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 .static inline const char *
553 .bfd_section_name (const asection *sec)
558 .static inline bfd_size_type
559 .bfd_section_size (const asection *sec)
564 .static inline bfd_vma
565 .bfd_section_vma (const asection *sec)
570 .static inline bfd_vma
571 .bfd_section_lma (const asection *sec)
576 .static inline unsigned int
577 .bfd_section_alignment (const asection *sec)
579 . return sec->alignment_power;
582 .static inline flagword
583 .bfd_section_flags (const asection *sec)
588 .static inline void *
589 .bfd_section_userdata (const asection *sec)
591 . return sec->userdata;
593 .static inline bfd_boolean
594 .bfd_is_com_section (const asection *sec)
596 . return (sec->flags & SEC_IS_COMMON) != 0;
599 .{* Note: the following are provided as inline functions rather than macros
600 . because not all callers use the return value. A macro implementation
601 . would use a comma expression, eg: "((ptr)->foo = val, TRUE)" and some
602 . compilers will complain about comma expressions that have no effect. *}
603 .static inline bfd_boolean
604 .bfd_set_section_userdata (asection *sec, void *val)
606 . sec->userdata = val;
610 .static inline bfd_boolean
611 .bfd_set_section_vma (asection *sec, bfd_vma val)
613 . sec->vma = sec->lma = val;
614 . sec->user_set_vma = TRUE;
618 .static inline bfd_boolean
619 .bfd_set_section_lma (asection *sec, bfd_vma val)
625 .static inline bfd_boolean
626 .bfd_set_section_alignment (asection *sec, unsigned int val)
628 . sec->alignment_power = val;
632 .{* These sections are global, and are managed by BFD. The application
633 . and target back end are not permitted to change the values in
635 .extern asection _bfd_std_section[4];
637 .#define BFD_ABS_SECTION_NAME "*ABS*"
638 .#define BFD_UND_SECTION_NAME "*UND*"
639 .#define BFD_COM_SECTION_NAME "*COM*"
640 .#define BFD_IND_SECTION_NAME "*IND*"
642 .{* Pointer to the common section. *}
643 .#define bfd_com_section_ptr (&_bfd_std_section[0])
644 .{* Pointer to the undefined section. *}
645 .#define bfd_und_section_ptr (&_bfd_std_section[1])
646 .{* Pointer to the absolute section. *}
647 .#define bfd_abs_section_ptr (&_bfd_std_section[2])
648 .{* Pointer to the indirect section. *}
649 .#define bfd_ind_section_ptr (&_bfd_std_section[3])
651 .static inline bfd_boolean
652 .bfd_is_und_section (const asection *sec)
654 . return sec == bfd_und_section_ptr;
657 .static inline bfd_boolean
658 .bfd_is_abs_section (const asection *sec)
660 . return sec == bfd_abs_section_ptr;
663 .static inline bfd_boolean
664 .bfd_is_ind_section (const asection *sec)
666 . return sec == bfd_ind_section_ptr;
669 .static inline bfd_boolean
670 .bfd_is_const_section (const asection *sec)
672 . return sec >= bfd_abs_section_ptr && sec <= bfd_ind_section_ptr;
675 .{* Return TRUE if input section SEC has been discarded. *}
676 .static inline bfd_boolean
677 .discarded_section (const asection *sec)
679 . return (!bfd_is_abs_section (sec)
680 . && bfd_is_abs_section (sec->output_section)
681 . && sec->sec_info_type != SEC_INFO_TYPE_MERGE
682 . && sec->sec_info_type != SEC_INFO_TYPE_JUST_SYMS);
685 .#define BFD_FAKE_SECTION(SEC, SYM, NAME, IDX, FLAGS) \
686 . {* name, id, index, next, prev, flags, user_set_vma, *} \
687 . { NAME, IDX, 0, NULL, NULL, FLAGS, 0, \
689 . {* linker_mark, linker_has_input, gc_mark, decompress_status, *} \
692 . {* segment_mark, sec_info_type, use_rela_p, *} \
695 . {* sec_flg0, sec_flg1, sec_flg2, sec_flg3, sec_flg4, sec_flg5, *} \
696 . 0, 0, 0, 0, 0, 0, \
698 . {* vma, lma, size, rawsize, compressed_size, relax, relax_count, *} \
699 . 0, 0, 0, 0, 0, 0, 0, \
701 . {* output_offset, output_section, alignment_power, *} \
704 . {* relocation, orelocation, reloc_count, filepos, rel_filepos, *} \
705 . NULL, NULL, 0, 0, 0, \
707 . {* line_filepos, userdata, contents, lineno, lineno_count, *} \
708 . 0, NULL, NULL, NULL, 0, \
710 . {* entsize, kept_section, moving_line_filepos, *} \
713 . {* target_index, used_by_bfd, constructor_chain, owner, *} \
714 . 0, NULL, NULL, NULL, \
716 . {* symbol, symbol_ptr_ptr, *} \
717 . (struct bfd_symbol *) SYM, &SEC.symbol, \
719 . {* map_head, map_tail *} \
720 . { NULL }, { NULL } \
723 .{* We use a macro to initialize the static asymbol structures because
724 . traditional C does not permit us to initialize a union member while
725 . gcc warns if we don't initialize it.
