1 /* Object file "section" support for the BFD library.
2 Copyright (C) 1990-2018 Free Software Foundation, Inc.
3 Written by Cygnus Support.
5 This file is part of BFD, the Binary File Descriptor library.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
20 MA 02110-1301, USA. */
26 The raw data contained within a BFD is maintained through the
27 section abstraction. A single BFD may have any number of
28 sections. It keeps hold of them by pointing to the first;
29 each one points to the next in the list.
31 Sections are supported in BFD in <<section.c>>.
37 @* section prototypes::
41 Section Input, Section Output, Sections, Sections
45 When a BFD is opened for reading, the section structures are
46 created and attached to the BFD.
48 Each section has a name which describes the section in the
49 outside world---for example, <<a.out>> would contain at least
50 three sections, called <<.text>>, <<.data>> and <<.bss>>.
52 Names need not be unique; for example a COFF file may have several
53 sections named <<.data>>.
55 Sometimes a BFD will contain more than the ``natural'' number of
56 sections. A back end may attach other sections containing
57 constructor data, or an application may add a section (using
58 <<bfd_make_section>>) to the sections attached to an already open
59 BFD. For example, the linker creates an extra section
60 <<COMMON>> for each input file's BFD to hold information about
63 The raw data is not necessarily read in when
64 the section descriptor is created. Some targets may leave the
65 data in place until a <<bfd_get_section_contents>> call is
66 made. Other back ends may read in all the data at once. For
67 example, an S-record file has to be read once to determine the
68 size of the data. An IEEE-695 file doesn't contain raw data in
69 sections, but data and relocation expressions intermixed, so
70 the data area has to be parsed to get out the data and
74 Section Output, typedef asection, Section Input, Sections
79 To write a new object style BFD, the various sections to be
80 written have to be created. They are attached to the BFD in
81 the same way as input sections; data is written to the
82 sections using <<bfd_set_section_contents>>.
84 Any program that creates or combines sections (e.g., the assembler
85 and linker) must use the <<asection>> fields <<output_section>> and
86 <<output_offset>> to indicate the file sections to which each
87 section must be written. (If the section is being created from
88 scratch, <<output_section>> should probably point to the section
89 itself and <<output_offset>> should probably be zero.)
91 The data to be written comes from input sections attached
92 (via <<output_section>> pointers) to
93 the output sections. The output section structure can be
94 considered a filter for the input section: the output section
95 determines the vma of the output data and the name, but the
96 input section determines the offset into the output section of
97 the data to be written.
99 E.g., to create a section "O", starting at 0x100, 0x123 long,
100 containing two subsections, "A" at offset 0x0 (i.e., at vma
101 0x100) and "B" at offset 0x20 (i.e., at vma 0x120) the <<asection>>
102 structures would look like:
107 | output_section -----------> section name "O"
109 | section name "B" | size 0x123
110 | output_offset 0x20 |
112 | output_section --------|
117 The data within a section is stored in a @dfn{link_order}.
118 These are much like the fixups in <<gas>>. The link_order
119 abstraction allows a section to grow and shrink within itself.
121 A link_order knows how big it is, and which is the next
122 link_order and where the raw data for it is; it also points to
123 a list of relocations which apply to it.
125 The link_order is used by the linker to perform relaxing on
126 final code. The compiler creates code which is as big as
127 necessary to make it work without relaxing, and the user can
128 select whether to relax. Sometimes relaxing takes a lot of
129 time. The linker runs around the relocations to see if any
130 are attached to data which can be shrunk, if so it does it on
131 a link_order by link_order basis.
143 typedef asection, section prototypes, Section Output, Sections
147 Here is the section structure:
151 .typedef struct bfd_section
153 . {* The name of the section; the name isn't a copy, the pointer is
154 . the same as that passed to bfd_make_section. *}
157 . {* A unique sequence number. *}
160 . {* Which section in the bfd; 0..n-1 as sections are created in a bfd. *}
161 . unsigned int index;
163 . {* The next section in the list belonging to the BFD, or NULL. *}
164 . struct bfd_section *next;
166 . {* The previous section in the list belonging to the BFD, or NULL. *}
167 . struct bfd_section *prev;
169 . {* The field flags contains attributes of the section. Some
170 . flags are read in from the object file, and some are
171 . synthesized from other information. *}
174 .#define SEC_NO_FLAGS 0x0
176 . {* Tells the OS to allocate space for this section when loading.
177 . This is clear for a section containing debug information only. *}
178 .#define SEC_ALLOC 0x1
180 . {* Tells the OS to load the section from the file when loading.
181 . This is clear for a .bss section. *}
182 .#define SEC_LOAD 0x2
184 . {* The section contains data still to be relocated, so there is
185 . some relocation information too. *}
186 .#define SEC_RELOC 0x4
188 . {* A signal to the OS that the section contains read only data. *}
189 .#define SEC_READONLY 0x8
191 . {* The section contains code only. *}
192 .#define SEC_CODE 0x10
194 . {* The section contains data only. *}
195 .#define SEC_DATA 0x20
197 . {* The section will reside in ROM. *}
198 .#define SEC_ROM 0x40
200 . {* The section contains constructor information. This section
201 . type is used by the linker to create lists of constructors and
202 . destructors used by <<g++>>. When a back end sees a symbol
203 . which should be used in a constructor list, it creates a new
204 . section for the type of name (e.g., <<__CTOR_LIST__>>), attaches
205 . the symbol to it, and builds a relocation. To build the lists
206 . of constructors, all the linker has to do is catenate all the
207 . sections called <<__CTOR_LIST__>> and relocate the data
208 . contained within - exactly the operations it would peform on
210 .#define SEC_CONSTRUCTOR 0x80
212 . {* The section has contents - a data section could be
213 . <<SEC_ALLOC>> | <<SEC_HAS_CONTENTS>>; a debug section could be
214 . <<SEC_HAS_CONTENTS>> *}
215 .#define SEC_HAS_CONTENTS 0x100
217 . {* An instruction to the linker to not output the section
218 . even if it has information which would normally be written. *}
219 .#define SEC_NEVER_LOAD 0x200
221 . {* The section contains thread local data. *}
222 .#define SEC_THREAD_LOCAL 0x400
224 . {* The section's size is fixed. Generic linker code will not
225 . recalculate it and it is up to whoever has set this flag to
226 . get the size right. *}
227 .#define SEC_FIXED_SIZE 0x800
229 . {* The section contains common symbols (symbols may be defined
230 . multiple times, the value of a symbol is the amount of
231 . space it requires, and the largest symbol value is the one
232 . used). Most targets have exactly one of these (which we
233 . translate to bfd_com_section_ptr), but ECOFF has two. *}
234 .#define SEC_IS_COMMON 0x1000
236 . {* The section contains only debugging information. For
237 . example, this is set for ELF .debug and .stab sections.
