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
551 .extern asection std_section[4];
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 .{* Pointer to the common section. *}
559 .#define bfd_com_section_ptr (&std_section[0])
560 .{* Pointer to the undefined section. *}
561 .#define bfd_und_section_ptr (&std_section[1])
562 .{* Pointer to the absolute section. *}
563 .#define bfd_abs_section_ptr (&std_section[2])
564 .{* Pointer to the indirect section. *}
565 .#define bfd_ind_section_ptr (&std_section[3])
567 .#define bfd_is_und_section(sec) ((sec) == bfd_und_section_ptr)
568 .#define bfd_is_abs_section(sec) ((sec) == bfd_abs_section_ptr)
569 .#define bfd_is_ind_section(sec) ((sec) == bfd_ind_section_ptr)
571 .#define bfd_is_const_section(SEC) \
572 . ( ((SEC) == bfd_abs_section_ptr) \
573 . || ((SEC) == bfd_und_section_ptr) \
574 . || ((SEC) == bfd_com_section_ptr) \
575 . || ((SEC) == bfd_ind_section_ptr))
577 .{* Macros to handle insertion and deletion of a bfd's sections. These
578 . only handle the list pointers, ie. do not adjust section_count,
579 . target_index etc. *}
580 .#define bfd_section_list_remove(ABFD, S) \
583 . asection *_s = S; \
584 . asection *_next = _s->next; \
585 . asection *_prev = _s->prev; \
587 . _prev->next = _next; \
589 . (ABFD)->sections = _next; \
591 . _next->prev = _prev; \
593 . (ABFD)->section_last = _prev; \
596 .#define bfd_section_list_append(ABFD, S) \
599 . asection *_s = S; \
600 . bfd *_abfd = ABFD; \
602 . if (_abfd->section_last) \
604 . _s->prev = _abfd->section_last; \
605 . _abfd->section_last->next = _s; \
610 . _abfd->sections = _s; \
612 . _abfd->section_last = _s; \
615 .#define bfd_section_list_prepend(ABFD, S) \
618 . asection *_s = S; \
619 . bfd *_abfd = ABFD; \
621 . if (_abfd->sections) \
623 . _s->next = _abfd->sections; \
624 . _abfd->sections->prev = _s; \
629 . _abfd->section_last = _s; \
631 . _abfd->sections = _s; \
634 .#define bfd_section_list_insert_after(ABFD, A, S) \
637 . asection *_a = A; \
638 . asection *_s = S; \
639 . asection *_next = _a->next; \
640 . _s->next = _next; \
644 . _next->prev = _s; \
646 . (ABFD)->section_last = _s; \
649 .#define bfd_section_list_insert_before(ABFD, B, S) \
652 . asection *_b = B; \
653 . asection *_s = S; \
654 . asection *_prev = _b->prev; \
655 . _s->prev = _prev; \
659 . _prev->next = _s; \
661 . (ABFD)->sections = _s; \
664 .#define bfd_section_removed_from_list(ABFD, S) \
665 . ((S)->next == NULL ? (ABFD)->section_last != (S) : (S)->next->prev != (S))
667 .#define BFD_FAKE_SECTION(SEC, FLAGS, SYM, NAME, IDX) \
668 . {* name, id, index, next, prev, flags, user_set_vma, *} \
669 . { NAME, IDX, 0, NULL, NULL, FLAGS, 0, \
671 . {* linker_mark, linker_has_input, gc_mark, decompress_status, *} \
674 . {* segment_mark, sec_info_type, use_rela_p, *} \
677 . {* sec_flg0, sec_flg1, sec_flg2, sec_flg3, sec_flg4, sec_flg5, *} \
678 . 0, 0, 0, 0, 0, 0, \
680 . {* vma, lma, size, rawsize, compressed_size, relax, relax_count, *} \
681 . 0, 0, 0, 0, 0, 0, 0, \
683 . {* output_offset, output_section, alignment_power, *} \
686 . {* relocation, orelocation, reloc_count, filepos, rel_filepos, *} \
687 . NULL, NULL, 0, 0, 0, \
689 . {* line_filepos, userdata, contents, lineno, lineno_count, *} \
690 . 0, NULL, NULL, NULL, 0, \
692 . {* entsize, kept_section, moving_line_filepos, *} \
695 . {* target_index, used_by_bfd, constructor_chain, owner, *} \
696 . 0, NULL, NULL, NULL, \
701 . {* symbol, symbol_ptr_ptr, *} \
702 . (struct bfd_symbol *) SYM, &SEC.symbol, \
704 . {* map_head, map_tail *} \
705 . { NULL }, { NULL } \
