1 /* Object file "section" support for the BFD library.
2 Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011,
5 Free Software Foundation, Inc.
6 Written by Cygnus Support.
8 This file is part of BFD, the Binary File Descriptor library.
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program; if not, write to the Free Software
22 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
23 MA 02110-1301, USA. */
29 The raw data contained within a BFD is maintained through the
30 section abstraction. A single BFD may have any number of
31 sections. It keeps hold of them by pointing to the first;
32 each one points to the next in the list.
34 Sections are supported in BFD in <<section.c>>.
40 @* section prototypes::
44 Section Input, Section Output, Sections, Sections
48 When a BFD is opened for reading, the section structures are
49 created and attached to the BFD.
51 Each section has a name which describes the section in the
52 outside world---for example, <<a.out>> would contain at least
53 three sections, called <<.text>>, <<.data>> and <<.bss>>.
55 Names need not be unique; for example a COFF file may have several
56 sections named <<.data>>.
58 Sometimes a BFD will contain more than the ``natural'' number of
59 sections. A back end may attach other sections containing
60 constructor data, or an application may add a section (using
61 <<bfd_make_section>>) to the sections attached to an already open
62 BFD. For example, the linker creates an extra section
63 <<COMMON>> for each input file's BFD to hold information about
66 The raw data is not necessarily read in when
67 the section descriptor is created. Some targets may leave the
68 data in place until a <<bfd_get_section_contents>> call is
69 made. Other back ends may read in all the data at once. For
70 example, an S-record file has to be read once to determine the
71 size of the data. An IEEE-695 file doesn't contain raw data in
72 sections, but data and relocation expressions intermixed, so
73 the data area has to be parsed to get out the data and
77 Section Output, typedef asection, Section Input, Sections
82 To write a new object style BFD, the various sections to be
83 written have to be created. They are attached to the BFD in
84 the same way as input sections; data is written to the
85 sections using <<bfd_set_section_contents>>.
87 Any program that creates or combines sections (e.g., the assembler
88 and linker) must use the <<asection>> fields <<output_section>> and
89 <<output_offset>> to indicate the file sections to which each
90 section must be written. (If the section is being created from
91 scratch, <<output_section>> should probably point to the section
92 itself and <<output_offset>> should probably be zero.)
94 The data to be written comes from input sections attached
95 (via <<output_section>> pointers) to
96 the output sections. The output section structure can be
97 considered a filter for the input section: the output section
98 determines the vma of the output data and the name, but the
99 input section determines the offset into the output section of
100 the data to be written.
102 E.g., to create a section "O", starting at 0x100, 0x123 long,
103 containing two subsections, "A" at offset 0x0 (i.e., at vma
104 0x100) and "B" at offset 0x20 (i.e., at vma 0x120) the <<asection>>
105 structures would look like:
110 | output_section -----------> section name "O"
112 | section name "B" | size 0x123
113 | output_offset 0x20 |
115 | output_section --------|
120 The data within a section is stored in a @dfn{link_order}.
121 These are much like the fixups in <<gas>>. The link_order
122 abstraction allows a section to grow and shrink within itself.
124 A link_order knows how big it is, and which is the next
125 link_order and where the raw data for it is; it also points to
126 a list of relocations which apply to it.
128 The link_order is used by the linker to perform relaxing on
129 final code. The compiler creates code which is as big as
130 necessary to make it work without relaxing, and the user can
131 select whether to relax. Sometimes relaxing takes a lot of
132 time. The linker runs around the relocations to see if any
133 are attached to data which can be shrunk, if so it does it on
134 a link_order by link_order basis.
146 typedef asection, section prototypes, Section Output, Sections
150 Here is the section structure:
154 .typedef struct bfd_section
156 . {* The name of the section; the name isn't a copy, the pointer is
157 . the same as that passed to bfd_make_section. *}
160 . {* A unique sequence number. *}
163 . {* Which section in the bfd; 0..n-1 as sections are created in a bfd. *}
166 . {* The next section in the list belonging to the BFD, or NULL. *}
167 . struct bfd_section *next;
169 . {* The previous section in the list belonging to the BFD, or NULL. *}
170 . struct bfd_section *prev;
172 . {* The field flags contains attributes of the section. Some
173 . flags are read in from the object file, and some are
174 . synthesized from other information. *}
177 .#define SEC_NO_FLAGS 0x000
179 . {* Tells the OS to allocate space for this section when loading.
180 . This is clear for a section containing debug information only. *}
181 .#define SEC_ALLOC 0x001
183 . {* Tells the OS to load the section from the file when loading.
184 . This is clear for a .bss section. *}
185 .#define SEC_LOAD 0x002
187 . {* The section contains data still to be relocated, so there is
188 . some relocation information too. *}
189 .#define SEC_RELOC 0x004
191 . {* A signal to the OS that the section contains read only data. *}
192 .#define SEC_READONLY 0x008
194 . {* The section contains code only. *}
195 .#define SEC_CODE 0x010
197 . {* The section contains data only. *}
198 .#define SEC_DATA 0x020
200 . {* The section will reside in ROM. *}
201 .#define SEC_ROM 0x040
203 . {* The section contains constructor information. This section
204 . type is used by the linker to create lists of constructors and
205 . destructors used by <<g++>>. When a back end sees a symbol
206 . which should be used in a constructor list, it creates a new
207 . section for the type of name (e.g., <<__CTOR_LIST__>>), attaches
208 . the symbol to it, and builds a relocation. To build the lists
209 . of constructors, all the linker has to do is catenate all the
210 . sections called <<__CTOR_LIST__>> and relocate the data
211 . contained within - exactly the operations it would peform on
213 .#define SEC_CONSTRUCTOR 0x080
215 . {* The section has contents - a data section could be
216 . <<SEC_ALLOC>> | <<SEC_HAS_CONTENTS>>; a debug section could be
217 . <<SEC_HAS_CONTENTS>> *}
218 .#define SEC_HAS_CONTENTS 0x100
220 . {* An instruction to the linker to not output the section
221 . even if it has information which would normally be written. *}
222 .#define SEC_NEVER_LOAD 0x200
224 . {* The section contains thread local data. *}
225 .#define SEC_THREAD_LOCAL 0x400
227 . {* The section has GOT references. This flag is only for the
228 . linker, and is currently only used by the elf32-hppa back end.