726 . the_bfd, name, value, attr, section [, udata] *}
728 .#define GLOBAL_SYM_INIT(NAME, SECTION) \
729 . { 0, NAME, 0, BSF_SECTION_SYM, SECTION, { 0 }}
731 .#define GLOBAL_SYM_INIT(NAME, SECTION) \
732 . { 0, NAME, 0, BSF_SECTION_SYM, SECTION }
737 /* These symbols are global, not specific to any BFD. Therefore, anything
738 that tries to change them is broken, and should be repaired. */
740 static const asymbol global_syms
[] =
742 GLOBAL_SYM_INIT (BFD_COM_SECTION_NAME
, bfd_com_section_ptr
),
743 GLOBAL_SYM_INIT (BFD_UND_SECTION_NAME
, bfd_und_section_ptr
),
744 GLOBAL_SYM_INIT (BFD_ABS_SECTION_NAME
, bfd_abs_section_ptr
),
745 GLOBAL_SYM_INIT (BFD_IND_SECTION_NAME
, bfd_ind_section_ptr
)
748 #define STD_SECTION(NAME, IDX, FLAGS) \
749 BFD_FAKE_SECTION(_bfd_std_section[IDX], &global_syms[IDX], NAME, IDX, FLAGS)
751 asection _bfd_std_section
[] = {
752 STD_SECTION (BFD_COM_SECTION_NAME
, 0, SEC_IS_COMMON
),
753 STD_SECTION (BFD_UND_SECTION_NAME
, 1, 0),
754 STD_SECTION (BFD_ABS_SECTION_NAME
, 2, 0),
755 STD_SECTION (BFD_IND_SECTION_NAME
, 3, 0)
759 /* Initialize an entry in the section hash table. */
761 struct bfd_hash_entry
*
762 bfd_section_hash_newfunc (struct bfd_hash_entry
*entry
,
763 struct bfd_hash_table
*table
,
766 /* Allocate the structure if it has not already been allocated by a
770 entry
= (struct bfd_hash_entry
*)
771 bfd_hash_allocate (table
, sizeof (struct section_hash_entry
));
776 /* Call the allocation method of the superclass. */
777 entry
= bfd_hash_newfunc (entry
, table
, string
);
779 memset (&((struct section_hash_entry
*) entry
)->section
, 0,
785 #define section_hash_lookup(table, string, create, copy) \
786 ((struct section_hash_entry *) \
787 bfd_hash_lookup ((table), (string), (create), (copy)))
789 /* Create a symbol whose only job is to point to this section. This
790 is useful for things like relocs which are relative to the base
794 _bfd_generic_new_section_hook (bfd
*abfd
, asection
*newsect
)
796 newsect
->symbol
= bfd_make_empty_symbol (abfd
);
797 if (newsect
->symbol
== NULL
)
800 newsect
->symbol
->name
= newsect
->name
;
801 newsect
->symbol
->value
= 0;
802 newsect
->symbol
->section
= newsect
;
803 newsect
->symbol
->flags
= BSF_SECTION_SYM
;
805 newsect
->symbol_ptr_ptr
= &newsect
->symbol
;
809 unsigned int _bfd_section_id
= 0x10; /* id 0 to 3 used by STD_SECTION. */
811 /* Initializes a new section. NEWSECT->NAME is already set. */
814 bfd_section_init (bfd
*abfd
, asection
*newsect
)
816 newsect
->id
= _bfd_section_id
;
817 newsect
->index
= abfd
->section_count
;
818 newsect
->owner
= abfd
;
820 if (! BFD_SEND (abfd
, _new_section_hook
, (abfd
, newsect
)))
824 abfd
->section_count
++;
825 bfd_section_list_append (abfd
, newsect
);
