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         int ret;
 104
 105         ret = DW_DLE_NONE;
 106         memset(&atref, 0, sizeof(atref));
 107         atref.at_die = die;
 108         atref.at_offset = *offsetp;
 109         atref.at_attrib = ad->ad_attrib;
 110         atref.at_form = indirect ? form : ad->ad_form;
 111         atref.at_indirect = indirect;
 112         atref.at_ld = NULL;
 113
 114         switch (form) {
 115         case DW_FORM_addr:
 116                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp,
 117                     cu->cu_pointer_size);
 118                 break;
 119         case DW_FORM_block:
 120         case DW_FORM_exprloc:
 121                 atref.u[0].u64 = _dwarf_read_uleb128(ds->ds_data, offsetp);
 122                 atref.u[1].u8p = _dwarf_read_block(ds->ds_data, offsetp,
 123                     atref.u[0].u64);
 124                 break;
 125         case DW_FORM_block1:
 126                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 1);
 127                 atref.u[1].u8p = _dwarf_read_block(ds->ds_data, offsetp,
 128                     atref.u[0].u64);
 129                 break;
 130         case DW_FORM_block2:
 131                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 2);
 132                 atref.u[1].u8p = _dwarf_read_block(ds->ds_data, offsetp,
 133                     atref.u[0].u64);
 134                 break;
 135         case DW_FORM_block4:
 136                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 4);
 137                 atref.u[1].u8p = _dwarf_read_block(ds->ds_data, offsetp,
 138                     atref.u[0].u64);
 139                 break;
 140         case DW_FORM_data1:
 141         case DW_FORM_flag:
 142         case DW_FORM_ref1:
 143                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 1);
 144                 break;
 145         case DW_FORM_data2:
 146         case DW_FORM_ref2:
 147                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 2);
 148                 break;
 149         case DW_FORM_data4:
 150         case DW_FORM_ref4:
 151                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 4);
 152                 break;
 153         case DW_FORM_data8:
 154         case DW_FORM_ref8:
 155                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, 8);
 156                 break;
 157         case DW_FORM_indirect:
 158                 form = _dwarf_read_uleb128(ds->ds_data, offsetp);
 159                 return (_dwarf_attr_init(dbg, ds, offsetp, dwarf_size, cu, die,
 160                     ad, form, 1, error));
 161         case DW_FORM_ref_addr:
 162                 if (cu->cu_version == 2)
 163                         atref.u[0].u64 = dbg->read(ds->ds_data, offsetp,
 164                             cu->cu_pointer_size);
 165                 else
 166                         atref.u[0].u64 = dbg->read(ds->ds_data, offsetp,
 167                             dwarf_size);
 168                 break;
 169         case DW_FORM_ref_udata:
 170         case DW_FORM_udata:
 171                 atref.u[0].u64 = _dwarf_read_uleb128(ds->ds_data, offsetp);
 172                 break;
 173         case DW_FORM_sdata:
 174                 atref.u[0].s64 = _dwarf_read_sleb128(ds->ds_data, offsetp);
 175                 break;
 176         case DW_FORM_sec_offset:
 177                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, dwarf_size);
 178                 break;
 179         case DW_FORM_string:
 180                 atref.u[0].s = _dwarf_read_string(ds->ds_data, ds->ds_size,
 181                     offsetp);
 182                 break;
 183         case DW_FORM_strp:
 184                 atref.u[0].u64 = dbg->read(ds->ds_data, offsetp, dwarf_size);
