Implement tp_richcompare for gdb.Block
[binutils-gdb.git] / bfd / section.c
blob778a6f75160e191e88304a9a723d3666bb5d8ec3
1 /* Object file "section" support for the BFD library.
2 Copyright (C) 1990-2024 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. */
23 SECTION
24 Sections
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>>.
33 @menu
34 @* Section Input::
35 @* Section Output::
36 @* typedef asection::
37 @* section prototypes::
38 @end menu
40 INODE
41 Section Input, Section Output, Sections, Sections
42 SUBSECTION
43 Section input
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
61 common storage.
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.
70 INODE
71 Section Output, typedef asection, Section Input, Sections
73 SUBSECTION
74 Section output
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:
101 | section name "A"
102 | output_offset 0x00
103 | size 0x20
104 | output_section -----------> section name "O"
105 | | vma 0x100
106 | section name "B" | size 0x123
107 | output_offset 0x20 |
108 | size 0x103 |
109 | output_section --------|
111 SUBSECTION
112 Link orders
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.
132 #include "sysdep.h"
133 #include "bfd.h"
134 #include "libbfd.h"
135 #include "bfdlink.h"
138 DOCDD
139 INODE
140 typedef asection, section prototypes, Section Output, Sections
141 SUBSECTION
142 typedef asection
144 Here is the section structure:
146 EXTERNAL
147 .{* Linenumber stuff. *}
148 .typedef struct lineno_cache_entry
150 . unsigned int line_number; {* Linenumber from start of function. *}
151 . union
153 . struct bfd_symbol *sym; {* Function name. *}
154 . bfd_vma offset; {* Offset into section. *}
155 . } u;
157 .alent;
160 CODE_FRAGMENT
161 .typedef struct bfd_section
163 . {* The name of the section; the name isn't a copy, the pointer is
164 . the same as that passed to bfd_make_section. *}
165 . const char *name;
167 . {* The next section in the list belonging to the BFD, or NULL. *}
168 . struct bfd_section *next;
170 . {* The previous section in the list belonging to the BFD, or NULL. *}
171 . struct bfd_section *prev;
173 . {* A unique sequence number. *}
174 . unsigned int id;
176 . {* A unique section number which can be used by assembler to
177 . distinguish different sections with the same section name. *}
178 . unsigned int section_id;
180 . {* Which section in the bfd; 0..n-1 as sections are created in a bfd. *}
181 . unsigned int index;
183 . {* The field flags contains attributes of the section. Some
184 . flags are read in from the object file, and some are
185 . synthesized from other information. *}
186 . flagword flags;
188 .#define SEC_NO_FLAGS 0x0
190 . {* Tells the OS to allocate space for this section when loading.
191 . This is clear for a section containing debug information only. *}
192 .#define SEC_ALLOC 0x1
194 . {* Tells the OS to load the section from the file when loading.
195 . This is clear for a .bss section. *}
196 .#define SEC_LOAD 0x2
198 . {* The section contains data still to be relocated, so there is
199 . some relocation information too. *}
200 .#define SEC_RELOC 0x4
202 . {* A signal to the OS that the section contains read only data. *}
203 .#define SEC_READONLY 0x8
205 . {* The section contains code only. *}
206 .#define SEC_CODE 0x10
208 . {* The section contains data only. *}
209 .#define SEC_DATA 0x20
211 . {* The section will reside in ROM. *}
212 .#define SEC_ROM 0x40
214 . {* The section contains constructor information. This section
215 . type is used by the linker to create lists of constructors and
216 . destructors used by <<g++>>. When a back end sees a symbol
217 . which should be used in a constructor list, it creates a new
218 . section for the type of name (e.g., <<__CTOR_LIST__>>), attaches
219 . the symbol to it, and builds a relocation. To build the lists
220 . of constructors, all the linker has to do is catenate all the
221 . sections called <<__CTOR_LIST__>> and relocate the data
222 . contained within - exactly the operations it would peform on
223 . standard data. *}
224 .#define SEC_CONSTRUCTOR 0x80
226 . {* The section has contents - a data section could be
227 . <<SEC_ALLOC>> | <<SEC_HAS_CONTENTS>>; a debug section could be
228 . <<SEC_HAS_CONTENTS>> *}
229 .#define SEC_HAS_CONTENTS 0x100
231 . {* An instruction to the linker to not output the section
232 . even if it has information which would normally be written. *}
233 .#define SEC_NEVER_LOAD 0x200
235 . {* The section contains thread local data. *}
236 .#define SEC_THREAD_LOCAL 0x400
238 . {* The section's size is fixed. Generic linker code will not
239 . recalculate it and it is up to whoever has set this flag to
240 . get the size right. *}
241 .#define SEC_FIXED_SIZE 0x800
243 . {* The section contains common symbols (symbols may be defined
244 . multiple times, the value of a symbol is the amount of
245 . space it requires, and the largest symbol value is the one
246 . used). Most targets have exactly one of these (which we
247 . translate to bfd_com_section_ptr), but ECOFF has two. *}
248 .#define SEC_IS_COMMON 0x1000
250 . {* The section contains only debugging information. For
251 . example, this is set for ELF .debug and .stab sections.
252 . strip tests this flag to see if a section can be
253 . discarded. *}
254 .#define SEC_DEBUGGING 0x2000
256 . {* The contents of this section are held in memory pointed to
257 . by the contents field. This is checked by bfd_get_section_contents,
258 . and the data is retrieved from memory if appropriate. *}
259 .#define SEC_IN_MEMORY 0x4000
261 . {* The contents of this section are to be excluded by the
262 . linker for executable and shared objects unless those
263 . objects are to be further relocated. *}
264 .#define SEC_EXCLUDE 0x8000
266 . {* The contents of this section are to be sorted based on the sum of
267 . the symbol and addend values specified by the associated relocation
268 . entries. Entries without associated relocation entries will be
269 . appended to the end of the section in an unspecified order. *}
270 .#define SEC_SORT_ENTRIES 0x10000
272 . {* When linking, duplicate sections of the same name should be
273 . discarded, rather than being combined into a single section as
274 . is usually done. This is similar to how common symbols are
275 . handled. See SEC_LINK_DUPLICATES below. *}
276 .#define SEC_LINK_ONCE 0x20000
278 . {* If SEC_LINK_ONCE is set, this bitfield describes how the linker
279 . should handle duplicate sections. *}
280 .#define SEC_LINK_DUPLICATES 0xc0000
282 . {* This value for SEC_LINK_DUPLICATES means that duplicate
283 . sections with the same name should simply be discarded. *}
284 .#define SEC_LINK_DUPLICATES_DISCARD 0x0
286 . {* This value for SEC_LINK_DUPLICATES means that the linker
287 . should warn if there are any duplicate sections, although
288 . it should still only link one copy. *}
289 .#define SEC_LINK_DUPLICATES_ONE_ONLY 0x40000
291 . {* This value for SEC_LINK_DUPLICATES means that the linker
292 . should warn if any duplicate sections are a different size. *}
293 .#define SEC_LINK_DUPLICATES_SAME_SIZE 0x80000
295 . {* This value for SEC_LINK_DUPLICATES means that the linker
296 . should warn if any duplicate sections contain different
297 . contents. *}
298 .#define SEC_LINK_DUPLICATES_SAME_CONTENTS \
299 . (SEC_LINK_DUPLICATES_ONE_ONLY | SEC_LINK_DUPLICATES_SAME_SIZE)
301 . {* This section was created by the linker as part of dynamic
302 . relocation or other arcane processing. It is skipped when
303 . going through the first-pass output, trusting that someone
304 . else up the line will take care of it later. *}
305 .#define SEC_LINKER_CREATED 0x100000
307 . {* This section contains a section ID to distinguish different
308 . sections with the same section name. *}
309 .#define SEC_ASSEMBLER_SECTION_ID 0x100000
311 . {* This section should not be subject to garbage collection.
