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252b5132 | 1 | /* Object file "section" support for the BFD library. |
7442e600 | 2 | Copyright (C) 1990, 91, 92, 93, 94, 95, 96, 97, 98, 1999 |
252b5132 RH |
3 | Free Software Foundation, Inc. |
4 | Written by Cygnus Support. | |
5 | ||
6 | This file is part of BFD, the Binary File Descriptor library. | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
20 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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. An IEEE-695 file doesn't contain raw data in | |
69 | sections, but data and relocation expressions intermixed, so | |
70 | the data area has to be parsed to get out the data and | |
71 | relocations. | |
72 | ||
73 | INODE | |
74 | Section Output, typedef asection, Section Input, Sections | |
75 | ||
76 | SUBSECTION | |
77 | Section output | |
78 | ||
79 | To write a new object style BFD, the various sections to be | |
80 | written have to be created. They are attached to the BFD in | |
81 | the same way as input sections; data is written to the | |
82 | sections using <<bfd_set_section_contents>>. | |
83 | ||
84 | Any program that creates or combines sections (e.g., the assembler | |
85 | and linker) must use the <<asection>> fields <<output_section>> and | |
86 | <<output_offset>> to indicate the file sections to which each | |
87 | section must be written. (If the section is being created from | |
88 | scratch, <<output_section>> should probably point to the section | |
89 | itself and <<output_offset>> should probably be zero.) | |
90 | ||
91 | The data to be written comes from input sections attached | |
92 | (via <<output_section>> pointers) to | |
93 | the output sections. The output section structure can be | |
94 | considered a filter for the input section: the output section | |
95 | determines the vma of the output data and the name, but the | |
96 | input section determines the offset into the output section of | |
97 | the data to be written. | |
98 | ||
99 | E.g., to create a section "O", starting at 0x100, 0x123 long, | |
100 | containing two subsections, "A" at offset 0x0 (i.e., at vma | |
101 | 0x100) and "B" at offset 0x20 (i.e., at vma 0x120) the <<asection>> | |
102 | structures would look like: | |
103 | ||
104 | | section name "A" | |
105 | | output_offset 0x00 | |
106 | | size 0x20 | |
107 | | output_section -----------> section name "O" | |
108 | | | vma 0x100 | |
109 | | section name "B" | size 0x123 | |
110 | | output_offset 0x20 | | |
111 | | size 0x103 | | |
112 | | output_section --------| | |
113 | ||
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 | ||
137 | #include "bfd.h" | |
138 | #include "sysdep.h" | |
139 | #include "libbfd.h" | |
140 | #include "bfdlink.h" | |
141 | ||
142 | /* | |
143 | DOCDD | |
144 | INODE | |
145 | typedef asection, section prototypes, Section Output, Sections | |
146 | SUBSECTION | |
147 | typedef asection | |
148 | ||
149 | Here is the section structure: | |
150 | ||
151 | CODE_FRAGMENT | |
152 | . | |
153 | .typedef struct sec | |
154 | .{ | |
155 | . {* The name of the section; the name isn't a copy, the pointer is | |
156 | . the same as that passed to bfd_make_section. *} | |
157 | . | |
158 | . CONST char *name; | |
159 | . | |
160 | . {* Which section is it; 0..nth. *} | |
161 | . | |
162 | . int index; | |
163 | . | |
164 | . {* The next section in the list belonging to the BFD, or NULL. *} | |
165 | . | |
166 | . struct sec *next; | |
167 | . | |
168 | . {* The field flags contains attributes of the section. Some | |
169 | . flags are read in from the object file, and some are | |
170 | . synthesized from other information. *} | |
171 | . | |
172 | . flagword flags; | |
173 | . | |
174 | .#define SEC_NO_FLAGS 0x000 | |
175 | . | |
176 | . {* Tells the OS to allocate space for this section when loading. | |
177 | . This is clear for a section containing debug information | |
178 | . only. *} | |
179 | .#define SEC_ALLOC 0x001 | |
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 0x002 | |
184 | . | |
185 | . {* The section contains data still to be relocated, so there is | |
186 | . some relocation information too. *} | |
187 | .#define SEC_RELOC 0x004 | |
188 | . | |
189 | .#if 0 {* Obsolete ? *} | |
190 | .#define SEC_BALIGN 0x008 | |
191 | .#endif | |
192 | . | |
193 | . {* A signal to the OS that the section contains read only | |
194 | . data. *} | |
195 | .#define SEC_READONLY 0x010 | |
196 | . | |
197 | . {* The section contains code only. *} | |
198 | .#define SEC_CODE 0x020 | |
199 | . | |
200 | . {* The section contains data only. *} | |
201 | .#define SEC_DATA 0x040 | |
202 | . | |