229 . It will be set if global offset table references were detected
230 . in this section, which indicate to the linker that the section
231 . contains PIC code, and must be handled specially when doing a
233 .#define SEC_HAS_GOT_REF 0x800
235 . {* The section contains common symbols (symbols may be defined
236 . multiple times, the value of a symbol is the amount of
237 . space it requires, and the largest symbol value is the one
238 . used). Most targets have exactly one of these (which we
239 . translate to bfd_com_section_ptr), but ECOFF has two. *}
240 .#define SEC_IS_COMMON 0x1000
242 . {* The section contains only debugging information. For
243 . example, this is set for ELF .debug and .stab sections.
244 . strip tests this flag to see if a section can be
246 .#define SEC_DEBUGGING 0x2000
248 . {* The contents of this section are held in memory pointed to
249 . by the contents field. This is checked by bfd_get_section_contents,
250 . and the data is retrieved from memory if appropriate. *}
251 .#define SEC_IN_MEMORY 0x4000
253 . {* The contents of this section are to be excluded by the
254 . linker for executable and shared objects unless those
255 . objects are to be further relocated. *}
256 .#define SEC_EXCLUDE 0x8000
258 . {* The contents of this section are to be sorted based on the sum of
259 . the symbol and addend values specified by the associated relocation
260 . entries. Entries without associated relocation entries will be
261 . appended to the end of the section in an unspecified order. *}
262 .#define SEC_SORT_ENTRIES 0x10000
264 . {* When linking, duplicate sections of the same name should be
265 . discarded, rather than being combined into a single section as
266 . is usually done. This is similar to how common symbols are
267 . handled. See SEC_LINK_DUPLICATES below. *}
268 .#define SEC_LINK_ONCE 0x20000
270 . {* If SEC_LINK_ONCE is set, this bitfield describes how the linker
271 . should handle duplicate sections. *}
272 .#define SEC_LINK_DUPLICATES 0xc0000
274 . {* This value for SEC_LINK_DUPLICATES means that duplicate
275 . sections with the same name should simply be discarded. *}
276 .#define SEC_LINK_DUPLICATES_DISCARD 0x0
278 . {* This value for SEC_LINK_DUPLICATES means that the linker
279 . should warn if there are any duplicate sections, although
280 . it should still only link one copy. *}
281 .#define SEC_LINK_DUPLICATES_ONE_ONLY 0x40000
283 . {* This value for SEC_LINK_DUPLICATES means that the linker
284 . should warn if any duplicate sections are a different size. *}
285 .#define SEC_LINK_DUPLICATES_SAME_SIZE 0x80000
287 . {* This value for SEC_LINK_DUPLICATES means that the linker
288 . should warn if any duplicate sections contain different
290 .#define SEC_LINK_DUPLICATES_SAME_CONTENTS \
291 . (SEC_LINK_DUPLICATES_ONE_ONLY | SEC_LINK_DUPLICATES_SAME_SIZE)
293 . {* This section was created by the linker as part of dynamic
294 . relocation or other arcane processing. It is skipped when
295 . going through the first-pass output, trusting that someone
296 . else up the line will take care of it later. *}
297 .#define SEC_LINKER_CREATED 0x100000
299 . {* This section should not be subject to garbage collection.
300 . Also set to inform the linker that this section should not be
301 . listed in the link map as discarded. *}
302 .#define SEC_KEEP 0x200000
304 . {* This section contains "short" data, and should be placed
306 .#define SEC_SMALL_DATA 0x400000
308 . {* Attempt to merge identical entities in the section.
