1 /* Object file "section" support for the BFD library. 2 Copyright (C) 1990-2022 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 3 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., 51 Franklin Street - Fifth Floor, Boston, 20 MA 02110-1301, USA. */ 21 22 /* 23 SECTION 24 Sections 25 26 The raw data contained within a BFD is maintained through the 27 section abstraction. A single BFD may have any number of 28 sections. It keeps hold of them by pointing to the first; 29 each one points to the next in the list. 30 31 Sections are supported in BFD in <<section.c>>. 32 33 @menu 34 @* Section Input:: 35 @* Section Output:: 36 @* typedef asection:: 37 @* section prototypes:: 38 @end menu 39 40 INODE 41 Section Input, Section Output, Sections, Sections 42 SUBSECTION 43 Section input 44 45 When a BFD is opened for reading, the section structures are 46 created and attached to the BFD. 47 48 Each section has a name which describes the section in the 49 outside world---for example, <<a.out>> would contain at least 50 three sections, called <<.text>>, <<.data>> and <<.bss>>. 51 52 Names need not be unique; for example a COFF file may have several 53 sections named <<.data>>. 54 55 Sometimes a BFD will contain more than the ``natural'' number of 56 sections. A back end may attach other sections containing 57 constructor data, or an application may add a section (using 58 <<bfd_make_section>>) to the sections attached to an already open 59 BFD. For example, the linker creates an extra section 60 <<COMMON>> for each input file's BFD to hold information about 61 common storage. 62 63 The raw data is not necessarily read in when 64 the section descriptor is created. Some targets may leave the 65 data in place until a <<bfd_get_section_contents>> call is 66 made. Other back ends may read in all the data at once. For 67 example, an S-record file has to be read once to determine the 68 size of the data. 69 70 INODE 71 Section Output, typedef asection, Section Input, Sections 72 73 SUBSECTION 74 Section output 75 76 To write a new object style BFD, the various sections to be 77 written have to be created. They are attached to the BFD in 78 the same way as input sections; data is written to the 79 sections using <<bfd_set_section_contents>>. 80 81 Any program that creates or combines sections (e.g., the assembler 82 and linker) must use the <<asection>> fields <<output_section>> and 83 <<output_offset>> to indicate the file sections to which each 84 section must be written. (If the section is being created from 85 scratch, <<output_section>> should probably point to the section 86 itself and <<output_offset>> should probably be zero.) 87 88 The data to be written comes from input sections attached 89 (via <<output_section>> pointers) to 90 the output sections. The output section structure can be 91 considered a filter for the input section: the output section 92 determines the vma of the output data and the name, but the 93 input section determines the offset into the output section of 94 the data to be written. 95 96 E.g., to create a section "O", starting at 0x100, 0x123 long, 97 containing two subsections, "A" at offset 0x0 (i.e., at vma 98 0x100) and "B" at offset 0x20 (i.e., at vma 0x120) the <<asection>> 99 structures would look like: 100 101 | section name "A" 102 | output_offset 0x00 103 | size 0x20 104 | output_section -----------> section name "O" 105 | | vma 0x100 106 | section name "B" | size 0x123 107 | output_offset 0x20 | 108 | size 0x103 | 109 | output_section --------| 110 111 SUBSECTION 112 Link orders 113 114 The data within a section is stored in a @dfn{link_order}. 115 These are much like the fixups in <<gas>>. The link_order 116 abstraction allows a section to grow and shrink within itself. 117 118 A link_order knows how big it is, and which is the next 119 link_order and where the raw data for it is; it also points to 120 a list of relocations which apply to it. 121 122 The link_order is used by the linker to perform relaxing on 123 final code. The compiler creates code which is as big as 124 necessary to make it work without relaxing, and the user can 125 select whether to relax. Sometimes relaxing takes a lot of 126 time. The linker runs around the relocations to see if any 127 are attached to data which can be shrunk, if so it does it on 128 a link_order by link_order basis. 129 130 */ 131 132 #include "sysdep.h" 133 #include "bfd.h" 134 #include "libbfd.h" 135 #include "bfdlink.h" 136 137 /* 138 DOCDD 139 INODE 140 typedef asection, section prototypes, Section Output, Sections 141 SUBSECTION 142 typedef asection 143 144 Here is the section structure: 145 146 CODE_FRAGMENT 147 . 148 .typedef struct bfd_section 149 .{ 150 . {* The name of the section; the name isn't a copy, the pointer is 151 . the same as that passed to bfd_make_section. *} 152 . const char *name; 153 . 154 . {* The next section in the list belonging to the BFD, or NULL. *} 155 . struct bfd_section *next; 156 . 157 . {* The previous section in the list belonging to the BFD, or NULL. *} 158 . struct bfd_section *prev; 159 . 160 . {* A unique sequence number. *} 161 . unsigned int id; 162 . 163 . {* A unique section number which can be used by assembler to 164 . distinguish different sections with the same section name. *} 165 . unsigned int section_id; 166 . 167 . {* Which section in the bfd; 0..n-1 as sections are created in a bfd. *} 168 . unsigned int index; 169 . 170 . {* The field flags contains attributes of the section. Some 171 . flags are read in from the object file, and some are 172 . synthesized from other information. *} 173 . flagword flags; 174 . 175 .#define SEC_NO_FLAGS 0x0 176 . 177 . {* Tells the OS to allocate space for this section when loading. 178 . This is clear for a section containing debug information only. *} 179 .#define SEC_ALLOC 0x1 180 . 181 . {* Tells the OS to load the section from the file when loading. 182 . This is clear for a .bss section. *} 183 .#define SEC_LOAD 0x2 184 . 185 . {* The section contains data still to be relocated, so there is 186 . some relocation information too. *} 187 .#define SEC_RELOC 0x4 188 . 189 . {* A signal to the OS that the section contains read only data. *} 190 .#define SEC_READONLY 0x8 191 . 192 . {* The section contains code only. *} 193 .#define SEC_CODE 0x10 194 . 195 . {* The section contains data only. *} 196 .#define SEC_DATA 0x20 197 . 198 . {* The section will reside in ROM. *} 199 .#define SEC_ROM 0x40 200 . 201 . {* The section contains constructor information. This section 202 . type is used by the linker to create lists of constructors and 203 . destructors used by <<g++>>. When a back end sees a symbol 204 . which should be used in a constructor list, it creates a new 205 . section for the type of name (e.g., <<__CTOR_LIST__>>), attaches 206 . the symbol to it, and builds a relocation. To build the lists 207 . of constructors, all the linker has to do is catenate all the 208 . sections called <<__CTOR_LIST__>> and relocate the data 209 . contained within - exactly the operations it would peform on 210 . standard data. *} 211 .