdata, contents, lineno, lineno_count, */ \
643
0, NULL, NULL, NULL, 0, \
645
/* entsize, kept_section, moving_line_filepos, */ \
648
/* target_index, used_by_bfd, constructor_chain, owner, */ \
649
0, NULL, NULL, NULL, \
651
/* symbol, symbol_ptr_ptr, */ \
652
(struct bfd_symbol *) SYM, &SEC.symbol, \
654
/* map_head, map_tail */ \
655
@{ NULL @}, @{ NULL @} \
660
@node section prototypes, , typedef asection, Sections
661
@subsection Section prototypes
662
These are the functions exported by the section handling part of BFD.
664
@findex bfd_section_list_clear
665
@subsubsection @code{bfd_section_list_clear}
668
void bfd_section_list_clear (bfd *);
670
@strong{Description}@*
671
Clears the section list, and also resets the section count and
674
@findex bfd_get_section_by_name
675
@subsubsection @code{bfd_get_section_by_name}
678
asection *bfd_get_section_by_name (bfd *abfd, const char *name);
680
@strong{Description}@*
681
Return the most recently created section attached to @var{abfd}
682
named @var{name}. Return NULL if no such section exists.
684
@findex bfd_get_next_section_by_name
685
@subsubsection @code{bfd_get_next_section_by_name}
688
asection *bfd_get_next_section_by_name (asection *sec);
690
@strong{Description}@*
691
Given @var{sec} is a section returned by @code{bfd_get_section_by_name},
692
return the next most recently created section attached to the same
693
BFD with the same name. Return NULL if no such section exists.
695
@findex bfd_get_linker_section
696
@subsubsection @code{bfd_get_linker_section}
699
asection *bfd_get_linker_section (bfd *abfd, const char *name);
701
@strong{Description}@*
702
Return the linker created section attached to @var{abfd}
703
named @var{name}. Return NULL if no such section exists.
705
@findex bfd_get_section_by_name_if
706
@subsubsection @code{bfd_get_section_by_name_if}
709
asection *bfd_get_section_by_name_if
712
bfd_boolean (*func) (bfd *abfd, asection *sect, void *obj),
715
@strong{Description}@*
716
Call the provided function @var{func} for each section
717
attached to the BFD @var{abfd} whose name matches @var{name},
718
passing @var{obj} as an argument. The function will be called
722
func (abfd, the_section, obj);
725
It returns the first section for which @var{func} returns true,
726
otherwise @code{NULL}.
728
@findex bfd_get_unique_section_name
729
@subsubsection @code{bfd_get_unique_section_name}
732
char *bfd_get_unique_section_name
733
(bfd *abfd, const char *templat, int *count);
735
@strong{Description}@*
736
Invent a section name that is unique in @var{abfd} by tacking
737
a dot and a digit suffix onto the original @var{templat}. If
738
@var{count} is non-NULL, then it specifies the first number
739
tried as a suffix to generate a unique name. The value
740
pointed to by @var{count} will be incremented in this case.
742
@findex bfd_make_section_old_way
743
@subsubsection @code{bfd_make_section_old_way}
746
asection *bfd_make_section_old_way (bfd *abfd, const char *name);
748
@strong{Description}@*
749
Create a new empty section called @var{name}
750
and attach it to the end of the chain of sections for the
751
BFD @var{abfd}. An attempt to create a section with a name which
752
is already in use returns its pointer without changing the
755
It has the funny name since this is the way it used to be
756
before it was rewritten....
762
@code{bfd_error_invalid_operation} -
763
If output has already started for this BFD.
765
@code{bfd_error_no_memory} -
766
If memory allocation fails.
769
@findex bfd_make_section_anyway_with_flags
770
@subsubsection @code{bfd_make_section_anyway_with_flags}
773
asection *bfd_make_section_anyway_with_flags
774
(bfd *abfd, const char *name, flagword flags);
776
@strong{Description}@*
777
Create a new empty section called @var{name} and attach it to the end of
778
the chain of sections for @var{abfd}. Create a new section even if there
779
is already a section with that name. Also set the attributes of the
780
new section to the value @var{flags}.
