xref: /netbsd-src/external/gpl3/binutils.old/dist/bfd/section.c (revision e992f068c547fd6e84b3f104dc2340adcc955732)
1 /* Object file "section" support for the BFD library.
2    Copyright (C) 1990-2022 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 .  {* The next section in the list belonging to the BFD, or NULL.  *}
155 .  struct bfd_section *next;
156 .
157 .  {* The previous section in the list belonging to the BFD, or NULL.  *}
158 .  struct bfd_section *prev;
159 .
160 .  {* A unique sequence number.  *}
161 .  unsigned int id;
162 .
163 .  {* A unique section number which can be used by assembler to
164 .     distinguish different sections with the same section name.  *}
165 .  unsigned int section_id;
166 .
167 .  {* Which section in the bfd; 0..n-1 as sections are created in a bfd.  *}
168 .  unsigned int index;
169 .
170 .  {* The field flags contains attributes of the section. Some
171 .     flags are read in from the object file, and some are
172 .     synthesized from other information.  *}
173 .  flagword flags;
174 .
175 .#define SEC_NO_FLAGS                      0x0
176 .
177 .  {* Tells the OS to allocate space for this section when loading.
178 .     This is clear for a section containing debug information only.  *}
179 .#define SEC_ALLOC                         0x1
180 .
181 .  {* Tells the OS to load the section from the file when loading.
182 .     This is clear for a .bss section.  *}
183 .#define SEC_LOAD                          0x2
184 .
185 .  {* The section contains data still to be relocated, so there is
186 .     some relocation information too.  *}
187 .#define SEC_RELOC                         0x4
188 .
189 .  {* A signal to the OS that the section contains read only data.  *}
190 .#define SEC_READONLY                      0x8
191 .
192 .  {* The section contains code only.  *}
193 .#define SEC_CODE                         0x10
194 .
195 .  {* The section contains data only.  *}
196 .#define SEC_DATA                         0x20
197 .
198 .  {* The section will reside in ROM.  *}
199 .#define SEC_ROM                          0x40
200 .
201 .  {* The section contains constructor information. This section
202 .     type is used by the linker to create lists of constructors and
203 .     destructors used by <<g++>>. When a back end sees a symbol
204 .     which should be used in a constructor list, it creates a new
205 .     section for the type of name (e.g., <<__CTOR_LIST__>>), attaches
206 .     the symbol to it, and builds a relocation. To build the lists
207 .     of constructors, all the linker has to do is catenate all the
208 .     sections called <<__CTOR_LIST__>> and relocate the data
209 .     contained within - exactly the operations it would peform on
210 .     standard data.  *}
211 .#define SEC_CONSTRUCTOR                  0x80
212 .
213 .  {* The section has contents - a data section could be
214 .     <<SEC_ALLOC>> | <<SEC_HAS_CONTENTS>>; a debug section could be
215 .     <<SEC_HAS_CONTENTS>>  *}
216 .#define SEC_HAS_CONTENTS                0x100
217 .
218 .  {* An instruction to the linker to not output the section
219 .     even if it has information which would normally be written.  *}
220 .#define SEC_NEVER_LOAD                  0x200
221 .
222 .  {* The section contains thread local data.  *}
223 .#define SEC_THREAD_LOCAL                0x400
224 .
225 .  {* The section's size is fixed.  Generic linker code will not
226 .     recalculate it and it is up to whoever has set this flag to
227 .     get the size right.  *}
228 .#define SEC_FIXED_SIZE                  0x800
229 .
230 .  {* The section contains common symbols (symbols may be defined
231 .     multiple times, the value of a symbol is the amount of
232 .     space it requires, and the largest symbol value is the one
233 .     used).  Most targets have exactly one of these (which we
234 .     translate to bfd_com_section_ptr), but ECOFF has two.  *}
235 .#define SEC_IS_COMMON                  0x1000
236 .
237 .  {* The section contains only debugging information.  For
238 .     example, this is set for ELF .debug and .stab sections.
239 .     strip tests this flag to see if a section can be
240 .     discarded.  *}
241 .#define SEC_DEBUGGING                  0x2000
242 .
243 .  {* The contents of this section are held in memory pointed to
244 .     by the contents field.  This is checked by bfd_get_section_contents,
245 .     and the data is retrieved from memory if appropriate.  *}
246 .#define SEC_IN_MEMORY                  0x4000
247 .
248 .  {* The contents of this section are to be excluded by the
249 .     linker for executable and shared objects unless those
250 .     objects are to be further relocated.  *}
251 .#define SEC_EXCLUDE                    0x8000
252 .
253 .  {* The contents of this section are to be sorted based on the sum of
254 .     the symbol and addend values specified by the associated relocation
255 .     entries.  Entries without associated relocation entries will be
256 .     appended to the end of the section in an unspecified order.  *}
257 .#define SEC_SORT_ENTRIES              0x10000
258 .
259 .  {* When linking, duplicate sections of the same name should be
260 .     discarded, rather than being combined into a single section as
261 .     is usually done.  This is similar to how common symbols are
262 .     handled.  See SEC_LINK_DUPLICATES below.  *}
263 .#define SEC_LINK_ONCE                 0x20000
264 .
265 .  {* If SEC_LINK_ONCE is set, this bitfield describes how the linker
266 .     should handle duplicate sections.  *}
267 .#define SEC_LINK_DUPLICATES           0xc0000
268 .
269 .  {* This value for SEC_LINK_DUPLICATES means that duplicate
270 .     sections with the same name should simply be discarded.  *}
271 .#define SEC_LINK_DUPLICATES_DISCARD       0x0
272 .
273 .  {* This value for SEC_LINK_DUPLICATES means that the linker
274 .     should warn if there are any duplicate sections, although
275 .     it should still only link one copy.  *}
276 .#define SEC_LINK_DUPLICATES_ONE_ONLY  0x40000
277 .
278 .  {* This value for SEC_LINK_DUPLICATES means that the linker
279 .     should warn if any duplicate sections are a different size.  *}
280 .#define SEC_LINK_DUPLICATES_SAME_SIZE 0x80000
281 .
282 .  {* This value for SEC_LINK_DUPLICATES means that the linker
283 .     should warn if any duplicate sections contain different
284 .     contents.  *}
285 .#define SEC_LINK_DUPLICATES_SAME_CONTENTS \
286 .  (SEC_LINK_DUPLICATES_ONE_ONLY | SEC_LINK_DUPLICATES_SAME_SIZE)
287 .
288 .  {* This section was created by the linker as part of dynamic
289 .     relocation or other arcane processing.  It is skipped when
290 .     going through the first-pass output, trusting that someone
291 .     else up the line will take care of it later.  *}
292 .#define SEC_LINKER_CREATED           0x100000
293 .
294 .  {* This section contains a section ID to distinguish different
295 .     sections with the same section name.  *}
296 .#define SEC_ASSEMBLER_SECTION_ID     0x100000
297 .
298 .  {* This section should not be subject to garbage collection.
299 .     Also set to inform the linker that this section should not be
300 .     listed in the link map as discarded.  *}
301 .#define SEC_KEEP                     0x200000
302 .
303 .  {* This section contains "short" data, and should be placed
304 .     "near" the GP.  *}
305 .#define SEC_SMALL_DATA               0x400000
306 .
307 .  {* Attempt to merge identical entities in the section.
308 .     Entity size is given in the entsize field.  *}
309 .#define SEC_MERGE                    0x800000
310 .
