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/* Object file "section" support for the BFD library.
2
   Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
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   2000, 2001
4
   Free Software Foundation, Inc.
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   Written by Cygnus Support.
6
 
7
This file is part of BFD, the Binary File Descriptor library.
8
 
9
This program is free software; you can redistribute it and/or modify
10
it under the terms of the GNU General Public License as published by
11
the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
13
 
14
This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17
GNU General Public License for more details.
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19
You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
21
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
22
 
23
/*
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SECTION
25
        Sections
26
 
27
        The raw data contained within a BFD is maintained through the
28
        section abstraction.  A single BFD may have any number of
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        sections.  It keeps hold of them by pointing to the first;
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        each one points to the next in the list.
31
 
32
        Sections are supported in BFD in <<section.c>>.
33
 
34
@menu
35
@* Section Input::
36
@* Section Output::
37
@* typedef asection::
38
@* section prototypes::
39
@end menu
40
 
41
INODE
42
Section Input, Section Output, Sections, Sections
43
SUBSECTION
44
        Section input
45
 
46
        When a BFD is opened for reading, the section structures are
47
        created and attached to the BFD.
48
 
49
        Each section has a name which describes the section in the
50
        outside world---for example, <<a.out>> would contain at least
51
        three sections, called <<.text>>, <<.data>> and <<.bss>>.
52
 
53
        Names need not be unique; for example a COFF file may have several
54
        sections named <<.data>>.
55
 
56
        Sometimes a BFD will contain more than the ``natural'' number of
57
        sections. A back end may attach other sections containing
58
        constructor data, or an application may add a section (using
59
        <<bfd_make_section>>) to the sections attached to an already open
60
        BFD. For example, the linker creates an extra section
61
        <<COMMON>> for each input file's BFD to hold information about
62
        common storage.
63
 
64
        The raw data is not necessarily read in when
65
        the section descriptor is created. Some targets may leave the
66
        data in place until a <<bfd_get_section_contents>> call is
67
        made. Other back ends may read in all the data at once.  For
68
        example, an S-record file has to be read once to determine the
69
        size of the data. An IEEE-695 file doesn't contain raw data in
70
        sections, but data and relocation expressions intermixed, so
71
        the data area has to be parsed to get out the data and
72
        relocations.
73
 
74
INODE
75
Section Output, typedef asection, Section Input, Sections
76
 
77
SUBSECTION
78
        Section output
79
 
80
        To write a new object style BFD, the various sections to be
81
        written have to be created. They are attached to the BFD in
82
        the same way as input sections; data is written to the
83
        sections using <<bfd_set_section_contents>>.
84
 
85
        Any program that creates or combines sections (e.g., the assembler
86
        and linker) must use the <<asection>> fields <<output_section>> and
87
        <<output_offset>> to indicate the file sections to which each
88
        section must be written.  (If the section is being created from
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        scratch, <<output_section>> should probably point to the section
90
        itself and <<output_offset>> should probably be zero.)
91
 
92
        The data to be written comes from input sections attached
93
        (via <<output_section>> pointers) to
94
        the output sections.  The output section structure can be
95
        considered a filter for the input section: the output section
96
        determines the vma of the output data and the name, but the
97
        input section determines the offset into the output section of
98
        the data to be written.
99
 
100
        E.g., to create a section "O", starting at 0x100, 0x123 long,
101
        containing two subsections, "A" at offset 0x0 (i.e., at vma
102
        0x100) and "B" at offset 0x20 (i.e., at vma 0x120) the <<asection>>
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        structures would look like:
104
 
105
|   section name          "A"
106
|     output_offset   0x00
107
|     size            0x20
108
|     output_section ----------->  section name    "O"
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|                             |    vma             0x100
110
|   section name          "B" |    size            0x123
111
|     output_offset   0x20    |
112
|     size            0x103   |
113
|     output_section  --------|
114
 
115
SUBSECTION
116
        Link orders
117
 
118
        The data within a section is stored in a @dfn{link_order}.
119
        These are much like the fixups in <<gas>>.  The link_order
120
        abstraction allows a section to grow and shrink within itself.
121
 
122
        A link_order knows how big it is, and which is the next
123
        link_order and where the raw data for it is; it also points to
124
        a list of relocations which apply to it.
125
 
126
        The link_order is used by the linker to perform relaxing on
127
        final code.  The compiler creates code which is as big as
128
        necessary to make it work without relaxing, and the user can
129
        select whether to relax.  Sometimes relaxing takes a lot of
130
        time.  The linker runs around the relocations to see if any
131
        are attached to data which can be shrunk, if so it does it on
132
        a link_order by link_order basis.
133
 
134
*/
135
 
136
#include "bfd.h"
137
#include "sysdep.h"
138
#include "libbfd.h"
139
#include "bfdlink.h"
140
 
141
/*
142
DOCDD
143
INODE
144
typedef asection, section prototypes, Section Output, Sections
145
SUBSECTION
146
        typedef asection
147
 
