lib/DebugInfo/DWARFDebugInfoEntry.cpp

   1 //===-- DWARFDebugInfoEntry.cpp -------------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "DWARFDebugInfoEntry.h"
  11 #include "DWARFCompileUnit.h"
  12 #include "DWARFContext.h"
  13 #include "DWARFDebugAbbrev.h"
  14 #include "DWARFFormValue.h"
  15 #include "llvm/Support/Dwarf.h"
  16 #include "llvm/Support/Format.h"
  17 #include "llvm/Support/raw_ostream.h"
  18 using namespace llvm;
  19 using namespace dwarf;
  20
  21 void DWARFDebugInfoEntryMinimal::dump(raw_ostream &OS,
  22                                       const DWARFCompileUnit *cu,
  23                                       unsigned recurseDepth,
  24                                       unsigned indent) const {
  25   DataExtractor debug_info_data = cu->getDebugInfoExtractor();
  26   uint32_t offset = Offset;
  27
  28   if (debug_info_data.isValidOffset(offset)) {
  29     uint32_t abbrCode = debug_info_data.getULEB128(&offset);
  30
  31     OS << format("\n0x%8.8x: ", Offset);
  32     if (abbrCode) {
  33       if (AbbrevDecl) {
  34         const char *tagString = TagString(getTag());
  35         if (tagString)
  36           OS.indent(indent) << tagString;
  37         else
  38           OS.indent(indent) << format("DW_TAG_Unknown_%x", getTag());
  39         OS << format(" [%u] %c\n", abbrCode,
  40                      AbbrevDecl->hasChildren() ? '*' : ' ');
  41
  42         // Dump all data in the .debug_info for the attributes
  43         const uint32_t numAttributes = AbbrevDecl->getNumAttributes();
  44         for (uint32_t i = 0; i != numAttributes; ++i) {
  45           uint16_t attr = AbbrevDecl->getAttrByIndex(i);
  46           uint16_t form = AbbrevDecl->getFormByIndex(i);
  47           dumpAttribute(OS, cu, &offset, attr, form, indent);
  48         }
  49
  50         const DWARFDebugInfoEntryMinimal *child = getFirstChild();
  51         if (recurseDepth > 0 && child) {
  52           while (child) {
  53             child->dump(OS, cu, recurseDepth-1, indent+2);
  54             child = child->getSibling();
  55           }
  56         }
  57       } else {
  58         OS << "Abbreviation code not found in 'debug_abbrev' class for code: "
  59            << abbrCode << '\n';
  60       }
  61     } else {
  62       OS.indent(indent) << "NULL\n";
  63     }
  64   }
  65 }
  66
  67 void DWARFDebugInfoEntryMinimal::dumpAttribute(raw_ostream &OS,
  68                                                const DWARFCompileUnit *cu,
  69                                                uint32_t* offset_ptr,
  70                                                uint16_t attr,
  71                                                uint16_t form,
  72                                                unsigned indent) const {
  73   OS << format("0x%8.8x: ", *offset_ptr);
  74   OS.indent(indent+2);
  75   const char *attrString = AttributeString(attr);
  76   if (attrString)
  77     OS << attrString;
  78   else
  79     OS << format("DW_AT_Unknown_%x", attr);
  80   const char *formString = FormEncodingString(form);
  81   if (formString)
  82     OS << " [" << formString << ']';
  83   else
  84     OS << format(" [DW_FORM_Unknown_%x]", form);
  85
  86   DWARFFormValue formValue(form);
  87
  88   if (!formValue.extractValue(cu->getDebugInfoExtractor(), offset_ptr, cu))
  89     return;
  90
  91   OS << "\t(";
  92   formValue.dump(OS, cu);
  93   OS << ")\n";
  94 }
  95
  96 bool DWARFDebugInfoEntryMinimal::extractFast(const DWARFCompileUnit *cu,
  97                                              const uint8_t *fixed_form_sizes,
  98                                              uint32_t *offset_ptr) {
  99   Offset = *offset_ptr;
 100
 101   DataExtractor debug_info_data = cu->getDebugInfoExtractor();
 102   uint64_t abbrCode = debug_info_data.getULEB128(offset_ptr);
 103
 104   assert(fixed_form_sizes); // For best performance this should be specified!