311 .  {* If given with SEC_MERGE, entities to merge are zero terminated
312 .     strings where entsize specifies character size instead of fixed
313 .     size entries.  *}
314 .#define SEC_STRINGS                 0x1000000
315 .
316 .  {* This section contains data about section groups.  *}
317 .#define SEC_GROUP                   0x2000000
318 .
319 .  {* The section is a COFF shared library section.  This flag is
320 .     only for the linker.  If this type of section appears in
321 .     the input file, the linker must copy it to the output file
322 .     without changing the vma or size.  FIXME: Although this
323 .     was originally intended to be general, it really is COFF
324 .     specific (and the flag was renamed to indicate this).  It
325 .     might be cleaner to have some more general mechanism to
326 .     allow the back end to control what the linker does with
327 .     sections.  *}
328 .#define SEC_COFF_SHARED_LIBRARY     0x4000000
329 .
330 .  {* This input section should be copied to output in reverse order
331 .     as an array of pointers.  This is for ELF linker internal use
332 .     only.  *}
333 .#define SEC_ELF_REVERSE_COPY        0x4000000
334 .
335 .  {* This section contains data which may be shared with other
336 .     executables or shared objects. This is for COFF only.  *}
337 .#define SEC_COFF_SHARED             0x8000000
338 .
339 .  {* This section should be compressed.  This is for ELF linker
340 .     internal use only.  *}
341 .#define SEC_ELF_COMPRESS            0x8000000
342 .
343 .  {* When a section with this flag is being linked, then if the size of
344 .     the input section is less than a page, it should not cross a page
345 .     boundary.  If the size of the input section is one page or more,
346 .     it should be aligned on a page boundary.  This is for TI
347 .     TMS320C54X only.  *}
348 .#define SEC_TIC54X_BLOCK           0x10000000
349 .
350 .  {* This section should be renamed.  This is for ELF linker
351 .     internal use only.  *}
352 .#define SEC_ELF_RENAME             0x10000000
353 .
354 .  {* Conditionally link this section; do not link if there are no
355 .     references found to any symbol in the section.  This is for TI
356 .     TMS320C54X only.  *}
357 .#define SEC_TIC54X_CLINK           0x20000000
358 .
359 .  {* This section contains vliw code.  This is for Toshiba MeP only.  *}
360 .#define SEC_MEP_VLIW               0x20000000
361 .
362 .  {* All symbols, sizes and relocations in this section are octets
363 .     instead of bytes.  Required for DWARF debug sections as DWARF
364 .     information is organized in octets, not bytes.  *}
365 .#define SEC_ELF_OCTETS             0x40000000
366 .
367 .  {* Indicate that section has the no read flag set. This happens
368 .     when memory read flag isn't set. *}
369 .#define SEC_COFF_NOREAD            0x40000000
370 .
371 .  {* Indicate that section has the purecode flag set.  *}
372 .#define SEC_ELF_PURECODE           0x80000000
373 .
374 .  {*  End of section flags.  *}
375 .
376 .  {* Some internal packed boolean fields.  *}
377 .
378 .  {* See the vma field.  *}
379 .  unsigned int user_set_vma : 1;
380 .
381 .  {* A mark flag used by some of the linker backends.  *}
382 .  unsigned int linker_mark : 1;
383 .
384 .  {* Another mark flag used by some of the linker backends.  Set for
385 .     output sections that have an input section.  *}
386 .  unsigned int linker_has_input : 1;
387 .
388 .  {* Mark flag used by some linker backends for garbage collection.  *}
389 .  unsigned int gc_mark : 1;
390 .
391 .  {* Section compression status.  *}
392 .  unsigned int compress_status : 2;
393 .#define COMPRESS_SECTION_NONE    0
394 .#define COMPRESS_SECTION_DONE    1
395 .#define DECOMPRESS_SECTION_SIZED 2
396 .
397 .  {* The following flags are used by the ELF linker. *}
398 .
399 .  {* Mark sections which have been allocated to segments.  *}
400 .  unsigned int segment_mark : 1;
401 .
402 .  {* Type of sec_info information.  *}
403 .  unsigned int sec_info_type:3;
404 .#define SEC_INFO_TYPE_NONE      0
405 .#define SEC_INFO_TYPE_STABS     1
406 .#define SEC_INFO_TYPE_MERGE     2
407 .#define SEC_INFO_TYPE_EH_FRAME  3
408 .#define SEC_INFO_TYPE_JUST_SYMS 4
409 .#define SEC_INFO_TYPE_TARGET    5
410 .#define SEC_INFO_TYPE_EH_FRAME_ENTRY 6
411 .
412 .  {* Nonzero if this section uses RELA relocations, rather than REL.  *}
413 .  unsigned int use_rela_p:1;
414 .
415 .  {* Bits used by various backends.  The generic code doesn't touch
416 .     these fields.  *}
417 .
418 .  unsigned int sec_flg0:1;
419 .  unsigned int sec_flg1:1;
420 .  unsigned int sec_flg2:1;
421 .  unsigned int sec_flg3:1;
422 .  unsigned int sec_flg4:1;
423 .  unsigned int sec_flg5:1;
424 .
425 .  {* End of internal packed boolean fields.  *}
426 .
427 .  {*  The virtual memory address of the section - where it will be
428 .      at run time.  The symbols are relocated against this.  The
429 .      user_set_vma flag is maintained by bfd; if it's not set, the
430 .      backend can assign addresses (for example, in <<a.out>>, where
431 .      the default address for <<.data>> is dependent on the specific
432 .      target and various flags).  *}
433 .  bfd_vma vma;
434 .
435 .  {*  The load address of the section - where it would be in a
436 .      rom image; really only used for writing section header
437 .      information.  *}
438 .  bfd_vma lma;
439 .
440 .  {* The size of the section in *octets*, as it will be output.
441 .     Contains a value even if the section has no contents (e.g., the
442 .     size of <<.bss>>).  *}
443 .  bfd_size_type size;
444 .
445 .  {* For input sections, the original size on disk of the section, in
446 .     octets.  This field should be set for any section whose size is
447 .     changed by linker relaxation.  It is required for sections where
448 .     the linker relaxation scheme doesn't cache altered section and
449 .     reloc contents (stabs, eh_frame, SEC_MERGE, some coff relaxing
450 .     targets), and thus the original size needs to be kept to read the
451 .     section multiple times.  For output sections, rawsize holds the
452 .     section size calculated on a previous linker relaxation pass.  *}
453 .  bfd_size_type rawsize;
454 .
455 .  {* The compressed size of the section in octets.  *}
456 .  bfd_size_type compressed_size;
457 .
458 .  {* If this section is going to be output, then this value is the
459 .     offset in *bytes* into the output section of the first byte in the
460 .     input section (byte ==> smallest addressable unit on the
461 .     target).  In most cases, if this was going to start at the
462 .     100th octet (8-bit quantity) in the output section, this value
463 .     would be 100.  However, if the target byte size is 16 bits
464 .     (bfd_octets_per_byte is "2"), this value would be 50.  *}
465 .  bfd_vma output_offset;
466 .
467 .  {* The output section through which to map on output.  *}
468 .  struct bfd_section *output_section;
469 .
470 .  {* If an input section, a pointer to a vector of relocation
471 .     records for the data in this section.  *}
472 .  struct reloc_cache_entry *relocation;
473 .
474 .  {* If an output section, a pointer to a vector of pointers to
475 .     relocation records for the data in this section.  *}
476 .  struct reloc_cache_entry **orelocation;
477 .
