1/* Read ELF (Executable and Linking Format) object files for GDB. 2 3 Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 4 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc. 5 6 Written by Fred Fish at Cygnus Support. 7 8 This file is part of GDB. 9 10 This program is free software; you can redistribute it and/or modify 11 it under the terms of the GNU General Public License as published by 12 the Free Software Foundation; either version 3 of the License, or 13 (at your option) any later version. 14 15 This program is distributed in the hope that it will be useful, 16 but WITHOUT ANY WARRANTY; without even the implied warranty of 17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 GNU General Public License for more details. 19 20 You should have received a copy of the GNU General Public License 21 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 22 23#include "defs.h" 24#include "bfd.h" 25#include "gdb_string.h" 26#include "elf-bfd.h" 27#include "elf/common.h" 28#include "elf/internal.h" 29#include "elf/mips.h" 30#include "symtab.h" 31#include "symfile.h" 32#include "objfiles.h" 33#include "buildsym.h" 34#include "stabsread.h" 35#include "gdb-stabs.h" 36#include "complaints.h" 37#include "demangle.h" 38 39extern void _initialize_elfread (void); 40 41/* The struct elfinfo is available only during ELF symbol table and 42 psymtab reading. It is destroyed at the completion of psymtab-reading. 43 It's local to elf_symfile_read. */ 44 45struct elfinfo 46 { 47 asection *stabsect; /* Section pointer for .stab section */ 48 asection *stabindexsect; /* Section pointer for .stab.index section */ 49 asection *mdebugsect; /* Section pointer for .mdebug section */ 50 }; 51 52static void free_elfinfo (void *); 53 54/* Locate the segments in ABFD. */ 55 56static struct symfile_segment_data * 57elf_symfile_segments (bfd *abfd) 58{ 59 Elf_Internal_Phdr *phdrs, **segments; 60 long phdrs_size; 61 int num_phdrs, num_segments, num_sections, i; 62 asection *sect; 63 struct symfile_segment_data *data; 64 65 phdrs_size = bfd_get_elf_phdr_upper_bound (abfd); 66 if (phdrs_size == -1) 67 return NULL; 68 69 phdrs = alloca (phdrs_size); 70 num_phdrs = bfd_get_elf_phdrs (abfd, phdrs); 71 if (num_phdrs == -1) 72 return NULL; 73 74 num_segments = 0; 75 segments = alloca (sizeof (Elf_Internal_Phdr *) * num_phdrs); 76 for (i = 0; i < num_phdrs; i++) 77 if (phdrs[i].p_type == PT_LOAD) 78 segments[num_segments++] = &phdrs[i]; 79 80 if (num_segments == 0) 81 return NULL; 82 83 data = XZALLOC (struct symfile_segment_data); 84 data->num_segments = num_segments; 85 data->segment_bases = XCALLOC (num_segments, CORE_ADDR); 86 data->segment_sizes = XCALLOC (num_segments, CORE_ADDR); 87 88 for (i = 0; i < num_segments; i++) 89 { 90 data->segment_bases[i] = segments[i]->p_vaddr; 91 data->segment_sizes[i] = segments[i]->p_memsz; 92 } 93 94 num_sections = bfd_count_sections (abfd); 95 data->segment_info = XCALLOC (num_sections, int); 96 97 for (i = 0, sect = abfd->sections; sect != NULL; i++, sect = sect->next) 98 { 99 int j; 100 CORE_ADDR vma; 101 102 if ((bfd_get_section_flags (abfd, sect) & SEC_ALLOC) == 0) 103 continue; 104 105 vma = bfd_get_section_vma (abfd, sect); 106 107 for (j = 0; j < num_segments; j++) 108 if (segments[j]->p_memsz > 0 109 && vma >= segments[j]->p_vaddr 110 && vma < segments[j]->p_vaddr + segments[j]->p_memsz) 111 { 112 data->segment_info[i] = j + 1; 113 break; 114 } 115 116 if (bfd_get_section_size (sect) > 0 && j == num_segments) 117 warning (_("Loadable segment \"%s\" outside of ELF segments"), 118 bfd_section_name (abfd, sect)); 119 } 120 121 return data; 122} 123 124/* We are called once per section from elf_symfile_read. We 125 need to examine each section we are passed, check to see 126 if it is something we are interested in processing, and 127 if so, stash away some access information for the section. 