312 . Also set to inform the linker that this section should not be
313 . listed in the link map as discarded. *}
314 .#define SEC_KEEP 0x200000
316 . {* This section contains "short" data, and should be placed
317 . "near" the GP. *}
318 .#define SEC_SMALL_DATA 0x400000
320 . {* Attempt to merge identical entities in the section.
321 . Entity size is given in the entsize field. *}
322 .#define SEC_MERGE 0x800000
324 . {* If given with SEC_MERGE, entities to merge are zero terminated
325 . strings where entsize specifies character size instead of fixed
326 . size entries. *}
327 .#define SEC_STRINGS 0x1000000
329 . {* This section contains data about section groups. *}
330 .#define SEC_GROUP 0x2000000
332 . {* The section is a COFF shared library section. This flag is
333 . only for the linker. If this type of section appears in
334 . the input file, the linker must copy it to the output file
335 . without changing the vma or size. FIXME: Although this
336 . was originally intended to be general, it really is COFF
337 . specific (and the flag was renamed to indicate this). It
338 . might be cleaner to have some more general mechanism to
339 . allow the back end to control what the linker does with
340 . sections. *}
341 .#define SEC_COFF_SHARED_LIBRARY 0x4000000
343 . {* This input section should be copied to output in reverse order
344 . as an array of pointers. This is for ELF linker internal use
345 . only. *}
346 .#define SEC_ELF_REVERSE_COPY 0x4000000
348 . {* This section contains data which may be shared with other
349 . executables or shared objects. This is for COFF only. *}
350 .#define SEC_COFF_SHARED 0x8000000
352 . {* Indicate that section has the purecode flag set. *}
353 .#define SEC_ELF_PURECODE 0x8000000
355 . {* When a section with this flag is being linked, then if the size of
356 . the input section is less than a page, it should not cross a page
357 . boundary. If the size of the input section is one page or more,
358 . it should be aligned on a page boundary. This is for TI
359 . TMS320C54X only. *}
360 .#define SEC_TIC54X_BLOCK 0x10000000
362 . {* This section has the SHF_X86_64_LARGE flag. This is ELF x86-64 only. *}
363 .#define SEC_ELF_LARGE 0x10000000
365 . {* Conditionally link this section; do not link if there are no
366 . references found to any symbol in the section. This is for TI
367 . TMS320C54X only. *}
368 .#define SEC_TIC54X_CLINK 0x20000000
370 . {* This section contains vliw code. This is for Toshiba MeP only. *}
371 .#define SEC_MEP_VLIW 0x20000000
373 . {* All symbols, sizes and relocations in this section are octets
374 . instead of bytes. Required for DWARF debug sections as DWARF
375 . information is organized in octets, not bytes. *}
376 .#define SEC_ELF_OCTETS 0x40000000
378 . {* Indicate that section has the no read flag set. This happens
379 . when memory read flag isn't set. *}
380 .#define SEC_COFF_NOREAD 0x40000000
382 . {* End of section flags. *}
384 . {* Some internal packed boolean fields. *}
386 . {* See the vma field. *}
387 . unsigned int user_set_vma : 1;
389 . {* A mark flag used by some of the linker backends. *}
390 . unsigned int linker_mark : 1;
392 . {* Another mark flag used by some of the linker backends. Set for
393 . output sections that have an input section. *}
394 . unsigned int linker_has_input : 1;
396 . {* Mark flag used by some linker backends for garbage collection. *}
397 . unsigned int gc_mark : 1;
399 . {* Section compression status. *}
400 . unsigned int compress_status : 2;
401 .#define COMPRESS_SECTION_NONE 0
402 .#define COMPRESS_SECTION_DONE 1
403 .#define DECOMPRESS_SECTION_ZLIB 2
404 .#define DECOMPRESS_SECTION_ZSTD 3
406 . {* The following flags are used by the ELF linker. *}
408 . {* Mark sections which have been allocated to segments. *}
409 . unsigned int segment_mark : 1;
411 . {* Type of sec_info information. *}
412 . unsigned int sec_info_type:3;
413 .#define SEC_INFO_TYPE_NONE 0
414 .#define SEC_INFO_TYPE_STABS 1
415 .#define SEC_INFO_TYPE_MERGE 2
416 .#define SEC_INFO_TYPE_EH_FRAME 3
417 .#define SEC_INFO_TYPE_JUST_SYMS 4
418 .#define SEC_INFO_TYPE_TARGET 5
419 .#define SEC_INFO_TYPE_EH_FRAME_ENTRY 6
420 .#define SEC_INFO_TYPE_SFRAME 7
422 . {* Nonzero if this section uses RELA relocations, rather than REL. *}
423 . unsigned int use_rela_p:1;
425 . {* Nonzero if this section contents are mmapped, rather than malloced. *}
426 . unsigned int mmapped_p:1;
428 . {* Bits used by various backends. The generic code doesn't touch
429 . these fields. *}
431 . unsigned int sec_flg0:1;
432 . unsigned int sec_flg1:1;
433 . unsigned int sec_flg2:1;
434 . unsigned int sec_flg3:1;
435 . unsigned int sec_flg4:1;
436 . unsigned int sec_flg5:1;
438 . {* End of internal packed boolean fields. *}
440 . {* The virtual memory address of the section - where it will be
441 . at run time. The symbols are relocated against this. The
442 . user_set_vma flag is maintained by bfd; if it's not set, the
443 . backend can assign addresses (for example, in <<a.out>>, where
444 . the default address for <<.data>> is dependent on the specific
445 . target and various flags). *}
446 . bfd_vma vma;
448 . {* The load address of the section - where it would be in a
449 . rom image; really only used for writing section header
450 . information. *}
451 . bfd_vma lma;
453 . {* The size of the section in *octets*, as it will be output.