203 | . {* The section will reside in ROM. *} | |
204 | .#define SEC_ROM 0x080 | |
205 | . | |
206 | . {* The section contains constructor information. This section | |
207 | . type is used by the linker to create lists of constructors and | |
208 | . destructors used by <<g++>>. When a back end sees a symbol | |
209 | . which should be used in a constructor list, it creates a new | |
210 | . section for the type of name (e.g., <<__CTOR_LIST__>>), attaches | |
211 | . the symbol to it, and builds a relocation. To build the lists | |
212 | . of constructors, all the linker has to do is catenate all the | |
213 | . sections called <<__CTOR_LIST__>> and relocate the data | |
214 | . contained within - exactly the operations it would peform on | |
215 | . standard data. *} | |
216 | .#define SEC_CONSTRUCTOR 0x100 | |
217 | . | |
218 | . {* The section is a constructor, and should be placed at the | |
219 | . end of the text, data, or bss section(?). *} | |
220 | .#define SEC_CONSTRUCTOR_TEXT 0x1100 | |
221 | .#define SEC_CONSTRUCTOR_DATA 0x2100 | |
222 | .#define SEC_CONSTRUCTOR_BSS 0x3100 | |
223 | . | |
224 | . {* The section has contents - a data section could be | |
225 | . <<SEC_ALLOC>> | <<SEC_HAS_CONTENTS>>; a debug section could be | |
226 | . <<SEC_HAS_CONTENTS>> *} | |
227 | .#define SEC_HAS_CONTENTS 0x200 | |
228 | . | |
229 | . {* An instruction to the linker to not output the section | |
230 | . even if it has information which would normally be written. *} | |
231 | .#define SEC_NEVER_LOAD 0x400 | |
232 | . | |
233 | . {* The section is a COFF shared library section. This flag is | |
234 | . only for the linker. If this type of section appears in | |
235 | . the input file, the linker must copy it to the output file | |
236 | . without changing the vma or size. FIXME: Although this | |
237 | . was originally intended to be general, it really is COFF | |
238 | . specific (and the flag was renamed to indicate this). It | |
239 | . might be cleaner to have some more general mechanism to | |
240 | . allow the back end to control what the linker does with | |
241 | . sections. *} | |
242 | .#define SEC_COFF_SHARED_LIBRARY 0x800 | |
243 | . | |
244 | . {* The section contains common symbols (symbols may be defined | |
245 | . multiple times, the value of a symbol is the amount of | |
246 | . space it requires, and the largest symbol value is the one | |
247 | . used). Most targets have exactly one of these (which we | |
248 | . translate to bfd_com_section_ptr), but ECOFF has two. *} | |
249 | .#define SEC_IS_COMMON 0x8000 | |
250 | . | |
251 | . {* The section contains only debugging information. For | |
252 | . example, this is set for ELF .debug and .stab sections. | |
253 | . strip tests this flag to see if a section can be | |
254 | . discarded. *} | |
255 | .#define SEC_DEBUGGING 0x10000 | |
256 | . | |
257 | . {* The contents of this section are held in memory pointed to | |
258 | . by the contents field. This is checked by | |
259 | . bfd_get_section_contents, and the data is retrieved from | |
260 | . memory if appropriate. *} | |
261 | .#define SEC_IN_MEMORY 0x20000 | |
262 | . | |
263 | . {* The contents of this section are to be excluded by the | |
264 | . linker for executable and shared objects unless those | |
265 | . objects are to be further relocated. *} | |
266 | .#define SEC_EXCLUDE 0x40000 | |
267 | . | |
268 | . {* The contents of this section are to be sorted by the | |
269 | . based on the address specified in the associated symbol | |
270 | . table. *} | |
271 | .#define SEC_SORT_ENTRIES 0x80000 | |
272 | . | |
273 | . {* When linking, duplicate sections of the same name should be | |
274 | . discarded, rather than being combined into a single section as | |
275 | . is usually done. This is similar to how common symbols are | |
276 | . handled. See SEC_LINK_DUPLICATES below. *} | |
277 | .#define SEC_LINK_ONCE 0x100000 | |
278 | . | |
279 | . {* If SEC_LINK_ONCE is set, this bitfield describes how the linker | |
280 | . should handle duplicate sections. *} | |
281 | .#define SEC_LINK_DUPLICATES 0x600000 | |
282 | . | |
283 | . {* This value for SEC_LINK_DUPLICATES means that duplicate | |
284 | . sections with the same name should simply be discarded. *} | |
285 | .#define SEC_LINK_DUPLICATES_DISCARD 0x0 | |
286 | . | |
287 | . {* This value for SEC_LINK_DUPLICATES means that the linker | |
288 | . should warn if there are any duplicate sections, although | |
289 | . it should still only link one copy. *} | |
290 | .#define SEC_LINK_DUPLICATES_ONE_ONLY 0x200000 | |
291 | . | |
292 | . {* This value for SEC_LINK_DUPLICATES means that the linker | |
293 | . should warn if any duplicate sections are a different size. *} | |