148
        Here is the section structure:
149
 
150
CODE_FRAGMENT
151
.
152
.{* This structure is used for a comdat section, as in PE.  A comdat
153
.   section is associated with a particular symbol.  When the linker
154
.   sees a comdat section, it keeps only one of the sections with a
155
.   given name and associated with a given symbol.  *}
156
.
157
.struct bfd_comdat_info
158
.{
159
.  {* The name of the symbol associated with a comdat section.  *}
160
.  const char *name;
161
.
162
.  {* The local symbol table index of the symbol associated with a
163
.     comdat section.  This is only meaningful to the object file format
164
.     specific code; it is not an index into the list returned by
165
.     bfd_canonicalize_symtab.  *}
166
.  long symbol;
167
.};
168
.
169
.typedef struct sec
170
.{
171
.  {* The name of the section; the name isn't a copy, the pointer is
172
.     the same as that passed to bfd_make_section.  *}
173
.
174
.  const char *name;
175
.
176
.  {* A unique sequence number.  *}
177
.
178
.  int id;
179
.
180
.  {* Which section is it; 0..nth.  *}
181
.
182
.  int index;
183
.
184
.  {* The next section in the list belonging to the BFD, or NULL.  *}
185
.
186
.  struct sec *next;
187
.
188
.  {* The field flags contains attributes of the section. Some
189
.     flags are read in from the object file, and some are
190
.     synthesized from other information.  *}
191
.
192
.  flagword flags;
193
.
194
.#define SEC_NO_FLAGS   0x000
195
.
196
.  {* Tells the OS to allocate space for this section when loading.
197
.     This is clear for a section containing debug information only.  *}
198
.#define SEC_ALLOC      0x001
199
.
200
.  {* Tells the OS to load the section from the file when loading.
201
.     This is clear for a .bss section.  *}
202
.#define SEC_LOAD       0x002
203
.
204
.  {* The section contains data still to be relocated, so there is
205
.     some relocation information too.  *}
206
.#define SEC_RELOC      0x004
207
.
208
.#if 0   {* Obsolete ? *}
209
.#define SEC_BALIGN     0x008
210
.#endif
211
.
212
.  {* A signal to the OS that the section contains read only data.  *}
213
.#define SEC_READONLY   0x010
214
.
215
.  {* The section contains code only.  *}
216
.#define SEC_CODE       0x020
217
.
218
.  {* The section contains data only.  *}
219
.#define SEC_DATA       0x040
220
.
221
.  {* The section will reside in ROM.  *}
222
.#define SEC_ROM        0x080
223
.
224
.  {* The section contains constructor information. This section
225
.     type is used by the linker to create lists of constructors and
226
.     destructors used by <<g++>>. When a back end sees a symbol
227
.     which should be used in a constructor list, it creates a new
228
.     section for the type of name (e.g., <<__CTOR_LIST__>>), attaches
229
.     the symbol to it, and builds a relocation. To build the lists
230
.     of constructors, all the linker has to do is catenate all the
231
.     sections called <<__CTOR_LIST__>> and relocate the data
232
.     contained within - exactly the operations it would peform on
233
.     standard data.  *}
234
.#define SEC_CONSTRUCTOR 0x100
235
.
236
.  {* The section is a constructor, and should be placed at the
237
.     end of the text, data, or bss section(?).  *}
238
.#define SEC_CONSTRUCTOR_TEXT 0x1100
239
.#define SEC_CONSTRUCTOR_DATA 0x2100
240
.#define SEC_CONSTRUCTOR_BSS  0x3100
241
.
242
.  {* The section has contents - a data section could be
243
.     <<SEC_ALLOC>> | <<SEC_HAS_CONTENTS>>; a debug section could be
244
.     <<SEC_HAS_CONTENTS>>  *}
245
.#define SEC_HAS_CONTENTS 0x200
246
.
247
.  {* An instruction to the linker to not output the section
248
.     even if it has information which would normally be written.  *}
249
.#define SEC_NEVER_LOAD 0x400
250
.
251
.  {* The section is a COFF shared library section.  This flag is
252
.     only for the linker.  If this type of section appears in
253
.     the input file, the linker must copy it to the output file
254
.     without changing the vma or size.  FIXME: Although this
255
.     was originally intended to be general, it really is COFF
256
.     specific (and the flag was renamed to indicate this).  It
257
.     might be cleaner to have some more general mechanism to
258
.     allow the back end to control what the linker does with
259
.     sections.  *}
260
.#define SEC_COFF_SHARED_LIBRARY 0x800
261
.
262
.  {* The section has GOT references.  This flag is only for the
263
.     linker, and is currently only used by the elf32-hppa back end.
264
.     It will be set if global offset table references were detected
265
.     in this section, which indicate to the linker that the section
266
.     contains PIC code, and must be handled specially when doing a
267
.     static link.  *}
268
.#define SEC_HAS_GOT_REF 0x4000
269
.
270
.  {* The section contains common symbols (symbols may be defined
271
.     multiple times, the value of a symbol is the amount of
272
.     space it requires, and the largest symbol value is the one
273
.     used).  Most targets have exactly one of these (which we
274
.     translate to bfd_com_section_ptr), but ECOFF has two.  *}
275
.#define SEC_IS_COMMON 0x8000
276
.
277
.  {* The section contains only debugging information.  For
278
.     example, this is set for ELF .debug and .stab sections.
279
.     strip tests this flag to see if a section can be
280
.     discarded.  *}
281
.#define SEC_DEBUGGING 0x10000
282
.
283
.  {* The contents of this section are held in memory pointed to
284
.     by the contents field.  This is checked by bfd_get_section_contents,
285
.     and the data is retrieved from memory if appropriate.  *}
286
.#define SEC_IN_MEMORY 0x20000
287
.
288
.  {* The contents of this section are to be excluded by the
289
.     linker for executable and shared objects unless those
290
.     objects are to be further relocated.  *}
291
.#define SEC_EXCLUDE 0x40000
292
.
293
.  {* The contents of this section are to be sorted by the
294
.     based on the address specified in the associated symbol
295
.     table.  *}
296
.#define SEC_SORT_ENTRIES 0x80000
297
.
298
.  {* When linking, duplicate sections of the same name should be
299
.     discarded, rather than being combined into a single section as
300
.     is usually done.  This is similar to how common symbols are
301
.     handled.  See SEC_LINK_DUPLICATES below.  *}
302
.#define SEC_LINK_ONCE 0x100000
303
.
304
.  {* If SEC_LINK_ONCE is set, this bitfield describes how the linker
305
.     should handle duplicate sections.  *}
306
.#define SEC_LINK_DUPLICATES 0x600000
307
.
308
.  {* This value for SEC_LINK_DUPLICATES means that duplicate
309
.     sections with the same name should simply be discarded.  *}
310
.#define SEC_LINK_DUPLICATES_DISCARD 0x0
311
.
312
.  {* This value for SEC_LINK_DUPLICATES means that the linker
313
.     should warn if there are any duplicate sections, although
314
.     it should still only link one copy.  *}
315
.#define SEC_LINK_DUPLICATES_ONE_ONLY 0x200000
316
.
317
.  {* This value for SEC_LINK_DUPLICATES means that the linker
318
.     should warn if any duplicate sections are a different size.  *}
319
.#define SEC_LINK_DUPLICATES_SAME_SIZE 0x400000
320
.
321
.  {* This value for SEC_LINK_DUPLICATES means that the linker
322
.     should warn if any duplicate sections contain different
323
.     contents.  *}
324
.#define SEC_LINK_DUPLICATES_SAME_CONTENTS 0x600000
325
.
326
.  {* This section was created by the linker as part of dynamic
327
.     relocation or other arcane processing.  It is skipped when
328
.     going through the first-pass output, trusting that someone
329
.     else up the line will take care of it later.  *}
330
.#define SEC_LINKER_CREATED 0x800000
331
.
332
.  {* This section should not be subject to garbage collection.  *}
333
.#define SEC_KEEP 0x1000000
334
.
335
.  {* This section contains "short" data, and should be placed
336
.     "near" the GP.  *}
337
.#define SEC_SMALL_DATA 0x2000000
338
.
339