238 . strip tests this flag to see if a section can be
240 .#define SEC_DEBUGGING 0x2000
242 . {* The contents of this section are held in memory pointed to
243 . by the contents field. This is checked by bfd_get_section_contents,
244 . and the data is retrieved from memory if appropriate. *}
245 .#define SEC_IN_MEMORY 0x4000
247 . {* The contents of this section are to be excluded by the
248 . linker for executable and shared objects unless those
249 . objects are to be further relocated. *}
250 .#define SEC_EXCLUDE 0x8000
252 . {* The contents of this section are to be sorted based on the sum of
253 . the symbol and addend values specified by the associated relocation
254 . entries. Entries without associated relocation entries will be
255 . appended to the end of the section in an unspecified order. *}
256 .#define SEC_SORT_ENTRIES 0x10000
258 . {* When linking, duplicate sections of the same name should be
259 . discarded, rather than being combined into a single section as
260 . is usually done. This is similar to how common symbols are
261 . handled. See SEC_LINK_DUPLICATES below. *}
262 .#define SEC_LINK_ONCE 0x20000
264 . {* If SEC_LINK_ONCE is set, this bitfield describes how the linker
265 . should handle duplicate sections. *}
266 .#define SEC_LINK_DUPLICATES 0xc0000
268 . {* This value for SEC_LINK_DUPLICATES means that duplicate
269 . sections with the same name should simply be discarded. *}
270 .#define SEC_LINK_DUPLICATES_DISCARD 0x0
272 . {* This value for SEC_LINK_DUPLICATES means that the linker
273 . should warn if there are any duplicate sections, although
274 . it should still only link one copy. *}
275 .#define SEC_LINK_DUPLICATES_ONE_ONLY 0x40000
277 . {* This value for SEC_LINK_DUPLICATES means that the linker
278 . should warn if any duplicate sections are a different size. *}
279 .#define SEC_LINK_DUPLICATES_SAME_SIZE 0x80000
281 . {* This value for SEC_LINK_DUPLICATES means that the linker
282 . should warn if any duplicate sections contain different
284 .#define SEC_LINK_DUPLICATES_SAME_CONTENTS \
285 . (SEC_LINK_DUPLICATES_ONE_ONLY | SEC_LINK_DUPLICATES_SAME_SIZE)
287 . {* This section was created by the linker as part of dynamic
288 . relocation or other arcane processing. It is skipped when
289 . going through the first-pass output, trusting that someone
290 . else up the line will take care of it later. *}
291 .#define SEC_LINKER_CREATED 0x100000
293 . {* This section should not be subject to garbage collection.
294 . Also set to inform the linker that this section should not be
295 . listed in the link map as discarded. *}
296 .#define SEC_KEEP 0x200000
298 . {* This section contains "short" data, and should be placed
300 .#define SEC_SMALL_DATA 0x400000
302 . {* Attempt to merge identical entities in the section.
303 . Entity size is given in the entsize field. *}
304 .#define SEC_MERGE 0x800000
306 . {* If given with SEC_MERGE, entities to merge are zero terminated
307 . strings where entsize specifies character size instead of fixed
309 .#define SEC_STRINGS 0x1000000
311 . {* This section contains data about section groups. *}
312 .#define SEC_GROUP 0x2000000
314 . {* The section is a COFF shared library section. This flag is
315 . only for the linker. If this type of section appears in
316 . the input file, the linker must copy it to the output file
317 . without changing the vma or size. FIXME: Although this
318 . was originally intended to be general, it really is COFF
319 . specific (and the flag was renamed to indicate this). It
320 . might be cleaner to have some more general mechanism to
321 . allow the back end to control what the linker does with
323 .#define SEC_COFF_SHARED_LIBRARY 0x4000000
325 . {* This input section should be copied to output in reverse order
326 . as an array of pointers. This is for ELF linker internal use
328 .#define SEC_ELF_REVERSE_COPY 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 . {* This section should be compressed. This is for ELF linker
335 . internal use only. *}
336 .#define SEC_ELF_COMPRESS 0x8000000
338 . {* When a section with this flag is being linked, then if the size of
339 . the input section is less than a page, it should not cross a page
340 . boundary. If the size of the input section is one page or more,
341 . it should be aligned on a page boundary. This is for TI
342 . TMS320C54X only. *}
343 .#define SEC_TIC54X_BLOCK 0x10000000
345 . {* This section should be renamed. This is for ELF linker
346 . internal use only. *}
347 .#define SEC_ELF_RENAME 0x10000000
349 . {* Conditionally link this section; do not link if there are no
350 . references found to any symbol in the section. This is for TI
351 . TMS320C54X only. *}
352 .#define SEC_TIC54X_CLINK 0x20000000
354 . {* This section contains vliw code. This is for Toshiba MeP only. *}
355 .#define SEC_MEP_VLIW 0x20000000
357 . {* Indicate that section has the no read flag set. This happens
358 . when memory read flag isn't set. *}
359 .#define SEC_COFF_NOREAD 0x40000000
361 . {* Indicate that section has the purecode flag set. *}
362 .#define SEC_ELF_PURECODE 0x80000000
364 . {* End of section flags. *}
366 . {* Some internal packed boolean fields. *}
368 . {* See the vma field. *}
369 . unsigned int user_set_vma : 1;
371 . {* A mark flag used by some of the linker backends. *}
372 . unsigned int linker_mark : 1;
