| 1 | /* Object file "section" support for the BFD library. |
| 2 | Copyright (C) 1990, 91, 92, 93, 94, 95, 1996 Free Software Foundation, Inc. |
| 3 | Written by Cygnus Support. |
| 4 | |
| 5 | This file is part of BFD, the Binary File Descriptor library. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 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 |
| 19 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 20 | |
| 21 | /* |
| 22 | SECTION |
| 23 | Sections |
| 24 | |
| 25 | The raw data contained within a BFD is maintained through the |
| 26 | section abstraction. A single BFD may have any number of |
| 27 | sections. It keeps hold of them by pointing to the first; |
| 28 | each one points to the next in the list. |
| 29 | |
| 30 | Sections are supported in BFD in <<section.c>>. |
| 31 | |
| 32 | @menu |
| 33 | @* Section Input:: |
| 34 | @* Section Output:: |
| 35 | @* typedef asection:: |
| 36 | @* section prototypes:: |
| 37 | @end menu |
| 38 | |
| 39 | INODE |
| 40 | Section Input, Section Output, Sections, Sections |
| 41 | SUBSECTION |
| 42 | Section input |
| 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 |
| 48 | outside world---for example, <<a.out>> would contain at least |
| 49 | three sections, called <<.text>>, <<.data>> and <<.bss>>. |
| 50 | |
| 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 |
| 55 | sections. A back end may attach other sections containing |
| 56 | constructor data, or an application may add a section (using |
| 57 | <<bfd_make_section>>) to the sections attached to an already open |
| 58 | BFD. For example, the linker creates an extra section |
| 59 | <<COMMON>> for each input file's BFD to hold information about |
| 60 | common storage. |
| 61 | |
| 62 | The raw data is not necessarily read in when |
| 63 | the section descriptor is created. Some targets may leave the |
| 64 | data in place until a <<bfd_get_section_contents>> call is |
| 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 |
| 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 | |
| 72 | INODE |
| 73 | Section Output, typedef asection, Section Input, Sections |
| 74 | |
| 75 | SUBSECTION |
| 76 | Section output |
| 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 |
| 80 | the same way as input sections; data is written to the |
| 81 | sections using <<bfd_set_section_contents>>. |
| 82 | |
| 83 | Any program that creates or combines sections (e.g., the assembler |
| 84 | and linker) must use the <<asection>> fields <<output_section>> and |
| 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 |
| 88 | itself and <<output_offset>> should probably be zero.) |
| 89 | |
| 90 | The data to be written comes from input sections attached |
| 91 | (via <<output_section>> pointers) to |
| 92 | the output sections. The output section structure can be |
| 93 | considered a filter for the input section: the output section |
| 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 | |
| 98 | E.g., to create a section "O", starting at 0x100, 0x123 long, |
| 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: |
| 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 | |
| 113 | |
| 114 | SUBSECTION |
| 115 | Link orders |
| 116 | |
| 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. |
| 120 | |
| 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. |
| 124 | |
| 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 |
| 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 |
| 131 | a link_order by link_order basis. |
| 132 | |
| 133 | */ |
| 134 | |
| 135 | |
| 136 | #include "bfd.h" |
| 137 | #include "sysdep.h" |
| 138 | #include "libbfd.h" |
| 139 | |
| 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 | .typedef struct sec |
| 153 | .{ |
| 154 | . {* The name of the section; the name isn't a copy, the pointer is |
| 155 | . the same as that passed to bfd_make_section. *} |
| 156 | . |
| 157 | . CONST char *name; |
| 158 | . |
| 159 | . {* Which section is it; 0..nth. *} |
| 160 | . |
| 161 | . int index; |
| 162 | . |
| 163 | . {* The next section in the list belonging to the BFD, or NULL. *} |
| 164 | . |
| 165 | . struct sec *next; |
| 166 | . |
