1 /* Object file "section" support for the BFD library.
2 Copyright (C) 1990-2019 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
71 Section Output, typedef asection, Section Input, Sections
76 To write a new object style BFD, the various sections to be
77 written have to be created. They are attached to the BFD in
78 the same way as input sections; data is written to the
79 sections using <<bfd_set_section_contents>>.
81 Any program that creates or combines sections (e.g., the assembler
82 and linker) must use the <<asection>> fields <<output_section>> and
83 <<output_offset>> to indicate the file sections to which each
84 section must be written. (If the section is being created from
85 scratch, <<output_section>> should probably point to the section
86 itself and <<output_offset>> should probably be zero.)
88 The data to be written comes from input sections attached
89 (via <<output_section>> pointers) to
90 the output sections. The output section structure can be
91 considered a filter for the input section: the output section
92 determines the vma of the output data and the name, but the
93 input section determines the offset into the output section of
94 the data to be written.
96 E.g., to create a section "O", starting at 0x100, 0x123 long,
97 containing two subsections, "A" at offset 0x0 (i.e., at vma
98 0x100) and "B" at offset 0x20 (i.e., at vma 0x120) the <<asection>>
99 structures would look like:
104 | output_section -----------> section name "O"
106 | section name "B" | size 0x123
107 | output_offset 0x20 |
109 | output_section --------|
114 The data within a section is stored in a @dfn{link_order}.
115 These are much like the fixups in <<gas>>. The link_order
116 abstraction allows a section to grow and shrink within itself.
118 A link_order knows how big it is, and which is the next
119 link_order and where the raw data for it is; it also points to
120 a list of relocations which apply to it.
122 The link_order is used by the linker to perform relaxing on
123 final code. The compiler creates code which is as big as
124 necessary to make it work without relaxing, and the user can
125 select whether to relax. Sometimes relaxing takes a lot of
126 time. The linker runs around the relocations to see if any
127 are attached to data which can be shrunk, if so it does it on
128 a link_order by link_order basis.
140 typedef asection, section prototypes, Section Output, Sections
144 Here is the section structure:
148 .typedef struct bfd_section
150 . {* The name of the section; the name isn't a copy, the pointer is
151 . the same as that passed to bfd_make_section. *}
154 . {* A unique sequence number. *}
157 . {* Which section in the bfd; 0..n-1 as sections are created in a bfd. *}
158 . unsigned int index;
160 . {* The next section in the list belonging to the BFD, or NULL. *}
161 . struct bfd_section *next;
163 . {* The previous section in the list belonging to the BFD, or NULL. *}
164 . struct bfd_section *prev;
166 . {* The field flags contains attributes of the section. Some
167 . flags are read in from the object file, and some are
168 . synthesized from other information. *}
171 .#define SEC_NO_FLAGS 0x0
173 . {* Tells the OS to allocate space for this section when loading.
174 . This is clear for a section containing debug information only. *}
175 .#define SEC_ALLOC 0x1
177 . {* Tells the OS to load the section from the file when loading.
178 . This is clear for a .bss section. *}
179 .#define SEC_LOAD 0x2
181 . {* The section contains data still to be relocated, so there is
182 . some relocation information too. *}
183 .#define SEC_RELOC 0x4
185 . {* A signal to the OS that the section contains read only data. *}
186 .#define SEC_READONLY 0x8
188 . {* The section contains code only. *}
189 .#define SEC_CODE 0x10
191 . {* The section contains data only. *}
192 .#define SEC_DATA 0x20
194 . {* The section will reside in ROM. *}
195 .#define SEC_ROM 0x40
197 . {* The section contains constructor information. This section
198 . type is used by the linker to create lists of constructors and
199 . destructors used by <<g++>>. When a back end sees a symbol
200 . which should be used in a constructor list, it creates a new
201 . section for the type of name (e.g., <<__CTOR_LIST__>>), attaches
202 . the symbol to it, and builds a relocation. To build the lists
203 . of constructors, all the linker has to do is catenate all the
204 . sections called <<__CTOR_LIST__>> and relocate the data
205 . contained within - exactly the operations it would peform on
207 .#define SEC_CONSTRUCTOR 0x80
209 . {* The section has contents - a data section could be
210 . <<SEC_ALLOC>> | <<SEC_HAS_CONTENTS>>; a debug section could be
211 . <<SEC_HAS_CONTENTS>> *}
212 .#define SEC_HAS_CONTENTS 0x100
214 . {* An instruction to the linker to not output the section
215 . even if it has information which would normally be written. *}
216 .#define SEC_NEVER_LOAD 0x200
218 . {* The section contains thread local data. *}
219 .#define SEC_THREAD_LOCAL 0x400
221 . {* The section's size is fixed. Generic linker code will not
222 . recalculate it and it is up to whoever has set this flag to
223 . get the size right. *}
224 .#define SEC_FIXED_SIZE 0x800
226 . {* The section contains common symbols (symbols may be defined
227 . multiple times, the value of a symbol is the amount of
228 . space it requires, and the largest symbol value is the one
229 . used). Most targets have exactly one of these (which we
230 . translate to bfd_com_section_ptr), but ECOFF has two. *}
231 .#define SEC_IS_COMMON 0x1000
233 . {* The section contains only debugging information. For
234 . example, this is set for ELF .debug and .stab sections.