128 129 For now we recognize the dwarf debug information sections and 130 line number sections from matching their section names. The 131 ELF definition is no real help here since it has no direct 132 knowledge of DWARF (by design, so any debugging format can be 133 used). 134 135 We also recognize the ".stab" sections used by the Sun compilers 136 released with Solaris 2. 137 138 FIXME: The section names should not be hardwired strings (what 139 should they be? I don't think most object file formats have enough 140 section flags to specify what kind of debug section it is 141 -kingdon). */ 142 143static void 144elf_locate_sections (bfd *ignore_abfd, asection *sectp, void *eip) 145{ 146 struct elfinfo *ei; 147 148 ei = (struct elfinfo *) eip; 149 if (strcmp (sectp->name, ".stab") == 0) 150 { 151 ei->stabsect = sectp; 152 } 153 else if (strcmp (sectp->name, ".stab.index") == 0) 154 { 155 ei->stabindexsect = sectp; 156 } 157 else if (strcmp (sectp->name, ".mdebug") == 0) 158 { 159 ei->mdebugsect = sectp; 160 } 161} 162 163static struct minimal_symbol * 164record_minimal_symbol (char *name, CORE_ADDR address, 165 enum minimal_symbol_type ms_type, 166 asection *bfd_section, struct objfile *objfile) 167{ 168 if (ms_type == mst_text || ms_type == mst_file_text) 169 address = gdbarch_smash_text_address (current_gdbarch, address); 170 171 return prim_record_minimal_symbol_and_info 172 (name, address, ms_type, NULL, bfd_section->index, bfd_section, objfile); 173} 174 175/* 176 177 LOCAL FUNCTION 178 179 elf_symtab_read -- read the symbol table of an ELF file 180 181 SYNOPSIS 182 183 void elf_symtab_read (struct objfile *objfile, int dynamic, 184 long number_of_symbols, asymbol **symbol_table) 185 186 DESCRIPTION 187 188 Given an objfile, a symbol table, and a flag indicating whether the 189 symbol table contains dynamic symbols, add all the global function 190 and data symbols to the minimal symbol table. 191 192 In stabs-in-ELF, as implemented by Sun, there are some local symbols 193 defined in the ELF symbol table, which can be used to locate 194 the beginnings of sections from each ".o" file that was linked to 195 form the executable objfile. We gather any such info and record it 196 in data structures hung off the objfile's private data. 197 198 */ 199 200static void 201elf_symtab_read (struct objfile *objfile, int dynamic, 202 long number_of_symbols, asymbol **symbol_table) 203{ 204 long storage_needed; 205 asymbol *sym; 206 long i; 207 CORE_ADDR symaddr; 208 CORE_ADDR offset; 209 enum minimal_symbol_type ms_type; 210 /* If sectinfo is nonNULL, it contains section info that should end up 211 filed in the objfile. */ 212 struct stab_section_info *sectinfo = NULL; 213 /* If filesym is nonzero, it points to a file symbol, but we haven't 214 seen any section info for it yet. */ 215 asymbol *filesym = 0; 216#ifdef SOFUN_ADDRESS_MAYBE_MISSING 217 /* Name of filesym, as saved on the objfile_obstack. */ 218 char *filesymname = obsavestring ("", 0, &objfile->objfile_obstack); 219#endif 220 struct dbx_symfile_info *dbx = objfile->deprecated_sym_stab_info; 221 int stripped = (bfd_get_symcount (objfile->obfd) == 0); 222 223 for (i = 0; i < number_of_symbols; i++) 224 { 225 sym = symbol_table[i]; 226 if (sym->name == NULL || *sym->name == '\0') 227 { 228 /* Skip names that don't exist (shouldn't happen), or names 229 that are null strings (may happen). */ 230 continue; 231 } 232 233 /* Skip "special" symbols, e.g. ARM mapping symbols. These are 234 symbols which do not correspond to objects in the symbol table, 235 but have some other target-specific meaning. */ 236 if (bfd_is_target_special_symbol (objfile->obfd, sym)) 237 continue; 238 239 offset = ANOFFSET (objfile->section_offsets, sym->section->index); 240 if (dynamic 241 && sym->section == &bfd_und_section 242 && (sym->flags & BSF_FUNCTION)) 243 { 244 struct minimal_symbol *msym; 245 246 /* Symbol is a reference to a function defined in 247 a shared library. 