309 . Entity size is given in the entsize field. *}
310 .#define SEC_MERGE 0x800000
312 . {* If given with SEC_MERGE, entities to merge are zero terminated
313 . strings where entsize specifies character size instead of fixed
315 .#define SEC_STRINGS 0x1000000
317 . {* This section contains data about section groups. *}
318 .#define SEC_GROUP 0x2000000
320 . {* The section is a COFF shared library section. This flag is
321 . only for the linker. If this type of section appears in
322 . the input file, the linker must copy it to the output file
323 . without changing the vma or size. FIXME: Although this
324 . was originally intended to be general, it really is COFF
325 . specific (and the flag was renamed to indicate this). It
326 . might be cleaner to have some more general mechanism to
327 . allow the back end to control what the linker does with
329 .#define SEC_COFF_SHARED_LIBRARY 0x4000000
331 . {* This input section should be copied to output in reverse order
332 . as an array of pointers. This is for ELF linker internal use
334 .#define SEC_ELF_REVERSE_COPY 0x4000000
336 . {* This section contains data which may be shared with other
337 . executables or shared objects. This is for COFF only. *}
338 .#define SEC_COFF_SHARED 0x8000000
340 . {* When a section with this flag is being linked, then if the size of
341 . the input section is less than a page, it should not cross a page
342 . boundary. If the size of the input section is one page or more,
343 . it should be aligned on a page boundary. This is for TI
344 . TMS320C54X only. *}
345 .#define SEC_TIC54X_BLOCK 0x10000000
347 . {* Conditionally link this section; do not link if there are no
348 . references found to any symbol in the section. This is for TI
349 . TMS320C54X only. *}
350 .#define SEC_TIC54X_CLINK 0x20000000
352 . {* Indicate that section has the no read flag set. This happens
353 . when memory read flag isn't set. *}
354 .#define SEC_COFF_NOREAD 0x40000000
356 . {* End of section flags. *}
358 . {* Some internal packed boolean fields. *}
360 . {* See the vma field. *}
361 . unsigned int user_set_vma : 1;
363 . {* A mark flag used by some of the linker backends. *}
364 . unsigned int linker_mark : 1;
366 . {* Another mark flag used by some of the linker backends. Set for
367 . output sections that have an input section. *}
368 . unsigned int linker_has_input : 1;
370 . {* Mark flag used by some linker backends for garbage collection. *}
371 . unsigned int gc_mark : 1;
373 . {* Section compression status. *}
374 . unsigned int compress_status : 2;
375 .#define COMPRESS_SECTION_NONE 0
376 .#define COMPRESS_SECTION_DONE 1
377 .#define DECOMPRESS_SECTION_SIZED 2
379 . {* The following flags are used by the ELF linker. *}
381 . {* Mark sections which have been allocated to segments. *}
382 . unsigned int segment_mark : 1;
384 . {* Type of sec_info information. *}
385 . unsigned int sec_info_type:3;
386 .#define SEC_INFO_TYPE_NONE 0
387 .#define SEC_INFO_TYPE_STABS 1
388 .#define SEC_INFO_TYPE_MERGE 2
389 .#define SEC_INFO_TYPE_EH_FRAME 3
390 .#define SEC_INFO_TYPE_JUST_SYMS 4
392 . {* Nonzero if this section uses RELA relocations, rather than REL. *}
393 . unsigned int use_rela_p:1;
395 . {* Bits used by various backends. The generic code doesn't touch
398 . unsigned int sec_flg0:1;
399 . unsigned int sec_flg1:1;
400 . unsigned int sec_flg2:1;
401 . unsigned int sec_flg3:1;
402 . unsigned int sec_flg4:1;
403 . unsigned int sec_flg5:1;
405 . {* End of internal packed boolean fields. *}
407 . {* The virtual memory address of the section - where it will be
408 . at run time. The symbols are relocated against this. The
409 . user_set_vma flag is maintained by bfd; if it's not set, the
410 . backend can assign addresses (for example, in <<a.out>>, where
411 . the default address for <<.data>> is dependent on the specific
412 . target and various flags). *}
415 . {* The load address of the section - where it would be in a
416 . rom image; really only used for writing section header
420 . {* The size of the section in octets, as it will be output.
421 . Contains a value even if the section has no contents (e.g., the
422 . size of <<.bss>>). *}
423 . bfd_size_type size;
425 . {* For input sections, the original size on disk of the section, in
426 . octets. This field should be set for any section whose size is
427 . changed by linker relaxation. It is required for sections where
428 . the linker relaxation scheme doesn't cache altered section and
429 . reloc contents (stabs, eh_frame, SEC_MERGE, some coff relaxing
430 . targets), and thus the original size needs to be kept to read the
431 . section multiple times. For output sections, rawsize holds the
432 . section size calculated on a previous linker relaxation pass. *}
433 . bfd_size_type rawsize;
435 . {* The compressed size of the section in octets. *}
436 . bfd_size_type compressed_size;
438 . {* Relaxation table. *}
439 . struct relax_table *relax;
441 . {* Count of used relaxation table entries. *}
445 . {* If this section is going to be output, then this value is the
446 . offset in *bytes* into the output section of the first byte in the
447 . input section (byte ==> smallest addressable unit on the
448 . target). In most cases, if this was going to start at the
449 . 100th octet (8-bit quantity) in the output section, this value
450 . would be 100. However, if the target byte size is 16 bits
