1 /* Generic symbol-table support for the BFD library. 2 Copyright (C) 1990-2016 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 Symbols 25 26 BFD tries to maintain as much symbol information as it can when 27 it moves information from file to file. BFD passes information 28 to applications though the <<asymbol>> structure. When the 29 application requests the symbol table, BFD reads the table in 30 the native form and translates parts of it into the internal 31 format. To maintain more than the information passed to 32 applications, some targets keep some information ``behind the 33 scenes'' in a structure only the particular back end knows 34 about. For example, the coff back end keeps the original 35 symbol table structure as well as the canonical structure when 36 a BFD is read in. On output, the coff back end can reconstruct 37 the output symbol table so that no information is lost, even 38 information unique to coff which BFD doesn't know or 39 understand. If a coff symbol table were read, but were written 40 through an a.out back end, all the coff specific information 41 would be lost. The symbol table of a BFD 42 is not necessarily read in until a canonicalize request is 43 made. Then the BFD back end fills in a table provided by the 44 application with pointers to the canonical information. To 45 output symbols, the application provides BFD with a table of 46 pointers to pointers to <<asymbol>>s. This allows applications 47 like the linker to output a symbol as it was read, since the ``behind 48 the scenes'' information will be still available. 49 @menu 50 @* Reading Symbols:: 51 @* Writing Symbols:: 52 @* Mini Symbols:: 53 @* typedef asymbol:: 54 @* symbol handling functions:: 55 @end menu 56 57 INODE 58 Reading Symbols, Writing Symbols, Symbols, Symbols 59 SUBSECTION 60 Reading symbols 61 62 There are two stages to reading a symbol table from a BFD: 63 allocating storage, and the actual reading process. This is an 64 excerpt from an application which reads the symbol table: 65 66 | long storage_needed; 67 | asymbol **symbol_table; 68 | long number_of_symbols; 69 | long i; 70 | 71 | storage_needed = bfd_get_symtab_upper_bound (abfd); 72 | 73 | if (storage_needed < 0) 74 | FAIL 75 | 76 | if (storage_needed == 0) 77 | return; 78 | 79 | symbol_table = xmalloc (storage_needed); 80 | ... 81 | number_of_symbols = 82 | bfd_canonicalize_symtab (abfd, symbol_table); 83 | 84 | if (number_of_symbols < 0) 85 | FAIL 86 | 87 | for (i = 0; i < number_of_symbols; i++) 88 | process_symbol (symbol_table[i]); 89 90 All storage for the symbols themselves is in an objalloc 91 connected to the BFD; it is freed when the BFD is closed. 92 93 INODE 94 Writing Symbols, Mini Symbols, Reading Symbols, Symbols 95 SUBSECTION 96 Writing symbols 97 98 Writing of a symbol table is automatic when a BFD open for 99 writing is closed. The application attaches a vector of 100 pointers to pointers to symbols to the BFD being written, and 101 fills in the symbol count. The close and cleanup code reads 102 through the table provided and performs all the necessary 103 operations. The BFD output code must always be provided with an 104 ``owned'' symbol: one which has come from another BFD, or one 105 which has been created using <<bfd_make_empty_symbol>>. Here is an 106 example showing the creation of a symbol table with only one element: 107 108 | #include "sysdep.h" 109 | #include "bfd.h" 110 | int main (void) 111 | { 112 | bfd *abfd; 113 | asymbol *ptrs[2]; 114 | asymbol *new; 115 | 116 | abfd = bfd_openw ("foo","a.out-sunos-big"); 117 | bfd_set_format (abfd, bfd_object); 118 | new = bfd_make_empty_symbol (abfd); 119 | new->name = "dummy_symbol"; 120 | new->section = bfd_make_section_old_way (abfd, ".text"); 121 | new->flags = BSF_GLOBAL; 122 | new->value = 0x12345; 123 | 124 | ptrs[0] = new; 125 | ptrs[1] = 0; 126 | 127 | bfd_set_symtab (abfd, ptrs, 1); 128 | bfd_close (abfd); 129 | return 0; 130 | } 131 | 132 | ./makesym 133 | nm foo 134 | 00012345 A dummy_symbol 135 136 Many formats cannot represent arbitrary symbol information; for 137 instance, the <<a.out>> object format does not allow an 138 arbitrary number of sections. A symbol pointing to a section 139 which is not one of <<.text>>, <<.data>> or <<.bss>> cannot 140 be described. 141 142 INODE 143 Mini Symbols, typedef asymbol, Writing Symbols, Symbols 144 SUBSECTION 145 Mini Symbols 146 147 Mini symbols provide read-only access to the symbol table. 148 They use less memory space, but require more time to access. 149 They can be useful for tools like nm or objdump, which may 150 have to handle symbol tables of extremely large executables. 151 152 The <<bfd_read_minisymbols>> function will read the symbols 153 into memory in an internal form. It will return a <<void *>> 154 pointer to a block of memory, a symbol count, and the size of 155 each symbol. The pointer is allocated using <<malloc>>, and 156 should be freed by the caller when it is no longer needed. 157 158 The function <<bfd_minisymbol_to_symbol>> will take a pointer 159 to a minisymbol, and a pointer to a structure returned by 160 <<bfd_make_empty_symbol>>, and return a <<asymbol>> structure. 