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
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 input section should be copied to output in reverse order
331 . as an array of pointers. This is for ELF linker internal use
333 .#define SEC_ELF_REVERSE_COPY 0x4000000
335 . {* This section contains data which may be shared with other
336 . executables or shared objects. This is for COFF only. *}
337 .#define SEC_COFF_SHARED 0x8000000
339 . {* When a section with this flag is being linked, then if the size of
340 . the input section is less than a page, it should not cross a page
341 . boundary. If the size of the input section is one page or more,
342 . it should be aligned on a page boundary. This is for TI
343 . TMS320C54X only. *}
344 .#define SEC_TIC54X_BLOCK 0x10000000
346 . {* Conditionally link this section; do not link if there are no
347 . references found to any symbol in the section. This is for TI
348 . TMS320C54X only. *}
349 .#define SEC_TIC54X_CLINK 0x20000000
351 . {* Indicate that section has the no read flag set. This happens
352 . when memory read flag isn't set. *}
353 .#define SEC_COFF_NOREAD 0x40000000
355 . {* End of section flags. *}
357 . {* Some internal packed boolean fields. *}
359 . {* See the vma field. *}
360 . unsigned int user_set_vma : 1;
362 . {* A mark flag used by some of the linker backends. *}
363 . unsigned int linker_mark : 1;
365 . {* Another mark flag used by some of the linker backends. Set for
366 . output sections that have an input section. *}
367 . unsigned int linker_has_input : 1;
369 . {* Mark flag used by some linker backends for garbage collection. *}
370 . unsigned int gc_mark : 1;
372 . {* Section compression status. *}
373 . unsigned int compress_status : 2;
374 .#define COMPRESS_SECTION_NONE 0
375 .#define COMPRESS_SECTION_DONE 1
376 .#define DECOMPRESS_SECTION_SIZED 2
378 . {* The following flags are used by the ELF linker. *}
380 . {* Mark sections which have been allocated to segments. *}
381 . unsigned int segment_mark : 1;
383 . {* Type of sec_info information. *}
384 . unsigned int sec_info_type:3;
385 .#define ELF_INFO_TYPE_NONE 0
386 .#define ELF_INFO_TYPE_STABS 1
387 .#define ELF_INFO_TYPE_MERGE 2
388 .#define ELF_INFO_TYPE_EH_FRAME 3
389 .#define ELF_INFO_TYPE_JUST_SYMS 4
391 . {* Nonzero if this section uses RELA relocations, rather than REL. *}
392 . unsigned int use_rela_p:1;
394 . {* Bits used by various backends. The generic code doesn't touch
397 . unsigned int sec_flg0:1;
398 . unsigned int sec_flg1:1;
399 . unsigned int sec_flg2:1;
400 . unsigned int sec_flg3:1;
401 . unsigned int sec_flg4:1;
402 . unsigned int sec_flg5:1;
404 . {* End of internal packed boolean fields. *}
406 . {* The virtual memory address of the section - where it will be
407 . at run time. The symbols are relocated against this. The
408 . user_set_vma flag is maintained by bfd; if it's not set, the
409 . backend can assign addresses (for example, in <<a.out>>, where
410 . the default address for <<.data>> is dependent on the specific
411 . target and various flags). *}
414 . {* The load address of the section - where it would be in a
415 . rom image; really only used for writing section header
419 . {* The size of the section in octets, as it will be output.
