contrib/elftoolchain/libdwarf/libdwarf_die.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_die.c 3039 2014-05-18 15:10:56Z kaiwang27 $");
  31
  32 int
  33 _dwarf_die_alloc(Dwarf_Debug dbg, Dwarf_Die *ret_die, Dwarf_Error *error)
  34 {
  35         Dwarf_Die die;
  36
  37         assert(ret_die != NULL);
  38
  39         if ((die = calloc(1, sizeof(struct _Dwarf_Die))) == NULL) {
  40                 DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
  41                 return (DW_DLE_MEMORY);
  42         }
  43
  44         STAILQ_INIT(&die->die_attr);
  45
  46         *ret_die = die;
  47
  48         return (DW_DLE_NONE);
  49 }
  50
  51 static int
  52 _dwarf_die_add(Dwarf_CU cu, uint64_t offset, uint64_t abnum, Dwarf_Abbrev ab,
  53     Dwarf_Die *diep, Dwarf_Error *error)
  54 {
  55         Dwarf_Debug dbg;
  56         Dwarf_Die die;
  57         int ret;
  58
  59         assert(cu != NULL);
  60         assert(ab != NULL);
  61
  62         dbg = cu->cu_dbg;
  63
  64         if ((ret = _dwarf_die_alloc(dbg, &die, error)) != DW_DLE_NONE)
  65                 return (ret);
  66
  67         die->die_offset = offset;
  68         die->die_abnum  = abnum;
  69         die->die_ab     = ab;
  70         die->die_cu     = cu;
  71         die->die_dbg    = cu->cu_dbg;
  72
  73         *diep = die;
  74
  75         return (DW_DLE_NONE);
  76 }
  77
  78 /* Find die at offset 'off' within the same CU. */
  79 Dwarf_Die
  80 _dwarf_die_find(Dwarf_Die die, Dwarf_Unsigned off)
  81 {
  82         Dwarf_Debug dbg;
  83         Dwarf_Section *ds;
  84         Dwarf_CU cu;
  85         Dwarf_Die die1;
  86         Dwarf_Error de;
  87         int ret;
  88
  89         cu = die->die_cu;
  90         dbg = die->die_dbg;
  91         ds = cu->cu_is_info ? dbg->dbg_info_sec : dbg->dbg_types_sec;
  92
  93         ret = _dwarf_die_parse(dbg, ds, cu, cu->cu_dwarf_size, off,
  94             cu->cu_next_offset, &die1, 0, &de);
  95
  96         if (ret == DW_DLE_NONE)
  97                 return (die1);
  98         else
  99                 return (NULL);
 100 }
 101
 102 int
 103 _dwarf_die_parse(Dwarf_Debug dbg, Dwarf_Section *ds, Dwarf_CU cu,
 104     int dwarf_size, uint64_t offset, uint64_t next_offset, Dwarf_Die *ret_die,
 105     int search_sibling, Dwarf_Error *error)
 106 {
 107         Dwarf_Abbrev ab;
 108         Dwarf_AttrDef ad;
 109         Dwarf_Die die;
 110         uint64_t abnum;
 111         uint64_t die_offset;
 112         int ret, level;
 113
 114         assert(cu != NULL);
 115
 116         level = 1;
 117         die = NULL;
 118
 119         while (offset < next_offset && offset < ds->ds_size) {
 120
 121                 die_offset = offset;
 122
 123                 abnum = _dwarf_read_uleb128(ds->ds_data, &offset);
 124
 125                 if (abnum == 0) {
 126                         if (level == 0 || !search_sibling)
 127                                 return (DW_DLE_NO_ENTRY);
 128
 129                         /*
 130                          * Return to previous DIE level.
