| 1 | /* Read ELF (Executable and Linking Format) object files for GDB. |
| 2 | Copyright 1991, 1992 Free Software Foundation, Inc. |
| 3 | Written by Fred Fish at Cygnus Support. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 20 | |
| 21 | /************************************************************************ |
| 22 | * * |
| 23 | * NOTICE * |
| 24 | * * |
| 25 | * This file is still under construction. When it is complete, this * |
| 26 | * notice will be removed. Until then, direct any questions or changes * |
| 27 | * to Fred Fish at Cygnus Support (fnf@cygnus.com) * |
| 28 | * * |
| 29 | * FIXME Still needs support for shared libraries. * |
| 30 | * FIXME Still needs support for core files. * |
| 31 | * FIXME The ".debug" and ".line" section names are hardwired. * |
| 32 | * * |
| 33 | ************************************************************************/ |
| 34 | |
| 35 | #include "defs.h" |
| 36 | #include "elf/common.h" |
| 37 | #include "elf/external.h" |
| 38 | #include "elf/internal.h" |
| 39 | #include "bfd.h" |
| 40 | #include "libbfd.h" /* For bfd_elf_find_section */ |
| 41 | #include "symtab.h" |
| 42 | #include "symfile.h" |
| 43 | #include "objfiles.h" |
| 44 | #include "buildsym.h" |
| 45 | |
| 46 | #include <sys/types.h> /* For off_t for gdb-stabs.h */ |
| 47 | #include "gdb-stabs.h" |
| 48 | |
| 49 | #define STREQ(a,b) (strcmp((a),(b))==0) |
| 50 | |
| 51 | /* The struct elfinfo is available only during ELF symbol table and |
| 52 | psymtab reading. It is destroyed at the complation of psymtab-reading. |
| 53 | It's local to elf_symfile_read. */ |
| 54 | |
| 55 | struct elfinfo { |
| 56 | unsigned int dboffset; /* Offset to dwarf debug section */ |
| 57 | unsigned int dbsize; /* Size of dwarf debug section */ |
| 58 | unsigned int lnoffset; /* Offset to dwarf line number section */ |
| 59 | unsigned int lnsize; /* Size of dwarf line number section */ |
| 60 | asection *stabsect; /* Section pointer for .stab section */ |
| 61 | asection *stabindexsect; /* Section pointer for .stab.index section */ |
| 62 | }; |
| 63 | |
| 64 | /* Various things we might complain about... */ |
| 65 | |
| 66 | struct complaint section_info_complaint = |
| 67 | {"elf/stab section information %s without a preceding file symbol", 0, 0}; |
| 68 | |
| 69 | struct complaint section_info_dup_complaint = |
| 70 | {"duplicated elf/stab section information for %s", 0, 0}; |
| 71 | |
| 72 | struct complaint stab_info_mismatch_complaint = |
| 73 | {"elf/stab section information missing for %s", 0, 0}; |
| 74 | |
| 75 | struct complaint stab_info_questionable_complaint = |
| 76 | {"elf/stab section information questionable for %s", 0, 0}; |
| 77 | |
| 78 | static void |
| 79 | elf_symfile_init PARAMS ((struct objfile *)); |
| 80 | |
| 81 | static void |
| 82 | elf_new_init PARAMS ((struct objfile *)); |
| 83 | |
| 84 | static void |
| 85 | elf_symfile_read PARAMS ((struct objfile *, struct section_offsets *, int)); |
| 86 | |
| 87 | static void |
| 88 | elf_symfile_finish PARAMS ((struct objfile *)); |
| 89 | |
| 90 | static void |
| 91 | elf_symtab_read PARAMS ((bfd *, CORE_ADDR, struct objfile *)); |
| 92 | |
| 93 | static void |
| 94 | free_elfinfo PARAMS ((PTR)); |
| 95 | |
| 96 | static struct section_offsets * |
