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
4 Free Software Foundation, Inc.
5 Written by Cygnus Support.
7 This file is part of BFD, the Binary File Descriptor library.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
22 MA 02110-1301, USA. */
28 The raw data contained within a BFD is maintained through the
29 section abstraction. A single BFD may have any number of
30 sections. It keeps hold of them by pointing to the first;
31 each one points to the next in the list.
33 Sections are supported in BFD in <<section.c>>.
39 @* section prototypes::
43 Section Input, Section Output, Sections, Sections
47 When a BFD is opened for reading, the section structures are
48 created and attached to the BFD.
50 Each section has a name which describes the section in the
51 outside world---for example, <<a.out>> would contain at least
52 three sections, called <<.text>>, <<.data>> and <<.bss>>.
54 Names need not be unique; for example a COFF file may have several
55 sections named <<.data>>.
57 Sometimes a BFD will contain more than the ``natural'' number of
58 sections. A back end may attach other sections containing
59 constructor data, or an application may add a section (using
60 <<bfd_make_section>>) to the sections attached to an already open
61 BFD. For example, the linker creates an extra section
62 <<COMMON>> for each input file's BFD to hold information about
65 The raw data is not necessarily read in when
66 the section descriptor is created. Some targets may leave the
67 data in place until a <<bfd_get_section_contents>> call is
68 made. Other back ends may read in all the data at once. For
69 example, an S-record file has to be read once to determine the
70 size of the data. An IEEE-695 file doesn't contain raw data in
71 sections, but data and relocation expressions intermixed, so
72 the data area has to be parsed to get out the data and
76 Section Output, typedef asection, Section Input, Sections
81 To write a new object style BFD, the various sections to be
82 written have to be created. They are attached to the BFD in
83 the same way as input sections; data is written to the
84 sections using <<bfd_set_section_contents>>.
86 Any program that creates or combines sections (e.g., the assembler
87 and linker) must use the <<asection>> fields <<output_section>> and
88 <<output_offset>> to indicate the file sections to which each
89 section must be written. (If the section is being created from
90 scratch, <<output_section>> should probably point to the section
91 itself and <<output_offset>> should probably be zero.)
93 The data to be written comes from input sections attached
94 (via <<output_section>> pointers) to
95 the output sections. The output section structure can be
96 considered a filter for the input section: the output section
97 determines the vma of the output data and the name, but the
98 input section determines the offset into the output section of
99 the data to be written.
101 E.g., to create a section "O", starting at 0x100, 0x123 long,
102 containing two subsections, "A" at offset 0x0 (i.e., at vma
103 0x100) and "B" at offset 0x20 (i.e., at vma 0x120) the <<asection>>
104 structures would look like:
109 | output_section -----------> section name "O"
111 | section name "B" | size 0x123
112 | output_offset 0x20 |
114 | output_section --------|
119 The data within a section is stored in a @dfn{link_order}.
120 These are much like the fixups in <<gas>>. The link_order
121 abstraction allows a section to grow and shrink within itself.
123 A link_order knows how big it is, and which is the next
124 link_order and where the raw data for it is; it also points to
125 a list of relocations which apply to it.
127 The link_order is used by the linker to perform relaxing on
128 final code. The compiler creates code which is as big as
129 necessary to make it work without relaxing, and the user can
130 select whether to relax. Sometimes relaxing takes a lot of
131 time. The linker runs around the relocations to see if any
132 are attached to data which can be shrunk, if so it does it on
133 a link_order by link_order basis.
145 typedef asection, section prototypes, Section Output, Sections
149 Here is the section structure:
153 .typedef struct bfd_section
155 . {* The name of the section; the name isn't a copy, the pointer is
156 . the same as that passed to bfd_make_section. *}
159 . {* A unique sequence number. *}
162 . {* Which section in the bfd; 0..n-1 as sections are created in a bfd. *}
165 . {* The next section in the list belonging to the BFD, or NULL. *}
166 . struct bfd_section *next;
168 . {* The previous section in the list belonging to the BFD, or NULL. *}
169 . struct bfd_section *prev;
171 . {* The field flags contains attributes of the section. Some
172 . flags are read in from the object file, and some are
173 . synthesized from other information. *}
176 .#define SEC_NO_FLAGS 0x000
178 . {* Tells the OS to allocate space for this section when loading.
179 . This is clear for a section containing debug information only. *}
180 .#define SEC_ALLOC 0x001
182 . {* Tells the OS to load the section from the file when loading.
183 . This is clear for a .bss section. *}
184 .#define SEC_LOAD 0x002
186 . {* The section contains data still to be relocated, so there is
187 . some relocation information too. *}
188 .#define SEC_RELOC 0x004
190 . {* A signal to the OS that the section contains read only data. *}
191 .#define SEC_READONLY 0x008
193 . {* The section contains code only. *}
194 .#define SEC_CODE 0x010
196 . {* The section contains data only. *}
197 .#define SEC_DATA 0x020
199 . {* The section will reside in ROM. *}
200 .#define SEC_ROM 0x040
202 . {* The section contains constructor information. This section
203 . type is used by the linker to create lists of constructors and
204 . destructors used by <<g++>>. When a back end sees a symbol
205 . which should be used in a constructor list, it creates a new
206 . section for the type of name (e.g., <<__CTOR_LIST__>>), attaches
207 . the symbol to it, and builds a relocation. To build the lists
208 . of constructors, all the linker has to do is catenate all the
209 . sections called <<__CTOR_LIST__>> and relocate the data
210 . contained within - exactly the operations it would peform on
212 .#define SEC_CONSTRUCTOR 0x080
214 . {* The section has contents - a data section could be
215 . <<SEC_ALLOC>> | <<SEC_HAS_CONTENTS>>; a debug section could be
216 . <<SEC_HAS_CONTENTS>> *}
217 .#define SEC_HAS_CONTENTS 0x100
219 . {* An instruction to the linker to not output the section
220 . even if it has information which would normally be written. *}
221 .#define SEC_NEVER_LOAD 0x200
223 . {* The section contains thread local data. *}
224 .#define SEC_THREAD_LOCAL 0x400
226 . {* The section has GOT references. This flag is only for the
227 . linker, and is currently only used by the elf32-hppa back end.