832 section prototypes, , typedef asection, Sections
836 These are the functions exported by the section handling part of BFD.
841 bfd_section_list_clear
844 void bfd_section_list_clear (bfd *);
847 Clears the section list, and also resets the section count and
852 bfd_section_list_clear (bfd
*abfd
)
854 abfd
->sections
= NULL
;
855 abfd
->section_last
= NULL
;
856 abfd
->section_count
= 0;
857 memset (abfd
->section_htab
.table
, 0,
858 abfd
->section_htab
.size
* sizeof (struct bfd_hash_entry
*));
859 abfd
->section_htab
.count
= 0;
864 bfd_get_section_by_name
867 asection *bfd_get_section_by_name (bfd *abfd, const char *name);
870 Return the most recently created section attached to @var{abfd}
871 named @var{name}. Return NULL if no such section exists.
875 bfd_get_section_by_name (bfd
*abfd
, const char *name
)
877 struct section_hash_entry
*sh
;
879 sh
= section_hash_lookup (&abfd
->section_htab
, name
, FALSE
, FALSE
);
888 bfd_get_next_section_by_name
891 asection *bfd_get_next_section_by_name (bfd *ibfd, asection *sec);
894 Given @var{sec} is a section returned by @code{bfd_get_section_by_name},
895 return the next most recently created section attached to the same
896 BFD with the same name, or if no such section exists in the same BFD and
897 IBFD is non-NULL, the next section with the same name in any input
898 BFD following IBFD. Return NULL on finding no section.
902 bfd_get_next_section_by_name (bfd
*ibfd
, asection
*sec
)
904 struct section_hash_entry
*sh
;
908 sh
= ((struct section_hash_entry
*)
909 ((char *) sec
- offsetof (struct section_hash_entry
, section
)));
911 hash
= sh
->root
.hash
;
913 for (sh
= (struct section_hash_entry
*) sh
->root
.next
;
915 sh
= (struct section_hash_entry
*) sh
->root
.next
)
916 if (sh
->root
.hash
== hash
917 && strcmp (sh
->root
.string
, name
) == 0)
922 while ((ibfd
= ibfd
->link
.next
) != NULL
)
924 asection
*s
= bfd_get_section_by_name (ibfd
, name
);
935 bfd_get_linker_section
938 asection *bfd_get_linker_section (bfd *abfd, const char *name);
941 Return the linker created section attached to @var{abfd}
942 named @var{name}. Return NULL if no such section exists.
946 bfd_get_linker_section (bfd
*abfd
, const char *name
)
948 asection
*sec
= bfd_get_section_by_name (abfd
, name
);
950 while (sec
!= NULL
&& (sec
->flags
& SEC_LINKER_CREATED
) == 0)
951 sec
= bfd_get_next_section_by_name (NULL
, sec
);
957 bfd_get_section_by_name_if
960 asection *bfd_get_section_by_name_if
963 bfd_boolean (*func) (bfd *abfd, asection *sect, void *obj),
967 Call the provided function @var{func} for each section
968 attached to the BFD @var{abfd} whose name matches @var{name},
969 passing @var{obj} as an argument. The function will be called
972 | func (abfd, the_section, obj);
974 It returns the first section for which @var{func} returns true,
980 bfd_get_section_by_name_if (bfd
*abfd
, const char *name
,
981 bfd_boolean (*operation
) (bfd
*,
986 struct section_hash_entry
*sh
;
989 sh
= section_hash_lookup (&abfd
->section_htab
, name
, FALSE
, FALSE
);
993 hash
= sh
->root
.hash
;
994 for (; sh
!= NULL
; sh
= (struct section_hash_entry
*) sh
->root
.next
)
995 if (sh
->root
.hash
== hash
996 && strcmp (sh
->root
.string
, name
) == 0
997 && (*operation
) (abfd
, &sh
->section
, user_storage
))
1005 bfd_get_unique_section_name
1008 char *bfd_get_unique_section_name
1009 (bfd *abfd, const char *templat, int *count);
1012 Invent a section name that is unique in @var{abfd} by tacking
1013 a dot and a digit suffix onto the original @var{templat}. If
1014 @var{count} is non-NULL, then it specifies the first number
1015 tried as a suffix to generate a unique name. The value
1016 pointed to by @var{count} will be incremented in this case.