454 . Contains a value even if the section has no contents (e.g., the
455 . size of <<.bss>>). *}
456 . bfd_size_type size;
458 . {* For input sections, the original size on disk of the section, in
459 . octets. This field should be set for any section whose size is
460 . changed by linker relaxation. It is required for sections where
461 . the linker relaxation scheme doesn't cache altered section and
462 . reloc contents (stabs, eh_frame, SEC_MERGE, some coff relaxing
463 . targets), and thus the original size needs to be kept to read the
464 . section multiple times. For output sections, rawsize holds the
465 . section size calculated on a previous linker relaxation pass. *}
466 . bfd_size_type rawsize;
468 . {* The compressed size of the section in octets. *}
469 . bfd_size_type compressed_size;
471 . {* If this section is going to be output, then this value is the
472 . offset in *bytes* into the output section of the first byte in the
473 . input section (byte ==> smallest addressable unit on the
474 . target). In most cases, if this was going to start at the
475 . 100th octet (8-bit quantity) in the output section, this value
476 . would be 100. However, if the target byte size is 16 bits
477 . (bfd_octets_per_byte is "2"), this value would be 50. *}
478 . bfd_vma output_offset;
480 . {* The output section through which to map on output. *}
481 . struct bfd_section *output_section;
483 . {* If an input section, a pointer to a vector of relocation
484 . records for the data in this section. *}
485 . struct reloc_cache_entry *relocation;
487 . {* If an output section, a pointer to a vector of pointers to
488 . relocation records for the data in this section. *}
489 . struct reloc_cache_entry **orelocation;
491 . {* The number of relocation records in one of the above. *}
492 . unsigned reloc_count;
494 . {* The alignment requirement of the section, as an exponent of 2 -
495 . e.g., 3 aligns to 2^3 (or 8). *}
496 . unsigned int alignment_power;
498 . {* Information below is back end specific - and not always used
499 . or updated. *}
501 . {* File position of section data. *}
502 . file_ptr filepos;
504 . {* File position of relocation info. *}
505 . file_ptr rel_filepos;
507 . {* File position of line data. *}
508 . file_ptr line_filepos;
510 . {* Pointer to data for applications. *}
511 . void *userdata;
513 . {* If the SEC_IN_MEMORY flag is set, this points to the actual
514 . contents. *}
515 . bfd_byte *contents;
517 . {* Attached line number information. *}
518 . alent *lineno;
520 . {* Number of line number records. *}
521 . unsigned int lineno_count;
523 . {* Entity size for merging purposes. *}
524 . unsigned int entsize;
526 . {* Points to the kept section if this section is a link-once section,
527 . and is discarded. *}
528 . struct bfd_section *kept_section;
530 . {* When a section is being output, this value changes as more
531 . linenumbers are written out. *}
532 . file_ptr moving_line_filepos;
534 . {* What the section number is in the target world. *}
535 . int target_index;
537 . void *used_by_bfd;
539 . {* If this is a constructor section then here is a list of the
540 . relocations created to relocate items within it. *}
541 . struct relent_chain *constructor_chain;
543 . {* The BFD which owns the section. *}
544 . bfd *owner;
546 . {* A symbol which points at this section only. *}
547 . struct bfd_symbol *symbol;
548 . struct bfd_symbol **symbol_ptr_ptr;
550 . {* Early in the link process, map_head and map_tail are used to build
551 . a list of input sections attached to an output section. Later,
552 . output sections use these fields for a list of bfd_link_order
553 . structs. The linked_to_symbol_name field is for ELF assembler
554 . internal use. *}
555 . union {
556 . struct bfd_link_order *link_order;
557 . struct bfd_section *s;
558 . const char *linked_to_symbol_name;
559 . } map_head, map_tail;
561 . {* Points to the output section this section is already assigned to,
562 . if any. This is used when support for non-contiguous memory
563 . regions is enabled. *}
564 . struct bfd_section *already_assigned;
566 . {* Explicitly specified section type, if non-zero. *}
567 . unsigned int type;
569 .} asection;
572 EXTERNAL
573 .static inline const char *
574 .bfd_section_name (const asection *sec)
576 . return sec->name;
579 .static inline bfd_size_type
580 .bfd_section_size (const asection *sec)
582 . return sec->size;
585 .static inline bfd_vma
586 .bfd_section_vma (const asection *sec)
588 . return sec->vma;
591 .static inline bfd_vma
592 .bfd_section_lma (const asection *sec)
594 . return sec->lma;
597 .static inline unsigned int
598 .bfd_section_alignment (const asection *sec)
600 . return sec->alignment_power;
603 .static inline flagword
604 .bfd_section_flags (const asection *sec)
606 . return sec->flags;
609 .static inline void *
610 .bfd_section_userdata (const asection *sec)
612 . return sec->userdata;
614 .static inline bool
615 .bfd_is_com_section (const asection *sec)
617 . return (sec->flags & SEC_IS_COMMON) != 0;
620 .{* Note: the following are provided as inline functions rather than macros
621 . because not all callers use the return value. A macro implementation
622 . would use a comma expression, eg: "((ptr)->foo = val, TRUE)" and some
623 . compilers will complain about comma expressions that have no effect. *}
624 .static inline bool
625 .bfd_set_section_userdata (asection *sec, void *val)
627 . sec->userdata = val;
628 . return true;
631 .static inline bool
632 .bfd_set_section_vma (asection *sec, bfd_vma val)
634 . sec->vma = sec->lma = val;
635 . sec->user_set_vma = true;
636 . return true;
639 .static inline bool
640 .bfd_set_section_lma (asection *sec, bfd_vma val)
642 . sec->lma = val;
643 . return true;
646 .static inline bool
647 .bfd_set_section_alignment (asection *sec, unsigned int val)
649 . if (val >= sizeof (bfd_vma) * 8 - 1)
650 . return false;
651 . sec->alignment_power = val;
652 . return true;
655 .{* These sections are global, and are managed by BFD. The application
656 . and target back end are not permitted to change the values in
657 . these sections. *}
658 .extern asection _bfd_std_section[4];
660 .#define BFD_ABS_SECTION_NAME "*ABS*"