#define SEC_CONSTRUCTOR 0x80 212 . 213 . {* The section has contents - a data section could be 214 . <<SEC_ALLOC>> | <<SEC_HAS_CONTENTS>>; a debug section could be 215 . <<SEC_HAS_CONTENTS>> *} 216 .#define SEC_HAS_CONTENTS 0x100 217 . 218 . {* An instruction to the linker to not output the section 219 . even if it has information which would normally be written. *} 220 .#define SEC_NEVER_LOAD 0x200 221 . 222 . {* The section contains thread local data. *} 223 .#define SEC_THREAD_LOCAL 0x400 224 . 225 . {* The section's size is fixed. Generic linker code will not 226 . recalculate it and it is up to whoever has set this flag to 227 . get the size right. *} 228 .#define SEC_FIXED_SIZE 0x800 229 . 230 . {* The section contains common symbols (symbols may be defined 231 . multiple times, the value of a symbol is the amount of 232 . space it requires, and the largest symbol value is the one 233 . used). Most targets have exactly one of these (which we 234 . translate to bfd_com_section_ptr), but ECOFF has two. *} 235 .#define SEC_IS_COMMON 0x1000 236 . 237 . {* The section contains only debugging information. For 238 . example, this is set for ELF .debug and .stab sections. 239 . strip tests this flag to see if a section can be 240 . discarded. *} 241 .#define SEC_DEBUGGING 0x2000 242 . 243 . {* The contents of this section are held in memory pointed to 244 . by the contents field. This is checked by bfd_get_section_contents, 245 . and the data is retrieved from memory if appropriate. *} 246 .#define SEC_IN_MEMORY 0x4000 247 . 248 . {* The contents of this section are to be excluded by the 249 . linker for executable and shared objects unless those 250 . objects are to be further relocated. *} 251 .#define SEC_EXCLUDE 0x8000 252 . 253 . {* The contents of this section are to be sorted based on the sum of 254 . the symbol and addend values specified by the associated relocation 255 . entries. Entries without associated relocation entries will be 256 . appended to the end of the section in an unspecified order. *} 257 .#define SEC_SORT_ENTRIES 0x10000 258 . 259 . {* When linking, duplicate sections of the same name should be 260 . discarded, rather than being combined into a single section as 261 . is usually done. This is similar to how common symbols are 262 . handled. See SEC_LINK_DUPLICATES below. *} 263 .#define SEC_LINK_ONCE 0x20000 264 . 265 . {* If SEC_LINK_ONCE is set, this bitfield describes how the linker 266 . should handle duplicate sections. *} 267 .#define SEC_LINK_DUPLICATES 0xc0000 268 . 269 . {* This value for SEC_LINK_DUPLICATES means that duplicate 270 . sections with the same name should simply be discarded. *} 271 .#define SEC_LINK_DUPLICATES_DISCARD 0x0 272 . 273 . {* This value for SEC_LINK_DUPLICATES means that the linker 274 . should warn if there are any duplicate sections, although 275 . it should still only link one copy. *} 276 .#define SEC_LINK_DUPLICATES_ONE_ONLY 0x40000 277 . 278 . {* This value for SEC_LINK_DUPLICATES means that the linker 279 . should warn if any duplicate sections are a different size. *} 280 .#define SEC_LINK_DUPLICATES_SAME_SIZE 0x80000 281 . 282 . {* This value for SEC_LINK_DUPLICATES means that the linker 283 . should warn if any duplicate sections contain different 284 . contents. *} 285 .#define SEC_LINK_DUPLICATES_SAME_CONTENTS \ 286 . (SEC_LINK_DUPLICATES_ONE_ONLY | SEC_LINK_DUPLICATES_SAME_SIZE) 287 . 288 . {* This section was created by the linker as part of dynamic 289 . relocation or other arcane processing. It is skipped when 290 . going through the first-pass output, trusting that someone 291 . else up the line will take care of it later. *} 292 .#define SEC_LINKER_CREATED 0x100000 293 . 294 . {* This section contains a section ID to distinguish different 295 . sections with the same section name. *} 296 .#define SEC_ASSEMBLER_SECTION_ID 0x100000 297 . 298 . {* This section should not be subject to garbage collection. 299 . Also set to inform the linker that this section should not be 300 . listed in the link map as discarded. *} 301 .#define SEC_KEEP 0x200000 302 . 303 . {* This section contains "short" data, and should be placed 304 . "near" the GP. *} 305 .#define SEC_SMALL_DATA 0x400000 306 . 307 . {* Attempt to merge identical entities in the section. 308 . Entity size is given in the entsize field. *} 309 .#define SEC_MERGE 0x800000 310 . 311 . {* If given with SEC_MERGE, entities to merge are zero terminated 312 . strings where entsize specifies character size instead of fixed 313 . size entries. *} 314 .#define SEC_STRINGS 0x1000000 315 . 316 . {* This section contains data about section groups. *} 317 .#define SEC_GROUP 0x2000000 318 . 319 . {* The section is a COFF shared library section. This flag is 320 . only for the linker. If this type of section appears in 321 . the input file, the linker must copy it to the output file 322 . without changing the vma or size. FIXME: Although this 323 . was originally intended to be general, it really is COFF 324 . specific (and the flag was renamed to indicate this). It 325 . might be cleaner to have some more general mechanism to 326 . allow the back end to control what the linker does with 327 . sections. *} 328 .#define SEC_COFF_SHARED_LIBRARY 0x4000000 329 . 330 . {* This input section should be copied to output in reverse order 331 . as an array of pointers. This is for ELF linker internal use 332 . only. *} 333 .#define SEC_ELF_REVERSE_COPY 0x4000000 334 . 335 . {* This section contains data which may be shared with other 336 . executables or shared objects. This is for COFF only. *} 337 .#define SEC_COFF_SHARED 0x8000000 338 . 339 . {* Indicate that section has the purecode flag set. *} 340 .#define SEC_ELF_PURECODE 0x8000000 341 . 342 . {* When a section with this flag is being linked, then if the size of 343 . the input section is less than a page, it should not cross a page 344 . boundary. If the size of the input section is one page or more, 345 . it should be aligned on a page boundary. This is for TI 346 . TMS320C54X only. *} 347 .#define SEC_TIC54X_BLOCK 0x10000000 348 . 349 . {* Conditionally link this section; do not link if there are no 350 . references found to any symbol in the section. This is for TI 351 . TMS320C54X only. *} 352 .#define SEC_TIC54X_CLINK 0x20000000 353 . 354 . {* This section contains vliw code. This is for Toshiba MeP only. *} 355 .#define SEC_MEP_VLIW 0x20000000 356 . 357 . {* All symbols, sizes and relocations in this section are octets 358 . instead of bytes. Required for DWARF debug sections as DWARF 359 . information is organized in octets, not bytes. *} 360 .