1020 bfd_get_unique_section_name (bfd
*abfd
, const char *templat
, int *count
)
1026 len
= strlen (templat
);
1027 sname
= (char *) bfd_malloc (len
+ 8);
1030 memcpy (sname
, templat
, len
);
1037 /* If we have a million sections, something is badly wrong. */
1040 sprintf (sname
+ len
, ".%d", num
++);
1042 while (section_hash_lookup (&abfd
->section_htab
, sname
, FALSE
, FALSE
));
1051 bfd_make_section_old_way
1054 asection *bfd_make_section_old_way (bfd *abfd, const char *name);
1057 Create a new empty section called @var{name}
1058 and attach it to the end of the chain of sections for the
1059 BFD @var{abfd}. An attempt to create a section with a name which
1060 is already in use returns its pointer without changing the
1063 It has the funny name since this is the way it used to be
1064 before it was rewritten....
1066 Possible errors are:
1067 o <<bfd_error_invalid_operation>> -
1068 If output has already started for this BFD.
1069 o <<bfd_error_no_memory>> -
1070 If memory allocation fails.
1075 bfd_make_section_old_way (bfd
*abfd
, const char *name
)
1079 if (abfd
->output_has_begun
)
1081 bfd_set_error (bfd_error_invalid_operation
);
1085 if (strcmp (name
, BFD_ABS_SECTION_NAME
) == 0)
1086 newsect
= bfd_abs_section_ptr
;
1087 else if (strcmp (name
, BFD_COM_SECTION_NAME
) == 0)
1088 newsect
= bfd_com_section_ptr
;
1089 else if (strcmp (name
, BFD_UND_SECTION_NAME
) == 0)
1090 newsect
= bfd_und_section_ptr
;
1091 else if (strcmp (name
, BFD_IND_SECTION_NAME
) == 0)
1092 newsect
= bfd_ind_section_ptr
;
1095 struct section_hash_entry
*sh
;
1097 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1101 newsect
= &sh
->section
;
1102 if (newsect
->name
!= NULL
)
1104 /* Section already exists. */
1108 newsect
->name
= name
;
1109 return bfd_section_init (abfd
, newsect
);
1112 /* Call new_section_hook when "creating" the standard abs, com, und
1113 and ind sections to tack on format specific section data.
1114 Also, create a proper section symbol. */
1115 if (! BFD_SEND (abfd
, _new_section_hook
, (abfd
, newsect
)))
1122 bfd_make_section_anyway_with_flags
1125 asection *bfd_make_section_anyway_with_flags
1126 (bfd *abfd, const char *name, flagword flags);
1129 Create a new empty section called @var{name} and attach it to the end of
1130 the chain of sections for @var{abfd}. Create a new section even if there
1131 is already a section with that name. Also set the attributes of the
1132 new section to the value @var{flags}.
1134 Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1135 o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1136 o <<bfd_error_no_memory>> - If memory allocation fails.
1140 bfd_make_section_anyway_with_flags (bfd
*abfd
, const char *name
,
1143 struct section_hash_entry
*sh
;
1146 if (abfd
->output_has_begun
)
1148 bfd_set_error (bfd_error_invalid_operation
);
1152 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1156 newsect
= &sh
->section
;
1157 if (newsect
->name
!= NULL
)
1159 /* We are making a section of the same name. Put it in the
1160 section hash table. Even though we can't find it directly by a
1161 hash lookup, we'll be able to find the section by traversing
1162 sh->root.next quicker than looking at all the bfd sections. */
1163 struct section_hash_entry
*new_sh
;
1164 new_sh
= (struct section_hash_entry
*)
1165 bfd_section_hash_newfunc (NULL
, &abfd
->section_htab
, name
);
1169 new_sh
->root
= sh
->root
;
1170 sh
->root
.next
= &new_sh
->root
;
1171 newsect
= &new_sh
->section
;
1174 newsect
->flags
= flags
;
1175 newsect
->name
= name
;
1176 return bfd_section_init (abfd
, newsect
);
1181 bfd_make_section_anyway
1184 asection *bfd_make_section_anyway (bfd *abfd, const char *name);
1187 Create a new empty section called @var{name} and attach it to the end of
1188 the chain of sections for @var{abfd}. Create a new section even if there
1189 is already a section with that name.