235 . strip tests this flag to see if a section can be
237 .#define SEC_DEBUGGING 0x2000
239 . {* The contents of this section are held in memory pointed to
240 . by the contents field. This is checked by bfd_get_section_contents,
241 . and the data is retrieved from memory if appropriate. *}
242 .#define SEC_IN_MEMORY 0x4000
244 . {* The contents of this section are to be excluded by the
245 . linker for executable and shared objects unless those
246 . objects are to be further relocated. *}
247 .#define SEC_EXCLUDE 0x8000
249 . {* The contents of this section are to be sorted based on the sum of
250 . the symbol and addend values specified by the associated relocation
251 . entries. Entries without associated relocation entries will be
252 . appended to the end of the section in an unspecified order. *}
253 .#define SEC_SORT_ENTRIES 0x10000
255 . {* When linking, duplicate sections of the same name should be
256 . discarded, rather than being combined into a single section as
257 . is usually done. This is similar to how common symbols are
258 . handled. See SEC_LINK_DUPLICATES below. *}
259 .#define SEC_LINK_ONCE 0x20000
261 . {* If SEC_LINK_ONCE is set, this bitfield describes how the linker
262 . should handle duplicate sections. *}
263 .#define SEC_LINK_DUPLICATES 0xc0000
265 . {* This value for SEC_LINK_DUPLICATES means that duplicate
266 . sections with the same name should simply be discarded. *}
267 .#define SEC_LINK_DUPLICATES_DISCARD 0x0
269 . {* This value for SEC_LINK_DUPLICATES means that the linker
270 . should warn if there are any duplicate sections, although
271 . it should still only link one copy. *}
272 .#define SEC_LINK_DUPLICATES_ONE_ONLY 0x40000
274 . {* This value for SEC_LINK_DUPLICATES means that the linker
275 . should warn if any duplicate sections are a different size. *}
276 .#define SEC_LINK_DUPLICATES_SAME_SIZE 0x80000
278 . {* This value for SEC_LINK_DUPLICATES means that the linker
279 . should warn if any duplicate sections contain different
281 .#define SEC_LINK_DUPLICATES_SAME_CONTENTS \
282 . (SEC_LINK_DUPLICATES_ONE_ONLY | SEC_LINK_DUPLICATES_SAME_SIZE)
284 . {* This section was created by the linker as part of dynamic
285 . relocation or other arcane processing. It is skipped when
286 . going through the first-pass output, trusting that someone
287 . else up the line will take care of it later. *}
288 .#define SEC_LINKER_CREATED 0x100000
290 . {* This section should not be subject to garbage collection.
291 . Also set to inform the linker that this section should not be
292 . listed in the link map as discarded. *}
293 .#define SEC_KEEP 0x200000
295 . {* This section contains "short" data, and should be placed
297 .#define SEC_SMALL_DATA 0x400000
299 . {* Attempt to merge identical entities in the section.
300 . Entity size is given in the entsize field. *}
301 .#define SEC_MERGE 0x800000
303 . {* If given with SEC_MERGE, entities to merge are zero terminated
304 . strings where entsize specifies character size instead of fixed
306 .#define SEC_STRINGS 0x1000000
308 . {* This section contains data about section groups. *}
309 .#define SEC_GROUP 0x2000000
311 . {* The section is a COFF shared library section. This flag is
312 . only for the linker. If this type of section appears in
313 . the input file, the linker must copy it to the output file
314 . without changing the vma or size. FIXME: Although this
315 . was originally intended to be general, it really is COFF
316 . specific (and the flag was renamed to indicate this). It
317 . might be cleaner to have some more general mechanism to
318 . allow the back end to control what the linker does with
320 .#define SEC_COFF_SHARED_LIBRARY 0x4000000
322 . {* This input section should be copied to output in reverse order
323 . as an array of pointers. This is for ELF linker internal use
325 .#define SEC_ELF_REVERSE_COPY 0x4000000
327 . {* This section contains data which may be shared with other
328 . executables or shared objects. This is for COFF only. *}
329 .#define SEC_COFF_SHARED 0x8000000
331 . {* This section should be compressed. This is for ELF linker
332 . internal use only. *}
333 .#define SEC_ELF_COMPRESS 0x8000000
335 . {* When a section with this flag is being linked, then if the size of
336 . the input section is less than a page, it should not cross a page
337 . boundary. If the size of the input section is one page or more,
338 . it should be aligned on a page boundary. This is for TI
339 . TMS320C54X only. *}
340 .#define SEC_TIC54X_BLOCK 0x10000000
342 . {* This section should be renamed. This is for ELF linker
343 . internal use only. *}
344 .#define SEC_ELF_RENAME 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 . {* This section contains vliw code. This is for Toshiba MeP only. *}
352 .#define SEC_MEP_VLIW 0x20000000
354 . {* Indicate that section has the no read flag set. This happens
355 . when memory read flag isn't set. *}
356 .#define SEC_COFF_NOREAD 0x40000000
358 . {* Indicate that section has the purecode flag set. *}
359 .#define SEC_ELF_PURECODE 0x80000000
361 . {* End of section flags. *}
363 . {* Some internal packed boolean fields. *}
365 . {* See the vma field. *}
366 . unsigned int user_set_vma : 1;
368 . {* A mark flag used by some of the linker backends. *}
369 . unsigned int linker_mark : 1;
371 . {* Another mark flag used by some of the linker backends. Set for
372 . output sections that have an input section. *}
373 . unsigned int linker_has_input : 1;
375 . {* Mark flag used by some linker backends for garbage collection. *}
376 . unsigned int gc_mark : 1;
378 . {* Section compression status. *}
379 . unsigned int compress_status : 2;
380 .#define COMPRESS_SECTION_NONE 0
381 .#define COMPRESS_SECTION_DONE 1
382 .#define DECOMPRESS_SECTION_SIZED 2
384 . {* The following flags are used by the ELF linker. *}
386 . {* Mark sections which have been allocated to segments. *}
387 . unsigned int segment_mark : 1;
389 . {* Type of sec_info information. *}
390 . unsigned int sec_info_type:3;
391 .#define SEC_INFO_TYPE_NONE 0
392 .#define SEC_INFO_TYPE_STABS 1
393 .#define SEC_INFO_TYPE_MERGE 2
394 .#define SEC_INFO_TYPE_EH_FRAME 3
395 .#define SEC_INFO_TYPE_JUST_SYMS 4
396 .#define SEC_INFO_TYPE_TARGET 5
397 .#define SEC_INFO_TYPE_EH_FRAME_ENTRY 6
399 . {* Nonzero if this section uses RELA relocations, rather than REL. *}
400 . unsigned int use_rela_p:1;
402 . {* Bits used by various backends. The generic code doesn't touch
405 . unsigned int sec_flg0:1;
406 . unsigned int sec_flg1:1;
407 . unsigned int sec_flg2:1;
408 . unsigned int sec_flg3:1;
409 . unsigned int sec_flg4:1;
410 . unsigned int sec_flg5:1;
412 . {* End of internal packed boolean fields. *}
414 . {* The virtual memory address of the section - where it will be
415 . at run time. The symbols are relocated against this. The
416 . user_set_vma flag is maintained by bfd; if it's not set, the
417 . backend can assign addresses (for example, in <<a.out>>, where
418 . the default address for <<.data>> is dependent on the specific
419 . target and various flags). *}
422 . {* The load address of the section - where it would be in a
423 . rom image; really only used for writing section header
427 . {* The size of the section in *octets*, as it will be output.