248 If its value is non zero then it is usually the address 249 of the corresponding entry in the procedure linkage table, 250 plus the desired section offset. 251 If its value is zero then the dynamic linker has to resolve 252 the symbol. We are unable to find any meaningful address 253 for this symbol in the executable file, so we skip it. */ 254 symaddr = sym->value; 255 if (symaddr == 0) 256 continue; 257 symaddr += offset; 258 msym = record_minimal_symbol 259 ((char *) sym->name, symaddr, 260 mst_solib_trampoline, sym->section, objfile); 261#ifdef SOFUN_ADDRESS_MAYBE_MISSING 262 if (msym != NULL) 263 msym->filename = filesymname; 264#endif 265 continue; 266 } 267 268 /* If it is a nonstripped executable, do not enter dynamic 269 symbols, as the dynamic symbol table is usually a subset 270 of the main symbol table. */ 271 if (dynamic && !stripped) 272 continue; 273 if (sym->flags & BSF_FILE) 274 { 275 /* STT_FILE debugging symbol that helps stabs-in-elf debugging. 276 Chain any old one onto the objfile; remember new sym. */ 277 if (sectinfo != NULL) 278 { 279 sectinfo->next = dbx->stab_section_info; 280 dbx->stab_section_info = sectinfo; 281 sectinfo = NULL; 282 } 283 filesym = sym; 284#ifdef SOFUN_ADDRESS_MAYBE_MISSING 285 filesymname = 286 obsavestring ((char *) filesym->name, strlen (filesym->name), 287 &objfile->objfile_obstack); 288#endif 289 } 290 else if (sym->flags & BSF_SECTION_SYM) 291 continue; 292 else if (sym->flags & (BSF_GLOBAL | BSF_LOCAL | BSF_WEAK)) 293 { 294 struct minimal_symbol *msym; 295 296 /* Select global/local/weak symbols. Note that bfd puts abs 297 symbols in their own section, so all symbols we are 298 interested in will have a section. */ 299 /* Bfd symbols are section relative. */ 300 symaddr = sym->value + sym->section->vma; 301 /* Relocate all non-absolute symbols by the section offset. */ 302 if (sym->section != &bfd_abs_section) 303 { 304 symaddr += offset; 305 } 306 /* For non-absolute symbols, use the type of the section 307 they are relative to, to intuit text/data. Bfd provides 308 no way of figuring this out for absolute symbols. */ 309 if (sym->section == &bfd_abs_section) 310 { 311 /* This is a hack to get the minimal symbol type 312 right for Irix 5, which has absolute addresses 313 with special section indices for dynamic symbols. */ 314 unsigned short shndx = 315 ((elf_symbol_type *) sym)->internal_elf_sym.st_shndx; 316 317 switch (shndx) 318 { 319 case SHN_MIPS_TEXT: 320 ms_type = mst_text; 321 break; 322 case SHN_MIPS_DATA: 323 ms_type = mst_data; 324 break; 325 case SHN_MIPS_ACOMMON: 326 ms_type = mst_bss; 327 break; 328 default: 329 ms_type = mst_abs; 330 } 331 332 /* If it is an Irix dynamic symbol, skip section name 333 symbols, relocate all others by section offset. */ 334 if (ms_type != mst_abs) 335 { 336 if (sym->name[0] == '.') 337 continue; 338 symaddr += offset; 339 } 340 } 341 else if (sym->section->flags & SEC_CODE) 342 { 343 if (sym->flags & (BSF_GLOBAL | BSF_WEAK)) 344 { 345 ms_type = mst_text; 346 } 347 else if ((sym->name[0] == '.' && sym->name[1] == 'L') 348 || ((sym->flags & BSF_LOCAL) 349 && sym->name[0] == '$' 350 && sym->name[1] == 'L')) 351 /* Looks like a compiler-generated label. Skip 352 it. The assembler should be skipping these (to 353 keep executables small), but apparently with 354 gcc on the (deleted) delta m88k SVR4, it loses. 355 So to have us check too should be harmless (but 356 I encourage people to fix this in the assembler 357 instead of adding checks here). */ 358 continue; 359 else 360 { 361 ms_type = mst_file_text; 362 } 363 } 364 else if (sym->section->flags & SEC_ALLOC) 365 { 366 if (sym->flags & (BSF_GLOBAL | BSF_WEAK)) 367 { 368 if (sym->section->flags & SEC_LOAD) 369 { 370 ms_type = mst_data; 371 } 372 else 373 { 374 ms_type = mst_bss; 375 } 376 } 377 else if (sym->flags & BSF_LOCAL) 378 { 379 /* Named Local variable in a Data section. 