1191 Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1192 o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1193 o <<bfd_error_no_memory>> - If memory allocation fails.
1197 bfd_make_section_anyway (bfd
*abfd
, const char *name
)
1199 return bfd_make_section_anyway_with_flags (abfd
, name
, 0);
1204 bfd_make_section_with_flags
1207 asection *bfd_make_section_with_flags
1208 (bfd *, const char *name, flagword flags);
1211 Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1212 bfd_set_error ()) without changing the section chain if there is already a
1213 section named @var{name}. Also set the attributes of the new section to
1214 the value @var{flags}. If there is an error, return <<NULL>> and set
1219 bfd_make_section_with_flags (bfd
*abfd
, const char *name
,
1222 struct section_hash_entry
*sh
;
1225 if (abfd
== NULL
|| name
== NULL
|| abfd
->output_has_begun
)
1227 bfd_set_error (bfd_error_invalid_operation
);
1231 if (strcmp (name
, BFD_ABS_SECTION_NAME
) == 0
1232 || strcmp (name
, BFD_COM_SECTION_NAME
) == 0
1233 || strcmp (name
, BFD_UND_SECTION_NAME
) == 0
1234 || strcmp (name
, BFD_IND_SECTION_NAME
) == 0)
1237 sh
= section_hash_lookup (&abfd
->section_htab
, name
, TRUE
, FALSE
);
1241 newsect
= &sh
->section
;
1242 if (newsect
->name
!= NULL
)
1244 /* Section already exists. */
1248 newsect
->name
= name
;
1249 newsect
->flags
= flags
;
1250 return bfd_section_init (abfd
, newsect
);
1258 asection *bfd_make_section (bfd *, const char *name);
1261 Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1262 bfd_set_error ()) without changing the section chain if there is already a
1263 section named @var{name}. If there is an error, return <<NULL>> and set
1268 bfd_make_section (bfd
*abfd
, const char *name
)
1270 return bfd_make_section_with_flags (abfd
, name
, 0);
1275 bfd_set_section_flags
1278 bfd_boolean bfd_set_section_flags (asection *sec, flagword flags);
1281 Set the attributes of the section @var{sec} to the value @var{flags}.
1282 Return <<TRUE>> on success, <<FALSE>> on error. Possible error
1285 o <<bfd_error_invalid_operation>> -
1286 The section cannot have one or more of the attributes
1287 requested. For example, a .bss section in <<a.out>> may not
1288 have the <<SEC_HAS_CONTENTS>> field set.
1293 bfd_set_section_flags (asection
*section
, flagword flags
)
1295 section
->flags
= flags
;
1304 void bfd_rename_section
1305 (asection *sec, const char *newname);
1308 Rename section @var{sec} to @var{newname}.
1312 bfd_rename_section (asection
*sec
, const char *newname
)
1314 struct section_hash_entry
*sh
;
1316 sh
= (struct section_hash_entry
*)
1317 ((char *) sec
- offsetof (struct section_hash_entry
, section
));
1318 sh
->section
.name
= newname
;
1319 bfd_hash_rename (&sec
->owner
->section_htab
, newname
, &sh
->root
);
1324 bfd_map_over_sections
1327 void bfd_map_over_sections
1329 void (*func) (bfd *abfd, asection *sect, void *obj),
1333 Call the provided function @var{func} for each section
1334 attached to the BFD @var{abfd}, passing @var{obj} as an
1335 argument. The function will be called as if by
1337 | func (abfd, the_section, obj);
1339 This is the preferred method for iterating over sections; an
1340 alternative would be to use a loop:
1343 | for (p = abfd->sections; p != NULL; p = p->next)
1344 | func (abfd, p, ...)
