contrib/elftoolchain/addr2line/addr2line.c

   1 /*-
   2  * Copyright (c) 2009 Kai Wang
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 #include <sys/param.h>
  28 #include <dwarf.h>
  29 #include <err.h>
  30 #include <fcntl.h>
  31 #include <gelf.h>
  32 #include <getopt.h>
  33 #include <libdwarf.h>
  34 #include <libelftc.h>
  35 #include <libgen.h>
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39
  40 #include "uthash.h"
  41 #include "_elftc.h"
  42
  43 ELFTC_VCSID("$Id: addr2line.c 3446 2016-05-03 01:31:17Z emaste $");
  44
  45 struct Func {
  46         char *name;
  47         Dwarf_Unsigned lopc;
  48         Dwarf_Unsigned hipc;
  49         Dwarf_Unsigned call_file;
  50         Dwarf_Unsigned call_line;
  51         Dwarf_Ranges *ranges;
  52         Dwarf_Signed ranges_cnt;
  53         struct Func *inlined_caller;
  54         STAILQ_ENTRY(Func) next;
  55 };
  56
  57 struct CU {
  58         Dwarf_Off off;
  59         Dwarf_Unsigned lopc;
  60         Dwarf_Unsigned hipc;
  61         char **srcfiles;
  62         Dwarf_Signed nsrcfiles;
  63         STAILQ_HEAD(, Func) funclist;
  64         UT_hash_handle hh;
  65 };
  66
  67 static struct option longopts[] = {
  68         {"addresses", no_argument, NULL, 'a'},
  69         {"target" , required_argument, NULL, 'b'},
  70         {"demangle", no_argument, NULL, 'C'},
  71         {"exe", required_argument, NULL, 'e'},
  72         {"functions", no_argument, NULL, 'f'},
  73         {"inlines", no_argument, NULL, 'i'},
  74         {"section", required_argument, NULL, 'j'},
  75         {"pretty-print", no_argument, NULL, 'p'},
  76         {"basename", no_argument, NULL, 's'},
  77         {"help", no_argument, NULL, 'H'},
  78         {"version", no_argument, NULL, 'V'},
  79         {NULL, 0, NULL, 0}
  80 };
  81 static int demangle, func, base, inlines, print_addr, pretty_print;
  82 static char unknown[] = { '?', '?', '\0' };
  83 static Dwarf_Addr section_base;
  84 static struct CU *culist;
  85
  86 #define USAGE_MESSAGE   "\
  87 Usage: %s [options] hexaddress...\n\
  88   Map program addresses to source file names and line numbers.\n\n\
  89   Options:\n\
  90   -a      | --addresses       Display address prior to line number info.\n\
  91   -b TGT  | --target=TGT      (Accepted but ignored).\n\
  92   -e EXE  | --exe=EXE         Use program \"EXE\" to translate addresses.\n\
  93   -f      | --functions       Display function names.\n\
  94   -i      | --inlines         Display caller info for inlined functions.\n\
  95   -j NAME | --section=NAME    Values are offsets into section \"NAME\".\n\
  96   -p      | --pretty-print    Display line number info and function name\n\
  97                               in human readable manner.\n\
  98   -s      | --basename        Only show the base name for each file name.\n\
  99   -C      | --demangle        Demangle C++ names.\n\
 100   -H      | --help            Print a help message.\n\
 101   -V      | --version         Print a version identifier and exit.\n"
 102
 103 static void
 104 usage(void)
 105 {
 106         (void) fprintf(stderr, USAGE_MESSAGE, ELFTC_GETPROGNAME());
 107         exit(1);
 108 }
 109
 110 static void
 111 version(void)
 112 {
 113
 114         fprintf(stderr, "%s (%s)\n", ELFTC_GETPROGNAME(), elftc_version());
 115         exit(0);
 116 }
 117
 118 /*
 119  * Handle DWARF 4 'offset from' DW_AT_high_pc.  Although we don't
 120  * fully support DWARF 4, some compilers (like FreeBSD Clang 3.5.1)
 121  * generate DW_AT_high_pc as an offset from DW_AT_low_pc.