380 Check its name for stabs-in-elf. */ 381 int special_local_sect; 382 if (strcmp ("Bbss.bss", sym->name) == 0) 383 special_local_sect = SECT_OFF_BSS (objfile); 384 else if (strcmp ("Ddata.data", sym->name) == 0) 385 special_local_sect = SECT_OFF_DATA (objfile); 386 else if (strcmp ("Drodata.rodata", sym->name) == 0) 387 special_local_sect = SECT_OFF_RODATA (objfile); 388 else 389 special_local_sect = -1; 390 if (special_local_sect >= 0) 391 { 392 /* Found a special local symbol. Allocate a 393 sectinfo, if needed, and fill it in. */ 394 if (sectinfo == NULL) 395 { 396 int max_index; 397 size_t size; 398 399 max_index 400 = max (SECT_OFF_BSS (objfile), 401 max (SECT_OFF_DATA (objfile), 402 SECT_OFF_RODATA (objfile))); 403 404 /* max_index is the largest index we'll 405 use into this array, so we must 406 allocate max_index+1 elements for it. 407 However, 'struct stab_section_info' 408 already includes one element, so we 409 need to allocate max_index aadditional 410 elements. */ 411 size = (sizeof (struct stab_section_info) 412 + (sizeof (CORE_ADDR) 413 * max_index)); 414 sectinfo = (struct stab_section_info *) 415 xmalloc (size); 416 memset (sectinfo, 0, size); 417 sectinfo->num_sections = max_index; 418 if (filesym == NULL) 419 { 420 complaint (&symfile_complaints, 421 _("elf/stab section information %s without a preceding file symbol"), 422 sym->name); 423 } 424 else 425 { 426 sectinfo->filename = 427 (char *) filesym->name; 428 } 429 } 430 if (sectinfo->sections[special_local_sect] != 0) 431 complaint (&symfile_complaints, 432 _("duplicated elf/stab section information for %s"), 433 sectinfo->filename); 434 /* BFD symbols are section relative. */ 435 symaddr = sym->value + sym->section->vma; 436 /* Relocate non-absolute symbols by the 437 section offset. */ 438 if (sym->section != &bfd_abs_section) 439 symaddr += offset; 440 sectinfo->sections[special_local_sect] = symaddr; 441 /* The special local symbols don't go in the 442 minimal symbol table, so ignore this one. */ 443 continue; 444 } 445 /* Not a special stabs-in-elf symbol, do regular 446 symbol processing. */ 447 if (sym->section->flags & SEC_LOAD) 448 { 449 ms_type = mst_file_data; 450 } 451 else 452 { 453 ms_type = mst_file_bss; 454 } 455 } 456 else 457 { 458 ms_type = mst_unknown; 459 } 460 } 461 else 462 { 463 /* FIXME: Solaris2 shared libraries include lots of 464 odd "absolute" and "undefined" symbols, that play 465 hob with actions like finding what function the PC 466 is in. Ignore them if they aren't text, data, or bss. */ 467 /* ms_type = mst_unknown; */ 468 continue; /* Skip this symbol. */ 469 } 470 msym = record_minimal_symbol 471 ((char *) sym->name, symaddr, 472 ms_type, sym->section, objfile); 473 if (msym) 474 { 475 /* Pass symbol size field in via BFD. FIXME!!! */ 476 unsigned long size = ((elf_symbol_type *) sym)->internal_elf_sym.st_size; 477 MSYMBOL_SIZE(msym) = size; 478 } 479#ifdef SOFUN_ADDRESS_MAYBE_MISSING 480 if (msym != NULL) 481 msym->filename = filesymname; 482#endif 483 gdbarch_elf_make_msymbol_special (current_gdbarch, sym, msym); 484 } 485 } 486} 487 488/* Scan and build partial symbols for a symbol file. 489 We have been initialized by a call to elf_symfile_init, which 490 currently does nothing. 491 492 SECTION_OFFSETS is a set of offsets to apply to relocate the symbols 493 in each section. We simplify it down to a single offset for all 494 symbols. FIXME. 495 496 MAINLINE is true if we are reading the main symbol 497 table (as opposed to a shared lib or dynamically loaded file). 498 499 This function only does the minimum work necessary for letting the 500 user "name" things symbolically; it does not read the entire symtab. 