| 167 | . {* The field flags contains attributes of the section. Some |
| 168 | . flags are read in from the object file, and some are |
| 169 | . synthesized from other information. *} |
| 170 | . |
| 171 | . flagword flags; |
| 172 | . |
| 173 | .#define SEC_NO_FLAGS 0x000 |
| 174 | . |
| 175 | . {* Tells the OS to allocate space for this section when loading. |
| 176 | . This is clear for a section containing debug information |
| 177 | . only. *} |
| 178 | .#define SEC_ALLOC 0x001 |
| 179 | . |
| 180 | . {* Tells the OS to load the section from the file when loading. |
| 181 | . This is clear for a .bss section. *} |
| 182 | .#define SEC_LOAD 0x002 |
| 183 | . |
| 184 | . {* The section contains data still to be relocated, so there is |
| 185 | . some relocation information too. *} |
| 186 | .#define SEC_RELOC 0x004 |
| 187 | . |
| 188 | .#if 0 {* Obsolete ? *} |
| 189 | .#define SEC_BALIGN 0x008 |
| 190 | .#endif |
| 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. *} |
| 197 | .#define SEC_CODE 0x020 |
| 198 | . |
| 199 | . {* The section contains data only. *} |
| 200 | .#define SEC_DATA 0x040 |
| 201 | . |
| 202 | . {* The section will reside in ROM. *} |
| 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 |
| 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 |
| 213 | . contained within - exactly the operations it would peform on |
| 214 | . standard data. *} |
| 215 | .#define SEC_CONSTRUCTOR 0x100 |
| 216 | . |
| 217 | . {* The section is a constuctor, and should be placed at the |
| 218 | . end of the text, data, or bss section(?). *} |
| 219 | .#define SEC_CONSTRUCTOR_TEXT 0x1100 |
| 220 | .#define SEC_CONSTRUCTOR_DATA 0x2100 |
| 221 | .#define SEC_CONSTRUCTOR_BSS 0x3100 |
| 222 | . |
| 223 | . {* The section has contents - a data section could be |
| 224 | . <<SEC_ALLOC>> | <<SEC_HAS_CONTENTS>>; a debug section could be |
| 225 | . <<SEC_HAS_CONTENTS>> *} |
| 226 | .#define SEC_HAS_CONTENTS 0x200 |
| 227 | . |
| 228 | . {* An instruction to the linker to not output the section |
| 229 | . even if it has information which would normally be written. *} |
| 230 | .#define SEC_NEVER_LOAD 0x400 |
| 231 | . |
| 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 |
| 242 | . |
| 243 | . {* The section contains common symbols (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 |
| 246 | . used). Most targets have exactly one of these (which we |
| 247 | . translate to bfd_com_section_ptr), but ECOFF has two. *} |
| 248 | .#define SEC_IS_COMMON 0x8000 |
| 249 | . |
| 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 | . |
| 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 | . |
| 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 | . |
| 272 | . {* When linking, duplicate sections of the same name should be |
| 273 | . discarded, rather than being combined into a single section as |
| 274 | . is usually done. This is similar to how common symbols are |
| 275 | . handled. See SEC_LINK_DUPLICATES below. *} |
| 276 | .#define SEC_LINK_ONCE 0x100000 |
| 277 | . |
| 278 | . {* If SEC_LINK_ONCE is set, this bitfield describes how the linker |
| 279 | . should handle duplicate sections. *} |
| 280 | .#define SEC_LINK_DUPLICATES 0x600000 |
| 281 | . |
| 282 | . {* This value for SEC_LINK_DUPLICATES means that duplicate |
| 283 | . sections with the same name should simply be discarded. *} |
| 284 | .#define SEC_LINK_DUPLICATES_DISCARD 0x0 |
| 285 | . |
| 286 | . {* This value for SEC_LINK_DUPLICATES means that the linker |
| 287 | . should warn if there are any duplicate sections, although |
| 288 | . it should still only link one copy. *} |
| 289 | .#define SEC_LINK_DUPLICATES_ONE_ONLY 0x200000 |
| 290 | . |
| 291 | . {* This value for SEC_LINK_DUPLICATES means that the linker |
| 292 | . should warn if any duplicate sections are a different size. *} |
| 293 | .#define SEC_LINK_DUPLICATES_SAME_SIZE 0x400000 |
| 294 | . |
| 295 | . {* This value for SEC_LINK_DUPLICATES means that the linker |
| 296 | . should warn if any duplicate sections contain different |
| 297 | . contents. *} |
| 298 | .#define SEC_LINK_DUPLICATES_SAME_CONTENTS 0x600000 |
| 299 | . |