 122  *
 123  * "If the value of the DW_AT_high_pc is of class address, it is the
 124  * relocated address of the first location past the last instruction
 125  * associated with the entity; if it is of class constant, the value
 126  * is an unsigned integer offset which when added to the low PC gives
 127  * the address of the first location past the last instruction
 128  * associated with the entity."
 129  *
 130  * DWARF4 spec, section 2.17.2.
 131  */
 132 static int
 133 handle_high_pc(Dwarf_Die die, Dwarf_Unsigned lopc, Dwarf_Unsigned *hipc)
 134 {
 135         Dwarf_Error de;
 136         Dwarf_Half form;
 137         Dwarf_Attribute at;
 138         int ret;
 139
 140         ret = dwarf_attr(die, DW_AT_high_pc, &at, &de);
 141         if (ret == DW_DLV_ERROR) {
 142                 warnx("dwarf_attr failed: %s", dwarf_errmsg(de));
 143                 return (ret);
 144         }
 145         ret = dwarf_whatform(at, &form, &de);
 146         if (ret == DW_DLV_ERROR) {
 147                 warnx("dwarf_whatform failed: %s", dwarf_errmsg(de));
 148                 return (ret);
 149         }
 150         if (dwarf_get_form_class(2, 0, 0, form) == DW_FORM_CLASS_CONSTANT)
 151                 *hipc += lopc;
 152
 153         return (DW_DLV_OK);
 154 }
 155
 156 static struct Func *
 157 search_func(struct CU *cu, Dwarf_Unsigned addr)
 158 {
 159         struct Func *f, *f0;
 160         Dwarf_Unsigned lopc, hipc, addr_base;
 161         int i;
 162
 163         f0 = NULL;
 164
 165         STAILQ_FOREACH(f, &cu->funclist, next) {
 166                 if (f->ranges != NULL) {
 167                         addr_base = 0;
 168                         for (i = 0; i < f->ranges_cnt; i++) {
 169                                 if (f->ranges[i].dwr_type == DW_RANGES_END)
 170                                         break;
 171                                 if (f->ranges[i].dwr_type ==
 172                                     DW_RANGES_ADDRESS_SELECTION) {
 173                                         addr_base = f->ranges[i].dwr_addr2;
 174                                         continue;
 175                                 }
 176
 177                                 /* DW_RANGES_ENTRY */
 178                                 lopc = f->ranges[i].dwr_addr1 + addr_base;
 179                                 hipc = f->ranges[i].dwr_addr2 + addr_base;
 180                                 if (addr >= lopc && addr < hipc) {
 181                                         if (f0 == NULL ||
 182                                             (lopc >= f0->lopc &&
 183                                             hipc <= f0->hipc)) {
 184                                                 f0 = f;
 185                                                 f0->lopc = lopc;
 186                                                 f0->hipc = hipc;
 187                                                 break;
 188                                         }
 189                                 }
 190                         }
 191                 } else if (addr >= f->lopc && addr < f->hipc) {
 192                         if (f0 == NULL ||
 193                             (f->lopc >= f0->lopc && f->hipc <= f0->hipc))
 194                                 f0 = f;
 195                 }
 196         }
 197
 198         return (f0);
 199 }
 200
 201 static void
 202 collect_func(Dwarf_Debug dbg, Dwarf_Die die, struct Func *parent, struct CU *cu)
 203 {
 204         Dwarf_Die ret_die, abst_die, spec_die;
 205         Dwarf_Error de;
 206         Dwarf_Half tag;
 207         Dwarf_Unsigned lopc, hipc, ranges_off;
 208         Dwarf_Signed ranges_cnt;
 209         Dwarf_Off ref;
 210         Dwarf_Attribute abst_at, spec_at;
 211         Dwarf_Ranges *ranges;
 212         const char *funcname;
 213         struct Func *f;
 214         int found_ranges, ret;
 215
 216         f = NULL;
 217         abst_die = spec_die = NULL;
 218
 219         if (dwarf_tag(die, &tag, &de)) {
 220                 warnx("dwarf_tag: %s", dwarf_errmsg(de));
 221                 goto cont_search;
 222         }
 223         if (tag == DW_TAG_subprogram || tag == DW_TAG_entry_point ||
 224             tag == DW_TAG_inlined_subroutine) {
 225                 /*
 226                  * Function address range can be specified by either
 227                  * a DW_AT_ranges attribute which points to a range list or
 228                  * by a pair of DW_AT_low_pc and DW_AT_high_pc attributes.