501 Instead, it reads the external and static symbols and puts them in partial 502 symbol tables. When more extensive information is requested of a 503 file, the corresponding partial symbol table is mutated into a full 504 fledged symbol table by going back and reading the symbols 505 for real. 506 507 We look for sections with specific names, to tell us what debug 508 format to look for: FIXME!!! 509 510 elfstab_build_psymtabs() handles STABS symbols; 511 mdebug_build_psymtabs() handles ECOFF debugging information. 512 513 Note that ELF files have a "minimal" symbol table, which looks a lot 514 like a COFF symbol table, but has only the minimal information necessary 515 for linking. We process this also, and use the information to 516 build gdb's minimal symbol table. This gives us some minimal debugging 517 capability even for files compiled without -g. */ 518 519static void 520elf_symfile_read (struct objfile *objfile, int mainline) 521{ 522 bfd *abfd = objfile->obfd; 523 struct elfinfo ei; 524 struct cleanup *back_to; 525 CORE_ADDR offset; 526 long symcount = 0, dynsymcount = 0, synthcount, storage_needed; 527 asymbol **symbol_table = NULL, **dyn_symbol_table = NULL; 528 asymbol *synthsyms; 529 530 init_minimal_symbol_collection (); 531 back_to = make_cleanup_discard_minimal_symbols (); 532 533 memset ((char *) &ei, 0, sizeof (ei)); 534 535 /* Allocate struct to keep track of the symfile */ 536 objfile->deprecated_sym_stab_info = (struct dbx_symfile_info *) 537 xmalloc (sizeof (struct dbx_symfile_info)); 538 memset ((char *) objfile->deprecated_sym_stab_info, 0, sizeof (struct dbx_symfile_info)); 539 make_cleanup (free_elfinfo, (void *) objfile); 540 541 /* Process the normal ELF symbol table first. This may write some 542 chain of info into the dbx_symfile_info in objfile->deprecated_sym_stab_info, 543 which can later be used by elfstab_offset_sections. */ 544 545 storage_needed = bfd_get_symtab_upper_bound (objfile->obfd); 546 if (storage_needed < 0) 547 error (_("Can't read symbols from %s: %s"), bfd_get_filename (objfile->obfd), 548 bfd_errmsg (bfd_get_error ())); 549 550 if (storage_needed > 0) 551 { 552 symbol_table = (asymbol **) xmalloc (storage_needed); 553 make_cleanup (xfree, symbol_table); 554 symcount = bfd_canonicalize_symtab (objfile->obfd, symbol_table); 555 556 if (symcount < 0) 557 error (_("Can't read symbols from %s: %s"), bfd_get_filename (objfile->obfd), 558 bfd_errmsg (bfd_get_error ())); 559 560 elf_symtab_read (objfile, 0, symcount, symbol_table); 561 } 562 563 /* Add the dynamic symbols. */ 564 565 storage_needed = bfd_get_dynamic_symtab_upper_bound (objfile->obfd); 566 567 if (storage_needed > 0) 568 { 569 dyn_symbol_table = (asymbol **) xmalloc (storage_needed); 570 make_cleanup (xfree, dyn_symbol_table); 571 dynsymcount = bfd_canonicalize_dynamic_symtab (objfile->obfd, 572 dyn_symbol_table); 573 574 if (dynsymcount < 0) 575 error (_("Can't read symbols from %s: %s"), bfd_get_filename (objfile->obfd), 576 bfd_errmsg (bfd_get_error ())); 577 578 elf_symtab_read (objfile, 1, dynsymcount, dyn_symbol_table); 579 } 580 581 /* Add synthetic symbols - for instance, names for any PLT entries. */ 582 583 synthcount = bfd_get_synthetic_symtab (abfd, symcount, symbol_table, 584 dynsymcount, dyn_symbol_table, 585 &synthsyms); 586 if (synthcount > 0) 587 { 588 asymbol **synth_symbol_table; 589 long i; 590 591 make_cleanup (xfree, synthsyms); 592 synth_symbol_table = xmalloc (sizeof (asymbol *) * synthcount); 593 for (i = 0; i < synthcount; i++) 594 synth_symbol_table[i] = synthsyms + i; 595 make_cleanup (xfree, synth_symbol_table); 596 elf_symtab_read (objfile, 0, synthcount, synth_symbol_table); 597 } 598 599 /* Install any minimal symbols that have been collected as the current 600 minimal symbols for this objfile. The