contrib/elftoolchain/libdwarf/libdwarf_attr.c

   1 /*-
   2  * Copyright (c) 2007 John Birrell (jb@freebsd.org)
   3  * Copyright (c) 2009-2011 Kai Wang
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  */
  27
  28 #include "_libdwarf.h"
  29
  30 ELFTC_VCSID("$Id: libdwarf_attr.c 3064 2014-06-06 19:35:55Z kaiwang27 $");
  31
  32 int
  33 _dwarf_attr_alloc(Dwarf_Die die, Dwarf_Attribute *atp, Dwarf_Error *error)
  34 {
  35         Dwarf_Attribute at;
  36
  37         assert(die != NULL);
  38         assert(atp != NULL);
  39
  40         if ((at = calloc(1, sizeof(struct _Dwarf_Attribute))) == NULL) {
  41                 DWARF_SET_ERROR(die->die_dbg, error, DW_DLE_MEMORY);
  42                 return (DW_DLE_MEMORY);
  43         }
  44
  45         *atp = at;
  46
  47         return (DW_DLE_NONE);
  48 }
  49
  50 static int
  51 _dwarf_attr_add(Dwarf_Die die, Dwarf_Attribute atref, Dwarf_Attribute *atp,
  52     Dwarf_Error *error)
  53 {
  54         Dwarf_Attribute at;
  55         int ret;
  56
  57         if ((ret = _dwarf_attr_alloc(die, &at, error)) != DW_DLE_NONE)
  58                 return (ret);
  59
  60         memcpy(at, atref, sizeof(struct _Dwarf_Attribute));
  61
  62         STAILQ_INSERT_TAIL(&die->die_attr, at, at_next);
  63
  64         /* Save a pointer to the attribute name if this is one. */
  65         if (at->at_attrib == DW_AT_name) {
  66                 switch (at->at_form) {
  67                 case DW_FORM_strp:
  68                         die->die_name = at->u[1].s;
  69                         break;
  70                 case DW_FORM_string:
  71                         die->die_name = at->u[0].s;
  72                         break;
  73                 default:
  74                         break;
  75                 }
  76         }
  77
  78         if (atp != NULL)
  79                 *atp = at;
  80
  81         return (DW_DLE_NONE);
  82 }
  83
  84 Dwarf_Attribute
  85 _dwarf_attr_find(Dwarf_Die die, Dwarf_Half attr)
  86 {
  87         Dwarf_Attribute at;
  88
  89         STAILQ_FOREACH(at, &die->die_attr, at_next) {
  90                 if (at->at_attrib == attr)
  91                         break;
  92         }
  93
  94         return (at);
  95 }
  96
  97 int
  98 _dwarf_attr_init(Dwarf_Debug dbg, Dwarf_Section *ds, uint64_t *offsetp,
  99     int dwarf_size, Dwarf_CU cu, Dwarf_Die die, Dwarf_AttrDef ad,
 100     uint64_t form, int indirect, Dwarf_Error *error)
 101 {
 102         struct _Dwarf_Attribute atref;
 103         Dwarf_Section *str;
 104         int ret;
 105
 106         ret = DW_DLE_NONE;
 107         memset(&atref, 0, sizeof(atref));
 108         atref.at_die = die;
 109         atref.at_offset = *offsetp;
 110         atref.at_attrib = ad->ad_attrib;
 111         atref.at_form = indirect ? form : ad->ad_form;
 112         atref.at_indirect = indirect;
 113         atref.at_ld = NULL;
 114
 115         switch (form) {
 116         case DW_FORM_addr:
 117                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp,
 118                     cu->cu_pointer_size);
 119                 break;
 120         case DW_FORM_block:
 121         case DW_FORM_exprloc:
 122                 atref.u[0].u64 = _dwarf_read_uleb128(ds->ds_data, offsetp);
 123                 atref.u[1].u8p = _dwarf_read_block(ds->ds_data, offsetp,
 124                     atref.u[0].u64);
 125                 break;
 126         case DW_FORM_block1:
 127                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 1);
 128                 atref.u[1].u8p = _dwarf_read_block(ds->ds_data, offsetp,
 129                     atref.u[0].u64);
 130                 break;
 131         case DW_FORM_block2:
 132                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 2);
 133                 atref.u[1].u8p = _dwarf_read_block(ds->ds_data, offsetp,
 134                     atref.u[0].u64);
 135                 break;
 136         case DW_FORM_block4:
 137                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 4);
 138                 atref.u[1].u8p = _dwarf_read_block(ds->ds_data, offsetp,
 139                     atref.u[0].u64);
 140                 break;
 141         case DW_FORM_data1:
 142         case DW_FORM_flag:
 143         case DW_FORM_ref1:
 144                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 1);
 145                 break;
 146         case DW_FORM_data2:
 147         case DW_FORM_ref2:
 148                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 2);
 149                 break;
 150         case DW_FORM_data4:
 151         case DW_FORM_ref4:
 152                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 4);
 153                 break;
 154         case DW_FORM_data8:
 155         case DW_FORM_ref8:
 156                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 8);
 157                 break;
 158         case DW_FORM_indirect:
 159                 form = _dwarf_read_uleb128(ds->ds_data, offsetp);
 160                 return (_dwarf_attr_init(dbg, ds, offsetp, dwarf_size, cu, die,
 161                     ad, form, 1, error));
 162         case DW_FORM_ref_addr:
 163                 if (cu->cu_version == 2)
 164                         atref.u[0].u64 = dbg->read(ds->ds_data, offsetp,
 165                             cu->cu_pointer_size);
 166                 else
 167                         atref.u[0].u64 = dbg->read(ds->ds_data, offsetp,
 168                             dwarf_size);
 169                 break;
 170         case DW_FORM_ref_udata:
 171         case DW_FORM_udata:
 172                 atref.u[0].u64 = _dwarf_read_uleb128(ds->ds_data, offsetp);
 173                 break;
 174         case DW_FORM_sdata:
 175                 atref.u[0].s64 = _dwarf_read_sleb128(ds->ds_data, offsetp);
 176                 break;
 177         case DW_FORM_sec_offset:
 178                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, dwarf_size);
 179                 break;
 180         case DW_FORM_string:
 181                 atref.u[0].s = _dwarf_read_string(ds->ds_data, ds->ds_size,
 182                     offsetp);
 183                 break;
 184         case DW_FORM_strp:
 185                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, dwarf_size);
 186                 str = _dwarf_find_section(dbg, ".debug_str");
 187                 assert(str != NULL);
 188                 atref.u[1].s = (char *) str->ds_data + atref.u[0].u64;
 189                 break;
 190         case DW_FORM_ref_sig8:
 191                 atref.u[0].u64 = 8;
 192                 atref.u[1].u8p = _dwarf_read_block(ds->ds_data, offsetp,
 193                     atref.u[0].u64);
 194                 break;
 195         case DW_FORM_flag_present:
 196                 /* This form has no value encoded in the DIE. */
 197                 atref.u[0].u64 = 1;
 198                 break;
 199         default:
 200                 DWARF_SET_ERROR(dbg, error, DW_DLE_ATTR_FORM_BAD);
 201                 ret = DW_DLE_ATTR_FORM_BAD;
 202                 break;
 203         }
 204
 205         if (ret == DW_DLE_NONE) {
 206                 if (form == DW_FORM_block || form == DW_FORM_block1 ||
 207                     form == DW_FORM_block2 || form == DW_FORM_block4) {
 208                         atref.at_block.bl_len = atref.u[0].u64;
 209                         atref.at_block.bl_data = atref.u[1].u8p;
 210                 }
 211                 ret = _dwarf_attr_add(die, &atref, NULL, error);
 212         }
 213
 214         return (ret);
 215 }
 216
 217 static int
 218 _dwarf_attr_write(Dwarf_P_Debug dbg, Dwarf_P_Section ds, Dwarf_Rel_Section drs,
 219     Dwarf_CU cu, Dwarf_Attribute at, int pass2, Dwarf_Error *error)
 220 {
 221         struct _Dwarf_P_Expr_Entry *ee;
 222         uint64_t value, offset, bs;
 223         int ret;
 224
 225         assert(dbg != NULL && ds != NULL && cu != NULL && at != NULL);
 226
 227         /* Fill in reference to other DIE in the second pass. */
 228         if (pass2) {
 229                 if (at->at_form != DW_FORM_ref4 && at->at_form != DW_FORM_ref8)
 230                         return (DW_DLE_NONE);
 231                 if (at->at_refdie == NULL || at->at_offset == 0)
 232                         return (DW_DLE_NONE);
 233                 offset = at->at_offset;
 234                 dbg->write(ds->ds_data, &offset, at->at_refdie->die_offset,
 235                     at->at_form == DW_FORM_ref4 ? 4 : 8);
 236                 return (DW_DLE_NONE);