.  {* This section contains data which may be shared with other
340
.     executables or shared objects.  *}
341
.#define SEC_SHARED 0x4000000
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, it
346
.     should be aligned on a page boundary.  *}
347
.#define SEC_BLOCK 0x8000000
348
.
349
.  {* Conditionally link this section; do not link if there are no
350
.     references found to any symbol in the section.  *}
351
.#define SEC_CLINK 0x10000000
352
.
353
.  {* Attempt to merge identical entities in the section.
354
.     Entity size is given in the entsize field.  *}
355
.#define SEC_MERGE 0x20000000
356
.
357
.  {* If given with SEC_MERGE, entities to merge are zero terminated
358
.     strings where entsize specifies character size instead of fixed
359
.     size entries.  *}
360
.#define SEC_STRINGS 0x40000000
361
.
362
.  {*  End of section flags.  *}
363
.
364
.  {* Some internal packed boolean fields.  *}
365
.
366
.  {* See the vma field.  *}
367
.  unsigned int user_set_vma : 1;
368
.
369
.  {* Whether relocations have been processed.  *}
370
.  unsigned int reloc_done : 1;
371
.
372
.  {* A mark flag used by some of the linker backends.  *}
373
.  unsigned int linker_mark : 1;
374
.
375
.  {* Another mark flag used by some of the linker backends.  Set for
376
.     output sections that have a input section.  *}
377
.  unsigned int linker_has_input : 1;
378
.
379
.  {* A mark flag used by some linker backends for garbage collection.  *}
380
.  unsigned int gc_mark : 1;
381
.
382
.  {* Used by the ELF code to mark sections which have been allocated to segments.  *}
383
.  unsigned int segment_mark : 1;
384
.
385
.  {* End of internal packed boolean fields.  *}
386
.
387
.  {*  The virtual memory address of the section - where it will be
388
.      at run time.  The symbols are relocated against this.  The
389
.      user_set_vma flag is maintained by bfd; if it's not set, the
390
.      backend can assign addresses (for example, in <<a.out>>, where
391
.      the default address for <<.data>> is dependent on the specific
392
.      target and various flags).  *}
393
.
394
.  bfd_vma vma;
395
.
396
.  {*  The load address of the section - where it would be in a
397
.      rom image; really only used for writing section header
398
.      information. *}
399
.
400
.  bfd_vma lma;
401
.
402
.  {* The size of the section in octets, as it will be output.
403
.     Contains a value even if the section has no contents (e.g., the
404
.     size of <<.bss>>).  This will be filled in after relocation.  *}
405
.
406
.  bfd_size_type _cooked_size;
407
.
408
.  {* The original size on disk of the section, in octets.  Normally this
409
.     value is the same as the size, but if some relaxing has
410
.     been done, then this value will be bigger.  *}
411
.
412
.  bfd_size_type _raw_size;
413
.
414
.  {* If this section is going to be output, then this value is the
415
.     offset in *bytes* into the output section of the first byte in the
416
.     input section (byte ==> smallest addressable unit on the
417
.     target).  In most cases, if this was going to start at the
418
.     100th octet (8-bit quantity) in the output section, this value
419
.     would be 100.  However, if the target byte size is 16 bits
420
.     (bfd_octets_per_byte is "2"), this value would be 50.  *}
421
.
422
.  bfd_vma output_offset;
423
.
424
.  {* The output section through which to map on output.  *}
425
.
426
.  struct sec *output_section;
427
.
428
.  {* The alignment requirement of the section, as an exponent of 2 -
429
.     e.g., 3 aligns to 2^3 (or 8).  *}
430
.
431
.  unsigned int alignment_power;
432
.
433
.  {* If an input section, a pointer to a vector of relocation
434
.     records for the data in this section.  *}
435
.
436
.  struct reloc_cache_entry *relocation;
437
.
438
.  {* If an output section, a pointer to a vector of pointers to
439
.     relocation records for the data in this section.  *}
440
.
441
.  struct reloc_cache_entry **orelocation;
442
.
443
.  {* The number of relocation records in one of the above  *}
444
.
445
.  unsigned reloc_count;
446
.
447
.  {* Information below is back end specific - and not always used
448
.     or updated.  *}
449
.
450
.  {* File position of section data.  *}
451
.
452
.  file_ptr filepos;
453
.
454
.  {* File position of relocation info.  *}
455
.
456
.  file_ptr rel_filepos;
457
.
458
.  {* File position of line data.  *}
459
.
460
.  file_ptr line_filepos;
461
.
462
.  {* Pointer to data for applications.  *}
463
.
464
.  PTR userdata;
465
.
466
.  {* If the SEC_IN_MEMORY flag is set, this points to the actual
467
.     contents.  *}
468
.  unsigned char *contents;
469
.
470
.  {* Attached line number information.  *}
471
.
472
.  alent *lineno;
473
.
474
.  {* Number of line number records.  *}
475
.
476
.  unsigned int lineno_count;
477
.
478
.  {* Entity size for merging purposes.  *}
479
.
480
.  unsigned int entsize;
481
.
482
.  {* Optional information about a COMDAT entry; NULL if not COMDAT.  *}
483
.
484
.  struct bfd_comdat_info *comdat;
485
.
486
.  {* Points to the kept section if this section is a link-once section,
487
.     and is discarded.  *}
488
.  struct sec *kept_section;
489
.
490
.  {* When a section is being output, this value changes as more
491
.     linenumbers are written out.  *}
492
.
493
.  file_ptr moving_line_filepos;
494
.
495
.  {* What the section number is in the target world.  *}
496
.
497
.  int target_index;
498
.
499
.  PTR used_by_bfd;
500
.
501
.  {* If this is a constructor section then here is a list of the
502
.     relocations created to relocate items within it.  *}
503
.
504
.  struct relent_chain *constructor_chain;
505
.
506
.  {* The BFD which owns the section.  *}
507
.
508
.  bfd *owner;
509
.
510
.  {* A symbol which points at this section only *}
511
.  struct symbol_cache_entry *symbol;
512
.  struct symbol_cache_entry **symbol_ptr_ptr;
513
.
514
.  struct bfd_link_order *link_order_head;
515
.  struct bfd_link_order *link_order_tail;
516
.} asection ;
517
.
518
.{* These sections are global, and are managed by BFD.  The application
519
.   and target back end are not permitted to change the values in
520
.   these sections.  New code should use the section_ptr macros rather
521
.   than referring directly to the const sections.  The const sections
522
.   may eventually vanish.  *}
523
.#define BFD_ABS_SECTION_NAME "*ABS*"
524
.#define BFD_UND_SECTION_NAME "*UND*"
525
.#define BFD_COM_SECTION_NAME "*COM*"
526
.#define BFD_IND_SECTION_NAME "*IND*"
527
.
528
.{* the absolute section *}
529
.extern const asection bfd_abs_section;
530
.#define bfd_abs_section_ptr ((asection *) &bfd_abs_section)
531
.#define bfd_is_abs_section(sec) ((sec) == bfd_abs_section_ptr)
532
.{* Pointer to the undefined section *}
533
.extern const asection bfd_und_section;
534
.#define bfd_und_section_ptr ((asection *) &bfd_und_section)
535
.#define bfd_is_und_section(sec) ((sec) == bfd_und_section_ptr)
536
.{* Pointer to the common section *}
537
.extern const asection bfd_com_section;
538
.#define bfd_com_section_ptr ((asection *) &bfd_com_section)
539
.{* Pointer to the indirect section *}
540
.extern const asection bfd_ind_section;
541
.#define bfd_ind_section_ptr ((asection *) &bfd_ind_section)
542
.#define bfd_is_ind_section(sec) ((sec) == bfd_ind_section_ptr)
543
.
544
.extern const struct symbol_cache_entry * const bfd_abs_symbol;
545
.extern const struct symbol_cache_entry * const bfd_com_symbol;
546
.extern const struct symbol_cache_entry * const bfd_und_symbol;
547
.extern const struct symbol_cache_entry * const bfd_ind_symbol;
548
.#define bfd_get_section_size_before_reloc(section) \
549
.     ((section)->reloc_done ? (abort (), (bfd_size_type) 1) \
550
.                            : (section)->_raw_size)
551
.#define bfd_get_section_size_after_reloc(section) \
552
.     ((section)->reloc_done ? (section)->_cooked_size \
553
.                            : (abort (), (bfd_size_type) 1))
554
*/
555
 
