1@section Sections 2The raw data contained within a BFD is maintained through the 3section abstraction. A single BFD may have any number of 4sections. It keeps hold of them by pointing to the first; 5each one points to the next in the list. 6 7Sections are supported in BFD in @code{section.c}. 8 9@menu 10* Section Input:: 11* Section Output:: 12* typedef asection:: 13* section prototypes:: 14@end menu 15 16@node Section Input, Section Output, Sections, Sections 17@subsection Section input 18When a BFD is opened for reading, the section structures are 19created and attached to the BFD. 20 21Each section has a name which describes the section in the 22outside world---for example, @code{a.out} would contain at least 23three sections, called @code{.text}, @code{.data} and @code{.bss}. 24 25Names need not be unique; for example a COFF file may have several 26sections named @code{.data}. 27 28Sometimes a BFD will contain more than the ``natural'' number of 29sections. A back end may attach other sections containing 30constructor data, or an application may add a section (using 31@code{bfd_make_section}) to the sections attached to an already open 32BFD. For example, the linker creates an extra section 33@code{COMMON} for each input file's BFD to hold information about 34common storage. 35 36The raw data is not necessarily read in when 37the section descriptor is created. Some targets may leave the 38data in place until a @code{bfd_get_section_contents} call is 39made. Other back ends may read in all the data at once. For 40example, an S-record file has to be read once to determine the 41size of the data. An IEEE-695 file doesn't contain raw data in 42sections, but data and relocation expressions intermixed, so 43the data area has to be parsed to get out the data and 44relocations. 45 46@node Section Output, typedef asection, Section Input, Sections 47@subsection Section output 48To write a new object style BFD, the various sections to be 49written have to be created. They are attached to the BFD in 50the same way as input sections; data is written to the 51sections using @code{bfd_set_section_contents}. 52 53Any program that creates or combines sections (e.g., the assembler 54and linker) must use the @code{asection} fields @code{output_section} and 55@code{output_offset} to indicate the file sections to which each 56section must be written. (If the section is being created from 57scratch, @code{output_section} should probably point to the section 58itself and @code{output_offset} should probably be zero.) 59 60The data to be written comes from input sections attached 61(via @code{output_section} pointers) to 62the output sections. The output section structure can be 63considered a filter for the input section: the output section 64determines the vma of the output data and the name, but the 65input section determines the offset into the output section of 66the data to be written. 67 68E.g., to create a section "O", starting at 0x100, 0x123 long, 69containing two subsections, "A" at offset 0x0 (i.e., at vma 700x100) and "B" at offset 0x20 (i.e., at vma 0x120) the @code{asection} 71structures would look like: 72 73@example 74 section name "A" 75 output_offset 0x00 76 size 0x20 77 output_section -----------> section name "O" 78 | vma 0x100 79 section name "B" | size 0x123 80 output_offset 0x20 | 81 size 0x103 | 82 output_section --------| 83@end example 84 85@subsection Link orders 86The data within a section is stored in a @dfn{link_order}. 87These are much like the fixups in @code{gas}. The link_order 88abstraction allows a section to grow and shrink within itself. 89 90A link_order knows how big it is, and which is the next 91link_order and where the raw data for it is; it also points to 92a list of relocations which apply to it. 93 94The link_order is used by the linker to perform relaxing on 95final code. The compiler creates code which is as big as 96necessary to make it work without relaxing, and the user can 97select whether to relax. Sometimes relaxing takes a lot of 98time. The linker runs around the relocations to see if any 99are attached to data which can be shrunk, if so it does it on 100a link_order by link_order basis. 