161 The return value may or may not be the same as the value from 162 <<bfd_make_empty_symbol>> which was passed in. 163 164 */ 165 166 /* 167 DOCDD 168 INODE 169 typedef asymbol, symbol handling functions, Mini Symbols, Symbols 170 171 */ 172 /* 173 SUBSECTION 174 typedef asymbol 175 176 An <<asymbol>> has the form: 177 178 */ 179 180 /* 181 CODE_FRAGMENT 182 183 . 184 .typedef struct bfd_symbol 185 .{ 186 . {* A pointer to the BFD which owns the symbol. This information 187 . is necessary so that a back end can work out what additional 188 . information (invisible to the application writer) is carried 189 . with the symbol. 190 . 191 . This field is *almost* redundant, since you can use section->owner 192 . instead, except that some symbols point to the global sections 193 . bfd_{abs,com,und}_section. This could be fixed by making 194 . these globals be per-bfd (or per-target-flavor). FIXME. *} 195 . struct bfd *the_bfd; {* Use bfd_asymbol_bfd(sym) to access this field. *} 196 . 197 . {* The text of the symbol. The name is left alone, and not copied; the 198 . application may not alter it. *} 199 . const char *name; 200 . 201 . {* The value of the symbol. This really should be a union of a 202 . numeric value with a pointer, since some flags indicate that 203 . a pointer to another symbol is stored here. *} 204 . symvalue value; 205 . 206 . {* Attributes of a symbol. *} 207 .#define BSF_NO_FLAGS 0x00 208 . 209 . {* The symbol has local scope; <<static>> in <<C>>. The value 210 . is the offset into the section of the data. *} 211 .#define BSF_LOCAL (1 << 0) 212 . 213 . {* The symbol has global scope; initialized data in <<C>>. The 214 . value is the offset into the section of the data. *} 215 .#define BSF_GLOBAL (1 << 1) 216 . 217 . {* The symbol has global scope and is exported. The value is 218 . the offset into the section of the data. *} 219 .#define BSF_EXPORT BSF_GLOBAL {* No real difference. *} 220 . 221 . {* A normal C symbol would be one of: 222 . <<BSF_LOCAL>>, <<BSF_UNDEFINED>> or <<BSF_GLOBAL>>. *} 223 . 224 . {* The symbol is a debugging record. The value has an arbitrary 225 . meaning, unless BSF_DEBUGGING_RELOC is also set. *} 226 .#define BSF_DEBUGGING (1 << 2) 227 . 228 . {* The symbol denotes a function entry point. Used in ELF, 229 . perhaps others someday. *} 230 .#define BSF_FUNCTION (1 << 3) 231 . 232 . {* Used by the linker. *} 233 .#define BSF_KEEP (1 << 5) 234 . 235 . {* An ELF common symbol. *} 236 .#define BSF_ELF_COMMON (1 << 6) 237 . 238 . {* A weak global symbol, overridable without warnings by 239 . a regular global symbol of the same name. *} 240 .#define BSF_WEAK (1 << 7) 241 . 242 . {* This symbol was created to point to a section, e.g. ELF's 243 . STT_SECTION symbols. *} 244 .#define BSF_SECTION_SYM (1 << 8) 245 . 246 . {* The symbol used to be a common symbol, but now it is 247 . allocated. *} 248 .#define BSF_OLD_COMMON (1 << 9) 249 . 250 . {* In some files the type of a symbol sometimes alters its 251 . location in an output file - ie in coff a <<ISFCN>> symbol 252 . which is also <<C_EXT>> symbol appears where it was 253 . declared and not at the end of a section. This bit is set 254 . by the target BFD part to convey this information. *} 255 .#define BSF_NOT_AT_END (1 << 10) 256 . 257 . {* Signal that the symbol is the label of constructor section. *} 258 .#define BSF_CONSTRUCTOR (1 << 11) 259 . 260 . {* Signal that the symbol is a warning symbol. The name is a 261 . warning. The name of the next symbol is the one to warn about; 262 . if a reference is made to a symbol with the same name as the next 263 . symbol, a warning is issued by the linker. *} 264 .#define BSF_WARNING (1 << 12) 265 . 266 . {* Signal that the symbol is indirect. This symbol is an indirect 267 . pointer to the symbol with the same name as the next symbol. *} 268 .#define BSF_INDIRECT (1 << 13) 269 . 270 . {* BSF_FILE marks symbols that contain a file name. This is used 271 . for ELF STT_FILE symbols. *} 272 .#define BSF_FILE (1 << 14) 273 . 274 . {* Symbol is from dynamic linking information. *} 275 .#define BSF_DYNAMIC (1 << 15) 276 . 277 . {* The symbol denotes a data object. Used in ELF, and perhaps 278 . others someday. *} 279 .#define BSF_OBJECT (1 << 16) 280 . 281 . {* This symbol is a debugging symbol. The value is the offset 282 . into the section of the data. BSF_DEBUGGING should be set 283 . as well. *} 284 .#define BSF_DEBUGGING_RELOC (1 << 17) 285 . 286 . {* This symbol is thread local. Used in ELF. *} 287 .#define BSF_THREAD_LOCAL (1 << 18) 288 . 289 . {* This symbol represents a complex relocation expression, 290 . with the expression tree serialized in the symbol name. *} 291 .#define BSF_RELC (1 << 19) 292 . 293 . {* This symbol represents a signed complex relocation expression, 294 . with the expression tree serialized in the symbol name. *} 295 .#define BSF_SRELC (1 << 20) 296 . 297 . {* This symbol was created by bfd_get_synthetic_symtab. *} 298 .#define BSF_SYNTHETIC (1 << 21) 299 . 300 . {* This symbol is an indirect code object. Unrelated to BSF_INDIRECT. 301 . The dynamic linker will compute the value of this symbol by 302 . calling the function that it points to. BSF_FUNCTION must 303 . also be also set. *} 304 .