 105
 106   if (abbrCode) {
 107     uint32_t offset = *offset_ptr;
 108
 109     AbbrevDecl = cu->getAbbreviations()->getAbbreviationDeclaration(abbrCode);
 110
 111     // Skip all data in the .debug_info for the attributes
 112     const uint32_t numAttributes = AbbrevDecl->getNumAttributes();
 113     uint32_t i;
 114     uint16_t form;
 115     for (i=0; i<numAttributes; ++i) {
 116       form = AbbrevDecl->getFormByIndex(i);
 117
 118       const uint8_t fixed_skip_size = fixed_form_sizes[form];
 119       if (fixed_skip_size)
 120         offset += fixed_skip_size;
 121       else {
 122         bool form_is_indirect = false;
 123         do {
 124           form_is_indirect = false;
 125           uint32_t form_size = 0;
 126           switch (form) {
 127           // Blocks if inlined data that have a length field and the data bytes
 128           // inlined in the .debug_info.
 129           case DW_FORM_exprloc:
 130           case DW_FORM_block:
 131             form_size = debug_info_data.getULEB128(&offset);
 132             break;
 133           case DW_FORM_block1:
 134             form_size = debug_info_data.getU8(&offset);
 135             break;
 136           case DW_FORM_block2:
 137             form_size = debug_info_data.getU16(&offset);
 138             break;
 139           case DW_FORM_block4:
 140             form_size = debug_info_data.getU32(&offset);
 141             break;
 142
 143           // Inlined NULL terminated C-strings
 144           case DW_FORM_string:
 145             debug_info_data.getCStr(&offset);
 146             break;
 147
 148           // Compile unit address sized values
 149           case DW_FORM_addr:
 150           case DW_FORM_ref_addr:
 151             form_size = cu->getAddressByteSize();
 152             break;
 153
 154           // 0 sized form.
 155           case DW_FORM_flag_present:
 156             form_size = 0;
 157             break;
 158
 159           // 1 byte values
 160           case DW_FORM_data1:
 161           case DW_FORM_flag:
 162           case DW_FORM_ref1:
 163             form_size = 1;
 164             break;
 165
 166           // 2 byte values
 167           case DW_FORM_data2:
 168           case DW_FORM_ref2:
 169             form_size = 2;
 170             break;
 171
 172           // 4 byte values
 173           case DW_FORM_strp:
 174           case DW_FORM_data4:
 175           case DW_FORM_ref4:
 176             form_size = 4;
 177             break;
 178
 179           // 8 byte values
 180           case DW_FORM_data8:
 181           case DW_FORM_ref8:
 182           case DW_FORM_ref_sig8:
 183             form_size = 8;
 184             break;
 185
 186           // signed or unsigned LEB 128 values
 187           case DW_FORM_sdata:
 188           case DW_FORM_udata:
 189           case DW_FORM_ref_udata:
 190             debug_info_data.getULEB128(&offset);
 191             break;
 192
 193           case DW_FORM_indirect:
 194             form_is_indirect = true;
 195             form = debug_info_data.getULEB128(&offset);
 196             break;
 197
 198           case DW_FORM_sec_offset:
 199             if (cu->getAddressByteSize() == 4)
 200               debug_info_data.getU32(offset_ptr);
 201             else
 202               debug_info_data.getU64(offset_ptr);
 203             break;
 204
 205           default:
 206             *offset_ptr = Offset;
 207             return false;
 208           }
 209           offset += form_size;
 210
 211         } while (form_is_indirect);
 212       }
 213     }
 214     *offset_ptr = offset;
 215     return true;
 216   } else {
 217     AbbrevDecl = NULL;
 218     return true; // NULL debug tag entry
 219   }
 220 }
 221
 222 bool