710 /* We use a macro to initialize the static asymbol structures because
711 traditional C does not permit us to initialize a union member while
712 gcc warns if we don't initialize it. */
713 /* the_bfd, name, value, attr, section [, udata] */
715 #define GLOBAL_SYM_INIT(NAME, SECTION) \
716 { 0, NAME, 0, BSF_SECTION_SYM, SECTION, { 0 }}
718 #define GLOBAL_SYM_INIT(NAME, SECTION) \
719 { 0, NAME, 0, BSF_SECTION_SYM, SECTION }
722 /* These symbols are global, not specific to any BFD. Therefore, anything
723 that tries to change them is broken, and should be repaired. */
725 static const asymbol global_syms
[] =
727 GLOBAL_SYM_INIT (BFD_COM_SECTION_NAME
, bfd_com_section_ptr
),
728 GLOBAL_SYM_INIT (BFD_UND_SECTION_NAME
, bfd_und_section_ptr
),
729 GLOBAL_SYM_INIT (BFD_ABS_SECTION_NAME
, bfd_abs_section_ptr
),
730 GLOBAL_SYM_INIT (BFD_IND_SECTION_NAME
, bfd_ind_section_ptr
)
733 #define STD_SECTION(NAME, IDX, FLAGS) \
734 BFD_FAKE_SECTION(std_section[IDX], FLAGS, &global_syms[IDX], NAME, IDX)
736 asection std_section
[] = {
737 STD_SECTION (BFD_COM_SECTION_NAME
, 0, SEC_IS_COMMON
),
738 STD_SECTION (BFD_UND_SECTION_NAME
, 1, 0),
739 STD_SECTION (BFD_ABS_SECTION_NAME
, 2, 0),
740 STD_SECTION (BFD_IND_SECTION_NAME
, 3, 0)
744 /* Initialize an entry in the section hash table. */
746 struct bfd_hash_entry
*
747 bfd_section_hash_newfunc (struct bfd_hash_entry
*entry
,
748 struct bfd_hash_table
*table
,
751 /* Allocate the structure if it has not already been allocated by a
755 entry
= (struct bfd_hash_entry
*)
756 bfd_hash_allocate (table
, sizeof (struct section_hash_entry
));
761 /* Call the allocation method of the superclass. */
762 entry
= bfd_hash_newfunc (entry
, table
, string
);
764 memset (&((struct section_hash_entry
*) entry
)->section
, 0,
770 #define section_hash_lookup(table, string, create, copy) \
771 ((struct section_hash_entry *) \
772 bfd_hash_lookup ((table), (string), (create), (copy)))
774 /* Create a symbol whose only job is to point to this section. This
775 is useful for things like relocs which are relative to the base
779 _bfd_generic_new_section_hook (bfd
*abfd
, asection
*newsect
)
781 newsect
->symbol
= bfd_make_empty_symbol (abfd
);
782 if (newsect
->symbol
== NULL
)
785 newsect
->symbol
->name
= newsect
->name
;
786 newsect
->symbol
->value
= 0;
787 newsect
->symbol
->section
= newsect
;
788 newsect
->symbol
->flags
= BSF_SECTION_SYM
;
790 newsect
->symbol_ptr_ptr
= &newsect
->symbol
;
794 /* Initializes a new section. NEWSECT->NAME is already set. */
797 bfd_section_init (bfd
*abfd
, asection
*newsect
)
799 static int section_id
= 0x10; /* id 0 to 3 used by STD_SECTION. */
801 newsect
->id
= section_id
;
802 newsect
->index
= abfd
->section_count
;
803 newsect
->owner
= abfd
;
805 if (! BFD_SEND (abfd
, _new_section_hook
, (abfd
, newsect
)))
809 abfd
->section_count
++;
810 bfd_section_list_append (abfd
, newsect
);
817 section prototypes, , typedef asection, Sections
821 These are the functions exported by the section handling part of BFD.
826 bfd_section_list_clear
829 void bfd_section_list_clear (bfd *);
832 Clears the section list, and also resets the section count and
837 bfd_section_list_clear (bfd
*abfd
)
839 abfd
->sections
= NULL
;
840 abfd
->section_last
= NULL
;
841 abfd
->section_count
= 0;
842 memset (abfd
->section_htab
.table
, 0,
843 abfd
->section_htab
.size
* sizeof (struct bfd_hash_entry
*));
848 bfd_get_section_by_name
851 asection *bfd_get_section_by_name (bfd *abfd, const char *name);
854 Run through @var{abfd} and return the one of the
855 <<asection>>s whose name matches @var{name}, otherwise <<NULL>>.
