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6724ff46 | 1 | /* Object file "section" support for the BFD library. |
7ec49f91 | 2 | Copyright (C) 1990, 91, 92, 93, 94, 95, 1996 Free Software Foundation, Inc. |
6724ff46 RP |
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 2 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 | |
83f4323e | 19 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
6724ff46 | 20 | |
4a96bc04 SC |
21 | /* |
22 | SECTION | |
23 | Sections | |
985fca12 | 24 | |
4a96bc04 SC |
25 | The raw data contained within a BFD is maintained through the |
26 | section abstraction. A single BFD may have any number of | |
c188b0be | 27 | sections. It keeps hold of them by pointing to the first; |
4a96bc04 | 28 | each one points to the next in the list. |
985fca12 | 29 | |
c188b0be DM |
30 | Sections are supported in BFD in <<section.c>>. |
31 | ||
985fca12 | 32 | @menu |
151760d0 RP |
33 | @* Section Input:: |
34 | @* Section Output:: | |
35 | @* typedef asection:: | |
36 | @* section prototypes:: | |
985fca12 SC |
37 | @end menu |
38 | ||
fefb4b30 JG |
39 | INODE |
40 | Section Input, Section Output, Sections, Sections | |
4a96bc04 | 41 | SUBSECTION |
1adbf662 | 42 | Section input |
4a96bc04 SC |
43 | |
44 | When a BFD is opened for reading, the section structures are | |
45 | created and attached to the BFD. | |
46 | ||
47 | Each section has a name which describes the section in the | |
c188b0be | 48 | outside world---for example, <<a.out>> would contain at least |
57a1867e | 49 | three sections, called <<.text>>, <<.data>> and <<.bss>>. |
4a96bc04 | 50 | |
c188b0be DM |
51 | Names need not be unique; for example a COFF file may have several |
52 | sections named <<.data>>. | |
53 | ||
54 | Sometimes a BFD will contain more than the ``natural'' number of | |
4a96bc04 SC |
55 | sections. A back end may attach other sections containing |
56 | constructor data, or an application may add a section (using | |
c188b0be DM |
57 | <<bfd_make_section>>) to the sections attached to an already open |
58 | BFD. For example, the linker creates an extra section | |
4a96bc04 SC |
59 | <<COMMON>> for each input file's BFD to hold information about |
60 | common storage. | |
61 | ||
c188b0be | 62 | The raw data is not necessarily read in when |
4a96bc04 SC |
63 | the section descriptor is created. Some targets may leave the |
64 | data in place until a <<bfd_get_section_contents>> call is | |
c188b0be DM |
65 | made. Other back ends may read in all the data at once. For |
66 | example, an S-record file has to be read once to determine the | |
4a96bc04 SC |
67 | size of the data. An IEEE-695 file doesn't contain raw data in |
68 | sections, but data and relocation expressions intermixed, so | |
69 | the data area has to be parsed to get out the data and | |
70 | relocations. | |
71 | ||
fefb4b30 JG |
72 | INODE |
73 | Section Output, typedef asection, Section Input, Sections | |
4a96bc04 SC |
74 | |
75 | SUBSECTION | |
1adbf662 | 76 | Section output |
4a96bc04 SC |
77 | |
78 | To write a new object style BFD, the various sections to be | |
79 | written have to be created. They are attached to the BFD in | |
c188b0be | 80 | the same way as input sections; data is written to the |
57a1867e | 81 | sections using <<bfd_set_section_contents>>. |
4a96bc04 | 82 | |
fefb4b30 | 83 | Any program that creates or combines sections (e.g., the assembler |
c188b0be | 84 | and linker) must use the <<asection>> fields <<output_section>> and |
fefb4b30 JG |
85 | <<output_offset>> to indicate the file sections to which each |
86 | section must be written. (If the section is being created from | |
87 | scratch, <<output_section>> should probably point to the section | |
c188b0be | 88 | itself and <<output_offset>> should probably be zero.) |
4a96bc04 | 89 | |
c188b0be DM |
90 | The data to be written comes from input sections attached |
91 | (via <<output_section>> pointers) to | |
4a96bc04 | 92 | the output sections. The output section structure can be |
c188b0be | 93 | considered a filter for the input section: the output section |
4a96bc04 SC |
94 | determines the vma of the output data and the name, but the |
95 | input section determines the offset into the output section of | |
96 | the data to be written. | |
97 | ||
fefb4b30 | 98 | E.g., to create a section "O", starting at 0x100, 0x123 long, |
c188b0be DM |
99 | containing two subsections, "A" at offset 0x0 (i.e., at vma |
100 | 0x100) and "B" at offset 0x20 (i.e., at vma 0x120) the <<asection>> | |
101 | structures would look like: | |
4a96bc04 SC |
102 | |
103 | | section name "A" | |
104 | | output_offset 0x00 | |
105 | | size 0x20 | |
106 | | output_section -----------> section name "O" | |
107 | | | vma 0x100 | |
108 | | section name "B" | size 0x123 | |
109 | | output_offset 0x20 | | |
110 | | size 0x103 | | |
111 | | output_section --------| | |
112 | ||
985fca12 | 113 | |
e98e6ec1 | 114 | SUBSECTION |
4c3721d5 | 115 | Link orders |
e98e6ec1 | 116 | |