661 .#define BFD_UND_SECTION_NAME "*UND*"
662 .#define BFD_COM_SECTION_NAME "*COM*"
663 .#define BFD_IND_SECTION_NAME "*IND*"
665 .{* Pointer to the common section. *}
666 .#define bfd_com_section_ptr (&_bfd_std_section[0])
667 .{* Pointer to the undefined section. *}
668 .#define bfd_und_section_ptr (&_bfd_std_section[1])
669 .{* Pointer to the absolute section. *}
670 .#define bfd_abs_section_ptr (&_bfd_std_section[2])
671 .{* Pointer to the indirect section. *}
672 .#define bfd_ind_section_ptr (&_bfd_std_section[3])
674 .static inline bool
675 .bfd_is_und_section (const asection *sec)
677 . return sec == bfd_und_section_ptr;
680 .static inline bool
681 .bfd_is_abs_section (const asection *sec)
683 . return sec == bfd_abs_section_ptr;
686 .static inline bool
687 .bfd_is_ind_section (const asection *sec)
689 . return sec == bfd_ind_section_ptr;
692 .static inline bool
693 .bfd_is_const_section (const asection *sec)
695 . return (sec >= _bfd_std_section
696 . && sec < _bfd_std_section + (sizeof (_bfd_std_section)
697 . / sizeof (_bfd_std_section[0])));
700 .{* Return TRUE if input section SEC has been discarded. *}
701 .static inline bool
702 .discarded_section (const asection *sec)
704 . return (!bfd_is_abs_section (sec)
705 . && bfd_is_abs_section (sec->output_section)
706 . && sec->sec_info_type != SEC_INFO_TYPE_MERGE
707 . && sec->sec_info_type != SEC_INFO_TYPE_JUST_SYMS);
710 .#define BFD_FAKE_SECTION(SEC, SYM, NAME, IDX, FLAGS) \
711 . {* name, next, prev, id, section_id, index, flags, user_set_vma, *} \
712 . { NAME, NULL, NULL, IDX, 0, 0, FLAGS, 0, \
714 . {* linker_mark, linker_has_input, gc_mark, decompress_status, *} \
715 . 0, 0, 1, 0, \
717 . {* segment_mark, sec_info_type, use_rela_p, mmapped_p, *} \
718 . 0, 0, 0, 0, \
720 . {* sec_flg0, sec_flg1, sec_flg2, sec_flg3, sec_flg4, sec_flg5, *} \
721 . 0, 0, 0, 0, 0, 0, \
723 . {* vma, lma, size, rawsize, compressed_size, *} \
724 . 0, 0, 0, 0, 0, \
726 . {* output_offset, output_section, relocation, orelocation, *} \
727 . 0, &SEC, NULL, NULL, \
729 . {* reloc_count, alignment_power, filepos, rel_filepos, *} \
730 . 0, 0, 0, 0, \
732 . {* line_filepos, userdata, contents, lineno, lineno_count, *} \
733 . 0, NULL, NULL, NULL, 0, \
735 . {* entsize, kept_section, moving_line_filepos, *} \
736 . 0, NULL, 0, \
738 . {* target_index, used_by_bfd, constructor_chain, owner, *} \
739 . 0, NULL, NULL, NULL, \
741 . {* symbol, symbol_ptr_ptr, *} \
742 . (struct bfd_symbol *) SYM, &SEC.symbol, \
744 . {* map_head, map_tail, already_assigned, type *} \
745 . { NULL }, { NULL }, NULL, 0 \
749 .{* We use a macro to initialize the static asymbol structures because
750 . traditional C does not permit us to initialize a union member while
751 . gcc warns if we don't initialize it.
752 . the_bfd, name, value, attr, section [, udata] *}
753 .#ifdef __STDC__
754 .#define GLOBAL_SYM_INIT(NAME, SECTION) \
755 . { 0, NAME, 0, BSF_SECTION_SYM, SECTION, { 0 }}
756 .#else
757 .#define GLOBAL_SYM_INIT(NAME, SECTION) \
758 . { 0, NAME, 0, BSF_SECTION_SYM, SECTION }
759 .#endif
763 /* These symbols are global, not specific to any BFD. Therefore, anything
764 that tries to change them is broken, and should be repaired. */
766 static const asymbol global_syms[] =
768 GLOBAL_SYM_INIT (BFD_COM_SECTION_NAME, bfd_com_section_ptr),
769 GLOBAL_SYM_INIT (BFD_UND_SECTION_NAME, bfd_und_section_ptr),
770 GLOBAL_SYM_INIT (BFD_ABS_SECTION_NAME, bfd_abs_section_ptr),
771 GLOBAL_SYM_INIT (BFD_IND_SECTION_NAME, bfd_ind_section_ptr)
774 #define STD_SECTION(NAME, IDX, FLAGS) \
775 BFD_FAKE_SECTION(_bfd_std_section[IDX], &global_syms[IDX], NAME, IDX, FLAGS)
777 asection _bfd_std_section[] = {
778 STD_SECTION (BFD_COM_SECTION_NAME, 0, SEC_IS_COMMON),
779 STD_SECTION (BFD_UND_SECTION_NAME, 1, 0),
780 STD_SECTION (BFD_ABS_SECTION_NAME, 2, 0),
781 STD_SECTION (BFD_IND_SECTION_NAME, 3, 0)
783 #undef STD_SECTION
785 /* Initialize an entry in the section hash table. */
787 struct bfd_hash_entry *
788 bfd_section_hash_newfunc (struct bfd_hash_entry *entry,
789 struct bfd_hash_table *table,
790 const char *string)
792 /* Allocate the structure if it has not already been allocated by a
793 subclass. */
794 if (entry == NULL)
796 entry = (struct bfd_hash_entry *)
797 bfd_hash_allocate (table, sizeof (struct section_hash_entry));
798 if (entry == NULL)
799 return entry;
802 /* Call the allocation method of the superclass. */
803 entry = bfd_hash_newfunc (entry, table, string);
804 if (entry != NULL)
805 memset (&((struct section_hash_entry *) entry)->section, 0,
806 sizeof (asection));
808 return entry;
811 #define section_hash_lookup(table, string, create, copy) \
812 ((struct section_hash_entry *) \
813 bfd_hash_lookup ((table), (string), (create), (copy)))
815 /* Create a symbol whose only job is to point to this section. This
816 is useful for things like relocs which are relative to the base
817 of a section. */
819 bool
820 _bfd_generic_new_section_hook (bfd *abfd, asection *newsect)
822 newsect->symbol = bfd_make_empty_symbol (abfd);
823 if (newsect->symbol == NULL)
824 return false;
826 newsect->symbol->name = newsect->name;
827 newsect->symbol->value = 0;
828 newsect->symbol->section = newsect;
829 newsect->symbol->flags = BSF_SECTION_SYM;
831 newsect->symbol_ptr_ptr = &newsect->symbol;
832 return true;
835 unsigned int _bfd_section_id = 0x10; /* id 0 to 3 used by STD_SECTION. */
837 /* Initializes a new section. NEWSECT->NAME is already set. */
839 static asection *
840 bfd_section_init (bfd *abfd, asection *newsect)
842 newsect->id = _bfd_section_id;
843 newsect->index = abfd->section_count;
844 newsect->owner = abfd;
846 if (! BFD_SEND (abfd, _new_section_hook, (abfd, newsect)))
847 return NULL;
849 _bfd_section_id++;
850 abfd->section_count++;
851 bfd_section_list_append (abfd, newsect);
852 return newsect;
856 DOCDD
857 INODE
858 section prototypes, , typedef asection, Sections
859 SUBSECTION
860 Section prototypes
862 These are the functions exported by the section handling part of BFD.
866 FUNCTION
867 bfd_section_list_clear
869 SYNOPSIS
870 void bfd_section_list_clear (bfd *);
872 DESCRIPTION
873 Clears the section list, and also resets the section count and
874 hash table entries.