| 97 | elf_symfile_offsets PARAMS ((struct objfile *, CORE_ADDR)); |
| 98 | |
| 99 | #if 0 |
| 100 | static void |
| 101 | record_minimal_symbol PARAMS ((char *, CORE_ADDR, enum minimal_symbol_type, |
| 102 | struct objfile *)); |
| 103 | #endif |
| 104 | |
| 105 | static void |
| 106 | record_minimal_symbol_and_info PARAMS ((char *, CORE_ADDR, |
| 107 | enum minimal_symbol_type, char *, |
| 108 | struct objfile *)); |
| 109 | |
| 110 | static void |
| 111 | elf_locate_sections PARAMS ((bfd *, asection *, PTR)); |
| 112 | |
| 113 | /* We are called once per section from elf_symfile_read. We |
| 114 | need to examine each section we are passed, check to see |
| 115 | if it is something we are interested in processing, and |
| 116 | if so, stash away some access information for the section. |
| 117 | |
| 118 | For now we recognize the dwarf debug information sections and |
| 119 | line number sections from matching their section names. The |
| 120 | ELF definition is no real help here since it has no direct |
| 121 | knowledge of DWARF (by design, so any debugging format can be |
| 122 | used). |
| 123 | |
| 124 | We also recognize the ".stab" sections used by the Sun compilers |
| 125 | released with Solaris 2. |
| 126 | |
| 127 | FIXME: The section names should not be hardwired strings. */ |
| 128 | |
| 129 | static void |
| 130 | elf_locate_sections (ignore_abfd, sectp, eip) |
| 131 | bfd *ignore_abfd; |
| 132 | asection *sectp; |
| 133 | PTR eip; |
| 134 | { |
| 135 | register struct elfinfo *ei; |
| 136 | |
| 137 | ei = (struct elfinfo *) eip; |
| 138 | if (STREQ (sectp -> name, ".debug")) |
| 139 | { |
| 140 | ei -> dboffset = sectp -> filepos; |
| 141 | ei -> dbsize = bfd_get_section_size_before_reloc (sectp); |
| 142 | } |
| 143 | else if (STREQ (sectp -> name, ".line")) |
| 144 | { |
| 145 | ei -> lnoffset = sectp -> filepos; |
| 146 | ei -> lnsize = bfd_get_section_size_before_reloc (sectp); |
| 147 | } |
| 148 | else if (STREQ (sectp -> name, ".stab")) |
| 149 | { |
| 150 | ei -> stabsect = sectp; |
| 151 | } |
| 152 | else if (STREQ (sectp -> name, ".stab.index")) |
| 153 | { |
| 154 | ei -> stabindexsect = sectp; |
| 155 | } |
| 156 | } |
| 157 | |
| 158 | #if 0 /* Currently unused */ |
| 159 | |
| 160 | char * |
| 161 | elf_interpreter (abfd) |
| 162 | bfd *abfd; |
| 163 | { |
| 164 | sec_ptr interp_sec; |
| 165 | unsigned size; |
| 166 | char *interp = NULL; |
| 167 | |
| 168 | interp_sec = bfd_get_section_by_name (abfd, ".interp"); |
| 169 | if (interp_sec) |
| 170 | { |
| 171 | size = bfd_section_size (abfd, interp_sec); |
| 172 | interp = alloca (size); |
| 173 | if (bfd_get_section_contents (abfd, interp_sec, interp, (file_ptr)0, |
| 174 | size)) |
| 175 | { |
| 176 | interp = savestring (interp, size - 1); |
| 177 | } |
| 178 | else |
| 179 | { |
| 180 | interp = NULL; |
| 181 | } |
| 182 | } |
| 183 | return (interp); |
| 184 | } |
| 185 | |
| 186 | #endif |
| 187 | |
| 188 | /* |
| 189 | |
| 190 | LOCAL FUNCTION |
| 191 | |
| 192 | record_minimal_symbol -- add entry to minimal symbol table |
| 193 | |
| 194 | SYNOPSIS |
| 195 | |
| 196 | static void record_minimal_symbol (char *name, CORE_ADDR address) |
| 197 | |
| 198 | DESCRIPTION |
| 199 | |
| 200 | Given a pointer to the name of a symbol that should be added to the |