451 . (bfd_octets_per_byte is "2"), this value would be 50. *}
452 . bfd_vma output_offset;
454 . {* The output section through which to map on output. *}
455 . struct bfd_section *output_section;
457 . {* The alignment requirement of the section, as an exponent of 2 -
458 . e.g., 3 aligns to 2^3 (or 8). *}
459 . unsigned int alignment_power;
461 . {* If an input section, a pointer to a vector of relocation
462 . records for the data in this section. *}
463 . struct reloc_cache_entry *relocation;
465 . {* If an output section, a pointer to a vector of pointers to
466 . relocation records for the data in this section. *}
467 . struct reloc_cache_entry **orelocation;
469 . {* The number of relocation records in one of the above. *}
470 . unsigned reloc_count;
472 . {* Information below is back end specific - and not always used
475 . {* File position of section data. *}
478 . {* File position of relocation info. *}
479 . file_ptr rel_filepos;
481 . {* File position of line data. *}
482 . file_ptr line_filepos;
484 . {* Pointer to data for applications. *}
487 . {* If the SEC_IN_MEMORY flag is set, this points to the actual
489 . unsigned char *contents;
491 . {* Attached line number information. *}
494 . {* Number of line number records. *}
495 . unsigned int lineno_count;
497 . {* Entity size for merging purposes. *}
498 . unsigned int entsize;
500 . {* Points to the kept section if this section is a link-once section,
501 . and is discarded. *}
502 . struct bfd_section *kept_section;
504 . {* When a section is being output, this value changes as more
505 . linenumbers are written out. *}
506 . file_ptr moving_line_filepos;
508 . {* What the section number is in the target world. *}
513 . {* If this is a constructor section then here is a list of the
514 . relocations created to relocate items within it. *}
515 . struct relent_chain *constructor_chain;
517 . {* The BFD which owns the section. *}
520 . {* INPUT_SECTION_FLAGS if specified in the linker script. *}
521 . struct flag_info *section_flag_info;
523 . {* A symbol which points at this section only. *}
524 . struct bfd_symbol *symbol;
525 . struct bfd_symbol **symbol_ptr_ptr;
527 . {* Early in the link process, map_head and map_tail are used to build
528 . a list of input sections attached to an output section. Later,
529 . output sections use these fields for a list of bfd_link_order
532 . struct bfd_link_order *link_order;
533 . struct bfd_section *s;
534 . } map_head, map_tail;
537 .{* Relax table contains information about instructions which can
538 . be removed by relaxation -- replacing a long address with a
540 .struct relax_table {
541 . {* Address where bytes may be deleted. *}
544 . {* Number of bytes to be deleted. *}
548 .{* These sections are global, and are managed by BFD. The application
549 . and target back end are not permitted to change the values in
550 . these sections. New code should use the section_ptr macros rather
551 . than referring directly to the const sections. The const sections
552 . may eventually vanish. *}
553 .#define BFD_ABS_SECTION_NAME "*ABS*"
554 .#define BFD_UND_SECTION_NAME "*UND*"
555 .#define BFD_COM_SECTION_NAME "*COM*"
556 .#define BFD_IND_SECTION_NAME "*IND*"
558 .{* The absolute section. *}
559 .extern asection bfd_abs_section;
560 .#define bfd_abs_section_ptr ((asection *) &bfd_abs_section)
561 .#define bfd_is_abs_section(sec) ((sec) == bfd_abs_section_ptr)
562 .{* Pointer to the undefined section. *}
563 .extern asection bfd_und_section;
564 .#define bfd_und_section_ptr ((asection *) &bfd_und_section)
565 .#define bfd_is_und_section(sec) ((sec) == bfd_und_section_ptr)
566 .{* Pointer to the common section. *}
567 .extern asection bfd_com_section;
568 .#define bfd_com_section_ptr ((asection *) &bfd_com_section)
569 .{* Pointer to the indirect section. *}
570 .extern asection bfd_ind_section;
571 .#define bfd_ind_section_ptr ((asection *) &bfd_ind_section)
572 .#define bfd_is_ind_section(sec) ((sec) == bfd_ind_section_ptr)
574 .#define bfd_is_const_section(SEC) \
575 . ( ((SEC) == bfd_abs_section_ptr) \
576 . || ((SEC) == bfd_und_section_ptr) \
577 . || ((SEC) == bfd_com_section_ptr) \
578 . || ((SEC) == bfd_ind_section_ptr))
580 .{* Macros to handle insertion and deletion of a bfd's sections. These
581 . only handle the list pointers, ie. do not adjust section_count,
582 . target_index etc. *}
583 .#define bfd_section_list_remove(ABFD, S) \
586 . asection *_s = S; \
587 . asection *_next = _s->next; \
588 . asection *_prev = _s->prev; \
590 . _prev->next = _next; \
592 . (ABFD)->sections = _next; \
594 . _next->prev = _prev; \
596 . (ABFD)->section_last = _prev; \
599 .#define bfd_section_list_append(ABFD, S) \
602 . asection *_s = S; \
603 . bfd *_abfd = ABFD; \
605 . if (_abfd->section_last) \
607 . _s->prev = _abfd->section_last; \
608 . _abfd->section_last->next = _s; \
613 . _abfd->sections = _s; \
615 . _abfd->section_last = _s; \
618 .#define bfd_section_list_prepend(ABFD, S) \
621 . asection *_s = S; \
622 . bfd *_abfd = ABFD; \
624 . if (_abfd->sections) \
626 . _s->next = _abfd->sections; \
627 . _abfd->sections->prev = _s; \
632 . _abfd->section_last = _s; \
634 . _abfd->sections = _s; \
637 .#define bfd_section_list_insert_after(ABFD, A, S) \
640 . asection *_a = A; \
641 . asection *_s = S; \
642 . asection *_next = _a->next; \
643 . _s->next = _next; \
647 . _next->prev = _s; \
649 . (ABFD)->section_last = _s; \