420 . Contains a value even if the section has no contents (e.g., the
421 . size of <<.bss>>). *}
422 . bfd_size_type size;
424 . {* For input sections, the original size on disk of the section, in
425 . octets. This field should be set for any section whose size is
426 . changed by linker relaxation. It is required for sections where
427 . the linker relaxation scheme doesn't cache altered section and
428 . reloc contents (stabs, eh_frame, SEC_MERGE, some coff relaxing
429 . targets), and thus the original size needs to be kept to read the
430 . section multiple times. For output sections, rawsize holds the
431 . section size calculated on a previous linker relaxation pass. *}
432 . bfd_size_type rawsize;
434 . {* The compressed size of the section in octets. *}
435 . bfd_size_type compressed_size;
437 . {* Relaxation table. *}
438 . struct relax_table *relax;
440 . {* Count of used relaxation table entries. *}
444 . {* If this section is going to be output, then this value is the
445 . offset in *bytes* into the output section of the first byte in the
446 . input section (byte ==> smallest addressable unit on the
447 . target). In most cases, if this was going to start at the
448 . 100th octet (8-bit quantity) in the output section, this value
449 . would be 100. However, if the target byte size is 16 bits
450 . (bfd_octets_per_byte is "2"), this value would be 50. *}
451 . bfd_vma output_offset;
453 . {* The output section through which to map on output. *}
454 . struct bfd_section *output_section;
456 . {* The alignment requirement of the section, as an exponent of 2 -
457 . e.g., 3 aligns to 2^3 (or 8). *}
458 . unsigned int alignment_power;
460 . {* If an input section, a pointer to a vector of relocation
461 . records for the data in this section. *}
462 . struct reloc_cache_entry *relocation;
464 . {* If an output section, a pointer to a vector of pointers to
465 . relocation records for the data in this section. *}
466 . struct reloc_cache_entry **orelocation;
468 . {* The number of relocation records in one of the above. *}
469 . unsigned reloc_count;
471 . {* Information below is back end specific - and not always used
474 . {* File position of section data. *}
477 . {* File position of relocation info. *}
478 . file_ptr rel_filepos;
480 . {* File position of line data. *}
481 . file_ptr line_filepos;
483 . {* Pointer to data for applications. *}
486 . {* If the SEC_IN_MEMORY flag is set, this points to the actual
488 . unsigned char *contents;
490 . {* Attached line number information. *}
493 . {* Number of line number records. *}
494 . unsigned int lineno_count;
496 . {* Entity size for merging purposes. *}
497 . unsigned int entsize;
499 . {* Points to the kept section if this section is a link-once section,
500 . and is discarded. *}
501 . struct bfd_section *kept_section;
503 . {* When a section is being output, this value changes as more
504 . linenumbers are written out. *}
505 . file_ptr moving_line_filepos;
507 . {* What the section number is in the target world. *}
512 . {* If this is a constructor section then here is a list of the
513 . relocations created to relocate items within it. *}
514 . struct relent_chain *constructor_chain;
516 . {* The BFD which owns the section. *}
519 . {* A symbol which points at this section only. *}
520 . struct bfd_symbol *symbol;
521 . struct bfd_symbol **symbol_ptr_ptr;
523 . {* Early in the link process, map_head and map_tail are used to build
524 . a list of input sections attached to an output section. Later,
525 . output sections use these fields for a list of bfd_link_order
528 . struct bfd_link_order *link_order;
529 . struct bfd_section *s;
530 . } map_head, map_tail;
533 .{* Relax table contains information about instructions which can
534 . be removed by relaxation -- replacing a long address with a
536 .struct relax_table {
537 . {* Address where bytes may be deleted. *}
540 . {* Number of bytes to be deleted. *}