 131                          */
 132                         level--;
 133                         continue;
 134                 }
 135
 136                 if ((ret = _dwarf_abbrev_find(cu, abnum, &ab, error)) !=
 137                     DW_DLE_NONE)
 138                         return (ret);
 139
 140                 if ((ret = _dwarf_die_add(cu, die_offset, abnum, ab, &die,
 141                     error)) != DW_DLE_NONE)
 142                         return (ret);
 143
 144                 STAILQ_FOREACH(ad, &ab->ab_attrdef, ad_next) {
 145                         if ((ret = _dwarf_attr_init(dbg, ds, &offset,
 146                             dwarf_size, cu, die, ad, ad->ad_form, 0,
 147                             error)) != DW_DLE_NONE)
 148                                 return (ret);
 149                 }
 150
 151                 die->die_next_off = offset;
 152                 if (search_sibling && level > 0) {
 153                         dwarf_dealloc(dbg, die, DW_DLA_DIE);
 154                         if (ab->ab_children == DW_CHILDREN_yes) {
 155                                 /* Advance to next DIE level. */
 156                                 level++;
 157                         }
 158                 } else {
 159                         *ret_die = die;
 160                         return (DW_DLE_NONE);
 161                 }
 162         }
 163
 164         return (DW_DLE_NO_ENTRY);
 165 }
 166
 167 void
 168 _dwarf_die_link(Dwarf_P_Die die, Dwarf_P_Die parent, Dwarf_P_Die child,
 169     Dwarf_P_Die left_sibling, Dwarf_P_Die right_sibling)
 170 {
 171         Dwarf_P_Die last_child;
 172
 173         assert(die != NULL);
 174
 175         if (parent) {
 176
 177                 /* Disconnect from old parent. */
 178                 if (die->die_parent) {
 179                         if (die->die_parent != parent) {
 180                                 if (die->die_parent->die_child == die)
 181                                         die->die_parent->die_child = NULL;
 182                                 die->die_parent = NULL;
 183                      }
 184                 }
 185
 186                 /* Find the last child of this parent. */
 187                 last_child = parent->die_child;
 188                 if (last_child) {
 189                         while (last_child->die_right != NULL)
 190                                 last_child = last_child->die_right;
 191                 }
 192
 193                 /* Connect to new parent. */
 194                 die->die_parent = parent;
 195
 196                 /*
 197                  * Attach this DIE to the end of sibling list. If new
 198                  * parent doesn't have any child, set this DIE as the
 199                  * first child.
 200                  */
 201                 if (last_child) {
 202                         assert(last_child->die_right == NULL);
 203                         last_child->die_right = die;
 204                         die->die_left = last_child;
 205                 } else
 206                         parent->die_child = die;
 207         }
 208
 209         if (child) {
 210
 211                 /* Disconnect from old child. */
 212                 if (die->die_child) {
 213                         if (die->die_child != child) {
 214                                 die->die_child->die_parent = NULL;
 215                                 die->die_child = NULL;
 216                         }
 217                 }
 218
 219                 /* Connect to new child. */
 220                 die->die_child = child;
 221                 child->die_parent = die;
 222         }
 223
 224         if (left_sibling) {
 225
 226                 /* Disconnect from old left sibling. */
 227                 if (die->die_left) {
 228                         if (die->die_left != left_sibling) {
 229                                 die->die_left->die_right = NULL;
 230                                 die->die_left = NULL;
 231                         }
 232                 }
 233
 234                 /* Connect to new right sibling. */
 235                 die->die_left = left_sibling;
 236                 left_sibling->die_right = die;
 237         }
 238
 239         if (right_sibling) {
 240
 241                 /* Disconnect from old right sibling. */
 242                 if (die->die_right) {
 243                         if (die->die_right != right_sibling) {
 244                                 die->die_right->die_left = NULL;
 245                                 die->die_right = NULL;
 246                         }
 247                 }
 248
 249                 /* Connect to new right sibling. */
 250                 die->die_right = right_sibling;
 251                 right_sibling->die_left = die;
 252         }
 253 }
 254
 255 int
 256 _dwarf_die_count_links(Dwarf_P_Die parent, Dwarf_P_Die child,
 257     Dwarf_P_Die left_sibling, Dwarf_P_Die right_sibling)
 258 {
 259         int count;
 260
 261         count = 0;
 262
 263         if (parent)
 264                 count++;
 265         if (child)
 266                 count++;
 267         if (left_sibling)
 268                 count++;
 269         if (right_sibling)
 270                 count++;
 271
 272         return (count);
 273 }
 274
 275 static int
 276 _dwarf_die_gen_recursive(Dwarf_P_Debug dbg, Dwarf_CU cu, Dwarf_Rel_Section drs,
 277     Dwarf_P_Die die, int pass2, Dwarf_Error *error)
 278 {
 279         Dwarf_P_Section ds;
 280         Dwarf_Abbrev ab;
 281         Dwarf_Attribute at;
 282         Dwarf_AttrDef ad;
 283         int match, ret;
 284
 285         ds = dbg->dbgp_info;
 286         assert(ds != NULL);
 287
 288         if (pass2)
 289                 goto attr_gen;
 290
 291         /*
 292          * Add DW_AT_sibling attribute for DIEs with children, so consumers
 293          * can quickly scan chains of siblings, while ignoring the children
 294          * of individual siblings.