101 102 103@node typedef asection, section prototypes, Section Output, Sections 104@subsection typedef asection 105Here is the section structure: 106 107 108@example 109 110typedef struct bfd_section 111@{ 112 /* The name of the section; the name isn't a copy, the pointer is 113 the same as that passed to bfd_make_section. */ 114 const char *name; 115 116 /* A unique sequence number. */ 117 int id; 118 119 /* Which section in the bfd; 0..n-1 as sections are created in a bfd. */ 120 int index; 121 122 /* The next section in the list belonging to the BFD, or NULL. */ 123 struct bfd_section *next; 124 125 /* The previous section in the list belonging to the BFD, or NULL. */ 126 struct bfd_section *prev; 127 128 /* The field flags contains attributes of the section. Some 129 flags are read in from the object file, and some are 130 synthesized from other information. */ 131 flagword flags; 132 133#define SEC_NO_FLAGS 0x000 134 135 /* Tells the OS to allocate space for this section when loading. 136 This is clear for a section containing debug information only. */ 137#define SEC_ALLOC 0x001 138 139 /* Tells the OS to load the section from the file when loading. 140 This is clear for a .bss section. */ 141#define SEC_LOAD 0x002 142 143 /* The section contains data still to be relocated, so there is 144 some relocation information too. */ 145#define SEC_RELOC 0x004 146 147 /* A signal to the OS that the section contains read only data. */ 148#define SEC_READONLY 0x008 149 150 /* The section contains code only. */ 151#define SEC_CODE 0x010 152 153 /* The section contains data only. */ 154#define SEC_DATA 0x020 155 156 /* The section will reside in ROM. */ 157#define SEC_ROM 0x040 158 159 /* The section contains constructor information. This section 160 type is used by the linker to create lists of constructors and 161 destructors used by @code{g++}. When a back end sees a symbol 162 which should be used in a constructor list, it creates a new 163 section for the type of name (e.g., @code{__CTOR_LIST__}), attaches 164 the symbol to it, and builds a relocation. To build the lists 165 of constructors, all the linker has to do is catenate all the 166 sections called @code{__CTOR_LIST__} and relocate the data 167 contained within - exactly the operations it would peform on 168 standard data. */ 169#define SEC_CONSTRUCTOR 0x080 170 171 /* The section has contents - a data section could be 172 @code{SEC_ALLOC} | @code{SEC_HAS_CONTENTS}; a debug section could be 173 @code{SEC_HAS_CONTENTS} */ 174#define SEC_HAS_CONTENTS 0x100 175 176 /* An instruction to the linker to not output the section 177 even if it has information which would normally be written. */ 178#define SEC_NEVER_LOAD 0x200 179 180 /* The section contains thread local data. */ 181#define SEC_THREAD_LOCAL 0x400 182 183 /* The section has GOT references. This flag is only for the 184 linker, and is currently only used by the elf32-hppa back end. 185 It will be set if global offset table references were detected 186 in this section, which indicate to the linker that the section 187 contains PIC code, and must be handled specially when doing a 188 static link. */ 189#define SEC_HAS_GOT_REF 0x800 190 191 /* The section contains common symbols (symbols may be defined 192 multiple times, the value of a symbol is the amount of 193 space it requires, and the largest symbol value is the one 194 used). Most targets have exactly one of these (which we 195 translate to bfd_com_section_ptr), but ECOFF has two. */ 196#define SEC_IS_COMMON 0x1000 197 198 /* The section contains only debugging information. For 199 example, this is set for ELF .debug and .stab sections. 200 strip tests this flag to see if a section can be 201 discarded. */ 202#define SEC_DEBUGGING 0x2000 203 204 /* The contents of this section are held in memory pointed to 205 by the contents field. This is checked by bfd_get_section_contents, 206 and the data is retrieved from memory if appropriate. */ 207#define SEC_IN_MEMORY 0x4000 208 209 /* The contents of this section are to be excluded by the 210 linker for executable and shared objects unless those 211 objects are to be further relocated. */ 212#define SEC_EXCLUDE 0x8000 213 214 /* The contents of this section are to be sorted based on the sum of 215 the symbol and addend values specified by the associated relocation 216 entries. Entries without associated relocation entries will be 217 appended to the end of the section in an unspecified order. */ 218#define