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 2948 2013-05-30 21:25:52Z 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         if (diep != NULL)
  74                 *diep = die;
  75
  76         return (DW_DLE_NONE);
  77 }
  78
  79 /* Find die at offset 'off' within the same CU. */
  80 Dwarf_Die
  81 _dwarf_die_find(Dwarf_Die die, Dwarf_Unsigned off)
  82 {
  83         Dwarf_Debug dbg;
  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
  92         ret = _dwarf_die_parse(dbg, dbg->dbg_info_sec, cu, cu->cu_dwarf_size,
  93             off, cu->cu_next_offset, &die1, 0, &de);
  94
  95         if (ret == DW_DLE_NONE)
  96                 return (die1);
  97         else
  98                 return (NULL);
  99 }
 100
 101 int
 102 _dwarf_die_parse(Dwarf_Debug dbg, Dwarf_Section *ds, Dwarf_CU cu,
 103     int dwarf_size, uint64_t offset, uint64_t next_offset, Dwarf_Die *ret_die,
 104     int search_sibling, Dwarf_Error *error)
 105 {
 106         Dwarf_Abbrev ab;
 107         Dwarf_AttrDef ad;
 108         Dwarf_Die die;
 109         uint64_t abnum;
 110         uint64_t die_offset;
 111         int ret, level;
 112
 113         assert(cu != NULL);
 114
 115         level = 1;
 116         die = NULL;
 117
 118         while (offset < next_offset && offset < ds->ds_size) {
 119
 120                 die_offset = offset;
 121
 122                 abnum = _dwarf_read_uleb128(ds->ds_data, &offset);
 123
 124                 if (abnum == 0) {
 125                         if (level == 0 || !search_sibling)
 126                                 return (DW_DLE_NO_ENTRY);
 127
 128                         /*
 129                          * Return to previous DIE level.
 130                          */
 131                         level--;
 132                         continue;
 133                 }
 134
 135                 if ((ret = _dwarf_abbrev_find(cu, abnum, &ab, error)) !=
 136                     DW_DLE_NONE)
 137                         return (ret);
 138
 139                 if ((ret = _dwarf_die_add(cu, die_offset, abnum, ab, &die,
 140                     error)) != DW_DLE_NONE)
 141                         return (ret);
 142
 143                 STAILQ_FOREACH(ad, &ab->ab_attrdef, ad_next) {
 144                         if ((ret = _dwarf_attr_init(dbg, ds, &offset,
 145                             dwarf_size, cu, die, ad, ad->ad_form, 0,
 146                             error)) != DW_DLE_NONE)
 147                                 return (ret);
 148                 }
 149
 150                 die->die_next_off = offset;
 151                 if (search_sibling && level > 0) {
 152                         dwarf_dealloc(dbg, die, DW_DLA_DIE);
 153                         if (ab->ab_children == DW_CHILDREN_yes) {
 154                                 /* Advance to next DIE level. */
 155                                 level++;
 156                         }
 157                 } else {
 158                         *ret_die = die;
 159                         return (DW_DLE_NONE);
 160                 }
 161         }
 162
 163         return (DW_DLE_NO_ENTRY);
 164 }
 165
 166 void
 167 _dwarf_die_link(Dwarf_P_Die die, Dwarf_P_Die parent, Dwarf_P_Die child,
 168     Dwarf_P_Die left_sibling, Dwarf_P_Die right_sibling)
 169 {
 170         Dwarf_P_Die last_child;
 171
 172         assert(die != NULL);
 173
 174         if (parent) {
 175
 176                 /* Disconnect from old parent. */
 177                 if (die->die_parent) {
 178                         if (die->die_parent != parent) {
 179                                 if (die->die_parent->die_child == die)
 180                                         die->die_parent->die_child = NULL;
 181                                 die->die_parent = NULL;
 182                      }
 183                 }
 184
 185                 /* Find the last child of this parent. */
 186                 last_child = parent->die_child;
 187                 if (last_child) {
 188                         while (last_child->die_right != NULL)
 189                                 last_child = last_child->die_right;
 190                 }
 191
 192                 /* Connect to new parent. */
 193                 die->die_parent = parent;
 194
 195                 /*
 196                  * Attach this DIE to the end of sibling list. If new
 197                  * parent doesn't have any child, set this DIE as the
 198                  * first child.