228 . It will be set if global offset table references were detected
229 . in this section, which indicate to the linker that the section
230 . contains PIC code, and must be handled specially when doing a
232 .#define SEC_HAS_GOT_REF 0x800
234 . {* The section contains common symbols (symbols may be defined
235 . multiple times, the value of a symbol is the amount of
236 . space it requires, and the largest symbol value is the one
237 . used). Most targets have exactly one of these (which we
238 . translate to bfd_com_section_ptr), but ECOFF has two. *}
239 .#define SEC_IS_COMMON 0x1000
241 . {* The section contains only debugging information. For
242 . example, this is set for ELF .debug and .stab sections.
243 . strip tests this flag to see if a section can be
245 .#define SEC_DEBUGGING 0x2000
247 . {* The contents of this section are held in memory pointed to
248 . by the contents field. This is checked by bfd_get_section_contents,
249 . and the data is retrieved from memory if appropriate. *}
250 .#define SEC_IN_MEMORY 0x4000
252 . {* The contents of this section are to be excluded by the
253 . linker for executable and shared objects unless those
254 . objects are to be further relocated. *}
255 .#define SEC_EXCLUDE 0x8000
257 . {* The contents of this section are to be sorted based on the sum of
258 . the symbol and addend values specified by the associated relocation
259 . entries. Entries without associated relocation entries will be
260 . appended to the end of the section in an unspecified order. *}
261 .#define SEC_SORT_ENTRIES 0x10000
263 . {* When linking, duplicate sections of the same name should be
264 . discarded, rather than being combined into a single section as
265 . is usually done. This is similar to how common symbols are
266 . handled. See SEC_LINK_DUPLICATES below. *}
267 .#define SEC_LINK_ONCE 0x20000
269 . {* If SEC_LINK_ONCE is set, this bitfield describes how the linker
270 . should handle duplicate sections. *}
271 .#define SEC_LINK_DUPLICATES 0xc0000
273 . {* This value for SEC_LINK_DUPLICATES means that duplicate
274 . sections with the same name should simply be discarded. *}
275 .#define SEC_LINK_DUPLICATES_DISCARD 0x0
277 . {* This value for SEC_LINK_DUPLICATES means that the linker
278 . should warn if there are any duplicate sections, although
279 . it should still only link one copy. *}
280 .#define SEC_LINK_DUPLICATES_ONE_ONLY 0x40000
282 . {* This value for SEC_LINK_DUPLICATES means that the linker
283 . should warn if any duplicate sections are a different size. *}
284 .#define SEC_LINK_DUPLICATES_SAME_SIZE 0x80000
286 . {* This value for SEC_LINK_DUPLICATES means that the linker
287 . should warn if any duplicate sections contain different
289 .#define SEC_LINK_DUPLICATES_SAME_CONTENTS \
290 . (SEC_LINK_DUPLICATES_ONE_ONLY | SEC_LINK_DUPLICATES_SAME_SIZE)
292 . {* This section was created by the linker as part of dynamic
293 . relocation or other arcane processing. It is skipped when
294 . going through the first-pass output, trusting that someone
295 . else up the line will take care of it later. *}
296 .#define SEC_LINKER_CREATED 0x100000
298 . {* This section should not be subject to garbage collection.
299 . Also set to inform the linker that this section should not be
300 . listed in the link map as discarded. *}
301 .#define SEC_KEEP 0x200000
303 . {* This section contains "short" data, and should be placed
305 .#define SEC_SMALL_DATA 0x400000
307 . {* Attempt to merge identical entities in the section.