478 .  {* The number of relocation records in one of the above.  *}
479 .  unsigned reloc_count;
480 .
481 .  {* The alignment requirement of the section, as an exponent of 2 -
482 .     e.g., 3 aligns to 2^3 (or 8).  *}
483 .  unsigned int alignment_power;
484 .
485 .  {* Information below is back end specific - and not always used
486 .     or updated.  *}
487 .
488 .  {* File position of section data.  *}
489 .  file_ptr filepos;
490 .
491 .  {* File position of relocation info.  *}
492 .  file_ptr rel_filepos;
493 .
494 .  {* File position of line data.  *}
495 .  file_ptr line_filepos;
496 .
497 .  {* Pointer to data for applications.  *}
498 .  void *userdata;
499 .
500 .  {* If the SEC_IN_MEMORY flag is set, this points to the actual
501 .     contents.  *}
502 .  unsigned char *contents;
503 .
504 .  {* Attached line number information.  *}
505 .  alent *lineno;
506 .
507 .  {* Number of line number records.  *}
508 .  unsigned int lineno_count;
509 .
510 .  {* Entity size for merging purposes.  *}
511 .  unsigned int entsize;
512 .
513 .  {* Points to the kept section if this section is a link-once section,
514 .     and is discarded.  *}
515 .  struct bfd_section *kept_section;
516 .
517 .  {* When a section is being output, this value changes as more
518 .     linenumbers are written out.  *}
519 .  file_ptr moving_line_filepos;
520 .
521 .  {* What the section number is in the target world.  *}
522 .  int target_index;
523 .
524 .  void *used_by_bfd;
525 .
526 .  {* If this is a constructor section then here is a list of the
527 .     relocations created to relocate items within it.  *}
528 .  struct relent_chain *constructor_chain;
529 .
530 .  {* The BFD which owns the section.  *}
531 .  bfd *owner;
532 .
533 .  {* A symbol which points at this section only.  *}
534 .  struct bfd_symbol *symbol;
535 .  struct bfd_symbol **symbol_ptr_ptr;
536 .
537 .  {* Early in the link process, map_head and map_tail are used to build
538 .     a list of input sections attached to an output section.  Later,
539 .     output sections use these fields for a list of bfd_link_order
540 .     structs.  The linked_to_symbol_name field is for ELF assembler
541 .     internal use.  *}
542 .  union {
543 .    struct bfd_link_order *link_order;
544 .    struct bfd_section *s;
545 .    const char *linked_to_symbol_name;
546 .  } map_head, map_tail;
547 .
548 .  {* Points to the output section this section is already assigned to,
549 .     if any.  This is used when support for non-contiguous memory
550 .     regions is enabled.  *}
551 .  struct bfd_section *already_assigned;
552 .
553 .  {* Explicitly specified section type, if non-zero.  *}
554 .  unsigned int type;
555 .
556 .} asection;
557 .
558 .static inline const char *
559 .bfd_section_name (const asection *sec)
560 .{
561 .  return sec->name;
562 .}
563 .
564 .static inline bfd_size_type
565 .bfd_section_size (const asection *sec)
566 .{
567 .  return sec->size;
568 .}
569 .
570 .static inline bfd_vma
571 .bfd_section_vma (const asection *sec)
572 .{
573 .  return sec->vma;
574 .}
575 .
576 .static inline bfd_vma
577 .bfd_section_lma (const asection *sec)
578 .{
579 .  return sec->lma;
580 .}
581 .
582 .static inline unsigned int
583 .bfd_section_alignment (const asection *sec)
584 .{
585 .  return sec->alignment_power;
586 .}
587 .
588 .static inline flagword
589 .bfd_section_flags (const asection *sec)
590 .{
591 .  return sec->flags;
592 .}
593 .
594 .static inline void *
595 .bfd_section_userdata (const asection *sec)
596 .{
597 .  return sec->userdata;
598 .}
599 .static inline bool
600 .bfd_is_com_section (const asection *sec)
601 .{
602 .  return (sec->flags & SEC_IS_COMMON) != 0;
603 .}
604 .
605 .{* Note: the following are provided as inline functions rather than macros
606 .   because not all callers use the return value.  A macro implementation
607 .   would use a comma expression, eg: "((ptr)->foo = val, TRUE)" and some
608 .   compilers will complain about comma expressions that have no effect.  *}
609 .static inline bool
610 .bfd_set_section_userdata (asection *sec, void *val)
611 .{
612 .  sec->userdata = val;
613 .  return true;
614 .}
615 .
616 .static inline bool
617 .bfd_set_section_vma (asection *sec, bfd_vma val)
618 .{
619 .  sec->vma = sec->lma = val;
620 .  sec->user_set_vma = true;
621 .  return true;
622 .}
623 .
624 .static inline bool
625 .bfd_set_section_lma (asection *sec, bfd_vma val)
626 .{
627 .  sec->lma = val;
628 .  return true;
629 .}
630 .
631 .static inline bool
632 .bfd_set_section_alignment (asection *sec, unsigned int val)
633 .{
634 .  sec->alignment_power = val;
635 .  return true;
636 .}
637 .
638 .{* These sections are global, and are managed by BFD.  The application
639 .   and target back end are not permitted to change the values in
640 .   these sections.  *}
641 .extern asection _bfd_std_section[4];
642 .
643 .#define BFD_ABS_SECTION_NAME "*ABS*"
644 .#define BFD_UND_SECTION_NAME "*UND*"
645 .#define BFD_COM_SECTION_NAME "*COM*"
646 .#define BFD_IND_SECTION_NAME "*IND*"
647 .
648 .{* Pointer to the common section.  *}
649 .#define bfd_com_section_ptr (&_bfd_std_section[0])
650 .{* Pointer to the undefined section.  *}
651 .#define bfd_und_section_ptr (&_bfd_std_section[1])
652 .{* Pointer to the absolute section.  *}
653 .#define bfd_abs_section_ptr (&_bfd_std_section[2])
654 .{* Pointer to the indirect section.  *}
655 .#define bfd_ind_section_ptr (&_bfd_std_section[3])
656 .
657 .static inline bool
658 .bfd_is_und_section (const asection *sec)
659 .{
660 .  return sec == bfd_und_section_ptr;
661 .}
662 .
663 .static inline bool
664 .bfd_is_abs_section (const asection *sec)
665 .{
666 .  return sec == bfd_abs_section_ptr;
667 .}
668 .
669 .static inline bool
670 .bfd_is_ind_section (const asection *sec)
671 .{
672 .  return sec == bfd_ind_section_ptr;
673 .}
674 .
675 .static inline bool
676 .bfd_is_const_section (const asection *sec)
677 .{
678 .  return (sec >= _bfd_std_section
679 .          && sec < _bfd_std_section + (sizeof (_bfd_std_section)
680 .                                       / sizeof (_bfd_std_section[0])));
681 .}
682 .
683 .{* Return TRUE if input section SEC has been discarded.  *}
684 .static inline bool
685 .discarded_section (const asection *sec)
686 .{
687 .  return (!bfd_is_abs_section (sec)
688 .          && bfd_is_abs_section (sec->output_section)
689 .          && sec->sec_info_type != SEC_INFO_TYPE_MERGE
690 .          && sec->sec_info_type != SEC_INFO_TYPE_JUST_SYMS);
691 .}
692 .