SEC_SORT_ENTRIES 0x10000 219 220 /* When linking, duplicate sections of the same name should be 221 discarded, rather than being combined into a single section as 222 is usually done. This is similar to how common symbols are 223 handled. See SEC_LINK_DUPLICATES below. */ 224#define SEC_LINK_ONCE 0x20000 225 226 /* If SEC_LINK_ONCE is set, this bitfield describes how the linker 227 should handle duplicate sections. */ 228#define SEC_LINK_DUPLICATES 0x40000 229 230 /* This value for SEC_LINK_DUPLICATES means that duplicate 231 sections with the same name should simply be discarded. */ 232#define SEC_LINK_DUPLICATES_DISCARD 0x0 233 234 /* This value for SEC_LINK_DUPLICATES means that the linker 235 should warn if there are any duplicate sections, although 236 it should still only link one copy. */ 237#define SEC_LINK_DUPLICATES_ONE_ONLY 0x80000 238 239 /* This value for SEC_LINK_DUPLICATES means that the linker 240 should warn if any duplicate sections are a different size. */ 241#define SEC_LINK_DUPLICATES_SAME_SIZE 0x100000 242 243 /* This value for SEC_LINK_DUPLICATES means that the linker 244 should warn if any duplicate sections contain different 245 contents. */ 246#define SEC_LINK_DUPLICATES_SAME_CONTENTS \ 247 (SEC_LINK_DUPLICATES_ONE_ONLY | SEC_LINK_DUPLICATES_SAME_SIZE) 248 249 /* This section was created by the linker as part of dynamic 250 relocation or other arcane processing. It is skipped when 251 going through the first-pass output, trusting that someone 252 else up the line will take care of it later. */ 253#define SEC_LINKER_CREATED 0x200000 254 255 /* This section should not be subject to garbage collection. 256 Also set to inform the linker that this section should not be 257 listed in the link map as discarded. */ 258#define SEC_KEEP 0x400000 259 260 /* This section contains "short" data, and should be placed 261 "near" the GP. */ 262#define SEC_SMALL_DATA 0x800000 263 264 /* Attempt to merge identical entities in the section. 265 Entity size is given in the entsize field. */ 266#define SEC_MERGE 0x1000000 267 268 /* If given with SEC_MERGE, entities to merge are zero terminated 269 strings where entsize specifies character size instead of fixed 270 size entries. */ 271#define SEC_STRINGS 0x2000000 272 273 /* This section contains data about section groups. */ 274#define SEC_GROUP 0x4000000 275 276 /* The section is a COFF shared library section. This flag is 277 only for the linker. If this type of section appears in 278 the input file, the linker must copy it to the output file 279 without changing the vma or size. FIXME: Although this 280 was originally intended to be general, it really is COFF 281 specific (and the flag was renamed to indicate this). It 282 might be cleaner to have some more general mechanism to 283 allow the back end to control what the linker does with 284 sections. */ 285#define SEC_COFF_SHARED_LIBRARY 0x10000000 286 287 /* This section contains data which may be shared with other 288 executables or shared objects. This is for COFF only. */ 289#define SEC_COFF_SHARED 0x20000000 290 291 /* When a section with this flag is being linked, then if the size of 292 the input section is less than a page, it should not cross a page 293 boundary. If the size of the input section is one page or more, 294 it should be aligned on a page boundary. This is for TI 295 TMS320C54X only. */ 296#define SEC_TIC54X_BLOCK 0x40000000 297 298 /* Conditionally link this section; do not link if there are no 299 references found to any symbol in the section. This is for TI 300 TMS320C54X only. */ 301#define SEC_TIC54X_CLINK 0x80000000 302 303 /* End of section flags. */ 304 305 /* Some internal packed boolean fields. */ 306 307 /* See the vma field. */ 308 unsigned int user_set_vma : 1; 309 310 /* A mark flag used by some of the linker backends. */ 311 unsigned int linker_mark : 1; 312 313 /* Another mark flag used by some of the linker backends. Set for 314 output sections that have an input section. */ 315 unsigned int linker_has_input : 1; 316 317 /* Mark flags used by some linker backends for garbage collection. */ 318 unsigned int gc_mark : 1; 319 unsigned int gc_mark_from_eh : 1; 320 321 /* The following flags are used by the ELF linker. */ 322 323 /* Mark sections which have been allocated to segments. */ 324 unsigned int segment_mark : 1; 325 326 /* Type of sec_info information. */ 327 unsigned int sec_info_type:3; 328#define ELF_INFO_TYPE_NONE 0 329#define ELF_INFO_TYPE_STABS 1 330#define ELF_INFO_TYPE_MERGE 2 331#define ELF_INFO_TYPE_EH_FRAME 3 332#define ELF_INFO_TYPE_JUST_SYMS 4 333 334 /* Nonzero if this section uses RELA relocations, rather than REL. */ 335 unsigned int use_rela_p:1; 336 337 /* Bits used by various backends. The generic code doesn't touch 338 these fields. */ 339 340 /* Nonzero if this section has TLS related relocations. */ 341 unsigned int has_tls_reloc:1; 342 343 /* Nonzero if this section has a gp reloc. */ 344 unsigned int has_gp_reloc:1; 345 346 /* Nonzero if this section needs the relax finalize pass. */ 347 unsigned int need_finalize_relax:1; 348 349 /* Whether relocations have been processed. */ 350 unsigned int reloc_done : 1; 351 352 /* End of internal packed boolean fields. */ 353 354 /* The virtual memory address of the section - where it will be 355 at run time. The symbols are relocated against this. The 356 user_set_vma flag is maintained by bfd; if it's not set, the 357 backend can assign addresses (for example, in @code{a.out}, where 358 the default address for @code{.data} is dependent on the specific 359 target and various flags). */ 360 bfd_vma vma; 361 362 /* The load address of the section - where it would be in a 363 rom image; really only used for writing section header 364 information. */ 365 bfd_vma lma; 366 367 /* The size of the section in octets, as it will be output. 368 Contains a value even if the section has no contents (e.g., the 369 size of @code{.bss}). */ 370 bfd_size_type size; 371 372 /* For input sections, the original size on disk of the section, in 373 octets. This field is used by the linker relaxation code. It is 374 currently only set for sections where the linker relaxation scheme 375 doesn't cache altered section and reloc contents (stabs, eh_frame, 376 SEC_MERGE, some coff relaxing targets), and thus the original size 377 needs to be kept to read the section multiple times. 378 For output sections, rawsize holds the section size calculated on 379 a previous linker relaxation pass. */ 380 bfd_size_type rawsize; 381 382 /* If this section is going to be output, then this value is the 383 offset in *bytes* into the output section of the first byte in the 384 input section (byte ==> smallest addressable unit on the 385 target). In most cases, if this was going to start at the 386 100th octet (8-bit quantity) in the output section, this value 387 would be 100. However, if the target byte size is 16 bits 388 (bfd_octets_per_byte is "2"), this value would be 50. */ 389 bfd_vma output_offset; 390 391 /* The output section through which to map on output. */ 392 struct bfd_section *output_section; 393 394 /* The alignment requirement of the section, as an exponent of 2 - 395 e.g., 3 aligns to 2^3 (or 8). */ 396 unsigned int alignment_power; 397 398 /* If an input section, a pointer to a vector of relocation 399 records for the data in this section. */ 400 struct reloc_cache_entry *relocation; 401 402 /* If an output section, a pointer to a vector of pointers to 403 relocation records for the data in this section. */ 404 struct reloc_cache_entry **orelocation; 405 406 /* The number of relocation records in one of the above. */ 407 unsigned reloc_count; 408 409 /* Information below is back end specific - and not always used 410 or updated. */ 411 412 /* File position of section data. */ 413 file_ptr filepos; 414 415 /* File position of relocation info. */ 416 file_ptr rel_filepos; 417 418 /* File position of line data. */ 419 file_ptr line_filepos; 420 421 /* Pointer to data for applications. */ 422 void *userdata; 423 424 /* If the SEC_IN_MEMORY flag is set, this points to the actual 425 contents. */ 426 unsigned char *contents; 427 428 /* Attached line number information. */ 429 alent *lineno; 430 431 /* Number of line number records. */ 432 unsigned int lineno_count; 433 434 /* Entity size for merging purposes. */ 435 unsigned int entsize; 436 437 /* Points to the kept section if this section is a link-once section, 438 and is discarded. */ 439 struct bfd_section *kept_section; 440 441 /* When a section is being output, this value changes as more 442 linenumbers are written out. */ 443 file_ptr moving_line_filepos; 444 445 /* What the section number is