308 . Entity size is given in the entsize field. *}
309 .#define SEC_MERGE 0x800000
311 . {* If given with SEC_MERGE, entities to merge are zero terminated
312 . strings where entsize specifies character size instead of fixed
314 .#define SEC_STRINGS 0x1000000
316 . {* This section contains data about section groups. *}
317 .#define SEC_GROUP 0x2000000
319 . {* The section is a COFF shared library section. This flag is
320 . only for the linker. If this type of section appears in
321 . the input file, the linker must copy it to the output file
322 . without changing the vma or size. FIXME: Although this
323 . was originally intended to be general, it really is COFF
324 . specific (and the flag was renamed to indicate this). It
325 . might be cleaner to have some more general mechanism to
326 . allow the back end to control what the linker does with
328 .#define SEC_COFF_SHARED_LIBRARY 0x4000000
330 . {* This section contains data which may be shared with other
331 . executables or shared objects. This is for COFF only. *}
332 .#define SEC_COFF_SHARED 0x8000000
334 . {* When a section with this flag is being linked, then if the size of
335 . the input section is less than a page, it should not cross a page
336 . boundary. If the size of the input section is one page or more,
337 . it should be aligned on a page boundary. This is for TI
338 . TMS320C54X only. *}
339 .#define SEC_TIC54X_BLOCK 0x10000000
341 . {* Conditionally link this section; do not link if there are no
342 . references found to any symbol in the section. This is for TI
343 . TMS320C54X only. *}
344 .#define SEC_TIC54X_CLINK 0x20000000
346 . {* Indicate that section has the no read flag set. This happens
347 . when memory read flag isn't set. *}
348 .#define SEC_COFF_NOREAD 0x40000000
350 . {* End of section flags. *}
352 . {* Some internal packed boolean fields. *}
354 . {* See the vma field. *}
355 . unsigned int user_set_vma : 1;
357 . {* A mark flag used by some of the linker backends. *}
358 . unsigned int linker_mark : 1;
360 . {* Another mark flag used by some of the linker backends. Set for
361 . output sections that have an input section. *}
362 . unsigned int linker_has_input : 1;
364 . {* Mark flag used by some linker backends for garbage collection. *}
365 . unsigned int gc_mark : 1;
367 . {* Section compression status. *}
368 . unsigned int compress_status : 2;
369 .#define COMPRESS_SECTION_NONE 0
370 .#define COMPRESS_SECTION_DONE 1
371 .#define DECOMPRESS_SECTION_SIZED 2
373 . {* The following flags are used by the ELF linker. *}
375 . {* Mark sections which have been allocated to segments. *}
376 . unsigned int segment_mark : 1;
378 . {* Type of sec_info information. *}
379 . unsigned int sec_info_type:3;
380 .#define ELF_INFO_TYPE_NONE 0
381 .#define ELF_INFO_TYPE_STABS 1
382 .#define ELF_INFO_TYPE_MERGE 2
383 .#define ELF_INFO_TYPE_EH_FRAME 3
384 .#define ELF_INFO_TYPE_JUST_SYMS 4
386 . {* Nonzero if this section uses RELA relocations, rather than REL. *}
387 . unsigned int use_rela_p:1;
389 . {* Bits used by various backends. The generic code doesn't touch
392 . unsigned int sec_flg0:1;
393 . unsigned int sec_flg1:1;
394 . unsigned int sec_flg2:1;
395 . unsigned int sec_flg3:1;
396 . unsigned int sec_flg4:1;
397 . unsigned int sec_flg5:1;
399 . {* End of internal packed boolean fields. *}
401 . {* The virtual memory address of the section - where it will be
402 . at run time. The symbols are relocated against this. The
403 . user_set_vma flag is maintained by bfd; if it's not set, the
404 . backend can assign addresses (for example, in <<a.out>>, where
405 . the default address for <<.data>> is dependent on the specific
406 . target and various flags). *}
409 . {* The load address of the section - where it would be in a
410 . rom image; really only used for writing section header
414 . {* The size of the section in octets, as it will be output.
415 . Contains a value even if the section has no contents (e.g., the
416 . size of <<.bss>>). *}
417 . bfd_size_type size;
419 . {* For input sections, the original size on disk of the section, in
420 . octets. This field should be set for any section whose size is
421 . changed by linker relaxation. It is required for sections where
422 . the linker relaxation scheme doesn't cache altered section and
423 . reloc contents (stabs, eh_frame, SEC_MERGE, some coff relaxing
424 . targets), and thus the original size needs to be kept to read the
425 . section multiple times. For output sections, rawsize holds the
426 . section size calculated on a previous linker relaxation pass. *}
427 . bfd_size_type rawsize;
429 . {* The compressed size of the section in octets. *}
430 . bfd_size_type compressed_size;
432 . {* Relaxation table. *}
433 . struct relax_table *relax;
435 . {* Count of used relaxation table entries. *}
439 . {* If this section is going to be output, then this value is the
440 . offset in *bytes* into the output section of the first byte in the
441 . input section (byte ==> smallest addressable unit on the
442 . target). In most cases, if this was going to start at the
443 . 100th octet (8-bit quantity) in the output section, this value
444 . would be 100. However, if the target byte size is 16 bits
445 . (bfd_octets_per_byte is "2"), this value would be 50. *}
446 . bfd_vma output_offset;