877 void
878 bfd_section_list_clear (bfd *abfd)
880 abfd->sections = NULL;
881 abfd->section_last = NULL;
882 abfd->section_count = 0;
883 memset (abfd->section_htab.table, 0,
884 abfd->section_htab.size * sizeof (struct bfd_hash_entry *));
885 abfd->section_htab.count = 0;
889 FUNCTION
890 bfd_get_section_by_name
892 SYNOPSIS
893 asection *bfd_get_section_by_name (bfd *abfd, const char *name);
895 DESCRIPTION
896 Return the most recently created section attached to @var{abfd}
897 named @var{name}. Return NULL if no such section exists.
900 asection *
901 bfd_get_section_by_name (bfd *abfd, const char *name)
903 struct section_hash_entry *sh;
905 if (name == NULL)
906 return NULL;
908 sh = section_hash_lookup (&abfd->section_htab, name, false, false);
909 if (sh != NULL)
910 return &sh->section;
912 return NULL;
916 FUNCTION
917 bfd_get_next_section_by_name
919 SYNOPSIS
920 asection *bfd_get_next_section_by_name (bfd *ibfd, asection *sec);
922 DESCRIPTION
923 Given @var{sec} is a section returned by @code{bfd_get_section_by_name},
924 return the next most recently created section attached to the same
925 BFD with the same name, or if no such section exists in the same BFD and
926 IBFD is non-NULL, the next section with the same name in any input
927 BFD following IBFD. Return NULL on finding no section.
930 asection *
931 bfd_get_next_section_by_name (bfd *ibfd, asection *sec)
933 struct section_hash_entry *sh;
934 const char *name;
935 unsigned long hash;
937 sh = ((struct section_hash_entry *)
938 ((char *) sec - offsetof (struct section_hash_entry, section)));
940 hash = sh->root.hash;
941 name = sec->name;
942 for (sh = (struct section_hash_entry *) sh->root.next;
943 sh != NULL;
944 sh = (struct section_hash_entry *) sh->root.next)
945 if (sh->root.hash == hash
946 && strcmp (sh->root.string, name) == 0)
947 return &sh->section;
949 if (ibfd != NULL)
951 while ((ibfd = ibfd->link.next) != NULL)
953 asection *s = bfd_get_section_by_name (ibfd, name);
954 if (s != NULL)
955 return s;
959 return NULL;
963 FUNCTION
964 bfd_get_linker_section
966 SYNOPSIS
967 asection *bfd_get_linker_section (bfd *abfd, const char *name);
969 DESCRIPTION
970 Return the linker created section attached to @var{abfd}
971 named @var{name}. Return NULL if no such section exists.
974 asection *
975 bfd_get_linker_section (bfd *abfd, const char *name)
977 asection *sec = bfd_get_section_by_name (abfd, name);
979 while (sec != NULL && (sec->flags & SEC_LINKER_CREATED) == 0)
980 sec = bfd_get_next_section_by_name (NULL, sec);
981 return sec;
985 FUNCTION
986 bfd_get_section_by_name_if
988 SYNOPSIS
989 asection *bfd_get_section_by_name_if
990 (bfd *abfd,
991 const char *name,
992 bool (*func) (bfd *abfd, asection *sect, void *obj),
993 void *obj);
995 DESCRIPTION
996 Call the provided function @var{func} for each section
997 attached to the BFD @var{abfd} whose name matches @var{name},
998 passing @var{obj} as an argument. The function will be called
999 as if by
1001 | func (abfd, the_section, obj);
1003 It returns the first section for which @var{func} returns true,
1004 otherwise <<NULL>>.
1008 asection *
1009 bfd_get_section_by_name_if (bfd *abfd, const char *name,
1010 bool (*operation) (bfd *, asection *, void *),
1011 void *user_storage)
1013 struct section_hash_entry *sh;
1014 unsigned long hash;
1016 if (name == NULL)
1017 return NULL;
1019 sh = section_hash_lookup (&abfd->section_htab, name, false, false);
1020 if (sh == NULL)
1021 return NULL;
1023 hash = sh->root.hash;
1024 for (; sh != NULL; sh = (struct section_hash_entry *) sh->root.next)
1025 if (sh->root.hash == hash
1026 && strcmp (sh->root.string, name) == 0
1027 && (*operation) (abfd, &sh->section, user_storage))
1028 return &sh->section;
1030 return NULL;
1034 FUNCTION
1035 bfd_get_unique_section_name
1037 SYNOPSIS
1038 char *bfd_get_unique_section_name
1039 (bfd *abfd, const char *templat, int *count);
1041 DESCRIPTION
1042 Invent a section name that is unique in @var{abfd} by tacking
1043 a dot and a digit suffix onto the original @var{templat}. If
1044 @var{count} is non-NULL, then it specifies the first number
1045 tried as a suffix to generate a unique name. The value
1046 pointed to by @var{count} will be incremented in this case.
1049 char *
1050 bfd_get_unique_section_name (bfd *abfd, const char *templat, int *count)
1052 int num;
1053 unsigned int len;
1054 char *sname;
1056 len = strlen (templat);
1057 sname = (char *) bfd_malloc (len + 8);
1058 if (sname == NULL)
1059 return NULL;
1060 memcpy (sname, templat, len);
1061 num = 1;
1062 if (count != NULL)
1063 num = *count;
1067 /* If we have a million sections, something is badly wrong. */
1068 if (num > 999999)
1069 abort ();
1070 sprintf (sname + len, ".%d", num++);
1072 while (section_hash_lookup (&abfd->section_htab, sname, false, false));
1074 if (count != NULL)
1075 *count = num;
1076 return sname;
1080 FUNCTION
1081 bfd_make_section_old_way
1083 SYNOPSIS
1084 asection *bfd_make_section_old_way (bfd *abfd, const char *name);
1086 DESCRIPTION
1087 Create a new empty section called @var{name}
1088 and attach it to the end of the chain of sections for the
1089 BFD @var{abfd}. An attempt to create a section with a name which
1090 is already in use returns its pointer without changing the
1091 section chain.
1093 It has the funny name since this is the way it used to be
1094 before it was rewritten....