428 . Contains a value even if the section has no contents (e.g., the
429 . size of <<.bss>>). *}
430 . bfd_size_type size;
432 . {* For input sections, the original size on disk of the section, in
433 . octets. This field should be set for any section whose size is
434 . changed by linker relaxation. It is required for sections where
435 . the linker relaxation scheme doesn't cache altered section and
436 . reloc contents (stabs, eh_frame, SEC_MERGE, some coff relaxing
437 . targets), and thus the original size needs to be kept to read the
438 . section multiple times. For output sections, rawsize holds the
439 . section size calculated on a previous linker relaxation pass. *}
440 . bfd_size_type rawsize;
442 . {* The compressed size of the section in octets. *}
443 . bfd_size_type compressed_size;
445 . {* Relaxation table. *}
446 . struct relax_table *relax;
448 . {* Count of used relaxation table entries. *}
452 . {* If this section is going to be output, then this value is the
453 . offset in *bytes* into the output section of the first byte in the
454 . input section (byte ==> smallest addressable unit on the
455 . target). In most cases, if this was going to start at the
456 . 100th octet (8-bit quantity) in the output section, this value
457 . would be 100. However, if the target byte size is 16 bits
458 . (bfd_octets_per_byte is "2"), this value would be 50. *}
459 . bfd_vma output_offset;
461 . {* The output section through which to map on output. *}
462 . struct bfd_section *output_section;
464 . {* The alignment requirement of the section, as an exponent of 2 -
465 . e.g., 3 aligns to 2^3 (or 8). *}
466 . unsigned int alignment_power;
468 . {* If an input section, a pointer to a vector of relocation
469 . records for the data in this section. *}
470 . struct reloc_cache_entry *relocation;
472 . {* If an output section, a pointer to a vector of pointers to
473 . relocation records for the data in this section. *}
474 . struct reloc_cache_entry **orelocation;
476 . {* The number of relocation records in one of the above. *}
477 . unsigned reloc_count;
479 . {* Information below is back end specific - and not always used
482 . {* File position of section data. *}
485 . {* File position of relocation info. *}
486 . file_ptr rel_filepos;
488 . {* File position of line data. *}
489 . file_ptr line_filepos;
491 . {* Pointer to data for applications. *}
494 . {* If the SEC_IN_MEMORY flag is set, this points to the actual
496 . unsigned char *contents;
498 . {* Attached line number information. *}
501 . {* Number of line number records. *}
502 . unsigned int lineno_count;
504 . {* Entity size for merging purposes. *}
505 . unsigned int entsize;
507 . {* Points to the kept section if this section is a link-once section,
508 . and is discarded. *}
509 . struct bfd_section *kept_section;
511 . {* When a section is being output, this value changes as more
512 . linenumbers are written out. *}
513 . file_ptr moving_line_filepos;
515 . {* What the section number is in the target world. *}
520 . {* If this is a constructor section then here is a list of the
521 . relocations created to relocate items within it. *}
522 . struct relent_chain *constructor_chain;
524 . {* The BFD which owns the section. *}
527 . {* A symbol which points at this section only. *}
528 . struct bfd_symbol *symbol;
529 . struct bfd_symbol **symbol_ptr_ptr;
531 . {* Early in the link process, map_head and map_tail are used to build
532 . a list of input sections attached to an output section. Later,
533 . output sections use these fields for a list of bfd_link_order
536 . struct bfd_link_order *link_order;
537 . struct bfd_section *s;
538 . } map_head, map_tail;
541 .{* Relax table contains information about instructions which can
542 . be removed by relaxation -- replacing a long address with a
544 .struct relax_table {
545 . {* Address where bytes may be deleted. *}
548 . {* Number of bytes to be deleted. *}
552 .{* Note: the following are provided as inline functions rather than macros
553 . because not all callers use the return value. A macro implementation
554 . would use a comma expression, eg: "((ptr)->foo = val, TRUE)" and some
555 . compilers will complain about comma expressions that have no effect. *}
556 .static inline bfd_boolean
557 .bfd_set_section_userdata (asection *sec, void *val)
559 . sec->userdata = val;