in the target world. */ 446 int target_index; 447 448 void *used_by_bfd; 449 450 /* If this is a constructor section then here is a list of the 451 relocations created to relocate items within it. */ 452 struct relent_chain *constructor_chain; 453 454 /* The BFD which owns the section. */ 455 bfd *owner; 456 457 /* A symbol which points at this section only. */ 458 struct bfd_symbol *symbol; 459 struct bfd_symbol **symbol_ptr_ptr; 460 461 /* Early in the link process, map_head and map_tail are used to build 462 a list of input sections attached to an output section. Later, 463 output sections use these fields for a list of bfd_link_order 464 structs. */ 465 union @{ 466 struct bfd_link_order *link_order; 467 struct bfd_section *s; 468 @} map_head, map_tail; 469@} asection; 470 471/* These sections are global, and are managed by BFD. The application 472 and target back end are not permitted to change the values in 473 these sections. New code should use the section_ptr macros rather 474 than referring directly to the const sections. The const sections 475 may eventually vanish. */ 476#define BFD_ABS_SECTION_NAME "*ABS*" 477#define BFD_UND_SECTION_NAME "*UND*" 478#define BFD_COM_SECTION_NAME "*COM*" 479#define BFD_IND_SECTION_NAME "*IND*" 480 481/* The absolute section. */ 482extern asection bfd_abs_section; 483#define bfd_abs_section_ptr ((asection *) &bfd_abs_section) 484#define bfd_is_abs_section(sec) ((sec) == bfd_abs_section_ptr) 485/* Pointer to the undefined section. */ 486extern asection bfd_und_section; 487#define bfd_und_section_ptr ((asection *) &bfd_und_section) 488#define bfd_is_und_section(sec) ((sec) == bfd_und_section_ptr) 489/* Pointer to the common section. */ 490extern asection bfd_com_section; 491#define bfd_com_section_ptr ((asection *) &bfd_com_section) 492/* Pointer to the indirect section. */ 493extern asection bfd_ind_section; 494#define bfd_ind_section_ptr ((asection *) &bfd_ind_section) 495#define bfd_is_ind_section(sec) ((sec) == bfd_ind_section_ptr) 496 497#define bfd_is_const_section(SEC) \ 498 ( ((SEC) == bfd_abs_section_ptr) \ 499 || ((SEC) == bfd_und_section_ptr) \ 500 || ((SEC) == bfd_com_section_ptr) \ 501 || ((SEC) == bfd_ind_section_ptr)) 502 503/* Macros to handle insertion and deletion of a bfd's sections. These 504 only handle the list pointers, ie. do not adjust section_count, 505 target_index etc. */ 506#define bfd_section_list_remove(ABFD, S) \ 507 do \ 508 @{ \ 509 asection *_s = S; \ 510 asection *_next = _s->next; \ 511 asection *_prev = _s->prev; \ 512 if (_prev) \ 513 _prev->next = _next; \ 514 else \ 515 (ABFD)->sections = _next; \ 516 if (_next) \ 517 _next->prev = _prev; \ 518 else \ 519 (ABFD)->section_last = _prev; \ 520 @} \ 521 while (0) 522#define bfd_section_list_append(ABFD, S) \ 523 do \ 524 @{ \ 525 asection *_s = S; \ 526 bfd *_abfd = ABFD; \ 527 _s->next = NULL; \ 528 if (_abfd->section_last) \ 529 @{ \ 530 _s->prev = _abfd->section_last; \ 531 _abfd->section_last->next = _s; \ 532 @} \ 533 else \ 534 @{ \ 535 _s->prev = NULL; \ 536 _abfd->sections = _s; \ 537 @} \ 538 _abfd->section_last = _s; \ 539 @} \ 540 while (0) 541#define bfd_section_list_prepend(ABFD, S) \ 542 do \ 543 @{ \ 544 asection *_s = S; \ 545 bfd *_abfd = ABFD; \ 546 _s->prev = NULL; \ 547 if (_abfd->sections) \ 548 @{ \ 549 _s->next = _abfd->sections; \ 550 _abfd->sections->prev = _s; \ 551 @} \ 552 else \ 553 @{ \ 554 _s->next = NULL; \ 555 _abfd->section_last = _s; \ 556 @} \ 557 _abfd->sections = _s; \ 558 @} \ 559 while (0) 560#define bfd_section_list_insert_after(ABFD, A, S) \ 561 do \ 562 @{ \ 563 asection *_a = A; \ 564 asection *_s = S; \ 565 asection *_next = _a->next; \ 566 _s->next = _next; \ 567 _s->prev = _a; \ 568 _a->next = _s; \ 569 if (_next) \ 570 _next->prev = _s; \ 571 else \ 572 (ABFD)->section_last = _s; \ 573 @} \ 574 while (0) 575#define bfd_section_list_insert_before(ABFD, B, S) \ 576 do \ 577 @{ \ 578 asection *_b = B; \ 579 asection *_s = S; \ 580 asection *_prev = _b->prev; \ 581 _s->prev = _prev; \ 582 _s->next = _b; \ 583 _b->prev = _s; \ 584 if (_prev) \ 585 _prev->next = _s; \ 586 else \ 587 (ABFD)->sections = _s; \ 588 @} \ 589 while (0) 590#define bfd_section_removed_from_list(ABFD, S) \ 591 ((S)->next == NULL ? (ABFD)->section_last != (S) : (S)->next->prev != (S)) 592 593#define BFD_FAKE_SECTION(SEC, FLAGS, SYM, NAME, IDX) \ 