556
/* We use a macro to initialize the static asymbol structures because
557
   traditional C does not permit us to initialize a union member while
558
   gcc warns if we don't initialize it.  */
559
 /* the_bfd, name, value, attr, section [, udata] */
560
#ifdef __STDC__
561
#define GLOBAL_SYM_INIT(NAME, SECTION) \
562
  { 0, NAME, 0, BSF_SECTION_SYM, (asection *) SECTION, { 0 }}
563
#else
564
#define GLOBAL_SYM_INIT(NAME, SECTION) \
565
  { 0, NAME, 0, BSF_SECTION_SYM, (asection *) SECTION }
566
#endif
567
 
568
/* These symbols are global, not specific to any BFD.  Therefore, anything
569
   that tries to change them is broken, and should be repaired.  */
570
 
571
static const asymbol global_syms[] =
572
{
573
  GLOBAL_SYM_INIT (BFD_COM_SECTION_NAME, &bfd_com_section),
574
  GLOBAL_SYM_INIT (BFD_UND_SECTION_NAME, &bfd_und_section),
575
  GLOBAL_SYM_INIT (BFD_ABS_SECTION_NAME, &bfd_abs_section),
576
  GLOBAL_SYM_INIT (BFD_IND_SECTION_NAME, &bfd_ind_section)
577
};
578
 