374 . {* Another mark flag used by some of the linker backends. Set for
375 . output sections that have an input section. *}
376 . unsigned int linker_has_input : 1;
378 . {* Mark flag used by some linker backends for garbage collection. *}
379 . unsigned int gc_mark : 1;
381 . {* Section compression status. *}
382 . unsigned int compress_status : 2;
383 .#define COMPRESS_SECTION_NONE 0
384 .#define COMPRESS_SECTION_DONE 1
385 .#define DECOMPRESS_SECTION_SIZED 2
387 . {* The following flags are used by the ELF linker. *}
389 . {* Mark sections which have been allocated to segments. *}
390 . unsigned int segment_mark : 1;
392 . {* Type of sec_info information. *}
393 . unsigned int sec_info_type:3;
394 .#define SEC_INFO_TYPE_NONE 0
395 .#define SEC_INFO_TYPE_STABS 1
396 .#define SEC_INFO_TYPE_MERGE 2
397 .#define SEC_INFO_TYPE_EH_FRAME 3
398 .#define SEC_INFO_TYPE_JUST_SYMS 4
399 .#define SEC_INFO_TYPE_TARGET 5
400 .#define SEC_INFO_TYPE_EH_FRAME_ENTRY 6
402 . {* Nonzero if this section uses RELA relocations, rather than REL. *}
403 . unsigned int use_rela_p:1;
405 . {* Bits used by various backends. The generic code doesn't touch
408 . unsigned int sec_flg0:1;
409 . unsigned int sec_flg1:1;
410 . unsigned int sec_flg2:1;
411 . unsigned int sec_flg3:1;
412 . unsigned int sec_flg4:1;
413 . unsigned int sec_flg5:1;
415 . {* End of internal packed boolean fields. *}
417 . {* The virtual memory address of the section - where it will be
418 . at run time. The symbols are relocated against this. The
419 . user_set_vma flag is maintained by bfd; if it's not set, the
420 . backend can assign addresses (for example, in <<a.out>>, where
421 . the default address for <<.data>> is dependent on the specific
422 . target and various flags). *}
425 . {* The load address of the section - where it would be in a
426 . rom image; really only used for writing section header
430 . {* The size of the section in *octets*, as it will be output.
431 . Contains a value even if the section has no contents (e.g., the
432 . size of <<.bss>>). *}
433 . bfd_size_type size;
435 . {* For input sections, the original size on disk of the section, in
436 . octets. This field should be set for any section whose size is
437 . changed by linker relaxation. It is required for sections where
438 . the linker relaxation scheme doesn't cache altered section and
439 . reloc contents (stabs, eh_frame, SEC_MERGE, some coff relaxing
440 . targets), and thus the original size needs to be kept to read the
441 . section multiple times. For output sections, rawsize holds the
442 . section size calculated on a previous linker relaxation pass. *}
443 . bfd_size_type rawsize;
445 . {* The compressed size of the section in octets. *}
446 . bfd_size_type compressed_size;
448 . {* Relaxation table. *}
449 . struct relax_table *relax;
451 . {* Count of used relaxation table entries. *}
455 . {* If this section is going to be output, then this value is the
456 . offset in *bytes* into the output section of the first byte in the
457 . input section (byte ==> smallest addressable unit on the
458 . target). In most cases, if this was going to start at the
459 . 100th octet (8-bit quantity) in the output section, this value
460 . would be 100. However, if the target byte size is 16 bits
461 . (bfd_octets_per_byte is "2"), this value would be 50. *}
462 . bfd_vma output_offset;
464 . {* The output section through which to map on output. *}
465 . struct bfd_section *output_section;
467 . {* The alignment requirement of the section, as an exponent of 2 -
468 . e.g., 3 aligns to 2^3 (or 8). *}
469 . unsigned int alignment_power;
471 . {* If an input section, a pointer to a vector of relocation
472 . records for the data in this section. *}
473 . struct reloc_cache_entry *relocation;
475 . {* If an output section, a pointer to a vector of pointers to
476 . relocation records for the data in this section. *}
477 . struct reloc_cache_entry **orelocation;
479 . {* The number of relocation records in one of the above. *}
480 . unsigned reloc_count;
482 . {* Information below is back end specific - and not always used
485 . {* File position of section data. *}
488 . {* File position of relocation info. *}
489 . file_ptr rel_filepos;
491 . {* File position of line data. *}
492 . file_ptr line_filepos;
494 . {* Pointer to data for applications. *}
497 . {* If the SEC_IN_MEMORY flag is set, this points to the actual
499 . unsigned char *contents;
501 . {* Attached line number information. *}
504 . {* Number of line number records. *}
505 . unsigned int lineno_count;
507 . {* Entity size for merging purposes. *}
508 . unsigned int entsize;
510 . {* Points to the kept section if this section is a link-once section,
511 . and is discarded. *}
512 . struct bfd_section *kept_section;
514 . {* When a section is being output, this value changes as more
515 . linenumbers are written out. *}
516 . file_ptr moving_line_filepos;
518 . {* What the section number is in the target world. *}
523 . {* If this is a constructor section then here is a list of the
524 . relocations created to relocate items within it. *}
525 . struct relent_chain *constructor_chain;
527 . {* The BFD which owns the section. *}
530 . {* A symbol which points at this section only. *}
531 . struct bfd_symbol *symbol;
532 . struct bfd_symbol **symbol_ptr_ptr;