856 @xref{Sections}, for more information.
858 This should only be used in special cases; the normal way to process
859 all sections of a given name is to use <<bfd_map_over_sections>> and
860 <<strcmp>> on the name (or better yet, base it on the section flags
861 or something else) for each section.
865 bfd_get_section_by_name (bfd
*abfd
, const char *name
)
867 struct section_hash_entry
*sh
;
869 sh
= section_hash_lookup (&abfd
->section_htab
, name
, FALSE
, FALSE
);
878 bfd_get_section_by_name_if
881 asection *bfd_get_section_by_name_if
884 bfd_boolean (*func) (bfd *abfd, asection *sect, void *obj),
888 Call the provided function @var{func} for each section
889 attached to the BFD @var{abfd} whose name matches @var{name},
890 passing @var{obj} as an argument. The function will be called
893 | func (abfd, the_section, obj);
895 It returns the first section for which @var{func} returns true,
901 bfd_get_section_by_name_if (bfd
*abfd
, const char *name
,
902 bfd_boolean (*operation
) (bfd
*,
907 struct section_hash_entry
*sh
;
910 sh
= section_hash_lookup (&abfd
->section_htab
, name
, FALSE
, FALSE
);
914 hash
= sh
->root
.hash
;
917 if ((*operation
) (abfd
, &sh
->section
, user_storage
))
919 sh
= (struct section_hash_entry
*) sh
->root
.next
;
921 while (sh
!= NULL
&& sh
->root
.hash
== hash
922 && strcmp (sh
->root
.string
, name
) == 0);
929 bfd_get_unique_section_name
932 char *bfd_get_unique_section_name
933 (bfd *abfd, const char *templat, int *count);
936 Invent a section name that is unique in @var{abfd} by tacking
937 a dot and a digit suffix onto the original @var{templat}. If
938 @var{count} is non-NULL, then it specifies the first number
939 tried as a suffix to generate a unique name. The value
940 pointed to by @var{count} will be incremented in this case.
944 bfd_get_unique_section_name (bfd
*abfd
, const char *templat
, int *count
)
950 len
= strlen (templat
);
951 sname
= (char *) bfd_malloc (len
+ 8);
954 memcpy (sname
, templat
, len
);
961 /* If we have a million sections, something is badly wrong. */
964 sprintf (sname
+ len
, ".%d", num
++);
966 while (section_hash_lookup (&abfd
->section_htab
, sname
, FALSE
, FALSE
));
975 bfd_make_section_old_way
978 asection *bfd_make_section_old_way (bfd *abfd, const char *name);
981 Create a new empty section called @var{name}
982 and attach it to the end of the chain of sections for the
983 BFD @var{abfd}. An attempt to create a section with a name which
984 is already in use returns its pointer without changing the
987 It has the funny name since this is the way it used to be
988 before it was rewritten....
991 o <<bfd_error_invalid_operation>> -
992 If output has already started for this BFD.
993 o <<bfd_error_no_memory>> -
994 If memory allocation fails.
999 bfd_make_section_old_way (bfd
*abfd
, const char *name
)
1003 if (abfd
->output_has_begun
)
1005 bfd_set_error (bfd_error_invalid_operation
);
1009 if (strcmp (name
, BFD_ABS_SECTION_NAME
) == 0)
1010 newsect
= bfd_abs_section_ptr
;
1011 else if (strcmp (name
, BFD_COM_SECTION_NAME
) == 0)
1012 newsect
= bfd_com_section_ptr
;
1013 else if (strcmp (name
, BFD_UND_SECTION_NAME
) == 0)
1014 newsect
= bfd_und_section_ptr
;
1015 else if (strcmp (name
, BFD_IND_SECTION_NAME
) == 0)
1016 newsect
= bfd_ind_section_ptr
;
1019 struct section_hash_entry
*sh
;
1021 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1025 newsect
= &sh
->section
;
1026 if (newsect
->name
!= NULL
)
1028 /* Section already exists. */
1032 newsect
->name
= name
;
1033 return bfd_section_init (abfd
, newsect
);
1036 /* Call new_section_hook when "creating" the standard abs, com, und
1037 and ind sections to tack on format specific section data.