579
#define STD_SECTION(SEC, FLAGS, SYM, NAME, IDX)                         \
580
  const asymbol * const SYM = (asymbol *) &global_syms[IDX];            \
581
  const asection SEC =                                                  \
582
    /* name, id,  index, next, flags, user_set_vma, reloc_done,      */ \
583
    { NAME,  IDX, 0,     NULL, FLAGS, 0,            0,                     \
584
                                                                        \
585
    /* linker_mark, linker_has_input, gc_mark, segment_mark,         */ \
586
       0,           0,                1,       0,                  \
587
                                                                        \
588
    /* vma, lma, _cooked_size, _raw_size,                            */ \
589
       0,   0,   0,            0,                                   \
590
                                                                        \
591
    /* output_offset, output_section,      alignment_power,          */ \
592
       0,             (struct sec *) &SEC, 0,                             \
593
                                                                        \
594
    /* relocation, orelocation, reloc_count, filepos, rel_filepos,   */ \
595
       NULL,       NULL,        0,           0,       0,           \
596
                                                                        \
597
    /* line_filepos, userdata, contents, lineno, lineno_count,       */ \
598
       0,            NULL,     NULL,     NULL,   0,                       \
599
                                                                        \
600
    /* entsize, comdat, kept_section, moving_line_filepos,           */ \
601
       0,       NULL,   NULL,         0,                          \
602
                                                                        \
603
    /* target_index, used_by_bfd, constructor_chain, owner,          */ \
604
       0,            NULL,        NULL,              NULL,               \
605
                                                                        \
606
    /* symbol,                                                       */ \
607
       (struct symbol_cache_entry *) &global_syms[IDX],                 \
608
                                                                        \
609
    /* symbol_ptr_ptr,                                               */ \
610
       (struct symbol_cache_entry **) &SYM,                             \
611
                                                                        \
612
    /* link_order_head, link_order_tail                              */ \
613
       NULL,            NULL                                            \
614
    }
615
 
616
STD_SECTION (bfd_com_section, SEC_IS_COMMON, bfd_com_symbol,
617
             BFD_COM_SECTION_NAME, 0);
618
STD_SECTION (bfd_und_section, 0, bfd_und_symbol, BFD_UND_SECTION_NAME, 1);
619
STD_SECTION (bfd_abs_section, 0, bfd_abs_symbol, BFD_ABS_SECTION_NAME, 2);
620
STD_SECTION (bfd_ind_section, 0, bfd_ind_symbol, BFD_IND_SECTION_NAME, 3);
621
#undef STD_SECTION
622
 
623
/*
624
DOCDD
625
INODE
626
section prototypes,  , typedef asection, Sections
627
SUBSECTION
628
        Section prototypes
629
 
630
These are the functions exported by the section handling part of BFD.
631
*/
632
 
633
/*
634
FUNCTION
635
        bfd_get_section_by_name
636
 
637
SYNOPSIS
638
        asection *bfd_get_section_by_name(bfd *abfd, const char *name);
639
 
640
DESCRIPTION
641
        Run through @var{abfd} and return the one of the
642
        <<asection>>s whose name matches @var{name}, otherwise <<NULL>>.
643
        @xref{Sections}, for more information.
644
 
645
        This should only be used in special cases; the normal way to process
646
        all sections of a given name is to use <<bfd_map_over_sections>> and
647
        <<strcmp>> on the name (or better yet, base it on the section flags
648
        or something else) for each section.
649
*/
650
 
651
asection *
652
bfd_get_section_by_name (abfd, name)
653
     bfd *abfd;
654
     const char *name;
655
{
656
  asection *sect;
657
 
658
  for (sect = abfd->sections; sect != NULL; sect = sect->next)
659
    if (!strcmp (sect->name, name))
660
      return sect;
661
  return NULL;
662
}
663
 
664
/*
665
FUNCTION
666
        bfd_get_unique_section_name
667
 
668
SYNOPSIS
669
        char *bfd_get_unique_section_name(bfd *abfd,
670
                                          const char *templat,
671
                                          int *count);
672
 
673
DESCRIPTION
674
        Invent a section name that is unique in @var{abfd} by tacking
675
        a dot and a digit suffix onto the original @var{templat}.  If
676
        @var{count} is non-NULL, then it specifies the first number
677
        tried as a suffix to generate a unique name.  The value
678
        pointed to by @var{count} will be incremented in this case.
679
*/
680
 
681
char *
682
bfd_get_unique_section_name (abfd, templat, count)
683
     bfd *abfd;
684
     const char *templat;
685
     int *count;
686
{
687
  int num;
688
  unsigned int len;
689
  char *sname;
690
 
691
  len = strlen (templat);
692
  sname = bfd_malloc (len + 8);
693
  if (sname == NULL)
694
    return NULL;
695
  strcpy (sname, templat);
696
  num = 1;
697
  if (count != NULL)
698
    num = *count;
699
 
700
  do
701
    {
702
      /* If we have a million sections, something is badly wrong.  */
703
      if (num > 999999)
704
        abort ();
705
      sprintf (sname + len, ".%d", num++);
706
    }
707
  while (bfd_get_section_by_name (abfd, sname) != NULL);
708
 
709
  if (count != NULL)
710
    *count = num;
711
  return sname;
712
}
713
 
714
/*
715
FUNCTION
716
        bfd_make_section_old_way
717
 
718
SYNOPSIS
719
        asection *bfd_make_section_old_way(bfd *abfd, const char *name);
720
 
721
DESCRIPTION
722
        Create a new empty section called @var{name}
723
        and attach it to the end of the chain of sections for the
724
        BFD @var{abfd}. An attempt to create a section with a name which
725
        is already in use returns its pointer without changing the
726
        section chain.
727
 
728
        It has the funny name since this is the way it used to be
729
        before it was rewritten....
730
 
731
        Possible errors are:
732
        o <<bfd_error_invalid_operation>> -
733
        If output has already started for this BFD.
734
        o <<bfd_error_no_memory>> -
735
        If memory allocation fails.
736
 
737
*/
738
 
739
asection *
740
bfd_make_section_old_way (abfd, name)
741
     bfd *abfd;
742
     const char *name;
743
{
744
  asection *sec = bfd_get_section_by_name (abfd, name);
745
  if (sec == (asection *) NULL)
746
    {
747
      sec = bfd_make_section (abfd, name);
748
    }
749
  return sec;
750
}
751
 