534 . {* Early in the link process, map_head and map_tail are used to build
535 . a list of input sections attached to an output section. Later,
536 . output sections use these fields for a list of bfd_link_order
539 . struct bfd_link_order *link_order;
540 . struct bfd_section *s;
541 . } map_head, map_tail;
544 .{* Relax table contains information about instructions which can
545 . be removed by relaxation -- replacing a long address with a
547 .struct relax_table {
548 . {* Address where bytes may be deleted. *}
551 . {* Number of bytes to be deleted. *}
555 .{* Note: the following are provided as inline functions rather than macros
556 . because not all callers use the return value. A macro implementation
557 . would use a comma expression, eg: "((ptr)->foo = val, TRUE)" and some
558 . compilers will complain about comma expressions that have no effect. *}
559 .static inline bfd_boolean
560 .bfd_set_section_userdata (bfd * abfd ATTRIBUTE_UNUSED, asection * ptr,
563 . ptr->userdata = val;
567 .static inline bfd_boolean
568 .bfd_set_section_vma (bfd * abfd ATTRIBUTE_UNUSED, asection * ptr, bfd_vma val)
570 . ptr->vma = ptr->lma = val;
571 . ptr->user_set_vma = TRUE;
575 .static inline bfd_boolean
576 .bfd_set_section_alignment (bfd * abfd ATTRIBUTE_UNUSED, asection * ptr,
579 . ptr->alignment_power = val;
583 .{* These sections are global, and are managed by BFD. The application
584 . and target back end are not permitted to change the values in
586 .extern asection _bfd_std_section[4];
588 .#define BFD_ABS_SECTION_NAME "*ABS*"
589 .#define BFD_UND_SECTION_NAME "*UND*"
590 .#define BFD_COM_SECTION_NAME "*COM*"
591 .#define BFD_IND_SECTION_NAME "*IND*"
593 .{* Pointer to the common section. *}
594 .#define bfd_com_section_ptr (&_bfd_std_section[0])
595 .{* Pointer to the undefined section. *}
596 .#define bfd_und_section_ptr (&_bfd_std_section[1])
597 .{* Pointer to the absolute section. *}
598 .#define bfd_abs_section_ptr (&_bfd_std_section[2])
599 .{* Pointer to the indirect section. *}
600 .#define bfd_ind_section_ptr (&_bfd_std_section[3])
602 .#define bfd_is_und_section(sec) ((sec) == bfd_und_section_ptr)
603 .#define bfd_is_abs_section(sec) ((sec) == bfd_abs_section_ptr)
604 .#define bfd_is_ind_section(sec) ((sec) == bfd_ind_section_ptr)
606 .#define bfd_is_const_section(SEC) \
607 . ( ((SEC) == bfd_abs_section_ptr) \
608 . || ((SEC) == bfd_und_section_ptr) \
609 . || ((SEC) == bfd_com_section_ptr) \
610 . || ((SEC) == bfd_ind_section_ptr))
612 .{* Macros to handle insertion and deletion of a bfd's sections. These
613 . only handle the list pointers, ie. do not adjust section_count,
614 . target_index etc. *}
615 .#define bfd_section_list_remove(ABFD, S) \
618 . asection *_s = S; \
619 . asection *_next = _s->next; \
620 . asection *_prev = _s->prev; \
622 . _prev->next = _next; \
624 . (ABFD)->sections = _next; \
626 . _next->prev = _prev; \
628 . (ABFD)->section_last = _prev; \
631 .#define bfd_section_list_append(ABFD, S) \
634 . asection *_s = S; \
635 . bfd *_abfd = ABFD; \
637 . if (_abfd->section_last) \
639 . _s->prev = _abfd->section_last; \
640 . _abfd->section_last->next = _s; \
645 . _abfd->sections = _s; \
647 . _abfd->section_last = _s; \
650 .#define bfd_section_list_prepend(ABFD, S) \
653 . asection *_s = S; \
654 . bfd *_abfd = ABFD; \
656 . if (_abfd->sections) \
658 . _s->next = _abfd->sections; \
659 . _abfd->sections->prev = _s; \
664 . _abfd->section_last = _s; \
666 . _abfd->sections = _s; \
669 .#define bfd_section_list_insert_after(ABFD, A, S) \
672 . asection *_a = A; \
673 . asection *_s = S; \
674 . asection *_next = _a->next; \
675 . _s->next = _next; \
679 . _next->prev = _s; \
681 . (ABFD)->section_last = _s; \
684 .#define bfd_section_list_insert_before(ABFD, B, S) \
687 . asection *_b = B; \
688 . asection *_s = S; \
689 . asection *_prev = _b->prev; \
690 . _s->prev = _prev; \
694 . _prev->next = _s; \
696 . (ABFD)->sections = _s; \
699 .#define bfd_section_removed_from_list(ABFD, S) \
700 . ((S)->next == NULL ? (ABFD)->section_last != (S) : (S)->next->prev != (S))
702 .#define BFD_FAKE_SECTION(SEC, SYM, NAME, IDX, FLAGS) \
703 . {* name, id, index, next, prev, flags, user_set_vma, *} \
704 . { NAME, IDX, 0, NULL, NULL, FLAGS, 0, \
706 . {* linker_mark, linker_has_input, gc_mark, decompress_status, *} \
709 . {* segment_mark, sec_info_type, use_rela_p, *} \
712 . {* sec_flg0, sec_flg1, sec_flg2, sec_flg3, sec_flg4, sec_flg5, *} \
713 . 0, 0, 0, 0, 0, 0, \
715 . {* vma, lma, size, rawsize, compressed_size, relax, relax_count, *} \
716 . 0, 0, 0, 0, 0, 0, 0, \
718 . {* output_offset, output_section, alignment_power, *} \
721 . {* relocation, orelocation, reloc_count, filepos, rel_filepos, *} \
722 . NULL, NULL, 0, 0, 0, \
724 . {* line_filepos, userdata, contents, lineno, lineno_count, *} \
725 . 0, NULL, NULL, NULL, 0, \
727 . {* entsize, kept_section, moving_line_filepos, *} \
730 . {* target_index, used_by_bfd, constructor_chain, owner, *} \
731 . 0, NULL, NULL, NULL, \
733 . {* symbol, symbol_ptr_ptr, *} \
734 . (struct bfd_symbol *) SYM, &SEC.symbol, \
736 . {* map_head, map_tail *} \
737 . { NULL }, { NULL } \
740 .{* We use a macro to initialize the static asymbol structures because
741 . traditional C does not permit us to initialize a union member while
742 . gcc warns if we don't initialize it.