1038 Also, create a proper section symbol. */
1039 if (! BFD_SEND (abfd
, _new_section_hook
, (abfd
, newsect
)))
1046 bfd_make_section_anyway_with_flags
1049 asection *bfd_make_section_anyway_with_flags
1050 (bfd *abfd, const char *name, flagword flags);
1053 Create a new empty section called @var{name} and attach it to the end of
1054 the chain of sections for @var{abfd}. Create a new section even if there
1055 is already a section with that name. Also set the attributes of the
1056 new section to the value @var{flags}.
1058 Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1059 o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1060 o <<bfd_error_no_memory>> - If memory allocation fails.
1064 bfd_make_section_anyway_with_flags (bfd
*abfd
, const char *name
,
1067 struct section_hash_entry
*sh
;
1070 if (abfd
->output_has_begun
)
1072 bfd_set_error (bfd_error_invalid_operation
);
1076 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1080 newsect
= &sh
->section
;
1081 if (newsect
->name
!= NULL
)
1083 /* We are making a section of the same name. Put it in the
1084 section hash table. Even though we can't find it directly by a
1085 hash lookup, we'll be able to find the section by traversing
1086 sh->root.next quicker than looking at all the bfd sections. */
1087 struct section_hash_entry
*new_sh
;
1088 new_sh
= (struct section_hash_entry
*)
1089 bfd_section_hash_newfunc (NULL
, &abfd
->section_htab
, name
);
1093 new_sh
->root
= sh
->root
;
1094 sh
->root
.next
= &new_sh
->root
;
1095 newsect
= &new_sh
->section
;
1098 newsect
->flags
= flags
;
1099 newsect
->name
= name
;
1100 return bfd_section_init (abfd
, newsect
);
1105 bfd_make_section_anyway
1108 asection *bfd_make_section_anyway (bfd *abfd, const char *name);
1111 Create a new empty section called @var{name} and attach it to the end of
1112 the chain of sections for @var{abfd}. Create a new section even if there
1113 is already a section with that name.
1115 Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1116 o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1117 o <<bfd_error_no_memory>> - If memory allocation fails.
1121 bfd_make_section_anyway (bfd
*abfd
, const char *name
)
1123 return bfd_make_section_anyway_with_flags (abfd
, name
, 0);
1128 bfd_make_section_with_flags
1131 asection *bfd_make_section_with_flags
1132 (bfd *, const char *name, flagword flags);
1135 Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1136 bfd_set_error ()) without changing the section chain if there is already a
1137 section named @var{name}. Also set the attributes of the new section to
1138 the value @var{flags}. If there is an error, return <<NULL>> and set
1143 bfd_make_section_with_flags (bfd
*abfd
, const char *name
,
1146 struct section_hash_entry
*sh
;
1149 if (abfd
->output_has_begun
)
1151 bfd_set_error (bfd_error_invalid_operation
);
1155 if (strcmp (name
, BFD_ABS_SECTION_NAME
) == 0
1156 || strcmp (name
, BFD_COM_SECTION_NAME
) == 0
1157 || strcmp (name
, BFD_UND_SECTION_NAME
) == 0
1158 || strcmp (name
, BFD_IND_SECTION_NAME
) == 0)
1161 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1165 newsect
= &sh
->section
;
1166 if (newsect
->name
!= NULL
)
1168 /* Section already exists. */
1172 newsect
->name
= name
;
1173 newsect
->flags
= flags
;
1174 return bfd_section_init (abfd
, newsect
);
1182 asection *bfd_make_section (bfd *, const char *name);
1185 Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1186 bfd_set_error ()) without changing the section chain if there is already a
1187 section named @var{name}. If there is an error, return <<NULL>> and set
1192 bfd_make_section (bfd
*abfd
, const char *name
)
1194 return bfd_make_section_with_flags (abfd
, name
, 0);
1199 bfd_set_section_flags
1202 bfd_boolean bfd_set_section_flags
1203 (bfd *abfd, asection *sec, flagword flags);
1206 Set the attributes of the section @var{sec} in the BFD
1207 @var{abfd} to the value @var{flags}. Return <<TRUE>> on success,
1208 <<FALSE>> on error. Possible error returns are:
1210 o <<bfd_error_invalid_operation>> -
1211 The section cannot have one or more of the attributes
1212 requested. For example, a .bss section in <<a.out>> may not
1213 have the <<SEC_HAS_CONTENTS>> field set.