| 300 | . {* This section was created by the linker as part of dynamic |
| 301 | . relocation or other arcane processing. It is skipped when |
| 302 | . going through the first-pass output, trusting that someone |
| 303 | . else up the line will take care of it later. *} |
| 304 | .#define SEC_LINKER_CREATED 0x800000 |
| 305 | . |
| 306 | . {* End of section flags. *} |
| 307 | . |
| 308 | . {* Some internal packed boolean fields. *} |
| 309 | . |
| 310 | . {* See the vma field. *} |
| 311 | . unsigned int user_set_vma : 1; |
| 312 | . |
| 313 | . {* Whether relocations have been processed. *} |
| 314 | . unsigned int reloc_done : 1; |
| 315 | . |
| 316 | . {* A mark flag used by some of the linker backends. *} |
| 317 | . unsigned int linker_mark : 1; |
| 318 | . |
| 319 | . {* End of internal packed boolean fields. *} |
| 320 | . |
| 321 | . {* The virtual memory address of the section - where it will be |
| 322 | . at run time. The symbols are relocated against this. The |
| 323 | . user_set_vma flag is maintained by bfd; if it's not set, the |
| 324 | . backend can assign addresses (for example, in <<a.out>>, where |
| 325 | . the default address for <<.data>> is dependent on the specific |
| 326 | . target and various flags). *} |
| 327 | . |
| 328 | . bfd_vma vma; |
| 329 | . |
| 330 | . {* The load address of the section - where it would be in a |
| 331 | . rom image; really only used for writing section header |
| 332 | . information. *} |
| 333 | . |
| 334 | . bfd_vma lma; |
| 335 | . |
| 336 | . {* The size of the section in bytes, as it will be output. |
| 337 | . contains a value even if the section has no contents (e.g., the |
| 338 | . size of <<.bss>>). This will be filled in after relocation *} |
| 339 | . |
| 340 | . bfd_size_type _cooked_size; |
| 341 | . |
| 342 | . {* The original size on disk of the section, in bytes. Normally this |
| 343 | . value is the same as the size, but if some relaxing has |
| 344 | . been done, then this value will be bigger. *} |
| 345 | . |
| 346 | . bfd_size_type _raw_size; |
| 347 | . |
| 348 | . {* If this section is going to be output, then this value is the |
| 349 | . offset into the output section of the first byte in the input |
| 350 | . section. E.g., if this was going to start at the 100th byte in |
| 351 | . the output section, this value would be 100. *} |
| 352 | . |
| 353 | . bfd_vma output_offset; |
| 354 | . |
| 355 | . {* The output section through which to map on output. *} |
| 356 | . |
| 357 | . struct sec *output_section; |
| 358 | . |
| 359 | . {* The alignment requirement of the section, as an exponent of 2 - |
| 360 | . e.g., 3 aligns to 2^3 (or 8). *} |
| 361 | . |
| 362 | . unsigned int alignment_power; |
| 363 | . |
| 364 | . {* If an input section, a pointer to a vector of relocation |
| 365 | . records for the data in this section. *} |
| 366 | . |
| 367 | . struct reloc_cache_entry *relocation; |
| 368 | . |
| 369 | . {* If an output section, a pointer to a vector of pointers to |
| 370 | . relocation records for the data in this section. *} |
| 371 | . |
| 372 | . struct reloc_cache_entry **orelocation; |
| 373 | . |
| 374 | . {* The number of relocation records in one of the above *} |
| 375 | . |
| 376 | . unsigned reloc_count; |
| 377 | . |
| 378 | . {* Information below is back end specific - and not always used |
| 379 | . or updated. *} |
| 380 | . |
| 381 | . {* File position of section data *} |
| 382 | . |
| 383 | . file_ptr filepos; |
| 384 | . |
| 385 | . {* File position of relocation info *} |
| 386 | . |
| 387 | . file_ptr rel_filepos; |
| 388 | . |
| 389 | . {* File position of line data *} |
| 390 | . |
| 391 | . file_ptr line_filepos; |
| 392 | . |
| 393 | . {* Pointer to data for applications *} |
| 394 | . |
| 395 | . PTR userdata; |
| 396 | . |
| 397 | . {* If the SEC_IN_MEMORY flag is set, this points to the actual |
| 398 | . contents. *} |
| 399 | . unsigned char *contents; |
| 400 | . |
| 401 | . {* Attached line number information *} |
| 402 | . |
| 403 | . alent *lineno; |
| 404 | . |
| 405 | . {* Number of line number records *} |
| 406 | . |
| 407 | . unsigned int lineno_count; |