#define SEC_ELF_OCTETS 0x40000000 361 . 362 . {* Indicate that section has the no read flag set. This happens 363 . when memory read flag isn't set. *} 364 .#define SEC_COFF_NOREAD 0x40000000 365 . 366 . {* End of section flags. *} 367 . 368 . {* Some internal packed boolean fields. *} 369 . 370 . {* See the vma field. *} 371 . unsigned int user_set_vma : 1; 372 . 373 . {* A mark flag used by some of the linker backends. *} 374 . unsigned int linker_mark : 1; 375 . 376 . {* Another mark flag used by some of the linker backends. Set for 377 . output sections that have an input section. *} 378 . unsigned int linker_has_input : 1; 379 . 380 . {* Mark flag used by some linker backends for garbage collection. *} 381 . unsigned int gc_mark : 1; 382 . 383 . {* Section compression status. *} 384 . unsigned int compress_status : 2; 385 .#define COMPRESS_SECTION_NONE 0 386 .#define COMPRESS_SECTION_DONE 1 387 .#define DECOMPRESS_SECTION_ZLIB 2 388 .#define DECOMPRESS_SECTION_ZSTD 3 389 . 390 . {* The following flags are used by the ELF linker. *} 391 . 392 . {* Mark sections which have been allocated to segments. *} 393 . unsigned int segment_mark : 1; 394 . 395 . {* Type of sec_info information. *} 396 . unsigned int sec_info_type:3; 397 .#define SEC_INFO_TYPE_NONE 0 398 .#define SEC_INFO_TYPE_STABS 1 399 .#define SEC_INFO_TYPE_MERGE 2 400 .#define SEC_INFO_TYPE_EH_FRAME 3 401 .#define SEC_INFO_TYPE_JUST_SYMS 4 402 .#define SEC_INFO_TYPE_TARGET 5 403 .#define SEC_INFO_TYPE_EH_FRAME_ENTRY 6 404 .#define SEC_INFO_TYPE_SFRAME 7 405 . 406 . {* Nonzero if this section uses RELA relocations, rather than REL. *} 407 . unsigned int use_rela_p:1; 408 . 409 . {* Bits used by various backends. The generic code doesn't touch 410 . these fields. *} 411 . 412 . unsigned int sec_flg0:1; 413 . unsigned int sec_flg1:1; 414 . unsigned int sec_flg2:1; 415 . unsigned int sec_flg3:1; 416 . unsigned int sec_flg4:1; 417 . unsigned int sec_flg5:1; 418 . 419 . {* End of internal packed boolean fields. *} 420 . 421 . {* The virtual memory address of the section - where it will be 422 . at run time. The symbols are relocated against this. The 423 . user_set_vma flag is maintained by bfd; if it's not set, the 424 . backend can assign addresses (for example, in <<a.out>>, where 425 . the default address for <<.data>> is dependent on the specific 426 . target and various flags). *} 427 . bfd_vma vma; 428 . 429 . {* The load address of the section - where it would be in a 430 . rom image; really only used for writing section header 431 . information. *} 432 . bfd_vma lma; 433 . 434 . {* The size of the section in *octets*, as it will be output. 435 . Contains a value even if the section has no contents (e.g., the 436 . size of <<.bss>>). *} 437 . bfd_size_type size; 438 . 439 . {* For input sections, the original size on disk of the section, in 440 . octets. This field should be set for any section whose size is 441 . changed by linker relaxation. It is required for sections where 442 . the linker relaxation scheme doesn't cache altered section and 443 . reloc contents (stabs, eh_frame, SEC_MERGE, some coff relaxing 444 . targets), and thus the original size needs to be kept to read the 445 . section multiple times. For output sections, rawsize holds the 446 . section size calculated on a previous linker relaxation pass. *} 447 . bfd_size_type rawsize; 448 . 449 . {* The compressed size of the section in octets. *} 450 . bfd_size_type compressed_size; 451 . 452 . {* If this section is going to be output, then this value is the 453 . offset in *bytes* into the output section of the first byte in the 454 . input section (byte ==> smallest addressable unit on the 455 . target). In most cases, if this was going to start at the 456 . 100th octet (8-bit quantity) in the output section, this value 457 . would be 100. However, if the target byte size is 16 bits 458 . (bfd_octets_per_byte is "2"), this value would be 50. *} 459 . bfd_vma output_offset; 460 . 461 . {* The output section through which to map on output. *} 462 . struct bfd_section *output_section; 463 . 464 . {* If an input section, a pointer to a vector of relocation 465 . records for the data in this section. *} 466 . struct reloc_cache_entry *relocation; 467 . 468 . {* If an output section, a pointer to a vector of pointers to 469 . relocation records for the data in this section. *} 470 . struct reloc_cache_entry **orelocation; 471 . 472 . {* The number of relocation records in one of the above. *} 473 . unsigned reloc_count; 474 . 475 . {* The alignment requirement of the section, as an exponent of 2 - 476 . e.g., 3 aligns to 2^3 (or 8). *} 477 . unsigned int alignment_power; 478 . 479 . {* Information below is back end specific - and not always used 480 . or updated. *} 481 . 482 . {* File position of section data. *} 483 . file_ptr filepos; 484 . 485 . {* File position of relocation info. *} 486 . file_ptr rel_filepos; 487 . 488 . {* File position of line data. *} 489 . file_ptr line_filepos; 490 . 491 . {* Pointer to data for applications. *} 492 . void *userdata; 493 . 494 . {* If the SEC_IN_MEMORY flag is set, this points to the actual 495 . contents. *} 496 . unsigned char *contents; 497 . 498 . {* Attached line number information. *} 499 . alent *lineno; 500 . 501 . {* Number of line number records. *} 502 . unsigned int lineno_count; 503 . 504 . {* Entity size for merging purposes. *} 505 . unsigned int entsize; 506 . 507 . {* Points to the kept section if this section is a link-once section, 508 . and is discarded. *} 509 . struct bfd_section *kept_section; 510 . 511 . {* When a section is being output, this value changes as more 512 . linenumbers are written out. *} 513 . file_ptr moving_line_filepos; 514 . 515 . {* What the section number is in the target world. *} 516 . int target_index; 517 . 518 . void *used_by_bfd; 519 . 520 . {* If this is a constructor section then here is a list of the 521 . relocations created to relocate items within it. *} 522 . struct relent_chain *constructor_chain; 523 . 524 . {* The BFD which owns the section. *} 525 . bfd *owner; 526 . 527 . {* A symbol which points at this section only. *} 528 . struct bfd_symbol *symbol; 529 . struct bfd_symbol **symbol_ptr_ptr; 530 . 531 . {* Early in the link process, map_head and map_tail are used to build 532 . a list of input sections attached to an output section. Later, 533 . output sections use these fields for a list of bfd_link_order 534 . structs. The linked_to_symbol_name field is for ELF assembler 535 . internal use. *} 536 . union { 537 . struct bfd_link_order *link_order; 538 . struct bfd_section *s; 539 . const char *linked_to_symbol_name; 540 . } map_head, map_tail; 541 . 