| 201 | minimal symbol table and the address associated with that symbol, records |
| 202 | this information for later use in building the minimal symbol table. |
| 203 | |
| 204 | */ |
| 205 | |
| 206 | #if 0 /* FIXME: Unused */ |
| 207 | |
| 208 | static void |
| 209 | record_minimal_symbol (name, address, ms_type, objfile) |
| 210 | char *name; |
| 211 | CORE_ADDR address; |
| 212 | enum minimal_symbol_type ms_type; |
| 213 | struct objfile *objfile; |
| 214 | { |
| 215 | name = obsavestring (name, strlen (name), &objfile -> symbol_obstack); |
| 216 | prim_record_minimal_symbol (name, address, ms_type); |
| 217 | } |
| 218 | |
| 219 | #endif |
| 220 | |
| 221 | static void |
| 222 | record_minimal_symbol_and_info (name, address, ms_type, info, objfile) |
| 223 | char *name; |
| 224 | CORE_ADDR address; |
| 225 | enum minimal_symbol_type ms_type; |
| 226 | char *info; /* FIXME, is this really char *? */ |
| 227 | struct objfile *objfile; |
| 228 | { |
| 229 | name = obsavestring (name, strlen (name), &objfile -> symbol_obstack); |
| 230 | prim_record_minimal_symbol_and_info (name, address, ms_type, info); |
| 231 | } |
| 232 | |
| 233 | /* |
| 234 | |
| 235 | LOCAL FUNCTION |
| 236 | |
| 237 | elf_symtab_read -- read the symbol table of an ELF file |
| 238 | |
| 239 | SYNOPSIS |
| 240 | |
| 241 | void elf_symtab_read (bfd *abfd, CORE_ADDR addr, |
| 242 | struct objfile *objfile) |
| 243 | |
| 244 | DESCRIPTION |
| 245 | |
| 246 | Given an open bfd, a base address to relocate symbols to, and a |
| 247 | flag that specifies whether or not this bfd is for an executable |
| 248 | or not (may be shared library for example), add all the global |
| 249 | function and data symbols to the minimal symbol table. |
| 250 | |
| 251 | In stabs-in-ELF, as implemented by Sun, there are some local symbols |
| 252 | defined in the ELF symbol table, which can be used to locate |
| 253 | the beginnings of sections from each ".o" file that was linked to |
| 254 | form the executable objfile. We gather any such info and record it |
| 255 | in data structures hung off the objfile's private data. |
| 256 | |
| 257 | */ |
| 258 | |
| 259 | static void |
| 260 | elf_symtab_read (abfd, addr, objfile) |
| 261 | bfd *abfd; |
| 262 | CORE_ADDR addr; |
| 263 | struct objfile *objfile; |
| 264 | { |
| 265 | unsigned int storage_needed; |
| 266 | asymbol *sym; |
| 267 | asymbol **symbol_table; |
| 268 | unsigned int number_of_symbols; |
| 269 | unsigned int i; |
| 270 | int index; |
| 271 | struct cleanup *back_to; |
| 272 | CORE_ADDR symaddr; |
| 273 | enum minimal_symbol_type ms_type; |
| 274 | /* If sectinfo is nonzero, it contains section info that should end up |
| 275 | filed in the objfile. */ |
| 276 | struct stab_section_info *sectinfo = 0; |
| 277 | /* If filesym is nonzero, it points to a file symbol, but we haven't |
| 278 | seen any section info for it yet. */ |
| 279 | asymbol *filesym = 0; |
| 280 | struct dbx_symfile_info *dbx = (struct dbx_symfile_info *) |
| 281 | objfile->sym_private; |
| 282 | |
| 283 | storage_needed = get_symtab_upper_bound (abfd); |
| 284 | |
| 285 | if (storage_needed > 0) |
| 286 | { |
| 287 | symbol_table = (asymbol **) xmalloc (storage_needed); |
| 288 | back_to = make_cleanup (free, symbol_table); |