563 .static inline bfd_boolean
564 .bfd_set_section_vma (asection *sec, bfd_vma val)
566 . sec->vma = sec->lma = val;
567 . sec->user_set_vma = TRUE;
571 .static inline bfd_boolean
572 .bfd_set_section_lma (asection *sec, bfd_vma val)
578 .static inline bfd_boolean
579 .bfd_set_section_alignment (asection *sec, unsigned int val)
581 . sec->alignment_power = val;
585 .{* These sections are global, and are managed by BFD. The application
586 . and target back end are not permitted to change the values in
588 .extern asection _bfd_std_section[4];
590 .#define BFD_ABS_SECTION_NAME "*ABS*"
591 .#define BFD_UND_SECTION_NAME "*UND*"
592 .#define BFD_COM_SECTION_NAME "*COM*"
593 .#define BFD_IND_SECTION_NAME "*IND*"
595 .{* Pointer to the common section. *}
596 .#define bfd_com_section_ptr (&_bfd_std_section[0])
597 .{* Pointer to the undefined section. *}
598 .#define bfd_und_section_ptr (&_bfd_std_section[1])
599 .{* Pointer to the absolute section. *}
600 .#define bfd_abs_section_ptr (&_bfd_std_section[2])
601 .{* Pointer to the indirect section. *}
602 .#define bfd_ind_section_ptr (&_bfd_std_section[3])
604 .#define bfd_is_und_section(sec) ((sec) == bfd_und_section_ptr)
605 .#define bfd_is_abs_section(sec) ((sec) == bfd_abs_section_ptr)
606 .#define bfd_is_ind_section(sec) ((sec) == bfd_ind_section_ptr)
608 .#define bfd_is_const_section(SEC) \
609 . ( ((SEC) == bfd_abs_section_ptr) \
610 . || ((SEC) == bfd_und_section_ptr) \
611 . || ((SEC) == bfd_com_section_ptr) \
612 . || ((SEC) == bfd_ind_section_ptr))
614 .{* Macros to handle insertion and deletion of a bfd's sections. These
615 . only handle the list pointers, ie. do not adjust section_count,
616 . target_index etc. *}
617 .#define bfd_section_list_remove(ABFD, S) \
620 . asection *_s = S; \
621 . asection *_next = _s->next; \
622 . asection *_prev = _s->prev; \
624 . _prev->next = _next; \
626 . (ABFD)->sections = _next; \
628 . _next->prev = _prev; \
630 . (ABFD)->section_last = _prev; \
633 .#define bfd_section_list_append(ABFD, S) \
636 . asection *_s = S; \
637 . bfd *_abfd = ABFD; \
639 . if (_abfd->section_last) \
641 . _s->prev = _abfd->section_last; \
642 . _abfd->section_last->next = _s; \
647 . _abfd->sections = _s; \
649 . _abfd->section_last = _s; \
652 .#define bfd_section_list_prepend(ABFD, S) \
655 . asection *_s = S; \
656 . bfd *_abfd = ABFD; \
658 . if (_abfd->sections) \
660 . _s->next = _abfd->sections; \
661 . _abfd->sections->prev = _s; \
666 . _abfd->section_last = _s; \
668 . _abfd->sections = _s; \
671 .#define bfd_section_list_insert_after(ABFD, A, S) \
674 . asection *_a = A; \
675 . asection *_s = S; \
676 . asection *_next = _a->next; \
677 . _s->next = _next; \
681 . _next->prev = _s; \
683 . (ABFD)->section_last = _s; \
686 .#define bfd_section_list_insert_before(ABFD, B, S) \
689 . asection *_b = B; \
690 . asection *_s = S; \
691 . asection *_prev = _b->prev; \
692 . _s->prev = _prev; \
696 . _prev->next = _s; \
698 . (ABFD)->sections = _s; \
701 .#define bfd_section_removed_from_list(ABFD, S) \
702 . ((S)->next == NULL ? (ABFD)->section_last != (S) : (S)->next->prev != (S))
704 .#define BFD_FAKE_SECTION(SEC, SYM, NAME, IDX, FLAGS) \
705 . {* name, id, index, next, prev, flags, user_set_vma, *} \
706 . { NAME, IDX, 0, NULL, NULL, FLAGS, 0, \
708 . {* linker_mark, linker_has_input, gc_mark, decompress_status, *} \
711 . {* segment_mark, sec_info_type, use_rela_p, *} \
714 . {* sec_flg0, sec_flg1, sec_flg2, sec_flg3, sec_flg4, sec_flg5, *} \
715 . 0, 0, 0, 0, 0, 0, \
717 . {* vma, lma, size, rawsize, compressed_size, relax, relax_count, *} \
718 . 0, 0, 0, 0, 0, 0, 0, \
720 . {* output_offset, output_section, alignment_power, *} \
723 . {* relocation, orelocation, reloc_count, filepos, rel_filepos, *} \
724 . NULL, NULL, 0, 0, 0, \
726 . {* line_filepos, userdata, contents, lineno, lineno_count, *} \
727 . 0, NULL, NULL, NULL, 0, \
729 . {* entsize, kept_section, moving_line_filepos, *} \
732 . {* target_index, used_by_bfd, constructor_chain, owner, *} \
733 . 0, NULL, NULL, NULL, \
735 . {* symbol, symbol_ptr_ptr, *} \
736 . (struct bfd_symbol *) SYM, &SEC.symbol, \
738 . {* map_head, map_tail *} \
739 . { NULL }, { NULL } \
742 .{* We use a macro to initialize the static asymbol structures because
743 . traditional C does not permit us to initialize a union member while
744 . gcc warns if we don't initialize it.