448 . {* The output section through which to map on output. *}
449 . struct bfd_section *output_section;
451 . {* The alignment requirement of the section, as an exponent of 2 -
452 . e.g., 3 aligns to 2^3 (or 8). *}
453 . unsigned int alignment_power;
455 . {* If an input section, a pointer to a vector of relocation
456 . records for the data in this section. *}
457 . struct reloc_cache_entry *relocation;
459 . {* If an output section, a pointer to a vector of pointers to
460 . relocation records for the data in this section. *}
461 . struct reloc_cache_entry **orelocation;
463 . {* The number of relocation records in one of the above. *}
464 . unsigned reloc_count;
466 . {* Information below is back end specific - and not always used
469 . {* File position of section data. *}
472 . {* File position of relocation info. *}
473 . file_ptr rel_filepos;
475 . {* File position of line data. *}
476 . file_ptr line_filepos;
478 . {* Pointer to data for applications. *}
481 . {* If the SEC_IN_MEMORY flag is set, this points to the actual
483 . unsigned char *contents;
485 . {* Attached line number information. *}
488 . {* Number of line number records. *}
489 . unsigned int lineno_count;
491 . {* Entity size for merging purposes. *}
492 . unsigned int entsize;
494 . {* Points to the kept section if this section is a link-once section,
495 . and is discarded. *}
496 . struct bfd_section *kept_section;
498 . {* When a section is being output, this value changes as more
499 . linenumbers are written out. *}
500 . file_ptr moving_line_filepos;
502 . {* What the section number is in the target world. *}
507 . {* If this is a constructor section then here is a list of the
508 . relocations created to relocate items within it. *}
509 . struct relent_chain *constructor_chain;
511 . {* The BFD which owns the section. *}
514 . {* A symbol which points at this section only. *}
515 . struct bfd_symbol *symbol;
516 . struct bfd_symbol **symbol_ptr_ptr;
518 . {* Early in the link process, map_head and map_tail are used to build
519 . a list of input sections attached to an output section. Later,
520 . output sections use these fields for a list of bfd_link_order
523 . struct bfd_link_order *link_order;
524 . struct bfd_section *s;
525 . } map_head, map_tail;
528 .{* Relax table contains information about instructions which can
529 . be removed by relaxation -- replacing a long address with a
531 .struct relax_table {
532 . {* Address where bytes may be deleted. *}
535 . {* Number of bytes to be deleted. *}
539 .{* These sections are global, and are managed by BFD. The application
540 . and target back end are not permitted to change the values in
541 . these sections. New code should use the section_ptr macros rather
542 . than referring directly to the const sections. The const sections
543 . may eventually vanish. *}
544 .#define BFD_ABS_SECTION_NAME "*ABS*"
545 .#define BFD_UND_SECTION_NAME "*UND*"
546 .#define BFD_COM_SECTION_NAME "*COM*"
547 .#define BFD_IND_SECTION_NAME "*IND*"
549 .{* The absolute section. *}
550 .extern asection bfd_abs_section;
551 .#define bfd_abs_section_ptr ((asection *) &bfd_abs_section)
552 .#define bfd_is_abs_section(sec) ((sec) == bfd_abs_section_ptr)
553 .{* Pointer to the undefined section. *}
554 .extern asection bfd_und_section;
555 .#define bfd_und_section_ptr ((asection *) &bfd_und_section)
556 .#define bfd_is_und_section(sec) ((sec) == bfd_und_section_ptr)
557 .{* Pointer to the common section. *}
558 .extern asection bfd_com_section;
559 .#define bfd_com_section_ptr ((asection *) &bfd_com_section)
560 .{* Pointer to the indirect section. *}
561 .extern asection bfd_ind_section;
562 .#define bfd_ind_section_ptr ((asection *) &bfd_ind_section)
563 .#define bfd_is_ind_section(sec) ((sec) == bfd_ind_section_ptr)
565 .#define bfd_is_const_section(SEC) \
566 . ( ((SEC) == bfd_abs_section_ptr) \
567 . || ((SEC) == bfd_und_section_ptr) \
568 . || ((SEC) == bfd_com_section_ptr) \
569 . || ((SEC) == bfd_ind_section_ptr))
571 .{* Macros to handle insertion and deletion of a bfd's sections. These
572 . only handle the list pointers, ie. do not adjust section_count,
573 . target_index etc. *}
574 .#define bfd_section_list_remove(ABFD, S) \
577 . asection *_s = S; \
578 . asection *_next = _s->next; \
579 . asection *_prev = _s->prev; \
581 . _prev->next = _next; \
583 . (ABFD)->sections = _next; \
585 . _next->prev = _prev; \
587 . (ABFD)->section_last = _prev; \
590 .#define bfd_section_list_append(ABFD, S) \
593 . asection *_s = S; \
594 . bfd *_abfd = ABFD; \
596 . if (_abfd->section_last) \
598 . _s->prev = _abfd->section_last; \
599 . _abfd->section_last->next = _s; \
604 . _abfd->sections = _s; \
606 . _abfd->section_last = _s; \
609 .#define bfd_section_list_prepend(ABFD, S) \
612 . asection *_s = S; \
613 . bfd *_abfd = ABFD; \
615 . if (_abfd->sections) \
617 . _s->next = _abfd->sections; \
618 . _abfd->sections->prev = _s; \
623 . _abfd->section_last = _s; \
625 . _abfd->sections = _s; \
628 .#define bfd_section_list_insert_after(ABFD, A, S) \
631 . asection *_a = A; \
632 . asection *_s = S; \
633 . asection *_next = _a->next; \
634 . _s->next = _next; \
638 . _next->prev = _s; \
640 . (ABFD)->section_last = _s; \
643 .#define bfd_section_list_insert_before(ABFD, B, S) \
646 . asection *_b = B; \
647 . asection *_s = S; \