544 .{* These sections are global, and are managed by BFD. The application
545 . and target back end are not permitted to change the values in
546 . these sections. New code should use the section_ptr macros rather
547 . than referring directly to the const sections. The const sections
548 . may eventually vanish. *}
549 .#define BFD_ABS_SECTION_NAME "*ABS*"
550 .#define BFD_UND_SECTION_NAME "*UND*"
551 .#define BFD_COM_SECTION_NAME "*COM*"
552 .#define BFD_IND_SECTION_NAME "*IND*"
554 .{* The absolute section. *}
555 .extern asection bfd_abs_section;
556 .#define bfd_abs_section_ptr ((asection *) &bfd_abs_section)
557 .#define bfd_is_abs_section(sec) ((sec) == bfd_abs_section_ptr)
558 .{* Pointer to the undefined section. *}
559 .extern asection bfd_und_section;
560 .#define bfd_und_section_ptr ((asection *) &bfd_und_section)
561 .#define bfd_is_und_section(sec) ((sec) == bfd_und_section_ptr)
562 .{* Pointer to the common section. *}
563 .extern asection bfd_com_section;
564 .#define bfd_com_section_ptr ((asection *) &bfd_com_section)
565 .{* Pointer to the indirect section. *}
566 .extern asection bfd_ind_section;
567 .#define bfd_ind_section_ptr ((asection *) &bfd_ind_section)
568 .#define bfd_is_ind_section(sec) ((sec) == bfd_ind_section_ptr)
570 .#define bfd_is_const_section(SEC) \
571 . ( ((SEC) == bfd_abs_section_ptr) \
572 . || ((SEC) == bfd_und_section_ptr) \
573 . || ((SEC) == bfd_com_section_ptr) \
574 . || ((SEC) == bfd_ind_section_ptr))
576 .{* Macros to handle insertion and deletion of a bfd's sections. These
577 . only handle the list pointers, ie. do not adjust section_count,
578 . target_index etc. *}
579 .#define bfd_section_list_remove(ABFD, S) \
582 . asection *_s = S; \
583 . asection *_next = _s->next; \
584 . asection *_prev = _s->prev; \
586 . _prev->next = _next; \
588 . (ABFD)->sections = _next; \
590 . _next->prev = _prev; \
592 . (ABFD)->section_last = _prev; \
595 .#define bfd_section_list_append(ABFD, S) \
598 . asection *_s = S; \
599 . bfd *_abfd = ABFD; \
601 . if (_abfd->section_last) \
603 . _s->prev = _abfd->section_last; \
604 . _abfd->section_last->next = _s; \
609 . _abfd->sections = _s; \
611 . _abfd->section_last = _s; \
614 .#define bfd_section_list_prepend(ABFD, S) \
617 . asection *_s = S; \
618 . bfd *_abfd = ABFD; \
620 . if (_abfd->sections) \
622 . _s->next = _abfd->sections; \
623 . _abfd->sections->prev = _s; \
628 . _abfd->section_last = _s; \
630 . _abfd->sections = _s; \
633 .#define bfd_section_list_insert_after(ABFD, A, S) \
636 . asection *_a = A; \
637 . asection *_s = S; \
638 . asection *_next = _a->next; \
639 . _s->next = _next; \
643 . _next->prev = _s; \
645 . (ABFD)->section_last = _s; \
648 .#define bfd_section_list_insert_before(ABFD, B, S) \
651 . asection *_b = B; \
652 . asection *_s = S; \
653 . asection *_prev = _b->prev; \
654 . _s->prev = _prev; \
658 . _prev->next = _s; \
660 . (ABFD)->sections = _s; \
663 .#define bfd_section_removed_from_list(ABFD, S) \
664 . ((S)->next == NULL ? (ABFD)->section_last != (S) : (S)->next->prev != (S))
666 .#define BFD_FAKE_SECTION(SEC, FLAGS, SYM, NAME, IDX) \
667 . {* name, id, index, next, prev, flags, user_set_vma, *} \
668 . { NAME, IDX, 0, NULL, NULL, FLAGS, 0, \
670 . {* linker_mark, linker_has_input, gc_mark, decompress_status, *} \
673 . {* segment_mark, sec_info_type, use_rela_p, *} \
676 . {* sec_flg0, sec_flg1, sec_flg2, sec_flg3, sec_flg4, sec_flg5, *} \
677 . 0, 0, 0, 0, 0, 0, \
679 . {* vma, lma, size, rawsize, compressed_size, relax, relax_count, *} \
680 . 0, 0, 0, 0, 0, 0, 0, \
682 . {* output_offset, output_section, alignment_power, *} \
683 . 0, (struct bfd_section *) &SEC, 0, \
685 . {* relocation, orelocation, reloc_count, filepos, rel_filepos, *} \
686 . NULL, NULL, 0, 0, 0, \
688 . {* line_filepos, userdata, contents, lineno, lineno_count, *} \
689 . 0, NULL, NULL, NULL, 0, \
691 . {* entsize, kept_section, moving_line_filepos, *} \