1096 Possible errors are:
1097 o <<bfd_error_invalid_operation>> -
1098 If output has already started for this BFD.
1099 o <<bfd_error_no_memory>> -
1100 If memory allocation fails.
1104 asection *
1105 bfd_make_section_old_way (bfd *abfd, const char *name)
1107 asection *newsect;
1109 if (abfd->output_has_begun)
1111 bfd_set_error (bfd_error_invalid_operation);
1112 return NULL;
1115 if (strcmp (name, BFD_ABS_SECTION_NAME) == 0)
1116 newsect = bfd_abs_section_ptr;
1117 else if (strcmp (name, BFD_COM_SECTION_NAME) == 0)
1118 newsect = bfd_com_section_ptr;
1119 else if (strcmp (name, BFD_UND_SECTION_NAME) == 0)
1120 newsect = bfd_und_section_ptr;
1121 else if (strcmp (name, BFD_IND_SECTION_NAME) == 0)
1122 newsect = bfd_ind_section_ptr;
1123 else
1125 struct section_hash_entry *sh;
1127 sh = section_hash_lookup (&abfd->section_htab, name, true, false);
1128 if (sh == NULL)
1129 return NULL;
1131 newsect = &sh->section;
1132 if (newsect->name != NULL)
1134 /* Section already exists. */
1135 return newsect;
1138 newsect->name = name;
1139 return bfd_section_init (abfd, newsect);
1142 /* Call new_section_hook when "creating" the standard abs, com, und
1143 and ind sections to tack on format specific section data.
1144 Also, create a proper section symbol. */
1145 if (! BFD_SEND (abfd, _new_section_hook, (abfd, newsect)))
1146 return NULL;
1147 return newsect;
1151 FUNCTION
1152 bfd_make_section_anyway_with_flags
1154 SYNOPSIS
1155 asection *bfd_make_section_anyway_with_flags
1156 (bfd *abfd, const char *name, flagword flags);
1158 DESCRIPTION
1159 Create a new empty section called @var{name} and attach it to the end of
1160 the chain of sections for @var{abfd}. Create a new section even if there
1161 is already a section with that name. Also set the attributes of the
1162 new section to the value @var{flags}.
1164 Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1165 o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1166 o <<bfd_error_no_memory>> - If memory allocation fails.
1169 sec_ptr
1170 bfd_make_section_anyway_with_flags (bfd *abfd, const char *name,
1171 flagword flags)
1173 struct section_hash_entry *sh;
1174 asection *newsect;
1176 if (abfd->output_has_begun)
1178 bfd_set_error (bfd_error_invalid_operation);
1179 return NULL;
1182 sh = section_hash_lookup (&abfd->section_htab, name, true, false);
1183 if (sh == NULL)
1184 return NULL;
1186 newsect = &sh->section;
1187 if (newsect->name != NULL)
1189 /* We are making a section of the same name. Put it in the
1190 section hash table. Even though we can't find it directly by a
1191 hash lookup, we'll be able to find the section by traversing
1192 sh->root.next quicker than looking at all the bfd sections. */
1193 struct section_hash_entry *new_sh;
1194 new_sh = (struct section_hash_entry *)
1195 bfd_section_hash_newfunc (NULL, &abfd->section_htab, name);
1196 if (new_sh == NULL)
1197 return NULL;
1199 new_sh->root = sh->root;
1200 sh->root.next = &new_sh->root;
1201 newsect = &new_sh->section;
1204 newsect->flags = flags;
1205 newsect->name = name;
1206 return bfd_section_init (abfd, newsect);
1210 FUNCTION
1211 bfd_make_section_anyway
1213 SYNOPSIS
1214 asection *bfd_make_section_anyway (bfd *abfd, const char *name);
1216 DESCRIPTION
1217 Create a new empty section called @var{name} and attach it to the end of
1218 the chain of sections for @var{abfd}. Create a new section even if there
1219 is already a section with that name.
1221 Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1222 o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1223 o <<bfd_error_no_memory>> - If memory allocation fails.
1226 sec_ptr
1227 bfd_make_section_anyway (bfd *abfd, const char *name)
1229 return bfd_make_section_anyway_with_flags (abfd, name, 0);
1233 FUNCTION
1234 bfd_make_section_with_flags
1236 SYNOPSIS
1237 asection *bfd_make_section_with_flags
1238 (bfd *, const char *name, flagword flags);
1240 DESCRIPTION
1241 Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1242 bfd_set_error ()) without changing the section chain if there is already a
1243 section named @var{name}. Also set the attributes of the new section to
1244 the value @var{flags}. If there is an error, return <<NULL>> and set
1245 <<bfd_error>>.
1248 asection *
1249 bfd_make_section_with_flags (bfd *abfd, const char *name,
1250 flagword flags)
1252 struct section_hash_entry *sh;
1253 asection *newsect;
1255 if (abfd == NULL || name == NULL || abfd->output_has_begun)
1257 bfd_set_error (bfd_error_invalid_operation);
1258 return NULL;
1261 if (strcmp (name, BFD_ABS_SECTION_NAME) == 0
1262 || strcmp (name, BFD_COM_SECTION_NAME) == 0
1263 || strcmp (name, BFD_UND_SECTION_NAME) == 0
1264 || strcmp (name, BFD_IND_SECTION_NAME) == 0)
1265 return NULL;
1267 sh = section_hash_lookup (&abfd->section_htab, name, true, false);
1268 if (sh == NULL)
1269 return NULL;
1271 newsect = &sh->section;
1272 if (newsect->name != NULL)
1274 /* Section already exists. */
1275 return NULL;
1278 newsect->name = name;
1279 newsect->flags = flags;
1280 return bfd_section_init (abfd, newsect);
1284 FUNCTION
1285 bfd_make_section
1287 SYNOPSIS
1288 asection *bfd_make_section (bfd *, const char *name);
1290 DESCRIPTION
1291 Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1292 bfd_set_error ()) without changing the section chain if there is already a
1293 section named @var{name}. If there is an error, return <<NULL>> and set
1294 <<bfd_error>>.
1297 asection *
1298 bfd_make_section (bfd *abfd, const char *name)
1300 return bfd_make_section_with_flags (abfd, name, 0);
1304 FUNCTION
1305 bfd_set_section_flags
1307 SYNOPSIS
1308 bool bfd_set_section_flags (asection *sec, flagword flags);
1310 DESCRIPTION
1311 Set the attributes of the section @var{sec} to the value @var{flags}.
1312 Return <<TRUE>> on success, <<FALSE>> on error. Possible error
1313 returns are:
1315 o <<bfd_error_invalid_operation>> -
1316 The section cannot have one or more of the attributes
1317 requested. For example, a .bss section in <<a.out>> may not
1318 have the <<SEC_HAS_CONTENTS>> field set.