743 . the_bfd, name, value, attr, section [, udata] *}
745 .#define GLOBAL_SYM_INIT(NAME, SECTION) \
746 . { 0, NAME, 0, BSF_SECTION_SYM, SECTION, { 0 }}
748 .#define GLOBAL_SYM_INIT(NAME, SECTION) \
749 . { 0, NAME, 0, BSF_SECTION_SYM, SECTION }
754 /* These symbols are global, not specific to any BFD. Therefore, anything
755 that tries to change them is broken, and should be repaired. */
757 static const asymbol global_syms
[] =
759 GLOBAL_SYM_INIT (BFD_COM_SECTION_NAME
, bfd_com_section_ptr
),
760 GLOBAL_SYM_INIT (BFD_UND_SECTION_NAME
, bfd_und_section_ptr
),
761 GLOBAL_SYM_INIT (BFD_ABS_SECTION_NAME
, bfd_abs_section_ptr
),
762 GLOBAL_SYM_INIT (BFD_IND_SECTION_NAME
, bfd_ind_section_ptr
)
765 #define STD_SECTION(NAME, IDX, FLAGS) \
766 BFD_FAKE_SECTION(_bfd_std_section[IDX], &global_syms[IDX], NAME, IDX, FLAGS)
768 asection _bfd_std_section
[] = {
769 STD_SECTION (BFD_COM_SECTION_NAME
, 0, SEC_IS_COMMON
),
770 STD_SECTION (BFD_UND_SECTION_NAME
, 1, 0),
771 STD_SECTION (BFD_ABS_SECTION_NAME
, 2, 0),
772 STD_SECTION (BFD_IND_SECTION_NAME
, 3, 0)
776 /* Initialize an entry in the section hash table. */
778 struct bfd_hash_entry
*
779 bfd_section_hash_newfunc (struct bfd_hash_entry
*entry
,
780 struct bfd_hash_table
*table
,
783 /* Allocate the structure if it has not already been allocated by a
787 entry
= (struct bfd_hash_entry
*)
788 bfd_hash_allocate (table
, sizeof (struct section_hash_entry
));
793 /* Call the allocation method of the superclass. */
794 entry
= bfd_hash_newfunc (entry
, table
, string
);
796 memset (&((struct section_hash_entry
*) entry
)->section
, 0,
802 #define section_hash_lookup(table, string, create, copy) \
803 ((struct section_hash_entry *) \
804 bfd_hash_lookup ((table), (string), (create), (copy)))
806 /* Create a symbol whose only job is to point to this section. This
807 is useful for things like relocs which are relative to the base
811 _bfd_generic_new_section_hook (bfd
*abfd
, asection
*newsect
)
813 newsect
->symbol
= bfd_make_empty_symbol (abfd
);
814 if (newsect
->symbol
== NULL
)
817 newsect
->symbol
->name
= newsect
->name
;
818 newsect
->symbol
->value
= 0;
819 newsect
->symbol
->section
= newsect
;
820 newsect
->symbol
->flags
= BSF_SECTION_SYM
;
822 newsect
->symbol_ptr_ptr
= &newsect
->symbol
;
826 static unsigned int section_id
= 0x10; /* id 0 to 3 used by STD_SECTION. */
828 /* Initializes a new section. NEWSECT->NAME is already set. */
831 bfd_section_init (bfd
*abfd
, asection
*newsect
)
833 newsect
->id
= section_id
;
834 newsect
->index
= abfd
->section_count
;
835 newsect
->owner
= abfd
;
837 if (! BFD_SEND (abfd
, _new_section_hook
, (abfd
, newsect
)))
841 abfd
->section_count
++;
842 bfd_section_list_append (abfd
, newsect
);
849 section prototypes, , typedef asection, Sections
853 These are the functions exported by the section handling part of BFD.
858 bfd_section_list_clear
861 void bfd_section_list_clear (bfd *);
864 Clears the section list, and also resets the section count and
869 bfd_section_list_clear (bfd
*abfd
)
871 abfd
->sections
= NULL
;
872 abfd
->section_last
= NULL
;
873 abfd
->section_count
= 0;
874 memset (abfd
->section_htab
.table
, 0,
875 abfd
->section_htab
.size
* sizeof (struct bfd_hash_entry
*));
876 abfd
->section_htab
.count
= 0;
881 bfd_get_section_by_name
884 asection *bfd_get_section_by_name (bfd *abfd, const char *name);
887 Return the most recently created section attached to @var{abfd}
888 named @var{name}. Return NULL if no such section exists.
892 bfd_get_section_by_name (bfd
*abfd
, const char *name
)
894 struct section_hash_entry
*sh
;
896 sh
= section_hash_lookup (&abfd
->section_htab
, name
, FALSE
, FALSE
);
905 bfd_get_next_section_by_name
908 asection *bfd_get_next_section_by_name (bfd *ibfd, asection *sec);
911 Given @var{sec} is a section returned by @code{bfd_get_section_by_name},
912 return the next most recently created section attached to the same
913 BFD with the same name, or if no such section exists in the same BFD and
914 IBFD is non-NULL, the next section with the same name in any input
915 BFD following IBFD. Return NULL on finding no section.
919 bfd_get_next_section_by_name (bfd
*ibfd
, asection
*sec
)
921 struct section_hash_entry
*sh
;
925 sh
= ((struct section_hash_entry
*)
926 ((char *) sec
- offsetof (struct section_hash_entry
, section
)));
928 hash
= sh
->root
.hash
;
930 for (sh
= (struct section_hash_entry
*) sh
->root
.next
;
932 sh
= (struct section_hash_entry
*) sh
->root
.next
)
933 if (sh
->root
.hash
== hash
934 && strcmp (sh
->root
.string
, name
) == 0)
939 while ((ibfd
= ibfd
->link
.next
) != NULL
)
941 asection
*s
= bfd_get_section_by_name (ibfd
, name
);
952 bfd_get_linker_section
955 asection *bfd_get_linker_section (bfd *abfd, const char *name);
958 Return the linker created section attached to @var{abfd}
959 named @var{name}. Return NULL if no such section exists.