4c3721d5 ILT |
117 | The data within a section is stored in a @dfn{link_order}. |
118 | These are much like the fixups in <<gas>>. The link_order | |
119 | abstraction allows a section to grow and shrink within itself. | |
e98e6ec1 | 120 | |
4c3721d5 ILT |
121 | A link_order knows how big it is, and which is the next |
122 | link_order and where the raw data for it is; it also points to | |
123 | a list of relocations which apply to it. | |
e98e6ec1 | 124 | |
4c3721d5 ILT |
125 | The link_order is used by the linker to perform relaxing on |
126 | final code. The compiler creates code which is as big as | |
e98e6ec1 SC |
127 | necessary to make it work without relaxing, and the user can |
128 | select whether to relax. Sometimes relaxing takes a lot of | |
129 | time. The linker runs around the relocations to see if any | |
130 | are attached to data which can be shrunk, if so it does it on | |
4c3721d5 | 131 | a link_order by link_order basis. |
e98e6ec1 | 132 | |
985fca12 SC |
133 | */ |
134 | ||
135 | ||
985fca12 | 136 | #include "bfd.h" |
cbdc7909 | 137 | #include "sysdep.h" |
985fca12 SC |
138 | #include "libbfd.h" |
139 | ||
4a96bc04 | 140 | |
fefb4b30 JG |
141 | /* |
142 | DOCDD | |
143 | INODE | |
144 | typedef asection, section prototypes, Section Output, Sections | |
4a96bc04 SC |
145 | SUBSECTION |
146 | typedef asection | |
147 | ||
c188b0be | 148 | Here is the section structure: |
4a96bc04 SC |
149 | |
150 | CODE_FRAGMENT | |
151 | . | |
57a1867e | 152 | .typedef struct sec |
4a96bc04 | 153 | .{ |
c188b0be | 154 | . {* The name of the section; the name isn't a copy, the pointer is |
4a96bc04 SC |
155 | . the same as that passed to bfd_make_section. *} |
156 | . | |
157 | . CONST char *name; | |
158 | . | |
c188b0be | 159 | . {* Which section is it; 0..nth. *} |
e98e6ec1 | 160 | . |
57a1867e | 161 | . int index; |
e98e6ec1 | 162 | . |
4a96bc04 SC |
163 | . {* The next section in the list belonging to the BFD, or NULL. *} |
164 | . | |
165 | . struct sec *next; | |
166 | . | |
c188b0be | 167 | . {* The field flags contains attributes of the section. Some |
4a96bc04 | 168 | . flags are read in from the object file, and some are |
57a1867e | 169 | . synthesized from other information. *} |
4a96bc04 SC |
170 | . |
171 | . flagword flags; | |
172 | . | |
173 | .#define SEC_NO_FLAGS 0x000 | |
174 | . | |
c188b0be DM |
175 | . {* Tells the OS to allocate space for this section when loading. |
176 | . This is clear for a section containing debug information | |
4a96bc04 | 177 | . only. *} |
4a96bc04 | 178 | .#define SEC_ALLOC 0x001 |
57a1867e | 179 | . |
4a96bc04 | 180 | . {* Tells the OS to load the section from the file when loading. |
c188b0be | 181 | . This is clear for a .bss section. *} |
4a96bc04 | 182 | .#define SEC_LOAD 0x002 |
a8a4b6b5 | 183 | . |
c188b0be DM |
184 | . {* The section contains data still to be relocated, so there is |
185 | . some relocation information too. *} | |
4a96bc04 SC |
186 | .#define SEC_RELOC 0x004 |
187 | . | |
a8a4b6b5 | 188 | .#if 0 {* Obsolete ? *} |
4a96bc04 | 189 | .#define SEC_BALIGN 0x008 |
a8a4b6b5 | 190 | .#endif |
4a96bc04 SC |
191 | . |
192 | . {* A signal to the OS that the section contains read only | |
193 | . data. *} | |
194 | .#define SEC_READONLY 0x010 | |
195 | . | |
196 | . {* The section contains code only. *} | |
4a96bc04 SC |
197 | .#define SEC_CODE 0x020 |
198 | . | |
199 | . {* The section contains data only. *} | |
a8a4b6b5 | 200 | .#define SEC_DATA 0x040 |
4a96bc04 SC |
201 | . |
202 | . {* The section will reside in ROM. *} | |
4a96bc04 SC |
203 | .#define SEC_ROM 0x080 |
204 | . | |
205 | . {* The section contains constructor information. This section | |
206 | . type is used by the linker to create lists of constructors and | |
207 | . destructors used by <<g++>>. When a back end sees a symbol | |
208 | . which should be used in a constructor list, it creates a new | |
c188b0be DM |
209 | . section for the type of name (e.g., <<__CTOR_LIST__>>), attaches |
210 | . the symbol to it, and builds a relocation. To build the lists | |
211 | . of constructors, all the linker has to do is catenate all the | |
212 | . sections called <<__CTOR_LIST__>> and relocate the data | |
4a96bc04 SC |
213 | . contained within - exactly the operations it would peform on |
214 | . standard data. *} | |
4a96bc04 SC |
215 | .#define SEC_CONSTRUCTOR 0x100 |
216 | . | |
217 | . {* The section is a constuctor, and should be placed at the | |
a8a4b6b5 | 218 | . end of the text, data, or bss section(?). *} |
4a96bc04 | 219 | .#define SEC_CONSTRUCTOR_TEXT 0x1100 |
4a96bc04 | 220 | .#define SEC_CONSTRUCTOR_DATA 0x2100 |
4a96bc04 SC |
221 | .#define SEC_CONSTRUCTOR_BSS 0x3100 |
222 | . | |
21c77703 | 223 | . {* The section has contents - a data section could be |
c188b0be | 224 | . <<SEC_ALLOC>> | <<SEC_HAS_CONTENTS>>; a debug section could be |
4a96bc04 | 225 | . <<SEC_HAS_CONTENTS>> *} |
4a96bc04 SC |
226 | .#define SEC_HAS_CONTENTS 0x200 |
227 | . | |