594 /* name, id, index, next, prev, flags, user_set_vma, */ \ 595 @{ NAME, IDX, 0, NULL, NULL, FLAGS, 0, \ 596 \ 597 /* linker_mark, linker_has_input, gc_mark, gc_mark_from_eh, */ \ 598 0, 0, 1, 0, \ 599 \ 600 /* segment_mark, sec_info_type, use_rela_p, has_tls_reloc, */ \ 601 0, 0, 0, 0, \ 602 \ 603 /* has_gp_reloc, need_finalize_relax, reloc_done, */ \ 604 0, 0, 0, \ 605 \ 606 /* vma, lma, size, rawsize */ \ 607 0, 0, 0, 0, \ 608 \ 609 /* output_offset, output_section, alignment_power, */ \ 610 0, (struct bfd_section *) &SEC, 0, \ 611 \ 612 /* relocation, orelocation, reloc_count, filepos, rel_filepos, */ \ 613 NULL, NULL, 0, 0, 0, \ 614 \ 615 /* line_filepos, userdata, contents, lineno, lineno_count, */ \ 616 0, NULL, NULL, NULL, 0, \ 617 \ 618 /* entsize, kept_section, moving_line_filepos, */ \ 619 0, NULL, 0, \ 620 \ 621 /* target_index, used_by_bfd, constructor_chain, owner, */ \ 622 0, NULL, NULL, NULL, \ 623 \ 624 /* symbol, symbol_ptr_ptr, */ \ 625 (struct bfd_symbol *) SYM, &SEC.symbol, \ 626 \ 627 /* map_head, map_tail */ \ 628 @{ NULL @}, @{ NULL @} \ 629 @} 630 631@end example 632 633@node section prototypes, , typedef asection, Sections 634@subsection Section prototypes 635These are the functions exported by the section handling part of BFD. 636 637@findex bfd_section_list_clear 638@subsubsection @code{bfd_section_list_clear} 639@strong{Synopsis} 640@example 641void bfd_section_list_clear (bfd *); 642@end example 643@strong{Description}@* 644Clears the section list, and also resets the section count and 645hash table entries. 646 647@findex bfd_get_section_by_name 648@subsubsection @code{bfd_get_section_by_name} 649@strong{Synopsis} 650@example 651asection *bfd_get_section_by_name (bfd *abfd, const char *name); 652@end example 653@strong{Description}@* 654Run through @var{abfd} and return the one of the 655@code{asection}s whose name matches @var{name}, otherwise @code{NULL}. 656@xref{Sections}, for more information. 657 658This should only be used in special cases; the normal way to process 659all sections of a given name is to use @code{bfd_map_over_sections} and 660@code{strcmp} on the name (or better yet, base it on the section flags 661or something else) for each section. 662 663@findex bfd_get_section_by_name_if 664@subsubsection @code{bfd_get_section_by_name_if} 665@strong{Synopsis} 666@example 667asection *bfd_get_section_by_name_if 668 (bfd *abfd, 669 const char *name, 670 bfd_boolean (*func) (bfd *abfd, asection *sect, void *obj), 671 void *obj); 672@end example 673@strong{Description}@* 674Call the provided function @var{func} for each section 675attached to the BFD @var{abfd} whose name matches @var{name}, 676passing @var{obj} as an argument. The function will be called 677as if by 678 679@example 680 func (abfd, the_section, obj); 681@end example 682 683It returns the first section for which @var{func} returns true, 684otherwise @code{NULL}. 685 686@findex bfd_get_unique_section_name 687@subsubsection @code{bfd_get_unique_section_name} 688@strong{Synopsis} 689@example 690char *bfd_get_unique_section_name 691 (bfd *abfd, const char *templat, int *count); 692@end example 693@strong{Description}@* 694Invent a section name that is unique in @var{abfd} by tacking 695a dot and a digit suffix onto the original @var{templat}. If 696@var{count} is non-NULL, then it specifies the first number 697tried as a suffix to generate a unique name. The value 698pointed to by @var{count} will be incremented in this case. 699 700@findex bfd_make_section_old_way 701@subsubsection @code{bfd_make_section_old_way} 702@strong{Synopsis} 703@example 704asection *bfd_make_section_old_way (bfd *abfd, const char *name); 705@end example 706@strong{Description}@* 707Create a new empty section called @var{name} 708and attach it to the end of the chain of sections for the 709BFD @var{abfd}. An attempt to create a section with a name which 710is already in use returns its pointer without changing the 711section chain. 712 713It has the funny name since this is the way it used to be 714before it was rewritten.... 715 716Possible errors are: 717@itemize @bullet 718 719@item 720@code{bfd_error_invalid_operation} - 721If output has already started for this BFD. 722@item 723@code{bfd_error_no_memory} - 724If memory allocation fails. 