542 . {* Points to the output section this section is already assigned to, 543 . if any. This is used when support for non-contiguous memory 544 . regions is enabled. *} 545 . struct bfd_section *already_assigned; 546 . 547 . {* Explicitly specified section type, if non-zero. *} 548 . unsigned int type; 549 . 550 .} asection; 551 . 552 .static inline const char * 553 .bfd_section_name (const asection *sec) 554 .{ 555 . return sec->name; 556 .} 557 . 558 .static inline bfd_size_type 559 .bfd_section_size (const asection *sec) 560 .{ 561 . return sec->size; 562 .} 563 . 564 .static inline bfd_vma 565 .bfd_section_vma (const asection *sec) 566 .{ 567 . return sec->vma; 568 .} 569 . 570 .static inline bfd_vma 571 .bfd_section_lma (const asection *sec) 572 .{ 573 . return sec->lma; 574 .} 575 . 576 .static inline unsigned int 577 .bfd_section_alignment (const asection *sec) 578 .{ 579 . return sec->alignment_power; 580 .} 581 . 582 .static inline flagword 583 .bfd_section_flags (const asection *sec) 584 .{ 585 . return sec->flags; 586 .} 587 . 588 .static inline void * 589 .bfd_section_userdata (const asection *sec) 590 .{ 591 . return sec->userdata; 592 .} 593 .static inline bool 594 .bfd_is_com_section (const asection *sec) 595 .{ 596 . return (sec->flags & SEC_IS_COMMON) != 0; 597 .} 598 . 599 .{* Note: the following are provided as inline functions rather than macros 600 . because not all callers use the return value. A macro implementation 601 . would use a comma expression, eg: "((ptr)->foo = val, TRUE)" and some 602 . compilers will complain about comma expressions that have no effect. *} 603 .static inline bool 604 .bfd_set_section_userdata (asection *sec, void *val) 605 .{ 606 . sec->userdata = val; 607 . return true; 608 .} 609 . 610 .static inline bool 611 .bfd_set_section_vma (asection *sec, bfd_vma val) 612 .{ 613 . sec->vma = sec->lma = val; 614 . sec->user_set_vma = true; 615 . return true; 616 .} 617 . 618 .static inline bool 619 .bfd_set_section_lma (asection *sec, bfd_vma val) 620 .{ 621 . sec->lma = val; 622 . return true; 623 .} 624 . 625 .static inline bool 626 .bfd_set_section_alignment (asection *sec, unsigned int val) 627 .{ 628 . if (val >= sizeof (bfd_vma) * 8 - 1) 629 . return false; 630 . sec->alignment_power = val; 631 . return true; 632 .} 633 . 634 .{* These sections are global, and are managed by BFD. The application 635 . and target back end are not permitted to change the values in 636 . these sections. *} 637 .extern asection _bfd_std_section[4]; 638 . 639 .#define BFD_ABS_SECTION_NAME "*ABS*" 640 .#define BFD_UND_SECTION_NAME "*UND*" 641 .#define BFD_COM_SECTION_NAME "*COM*" 642 .#define BFD_IND_SECTION_NAME "*IND*" 643 . 644 .{* Pointer to the common section. *} 645 .#define bfd_com_section_ptr (&_bfd_std_section[0]) 646 .{* Pointer to the undefined section. *} 647 .#define bfd_und_section_ptr (&_bfd_std_section[1]) 648 .{* Pointer to the absolute section. *} 649 .#define bfd_abs_section_ptr (&_bfd_std_section[2]) 650 .{* Pointer to the indirect section. *} 651 .#define bfd_ind_section_ptr (&_bfd_std_section[3]) 652 . 653 .static inline bool 654 .bfd_is_und_section (const asection *sec) 655 .{ 656 . return sec == bfd_und_section_ptr; 657 .} 658 . 659 .static inline bool 660 .bfd_is_abs_section (const asection *sec) 661 .{ 662 . return sec == bfd_abs_section_ptr; 663 .} 664 . 665 .static inline bool 666 .bfd_is_ind_section (const asection *sec) 667 .{ 668 . return sec == bfd_ind_section_ptr; 669 .} 670 . 671 .static inline bool 672 .bfd_is_const_section (const asection *sec) 673 .{ 674 . return (sec >= _bfd_std_section 675 . && sec < _bfd_std_section + (sizeof (_bfd_std_section) 676 . / sizeof (_bfd_std_section[0]))); 677 .} 678 . 679 .{* Return TRUE if input section SEC has been discarded. *} 680 .static inline bool 681 .discarded_section (const asection *sec) 682 .{ 683 . return (!bfd_is_abs_section (sec) 684 . && bfd_is_abs_section (sec->output_section) 685 . && sec->sec_info_type != SEC_INFO_TYPE_MERGE 686 . && sec->sec_info_type != SEC_INFO_TYPE_JUST_SYMS); 687 .} 688 . 689 .#define BFD_FAKE_SECTION(SEC, SYM, NAME, IDX, FLAGS) \ 690 . {* name, next, prev, id, section_id, index, flags, user_set_vma, *} \ 691 . { NAME, NULL, NULL, IDX, 0, 0, FLAGS, 0, \ 692 . \ 693 . {* linker_mark, linker_has_input, gc_mark, decompress_status, *} \ 694 . 0, 0, 1, 0, \ 695 . \ 696 . {* segment_mark, sec_info_type, use_rela_p, *} \ 697 . 0, 0, 0, \ 698 . \ 699 . {* sec_flg0, sec_flg1, sec_flg2, sec_flg3, sec_flg4, sec_flg5, *} \ 700 . 0, 0, 0, 0, 0, 0, \ 701 . \ 702 . {* vma, lma, size, rawsize, compressed_size, *} \ 703 . 0, 0, 0, 0, 0, \ 704 . \ 705 . {* output_offset, output_section, relocation, orelocation, *} \ 706 . 0, &SEC, NULL, NULL, \ 707 . \ 708 . {* reloc_count, alignment_power, filepos, rel_filepos, *} \ 709 . 0, 0, 0, 0, \ 710 . \ 711 . {* line_filepos, userdata, contents, lineno, lineno_count, *} \ 712 . 0, NULL, NULL, NULL, 0, \ 713 . \ 714 . {* entsize, kept_section, moving_line_filepos, *} \ 715 . 0, NULL, 0, \ 716 . \ 717 . {* target_index, used_by_bfd, constructor_chain, owner, *} \ 718 . 0, NULL, NULL, NULL, \ 719 . \ 720 . {* symbol, symbol_ptr_ptr, *} \ 721 . (struct bfd_symbol *) SYM, &SEC.symbol, \ 722 . \ 723 . {* map_head, map_tail, already_assigned, type *} \ 724 . { NULL }, { NULL }, NULL, 0 \ 725 . \ 726 . } 727 . 728 .{* We use a macro to initialize the static asymbol structures because 729 . traditional C does not permit us to initialize a union member while 730 . gcc warns if we don't initialize it. 731 . the_bfd, name, value, attr, section [, udata] *} 732 .#ifdef __STDC__ 733 .#define GLOBAL_SYM_INIT(NAME, SECTION) \ 734 . { 0, NAME, 0, BSF_SECTION_SYM, SECTION, { 0 }} 735 .#else 736 .#define GLOBAL_SYM_INIT(NAME, SECTION) \ 737 . { 0, NAME, 0, BSF_SECTION_SYM, SECTION } 738 .#endif 739 . 740 */ 741 742 /* These symbols are global, not specific to any BFD. Therefore, anything 743 that tries to change them is broken, and should be repaired. */ 744 745 static const asymbol global_syms[] = 746 { 747 GLOBAL_SYM_INIT (BFD_COM_SECTION_NAME, bfd_com_section_ptr), 748 GLOBAL_SYM_INIT (BFD_UND_SECTION_NAME, bfd_und_section_ptr), 749 GLOBAL_SYM_INIT (BFD_ABS_SECTION_NAME, bfd_abs_section_ptr), 750 GLOBAL_SYM_INIT (BFD_IND_SECTION_NAME, bfd_ind_section_ptr) 751 }; 752 753 #define STD_SECTION(NAME, IDX, FLAGS) \ 754 BFD_FAKE_SECTION(_bfd_std_section[IDX], &global_syms[IDX], NAME, IDX, FLAGS) 755 756 asection _bfd_std_section[] = { 757 STD_SECTION (BFD_COM_SECTION_NAME, 0, SEC_IS_COMMON), 758 STD_SECTION (BFD_UND_SECTION_NAME, 1, 0), 759 STD_SECTION (BFD_ABS_SECTION_NAME, 2, 0), 760 STD_SECTION (BFD_IND_SECTION_NAME, 3, 0) 761 }; 762 #undef STD_SECTION 763 764 /* Initialize an entry in the section hash table. */ 765 766 struct bfd_hash_entry * 767 bfd_section_hash_newfunc (struct bfd_hash_entry *entry, 768 struct bfd_hash_table *table, 769 const char *string) 770 { 771 /* Allocate the structure if it has not already been allocated by a 772 subclass. */ 773 if (entry == NULL) 774 { 775 entry = (struct bfd_hash_entry *) 776 bfd_hash_allocate (table, sizeof (struct section_hash_entry)); 777 if (entry == NULL) 778 return entry; 779 } 780 781 /* Call the allocation method of the superclass. */ 782 entry = bfd_hash_newfunc (entry, table, string); 783 if (entry != NULL) 784 memset (&((struct section_hash_entry *) entry)->section, 0, 785 sizeof (asection)); 786 787 return entry; 788 } 789 790 #define section_hash_lookup(table, string, create, copy) \ 791 ((struct section_hash_entry *) \ 792 bfd_hash_lookup ((table), (string), (create), (copy))) 793 794 /* Create a symbol whose only job is to point to this section. This 795 is useful for things like relocs which are relative to the base 796 of a section. */ 797 798 bool 799 _bfd_generic_new_section_hook (bfd *abfd, asection *newsect) 800 { 801 newsect->symbol = bfd_make_empty_symbol (abfd); 802 if (newsect->symbol == NULL) 803 return false; 804 805 newsect->symbol->name = newsect->name; 806 newsect->symbol->value = 0; 807 newsect->symbol->section = newsect; 808 newsect->symbol->flags = BSF_SECTION_SYM; 809 810 newsect->symbol_ptr_ptr = &newsect->symbol; 811 return true; 812 } 813 814 unsigned int _bfd_section_id = 0x10; /* id 0 to 3 used by STD_SECTION. */ 815 816 /* Initializes a new section. NEWSECT->NAME is already set. */ 817 818 static asection * 819 bfd_section_init (bfd *abfd, asection *newsect) 820 { 821 newsect->id = _bfd_section_id; 822 newsect->index = abfd->section_count; 823 newsect->owner = abfd; 824 825 if (! BFD_SEND (abfd, _new_section_hook, (abfd, newsect))) 826 return NULL; 827 828 _bfd_section_id++; 829 abfd->section_count++; 830 bfd_section_list_append (abfd, newsect); 831 return newsect; 832 } 833 834 /* 835 DOCDD 836 INODE 837 section prototypes, , typedef asection, Sections 838 SUBSECTION 839 Section prototypes 840 841 These are the functions exported by the section handling part of BFD. 842 */ 843 844 /* 845 FUNCTION 846 bfd_section_list_clear 847 848 SYNOPSIS 849 void bfd_section_list_clear (bfd *); 850 851 DESCRIPTION 852 Clears the section list, and also resets the section count and 853 hash table entries. 854 */ 855 856 void 857 bfd_section_list_clear (bfd *abfd) 858 { 859 abfd->sections = NULL; 860 abfd->section_last = NULL; 861 abfd->section_count = 0; 862 memset (abfd->section_htab.table, 0, 863 abfd->section_htab.size * sizeof (struct bfd_hash_entry *)); 864 abfd->section_htab.count = 0; 865 } 866 867 /* 868 FUNCTION 869 bfd_get_section_by_name 870 871 SYNOPSIS 872 asection *bfd_get_section_by_name (bfd *abfd, const char *name); 873 874 DESCRIPTION 875 Return the most recently created section attached to @var{abfd} 876 named @var{name}. Return NULL if no such section exists. 877 */ 878 879 asection * 880 bfd_get_section_by_name (bfd *abfd, const char *name) 881 { 882 struct section_hash_entry *sh; 883 884 if (name == NULL) 885 return NULL; 886 887 sh = section_hash_lookup (&abfd->section_htab, name, false, false); 888 if (sh != NULL) 889 return &sh->section; 890 891 return NULL; 892 } 893 894 /* 895 FUNCTION 896 bfd_get_next_section_by_name 897 898 SYNOPSIS 899 asection *bfd_get_next_section_by_name (bfd *ibfd, asection *sec); 900 901 DESCRIPTION 902 Given @var{sec} is a section returned by @code{bfd_get_section_by_name}, 903 return the next most recently created section attached to the same 904 BFD with the same name, or if no such section exists in the same BFD and 905 IBFD is non-NULL, the next section with the same name in any input 906 BFD following IBFD. Return NULL on finding no section. 907 */ 908 909 asection * 910 bfd_get_next_section_by_name (bfd *ibfd, asection *sec) 911 { 912 struct section_hash_entry *sh; 913 const char *name; 914 unsigned long hash; 915 916 sh = ((struct section_hash_entry *) 917 ((char *) sec - offsetof (struct section_hash_entry, section))); 918 919 hash = sh->root.hash; 920 name = sec->name; 921 for (sh = (struct section_hash_entry *) sh->root.next; 922 sh != NULL; 923 sh = (struct section_hash_entry *) sh->root.next) 924 if (sh->root.hash == hash 925 && strcmp (sh->root.string, name) == 0) 926 return &sh->section; 927 928 if (ibfd != NULL) 929 { 930 while ((ibfd = ibfd->link.next) != NULL) 931 { 932 asection *s = bfd_get_section_by_name (ibfd, name); 933 if (s != NULL) 934 return s; 935 } 936 } 937 938 return NULL; 939 } 940 941 /* 942 FUNCTION 943 bfd_get_linker_section 944 945 SYNOPSIS 946 asection *bfd_get_linker_section (bfd *abfd, const char *name); 947 948 DESCRIPTION 949 Return the linker created section attached to @var{abfd} 950 named @var{name}. Return NULL if no such section exists. 951 */ 952 953 asection * 954 bfd_get_linker_section (bfd *abfd, const char *name) 955 { 956 asection *sec = bfd_get_section_by_name (abfd, name); 957 958 while (sec != NULL && (sec->flags & SEC_LINKER_CREATED) == 0) 959 sec = bfd_get_next_section_by_name (NULL, sec); 960 return sec; 961 } 962 963 /* 964 FUNCTION 965 bfd_get_section_by_name_if 966 967 SYNOPSIS 968 asection *bfd_get_section_by_name_if 969 (bfd *abfd, 970 const char *name, 971 bool (*func) (bfd *abfd, asection *sect, void *obj), 972 void *obj); 973 974 DESCRIPTION 975 Call the provided function @var{func} for each section 976 attached to the BFD @var{abfd} whose name matches @var{name}, 977 passing @var{obj} as an argument. The function will be called 978 as if by 979 980 | func (abfd, the_section, obj); 981 982 It returns the first section for which @var{func} returns true, 983 otherwise <<NULL>>. 984 985 */ 986 987 asection * 988 bfd_get_section_by_name_if (bfd *abfd, const char *name, 989 bool (*operation) (bfd *, asection *, void *), 990 void *user_storage) 991 { 992 struct section_hash_entry *sh; 993 unsigned long hash; 994 995 if (name == NULL) 996 return NULL; 997 998 sh = section_hash_lookup (&abfd->section_htab, name, false, false); 999 if (sh == NULL) 1000 return NULL; 1001 1002 hash = sh->root.hash; 1003 for (; sh != NULL; sh = (struct section_hash_entry *) sh->root.next) 1004 if (sh->root.hash == hash 1005 && strcmp (sh->root.string, name) == 0 1006 && (*operation) (abfd, &sh->section, user_storage)) 1007 return &sh->section; 1008 1009 return NULL; 1010 } 1011 1012 /* 1013 FUNCTION 1014 bfd_get_unique_section_name 1015 1016 SYNOPSIS 1017 char *bfd_get_unique_section_name 1018 (bfd *abfd, const char *templat, int *count); 1019 1020 DESCRIPTION 1021 Invent a section name that is unique in @var{abfd} by tacking 1022 a dot and a digit suffix onto the original @var{templat}. If 1023 @var{count} is non-NULL, then it specifies the first number 1024 tried as a suffix to generate a unique name. The value 1025 pointed to by @var{count} will be incremented in this case. 1026 */ 1027 1028 char * 1029 bfd_get_unique_section_name (bfd *abfd, const char *templat, int *count) 1030 { 1031 int num; 1032 unsigned int len; 1033 char *sname; 1034 1035 len = strlen (templat); 1036 sname = (char *) bfd_malloc (len + 8); 1037 if (sname == NULL) 1038 return NULL; 1039 memcpy (sname, templat, len); 1040 num = 1; 1041 if (count != NULL) 1042 num = *count; 1043 1044 do 1045 { 1046 /* If we have a million sections, something is badly wrong. */ 1047 if (num > 999999) 1048 abort (); 1049 sprintf (sname + len, ".