1 /* Object file "section" support for the BFD library.
2    Copyright (C) 1990-2020 Free Software Foundation, Inc.
3    Written by Cygnus Support.
4 
5    This file is part of BFD, the Binary File Descriptor library.
6 
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.
11 
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.
16 
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.  */
21 
22 /*
23 SECTION
24 	Sections
25 
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.
30 
31 	Sections are supported in BFD in <<section.c>>.
32 
33 @menu
34 @* Section Input::
35 @* Section Output::
36 @* typedef asection::
37 @* section prototypes::
38 @end menu
39 
40 INODE
41 Section Input, Section Output, Sections, Sections
42 SUBSECTION
43 	Section input
44 
45 	When a BFD is opened for reading, the section structures are
46 	created and attached to the BFD.
47 
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>>.
51 
52 	Names need not be unique; for example a COFF file may have several
53 	sections named <<.data>>.
54 
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.
62 
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.
69 
70 INODE
71 Section Output, typedef asection, Section Input, Sections
72 
73 SUBSECTION
74 	Section output
75 
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>>.
80 
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.)
87 
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.
95 
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:
100 
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  --------|
110 
111 SUBSECTION
112 	Link orders
113 
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.
117 
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.
121 
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.
129 
130 */
131 
132 #include "sysdep.h"
133 #include "bfd.h"
134 #include "libbfd.h"
135 #include "bfdlink.h"
136 
137 /*
138 DOCDD
139 INODE
140 typedef asection, section prototypes, Section Output, Sections
141 SUBSECTION
142 	typedef asection
143 
144 	Here is the section structure:
145 
146 CODE_FRAGMENT
147 .
148 .typedef struct bfd_section
149 .{
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.  *}
152 .  const char *name;
153 .
154 .  {* A unique sequence number.  *}
155 .  unsigned int id;
156 .
157 .  {* Which section in the bfd; 0..n-1 as sections are created in a bfd.  *}
158 .  unsigned int index;
159 .
160 .  {* The next section in the list belonging to the BFD, or NULL.  *}
161 .  struct bfd_section *next;
162 .
163 .  {* The previous section in the list belonging to the BFD, or NULL.  *}
164 .  struct bfd_section *prev;
165 .
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.  *}
169 .  flagword flags;
170 .
171 .#define SEC_NO_FLAGS                      0x0
172 .
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
176 .
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
180 .
181 .  {* The section contains data still to be relocated, so there is
182 .     some relocation information too.  *}
183 .#define SEC_RELOC                         0x4
184 .
185 .  {* A signal to the OS that the section contains read only data.  *}
186 .#define SEC_READONLY                      0x8
187 .
188 .  {* The section contains code only.  *}
189 .#define SEC_CODE                         0x10
190 .
191 .  {* The section contains data only.  *}
192 .#define SEC_DATA                         0x20
193 .
194 .  {* The section will reside in ROM.  *}
195 .#define SEC_ROM                          0x40
196 .
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
206 .     standard data.  *}
207 .#define SEC_CONSTRUCTOR                  0x80
208 .
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
213 .
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
217 .
218 .  {* The section contains thread local data.  *}
219 .#define SEC_THREAD_LOCAL                0x400
220 .
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
225 .
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
232 .
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
236 .     discarded.  *}
237 .#define SEC_DEBUGGING                  0x2000
238 .
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
243 .
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
248 .
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
254 .
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
260 .
261 .  {* If SEC_LINK_ONCE is set, this bitfield describes how the linker
262 .     should handle duplicate sections.  *}
263 .#define SEC_LINK_DUPLICATES           0xc0000
264 .
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
268 .
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
273 .
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
277 .
278 .  {* This value for SEC_LINK_DUPLICATES means that the linker
279 .     should warn if any duplicate sections contain different
280 .     contents.  *}
281 .#define SEC_LINK_DUPLICATES_SAME_CONTENTS \
282 .  (SEC_LINK_DUPLICATES_ONE_ONLY | SEC_LINK_DUPLICATES_SAME_SIZE)
283 .
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
289 .
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
294 .
295 .  {* This section contains "short" data, and should be placed
296 .     "near" the GP.  *}
297 .#define SEC_SMALL_DATA               0x400000
298 .
299 .  {* Attempt to merge identical entities in the section.
300 .     Entity size is given in the entsize field.  *}
301 .#define SEC_MERGE                    0x800000
302 .
303 .  {* If given with SEC_MERGE, entities to merge are zero terminated
304 .     strings where entsize specifies character size instead of fixed
305 .     size entries.  *}
306 .#define SEC_STRINGS                 0x1000000
307 .
308 .  {* This section contains data about section groups.  *}
309 .#define SEC_GROUP                   0x2000000
310 .
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
319 .     sections.  *}
320 .#define SEC_COFF_SHARED_LIBRARY     0x4000000
321 .
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
324 .     only.  *}
325 .#define SEC_ELF_REVERSE_COPY        0x4000000
326 .
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
330 .
331 .  {* This section should be compressed.  This is for ELF linker
332 .     internal use only.  *}
333 .#define SEC_ELF_COMPRESS            0x8000000
334 .
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
341 .
342 .  {* This section should be renamed.  This is for ELF linker
343 .     internal use only.  *}
344 .#define SEC_ELF_RENAME             0x10000000
345 .
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
350 .
351 .  {* This section contains vliw code.  This is for Toshiba MeP only.  *}
352 .#define SEC_MEP_VLIW               0x20000000
353 .
354 .  {* All symbols, sizes and relocations in this section are octets
355 .     instead of bytes.  Required for DWARF debug sections as DWARF
356 .     information is organized in octets, not bytes.  *}
357 .#define SEC_ELF_OCTETS             0x40000000
358 .
359 .  {* Indicate that section has the no read flag set. This happens
360 .     when memory read flag isn't set. *}
361 .#define SEC_COFF_NOREAD            0x40000000
362 .
363 .  {* Indicate that section has the purecode flag set.  *}
364 .#define SEC_ELF_PURECODE           0x80000000
365 .
366 .  {*  End of section flags.  *}
367 .
368 .  {* Some internal packed boolean fields.  *}
369 .
370 .  {* See the vma field.  *}
371 .  unsigned int user_set_vma : 1;
372 .
373 .  {* A mark flag used by some of the linker backends.  *}
374 .  unsigned int linker_mark : 1;
375 .
376 .  {* Another mark flag used by some of the linker backends.  Set for
377 .     output sections that have an input section.  *}
378 .  unsigned int linker_has_input : 1;
379 .
380 .  {* Mark flag used by some linker backends for garbage collection.  *}
381 .  unsigned int gc_mark : 1;
382 .