652 .#define bfd_section_list_insert_before(ABFD, B, S) \
655 . asection *_b = B; \
656 . asection *_s = S; \
657 . asection *_prev = _b->prev; \
658 . _s->prev = _prev; \
662 . _prev->next = _s; \
664 . (ABFD)->sections = _s; \
667 .#define bfd_section_removed_from_list(ABFD, S) \
668 . ((S)->next == NULL ? (ABFD)->section_last != (S) : (S)->next->prev != (S))
670 .#define BFD_FAKE_SECTION(SEC, FLAGS, SYM, NAME, IDX) \
671 . {* name, id, index, next, prev, flags, user_set_vma, *} \
672 . { NAME, IDX, 0, NULL, NULL, FLAGS, 0, \
674 . {* linker_mark, linker_has_input, gc_mark, decompress_status, *} \
677 . {* segment_mark, sec_info_type, use_rela_p, *} \
680 . {* sec_flg0, sec_flg1, sec_flg2, sec_flg3, sec_flg4, sec_flg5, *} \
681 . 0, 0, 0, 0, 0, 0, \
683 . {* vma, lma, size, rawsize, compressed_size, relax, relax_count, *} \
684 . 0, 0, 0, 0, 0, 0, 0, \
686 . {* output_offset, output_section, alignment_power, *} \
687 . 0, (struct bfd_section *) &SEC, 0, \
689 . {* relocation, orelocation, reloc_count, filepos, rel_filepos, *} \
690 . NULL, NULL, 0, 0, 0, \
692 . {* line_filepos, userdata, contents, lineno, lineno_count, *} \
693 . 0, NULL, NULL, NULL, 0, \
695 . {* entsize, kept_section, moving_line_filepos, *} \
698 . {* target_index, used_by_bfd, constructor_chain, owner, *} \
699 . 0, NULL, NULL, NULL, \
704 . {* symbol, symbol_ptr_ptr, *} \
705 . (struct bfd_symbol *) SYM, &SEC.symbol, \
707 . {* map_head, map_tail *} \
708 . { NULL }, { NULL } \
713 /* We use a macro to initialize the static asymbol structures because
714 traditional C does not permit us to initialize a union member while
715 gcc warns if we don't initialize it. */
716 /* the_bfd, name, value, attr, section [, udata] */
718 #define GLOBAL_SYM_INIT(NAME, SECTION) \
719 { 0, NAME, 0, BSF_SECTION_SYM, (asection *) SECTION, { 0 }}
721 #define GLOBAL_SYM_INIT(NAME, SECTION) \
722 { 0, NAME, 0, BSF_SECTION_SYM, (asection *) SECTION }
725 /* These symbols are global, not specific to any BFD. Therefore, anything
726 that tries to change them is broken, and should be repaired. */
728 static const asymbol global_syms
[] =
730 GLOBAL_SYM_INIT (BFD_COM_SECTION_NAME
, &bfd_com_section
),
731 GLOBAL_SYM_INIT (BFD_UND_SECTION_NAME
, &bfd_und_section
),
732 GLOBAL_SYM_INIT (BFD_ABS_SECTION_NAME
, &bfd_abs_section
),
733 GLOBAL_SYM_INIT (BFD_IND_SECTION_NAME
, &bfd_ind_section
)
736 #define STD_SECTION(SEC, FLAGS, NAME, IDX) \
737 asection SEC = BFD_FAKE_SECTION(SEC, FLAGS, &global_syms[IDX], \
740 STD_SECTION (bfd_com_section
, SEC_IS_COMMON
, BFD_COM_SECTION_NAME
, 0);
741 STD_SECTION (bfd_und_section
, 0, BFD_UND_SECTION_NAME
, 1);
742 STD_SECTION (bfd_abs_section
, 0, BFD_ABS_SECTION_NAME
, 2);
743 STD_SECTION (bfd_ind_section
, 0, BFD_IND_SECTION_NAME
, 3);
746 /* Initialize an entry in the section hash table. */
748 struct bfd_hash_entry
*
749 bfd_section_hash_newfunc (struct bfd_hash_entry
*entry
,
750 struct bfd_hash_table
*table
,
753 /* Allocate the structure if it has not already been allocated by a
757 entry
= (struct bfd_hash_entry
*)
758 bfd_hash_allocate (table
, sizeof (struct section_hash_entry
));
763 /* Call the allocation method of the superclass. */
764 entry
= bfd_hash_newfunc (entry
, table
, string
);
766 memset (&((struct section_hash_entry
*) entry
)->section
, 0,
772 #define section_hash_lookup(table, string, create, copy) \
773 ((struct section_hash_entry *) \
774 bfd_hash_lookup ((table), (string), (create), (copy)))
776 /* Create a symbol whose only job is to point to this section. This
777 is useful for things like relocs which are relative to the base
781 _bfd_generic_new_section_hook (bfd
*abfd
, asection
*newsect
)
783 newsect
->symbol
= bfd_make_empty_symbol (abfd
);
784 if (newsect
->symbol
== NULL
)
787 newsect
->symbol
->name
= newsect
->name
;
788 newsect
->symbol
->value
= 0;
789 newsect
->symbol
->section
= newsect
;
790 newsect
->symbol
->flags
= BSF_SECTION_SYM
;
792 newsect
->symbol_ptr_ptr
= &newsect
->symbol
;
796 /* Initializes a new section. NEWSECT->NAME is already set. */
799 bfd_section_init (bfd
*abfd
, asection
*newsect
)
801 static int section_id
= 0x10; /* id 0 to 3 used by STD_SECTION. */
803 newsect
->id
= section_id
;
804 newsect
->index
= abfd
->section_count
;
805 newsect
->owner
= abfd
;
807 if (! BFD_SEND (abfd
, _new_section_hook
, (abfd
, newsect
)))
811 abfd
->section_count
++;
812 bfd_section_list_append (abfd
, newsect
);
819 section prototypes, , typedef asection, Sections
823 These are the functions exported by the section handling part of BFD.
828 bfd_section_list_clear
831 void bfd_section_list_clear (bfd *);
834 Clears the section list, and also resets the section count and
839 bfd_section_list_clear (bfd
*abfd
)
841 abfd
->sections
= NULL
;
842 abfd
->section_last
= NULL
;
843 abfd
->section_count
= 0;
844 memset (abfd
->section_htab
.table
, 0,
845 abfd
->section_htab
.size
* sizeof (struct bfd_hash_entry
*));
850 bfd_get_section_by_name
853 asection *bfd_get_section_by_name (bfd *abfd, const char *name);
856 Run through @var{abfd} and return the one of the
857 <<asection>>s whose name matches @var{name}, otherwise <<NULL>>.
858 @xref{Sections}, for more information.
860 This should only be used in special cases; the normal way to process
861 all sections of a given name is to use <<bfd_map_over_sections>> and
862 <<strcmp>> on the name (or better yet, base it on the section flags
863 or something else) for each section.