 229                  */
 230                 ranges = NULL;
 231                 ranges_cnt = 0;
 232                 found_ranges = 0;
 233                 if (dwarf_attrval_unsigned(die, DW_AT_ranges, &ranges_off,
 234                     &de) == DW_DLV_OK &&
 235                     dwarf_get_ranges(dbg, (Dwarf_Off) ranges_off, &ranges,
 236                     &ranges_cnt, NULL, &de) == DW_DLV_OK) {
 237                         if (ranges != NULL && ranges_cnt > 0) {
 238                                 found_ranges = 1;
 239                                 goto get_func_name;
 240                         }
 241                 }
 242
 243                 /*
 244                  * Search for DW_AT_low_pc/DW_AT_high_pc if ranges pointer
 245                  * not found.
 246                  */
 247                 if (dwarf_attrval_unsigned(die, DW_AT_low_pc, &lopc, &de) ||
 248                     dwarf_attrval_unsigned(die, DW_AT_high_pc, &hipc, &de))
 249                         goto cont_search;
 250                 if (handle_high_pc(die, lopc, &hipc) != DW_DLV_OK)
 251                         goto cont_search;
 252
 253         get_func_name:
 254                 /*
 255                  * Most common case the function name is stored in DW_AT_name
 256                  * attribute.
 257                  */
 258                 if (dwarf_attrval_string(die, DW_AT_name, &funcname, &de) ==
 259                     DW_DLV_OK)
 260                         goto add_func;
 261
 262                 /*
 263                  * For inlined function, the actual name is probably in the DIE
 264                  * referenced by DW_AT_abstract_origin. (if present)
 265                  */
 266                 if (dwarf_attr(die, DW_AT_abstract_origin, &abst_at, &de) ==
 267                     DW_DLV_OK &&
 268                     dwarf_global_formref(abst_at, &ref, &de) == DW_DLV_OK &&
 269                     dwarf_offdie(dbg, ref, &abst_die, &de) == DW_DLV_OK &&
 270                     dwarf_attrval_string(abst_die, DW_AT_name, &funcname,
 271                     &de) == DW_DLV_OK)
 272                         goto add_func;
 273
 274                 /*
 275                  * If DW_AT_name is not present, but DW_AT_specification is
 276                  * present, then probably the actual name is in the DIE
 277                  * referenced by DW_AT_specification.
 278                  */
 279                 if (dwarf_attr(die, DW_AT_specification, &spec_at, &de) ==
 280                     DW_DLV_OK &&
 281                     dwarf_global_formref(spec_at, &ref, &de) == DW_DLV_OK &&
 282                     dwarf_offdie(dbg, ref, &spec_die, &de) == DW_DLV_OK &&
 283                     dwarf_attrval_string(spec_die, DW_AT_name, &funcname,
 284                     &de) == DW_DLV_OK)
 285                         goto add_func;
 286
 287                 /* Skip if no name associated with this DIE. */
 288                 goto cont_search;
 289
 290         add_func:
 291                 if ((f = calloc(1, sizeof(*f))) == NULL)
 292                         err(EXIT_FAILURE, "calloc");
 293                 if ((f->name = strdup(funcname)) == NULL)
 294                         err(EXIT_FAILURE, "strdup");
 295                 if (found_ranges) {
 296                         f->ranges = ranges;
 297                         f->ranges_cnt = ranges_cnt;
 298                 } else {
 299                         f->lopc = lopc;
 300                         f->hipc = hipc;
 301                 }
 302                 if (tag == DW_TAG_inlined_subroutine) {
 303                         f->inlined_caller = parent;
 304                         dwarf_attrval_unsigned(die, DW_AT_call_file,
 305                             &f->call_file, &de);
 306                         dwarf_attrval_unsigned(die, DW_AT_call_line,
 307                             &f->call_line, &de);
 308                 }
 309                 STAILQ_INSERT_TAIL(&cu->funclist, f, next);
 310         }
 311
 312 cont_search:
 313
 314         /* Search children. */
 315         ret = dwarf_child(die, &ret_die, &de);
 316         if (ret == DW_DLV_ERROR)
 317                 warnx("dwarf_child: %s", dwarf_errmsg(de));
 318         else if (ret == DW_DLV_OK) {
 319                 if (f != NULL)
 320                         collect_func(dbg, ret_die, f, cu);