693 .#define BFD_FAKE_SECTION(SEC, SYM, NAME, IDX, FLAGS)			\
694 .  {* name, next, prev, id,  section_id, index, flags, user_set_vma, *}	\
695 .  {  NAME, NULL, NULL, IDX, 0,          0,     FLAGS, 0,		\
696 .									\
697 .  {* linker_mark, linker_has_input, gc_mark, decompress_status,     *}	\
698 .     0,           0,                1,       0,			\
699 .									\
700 .  {* segment_mark, sec_info_type, use_rela_p,                       *}	\
701 .     0,            0,             0,					\
702 .									\
703 .  {* sec_flg0, sec_flg1, sec_flg2, sec_flg3, sec_flg4, sec_flg5,    *}	\
704 .     0,        0,        0,        0,        0,        0,		\
705 .									\
706 .  {* vma, lma, size, rawsize, compressed_size,                      *}	\
707 .     0,   0,   0,    0,       0,					\
708 .									\
709 .  {* output_offset, output_section, relocation, orelocation,        *}	\
710 .     0,             &SEC,           NULL,       NULL,			\
711 .									\
712 .  {* reloc_count, alignment_power, filepos, rel_filepos,            *}	\
713 .     0,           0,               0,       0,				\
714 .									\
715 .  {* line_filepos, userdata, contents, lineno, lineno_count,        *}	\
716 .     0,            NULL,     NULL,     NULL,   0,			\
717 .									\
718 .  {* entsize, kept_section, moving_line_filepos,                    *}	\
719 .     0,       NULL,         0,						\
720 .									\
721 .  {* target_index, used_by_bfd, constructor_chain, owner,           *}	\
722 .     0,            NULL,        NULL,              NULL,		\
723 .									\
724 .  {* symbol,                    symbol_ptr_ptr,                     *}	\
725 .     (struct bfd_symbol *) SYM, &SEC.symbol,				\
726 .									\
727 .  {* map_head, map_tail, already_assigned, type                     *}	\
728 .     { NULL }, { NULL }, NULL,             0				\
729 .									\
730 .    }
731 .
732 .{* We use a macro to initialize the static asymbol structures because
733 .   traditional C does not permit us to initialize a union member while
734 .   gcc warns if we don't initialize it.
735 .   the_bfd, name, value, attr, section [, udata]  *}
736 .#ifdef __STDC__
737 .#define GLOBAL_SYM_INIT(NAME, SECTION) \
738 .  { 0, NAME, 0, BSF_SECTION_SYM, SECTION, { 0 }}
739 .#else
740 .#define GLOBAL_SYM_INIT(NAME, SECTION) \
741 .  { 0, NAME, 0, BSF_SECTION_SYM, SECTION }
742 .#endif
743 .
744 */
745 
746 /* These symbols are global, not specific to any BFD.  Therefore, anything
747    that tries to change them is broken, and should be repaired.  */
748 
749 static const asymbol global_syms[] =
750 {
751   GLOBAL_SYM_INIT (BFD_COM_SECTION_NAME, bfd_com_section_ptr),
752   GLOBAL_SYM_INIT (BFD_UND_SECTION_NAME, bfd_und_section_ptr),
753   GLOBAL_SYM_INIT (BFD_ABS_SECTION_NAME, bfd_abs_section_ptr),
754   GLOBAL_SYM_INIT (BFD_IND_SECTION_NAME, bfd_ind_section_ptr)
755 };
756 
757 #define STD_SECTION(NAME, IDX, FLAGS) \
758   BFD_FAKE_SECTION(_bfd_std_section[IDX], &global_syms[IDX], NAME, IDX, FLAGS)
759 
760 asection _bfd_std_section[] = {
761   STD_SECTION (BFD_COM_SECTION_NAME, 0, SEC_IS_COMMON),
762   STD_SECTION (BFD_UND_SECTION_NAME, 1, 0),
763   STD_SECTION (BFD_ABS_SECTION_NAME, 2, 0),
764   STD_SECTION (BFD_IND_SECTION_NAME, 3, 0)
765 };
766 #undef STD_SECTION
767 
768 /* Initialize an entry in the section hash table.  */
769 
770 struct bfd_hash_entry *
bfd_section_hash_newfunc(struct bfd_hash_entry * entry,struct bfd_hash_table * table,const char * string)771 bfd_section_hash_newfunc (struct bfd_hash_entry *entry,
772 			  struct bfd_hash_table *table,
773 			  const char *string)
774 {
775   /* Allocate the structure if it has not already been allocated by a
776      subclass.  */
777   if (entry == NULL)
778     {
779       entry = (struct bfd_hash_entry *)
780 	bfd_hash_allocate (table, sizeof (struct section_hash_entry));
781       if (entry == NULL)
782 	return entry;
783     }
784 
785   /* Call the allocation method of the superclass.  */
786   entry = bfd_hash_newfunc (entry, table, string);
787   if (entry != NULL)
788     memset (&((struct section_hash_entry *) entry)->section, 0,
789 	    sizeof (asection));
790 
791   return entry;
792 }
793 
794 #define section_hash_lookup(table, string, create, copy) \
795   ((struct section_hash_entry *) \
796    bfd_hash_lookup ((table), (string), (create), (copy)))
797 
798 /* Create a symbol whose only job is to point to this section.  This
799    is useful for things like relocs which are relative to the base
800    of a section.  */
801 
802 bool
_bfd_generic_new_section_hook(bfd * abfd,asection * newsect)803 _bfd_generic_new_section_hook (bfd *abfd, asection *newsect)
804 {
805   newsect->symbol = bfd_make_empty_symbol (abfd);
806   if (newsect->symbol == NULL)
807     return false;
808 
809   newsect->symbol->name = newsect->name;
810   newsect->symbol->value = 0;
811   newsect->symbol->section = newsect;
812   newsect->symbol->flags = BSF_SECTION_SYM;
813 
814   newsect->symbol_ptr_ptr = &newsect->symbol;
815   return true;
816 }
817 
818 unsigned int _bfd_section_id = 0x10;  /* id 0 to 3 used by STD_SECTION.  */
819 
820 /* Initializes a new section.  NEWSECT->NAME is already set.  */
821 
822 static asection *
bfd_section_init(bfd * abfd,asection * newsect)823 bfd_section_init (bfd *abfd, asection *newsect)
824 {
825   newsect->id = _bfd_section_id;
826   newsect->index = abfd->section_count;
827   newsect->owner = abfd;
828 
829   if (! BFD_SEND (abfd, _new_section_hook, (abfd, newsect)))
830     return NULL;
831 
832   _bfd_section_id++;
833   abfd->section_count++;
834   bfd_section_list_append (abfd, newsect);
835   return newsect;
836 }
837 
838 /*
839 DOCDD
840 INODE
841 section prototypes,  , typedef asection, Sections
842 SUBSECTION
843 	Section prototypes
844 
845 These are the functions exported by the section handling part of BFD.
846 */
847 
848 /*
849 FUNCTION
850 	bfd_section_list_clear
851 
852 SYNOPSIS
853 	void bfd_section_list_clear (bfd *);
854 
855 DESCRIPTION
856 	Clears the section list, and also resets the section count and
857 	hash table entries.