c188b0be | 228 | . {* An instruction to the linker to not output the section |
83f4323e | 229 | . even if it has information which would normally be written. *} |
4a96bc04 SC |
230 | .#define SEC_NEVER_LOAD 0x400 |
231 | . | |
83f4323e MM |
232 | . {* The section is a COFF shared library section. This flag is |
233 | . only for the linker. If this type of section appears in | |
234 | . the input file, the linker must copy it to the output file | |
235 | . without changing the vma or size. FIXME: Although this | |
236 | . was originally intended to be general, it really is COFF | |
237 | . specific (and the flag was renamed to indicate this). It | |
238 | . might be cleaner to have some more general mechanism to | |
239 | . allow the back end to control what the linker does with | |
240 | . sections. *} | |
241 | .#define SEC_COFF_SHARED_LIBRARY 0x800 | |
21c77703 SC |
242 | . |
243 | . {* The section is a common section (symbols may be defined | |
244 | . multiple times, the value of a symbol is the amount of | |
245 | . space it requires, and the largest symbol value is the one | |
a8a4b6b5 | 246 | . used). Most targets have exactly one of these (which we |
83f4323e | 247 | . translate to bfd_com_section_ptr), but ECOFF has two. *} |
21c77703 | 248 | .#define SEC_IS_COMMON 0x8000 |
a8a4b6b5 | 249 | . |
c188b0be DM |
250 | . {* The section contains only debugging information. For |
251 | . example, this is set for ELF .debug and .stab sections. | |
252 | . strip tests this flag to see if a section can be | |
253 | . discarded. *} | |
254 | .#define SEC_DEBUGGING 0x10000 | |
255 | . | |
57a1867e DM |
256 | . {* The contents of this section are held in memory pointed to |
257 | . by the contents field. This is checked by | |
258 | . bfd_get_section_contents, and the data is retrieved from | |
259 | . memory if appropriate. *} | |
260 | .#define SEC_IN_MEMORY 0x20000 | |
261 | . | |
83f4323e MM |
262 | . {* The contents of this section are to be excluded by the |
263 | . linker for executable and shared objects unless those | |
264 | . objects are to be further relocated. *} | |
265 | .#define SEC_EXCLUDE 0x40000 | |
266 | . | |
267 | . {* The contents of this section are to be sorted by the | |
268 | . based on the address specified in the associated symbol | |
269 | . table. *} | |
270 | .#define SEC_SORT_ENTRIES 0x80000 | |
271 | . | |
7ec49f91 ILT |
272 | . {* A mark flag used by some of the linker backends. This |
273 | . should not be set by application code. *} | |
274 | .#define SEC_LINKER_MARK 0x100000 | |
275 | . | |
a8a4b6b5 KR |
276 | . {* End of section flags. *} |
277 | . | |
278 | . {* The virtual memory address of the section - where it will be | |
279 | . at run time. The symbols are relocated against this. The | |
280 | . user_set_vma flag is maintained by bfd; if it's not set, the | |
281 | . backend can assign addresses (for example, in <<a.out>>, where | |
282 | . the default address for <<.data>> is dependent on the specific | |
283 | . target and various flags). *} | |
284 | . | |
4a96bc04 | 285 | . bfd_vma vma; |
fefb4b30 | 286 | . boolean user_set_vma; |
4a96bc04 | 287 | . |
a8a4b6b5 | 288 | . {* The load address of the section - where it would be in a |
c188b0be | 289 | . rom image; really only used for writing section header |
a8a4b6b5 KR |
290 | . information. *} |
291 | . | |
292 | . bfd_vma lma; | |
293 | . | |
e98e6ec1 | 294 | . {* The size of the section in bytes, as it will be output. |
c188b0be | 295 | . contains a value even if the section has no contents (e.g., the |
e98e6ec1 SC |
296 | . size of <<.bss>>). This will be filled in after relocation *} |
297 | . | |
57a1867e | 298 | . bfd_size_type _cooked_size; |
e98e6ec1 | 299 | . |
c188b0be | 300 | . {* The original size on disk of the section, in bytes. Normally this |
e98e6ec1 SC |
301 | . value is the same as the size, but if some relaxing has |
302 | . been done, then this value will be bigger. *} | |
4a96bc04 | 303 | . |
57a1867e | 304 | . bfd_size_type _raw_size; |
4a96bc04 SC |
305 | . |
306 | . {* If this section is going to be output, then this value is the | |
307 | . offset into the output section of the first byte in the input | |
c188b0be | 308 | . section. E.g., if this was going to start at the 100th byte in |
4a96bc04 SC |
309 | . the output section, this value would be 100. *} |
310 | . | |
311 | . bfd_vma output_offset; | |
312 | . | |
313 | . {* The output section through which to map on output. *} | |
314 | . | |
315 | . struct sec *output_section; | |
316 | . | |
c188b0be DM |
317 | . {* The alignment requirement of the section, as an exponent of 2 - |
318 | . e.g., 3 aligns to 2^3 (or 8). *} | |
4a96bc04 SC |
319 | . |
320 | . unsigned int alignment_power; | |
321 | . | |
322 | . {* If an input section, a pointer to a vector of relocation | |
323 | . records for the data in this section. *} | |
324 | . | |
325 | . struct reloc_cache_entry *relocation; | |
326 | . | |
327 | . {* If an output section, a pointer to a vector of pointers to | |