752
/*
753
FUNCTION
754
        bfd_make_section_anyway
755
 
756
SYNOPSIS
757
        asection *bfd_make_section_anyway(bfd *abfd, const char *name);
758
 
759
DESCRIPTION
760
   Create a new empty section called @var{name} and attach it to the end of
761
   the chain of sections for @var{abfd}.  Create a new section even if there
762
   is already a section with that name.
763
 
764
   Return <<NULL>> and set <<bfd_error>> on error; possible errors are:
765
   o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}.
766
   o <<bfd_error_no_memory>> - If memory allocation fails.
767
*/
768
 
769
sec_ptr
770
bfd_make_section_anyway (abfd, name)
771
     bfd *abfd;
772
     const char *name;
773
{
774
  static int section_id = 0x10;  /* id 0 to 3 used by STD_SECTION.  */
775
  asection *newsect;
776
  asection **prev = &abfd->sections;
777
  asection *sect = abfd->sections;
778
 
779
  if (abfd->output_has_begun)
780
    {
781
      bfd_set_error (bfd_error_invalid_operation);
782
      return NULL;
783
    }
784
 
785
  while (sect)
786
    {
787
      prev = &sect->next;
788
      sect = sect->next;
789
    }
790
 
791
  newsect = (asection *) bfd_zalloc (abfd, sizeof (asection));
792
  if (newsect == NULL)
793
    return NULL;
794
 
795
  newsect->name = name;
796
  newsect->id = section_id++;
797
  newsect->index = abfd->section_count++;
798
  newsect->flags = SEC_NO_FLAGS;
799
 
800
  newsect->userdata = NULL;
801
  newsect->contents = NULL;
802
  newsect->next = (asection *) NULL;
803
  newsect->relocation = (arelent *) NULL;
804
  newsect->reloc_count = 0;
805
  newsect->line_filepos = 0;
806
  newsect->owner = abfd;
807
  newsect->comdat = NULL;
808
  newsect->kept_section = NULL;
809
 
810
  /* Create a symbol whos only job is to point to this section. This is
811
     useful for things like relocs which are relative to the base of a
812
     section.  */
813
  newsect->symbol = bfd_make_empty_symbol (abfd);
814
  if (newsect->symbol == NULL)
815
    {
816
      bfd_release (abfd, newsect);
817
      return NULL;
818
    }
819
  newsect->symbol->name = name;
820
  newsect->symbol->value = 0;
821
  newsect->symbol->section = newsect;
822
  newsect->symbol->flags = BSF_SECTION_SYM;
823
 
824
  newsect->symbol_ptr_ptr = &newsect->symbol;
825
 
826
  if (BFD_SEND (abfd, _new_section_hook, (abfd, newsect)) != true)
827
    {
828
      bfd_release (abfd, newsect);
829
      return NULL;
830
    }
831
 
832
  *prev = newsect;
833
  return newsect;
834
}
835
 
836
/*
837
FUNCTION
838
        bfd_make_section
839
 
840
SYNOPSIS
841
        asection *bfd_make_section(bfd *, const char *name);
842
 
843
DESCRIPTION
844
   Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling
845
   bfd_set_error ()) without changing the section chain if there is already a
846
   section named @var{name}.  If there is an error, return <<NULL>> and set
847
   <<bfd_error>>.
848
*/
849
 
850
asection *
851
bfd_make_section (abfd, name)
852
     bfd *abfd;
853
     const char *name;
854
{
855
  asection *sect = abfd->sections;
856
 
857
  if (strcmp (name, BFD_ABS_SECTION_NAME) == 0)
858
    {
859
      return bfd_abs_section_ptr;
860
    }
861
  if (strcmp (name, BFD_COM_SECTION_NAME) == 0)
862
    {
863
      return bfd_com_section_ptr;
864
    }
865
  if (strcmp (name, BFD_UND_SECTION_NAME) == 0)
866
    {
867
      return bfd_und_section_ptr;
868
    }
869
 
870
  if (strcmp (name, BFD_IND_SECTION_NAME) == 0)
871
    {
872
      return bfd_ind_section_ptr;
873
    }
874
 
875
  while (sect)
876
    {
877
      if (!strcmp (sect->name, name))
878
        return NULL;
879
      sect = sect->next;
880
    }
881
 
882
  /* The name is not already used; go ahead and make a new section.  */
883
  return bfd_make_section_anyway (abfd, name);
884
}
885
 
886
/*
887
FUNCTION
888
        bfd_set_section_flags
889
 
890
SYNOPSIS
891
        boolean bfd_set_section_flags(bfd *abfd, asection *sec, flagword flags);
892
 
893
DESCRIPTION
894
        Set the attributes of the section @var{sec} in the BFD
895
        @var{abfd} to the value @var{flags}. Return <<true>> on success,
896
        <<false>> on error. Possible error returns are:
897
 
898
        o <<bfd_error_invalid_operation>> -
899
        The section cannot have one or more of the attributes
900
        requested. For example, a .bss section in <<a.out>> may not
901
        have the <<SEC_HAS_CONTENTS>> field set.
902
 
903
*/
904
 
905
/*ARGSUSED*/
906
boolean
907
bfd_set_section_flags (abfd, section, flags)
908
     bfd *abfd ATTRIBUTE_UNUSED;
909
     sec_ptr section;
910
     flagword flags;
911
{
912
#if 0
913
  /* If you try to copy a text section from an input file (where it
914
     has the SEC_CODE flag set) to an output file, this loses big if
915
     the bfd_applicable_section_flags (abfd) doesn't have the SEC_CODE
916
     set - which it doesn't, at least not for a.out.  FIXME */
917
 
918
  if ((flags & bfd_applicable_section_flags (abfd)) != flags)
919
    {
920
      bfd_set_error (bfd_error_invalid_operation);
921
      return false;
922
    }
923
#endif
924
 