 237         }
 238
 239         switch (at->at_form) {
 240         case DW_FORM_addr:
 241                 if (at->at_relsym)
 242                         ret = _dwarf_reloc_entry_add(dbg, drs, ds,
 243                             dwarf_drt_data_reloc, cu->cu_pointer_size,
 244                             ds->ds_size, at->at_relsym, at->u[0].u64, NULL,
 245                             error);
 246                 else
 247                         ret = WRITE_VALUE(at->u[0].u64, cu->cu_pointer_size);
 248                 break;
 249         case DW_FORM_block:
 250         case DW_FORM_block1:
 251         case DW_FORM_block2:
 252         case DW_FORM_block4:
 253                 /* Write block size. */
 254                 if (at->at_form == DW_FORM_block) {
 255                         ret = _dwarf_write_uleb128_alloc(&ds->ds_data,
 256                             &ds->ds_cap, &ds->ds_size, at->u[0].u64, error);
 257                         if (ret != DW_DLE_NONE)
 258                                 break;
 259                 } else {
 260                         if (at->at_form == DW_FORM_block1)
 261                                 bs = 1;
 262                         else if (at->at_form == DW_FORM_block2)
 263                                 bs = 2;
 264                         else
 265                                 bs = 4;
 266                         ret = WRITE_VALUE(at->u[0].u64, bs);
 267                         if (ret != DW_DLE_NONE)
 268                                 break;
 269                 }
 270
 271                 /* Keep block data offset for later use. */
 272                 offset = ds->ds_size;
 273
 274                 /* Write block data. */
 275                 ret = WRITE_BLOCK(at->u[1].u8p, at->u[0].u64);
 276                 if (ret != DW_DLE_NONE)
 277                         break;
 278                 if (at->at_expr == NULL)
 279                         break;
 280
 281                 /* Generate relocation entry for DW_OP_addr expressions. */
 282                 STAILQ_FOREACH(ee, &at->at_expr->pe_eelist, ee_next) {
 283                         if (ee->ee_loc.lr_atom != DW_OP_addr || ee->ee_sym == 0)
 284                                 continue;
 285                         ret = _dwarf_reloc_entry_add(dbg, drs, ds,
 286                             dwarf_drt_data_reloc, dbg->dbg_pointer_size,
 287                             offset + ee->ee_loc.lr_offset + 1, ee->ee_sym,
 288                             ee->ee_loc.lr_number, NULL, error);
 289                         if (ret != DW_DLE_NONE)
 290                                 break;
 291                 }
 292                 break;
 293         case DW_FORM_data1:
 294         case DW_FORM_flag:
 295         case DW_FORM_ref1:
 296                 ret = WRITE_VALUE(at->u[0].u64, 1);
 297                 break;
 298         case DW_FORM_data2:
 299         case DW_FORM_ref2:
 300                 ret = WRITE_VALUE(at->u[0].u64, 2);
 301                 break;
 302         case DW_FORM_data4:
 303                 if (at->at_relsym || at->at_relsec != NULL)
 304                         ret = _dwarf_reloc_entry_add(dbg, drs, ds,
 305                             dwarf_drt_data_reloc, 4, ds->ds_size, at->at_relsym,
 306                             at->u[0].u64, at->at_relsec, error);
 307                 else
 308                         ret = WRITE_VALUE(at->u[0].u64, 4);
 309                 break;
 310         case DW_FORM_data8:
 311                 if (at->at_relsym || at->at_relsec != NULL)
 312                         ret = _dwarf_reloc_entry_add(dbg, drs, ds,
 313                             dwarf_drt_data_reloc, 8, ds->ds_size, at->at_relsym,
 314                             at->u[0].u64, at->at_relsec, error);
 315                 else
 316                         ret = WRITE_VALUE(at->u[0].u64, 8);
 317                 break;
 318         case DW_FORM_ref4:
 319         case DW_FORM_ref8:
 320                 /*
 321                  * The value of ref4 and ref8 could be a reference to another
 322                  * DIE within the CU. And if we don't know the ref DIE's
 323                  * offset at the moement, then we remember at_offset and fill
 324                  * it in the second pass.