#define BSF_GNU_INDIRECT_FUNCTION (1 << 22) 305 . {* This symbol is a globally unique data object. The dynamic linker 306 . will make sure that in the entire process there is just one symbol 307 . with this name and type in use. BSF_OBJECT must also be set. *} 308 .#define BSF_GNU_UNIQUE (1 << 23) 309 . 310 . flagword flags; 311 . 312 . {* A pointer to the section to which this symbol is 313 . relative. This will always be non NULL, there are special 314 . sections for undefined and absolute symbols. *} 315 . struct bfd_section *section; 316 . 317 . {* Back end special data. *} 318 . union 319 . { 320 . void *p; 321 . bfd_vma i; 322 . } 323 . udata; 324 .} 325 .asymbol; 326 . 327 */ 328 329 #include "sysdep.h" 330 #include "bfd.h" 331 #include "libbfd.h" 332 #include "safe-ctype.h" 333 #include "bfdlink.h" 334 #include "aout/stab_gnu.h" 335 336 /* 337 DOCDD 338 INODE 339 symbol handling functions, , typedef asymbol, Symbols 340 SUBSECTION 341 Symbol handling functions 342 */ 343 344 /* 345 FUNCTION 346 bfd_get_symtab_upper_bound 347 348 DESCRIPTION 349 Return the number of bytes required to store a vector of pointers 350 to <<asymbols>> for all the symbols in the BFD @var{abfd}, 351 including a terminal NULL pointer. If there are no symbols in 352 the BFD, then return 0. If an error occurs, return -1. 353 354 .#define bfd_get_symtab_upper_bound(abfd) \ 355 . BFD_SEND (abfd, _bfd_get_symtab_upper_bound, (abfd)) 356 . 357 */ 358 359 /* 360 FUNCTION 361 bfd_is_local_label 362 363 SYNOPSIS 364 bfd_boolean bfd_is_local_label (bfd *abfd, asymbol *sym); 365 366 DESCRIPTION 367 Return TRUE if the given symbol @var{sym} in the BFD @var{abfd} is 368 a compiler generated local label, else return FALSE. 369 */ 370 371 bfd_boolean 372 bfd_is_local_label (bfd *abfd, asymbol *sym) 373 { 374 /* The BSF_SECTION_SYM check is needed for IA-64, where every label that 375 starts with '.' is local. This would accidentally catch section names 376 if we didn't reject them here. */ 377 if ((sym->flags & (BSF_GLOBAL | BSF_WEAK | BSF_FILE | BSF_SECTION_SYM)) != 0) 378 return FALSE; 379 if (sym->name == NULL) 380 return FALSE; 381 return bfd_is_local_label_name (abfd, sym->name); 382 } 383 384 /* 385 FUNCTION 386 bfd_is_local_label_name 387 388 SYNOPSIS 389 bfd_boolean bfd_is_local_label_name (bfd *abfd, const char *name); 390 391 DESCRIPTION 392 Return TRUE if a symbol with the name @var{name} in the BFD 393 @var{abfd} is a compiler generated local label, else return 394 FALSE. This just checks whether the name has the form of a 395 local label. 396 397 .#define bfd_is_local_label_name(abfd, name) \ 398 . BFD_SEND (abfd, _bfd_is_local_label_name, (abfd, name)) 399 . 400 */ 401 402 /* 403 FUNCTION 404 bfd_is_target_special_symbol 405 406 SYNOPSIS 407 bfd_boolean bfd_is_target_special_symbol (bfd *abfd, asymbol *sym); 408 409 DESCRIPTION 410 Return TRUE iff a symbol @var{sym} in the BFD @var{abfd} is something 411 special to the particular target represented by the BFD. Such symbols 412 should normally not be mentioned to the user. 413 414 .#define bfd_is_target_special_symbol(abfd, sym) \ 415 . BFD_SEND (abfd, _bfd_is_target_special_symbol, (abfd, sym)) 416 . 417 */ 418 419 /* 420 FUNCTION 421 bfd_canonicalize_symtab 422 423 DESCRIPTION 424 Read the symbols from the BFD @var{abfd}, and fills in 425 the vector @var{location} with pointers to the symbols and 426 a trailing NULL. 427 Return the actual number of symbol pointers, not 428 including the NULL. 429 430 .#define bfd_canonicalize_symtab(abfd, location) \ 431 . BFD_SEND (abfd, _bfd_canonicalize_symtab, (abfd, location)) 432 . 433 */ 434 435 /* 436 FUNCTION 437 bfd_set_symtab 438 439 SYNOPSIS 440 bfd_boolean bfd_set_symtab 441 (bfd *abfd, asymbol **location, unsigned int count); 442 443 DESCRIPTION 444 Arrange that when the output BFD @var{abfd} is closed, 445 the table @var{location} of @var{count} pointers to symbols 446 will be written. 447 */ 448 449 bfd_boolean 450 bfd_set_symtab (bfd *abfd, asymbol **location, unsigned int symcount) 451 { 452 if (abfd->format != bfd_object || bfd_read_p (abfd)) 453 { 454 bfd_set_error (bfd_error_invalid_operation); 455 return FALSE; 456 } 457 458 bfd_get_outsymbols (abfd) = location; 459 bfd_get_symcount (abfd) = symcount; 460 return TRUE; 461 } 462 463 /* 464 FUNCTION 465 bfd_print_symbol_vandf 466 467 SYNOPSIS 468 void bfd_print_symbol_vandf (bfd *abfd, void *file, asymbol *symbol); 469 470 DESCRIPTION 471 Print the value and flags of the @var{symbol} supplied to the 472 stream @var{file}. 473 */ 474 void 475 bfd_print_symbol_vandf (bfd *abfd, void *arg, asymbol *symbol) 476 { 477 FILE *file = (FILE *) arg; 478 479 flagword type = symbol->flags; 480 481 if (symbol->section != NULL) 482 bfd_fprintf_vma (abfd, file, symbol->value + symbol->section->vma); 483 else 484 bfd_fprintf_vma (abfd, file, symbol->value); 485 486 /* This presumes that a symbol can not be both BSF_DEBUGGING and 487 BSF_DYNAMIC, nor more than one of BSF_FUNCTION, BSF_FILE, and 488 BSF_OBJECT. */ 489 fprintf (file, " %c%c%c%c%c%c%c", 490 ((type & BSF_LOCAL) 491 ? (type & BSF_GLOBAL) ? '!' : 'l' 492 : (type & BSF_GLOBAL) ? 'g' 493 : (type & BSF_GNU_UNIQUE) ? 'u' : ' '), 494 (type & BSF_WEAK) ? 'w' : ' ', 495 (type & BSF_CONSTRUCTOR) ? 