| 289 | number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table); |
| 290 | |
| 291 | for (i = 0; i < number_of_symbols; i++) |
| 292 | { |
| 293 | sym = symbol_table[i]; |
| 294 | /* Select global/weak symbols that are defined in a specific section. |
| 295 | Note that bfd now puts abs symbols in their own section, so |
| 296 | all symbols we are interested in will have a section. */ |
| 297 | if ((sym -> flags & (BSF_GLOBAL | BSF_WEAK)) |
| 298 | && (sym -> section != NULL)) |
| 299 | { |
| 300 | symaddr = sym -> value; |
| 301 | /* Relocate all non-absolute symbols by base address. */ |
| 302 | if (sym -> section != &bfd_abs_section) |
| 303 | symaddr += addr; |
| 304 | |
| 305 | /* For non-absolute symbols, use the type of the section |
| 306 | they are relative to, to intuit text/data. Bfd provides |
| 307 | no way of figuring this out for absolute symbols. */ |
| 308 | if (sym -> section -> flags & SEC_CODE) |
| 309 | { |
| 310 | ms_type = mst_text; |
| 311 | } |
| 312 | else if (sym -> section -> flags & SEC_DATA) |
| 313 | { |
| 314 | ms_type = mst_data; |
| 315 | } |
| 316 | else |
| 317 | { |
| 318 | /* FIXME: Solaris2 shared libraries include lots of |
| 319 | odd "absolute" and "undefined" symbols, that play |
| 320 | hob with actions like finding what function the PC |
| 321 | is in. Ignore them if they aren't text or data. */ |
| 322 | /* ms_type = mst_unknown; */ |
| 323 | continue; /* Skip this symbol. */ |
| 324 | } |
| 325 | /* Pass symbol size field in via BFD. FIXME!!! */ |
| 326 | record_minimal_symbol_and_info ((char *) sym -> name, |
| 327 | symaddr, ms_type, sym->udata, objfile); |
| 328 | } |
| 329 | |
| 330 | /* See if this is a debugging symbol that helps Solaris |
| 331 | stabs-in-elf debugging. */ |
| 332 | |
| 333 | else if (sym->flags & BSF_FILE) |
| 334 | { |
| 335 | /* Chain any old one onto the objfile; remember new sym. */ |
| 336 | if (sectinfo) |
| 337 | { |
| 338 | sectinfo->next = dbx->stab_section_info; |
| 339 | dbx->stab_section_info = sectinfo; |
| 340 | sectinfo = 0; |
| 341 | } |
| 342 | filesym = sym; |
| 343 | } |
| 344 | else if ((sym->flags & BSF_LOCAL) && |
| 345 | (sym->section) && |
| 346 | (sym->section->flags & SEC_DATA) && |
| 347 | (sym->name)) |
| 348 | { |
| 349 | /* Named Local variable in a Data section. Check its name. */ |
| 350 | index = -1; |
| 351 | switch (sym->name[1]) |
| 352 | { |
| 353 | case 'b': |
| 354 | if (!strcmp ("Bbss.bss", sym->name)) |
| 355 | index = SECT_OFF_BSS; |
| 356 | break; |
| 357 | case 'd': |
| 358 | if (!strcmp ("Ddata.data", sym->name)) |
| 359 | index = SECT_OFF_DATA; |
| 360 | break; |
| 361 | case 'r': |
| 362 | if (!strcmp ("Drodata.rodata", sym->name)) |
| 363 | index = SECT_OFF_RODATA; |
| 364 | break; |
| 365 | } |
| 366 | if (index > 0) |
| 367 | { |
| 368 | /* We have some new info. Allocate a sectinfo, if |
| 369 | needed, and fill it in. */ |
| 370 | if (!sectinfo) |
| 371 | { |
| 372 | sectinfo = (struct stab_section_info *) |
| 373 | xmmalloc (objfile -> md, |
| 374 | sizeof (*sectinfo)); |
| 375 | memset ((PTR) sectinfo, 0, sizeof (*sectinfo)); |
| 376 | if (!filesym) |
| 377 | complain (§ion_info_complaint, (char *)sym->name); |
| 378 | else |
| 379 | sectinfo->filename = (char *)filesym->name; |