294 | .#define SEC_LINK_DUPLICATES_SAME_SIZE 0x400000 | |
295 | . | |
296 | . {* This value for SEC_LINK_DUPLICATES means that the linker | |
297 | . should warn if any duplicate sections contain different | |
298 | . contents. *} | |
299 | .#define SEC_LINK_DUPLICATES_SAME_CONTENTS 0x600000 | |
300 | . | |
301 | . {* This section was created by the linker as part of dynamic | |
302 | . relocation or other arcane processing. It is skipped when | |
303 | . going through the first-pass output, trusting that someone | |
304 | . else up the line will take care of it later. *} | |
305 | .#define SEC_LINKER_CREATED 0x800000 | |
306 | . | |
307 | . {* This section should not be subject to garbage collection. *} | |
308 | .#define SEC_KEEP 0x1000000 | |
309 | . | |
0c3ff40b RH |
310 | . {* This section contains "short" data, and should be placed |
311 | . "near" the GP. *} | |
851edbaf | 312 | .#define SEC_SMALL_DATA 0x2000000 |
0c3ff40b | 313 | . |
bd826630 ILT |
314 | . {* This section contains data which may be shared with other |
315 | . executables or shared objects. *} | |
316 | .#define SEC_SHARED 0x4000000 | |
317 | . | |
252b5132 RH |
318 | . {* End of section flags. *} |
319 | . | |
320 | . {* Some internal packed boolean fields. *} | |
321 | . | |
322 | . {* See the vma field. *} | |
323 | . unsigned int user_set_vma : 1; | |
324 | . | |
325 | . {* Whether relocations have been processed. *} | |
326 | . unsigned int reloc_done : 1; | |
327 | . | |
328 | . {* A mark flag used by some of the linker backends. *} | |
329 | . unsigned int linker_mark : 1; | |
330 | . | |
331 | . {* A mark flag used by some linker backends for garbage collection. *} | |
332 | . unsigned int gc_mark : 1; | |
333 | . | |
334 | . {* End of internal packed boolean fields. *} | |
335 | . | |
336 | . {* The virtual memory address of the section - where it will be | |
337 | . at run time. The symbols are relocated against this. The | |
338 | . user_set_vma flag is maintained by bfd; if it's not set, the | |
339 | . backend can assign addresses (for example, in <<a.out>>, where | |
340 | . the default address for <<.data>> is dependent on the specific | |
341 | . target and various flags). *} | |
342 | . | |
343 | . bfd_vma vma; | |
344 | . | |
345 | . {* The load address of the section - where it would be in a | |
346 | . rom image; really only used for writing section header | |
347 | . information. *} | |
348 | . | |
349 | . bfd_vma lma; | |
350 | . | |
351 | . {* The size of the section in bytes, as it will be output. | |
352 | . contains a value even if the section has no contents (e.g., the | |
353 | . size of <<.bss>>). This will be filled in after relocation *} | |
354 | . | |
355 | . bfd_size_type _cooked_size; | |
356 | . | |
357 | . {* The original size on disk of the section, in bytes. Normally this | |
358 | . value is the same as the size, but if some relaxing has | |
359 | . been done, then this value will be bigger. *} | |
360 | . | |
361 | . bfd_size_type _raw_size; | |
362 | . | |
363 | . {* If this section is going to be output, then this value is the | |
364 | . offset into the output section of the first byte in the input | |
365 | . section. E.g., if this was going to start at the 100th byte in | |
366 | . the output section, this value would be 100. *} | |
367 | . | |
368 | . bfd_vma output_offset; | |
369 | . | |
370 | . {* The output section through which to map on output. *} | |
371 | . | |
372 | . struct sec *output_section; | |
373 | . | |
374 | . {* The alignment requirement of the section, as an exponent of 2 - | |
375 | . e.g., 3 aligns to 2^3 (or 8). *} | |
376 | . | |
377 | . unsigned int alignment_power; | |
378 | . | |
379 | . {* If an input section, a pointer to a vector of relocation | |
380 | . records for the data in this section. *} | |
381 | . | |
382 | . struct reloc_cache_entry *relocation; | |
383 | . | |
384 | . {* If an output section, a pointer to a vector of pointers to | |
385 | . relocation records for the data in this section. *} | |
386 | . | |
387 | . struct reloc_cache_entry **orelocation; | |
388 | . | |
389 | . {* The number of relocation records in one of the above *} | |
390 | . | |
391 | . unsigned reloc_count; | |
392 | . | |
393 | . {* Information below is back end specific - and not always used | |
394 | . or updated. *} | |
395 | . | |
396 | . {* File position of section data *} | |
397 | . | |
398 | . file_ptr filepos; | |
399 | . | |
400 | . {* File position of relocation info *} | |
401 | . | |
402 | . file_ptr rel_filepos; | |
403 | . | |
404 | . {* File position of line data *} | |
405 | . | |
406 | . file_ptr line_filepos; | |