 321                 else
 322                         collect_func(dbg, ret_die, parent, cu);
 323         }
 324
 325         /* Search sibling. */
 326         ret = dwarf_siblingof(dbg, die, &ret_die, &de);
 327         if (ret == DW_DLV_ERROR)
 328                 warnx("dwarf_siblingof: %s", dwarf_errmsg(de));
 329         else if (ret == DW_DLV_OK)
 330                 collect_func(dbg, ret_die, parent, cu);
 331
 332         /* Cleanup */
 333         dwarf_dealloc(dbg, die, DW_DLA_DIE);
 334
 335         if (abst_die != NULL)
 336                 dwarf_dealloc(dbg, abst_die, DW_DLA_DIE);
 337
 338         if (spec_die != NULL)
 339                 dwarf_dealloc(dbg, spec_die, DW_DLA_DIE);
 340 }
 341
 342 static void
 343 print_inlines(struct CU *cu, struct Func *f, Dwarf_Unsigned call_file,
 344     Dwarf_Unsigned call_line)
 345 {
 346         char demangled[1024];
 347         char *file;
 348
 349         if (call_file > 0 && (Dwarf_Signed) call_file <= cu->nsrcfiles)
 350                 file = cu->srcfiles[call_file - 1];
 351         else
 352                 file = unknown;
 353
 354         if (pretty_print)
 355                 printf(" (inlined by) ");
 356
 357         if (func) {
 358                 if (demangle && !elftc_demangle(f->name, demangled,
 359                     sizeof(demangled), 0)) {
 360                         if (pretty_print)
 361                                 printf("%s at ", demangled);
 362                         else
 363                                 printf("%s\n", demangled);
 364                 } else {
 365                         if (pretty_print)
 366                                 printf("%s at ", f->name);
 367                         else
 368                                 printf("%s\n", f->name);
 369                 }
 370         }
 371         (void) printf("%s:%ju\n", base ? basename(file) : file,
 372             (uintmax_t) call_line);
 373
 374         if (f->inlined_caller != NULL)
 375                 print_inlines(cu, f->inlined_caller, f->call_file,
 376                     f->call_line);
 377 }
 378
 379 static void
 380 translate(Dwarf_Debug dbg, Elf *e, const char* addrstr)
 381 {
 382         Dwarf_Die die, ret_die;
 383         Dwarf_Line *lbuf;
 384         Dwarf_Error de;
 385         Dwarf_Half tag;
 386         Dwarf_Unsigned lopc, hipc, addr, lineno, plineno;
 387         Dwarf_Signed lcount;
 388         Dwarf_Addr lineaddr, plineaddr;
 389         Dwarf_Off off;
 390         struct CU *cu;
 391         struct Func *f;
 392         const char *funcname;
 393         char *file, *file0, *pfile;
 394         char demangled[1024];
 395         int ec, i, ret;
 396
 397         addr = strtoull(addrstr, NULL, 16);
 398         addr += section_base;
 399         lineno = 0;
 400         file = unknown;
 401         cu = NULL;
 402         die = NULL;
 403
 404         while ((ret = dwarf_next_cu_header(dbg, NULL, NULL, NULL, NULL, NULL,
 405             &de)) ==  DW_DLV_OK) {
 406                 die = NULL;
 407                 while (dwarf_siblingof(dbg, die, &ret_die, &de) == DW_DLV_OK) {
 408                         if (die != NULL)
 409                                 dwarf_dealloc(dbg, die, DW_DLA_DIE);
 410                         die = ret_die;
 411                         if (dwarf_tag(die, &tag, &de) != DW_DLV_OK) {
 412                                 warnx("dwarf_tag failed: %s",
 413                                     dwarf_errmsg(de));
 414                                 goto next_cu;
 415                         }
 416
 417                         /* XXX: What about DW_TAG_partial_unit? */
 418                         if (tag == DW_TAG_compile_unit)
 419                                 break;
 420                 }
 421                 if (ret_die == NULL) {
 422                         warnx("could not find DW_TAG_compile_unit die");
 423                         goto next_cu;
 424                 }
 425                 if (dwarf_attrval_unsigned(die, DW_AT_low_pc, &lopc, &de) ==
 426                     DW_DLV_OK) {
 427                         if (dwarf_attrval_unsigned(die, DW_AT_high_pc, &hipc,
 428                            &de) == DW_DLV_OK) {
 429                                 /*
 430                                  * Check if the address falls into the PC
 431                                  * range of this CU.