745 . the_bfd, name, value, attr, section [, udata] *}
747 .#define GLOBAL_SYM_INIT(NAME, SECTION) \
748 . { 0, NAME, 0, BSF_SECTION_SYM, SECTION, { 0 }}
750 .#define GLOBAL_SYM_INIT(NAME, SECTION) \
751 . { 0, NAME, 0, BSF_SECTION_SYM, SECTION }
756 /* These symbols are global, not specific to any BFD. Therefore, anything
757 that tries to change them is broken, and should be repaired. */
759 static const asymbol global_syms
[] =
761 GLOBAL_SYM_INIT (BFD_COM_SECTION_NAME
, bfd_com_section_ptr
),
762 GLOBAL_SYM_INIT (BFD_UND_SECTION_NAME
, bfd_und_section_ptr
),
763 GLOBAL_SYM_INIT (BFD_ABS_SECTION_NAME
, bfd_abs_section_ptr
),
764 GLOBAL_SYM_INIT (BFD_IND_SECTION_NAME
, bfd_ind_section_ptr
)
767 #define STD_SECTION(NAME, IDX, FLAGS) \
768 BFD_FAKE_SECTION(_bfd_std_section[IDX], &global_syms[IDX], NAME, IDX, FLAGS)
770 asection _bfd_std_section
[] = {
771 STD_SECTION (BFD_COM_SECTION_NAME
, 0, SEC_IS_COMMON
),
772 STD_SECTION (BFD_UND_SECTION_NAME
, 1, 0),
773 STD_SECTION (BFD_ABS_SECTION_NAME
, 2, 0),
774 STD_SECTION (BFD_IND_SECTION_NAME
, 3, 0)
778 /* Initialize an entry in the section hash table. */
780 struct bfd_hash_entry
*
781 bfd_section_hash_newfunc (struct bfd_hash_entry
*entry
,
782 struct bfd_hash_table
*table
,
785 /* Allocate the structure if it has not already been allocated by a
789 entry
= (struct bfd_hash_entry
*)
790 bfd_hash_allocate (table
, sizeof (struct section_hash_entry
));
795 /* Call the allocation method of the superclass. */
796 entry
= bfd_hash_newfunc (entry
, table
, string
);
798 memset (&((struct section_hash_entry
*) entry
)->section
, 0,
804 #define section_hash_lookup(table, string, create, copy) \
805 ((struct section_hash_entry *) \
806 bfd_hash_lookup ((table), (string), (create), (copy)))
808 /* Create a symbol whose only job is to point to this section. This
809 is useful for things like relocs which are relative to the base
813 _bfd_generic_new_section_hook (bfd
*abfd
, asection
*newsect
)
815 newsect
->symbol
= bfd_make_empty_symbol (abfd
);
816 if (newsect
->symbol
== NULL
)
819 newsect
->symbol
->name
= newsect
->name
;
820 newsect
->symbol
->value
= 0;
821 newsect
->symbol
->section
= newsect
;
822 newsect
->symbol
->flags
= BSF_SECTION_SYM
;
824 newsect
->symbol_ptr_ptr
= &newsect
->symbol
;
828 unsigned int _bfd_section_id
= 0x10; /* id 0 to 3 used by STD_SECTION. */
830 /* Initializes a new section. NEWSECT->NAME is already set. */
833 bfd_section_init (bfd
*abfd
, asection
*newsect
)
835 newsect
->id
= _bfd_section_id
;
836 newsect
->index
= abfd
->section_count
;
837 newsect
->owner
= abfd
;
839 if (! BFD_SEND (abfd
, _new_section_hook
, (abfd
, newsect
)))
843 abfd
->section_count
++;
844 bfd_section_list_append (abfd
, newsect
);
851 section prototypes, , typedef asection, Sections
855 These are the functions exported by the section handling part of BFD.
860 bfd_section_list_clear
863 void bfd_section_list_clear (bfd *);
866 Clears the section list, and also resets the section count and
871 bfd_section_list_clear (bfd
*abfd
)
873 abfd
->sections
= NULL
;
874 abfd
->section_last
= NULL
;
875 abfd
->section_count
= 0;
876 memset (abfd
->section_htab
.table
, 0,
877 abfd
->section_htab
.size
* sizeof (struct bfd_hash_entry
*));
878 abfd
->section_htab
.count
= 0;
883 bfd_get_section_by_name
886 asection *bfd_get_section_by_name (bfd *abfd, const char *name);
889 Return the most recently created section attached to @var{abfd}
890 named @var{name}. Return NULL if no such section exists.
894 bfd_get_section_by_name (bfd
*abfd
, const char *name
)
896 struct section_hash_entry
*sh
;
898 sh
= section_hash_lookup (&abfd
->section_htab
, name
, FALSE
, FALSE
);
907 bfd_get_next_section_by_name
910 asection *bfd_get_next_section_by_name (bfd *ibfd, asection *sec);
913 Given @var{sec} is a section returned by @code{bfd_get_section_by_name},
914 return the next most recently created section attached to the same
915 BFD with the same name, or if no such section exists in the same BFD and
916 IBFD is non-NULL, the next section with the same name in any input
917 BFD following IBFD. Return NULL on finding no section.
921 bfd_get_next_section_by_name (bfd
*ibfd
, asection
*sec
)
923 struct section_hash_entry
*sh
;
927 sh
= ((struct section_hash_entry
*)
928 ((char *) sec
- offsetof (struct section_hash_entry
, section
)));
930 hash
= sh
->root
.hash
;
932 for (sh
= (struct section_hash_entry
*) sh
->root
.next
;
934 sh
= (struct section_hash_entry
*) sh
->root
.next
)
935 if (sh
->root
.hash
== hash
936 && strcmp (sh
->root
.string
, name
) == 0)
941 while ((ibfd
= ibfd
->link
.next
) != NULL
)
943 asection
*s
= bfd_get_section_by_name (ibfd
, name
);
954 bfd_get_linker_section
957 asection *bfd_get_linker_section (bfd *abfd, const char *name);
960 Return the linker created section attached to @var{abfd}
961 named @var{name}. Return NULL if no such section exists.
