external/bsd/elftoolchain/dist/libdwarf/libdwarf_attr.c

   1 /*      $NetBSD: libdwarf_attr.c,v 1.2 2014/03/09 16:58:04 christos Exp $       */
   2
   3 /*-
   4  * Copyright (c) 2007 John Birrell (jb@freebsd.org)
   5  * Copyright (c) 2009-2011 Kai Wang
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #include "_libdwarf.h"
  31
  32 __RCSID("$NetBSD: libdwarf_attr.c,v 1.2 2014/03/09 16:58:04 christos Exp $");
  33 ELFTC_VCSID("Id: libdwarf_attr.c 2966 2013-09-21 14:40:14Z kaiwang27 ");
  34
  35 int
  36 _dwarf_attr_alloc(Dwarf_Die die, Dwarf_Attribute *atp, Dwarf_Error *error)
  37 {
  38         Dwarf_Attribute at;
  39
  40         assert(die != NULL);
  41         assert(atp != NULL);
  42
  43         if ((at = calloc(1, sizeof(struct _Dwarf_Attribute))) == NULL) {
  44                 DWARF_SET_ERROR(die->die_dbg, error, DW_DLE_MEMORY);
  45                 return (DW_DLE_MEMORY);
  46         }
  47
  48         *atp = at;
  49
  50         return (DW_DLE_NONE);
  51 }
  52
  53 static int
  54 _dwarf_attr_add(Dwarf_Die die, Dwarf_Attribute atref, Dwarf_Attribute *atp,
  55     Dwarf_Error *error)
  56 {
  57         Dwarf_Attribute at;
  58         int ret;
  59
  60         if ((ret = _dwarf_attr_alloc(die, &at, error)) != DW_DLE_NONE)
  61                 return (ret);
  62
  63         memcpy(at, atref, sizeof(struct _Dwarf_Attribute));
  64
  65         STAILQ_INSERT_TAIL(&die->die_attr, at, at_next);
  66
  67         /* Save a pointer to the attribute name if this is one. */
  68         if (at->at_attrib == DW_AT_name) {
  69                 switch (at->at_form) {
  70                 case DW_FORM_strp:
  71                         die->die_name = at->u[1].s;
  72                         break;
  73                 case DW_FORM_string:
  74                         die->die_name = at->u[0].s;
  75                         break;
  76                 default:
  77                         break;
  78                 }
  79         }
  80
  81         if (atp != NULL)
  82                 *atp = at;
  83
  84         return (DW_DLE_NONE);
  85 }
  86
  87 Dwarf_Attribute
  88 _dwarf_attr_find(Dwarf_Die die, Dwarf_Half attr)
  89 {
  90         Dwarf_Attribute at;
  91
  92         STAILQ_FOREACH(at, &die->die_attr, at_next) {
  93                 if (at->at_attrib == attr)
  94                         break;
  95         }
  96
  97         return (at);
  98 }
  99
 100 int
 101 _dwarf_attr_init(Dwarf_Debug dbg, Dwarf_Section *ds, uint64_t *offsetp,
 102     int dwarf_size, Dwarf_CU cu, Dwarf_Die die, Dwarf_AttrDef ad,
 103     uint64_t form, int indirect, Dwarf_Error *error)
 104 {
 105         struct _Dwarf_Attribute atref;
 106         Dwarf_Section *str;
 107         int ret;
 108
 109         ret = DW_DLE_NONE;
 110         memset(&atref, 0, sizeof(atref));
 111         atref.at_die = die;
 112         atref.at_attrib = ad->ad_attrib;
 113         atref.at_form = indirect ? form : ad->ad_form;
 114         atref.at_indirect = indirect;
 115         atref.at_ld = NULL;
 116
 117         switch (form) {
 118         case DW_FORM_addr:
 119                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp,
 120                     cu->cu_pointer_size);
 121                 break;
 122         case DW_FORM_block:
 123         case DW_FORM_exprloc:
 124                 atref.u[0].u64 = _dwarf_read_uleb128(ds->ds_data, offsetp);
 125                 atref.u[1].u8p = _dwarf_read_block(ds->ds_data, offsetp,
 126                     atref.u[0].u64);
 127                 break;
 128         case DW_FORM_block1:
 129                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 1);
 130                 atref.u[1].u8p = _dwarf_read_block(ds->ds_data, offsetp,
 131                     atref.u[0].u64);
 132                 break;
 133         case DW_FORM_block2:
 134                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 2);
 135                 atref.u[1].u8p = _dwarf_read_block(ds->ds_data, offsetp,
 136                     atref.u[0].u64);
 137                 break;
 138         case DW_FORM_block4:
 139                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 4);
 140                 atref.u[1].u8p = _dwarf_read_block(ds->ds_data, offsetp,
 141                     atref.u[0].u64);
 142                 break;