407 | . | |
408 | . {* Pointer to data for applications *} | |
409 | . | |
410 | . PTR userdata; | |
411 | . | |
412 | . {* If the SEC_IN_MEMORY flag is set, this points to the actual | |
413 | . contents. *} | |
414 | . unsigned char *contents; | |
415 | . | |
416 | . {* Attached line number information *} | |
417 | . | |
418 | . alent *lineno; | |
419 | . | |
420 | . {* Number of line number records *} | |
421 | . | |
422 | . unsigned int lineno_count; | |
423 | . | |
424 | . {* When a section is being output, this value changes as more | |
425 | . linenumbers are written out *} | |
426 | . | |
427 | . file_ptr moving_line_filepos; | |
428 | . | |
429 | . {* What the section number is in the target world *} | |
430 | . | |
431 | . int target_index; | |
432 | . | |
433 | . PTR used_by_bfd; | |
434 | . | |
435 | . {* If this is a constructor section then here is a list of the | |
436 | . relocations created to relocate items within it. *} | |
437 | . | |
438 | . struct relent_chain *constructor_chain; | |
439 | . | |
440 | . {* The BFD which owns the section. *} | |
441 | . | |
442 | . bfd *owner; | |
443 | . | |
444 | . {* A symbol which points at this section only *} | |
445 | . struct symbol_cache_entry *symbol; | |
446 | . struct symbol_cache_entry **symbol_ptr_ptr; | |
447 | . | |
448 | . struct bfd_link_order *link_order_head; | |
449 | . struct bfd_link_order *link_order_tail; | |
450 | .} asection ; | |
451 | . | |
452 | . {* These sections are global, and are managed by BFD. The application | |
453 | . and target back end are not permitted to change the values in | |
454 | . these sections. New code should use the section_ptr macros rather | |
455 | . than referring directly to the const sections. The const sections | |
456 | . may eventually vanish. *} | |
457 | .#define BFD_ABS_SECTION_NAME "*ABS*" | |
458 | .#define BFD_UND_SECTION_NAME "*UND*" | |
459 | .#define BFD_COM_SECTION_NAME "*COM*" | |
460 | .#define BFD_IND_SECTION_NAME "*IND*" | |
461 | . | |
462 | . {* the absolute section *} | |
463 | .extern const asection bfd_abs_section; | |
464 | .#define bfd_abs_section_ptr ((asection *) &bfd_abs_section) | |
465 | .#define bfd_is_abs_section(sec) ((sec) == bfd_abs_section_ptr) | |
466 | . {* Pointer to the undefined section *} | |
467 | .extern const asection bfd_und_section; | |
468 | .#define bfd_und_section_ptr ((asection *) &bfd_und_section) | |
469 | .#define bfd_is_und_section(sec) ((sec) == bfd_und_section_ptr) | |
470 | . {* Pointer to the common section *} | |
471 | .extern const asection bfd_com_section; | |
472 | .#define bfd_com_section_ptr ((asection *) &bfd_com_section) | |
473 | . {* Pointer to the indirect section *} | |
474 | .extern const asection bfd_ind_section; | |
475 | .#define bfd_ind_section_ptr ((asection *) &bfd_ind_section) | |
476 | .#define bfd_is_ind_section(sec) ((sec) == bfd_ind_section_ptr) | |
477 | . | |
478 | .extern const struct symbol_cache_entry * const bfd_abs_symbol; | |
479 | .extern const struct symbol_cache_entry * const bfd_com_symbol; | |
480 | .extern const struct symbol_cache_entry * const bfd_und_symbol; | |
481 | .extern const struct symbol_cache_entry * const bfd_ind_symbol; | |
482 | .#define bfd_get_section_size_before_reloc(section) \ | |
483 | . (section->reloc_done ? (abort(),1): (section)->_raw_size) | |
484 | .#define bfd_get_section_size_after_reloc(section) \ | |
485 | . ((section->reloc_done) ? (section)->_cooked_size: (abort(),1)) | |
486 | */ | |
487 | ||
22bc497d ILT |
488 | /* We use a macro to initialize the static asymbol structures because |
489 | traditional C does not permit us to initialize a union member while | |
490 | gcc warns if we don't initialize it. */ | |
491 | /* the_bfd, name, value, attr, section [, udata] */ | |
492 | #ifdef __STDC__ | |
493 | #define GLOBAL_SYM_INIT(NAME, SECTION) \ | |
494 | { 0, NAME, 0, BSF_SECTION_SYM, (asection *) SECTION, { 0 }} | |
495 | #else | |
496 | #define GLOBAL_SYM_INIT(NAME, SECTION) \ | |
497 | { 0, NAME, 0, BSF_SECTION_SYM, (asection *) SECTION } | |
498 | #endif | |
499 | ||
252b5132 RH |
500 | /* These symbols are global, not specific to any BFD. Therefore, anything |
501 | that tries to change them is broken, and should be repaired. */ | |
22bc497d | 502 | |
252b5132 RH |
503 | static const asymbol global_syms[] = |
504 | { | |
22bc497d ILT |
505 | GLOBAL_SYM_INIT (BFD_COM_SECTION_NAME, &bfd_com_section), |
506 | GLOBAL_SYM_INIT (BFD_UND_SECTION_NAME, &bfd_und_section), | |
507 | GLOBAL_SYM_INIT (BFD_ABS_SECTION_NAME, &bfd_abs_section), | |
508 | GLOBAL_SYM_INIT (BFD_IND_SECTION_NAME, &bfd_ind_section) | |
252b5132 RH |
509 | }; |
510 | ||
511 | #define STD_SECTION(SEC, FLAGS, SYM, NAME, IDX) \ | |