867 bfd_get_section_by_name (bfd
*abfd
, const char *name
)
869 struct section_hash_entry
*sh
;
871 sh
= section_hash_lookup (&abfd
->section_htab
, name
, FALSE
, FALSE
);
880 bfd_get_section_by_name_if
883 asection *bfd_get_section_by_name_if
886 bfd_boolean (*func) (bfd *abfd, asection *sect, void *obj),
890 Call the provided function @var{func} for each section
891 attached to the BFD @var{abfd} whose name matches @var{name},
892 passing @var{obj} as an argument. The function will be called
895 | func (abfd, the_section, obj);
897 It returns the first section for which @var{func} returns true,
903 bfd_get_section_by_name_if (bfd
*abfd
, const char *name
,
904 bfd_boolean (*operation
) (bfd
*,
909 struct section_hash_entry
*sh
;
912 sh
= section_hash_lookup (&abfd
->section_htab
, name
, FALSE
, FALSE
);
916 hash
= sh
->root
.hash
;
919 if ((*operation
) (abfd
, &sh
->section
, user_storage
))
921 sh
= (struct section_hash_entry
*) sh
->root
.next
;
923 while (sh
!= NULL
&& sh
->root
.hash
== hash
924 && strcmp (sh
->root
.string
, name
) == 0);
931 bfd_get_unique_section_name
934 char *bfd_get_unique_section_name
935 (bfd *abfd, const char *templat, int *count);
938 Invent a section name that is unique in @var{abfd} by tacking
939 a dot and a digit suffix onto the original @var{templat}. If
940 @var{count} is non-NULL, then it specifies the first number
941 tried as a suffix to generate a unique name. The value
942 pointed to by @var{count} will be incremented in this case.
946 bfd_get_unique_section_name (bfd
*abfd
, const char *templat
, int *count
)
952 len
= strlen (templat
);
953 sname
= (char *) bfd_malloc (len
+ 8);
956 memcpy (sname
, templat
, len
);
963 /* If we have a million sections, something is badly wrong. */
966 sprintf (sname
+ len
, ".%d", num
++);
968 while (section_hash_lookup (&abfd
->section_htab
, sname
, FALSE
, FALSE
));
977 bfd_make_section_old_way
980 asection *bfd_make_section_old_way (bfd *abfd, const char *name);
983 Create a new empty section called @var{name}
984 and attach it to the end of the chain of sections for the
985 BFD @var{abfd}. An attempt to create a section with a name which
986 is already in use returns its pointer without changing the
989 It has the funny name since this is the way it used to be
990 before it was rewritten....
993 o <<bfd_error_invalid_operation>> -
994 If output has already started for this BFD.
995 o <<bfd_error_no_memory>> -
996 If memory allocation fails.
1001 bfd_make_section_old_way (bfd
*abfd
, const char *name
)
1005 if (abfd
->output_has_begun
)
1007 bfd_set_error (bfd_error_invalid_operation
);
1011 if (strcmp (name
, BFD_ABS_SECTION_NAME
) == 0)
1012 newsect
= bfd_abs_section_ptr
;
1013 else if (strcmp (name
, BFD_COM_SECTION_NAME
) == 0)
1014 newsect
= bfd_com_section_ptr
;
1015 else if (strcmp (name
, BFD_UND_SECTION_NAME
) == 0)
1016 newsect
= bfd_und_section_ptr
;
1017 else if (strcmp (name
, BFD_IND_SECTION_NAME
) == 0)
1018 newsect
= bfd_ind_section_ptr
;
1021 struct section_hash_entry
*sh
;
1023 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1027 newsect
= &sh
->section
;
1028 if (newsect
->name
!= NULL
)
1030 /* Section already exists. */
1034 newsect
->name
= name
;
1035 return bfd_section_init (abfd
, newsect
);
1038 /* Call new_section_hook when "creating" the standard abs, com, und
1039 and ind sections to tack on format specific section data.
1040 Also, create a proper section symbol. */
1041 if (! BFD_SEND (abfd
, _new_section_hook
, (abfd
, newsect
)))
1048 bfd_make_section_anyway_with_flags
1051 asection *bfd_make_section_anyway_with_flags
1052 (bfd *abfd, const char *name, flagword flags);
1055 Create a new empty section called @var{name} and attach it to the end of
1056 the chain of sections for @var{abfd}. Create a new section even if there
1057 is already a section with that name. Also set the attributes of the
1058 new section to the value @var{flags}.
1060 Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1061 o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1062 o <<bfd_error_no_memory>> - If memory allocation fails.
1066 bfd_make_section_anyway_with_flags (bfd
*abfd
, const char *name
,
1069 struct section_hash_entry
*sh
;
1072 if (abfd
->output_has_begun
)
1074 bfd_set_error (bfd_error_invalid_operation
);
1078 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1082 newsect
= &sh
->section
;
1083 if (newsect
->name
!= NULL
)
1085 /* We are making a section of the same name. Put it in the
1086 section hash table. Even though we can't find it directly by a
1087 hash lookup, we'll be able to find the section by traversing
1088 sh->root.next quicker than looking at all the bfd sections. */
1089 struct section_hash_entry
*new_sh
;
1090 new_sh
= (struct section_hash_entry
*)
1091 bfd_section_hash_newfunc (NULL
, &abfd
->section_htab
, name
);
1095 new_sh
->root
= sh
->root
;
1096 sh
->root
.next
= &new_sh
->root
;
1097 newsect
= &new_sh
->section
;
1100 newsect
->flags
= flags
;
1101 newsect
->name
= name
;
1102 return bfd_section_init (abfd
, newsect
);
1107 bfd_make_section_anyway
1110 asection *bfd_make_section_anyway (bfd *abfd, const char *name);
1113 Create a new empty section called @var{name} and attach it to the end of
1114 the chain of sections for @var{abfd}. Create a new section even if there
1115 is already a section with that name.