925
  section->flags = flags;
926
  return true;
927
}
928
 
929
/*
930
FUNCTION
931
        bfd_map_over_sections
932
 
933
SYNOPSIS
934
        void bfd_map_over_sections(bfd *abfd,
935
                                   void (*func) (bfd *abfd,
936
                                                asection *sect,
937
                                                PTR obj),
938
                                   PTR obj);
939
 
940
DESCRIPTION
941
        Call the provided function @var{func} for each section
942
        attached to the BFD @var{abfd}, passing @var{obj} as an
943
        argument. The function will be called as if by
944
 
945
|       func(abfd, the_section, obj);
946
 
947
        This is the prefered method for iterating over sections; an
948
        alternative would be to use a loop:
949
 
950
|          section *p;
951
|          for (p = abfd->sections; p != NULL; p = p->next)
952
|             func(abfd, p, ...)
953
 
954
*/
955
 
956
/*VARARGS2*/
957
void
958
bfd_map_over_sections (abfd, operation, user_storage)
959
     bfd *abfd;
960
     void (*operation) PARAMS ((bfd * abfd, asection * sect, PTR obj));
961
     PTR user_storage;
962
{
963
  asection *sect;
964
  unsigned int i = 0;
965
 
966
  for (sect = abfd->sections; sect != NULL; i++, sect = sect->next)
967
    (*operation) (abfd, sect, user_storage);
968
 
969
  if (i != abfd->section_count) /* Debugging */
970
    abort ();
971
}
972
 
973
/*
974
FUNCTION
975
        bfd_set_section_size
976
 
977
SYNOPSIS
978
        boolean bfd_set_section_size(bfd *abfd, asection *sec, bfd_size_type val);
979
 
980
DESCRIPTION
981
        Set @var{sec} to the size @var{val}. If the operation is
982
        ok, then <<true>> is returned, else <<false>>.
983
 
984
        Possible error returns:
985
        o <<bfd_error_invalid_operation>> -
986
        Writing has started to the BFD, so setting the size is invalid.
987
 
988
*/
989
 
990
boolean
991
bfd_set_section_size (abfd, ptr, val)
992
     bfd *abfd;
993
     sec_ptr ptr;
994
     bfd_size_type val;
995
{
996
  /* Once you've started writing to any section you cannot create or change
997
     the size of any others.  */
998
 
999
  if (abfd->output_has_begun)
1000
    {
1001
      bfd_set_error (bfd_error_invalid_operation);
1002
      return false;
1003
    }
1004
 
1005
  ptr->_cooked_size = val;
1006
  ptr->_raw_size = val;
1007
 
1008
  return true;
1009
}
1010
 
1011
/*
1012
FUNCTION
1013
        bfd_set_section_contents
1014
 
1015
SYNOPSIS
1016
        boolean bfd_set_section_contents
1017
         (bfd *abfd,
1018
         asection *section,
1019
         PTR data,
1020
         file_ptr offset,
1021
         bfd_size_type count);
1022
 
1023
DESCRIPTION
1024
        Sets the contents of the section @var{section} in BFD
1025
        @var{abfd} to the data starting in memory at @var{data}. The
1026
        data is written to the output section starting at offset
1027
        @var{offset} for @var{count} octets.
1028
 
1029
        Normally <<true>> is returned, else <<false>>. Possible error
1030
        returns are:
1031
        o <<bfd_error_no_contents>> -
1032
        The output section does not have the <<SEC_HAS_CONTENTS>>
1033
        attribute, so nothing can be written to it.
1034
        o and some more too
1035
 
1036
        This routine is front end to the back end function
1037
        <<_bfd_set_section_contents>>.
1038
 
1039
*/
1040
 
1041
#define bfd_get_section_size_now(abfd,sec) \
1042
(sec->reloc_done \
1043
 ? bfd_get_section_size_after_reloc (sec) \
1044
 : bfd_get_section_size_before_reloc (sec))
1045
 
1046
boolean
1047
bfd_set_section_contents (abfd, section, location, offset, count)
1048
     bfd *abfd;
1049
     sec_ptr section;
1050
     PTR location;
1051
     file_ptr offset;
1052
     bfd_size_type count;
1053
{
1054
  bfd_size_type sz;
1055
 
1056
  if (!(bfd_get_section_flags (abfd, section) & SEC_HAS_CONTENTS))
1057
    {
1058
      bfd_set_error (bfd_error_no_contents);
1059
      return (false);
1060
    }
1061
 
1062
  if (offset < 0)
1063
    {
1064
    bad_val:
1065
      bfd_set_error (bfd_error_bad_value);
1066
      return false;
1067
    }
1068
  sz = bfd_get_section_size_now (abfd, section);
1069
  if ((bfd_size_type) offset > sz
1070
      || count > sz
1071
      || offset + count > sz)
1072
    goto bad_val;
1073
 
1074
  switch (abfd->direction)
1075
    {
1076
    case read_direction:
1077
    case no_direction:
1078
      bfd_set_error (bfd_error_invalid_operation);
1079
      return false;
1080
 
1081
    case write_direction:
1082
      break;
1083
 
1084
    case both_direction:
1085
      /* File is opened for update. `output_has_begun' some time ago when
1086
           the file was created.  Do not recompute sections sizes or alignments
1087
           in _bfd_set_section_content.  */
1088
      abfd->output_has_begun = true;
1089
      break;
1090
    }
1091
 
1092
  /* Record a copy of the data in memory if desired.  */
1093
  if (section->contents
1094
      && location != section->contents + offset)
1095
    memcpy (section->contents + offset, location, count);
1096
 
1097
  if (BFD_SEND (abfd, _bfd_set_section_contents,
1098
                (abfd, section, location, offset, count)))
1099
    {
1100
      abfd->output_has_begun = true;
1101
      return true;
1102
    }
1103
 
1104
  return false;
1105
}
1106
 
1107
/*
1108
FUNCTION
1109
        bfd_get_section_contents
1110
 
1111
SYNOPSIS
1112
        boolean bfd_get_section_contents
1113
        (bfd *abfd, asection *section, PTR location,
1114
         file_ptr offset, bfd_size_type count);
1115
 