1218 bfd_set_section_flags (bfd
*abfd ATTRIBUTE_UNUSED
,
1222 section
->flags
= flags
;
1231 void bfd_rename_section
1232 (bfd *abfd, asection *sec, const char *newname);
1235 Rename section @var{sec} in @var{abfd} to @var{newname}.
1239 bfd_rename_section (bfd
*abfd
, sec_ptr sec
, const char *newname
)
1241 struct section_hash_entry
*sh
;
1243 sh
= (struct section_hash_entry
*)
1244 ((char *) sec
- offsetof (struct section_hash_entry
, section
));
1245 sh
->section
.name
= newname
;
1246 bfd_hash_rename (&abfd
->section_htab
, newname
, &sh
->root
);
1251 bfd_map_over_sections
1254 void bfd_map_over_sections
1256 void (*func) (bfd *abfd, asection *sect, void *obj),
1260 Call the provided function @var{func} for each section
1261 attached to the BFD @var{abfd}, passing @var{obj} as an
1262 argument. The function will be called as if by
1264 | func (abfd, the_section, obj);
1266 This is the preferred method for iterating over sections; an
1267 alternative would be to use a loop:
1270 | for (p = abfd->sections; p != NULL; p = p->next)
1271 | func (abfd, p, ...)
1276 bfd_map_over_sections (bfd
*abfd
,
1277 void (*operation
) (bfd
*, asection
*, void *),
1283 for (sect
= abfd
->sections
; sect
!= NULL
; i
++, sect
= sect
->next
)
1284 (*operation
) (abfd
, sect
, user_storage
);
1286 if (i
!= abfd
->section_count
) /* Debugging */
1292 bfd_sections_find_if
1295 asection *bfd_sections_find_if
1297 bfd_boolean (*operation) (bfd *abfd, asection *sect, void *obj),
1301 Call the provided function @var{operation} for each section
1302 attached to the BFD @var{abfd}, passing @var{obj} as an
1303 argument. The function will be called as if by
1305 | operation (abfd, the_section, obj);
1307 It returns the first section for which @var{operation} returns true.
1312 bfd_sections_find_if (bfd
*abfd
,
1313 bfd_boolean (*operation
) (bfd
*, asection
*, void *),
1318 for (sect
= abfd
->sections
; sect
!= NULL
; sect
= sect
->next
)
1319 if ((*operation
) (abfd
, sect
, user_storage
))
1327 bfd_set_section_size
1330 bfd_boolean bfd_set_section_size
1331 (bfd *abfd, asection *sec, bfd_size_type val);
1334 Set @var{sec} to the size @var{val}. If the operation is
1335 ok, then <<TRUE>> is returned, else <<FALSE>>.
1337 Possible error returns:
1338 o <<bfd_error_invalid_operation>> -
1339 Writing has started to the BFD, so setting the size is invalid.
1344 bfd_set_section_size (bfd
*abfd
, sec_ptr ptr
, bfd_size_type val
)
1346 /* Once you've started writing to any section you cannot create or change
1347 the size of any others. */
1349 if (abfd
->output_has_begun
)
1351 bfd_set_error (bfd_error_invalid_operation
);
1361 bfd_set_section_contents
1364 bfd_boolean bfd_set_section_contents
1365 (bfd *abfd, asection *section, const void *data,
1366 file_ptr offset, bfd_size_type count);
1369 Sets the contents of the section @var{section} in BFD
1370 @var{abfd} to the data starting in memory at @var{data}. The
1371 data is written to the output section starting at offset
1372 @var{offset} for @var{count} octets.
1374 Normally <<TRUE>> is returned, else <<FALSE>>. Possible error
1376 o <<bfd_error_no_contents>> -
1377 The output section does not have the <<SEC_HAS_CONTENTS>>
1378 attribute, so nothing can be written to it.
1381 This routine is front end to the back end function
1382 <<_bfd_set_section_contents>>.