 199                  */
 200                 if (last_child) {
 201                         assert(last_child->die_right == NULL);
 202                         last_child->die_right = die;
 203                         die->die_left = last_child;
 204                 } else
 205                         parent->die_child = die;
 206         }
 207
 208         if (child) {
 209
 210                 /* Disconnect from old child. */
 211                 if (die->die_child) {
 212                         if (die->die_child != child) {
 213                                 die->die_child->die_parent = NULL;
 214                                 die->die_child = NULL;
 215                         }
 216                 }
 217
 218                 /* Connect to new child. */
 219                 die->die_child = child;
 220                 child->die_parent = die;
 221         }
 222
 223         if (left_sibling) {
 224
 225                 /* Disconnect from old left sibling. */
 226                 if (die->die_left) {
 227                         if (die->die_left != left_sibling) {
 228                                 die->die_left->die_right = NULL;
 229                                 die->die_left = NULL;
 230                         }
 231                 }
 232
 233                 /* Connect to new right sibling. */
 234                 die->die_left = left_sibling;
 235                 left_sibling->die_right = die;
 236         }
 237
 238         if (right_sibling) {
 239
 240                 /* Disconnect from old right sibling. */
 241                 if (die->die_right) {
 242                         if (die->die_right != right_sibling) {
 243                                 die->die_right->die_left = NULL;
 244                                 die->die_right = NULL;
 245                         }
 246                 }
 247
 248                 /* Connect to new right sibling. */
 249                 die->die_right = right_sibling;
 250                 right_sibling->die_left = die;
 251         }
 252 }
 253
 254 int
 255 _dwarf_die_count_links(Dwarf_P_Die parent, Dwarf_P_Die child,
 256     Dwarf_P_Die left_sibling, Dwarf_P_Die right_sibling)
 257 {
 258         int count;
 259
 260         count = 0;
 261
 262         if (parent)
 263                 count++;
 264         if (child)
 265                 count++;
 266         if (left_sibling)
 267                 count++;
 268         if (right_sibling)
 269                 count++;
 270
 271         return (count);
 272 }
 273
 274 static int
 275 _dwarf_die_gen_recursive(Dwarf_P_Debug dbg, Dwarf_CU cu, Dwarf_Rel_Section drs,
 276     Dwarf_P_Die die, int pass2, Dwarf_Error *error)
 277 {
 278         Dwarf_P_Section ds;
 279         Dwarf_Abbrev ab;
 280         Dwarf_Attribute at;
 281         Dwarf_AttrDef ad;
 282         int match, ret;
 283
 284         ds = dbg->dbgp_info;
 285         assert(ds != NULL);
 286
 287         if (pass2)
 288                 goto attr_gen;
 289
 290         /*
 291          * Add DW_AT_sibling attribute for DIEs with children, so consumers
 292          * can quickly scan chains of siblings, while ignoring the children
 293          * of individual siblings.
 294          */
 295         if (die->die_child && die->die_right) {
 296                 if (_dwarf_attr_find(die, DW_AT_sibling) == NULL)
 297                         (void) dwarf_add_AT_reference(dbg, die, DW_AT_sibling,
 298                             die->die_right, error);
 299         }
 300
 301         /*
 302          * Search abbrev list to find a matching entry.
 303          */
 304         die->die_ab = NULL;
 305         for (ab = cu->cu_abbrev_hash; ab != NULL; ab = ab->ab_hh.next) {
 306                 if (die->die_tag != ab->ab_tag)
 307                         continue;
 308                 if (ab->ab_children == DW_CHILDREN_no && die->die_child != NULL)
 309                         continue;
 310                 if (ab->ab_children == DW_CHILDREN_yes &&
 311                     die->die_child == NULL)
 312                         continue;
 313                 at = STAILQ_FIRST(&die->die_attr);
 314                 ad = STAILQ_FIRST(&ab->ab_attrdef);
 315                 match = 1;
 316                 while (at != NULL && ad != NULL) {
 317                         if (at->at_attrib != ad->ad_attrib ||
 318                             at->at_form != ad->ad_form) {
 319                                 match = 0;
 320                                 break;
 321                         }
 322                         at = STAILQ_NEXT(at, at_next);
 323                         ad = STAILQ_NEXT(ad, ad_next);
 324                 }
 325                 if ((at == NULL && ad != NULL) || (at != NULL && ad == NULL))
 326                         match = 0;
 327                 if (match) {
 328                         die->die_ab = ab;
 329                         break;
 330                 }
 331         }
 332
 333         /*
 334          * Create a new abbrev entry if we can not reuse any existing one.
 335          */
 336         if (die->die_ab == NULL) {
 337                 ret = _dwarf_abbrev_add(cu, ++cu->cu_abbrev_cnt, die->die_tag,
 338                     die->die_child != NULL ? DW_CHILDREN_yes : DW_CHILDREN_no,
 339                     0, &ab, error);
 340                 if (ret != DW_DLE_NONE)
 341                         return (ret);
 342                 STAILQ_FOREACH(at, &die->die_attr, at_next) {
 343                         ret = _dwarf_attrdef_add(dbg, ab, at->at_attrib,
 344                             at->at_form, 0, NULL, error);
 345                         if (ret != DW_DLE_NONE)
 346                                 return (ret);
 347                 }
 348                 die->die_ab = ab;
 349         }
 350
 351         die->die_offset = ds->ds_size;
 352
 353         /*
 354          * Transform the DIE to bytes stream.