| 408 | . |
| 409 | . {* When a section is being output, this value changes as more |
| 410 | . linenumbers are written out *} |
| 411 | . |
| 412 | . file_ptr moving_line_filepos; |
| 413 | . |
| 414 | . {* What the section number is in the target world *} |
| 415 | . |
| 416 | . int target_index; |
| 417 | . |
| 418 | . PTR used_by_bfd; |
| 419 | . |
| 420 | . {* If this is a constructor section then here is a list of the |
| 421 | . relocations created to relocate items within it. *} |
| 422 | . |
| 423 | . struct relent_chain *constructor_chain; |
| 424 | . |
| 425 | . {* The BFD which owns the section. *} |
| 426 | . |
| 427 | . bfd *owner; |
| 428 | . |
| 429 | . {* A symbol which points at this section only *} |
| 430 | . struct symbol_cache_entry *symbol; |
| 431 | . struct symbol_cache_entry **symbol_ptr_ptr; |
| 432 | . |
| 433 | . struct bfd_link_order *link_order_head; |
| 434 | . struct bfd_link_order *link_order_tail; |
| 435 | .} asection ; |
| 436 | . |
| 437 | . {* These sections are global, and are managed by BFD. The application |
| 438 | . and target back end are not permitted to change the values in |
| 439 | . these sections. New code should use the section_ptr macros rather |
| 440 | . than referring directly to the const sections. The const sections |
| 441 | . may eventually vanish. *} |
| 442 | .#define BFD_ABS_SECTION_NAME "*ABS*" |
| 443 | .#define BFD_UND_SECTION_NAME "*UND*" |
| 444 | .#define BFD_COM_SECTION_NAME "*COM*" |
| 445 | .#define BFD_IND_SECTION_NAME "*IND*" |
| 446 | . |
| 447 | . {* the absolute section *} |
| 448 | .extern const asection bfd_abs_section; |
| 449 | .#define bfd_abs_section_ptr ((asection *) &bfd_abs_section) |
| 450 | .#define bfd_is_abs_section(sec) ((sec) == bfd_abs_section_ptr) |
| 451 | . {* Pointer to the undefined section *} |
| 452 | .extern const asection bfd_und_section; |
| 453 | .#define bfd_und_section_ptr ((asection *) &bfd_und_section) |
| 454 | .#define bfd_is_und_section(sec) ((sec) == bfd_und_section_ptr) |
| 455 | . {* Pointer to the common section *} |
| 456 | .extern const asection bfd_com_section; |
| 457 | .#define bfd_com_section_ptr ((asection *) &bfd_com_section) |
| 458 | . {* Pointer to the indirect section *} |
| 459 | .extern const asection bfd_ind_section; |
| 460 | .#define bfd_ind_section_ptr ((asection *) &bfd_ind_section) |
| 461 | .#define bfd_is_ind_section(sec) ((sec) == bfd_ind_section_ptr) |
| 462 | . |
| 463 | .extern const struct symbol_cache_entry * const bfd_abs_symbol; |
| 464 | .extern const struct symbol_cache_entry * const bfd_com_symbol; |
| 465 | .extern const struct symbol_cache_entry * const bfd_und_symbol; |
| 466 | .extern const struct symbol_cache_entry * const bfd_ind_symbol; |
| 467 | .#define bfd_get_section_size_before_reloc(section) \ |
| 468 | . (section->reloc_done ? (abort(),1): (section)->_raw_size) |
| 469 | .#define bfd_get_section_size_after_reloc(section) \ |
| 470 | . ((section->reloc_done) ? (section)->_cooked_size: (abort(),1)) |
| 471 | */ |
| 472 | |
| 473 | /* These symbols are global, not specific to any BFD. Therefore, anything |
| 474 | that tries to change them is broken, and should be repaired. */ |
| 475 | static const asymbol global_syms[] = |
| 476 | { |
| 477 | /* the_bfd, name, value, attr, section [, udata] */ |
| 478 | {0, BFD_COM_SECTION_NAME, 0, BSF_SECTION_SYM, (asection *) &bfd_com_section}, |
| 479 | {0, BFD_UND_SECTION_NAME, 0, BSF_SECTION_SYM, (asection *) &bfd_und_section}, |
| 480 | {0, BFD_ABS_SECTION_NAME, 0, BSF_SECTION_SYM, (asection *) &bfd_abs_section}, |
| 481 | {0, BFD_IND_SECTION_NAME, 0, BSF_SECTION_SYM, (asection *) &bfd_ind_section}, |
| 482 | }; |
| 483 | |
| 484 | #define STD_SECTION(SEC, FLAGS, SYM, NAME, IDX) \ |
| 485 | const asymbol * const SYM = (asymbol *) &global_syms[IDX]; \ |
| 486 | const asection SEC = \ |
| 487 | { NAME, 0, 0, FLAGS, 0, 0, 0, 0, 0, 0, 0, 0, (asection *) &SEC, \ |
| 488 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \ |
| 489 | (asymbol *) &global_syms[IDX], (asymbol **) &SYM, 0, 0 } |
| 490 | |
| 491 | STD_SECTION (bfd_com_section, SEC_IS_COMMON, bfd_com_symbol, |
| 492 | BFD_COM_SECTION_NAME, 0); |