383 .  {* Section compression status.  *}
384 .  unsigned int compress_status : 2;
385 .#define COMPRESS_SECTION_NONE    0
386 .#define COMPRESS_SECTION_DONE    1
387 .#define DECOMPRESS_SECTION_SIZED 2
388 .
389 .  {* The following flags are used by the ELF linker. *}
390 .
391 .  {* Mark sections which have been allocated to segments.  *}
392 .  unsigned int segment_mark : 1;
393 .
394 .  {* Type of sec_info information.  *}
395 .  unsigned int sec_info_type:3;
396 .#define SEC_INFO_TYPE_NONE      0
397 .#define SEC_INFO_TYPE_STABS     1
398 .#define SEC_INFO_TYPE_MERGE     2
399 .#define SEC_INFO_TYPE_EH_FRAME  3
400 .#define SEC_INFO_TYPE_JUST_SYMS 4
401 .#define SEC_INFO_TYPE_TARGET    5
402 .#define SEC_INFO_TYPE_EH_FRAME_ENTRY 6
403 .
404 .  {* Nonzero if this section uses RELA relocations, rather than REL.  *}
405 .  unsigned int use_rela_p:1;
406 .
407 .  {* Bits used by various backends.  The generic code doesn't touch
408 .     these fields.  *}
409 .
410 .  unsigned int sec_flg0:1;
411 .  unsigned int sec_flg1:1;
412 .  unsigned int sec_flg2:1;
413 .  unsigned int sec_flg3:1;
414 .  unsigned int sec_flg4:1;
415 .  unsigned int sec_flg5:1;
416 .
417 .  {* End of internal packed boolean fields.  *}
418 .
419 .  {*  The virtual memory address of the section - where it will be
420 .      at run time.  The symbols are relocated against this.  The
421 .      user_set_vma flag is maintained by bfd; if it's not set, the
422 .      backend can assign addresses (for example, in <<a.out>>, where
423 .      the default address for <<.data>> is dependent on the specific
424 .      target and various flags).  *}
425 .  bfd_vma vma;
426 .
427 .  {*  The load address of the section - where it would be in a
428 .      rom image; really only used for writing section header
429 .      information.  *}
430 .  bfd_vma lma;
431 .
432 .  {* The size of the section in *octets*, as it will be output.
433 .     Contains a value even if the section has no contents (e.g., the
434 .     size of <<.bss>>).  *}
435 .  bfd_size_type size;
436 .
437 .  {* For input sections, the original size on disk of the section, in
438 .     octets.  This field should be set for any section whose size is
439 .     changed by linker relaxation.  It is required for sections where
440 .     the linker relaxation scheme doesn't cache altered section and
441 .     reloc contents (stabs, eh_frame, SEC_MERGE, some coff relaxing
442 .     targets), and thus the original size needs to be kept to read the
443 .     section multiple times.  For output sections, rawsize holds the
444 .     section size calculated on a previous linker relaxation pass.  *}
445 .  bfd_size_type rawsize;
446 .
447 .  {* The compressed size of the section in octets.  *}
448 .  bfd_size_type compressed_size;
449 .
450 .  {* Relaxation table. *}
451 .  struct relax_table *relax;
452 .
453 .  {* Count of used relaxation table entries. *}
454 .  int relax_count;
455 .
456 .
457 .  {* If this section is going to be output, then this value is the
458 .     offset in *bytes* into the output section of the first byte in the
459 .     input section (byte ==> smallest addressable unit on the
460 .     target).  In most cases, if this was going to start at the
461 .     100th octet (8-bit quantity) in the output section, this value
462 .     would be 100.  However, if the target byte size is 16 bits
463 .     (bfd_octets_per_byte is "2"), this value would be 50.  *}
464 .  bfd_vma output_offset;
465 .
466 .  {* The output section through which to map on output.  *}
467 .  struct bfd_section *output_section;
468 .
469 .  {* The alignment requirement of the section, as an exponent of 2 -
470 .     e.g., 3 aligns to 2^3 (or 8).  *}
471 .  unsigned int alignment_power;
472 .
473 .  {* If an input section, a pointer to a vector of relocation
474 .     records for the data in this section.  *}
475 .  struct reloc_cache_entry *relocation;
476 .
477 .  {* If an output section, a pointer to a vector of pointers to
478 .     relocation records for the data in this section.  *}
479 .  struct reloc_cache_entry **orelocation;
480 .
481 .  {* The number of relocation records in one of the above.  *}
482 .  unsigned reloc_count;
483 .
484 .  {* Information below is back end specific - and not always used
485 .     or updated.  *}
486 .
487 .  {* File position of section data.  *}
488 .  file_ptr filepos;
489 .
490 .  {* File position of relocation info.  *}
491 .  file_ptr rel_filepos;
492 .
493 .  {* File position of line data.  *}
494 .  file_ptr line_filepos;
495 .
496 .  {* Pointer to data for applications.  *}
497 .  void *userdata;
498 .
499 .  {* If the SEC_IN_MEMORY flag is set, this points to the actual
500 .     contents.  *}
501 .  unsigned char *contents;
502 .
503 .  {* Attached line number information.  *}
504 .  alent *lineno;
505 .
506 .  {* Number of line number records.  *}
507 .  unsigned int lineno_count;
508 .
509 .  {* Entity size for merging purposes.  *}
510 .  unsigned int entsize;
511 .
512 .  {* Points to the kept section if this section is a link-once section,
513 .     and is discarded.  *}
514 .  struct bfd_section *kept_section;
515 .
516 .  {* When a section is being output, this value changes as more
517 .     linenumbers are written out.  *}
518 .  file_ptr moving_line_filepos;
519 .
520 .  {* What the section number is in the target world.  *}
521 .  int target_index;
522 .
523 .  void *used_by_bfd;
524 .
525 .  {* If this is a constructor section then here is a list of the
526 .     relocations created to relocate items within it.  *}
527 .  struct relent_chain *constructor_chain;
528 .
529 .  {* The BFD which owns the section.  *}
530 .  bfd *owner;
531 .
532 .  {* A symbol which points at this section only.  *}
533 .  struct bfd_symbol *symbol;
534 .  struct bfd_symbol **symbol_ptr_ptr;
535 .
536 .  {* Early in the link process, map_head and map_tail are used to build
537 .     a list of input sections attached to an output section.  Later,
538 .     output sections use these fields for a list of bfd_link_order
539 .     structs.  *}
540 .  union {
541 .    struct bfd_link_order *link_order;
542 .    struct bfd_section *s;
543 .  } map_head, map_tail;
544 .} asection;
545 .
546 .{* Relax table contains information about instructions which can
547 .   be removed by relaxation -- replacing a long address with a
548 .   short address.  *}
549 .struct relax_table {
550 .  {* Address where bytes may be deleted. *}
551 .  bfd_vma addr;
552 .