1116
DESCRIPTION
1117
        Read data from @var{section} in BFD @var{abfd}
1118
        into memory starting at @var{location}. The data is read at an
1119
        offset of @var{offset} from the start of the input section,
1120
        and is read for @var{count} bytes.
1121
 
1122
        If the contents of a constructor with the <<SEC_CONSTRUCTOR>>
1123
        flag set are requested or if the section does not have the
1124
        <<SEC_HAS_CONTENTS>> flag set, then the @var{location} is filled
1125
        with zeroes. If no errors occur, <<true>> is returned, else
1126
        <<false>>.
1127
 
1128
*/
1129
boolean
1130
bfd_get_section_contents (abfd, section, location, offset, count)
1131
     bfd *abfd;
1132
     sec_ptr section;
1133
     PTR location;
1134
     file_ptr offset;
1135
     bfd_size_type count;
1136
{
1137
  bfd_size_type sz;
1138
 
1139
  if (section->flags & SEC_CONSTRUCTOR)
1140
    {
1141
      memset (location, 0, (unsigned) count);
1142
      return true;
1143
    }
1144
 
1145
  if (offset < 0)
1146
    {
1147
    bad_val:
1148
      bfd_set_error (bfd_error_bad_value);
1149
      return false;
1150
    }
1151
  /* Even if reloc_done is true, this function reads unrelocated
1152
     contents, so we want the raw size.  */
1153
  sz = section->_raw_size;
1154
  if ((bfd_size_type) offset > sz || count > sz || offset + count > sz)
1155
    goto bad_val;
1156
 
1157
  if (count == 0)
1158
    /* Don't bother.  */
1159
    return true;
1160
 
1161
  if ((section->flags & SEC_HAS_CONTENTS) == 0)
1162
    {
1163
      memset (location, 0, (unsigned) count);
1164
      return true;
1165
    }
1166
 
1167
  if ((section->flags & SEC_IN_MEMORY) != 0)
1168
    {
1169
      memcpy (location, section->contents + offset, (size_t) count);
1170
      return true;
1171
    }
1172
 
1173
  return BFD_SEND (abfd, _bfd_get_section_contents,
1174
                   (abfd, section, location, offset, count));
1175
}
1176
 
1177
/*
1178
FUNCTION
1179
        bfd_copy_private_section_data
1180
 
1181
SYNOPSIS
1182
        boolean bfd_copy_private_section_data(bfd *ibfd, asection *isec, bfd *obfd, asection *osec);
1183
 
1184
DESCRIPTION
1185
        Copy private section information from @var{isec} in the BFD
1186
        @var{ibfd} to the section @var{osec} in the BFD @var{obfd}.
1187
        Return <<true>> on success, <<false>> on error.  Possible error
1188
        returns are:
1189
 
1190
        o <<bfd_error_no_memory>> -
1191
        Not enough memory exists to create private data for @var{osec}.
1192
 
1193
.#define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \
1194
.     BFD_SEND (obfd, _bfd_copy_private_section_data, \
1195
.               (ibfd, isection, obfd, osection))
1196
*/
1197
 
1198
/*
1199
FUNCTION
1200
        _bfd_strip_section_from_output
1201
 
1202
SYNOPSIS
1203
        void _bfd_strip_section_from_output
1204
        (struct bfd_link_info *info, asection *section);
1205
 
1206
DESCRIPTION
1207
        Remove @var{section} from the output.  If the output section
1208
        becomes empty, remove it from the output bfd.  @var{info} may
1209
        be NULL; if it is not, it is used to decide whether the output
1210
        section is empty.
1211
*/
1212
void
1213
_bfd_strip_section_from_output (info, s)
1214
     struct bfd_link_info *info;
1215
     asection *s;
1216
{
1217
  asection **spp, *os;
1218
  struct bfd_link_order *p, *pp;
1219
  boolean keep_os;
1220
 
1221
  /* Excise the input section from the link order.
1222
 
1223
     FIXME: For all calls that I can see to this function, the link
1224
     orders have not yet been set up.  So why are we checking them? --
1225
     Ian */
1226
  os = s->output_section;
1227
 
1228
  /* Handle a section that wasn't output.  */
1229
  if (os == NULL)
1230
    return;
1231
 
1232
  for (p = os->link_order_head, pp = NULL; p != NULL; pp = p, p = p->next)
1233
    if (p->type == bfd_indirect_link_order
1234
        && p->u.indirect.section == s)
1235
      {
1236
        if (pp)
1237
          pp->next = p->next;
1238
        else
1239
          os->link_order_head = p->next;
1240
        if (!p->next)
1241
          os->link_order_tail = pp;
1242
        break;
1243
      }
1244
 
1245
  keep_os = os->link_order_head != NULL;
1246
 
1247
  if (! keep_os && info != NULL)
1248
    {
1249
      bfd *abfd;
1250
      for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link_next)
1251
        {
1252
          asection *is;
1253
          for (is = abfd->sections; is != NULL; is = is->next)
1254
            {
1255
              if (is != s && is->output_section == os)
1256
                break;
1257
            }
1258
          if (is != NULL)
1259
            break;
1260
        }
1261
      if (abfd != NULL)
1262
        keep_os = true;
1263
    }
1264
 
1265
  /* If the output section is empty, remove it too.  Careful about sections
1266
     that have been discarded in the link script -- they are mapped to
1267
     bfd_abs_section, which has no owner.  */
1268
  if (!keep_os && os->owner != NULL)
1269
    {
1270
      for (spp = &os->owner->sections; *spp; spp = &(*spp)->next)
1271
        if (*spp == os)
1272
          {
1273
            *spp = os->next;
1274
            os->owner->section_count--;
1275
            break;
1276
          }
1277
    }
1278
}

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