1349 bfd_map_over_sections (bfd
*abfd
,
1350 void (*operation
) (bfd
*, asection
*, void *),
1356 for (sect
= abfd
->sections
; sect
!= NULL
; i
++, sect
= sect
->next
)
1357 (*operation
) (abfd
, sect
, user_storage
);
1359 if (i
!= abfd
->section_count
) /* Debugging */
1365 bfd_sections_find_if
1368 asection *bfd_sections_find_if
1370 bfd_boolean (*operation) (bfd *abfd, asection *sect, void *obj),
1374 Call the provided function @var{operation} for each section
1375 attached to the BFD @var{abfd}, passing @var{obj} as an
1376 argument. The function will be called as if by
1378 | operation (abfd, the_section, obj);
1380 It returns the first section for which @var{operation} returns true.
1385 bfd_sections_find_if (bfd
*abfd
,
1386 bfd_boolean (*operation
) (bfd
*, asection
*, void *),
1391 for (sect
= abfd
->sections
; sect
!= NULL
; sect
= sect
->next
)
1392 if ((*operation
) (abfd
, sect
, user_storage
))
1400 bfd_set_section_size
1403 bfd_boolean bfd_set_section_size (asection *sec, bfd_size_type val);
1406 Set @var{sec} to the size @var{val}. If the operation is
1407 ok, then <<TRUE>> is returned, else <<FALSE>>.
1409 Possible error returns:
1410 o <<bfd_error_invalid_operation>> -
1411 Writing has started to the BFD, so setting the size is invalid.
1416 bfd_set_section_size (asection
*sec
, bfd_size_type val
)
1418 /* Once you've started writing to any section you cannot create or change
1419 the size of any others. */
1421 if (sec
->owner
== NULL
|| sec
->owner
->output_has_begun
)
1423 bfd_set_error (bfd_error_invalid_operation
);
1433 bfd_set_section_contents
1436 bfd_boolean bfd_set_section_contents
1437 (bfd *abfd, asection *section, const void *data,
1438 file_ptr offset, bfd_size_type count);
1441 Sets the contents of the section @var{section} in BFD
1442 @var{abfd} to the data starting in memory at @var{location}.
1443 The data is written to the output section starting at offset
1444 @var{offset} for @var{count} octets.
1446 Normally <<TRUE>> is returned, but <<FALSE>> is returned if
1447 there was an error. Possible error returns are:
1448 o <<bfd_error_no_contents>> -
1449 The output section does not have the <<SEC_HAS_CONTENTS>>
1450 attribute, so nothing can be written to it.
1451 o <<bfd_error_bad_value>> -
1452 The section is unable to contain all of the data.
1453 o <<bfd_error_invalid_operation>> -
1454 The BFD is not writeable.
1455 o and some more too.
1457 This routine is front end to the back end function
1458 <<_bfd_set_section_contents>>.
1463 bfd_set_section_contents (bfd
*abfd
,
1465 const void *location
,
1467 bfd_size_type count
)
1471 if (!(bfd_section_flags (section
) & SEC_HAS_CONTENTS
))
1473 bfd_set_error (bfd_error_no_contents
);
1478 if ((bfd_size_type
) offset
> sz
1480 || offset
+ count
> sz
1481 || count
!= (size_t) count
)
1483 bfd_set_error (bfd_error_bad_value
);
1487 if (!bfd_write_p (abfd
))
1489 bfd_set_error (bfd_error_invalid_operation
);
1493 /* Record a copy of the data in memory if desired. */
1494 if (section
->contents
1495 && location
!= section
->contents
+ offset
)
1496 memcpy (section
->contents
+ offset
, location
, (size_t) count
);
1498 if (BFD_SEND (abfd
, _bfd_set_section_contents
,
1499 (abfd
, section
, location
, offset
, count
)))
1501 abfd
->output_has_begun
= TRUE
;
1510 bfd_get_section_contents
1513 bfd_boolean bfd_get_section_contents
1514 (bfd *abfd, asection *section, void *location, file_ptr offset,
1515 bfd_size_type count);
1518 Read data from @var{section} in BFD @var{abfd}
1519 into memory starting at @var{location}. The data is read at an
1520 offset of @var{offset} from the start of the input section,
1521 and is read for @var{count} bytes.