%d", num++); 1050 } 1051 while (section_hash_lookup (&abfd->section_htab, sname, false, false)); 1052 1053 if (count != NULL) 1054 *count = num; 1055 return sname; 1056 } 1057 1058 /* 1059 FUNCTION 1060 bfd_make_section_old_way 1061 1062 SYNOPSIS 1063 asection *bfd_make_section_old_way (bfd *abfd, const char *name); 1064 1065 DESCRIPTION 1066 Create a new empty section called @var{name} 1067 and attach it to the end of the chain of sections for the 1068 BFD @var{abfd}. An attempt to create a section with a name which 1069 is already in use returns its pointer without changing the 1070 section chain. 1071 1072 It has the funny name since this is the way it used to be 1073 before it was rewritten.... 1074 1075 Possible errors are: 1076 o <<bfd_error_invalid_operation>> - 1077 If output has already started for this BFD. 1078 o <<bfd_error_no_memory>> - 1079 If memory allocation fails. 1080 1081 */ 1082 1083 asection * 1084 bfd_make_section_old_way (bfd *abfd, const char *name) 1085 { 1086 asection *newsect; 1087 1088 if (abfd->output_has_begun) 1089 { 1090 bfd_set_error (bfd_error_invalid_operation); 1091 return NULL; 1092 } 1093 1094 if (strcmp (name, BFD_ABS_SECTION_NAME) == 0) 1095 newsect = bfd_abs_section_ptr; 1096 else if (strcmp (name, BFD_COM_SECTION_NAME) == 0) 1097 newsect = bfd_com_section_ptr; 1098 else if (strcmp (name, BFD_UND_SECTION_NAME) == 0) 1099 newsect = bfd_und_section_ptr; 1100 else if (strcmp (name, BFD_IND_SECTION_NAME) == 0) 1101 newsect = bfd_ind_section_ptr; 1102 else 1103 { 1104 struct section_hash_entry *sh; 1105 1106 sh = section_hash_lookup (&abfd->section_htab, name, true, false); 1107 if (sh == NULL) 1108 return NULL; 1109 1110 newsect = &sh->section; 1111 if (newsect->name != NULL) 1112 { 1113 /* Section already exists. */ 1114 return newsect; 1115 } 1116 1117 newsect->name = name; 1118 return bfd_section_init (abfd, newsect); 1119 } 1120 1121 /* Call new_section_hook when "creating" the standard abs, com, und 1122 and ind sections to tack on format specific section data. 1123 Also, create a proper section symbol. */ 1124 if (! BFD_SEND (abfd, _new_section_hook, (abfd, newsect))) 1125 return NULL; 1126 return newsect; 1127 } 1128 1129 /* 1130 FUNCTION 1131 bfd_make_section_anyway_with_flags 1132 1133 SYNOPSIS 1134 asection *bfd_make_section_anyway_with_flags 1135 (bfd *abfd, const char *name, flagword flags); 1136 1137 DESCRIPTION 1138 Create a new empty section called @var{name} and attach it to the end of 1139 the chain of sections for @var{abfd}. Create a new section even if there 1140 is already a section with that name. Also set the attributes of the 1141 new section to the value @var{flags}. 1142 1143 Return <<NULL>> and set <<bfd_error>> on error; possible errors are: 1144 o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}. 1145 o <<bfd_error_no_memory>> - If memory allocation fails. 1146 */ 1147 1148 sec_ptr 1149 bfd_make_section_anyway_with_flags (bfd *abfd, const char *name, 1150 flagword flags) 1151 { 1152 struct section_hash_entry *sh; 1153 asection *newsect; 1154 1155 if (abfd->output_has_begun) 1156 { 1157 bfd_set_error (bfd_error_invalid_operation); 1158 return NULL; 1159 } 1160 1161 sh = section_hash_lookup (&abfd->section_htab, name, true, false); 1162 if (sh == NULL) 1163 return NULL; 1164 1165 newsect = &sh->section; 1166 if (newsect->name != NULL) 1167 { 1168 /* We are making a section of the same name. Put it in the 1169 section hash table. Even though we can't find it directly by a 1170 hash lookup, we'll be able to find the section by traversing 1171 sh->root.next quicker than looking at all the bfd sections. */ 1172 struct section_hash_entry *new_sh; 1173 new_sh = (struct section_hash_entry *) 1174 bfd_section_hash_newfunc (NULL, &abfd->section_htab, name); 1175 if (new_sh == NULL) 1176 return NULL; 1177 1178 new_sh->root = sh->root; 1179 sh->root.next = &new_sh->root; 1180 newsect = &new_sh->section; 1181 } 1182 1183 newsect->flags = flags; 1184 newsect->name = name; 1185 return bfd_section_init (abfd, newsect); 1186 } 1187 1188 /* 1189 FUNCTION 1190 bfd_make_section_anyway 1191 1192 SYNOPSIS 1193 asection *bfd_make_section_anyway (bfd *abfd, const char *name); 1194 1195 DESCRIPTION 1196 Create a new empty section called @var{name} and attach it to the end of 1197 the chain of sections for @var{abfd}. Create a new section even if there 1198 is already a section with that name. 1199 1200 Return <<NULL>> and set <<bfd_error>> on error; possible errors are: 1201 o <<bfd_error_invalid_operation>> - If output has already started for @var{abfd}. 1202 o <<bfd_error_no_memory>> - If memory allocation fails. 1203 */ 1204 1205 sec_ptr 1206 bfd_make_section_anyway (bfd *abfd, const char *name) 1207 { 1208 return bfd_make_section_anyway_with_flags (abfd, name, 0); 1209 } 1210 1211 /* 1212 FUNCTION 1213 bfd_make_section_with_flags 1214 1215 SYNOPSIS 1216 asection *bfd_make_section_with_flags 1217 (bfd *, const char *name, flagword flags); 1218 1219 DESCRIPTION 1220 Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling 1221 bfd_set_error ()) without changing the section chain if there is already a 1222 section named @var{name}. Also set the attributes of the new section to 1223 the value @var{flags}. If there is an error, return <<NULL>> and set 1224 <<bfd_error>>. 1225 */ 1226 1227 asection * 1228 bfd_make_section_with_flags (bfd *abfd, const char *name, 1229 flagword flags) 1230 { 1231 struct section_hash_entry *sh; 1232 asection *newsect; 1233 1234 if (abfd == NULL || name == NULL || abfd->output_has_begun) 1235 { 1236 bfd_set_error (bfd_error_invalid_operation); 1237 return NULL; 1238 } 1239 1240 if (strcmp (name, BFD_ABS_SECTION_NAME) == 0 1241 || strcmp (name, BFD_COM_SECTION_NAME) == 0 1242 || strcmp (name, BFD_UND_SECTION_NAME) == 0 1243 || strcmp (name, BFD_IND_SECTION_NAME) == 0) 1244 return NULL; 1245 1246 sh = section_hash_lookup (&abfd->section_htab, name, true, false); 1247 if (sh == NULL) 1248 return NULL; 1249 1250 newsect = &sh->section; 1251 if (newsect->name != NULL) 1252 { 1253 /* Section already exists. */ 1254 return NULL; 1255 } 1256 1257 newsect->name = name; 1258 newsect->flags = flags; 1259 return bfd_section_init (abfd, newsect); 1260 } 1261 1262 /* 1263 FUNCTION 1264 bfd_make_section 1265 1266 SYNOPSIS 1267 asection *bfd_make_section (bfd *, const char *name); 1268 1269 DESCRIPTION 1270 Like <<bfd_make_section_anyway>>, but return <<NULL>> (without calling 1271 bfd_set_error ()) without changing the section chain if there is already a 1272 section named @var{name}. If there is an error, return <<NULL>> and set 1273 <<bfd_error>>. 