| 380 | } |
| 381 | if (sectinfo->sections[index]) |
| 382 | complain (§ion_info_dup_complaint, |
| 383 | (char *)sectinfo->filename); |
| 384 | |
| 385 | symaddr = sym -> value; |
| 386 | /* Relocate all non-absolute symbols by base address. */ |
| 387 | if (sym -> section != &bfd_abs_section) |
| 388 | symaddr += addr; |
| 389 | sectinfo->sections[index] = symaddr; |
| 390 | } |
| 391 | } |
| 392 | } |
| 393 | do_cleanups (back_to); |
| 394 | } |
| 395 | } |
| 396 | |
| 397 | /* Scan and build partial symbols for a symbol file. |
| 398 | We have been initialized by a call to elf_symfile_init, which |
| 399 | currently does nothing. |
| 400 | |
| 401 | SECTION_OFFSETS is a set of offsets to apply to relocate the symbols |
| 402 | in each section. We simplify it down to a single offset for all |
| 403 | symbols. FIXME. |
| 404 | |
| 405 | MAINLINE is true if we are reading the main symbol |
| 406 | table (as opposed to a shared lib or dynamically loaded file). |
| 407 | |
| 408 | This function only does the minimum work necessary for letting the |
| 409 | user "name" things symbolically; it does not read the entire symtab. |
| 410 | Instead, it reads the external and static symbols and puts them in partial |
| 411 | symbol tables. When more extensive information is requested of a |
| 412 | file, the corresponding partial symbol table is mutated into a full |
| 413 | fledged symbol table by going back and reading the symbols |
| 414 | for real. |
| 415 | |
| 416 | We look for sections with specific names, to tell us what debug |
| 417 | format to look for: FIXME!!! |
| 418 | |
| 419 | dwarf_build_psymtabs() builds psymtabs for DWARF symbols; |
| 420 | elfstab_build_psymtabs() handles STABS symbols. |
| 421 | |
| 422 | Note that ELF files have a "minimal" symbol table, which looks a lot |
| 423 | like a COFF symbol table, but has only the minimal information necessary |
| 424 | for linking. We process this also, and use the information to |
| 425 | build gdb's minimal symbol table. This gives us some minimal debugging |
| 426 | capability even for files compiled without -g. */ |
| 427 | |
| 428 | static void |
| 429 | elf_symfile_read (objfile, section_offsets, mainline) |
| 430 | struct objfile *objfile; |
| 431 | struct section_offsets *section_offsets; |
| 432 | int mainline; |
| 433 | { |
| 434 | bfd *abfd = objfile->obfd; |
| 435 | struct elfinfo ei; |
| 436 | struct dbx_symfile_info *dbx; |
| 437 | struct cleanup *back_to; |
| 438 | asection *text_sect; |
| 439 | CORE_ADDR offset; |
| 440 | |
| 441 | init_minimal_symbol_collection (); |
| 442 | back_to = make_cleanup (discard_minimal_symbols, 0); |
| 443 | |
| 444 | memset ((char *) &ei, 0, sizeof (ei)); |
| 445 | |
| 446 | /* Allocate struct to keep track of the symfile */ |
| 447 | objfile->sym_private = (PTR) |
| 448 | xmmalloc (objfile -> md, sizeof (struct dbx_symfile_info)); |
| 449 | memset ((char *) objfile->sym_private, 0, sizeof (struct dbx_symfile_info)); |
| 450 | make_cleanup (free_elfinfo, (PTR) objfile); |
| 451 | |
| 452 | /* Process the normal ELF symbol table first. This may write some |
| 453 | chain of info into the dbx_symfile_info in objfile->sym_private, |
| 454 | which can later be used by elfstab_offset_sections. */ |