725@end itemize 726 727@findex bfd_make_section_anyway_with_flags 728@subsubsection @code{bfd_make_section_anyway_with_flags} 729@strong{Synopsis} 730@example 731asection *bfd_make_section_anyway_with_flags 732 (bfd *abfd, const char *name, flagword flags); 733@end example 734@strong{Description}@* 735Create a new empty section called @var{name} and attach it to the end of 736the chain of sections for @var{abfd}. Create a new section even if there 737is already a section with that name. Also set the attributes of the 738new section to the value @var{flags}. 739 740Return @code{NULL} and set @code{bfd_error} on error; possible errors are: 741@itemize @bullet 742 743@item 744@code{bfd_error_invalid_operation} - If output has already started for @var{abfd}. 745@item 746@code{bfd_error_no_memory} - If memory allocation fails. 747@end itemize 748 749@findex bfd_make_section_anyway 750@subsubsection @code{bfd_make_section_anyway} 751@strong{Synopsis} 752@example 753asection *bfd_make_section_anyway (bfd *abfd, const char *name); 754@end example 755@strong{Description}@* 756Create a new empty section called @var{name} and attach it to the end of 757the chain of sections for @var{abfd}. Create a new section even if there 758is already a section with that name. 759 760Return @code{NULL} and set @code{bfd_error} on error; possible errors are: 761@itemize @bullet 762 763@item 764@code{bfd_error_invalid_operation} - If output has already started for @var{abfd}. 765@item 766@code{bfd_error_no_memory} - If memory allocation fails. 767@end itemize 768 769@findex bfd_make_section_with_flags 770@subsubsection @code{bfd_make_section_with_flags} 771@strong{Synopsis} 772@example 773asection *bfd_make_section_with_flags 774 (bfd *, const char *name, flagword flags); 775@end example 776@strong{Description}@* 777Like @code{bfd_make_section_anyway}, but return @code{NULL} (without calling 778bfd_set_error ()) without changing the section chain if there is already a 779section named @var{name}. Also set the attributes of the new section to 780the value @var{flags}. If there is an error, return @code{NULL} and set 781@code{bfd_error}. 782 783@findex bfd_make_section 784@subsubsection @code{bfd_make_section} 785@strong{Synopsis} 786@example 787asection *bfd_make_section (bfd *, const char *name); 788@end example 789@strong{Description}@* 790Like @code{bfd_make_section_anyway}, but return @code{NULL} (without calling 791bfd_set_error ()) without changing the section chain if there is already a 792section named @var{name}. If there is an error, return @code{NULL} and set 793@code{bfd_error}. 794 795@findex bfd_set_section_flags 796@subsubsection @code{bfd_set_section_flags} 797@strong{Synopsis} 798@example 799bfd_boolean bfd_set_section_flags 800 (bfd *abfd, asection *sec, flagword flags); 801@end example 802@strong{Description}@* 803Set the attributes of the section @var{sec} in the BFD 804@var{abfd} to the value @var{flags}. Return @code{TRUE} on success, 805@code{FALSE} on error. Possible error returns are: 806 807@itemize @bullet 808 809@item 810@code{bfd_error_invalid_operation} - 811The section cannot have one or more of the attributes 812requested. For example, a .bss section in @code{a.out} may not 813have the @code{SEC_HAS_CONTENTS} field set. 814@end itemize 815 816@findex bfd_map_over_sections 817@subsubsection @code{bfd_map_over_sections} 818@strong{Synopsis} 819@example 820void bfd_map_over_sections 821 (bfd *abfd, 822 void (*func) (bfd *abfd, asection *sect, void *obj), 823 void *obj); 824@end example 825@strong{Description}@* 826Call the provided function @var{func} for each section 827attached to the BFD @var{abfd}, passing @var{obj} as an 828argument. The function will be called as if by 829 830@example 831 func (abfd, the_section, obj); 832@end example 833 834This is the preferred method for iterating over sections; an 835alternative would be to use a loop: 836 837@example 838 section *p; 839 for (p = abfd->sections; p != NULL; p = p->next) 840 func (abfd, p, ...) 