782
Return @code{NULL} and set @code{bfd_error} on error; possible errors are:
786
@code{bfd_error_invalid_operation} - If output has already started for @var{abfd}.
788
@code{bfd_error_no_memory} - If memory allocation fails.
791
@findex bfd_make_section_anyway
792
@subsubsection @code{bfd_make_section_anyway}
795
asection *bfd_make_section_anyway (bfd *abfd, const char *name);
797
@strong{Description}@*
798
Create a new empty section called @var{name} and attach it to the end of
799
the chain of sections for @var{abfd}. Create a new section even if there
800
is already a section with that name.
802
Return @code{NULL} and set @code{bfd_error} on error; possible errors are:
806
@code{bfd_error_invalid_operation} - If output has already started for @var{abfd}.
808
@code{bfd_error_no_memory} - If memory allocation fails.
811
@findex bfd_make_section_with_flags
812
@subsubsection @code{bfd_make_section_with_flags}
815
asection *bfd_make_section_with_flags
816
(bfd *, const char *name, flagword flags);
818
@strong{Description}@*
819
Like @code{bfd_make_section_anyway}, but return @code{NULL} (without calling
820
bfd_set_error ()) without changing the section chain if there is already a
821
section named @var{name}. Also set the attributes of the new section to
822
the value @var{flags}. If there is an error, return @code{NULL} and set
825
@findex bfd_make_section
826
@subsubsection @code{bfd_make_section}
829
asection *bfd_make_section (bfd *, const char *name);
831
@strong{Description}@*
832
Like @code{bfd_make_section_anyway}, but return @code{NULL} (without calling
833
bfd_set_error ()) without changing the section chain if there is already a
834
section named @var{name}. If there is an error, return @code{NULL} and set
837
@findex bfd_set_section_flags
838
@subsubsection @code{bfd_set_section_flags}
841
bfd_boolean bfd_set_section_flags
842
(bfd *abfd, asection *sec, flagword flags);
844
@strong{Description}@*
845
Set the attributes of the section @var{sec} in the BFD
846
@var{abfd} to the value @var{flags}. Return @code{TRUE} on success,
847
@code{FALSE} on error. Possible error returns are:
852
@code{bfd_error_invalid_operation} -
853
The section cannot have one or more of the attributes
854
requested. For example, a .bss section in @code{a.out} may not
855
have the @code{SEC_HAS_CONTENTS} field set.
858
@findex bfd_rename_section
859
@subsubsection @code{bfd_rename_section}
862
void bfd_rename_section
863
(bfd *abfd, asection *sec, const char *newname);
865
@strong{Description}@*
866
Rename section @var{sec} in @var{abfd} to @var{newname}.
868
@findex bfd_map_over_sections
869
@subsubsection @code{bfd_map_over_sections}
872
void bfd_map_over_sections
874
void (*func) (bfd *abfd, asection *sect, void *obj),
877
@strong{Description}@*
878
Call the provided function @var{func} for each section
879
attached to the BFD @var{abfd}, passing @var{obj} as an
880
argument. The function will be called as if by
883
func (abfd, the_section, obj);
886
This is the preferred method for iterating over sections; an
887
alternative would be to use a loop:
891
for (p = abfd->sections; p != NULL; p = p->next)
895
@findex bfd_sections_find_if
896
@subsubsection @code{bfd_sections_find_if}
899
asection *bfd_sections_find_if
901
bfd_boolean (*operation) (bfd *abfd, asection *sect, void *obj),
904
@strong{Description}@*
905
Call the provided function @var{operation} 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
operation (abfd, the_section, obj);
913
It returns the first section for which @var{operation} returns true.