858 */
859 
860 void
bfd_section_list_clear(bfd * abfd)861 bfd_section_list_clear (bfd *abfd)
862 {
863   abfd->sections = NULL;
864   abfd->section_last = NULL;
865   abfd->section_count = 0;
866   memset (abfd->section_htab.table, 0,
867 	  abfd->section_htab.size * sizeof (struct bfd_hash_entry *));
868   abfd->section_htab.count = 0;
869 }
870 
871 /*
872 FUNCTION
873 	bfd_get_section_by_name
874 
875 SYNOPSIS
876 	asection *bfd_get_section_by_name (bfd *abfd, const char *name);
877 
878 DESCRIPTION
879 	Return the most recently created section attached to @var{abfd}
880 	named @var{name}.  Return NULL if no such section exists.
881 */
882 
883 asection *
bfd_get_section_by_name(bfd * abfd,const char * name)884 bfd_get_section_by_name (bfd *abfd, const char *name)
885 {
886   struct section_hash_entry *sh;
887 
888   if (name == NULL)
889     return NULL;
890 
891   sh = section_hash_lookup (&abfd->section_htab, name, false, false);
892   if (sh != NULL)
893     return &sh->section;
894 
895   return NULL;
896 }
897 
898 /*
899 FUNCTION
900        bfd_get_next_section_by_name
901 
902 SYNOPSIS
903        asection *bfd_get_next_section_by_name (bfd *ibfd, asection *sec);
904 
905 DESCRIPTION
906        Given @var{sec} is a section returned by @code{bfd_get_section_by_name},
907        return the next most recently created section attached to the same
908        BFD with the same name, or if no such section exists in the same BFD and
909        IBFD is non-NULL, the next section with the same name in any input
910        BFD following IBFD.  Return NULL on finding no section.
911 */
912 
913 asection *
bfd_get_next_section_by_name(bfd * ibfd,asection * sec)914 bfd_get_next_section_by_name (bfd *ibfd, asection *sec)
915 {
916   struct section_hash_entry *sh;
917   const char *name;
918   unsigned long hash;
919 
920   sh = ((struct section_hash_entry *)
921 	((char *) sec - offsetof (struct section_hash_entry, section)));
922 
923   hash = sh->root.hash;
924   name = sec->name;
925   for (sh = (struct section_hash_entry *) sh->root.next;
926        sh != NULL;
927        sh = (struct section_hash_entry *) sh->root.next)
928     if (sh->root.hash == hash
929        && strcmp (sh->root.string, name) == 0)
930       return &sh->section;
931 
932   if (ibfd != NULL)
933     {
934       while ((ibfd = ibfd->link.next) != NULL)
935 	{
936 	  asection *s = bfd_get_section_by_name (ibfd, name);
937 	  if (s != NULL)
938 	    return s;
939 	}
940     }
941 
942   return NULL;
943 }
944 
945 /*
946 FUNCTION
947 	bfd_get_linker_section
948 
949 SYNOPSIS
950 	asection *bfd_get_linker_section (bfd *abfd, const char *name);
951 
952 DESCRIPTION
953 	Return the linker created section attached to @var{abfd}
954 	named @var{name}.  Return NULL if no such section exists.
955 */
956 
957 asection *
bfd_get_linker_section(bfd * abfd,const char * name)958 bfd_get_linker_section (bfd *abfd, const char *name)
959 {
960   asection *sec = bfd_get_section_by_name (abfd, name);
961 
962   while (sec != NULL && (sec->flags & SEC_LINKER_CREATED) == 0)
963     sec = bfd_get_next_section_by_name (NULL, sec);
964   return sec;
965 }
966 
967 /*
968 FUNCTION
969 	bfd_get_section_by_name_if
970 
971 SYNOPSIS
972 	asection *bfd_get_section_by_name_if
973 	  (bfd *abfd,
974 	   const char *name,
975 	   bool (*func) (bfd *abfd, asection *sect, void *obj),
976 	   void *obj);
977 
978 DESCRIPTION
979 	Call the provided function @var{func} for each section
980 	attached to the BFD @var{abfd} whose name matches @var{name},
981 	passing @var{obj} as an argument. The function will be called
982 	as if by
983 
984 |	func (abfd, the_section, obj);
985 
986 	It returns the first section for which @var{func} returns true,
987 	otherwise <<NULL>>.
988 
989 */
990 
991 asection *
bfd_get_section_by_name_if(bfd * abfd,const char * name,bool (* operation)(bfd *,asection *,void *),void * user_storage)992 bfd_get_section_by_name_if (bfd *abfd, const char *name,
993 			    bool (*operation) (bfd *, asection *, void *),
994 			    void *user_storage)
995 {
996   struct section_hash_entry *sh;
997   unsigned long hash;
998 
999   if (name == NULL)
1000     return NULL;
1001 
1002   sh = section_hash_lookup (&abfd->section_htab, name, false, false);
1003   if (sh == NULL)
1004     return NULL;
1005 
1006   hash = sh->root.hash;
1007   for (; sh != NULL; sh = (struct section_hash_entry *) sh->root.next)
1008     if (sh->root.hash == hash
1009 	&& strcmp (sh->root.string, name) == 0
1010 	&& (*operation) (abfd, &sh->section, user_storage))
1011       return &sh->section;
1012 
1013   return NULL;
1014 }
1015 
1016 /*
1017 FUNCTION
1018 	bfd_get_unique_section_name
1019 
1020 SYNOPSIS
1021 	char *bfd_get_unique_section_name
1022 	  (bfd *abfd, const char *templat, int *count);
1023 
1024 DESCRIPTION
1025 	Invent a section name that is unique in @var{abfd} by tacking
1026 	a dot and a digit suffix onto the original @var{templat}.  If
1027 	@var{count} is non-NULL, then it specifies the first number
1028 	tried as a suffix to generate a unique name.  The value
1029 	pointed to by @var{count} will be incremented in this case.
1030 */
1031 
1032 char *
bfd_get_unique_section_name(bfd * abfd,const char * templat,int * count)1033 bfd_get_unique_section_name (bfd *abfd, const char *templat, int *count)
1034 {
1035   int num;
1036   unsigned int len;
1037   char *sname;
1038 
1039   len = strlen (templat);
1040   sname = (char *) bfd_malloc (len + 8);
1041   if (sname == NULL)
1042     return NULL;
1043   memcpy (sname, templat, len);
1044   num = 1;
1045   if (count != NULL)
1046     num = *count;
1047 
1048   do
1049     {
1050       /* If we have a million sections, something is badly wrong.  */
1051       if (num > 999999)
1052 	abort ();
1053       sprintf (sname + len, ".%d", num++);
1054     }
1055   while (section_hash_lookup (&abfd->section_htab, sname, false, false));
1056 
1057   if (count != NULL)
1058     *count = num;
1059   return sname;
1060 }
1061 
1062 /*
1063 FUNCTION
1064 	bfd_make_section_old_way
1065 
1066 SYNOPSIS
1067 	asection *bfd_make_section_old_way (bfd *abfd, const char *name);
1068 
1069 DESCRIPTION
1070 	Create a new empty section called @var{name}
1071 	and attach it to the end of the chain of sections for the
1072 	BFD @var{abfd}. An attempt to create a section with a name which
1073 	is already in use returns its pointer without changing the
1074 	section chain.
1075 
1076 	It has the funny name since this is the way it used to be
1077 	before it was rewritten....