debug readers below this point 601 should not generate new minimal symbols; if they do it's their 602 responsibility to install them. "mdebug" appears to be the only one 603 which will do this. */ 604 605 install_minimal_symbols (objfile); 606 do_cleanups (back_to); 607 608 /* Now process debugging information, which is contained in 609 special ELF sections. */ 610 611 /* If we are reinitializing, or if we have never loaded syms yet, 612 set table to empty. MAINLINE is cleared so that *_read_psymtab 613 functions do not all also re-initialize the psymbol table. */ 614 if (mainline) 615 { 616 init_psymbol_list (objfile, 0); 617 mainline = 0; 618 } 619 620 /* We first have to find them... */ 621 bfd_map_over_sections (abfd, elf_locate_sections, (void *) & ei); 622 623 /* ELF debugging information is inserted into the psymtab in the 624 order of least informative first - most informative last. Since 625 the psymtab table is searched `most recent insertion first' this 626 increases the probability that more detailed debug information 627 for a section is found. 628 629 For instance, an object file might contain both .mdebug (XCOFF) 630 and .debug_info (DWARF2) sections then .mdebug is inserted first 631 (searched last) and DWARF2 is inserted last (searched first). If 632 we don't do this then the XCOFF info is found first - for code in 633 an included file XCOFF info is useless. */ 634 635 if (ei.mdebugsect) 636 { 637 const struct ecoff_debug_swap *swap; 638 639 /* .mdebug section, presumably holding ECOFF debugging 640 information. */ 641 swap = get_elf_backend_data (abfd)->elf_backend_ecoff_debug_swap; 642 if (swap) 643 elfmdebug_build_psymtabs (objfile, swap, ei.mdebugsect); 644 } 645 if (ei.stabsect) 646 { 647 asection *str_sect; 648 649 /* Stab sections have an associated string table that looks like 650 a separate section. */ 651 str_sect = bfd_get_section_by_name (abfd, ".stabstr"); 652 653 /* FIXME should probably warn about a stab section without a stabstr. */ 654 if (str_sect) 655 elfstab_build_psymtabs (objfile, 656 mainline, 657 ei.stabsect, 658 str_sect->filepos, 659 bfd_section_size (abfd, str_sect)); 660 } 661 if (dwarf2_has_info (objfile)) 662 { 663 /* DWARF 2 sections */ 664 dwarf2_build_psymtabs (objfile, mainline); 665 } 666 667 /* FIXME: kettenis/20030504: This still needs to be integrated with 668 dwarf2read.c in a better way. */ 669 dwarf2_build_frame_info (objfile); 670} 671 672/* This cleans up the objfile's deprecated_sym_stab_info pointer, and 673 the chain of stab_section_info's, that might be dangling from 674 it. */ 675 676static void 677free_elfinfo (void *objp) 678{ 679 struct objfile *objfile = (struct objfile *) objp; 680 struct dbx_symfile_info *dbxinfo = objfile->deprecated_sym_stab_info; 681 struct stab_section_info *ssi, *nssi; 682 683 ssi = dbxinfo->stab_section_info; 684 while (ssi) 685 { 686 nssi = ssi->next; 687 xfree (ssi); 688 ssi = nssi; 689 } 690 691 dbxinfo->stab_section_info = 0; /* Just say No mo info about this. */ 692} 693 694 695/* Initialize anything that needs initializing when a completely new symbol 696 file is specified (not just adding some symbols from another file, e.g. a 697 shared library). 698 699 We reinitialize buildsym, since we may be reading stabs from an ELF file. */ 700 701static void 702elf_new_init (struct objfile *ignore) 703{ 704 stabsread_new_init (); 705 buildsym_new_init (); 706} 707 708/* Perform any local cleanups required when we are done with a particular 709 objfile. I.E, we are in the process of discarding all symbol information 710 for an objfile, freeing up all memory held for it, and unlinking the 711 objfile struct from the global list of known objfiles. */ 712 713static void 714elf_symfile_finish (struct objfile *objfile) 715{ 716 if (objfile->deprecated_sym_stab_info != NULL) 717 { 718 xfree (objfile->deprecated_sym_stab_info); 719 } 720} 721 722/* ELF specific initialization routine for reading symbols. 