963 bfd_get_linker_section (bfd
*abfd
, const char *name
)
965 asection
*sec
= bfd_get_section_by_name (abfd
, name
);
967 while (sec
!= NULL
&& (sec
->flags
& SEC_LINKER_CREATED
) == 0)
968 sec
= bfd_get_next_section_by_name (NULL
, sec
);
974 bfd_get_section_by_name_if
977 asection *bfd_get_section_by_name_if
980 bfd_boolean (*func) (bfd *abfd, asection *sect, void *obj),
984 Call the provided function @var{func} for each section
985 attached to the BFD @var{abfd} whose name matches @var{name},
986 passing @var{obj} as an argument. The function will be called
989 | func (abfd, the_section, obj);
991 It returns the first section for which @var{func} returns true,
997 bfd_get_section_by_name_if (bfd
*abfd
, const char *name
,
998 bfd_boolean (*operation
) (bfd
*,
1003 struct section_hash_entry
*sh
;
1006 sh
= section_hash_lookup (&abfd
->section_htab
, name
, FALSE
, FALSE
);
1010 hash
= sh
->root
.hash
;
1011 for (; sh
!= NULL
; sh
= (struct section_hash_entry
*) sh
->root
.next
)
1012 if (sh
->root
.hash
== hash
1013 && strcmp (sh
->root
.string
, name
) == 0
1014 && (*operation
) (abfd
, &sh
->section
, user_storage
))
1015 return &sh
->section
;
1022 bfd_get_unique_section_name
1025 char *bfd_get_unique_section_name
1026 (bfd *abfd, const char *templat, int *count);
1029 Invent a section name that is unique in @var{abfd} by tacking
1030 a dot and a digit suffix onto the original @var{templat}. If
1031 @var{count} is non-NULL, then it specifies the first number
1032 tried as a suffix to generate a unique name. The value
1033 pointed to by @var{count} will be incremented in this case.
1037 bfd_get_unique_section_name (bfd
*abfd
, const char *templat
, int *count
)
1043 len
= strlen (templat
);
1044 sname
= (char *) bfd_malloc (len
+ 8);
1047 memcpy (sname
, templat
, len
);
1054 /* If we have a million sections, something is badly wrong. */
1057 sprintf (sname
+ len
, ".%d", num
++);
1059 while (section_hash_lookup (&abfd
->section_htab
, sname
, FALSE
, FALSE
));
1068 bfd_make_section_old_way
1071 asection *bfd_make_section_old_way (bfd *abfd, const char *name);
1074 Create a new empty section called @var{name}
1075 and attach it to the end of the chain of sections for the
1076 BFD @var{abfd}. An attempt to create a section with a name which
1077 is already in use returns its pointer without changing the
1080 It has the funny name since this is the way it used to be
1081 before it was rewritten....
1083 Possible errors are:
1084 o <<bfd_error_invalid_operation>> -
1085 If output has already started for this BFD.
1086 o <<bfd_error_no_memory>> -
1087 If memory allocation fails.
1092 bfd_make_section_old_way (bfd
*abfd
, const char *name
)
1096 if (abfd
->output_has_begun
)
1098 bfd_set_error (bfd_error_invalid_operation
);
1102 if (strcmp (name
, BFD_ABS_SECTION_NAME
) == 0)
1103 newsect
= bfd_abs_section_ptr
;
1104 else if (strcmp (name
, BFD_COM_SECTION_NAME
) == 0)
1105 newsect
= bfd_com_section_ptr
;
1106 else if (strcmp (name
, BFD_UND_SECTION_NAME
) == 0)
1107 newsect
= bfd_und_section_ptr
;
1108 else if (strcmp (name
, BFD_IND_SECTION_NAME
) == 0)
1109 newsect
= bfd_ind_section_ptr
;
1112 struct section_hash_entry
*sh
;
1114 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1118 newsect
= &sh
->section
;
1119 if (newsect
->name
!= NULL
)
1121 /* Section already exists. */
1125 newsect
->name
= name
;
1126 return bfd_section_init (abfd
, newsect
);
1129 /* Call new_section_hook when "creating" the standard abs, com, und
1130 and ind sections to tack on format specific section data.
1131 Also, create a proper section symbol. */
1132 if (! BFD_SEND (abfd
, _new_section_hook
, (abfd
, newsect
)))
1139 bfd_make_section_anyway_with_flags
1142 asection *bfd_make_section_anyway_with_flags
1143 (bfd *abfd, const char *name, flagword flags);
1146 Create a new empty section called @var{name} and attach it to the end of
1147 the chain of sections for @var{abfd}. Create a new section even if there
1148 is already a section with that name. Also set the attributes of the
1149 new section to the value @var{flags}.
1151 Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1152 o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1153 o <<bfd_error_no_memory>> - If memory allocation fails.
1157 bfd_make_section_anyway_with_flags (bfd
*abfd
, const char *name
,
1160 struct section_hash_entry
*sh
;
1163 if (abfd
->output_has_begun
)
1165 bfd_set_error (bfd_error_invalid_operation
);
1169 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1173 newsect
= &sh
->section
;
1174 if (newsect
->name
!= NULL
)
1176 /* We are making a section of the same name. Put it in the
1177 section hash table. Even though we can't find it directly by a
1178 hash lookup, we'll be able to find the section by traversing
1179 sh->root.next quicker than looking at all the bfd sections. */
1180 struct section_hash_entry
*new_sh
;
1181 new_sh
= (struct section_hash_entry
*)
1182 bfd_section_hash_newfunc (NULL
, &abfd
->section_htab
, name
);
1186 new_sh
->root
= sh
->root
;
1187 sh
->root
.next
= &new_sh
->root
;
1188 newsect
= &new_sh
->section
;
1191 newsect
->flags
= flags
;
1192 newsect
->name
= name
;
1193 return bfd_section_init (abfd
, newsect
);
1198 bfd_make_section_anyway
1201 asection *bfd_make_section_anyway (bfd *abfd, const char *name);
1204 Create a new empty section called @var{name} and attach it to the end of
1205 the chain of sections for @var{abfd}. Create a new section even if there
1206 is already a section with that name.