328 | . relocation records for the data in this section. *} | |
329 | . | |
330 | . struct reloc_cache_entry **orelocation; | |
331 | . | |
332 | . {* The number of relocation records in one of the above *} | |
333 | . | |
334 | . unsigned reloc_count; | |
335 | . | |
4a96bc04 | 336 | . {* Information below is back end specific - and not always used |
a8a4b6b5 | 337 | . or updated. *} |
4a96bc04 | 338 | . |
a8a4b6b5 | 339 | . {* File position of section data *} |
4a96bc04 | 340 | . |
57a1867e DM |
341 | . file_ptr filepos; |
342 | . | |
4a96bc04 SC |
343 | . {* File position of relocation info *} |
344 | . | |
345 | . file_ptr rel_filepos; | |
346 | . | |
347 | . {* File position of line data *} | |
348 | . | |
349 | . file_ptr line_filepos; | |
350 | . | |
351 | . {* Pointer to data for applications *} | |
352 | . | |
353 | . PTR userdata; | |
354 | . | |
57a1867e DM |
355 | . {* If the SEC_IN_MEMORY flag is set, this points to the actual |
356 | . contents. *} | |
357 | . unsigned char *contents; | |
4a96bc04 SC |
358 | . |
359 | . {* Attached line number information *} | |
360 | . | |
361 | . alent *lineno; | |
57a1867e | 362 | . |
4a96bc04 SC |
363 | . {* Number of line number records *} |
364 | . | |
365 | . unsigned int lineno_count; | |
366 | . | |
367 | . {* When a section is being output, this value changes as more | |
368 | . linenumbers are written out *} | |
369 | . | |
370 | . file_ptr moving_line_filepos; | |
371 | . | |
c188b0be | 372 | . {* What the section number is in the target world *} |
4a96bc04 | 373 | . |
e98e6ec1 | 374 | . int target_index; |
4a96bc04 SC |
375 | . |
376 | . PTR used_by_bfd; | |
377 | . | |
378 | . {* If this is a constructor section then here is a list of the | |
379 | . relocations created to relocate items within it. *} | |
380 | . | |
381 | . struct relent_chain *constructor_chain; | |
382 | . | |
383 | . {* The BFD which owns the section. *} | |
384 | . | |
385 | . bfd *owner; | |
386 | . | |
e98e6ec1 SC |
387 | . boolean reloc_done; |
388 | . {* A symbol which points at this section only *} | |
57a1867e | 389 | . struct symbol_cache_entry *symbol; |
e98e6ec1 | 390 | . struct symbol_cache_entry **symbol_ptr_ptr; |
a8a4b6b5 | 391 | . |
4c3721d5 ILT |
392 | . struct bfd_link_order *link_order_head; |
393 | . struct bfd_link_order *link_order_tail; | |
4a96bc04 | 394 | .} asection ; |
e98e6ec1 | 395 | . |
a8a4b6b5 KR |
396 | . {* These sections are global, and are managed by BFD. The application |
397 | . and target back end are not permitted to change the values in | |
83f4323e MM |
398 | . these sections. New code should use the section_ptr macros rather |
399 | . than referring directly to the const sections. The const sections | |
400 | . may eventually vanish. *} | |
e98e6ec1 SC |
401 | .#define BFD_ABS_SECTION_NAME "*ABS*" |
402 | .#define BFD_UND_SECTION_NAME "*UND*" | |
403 | .#define BFD_COM_SECTION_NAME "*COM*" | |
21c77703 | 404 | .#define BFD_IND_SECTION_NAME "*IND*" |
e98e6ec1 SC |
405 | . |
406 | . {* the absolute section *} | |
83f4323e MM |
407 | .extern const asection bfd_abs_section; |
408 | .#define bfd_abs_section_ptr ((asection *) &bfd_abs_section) | |
409 | .#define bfd_is_abs_section(sec) ((sec) == bfd_abs_section_ptr) | |
e98e6ec1 | 410 | . {* Pointer to the undefined section *} |
83f4323e MM |
411 | .extern const asection bfd_und_section; |
412 | .#define bfd_und_section_ptr ((asection *) &bfd_und_section) | |
413 | .#define bfd_is_und_section(sec) ((sec) == bfd_und_section_ptr) | |
e98e6ec1 | 414 | . {* Pointer to the common section *} |
83f4323e MM |
415 | .extern const asection bfd_com_section; |
416 | .#define bfd_com_section_ptr ((asection *) &bfd_com_section) | |
21c77703 | 417 | . {* Pointer to the indirect section *} |
83f4323e MM |
418 | .extern const asection bfd_ind_section; |
419 | .#define bfd_ind_section_ptr ((asection *) &bfd_ind_section) | |
420 | .#define bfd_is_ind_section(sec) ((sec) == bfd_ind_section_ptr) | |
421 | . | |
422 | .extern const struct symbol_cache_entry * const bfd_abs_symbol; | |
423 | .extern const struct symbol_cache_entry * const bfd_com_symbol; | |
424 | .extern const struct symbol_cache_entry * const bfd_und_symbol; | |
425 | .extern const struct symbol_cache_entry * const bfd_ind_symbol; | |
e98e6ec1 SC |
426 | .#define bfd_get_section_size_before_reloc(section) \ |
427 | . (section->reloc_done ? (abort(),1): (section)->_raw_size) | |
428 | .#define bfd_get_section_size_after_reloc(section) \ | |
429 | . ((section->reloc_done) ? (section)->_cooked_size: (abort(),1)) | |
985fca12 SC |
430 | */ |
431 | ||
fefb4b30 JG |
432 | /* These symbols are global, not specific to any BFD. Therefore, anything |
433 | that tries to change them is broken, and should be repaired. */ | |
83f4323e | 434 | static const asymbol global_syms[] = |
57a1867e DM |
435 | { |
436 | /* the_bfd, name, value, attr, section [, udata] */ | |
83f4323e MM |
437 | {0, BFD_COM_SECTION_NAME, 0, BSF_SECTION_SYM, (asection *) &bfd_com_section}, |