 295          */
 296         if (die->die_child && die->die_right) {
 297                 if (_dwarf_attr_find(die, DW_AT_sibling) == NULL)
 298                         (void) dwarf_add_AT_reference(dbg, die, DW_AT_sibling,
 299                             die->die_right, error);
 300         }
 301
 302         /*
 303          * Search abbrev list to find a matching entry.
 304          */
 305         die->die_ab = NULL;
 306         for (ab = cu->cu_abbrev_hash; ab != NULL; ab = ab->ab_hh.next) {
 307                 if (die->die_tag != ab->ab_tag)
 308                         continue;
 309                 if (ab->ab_children == DW_CHILDREN_no && die->die_child != NULL)
 310                         continue;
 311                 if (ab->ab_children == DW_CHILDREN_yes &&
 312                     die->die_child == NULL)
 313                         continue;
 314                 at = STAILQ_FIRST(&die->die_attr);
 315                 ad = STAILQ_FIRST(&ab->ab_attrdef);
 316                 match = 1;
 317                 while (at != NULL && ad != NULL) {
 318                         if (at->at_attrib != ad->ad_attrib ||
 319                             at->at_form != ad->ad_form) {
 320                                 match = 0;
 321                                 break;
 322                         }
 323                         at = STAILQ_NEXT(at, at_next);
 324                         ad = STAILQ_NEXT(ad, ad_next);
 325                 }
 326                 if ((at == NULL && ad != NULL) || (at != NULL && ad == NULL))
 327                         match = 0;
 328                 if (match) {
 329                         die->die_ab = ab;
 330                         break;
 331                 }
 332         }
 333
 334         /*
 335          * Create a new abbrev entry if we can not reuse any existing one.
 336          */
 337         if (die->die_ab == NULL) {
 338                 ret = _dwarf_abbrev_add(cu, ++cu->cu_abbrev_cnt, die->die_tag,
 339                     die->die_child != NULL ? DW_CHILDREN_yes : DW_CHILDREN_no,
 340                     0, &ab, error);
 341                 if (ret != DW_DLE_NONE)
 342                         return (ret);
 343                 STAILQ_FOREACH(at, &die->die_attr, at_next) {
 344                         ret = _dwarf_attrdef_add(dbg, ab, at->at_attrib,
 345                             at->at_form, 0, NULL, error);
 346                         if (ret != DW_DLE_NONE)
 347                                 return (ret);
 348                 }
 349                 die->die_ab = ab;
 350         }
 351
 352         die->die_offset = ds->ds_size;
 353
 354         /*
 355          * Transform the DIE to bytes stream.