512 | const asymbol * const SYM = (asymbol *) &global_syms[IDX]; \ | |
513 | const asection SEC = \ | |
514 | { NAME, 0, 0, FLAGS, 0, 0, 0, 0, 0, 0, 0, 0, 0, (asection *) &SEC, \ | |
515 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \ | |
516 | (asymbol *) &global_syms[IDX], (asymbol **) &SYM, 0, 0 } | |
517 | ||
518 | STD_SECTION (bfd_com_section, SEC_IS_COMMON, bfd_com_symbol, | |
519 | BFD_COM_SECTION_NAME, 0); | |
520 | STD_SECTION (bfd_und_section, 0, bfd_und_symbol, BFD_UND_SECTION_NAME, 1); | |
521 | STD_SECTION (bfd_abs_section, 0, bfd_abs_symbol, BFD_ABS_SECTION_NAME, 2); | |
522 | STD_SECTION (bfd_ind_section, 0, bfd_ind_symbol, BFD_IND_SECTION_NAME, 3); | |
523 | #undef STD_SECTION | |
524 | ||
525 | /* | |
526 | DOCDD | |
527 | INODE | |
528 | section prototypes, , typedef asection, Sections | |
529 | SUBSECTION | |
530 | Section prototypes | |
531 | ||
532 | These are the functions exported by the section handling part of BFD. | |
533 | */ | |
534 | ||
535 | /* | |
536 | FUNCTION | |
537 | bfd_get_section_by_name | |
538 | ||
539 | SYNOPSIS | |
540 | asection *bfd_get_section_by_name(bfd *abfd, CONST char *name); | |
541 | ||
542 | DESCRIPTION | |
543 | Run through @var{abfd} and return the one of the | |
544 | <<asection>>s whose name matches @var{name}, otherwise <<NULL>>. | |
545 | @xref{Sections}, for more information. | |
546 | ||
547 | This should only be used in special cases; the normal way to process | |
548 | all sections of a given name is to use <<bfd_map_over_sections>> and | |
549 | <<strcmp>> on the name (or better yet, base it on the section flags | |
550 | or something else) for each section. | |
551 | */ | |
552 | ||
553 | asection * | |
554 | bfd_get_section_by_name (abfd, name) | |
555 | bfd *abfd; | |
556 | CONST char *name; | |
557 | { | |
558 | asection *sect; | |
559 | ||
560 | for (sect = abfd->sections; sect != NULL; sect = sect->next) | |
561 | if (!strcmp (sect->name, name)) | |
562 | return sect; | |
563 | return NULL; | |
564 | } | |
565 | ||
566 | ||
567 | /* | |
568 | FUNCTION | |
569 | bfd_make_section_old_way | |
570 | ||
571 | SYNOPSIS | |
572 | asection *bfd_make_section_old_way(bfd *abfd, CONST char *name); | |
573 | ||
574 | DESCRIPTION | |
575 | Create a new empty section called @var{name} | |
576 | and attach it to the end of the chain of sections for the | |
577 | BFD @var{abfd}. An attempt to create a section with a name which | |
578 | is already in use returns its pointer without changing the | |
579 | section chain. | |
580 | ||
581 | It has the funny name since this is the way it used to be | |
582 | before it was rewritten.... | |
583 | ||
584 | Possible errors are: | |
585 | o <<bfd_error_invalid_operation>> - | |
586 | If output has already started for this BFD. | |
587 | o <<bfd_error_no_memory>> - | |
588 | If memory allocation fails. | |
589 | ||
590 | */ | |
591 | ||
592 | ||
593 | asection * | |
594 | bfd_make_section_old_way (abfd, name) | |
595 | bfd *abfd; | |
596 | CONST char *name; | |
597 | { | |
598 | asection *sec = bfd_get_section_by_name (abfd, name); | |
599 | if (sec == (asection *) NULL) | |
600 | { | |
601 | sec = bfd_make_section (abfd, name); | |
602 | } | |
603 | return sec; | |
604 | } | |
605 | ||
606 | /* | |
607 | FUNCTION | |
608 | bfd_make_section_anyway | |
609 | ||
610 | SYNOPSIS | |
611 | asection *bfd_make_section_anyway(bfd *abfd, CONST char *name); | |
612 | ||
613 | DESCRIPTION | |
614 | Create a new empty section called @var{name} and attach it to the end of | |
615 | the chain of sections for @var{abfd}. Create a new section even if there | |
616 | is already a section with that name. | |
617 | ||
618 | Return <<NULL>> and set <<bfd_error>> on error; possible errors are: | |
619 | o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}. | |
620 | o <<bfd_error_no_memory>> - If memory allocation fails. | |
621 | */ | |
622 | ||
623 | sec_ptr | |
624 | bfd_make_section_anyway (abfd, name) | |
625 | bfd *abfd; | |
626 | CONST char *name; | |
627 | { | |
628 | asection *newsect; | |
629 | asection **prev = &abfd->sections; | |
630 | asection *sect = abfd->sections; | |
631 | ||
632 | if (abfd->output_has_begun) | |
633 | { | |
634 | bfd_set_error (bfd_error_invalid_operation); | |
635 | return NULL; | |
636 | } | |
637 | ||
638 | while (sect) | |
639 | { | |
640 | prev = §->next; | |
641 | sect = sect->next; | |
642 | } | |
643 | ||
644 | newsect = (asection *) bfd_zalloc (abfd, sizeof (asection)); | |
645 | if (newsect == NULL) | |
646 | return NULL; | |
647 | ||
648 | newsect->name = name; | |
649 | newsect->index = abfd->section_count++; | |
650 | newsect->flags = SEC_NO_FLAGS; | |