1208 Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1209 o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1210 o <<bfd_error_no_memory>> - If memory allocation fails.
1214 bfd_make_section_anyway (bfd
*abfd
, const char *name
)
1216 return bfd_make_section_anyway_with_flags (abfd
, name
, 0);
1221 bfd_make_section_with_flags
1224 asection *bfd_make_section_with_flags
1225 (bfd *, const char *name, flagword flags);
1228 Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1229 bfd_set_error ()) without changing the section chain if there is already a
1230 section named @var{name}. Also set the attributes of the new section to
1231 the value @var{flags}. If there is an error, return <<NULL>> and set
1236 bfd_make_section_with_flags (bfd
*abfd
, const char *name
,
1239 struct section_hash_entry
*sh
;
1242 if (abfd
== NULL
|| name
== NULL
|| abfd
->output_has_begun
)
1244 bfd_set_error (bfd_error_invalid_operation
);
1248 if (strcmp (name
, BFD_ABS_SECTION_NAME
) == 0
1249 || strcmp (name
, BFD_COM_SECTION_NAME
) == 0
1250 || strcmp (name
, BFD_UND_SECTION_NAME
) == 0
1251 || strcmp (name
, BFD_IND_SECTION_NAME
) == 0)
1254 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1258 newsect
= &sh
->section
;
1259 if (newsect
->name
!= NULL
)
1261 /* Section already exists. */
1265 newsect
->name
= name
;
1266 newsect
->flags
= flags
;
1267 return bfd_section_init (abfd
, newsect
);
1275 asection *bfd_make_section (bfd *, const char *name);
1278 Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1279 bfd_set_error ()) without changing the section chain if there is already a
1280 section named @var{name}. If there is an error, return <<NULL>> and set
1285 bfd_make_section (bfd
*abfd
, const char *name
)
1287 return bfd_make_section_with_flags (abfd
, name
, 0);
1292 bfd_get_next_section_id
1295 int bfd_get_next_section_id (void);
1298 Returns the id that the next section created will have.
1302 bfd_get_next_section_id (void)
1309 bfd_set_section_flags
1312 bfd_boolean bfd_set_section_flags
1313 (bfd *abfd, asection *sec, flagword flags);
1316 Set the attributes of the section @var{sec} in the BFD
1317 @var{abfd} to the value @var{flags}. Return <<TRUE>> on success,
1318 <<FALSE>> on error. Possible error returns are:
1320 o <<bfd_error_invalid_operation>> -
1321 The section cannot have one or more of the attributes
1322 requested. For example, a .bss section in <<a.out>> may not
1323 have the <<SEC_HAS_CONTENTS>> field set.
1328 bfd_set_section_flags (bfd
*abfd ATTRIBUTE_UNUSED
,
1332 section
->flags
= flags
;
1341 void bfd_rename_section
1342 (bfd *abfd, asection *sec, const char *newname);
1345 Rename section @var{sec} in @var{abfd} to @var{newname}.
1349 bfd_rename_section (bfd
*abfd
, sec_ptr sec
, const char *newname
)
1351 struct section_hash_entry
*sh
;
1353 sh
= (struct section_hash_entry
*)
1354 ((char *) sec
- offsetof (struct section_hash_entry
, section
));
1355 sh
->section
.name
= newname
;
1356 bfd_hash_rename (&abfd
->section_htab
, newname
, &sh
->root
);
1361 bfd_map_over_sections
1364 void bfd_map_over_sections
1366 void (*func) (bfd *abfd, asection *sect, void *obj),
1370 Call the provided function @var{func} for each section
1371 attached to the BFD @var{abfd}, passing @var{obj} as an
1372 argument. The function will be called as if by
1374 | func (abfd, the_section, obj);
1376 This is the preferred method for iterating over sections; an
1377 alternative would be to use a loop:
1380 | for (p = abfd->sections; p != NULL; p = p->next)
1381 | func (abfd, p, ...)
1386 bfd_map_over_sections (bfd
*abfd
,
1387 void (*operation
) (bfd
*, asection
*, void *),
1393 for (sect
= abfd
->sections
; sect
!= NULL
; i
++, sect
= sect
->next
)
1394 (*operation
) (abfd
, sect
, user_storage
);
1396 if (i
!= abfd
->section_count
) /* Debugging */
1402 bfd_sections_find_if
1405 asection *bfd_sections_find_if
1407 bfd_boolean (*operation) (bfd *abfd, asection *sect, void *obj),
1411 Call the provided function @var{operation} for each section
1412 attached to the BFD @var{abfd}, passing @var{obj} as an
1413 argument. The function will be called as if by
1415 | operation (abfd, the_section, obj);
1417 It returns the first section for which @var{operation} returns true.
1422 bfd_sections_find_if (bfd
*abfd
,
1423 bfd_boolean (*operation
) (bfd
*, asection
*, void *),
1428 for (sect
= abfd
->sections
; sect
!= NULL
; sect
= sect
->next
)
1429 if ((*operation
) (abfd
, sect
, user_storage
))
1437 bfd_set_section_size
1440 bfd_boolean bfd_set_section_size
1441 (bfd *abfd, asection *sec, bfd_size_type val);
1444 Set @var{sec} to the size @var{val}. If the operation is
1445 ok, then <<TRUE>> is returned, else <<FALSE>>.
1447 Possible error returns:
1448 o <<bfd_error_invalid_operation>> -
1449 Writing has started to the BFD, so setting the size is invalid.
1454 bfd_set_section_size (bfd
*abfd
, sec_ptr ptr
, bfd_size_type val
)
1456 /* Once you've started writing to any section you cannot create or change
1457 the size of any others. */
1459 if (abfd
->output_has_begun
)
1461 bfd_set_error (bfd_error_invalid_operation
);
1471 bfd_set_section_contents
1474 bfd_boolean bfd_set_section_contents
1475 (bfd *abfd, asection *section, const void *data,
1476 file_ptr offset, bfd_size_type count);
1479 Sets the contents of the section @var{section} in BFD
1480 @var{abfd} to the data starting in memory at @var{data}. The
1481 data is written to the output section starting at offset
1482 @var{offset} for @var{count} octets.