694 . {* target_index, used_by_bfd, constructor_chain, owner, *} \
695 . 0, NULL, NULL, NULL, \
697 . {* symbol, symbol_ptr_ptr, *} \
698 . (struct bfd_symbol *) SYM, &SEC.symbol, \
700 . {* map_head, map_tail *} \
701 . { NULL }, { NULL } \
706 /* We use a macro to initialize the static asymbol structures because
707 traditional C does not permit us to initialize a union member while
708 gcc warns if we don't initialize it. */
709 /* the_bfd, name, value, attr, section [, udata] */
711 #define GLOBAL_SYM_INIT(NAME, SECTION) \
712 { 0, NAME, 0, BSF_SECTION_SYM, (asection *) SECTION, { 0 }}
714 #define GLOBAL_SYM_INIT(NAME, SECTION) \
715 { 0, NAME, 0, BSF_SECTION_SYM, (asection *) SECTION }
718 /* These symbols are global, not specific to any BFD. Therefore, anything
719 that tries to change them is broken, and should be repaired. */
721 static const asymbol global_syms
[] =
723 GLOBAL_SYM_INIT (BFD_COM_SECTION_NAME
, &bfd_com_section
),
724 GLOBAL_SYM_INIT (BFD_UND_SECTION_NAME
, &bfd_und_section
),
725 GLOBAL_SYM_INIT (BFD_ABS_SECTION_NAME
, &bfd_abs_section
),
726 GLOBAL_SYM_INIT (BFD_IND_SECTION_NAME
, &bfd_ind_section
)
729 #define STD_SECTION(SEC, FLAGS, NAME, IDX) \
730 asection SEC = BFD_FAKE_SECTION(SEC, FLAGS, &global_syms[IDX], \
733 STD_SECTION (bfd_com_section
, SEC_IS_COMMON
, BFD_COM_SECTION_NAME
, 0);
734 STD_SECTION (bfd_und_section
, 0, BFD_UND_SECTION_NAME
, 1);
735 STD_SECTION (bfd_abs_section
, 0, BFD_ABS_SECTION_NAME
, 2);
736 STD_SECTION (bfd_ind_section
, 0, BFD_IND_SECTION_NAME
, 3);
739 /* Initialize an entry in the section hash table. */
741 struct bfd_hash_entry
*
742 bfd_section_hash_newfunc (struct bfd_hash_entry
*entry
,
743 struct bfd_hash_table
*table
,
746 /* Allocate the structure if it has not already been allocated by a
750 entry
= (struct bfd_hash_entry
*)
751 bfd_hash_allocate (table
, sizeof (struct section_hash_entry
));
756 /* Call the allocation method of the superclass. */
757 entry
= bfd_hash_newfunc (entry
, table
, string
);
759 memset (&((struct section_hash_entry
*) entry
)->section
, 0,
765 #define section_hash_lookup(table, string, create, copy) \
766 ((struct section_hash_entry *) \
767 bfd_hash_lookup ((table), (string), (create), (copy)))
769 /* Create a symbol whose only job is to point to this section. This
770 is useful for things like relocs which are relative to the base
774 _bfd_generic_new_section_hook (bfd
*abfd
, asection
*newsect
)
776 newsect
->symbol
= bfd_make_empty_symbol (abfd
);
777 if (newsect
->symbol
== NULL
)
780 newsect
->symbol
->name
= newsect
->name
;
781 newsect
->symbol
->value
= 0;
782 newsect
->symbol
->section
= newsect
;
783 newsect
->symbol
->flags
= BSF_SECTION_SYM
;
785 newsect
->symbol_ptr_ptr
= &newsect
->symbol
;
789 /* Initializes a new section. NEWSECT->NAME is already set. */
792 bfd_section_init (bfd
*abfd
, asection
*newsect
)
794 static int section_id
= 0x10; /* id 0 to 3 used by STD_SECTION. */
796 newsect
->id
= section_id
;
797 newsect
->index
= abfd
->section_count
;
798 newsect
->owner
= abfd
;
800 if (! BFD_SEND (abfd
, _new_section_hook
, (abfd
, newsect
)))
804 abfd
->section_count
++;
805 bfd_section_list_append (abfd
, newsect
);
812 section prototypes, , typedef asection, Sections
816 These are the functions exported by the section handling part of BFD.
821 bfd_section_list_clear
824 void bfd_section_list_clear (bfd *);
827 Clears the section list, and also resets the section count and
832 bfd_section_list_clear (bfd
*abfd
)
834 abfd
->sections
= NULL
;
835 abfd
->section_last
= NULL
;
836 abfd
->section_count
= 0;
837 memset (abfd
->section_htab
.table
, 0,
838 abfd
->section_htab
.size
* sizeof (struct bfd_hash_entry
*));
843 bfd_get_section_by_name
846 asection *bfd_get_section_by_name (bfd *abfd, const char *name);
849 Run through @var{abfd} and return the one of the
850 <<asection>>s whose name matches @var{name}, otherwise <<NULL>>.
851 @xref{Sections}, for more information.