 185                 atref.u[1].s = _dwarf_strtab_get_table(dbg) + atref.u[0].u64;
 186                 break;
 187         case DW_FORM_ref_sig8:
 188                 atref.u[0].u64 = 8;
 189                 atref.u[1].u8p = _dwarf_read_block(ds->ds_data, offsetp,
 190                     atref.u[0].u64);
 191                 break;
 192         case DW_FORM_flag_present:
 193                 /* This form has no value encoded in the DIE. */
 194                 atref.u[0].u64 = 1;
 195                 break;
 196         default:
 197                 DWARF_SET_ERROR(dbg, error, DW_DLE_ATTR_FORM_BAD);
 198                 ret = DW_DLE_ATTR_FORM_BAD;
 199                 break;
 200         }
 201
 202         if (ret == DW_DLE_NONE) {
 203                 if (form == DW_FORM_block || form == DW_FORM_block1 ||
 204                     form == DW_FORM_block2 || form == DW_FORM_block4) {
 205                         atref.at_block.bl_len = atref.u[0].u64;
 206                         atref.at_block.bl_data = atref.u[1].u8p;
 207                 }
 208                 ret = _dwarf_attr_add(die, &atref, NULL, error);
 209         }
 210
 211         return (ret);
 212 }
 213
 214 static int
 215 _dwarf_attr_write(Dwarf_P_Debug dbg, Dwarf_P_Section ds, Dwarf_Rel_Section drs,
 216     Dwarf_CU cu, Dwarf_Attribute at, int pass2, Dwarf_Error *error)
 217 {
 218         struct _Dwarf_P_Expr_Entry *ee;
 219         uint64_t value, offset, bs;
 220         int ret;
 221
 222         assert(dbg != NULL && ds != NULL && cu != NULL && at != NULL);
 223
 224         /* Fill in reference to other DIE in the second pass. */
 225         if (pass2) {
 226                 if (at->at_form != DW_FORM_ref4 && at->at_form != DW_FORM_ref8)
 227                         return (DW_DLE_NONE);
 228                 if (at->at_refdie == NULL || at->at_offset == 0)
 229                         return (DW_DLE_NONE);
 230                 offset = at->at_offset;
 231                 dbg->write(ds->ds_data, &offset, at->at_refdie->die_offset,
 232                     at->at_form == DW_FORM_ref4 ? 4 : 8);
 233                 return (DW_DLE_NONE);
 234         }
 235
 236         switch (at->at_form) {
 237         case DW_FORM_addr:
 238                 if (at->at_relsym)
 239                         ret = _dwarf_reloc_entry_add(dbg, drs, ds,
 240                             dwarf_drt_data_reloc, cu->cu_pointer_size,
 241                             ds->ds_size, at->at_relsym, at->u[0].u64, NULL,
 242                             error);
 243                 else
 244                         ret = WRITE_VALUE(at->u[0].u64, cu->cu_pointer_size);
 245                 break;
 246         case DW_FORM_block:
 247         case DW_FORM_block1:
 248         case DW_FORM_block2:
 249         case DW_FORM_block4:
 250                 /* Write block size. */
 251                 if (at->at_form == DW_FORM_block) {
 252                         ret = _dwarf_write_uleb128_alloc(&ds->ds_data,
 253                             &ds->ds_cap, &ds->ds_size, at->u[0].u64, error);
 254                         if (ret != DW_DLE_NONE)
 255                                 break;
 256                 } else {
 257                         if (at->at_form == DW_FORM_block1)
 258                                 bs = 1;
 259                         else if (at->at_form == DW_FORM_block2)
 260                                 bs = 2;
 261                         else
 262                                 bs = 4;
 263                         ret = WRITE_VALUE(at->u[0].u64, bs);
 264                         if (ret != DW_DLE_NONE)
 265                                 break;
 266                 }
 267
 268                 /* Keep block data offset for later use. */