438 | {0, BFD_UND_SECTION_NAME, 0, BSF_SECTION_SYM, (asection *) &bfd_und_section}, | |
439 | {0, BFD_ABS_SECTION_NAME, 0, BSF_SECTION_SYM, (asection *) &bfd_abs_section}, | |
440 | {0, BFD_IND_SECTION_NAME, 0, BSF_SECTION_SYM, (asection *) &bfd_ind_section}, | |
fefb4b30 JG |
441 | }; |
442 | ||
21c77703 | 443 | #define STD_SECTION(SEC, FLAGS, SYM, NAME, IDX) \ |
83f4323e MM |
444 | const asymbol * const SYM = (asymbol *) &global_syms[IDX]; \ |
445 | const asection SEC = \ | |
446 | { NAME, 0, 0, FLAGS, 0, false, 0, 0, 0, 0, (asection *) &SEC, \ | |
447 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, (boolean) 0, \ | |
448 | (asymbol *) &global_syms[IDX], (asymbol **) &SYM, } | |
449 | ||
450 | STD_SECTION (bfd_com_section, SEC_IS_COMMON, bfd_com_symbol, | |
451 | BFD_COM_SECTION_NAME, 0); | |
21c77703 SC |
452 | STD_SECTION (bfd_und_section, 0, bfd_und_symbol, BFD_UND_SECTION_NAME, 1); |
453 | STD_SECTION (bfd_abs_section, 0, bfd_abs_symbol, BFD_ABS_SECTION_NAME, 2); | |
454 | STD_SECTION (bfd_ind_section, 0, bfd_ind_symbol, BFD_IND_SECTION_NAME, 3); | |
fefb4b30 | 455 | #undef STD_SECTION |
e98e6ec1 SC |
456 | |
457 | /* | |
fefb4b30 JG |
458 | DOCDD |
459 | INODE | |
460 | section prototypes, , typedef asection, Sections | |
4a96bc04 | 461 | SUBSECTION |
1adbf662 | 462 | Section prototypes |
985fca12 | 463 | |
1adbf662 | 464 | These are the functions exported by the section handling part of BFD. |
4a96bc04 | 465 | */ |
985fca12 | 466 | |
4a96bc04 | 467 | /* |
57a1867e | 468 | FUNCTION |
4a96bc04 | 469 | bfd_get_section_by_name |
985fca12 | 470 | |
4a96bc04 SC |
471 | SYNOPSIS |
472 | asection *bfd_get_section_by_name(bfd *abfd, CONST char *name); | |
985fca12 | 473 | |
4a96bc04 | 474 | DESCRIPTION |
1adbf662 PS |
475 | Run through @var{abfd} and return the one of the |
476 | <<asection>>s whose name matches @var{name}, otherwise <<NULL>>. | |
4a96bc04 | 477 | @xref{Sections}, for more information. |
985fca12 | 478 | |
c188b0be | 479 | This should only be used in special cases; the normal way to process |
1adbf662 PS |
480 | all sections of a given name is to use <<bfd_map_over_sections>> and |
481 | <<strcmp>> on the name (or better yet, base it on the section flags | |
c188b0be | 482 | or something else) for each section. |
4a96bc04 | 483 | */ |
985fca12 | 484 | |
4a96bc04 | 485 | asection * |
57a1867e DM |
486 | bfd_get_section_by_name (abfd, name) |
487 | bfd *abfd; | |
488 | CONST char *name; | |
4a96bc04 SC |
489 | { |
490 | asection *sect; | |
985fca12 | 491 | |
4a96bc04 | 492 | for (sect = abfd->sections; sect != NULL; sect = sect->next) |
57a1867e DM |
493 | if (!strcmp (sect->name, name)) |
494 | return sect; | |
4a96bc04 SC |
495 | return NULL; |
496 | } | |
985fca12 | 497 | |
985fca12 | 498 | |
4a96bc04 SC |
499 | /* |
500 | FUNCTION | |
501 | bfd_make_section_old_way | |
985fca12 | 502 | |
4a96bc04 | 503 | SYNOPSIS |
c188b0be | 504 | asection *bfd_make_section_old_way(bfd *abfd, CONST char *name); |
985fca12 | 505 | |
4a96bc04 | 506 | DESCRIPTION |
c188b0be DM |
507 | Create a new empty section called @var{name} |
508 | and attach it to the end of the chain of sections for the | |
509 | BFD @var{abfd}. An attempt to create a section with a name which | |
1adbf662 | 510 | is already in use returns its pointer without changing the |
4a96bc04 | 511 | section chain. |
985fca12 | 512 | |
4a96bc04 | 513 | It has the funny name since this is the way it used to be |
c188b0be | 514 | before it was rewritten.... |
985fca12 | 515 | |
4a96bc04 | 516 | Possible errors are: |
d1ad85a6 | 517 | o <<bfd_error_invalid_operation>> - |
4a96bc04 | 518 | If output has already started for this BFD. |
d1ad85a6 | 519 | o <<bfd_error_no_memory>> - |
4a96bc04 | 520 | If obstack alloc fails. |
985fca12 SC |
521 | |
522 | */ | |
523 | ||
985fca12 | 524 | |
985fca12 | 525 | asection * |
57a1867e DM |
526 | bfd_make_section_old_way (abfd, name) |
527 | bfd *abfd; | |
528 | CONST char *name; | |
985fca12 | 529 | { |
57a1867e DM |
530 | asection *sec = bfd_get_section_by_name (abfd, name); |
531 | if (sec == (asection *) NULL) | |
4a96bc04 | 532 | { |
57a1867e | 533 | sec = bfd_make_section (abfd, name); |
4a96bc04 SC |
534 | } |
535 | return sec; | |
985fca12 SC |
536 | } |
537 | ||
4a96bc04 SC |
538 | /* |
539 | FUNCTION | |
c188b0be | 540 | bfd_make_section_anyway |
985fca12 | 541 | |
4a96bc04 | 542 | SYNOPSIS |
c188b0be | 543 | asection *bfd_make_section_anyway(bfd *abfd, CONST char *name); |
985fca12 | 544 | |
4a96bc04 | 545 | DESCRIPTION |
c188b0be DM |
546 | Create a new empty section called @var{name} and attach it to the end of |
547 | the chain of sections for @var{abfd}. Create a new section even if there | |
57a1867e | 548 | is already a section with that name. |
4a96bc04 | 549 | |
1adbf662 | 550 | Return <<NULL>> and set <<bfd_error>> on error; possible errors are: |
d1ad85a6 DM |
551 | o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}. |
552 | o <<bfd_error_no_memory>> - If obstack alloc fails. | |