853 This should only be used in special cases; the normal way to process
854 all sections of a given name is to use <<bfd_map_over_sections>> and
855 <<strcmp>> on the name (or better yet, base it on the section flags
856 or something else) for each section.
860 bfd_get_section_by_name (bfd
*abfd
, const char *name
)
862 struct section_hash_entry
*sh
;
864 sh
= section_hash_lookup (&abfd
->section_htab
, name
, FALSE
, FALSE
);
873 bfd_get_section_by_name_if
876 asection *bfd_get_section_by_name_if
879 bfd_boolean (*func) (bfd *abfd, asection *sect, void *obj),
883 Call the provided function @var{func} for each section
884 attached to the BFD @var{abfd} whose name matches @var{name},
885 passing @var{obj} as an argument. The function will be called
888 | func (abfd, the_section, obj);
890 It returns the first section for which @var{func} returns true,
896 bfd_get_section_by_name_if (bfd
*abfd
, const char *name
,
897 bfd_boolean (*operation
) (bfd
*,
902 struct section_hash_entry
*sh
;
905 sh
= section_hash_lookup (&abfd
->section_htab
, name
, FALSE
, FALSE
);
909 hash
= sh
->root
.hash
;
912 if ((*operation
) (abfd
, &sh
->section
, user_storage
))
914 sh
= (struct section_hash_entry
*) sh
->root
.next
;
916 while (sh
!= NULL
&& sh
->root
.hash
== hash
917 && strcmp (sh
->root
.string
, name
) == 0);
924 bfd_get_unique_section_name
927 char *bfd_get_unique_section_name
928 (bfd *abfd, const char *templat, int *count);
931 Invent a section name that is unique in @var{abfd} by tacking
932 a dot and a digit suffix onto the original @var{templat}. If
933 @var{count} is non-NULL, then it specifies the first number
934 tried as a suffix to generate a unique name. The value
935 pointed to by @var{count} will be incremented in this case.
939 bfd_get_unique_section_name (bfd
*abfd
, const char *templat
, int *count
)
945 len
= strlen (templat
);
946 sname
= (char *) bfd_malloc (len
+ 8);
949 memcpy (sname
, templat
, len
);
956 /* If we have a million sections, something is badly wrong. */
959 sprintf (sname
+ len
, ".%d", num
++);
961 while (section_hash_lookup (&abfd
->section_htab
, sname
, FALSE
, FALSE
));
970 bfd_make_section_old_way
973 asection *bfd_make_section_old_way (bfd *abfd, const char *name);
976 Create a new empty section called @var{name}
977 and attach it to the end of the chain of sections for the
978 BFD @var{abfd}. An attempt to create a section with a name which
979 is already in use returns its pointer without changing the
982 It has the funny name since this is the way it used to be
983 before it was rewritten....
986 o <<bfd_error_invalid_operation>> -
987 If output has already started for this BFD.
988 o <<bfd_error_no_memory>> -
989 If memory allocation fails.
994 bfd_make_section_old_way (bfd
*abfd
, const char *name
)
998 if (abfd
->output_has_begun
)
1000 bfd_set_error (bfd_error_invalid_operation
);
1004 if (strcmp (name
, BFD_ABS_SECTION_NAME
) == 0)
1005 newsect
= bfd_abs_section_ptr
;
1006 else if (strcmp (name
, BFD_COM_SECTION_NAME
) == 0)
1007 newsect
= bfd_com_section_ptr
;
1008 else if (strcmp (name
, BFD_UND_SECTION_NAME
) == 0)
1009 newsect
= bfd_und_section_ptr
;
1010 else if (strcmp (name
, BFD_IND_SECTION_NAME
) == 0)
1011 newsect
= bfd_ind_section_ptr
;
1014 struct section_hash_entry
*sh
;
1016 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1020 newsect
= &sh
->section
;
1021 if (newsect
->name
!= NULL
)
1023 /* Section already exists. */
1027 newsect
->name
= name
;
1028 return bfd_section_init (abfd
, newsect
);
1031 /* Call new_section_hook when "creating" the standard abs, com, und
1032 and ind sections to tack on format specific section data.