648 . asection *_prev = _b->prev; \
649 . _s->prev = _prev; \
653 . _prev->next = _s; \
655 . (ABFD)->sections = _s; \
658 .#define bfd_section_removed_from_list(ABFD, S) \
659 . ((S)->next == NULL ? (ABFD)->section_last != (S) : (S)->next->prev != (S))
661 .#define BFD_FAKE_SECTION(SEC, FLAGS, SYM, NAME, IDX) \
662 . {* name, id, index, next, prev, flags, user_set_vma, *} \
663 . { NAME, IDX, 0, NULL, NULL, FLAGS, 0, \
665 . {* linker_mark, linker_has_input, gc_mark, decompress_status, *} \
668 . {* segment_mark, sec_info_type, use_rela_p, *} \
671 . {* sec_flg0, sec_flg1, sec_flg2, sec_flg3, sec_flg4, sec_flg5, *} \
672 . 0, 0, 0, 0, 0, 0, \
674 . {* vma, lma, size, rawsize, compressed_size, relax, relax_count, *} \
675 . 0, 0, 0, 0, 0, 0, 0, \
677 . {* output_offset, output_section, alignment_power, *} \
678 . 0, (struct bfd_section *) &SEC, 0, \
680 . {* relocation, orelocation, reloc_count, filepos, rel_filepos, *} \
681 . NULL, NULL, 0, 0, 0, \
683 . {* line_filepos, userdata, contents, lineno, lineno_count, *} \
684 . 0, NULL, NULL, NULL, 0, \
686 . {* entsize, kept_section, moving_line_filepos, *} \
689 . {* target_index, used_by_bfd, constructor_chain, owner, *} \
690 . 0, NULL, NULL, NULL, \
692 . {* symbol, symbol_ptr_ptr, *} \
693 . (struct bfd_symbol *) SYM, &SEC.symbol, \
695 . {* map_head, map_tail *} \
696 . { NULL }, { NULL } \
701 /* We use a macro to initialize the static asymbol structures because
702 traditional C does not permit us to initialize a union member while
703 gcc warns if we don't initialize it. */
704 /* the_bfd, name, value, attr, section [, udata] */
706 #define GLOBAL_SYM_INIT(NAME, SECTION) \
707 { 0, NAME, 0, BSF_SECTION_SYM, (asection *) SECTION, { 0 }}
709 #define GLOBAL_SYM_INIT(NAME, SECTION) \
710 { 0, NAME, 0, BSF_SECTION_SYM, (asection *) SECTION }
713 /* These symbols are global, not specific to any BFD. Therefore, anything
714 that tries to change them is broken, and should be repaired. */
716 static const asymbol global_syms
[] =
718 GLOBAL_SYM_INIT (BFD_COM_SECTION_NAME
, &bfd_com_section
),
719 GLOBAL_SYM_INIT (BFD_UND_SECTION_NAME
, &bfd_und_section
),
720 GLOBAL_SYM_INIT (BFD_ABS_SECTION_NAME
, &bfd_abs_section
),
721 GLOBAL_SYM_INIT (BFD_IND_SECTION_NAME
, &bfd_ind_section
)
724 #define STD_SECTION(SEC, FLAGS, NAME, IDX) \
725 asection SEC = BFD_FAKE_SECTION(SEC, FLAGS, &global_syms[IDX], \
728 STD_SECTION (bfd_com_section
, SEC_IS_COMMON
, BFD_COM_SECTION_NAME
, 0);
729 STD_SECTION (bfd_und_section
, 0, BFD_UND_SECTION_NAME
, 1);
730 STD_SECTION (bfd_abs_section
, 0, BFD_ABS_SECTION_NAME
, 2);
731 STD_SECTION (bfd_ind_section
, 0, BFD_IND_SECTION_NAME
, 3);
734 /* Initialize an entry in the section hash table. */
736 struct bfd_hash_entry
*
737 bfd_section_hash_newfunc (struct bfd_hash_entry
*entry
,
738 struct bfd_hash_table
*table
,
741 /* Allocate the structure if it has not already been allocated by a
745 entry
= (struct bfd_hash_entry
*)
746 bfd_hash_allocate (table
, sizeof (struct section_hash_entry
));
751 /* Call the allocation method of the superclass. */
752 entry
= bfd_hash_newfunc (entry
, table
, string
);
754 memset (&((struct section_hash_entry
*) entry
)->section
, 0,
760 #define section_hash_lookup(table, string, create, copy) \
761 ((struct section_hash_entry *) \
762 bfd_hash_lookup ((table), (string), (create), (copy)))
764 /* Create a symbol whose only job is to point to this section. This
765 is useful for things like relocs which are relative to the base
769 _bfd_generic_new_section_hook (bfd
*abfd
, asection
*newsect
)
771 newsect
->symbol
= bfd_make_empty_symbol (abfd
);
772 if (newsect
->symbol
== NULL
)
775 newsect
->symbol
->name
= newsect
->name
;
776 newsect
->symbol
->value
= 0;
777 newsect
->symbol
->section
= newsect
;
778 newsect
->symbol
->flags
= BSF_SECTION_SYM
;
780 newsect
->symbol_ptr_ptr
= &newsect
->symbol
;
784 /* Initializes a new section. NEWSECT->NAME is already set. */
787 bfd_section_init (bfd
*abfd
, asection
*newsect
)
789 static int section_id
= 0x10; /* id 0 to 3 used by STD_SECTION. */
791 newsect
->id
= section_id
;
792 newsect
->index
= abfd
->section_count
;
793 newsect
->owner
= abfd
;
795 if (! BFD_SEND (abfd
, _new_section_hook
, (abfd
, newsect
)))
799 abfd
->section_count
++;
800 bfd_section_list_append (abfd
, newsect
);
807 section prototypes, , typedef asection, Sections
811 These are the functions exported by the section handling part of BFD.
816 bfd_section_list_clear
819 void bfd_section_list_clear (bfd *);
822 Clears the section list, and also resets the section count and
827 bfd_section_list_clear (bfd
*abfd
)
829 abfd
->sections
= NULL
;
830 abfd
->section_last
= NULL
;
831 abfd
->section_count
= 0;
832 memset (abfd
->section_htab
.table
, 0,
833 abfd
->section_htab
.size
* sizeof (struct bfd_hash_entry
*));
838 bfd_get_section_by_name
841 asection *bfd_get_section_by_name (bfd *abfd, const char *name);
844 Run through @var{abfd} and return the one of the
845 <<asection>>s whose name matches @var{name}, otherwise <<NULL>>.
846 @xref{Sections}, for more information.
848 This should only be used in special cases; the normal way to process
849 all sections of a given name is to use <<bfd_map_over_sections>> and
850 <<strcmp>> on the name (or better yet, base it on the section flags
851 or something else) for each section.