'C' : ' ', 496 (type & BSF_WARNING) ? 'W' : ' ', 497 (type & BSF_INDIRECT) ? 'I' : (type & BSF_GNU_INDIRECT_FUNCTION) ? 'i' : ' ', 498 (type & BSF_DEBUGGING) ? 'd' : (type & BSF_DYNAMIC) ? 'D' : ' ', 499 ((type & BSF_FUNCTION) 500 ? 'F' 501 : ((type & BSF_FILE) 502 ? 'f' 503 : ((type & BSF_OBJECT) ? 'O' : ' ')))); 504 } 505 506 /* 507 FUNCTION 508 bfd_make_empty_symbol 509 510 DESCRIPTION 511 Create a new <<asymbol>> structure for the BFD @var{abfd} 512 and return a pointer to it. 513 514 This routine is necessary because each back end has private 515 information surrounding the <<asymbol>>. Building your own 516 <<asymbol>> and pointing to it will not create the private 517 information, and will cause problems later on. 518 519 .#define bfd_make_empty_symbol(abfd) \ 520 . BFD_SEND (abfd, _bfd_make_empty_symbol, (abfd)) 521 . 522 */ 523 524 /* 525 FUNCTION 526 _bfd_generic_make_empty_symbol 527 528 SYNOPSIS 529 asymbol *_bfd_generic_make_empty_symbol (bfd *); 530 531 DESCRIPTION 532 Create a new <<asymbol>> structure for the BFD @var{abfd} 533 and return a pointer to it. Used by core file routines, 534 binary back-end and anywhere else where no private info 535 is needed. 536 */ 537 538 asymbol * 539 _bfd_generic_make_empty_symbol (bfd *abfd) 540 { 541 bfd_size_type amt = sizeof (asymbol); 542 asymbol *new_symbol = (asymbol *) bfd_zalloc (abfd, amt); 543 if (new_symbol) 544 new_symbol->the_bfd = abfd; 545 return new_symbol; 546 } 547 548 /* 549 FUNCTION 550 bfd_make_debug_symbol 551 552 DESCRIPTION 553 Create a new <<asymbol>> structure for the BFD @var{abfd}, 554 to be used as a debugging symbol. Further details of its use have 555 yet to be worked out. 556 557 .#define bfd_make_debug_symbol(abfd,ptr,size) \ 558 . BFD_SEND (abfd, _bfd_make_debug_symbol, (abfd, ptr, size)) 559 . 560 */ 561 562 struct section_to_type 563 { 564 const char *section; 565 char type; 566 }; 567 568 /* Map section names to POSIX/BSD single-character symbol types. 569 This table is probably incomplete. It is sorted for convenience of 570 adding entries. Since it is so short, a linear search is used. */ 571 static const struct section_to_type stt[] = 572 { 573 {".bss", 'b'}, 574 {"code", 't'}, /* MRI .text */ 575 {".data", 'd'}, 576 {"*DEBUG*", 'N'}, 577 {".debug", 'N'}, /* MSVC's .debug (non-standard debug syms) */ 578 {".drectve", 'i'}, /* MSVC's .drective section */ 579 {".edata", 'e'}, /* MSVC's .edata (export) section */ 580 {".fini", 't'}, /* ELF fini section */ 581 {".idata", 'i'}, /* MSVC's .idata (import) section */ 582 {".init", 't'}, /* ELF init section */ 583 {".pdata", 'p'}, /* MSVC's .pdata (stack unwind) section */ 584 {".rdata", 'r'}, /* Read only data. */ 585 {".rodata", 'r'}, /* Read only data. */ 586 {".sbss", 's'}, /* Small BSS (uninitialized data). */ 587 {".scommon", 'c'}, /* Small common. */ 588 {".sdata", 'g'}, /* Small initialized data. */ 589 {".text", 't'}, 590 {"vars", 'd'}, /* MRI .data */ 591 {"zerovars", 'b'}, /* MRI .bss */ 592 {0, 0} 593 }; 594 595 /* Return the single-character symbol type corresponding to 596 section S, or '?' for an unknown COFF section. 597 598 Check for any leading string which matches, so .text5 returns 599 't' as well as .text */ 600 601 static char 602 coff_section_type (const char *s) 603 { 604 const struct section_to_type *t; 605 606 for (t = &stt[0]; t->section; t++) 607 if (!strncmp (s, t->section, strlen (t->section))) 608 return t->type; 609 610 return '?'; 611 } 612 613 /* Return the single-character symbol type corresponding to section 614 SECTION, or '?' for an unknown section. This uses section flags to 615 identify sections. 616 617 FIXME These types are unhandled: c, i, e, p. If we handled these also, 618 we could perhaps obsolete coff_section_type. */ 619 620 static char 621 decode_section_type (const struct bfd_section *section) 622 { 623 if (section->flags & SEC_CODE) 624 return 't'; 625 if (section->flags & SEC_DATA) 626 { 627 if (section->flags & SEC_READONLY) 628 return 'r'; 629 else if (section->flags & SEC_SMALL_DATA) 630 return 'g'; 631 else 632 return 'd'; 633 } 634 if ((section->flags & SEC_HAS_CONTENTS) == 0) 635 { 636 if (section->flags & SEC_SMALL_DATA) 637 return 's'; 638 else 639 return 'b'; 640 } 641 if (section->flags & SEC_DEBUGGING) 642 return 'N'; 643 if ((section->flags & SEC_HAS_CONTENTS) && (section->flags & SEC_READONLY)) 644 return 'n'; 645 646 return '?'; 647 } 648 649 /* 650 FUNCTION 651 bfd_decode_symclass 652 653 DESCRIPTION 654 Return a character corresponding to the symbol 655 class of @var{symbol}, or '?' for an unknown class. 656 657 SYNOPSIS 658 int bfd_decode_symclass (asymbol *symbol); 659 */ 660 int 661 bfd_decode_symclass (asymbol *symbol) 662 { 663 char c; 664 665 if (symbol->section && bfd_is_com_section (symbol->section)) 666 return 'C'; 667 if (bfd_is_und_section (symbol->section)) 668 { 669 if (symbol->flags & BSF_WEAK) 670 { 671 /* If weak, determine if it's specifically an object 672 or non-object weak. */ 673 if (symbol->flags & BSF_OBJECT) 674 return 'v'; 675 else 676 return 'w'; 677 } 678 else 679 return 'U'; 680 } 681 if (bfd_is_ind_section (symbol->section)) 682 return 'I'; 683 if (symbol->flags & BSF_GNU_INDIRECT_FUNCTION) 684 return 'i'; 685 if (symbol->flags & BSF_WEAK) 686 { 687 /* If weak, determine if it's specifically an object 688 or non-object weak. */ 689 if (symbol->flags & BSF_OBJECT) 690 return 'V'; 691 else 692 return 'W'; 693 } 694 if (symbol->flags & BSF_GNU_UNIQUE) 695 return 'u'; 696 if (!