651 | ||
652 | newsect->userdata = NULL; | |
653 | newsect->contents = NULL; | |
654 | newsect->next = (asection *) NULL; | |
655 | newsect->relocation = (arelent *) NULL; | |
656 | newsect->reloc_count = 0; | |
657 | newsect->line_filepos = 0; | |
658 | newsect->owner = abfd; | |
659 | ||
660 | /* Create a symbol whos only job is to point to this section. This is | |
661 | useful for things like relocs which are relative to the base of a | |
662 | section. */ | |
663 | newsect->symbol = bfd_make_empty_symbol (abfd); | |
664 | if (newsect->symbol == NULL) | |
665 | return NULL; | |
666 | newsect->symbol->name = name; | |
667 | newsect->symbol->value = 0; | |
668 | newsect->symbol->section = newsect; | |
669 | newsect->symbol->flags = BSF_SECTION_SYM; | |
670 | ||
671 | newsect->symbol_ptr_ptr = &newsect->symbol; | |
672 | ||
673 | if (BFD_SEND (abfd, _new_section_hook, (abfd, newsect)) != true) | |
674 | { | |
675 | free (newsect); | |
676 | return NULL; | |
677 | } | |
678 | ||
679 | *prev = newsect; | |
680 | return newsect; | |
681 | } | |
682 | ||
683 | /* | |
684 | FUNCTION | |
685 | bfd_make_section | |
686 | ||
687 | SYNOPSIS | |
688 | asection *bfd_make_section(bfd *, CONST char *name); | |
689 | ||
690 | DESCRIPTION | |
691 | Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling | |
692 | bfd_set_error ()) without changing the section chain if there is already a | |
693 | section named @var{name}. If there is an error, return <<NULL>> and set | |
694 | <<bfd_error>>. | |
695 | */ | |
696 | ||
697 | asection * | |
698 | bfd_make_section (abfd, name) | |
699 | bfd *abfd; | |
700 | CONST char *name; | |
701 | { | |
702 | asection *sect = abfd->sections; | |
703 | ||
704 | if (strcmp (name, BFD_ABS_SECTION_NAME) == 0) | |
705 | { | |
706 | return bfd_abs_section_ptr; | |
707 | } | |
708 | if (strcmp (name, BFD_COM_SECTION_NAME) == 0) | |
709 | { | |
710 | return bfd_com_section_ptr; | |
711 | } | |
712 | if (strcmp (name, BFD_UND_SECTION_NAME) == 0) | |
713 | { | |
714 | return bfd_und_section_ptr; | |
715 | } | |
716 | ||
717 | if (strcmp (name, BFD_IND_SECTION_NAME) == 0) | |
718 | { | |
719 | return bfd_ind_section_ptr; | |
720 | } | |
721 | ||
722 | while (sect) | |
723 | { | |
724 | if (!strcmp (sect->name, name)) | |
725 | return NULL; | |
726 | sect = sect->next; | |
727 | } | |
728 | ||
729 | /* The name is not already used; go ahead and make a new section. */ | |
730 | return bfd_make_section_anyway (abfd, name); | |
731 | } | |
732 | ||
733 | ||
734 | /* | |
735 | FUNCTION | |
736 | bfd_set_section_flags | |
737 | ||
738 | SYNOPSIS | |
739 | boolean bfd_set_section_flags(bfd *abfd, asection *sec, flagword flags); | |
740 | ||
741 | DESCRIPTION | |
742 | Set the attributes of the section @var{sec} in the BFD | |
743 | @var{abfd} to the value @var{flags}. Return <<true>> on success, | |
744 | <<false>> on error. Possible error returns are: | |
745 | ||
746 | o <<bfd_error_invalid_operation>> - | |
747 | The section cannot have one or more of the attributes | |
748 | requested. For example, a .bss section in <<a.out>> may not | |
749 | have the <<SEC_HAS_CONTENTS>> field set. | |
750 | ||
751 | */ | |
752 | ||
753 | /*ARGSUSED*/ | |
754 | boolean | |
755 | bfd_set_section_flags (abfd, section, flags) | |
7442e600 | 756 | bfd *abfd ATTRIBUTE_UNUSED; |
252b5132 RH |
757 | sec_ptr section; |
758 | flagword flags; | |
759 | { | |
760 | #if 0 | |
761 | /* If you try to copy a text section from an input file (where it | |
762 | has the SEC_CODE flag set) to an output file, this loses big if | |
763 | the bfd_applicable_section_flags (abfd) doesn't have the SEC_CODE | |
764 | set - which it doesn't, at least not for a.out. FIXME */ | |
765 | ||
766 | if ((flags & bfd_applicable_section_flags (abfd)) != flags) | |
767 | { | |
768 | bfd_set_error (bfd_error_invalid_operation); | |
769 | return false; | |
770 | } | |
771 | #endif | |
772 | ||
773 | section->flags = flags; | |
774 | return true; | |
775 | } | |
776 | ||
777 | ||
778 | /* | |
779 | FUNCTION | |
780 | bfd_map_over_sections | |
781 | ||
782 | SYNOPSIS | |
783 | void bfd_map_over_sections(bfd *abfd, | |
784 | void (*func)(bfd *abfd, | |
785 | asection *sect, | |
786 | PTR obj), | |
787 | PTR obj); | |
788 | ||
789 | DESCRIPTION | |
790 | Call the provided function @var{func} for each section | |
791 | attached to the BFD @var{abfd}, passing @var{obj} as an | |
792 | argument. The function will be called as if by | |
793 | ||
794 | | func(abfd, the_section, obj); | |
795 | ||
796 | This is the prefered method for iterating over sections; an | |
797 | alternative would be to use a loop: | |
798 | ||
799 | | section *p; | |