| 455 | |
| 456 | /* FIXME, should take a section_offsets param, not just an offset. */ |
| 457 | offset = ANOFFSET (section_offsets, 0); |
| 458 | elf_symtab_read (abfd, offset, objfile); |
| 459 | |
| 460 | /* Now process debugging information, which is contained in |
| 461 | special ELF sections. We first have to find them... */ |
| 462 | |
| 463 | bfd_map_over_sections (abfd, elf_locate_sections, (PTR) &ei); |
| 464 | if (ei.dboffset && ei.lnoffset) |
| 465 | { |
| 466 | /* DWARF sections */ |
| 467 | dwarf_build_psymtabs (fileno ((FILE *)(abfd -> iostream)), |
| 468 | bfd_get_filename (abfd), |
| 469 | section_offsets, mainline, |
| 470 | ei.dboffset, ei.dbsize, |
| 471 | ei.lnoffset, ei.lnsize, objfile); |
| 472 | } |
| 473 | if (ei.stabsect) |
| 474 | { |
| 475 | /* STABS sections */ |
| 476 | |
| 477 | /* FIXME: Sun didn't really know how to implement this well. |
| 478 | They made .stab sections that don't point to the .stabstr |
| 479 | section with the sh_link field. BFD doesn't make string table |
| 480 | sections visible to the caller. So we have to search the |
| 481 | ELF section table, not the BFD section table, for the string |
| 482 | table. */ |
| 483 | struct elf_internal_shdr *elf_sect; |
| 484 | |
| 485 | elf_sect = bfd_elf_find_section (abfd, ".stabstr"); |
| 486 | if (elf_sect) |
| 487 | elfstab_build_psymtabs (objfile, |
| 488 | section_offsets, |
| 489 | mainline, |
| 490 | ei.stabsect->filepos, /* .stab offset */ |
| 491 | bfd_get_section_size_before_reloc (ei.stabsect),/* .stab size */ |
| 492 | elf_sect->sh_offset, /* .stabstr offset */ |
| 493 | elf_sect->sh_size); /* .stabstr size */ |
| 494 | } |
| 495 | |
| 496 | if (!have_partial_symbols ()) |
| 497 | { |
| 498 | wrap_here (""); |
| 499 | printf_filtered ("(no debugging symbols found)..."); |
| 500 | wrap_here (""); |
| 501 | } |
| 502 | |
| 503 | /* Install any minimal symbols that have been collected as the current |
| 504 | minimal symbols for this objfile. */ |
| 505 | |
| 506 | install_minimal_symbols (objfile); |
| 507 | |
| 508 | do_cleanups (back_to); |
| 509 | } |
| 510 | |
| 511 | /* This cleans up the objfile's sym_private pointer, and the chain of |
| 512 | stab_section_info's, that might be dangling from it. */ |
| 513 | |
| 514 | static void |
| 515 | free_elfinfo (objp) |
| 516 | PTR objp; |
| 517 | { |
| 518 | struct objfile *objfile = (struct objfile *)objp; |
| 519 | struct dbx_symfile_info *dbxinfo = (struct dbx_symfile_info *) |
| 520 | objfile->sym_private; |
| 521 | struct stab_section_info *ssi, *nssi; |
| 522 | |
| 523 | ssi = dbxinfo->stab_section_info; |
| 524 | while (ssi) |
| 525 | { |
| 526 | nssi = ssi->next; |
| 527 | mfree (objfile->md, ssi); |
| 528 | ssi = nssi; |
| 529 | } |
| 530 | |
| 531 | dbxinfo->stab_section_info = 0; /* Just say No mo info about this. */ |
| 532 | } |
| 533 | |
| 534 | |
| 535 | /* Initialize anything that needs initializing when a completely new symbol |
| 536 | file is specified (not just adding some symbols from another file, e.g. a |
| 537 | shared library). |
| 538 | |
| 539 | We reinitialize buildsym, since we may be reading stabs from an ELF file. */ |
| 540 | |
| 541 | static void |
| 542 | elf_new_init (ignore) |
| 543 | struct objfile *ignore; |
| 544 | { |