855 bfd_get_section_by_name (bfd
*abfd
, const char *name
)
857 struct section_hash_entry
*sh
;
859 sh
= section_hash_lookup (&abfd
->section_htab
, name
, FALSE
, FALSE
);
868 bfd_get_section_by_name_if
871 asection *bfd_get_section_by_name_if
874 bfd_boolean (*func) (bfd *abfd, asection *sect, void *obj),
878 Call the provided function @var{func} for each section
879 attached to the BFD @var{abfd} whose name matches @var{name},
880 passing @var{obj} as an argument. The function will be called
883 | func (abfd, the_section, obj);
885 It returns the first section for which @var{func} returns true,
891 bfd_get_section_by_name_if (bfd
*abfd
, const char *name
,
892 bfd_boolean (*operation
) (bfd
*,
897 struct section_hash_entry
*sh
;
900 sh
= section_hash_lookup (&abfd
->section_htab
, name
, FALSE
, FALSE
);
904 hash
= sh
->root
.hash
;
907 if ((*operation
) (abfd
, &sh
->section
, user_storage
))
909 sh
= (struct section_hash_entry
*) sh
->root
.next
;
911 while (sh
!= NULL
&& sh
->root
.hash
== hash
912 && strcmp (sh
->root
.string
, name
) == 0);
919 bfd_get_unique_section_name
922 char *bfd_get_unique_section_name
923 (bfd *abfd, const char *templat, int *count);
926 Invent a section name that is unique in @var{abfd} by tacking
927 a dot and a digit suffix onto the original @var{templat}. If
928 @var{count} is non-NULL, then it specifies the first number
929 tried as a suffix to generate a unique name. The value
930 pointed to by @var{count} will be incremented in this case.
934 bfd_get_unique_section_name (bfd
*abfd
, const char *templat
, int *count
)
940 len
= strlen (templat
);
941 sname
= (char *) bfd_malloc (len
+ 8);
944 memcpy (sname
, templat
, len
);
951 /* If we have a million sections, something is badly wrong. */
954 sprintf (sname
+ len
, ".%d", num
++);
956 while (section_hash_lookup (&abfd
->section_htab
, sname
, FALSE
, FALSE
));
965 bfd_make_section_old_way
968 asection *bfd_make_section_old_way (bfd *abfd, const char *name);
971 Create a new empty section called @var{name}
972 and attach it to the end of the chain of sections for the
973 BFD @var{abfd}. An attempt to create a section with a name which
974 is already in use returns its pointer without changing the
977 It has the funny name since this is the way it used to be
978 before it was rewritten....
981 o <<bfd_error_invalid_operation>> -
982 If output has already started for this BFD.
983 o <<bfd_error_no_memory>> -
984 If memory allocation fails.
989 bfd_make_section_old_way (bfd
*abfd
, const char *name
)
993 if (abfd
->output_has_begun
)
995 bfd_set_error (bfd_error_invalid_operation
);
999 if (strcmp (name
, BFD_ABS_SECTION_NAME
) == 0)
1000 newsect
= bfd_abs_section_ptr
;
1001 else if (strcmp (name
, BFD_COM_SECTION_NAME
) == 0)
1002 newsect
= bfd_com_section_ptr
;
1003 else if (strcmp (name
, BFD_UND_SECTION_NAME
) == 0)
1004 newsect
= bfd_und_section_ptr
;
1005 else if (strcmp (name
, BFD_IND_SECTION_NAME
) == 0)
1006 newsect
= bfd_ind_section_ptr
;
1009 struct section_hash_entry
*sh
;
1011 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1015 newsect
= &sh
->section
;
1016 if (newsect
->name
!= NULL
)
1018 /* Section already exists. */
1022 newsect
->name
= name
;
1023 return bfd_section_init (abfd
, newsect
);
1026 /* Call new_section_hook when "creating" the standard abs, com, und
1027 and ind sections to tack on format specific section data.
1028 Also, create a proper section symbol. */
1029 if (! BFD_SEND (abfd
, _new_section_hook
, (abfd
, newsect
)))
1036 bfd_make_section_anyway_with_flags
1039 asection *bfd_make_section_anyway_with_flags
1040 (bfd *abfd, const char *name, flagword flags);
1043 Create a new empty section called @var{name} and attach it to the end of
1044 the chain of sections for @var{abfd}. Create a new section even if there
1045 is already a section with that name. Also set the attributes of the
1046 new section to the value @var{flags}.
1048 Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1049 o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1050 o <<bfd_error_no_memory>> - If memory allocation fails.
1054 bfd_make_section_anyway_with_flags (bfd
*abfd
, const char *name
,
1057 struct section_hash_entry
*sh
;
1060 if (abfd
->output_has_begun
)
1062 bfd_set_error (bfd_error_invalid_operation
);
1066 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1070 newsect
= &sh
->section
;
1071 if (newsect
->name
!= NULL
)
1073 /* We are making a section of the same name. Put it in the
1074 section hash table. Even though we can't find it directly by a
1075 hash lookup, we'll be able to find the section by traversing
1076 sh->root.next quicker than looking at all the bfd sections. */
1077 struct section_hash_entry
*new_sh
;
1078 new_sh
= (struct section_hash_entry
*)
1079 bfd_section_hash_newfunc (NULL
, &abfd
->section_htab
, name
);
1083 new_sh
->root
= sh
->root
;
1084 sh
->root
.next
= &new_sh
->root
;
1085 newsect
= &new_sh
->section
;
1088 newsect
->flags
= flags
;
1089 newsect
->name
= name
;
1090 return bfd_section_init (abfd
, newsect
);
1095 bfd_make_section_anyway
1098 asection *bfd_make_section_anyway (bfd *abfd, const char *name);
1101 Create a new empty section called @var{name} and attach it to the end of
1102 the chain of sections for @var{abfd}. Create a new section even if there
1103 is already a section with that name.