(symbol->flags & (BSF_GLOBAL | BSF_LOCAL))) 697 return '?'; 698 699 if (bfd_is_abs_section (symbol->section)) 700 c = 'a'; 701 else if (symbol->section) 702 { 703 c = coff_section_type (symbol->section->name); 704 if (c == '?') 705 c = decode_section_type (symbol->section); 706 } 707 else 708 return '?'; 709 if (symbol->flags & BSF_GLOBAL) 710 c = TOUPPER (c); 711 return c; 712 713 /* We don't have to handle these cases just yet, but we will soon: 714 N_SETV: 'v'; 715 N_SETA: 'l'; 716 N_SETT: 'x'; 717 N_SETD: 'z'; 718 N_SETB: 's'; 719 N_INDR: 'i'; 720 */ 721 } 722 723 /* 724 FUNCTION 725 bfd_is_undefined_symclass 726 727 DESCRIPTION 728 Returns non-zero if the class symbol returned by 729 bfd_decode_symclass represents an undefined symbol. 730 Returns zero otherwise. 731 732 SYNOPSIS 733 bfd_boolean bfd_is_undefined_symclass (int symclass); 734 */ 735 736 bfd_boolean 737 bfd_is_undefined_symclass (int symclass) 738 { 739 return symclass == 'U' || symclass == 'w' || symclass == 'v'; 740 } 741 742 /* 743 FUNCTION 744 bfd_symbol_info 745 746 DESCRIPTION 747 Fill in the basic info about symbol that nm needs. 748 Additional info may be added by the back-ends after 749 calling this function. 750 751 SYNOPSIS 752 void bfd_symbol_info (asymbol *symbol, symbol_info *ret); 753 */ 754 755 void 756 bfd_symbol_info (asymbol *symbol, symbol_info *ret) 757 { 758 ret->type = bfd_decode_symclass (symbol); 759 760 if (bfd_is_undefined_symclass (ret->type)) 761 ret->value = 0; 762 else 763 ret->value = symbol->value + symbol->section->vma; 764 765 ret->name = symbol->name; 766 } 767 768 /* 769 FUNCTION 770 bfd_copy_private_symbol_data 771 772 SYNOPSIS 773 bfd_boolean bfd_copy_private_symbol_data 774 (bfd *ibfd, asymbol *isym, bfd *obfd, asymbol *osym); 775 776 DESCRIPTION 777 Copy private symbol information from @var{isym} in the BFD 778 @var{ibfd} to the symbol @var{osym} in the BFD @var{obfd}. 779 Return <<TRUE>> on success, <<FALSE>> on error. Possible error 780 returns are: 781 782 o <<bfd_error_no_memory>> - 783 Not enough memory exists to create private data for @var{osec}. 784 785 .#define bfd_copy_private_symbol_data(ibfd, isymbol, obfd, osymbol) \ 786 . BFD_SEND (obfd, _bfd_copy_private_symbol_data, \ 787 . (ibfd, isymbol, obfd, osymbol)) 788 . 789 */ 790 791 /* The generic version of the function which returns mini symbols. 792 This is used when the backend does not provide a more efficient 793 version. It just uses BFD asymbol structures as mini symbols. */ 794 795 long 796 _bfd_generic_read_minisymbols (bfd *abfd, 797 bfd_boolean dynamic, 798 void **minisymsp, 799 unsigned int *sizep) 800 { 801 long storage; 802 asymbol **syms = NULL; 803 long symcount; 804 805 if (dynamic) 806 storage = bfd_get_dynamic_symtab_upper_bound (abfd); 807 else 808 storage = bfd_get_symtab_upper_bound (abfd); 809 if (storage < 0) 810 goto error_return; 811 if (storage == 0) 812 return 0; 813 814 syms = (asymbol **) bfd_malloc (storage); 815 if (syms == NULL) 816 goto error_return; 817 818 if (dynamic) 819 symcount = bfd_canonicalize_dynamic_symtab (abfd, syms); 820 else 821 symcount = bfd_canonicalize_symtab (abfd, syms); 822 if (symcount < 0) 823 goto error_return; 824 825 *minisymsp = syms; 826 *sizep = sizeof (asymbol *); 827 828 return symcount; 829 830 error_return: 831 bfd_set_error (bfd_error_no_symbols); 832 if (syms != NULL) 833 free (syms); 834 return -1; 835 } 836 837 /* The generic version of the function which converts a minisymbol to 838 an asymbol. We don't worry about the sym argument we are passed; 839 we just return the asymbol the minisymbol points to. */ 840 841 asymbol * 842 _bfd_generic_minisymbol_to_symbol (bfd *abfd ATTRIBUTE_UNUSED, 843 bfd_boolean dynamic ATTRIBUTE_UNUSED, 844 const void *minisym, 845 asymbol *sym ATTRIBUTE_UNUSED) 846 { 847 return *(asymbol **) minisym; 848 } 849 850 /* Look through stabs debugging information in .stab and .stabstr 851 sections to find the source file and line closest to a desired 852 location. This is used by COFF and ELF targets. It sets *pfound 853 to TRUE if it finds some information. The *pinfo field is used to 854 pass cached information in and out of this routine; this first time 855 the routine is called for a BFD, *pinfo should be NULL. The value 856 placed in *pinfo should be saved with the BFD, and passed back each 857 time this function is called. */ 858 859 /* We use a cache by default. */ 860 861 #define ENABLE_CACHING 862 863 /* We keep an array of indexentry structures to record where in the 864 stabs section we should look to find line number information for a 865 particular address. */ 866 867 struct indexentry 868 { 869 bfd_vma val; 870 bfd_byte *stab; 871 bfd_byte *str; 872 char *directory_name; 873 char *file_name; 874 char *function_name; 875 }; 876 877 /* Compare two indexentry structures. This is called via qsort. */ 878 879 static int 880 cmpindexentry (const void *a, const void *b) 881 { 