1078 
1079 	Possible errors are:
1080 	o <<bfd_error_invalid_operation>> -
1081 	If output has already started for this BFD.
1082 	o <<bfd_error_no_memory>> -
1083 	If memory allocation fails.
1084 
1085 */
1086 
1087 asection *
bfd_make_section_old_way(bfd * abfd,const char * name)1088 bfd_make_section_old_way (bfd *abfd, const char *name)
1089 {
1090   asection *newsect;
1091 
1092   if (abfd->output_has_begun)
1093     {
1094       bfd_set_error (bfd_error_invalid_operation);
1095       return NULL;
1096     }
1097 
1098   if (strcmp (name, BFD_ABS_SECTION_NAME) == 0)
1099     newsect = bfd_abs_section_ptr;
1100   else if (strcmp (name, BFD_COM_SECTION_NAME) == 0)
1101     newsect = bfd_com_section_ptr;
1102   else if (strcmp (name, BFD_UND_SECTION_NAME) == 0)
1103     newsect = bfd_und_section_ptr;
1104   else if (strcmp (name, BFD_IND_SECTION_NAME) == 0)
1105     newsect = bfd_ind_section_ptr;
1106   else
1107     {
1108       struct section_hash_entry *sh;
1109 
1110       sh = section_hash_lookup (&abfd->section_htab, name, true, false);
1111       if (sh == NULL)
1112 	return NULL;
1113 
1114       newsect = &sh->section;
1115       if (newsect->name != NULL)
1116 	{
1117 	  /* Section already exists.  */
1118 	  return newsect;
1119 	}
1120 
1121       newsect->name = name;
1122       return bfd_section_init (abfd, newsect);
1123     }
1124 
1125   /* Call new_section_hook when "creating" the standard abs, com, und
1126      and ind sections to tack on format specific section data.
1127      Also, create a proper section symbol.  */
1128   if (! BFD_SEND (abfd, _new_section_hook, (abfd, newsect)))
1129     return NULL;
1130   return newsect;
1131 }
1132 
1133 /*
1134 FUNCTION
1135 	bfd_make_section_anyway_with_flags
1136 
1137 SYNOPSIS
1138 	asection *bfd_make_section_anyway_with_flags
1139 	  (bfd *abfd, const char *name, flagword flags);
1140 
1141 DESCRIPTION
1142    Create a new empty section called @var{name} and attach it to the end of
1143    the chain of sections for @var{abfd}.  Create a new section even if there
1144    is already a section with that name.  Also set the attributes of the
1145    new section to the value @var{flags}.
1146 
1147    Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1148    o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1149    o <<bfd_error_no_memory>> - If memory allocation fails.
1150 */
1151 
1152 sec_ptr
bfd_make_section_anyway_with_flags(bfd * abfd,const char * name,flagword flags)1153 bfd_make_section_anyway_with_flags (bfd *abfd, const char *name,
1154 				    flagword flags)
1155 {
1156   struct section_hash_entry *sh;
1157   asection *newsect;
1158 
1159   if (abfd->output_has_begun)
1160     {
1161       bfd_set_error (bfd_error_invalid_operation);
1162       return NULL;
1163     }
1164 
1165   sh = section_hash_lookup (&abfd->section_htab, name, true, false);
1166   if (sh == NULL)
1167     return NULL;
1168 
1169   newsect = &sh->section;
1170   if (newsect->name != NULL)
1171     {
1172       /* We are making a section of the same name.  Put it in the
1173 	 section hash table.  Even though we can't find it directly by a
1174 	 hash lookup, we'll be able to find the section by traversing
1175 	 sh->root.next quicker than looking at all the bfd sections.  */
1176       struct section_hash_entry *new_sh;
1177       new_sh = (struct section_hash_entry *)
1178 	bfd_section_hash_newfunc (NULL, &abfd->section_htab, name);
1179       if (new_sh == NULL)
1180 	return NULL;
1181 
1182       new_sh->root = sh->root;
1183       sh->root.next = &new_sh->root;
1184       newsect = &new_sh->section;
1185     }
1186 
1187   newsect->flags = flags;
1188   newsect->name = name;
1189   return bfd_section_init (abfd, newsect);
1190 }
1191 
1192 /*
1193 FUNCTION
1194 	bfd_make_section_anyway
1195 
1196 SYNOPSIS
1197 	asection *bfd_make_section_anyway (bfd *abfd, const char *name);
1198 
1199 DESCRIPTION
1200    Create a new empty section called @var{name} and attach it to the end of
1201    the chain of sections for @var{abfd}.  Create a new section even if there
1202    is already a section with that name.
1203 
1204    Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
1205    o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
1206    o <<bfd_error_no_memory>> - If memory allocation fails.
1207 */
1208 
1209 sec_ptr
bfd_make_section_anyway(bfd * abfd,const char * name)1210 bfd_make_section_anyway (bfd *abfd, const char *name)
1211 {
1212   return bfd_make_section_anyway_with_flags (abfd, name, 0);
1213 }
1214 
1215 /*
1216 FUNCTION
1217 	bfd_make_section_with_flags
1218 
1219 SYNOPSIS
1220 	asection *bfd_make_section_with_flags
1221 	  (bfd *, const char *name, flagword flags);
1222 
1223 DESCRIPTION
1224    Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1225    bfd_set_error ()) without changing the section chain if there is already a
1226    section named @var{name}.  Also set the attributes of the new section to
1227    the value @var{flags}.  If there is an error, return <<NULL>> and set
1228    <<bfd_error>>.
1229 */
1230 
1231 asection *
bfd_make_section_with_flags(bfd * abfd,const char * name,flagword flags)1232 bfd_make_section_with_flags (bfd *abfd, const char *name,
1233 			     flagword flags)
1234 {
1235   struct section_hash_entry *sh;
1236   asection *newsect;
1237 
1238   if (abfd == NULL || name == NULL || abfd->output_has_begun)
1239     {
1240       bfd_set_error (bfd_error_invalid_operation);
1241       return NULL;
1242     }
1243 
1244   if (strcmp (name, BFD_ABS_SECTION_NAME) == 0
1245       || strcmp (name, BFD_COM_SECTION_NAME) == 0
1246       || strcmp (name, BFD_UND_SECTION_NAME) == 0
1247       || strcmp (name, BFD_IND_SECTION_NAME) == 0)
1248     return NULL;
1249 
1250   sh = section_hash_lookup (&abfd->section_htab, name, true, false);
1251   if (sh == NULL)
1252     return NULL;
1253 
1254   newsect = &sh->section;
1255   if (newsect->name != NULL)
1256     {
1257       /* Section already exists.  */
1258       return NULL;
1259     }
1260 
1261   newsect->name = name;
1262   newsect->flags = flags;
1263   return bfd_section_init (abfd, newsect);
1264 }
1265 
1266 /*
1267 FUNCTION
1268 	bfd_make_section
1269 
1270 SYNOPSIS
1271 	asection *bfd_make_section (bfd *, const char *name);
1272 
1273 DESCRIPTION
1274    Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
1275    bfd_set_error ()) without changing the section chain if there is already a
1276    section named @var{name}.  If there is an error, return <<NULL>> and set
1277    <<bfd_error>>.
1278 */
1279 
1280 asection *
bfd_make_section(bfd * abfd,const char * name)1281 bfd_make_section (bfd *abfd, const char *name)
1282 {
1283   return bfd_make_section_with_flags (abfd, name, 0);
1284 }
1285 
1286 /*
1287 FUNCTION
1288 	bfd_set_section_flags
1289 
1290 SYNOPSIS
1291 	bool bfd_set_section_flags (asection *sec, flagword flags);
1292 
1293 DESCRIPTION
1294 	Set the attributes of the section @var{sec} to the value @var{flags}.
1295 	Return <<TRUE>> on success, <<FALSE>> on error.  Possible error
1296 	returns are:
1297 
1298 	o <<bfd_error_invalid_operation>> -
1299 	The section cannot have one or more of the attributes
1300 	requested. For example, a .bss section in <<a.out>> may not
1301 	have the <<SEC_HAS_CONTENTS>> field set.