| 545 | stabsread_new_init (); |
| 546 | buildsym_new_init (); |
| 547 | } |
| 548 | |
| 549 | /* Perform any local cleanups required when we are done with a particular |
| 550 | objfile. I.E, we are in the process of discarding all symbol information |
| 551 | for an objfile, freeing up all memory held for it, and unlinking the |
| 552 | objfile struct from the global list of known objfiles. */ |
| 553 | |
| 554 | static void |
| 555 | elf_symfile_finish (objfile) |
| 556 | struct objfile *objfile; |
| 557 | { |
| 558 | if (objfile -> sym_private != NULL) |
| 559 | { |
| 560 | mfree (objfile -> md, objfile -> sym_private); |
| 561 | } |
| 562 | } |
| 563 | |
| 564 | /* ELF specific initialization routine for reading symbols. |
| 565 | |
| 566 | It is passed a pointer to a struct sym_fns which contains, among other |
| 567 | things, the BFD for the file whose symbols are being read, and a slot for |
| 568 | a pointer to "private data" which we can fill with goodies. |
| 569 | |
| 570 | For now at least, we have nothing in particular to do, so this function is |
| 571 | just a stub. */ |
| 572 | |
| 573 | static void |
| 574 | elf_symfile_init (ignore) |
| 575 | struct objfile *ignore; |
| 576 | { |
| 577 | } |
| 578 | |
| 579 | /* ELF specific parsing routine for section offsets. |
| 580 | |
| 581 | Plain and simple for now. */ |
| 582 | |
| 583 | static |
| 584 | struct section_offsets * |
| 585 | elf_symfile_offsets (objfile, addr) |
| 586 | struct objfile *objfile; |
| 587 | CORE_ADDR addr; |
| 588 | { |
| 589 | struct section_offsets *section_offsets; |
| 590 | int i; |
| 591 | |
| 592 | section_offsets = (struct section_offsets *) |
| 593 | obstack_alloc (&objfile -> psymbol_obstack, |
| 594 | sizeof (struct section_offsets) + |
| 595 | sizeof (section_offsets->offsets) * (SECT_OFF_MAX-1)); |
| 596 | |
| 597 | for (i = 0; i < SECT_OFF_MAX; i++) |
| 598 | ANOFFSET (section_offsets, i) = addr; |
| 599 | |
| 600 | return section_offsets; |
| 601 | } |
| 602 | \f |
| 603 | /* When handling an ELF file that contains Sun STABS debug info, |
| 604 | some of the debug info is relative to the particular chunk of the |
| 605 | section that was generated in its individual .o file. E.g. |
| 606 | offsets to static variables are relative to the start of the data |
| 607 | segment *for that module before linking*. This information is |
| 608 | painfully squirreled away in the ELF symbol table as local symbols |
| 609 | with wierd names. Go get 'em when needed. */ |
| 610 | |
| 611 | void |
| 612 | elfstab_offset_sections (objfile, pst) |
| 613 | struct objfile *objfile; |
| 614 | struct partial_symtab *pst; |
| 615 | { |
| 616 | char *filename = pst->filename; |
| 617 | struct dbx_symfile_info *dbx = (struct dbx_symfile_info *) |
| 618 | objfile->sym_private; |
| 619 | struct stab_section_info *maybe = dbx->stab_section_info; |
| 620 | struct stab_section_info *questionable = 0; |
| 621 | int i; |
| 622 | char *p; |
| 623 | |
| 624 | /* The ELF symbol info doesn't include path names, so strip the path |
| 625 | (if any) from the psymtab filename. */ |
| 626 | while (0 != (p = strchr (filename, '/'))) |
| 627 | filename = p+1; |
| 628 | |
| 629 | /* FIXME: This linear search could speed up significantly |