985fca12 SC |
553 | */ |
554 | ||
985fca12 | 555 | sec_ptr |
c188b0be DM |
556 | bfd_make_section_anyway (abfd, name) |
557 | bfd *abfd; | |
558 | CONST char *name; | |
985fca12 | 559 | { |
c188b0be DM |
560 | asection *newsect; |
561 | asection **prev = &abfd->sections; | |
57a1867e | 562 | asection *sect = abfd->sections; |
985fca12 | 563 | |
c188b0be DM |
564 | if (abfd->output_has_begun) |
565 | { | |
d1ad85a6 | 566 | bfd_set_error (bfd_error_invalid_operation); |
c188b0be DM |
567 | return NULL; |
568 | } | |
21c77703 | 569 | |
57a1867e DM |
570 | while (sect) |
571 | { | |
572 | prev = §->next; | |
573 | sect = sect->next; | |
574 | } | |
985fca12 | 575 | |
57a1867e DM |
576 | newsect = (asection *) bfd_zalloc (abfd, sizeof (asection)); |
577 | if (newsect == NULL) | |
83f4323e | 578 | return NULL; |
985fca12 SC |
579 | |
580 | newsect->name = name; | |
581 | newsect->index = abfd->section_count++; | |
582 | newsect->flags = SEC_NO_FLAGS; | |
583 | ||
57a1867e DM |
584 | newsect->userdata = NULL; |
585 | newsect->contents = NULL; | |
586 | newsect->next = (asection *) NULL; | |
587 | newsect->relocation = (arelent *) NULL; | |
985fca12 | 588 | newsect->reloc_count = 0; |
57a1867e | 589 | newsect->line_filepos = 0; |
985fca12 | 590 | newsect->owner = abfd; |
e98e6ec1 | 591 | |
fefb4b30 JG |
592 | /* Create a symbol whos only job is to point to this section. This is |
593 | useful for things like relocs which are relative to the base of a | |
594 | section. */ | |
57a1867e | 595 | newsect->symbol = bfd_make_empty_symbol (abfd); |
83f4323e | 596 | if (newsect->symbol == NULL) |
9783e04a | 597 | return NULL; |
e98e6ec1 SC |
598 | newsect->symbol->name = name; |
599 | newsect->symbol->value = 0; | |
600 | newsect->symbol->section = newsect; | |
601 | newsect->symbol->flags = BSF_SECTION_SYM; | |
e98e6ec1 SC |
602 | |
603 | newsect->symbol_ptr_ptr = &newsect->symbol; | |
c188b0be | 604 | |
57a1867e DM |
605 | if (BFD_SEND (abfd, _new_section_hook, (abfd, newsect)) != true) |
606 | { | |
607 | free (newsect); | |
608 | return NULL; | |
609 | } | |
985fca12 SC |
610 | |
611 | *prev = newsect; | |
612 | return newsect; | |
613 | } | |
614 | ||
c188b0be DM |
615 | /* |
616 | FUNCTION | |
617 | bfd_make_section | |
618 | ||
619 | SYNOPSIS | |
620 | asection *bfd_make_section(bfd *, CONST char *name); | |
621 | ||
622 | DESCRIPTION | |
d1ad85a6 DM |
623 | Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling |
624 | bfd_set_error ()) without changing the section chain if there is already a | |
1adbf662 PS |
625 | section named @var{name}. If there is an error, return <<NULL>> and set |
626 | <<bfd_error>>. | |
c188b0be DM |
627 | */ |
628 | ||
83f4323e | 629 | asection * |
57a1867e DM |
630 | bfd_make_section (abfd, name) |
631 | bfd *abfd; | |
632 | CONST char *name; | |
c188b0be | 633 | { |
57a1867e DM |
634 | asection *sect = abfd->sections; |
635 | ||
636 | if (strcmp (name, BFD_ABS_SECTION_NAME) == 0) | |
637 | { | |
83f4323e | 638 | return bfd_abs_section_ptr; |
57a1867e DM |
639 | } |
640 | if (strcmp (name, BFD_COM_SECTION_NAME) == 0) | |
641 | { | |
83f4323e | 642 | return bfd_com_section_ptr; |
57a1867e DM |
643 | } |
644 | if (strcmp (name, BFD_UND_SECTION_NAME) == 0) | |
645 | { | |
83f4323e | 646 | return bfd_und_section_ptr; |
57a1867e DM |
647 | } |
648 | ||
649 | if (strcmp (name, BFD_IND_SECTION_NAME) == 0) | |
650 | { | |
83f4323e | 651 | return bfd_ind_section_ptr; |
57a1867e DM |
652 | } |
653 | ||
654 | while (sect) | |
655 | { | |
656 | if (!strcmp (sect->name, name)) | |
657 | return NULL; | |
658 | sect = sect->next; | |
659 | } | |
c188b0be DM |
660 | |
661 | /* The name is not already used; go ahead and make a new section. */ | |
662 | return bfd_make_section_anyway (abfd, name); | |
663 | } | |
664 | ||
985fca12 | 665 | |
4a96bc04 SC |
666 | /* |
667 | FUNCTION | |
668 | bfd_set_section_flags | |
669 | ||
670 | SYNOPSIS | |
c188b0be | 671 | boolean bfd_set_section_flags(bfd *abfd, asection *sec, flagword flags); |
4a96bc04 SC |
672 | |
673 | DESCRIPTION | |
c188b0be | 674 | Set the attributes of the section @var{sec} in the BFD |
1adbf662 | 675 | @var{abfd} to the value @var{flags}. Return <<true>> on success, |
c188b0be | 676 | <<false>> on error. Possible error returns are: |
4a96bc04 | 677 | |
d1ad85a6 | 678 | o <<bfd_error_invalid_operation>> - |
4a96bc04 SC |
679 | The section cannot have one or more of the attributes |
680 | requested. For example, a .bss section in <<a.out>> may not | |
681 | have the <<SEC_HAS_CONTENTS>> field set. | |
985fca12 | 682 | |
985fca12 SC |
683 | */ |
684 | ||
9783e04a | 685 | /*ARGSUSED*/ |
985fca12 | 686 | boolean |
57a1867e DM |
687 | bfd_set_section_flags (abfd, section, flags) |
688 | bfd *abfd; | |
689 | sec_ptr section; | |
690 | flagword flags; | |
985fca12 | 691 | { |
fefb4b30 JG |
692 | #if 0 |
693 | /* If you try to copy a text section from an input file (where it | |
694 | has the SEC_CODE flag set) to an output file, this loses big if | |