723 724 It is passed a pointer to a struct sym_fns which contains, among other 725 things, the BFD for the file whose symbols are being read, and a slot for 726 a pointer to "private data" which we can fill with goodies. 727 728 For now at least, we have nothing in particular to do, so this function is 729 just a stub. */ 730 731static void 732elf_symfile_init (struct objfile *objfile) 733{ 734 /* ELF objects may be reordered, so set OBJF_REORDERED. If we 735 find this causes a significant slowdown in gdb then we could 736 set it in the debug symbol readers only when necessary. */ 737 objfile->flags |= OBJF_REORDERED; 738} 739 740/* When handling an ELF file that contains Sun STABS debug info, 741 some of the debug info is relative to the particular chunk of the 742 section that was generated in its individual .o file. E.g. 743 offsets to static variables are relative to the start of the data 744 segment *for that module before linking*. This information is 745 painfully squirreled away in the ELF symbol table as local symbols 746 with wierd names. Go get 'em when needed. */ 747 748void 749elfstab_offset_sections (struct objfile *objfile, struct partial_symtab *pst) 750{ 751 char *filename = pst->filename; 752 struct dbx_symfile_info *dbx = objfile->deprecated_sym_stab_info; 753 struct stab_section_info *maybe = dbx->stab_section_info; 754 struct stab_section_info *questionable = 0; 755 int i; 756 char *p; 757 758 /* The ELF symbol info doesn't include path names, so strip the path 759 (if any) from the psymtab filename. */ 760 while (0 != (p = strchr (filename, '/'))) 761 filename = p + 1; 762 763 /* FIXME: This linear search could speed up significantly 764 if it was chained in the right order to match how we search it, 765 and if we unchained when we found a match. */ 766 for (; maybe; maybe = maybe->next) 767 { 768 if (filename[0] == maybe->filename[0] 769 && strcmp (filename, maybe->filename) == 0) 770 { 771 /* We found a match. But there might be several source files 772 (from different directories) with the same name. */ 773 if (0 == maybe->found) 774 break; 775 questionable = maybe; /* Might use it later. */ 776 } 777 } 778 779 if (maybe == 0 && questionable != 0) 780 { 781 complaint (&symfile_complaints, 782 _("elf/stab section information questionable for %s"), filename); 783 maybe = questionable; 784 } 785 786 if (maybe) 787 { 788 /* Found it! Allocate a new psymtab struct, and fill it in. */ 789 maybe->found++; 790 pst->section_offsets = (struct section_offsets *) 791 obstack_alloc (&objfile->objfile_obstack, 792 SIZEOF_N_SECTION_OFFSETS (objfile->num_sections)); 793 for (i = 0; i < maybe->num_sections; i++) 794 (pst->section_offsets)->offsets[i] = maybe->sections[i]; 795 return; 796 } 797 798 /* We were unable to find any offsets for this file. Complain. */ 799 if (dbx->stab_section_info) /* If there *is* any info, */ 800 complaint (&symfile_complaints, 801 _("elf/stab section information missing for %s"), filename); 802} 803 804/* Register that we are able to handle ELF object file formats. */ 805 806static struct sym_fns elf_sym_fns = 807{ 808 bfd_target_elf_flavour, 809 elf_new_init, /* sym_new_init: init anything gbl to entire symtab */ 810 elf_symfile_init, /* sym_init: read initial info, setup for sym_read() */ 811 elf_symfile_read, /* sym_read: read a symbol file into symtab */ 812 elf_symfile_finish, /* sym_finish: finished with file, cleanup */ 813 default_symfile_offsets, /* sym_offsets: Translate ext. to int. relocation */ 814 elf_symfile_segments, /* sym_segments: Get segment information from 815 a file. */ 816 NULL /* next: pointer to next struct sym_fns */ 817}; 818 819void 820_initialize_elfread (void) 821{ 822 add_symtab_fns (&elf_sym_fns); 823} 824