 432                                  */
 433                                 if (handle_high_pc(die, lopc, &hipc) !=
 434                                     DW_DLV_OK)
 435                                         goto out;
 436                         } else {
 437                                 /* Assume ~0ULL if DW_AT_high_pc not present */
 438                                 hipc = ~0ULL;
 439                         }
 440
 441                         /*
 442                          * Record the CU in the hash table for faster lookup
 443                          * later.
 444                          */
 445                         if (dwarf_dieoffset(die, &off, &de) != DW_DLV_OK) {
 446                                 warnx("dwarf_dieoffset failed: %s",
 447                                     dwarf_errmsg(de));
 448                                 goto out;
 449                         }
 450                         HASH_FIND(hh, culist, &off, sizeof(off), cu);
 451                         if (cu == NULL) {
 452                                 if ((cu = calloc(1, sizeof(*cu))) == NULL)
 453                                         err(EXIT_FAILURE, "calloc");
 454                                 cu->off = off;
 455                                 cu->lopc = lopc;
 456                                 cu->hipc = hipc;
 457                                 STAILQ_INIT(&cu->funclist);
 458                                 HASH_ADD(hh, culist, off, sizeof(off), cu);
 459                         }
 460
 461                         if (addr >= lopc && addr < hipc)
 462                                 break;
 463                 }
 464
 465         next_cu:
 466                 if (die != NULL) {
 467                         dwarf_dealloc(dbg, die, DW_DLA_DIE);
 468                         die = NULL;
 469                 }
 470         }
 471
 472         if (ret != DW_DLV_OK || die == NULL)
 473                 goto out;
 474
 475         switch (dwarf_srclines(die, &lbuf, &lcount, &de)) {
 476         case DW_DLV_OK:
 477                 break;
 478         case DW_DLV_NO_ENTRY:
 479                 /* If a CU lacks debug info, just skip it. */
 480                 goto out;
 481         default:
 482                 warnx("dwarf_srclines: %s", dwarf_errmsg(de));
 483                 goto out;
 484         }
 485
 486         plineaddr = ~0ULL;
 487         plineno = 0;
 488         pfile = unknown;
 489         for (i = 0; i < lcount; i++) {
 490                 if (dwarf_lineaddr(lbuf[i], &lineaddr, &de)) {
 491                         warnx("dwarf_lineaddr: %s", dwarf_errmsg(de));
 492                         goto out;
 493                 }
 494                 if (dwarf_lineno(lbuf[i], &lineno, &de)) {
 495                         warnx("dwarf_lineno: %s", dwarf_errmsg(de));
 496                         goto out;
 497                 }
 498                 if (dwarf_linesrc(lbuf[i], &file0, &de)) {
 499                         warnx("dwarf_linesrc: %s", dwarf_errmsg(de));
 500                 } else
 501                         file = file0;
 502                 if (addr == lineaddr)
 503                         goto out;
 504                 else if (addr < lineaddr && addr > plineaddr) {
 505                         lineno = plineno;
 506                         file = pfile;
 507                         goto out;
 508                 }
 509                 plineaddr = lineaddr;
 510                 plineno = lineno;
 511                 pfile = file;
 512         }
 513
 514 out:
 515         f = NULL;
 516         funcname = NULL;
 517         if (ret == DW_DLV_OK && (func || inlines) && cu != NULL) {
 518                 if (cu->srcfiles == NULL)
 519                         if (dwarf_srcfiles(die, &cu->srcfiles, &cu->nsrcfiles,
 520                             &de))
 521                                 warnx("dwarf_srcfiles: %s", dwarf_errmsg(de));
 522                 if (STAILQ_EMPTY(&cu->funclist)) {
 523                         collect_func(dbg, die, NULL, cu);
 524                         die = NULL;
 525                 }