 356          */
 357         ret = _dwarf_write_uleb128_alloc(&ds->ds_data, &ds->ds_cap,
 358             &ds->ds_size, die->die_ab->ab_entry, error);
 359         if (ret != DW_DLE_NONE)
 360                 return (ret);
 361
 362 attr_gen:
 363
 364         /* Transform the attributes of this DIE. */
 365         ret = _dwarf_attr_gen(dbg, ds, drs, cu, die, pass2, error);
 366         if (ret != DW_DLE_NONE)
 367                 return (ret);
 368
 369         /* Proceed to child DIE. */
 370         if (die->die_child != NULL) {
 371                 ret = _dwarf_die_gen_recursive(dbg, cu, drs, die->die_child,
 372                     pass2, error);
 373                 if (ret != DW_DLE_NONE)
 374                         return (ret);
 375         }
 376
 377         /* Proceed to sibling DIE. */
 378         if (die->die_right != NULL) {
 379                 ret = _dwarf_die_gen_recursive(dbg, cu, drs, die->die_right,
 380                     pass2, error);
 381                 if (ret != DW_DLE_NONE)
 382                         return (ret);
 383         }
 384
 385         /* Write a null DIE indicating the end of current level. */
 386         if (die->die_right == NULL) {
 387                 ret = _dwarf_write_uleb128_alloc(&ds->ds_data, &ds->ds_cap,
 388                     &ds->ds_size, 0, error);
 389                 if (ret != DW_DLE_NONE)
 390                         return (ret);
 391         }
 392
 393         return (DW_DLE_NONE);
 394 }
 395
 396 int
 397 _dwarf_die_gen(Dwarf_P_Debug dbg, Dwarf_CU cu, Dwarf_Rel_Section drs,
 398     Dwarf_Error *error)
 399 {
 400         Dwarf_Abbrev ab, tab;
 401         Dwarf_AttrDef ad, tad;
 402         Dwarf_Die die;
 403         int ret;
 404
 405         assert(dbg != NULL && cu != NULL);
 406         assert(dbg->dbgp_root_die != NULL);
 407
 408         die = dbg->dbgp_root_die;
 409
 410         /*
 411          * Insert a DW_AT_stmt_list attribute into root DIE, if there are
 412          * line number information.
 413          */
 414         if (!STAILQ_EMPTY(&dbg->dbgp_lineinfo->li_lnlist))
 415                 RCHECK(_dwarf_add_AT_dataref(dbg, die, DW_AT_stmt_list, 0, 0,
 416                     ".debug_line", NULL, error));
 417
 418         RCHECK(_dwarf_die_gen_recursive(dbg, cu, drs, die, 0, error));
 419
 420         if (cu->cu_pass2)
 421                 RCHECK(_dwarf_die_gen_recursive(dbg, cu, drs, die, 1, error));
 422
 423         return (DW_DLE_NONE);
 424
 425 gen_fail:
 426
 427         HASH_ITER(ab_hh, cu->cu_abbrev_hash, ab, tab) {
 428                 HASH_DELETE(ab_hh, cu->cu_abbrev_hash, ab);
 429                 STAILQ_FOREACH_SAFE(ad, &ab->ab_attrdef, ad_next, tad) {
 430                         STAILQ_REMOVE(&ab->ab_attrdef, ad, _Dwarf_AttrDef,
 431                             ad_next);
 432                         free(ad);
 433                 }
 434                 free(ab);
 435         }
 436
 437         return (ret);
 438 }
 439
 440 void
 441 _dwarf_die_pro_cleanup(Dwarf_P_Debug dbg)
 442 {
 443         Dwarf_P_Die die, tdie;
 444         Dwarf_P_Attribute at, tat;
 445
 446         assert(dbg != NULL && dbg->dbg_mode == DW_DLC_WRITE);
 447
 448         STAILQ_FOREACH_SAFE(die, &dbg->dbgp_dielist, die_pro_next, tdie) {
 449                 STAILQ_FOREACH_SAFE(at, &die->die_attr, at_next, tat) {
 450                         STAILQ_REMOVE(&die->die_attr, at, _Dwarf_Attribute,
 451                             at_next);
 452                         free(at);
 453                 }
 454                 free(die);
 455         }
 456 }