 325                  */
 326                 if (at->at_refdie) {
 327                         value = at->at_refdie->die_offset;
 328                         if (value == 0) {
 329                                 cu->cu_pass2 = 1;
 330                                 at->at_offset = ds->ds_size;
 331                         }
 332                 } else
 333                         value = at->u[0].u64;
 334                 ret = WRITE_VALUE(value, at->at_form == DW_FORM_ref4 ? 4 : 8);
 335                 break;
 336         case DW_FORM_indirect:
 337                 /* TODO. */
 338                 DWARF_SET_ERROR(dbg, error, DW_DLE_ATTR_FORM_BAD);
 339                 ret = DW_DLE_ATTR_FORM_BAD;
 340                 break;
 341         case DW_FORM_ref_addr:
 342                 /* DWARF2 format. */
 343                 if (at->at_relsym)
 344                         ret = _dwarf_reloc_entry_add(dbg, drs, ds,
 345                             dwarf_drt_data_reloc, cu->cu_pointer_size,
 346                             ds->ds_size, at->at_relsym, at->u[0].u64, NULL,
 347                             error);
 348                 else
 349                         ret = WRITE_VALUE(at->u[0].u64, cu->cu_pointer_size);
 350                 break;
 351         case DW_FORM_ref_udata:
 352         case DW_FORM_udata:
 353                 ret = WRITE_ULEB128(at->u[0].u64);
 354                 break;
 355         case DW_FORM_sdata:
 356                 ret = WRITE_SLEB128(at->u[0].s64);
 357                 break;
 358         case DW_FORM_string:
 359                 assert(at->u[0].s != NULL);
 360                 ret = WRITE_STRING(at->u[0].s);
 361                 break;
 362         case DW_FORM_strp:
 363                 ret = _dwarf_reloc_entry_add(dbg, drs, ds, dwarf_drt_data_reloc,
 364                     4, ds->ds_size, 0, at->u[0].u64, ".debug_str", error);
 365                 break;
 366         default:
 367                 DWARF_SET_ERROR(dbg, error, DW_DLE_ATTR_FORM_BAD);
 368                 ret = DW_DLE_ATTR_FORM_BAD;
 369                 break;
 370         }
 371
 372         return (ret);
 373 }
 374
 375 int
 376 _dwarf_add_AT_dataref(Dwarf_P_Debug dbg, Dwarf_P_Die die, Dwarf_Half attr,
 377     Dwarf_Unsigned pc_value, Dwarf_Unsigned sym_index, const char *secname,
 378     Dwarf_P_Attribute *atp, Dwarf_Error *error)
 379 {
 380         Dwarf_Attribute at;
 381         int ret;
 382
 383         assert(dbg != NULL && die != NULL);
 384
 385         if ((ret = _dwarf_attr_alloc(die, &at, error)) != DW_DLE_NONE)
 386                 return (ret);
 387
 388         at->at_die = die;
 389         at->at_attrib = attr;
 390         if (dbg->dbg_pointer_size == 4)
 391                 at->at_form = DW_FORM_data4;
 392         else
 393                 at->at_form = DW_FORM_data8;
 394         at->at_relsym = sym_index;
 395         at->at_relsec = secname;
 396         at->u[0].u64 = pc_value;
 397
 398         STAILQ_INSERT_TAIL(&die->die_attr, at, at_next);
 399
 400         if (atp)
 401                 *atp = at;
 402
 403         return (DW_DLE_NONE);
 404 }
 405
 406 int
 407 _dwarf_add_string_attr(Dwarf_P_Die die, Dwarf_P_Attribute *atp, Dwarf_Half attr,
 408     char *string, Dwarf_Error *error)
 409 {
 410         Dwarf_Attribute at;
 411         Dwarf_Debug dbg;
 412         int ret;
 413
 414         dbg = die != NULL ? die->die_dbg : NULL;
 415
 416         assert(atp != NULL);
 417
 418         if (die == NULL || string == NULL) {
 419                 DWARF_SET_ERROR(dbg, error, DW_DLE_ARGUMENT);
 420                 return (DW_DLE_ARGUMENT);
 421         }
 422
 423         if ((ret = _dwarf_attr_alloc(die, &at, error)) != DW_DLE_NONE)
 424                 return (ret);
 425
 426         at->at_die = die;
 427         at->at_attrib = attr;
 428         at->at_form = DW_FORM_strp;
 429         if ((ret = _dwarf_strtab_add(dbg, string, &at->u[0].u64,
 430             error)) != DW_DLE_NONE) {
 431                 free(at);
 432                 return (ret);
 433         }
 434         at->u[1].s = _dwarf_strtab_get_table(dbg) + at->u[0].u64;
 435
 436         *atp = at;
 437
 438         STAILQ_INSERT_TAIL(&die->die_attr, at, at_next);
 439
 440         return (DW_DLE_NONE);
 441 }
 442
 443 int
 444 _dwarf_attr_gen(Dwarf_P_Debug dbg, Dwarf_P_Section ds, Dwarf_Rel_Section drs,
 445     Dwarf_CU cu, Dwarf_Die die, int pass2, Dwarf_Error *error)
 446 {
 447         Dwarf_Attribute at;
 448         int ret;
 449
 450         assert(dbg != NULL && ds != NULL && cu != NULL && die != NULL);
 451
 452         STAILQ_FOREACH(at, &die->die_attr, at_next) {
 453                 ret = _dwarf_attr_write(dbg, ds, drs, cu, at, pass2, error);
 454                 if (ret != DW_DLE_NONE)
 455                         return (ret);
 456         }
 457
 458         return (DW_DLE_NONE);
 459 }