915
@findex bfd_set_section_size
916
@subsubsection @code{bfd_set_section_size}
919
bfd_boolean bfd_set_section_size
920
(bfd *abfd, asection *sec, bfd_size_type val);
922
@strong{Description}@*
923
Set @var{sec} to the size @var{val}. If the operation is
924
ok, then @code{TRUE} is returned, else @code{FALSE}.
926
Possible error returns:
930
@code{bfd_error_invalid_operation} -
931
Writing has started to the BFD, so setting the size is invalid.
934
@findex bfd_set_section_contents
935
@subsubsection @code{bfd_set_section_contents}
938
bfd_boolean bfd_set_section_contents
939
(bfd *abfd, asection *section, const void *data,
940
file_ptr offset, bfd_size_type count);
942
@strong{Description}@*
943
Sets the contents of the section @var{section} in BFD
944
@var{abfd} to the data starting in memory at @var{data}. The
945
data is written to the output section starting at offset
946
@var{offset} for @var{count} octets.
948
Normally @code{TRUE} is returned, else @code{FALSE}. Possible error
953
@code{bfd_error_no_contents} -
954
The output section does not have the @code{SEC_HAS_CONTENTS}
955
attribute, so nothing can be written to it.
959
This routine is front end to the back end function
960
@code{_bfd_set_section_contents}.
962
@findex bfd_get_section_contents
963
@subsubsection @code{bfd_get_section_contents}
966
bfd_boolean bfd_get_section_contents
967
(bfd *abfd, asection *section, void *location, file_ptr offset,
968
bfd_size_type count);
970
@strong{Description}@*
971
Read data from @var{section} in BFD @var{abfd}
972
into memory starting at @var{location}. The data is read at an
973
offset of @var{offset} from the start of the input section,
974
and is read for @var{count} bytes.
976
If the contents of a constructor with the @code{SEC_CONSTRUCTOR}
977
flag set are requested or if the section does not have the
978
@code{SEC_HAS_CONTENTS} flag set, then the @var{location} is filled
979
with zeroes. If no errors occur, @code{TRUE} is returned, else
982
@findex bfd_malloc_and_get_section
983
@subsubsection @code{bfd_malloc_and_get_section}
986
bfd_boolean bfd_malloc_and_get_section
987
(bfd *abfd, asection *section, bfd_byte **buf);
989
@strong{Description}@*
990
Read all data from @var{section} in BFD @var{abfd}
991
into a buffer, *@var{buf}, malloc'd by this function.
993
@findex bfd_copy_private_section_data
994
@subsubsection @code{bfd_copy_private_section_data}
997
bfd_boolean bfd_copy_private_section_data
998
(bfd *ibfd, asection *isec, bfd *obfd, asection *osec);
1000
@strong{Description}@*
1001
Copy private section information from @var{isec} in the BFD
1002
@var{ibfd} to the section @var{osec} in the BFD @var{obfd}.
1003
Return @code{TRUE} on success, @code{FALSE} on error. Possible error
1009
@code{bfd_error_no_memory} -
1010
Not enough memory exists to create private data for @var{osec}.
1013
#define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \
1014
BFD_SEND (obfd, _bfd_copy_private_section_data, \
1015
(ibfd, isection, obfd, osection))
1018
@findex bfd_generic_is_group_section
1019
@subsubsection @code{bfd_generic_is_group_section}
1022
bfd_boolean bfd_generic_is_group_section (bfd *, const asection *sec);
1024
@strong{Description}@*
1025
Returns TRUE if @var{sec} is a member of a group.
1027
@findex bfd_generic_discard_group
1028
@subsubsection @code{bfd_generic_discard_group}
1031
bfd_boolean bfd_generic_discard_group (bfd *abfd, asection *group);
1033
@strong{Description}@*
1034
Remove all members of @var{group} from the output.
added
removed
binutils-2.23.52.20130611/builddir-aarch64-linux-gnu/bfd/doc/section.texi