| 493 | STD_SECTION (bfd_und_section, 0, bfd_und_symbol, BFD_UND_SECTION_NAME, 1); |
| 494 | STD_SECTION (bfd_abs_section, 0, bfd_abs_symbol, BFD_ABS_SECTION_NAME, 2); |
| 495 | STD_SECTION (bfd_ind_section, 0, bfd_ind_symbol, BFD_IND_SECTION_NAME, 3); |
| 496 | #undef STD_SECTION |
| 497 | |
| 498 | /* |
| 499 | DOCDD |
| 500 | INODE |
| 501 | section prototypes, , typedef asection, Sections |
| 502 | SUBSECTION |
| 503 | Section prototypes |
| 504 | |
| 505 | These are the functions exported by the section handling part of BFD. |
| 506 | */ |
| 507 | |
| 508 | /* |
| 509 | FUNCTION |
| 510 | bfd_get_section_by_name |
| 511 | |
| 512 | SYNOPSIS |
| 513 | asection *bfd_get_section_by_name(bfd *abfd, CONST char *name); |
| 514 | |
| 515 | DESCRIPTION |
| 516 | Run through @var{abfd} and return the one of the |
| 517 | <<asection>>s whose name matches @var{name}, otherwise <<NULL>>. |
| 518 | @xref{Sections}, for more information. |
| 519 | |
| 520 | This should only be used in special cases; the normal way to process |
| 521 | all sections of a given name is to use <<bfd_map_over_sections>> and |
| 522 | <<strcmp>> on the name (or better yet, base it on the section flags |
| 523 | or something else) for each section. |
| 524 | */ |
| 525 | |
| 526 | asection * |
| 527 | bfd_get_section_by_name (abfd, name) |
| 528 | bfd *abfd; |
| 529 | CONST char *name; |
| 530 | { |
| 531 | asection *sect; |
| 532 | |
| 533 | for (sect = abfd->sections; sect != NULL; sect = sect->next) |
| 534 | if (!strcmp (sect->name, name)) |
| 535 | return sect; |
| 536 | return NULL; |
| 537 | } |
| 538 | |
| 539 | |
| 540 | /* |
| 541 | FUNCTION |
| 542 | bfd_make_section_old_way |
| 543 | |
| 544 | SYNOPSIS |
| 545 | asection *bfd_make_section_old_way(bfd *abfd, CONST char *name); |
| 546 | |
| 547 | DESCRIPTION |
| 548 | Create a new empty section called @var{name} |
| 549 | and attach it to the end of the chain of sections for the |
| 550 | BFD @var{abfd}. An attempt to create a section with a name which |
| 551 | is already in use returns its pointer without changing the |
| 552 | section chain. |
| 553 | |
| 554 | It has the funny name since this is the way it used to be |
| 555 | before it was rewritten.... |
| 556 | |
| 557 | Possible errors are: |
| 558 | o <<bfd_error_invalid_operation>> - |
| 559 | If output has already started for this BFD. |
| 560 | o <<bfd_error_no_memory>> - |
| 561 | If obstack alloc fails. |
| 562 | |
| 563 | */ |
| 564 | |
| 565 | |
| 566 | asection * |
| 567 | bfd_make_section_old_way (abfd, name) |
| 568 | bfd *abfd; |
| 569 | CONST char *name; |
| 570 | { |
| 571 | asection *sec = bfd_get_section_by_name (abfd, name); |
| 572 | if (sec == (asection *) NULL) |
| 573 | { |
| 574 | sec = bfd_make_section (abfd, name); |
| 575 | } |
| 576 | return sec; |
| 577 | } |
| 578 | |
| 579 | /* |
| 580 | FUNCTION |
| 581 | bfd_make_section_anyway |
| 582 | |
| 583 | SYNOPSIS |
| 584 | asection *bfd_make_section_anyway(bfd *abfd, CONST char *name); |
| 585 | |
| 586 | DESCRIPTION |
| 587 | Create a new empty section called @var{name} and attach it to the end of |
| 588 | the chain of sections for @var{abfd}. Create a new section even if there |
| 589 | is already a section with that name. |
| 590 | |
| 591 | Return <<NULL>> and set <<bfd_error>> on error; possible errors are: |
| 592 | o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}. |
| 593 | o <<bfd_error_no_memory>> - If obstack alloc fails. |
| 594 | */ |
| 595 | |
| 596 | sec_ptr |
| 597 | bfd_make_section_anyway (abfd, name) |
| 598 | bfd *abfd; |
| 599 | CONST char *name; |
| 600 | { |
| 601 | asection *newsect; |
| 602 | asection **prev = &abfd->sections; |
| 603 | asection *sect = abfd->sections; |
| 604 | |
| 605 | if (abfd->output_has_begun) |
| 606 | { |
| 607 | bfd_set_error (bfd_error_invalid_operation); |
| 608 | return NULL; |
| 609 | } |
| 610 | |
| 611 | while (sect) |
| 612 | { |
| 613 | prev = §->next; |
| 614 | sect = sect->next; |
| 615 | } |
| 616 | |
| 617 | newsect = (asection *) bfd_zalloc (abfd, sizeof (asection)); |
| 618 | if (newsect == NULL) |
| 619 | return NULL; |
| 620 | |