 269                 offset = ds->ds_size;
 270
 271                 /* Write block data. */
 272                 ret = WRITE_BLOCK(at->u[1].u8p, at->u[0].u64);
 273                 if (ret != DW_DLE_NONE)
 274                         break;
 275                 if (at->at_expr == NULL)
 276                         break;
 277
 278                 /* Generate relocation entry for DW_OP_addr expressions. */
 279                 STAILQ_FOREACH(ee, &at->at_expr->pe_eelist, ee_next) {
 280                         if (ee->ee_loc.lr_atom != DW_OP_addr || ee->ee_sym == 0)
 281                                 continue;
 282                         ret = _dwarf_reloc_entry_add(dbg, drs, ds,
 283                             dwarf_drt_data_reloc, dbg->dbg_pointer_size,
 284                             offset + ee->ee_loc.lr_offset + 1, ee->ee_sym,
 285                             ee->ee_loc.lr_number, NULL, error);
 286                         if (ret != DW_DLE_NONE)
 287                                 break;
 288                 }
 289                 break;
 290         case DW_FORM_data1:
 291         case DW_FORM_flag:
 292         case DW_FORM_ref1:
 293                 ret = WRITE_VALUE(at->u[0].u64, 1);
 294                 break;
 295         case DW_FORM_data2:
 296         case DW_FORM_ref2:
 297                 ret = WRITE_VALUE(at->u[0].u64, 2);
 298                 break;
 299         case DW_FORM_data4:
 300                 if (at->at_relsym || at->at_relsec != NULL)
 301                         ret = _dwarf_reloc_entry_add(dbg, drs, ds,
 302                             dwarf_drt_data_reloc, 4, ds->ds_size, at->at_relsym,
 303                             at->u[0].u64, at->at_relsec, error);
 304                 else
 305                         ret = WRITE_VALUE(at->u[0].u64, 4);
 306                 break;
 307         case DW_FORM_data8:
 308                 if (at->at_relsym || at->at_relsec != NULL)
 309                         ret = _dwarf_reloc_entry_add(dbg, drs, ds,
 310                             dwarf_drt_data_reloc, 8, ds->ds_size, at->at_relsym,
 311                             at->u[0].u64, at->at_relsec, error);
 312                 else
 313                         ret = WRITE_VALUE(at->u[0].u64, 8);
 314                 break;
 315         case DW_FORM_ref4:
 316         case DW_FORM_ref8:
 317                 /*
 318                  * The value of ref4 and ref8 could be a reference to another
 319                  * DIE within the CU. And if we don't know the ref DIE's
 320                  * offset at the moement, then we remember at_offset and fill
 321                  * it in the second pass.
 322                  */
 323                 if (at->at_refdie) {
 324                         value = at->at_refdie->die_offset;
 325                         if (value == 0) {
 326                                 cu->cu_pass2 = 1;
 327                                 at->at_offset = ds->ds_size;
 328                         }
 329                 } else
 330                         value = at->u[0].u64;
 331                 ret = WRITE_VALUE(value, at->at_form == DW_FORM_ref4 ? 4 : 8);
 332                 break;
 333         case DW_FORM_indirect:
 334                 /* TODO. */
 335                 DWARF_SET_ERROR(dbg, error, DW_DLE_ATTR_FORM_BAD);
 336                 ret = DW_DLE_ATTR_FORM_BAD;
 337                 break;
 338         case DW_FORM_ref_addr:
 339                 /* DWARF2 format. */
 340                 if (at->at_relsym)
 341                         ret = _dwarf_reloc_entry_add(dbg, drs, ds,
 342                             dwarf_drt_data_reloc, cu->cu_pointer_size,
 343                             ds->ds_size, at->at_relsym, at->u[0].u64, NULL,