1033 Also, create a proper section symbol. */
1034 if (! BFD_SEND (abfd
, _new_section_hook
, (abfd
, newsect
)))
1041 bfd_make_section_anyway_with_flags
1044 asection *bfd_make_section_anyway_with_flags
1045 (bfd *abfd, const char *name, flagword flags);
1048 Create a new empty section called @var{name} and attach it to the end of
1049 the chain of sections for @var{abfd}. Create a new section even if there
1050 is already a section with that name. Also set the attributes of the
1051 new section to the value @var{flags}.
1053 Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1054 o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1055 o <<bfd_error_no_memory>> - If memory allocation fails.
1059 bfd_make_section_anyway_with_flags (bfd
*abfd
, const char *name
,
1062 struct section_hash_entry
*sh
;
1065 if (abfd
->output_has_begun
)
1067 bfd_set_error (bfd_error_invalid_operation
);
1071 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1075 newsect
= &sh
->section
;
1076 if (newsect
->name
!= NULL
)
1078 /* We are making a section of the same name. Put it in the
1079 section hash table. Even though we can't find it directly by a
1080 hash lookup, we'll be able to find the section by traversing
1081 sh->root.next quicker than looking at all the bfd sections. */
1082 struct section_hash_entry
*new_sh
;
1083 new_sh
= (struct section_hash_entry
*)
1084 bfd_section_hash_newfunc (NULL
, &abfd
->section_htab
, name
);
1088 new_sh
->root
= sh
->root
;
1089 sh
->root
.next
= &new_sh
->root
;
1090 newsect
= &new_sh
->section
;
1093 newsect
->flags
= flags
;
1094 newsect
->name
= name
;
1095 return bfd_section_init (abfd
, newsect
);
1100 bfd_make_section_anyway
1103 asection *bfd_make_section_anyway (bfd *abfd, const char *name);
1106 Create a new empty section called @var{name} and attach it to the end of
1107 the chain of sections for @var{abfd}. Create a new section even if there
1108 is already a section with that name.
1110 Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1111 o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1112 o <<bfd_error_no_memory>> - If memory allocation fails.
1116 bfd_make_section_anyway (bfd
*abfd
, const char *name
)
1118 return bfd_make_section_anyway_with_flags (abfd
, name
, 0);
1123 bfd_make_section_with_flags
1126 asection *bfd_make_section_with_flags
1127 (bfd *, const char *name, flagword flags);
1130 Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1131 bfd_set_error ()) without changing the section chain if there is already a
1132 section named @var{name}. Also set the attributes of the new section to
1133 the value @var{flags}. If there is an error, return <<NULL>> and set
1138 bfd_make_section_with_flags (bfd
*abfd
, const char *name
,
1141 struct section_hash_entry
*sh
;
1144 if (abfd
->output_has_begun
)
1146 bfd_set_error (bfd_error_invalid_operation
);
1150 if (strcmp (name
, BFD_ABS_SECTION_NAME
) == 0
1151 || strcmp (name
, BFD_COM_SECTION_NAME
) == 0
1152 || strcmp (name
, BFD_UND_SECTION_NAME
) == 0
1153 || strcmp (name
, BFD_IND_SECTION_NAME
) == 0)
1156 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1160 newsect
= &sh
->section
;
1161 if (newsect
->name
!= NULL
)
1163 /* Section already exists. */
1167 newsect
->name
= name
;
1168 newsect
->flags
= flags
;
1169 return bfd_section_init (abfd
, newsect
);
1177 asection *bfd_make_section (bfd *, const char *name);
1180 Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1181 bfd_set_error ()) without changing the section chain if there is already a
1182 section named @var{name}. If there is an error, return <<NULL>> and set
1187 bfd_make_section (bfd
*abfd
, const char *name
)
1189 return bfd_make_section_with_flags (abfd
, name
, 0);
1194 bfd_set_section_flags
1197 bfd_boolean bfd_set_section_flags
1198 (bfd *abfd, asection *sec, flagword flags);
1201 Set the attributes of the section @var{sec} in the BFD
1202 @var{abfd} to the value @var{flags}. Return <<TRUE>> on success,
1203 <<FALSE>> on error. Possible error returns are:
1205 o <<bfd_error_invalid_operation>> -
1206 The section cannot have one or more of the attributes
1207 requested. For example, a .bss section in <<a.out>> may not
1208 have the <<SEC_HAS_CONTENTS>> field set.