| 621 | newsect->name = name; |
| 622 | newsect->index = abfd->section_count++; |
| 623 | newsect->flags = SEC_NO_FLAGS; |
| 624 | |
| 625 | newsect->userdata = NULL; |
| 626 | newsect->contents = NULL; |
| 627 | newsect->next = (asection *) NULL; |
| 628 | newsect->relocation = (arelent *) NULL; |
| 629 | newsect->reloc_count = 0; |
| 630 | newsect->line_filepos = 0; |
| 631 | newsect->owner = abfd; |
| 632 | |
| 633 | /* Create a symbol whos only job is to point to this section. This is |
| 634 | useful for things like relocs which are relative to the base of a |
| 635 | section. */ |
| 636 | newsect->symbol = bfd_make_empty_symbol (abfd); |
| 637 | if (newsect->symbol == NULL) |
| 638 | return NULL; |
| 639 | newsect->symbol->name = name; |
| 640 | newsect->symbol->value = 0; |
| 641 | newsect->symbol->section = newsect; |
| 642 | newsect->symbol->flags = BSF_SECTION_SYM; |
| 643 | |
| 644 | newsect->symbol_ptr_ptr = &newsect->symbol; |
| 645 | |
| 646 | if (BFD_SEND (abfd, _new_section_hook, (abfd, newsect)) != true) |
| 647 | { |
| 648 | free (newsect); |
| 649 | return NULL; |
| 650 | } |
| 651 | |
| 652 | *prev = newsect; |
| 653 | return newsect; |
| 654 | } |
| 655 | |
| 656 | /* |
| 657 | FUNCTION |
| 658 | bfd_make_section |
| 659 | |
| 660 | SYNOPSIS |
| 661 | asection *bfd_make_section(bfd *, CONST char *name); |
| 662 | |
| 663 | DESCRIPTION |
| 664 | Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling |
| 665 | bfd_set_error ()) without changing the section chain if there is already a |
| 666 | section named @var{name}. If there is an error, return <<NULL>> and set |
| 667 | <<bfd_error>>. |
| 668 | */ |
| 669 | |
| 670 | asection * |
| 671 | bfd_make_section (abfd, name) |
| 672 | bfd *abfd; |
| 673 | CONST char *name; |
| 674 | { |
| 675 | asection *sect = abfd->sections; |
| 676 | |
| 677 | if (strcmp (name, BFD_ABS_SECTION_NAME) == 0) |
| 678 | { |
| 679 | return bfd_abs_section_ptr; |
| 680 | } |
| 681 | if (strcmp (name, BFD_COM_SECTION_NAME) == 0) |
| 682 | { |
| 683 | return bfd_com_section_ptr; |
| 684 | } |
| 685 | if (strcmp (name, BFD_UND_SECTION_NAME) == 0) |
| 686 | { |
| 687 | return bfd_und_section_ptr; |
| 688 | } |
| 689 | |
| 690 | if (strcmp (name, BFD_IND_SECTION_NAME) == 0) |
| 691 | { |
| 692 | return bfd_ind_section_ptr; |
| 693 | } |
| 694 | |
| 695 | while (sect) |
| 696 | { |
| 697 | if (!strcmp (sect->name, name)) |
| 698 | return NULL; |
| 699 | sect = sect->next; |
| 700 | } |
| 701 | |
| 702 | /* The name is not already used; go ahead and make a new section. */ |
| 703 | return bfd_make_section_anyway (abfd, name); |
| 704 | } |
| 705 | |
| 706 | |
| 707 | /* |
| 708 | FUNCTION |
| 709 | bfd_set_section_flags |
| 710 | |
| 711 | SYNOPSIS |
| 712 | boolean bfd_set_section_flags(bfd *abfd, asection *sec, flagword flags); |
| 713 | |
| 714 | DESCRIPTION |
| 715 | Set the attributes of the section @var{sec} in the BFD |
| 716 | @var{abfd} to the value @var{flags}. Return <<true>> on success, |
| 717 | <<false>> on error. Possible error returns are: |
| 718 | |
| 719 | o <<bfd_error_invalid_operation>> - |
| 720 | The section cannot have one or more of the attributes |
| 721 | requested. For example, a .bss section in <<a.out>> may not |
| 722 | have the <<SEC_HAS_CONTENTS>> field set. |
| 723 | |
| 724 | */ |
| 725 | |
| 726 | /*ARGSUSED*/ |
| 727 | boolean |
| 728 | bfd_set_section_flags (abfd, section, flags) |
| 729 | bfd *abfd; |
| 730 | sec_ptr section; |
| 731 | flagword flags; |
| 732 | { |
| 733 | #if 0 |
| 734 | /* If you try to copy a text section from an input file (where it |
| 735 | has the SEC_CODE flag set) to an output file, this loses big if |
| 736 | the bfd_applicable_section_flags (abfd) doesn't have the SEC_CODE |
| 737 | set - which it doesn't, at least not for a.out. FIXME */ |
| 738 | |
| 739 | if ((flags & bfd_applicable_section_flags (abfd)) != flags) |
| 740 | { |
| 741 | bfd_set_error (bfd_error_invalid_operation); |
| 742 | return false; |
| 743 | } |
| 744 | #endif |
| 745 | |
| 746 | section->flags = flags; |
| 747 | return true; |
| 748 | } |
| 749 | |
| 750 | |
| 751 | /* |
| 752 | FUNCTION |
| 753 | bfd_map_over_sections |