841@end example 842 843@findex bfd_sections_find_if 844@subsubsection @code{bfd_sections_find_if} 845@strong{Synopsis} 846@example 847asection *bfd_sections_find_if 848 (bfd *abfd, 849 bfd_boolean (*operation) (bfd *abfd, asection *sect, void *obj), 850 void *obj); 851@end example 852@strong{Description}@* 853Call the provided function @var{operation} for each section 854attached to the BFD @var{abfd}, passing @var{obj} as an 855argument. The function will be called as if by 856 857@example 858 operation (abfd, the_section, obj); 859@end example 860 861It returns the first section for which @var{operation} returns true. 862 863@findex bfd_set_section_size 864@subsubsection @code{bfd_set_section_size} 865@strong{Synopsis} 866@example 867bfd_boolean bfd_set_section_size 868 (bfd *abfd, asection *sec, bfd_size_type val); 869@end example 870@strong{Description}@* 871Set @var{sec} to the size @var{val}. If the operation is 872ok, then @code{TRUE} is returned, else @code{FALSE}. 873 874Possible error returns: 875@itemize @bullet 876 877@item 878@code{bfd_error_invalid_operation} - 879Writing has started to the BFD, so setting the size is invalid. 880@end itemize 881 882@findex bfd_set_section_contents 883@subsubsection @code{bfd_set_section_contents} 884@strong{Synopsis} 885@example 886bfd_boolean bfd_set_section_contents 887 (bfd *abfd, asection *section, const void *data, 888 file_ptr offset, bfd_size_type count); 889@end example 890@strong{Description}@* 891Sets the contents of the section @var{section} in BFD 892@var{abfd} to the data starting in memory at @var{data}. The 893data is written to the output section starting at offset 894@var{offset} for @var{count} octets. 895 896Normally @code{TRUE} is returned, else @code{FALSE}. Possible error 897returns are: 898@itemize @bullet 899 900@item 901@code{bfd_error_no_contents} - 902The output section does not have the @code{SEC_HAS_CONTENTS} 903attribute, so nothing can be written to it. 904@item 905and some more too 906@end itemize 907This routine is front end to the back end function 908@code{_bfd_set_section_contents}. 909 910@findex bfd_get_section_contents 911@subsubsection @code{bfd_get_section_contents} 912@strong{Synopsis} 913@example 914bfd_boolean bfd_get_section_contents 915 (bfd *abfd, asection *section, void *location, file_ptr offset, 916 bfd_size_type count); 917@end example 918@strong{Description}@* 919Read data from @var{section} in BFD @var{abfd} 920into memory starting at @var{location}. The data is read at an 921offset of @var{offset} from the start of the input section, 922and is read for @var{count} bytes. 923 924If the contents of a constructor with the @code{SEC_CONSTRUCTOR} 925flag set are requested or if the section does not have the 926@code{SEC_HAS_CONTENTS} flag set, then the @var{location} is filled 927with zeroes. If no errors occur, @code{TRUE} is returned, else 928@code{FALSE}. 929 930@findex bfd_malloc_and_get_section 931@subsubsection @code{bfd_malloc_and_get_section} 932@strong{Synopsis} 933@example 934bfd_boolean bfd_malloc_and_get_section 935 (bfd *abfd, asection *section, bfd_byte **buf); 936@end example 937@strong{Description}@* 938Read all data from @var{section} in BFD @var{abfd} 939into a buffer, *@var{buf}, malloc'd by this function. 940 941@findex bfd_copy_private_section_data 942@subsubsection @code{bfd_copy_private_section_data} 943@strong{Synopsis} 944@example 945bfd_boolean bfd_copy_private_section_data 946 (bfd *ibfd, asection *isec, bfd *obfd, asection *osec); 947@end example 948@strong{Description}@* 949Copy private section information from @var{isec} in the BFD 950@var{ibfd} to the section @var{osec} in the BFD @var{obfd}. 951Return @code{TRUE} on success, @code{FALSE} on error. Possible error 952returns are: 953 954@itemize @bullet 955 956@item 957@code{bfd_error_no_memory} - 958Not enough memory exists to create private data for @var{osec}. 959@end itemize 960@example 961#define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \ 962 BFD_SEND (obfd, _bfd_copy_private_section_data, \ 963 (ibfd, isection, obfd, osection)) 964@end example 965 966@findex bfd_generic_is_group_section 967@subsubsection @code{bfd_generic_is_group_section} 968@strong{Synopsis} 969@example 970bfd_boolean bfd_generic_is_group_section (bfd *, const asection *sec); 971@end example 972@strong{Description}@* 973Returns TRUE if @var{sec} is a member of a group. 974 975@findex bfd_generic_discard_group 976@subsubsection @code{bfd_generic_discard_group} 977@strong{Synopsis} 978@example 979bfd_boolean bfd_generic_discard_group (bfd *abfd, asection *group); 980@end example 981@strong{Description}@* 982Remove all members of @var{group} from the output. 983 984