1117 Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1118 o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1119 o <<bfd_error_no_memory>> - If memory allocation fails.
1123 bfd_make_section_anyway (bfd
*abfd
, const char *name
)
1125 return bfd_make_section_anyway_with_flags (abfd
, name
, 0);
1130 bfd_make_section_with_flags
1133 asection *bfd_make_section_with_flags
1134 (bfd *, const char *name, flagword flags);
1137 Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1138 bfd_set_error ()) without changing the section chain if there is already a
1139 section named @var{name}. Also set the attributes of the new section to
1140 the value @var{flags}. If there is an error, return <<NULL>> and set
1145 bfd_make_section_with_flags (bfd
*abfd
, const char *name
,
1148 struct section_hash_entry
*sh
;
1151 if (abfd
->output_has_begun
)
1153 bfd_set_error (bfd_error_invalid_operation
);
1157 if (strcmp (name
, BFD_ABS_SECTION_NAME
) == 0
1158 || strcmp (name
, BFD_COM_SECTION_NAME
) == 0
1159 || strcmp (name
, BFD_UND_SECTION_NAME
) == 0
1160 || strcmp (name
, BFD_IND_SECTION_NAME
) == 0)
1163 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1167 newsect
= &sh
->section
;
1168 if (newsect
->name
!= NULL
)
1170 /* Section already exists. */
1174 newsect
->name
= name
;
1175 newsect
->flags
= flags
;
1176 return bfd_section_init (abfd
, newsect
);
1184 asection *bfd_make_section (bfd *, const char *name);
1187 Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1188 bfd_set_error ()) without changing the section chain if there is already a
1189 section named @var{name}. If there is an error, return <<NULL>> and set
1194 bfd_make_section (bfd
*abfd
, const char *name
)
1196 return bfd_make_section_with_flags (abfd
, name
, 0);
1201 bfd_set_section_flags
1204 bfd_boolean bfd_set_section_flags
1205 (bfd *abfd, asection *sec, flagword flags);
1208 Set the attributes of the section @var{sec} in the BFD
1209 @var{abfd} to the value @var{flags}. Return <<TRUE>> on success,
1210 <<FALSE>> on error. Possible error returns are:
1212 o <<bfd_error_invalid_operation>> -
1213 The section cannot have one or more of the attributes
1214 requested. For example, a .bss section in <<a.out>> may not
1215 have the <<SEC_HAS_CONTENTS>> field set.
1220 bfd_set_section_flags (bfd
*abfd ATTRIBUTE_UNUSED
,
1224 section
->flags
= flags
;
1233 void bfd_rename_section
1234 (bfd *abfd, asection *sec, const char *newname);
1237 Rename section @var{sec} in @var{abfd} to @var{newname}.
1241 bfd_rename_section (bfd
*abfd
, sec_ptr sec
, const char *newname
)
1243 struct section_hash_entry
*sh
;
1245 sh
= (struct section_hash_entry
*)
1246 ((char *) sec
- offsetof (struct section_hash_entry
, section
));
1247 sh
->section
.name
= newname
;
1248 bfd_hash_rename (&abfd
->section_htab
, newname
, &sh
->root
);
1253 bfd_map_over_sections
1256 void bfd_map_over_sections
1258 void (*func) (bfd *abfd, asection *sect, void *obj),
1262 Call the provided function @var{func} for each section
1263 attached to the BFD @var{abfd}, passing @var{obj} as an
1264 argument. The function will be called as if by
1266 | func (abfd, the_section, obj);
1268 This is the preferred method for iterating over sections; an
1269 alternative would be to use a loop:
1272 | for (p = abfd->sections; p != NULL; p = p->next)
1273 | func (abfd, p, ...)
1278 bfd_map_over_sections (bfd
*abfd
,
1279 void (*operation
) (bfd
*, asection
*, void *),
1285 for (sect
= abfd
->sections
; sect
!= NULL
; i
++, sect
= sect
->next
)
1286 (*operation
) (abfd
, sect
, user_storage
);
1288 if (i
!= abfd
->section_count
) /* Debugging */
1294 bfd_sections_find_if
1297 asection *bfd_sections_find_if
1299 bfd_boolean (*operation) (bfd *abfd, asection *sect, void *obj),
1303 Call the provided function @var{operation} for each section
1304 attached to the BFD @var{abfd}, passing @var{obj} as an
1305 argument. The function will be called as if by
1307 | operation (abfd, the_section, obj);
1309 It returns the first section for which @var{operation} returns true.
1314 bfd_sections_find_if (bfd
*abfd
,
1315 bfd_boolean (*operation
) (bfd
*, asection
*, void *),
1320 for (sect
= abfd
->sections
; sect
!= NULL
; sect
= sect
->next
)
1321 if ((*operation
) (abfd
, sect
, user_storage
))
1329 bfd_set_section_size
1332 bfd_boolean bfd_set_section_size
1333 (bfd *abfd, asection *sec, bfd_size_type val);
1336 Set @var{sec} to the size @var{val}. If the operation is
1337 ok, then <<TRUE>> is returned, else <<FALSE>>.
1339 Possible error returns:
1340 o <<bfd_error_invalid_operation>> -
1341 Writing has started to the BFD, so setting the size is invalid.
1346 bfd_set_section_size (bfd
*abfd
, sec_ptr ptr
, bfd_size_type val
)
1348 /* Once you've started writing to any section you cannot create or change
1349 the size of any others. */
1351 if (abfd
->output_has_begun
)
1353 bfd_set_error (bfd_error_invalid_operation
);
1363 bfd_set_section_contents
1366 bfd_boolean bfd_set_section_contents
1367 (bfd *abfd, asection *section, const void *data,
1368 file_ptr offset, bfd_size_type count);
1371 Sets the contents of the section @var{section} in BFD
1372 @var{abfd} to the data starting in memory at @var{data}. The
1373 data is written to the output section starting at offset
1374 @var{offset} for @var{count} octets.