965 bfd_get_linker_section (bfd
*abfd
, const char *name
)
967 asection
*sec
= bfd_get_section_by_name (abfd
, name
);
969 while (sec
!= NULL
&& (sec
->flags
& SEC_LINKER_CREATED
) == 0)
970 sec
= bfd_get_next_section_by_name (NULL
, sec
);
976 bfd_get_section_by_name_if
979 asection *bfd_get_section_by_name_if
982 bfd_boolean (*func) (bfd *abfd, asection *sect, void *obj),
986 Call the provided function @var{func} for each section
987 attached to the BFD @var{abfd} whose name matches @var{name},
988 passing @var{obj} as an argument. The function will be called
991 | func (abfd, the_section, obj);
993 It returns the first section for which @var{func} returns true,
999 bfd_get_section_by_name_if (bfd
*abfd
, const char *name
,
1000 bfd_boolean (*operation
) (bfd
*,
1005 struct section_hash_entry
*sh
;
1008 sh
= section_hash_lookup (&abfd
->section_htab
, name
, FALSE
, FALSE
);
1012 hash
= sh
->root
.hash
;
1013 for (; sh
!= NULL
; sh
= (struct section_hash_entry
*) sh
->root
.next
)
1014 if (sh
->root
.hash
== hash
1015 && strcmp (sh
->root
.string
, name
) == 0
1016 && (*operation
) (abfd
, &sh
->section
, user_storage
))
1017 return &sh
->section
;
1024 bfd_get_unique_section_name
1027 char *bfd_get_unique_section_name
1028 (bfd *abfd, const char *templat, int *count);
1031 Invent a section name that is unique in @var{abfd} by tacking
1032 a dot and a digit suffix onto the original @var{templat}. If
1033 @var{count} is non-NULL, then it specifies the first number
1034 tried as a suffix to generate a unique name. The value
1035 pointed to by @var{count} will be incremented in this case.
1039 bfd_get_unique_section_name (bfd
*abfd
, const char *templat
, int *count
)
1045 len
= strlen (templat
);
1046 sname
= (char *) bfd_malloc (len
+ 8);
1049 memcpy (sname
, templat
, len
);
1056 /* If we have a million sections, something is badly wrong. */
1059 sprintf (sname
+ len
, ".%d", num
++);
1061 while (section_hash_lookup (&abfd
->section_htab
, sname
, FALSE
, FALSE
));
1070 bfd_make_section_old_way
1073 asection *bfd_make_section_old_way (bfd *abfd, const char *name);
1076 Create a new empty section called @var{name}
1077 and attach it to the end of the chain of sections for the
1078 BFD @var{abfd}. An attempt to create a section with a name which
1079 is already in use returns its pointer without changing the
1082 It has the funny name since this is the way it used to be
1083 before it was rewritten....
1085 Possible errors are:
1086 o <<bfd_error_invalid_operation>> -
1087 If output has already started for this BFD.
1088 o <<bfd_error_no_memory>> -
1089 If memory allocation fails.
1094 bfd_make_section_old_way (bfd
*abfd
, const char *name
)
1098 if (abfd
->output_has_begun
)
1100 bfd_set_error (bfd_error_invalid_operation
);
1104 if (strcmp (name
, BFD_ABS_SECTION_NAME
) == 0)
1105 newsect
= bfd_abs_section_ptr
;
1106 else if (strcmp (name
, BFD_COM_SECTION_NAME
) == 0)
1107 newsect
= bfd_com_section_ptr
;
1108 else if (strcmp (name
, BFD_UND_SECTION_NAME
) == 0)
1109 newsect
= bfd_und_section_ptr
;
1110 else if (strcmp (name
, BFD_IND_SECTION_NAME
) == 0)
1111 newsect
= bfd_ind_section_ptr
;
1114 struct section_hash_entry
*sh
;
1116 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1120 newsect
= &sh
->section
;
1121 if (newsect
->name
!= NULL
)
1123 /* Section already exists. */
1127 newsect
->name
= name
;
1128 return bfd_section_init (abfd
, newsect
);
1131 /* Call new_section_hook when "creating" the standard abs, com, und
1132 and ind sections to tack on format specific section data.
1133 Also, create a proper section symbol. */
1134 if (! BFD_SEND (abfd
, _new_section_hook
, (abfd
, newsect
)))
1141 bfd_make_section_anyway_with_flags
1144 asection *bfd_make_section_anyway_with_flags
1145 (bfd *abfd, const char *name, flagword flags);
1148 Create a new empty section called @var{name} and attach it to the end of
1149 the chain of sections for @var{abfd}. Create a new section even if there
1150 is already a section with that name. Also set the attributes of the
1151 new section to the value @var{flags}.
1153 Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1154 o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1155 o <<bfd_error_no_memory>> - If memory allocation fails.
1159 bfd_make_section_anyway_with_flags (bfd
*abfd
, const char *name
,
1162 struct section_hash_entry
*sh
;
1165 if (abfd
->output_has_begun
)
1167 bfd_set_error (bfd_error_invalid_operation
);
1171 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1175 newsect
= &sh
->section
;
1176 if (newsect
->name
!= NULL
)
1178 /* We are making a section of the same name. Put it in the
1179 section hash table. Even though we can't find it directly by a
1180 hash lookup, we'll be able to find the section by traversing
1181 sh->root.next quicker than looking at all the bfd sections. */
1182 struct section_hash_entry
*new_sh
;
1183 new_sh
= (struct section_hash_entry
*)
1184 bfd_section_hash_newfunc (NULL
, &abfd
->section_htab
, name
);
1188 new_sh
->root
= sh
->root
;
1189 sh
->root
.next
= &new_sh
->root
;
1190 newsect
= &new_sh
->section
;
1193 newsect
->flags
= flags
;
1194 newsect
->name
= name
;
1195 return bfd_section_init (abfd
, newsect
);
1200 bfd_make_section_anyway
1203 asection *bfd_make_section_anyway (bfd *abfd, const char *name);
1206 Create a new empty section called @var{name} and attach it to the end of
1207 the chain of sections for @var{abfd}. Create a new section even if there
1208 is already a section with that name.
1210 Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1211 o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1212 o <<bfd_error_no_memory>> - If memory allocation fails.