1105 Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1106 o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1107 o <<bfd_error_no_memory>> - If memory allocation fails.
1111 bfd_make_section_anyway (bfd
*abfd
, const char *name
)
1113 return bfd_make_section_anyway_with_flags (abfd
, name
, 0);
1118 bfd_make_section_with_flags
1121 asection *bfd_make_section_with_flags
1122 (bfd *, const char *name, flagword flags);
1125 Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1126 bfd_set_error ()) without changing the section chain if there is already a
1127 section named @var{name}. Also set the attributes of the new section to
1128 the value @var{flags}. If there is an error, return <<NULL>> and set
1133 bfd_make_section_with_flags (bfd
*abfd
, const char *name
,
1136 struct section_hash_entry
*sh
;
1139 if (abfd
->output_has_begun
)
1141 bfd_set_error (bfd_error_invalid_operation
);
1145 if (strcmp (name
, BFD_ABS_SECTION_NAME
) == 0
1146 || strcmp (name
, BFD_COM_SECTION_NAME
) == 0
1147 || strcmp (name
, BFD_UND_SECTION_NAME
) == 0
1148 || strcmp (name
, BFD_IND_SECTION_NAME
) == 0)
1151 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1155 newsect
= &sh
->section
;
1156 if (newsect
->name
!= NULL
)
1158 /* Section already exists. */
1162 newsect
->name
= name
;
1163 newsect
->flags
= flags
;
1164 return bfd_section_init (abfd
, newsect
);
1172 asection *bfd_make_section (bfd *, const char *name);
1175 Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1176 bfd_set_error ()) without changing the section chain if there is already a
1177 section named @var{name}. If there is an error, return <<NULL>> and set
1182 bfd_make_section (bfd
*abfd
, const char *name
)
1184 return bfd_make_section_with_flags (abfd
, name
, 0);
1189 bfd_set_section_flags
1192 bfd_boolean bfd_set_section_flags
1193 (bfd *abfd, asection *sec, flagword flags);
1196 Set the attributes of the section @var{sec} in the BFD
1197 @var{abfd} to the value @var{flags}. Return <<TRUE>> on success,
1198 <<FALSE>> on error. Possible error returns are:
1200 o <<bfd_error_invalid_operation>> -
1201 The section cannot have one or more of the attributes
1202 requested. For example, a .bss section in <<a.out>> may not
1203 have the <<SEC_HAS_CONTENTS>> field set.
1208 bfd_set_section_flags (bfd
*abfd ATTRIBUTE_UNUSED
,
1212 section
->flags
= flags
;
1221 void bfd_rename_section
1222 (bfd *abfd, asection *sec, const char *newname);
1225 Rename section @var{sec} in @var{abfd} to @var{newname}.
1229 bfd_rename_section (bfd
*abfd
, sec_ptr sec
, const char *newname
)
1231 struct section_hash_entry
*sh
;
1233 sh
= (struct section_hash_entry
*)
1234 ((char *) sec
- offsetof (struct section_hash_entry
, section
));
1235 sh
->section
.name
= newname
;
1236 bfd_hash_rename (&abfd
->section_htab
, newname
, &sh
->root
);
1241 bfd_map_over_sections
1244 void bfd_map_over_sections
1246 void (*func) (bfd *abfd, asection *sect, void *obj),
1250 Call the provided function @var{func} for each section
1251 attached to the BFD @var{abfd}, passing @var{obj} as an
1252 argument. The function will be called as if by
1254 | func (abfd, the_section, obj);
1256 This is the preferred method for iterating over sections; an
1257 alternative would be to use a loop:
1260 | for (p = abfd->sections; p != NULL; p = p->next)
1261 | func (abfd, p, ...)
1266 bfd_map_over_sections (bfd
*abfd
,
1267 void (*operation
) (bfd
*, asection
*, void *),
1273 for (sect
= abfd
->sections
; sect
!= NULL
; i
++, sect
= sect
->next
)
1274 (*operation
) (abfd
, sect
, user_storage
);
1276 if (i
!= abfd
->section_count
) /* Debugging */
1282 bfd_sections_find_if
1285 asection *bfd_sections_find_if
1287 bfd_boolean (*operation) (bfd *abfd, asection *sect, void *obj),
1291 Call the provided function @var{operation} for each section
1292 attached to the BFD @var{abfd}, passing @var{obj} as an
1293 argument. The function will be called as if by
1295 | operation (abfd, the_section, obj);
1297 It returns the first section for which @var{operation} returns true.
1302 bfd_sections_find_if (bfd
*abfd
,
1303 bfd_boolean (*operation
) (bfd
*, asection
*, void *),
1308 for (sect
= abfd
->sections
; sect
!= NULL
; sect
= sect
->next
)
1309 if ((*operation
) (abfd
, sect
, user_storage
))
1317 bfd_set_section_size
1320 bfd_boolean bfd_set_section_size
1321 (bfd *abfd, asection *sec, bfd_size_type val);
1324 Set @var{sec} to the size @var{val}. If the operation is
1325 ok, then <<TRUE>> is returned, else <<FALSE>>.
1327 Possible error returns:
1328 o <<bfd_error_invalid_operation>> -
1329 Writing has started to the BFD, so setting the size is invalid.
1334 bfd_set_section_size (bfd
*abfd
, sec_ptr ptr
, bfd_size_type val
)
1336 /* Once you've started writing to any section you cannot create or change
1337 the size of any others. */
1339 if (abfd
->output_has_begun
)
1341 bfd_set_error (bfd_error_invalid_operation
);
1351 bfd_set_section_contents
1354 bfd_boolean bfd_set_section_contents
1355 (bfd *abfd, asection *section, const void *data,
1356 file_ptr offset, bfd_size_type count);
1359 Sets the contents of the section @var{section} in BFD
1360 @var{abfd} to the data starting in memory at @var{data}. The
1361 data is written to the output section starting at offset
1362 @var{offset} for @var{count} octets.