1387 bfd_set_section_contents (bfd
*abfd
,
1389 const void *location
,
1391 bfd_size_type count
)
1395 if (!(bfd_get_section_flags (abfd
, section
) & SEC_HAS_CONTENTS
))
1397 bfd_set_error (bfd_error_no_contents
);
1402 if ((bfd_size_type
) offset
> sz
1404 || offset
+ count
> sz
1405 || count
!= (size_t) count
)
1407 bfd_set_error (bfd_error_bad_value
);
1411 if (!bfd_write_p (abfd
))
1413 bfd_set_error (bfd_error_invalid_operation
);
1417 /* Record a copy of the data in memory if desired. */
1418 if (section
->contents
1419 && location
!= section
->contents
+ offset
)
1420 memcpy (section
->contents
+ offset
, location
, (size_t) count
);
1422 if (BFD_SEND (abfd
, _bfd_set_section_contents
,
1423 (abfd
, section
, location
, offset
, count
)))
1425 abfd
->output_has_begun
= TRUE
;
1434 bfd_get_section_contents
1437 bfd_boolean bfd_get_section_contents
1438 (bfd *abfd, asection *section, void *location, file_ptr offset,
1439 bfd_size_type count);
1442 Read data from @var{section} in BFD @var{abfd}
1443 into memory starting at @var{location}. The data is read at an
1444 offset of @var{offset} from the start of the input section,
1445 and is read for @var{count} bytes.
1447 If the contents of a constructor with the <<SEC_CONSTRUCTOR>>
1448 flag set are requested or if the section does not have the
1449 <<SEC_HAS_CONTENTS>> flag set, then the @var{location} is filled
1450 with zeroes. If no errors occur, <<TRUE>> is returned, else
1455 bfd_get_section_contents (bfd
*abfd
,
1459 bfd_size_type count
)
1463 if (section
->flags
& SEC_CONSTRUCTOR
)
1465 memset (location
, 0, (size_t) count
);
1469 if (abfd
->direction
!= write_direction
&& section
->rawsize
!= 0)
1470 sz
= section
->rawsize
;
1473 if ((bfd_size_type
) offset
> sz
1475 || offset
+ count
> sz
1476 || count
!= (size_t) count
)
1478 bfd_set_error (bfd_error_bad_value
);
1486 if ((section
->flags
& SEC_HAS_CONTENTS
) == 0)
1488 memset (location
, 0, (size_t) count
);
1492 if ((section
->flags
& SEC_IN_MEMORY
) != 0)
1494 if (section
->contents
== NULL
)
1496 /* This can happen because of errors earlier on in the linking process.
1497 We do not want to seg-fault here, so clear the flag and return an
1499 section
->flags
&= ~ SEC_IN_MEMORY
;
1500 bfd_set_error (bfd_error_invalid_operation
);
1504 memcpy (location
, section
->contents
+ offset
, (size_t) count
);
1508 return BFD_SEND (abfd
, _bfd_get_section_contents
,
1509 (abfd
, section
, location
, offset
, count
));
1514 bfd_malloc_and_get_section
1517 bfd_boolean bfd_malloc_and_get_section
1518 (bfd *abfd, asection *section, bfd_byte **buf);
1521 Read all data from @var{section} in BFD @var{abfd}
1522 into a buffer, *@var{buf}, malloc'd by this function.
1526 bfd_malloc_and_get_section (bfd
*abfd
, sec_ptr sec
, bfd_byte
**buf
)
1529 return bfd_get_full_section_contents (abfd
, sec
, buf
);
1533 bfd_copy_private_section_data
1536 bfd_boolean bfd_copy_private_section_data
1537 (bfd *ibfd, asection *isec, bfd *obfd, asection *osec);
1540 Copy private section information from @var{isec} in the BFD
1541 @var{ibfd} to the section @var{osec} in the BFD @var{obfd}.
1542 Return <<TRUE>> on success, <<FALSE>> on error. Possible error
1545 o <<bfd_error_no_memory>> -
1546 Not enough memory exists to create private data for @var{osec}.
1548 .#define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \
1549 . BFD_SEND (obfd, _bfd_copy_private_section_data, \
1550 . (ibfd, isection, obfd, osection))
1555 bfd_generic_is_group_section
1558 bfd_boolean bfd_generic_is_group_section (bfd *, const asection *sec);
1561 Returns TRUE if @var{sec} is a member of a group.
1565 bfd_generic_is_group_section (bfd
*abfd ATTRIBUTE_UNUSED
,
1566 const asection
*sec ATTRIBUTE_UNUSED
)
1573 bfd_generic_discard_group
1576 bfd_boolean bfd_generic_discard_group (bfd *abfd, asection *group);
1579 Remove all members of @var{group} from the output.
1583 bfd_generic_discard_group (bfd
*abfd ATTRIBUTE_UNUSED
,
1584 asection
*group ATTRIBUTE_UNUSED
)