800 | | for (p = abfd->sections; p != NULL; p = p->next) | |
801 | | func(abfd, p, ...) | |
802 | ||
803 | ||
804 | */ | |
805 | ||
806 | /*VARARGS2*/ | |
807 | void | |
808 | bfd_map_over_sections (abfd, operation, user_storage) | |
809 | bfd *abfd; | |
810 | void (*operation) PARAMS ((bfd * abfd, asection * sect, PTR obj)); | |
811 | PTR user_storage; | |
812 | { | |
813 | asection *sect; | |
814 | unsigned int i = 0; | |
815 | ||
816 | for (sect = abfd->sections; sect != NULL; i++, sect = sect->next) | |
817 | (*operation) (abfd, sect, user_storage); | |
818 | ||
819 | if (i != abfd->section_count) /* Debugging */ | |
820 | abort (); | |
821 | } | |
822 | ||
823 | ||
824 | /* | |
825 | FUNCTION | |
826 | bfd_set_section_size | |
827 | ||
828 | SYNOPSIS | |
829 | boolean bfd_set_section_size(bfd *abfd, asection *sec, bfd_size_type val); | |
830 | ||
831 | DESCRIPTION | |
832 | Set @var{sec} to the size @var{val}. If the operation is | |
833 | ok, then <<true>> is returned, else <<false>>. | |
834 | ||
835 | Possible error returns: | |
836 | o <<bfd_error_invalid_operation>> - | |
837 | Writing has started to the BFD, so setting the size is invalid. | |
838 | ||
839 | */ | |
840 | ||
841 | boolean | |
842 | bfd_set_section_size (abfd, ptr, val) | |
843 | bfd *abfd; | |
844 | sec_ptr ptr; | |
845 | bfd_size_type val; | |
846 | { | |
847 | /* Once you've started writing to any section you cannot create or change | |
848 | the size of any others. */ | |
849 | ||
850 | if (abfd->output_has_begun) | |
851 | { | |
852 | bfd_set_error (bfd_error_invalid_operation); | |
853 | return false; | |
854 | } | |
855 | ||
856 | ptr->_cooked_size = val; | |
857 | ptr->_raw_size = val; | |
858 | ||
859 | return true; | |
860 | } | |
861 | ||
862 | /* | |
863 | FUNCTION | |
864 | bfd_set_section_contents | |
865 | ||
866 | SYNOPSIS | |
867 | boolean bfd_set_section_contents | |
868 | (bfd *abfd, | |
869 | asection *section, | |
870 | PTR data, | |
871 | file_ptr offset, | |
872 | bfd_size_type count); | |
873 | ||
874 | ||
875 | DESCRIPTION | |
876 | Sets the contents of the section @var{section} in BFD | |
877 | @var{abfd} to the data starting in memory at @var{data}. The | |
878 | data is written to the output section starting at offset | |
879 | @var{offset} for @var{count} bytes. | |
880 | ||
881 | ||
882 | ||
883 | Normally <<true>> is returned, else <<false>>. Possible error | |
884 | returns are: | |
885 | o <<bfd_error_no_contents>> - | |
886 | The output section does not have the <<SEC_HAS_CONTENTS>> | |
887 | attribute, so nothing can be written to it. | |
888 | o and some more too | |
889 | ||
890 | This routine is front end to the back end function | |
891 | <<_bfd_set_section_contents>>. | |
892 | ||
893 | ||
894 | */ | |
895 | ||
896 | #define bfd_get_section_size_now(abfd,sec) \ | |
897 | (sec->reloc_done \ | |
898 | ? bfd_get_section_size_after_reloc (sec) \ | |
899 | : bfd_get_section_size_before_reloc (sec)) | |
900 | ||
901 | boolean | |
902 | bfd_set_section_contents (abfd, section, location, offset, count) | |
903 | bfd *abfd; | |
904 | sec_ptr section; | |
905 | PTR location; | |
906 | file_ptr offset; | |
907 | bfd_size_type count; | |
908 | { | |
909 | bfd_size_type sz; | |
910 | ||
911 | if (!(bfd_get_section_flags (abfd, section) & SEC_HAS_CONTENTS)) | |
912 | { | |
913 | bfd_set_error (bfd_error_no_contents); | |
914 | return (false); | |
915 | } | |
916 | ||
917 | if (offset < 0) | |
918 | { | |
919 | bad_val: | |
920 | bfd_set_error (bfd_error_bad_value); | |
921 | return false; | |
922 | } | |
923 | sz = bfd_get_section_size_now (abfd, section); | |
924 | if ((bfd_size_type) offset > sz | |
925 | || count > sz | |
926 | || offset + count > sz) | |
927 | goto bad_val; | |
928 | ||
929 | switch (abfd->direction) | |
930 | { | |
931 | case read_direction: | |
932 | case no_direction: | |
933 | bfd_set_error (bfd_error_invalid_operation); | |
934 | return false; | |
935 | ||
936 | case write_direction: | |
937 | break; | |
938 | ||
939 | case both_direction: | |
940 | /* File is opened for update. `output_has_begun' some time ago when | |
941 | the file was created. Do not recompute sections sizes or alignments | |
942 | in _bfd_set_section_content. */ | |
943 | abfd->output_has_begun = true; | |
944 | break; | |
945 | } | |
946 | ||
947 | if (BFD_SEND (abfd, _bfd_set_section_contents, | |
948 | (abfd, section, location, offset, count))) | |
949 | { | |
950 | abfd->output_has_begun = true; | |
951 | return true; | |
952 | } | |
953 | ||
954 | return false; | |
955 | } | |
956 | ||
957 | /* | |
958 | FUNCTION | |
959 | bfd_get_section_contents | |
960 | ||
961 | SYNOPSIS | |
962 | boolean bfd_get_section_contents | |