553 .  {* Number of bytes to be deleted.  *}
554 .  int size;
555 .};
556 .
557 .static inline const char *
558 .bfd_section_name (const asection *sec)
559 .{
560 .  return sec->name;
561 .}
562 .
563 .static inline bfd_size_type
564 .bfd_section_size (const asection *sec)
565 .{
566 .  return sec->size;
567 .}
568 .
569 .static inline bfd_vma
570 .bfd_section_vma (const asection *sec)
571 .{
572 .  return sec->vma;
573 .}
574 .
575 .static inline bfd_vma
576 .bfd_section_lma (const asection *sec)
577 .{
578 .  return sec->lma;
579 .}
580 .
581 .static inline unsigned int
582 .bfd_section_alignment (const asection *sec)
583 .{
584 .  return sec->alignment_power;
585 .}
586 .
587 .static inline flagword
588 .bfd_section_flags (const asection *sec)
589 .{
590 .  return sec->flags;
591 .}
592 .
593 .static inline void *
594 .bfd_section_userdata (const asection *sec)
595 .{
596 .  return sec->userdata;
597 .}
598 .static inline bfd_boolean
599 .bfd_is_com_section (const asection *sec)
600 .{
601 .  return (sec->flags & SEC_IS_COMMON) != 0;
602 .}
603 .
604 .{* Note: the following are provided as inline functions rather than macros
605 .   because not all callers use the return value.  A macro implementation
606 .   would use a comma expression, eg: "((ptr)->foo = val, TRUE)" and some
607 .   compilers will complain about comma expressions that have no effect.  *}
608 .static inline bfd_boolean
609 .bfd_set_section_userdata (asection *sec, void *val)
610 .{
611 .  sec->userdata = val;
612 .  return TRUE;
613 .}
614 .
615 .static inline bfd_boolean
616 .bfd_set_section_vma (asection *sec, bfd_vma val)
617 .{
618 .  sec->vma = sec->lma = val;
619 .  sec->user_set_vma = TRUE;
620 .  return TRUE;
621 .}
622 .
623 .static inline bfd_boolean
624 .bfd_set_section_lma (asection *sec, bfd_vma val)
625 .{
626 .  sec->lma = val;
627 .  return TRUE;
628 .}
629 .
630 .static inline bfd_boolean
631 .bfd_set_section_alignment (asection *sec, unsigned int val)
632 .{
633 .  sec->alignment_power = val;
634 .  return TRUE;
635 .}
636 .
637 .{* These sections are global, and are managed by BFD.  The application
638 .   and target back end are not permitted to change the values in
639 .   these sections.  *}
640 .extern asection _bfd_std_section[4];
641 .
642 .#define BFD_ABS_SECTION_NAME "*ABS*"
643 .#define BFD_UND_SECTION_NAME "*UND*"
644 .#define BFD_COM_SECTION_NAME "*COM*"
645 .#define BFD_IND_SECTION_NAME "*IND*"
646 .
647 .{* Pointer to the common section.  *}
648 .#define bfd_com_section_ptr (&_bfd_std_section[0])
649 .{* Pointer to the undefined section.  *}
650 .#define bfd_und_section_ptr (&_bfd_std_section[1])
651 .{* Pointer to the absolute section.  *}
652 .#define bfd_abs_section_ptr (&_bfd_std_section[2])
653 .{* Pointer to the indirect section.  *}
654 .#define bfd_ind_section_ptr (&_bfd_std_section[3])
655 .
656 .static inline bfd_boolean
657 .bfd_is_und_section (const asection *sec)
658 .{
659 .  return sec == bfd_und_section_ptr;
660 .}
661 .
662 .static inline bfd_boolean
663 .bfd_is_abs_section (const asection *sec)
664 .{
665 .  return sec == bfd_abs_section_ptr;
666 .}
667 .
668 .static inline bfd_boolean
669 .bfd_is_ind_section (const asection *sec)
670 .{
671 .  return sec == bfd_ind_section_ptr;
672 .}
673 .
674 .static inline bfd_boolean
675 .bfd_is_const_section (const asection *sec)
676 .{
677 .  return sec >= bfd_abs_section_ptr && sec <= bfd_ind_section_ptr;
678 .}
679 .
680 .{* Return TRUE if input section SEC has been discarded.  *}
681 .static inline bfd_boolean
682 .discarded_section (const asection *sec)
683 .{
684 .  return (!bfd_is_abs_section (sec)
685 .          && bfd_is_abs_section (sec->output_section)
686 .          && sec->sec_info_type != SEC_INFO_TYPE_MERGE
687 .          && sec->sec_info_type != SEC_INFO_TYPE_JUST_SYMS);
688 .}
689 .
690 .#define BFD_FAKE_SECTION(SEC, SYM, NAME, IDX, FLAGS)			\
691 .  {* name, id,  index, next, prev, flags, user_set_vma,            *}	\
692 .  {  NAME, IDX, 0,     NULL, NULL, FLAGS, 0,				\
693 .									\
694 .  {* linker_mark, linker_has_input, gc_mark, decompress_status,    *}	\
695 .     0,           0,                1,       0,			\
696 .									\
697 .  {* segment_mark, sec_info_type, use_rela_p,                      *}	\
698 .     0,            0,             0,					\
699 .									\
700 .  {* sec_flg0, sec_flg1, sec_flg2, sec_flg3, sec_flg4, sec_flg5,   *}	\
701 .     0,        0,        0,        0,        0,        0,		\
702 .									\
703 .  {* vma, lma, size, rawsize, compressed_size, relax, relax_count, *}	\
704 .     0,   0,   0,    0,       0,               0,     0,		\
705 .									\
706 .  {* output_offset, output_section, alignment_power,               *}	\
707 .     0,             &SEC,           0,					\
708 .									\
709 .  {* relocation, orelocation, reloc_count, filepos, rel_filepos,   *}	\
710 .     NULL,       NULL,        0,           0,       0,			\
711 .									\
712 .  {* line_filepos, userdata, contents, lineno, lineno_count,       *}	\
713 .     0,            NULL,     NULL,     NULL,   0,			\
714 .									\
715 .  {* entsize, kept_section, moving_line_filepos,		     *}	\
716 .     0,       NULL,	      0,					\
717 .									\
718 .  {* target_index, used_by_bfd, constructor_chain, owner,          *}	\
719 .     0,            NULL,        NULL,              NULL,		\
720 .									\
721 .  {* symbol,                    symbol_ptr_ptr,                    *}	\
722 .     (struct bfd_symbol *) SYM, &SEC.symbol,				\
723 .									\
724 .  {* map_head, map_tail                                            *}	\
725 .     { NULL }, { NULL }						\
726 .    }
727 .