1302 
1303 */
1304 
1305 bool
bfd_set_section_flags(asection * section,flagword flags)1306 bfd_set_section_flags (asection *section, flagword flags)
1307 {
1308   section->flags = flags;
1309   return true;
1310 }
1311 
1312 /*
1313 FUNCTION
1314 	bfd_rename_section
1315 
1316 SYNOPSIS
1317 	void bfd_rename_section
1318 	  (asection *sec, const char *newname);
1319 
1320 DESCRIPTION
1321 	Rename section @var{sec} to @var{newname}.
1322 */
1323 
1324 void
bfd_rename_section(asection * sec,const char * newname)1325 bfd_rename_section (asection *sec, const char *newname)
1326 {
1327   struct section_hash_entry *sh;
1328 
1329   sh = (struct section_hash_entry *)
1330     ((char *) sec - offsetof (struct section_hash_entry, section));
1331   sh->section.name = newname;
1332   bfd_hash_rename (&sec->owner->section_htab, newname, &sh->root);
1333 }
1334 
1335 /*
1336 FUNCTION
1337 	bfd_map_over_sections
1338 
1339 SYNOPSIS
1340 	void bfd_map_over_sections
1341 	  (bfd *abfd,
1342 	   void (*func) (bfd *abfd, asection *sect, void *obj),
1343 	   void *obj);
1344 
1345 DESCRIPTION
1346 	Call the provided function @var{func} for each section
1347 	attached to the BFD @var{abfd}, passing @var{obj} as an
1348 	argument. The function will be called as if by
1349 
1350 |	func (abfd, the_section, obj);
1351 
1352 	This is the preferred method for iterating over sections; an
1353 	alternative would be to use a loop:
1354 
1355 |	   asection *p;
1356 |	   for (p = abfd->sections; p != NULL; p = p->next)
1357 |	      func (abfd, p, ...)
1358 
1359 */
1360 
1361 void
bfd_map_over_sections(bfd * abfd,void (* operation)(bfd *,asection *,void *),void * user_storage)1362 bfd_map_over_sections (bfd *abfd,
1363 		       void (*operation) (bfd *, asection *, void *),
1364 		       void *user_storage)
1365 {
1366   asection *sect;
1367   unsigned int i = 0;
1368 
1369   for (sect = abfd->sections; sect != NULL; i++, sect = sect->next)
1370     (*operation) (abfd, sect, user_storage);
1371 
1372   if (i != abfd->section_count)	/* Debugging */
1373     abort ();
1374 }
1375 
1376 /*
1377 FUNCTION
1378 	bfd_sections_find_if
1379 
1380 SYNOPSIS
1381 	asection *bfd_sections_find_if
1382 	  (bfd *abfd,
1383 	   bool (*operation) (bfd *abfd, asection *sect, void *obj),
1384 	   void *obj);
1385 
1386 DESCRIPTION
1387 	Call the provided function @var{operation} for each section
1388 	attached to the BFD @var{abfd}, passing @var{obj} as an
1389 	argument. The function will be called as if by
1390 
1391 |	operation (abfd, the_section, obj);
1392 
1393 	It returns the first section for which @var{operation} returns true.
1394 
1395 */
1396 
1397 asection *
bfd_sections_find_if(bfd * abfd,bool (* operation)(bfd *,asection *,void *),void * user_storage)1398 bfd_sections_find_if (bfd *abfd,
1399 		      bool (*operation) (bfd *, asection *, void *),
1400 		      void *user_storage)
1401 {
1402   asection *sect;
1403 
1404   for (sect = abfd->sections; sect != NULL; sect = sect->next)
1405     if ((*operation) (abfd, sect, user_storage))
1406       break;
1407 
1408   return sect;
1409 }
1410 
1411 /*
1412 FUNCTION
1413 	bfd_set_section_size
1414 
1415 SYNOPSIS
1416 	bool bfd_set_section_size (asection *sec, bfd_size_type val);
1417 
1418 DESCRIPTION
1419 	Set @var{sec} to the size @var{val}. If the operation is
1420 	ok, then <<TRUE>> is returned, else <<FALSE>>.
1421 
1422 	Possible error returns:
1423 	o <<bfd_error_invalid_operation>> -
1424 	Writing has started to the BFD, so setting the size is invalid.
1425 
1426 */
1427 
1428 bool
bfd_set_section_size(asection * sec,bfd_size_type val)1429 bfd_set_section_size (asection *sec, bfd_size_type val)
1430 {
1431   /* Once you've started writing to any section you cannot create or change
1432      the size of any others.  */
1433 
1434   if (sec->owner == NULL || sec->owner->output_has_begun)
1435     {
1436       bfd_set_error (bfd_error_invalid_operation);
1437       return false;
1438     }
1439 
1440   sec->size = val;
1441   return true;
1442 }
1443 
1444 /*
1445 FUNCTION
1446 	bfd_set_section_contents
1447 
1448 SYNOPSIS
1449 	bool bfd_set_section_contents
1450 	  (bfd *abfd, asection *section, const void *data,
1451 	   file_ptr offset, bfd_size_type count);
1452 
1453 DESCRIPTION
1454 	Sets the contents of the section @var{section} in BFD
1455 	@var{abfd} to the data starting in memory at @var{location}.
1456 	The data is written to the output section starting at offset
1457 	@var{offset} for @var{count} octets.
1458 
1459 	Normally <<TRUE>> is returned, but <<FALSE>> is returned if
1460 	there was an error.  Possible error returns are:
1461 	o <<bfd_error_no_contents>> -
1462 	The output section does not have the <<SEC_HAS_CONTENTS>>
1463 	attribute, so nothing can be written to it.
1464 	o <<bfd_error_bad_value>> -
1465 	The section is unable to contain all of the data.
1466 	o <<bfd_error_invalid_operation>> -
1467 	The BFD is not writeable.
1468 	o and some more too.
1469 
1470 	This routine is front end to the back end function
1471 	<<_bfd_set_section_contents>>.
1472 
1473 */
1474 
1475 bool
bfd_set_section_contents(bfd * abfd,sec_ptr section,const void * location,file_ptr offset,bfd_size_type count)1476 bfd_set_section_contents (bfd *abfd,
1477 			  sec_ptr section,
1478 			  const void *location,
1479 			  file_ptr offset,
1480 			  bfd_size_type count)
1481 {
1482   bfd_size_type sz;
1483 
1484   if (!(bfd_section_flags (section) & SEC_HAS_CONTENTS))
1485     {
1486       bfd_set_error (bfd_error_no_contents);
1487       return false;
1488     }
1489 
1490   sz = section->size;
1491   if ((bfd_size_type) offset > sz
1492       || count > sz - offset
1493       || count != (size_t) count)
1494     {
1495       bfd_set_error (bfd_error_bad_value);
1496       return false;
1497     }
1498 
1499   if (!bfd_write_p (abfd))
1500     {
1501       bfd_set_error (bfd_error_invalid_operation);
1502       return false;
1503     }
1504 
1505   /* Record a copy of the data in memory if desired.  */
1506   if (section->contents
1507       && location != section->contents + offset)
1508     memcpy (section->contents + offset, location, (size_t) count);
1509 
1510   if (BFD_SEND (abfd, _bfd_set_section_contents,
1511 		(abfd, section, location, offset, count)))
1512     {
1513       abfd->output_has_begun = true;
1514       return true;
1515     }
1516 
1517   return false;
1518 }
1519 
1520 /*
1521 FUNCTION
1522 	bfd_get_section_contents
1523 
1524 SYNOPSIS
1525 	bool bfd_get_section_contents
1526 	  (bfd *abfd, asection *section, void *location, file_ptr offset,
1527 	   bfd_size_type count);
1528 
1529 DESCRIPTION
1530 	Read data from @var{section} in BFD @var{abfd}
1531 	into memory starting at @var{location}. The data is read at an
1532 	offset of @var{offset} from the start of the input section,
1533 	and is read for @var{count} bytes.