| 754 | |
| 755 | SYNOPSIS |
| 756 | void bfd_map_over_sections(bfd *abfd, |
| 757 | void (*func)(bfd *abfd, |
| 758 | asection *sect, |
| 759 | PTR obj), |
| 760 | PTR obj); |
| 761 | |
| 762 | DESCRIPTION |
| 763 | Call the provided function @var{func} for each section |
| 764 | attached to the BFD @var{abfd}, passing @var{obj} as an |
| 765 | argument. The function will be called as if by |
| 766 | |
| 767 | | func(abfd, the_section, obj); |
| 768 | |
| 769 | This is the prefered method for iterating over sections; an |
| 770 | alternative would be to use a loop: |
| 771 | |
| 772 | | section *p; |
| 773 | | for (p = abfd->sections; p != NULL; p = p->next) |
| 774 | | func(abfd, p, ...) |
| 775 | |
| 776 | |
| 777 | */ |
| 778 | |
| 779 | /*VARARGS2*/ |
| 780 | void |
| 781 | bfd_map_over_sections (abfd, operation, user_storage) |
| 782 | bfd *abfd; |
| 783 | void (*operation) PARAMS ((bfd * abfd, asection * sect, PTR obj)); |
| 784 | PTR user_storage; |
| 785 | { |
| 786 | asection *sect; |
| 787 | unsigned int i = 0; |
| 788 | |
| 789 | for (sect = abfd->sections; sect != NULL; i++, sect = sect->next) |
| 790 | (*operation) (abfd, sect, user_storage); |
| 791 | |
| 792 | if (i != abfd->section_count) /* Debugging */ |
| 793 | abort (); |
| 794 | } |
| 795 | |
| 796 | |
| 797 | /* |
| 798 | FUNCTION |
| 799 | bfd_set_section_size |
| 800 | |
| 801 | SYNOPSIS |
| 802 | boolean bfd_set_section_size(bfd *abfd, asection *sec, bfd_size_type val); |
| 803 | |
| 804 | DESCRIPTION |
| 805 | Set @var{sec} to the size @var{val}. If the operation is |
| 806 | ok, then <<true>> is returned, else <<false>>. |
| 807 | |
| 808 | Possible error returns: |
| 809 | o <<bfd_error_invalid_operation>> - |
| 810 | Writing has started to the BFD, so setting the size is invalid. |
| 811 | |
| 812 | */ |
| 813 | |
| 814 | boolean |
| 815 | bfd_set_section_size (abfd, ptr, val) |
| 816 | bfd *abfd; |
| 817 | sec_ptr ptr; |
| 818 | bfd_size_type val; |
| 819 | { |
| 820 | /* Once you've started writing to any section you cannot create or change |
| 821 | the size of any others. */ |
| 822 | |
| 823 | if (abfd->output_has_begun) |
| 824 | { |
| 825 | bfd_set_error (bfd_error_invalid_operation); |
| 826 | return false; |
| 827 | } |
| 828 | |
| 829 | ptr->_cooked_size = val; |
| 830 | ptr->_raw_size = val; |
| 831 | |
| 832 | return true; |
| 833 | } |
| 834 | |
| 835 | /* |
| 836 | FUNCTION |
| 837 | bfd_set_section_contents |
| 838 | |
| 839 | SYNOPSIS |
| 840 | boolean bfd_set_section_contents |
| 841 | (bfd *abfd, |
| 842 | asection *section, |
| 843 | PTR data, |
| 844 | file_ptr offset, |
| 845 | bfd_size_type count); |
| 846 | |
| 847 | |
| 848 | DESCRIPTION |
| 849 | Sets the contents of the section @var{section} in BFD |
| 850 | @var{abfd} to the data starting in memory at @var{data}. The |
| 851 | data is written to the output section starting at offset |
| 852 | @var{offset} for @var{count} bytes. |
| 853 | |
| 854 | |
| 855 | |
| 856 | Normally <<true>> is returned, else <<false>>. Possible error |
| 857 | returns are: |
| 858 | o <<bfd_error_no_contents>> - |
| 859 | The output section does not have the <<SEC_HAS_CONTENTS>> |
| 860 | attribute, so nothing can be written to it. |
| 861 | o and some more too |
| 862 | |
| 863 | This routine is front end to the back end function |
| 864 | <<_bfd_set_section_contents>>. |
| 865 | |
| 866 | |
| 867 | */ |
| 868 | |
| 869 | #define bfd_get_section_size_now(abfd,sec) \ |
| 870 | (sec->reloc_done \ |
| 871 | ? bfd_get_section_size_after_reloc (sec) \ |
| 872 | : bfd_get_section_size_before_reloc (sec)) |
| 873 | |
| 874 | boolean |
| 875 | bfd_set_section_contents (abfd, section, location, offset, count) |
| 876 | bfd *abfd; |
| 877 | sec_ptr section; |
| 878 | PTR location; |
| 879 | file_ptr offset; |
| 880 | bfd_size_type count; |
| 881 | { |
| 882 | bfd_size_type sz; |
| 883 | |
| 884 | if (!(bfd_get_section_flags (abfd, section) & SEC_HAS_CONTENTS)) |
| 885 | { |
| 886 | bfd_set_error (bfd_error_no_contents); |
| 887 | return (false); |
| 888 | } |
| 889 | |
| 890 | if (offset < 0) |
| 891 | { |
| 892 | bad_val: |
| 893 | bfd_set_error (bfd_error_bad_value); |