728 .{* We use a macro to initialize the static asymbol structures because
729 .   traditional C does not permit us to initialize a union member while
730 .   gcc warns if we don't initialize it.
731 .   the_bfd, name, value, attr, section [, udata]  *}
732 .#ifdef __STDC__
733 .#define GLOBAL_SYM_INIT(NAME, SECTION) \
734 .  { 0, NAME, 0, BSF_SECTION_SYM, SECTION, { 0 }}
735 .#else
736 .#define GLOBAL_SYM_INIT(NAME, SECTION) \
737 .  { 0, NAME, 0, BSF_SECTION_SYM, SECTION }
738 .#endif
739 .
740 */
741 
742 /* These symbols are global, not specific to any BFD.  Therefore, anything
743    that tries to change them is broken, and should be repaired.  */
744 
745 static const asymbol global_syms[] =
746 {
747   GLOBAL_SYM_INIT (BFD_COM_SECTION_NAME, bfd_com_section_ptr),
748   GLOBAL_SYM_INIT (BFD_UND_SECTION_NAME, bfd_und_section_ptr),
749   GLOBAL_SYM_INIT (BFD_ABS_SECTION_NAME, bfd_abs_section_ptr),
750   GLOBAL_SYM_INIT (BFD_IND_SECTION_NAME, bfd_ind_section_ptr)
751 };
752 
753 #define STD_SECTION(NAME, IDX, FLAGS) \
754   BFD_FAKE_SECTION(_bfd_std_section[IDX], &global_syms[IDX], NAME, IDX, FLAGS)
755 
756 asection _bfd_std_section[] = {
757   STD_SECTION (BFD_COM_SECTION_NAME, 0, SEC_IS_COMMON),
758   STD_SECTION (BFD_UND_SECTION_NAME, 1, 0),
759   STD_SECTION (BFD_ABS_SECTION_NAME, 2, 0),
760   STD_SECTION (BFD_IND_SECTION_NAME, 3, 0)
761 };
762 #undef STD_SECTION
763 
764 /* Initialize an entry in the section hash table.  */
765 
766 struct bfd_hash_entry *
767 bfd_section_hash_newfunc (struct bfd_hash_entry *entry,
768 			  struct bfd_hash_table *table,
769 			  const char *string)
770 {
771   /* Allocate the structure if it has not already been allocated by a
772      subclass.  */
773   if (entry == NULL)
774     {
775       entry = (struct bfd_hash_entry *)
776 	bfd_hash_allocate (table, sizeof (struct section_hash_entry));
777       if (entry == NULL)
778 	return entry;
779     }
780 
781   /* Call the allocation method of the superclass.  */
782   entry = bfd_hash_newfunc (entry, table, string);
783   if (entry != NULL)
784     memset (&((struct section_hash_entry *) entry)->section, 0,
785 	    sizeof (asection));
786 
787   return entry;
788 }
789 
790 #define section_hash_lookup(table, string, create, copy) \
791   ((struct section_hash_entry *) \
792    bfd_hash_lookup ((table), (string), (create), (copy)))
793 
794 /* Create a symbol whose only job is to point to this section.  This
795    is useful for things like relocs which are relative to the base
796    of a section.  */
797 
798 bfd_boolean
799 _bfd_generic_new_section_hook (bfd *abfd, asection *newsect)
800 {
801   newsect->symbol = bfd_make_empty_symbol (abfd);
802   if (newsect->symbol == NULL)
803     return FALSE;
804 
805   newsect->symbol->name = newsect->name;
806   newsect->symbol->value = 0;
807   newsect->symbol->section = newsect;
808   newsect->symbol->flags = BSF_SECTION_SYM;
809 
810   newsect->symbol_ptr_ptr = &newsect->symbol;
811   return TRUE;
812 }
813 
814 unsigned int _bfd_section_id = 0x10;  /* id 0 to 3 used by STD_SECTION.  */
815 
816 /* Initializes a new section.  NEWSECT->NAME is already set.  */
817 
818 static asection *
819 bfd_section_init (bfd *abfd, asection *newsect)
820 {
821   newsect->id = _bfd_section_id;
822   newsect->index = abfd->section_count;
823   newsect->owner = abfd;
824 
825   if (! BFD_SEND (abfd, _new_section_hook, (abfd, newsect)))
826     return NULL;
827 
828   _bfd_section_id++;
829   abfd->section_count++;
830   bfd_section_list_append (abfd, newsect);
831   return newsect;
832 }
833 
834 /*
835 DOCDD
836 INODE
837 section prototypes,  , typedef asection, Sections
838 SUBSECTION
839 	Section prototypes
840 
841 These are the functions exported by the section handling part of BFD.
842 */
843 
844 /*
845 FUNCTION
846 	bfd_section_list_clear
847 
848 SYNOPSIS
849 	void bfd_section_list_clear (bfd *);
850 
851 DESCRIPTION
852 	Clears the section list, and also resets the section count and
853 	hash table entries.
854 */
855 
856 void
857 bfd_section_list_clear (bfd *abfd)
858 {
859   abfd->sections = NULL;
860   abfd->section_last = NULL;
861   abfd->section_count = 0;
862   memset (abfd->section_htab.table, 0,
863 	  abfd->section_htab.size * sizeof (struct bfd_hash_entry *));
864   abfd->section_htab.count = 0;
865 }
866 
867 /*
868 FUNCTION
869 	bfd_get_section_by_name
870 
871 SYNOPSIS
872 	asection *bfd_get_section_by_name (bfd *abfd, const char *name);
873 
874 DESCRIPTION
875 	Return the most recently created section attached to @var{abfd}
876 	named @var{name}.  Return NULL if no such section exists.