 355          */
 356         ret = _dwarf_write_uleb128_alloc(&ds->ds_data, &ds->ds_cap,
 357             &ds->ds_size, die->die_ab->ab_entry, error);
 358         if (ret != DW_DLE_NONE)
 359                 return (ret);
 360
 361 attr_gen:
 362
 363         /* Transform the attributes of this DIE. */
 364         ret = _dwarf_attr_gen(dbg, ds, drs, cu, die, pass2, error);
 365         if (ret != DW_DLE_NONE)
 366                 return (ret);
 367
 368         /* Proceed to child DIE. */
 369         if (die->die_child != NULL) {
 370                 ret = _dwarf_die_gen_recursive(dbg, cu, drs, die->die_child,
 371                     pass2, error);
 372                 if (ret != DW_DLE_NONE)
 373                         return (ret);
 374         }
 375
 376         /* Proceed to sibling DIE. */
 377         if (die->die_right != NULL) {
 378                 ret = _dwarf_die_gen_recursive(dbg, cu, drs, die->die_right,
 379                     pass2, error);
 380                 if (ret != DW_DLE_NONE)
 381                         return (ret);
 382         }
 383
 384         /* Write a null DIE indicating the end of current level. */
 385         if (die->die_right == NULL) {
 386                 ret = _dwarf_write_uleb128_alloc(&ds->ds_data, &ds->ds_cap,
 387                     &ds->ds_size, 0, error);
 388                 if (ret != DW_DLE_NONE)
 389                         return (ret);
 390         }
 391
 392         return (DW_DLE_NONE);
 393 }
 394
 395 int
 396 _dwarf_die_gen(Dwarf_P_Debug dbg, Dwarf_CU cu, Dwarf_Rel_Section drs,
 397     Dwarf_Error *error)
 398 {
 399         Dwarf_Abbrev ab, tab;
 400         Dwarf_AttrDef ad, tad;
 401         Dwarf_Die die;
 402         int ret;
 403
 404         assert(dbg != NULL && cu != NULL);
 405         assert(dbg->dbgp_root_die != NULL);
 406
 407         die = dbg->dbgp_root_die;
 408
 409         /*
 410          * Insert a DW_AT_stmt_list attribute into root DIE, if there are
 411          * line number information.
 412          */
 413         if (!STAILQ_EMPTY(&dbg->dbgp_lineinfo->li_lnlist))
 414                 RCHECK(_dwarf_add_AT_dataref(dbg, die, DW_AT_stmt_list, 0, 0,
 415                     ".debug_line", NULL, error));
 416
 417         RCHECK(_dwarf_die_gen_recursive(dbg, cu, drs, die, 0, error));
 418
 419         if (cu->cu_pass2)
 420                 RCHECK(_dwarf_die_gen_recursive(dbg, cu, drs, die, 1, error));
 421
 422         return (DW_DLE_NONE);
 423
 424 gen_fail:
 425
 426         HASH_ITER(ab_hh, cu->cu_abbrev_hash, ab, tab) {
 427                 HASH_DELETE(ab_hh, cu->cu_abbrev_hash, ab);
 428                 STAILQ_FOREACH_SAFE(ad, &ab->ab_attrdef, ad_next, tad) {
 429                         STAILQ_REMOVE(&ab->ab_attrdef, ad, _Dwarf_AttrDef,
 430                             ad_next);
 431                         free(ad);
 432                 }
 433                 free(ab);
 434         }
 435
 436         return (ret);
 437 }
 438
 439 void
 440 _dwarf_die_pro_cleanup(Dwarf_P_Debug dbg)
 441 {
 442         Dwarf_P_Die die, tdie;
 443         Dwarf_P_Attribute at, tat;
 444
 445         assert(dbg != NULL && dbg->dbg_mode == DW_DLC_WRITE);
 446
 447         STAILQ_FOREACH_SAFE(die, &dbg->dbgp_dielist, die_pro_next, tdie) {
 448                 STAILQ_FOREACH_SAFE(at, &die->die_attr, at_next, tat) {
 449                         STAILQ_REMOVE(&die->die_attr, at, _Dwarf_Attribute,
 450                             at_next);
 451                         free(at);
 452                 }
 453                 free(die);
 454         }
 455 }