 526                 f = search_func(cu, addr);
 527                 if (f != NULL)
 528                         funcname = f->name;
 529         }
 530
 531         if (print_addr) {
 532                 if ((ec = gelf_getclass(e)) == ELFCLASSNONE) {
 533                         warnx("gelf_getclass failed: %s", elf_errmsg(-1));
 534                         ec = ELFCLASS64;
 535                 }
 536                 if (ec == ELFCLASS32) {
 537                         if (pretty_print)
 538                                 printf("0x%08jx: ", (uintmax_t) addr);
 539                         else
 540                                 printf("0x%08jx\n", (uintmax_t) addr);
 541                 } else {
 542                         if (pretty_print)
 543                                 printf("0x%016jx: ", (uintmax_t) addr);
 544                         else
 545                                 printf("0x%016jx\n", (uintmax_t) addr);
 546                 }
 547         }
 548
 549         if (func) {
 550                 if (funcname == NULL)
 551                         funcname = unknown;
 552                 if (demangle && !elftc_demangle(funcname, demangled,
 553                     sizeof(demangled), 0)) {
 554                         if (pretty_print)
 555                                 printf("%s at ", demangled);
 556                         else
 557                                 printf("%s\n", demangled);
 558                 } else {
 559                         if (pretty_print)
 560                                 printf("%s at ", funcname);
 561                         else
 562                                 printf("%s\n", funcname);
 563                 }
 564         }
 565
 566         (void) printf("%s:%ju\n", base ? basename(file) : file,
 567             (uintmax_t) lineno);
 568
 569         if (ret == DW_DLV_OK && inlines && cu != NULL &&
 570             cu->srcfiles != NULL && f != NULL && f->inlined_caller != NULL)
 571                 print_inlines(cu, f->inlined_caller, f->call_file,
 572                     f->call_line);
 573
 574         if (die != NULL)
 575                 dwarf_dealloc(dbg, die, DW_DLA_DIE);
 576
 577         /*
 578          * Reset internal CU pointer, so we will start from the first CU
 579          * next round.
 580          */
 581         while (ret != DW_DLV_NO_ENTRY) {
 582                 if (ret == DW_DLV_ERROR)
 583                         errx(EXIT_FAILURE, "dwarf_next_cu_header: %s",
 584                             dwarf_errmsg(de));
 585                 ret = dwarf_next_cu_header(dbg, NULL, NULL, NULL, NULL, NULL,
 586                     &de);
 587         }
 588 }
 589
 590 static void
 591 find_section_base(const char *exe, Elf *e, const char *section)
 592 {
 593         Dwarf_Addr off;
 594         Elf_Scn *scn;
 595         GElf_Ehdr eh;
 596         GElf_Shdr sh;
 597         size_t shstrndx;
 598         int elferr;
 599         const char *name;
 600
 601         if (gelf_getehdr(e, &eh) != &eh) {
 602                 warnx("gelf_getehdr failed: %s", elf_errmsg(-1));
 603                 return;
 604         }
 605
 606         if (!elf_getshstrndx(e, &shstrndx)) {
 607                 warnx("elf_getshstrndx failed: %s", elf_errmsg(-1));
 608                 return;
 609         }
 610
 611         (void) elf_errno();
 612         off = 0;
 613         scn = NULL;
 614         while ((scn = elf_nextscn(e, scn)) != NULL) {
 615                 if (gelf_getshdr(scn, &sh) == NULL) {
 616                         warnx("gelf_getshdr failed: %s", elf_errmsg(-1));
 617                         continue;
 618                 }
 619                 if ((name = elf_strptr(e, shstrndx, sh.sh_name)) == NULL)
 620                         goto next;
 621                 if (!strcmp(section, name)) {
 622                         if (eh.e_type == ET_EXEC || eh.e_type == ET_DYN) {
 623                                 /*
 624                                  * For executables, section base is the virtual
 625                                  * address of the specified section.