877 */
878 
879 asection *
880 bfd_get_section_by_name (bfd *abfd, const char *name)
881 {
882   struct section_hash_entry *sh;
883 
884   sh = section_hash_lookup (&abfd->section_htab, name, FALSE, FALSE);
885   if (sh != NULL)
886     return &sh->section;
887 
888   return NULL;
889 }
890 
891 /*
892 FUNCTION
893        bfd_get_next_section_by_name
894 
895 SYNOPSIS
896        asection *bfd_get_next_section_by_name (bfd *ibfd, asection *sec);
897 
898 DESCRIPTION
899        Given @var{sec} is a section returned by @code{bfd_get_section_by_name},
900        return the next most recently created section attached to the same
901        BFD with the same name, or if no such section exists in the same BFD and
902        IBFD is non-NULL, the next section with the same name in any input
903        BFD following IBFD.  Return NULL on finding no section.
904 */
905 
906 asection *
907 bfd_get_next_section_by_name (bfd *ibfd, asection *sec)
908 {
909   struct section_hash_entry *sh;
910   const char *name;
911   unsigned long hash;
912 
913   sh = ((struct section_hash_entry *)
914 	((char *) sec - offsetof (struct section_hash_entry, section)));
915 
916   hash = sh->root.hash;
917   name = sec->name;
918   for (sh = (struct section_hash_entry *) sh->root.next;
919        sh != NULL;
920        sh = (struct section_hash_entry *) sh->root.next)
921     if (sh->root.hash == hash
922        && strcmp (sh->root.string, name) == 0)
923       return &sh->section;
924 
925   if (ibfd != NULL)
926     {
927       while ((ibfd = ibfd->link.next) != NULL)
928 	{
929 	  asection *s = bfd_get_section_by_name (ibfd, name);
930 	  if (s != NULL)
931 	    return s;
932 	}
933     }
934 
935   return NULL;
936 }
937 
938 /*
939 FUNCTION
940 	bfd_get_linker_section
941 
942 SYNOPSIS
943 	asection *bfd_get_linker_section (bfd *abfd, const char *name);
944 
945 DESCRIPTION
946 	Return the linker created section attached to @var{abfd}
947 	named @var{name}.  Return NULL if no such section exists.
948 */
949 
950 asection *
951 bfd_get_linker_section (bfd *abfd, const char *name)
952 {
953   asection *sec = bfd_get_section_by_name (abfd, name);
954 
955   while (sec != NULL && (sec->flags & SEC_LINKER_CREATED) == 0)
956     sec = bfd_get_next_section_by_name (NULL, sec);
957   return sec;
958 }
959 
960 /*
961 FUNCTION
962 	bfd_get_section_by_name_if
963 
964 SYNOPSIS
965 	asection *bfd_get_section_by_name_if
966 	  (bfd *abfd,
967 	   const char *name,
968 	   bfd_boolean (*func) (bfd *abfd, asection *sect, void *obj),
969 	   void *obj);
970 
971 DESCRIPTION
972 	Call the provided function @var{func} for each section
973 	attached to the BFD @var{abfd} whose name matches @var{name},
974 	passing @var{obj} as an argument. The function will be called
975 	as if by
976 
977 |	func (abfd, the_section, obj);
978 
979 	It returns the first section for which @var{func} returns true,
980 	otherwise <<NULL>>.
981 
982 */
983 
984 asection *
985 bfd_get_section_by_name_if (bfd *abfd, const char *name,
986 			    bfd_boolean (*operation) (bfd *,
987 						      asection *,
988 						      void *),
989 			    void *user_storage)
990 {
991   struct section_hash_entry *sh;
992   unsigned long hash;
993 
994   sh = section_hash_lookup (&abfd->section_htab, name, FALSE, FALSE);
995   if (sh == NULL)
996     return NULL;
997 
998   hash = sh->root.hash;
999   for (; sh != NULL; sh = (struct section_hash_entry *) sh->root.next)
1000     if (sh->root.hash == hash
1001 	&& strcmp (sh->root.string, name) == 0
1002 	&& (*operation) (abfd, &sh->section, user_storage))
1003       return &sh->section;
1004 
1005   return NULL;
1006 }
1007 
1008 /*
1009 FUNCTION
1010 	bfd_get_unique_section_name
1011 
1012 SYNOPSIS
1013 	char *bfd_get_unique_section_name
1014 	  (bfd *abfd, const char *templat, int *count);
1015 
1016 DESCRIPTION
1017 	Invent a section name that is unique in @var{abfd} by tacking
1018 	a dot and a digit suffix onto the original @var{templat}.  If
1019 	@var{count} is non-NULL, then it specifies the first number
1020 	tried as a suffix to generate a unique name.  The value
1021 	pointed to by @var{count} will be incremented in this case.
1022 */
1023 
1024 char *
1025 bfd_get_unique_section_name (bfd *abfd, const char *templat, int *count)
1026 {
1027   int num;
1028   unsigned int len;
1029   char *sname;
1030 
1031   len = strlen (templat);
1032   sname = (char *) bfd_malloc (len + 8);
1033   if (sname == NULL)
1034     return NULL;
1035   memcpy (sname, templat, len);
1036   num = 1;
1037   if (count != NULL)
1038     num = *count;
1039 
1040   do
1041     {
1042       /* If we have a million sections, something is badly wrong.  */
1043       if (num > 999999)
1044 	abort ();
1045       sprintf (sname + len, ".%d", num++);
1046     }
1047   while (section_hash_lookup (&abfd->section_htab, sname, FALSE, FALSE));
1048 
1049   if (count != NULL)
1050     *count = num;
1051   return sname;
1052 }
1053 
1054 /*
1055 FUNCTION
1056 	bfd_make_section_old_way
1057 
1058 SYNOPSIS
1059 	asection *bfd_make_section_old_way (bfd *abfd, const char *name);
1060 
1061 DESCRIPTION
1062 	Create a new empty section called @var{name}
1063 	and attach it to the end of the chain of sections for the
1064 	BFD @var{abfd}. An attempt to create a section with a name which
1065 	is already in use returns its pointer without changing the
1066 	section chain.
1067 
1068 	It has the funny name since this is the way it used to be
1069 	before it was rewritten....
1070 
1071 	Possible errors are:
1072 	o <<bfd_error_invalid_operation>> -
1073 	If output has already started for this BFD.
1074 	o <<bfd_error_no_memory>> -
1075 	If memory allocation fails.
1076 
1077 */
1078 
1079 asection *
1080 bfd_make_section_old_way (bfd *abfd, const char *name)
1081 {
1082   asection *newsect;
1083 
1084   if (abfd->output_has_begun)
1085     {
1086       bfd_set_error (bfd_error_invalid_operation);
1087       return NULL;
1088     }
1089 
1090   if (strcmp (name, BFD_ABS_SECTION_NAME) == 0)
1091     newsect = bfd_abs_section_ptr;
1092   else if (strcmp (name, BFD_COM_SECTION_NAME) == 0)
1093     newsect = bfd_com_section_ptr;
1094   else if (strcmp (name, BFD_UND_SECTION_NAME) == 0)
1095     newsect = bfd_und_section_ptr;
1096   else if (strcmp (name, BFD_IND_SECTION_NAME) == 0)
1097     newsect = bfd_ind_section_ptr;
1098   else
1099     {
1100       struct section_hash_entry *sh;
1101 
1102       sh = section_hash_lookup (&abfd->section_htab, name, TRUE, FALSE);
1103       if (sh == NULL)
1104 	return NULL;
1105 
1106       newsect = &sh->section;
1107       if (newsect->name != NULL)
1108 	{
1109 	  /* Section already exists.  */
1110 	  return newsect;
1111 	}
1112 
1113       newsect->name = name;
1114       return bfd_section_init (abfd, newsect);
1115     }
1116 
1117   /* Call new_section_hook when "creating" the standard abs, com, und
1118      and ind sections to tack on format specific section data.