 143         case DW_FORM_data1:
 144         case DW_FORM_flag:
 145         case DW_FORM_ref1:
 146                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 1);
 147                 break;
 148         case DW_FORM_data2:
 149         case DW_FORM_ref2:
 150                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 2);
 151                 break;
 152         case DW_FORM_data4:
 153         case DW_FORM_ref4:
 154                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 4);
 155                 break;
 156         case DW_FORM_data8:
 157         case DW_FORM_ref8:
 158                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 8);
 159                 break;
 160         case DW_FORM_indirect:
 161                 form = _dwarf_read_uleb128(ds->ds_data, offsetp);
 162                 return (_dwarf_attr_init(dbg, ds, offsetp, dwarf_size, cu, die,
 163                     ad, form, 1, error));
 164         case DW_FORM_ref_addr:
 165                 if (cu->cu_version == 2)
 166                         atref.u[0].u64 = dbg->read(ds->ds_data, offsetp,
 167                             cu->cu_pointer_size);
 168                 else if (cu->cu_version == 3)
 169                         atref.u[0].u64 = dbg->read(ds->ds_data, offsetp,
 170                             dwarf_size);
 171                 break;
 172         case DW_FORM_ref_udata:
 173         case DW_FORM_udata:
 174                 atref.u[0].u64 = _dwarf_read_uleb128(ds->ds_data, offsetp);
 175                 break;
 176         case DW_FORM_sdata:
 177                 atref.u[0].s64 = _dwarf_read_sleb128(ds->ds_data, offsetp);
 178                 break;
 179         case DW_FORM_sec_offset:
 180                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, dwarf_size);
 181                 break;
 182         case DW_FORM_string:
 183                 atref.u[0].s = _dwarf_read_string(ds->ds_data, ds->ds_size,
 184                     offsetp);
 185                 break;
 186         case DW_FORM_strp:
 187                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, dwarf_size);
 188                 str = _dwarf_find_section(dbg, ".debug_str");
 189                 assert(str != NULL);
 190                 atref.u[1].s = (char *) str->ds_data + atref.u[0].u64;
 191                 break;
 192         case DW_FORM_ref_sig8:
 193                 atref.u[0].u64 = 8;
 194                 atref.u[1].u8p = _dwarf_read_block(ds->ds_data, offsetp,
 195                     atref.u[0].u64);
 196                 break;
 197         case DW_FORM_flag_present:
 198                 /* This form has no value encoded in the DIE. */
 199                 atref.u[0].u64 = 1;
 200                 break;
 201         default:
 202                 DWARF_SET_ERROR(dbg, error, DW_DLE_ATTR_FORM_BAD);
 203                 ret = DW_DLE_ATTR_FORM_BAD;
 204                 break;
 205         }
 206
 207         if (ret == DW_DLE_NONE) {
 208                 if (form == DW_FORM_block || form == DW_FORM_block1 ||
 209                     form == DW_FORM_block2 || form == DW_FORM_block4) {
 210                         atref.at_block.bl_len = atref.u[0].u64;
 211                         atref.at_block.bl_data = atref.u[1].u8p;
 212                 }
 213                 ret = _dwarf_attr_add(die, &atref, NULL, error);
 214         }
 215
 216         return (ret);
 217 }
 218
 219 static int
 220 _dwarf_attr_write(Dwarf_P_Debug dbg, Dwarf_P_Section ds, Dwarf_Rel_Section drs,
 221     Dwarf_CU cu, Dwarf_Attribute at, int pass2, Dwarf_Error *error)
 222 {
 223         struct _Dwarf_P_Expr_Entry *ee;
 224         uint64_t value, offset, bs;
 225         int ret;
 226
 227         assert(dbg != NULL && ds != NULL && cu != NULL && at != NULL);
 228
 229         /* Fill in reference to other DIE in the second pass. */
 230         if (pass2) {
 231                 if (at->at_form != DW_FORM_ref4 && at->at_form != DW_FORM_ref8)
 232                         return (DW_DLE_NONE);
 233                 if (at->at_refdie == NULL || at->at_offset == 0)
 234                         return (DW_DLE_NONE);
 235                 offset = at->at_offset;
 236                 dbg->write(ds->ds_data, &offset, at->at_refdie->die_offset,
 237                     at->at_form == DW_FORM_ref4 ? 4 : 8);