| 630 | if it was chained in the right order to match how we search it, |
| 631 | and if we unchained when we found a match. */ |
| 632 | for (; maybe; maybe = maybe->next) |
| 633 | { |
| 634 | if (filename[0] == maybe->filename[0] |
| 635 | && !strcmp (filename, maybe->filename)) |
| 636 | { |
| 637 | /* We found a match. But there might be several source files |
| 638 | (from different directories) with the same name. */ |
| 639 | if (0 == maybe->found) |
| 640 | break; |
| 641 | questionable = maybe; /* Might use it later. */ |
| 642 | } |
| 643 | } |
| 644 | |
| 645 | if (maybe == 0 && questionable != 0) |
| 646 | { |
| 647 | complain (&stab_info_questionable_complaint, filename); |
| 648 | maybe = questionable; |
| 649 | } |
| 650 | |
| 651 | if (maybe) |
| 652 | { |
| 653 | /* Found it! Allocate a new psymtab struct, and fill it in. */ |
| 654 | maybe->found++; |
| 655 | pst->section_offsets = (struct section_offsets *) |
| 656 | obstack_alloc (&objfile -> psymbol_obstack, |
| 657 | sizeof (struct section_offsets) + |
| 658 | sizeof (pst->section_offsets->offsets) * (SECT_OFF_MAX-1)); |
| 659 | |
| 660 | for (i = 0; i < SECT_OFF_MAX; i++) |
| 661 | ANOFFSET (pst->section_offsets, i) = maybe->sections[i]; |
| 662 | return; |
| 663 | } |
| 664 | |
| 665 | /* We were unable to find any offsets for this file. Complain. */ |
| 666 | if (dbx->stab_section_info) /* If there *is* any info, */ |
| 667 | complain (&stab_info_mismatch_complaint, filename); |
| 668 | } |
| 669 | \f |
| 670 | /* Register that we are able to handle ELF object file formats and DWARF |
| 671 | debugging formats. |
| 672 | |
| 673 | Unlike other object file formats, where the debugging information format |
| 674 | is implied by the object file format, the ELF object file format and the |
| 675 | DWARF debugging information format are two distinct, and potentially |
| 676 | separate entities. I.E. it is perfectly possible to have ELF objects |
| 677 | with debugging formats other than DWARF. And it is conceivable that the |
| 678 | DWARF debugging format might be used with another object file format, |
| 679 | like COFF, by simply using COFF's custom section feature. |
| 680 | |
| 681 | GDB, and to a lesser extent BFD, should support the notion of separate |
| 682 | object file formats and debugging information formats. For now, we just |
| 683 | use "elf" in the same sense as "a.out" or "coff", to imply both the ELF |
| 684 | object file format and the DWARF debugging format. */ |
| 685 | |
| 686 | static struct sym_fns elf_sym_fns = |
| 687 | { |
| 688 | "elf", /* sym_name: name or name prefix of BFD target type */ |
| 689 | 3, /* sym_namelen: number of significant sym_name chars */ |
| 690 | elf_new_init, /* sym_new_init: init anything gbl to entire symtab */ |
| 691 | elf_symfile_init, /* sym_init: read initial info, setup for sym_read() */ |
| 692 | elf_symfile_read, /* sym_read: read a symbol file into symtab */ |
| 693 | elf_symfile_finish, /* sym_finish: finished with file, cleanup */ |
| 694 | elf_symfile_offsets, /* sym_offsets: Translate ext. to int. relocation */ |
| 695 | NULL /* next: pointer to next struct sym_fns */ |
| 696 | }; |
| 697 | |
| 698 | void |
| 699 | _initialize_elfread () |
| 700 | { |
| 701 | add_symtab_fns (&elf_sym_fns); |
| 702 | } |