695 | the bfd_applicable_section_flags (abfd) doesn't have the SEC_CODE | |
696 | set - which it doesn't, at least not for a.out. FIXME */ | |
697 | ||
57a1867e DM |
698 | if ((flags & bfd_applicable_section_flags (abfd)) != flags) |
699 | { | |
700 | bfd_set_error (bfd_error_invalid_operation); | |
701 | return false; | |
702 | } | |
fefb4b30 | 703 | #endif |
985fca12 SC |
704 | |
705 | section->flags = flags; | |
706 | return true; | |
707 | } | |
708 | ||
709 | ||
4a96bc04 SC |
710 | /* |
711 | FUNCTION | |
712 | bfd_map_over_sections | |
713 | ||
714 | SYNOPSIS | |
fefb4b30 JG |
715 | void bfd_map_over_sections(bfd *abfd, |
716 | void (*func)(bfd *abfd, | |
717 | asection *sect, | |
718 | PTR obj), | |
719 | PTR obj); | |
985fca12 | 720 | |
4a96bc04 | 721 | DESCRIPTION |
c188b0be | 722 | Call the provided function @var{func} for each section |
4a96bc04 | 723 | attached to the BFD @var{abfd}, passing @var{obj} as an |
57a1867e | 724 | argument. The function will be called as if by |
985fca12 | 725 | |
4a96bc04 | 726 | | func(abfd, the_section, obj); |
985fca12 | 727 | |
c188b0be | 728 | This is the prefered method for iterating over sections; an |
4a96bc04 SC |
729 | alternative would be to use a loop: |
730 | ||
731 | | section *p; | |
732 | | for (p = abfd->sections; p != NULL; p = p->next) | |
733 | | func(abfd, p, ...) | |
985fca12 | 734 | |
985fca12 | 735 | |
985fca12 SC |
736 | */ |
737 | ||
738 | /*VARARGS2*/ | |
739 | void | |
57a1867e DM |
740 | bfd_map_over_sections (abfd, operation, user_storage) |
741 | bfd *abfd; | |
742 | void (*operation) PARAMS ((bfd * abfd, asection * sect, PTR obj)); | |
743 | PTR user_storage; | |
985fca12 SC |
744 | { |
745 | asection *sect; | |
83f4323e | 746 | unsigned int i = 0; |
57a1867e | 747 | |
985fca12 SC |
748 | for (sect = abfd->sections; sect != NULL; i++, sect = sect->next) |
749 | (*operation) (abfd, sect, user_storage); | |
750 | ||
57a1867e DM |
751 | if (i != abfd->section_count) /* Debugging */ |
752 | abort (); | |
985fca12 SC |
753 | } |
754 | ||
755 | ||
4a96bc04 SC |
756 | /* |
757 | FUNCTION | |
758 | bfd_set_section_size | |
759 | ||
760 | SYNOPSIS | |
c188b0be | 761 | boolean bfd_set_section_size(bfd *abfd, asection *sec, bfd_size_type val); |
985fca12 | 762 | |
4a96bc04 | 763 | DESCRIPTION |
c188b0be | 764 | Set @var{sec} to the size @var{val}. If the operation is |
57a1867e | 765 | ok, then <<true>> is returned, else <<false>>. |
4a96bc04 SC |
766 | |
767 | Possible error returns: | |
d1ad85a6 | 768 | o <<bfd_error_invalid_operation>> - |
1adbf662 | 769 | Writing has started to the BFD, so setting the size is invalid. |
985fca12 | 770 | |
985fca12 SC |
771 | */ |
772 | ||
773 | boolean | |
57a1867e DM |
774 | bfd_set_section_size (abfd, ptr, val) |
775 | bfd *abfd; | |
776 | sec_ptr ptr; | |
777 | bfd_size_type val; | |
985fca12 SC |
778 | { |
779 | /* Once you've started writing to any section you cannot create or change | |
780 | the size of any others. */ | |
781 | ||
57a1867e DM |
782 | if (abfd->output_has_begun) |
783 | { | |
784 | bfd_set_error (bfd_error_invalid_operation); | |
785 | return false; | |
786 | } | |
985fca12 | 787 | |
e98e6ec1 SC |
788 | ptr->_cooked_size = val; |
789 | ptr->_raw_size = val; | |
57a1867e | 790 | |
985fca12 SC |
791 | return true; |
792 | } | |
793 | ||
4a96bc04 SC |
794 | /* |
795 | FUNCTION | |
796 | bfd_set_section_contents | |
797 | ||
798 | SYNOPSIS | |
799 | boolean bfd_set_section_contents | |
57a1867e | 800 | (bfd *abfd, |
985fca12 SC |
801 | asection *section, |
802 | PTR data, | |
803 | file_ptr offset, | |
4a96bc04 SC |
804 | bfd_size_type count); |
805 | ||
806 | ||
807 | DESCRIPTION | |
808 | Sets the contents of the section @var{section} in BFD | |
809 | @var{abfd} to the data starting in memory at @var{data}. The | |
810 | data is written to the output section starting at offset | |
57a1867e | 811 | @var{offset} for @var{count} bytes. |
4a96bc04 | 812 | |
e98e6ec1 SC |
813 | |
814 | ||
4a96bc04 SC |
815 | Normally <<true>> is returned, else <<false>>. Possible error |
816 | returns are: | |
d1ad85a6 | 817 | o <<bfd_error_no_contents>> - |
4a96bc04 SC |
818 | The output section does not have the <<SEC_HAS_CONTENTS>> |
819 | attribute, so nothing can be written to it. | |
820 | o and some more too | |
821 | ||
822 | This routine is front end to the back end function | |
823 | <<_bfd_set_section_contents>>. | |
824 | ||
985fca12 SC |
825 | |
826 | */ | |
827 | ||
fefb4b30 JG |
828 | #define bfd_get_section_size_now(abfd,sec) \ |
829 | (sec->reloc_done \ | |
830 | ? bfd_get_section_size_after_reloc (sec) \ | |
831 | : bfd_get_section_size_before_reloc (sec)) | |
832 | ||
985fca12 | 833 | boolean |
57a1867e DM |
834 | bfd_set_section_contents (abfd, section, location, offset, count) |
835 | bfd *abfd; | |
836 | sec_ptr section; | |
837 | PTR location; | |
838 | file_ptr offset; | |
839 | bfd_size_type count; | |
985fca12 | 840 | { |
fefb4b30 JG |
841 | bfd_size_type sz; |
842 | ||