1484 Normally <<TRUE>> is returned, else <<FALSE>>. Possible error
1486 o <<bfd_error_no_contents>> -
1487 The output section does not have the <<SEC_HAS_CONTENTS>>
1488 attribute, so nothing can be written to it.
1491 This routine is front end to the back end function
1492 <<_bfd_set_section_contents>>.
1497 bfd_set_section_contents (bfd
*abfd
,
1499 const void *location
,
1501 bfd_size_type count
)
1505 if (!(bfd_get_section_flags (abfd
, section
) & SEC_HAS_CONTENTS
))
1507 bfd_set_error (bfd_error_no_contents
);
1512 if ((bfd_size_type
) offset
> sz
1514 || offset
+ count
> sz
1515 || count
!= (size_t) count
)
1517 bfd_set_error (bfd_error_bad_value
);
1521 if (!bfd_write_p (abfd
))
1523 bfd_set_error (bfd_error_invalid_operation
);
1527 /* Record a copy of the data in memory if desired. */
1528 if (section
->contents
1529 && location
!= section
->contents
+ offset
)
1530 memcpy (section
->contents
+ offset
, location
, (size_t) count
);
1532 if (BFD_SEND (abfd
, _bfd_set_section_contents
,
1533 (abfd
, section
, location
, offset
, count
)))
1535 abfd
->output_has_begun
= TRUE
;
1544 bfd_get_section_contents
1547 bfd_boolean bfd_get_section_contents
1548 (bfd *abfd, asection *section, void *location, file_ptr offset,
1549 bfd_size_type count);
1552 Read data from @var{section} in BFD @var{abfd}
1553 into memory starting at @var{location}. The data is read at an
1554 offset of @var{offset} from the start of the input section,
1555 and is read for @var{count} bytes.
1557 If the contents of a constructor with the <<SEC_CONSTRUCTOR>>
1558 flag set are requested or if the section does not have the
1559 <<SEC_HAS_CONTENTS>> flag set, then the @var{location} is filled
1560 with zeroes. If no errors occur, <<TRUE>> is returned, else
1565 bfd_get_section_contents (bfd
*abfd
,
1569 bfd_size_type count
)
1573 if (section
->flags
& SEC_CONSTRUCTOR
)
1575 memset (location
, 0, (size_t) count
);
1579 if (abfd
->direction
!= write_direction
&& section
->rawsize
!= 0)
1580 sz
= section
->rawsize
;
1583 if ((bfd_size_type
) offset
> sz
1585 || offset
+ count
> sz
1586 || count
!= (size_t) count
)
1588 bfd_set_error (bfd_error_bad_value
);
1596 if ((section
->flags
& SEC_HAS_CONTENTS
) == 0)
1598 memset (location
, 0, (size_t) count
);
1602 if ((section
->flags
& SEC_IN_MEMORY
) != 0)
1604 if (section
->contents
== NULL
)
1606 /* This can happen because of errors earlier on in the linking process.
1607 We do not want to seg-fault here, so clear the flag and return an
1609 section
->flags
&= ~ SEC_IN_MEMORY
;
1610 bfd_set_error (bfd_error_invalid_operation
);
1614 memmove (location
, section
->contents
+ offset
, (size_t) count
);
1618 return BFD_SEND (abfd
, _bfd_get_section_contents
,
1619 (abfd
, section
, location
, offset
, count
));
1624 bfd_malloc_and_get_section
1627 bfd_boolean bfd_malloc_and_get_section
1628 (bfd *abfd, asection *section, bfd_byte **buf);
1631 Read all data from @var{section} in BFD @var{abfd}
1632 into a buffer, *@var{buf}, malloc'd by this function.
1636 bfd_malloc_and_get_section (bfd
*abfd
, sec_ptr sec
, bfd_byte
**buf
)
1639 return bfd_get_full_section_contents (abfd
, sec
, buf
);
1643 bfd_copy_private_section_data
1646 bfd_boolean bfd_copy_private_section_data
1647 (bfd *ibfd, asection *isec, bfd *obfd, asection *osec);
1650 Copy private section information from @var{isec} in the BFD
1651 @var{ibfd} to the section @var{osec} in the BFD @var{obfd}.
1652 Return <<TRUE>> on success, <<FALSE>> on error. Possible error
1655 o <<bfd_error_no_memory>> -
1656 Not enough memory exists to create private data for @var{osec}.
1658 .#define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \
1659 . BFD_SEND (obfd, _bfd_copy_private_section_data, \
1660 . (ibfd, isection, obfd, osection))
1665 bfd_generic_is_group_section
1668 bfd_boolean bfd_generic_is_group_section (bfd *, const asection *sec);
1671 Returns TRUE if @var{sec} is a member of a group.
1675 bfd_generic_is_group_section (bfd
*abfd ATTRIBUTE_UNUSED
,
1676 const asection
*sec ATTRIBUTE_UNUSED
)
1683 bfd_generic_discard_group
1686 bfd_boolean bfd_generic_discard_group (bfd *abfd, asection *group);
1689 Remove all members of @var{group} from the output.
1693 bfd_generic_discard_group (bfd
*abfd ATTRIBUTE_UNUSED
,
1694 asection
*group ATTRIBUTE_UNUSED
)
1700 _bfd_nowrite_set_section_contents (bfd
*abfd
,
1701 sec_ptr section ATTRIBUTE_UNUSED
,
1702 const void *location ATTRIBUTE_UNUSED
,
1703 file_ptr offset ATTRIBUTE_UNUSED
,
1704 bfd_size_type count ATTRIBUTE_UNUSED
)
1706 return _bfd_bool_bfd_false_error (abfd
);