1119      Also, create a proper section symbol.  */
1120   if (! BFD_SEND (abfd, _new_section_hook, (abfd, newsect)))
1121     return NULL;
1122   return newsect;
1123 }
1124 
1125 /*
1126 FUNCTION
1127 	bfd_make_section_anyway_with_flags
1128 
1129 SYNOPSIS
1130 	asection *bfd_make_section_anyway_with_flags
1131 	  (bfd *abfd, const char *name, flagword flags);
1132 
1133 DESCRIPTION
1134    Create a new empty section called @var{name} and attach it to the end of
1135    the chain of sections for @var{abfd}.  Create a new section even if there
1136    is already a section with that name.  Also set the attributes of the
1137    new section to the value @var{flags}.
1138 
1139    Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1140    o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1141    o <<bfd_error_no_memory>> - If memory allocation fails.
1142 */
1143 
1144 sec_ptr
1145 bfd_make_section_anyway_with_flags (bfd *abfd, const char *name,
1146 				    flagword flags)
1147 {
1148   struct section_hash_entry *sh;
1149   asection *newsect;
1150 
1151   if (abfd->output_has_begun)
1152     {
1153       bfd_set_error (bfd_error_invalid_operation);
1154       return NULL;
1155     }
1156 
1157   sh = section_hash_lookup (&abfd->section_htab, name, TRUE, FALSE);
1158   if (sh == NULL)
1159     return NULL;
1160 
1161   newsect = &sh->section;
1162   if (newsect->name != NULL)
1163     {
1164       /* We are making a section of the same name.  Put it in the
1165 	 section hash table.  Even though we can't find it directly by a
1166 	 hash lookup, we'll be able to find the section by traversing
1167 	 sh->root.next quicker than looking at all the bfd sections.  */
1168       struct section_hash_entry *new_sh;
1169       new_sh = (struct section_hash_entry *)
1170 	bfd_section_hash_newfunc (NULL, &abfd->section_htab, name);
1171       if (new_sh == NULL)
1172 	return NULL;
1173 
1174       new_sh->root = sh->root;
1175       sh->root.next = &new_sh->root;
1176       newsect = &new_sh->section;
1177     }
1178 
1179   newsect->flags = flags;
1180   newsect->name = name;
1181   return bfd_section_init (abfd, newsect);
1182 }
1183 
1184 /*
1185 FUNCTION
1186 	bfd_make_section_anyway
1187 
1188 SYNOPSIS
1189 	asection *bfd_make_section_anyway (bfd *abfd, const char *name);
1190 
1191 DESCRIPTION
1192    Create a new empty section called @var{name} and attach it to the end of
1193    the chain of sections for @var{abfd}.  Create a new section even if there
1194    is already a section with that name.
1195 
1196    Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1197    o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1198    o <<bfd_error_no_memory>> - If memory allocation fails.
1199 */
1200 
1201 sec_ptr
1202 bfd_make_section_anyway (bfd *abfd, const char *name)
1203 {
1204   return bfd_make_section_anyway_with_flags (abfd, name, 0);
1205 }
1206 
1207 /*
1208 FUNCTION
1209 	bfd_make_section_with_flags
1210 
1211 SYNOPSIS
1212 	asection *bfd_make_section_with_flags
1213 	  (bfd *, const char *name, flagword flags);
1214 
1215 DESCRIPTION
1216    Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1217    bfd_set_error ()) without changing the section chain if there is already a
1218    section named @var{name}.  Also set the attributes of the new section to
1219    the value @var{flags}.  If there is an error, return <<NULL>> and set
1220    <<bfd_error>>.
1221 */
1222 
1223 asection *
1224 bfd_make_section_with_flags (bfd *abfd, const char *name,
1225 			     flagword flags)
1226 {
1227   struct section_hash_entry *sh;
1228   asection *newsect;
1229 
1230   if (abfd == NULL || name == NULL || abfd->output_has_begun)
1231     {
1232       bfd_set_error (bfd_error_invalid_operation);
1233       return NULL;
1234     }
1235 
1236   if (strcmp (name, BFD_ABS_SECTION_NAME) == 0
1237       || strcmp (name, BFD_COM_SECTION_NAME) == 0
1238       || strcmp (name, BFD_UND_SECTION_NAME) == 0
1239       || strcmp (name, BFD_IND_SECTION_NAME) == 0)
1240     return NULL;
1241 
1242   sh = section_hash_lookup (&abfd->section_htab, name, TRUE, FALSE);
1243   if (sh == NULL)
1244     return NULL;
1245 
1246   newsect = &sh->section;
1247   if (newsect->name != NULL)
1248     {
1249       /* Section already exists.  */
1250       return NULL;
1251     }
1252 
1253   newsect->name = name;
1254   newsect->flags = flags;
1255   return bfd_section_init (abfd, newsect);
1256 }
1257 
1258 /*
1259 FUNCTION
1260 	bfd_make_section
1261 
1262 SYNOPSIS
1263 	asection *bfd_make_section (bfd *, const char *name);
1264 
1265 DESCRIPTION
1266    Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1267    bfd_set_error ()) without changing the section chain if there is already a
1268    section named @var{name}.  If there is an error, return <<NULL>> and set
1269    <<bfd_error>>.
1270 */
1271 
1272 asection *
1273 bfd_make_section (bfd *abfd, const char *name)
1274 {
1275   return bfd_make_section_with_flags (abfd, name, 0);
1276 }
1277 
1278 /*
1279 FUNCTION
1280 	bfd_set_section_flags
1281 
1282 SYNOPSIS
1283 	bfd_boolean bfd_set_section_flags (asection *sec, flagword flags);
1284 
1285 DESCRIPTION
1286 	Set the attributes of the section @var{sec} to the value @var{flags}.
1287 	Return <<TRUE>> on success, <<FALSE>> on error.  Possible error
1288 	returns are:
1289 
1290 	o <<bfd_error_invalid_operation>> -
1291 	The section cannot have one or more of the attributes
1292 	requested. For example, a .bss section in <<a.out>> may not
1293 	have the <<SEC_HAS_CONTENTS>> field set.