 238                 return (DW_DLE_NONE);
 239         }
 240
 241         switch (at->at_form) {
 242         case DW_FORM_addr:
 243                 if (at->at_relsym)
 244                         ret = _dwarf_reloc_entry_add(dbg, drs, ds,
 245                             dwarf_drt_data_reloc, cu->cu_pointer_size,
 246                             ds->ds_size, at->at_relsym, at->u[0].u64, NULL,
 247                             error);
 248                 else
 249                         ret = WRITE_VALUE(at->u[0].u64, cu->cu_pointer_size);
 250                 break;
 251         case DW_FORM_block:
 252         case DW_FORM_block1:
 253         case DW_FORM_block2:
 254         case DW_FORM_block4:
 255                 /* Write block size. */
 256                 if (at->at_form == DW_FORM_block) {
 257                         ret = _dwarf_write_uleb128_alloc(&ds->ds_data,
 258                             &ds->ds_cap, &ds->ds_size, at->u[0].u64, error);
 259                         if (ret != DW_DLE_NONE)
 260                                 break;
 261                 } else {
 262                         if (at->at_form == DW_FORM_block1)
 263                                 bs = 1;
 264                         else if (at->at_form == DW_FORM_block2)
 265                                 bs = 2;
 266                         else
 267                                 bs = 4;
 268                         ret = WRITE_VALUE(at->u[0].u64, bs);
 269                         if (ret != DW_DLE_NONE)
 270                                 break;
 271                 }
 272
 273                 /* Keep block data offset for later use. */
 274                 offset = ds->ds_size;
 275
 276                 /* Write block data. */
 277                 ret = WRITE_BLOCK(at->u[1].u8p, at->u[0].u64);
 278                 if (ret != DW_DLE_NONE)
 279                         break;
 280                 if (at->at_expr == NULL)
 281                         break;
 282
 283                 /* Generate relocation entry for DW_OP_addr expressions. */
 284                 STAILQ_FOREACH(ee, &at->at_expr->pe_eelist, ee_next) {
 285                         if (ee->ee_loc.lr_atom != DW_OP_addr || ee->ee_sym == 0)
 286                                 continue;
 287                         ret = _dwarf_reloc_entry_add(dbg, drs, ds,
 288                             dwarf_drt_data_reloc, dbg->dbg_pointer_size,
 289                             offset + ee->ee_loc.lr_offset + 1, ee->ee_sym,
 290                             ee->ee_loc.lr_number, NULL, error);
 291                         if (ret != DW_DLE_NONE)
 292                                 break;
 293                 }
 294                 break;
 295         case DW_FORM_data1:
 296         case DW_FORM_flag:
 297         case DW_FORM_ref1:
 298                 ret = WRITE_VALUE(at->u[0].u64, 1);
 299                 break;
 300         case DW_FORM_data2:
 301         case DW_FORM_ref2:
 302                 ret = WRITE_VALUE(at->u[0].u64, 2);
 303                 break;
 304         case DW_FORM_data4:
 305                 if (at->at_relsym || at->at_relsec != NULL)
 306                         ret = _dwarf_reloc_entry_add(dbg, drs, ds,
 307                             dwarf_drt_data_reloc, 4, ds->ds_size, at->at_relsym,
 308                             at->u[0].u64, at->at_relsec, error);
 309                 else
 310                         ret = WRITE_VALUE(at->u[0].u64, 4);
 311                 break;
 312         case DW_FORM_data8:
 313                 if (at->at_relsym || at->at_relsec != NULL)
 314                         ret = _dwarf_reloc_entry_add(dbg, drs, ds,
 315                             dwarf_drt_data_reloc, 8, ds->ds_size, at->at_relsym,
 316                             at->u[0].u64, at->at_relsec, error);
 317                 else
 318                         ret = WRITE_VALUE(at->u[0].u64, 8);
 319                 break;
 320         case DW_FORM_ref4:
 321         case DW_FORM_ref8:
 322                 /*
 323                  * The value of ref4 and ref8 could be a reference to another
 324                  * DIE within the CU. And if we don't know the ref DIE's
 325                  * offset at the moement, then we remember at_offset and fill
 326                  * it in the second pass.