882 const struct indexentry *contestantA = (const struct indexentry *) a; 883 const struct indexentry *contestantB = (const struct indexentry *) b; 884 885 if (contestantA->val < contestantB->val) 886 return -1; 887 else if (contestantA->val > contestantB->val) 888 return 1; 889 else 890 return 0; 891 } 892 893 /* A pointer to this structure is stored in *pinfo. */ 894 895 struct stab_find_info 896 { 897 /* The .stab section. */ 898 asection *stabsec; 899 /* The .stabstr section. */ 900 asection *strsec; 901 /* The contents of the .stab section. */ 902 bfd_byte *stabs; 903 /* The contents of the .stabstr section. */ 904 bfd_byte *strs; 905 906 /* A table that indexes stabs by memory address. */ 907 struct indexentry *indextable; 908 /* The number of entries in indextable. */ 909 int indextablesize; 910 911 #ifdef ENABLE_CACHING 912 /* Cached values to restart quickly. */ 913 struct indexentry *cached_indexentry; 914 bfd_vma cached_offset; 915 bfd_byte *cached_stab; 916 char *cached_file_name; 917 #endif 918 919 /* Saved ptr to malloc'ed filename. */ 920 char *filename; 921 }; 922 923 bfd_boolean 924 _bfd_stab_section_find_nearest_line (bfd *abfd, 925 asymbol **symbols, 926 asection *section, 927 bfd_vma offset, 928 bfd_boolean *pfound, 929 const char **pfilename, 930 const char **pfnname, 931 unsigned int *pline, 932 void **pinfo) 933 { 934 struct stab_find_info *info; 935 bfd_size_type stabsize, strsize; 936 bfd_byte *stab, *str; 937 bfd_byte *nul_fun, *nul_str; 938 bfd_size_type stroff; 939 struct indexentry *indexentry; 940 char *file_name; 941 char *directory_name; 942 bfd_boolean saw_line, saw_func; 943 944 *pfound = FALSE; 945 *pfilename = bfd_get_filename (abfd); 946 *pfnname = NULL; 947 *pline = 0; 948 949 /* Stabs entries use a 12 byte format: 950 4 byte string table index 951 1 byte stab type 952 1 byte stab other field 953 2 byte stab desc field 954 4 byte stab value 955 FIXME: This will have to change for a 64 bit object format. 956 957 The stabs symbols are divided into compilation units. For the 958 first entry in each unit, the type of 0, the value is the length 959 of the string table for this unit, and the desc field is the 960 number of stabs symbols for this unit. */ 961 962 #define STRDXOFF (0) 963 #define TYPEOFF (4) 964 #define OTHEROFF (5) 965 #define DESCOFF (6) 966 #define VALOFF (8) 967 #define STABSIZE (12) 968 969 info = (struct stab_find_info *) *pinfo; 970 if (info != NULL) 971 { 972 if (info->stabsec == NULL || info->strsec == NULL) 973 { 974 /* No stabs debugging information. */ 975 return TRUE; 976 } 977 978 stabsize = (info->stabsec->rawsize 979 ? info->stabsec->rawsize 980 : info->stabsec->size); 981 strsize = (info->strsec->rawsize 982 ? info->strsec->rawsize 983 : info->strsec->size); 984 } 985 else 986 { 987 long reloc_size, reloc_count; 988 arelent **reloc_vector; 989 int i; 990 char *function_name; 991 bfd_size_type amt = sizeof *info; 992 993 info = (struct stab_find_info *) bfd_zalloc (abfd, amt); 994 if (info == NULL) 995 return FALSE; 996 997 /* FIXME: When using the linker --split-by-file or 998 --split-by-reloc options, it is possible for the .stab and 999 .stabstr sections to be split. We should handle that. */ 1000 1001 info->stabsec = bfd_get_section_by_name (abfd, ".stab"); 1002 info->strsec = bfd_get_section_by_name (abfd, ".stabstr"); 1003 1004 if (info->stabsec == NULL || info->strsec == NULL) 1005 { 1006 /* Try SOM section names. */ 1007 info->stabsec = bfd_get_section_by_name (abfd, "$GDB_SYMBOLS$"); 1008 info->strsec = bfd_get_section_by_name (abfd, "$GDB_STRINGS$"); 1009 1010 if (info->stabsec == NULL || info->strsec == NULL) 1011 { 1012 /* No stabs debugging information. Set *pinfo so that we 1013 can return quickly in the info != NULL case above. */ 1014 *pinfo = info; 1015 return TRUE; 1016 } 1017 } 1018 1019 stabsize = (info->stabsec->rawsize 1020 ? info->stabsec->rawsize 1021 : info->stabsec->size); 1022 stabsize = (stabsize / STABSIZE) * STABSIZE; 1023 strsize = (info->strsec->rawsize 1024 ? info->strsec->rawsize 1025 : info->strsec->size); 1026 1027 info->stabs = (bfd_byte *) bfd_alloc (abfd, stabsize); 1028 info->strs = (bfd_byte *) bfd_alloc (abfd, strsize); 1029 if (info->stabs == NULL || info->strs == NULL) 1030 return FALSE; 1031 1032 if (! bfd_get_section_contents (abfd, info->stabsec, info->stabs, 1033 0, stabsize) 1034 || ! bfd_get_section_contents (abfd, info->strsec, info->strs, 1035 0, strsize)) 1036 return FALSE; 1037 1038 /* If this is a relocatable object file, we have to relocate 1039 the entries in .stab. This should always be simple 32 bit 1040 relocations against symbols defined in this object file, so 1041 this should be no big deal. */ 1042 reloc_size = bfd_get_reloc_upper_bound (abfd, info->stabsec); 1043 if (reloc_size < 0) 1044 return FALSE; 1045 reloc_vector = (arelent **) bfd_malloc (reloc_size); 1046 if (reloc_vector == NULL && reloc_size != 0) 1047 return FALSE; 1048 reloc_count = bfd_canonicalize_reloc (abfd, info->stabsec, reloc_vector, 1049 symbols); 1050 if (reloc_count < 0) 1051 { 1052 if (reloc_vector != NULL) 1053 free (reloc_vector); 1054 return FALSE; 1055 } 1056 if (reloc_count > 0) 1057 { 1058 arelent **pr; 1059 1060 for (pr = reloc_vector; *pr != NULL; pr++) 1061 { 1062 arelent *r; 1063 unsigned long val; 1064 asymbol *sym; 1065 1066 r = *pr; 1067 /* Ignore R_*_NONE relocs. */ 1068 if (r->howto->dst_mask == 0) 1069 continue; 1070 1071 if (r->howto->rightshift != 0 1072 || r->howto->size != 2 1073 || r->howto->bitsize != 32 1074 || r->howto->pc_relative 1075 || r->howto->bitpos != 0 1076 || r->howto->dst_mask != 0xffffffff) 1077 { 1078 (*_bfd_error_handler) 1079 (_("Unsupported .stab relocation")); 1080 bfd_set_error (bfd_error_invalid_operation); 1081 if (reloc_vector != NULL) 1082 free (reloc_vector); 1083 return FALSE; 1084 } 1085 1086 val = bfd_get_32 (abfd, info->stabs 1087 + r->address * bfd_octets_per_byte (abfd)); 1088 val &= r->howto->src_mask; 1089 sym = *r->sym_ptr_ptr; 1090 val += sym->value + sym->section->vma + r->addend; 1091 bfd_put_32 (abfd, (bfd_vma) val, info->stabs 1092 + r->address * bfd_octets_per_byte (abfd)); 1093 } 1094 } 1095 1096 if (reloc_vector != NULL) 1097 free (reloc_vector); 1098 1099 /* First time through this function, build a table matching 1100 function VM addresses to stabs, then sort based on starting 1101 VM address. Do this in two passes: once to count how many 1102 table entries we'll need, and a second to actually build the 1103 table. */ 1104 1105 info->indextablesize = 0; 1106 nul_fun = NULL; 1107 for (stab = info->stabs; stab < info->stabs + stabsize; stab += STABSIZE) 1108 { 1109 if (stab[TYPEOFF] == (bfd_byte) N_SO) 1110 { 1111 /* if we did not see a function def, leave space for one. */ 1112 if (nul_fun != NULL) 1113 ++info->indextablesize; 1114 1115 /* N_SO with null name indicates EOF */ 1116 if (bfd_get_32 (abfd, stab + STRDXOFF) == 0) 1117 nul_fun = NULL; 1118 else 1119 { 1120 nul_fun = stab; 1121 1122 /* two N_SO's in a row is a filename and directory. Skip */ 1123 if (stab + STABSIZE + TYPEOFF < info->stabs + stabsize 1124 && *(stab + STABSIZE + TYPEOFF) == (bfd_byte) N_SO) 1125 stab += STABSIZE; 1126 } 1127 } 1128 else if (stab[TYPEOFF] == (bfd_byte) N_FUN 1129 && bfd_get_32 (abfd, stab + STRDXOFF) != 0) 1130 { 1131 nul_fun = NULL; 1132 ++info->indextablesize; 1133 } 1134 } 1135 1136 if (nul_fun != NULL) 1137 ++info->indextablesize; 1138 1139 if (info->indextablesize == 0) 1140 return TRUE; 1141 ++info->indextablesize; 1142 1143 amt = info->indextablesize; 1144 amt *= sizeof (struct indexentry); 1145 info->indextable = (struct indexentry *) bfd_alloc (abfd, amt); 1146 if (info->indextable == NULL) 1147 return FALSE; 1148 1149 file_name = NULL; 1150 directory_name = NULL; 1151 nul_fun = NULL; 1152 stroff = 0; 1153 1154 for (i = 0, stab = info->stabs, nul_str = str = info->strs; 1155 i < info->indextablesize && stab < info->stabs + stabsize; 1156 stab += STABSIZE) 1157 { 1158 switch (stab[TYPEOFF]) 1159 { 1160 case 0: 1161 /* This is the first entry in a compilation unit. */ 1162 if ((bfd_size_type) ((info->strs + strsize) - str) < stroff) 1163 break; 1164 str += stroff; 1165 stroff = bfd_get_32 (abfd, stab + VALOFF); 1166 break; 1167 1168 case N_SO: 1169 /* The main file name. */ 1170 1171 /* The following code creates a new indextable entry with 1172 a NULL function name if there were no N_FUNs in a file. 1173 Note that a N_SO without a file name is an EOF and 1174 there could be 2 N_SO following it with the new filename 1175 and directory. */ 1176 if (nul_fun != NULL) 1177 { 1178 info->indextable[i].val = bfd_get_32 (abfd, nul_fun + VALOFF); 1179 info->indextable[i].stab = nul_fun; 1180 info->indextable[i].str = nul_str; 1181 info->indextable[i].directory_name = directory_name; 1182 info->indextable[i].file_name = file_name; 1183 info->indextable[i].function_name = NULL; 1184 ++i; 1185 } 1186 1187 directory_name = NULL; 1188 file_name = (char *) str + bfd_get_32 (abfd, stab + STRDXOFF); 1189 if (file_name == (char *) str) 1190 { 1191 file_name = NULL; 1192 nul_fun = NULL; 1193 } 1194 else 1195 { 1196 nul_fun = stab; 1197 nul_str = str; 1198 if (file_name >= (char *) info->strs + strsize || file_name < (char *) str) 1199 file_name = NULL; 1200 if (stab + STABSIZE + TYPEOFF < info->stabs + stabsize 1201 && *(stab + STABSIZE + TYPEOFF) == (bfd_byte) N_SO) 1202 { 1203 /* Two consecutive N_SOs are a directory and a 1204 file name. */ 1205 stab += STABSIZE; 1206 directory_name = file_name; 1207 file_name = ((char *) str 1208 + bfd_get_32 (abfd, stab + STRDXOFF)); 1209 if (file_name >= (char *) info->strs + strsize || file_name < (char *) str) 1210 file_name = NULL; 1211 } 1212 } 1213 break; 1214 1215 case N_SOL: 1216 /* The name of an include file. */ 1217 file_name = (char *) str + bfd_get_32 (abfd, stab + STRDXOFF); 1218 /* PR 17512: file: 0c680a1f. */ 1219 /* PR 17512: file: 5da8aec4. */ 1220 if (file_name >= (char *) info->strs + strsize || file_name < (char *) str) 1221 file_name = NULL; 1222 break; 1223 1224 case N_FUN: 1225 /* A function name. */ 1226 function_name = (char *) str + bfd_get_32 (abfd, stab + STRDXOFF); 1227 if (function_name == (char *) str) 1228 continue; 1229 if (function_name >= (char *) info->strs + strsize) 1230 function_name = NULL; 1231 1232 nul_fun = NULL; 1233 info->indextable[i].val = bfd_get_32 (abfd, stab + VALOFF); 1234 info->indextable[i].stab = stab; 1235 info->indextable[i].str = str; 1236 info->indextable[i].directory_name = directory_name; 1237 info->indextable[i].file_name = file_name; 1238 info->indextable[i].function_name = function_name; 1239 ++i; 1240 break; 1241 } 1242 } 1243 1244 if (nul_fun != NULL) 1245 { 1246 info->indextable[i].val = bfd_get_32 (abfd, nul_fun + VALOFF); 1247 info->indextable[i].stab = nul_fun; 1248 info->indextable[i].str = nul_str; 1249 info->indextable[i].directory_name = directory_name; 1250 info->indextable[i].file_name = file_name; 1251 info->indextable[i].function_name = NULL; 1252 ++i; 1253 } 1254 1255 info->indextable[i].val = (bfd_vma) -1; 1256 info->indextable[i].stab = info->stabs + stabsize; 1257 info->indextable[i].str = str; 1258 info->indextable[i].directory_name = NULL; 1259 info->indextable[i].file_name = NULL; 1260 info->indextable[i].function_name = NULL; 1261 ++i; 1262 1263 info->indextablesize = i; 1264 qsort (info->indextable, (size_t) i, sizeof (struct indexentry), 1265 cmpindexentry); 1266 1267 *pinfo = info; 1268 } 1269 1270 /* We are passed a section relative offset. The offsets in the 1271 stabs information are absolute. */ 1272 offset += bfd_get_section_vma (abfd, section); 1273 1274 #ifdef ENABLE_CACHING 1275 if (info->cached_indexentry != NULL 1276 && offset >= info->cached_offset 1277 && offset < (info->cached_indexentry + 1)->val) 1278 { 1279 stab = info->cached_stab; 1280 indexentry = info->cached_indexentry; 1281 file_name = info->cached_file_name; 1282 } 1283 else 1284 #endif 1285 { 1286 long low, high; 1287 long mid = -1; 1288 1289 /* Cache non-existent or invalid. Do binary search on 1290 indextable. */ 1291 indexentry = NULL; 1292 1293 low = 0; 1294 high = info->indextablesize - 1; 1295 while (low != high) 1296 { 1297 mid = (high + low) / 2; 1298 if (offset >= info->indextable[mid].val 1299 && offset < info->indextable[mid + 1].val) 1300 { 1301 indexentry = &info->indextable[mid]; 1302 break; 1303 } 1304 1305 if (info->indextable[mid].val > offset) 1306 high = mid; 1307 else 1308 low = mid + 1; 1309 } 1310 1311 if (indexentry == NULL) 1312 return TRUE; 1313 1314 stab = indexentry->stab + STABSIZE; 1315 file_name = indexentry->file_name; 1316 } 1317 1318 directory_name = indexentry->directory_name; 1319 str = indexentry->str; 1320 1321 saw_line = FALSE; 1322 saw_func = FALSE; 1323 for (; stab < (indexentry+1)->stab; stab += STABSIZE) 1324 { 1325 bfd_boolean done; 1326 bfd_vma val; 1327 1328 done = FALSE; 1329 1330 switch (stab[TYPEOFF]) 1331 { 1332 case N_SOL: 1333 /* The name of an include file. */ 1334 val = bfd_get_32 (abfd, stab + VALOFF); 1335 if (val <= offset) 1336 { 1337 file_name = (char *) str + bfd_get_32 (abfd, stab + STRDXOFF); 1338 if (file_name >= (char *) info->strs + strsize || file_name < (char *) str) 1339 file_name = NULL; 1340 *pline = 0; 1341 } 1342 break; 1343 1344 case N_SLINE: 1345 case N_DSLINE: 1346 case N_BSLINE: 1347 /* A line number. If the function was specified, then the value 1348 is relative to the start of the function. Otherwise, the 1349 value is an absolute address. */ 1350 val = ((indexentry->function_name ? indexentry->val : 0) 1351 + bfd_get_32 (abfd, stab + VALOFF)); 1352 /* If this line starts before our desired offset, or if it's 1353 the first line we've been able to find, use it. The 1354 !saw_line check works around a bug in GCC 2.95.3, which emits 1355 the first N_SLINE late. */ 1356 if (!saw_line || val <= offset) 1357 { 1358 *pline = bfd_get_16 (abfd, stab + DESCOFF); 1359 1360 #ifdef ENABLE_CACHING 1361 info->cached_stab = stab; 1362 info->cached_offset = val; 1363 info->cached_file_name = file_name; 1364 info->cached_indexentry = indexentry; 1365 #endif 1366 } 1367 if (val > offset) 1368 done = TRUE; 1369 saw_line = TRUE; 1370 break; 1371 1372 case N_FUN: 1373 case N_SO: 1374 if (saw_func || saw_line) 1375 done = TRUE; 1376 saw_func = TRUE; 1377 break; 1378 } 1379 1380 if (done) 1381 break; 1382 } 1383 1384 *pfound = TRUE; 1385 1386 if (file_name == NULL || IS_ABSOLUTE_PATH (file_name) 1387 || directory_name == NULL) 1388 *pfilename = file_name; 1389 else 1390 { 1391 size_t dirlen; 1392 1393 dirlen = strlen (directory_name); 1394 if (info->filename == NULL 1395 || filename_ncmp (info->filename, directory_name, dirlen) != 0 1396 || filename_cmp (info->filename + dirlen, file_name) != 0) 1397 { 1398 size_t len; 1399 1400 /* Don't free info->filename here. objdump and other 1401 apps keep a copy of a previously returned file name 1402 pointer. */ 1403 len = strlen (file_name) + 1; 1404 info->filename = (char *) bfd_alloc (abfd, dirlen + len); 1405 if (info->filename == NULL) 1406 return FALSE; 1407 memcpy (info->filename, directory_name, dirlen); 1408 memcpy (info->filename + dirlen, file_name, len); 1409 } 1410 1411 *pfilename = info->filename; 1412 } 1413 1414 if (indexentry->function_name != NULL) 1415 { 1416 char *s; 1417 1418 /* This will typically be something like main:F(0,1), so we want 1419 to clobber the colon. It's OK to change the name, since the 1420 string is in our own local storage anyhow. */ 1421 s = strchr (indexentry->function_name, ':'); 1422 if (s != NULL) 1423 *s = '\0'; 1424 1425 *pfnname = indexentry->function_name; 1426 } 1427 1428 return TRUE; 1429 } 1430