1523 If the contents of a constructor with the <<SEC_CONSTRUCTOR>>
1524 flag set are requested or if the section does not have the
1525 <<SEC_HAS_CONTENTS>> flag set, then the @var{location} is filled
1526 with zeroes. If no errors occur, <<TRUE>> is returned, else
1531 bfd_get_section_contents (bfd
*abfd
,
1535 bfd_size_type count
)
1539 if (section
->flags
& SEC_CONSTRUCTOR
)
1541 memset (location
, 0, (size_t) count
);
1545 if (abfd
->direction
!= write_direction
&& section
->rawsize
!= 0)
1546 sz
= section
->rawsize
;
1549 if ((bfd_size_type
) offset
> sz
1551 || offset
+ count
> sz
1552 || count
!= (size_t) count
)
1554 bfd_set_error (bfd_error_bad_value
);
1562 if ((section
->flags
& SEC_HAS_CONTENTS
) == 0)
1564 memset (location
, 0, (size_t) count
);
1568 if ((section
->flags
& SEC_IN_MEMORY
) != 0)
1570 if (section
->contents
== NULL
)
1572 /* This can happen because of errors earlier on in the linking process.
1573 We do not want to seg-fault here, so clear the flag and return an
1575 section
->flags
&= ~ SEC_IN_MEMORY
;
1576 bfd_set_error (bfd_error_invalid_operation
);
1580 memmove (location
, section
->contents
+ offset
, (size_t) count
);
1584 return BFD_SEND (abfd
, _bfd_get_section_contents
,
1585 (abfd
, section
, location
, offset
, count
));
1590 bfd_malloc_and_get_section
1593 bfd_boolean bfd_malloc_and_get_section
1594 (bfd *abfd, asection *section, bfd_byte **buf);
1597 Read all data from @var{section} in BFD @var{abfd}
1598 into a buffer, *@var{buf}, malloc'd by this function.
1602 bfd_malloc_and_get_section (bfd
*abfd
, sec_ptr sec
, bfd_byte
**buf
)
1605 return bfd_get_full_section_contents (abfd
, sec
, buf
);
1609 bfd_copy_private_section_data
1612 bfd_boolean bfd_copy_private_section_data
1613 (bfd *ibfd, asection *isec, bfd *obfd, asection *osec);
1616 Copy private section information from @var{isec} in the BFD
1617 @var{ibfd} to the section @var{osec} in the BFD @var{obfd}.
1618 Return <<TRUE>> on success, <<FALSE>> on error. Possible error
1621 o <<bfd_error_no_memory>> -
1622 Not enough memory exists to create private data for @var{osec}.
1624 .#define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \
1625 . BFD_SEND (obfd, _bfd_copy_private_section_data, \
1626 . (ibfd, isection, obfd, osection))
1631 bfd_generic_is_group_section
1634 bfd_boolean bfd_generic_is_group_section (bfd *, const asection *sec);
1637 Returns TRUE if @var{sec} is a member of a group.
1641 bfd_generic_is_group_section (bfd
*abfd ATTRIBUTE_UNUSED
,
1642 const asection
*sec ATTRIBUTE_UNUSED
)
1649 bfd_generic_group_name
1652 const char *bfd_generic_group_name (bfd *, const asection *sec);
1655 Returns group name if @var{sec} is a member of a group.
1659 bfd_generic_group_name (bfd
*abfd ATTRIBUTE_UNUSED
,
1660 const asection
*sec ATTRIBUTE_UNUSED
)
1667 bfd_generic_discard_group
1670 bfd_boolean bfd_generic_discard_group (bfd *abfd, asection *group);
1673 Remove all members of @var{group} from the output.
1677 bfd_generic_discard_group (bfd
*abfd ATTRIBUTE_UNUSED
,
1678 asection
*group ATTRIBUTE_UNUSED
)
1684 _bfd_nowrite_set_section_contents (bfd
*abfd
,
1685 sec_ptr section ATTRIBUTE_UNUSED
,
1686 const void *location ATTRIBUTE_UNUSED
,
1687 file_ptr offset ATTRIBUTE_UNUSED
,
1688 bfd_size_type count ATTRIBUTE_UNUSED
)
1690 return _bfd_bool_bfd_false_error (abfd
);