1216 bfd_make_section_anyway (bfd
*abfd
, const char *name
)
1218 return bfd_make_section_anyway_with_flags (abfd
, name
, 0);
1223 bfd_make_section_with_flags
1226 asection *bfd_make_section_with_flags
1227 (bfd *, const char *name, flagword flags);
1230 Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1231 bfd_set_error ()) without changing the section chain if there is already a
1232 section named @var{name}. Also set the attributes of the new section to
1233 the value @var{flags}. If there is an error, return <<NULL>> and set
1238 bfd_make_section_with_flags (bfd
*abfd
, const char *name
,
1241 struct section_hash_entry
*sh
;
1244 if (abfd
== NULL
|| name
== NULL
|| abfd
->output_has_begun
)
1246 bfd_set_error (bfd_error_invalid_operation
);
1250 if (strcmp (name
, BFD_ABS_SECTION_NAME
) == 0
1251 || strcmp (name
, BFD_COM_SECTION_NAME
) == 0
1252 || strcmp (name
, BFD_UND_SECTION_NAME
) == 0
1253 || strcmp (name
, BFD_IND_SECTION_NAME
) == 0)
1256 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1260 newsect
= &sh
->section
;
1261 if (newsect
->name
!= NULL
)
1263 /* Section already exists. */
1267 newsect
->name
= name
;
1268 newsect
->flags
= flags
;
1269 return bfd_section_init (abfd
, newsect
);
1277 asection *bfd_make_section (bfd *, const char *name);
1280 Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1281 bfd_set_error ()) without changing the section chain if there is already a
1282 section named @var{name}. If there is an error, return <<NULL>> and set
1287 bfd_make_section (bfd
*abfd
, const char *name
)
1289 return bfd_make_section_with_flags (abfd
, name
, 0);
1294 bfd_set_section_flags
1297 bfd_boolean bfd_set_section_flags (asection *sec, flagword flags);
1300 Set the attributes of the section @var{sec} to the value @var{flags}.
1301 Return <<TRUE>> on success, <<FALSE>> on error. Possible error
1304 o <<bfd_error_invalid_operation>> -
1305 The section cannot have one or more of the attributes
1306 requested. For example, a .bss section in <<a.out>> may not
1307 have the <<SEC_HAS_CONTENTS>> field set.
1312 bfd_set_section_flags (asection
*section
, flagword flags
)
1314 section
->flags
= flags
;
1323 void bfd_rename_section
1324 (asection *sec, const char *newname);
1327 Rename section @var{sec} to @var{newname}.
1331 bfd_rename_section (asection
*sec
, const char *newname
)
1333 struct section_hash_entry
*sh
;
1335 sh
= (struct section_hash_entry
*)
1336 ((char *) sec
- offsetof (struct section_hash_entry
, section
));
1337 sh
->section
.name
= newname
;
1338 bfd_hash_rename (&sec
->owner
->section_htab
, newname
, &sh
->root
);
1343 bfd_map_over_sections
1346 void bfd_map_over_sections
1348 void (*func) (bfd *abfd, asection *sect, void *obj),
1352 Call the provided function @var{func} for each section
1353 attached to the BFD @var{abfd}, passing @var{obj} as an
1354 argument. The function will be called as if by
1356 | func (abfd, the_section, obj);
1358 This is the preferred method for iterating over sections; an
1359 alternative would be to use a loop:
1362 | for (p = abfd->sections; p != NULL; p = p->next)
1363 | func (abfd, p, ...)
1368 bfd_map_over_sections (bfd
*abfd
,
1369 void (*operation
) (bfd
*, asection
*, void *),
1375 for (sect
= abfd
->sections
; sect
!= NULL
; i
++, sect
= sect
->next
)
1376 (*operation
) (abfd
, sect
, user_storage
);
1378 if (i
!= abfd
->section_count
) /* Debugging */
1384 bfd_sections_find_if
1387 asection *bfd_sections_find_if
1389 bfd_boolean (*operation) (bfd *abfd, asection *sect, void *obj),
1393 Call the provided function @var{operation} for each section
1394 attached to the BFD @var{abfd}, passing @var{obj} as an
1395 argument. The function will be called as if by
1397 | operation (abfd, the_section, obj);
1399 It returns the first section for which @var{operation} returns true.
1404 bfd_sections_find_if (bfd
*abfd
,
1405 bfd_boolean (*operation
) (bfd
*, asection
*, void *),
1410 for (sect
= abfd
->sections
; sect
!= NULL
; sect
= sect
->next
)
1411 if ((*operation
) (abfd
, sect
, user_storage
))
1419 bfd_set_section_size
1422 bfd_boolean bfd_set_section_size (asection *sec, bfd_size_type val);
1425 Set @var{sec} to the size @var{val}. If the operation is
1426 ok, then <<TRUE>> is returned, else <<FALSE>>.
1428 Possible error returns:
1429 o <<bfd_error_invalid_operation>> -
1430 Writing has started to the BFD, so setting the size is invalid.
1435 bfd_set_section_size (asection
*sec
, bfd_size_type val
)
1437 /* Once you've started writing to any section you cannot create or change
1438 the size of any others. */
1440 if (sec
->owner
== NULL
|| sec
->owner
->output_has_begun
)
1442 bfd_set_error (bfd_error_invalid_operation
);
1452 bfd_set_section_contents
1455 bfd_boolean bfd_set_section_contents
1456 (bfd *abfd, asection *section, const void *data,
1457 file_ptr offset, bfd_size_type count);
1460 Sets the contents of the section @var{section} in BFD
1461 @var{abfd} to the data starting in memory at @var{location}.
1462 The data is written to the output section starting at offset
1463 @var{offset} for @var{count} octets.
1465 Normally <<TRUE>> is returned, but <<FALSE>> is returned if
1466 there was an error. Possible error returns are:
1467 o <<bfd_error_no_contents>> -
1468 The output section does not have the <<SEC_HAS_CONTENTS>>
1469 attribute, so nothing can be written to it.