1213 bfd_set_section_flags (bfd
*abfd ATTRIBUTE_UNUSED
,
1217 section
->flags
= flags
;
1226 void bfd_rename_section
1227 (bfd *abfd, asection *sec, const char *newname);
1230 Rename section @var{sec} in @var{abfd} to @var{newname}.
1234 bfd_rename_section (bfd
*abfd
, sec_ptr sec
, const char *newname
)
1236 struct section_hash_entry
*sh
;
1238 sh
= (struct section_hash_entry
*)
1239 ((char *) sec
- offsetof (struct section_hash_entry
, section
));
1240 sh
->section
.name
= newname
;
1241 bfd_hash_rename (&abfd
->section_htab
, newname
, &sh
->root
);
1246 bfd_map_over_sections
1249 void bfd_map_over_sections
1251 void (*func) (bfd *abfd, asection *sect, void *obj),
1255 Call the provided function @var{func} for each section
1256 attached to the BFD @var{abfd}, passing @var{obj} as an
1257 argument. The function will be called as if by
1259 | func (abfd, the_section, obj);
1261 This is the preferred method for iterating over sections; an
1262 alternative would be to use a loop:
1265 | for (p = abfd->sections; p != NULL; p = p->next)
1266 | func (abfd, p, ...)
1271 bfd_map_over_sections (bfd
*abfd
,
1272 void (*operation
) (bfd
*, asection
*, void *),
1278 for (sect
= abfd
->sections
; sect
!= NULL
; i
++, sect
= sect
->next
)
1279 (*operation
) (abfd
, sect
, user_storage
);
1281 if (i
!= abfd
->section_count
) /* Debugging */
1287 bfd_sections_find_if
1290 asection *bfd_sections_find_if
1292 bfd_boolean (*operation) (bfd *abfd, asection *sect, void *obj),
1296 Call the provided function @var{operation} for each section
1297 attached to the BFD @var{abfd}, passing @var{obj} as an
1298 argument. The function will be called as if by
1300 | operation (abfd, the_section, obj);
1302 It returns the first section for which @var{operation} returns true.
1307 bfd_sections_find_if (bfd
*abfd
,
1308 bfd_boolean (*operation
) (bfd
*, asection
*, void *),
1313 for (sect
= abfd
->sections
; sect
!= NULL
; sect
= sect
->next
)
1314 if ((*operation
) (abfd
, sect
, user_storage
))
1322 bfd_set_section_size
1325 bfd_boolean bfd_set_section_size
1326 (bfd *abfd, asection *sec, bfd_size_type val);
1329 Set @var{sec} to the size @var{val}. If the operation is
1330 ok, then <<TRUE>> is returned, else <<FALSE>>.
1332 Possible error returns:
1333 o <<bfd_error_invalid_operation>> -
1334 Writing has started to the BFD, so setting the size is invalid.
1339 bfd_set_section_size (bfd
*abfd
, sec_ptr ptr
, bfd_size_type val
)
1341 /* Once you've started writing to any section you cannot create or change
1342 the size of any others. */
1344 if (abfd
->output_has_begun
)
1346 bfd_set_error (bfd_error_invalid_operation
);
1356 bfd_set_section_contents
1359 bfd_boolean bfd_set_section_contents
1360 (bfd *abfd, asection *section, const void *data,
1361 file_ptr offset, bfd_size_type count);
1364 Sets the contents of the section @var{section} in BFD
1365 @var{abfd} to the data starting in memory at @var{data}. The
1366 data is written to the output section starting at offset
1367 @var{offset} for @var{count} octets.
1369 Normally <<TRUE>> is returned, else <<FALSE>>. Possible error
1371 o <<bfd_error_no_contents>> -
1372 The output section does not have the <<SEC_HAS_CONTENTS>>
1373 attribute, so nothing can be written to it.
1376 This routine is front end to the back end function
1377 <<_bfd_set_section_contents>>.