1294 
1295 */
1296 
1297 bfd_boolean
1298 bfd_set_section_flags (asection *section, flagword flags)
1299 {
1300   section->flags = flags;
1301   return TRUE;
1302 }
1303 
1304 /*
1305 FUNCTION
1306 	bfd_rename_section
1307 
1308 SYNOPSIS
1309 	void bfd_rename_section
1310 	  (asection *sec, const char *newname);
1311 
1312 DESCRIPTION
1313 	Rename section @var{sec} to @var{newname}.
1314 */
1315 
1316 void
1317 bfd_rename_section (asection *sec, const char *newname)
1318 {
1319   struct section_hash_entry *sh;
1320 
1321   sh = (struct section_hash_entry *)
1322     ((char *) sec - offsetof (struct section_hash_entry, section));
1323   sh->section.name = newname;
1324   bfd_hash_rename (&sec->owner->section_htab, newname, &sh->root);
1325 }
1326 
1327 /*
1328 FUNCTION
1329 	bfd_map_over_sections
1330 
1331 SYNOPSIS
1332 	void bfd_map_over_sections
1333 	  (bfd *abfd,
1334 	   void (*func) (bfd *abfd, asection *sect, void *obj),
1335 	   void *obj);
1336 
1337 DESCRIPTION
1338 	Call the provided function @var{func} for each section
1339 	attached to the BFD @var{abfd}, passing @var{obj} as an
1340 	argument. The function will be called as if by
1341 
1342 |	func (abfd, the_section, obj);
1343 
1344 	This is the preferred method for iterating over sections; an
1345 	alternative would be to use a loop:
1346 
1347 |	   asection *p;
1348 |	   for (p = abfd->sections; p != NULL; p = p->next)
1349 |	      func (abfd, p, ...)
1350 
1351 */
1352 
1353 void
1354 bfd_map_over_sections (bfd *abfd,
1355 		       void (*operation) (bfd *, asection *, void *),
1356 		       void *user_storage)
1357 {
1358   asection *sect;
1359   unsigned int i = 0;
1360 
1361   for (sect = abfd->sections; sect != NULL; i++, sect = sect->next)
1362     (*operation) (abfd, sect, user_storage);
1363 
1364   if (i != abfd->section_count)	/* Debugging */
1365     abort ();
1366 }
1367 
1368 /*
1369 FUNCTION
1370 	bfd_sections_find_if
1371 
1372 SYNOPSIS
1373 	asection *bfd_sections_find_if
1374 	  (bfd *abfd,
1375 	   bfd_boolean (*operation) (bfd *abfd, asection *sect, void *obj),
1376 	   void *obj);
1377 
1378 DESCRIPTION
1379 	Call the provided function @var{operation} for each section
1380 	attached to the BFD @var{abfd}, passing @var{obj} as an
1381 	argument. The function will be called as if by
1382 
1383 |	operation (abfd, the_section, obj);
1384 
1385 	It returns the first section for which @var{operation} returns true.
1386 
1387 */
1388 
1389 asection *
1390 bfd_sections_find_if (bfd *abfd,
1391 		      bfd_boolean (*operation) (bfd *, asection *, void *),
1392 		      void *user_storage)
1393 {
1394   asection *sect;
1395 
1396   for (sect = abfd->sections; sect != NULL; sect = sect->next)
1397     if ((*operation) (abfd, sect, user_storage))
1398       break;
1399 
1400   return sect;
1401 }
1402 
1403 /*
1404 FUNCTION
1405 	bfd_set_section_size
1406 
1407 SYNOPSIS
1408 	bfd_boolean bfd_set_section_size (asection *sec, bfd_size_type val);
1409 
1410 DESCRIPTION
1411 	Set @var{sec} to the size @var{val}. If the operation is
1412 	ok, then <<TRUE>> is returned, else <<FALSE>>.
1413 
1414 	Possible error returns:
1415 	o <<bfd_error_invalid_operation>> -
1416 	Writing has started to the BFD, so setting the size is invalid.
1417 
1418 */
1419 
1420 bfd_boolean
1421 bfd_set_section_size (asection *sec, bfd_size_type val)
1422 {
1423   /* Once you've started writing to any section you cannot create or change
1424      the size of any others.  */
1425 
1426   if (sec->owner == NULL || sec->owner->output_has_begun)
1427     {
1428       bfd_set_error (bfd_error_invalid_operation);
1429       return FALSE;
1430     }
1431 
1432   sec->size = val;
1433   return TRUE;
1434 }
1435 
1436 /*
1437 FUNCTION
1438 	bfd_set_section_contents
1439 
1440 SYNOPSIS
1441 	bfd_boolean bfd_set_section_contents
1442 	  (bfd *abfd, asection *section, const void *data,
1443 	   file_ptr offset, bfd_size_type count);
1444 
1445 DESCRIPTION
1446 	Sets the contents of the section @var{section} in BFD
1447 	@var{abfd} to the data starting in memory at @var{location}.
1448 	The data is written to the output section starting at offset
1449 	@var{offset} for @var{count} octets.
1450 
1451 	Normally <<TRUE>> is returned, but <<FALSE>> is returned if
1452 	there was an error.  Possible error returns are:
1453 	o <<bfd_error_no_contents>> -
1454 	The output section does not have the <<SEC_HAS_CONTENTS>>
1455 	attribute, so nothing can be written to it.
1456 	o <<bfd_error_bad_value>> -
1457 	The section is unable to contain all of the data.
1458 	o <<bfd_error_invalid_operation>> -
1459 	The BFD is not writeable.
1460 	o and some more too.
1461 
1462 	This routine is front end to the back end function
1463 	<<_bfd_set_section_contents>>.
1464 
1465 */
1466 
1467 bfd_boolean
1468 bfd_set_section_contents (bfd *abfd,
1469 			  sec_ptr section,
1470 			  const void *location,
1471 			  file_ptr offset,
1472 			  bfd_size_type count)
1473 {
1474   bfd_size_type sz;
1475 
1476   if (!(bfd_section_flags (section) & SEC_HAS_CONTENTS))
1477     {
1478       bfd_set_error (bfd_error_no_contents);
1479       return FALSE;
1480     }
1481 
1482   sz = section->size;
1483   if ((bfd_size_type) offset > sz
1484       || count > sz
1485       || offset + count > sz
1486       || count != (size_t) count)
1487     {
1488       bfd_set_error (bfd_error_bad_value);
1489       return FALSE;
1490     }
1491 
1492   if (!bfd_write_p (abfd))
1493     {
1494       bfd_set_error (bfd_error_invalid_operation);
1495       return FALSE;
1496     }
1497 
1498   /* Record a copy of the data in memory if desired.  */
1499   if (section->contents
1500       && location != section->contents + offset)
1501     memcpy (section->contents + offset, location, (size_t) count);
1502 
1503   if (BFD_SEND (abfd, _bfd_set_section_contents,
1504 		(abfd, section, location, offset, count)))
1505     {
1506       abfd->output_has_begun = TRUE;
1507       return TRUE;
1508     }
1509 
1510   return FALSE;
1511 }
1512 
1513 /*
1514 FUNCTION
1515 	bfd_get_section_contents
1516 
1517 SYNOPSIS
1518 	bfd_boolean bfd_get_section_contents
1519 	  (bfd *abfd, asection *section, void *location, file_ptr offset,
1520 	   bfd_size_type count);
1521 
1522 DESCRIPTION
1523 	Read data from @var{section} in BFD @var{abfd}
1524 	into memory starting at @var{location}. The data is read at an
1525 	offset of @var{offset} from the start of the input section,
1526 	and is read for @var{count} bytes.