1364 Normally <<TRUE>> is returned, else <<FALSE>>. Possible error
1366 o <<bfd_error_no_contents>> -
1367 The output section does not have the <<SEC_HAS_CONTENTS>>
1368 attribute, so nothing can be written to it.
1371 This routine is front end to the back end function
1372 <<_bfd_set_section_contents>>.
1377 bfd_set_section_contents (bfd
*abfd
,
1379 const void *location
,
1381 bfd_size_type count
)
1385 if (!(bfd_get_section_flags (abfd
, section
) & SEC_HAS_CONTENTS
))
1387 bfd_set_error (bfd_error_no_contents
);
1392 if ((bfd_size_type
) offset
> sz
1394 || offset
+ count
> sz
1395 || count
!= (size_t) count
)
1397 bfd_set_error (bfd_error_bad_value
);
1401 if (!bfd_write_p (abfd
))
1403 bfd_set_error (bfd_error_invalid_operation
);
1407 /* Record a copy of the data in memory if desired. */
1408 if (section
->contents
1409 && location
!= section
->contents
+ offset
)
1410 memcpy (section
->contents
+ offset
, location
, (size_t) count
);
1412 if (BFD_SEND (abfd
, _bfd_set_section_contents
,
1413 (abfd
, section
, location
, offset
, count
)))
1415 abfd
->output_has_begun
= TRUE
;
1424 bfd_get_section_contents
1427 bfd_boolean bfd_get_section_contents
1428 (bfd *abfd, asection *section, void *location, file_ptr offset,
1429 bfd_size_type count);
1432 Read data from @var{section} in BFD @var{abfd}
1433 into memory starting at @var{location}. The data is read at an
1434 offset of @var{offset} from the start of the input section,
1435 and is read for @var{count} bytes.
1437 If the contents of a constructor with the <<SEC_CONSTRUCTOR>>
1438 flag set are requested or if the section does not have the
1439 <<SEC_HAS_CONTENTS>> flag set, then the @var{location} is filled
1440 with zeroes. If no errors occur, <<TRUE>> is returned, else
1445 bfd_get_section_contents (bfd
*abfd
,
1449 bfd_size_type count
)
1453 if (section
->flags
& SEC_CONSTRUCTOR
)
1455 memset (location
, 0, (size_t) count
);
1459 sz
= section
->rawsize
? section
->rawsize
: section
->size
;
1460 if ((bfd_size_type
) offset
> sz
1462 || offset
+ count
> sz
1463 || count
!= (size_t) count
)
1465 bfd_set_error (bfd_error_bad_value
);
1473 if ((section
->flags
& SEC_HAS_CONTENTS
) == 0)
1475 memset (location
, 0, (size_t) count
);
1479 if ((section
->flags
& SEC_IN_MEMORY
) != 0)
1481 if (section
->contents
== NULL
)
1483 /* This can happen because of errors earlier on in the linking process.
1484 We do not want to seg-fault here, so clear the flag and return an
1486 section
->flags
&= ~ SEC_IN_MEMORY
;
1487 bfd_set_error (bfd_error_invalid_operation
);
1491 memcpy (location
, section
->contents
+ offset
, (size_t) count
);
1495 return BFD_SEND (abfd
, _bfd_get_section_contents
,
1496 (abfd
, section
, location
, offset
, count
));
1501 bfd_malloc_and_get_section
1504 bfd_boolean bfd_malloc_and_get_section
1505 (bfd *abfd, asection *section, bfd_byte **buf);
1508 Read all data from @var{section} in BFD @var{abfd}
1509 into a buffer, *@var{buf}, malloc'd by this function.
1513 bfd_malloc_and_get_section (bfd
*abfd
, sec_ptr sec
, bfd_byte
**buf
)
1516 return bfd_get_full_section_contents (abfd
, sec
, buf
);
1520 bfd_copy_private_section_data
1523 bfd_boolean bfd_copy_private_section_data
1524 (bfd *ibfd, asection *isec, bfd *obfd, asection *osec);
1527 Copy private section information from @var{isec} in the BFD
1528 @var{ibfd} to the section @var{osec} in the BFD @var{obfd}.
1529 Return <<TRUE>> on success, <<FALSE>> on error. Possible error
1532 o <<bfd_error_no_memory>> -
1533 Not enough memory exists to create private data for @var{osec}.
1535 .#define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \
1536 . BFD_SEND (obfd, _bfd_copy_private_section_data, \
1537 . (ibfd, isection, obfd, osection))
1542 bfd_generic_is_group_section
1545 bfd_boolean bfd_generic_is_group_section (bfd *, const asection *sec);
1548 Returns TRUE if @var{sec} is a member of a group.
1552 bfd_generic_is_group_section (bfd
*abfd ATTRIBUTE_UNUSED
,
1553 const asection
*sec ATTRIBUTE_UNUSED
)
1560 bfd_generic_discard_group
1563 bfd_boolean bfd_generic_discard_group (bfd *abfd, asection *group);
1566 Remove all members of @var{group} from the output.
1570 bfd_generic_discard_group (bfd
*abfd ATTRIBUTE_UNUSED
,
1571 asection
*group ATTRIBUTE_UNUSED
)