 327                  */
 328                 if (at->at_refdie) {
 329                         value = at->at_refdie->die_offset;
 330                         if (value == 0) {
 331                                 cu->cu_pass2 = 1;
 332                                 at->at_offset = ds->ds_size;
 333                         }
 334                 } else
 335                         value = at->u[0].u64;
 336                 ret = WRITE_VALUE(value, at->at_form == DW_FORM_ref4 ? 4 : 8);
 337                 break;
 338         case DW_FORM_indirect:
 339                 /* TODO. */
 340                 DWARF_SET_ERROR(dbg, error, DW_DLE_ATTR_FORM_BAD);
 341                 ret = DW_DLE_ATTR_FORM_BAD;
 342                 break;
 343         case DW_FORM_ref_addr:
 344                 /* DWARF2 format. */
 345                 if (at->at_relsym)
 346                         ret = _dwarf_reloc_entry_add(dbg, drs, ds,
 347                             dwarf_drt_data_reloc, cu->cu_pointer_size,
 348                             ds->ds_size, at->at_relsym, at->u[0].u64, NULL,
 349                             error);
 350                 else
 351                         ret = WRITE_VALUE(at->u[0].u64, cu->cu_pointer_size);
 352                 break;
 353         case DW_FORM_ref_udata:
 354         case DW_FORM_udata:
 355                 ret = WRITE_ULEB128(at->u[0].u64);
 356                 break;
 357         case DW_FORM_sdata:
 358                 ret = WRITE_SLEB128(at->u[0].s64);
 359                 break;
 360         case DW_FORM_string:
 361                 assert(at->u[0].s != NULL);
 362                 ret = WRITE_STRING(at->u[0].s);
 363                 break;
 364         case DW_FORM_strp:
 365                 ret = _dwarf_reloc_entry_add(dbg, drs, ds, dwarf_drt_data_reloc,
 366                     4, ds->ds_size, 0, at->u[0].u64, ".debug_str", error);
 367                 break;
 368         default:
 369                 DWARF_SET_ERROR(dbg, error, DW_DLE_ATTR_FORM_BAD);
 370                 ret = DW_DLE_ATTR_FORM_BAD;
 371                 break;
 372         }
 373
 374         return (ret);
 375 }
 376
 377 int
 378 _dwarf_add_AT_dataref(Dwarf_P_Debug dbg, Dwarf_P_Die die, Dwarf_Half attr,
 379     Dwarf_Unsigned pc_value, Dwarf_Unsigned sym_index, const char *secname,
 380     Dwarf_P_Attribute *atp, Dwarf_Error *error)
 381 {
 382         Dwarf_Attribute at;
 383         int ret;
 384
 385         assert(dbg != NULL && die != NULL);
 386
 387         if ((ret = _dwarf_attr_alloc(die, &at, error)) != DW_DLE_NONE)
 388                 return (ret);
 389
 390         at->at_die = die;
 391         at->at_attrib = attr;
 392         if (dbg->dbg_pointer_size == 4)
 393                 at->at_form = DW_FORM_data4;
 394         else
 395                 at->at_form = DW_FORM_data8;
 396         at->at_relsym = sym_index;
 397         at->at_relsec = secname;
 398         at->u[0].u64 = pc_value;
 399
 400         STAILQ_INSERT_TAIL(&die->die_attr, at, at_next);
 401
 402         if (atp)
 403                 *atp = at;
 404
 405         return (DW_DLE_NONE);
 406 }
 407
 408 int
 409 _dwarf_add_string_attr(Dwarf_P_Die die, Dwarf_P_Attribute *atp, Dwarf_Half attr,
 410     char *string, Dwarf_Error *error)
 411 {
 412         Dwarf_Attribute at;
 413         Dwarf_Debug dbg;
 414         int ret;
 415
 416         dbg = die != NULL ? die->die_dbg : NULL;
 417
 418         assert(atp != NULL);
 419
 420         if (die == NULL || string == NULL) {
 421                 DWARF_SET_ERROR(dbg, error, DW_DLE_ARGUMENT);
 422                 return (DW_DLE_ARGUMENT);
 423         }
 424
 425         if ((ret = _dwarf_attr_alloc(die, &at, error)) != DW_DLE_NONE)
 426                 return (ret);
 427
 428         at->at_die = die;
 429         at->at_attrib = attr;
 430         at->at_form = DW_FORM_strp;
 431         if ((ret = _dwarf_strtab_add(dbg, string, &at->u[0].u64,
 432             error)) != DW_DLE_NONE) {
 433                 free(at);
 434                 return (ret);
 435         }
 436         at->u[1].s = _dwarf_strtab_get_table(dbg) + at->u[0].u64;
 437
 438         *atp = at;
 439
 440         STAILQ_INSERT_TAIL(&die->die_attr, at, at_next);
 441
 442         return (DW_DLE_NONE);
 443 }
 444
 445 int
 446 _dwarf_attr_gen(Dwarf_P_Debug dbg, Dwarf_P_Section ds, Dwarf_Rel_Section drs,
 447     Dwarf_CU cu, Dwarf_Die die, int pass2, Dwarf_Error *error)
 448 {
 449         Dwarf_Attribute at;
 450         int ret;
 451
 452         assert(dbg != NULL && ds != NULL && cu != NULL && die != NULL);
 453
 454         STAILQ_FOREACH(at, &die->die_attr, at_next) {
 455                 ret = _dwarf_attr_write(dbg, ds, drs, cu, at, pass2, error);
 456                 if (ret != DW_DLE_NONE)
 457                         return (ret);
 458         }
 459
 460         return (DW_DLE_NONE);
 461 }