1322 bool
1323 bfd_set_section_flags (asection *section, flagword flags)
1325 section->flags = flags;
1326 return true;
1330 FUNCTION
1331 bfd_rename_section
1333 SYNOPSIS
1334 void bfd_rename_section
1335 (asection *sec, const char *newname);
1337 DESCRIPTION
1338 Rename section @var{sec} to @var{newname}.
1341 void
1342 bfd_rename_section (asection *sec, const char *newname)
1344 struct section_hash_entry *sh;
1346 sh = (struct section_hash_entry *)
1347 ((char *) sec - offsetof (struct section_hash_entry, section));
1348 sh->section.name = newname;
1349 bfd_hash_rename (&sec->owner->section_htab, newname, &sh->root);
1353 FUNCTION
1354 bfd_map_over_sections
1356 SYNOPSIS
1357 void bfd_map_over_sections
1358 (bfd *abfd,
1359 void (*func) (bfd *abfd, asection *sect, void *obj),
1360 void *obj);
1362 DESCRIPTION
1363 Call the provided function @var{func} for each section
1364 attached to the BFD @var{abfd}, passing @var{obj} as an
1365 argument. The function will be called as if by
1367 | func (abfd, the_section, obj);
1369 This is the preferred method for iterating over sections; an
1370 alternative would be to use a loop:
1372 | asection *p;
1373 | for (p = abfd->sections; p != NULL; p = p->next)
1374 | func (abfd, p, ...)
1378 void
1379 bfd_map_over_sections (bfd *abfd,
1380 void (*operation) (bfd *, asection *, void *),
1381 void *user_storage)
1383 asection *sect;
1384 unsigned int i = 0;
1386 for (sect = abfd->sections; sect != NULL; i++, sect = sect->next)
1387 (*operation) (abfd, sect, user_storage);
1389 if (i != abfd->section_count) /* Debugging */
1390 abort ();
1394 FUNCTION
1395 bfd_sections_find_if
1397 SYNOPSIS
1398 asection *bfd_sections_find_if
1399 (bfd *abfd,
1400 bool (*operation) (bfd *abfd, asection *sect, void *obj),
1401 void *obj);
1403 DESCRIPTION
1404 Call the provided function @var{operation} for each section
1405 attached to the BFD @var{abfd}, passing @var{obj} as an
1406 argument. The function will be called as if by
1408 | operation (abfd, the_section, obj);
1410 It returns the first section for which @var{operation} returns true.
1414 asection *
1415 bfd_sections_find_if (bfd *abfd,
1416 bool (*operation) (bfd *, asection *, void *),
1417 void *user_storage)
1419 asection *sect;
1421 for (sect = abfd->sections; sect != NULL; sect = sect->next)
1422 if ((*operation) (abfd, sect, user_storage))
1423 break;
1425 return sect;
1429 FUNCTION
1430 bfd_set_section_size
1432 SYNOPSIS
1433 bool bfd_set_section_size (asection *sec, bfd_size_type val);
1435 DESCRIPTION
1436 Set @var{sec} to the size @var{val}. If the operation is
1437 ok, then <<TRUE>> is returned, else <<FALSE>>.
1439 Possible error returns:
1440 o <<bfd_error_invalid_operation>> -
1441 Writing has started to the BFD, so setting the size is invalid.
1445 bool
1446 bfd_set_section_size (asection *sec, bfd_size_type val)
1448 /* Once you've started writing to any section you cannot create or change
1449 the size of any others. */
1451 if (sec->owner == NULL || sec->owner->output_has_begun)
1453 bfd_set_error (bfd_error_invalid_operation);
1454 return false;
1457 sec->size = val;
1458 return true;
1462 FUNCTION
1463 bfd_set_section_contents
1465 SYNOPSIS
1466 bool bfd_set_section_contents
1467 (bfd *abfd, asection *section, const void *data,
1468 file_ptr offset, bfd_size_type count);
1470 DESCRIPTION
1471 Sets the contents of the section @var{section} in BFD
1472 @var{abfd} to the data starting in memory at @var{location}.
1473 The data is written to the output section starting at offset
1474 @var{offset} for @var{count} octets.
1476 Normally <<TRUE>> is returned, but <<FALSE>> is returned if
1477 there was an error. Possible error returns are:
1478 o <<bfd_error_no_contents>> -
1479 The output section does not have the <<SEC_HAS_CONTENTS>>
1480 attribute, so nothing can be written to it.
1481 o <<bfd_error_bad_value>> -
1482 The section is unable to contain all of the data.
1483 o <<bfd_error_invalid_operation>> -
1484 The BFD is not writeable.
1485 o and some more too.
1487 This routine is front end to the back end function
1488 <<_bfd_set_section_contents>>.
1492 bool
1493 bfd_set_section_contents (bfd *abfd,
1494 sec_ptr section,
1495 const void *location,
1496 file_ptr offset,
1497 bfd_size_type count)
1499 bfd_size_type sz;
1501 if (!(bfd_section_flags (section) & SEC_HAS_CONTENTS))
1503 bfd_set_error (bfd_error_no_contents);
1504 return false;
1507 sz = section->size;
1508 if ((bfd_size_type) offset > sz
1509 || count > sz - offset
1510 || count != (size_t) count)
1512 bfd_set_error (bfd_error_bad_value);
1513 return false;
1516 if (!bfd_write_p (abfd))
1518 bfd_set_error (bfd_error_invalid_operation);
1519 return false;
1522 /* Record a copy of the data in memory if desired. */
1523 if (section->contents
1524 && location != section->contents + offset)
1525 memcpy (section->contents + offset, location, (size_t) count);
1527 if (BFD_SEND (abfd, _bfd_set_section_contents,
1528 (abfd, section, location, offset, count)))
1530 abfd->output_has_begun = true;
1531 return true;
1534 return false;
1538 FUNCTION
1539 bfd_get_section_contents
1541 SYNOPSIS
1542 bool bfd_get_section_contents
1543 (bfd *abfd, asection *section, void *location, file_ptr offset,
1544 bfd_size_type count);
1546 DESCRIPTION
1547 Read data from @var{section} in BFD @var{abfd}
1548 into memory starting at @var{location}. The data is read at an
1549 offset of @var{offset} from the start of the input section,
1550 and is read for @var{count} bytes.
1552 If the contents of a constructor with the <<SEC_CONSTRUCTOR>>
1553 flag set are requested or if the section does not have the
1554 <<SEC_HAS_CONTENTS>> flag set, then the @var{location} is filled
1555 with zeroes. If no errors occur, <<TRUE>> is returned, else
1556 <<FALSE>>.