1470 o <<bfd_error_bad_value>> -
1471 The section is unable to contain all of the data.
1472 o <<bfd_error_invalid_operation>> -
1473 The BFD is not writeable.
1474 o and some more too.
1476 This routine is front end to the back end function
1477 <<_bfd_set_section_contents>>.
1482 bfd_set_section_contents (bfd
*abfd
,
1484 const void *location
,
1486 bfd_size_type count
)
1490 if (!(bfd_section_flags (section
) & SEC_HAS_CONTENTS
))
1492 bfd_set_error (bfd_error_no_contents
);
1497 if ((bfd_size_type
) offset
> sz
1499 || offset
+ count
> sz
1500 || count
!= (size_t) count
)
1502 bfd_set_error (bfd_error_bad_value
);
1506 if (!bfd_write_p (abfd
))
1508 bfd_set_error (bfd_error_invalid_operation
);
1512 /* Record a copy of the data in memory if desired. */
1513 if (section
->contents
1514 && location
!= section
->contents
+ offset
)
1515 memcpy (section
->contents
+ offset
, location
, (size_t) count
);
1517 if (BFD_SEND (abfd
, _bfd_set_section_contents
,
1518 (abfd
, section
, location
, offset
, count
)))
1520 abfd
->output_has_begun
= TRUE
;
1529 bfd_get_section_contents
1532 bfd_boolean bfd_get_section_contents
1533 (bfd *abfd, asection *section, void *location, file_ptr offset,
1534 bfd_size_type count);
1537 Read data from @var{section} in BFD @var{abfd}
1538 into memory starting at @var{location}. The data is read at an
1539 offset of @var{offset} from the start of the input section,
1540 and is read for @var{count} bytes.
1542 If the contents of a constructor with the <<SEC_CONSTRUCTOR>>
1543 flag set are requested or if the section does not have the
1544 <<SEC_HAS_CONTENTS>> flag set, then the @var{location} is filled
1545 with zeroes. If no errors occur, <<TRUE>> is returned, else
1550 bfd_get_section_contents (bfd
*abfd
,
1554 bfd_size_type count
)
1558 if (section
->flags
& SEC_CONSTRUCTOR
)
1560 memset (location
, 0, (size_t) count
);
1564 if (abfd
->direction
!= write_direction
&& section
->rawsize
!= 0)
1565 sz
= section
->rawsize
;
1568 if ((bfd_size_type
) offset
> sz
1570 || offset
+ count
> sz
1571 || count
!= (size_t) count
)
1573 bfd_set_error (bfd_error_bad_value
);
1581 if ((section
->flags
& SEC_HAS_CONTENTS
) == 0)
1583 memset (location
, 0, (size_t) count
);
1587 if ((section
->flags
& SEC_IN_MEMORY
) != 0)
1589 if (section
->contents
== NULL
)
1591 /* This can happen because of errors earlier on in the linking process.
1592 We do not want to seg-fault here, so clear the flag and return an
1594 section
->flags
&= ~ SEC_IN_MEMORY
;
1595 bfd_set_error (bfd_error_invalid_operation
);
1599 memmove (location
, section
->contents
+ offset
, (size_t) count
);
1603 return BFD_SEND (abfd
, _bfd_get_section_contents
,
1604 (abfd
, section
, location
, offset
, count
));
1609 bfd_malloc_and_get_section
1612 bfd_boolean bfd_malloc_and_get_section
1613 (bfd *abfd, asection *section, bfd_byte **buf);
1616 Read all data from @var{section} in BFD @var{abfd}
1617 into a buffer, *@var{buf}, malloc'd by this function.
1621 bfd_malloc_and_get_section (bfd
*abfd
, sec_ptr sec
, bfd_byte
**buf
)
1624 return bfd_get_full_section_contents (abfd
, sec
, buf
);
1628 bfd_copy_private_section_data
1631 bfd_boolean bfd_copy_private_section_data
1632 (bfd *ibfd, asection *isec, bfd *obfd, asection *osec);
1635 Copy private section information from @var{isec} in the BFD
1636 @var{ibfd} to the section @var{osec} in the BFD @var{obfd}.
1637 Return <<TRUE>> on success, <<FALSE>> on error. Possible error
1640 o <<bfd_error_no_memory>> -
1641 Not enough memory exists to create private data for @var{osec}.
1643 .#define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \
1644 . BFD_SEND (obfd, _bfd_copy_private_section_data, \
1645 . (ibfd, isection, obfd, osection))
1650 bfd_generic_is_group_section
1653 bfd_boolean bfd_generic_is_group_section (bfd *, const asection *sec);
1656 Returns TRUE if @var{sec} is a member of a group.
1660 bfd_generic_is_group_section (bfd
*abfd ATTRIBUTE_UNUSED
,
1661 const asection
*sec ATTRIBUTE_UNUSED
)
1668 bfd_generic_group_name
1671 const char *bfd_generic_group_name (bfd *, const asection *sec);
1674 Returns group name if @var{sec} is a member of a group.
1678 bfd_generic_group_name (bfd
*abfd ATTRIBUTE_UNUSED
,
1679 const asection
*sec ATTRIBUTE_UNUSED
)
1686 bfd_generic_discard_group
1689 bfd_boolean bfd_generic_discard_group (bfd *abfd, asection *group);
1692 Remove all members of @var{group} from the output.
1696 bfd_generic_discard_group (bfd
*abfd ATTRIBUTE_UNUSED
,
1697 asection
*group ATTRIBUTE_UNUSED
)
1703 _bfd_nowrite_set_section_contents (bfd
*abfd
,
1704 sec_ptr section ATTRIBUTE_UNUSED
,
1705 const void *location ATTRIBUTE_UNUSED
,
1706 file_ptr offset ATTRIBUTE_UNUSED
,
1707 bfd_size_type count ATTRIBUTE_UNUSED
)
1709 return _bfd_bool_bfd_false_error (abfd
);