1527 
1528 	If the contents of a constructor with the <<SEC_CONSTRUCTOR>>
1529 	flag set are requested or if the section does not have the
1530 	<<SEC_HAS_CONTENTS>> flag set, then the @var{location} is filled
1531 	with zeroes. If no errors occur, <<TRUE>> is returned, else
1532 	<<FALSE>>.
1533 
1534 */
1535 bfd_boolean
1536 bfd_get_section_contents (bfd *abfd,
1537 			  sec_ptr section,
1538 			  void *location,
1539 			  file_ptr offset,
1540 			  bfd_size_type count)
1541 {
1542   bfd_size_type sz;
1543 
1544   if (section->flags & SEC_CONSTRUCTOR)
1545     {
1546       memset (location, 0, (size_t) count);
1547       return TRUE;
1548     }
1549 
1550   if (abfd->direction != write_direction && section->rawsize != 0)
1551     sz = section->rawsize;
1552   else
1553     sz = section->size;
1554   if ((bfd_size_type) offset > sz
1555       || count > sz
1556       || offset + count > sz
1557       || count != (size_t) count)
1558     {
1559       bfd_set_error (bfd_error_bad_value);
1560       return FALSE;
1561     }
1562 
1563   if (count == 0)
1564     /* Don't bother.  */
1565     return TRUE;
1566 
1567   if ((section->flags & SEC_HAS_CONTENTS) == 0)
1568     {
1569       memset (location, 0, (size_t) count);
1570       return TRUE;
1571     }
1572 
1573   if ((section->flags & SEC_IN_MEMORY) != 0)
1574     {
1575       if (section->contents == NULL)
1576 	{
1577 	  /* This can happen because of errors earlier on in the linking process.
1578 	     We do not want to seg-fault here, so clear the flag and return an
1579 	     error code.  */
1580 	  section->flags &= ~ SEC_IN_MEMORY;
1581 	  bfd_set_error (bfd_error_invalid_operation);
1582 	  return FALSE;
1583 	}
1584 
1585       memmove (location, section->contents + offset, (size_t) count);
1586       return TRUE;
1587     }
1588 
1589   return BFD_SEND (abfd, _bfd_get_section_contents,
1590 		   (abfd, section, location, offset, count));
1591 }
1592 
1593 /*
1594 FUNCTION
1595 	bfd_malloc_and_get_section
1596 
1597 SYNOPSIS
1598 	bfd_boolean bfd_malloc_and_get_section
1599 	  (bfd *abfd, asection *section, bfd_byte **buf);
1600 
1601 DESCRIPTION
1602 	Read all data from @var{section} in BFD @var{abfd}
1603 	into a buffer, *@var{buf}, malloc'd by this function.
1604 */
1605 
1606 bfd_boolean
1607 bfd_malloc_and_get_section (bfd *abfd, sec_ptr sec, bfd_byte **buf)
1608 {
1609   *buf = NULL;
1610   return bfd_get_full_section_contents (abfd, sec, buf);
1611 }
1612 /*
1613 FUNCTION
1614 	bfd_copy_private_section_data
1615 
1616 SYNOPSIS
1617 	bfd_boolean bfd_copy_private_section_data
1618 	  (bfd *ibfd, asection *isec, bfd *obfd, asection *osec);
1619 
1620 DESCRIPTION
1621 	Copy private section information from @var{isec} in the BFD
1622 	@var{ibfd} to the section @var{osec} in the BFD @var{obfd}.
1623 	Return <<TRUE>> on success, <<FALSE>> on error.  Possible error
1624 	returns are:
1625 
1626 	o <<bfd_error_no_memory>> -
1627 	Not enough memory exists to create private data for @var{osec}.
1628 
1629 .#define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \
1630 .	BFD_SEND (obfd, _bfd_copy_private_section_data, \
1631 .		  (ibfd, isection, obfd, osection))
1632 */
1633 
1634 /*
1635 FUNCTION
1636 	bfd_generic_is_group_section
1637 
1638 SYNOPSIS
1639 	bfd_boolean bfd_generic_is_group_section (bfd *, const asection *sec);
1640 
1641 DESCRIPTION
1642 	Returns TRUE if @var{sec} is a member of a group.
1643 */
1644 
1645 bfd_boolean
1646 bfd_generic_is_group_section (bfd *abfd ATTRIBUTE_UNUSED,
1647 			      const asection *sec ATTRIBUTE_UNUSED)
1648 {
1649   return FALSE;
1650 }
1651 
1652 /*
1653 FUNCTION
1654 	bfd_generic_group_name
1655 
1656 SYNOPSIS
1657 	const char *bfd_generic_group_name (bfd *, const asection *sec);
1658 
1659 DESCRIPTION
1660 	Returns group name if @var{sec} is a member of a group.
1661 */
1662 
1663 const char *
1664 bfd_generic_group_name (bfd *abfd ATTRIBUTE_UNUSED,
1665 			const asection *sec ATTRIBUTE_UNUSED)
1666 {
1667   return NULL;
1668 }
1669 
1670 /*
1671 FUNCTION
1672 	bfd_generic_discard_group
1673 
1674 SYNOPSIS
1675 	bfd_boolean bfd_generic_discard_group (bfd *abfd, asection *group);
1676 
1677 DESCRIPTION
1678 	Remove all members of @var{group} from the output.
1679 */
1680 
1681 bfd_boolean
1682 bfd_generic_discard_group (bfd *abfd ATTRIBUTE_UNUSED,
1683 			   asection *group ATTRIBUTE_UNUSED)
1684 {
1685   return TRUE;
1686 }
1687 
1688 bfd_boolean
1689 _bfd_nowrite_set_section_contents (bfd *abfd,
1690 				   sec_ptr section ATTRIBUTE_UNUSED,
1691 				   const void *location ATTRIBUTE_UNUSED,
1692 				   file_ptr offset ATTRIBUTE_UNUSED,
1693 				   bfd_size_type count ATTRIBUTE_UNUSED)
1694 {
1695   return _bfd_bool_bfd_false_error (abfd);
1696 }
1697