1274 */ 1275 1276 asection * 1277 bfd_make_section (bfd *abfd, const char *name) 1278 { 1279 return bfd_make_section_with_flags (abfd, name, 0); 1280 } 1281 1282 /* 1283 FUNCTION 1284 bfd_set_section_flags 1285 1286 SYNOPSIS 1287 bool bfd_set_section_flags (asection *sec, flagword flags); 1288 1289 DESCRIPTION 1290 Set the attributes of the section @var{sec} to the value @var{flags}. 1291 Return <<TRUE>> on success, <<FALSE>> on error. Possible error 1292 returns are: 1293 1294 o <<bfd_error_invalid_operation>> - 1295 The section cannot have one or more of the attributes 1296 requested. For example, a .bss section in <<a.out>> may not 1297 have the <<SEC_HAS_CONTENTS>> field set. 1298 1299 */ 1300 1301 bool 1302 bfd_set_section_flags (asection *section, flagword flags) 1303 { 1304 section->flags = flags; 1305 return true; 1306 } 1307 1308 /* 1309 FUNCTION 1310 bfd_rename_section 1311 1312 SYNOPSIS 1313 void bfd_rename_section 1314 (asection *sec, const char *newname); 1315 1316 DESCRIPTION 1317 Rename section @var{sec} to @var{newname}. 1318 */ 1319 1320 void 1321 bfd_rename_section (asection *sec, const char *newname) 1322 { 1323 struct section_hash_entry *sh; 1324 1325 sh = (struct section_hash_entry *) 1326 ((char *) sec - offsetof (struct section_hash_entry, section)); 1327 sh->section.name = newname; 1328 bfd_hash_rename (&sec->owner->section_htab, newname, &sh->root); 1329 } 1330 1331 /* 1332 FUNCTION 1333 bfd_map_over_sections 1334 1335 SYNOPSIS 1336 void bfd_map_over_sections 1337 (bfd *abfd, 1338 void (*func) (bfd *abfd, asection *sect, void *obj), 1339 void *obj); 1340 1341 DESCRIPTION 1342 Call the provided function @var{func} for each section 1343 attached to the BFD @var{abfd}, passing @var{obj} as an 1344 argument. The function will be called as if by 1345 1346 | func (abfd, the_section, obj); 1347 1348 This is the preferred method for iterating over sections; an 1349 alternative would be to use a loop: 1350 1351 | asection *p; 1352 | for (p = abfd->sections; p != NULL; p = p->next) 1353 | func (abfd, p, ...) 1354 1355 */ 1356 1357 void 1358 bfd_map_over_sections (bfd *abfd, 1359 void (*operation) (bfd *, asection *, void *), 1360 void *user_storage) 1361 { 1362 asection *sect; 1363 unsigned int i = 0; 1364 1365 for (sect = abfd->sections; sect != NULL; i++, sect = sect->next) 1366 (*operation) (abfd, sect, user_storage); 1367 1368 if (i != abfd->section_count) /* Debugging */ 1369 abort (); 1370 } 1371 1372 /* 1373 FUNCTION 1374 bfd_sections_find_if 1375 1376 SYNOPSIS 1377 asection *bfd_sections_find_if 1378 (bfd *abfd, 1379 bool (*operation) (bfd *abfd, asection *sect, void *obj), 1380 void *obj); 1381 1382 DESCRIPTION 1383 Call the provided function @var{operation} for each section 1384 attached to the BFD @var{abfd}, passing @var{obj} as an 1385 argument. The function will be called as if by 1386 1387 | operation (abfd, the_section, obj); 1388 1389 It returns the first section for which @var{operation} returns true. 1390 1391 */ 1392 1393 asection * 1394 bfd_sections_find_if (bfd *abfd, 1395 bool (*operation) (bfd *, asection *, void *), 1396 void *user_storage) 1397 { 1398 asection *sect; 1399 1400 for (sect = abfd->sections; sect != NULL; sect = sect->next) 1401 if ((*operation) (abfd, sect, user_storage)) 1402 break; 1403 1404 return sect; 1405 } 1406 1407 /* 1408 FUNCTION 1409 bfd_set_section_size 1410 1411 SYNOPSIS 1412 bool bfd_set_section_size (asection *sec, bfd_size_type val); 1413 1414 DESCRIPTION 1415 Set @var{sec} to the size @var{val}. If the operation is 1416 ok, then <<TRUE>> is returned, else <<FALSE>>. 1417 1418 Possible error returns: 1419 o <<bfd_error_invalid_operation>> - 1420 Writing has started to the BFD, so setting the size is invalid. 1421 1422 */ 1423 1424 bool 1425 bfd_set_section_size (asection *sec, bfd_size_type val) 1426 { 1427 /* Once you've started writing to any section you cannot create or change 1428 the size of any others. */ 1429 1430 if (sec->owner == NULL || sec->owner->output_has_begun) 1431 { 1432 bfd_set_error (bfd_error_invalid_operation); 1433 return false; 1434 } 1435 1436 sec->size = val; 1437 return true; 1438 } 1439 1440 /* 1441 FUNCTION 1442 bfd_set_section_contents 1443 1444 SYNOPSIS 1445 bool bfd_set_section_contents 1446 (bfd *abfd, asection *section, const void *data, 1447 file_ptr offset, bfd_size_type count); 1448 1449 DESCRIPTION 1450 Sets the contents of the section @var{section} in BFD 1451 @var{abfd} to the data starting in memory at @var{location}. 1452 The data is written to the output section starting at offset 1453 @var{offset} for @var{count} octets. 1454 1455 Normally <<TRUE>> is returned, but <<FALSE>> is returned if 1456 there was an error. Possible error returns are: 1457 o <<bfd_error_no_contents>> - 1458 The output section does not have the <<SEC_HAS_CONTENTS>> 1459 attribute, so nothing can be written to it. 1460 o <<bfd_error_bad_value>> - 1461 The section is unable to contain all of the data. 1462 o <<bfd_error_invalid_operation>> - 1463 The BFD is not writeable. 1464 o and some more too. 1465 1466 This routine is front end to the back end function 1467 <<_bfd_set_section_contents>>. 1468 1469 */ 1470 1471 bool 1472 bfd_set_section_contents (bfd *abfd, 1473 sec_ptr section, 1474 const void *location, 1475 file_ptr offset, 1476 bfd_size_type count) 1477 { 1478 bfd_size_type sz; 1479 1480 if (!(bfd_section_flags (section) & SEC_HAS_CONTENTS)) 1481 { 1482 bfd_set_error (bfd_error_no_contents); 1483 return false; 1484 } 1485 1486 sz = section->size; 1487 if ((bfd_size_type) offset > sz 1488 || count > sz - offset 1489 || count != (size_t) count) 1490 { 1491 bfd_set_error (bfd_error_bad_value); 1492 return false; 1493 } 1494 1495 if (!bfd_write_p (abfd)) 1496 { 1497 bfd_set_error (bfd_error_invalid_operation); 1498 return false; 1499 } 1500 1501 /* Record a copy of the data in memory if desired. */ 1502 if (section->contents 1503 && location != section->contents + offset) 1504 memcpy (section->contents + offset, location, (size_t) count); 1505 1506 if (BFD_SEND (abfd, _bfd_set_section_contents, 1507 (abfd, section, location, offset, count))) 1508 { 1509 abfd->output_has_begun = true; 1510 return true; 1511 } 1512 1513 return false; 1514 } 1515 1516 /* 1517 FUNCTION 1518 bfd_get_section_contents 1519 1520 SYNOPSIS 1521 bool bfd_get_section_contents 1522 (bfd *abfd, asection *section, void *location, file_ptr offset, 1523 bfd_size_type count); 1524 1525 DESCRIPTION 1526 Read data from @var{section} in BFD @var{abfd} 1527 into memory starting at @var{location}. The data is read at an 1528 offset of @var{offset} from the start of the input section, 1529 and is read for @var{count} bytes. 