 626                                  */
 627                                 section_base = sh.sh_addr;
 628                         } else if (eh.e_type == ET_REL) {
 629                                 /*
 630                                  * For relocatables, section base is the
 631                                  * relative offset of the specified section
 632                                  * to the start of the first section.
 633                                  */
 634                                 section_base = off;
 635                         } else
 636                                 warnx("unknown e_type %u", eh.e_type);
 637                         return;
 638                 }
 639         next:
 640                 off += sh.sh_size;
 641         }
 642         elferr = elf_errno();
 643         if (elferr != 0)
 644                 warnx("elf_nextscn failed: %s", elf_errmsg(elferr));
 645
 646         errx(EXIT_FAILURE, "%s: cannot find section %s", exe, section);
 647 }
 648
 649 int
 650 main(int argc, char **argv)
 651 {
 652         Elf *e;
 653         Dwarf_Debug dbg;
 654         Dwarf_Error de;
 655         const char *exe, *section;
 656         char line[1024];
 657         int fd, i, opt;
 658
 659         exe = NULL;
 660         section = NULL;
 661         while ((opt = getopt_long(argc, argv, "ab:Ce:fij:psHV", longopts,
 662             NULL)) != -1) {
 663                 switch (opt) {
 664                 case 'a':
 665                         print_addr = 1;
 666                         break;
 667                 case 'b':
 668                         /* ignored */
 669                         break;
 670                 case 'C':
 671                         demangle = 1;
 672                         break;
 673                 case 'e':
 674                         exe = optarg;
 675                         break;
 676                 case 'f':
 677                         func = 1;
 678                         break;
 679                 case 'i':
 680                         inlines = 1;
 681                         break;
 682                 case 'j':
 683                         section = optarg;
 684                         break;
 685                 case 'p':
 686                         pretty_print = 1;
 687                         break;
 688                 case 's':
 689                         base = 1;
 690                         break;
 691                 case 'H':
 692                         usage();
 693                 case 'V':
 694                         version();
 695                 default:
 696                         usage();
 697                 }
 698         }
 699
 700         argv += optind;
 701         argc -= optind;
 702
 703         if (exe == NULL)
 704                 exe = "a.out";
 705
 706         if ((fd = open(exe, O_RDONLY)) < 0)
 707                 err(EXIT_FAILURE, "%s", exe);
 708
 709         if (dwarf_init(fd, DW_DLC_READ, NULL, NULL, &dbg, &de))
 710                 errx(EXIT_FAILURE, "dwarf_init: %s", dwarf_errmsg(de));
 711
 712         if (dwarf_get_elf(dbg, &e, &de) != DW_DLV_OK)
 713                 errx(EXIT_FAILURE, "dwarf_get_elf: %s", dwarf_errmsg(de));
 714
 715         if (section)
 716                 find_section_base(exe, e, section);
 717         else
 718                 section_base = 0;
 719
 720         if (argc > 0)
 721                 for (i = 0; i < argc; i++)
 722                         translate(dbg, e, argv[i]);
 723         else
 724                 while (fgets(line, sizeof(line), stdin) != NULL) {
 725                         translate(dbg, e, line);
 726                         fflush(stdout);
 727                 }
 728
 729         dwarf_finish(dbg, &de);
 730
 731         (void) elf_end(e);
 732
 733         exit(0);
 734 }