963 | (bfd *abfd, asection *section, PTR location, | |
964 | file_ptr offset, bfd_size_type count); | |
965 | ||
966 | DESCRIPTION | |
967 | Read data from @var{section} in BFD @var{abfd} | |
968 | into memory starting at @var{location}. The data is read at an | |
969 | offset of @var{offset} from the start of the input section, | |
970 | and is read for @var{count} bytes. | |
971 | ||
972 | If the contents of a constructor with the <<SEC_CONSTRUCTOR>> | |
973 | flag set are requested or if the section does not have the | |
974 | <<SEC_HAS_CONTENTS>> flag set, then the @var{location} is filled | |
975 | with zeroes. If no errors occur, <<true>> is returned, else | |
976 | <<false>>. | |
977 | ||
978 | ||
979 | ||
980 | */ | |
981 | boolean | |
982 | bfd_get_section_contents (abfd, section, location, offset, count) | |
983 | bfd *abfd; | |
984 | sec_ptr section; | |
985 | PTR location; | |
986 | file_ptr offset; | |
987 | bfd_size_type count; | |
988 | { | |
989 | bfd_size_type sz; | |
990 | ||
991 | if (section->flags & SEC_CONSTRUCTOR) | |
992 | { | |
993 | memset (location, 0, (unsigned) count); | |
994 | return true; | |
995 | } | |
996 | ||
997 | if (offset < 0) | |
998 | { | |
999 | bad_val: | |
1000 | bfd_set_error (bfd_error_bad_value); | |
1001 | return false; | |
1002 | } | |
1003 | /* Even if reloc_done is true, this function reads unrelocated | |
1004 | contents, so we want the raw size. */ | |
1005 | sz = section->_raw_size; | |
1006 | if ((bfd_size_type) offset > sz || count > sz || offset + count > sz) | |
1007 | goto bad_val; | |
1008 | ||
1009 | if (count == 0) | |
1010 | /* Don't bother. */ | |
1011 | return true; | |
1012 | ||
1013 | if ((section->flags & SEC_HAS_CONTENTS) == 0) | |
1014 | { | |
1015 | memset (location, 0, (unsigned) count); | |
1016 | return true; | |
1017 | } | |
1018 | ||
1019 | if ((section->flags & SEC_IN_MEMORY) != 0) | |
1020 | { | |
1021 | memcpy (location, section->contents + offset, (size_t) count); | |
1022 | return true; | |
1023 | } | |
1024 | ||
1025 | return BFD_SEND (abfd, _bfd_get_section_contents, | |
1026 | (abfd, section, location, offset, count)); | |
1027 | } | |
1028 | ||
1029 | /* | |
1030 | FUNCTION | |
1031 | bfd_copy_private_section_data | |
1032 | ||
1033 | SYNOPSIS | |
1034 | boolean bfd_copy_private_section_data(bfd *ibfd, asection *isec, bfd *obfd, asection *osec); | |
1035 | ||
1036 | DESCRIPTION | |
1037 | Copy private section information from @var{isec} in the BFD | |
1038 | @var{ibfd} to the section @var{osec} in the BFD @var{obfd}. | |
1039 | Return <<true>> on success, <<false>> on error. Possible error | |
1040 | returns are: | |
1041 | ||
1042 | o <<bfd_error_no_memory>> - | |
1043 | Not enough memory exists to create private data for @var{osec}. | |
1044 | ||
1045 | .#define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \ | |
1046 | . BFD_SEND (obfd, _bfd_copy_private_section_data, \ | |
1047 | . (ibfd, isection, obfd, osection)) | |
1048 | */ | |
1049 | ||
1050 | /* | |
1051 | FUNCTION | |
1052 | _bfd_strip_section_from_output | |
1053 | ||
1054 | SYNOPSIS | |
1055 | void _bfd_strip_section_from_output | |
1056 | (asection *section); | |
1057 | ||
1058 | DESCRIPTION | |
1059 | Remove @var{section} from the output. If the output section becomes | |
1060 | empty, remove it from the output bfd. | |
1061 | */ | |
1062 | void | |
1063 | _bfd_strip_section_from_output (s) | |
1064 | asection *s; | |
1065 | { | |
1066 | asection **spp, *os; | |
1067 | struct bfd_link_order *p, *pp; | |
1068 | ||
9d7428a9 | 1069 | /* Excise the input section from the link order. */ |
252b5132 RH |
1070 | os = s->output_section; |
1071 | for (p = os->link_order_head, pp = NULL; p != NULL; pp = p, p = p->next) | |
1072 | if (p->type == bfd_indirect_link_order | |
1073 | && p->u.indirect.section == s) | |
1074 | { | |
252b5132 RH |
1075 | if (pp) |
1076 | pp->next = p->next; | |
1077 | else | |
1078 | os->link_order_head = p->next; | |
1079 | if (!p->next) | |
1080 | os->link_order_tail = pp; | |
9d7428a9 RH |
1081 | break; |
1082 | } | |
252b5132 | 1083 | |
0bde07d4 RH |
1084 | /* If the output section is empty, remove it too. Careful about sections |
1085 | that have been discarded in the link script -- they are mapped to | |
1086 | bfd_abs_section, which has no owner. */ | |
1087 | if (!os->link_order_head && os->owner) | |
9d7428a9 RH |
1088 | { |
1089 | for (spp = &os->owner->sections; *spp; spp = &(*spp)->next) | |
1090 | if (*spp == os) | |
252b5132 | 1091 | { |
9d7428a9 RH |
1092 | *spp = os->next; |
1093 | os->owner->section_count--; | |
1094 | break; | |
252b5132 | 1095 | } |
9d7428a9 | 1096 | } |
252b5132 | 1097 | } |