1382 bfd_set_section_contents (bfd
*abfd
,
1384 const void *location
,
1386 bfd_size_type count
)
1390 if (!(bfd_get_section_flags (abfd
, section
) & SEC_HAS_CONTENTS
))
1392 bfd_set_error (bfd_error_no_contents
);
1397 if ((bfd_size_type
) offset
> sz
1399 || offset
+ count
> sz
1400 || count
!= (size_t) count
)
1402 bfd_set_error (bfd_error_bad_value
);
1406 if (!bfd_write_p (abfd
))
1408 bfd_set_error (bfd_error_invalid_operation
);
1412 /* Record a copy of the data in memory if desired. */
1413 if (section
->contents
1414 && location
!= section
->contents
+ offset
)
1415 memcpy (section
->contents
+ offset
, location
, (size_t) count
);
1417 if (BFD_SEND (abfd
, _bfd_set_section_contents
,
1418 (abfd
, section
, location
, offset
, count
)))
1420 abfd
->output_has_begun
= TRUE
;
1429 bfd_get_section_contents
1432 bfd_boolean bfd_get_section_contents
1433 (bfd *abfd, asection *section, void *location, file_ptr offset,
1434 bfd_size_type count);
1437 Read data from @var{section} in BFD @var{abfd}
1438 into memory starting at @var{location}. The data is read at an
1439 offset of @var{offset} from the start of the input section,
1440 and is read for @var{count} bytes.
1442 If the contents of a constructor with the <<SEC_CONSTRUCTOR>>
1443 flag set are requested or if the section does not have the
1444 <<SEC_HAS_CONTENTS>> flag set, then the @var{location} is filled
1445 with zeroes. If no errors occur, <<TRUE>> is returned, else
1450 bfd_get_section_contents (bfd
*abfd
,
1454 bfd_size_type count
)
1458 if (section
->flags
& SEC_CONSTRUCTOR
)
1460 memset (location
, 0, (size_t) count
);
1464 if (abfd
->direction
!= write_direction
&& section
->rawsize
!= 0)
1465 sz
= section
->rawsize
;
1468 if ((bfd_size_type
) offset
> sz
1470 || offset
+ count
> sz
1471 || count
!= (size_t) count
)
1473 bfd_set_error (bfd_error_bad_value
);
1481 if ((section
->flags
& SEC_HAS_CONTENTS
) == 0)
1483 memset (location
, 0, (size_t) count
);
1487 if ((section
->flags
& SEC_IN_MEMORY
) != 0)
1489 if (section
->contents
== NULL
)
1491 /* This can happen because of errors earlier on in the linking process.
1492 We do not want to seg-fault here, so clear the flag and return an
1494 section
->flags
&= ~ SEC_IN_MEMORY
;
1495 bfd_set_error (bfd_error_invalid_operation
);
1499 memcpy (location
, section
->contents
+ offset
, (size_t) count
);
1503 return BFD_SEND (abfd
, _bfd_get_section_contents
,
1504 (abfd
, section
, location
, offset
, count
));
1509 bfd_malloc_and_get_section
1512 bfd_boolean bfd_malloc_and_get_section
1513 (bfd *abfd, asection *section, bfd_byte **buf);
1516 Read all data from @var{section} in BFD @var{abfd}
1517 into a buffer, *@var{buf}, malloc'd by this function.
1521 bfd_malloc_and_get_section (bfd
*abfd
, sec_ptr sec
, bfd_byte
**buf
)
1524 return bfd_get_full_section_contents (abfd
, sec
, buf
);
1528 bfd_copy_private_section_data
1531 bfd_boolean bfd_copy_private_section_data
1532 (bfd *ibfd, asection *isec, bfd *obfd, asection *osec);
1535 Copy private section information from @var{isec} in the BFD
1536 @var{ibfd} to the section @var{osec} in the BFD @var{obfd}.
1537 Return <<TRUE>> on success, <<FALSE>> on error. Possible error
1540 o <<bfd_error_no_memory>> -
1541 Not enough memory exists to create private data for @var{osec}.
1543 .#define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \
1544 . BFD_SEND (obfd, _bfd_copy_private_section_data, \
1545 . (ibfd, isection, obfd, osection))
1550 bfd_generic_is_group_section
1553 bfd_boolean bfd_generic_is_group_section (bfd *, const asection *sec);
1556 Returns TRUE if @var{sec} is a member of a group.
1560 bfd_generic_is_group_section (bfd
*abfd ATTRIBUTE_UNUSED
,
1561 const asection
*sec ATTRIBUTE_UNUSED
)
1568 bfd_generic_discard_group
1571 bfd_boolean bfd_generic_discard_group (bfd *abfd, asection *group);
1574 Remove all members of @var{group} from the output.
1578 bfd_generic_discard_group (bfd
*abfd ATTRIBUTE_UNUSED
,
1579 asection
*group ATTRIBUTE_UNUSED
)