1376 Normally <<TRUE>> is returned, else <<FALSE>>. Possible error
1378 o <<bfd_error_no_contents>> -
1379 The output section does not have the <<SEC_HAS_CONTENTS>>
1380 attribute, so nothing can be written to it.
1383 This routine is front end to the back end function
1384 <<_bfd_set_section_contents>>.
1389 bfd_set_section_contents (bfd
*abfd
,
1391 const void *location
,
1393 bfd_size_type count
)
1397 if (!(bfd_get_section_flags (abfd
, section
) & SEC_HAS_CONTENTS
))
1399 bfd_set_error (bfd_error_no_contents
);
1404 if ((bfd_size_type
) offset
> sz
1406 || offset
+ count
> sz
1407 || count
!= (size_t) count
)
1409 bfd_set_error (bfd_error_bad_value
);
1413 if (!bfd_write_p (abfd
))
1415 bfd_set_error (bfd_error_invalid_operation
);
1419 /* Record a copy of the data in memory if desired. */
1420 if (section
->contents
1421 && location
!= section
->contents
+ offset
)
1422 memcpy (section
->contents
+ offset
, location
, (size_t) count
);
1424 if (BFD_SEND (abfd
, _bfd_set_section_contents
,
1425 (abfd
, section
, location
, offset
, count
)))
1427 abfd
->output_has_begun
= TRUE
;
1436 bfd_get_section_contents
1439 bfd_boolean bfd_get_section_contents
1440 (bfd *abfd, asection *section, void *location, file_ptr offset,
1441 bfd_size_type count);
1444 Read data from @var{section} in BFD @var{abfd}
1445 into memory starting at @var{location}. The data is read at an
1446 offset of @var{offset} from the start of the input section,
1447 and is read for @var{count} bytes.
1449 If the contents of a constructor with the <<SEC_CONSTRUCTOR>>
1450 flag set are requested or if the section does not have the
1451 <<SEC_HAS_CONTENTS>> flag set, then the @var{location} is filled
1452 with zeroes. If no errors occur, <<TRUE>> is returned, else
1457 bfd_get_section_contents (bfd
*abfd
,
1461 bfd_size_type count
)
1465 if (section
->flags
& SEC_CONSTRUCTOR
)
1467 memset (location
, 0, (size_t) count
);
1471 if (abfd
->direction
!= write_direction
&& section
->rawsize
!= 0)
1472 sz
= section
->rawsize
;
1475 if ((bfd_size_type
) offset
> sz
1477 || offset
+ count
> sz
1478 || count
!= (size_t) count
)
1480 bfd_set_error (bfd_error_bad_value
);
1488 if ((section
->flags
& SEC_HAS_CONTENTS
) == 0)
1490 memset (location
, 0, (size_t) count
);
1494 if ((section
->flags
& SEC_IN_MEMORY
) != 0)
1496 if (section
->contents
== NULL
)
1498 /* This can happen because of errors earlier on in the linking process.
1499 We do not want to seg-fault here, so clear the flag and return an
1501 section
->flags
&= ~ SEC_IN_MEMORY
;
1502 bfd_set_error (bfd_error_invalid_operation
);
1506 memcpy (location
, section
->contents
+ offset
, (size_t) count
);
1510 return BFD_SEND (abfd
, _bfd_get_section_contents
,
1511 (abfd
, section
, location
, offset
, count
));
1516 bfd_malloc_and_get_section
1519 bfd_boolean bfd_malloc_and_get_section
1520 (bfd *abfd, asection *section, bfd_byte **buf);
1523 Read all data from @var{section} in BFD @var{abfd}
1524 into a buffer, *@var{buf}, malloc'd by this function.
1528 bfd_malloc_and_get_section (bfd
*abfd
, sec_ptr sec
, bfd_byte
**buf
)
1531 return bfd_get_full_section_contents (abfd
, sec
, buf
);
1535 bfd_copy_private_section_data
1538 bfd_boolean bfd_copy_private_section_data
1539 (bfd *ibfd, asection *isec, bfd *obfd, asection *osec);
1542 Copy private section information from @var{isec} in the BFD
1543 @var{ibfd} to the section @var{osec} in the BFD @var{obfd}.
1544 Return <<TRUE>> on success, <<FALSE>> on error. Possible error
1547 o <<bfd_error_no_memory>> -
1548 Not enough memory exists to create private data for @var{osec}.
1550 .#define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \
1551 . BFD_SEND (obfd, _bfd_copy_private_section_data, \
1552 . (ibfd, isection, obfd, osection))
1557 bfd_generic_is_group_section
1560 bfd_boolean bfd_generic_is_group_section (bfd *, const asection *sec);
1563 Returns TRUE if @var{sec} is a member of a group.
1567 bfd_generic_is_group_section (bfd
*abfd ATTRIBUTE_UNUSED
,
1568 const asection
*sec ATTRIBUTE_UNUSED
)
1575 bfd_generic_discard_group
1578 bfd_boolean bfd_generic_discard_group (bfd *abfd, asection *group);
1581 Remove all members of @var{group} from the output.
1585 bfd_generic_discard_group (bfd
*abfd ATTRIBUTE_UNUSED
,
1586 asection
*group ATTRIBUTE_UNUSED
)