1530 1531 If the contents of a constructor with the <<SEC_CONSTRUCTOR>> 1532 flag set are requested or if the section does not have the 1533 <<SEC_HAS_CONTENTS>> flag set, then the @var{location} is filled 1534 with zeroes. If no errors occur, <<TRUE>> is returned, else 1535 <<FALSE>>. 1536 1537 */ 1538 bool 1539 bfd_get_section_contents (bfd *abfd, 1540 sec_ptr section, 1541 void *location, 1542 file_ptr offset, 1543 bfd_size_type count) 1544 { 1545 bfd_size_type sz; 1546 1547 if (section->flags & SEC_CONSTRUCTOR) 1548 { 1549 memset (location, 0, (size_t) count); 1550 return true; 1551 } 1552 1553 if (abfd->direction != write_direction && section->rawsize != 0) 1554 sz = section->rawsize; 1555 else 1556 sz = section->size; 1557 if ((bfd_size_type) offset > sz 1558 || count > sz - offset 1559 || count != (size_t) count) 1560 { 1561 bfd_set_error (bfd_error_bad_value); 1562 return false; 1563 } 1564 1565 if (count == 0) 1566 /* Don't bother. */ 1567 return true; 1568 1569 if ((section->flags & SEC_HAS_CONTENTS) == 0) 1570 { 1571 memset (location, 0, (size_t) count); 1572 return true; 1573 } 1574 1575 if ((section->flags & SEC_IN_MEMORY) != 0) 1576 { 1577 if (section->contents == NULL) 1578 { 1579 /* This can happen because of errors earlier on in the linking process. 1580 We do not want to seg-fault here, so clear the flag and return an 1581 error code. */ 1582 section->flags &= ~ SEC_IN_MEMORY; 1583 bfd_set_error (bfd_error_invalid_operation); 1584 return false; 1585 } 1586 1587 memmove (location, section->contents + offset, (size_t) count); 1588 return true; 1589 } 1590 1591 return BFD_SEND (abfd, _bfd_get_section_contents, 1592 (abfd, section, location, offset, count)); 1593 } 1594 1595 /* 1596 FUNCTION 1597 bfd_malloc_and_get_section 1598 1599 SYNOPSIS 1600 bool bfd_malloc_and_get_section 1601 (bfd *abfd, asection *section, bfd_byte **buf); 1602 1603 DESCRIPTION 1604 Read all data from @var{section} in BFD @var{abfd} 1605 into a buffer, *@var{buf}, malloc'd by this function. 1606 */ 1607 1608 bool 1609 bfd_malloc_and_get_section (bfd *abfd, sec_ptr sec, bfd_byte **buf) 1610 { 1611 *buf = NULL; 1612 return bfd_get_full_section_contents (abfd, sec, buf); 1613 } 1614 /* 1615 FUNCTION 1616 bfd_copy_private_section_data 1617 1618 SYNOPSIS 1619 bool bfd_copy_private_section_data 1620 (bfd *ibfd, asection *isec, bfd *obfd, asection *osec); 1621 1622 DESCRIPTION 1623 Copy private section information from @var{isec} in the BFD 1624 @var{ibfd} to the section @var{osec} in the BFD @var{obfd}. 1625 Return <<TRUE>> on success, <<FALSE>> on error. Possible error 1626 returns are: 1627 1628 o <<bfd_error_no_memory>> - 1629 Not enough memory exists to create private data for @var{osec}. 1630 1631 .#define bfd_copy_private_section_data(ibfd, isection, obfd, osection) \ 1632 . BFD_SEND (obfd, _bfd_copy_private_section_data, \ 1633 . (ibfd, isection, obfd, osection)) 1634 */ 1635 1636 /* 1637 FUNCTION 1638 bfd_generic_is_group_section 1639 1640 SYNOPSIS 1641 bool bfd_generic_is_group_section (bfd *, const asection *sec); 1642 1643 DESCRIPTION 1644 Returns TRUE if @var{sec} is a member of a group. 1645 */ 1646 1647 bool 1648 bfd_generic_is_group_section (bfd *abfd ATTRIBUTE_UNUSED, 1649 const asection *sec ATTRIBUTE_UNUSED) 1650 { 1651 return false; 1652 } 1653 1654 /* 1655 FUNCTION 1656 bfd_generic_group_name 1657 1658 SYNOPSIS 1659 const char *bfd_generic_group_name (bfd *, const asection *sec); 1660 1661 DESCRIPTION 1662 Returns group name if @var{sec} is a member of a group. 1663 */ 1664 1665 const char * 1666 bfd_generic_group_name (bfd *abfd ATTRIBUTE_UNUSED, 1667 const asection *sec ATTRIBUTE_UNUSED) 1668 { 1669 return NULL; 1670 } 1671 1672 /* 1673 FUNCTION 1674 bfd_generic_discard_group 1675 1676 SYNOPSIS 1677 bool bfd_generic_discard_group (bfd *abfd, asection *group); 1678 1679 DESCRIPTION 1680 Remove all members of @var{group} from the output. 1681 */ 1682 1683 bool 1684 bfd_generic_discard_group (bfd *abfd ATTRIBUTE_UNUSED, 1685 asection *group ATTRIBUTE_UNUSED) 1686 { 1687 return true; 1688 } 1689 1690 bool 1691 _bfd_nowrite_set_section_contents (bfd *abfd, 1692 sec_ptr section ATTRIBUTE_UNUSED, 1693 const void *location ATTRIBUTE_UNUSED, 1694 file_ptr offset ATTRIBUTE_UNUSED, 1695 bfd_size_type count ATTRIBUTE_UNUSED) 1696 { 1697 return _bfd_bool_bfd_false_error (abfd); 1698 } 1699 1700 /* 1701 INTERNAL_FUNCTION 1702 _bfd_section_size_insane 1703 1704 SYNOPSIS 1705 bool _bfd_section_size_insane (bfd *abfd, asection *sec); 1706 1707 DESCRIPTION 1708 Returns true if the given section has a size that indicates 1709 it cannot be read from file. Return false if the size is OK 1710 *or* this function can't say one way or the other. 1711 1712 */ 1713 1714 bool 1715 _bfd_section_size_insane (bfd *abfd, asection *sec) 1716 { 1717 bfd_size_type size = bfd_get_section_limit_octets (abfd, sec); 1718 if (size == 0) 1719 return false; 1720 1721 if ((bfd_section_flags (sec) & SEC_IN_MEMORY) != 0 1722 /* PR 24753: Linker created sections can be larger than 1723 the file size, eg if they are being used to hold stubs. */ 1724 || (bfd_section_flags (sec) & SEC_LINKER_CREATED) != 0 1725 /* PR 24753: Sections which have no content should also be 1726 excluded as they contain no size on disk. */ 1727 || (bfd_section_flags (sec) & SEC_HAS_CONTENTS) == 0 1728 /* The MMO file format supports its own special compression 1729 technique, but it uses COMPRESS_SECTION_NONE when loading 1730 a section's contents. */ 1731 || bfd_get_flavour (abfd) == bfd_target_mmo_flavour) 1732 return false; 1733 1734 ufile_ptr filesize = bfd_get_file_size (abfd); 1735 if (filesize == 0) 1736 return false; 1737 1738 if (sec->compress_status == DECOMPRESS_SECTION_ZSTD 1739 || sec->compress_status == DECOMPRESS_SECTION_ZLIB) 1740 { 1741 /* PR26946, PR28834: Sanity check compress header uncompressed 1742 size against the original file size, and check that the 1743 compressed section can be read from file. We choose an 1744 arbitrary uncompressed size of 10x the file size, rather than 1745 a compress ratio. The reason being that compiling 1746 "int aaa..a;" with "a" repeated enough times can result in 1747 compression ratios without limit for .debug_str, whereas such 1748 a file will usually also have the enormous symbol 1749 uncompressed in .symtab. */ 1750 if (size / 10 > filesize) 1751 { 1752 bfd_set_error (bfd_error_bad_value); 1753 return true; 1754 } 1755 size = sec->compressed_size; 1756 } 1757 1758 if ((ufile_ptr) sec->filepos > filesize || size > filesize - sec->filepos) 1759 { 1760 bfd_set_error (bfd_error_file_truncated); 1761 return true; 1762 } 1763 return false; 1764 } 1765