1559 bool
1560 bfd_get_section_contents (bfd *abfd,
1561 sec_ptr section,
1562 void *location,
1563 file_ptr offset,
1564 bfd_size_type count)
1566 bfd_size_type sz;
1568 if (section->flags & SEC_CONSTRUCTOR)
1570 memset (location, 0, (size_t) count);
1571 return true;
1574 sz = bfd_get_section_limit_octets (abfd, section);
1575 if ((bfd_size_type) offset > sz
1576 || count > sz - offset
1577 || count != (size_t) count)
1579 bfd_set_error (bfd_error_bad_value);
1580 return false;
1583 if (count == 0)
1584 /* Don't bother. */
1585 return true;
1587 if ((section->flags & SEC_HAS_CONTENTS) == 0)
1589 memset (location, 0, (size_t) count);
1590 return true;
1593 if ((section->flags & SEC_IN_MEMORY) != 0)
1595 if (section->contents == NULL)
1597 /* This can happen because of errors earlier on in the linking process.
1598 We do not want to seg-fault here, so clear the flag and return an
1599 error code. */
1600 section->flags &= ~ SEC_IN_MEMORY;
1601 bfd_set_error (bfd_error_invalid_operation);
1602 return false;
1605 memmove (location, section->contents + offset, (size_t) count);
1606 return true;
1609 return BFD_SEND (abfd, _bfd_get_section_contents,
1610 (abfd, section, location, offset, count));
1614 FUNCTION
1615 bfd_malloc_and_get_section
1617 SYNOPSIS
1618 bool bfd_malloc_and_get_section
1619 (bfd *abfd, asection *section, bfd_byte **buf);
1621 DESCRIPTION
1622 Read all data from @var{section} in BFD @var{abfd}
1623 into a buffer, *@var{buf}, malloc'd by this function.
1624 Return @code{true} on success, @code{false} on failure in which
1625 case *@var{buf} will be NULL.
1628 bool
1629 bfd_malloc_and_get_section (bfd *abfd, sec_ptr sec, bfd_byte **buf)
1631 if (sec->mmapped_p)
1632 abort ();
1633 *buf = NULL;
1634 return bfd_get_full_section_contents (abfd, sec, buf);
1637 FUNCTION
1638 bfd_copy_private_section_data
1640 SYNOPSIS
1641 bool bfd_copy_private_section_data
1642 (bfd *ibfd, asection *isec, bfd *obfd, asection *osec);
1644 DESCRIPTION
1645 Copy private section information from @var{isec} in the BFD
1646 @var{ibfd} to the section @var{osec} in the BFD @var{obfd}.
1647 Return <<TRUE>> on success, <<FALSE>> on error. Possible error
1648 returns are:
1650 o <<bfd_error_no_memory>> -
1651 Not enough memory exists to create private data for @var{osec}.
1653 .#define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \
1654 . BFD_SEND (obfd, _bfd_copy_private_section_data, \
1655 . (ibfd, isection, obfd, osection))
1659 FUNCTION
1660 bfd_generic_is_group_section
1662 SYNOPSIS
1663 bool bfd_generic_is_group_section (bfd *, const asection *sec);
1665 DESCRIPTION
1666 Returns TRUE if @var{sec} is a member of a group.
1669 bool
1670 bfd_generic_is_group_section (bfd *abfd ATTRIBUTE_UNUSED,
1671 const asection *sec ATTRIBUTE_UNUSED)
1673 return false;
1677 FUNCTION
1678 bfd_generic_group_name
1680 SYNOPSIS
1681 const char *bfd_generic_group_name (bfd *, const asection *sec);
1683 DESCRIPTION
1684 Returns group name if @var{sec} is a member of a group.
1687 const char *
1688 bfd_generic_group_name (bfd *abfd ATTRIBUTE_UNUSED,
1689 const asection *sec ATTRIBUTE_UNUSED)
1691 return NULL;
1695 FUNCTION
1696 bfd_generic_discard_group
1698 SYNOPSIS
1699 bool bfd_generic_discard_group (bfd *abfd, asection *group);
1701 DESCRIPTION
1702 Remove all members of @var{group} from the output.
1705 bool
1706 bfd_generic_discard_group (bfd *abfd ATTRIBUTE_UNUSED,
1707 asection *group ATTRIBUTE_UNUSED)
1709 return true;
1712 bool
1713 _bfd_nowrite_set_section_contents (bfd *abfd,
1714 sec_ptr section ATTRIBUTE_UNUSED,
1715 const void *location ATTRIBUTE_UNUSED,
1716 file_ptr offset ATTRIBUTE_UNUSED,
1717 bfd_size_type count ATTRIBUTE_UNUSED)
1719 return _bfd_bool_bfd_false_error (abfd);
1723 FUNCTION
1724 bfd_section_size_insane
1726 SYNOPSIS
1727 bool bfd_section_size_insane (bfd *abfd, asection *sec);
1729 DESCRIPTION
1730 Returns true if the given section has a size that indicates
1731 it cannot be read from file. Return false if the size is OK
1732 *or* this function can't say one way or the other.
1736 bool
1737 bfd_section_size_insane (bfd *abfd, asection *sec)
1739 bfd_size_type size = bfd_get_section_limit_octets (abfd, sec);
1740 if (size == 0)
1741 return false;
1743 if ((bfd_section_flags (sec) & SEC_IN_MEMORY) != 0
1744 /* PR 24753: Linker created sections can be larger than
1745 the file size, eg if they are being used to hold stubs. */
1746 || (bfd_section_flags (sec) & SEC_LINKER_CREATED) != 0
1747 /* PR 24753: Sections which have no content should also be
1748 excluded as they contain no size on disk. */
1749 || (bfd_section_flags (sec) & SEC_HAS_CONTENTS) == 0
1750 /* The MMO file format supports its own special compression
1751 technique, but it uses COMPRESS_SECTION_NONE when loading
1752 a section's contents. */
1753 || bfd_get_flavour (abfd) == bfd_target_mmo_flavour)
1754 return false;
1756 ufile_ptr filesize = bfd_get_file_size (abfd);
1757 if (filesize == 0)
1758 return false;
1760 if (sec->compress_status == DECOMPRESS_SECTION_ZSTD
1761 || sec->compress_status == DECOMPRESS_SECTION_ZLIB)
1763 /* PR26946, PR28834: Sanity check compress header uncompressed
1764 size against the original file size, and check that the
1765 compressed section can be read from file. We choose an
1766 arbitrary uncompressed size of 10x the file size, rather than
1767 a compress ratio. The reason being that compiling
1768 "int aaa..a;" with "a" repeated enough times can result in
1769 compression ratios without limit for .debug_str, whereas such
1770 a file will usually also have the enormous symbol
1771 uncompressed in .symtab. */
1772 if (size / 10 > filesize)
1774 bfd_set_error (bfd_error_bad_value);
1775 return true;
1777 size = sec->compressed_size;
1780 if ((ufile_ptr) sec->filepos > filesize || size > filesize - sec->filepos)
1782 bfd_set_error (bfd_error_file_truncated);
1783 return true;
1785 return false;