 344                             error);
 345                 else
 346                         ret = WRITE_VALUE(at->u[0].u64, cu->cu_pointer_size);
 347                 break;
 348         case DW_FORM_ref_udata:
 349         case DW_FORM_udata:
 350                 ret = WRITE_ULEB128(at->u[0].u64);
 351                 break;
 352         case DW_FORM_sdata:
 353                 ret = WRITE_SLEB128(at->u[0].s64);
 354                 break;
 355         case DW_FORM_string:
 356                 assert(at->u[0].s != NULL);
 357                 ret = WRITE_STRING(at->u[0].s);
 358                 break;
 359         case DW_FORM_strp:
 360                 ret = _dwarf_reloc_entry_add(dbg, drs, ds, dwarf_drt_data_reloc,
 361                     4, ds->ds_size, 0, at->u[0].u64, ".debug_str", error);
 362                 break;
 363         default:
 364                 DWARF_SET_ERROR(dbg, error, DW_DLE_ATTR_FORM_BAD);
 365                 ret = DW_DLE_ATTR_FORM_BAD;
 366                 break;
 367         }
 368
 369         return (ret);
 370 }
 371
 372 int
 373 _dwarf_add_AT_dataref(Dwarf_P_Debug dbg, Dwarf_P_Die die, Dwarf_Half attr,
 374     Dwarf_Unsigned pc_value, Dwarf_Unsigned sym_index, const char *secname,
 375     Dwarf_P_Attribute *atp, Dwarf_Error *error)
 376 {
 377         Dwarf_Attribute at;
 378         int ret;
 379
 380         assert(dbg != NULL && die != NULL);
 381
 382         if ((ret = _dwarf_attr_alloc(die, &at, error)) != DW_DLE_NONE)
 383                 return (ret);
 384
 385         at->at_die = die;
 386         at->at_attrib = attr;
 387         if (dbg->dbg_pointer_size == 4)
 388                 at->at_form = DW_FORM_data4;
 389         else
 390                 at->at_form = DW_FORM_data8;
 391         at->at_relsym = sym_index;
 392         at->at_relsec = secname;
 393         at->u[0].u64 = pc_value;
 394
 395         STAILQ_INSERT_TAIL(&die->die_attr, at, at_next);
 396
 397         if (atp)
 398                 *atp = at;
 399
 400         return (DW_DLE_NONE);
 401 }
 402
 403 int
 404 _dwarf_add_string_attr(Dwarf_P_Die die, Dwarf_P_Attribute *atp, Dwarf_Half attr,
 405     char *string, Dwarf_Error *error)
 406 {
 407         Dwarf_Attribute at;
 408         Dwarf_Debug dbg;
 409         int ret;
 410
 411         dbg = die != NULL ? die->die_dbg : NULL;
 412
 413         assert(atp != NULL);
 414
 415         if (die == NULL || string == NULL) {
 416                 DWARF_SET_ERROR(dbg, error, DW_DLE_ARGUMENT);
 417                 return (DW_DLE_ARGUMENT);
 418         }
 419
 420         if ((ret = _dwarf_attr_alloc(die, &at, error)) != DW_DLE_NONE)
 421                 return (ret);
 422
 423         at->at_die = die;
 424         at->at_attrib = attr;
 425         at->at_form = DW_FORM_strp;
 426         if ((ret = _dwarf_strtab_add(dbg, string, &at->u[0].u64,
 427             error)) != DW_DLE_NONE) {
 428                 free(at);
 429                 return (ret);
 430         }
 431         at->u[1].s = _dwarf_strtab_get_table(dbg) + at->u[0].u64;
 432
 433         *atp = at;
 434
 435         STAILQ_INSERT_TAIL(&die->die_attr, at, at_next);
 436
 437         return (DW_DLE_NONE);
 438 }
 439
 440 int
 441 _dwarf_attr_gen(Dwarf_P_Debug dbg, Dwarf_P_Section ds, Dwarf_Rel_Section drs,
 442     Dwarf_CU cu, Dwarf_Die die, int pass2, Dwarf_Error *error)
 443 {
 444         Dwarf_Attribute at;
 445         int ret;
 446
 447         assert(dbg != NULL && ds != NULL && cu != NULL && die != NULL);
 448
 449         STAILQ_FOREACH(at, &die->die_attr, at_next) {
 450                 ret = _dwarf_attr_write(dbg, ds, drs, cu, at, pass2, error);
 451                 if (ret != DW_DLE_NONE)
 452                         return (ret);
 453         }
 454
 455         return (DW_DLE_NONE);
 456 }