| 894 | return false; |
| 895 | } |
| 896 | sz = bfd_get_section_size_now (abfd, section); |
| 897 | if ((bfd_size_type) offset > sz |
| 898 | || count > sz |
| 899 | || offset + count > sz) |
| 900 | goto bad_val; |
| 901 | |
| 902 | switch (abfd->direction) |
| 903 | { |
| 904 | case read_direction: |
| 905 | case no_direction: |
| 906 | bfd_set_error (bfd_error_invalid_operation); |
| 907 | return false; |
| 908 | |
| 909 | case write_direction: |
| 910 | break; |
| 911 | |
| 912 | case both_direction: |
| 913 | /* File is opened for update. `output_has_begun' some time ago when |
| 914 | the file was created. Do not recompute sections sizes or alignments |
| 915 | in _bfd_set_section_content. */ |
| 916 | abfd->output_has_begun = true; |
| 917 | break; |
| 918 | } |
| 919 | |
| 920 | if (BFD_SEND (abfd, _bfd_set_section_contents, |
| 921 | (abfd, section, location, offset, count))) |
| 922 | { |
| 923 | abfd->output_has_begun = true; |
| 924 | return true; |
| 925 | } |
| 926 | |
| 927 | return false; |
| 928 | } |
| 929 | |
| 930 | /* |
| 931 | FUNCTION |
| 932 | bfd_get_section_contents |
| 933 | |
| 934 | SYNOPSIS |
| 935 | boolean bfd_get_section_contents |
| 936 | (bfd *abfd, asection *section, PTR location, |
| 937 | file_ptr offset, bfd_size_type count); |
| 938 | |
| 939 | DESCRIPTION |
| 940 | Read data from @var{section} in BFD @var{abfd} |
| 941 | into memory starting at @var{location}. The data is read at an |
| 942 | offset of @var{offset} from the start of the input section, |
| 943 | and is read for @var{count} bytes. |
| 944 | |
| 945 | If the contents of a constructor with the <<SEC_CONSTRUCTOR>> |
| 946 | flag set are requested or if the section does not have the |
| 947 | <<SEC_HAS_CONTENTS>> flag set, then the @var{location} is filled |
| 948 | with zeroes. If no errors occur, <<true>> is returned, else |
| 949 | <<false>>. |
| 950 | |
| 951 | |
| 952 | |
| 953 | */ |
| 954 | boolean |
| 955 | bfd_get_section_contents (abfd, section, location, offset, count) |
| 956 | bfd *abfd; |
| 957 | sec_ptr section; |
| 958 | PTR location; |
| 959 | file_ptr offset; |
| 960 | bfd_size_type count; |
| 961 | { |
| 962 | bfd_size_type sz; |
| 963 | |
| 964 | if (section->flags & SEC_CONSTRUCTOR) |
| 965 | { |
| 966 | memset (location, 0, (unsigned) count); |
| 967 | return true; |
| 968 | } |
| 969 | |
| 970 | if (offset < 0) |
| 971 | { |
| 972 | bad_val: |
| 973 | bfd_set_error (bfd_error_bad_value); |
| 974 | return false; |
| 975 | } |
| 976 | /* Even if reloc_done is true, this function reads unrelocated |
| 977 | contents, so we want the raw size. */ |
| 978 | sz = section->_raw_size; |
| 979 | if ((bfd_size_type) offset > sz || count > sz || offset + count > sz) |
| 980 | goto bad_val; |
| 981 | |
| 982 | if (count == 0) |
| 983 | /* Don't bother. */ |
| 984 | return true; |
| 985 | |
| 986 | if ((section->flags & SEC_HAS_CONTENTS) == 0) |
| 987 | { |
| 988 | memset (location, 0, (unsigned) count); |
| 989 | return true; |
| 990 | } |
| 991 | |
| 992 | if ((section->flags & SEC_IN_MEMORY) != 0) |
| 993 | { |
| 994 | memcpy (location, section->contents + offset, (size_t) count); |
| 995 | return true; |
| 996 | } |
| 997 | |
| 998 | return BFD_SEND (abfd, _bfd_get_section_contents, |
| 999 | (abfd, section, location, offset, count)); |
| 1000 | } |
| 1001 | |
| 1002 | /* |
| 1003 | FUNCTION |
| 1004 | bfd_copy_private_section_data |
| 1005 | |
| 1006 | SYNOPSIS |
| 1007 | boolean bfd_copy_private_section_data(bfd *ibfd, asection *isec, bfd *obfd, asection *osec); |
| 1008 | |
| 1009 | DESCRIPTION |
| 1010 | Copy private section information from @var{isec} in the BFD |
| 1011 | @var{ibfd} to the section @var{osec} in the BFD @var{obfd}. |
| 1012 | Return <<true>> on success, <<false>> on error. Possible error |
| 1013 | returns are: |
| 1014 | |
| 1015 | o <<bfd_error_no_memory>> - |
| 1016 | Not enough memory exists to create private data for @var{osec}. |
| 1017 | |
| 1018 | .#define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \ |
| 1019 | . BFD_SEND (obfd, _bfd_copy_private_section_data, \ |
| 1020 | . (ibfd, isection, obfd, osection)) |
| 1021 | */ |