83f4323e | 843 | if (!(bfd_get_section_flags (abfd, section) & SEC_HAS_CONTENTS)) |
57a1867e DM |
844 | { |
845 | bfd_set_error (bfd_error_no_contents); | |
846 | return (false); | |
847 | } | |
fefb4b30 | 848 | |
a8a4b6b5 | 849 | if (offset < 0) |
fefb4b30 JG |
850 | { |
851 | bad_val: | |
d1ad85a6 | 852 | bfd_set_error (bfd_error_bad_value); |
fefb4b30 JG |
853 | return false; |
854 | } | |
855 | sz = bfd_get_section_size_now (abfd, section); | |
83f4323e | 856 | if ((bfd_size_type) offset > sz |
fefb4b30 JG |
857 | || count > sz |
858 | || offset + count > sz) | |
859 | goto bad_val; | |
985fca12 | 860 | |
a8a4b6b5 KR |
861 | switch (abfd->direction) |
862 | { | |
57a1867e DM |
863 | case read_direction: |
864 | case no_direction: | |
865 | bfd_set_error (bfd_error_invalid_operation); | |
866 | return false; | |
a8a4b6b5 | 867 | |
57a1867e DM |
868 | case write_direction: |
869 | break; | |
a8a4b6b5 | 870 | |
57a1867e DM |
871 | case both_direction: |
872 | /* File is opened for update. `output_has_begun' some time ago when | |
a8a4b6b5 KR |
873 | the file was created. Do not recompute sections sizes or alignments |
874 | in _bfd_set_section_content. */ | |
57a1867e DM |
875 | abfd->output_has_begun = true; |
876 | break; | |
a8a4b6b5 KR |
877 | } |
878 | ||
985fca12 | 879 | if (BFD_SEND (abfd, _bfd_set_section_contents, |
57a1867e DM |
880 | (abfd, section, location, offset, count))) |
881 | { | |
882 | abfd->output_has_begun = true; | |
883 | return true; | |
884 | } | |
985fca12 SC |
885 | |
886 | return false; | |
887 | } | |
888 | ||
4a96bc04 SC |
889 | /* |
890 | FUNCTION | |
891 | bfd_get_section_contents | |
985fca12 | 892 | |
4a96bc04 | 893 | SYNOPSIS |
57a1867e | 894 | boolean bfd_get_section_contents |
4a96bc04 SC |
895 | (bfd *abfd, asection *section, PTR location, |
896 | file_ptr offset, bfd_size_type count); | |
985fca12 | 897 | |
4a96bc04 | 898 | DESCRIPTION |
c188b0be | 899 | Read data from @var{section} in BFD @var{abfd} |
4a96bc04 SC |
900 | into memory starting at @var{location}. The data is read at an |
901 | offset of @var{offset} from the start of the input section, | |
902 | and is read for @var{count} bytes. | |
985fca12 | 903 | |
1adbf662 PS |
904 | If the contents of a constructor with the <<SEC_CONSTRUCTOR>> |
905 | flag set are requested or if the section does not have the | |
906 | <<SEC_HAS_CONTENTS>> flag set, then the @var{location} is filled | |
907 | with zeroes. If no errors occur, <<true>> is returned, else | |
4a96bc04 | 908 | <<false>>. |
985fca12 | 909 | |
985fca12 SC |
910 | |
911 | ||
912 | */ | |
913 | boolean | |
57a1867e DM |
914 | bfd_get_section_contents (abfd, section, location, offset, count) |
915 | bfd *abfd; | |
916 | sec_ptr section; | |
917 | PTR location; | |
918 | file_ptr offset; | |
919 | bfd_size_type count; | |
985fca12 | 920 | { |
fefb4b30 | 921 | bfd_size_type sz; |
e98e6ec1 | 922 | |
57a1867e | 923 | if (section->flags & SEC_CONSTRUCTOR) |
fefb4b30 | 924 | { |
57a1867e | 925 | memset (location, 0, (unsigned) count); |
fefb4b30 JG |
926 | return true; |
927 | } | |
e98e6ec1 | 928 | |
a8a4b6b5 | 929 | if (offset < 0) |
fefb4b30 JG |
930 | { |
931 | bad_val: | |
d1ad85a6 | 932 | bfd_set_error (bfd_error_bad_value); |
fefb4b30 JG |
933 | return false; |
934 | } | |
aaa486c3 KR |
935 | /* Even if reloc_done is true, this function reads unrelocated |
936 | contents, so we want the raw size. */ | |
937 | sz = section->_raw_size; | |
83f4323e | 938 | if ((bfd_size_type) offset > sz || count > sz || offset + count > sz) |
fefb4b30 JG |
939 | goto bad_val; |
940 | ||
941 | if (count == 0) | |
942 | /* Don't bother. */ | |
943 | return true; | |
944 | ||
1adbf662 PS |
945 | if ((section->flags & SEC_HAS_CONTENTS) == 0) |
946 | { | |
57a1867e DM |
947 | memset (location, 0, (unsigned) count); |
948 | return true; | |
949 | } | |
950 | ||
951 | if ((section->flags & SEC_IN_MEMORY) != 0) | |
952 | { | |
83f4323e | 953 | memcpy (location, section->contents + offset, (size_t) count); |
1adbf662 PS |
954 | return true; |
955 | } | |
956 | ||
fefb4b30 JG |
957 | return BFD_SEND (abfd, _bfd_get_section_contents, |
958 | (abfd, section, location, offset, count)); | |
e98e6ec1 | 959 | } |
83f4323e MM |
960 | |
961 | /* | |
962 | FUNCTION | |
963 | bfd_copy_private_section_data | |
964 | ||
965 | SYNOPSIS | |
966 | boolean bfd_copy_private_section_data(bfd *ibfd, asection *isec, bfd *obfd, asection *osec); | |
967 | ||
968 | DESCRIPTION | |
969 | Copy private section information from @var{isec} in the BFD | |
970 | @var{ibfd} to the section @var{osec} in the BFD @var{obfd}. | |
971 | Return <<true>> on success, <<false>> on error. Possible error | |
972 | returns are: | |
973 | ||
974 | o <<bfd_error_no_memory>> - | |
975 | Not enough memory exists to create private data for @var{osec}. | |
976 | ||
977 | .#define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \ | |
978 | . BFD_SEND (ibfd, _bfd_copy_private_section_data, \ | |
979 | . (ibfd, isection, obfd, osection)) | |
980 | */ |