1534 
1535 	If the contents of a constructor with the <<SEC_CONSTRUCTOR>>
1536 	flag set are requested or if the section does not have the
1537 	<<SEC_HAS_CONTENTS>> flag set, then the @var{location} is filled
1538 	with zeroes. If no errors occur, <<TRUE>> is returned, else
1539 	<<FALSE>>.
1540 
1541 */
1542 bool
bfd_get_section_contents(bfd * abfd,sec_ptr section,void * location,file_ptr offset,bfd_size_type count)1543 bfd_get_section_contents (bfd *abfd,
1544 			  sec_ptr section,
1545 			  void *location,
1546 			  file_ptr offset,
1547 			  bfd_size_type count)
1548 {
1549   bfd_size_type sz;
1550 
1551   if (section->flags & SEC_CONSTRUCTOR)
1552     {
1553       memset (location, 0, (size_t) count);
1554       return true;
1555     }
1556 
1557   if (abfd->direction != write_direction && section->rawsize != 0)
1558     sz = section->rawsize;
1559   else
1560     sz = section->size;
1561   if ((bfd_size_type) offset > sz
1562       || count > sz - offset
1563       || count != (size_t) count)
1564     {
1565       bfd_set_error (bfd_error_bad_value);
1566       return false;
1567     }
1568 
1569   if (count == 0)
1570     /* Don't bother.  */
1571     return true;
1572 
1573   if ((section->flags & SEC_HAS_CONTENTS) == 0)
1574     {
1575       memset (location, 0, (size_t) count);
1576       return true;
1577     }
1578 
1579   if ((section->flags & SEC_IN_MEMORY) != 0)
1580     {
1581       if (section->contents == NULL)
1582 	{
1583 	  /* This can happen because of errors earlier on in the linking process.
1584 	     We do not want to seg-fault here, so clear the flag and return an
1585 	     error code.  */
1586 	  section->flags &= ~ SEC_IN_MEMORY;
1587 	  bfd_set_error (bfd_error_invalid_operation);
1588 	  return false;
1589 	}
1590 
1591       memmove (location, section->contents + offset, (size_t) count);
1592       return true;
1593     }
1594 
1595   return BFD_SEND (abfd, _bfd_get_section_contents,
1596 		   (abfd, section, location, offset, count));
1597 }
1598 
1599 /*
1600 FUNCTION
1601 	bfd_malloc_and_get_section
1602 
1603 SYNOPSIS
1604 	bool bfd_malloc_and_get_section
1605 	  (bfd *abfd, asection *section, bfd_byte **buf);
1606 
1607 DESCRIPTION
1608 	Read all data from @var{section} in BFD @var{abfd}
1609 	into a buffer, *@var{buf}, malloc'd by this function.
1610 */
1611 
1612 bool
bfd_malloc_and_get_section(bfd * abfd,sec_ptr sec,bfd_byte ** buf)1613 bfd_malloc_and_get_section (bfd *abfd, sec_ptr sec, bfd_byte **buf)
1614 {
1615   *buf = NULL;
1616   return bfd_get_full_section_contents (abfd, sec, buf);
1617 }
1618 /*
1619 FUNCTION
1620 	bfd_copy_private_section_data
1621 
1622 SYNOPSIS
1623 	bool bfd_copy_private_section_data
1624 	  (bfd *ibfd, asection *isec, bfd *obfd, asection *osec);
1625 
1626 DESCRIPTION
1627 	Copy private section information from @var{isec} in the BFD
1628 	@var{ibfd} to the section @var{osec} in the BFD @var{obfd}.
1629 	Return <<TRUE>> on success, <<FALSE>> on error.  Possible error
1630 	returns are:
1631 
1632 	o <<bfd_error_no_memory>> -
1633 	Not enough memory exists to create private data for @var{osec}.
1634 
1635 .#define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \
1636 .	BFD_SEND (obfd, _bfd_copy_private_section_data, \
1637 .		  (ibfd, isection, obfd, osection))
1638 */
1639 
1640 /*
1641 FUNCTION
1642 	bfd_generic_is_group_section
1643 
1644 SYNOPSIS
1645 	bool bfd_generic_is_group_section (bfd *, const asection *sec);
1646 
1647 DESCRIPTION
1648 	Returns TRUE if @var{sec} is a member of a group.
1649 */
1650 
1651 bool
bfd_generic_is_group_section(bfd * abfd ATTRIBUTE_UNUSED,const asection * sec ATTRIBUTE_UNUSED)1652 bfd_generic_is_group_section (bfd *abfd ATTRIBUTE_UNUSED,
1653 			      const asection *sec ATTRIBUTE_UNUSED)
1654 {
1655   return false;
1656 }
1657 
1658 /*
1659 FUNCTION
1660 	bfd_generic_group_name
1661 
1662 SYNOPSIS
1663 	const char *bfd_generic_group_name (bfd *, const asection *sec);
1664 
1665 DESCRIPTION
1666 	Returns group name if @var{sec} is a member of a group.
1667 */
1668 
1669 const char *
bfd_generic_group_name(bfd * abfd ATTRIBUTE_UNUSED,const asection * sec ATTRIBUTE_UNUSED)1670 bfd_generic_group_name (bfd *abfd ATTRIBUTE_UNUSED,
1671 			const asection *sec ATTRIBUTE_UNUSED)
1672 {
1673   return NULL;
1674 }
1675 
1676 /*
1677 FUNCTION
1678 	bfd_generic_discard_group
1679 
1680 SYNOPSIS
1681 	bool bfd_generic_discard_group (bfd *abfd, asection *group);
1682 
1683 DESCRIPTION
1684 	Remove all members of @var{group} from the output.
1685 */
1686 
1687 bool
bfd_generic_discard_group(bfd * abfd ATTRIBUTE_UNUSED,asection * group ATTRIBUTE_UNUSED)1688 bfd_generic_discard_group (bfd *abfd ATTRIBUTE_UNUSED,
1689 			   asection *group ATTRIBUTE_UNUSED)
1690 {
1691   return true;
1692 }
1693 
1694 bool
_bfd_nowrite_set_section_contents(bfd * abfd,sec_ptr section ATTRIBUTE_UNUSED,const void * location ATTRIBUTE_UNUSED,file_ptr offset ATTRIBUTE_UNUSED,bfd_size_type count ATTRIBUTE_UNUSED)1695 _bfd_nowrite_set_section_contents (bfd *abfd,
1696 				   sec_ptr section ATTRIBUTE_UNUSED,
1697 				   const void *location ATTRIBUTE_UNUSED,
1698 				   file_ptr offset ATTRIBUTE_UNUSED,
1699 				   bfd_size_type count ATTRIBUTE_UNUSED)
1700 {
1701   return _bfd_bool_bfd_false_error (abfd);
1702 }
1703