 223 DWARFDebugInfoEntryMinimal::extract(const DWARFCompileUnit *cu,
 224                                     uint32_t *offset_ptr) {
 225   DataExtractor debug_info_data = cu->getDebugInfoExtractor();
 226   const uint32_t cu_end_offset = cu->getNextCompileUnitOffset();
 227   const uint8_t cu_addr_size = cu->getAddressByteSize();
 228   uint32_t offset = *offset_ptr;
 229   if ((offset < cu_end_offset) && debug_info_data.isValidOffset(offset)) {
 230     Offset = offset;
 231
 232     uint64_t abbrCode = debug_info_data.getULEB128(&offset);
 233
 234     if (abbrCode) {
 235       AbbrevDecl = cu->getAbbreviations()->getAbbreviationDeclaration(abbrCode);
 236
 237       if (AbbrevDecl) {
 238         uint16_t tag = AbbrevDecl->getTag();
 239
 240         bool isCompileUnitTag = tag == DW_TAG_compile_unit;
 241         if(cu && isCompileUnitTag)
 242           const_cast<DWARFCompileUnit*>(cu)->setBaseAddress(0);
 243
 244         // Skip all data in the .debug_info for the attributes
 245         const uint32_t numAttributes = AbbrevDecl->getNumAttributes();
 246         for (uint32_t i = 0; i != numAttributes; ++i) {
 247           uint16_t attr = AbbrevDecl->getAttrByIndex(i);
 248           uint16_t form = AbbrevDecl->getFormByIndex(i);
 249
 250           if (isCompileUnitTag &&
 251               ((attr == DW_AT_entry_pc) || (attr == DW_AT_low_pc))) {
 252             DWARFFormValue form_value(form);
 253             if (form_value.extractValue(debug_info_data, &offset, cu)) {
 254               if (attr == DW_AT_low_pc || attr == DW_AT_entry_pc)
 255                 const_cast<DWARFCompileUnit*>(cu)
 256                   ->setBaseAddress(form_value.getUnsigned());
 257             }
 258           } else {
 259             bool form_is_indirect = false;
 260             do {
 261               form_is_indirect = false;
 262               register uint32_t form_size = 0;
 263               switch (form) {
 264               // Blocks if inlined data that have a length field and the data
 265               // bytes // inlined in the .debug_info
 266               case DW_FORM_exprloc:
 267               case DW_FORM_block:
 268                 form_size = debug_info_data.getULEB128(&offset);
 269                 break;
 270               case DW_FORM_block1:
 271                 form_size = debug_info_data.getU8(&offset);
 272                 break;
 273               case DW_FORM_block2:
 274                 form_size = debug_info_data.getU16(&offset);
 275                 break;
 276               case DW_FORM_block4:
 277                 form_size = debug_info_data.getU32(&offset);
 278                 break;
 279
 280               // Inlined NULL terminated C-strings
 281               case DW_FORM_string:
 282                 debug_info_data.getCStr(&offset);
 283                 break;
 284
 285               // Compile unit address sized values
 286               case DW_FORM_addr:
 287               case DW_FORM_ref_addr:
 288                 form_size = cu_addr_size;
 289                 break;
 290
 291               // 0 byte value
 292               case DW_FORM_flag_present:
 293                 form_size = 0;
 294                 break;
 295
 296               // 1 byte values
 297               case DW_FORM_data1:
 298               case DW_FORM_flag:
 299               case DW_FORM_ref1:
 300                 form_size = 1;
 301                 break;
 302
 303               // 2 byte values
 304               case DW_FORM_data2:
 305               case DW_FORM_ref2:
 306                 form_size = 2;
 307                 break;
 308
 309                 // 4 byte values
 310               case DW_FORM_strp:
 311                 form_size = 4;
 312                 break;
 313
 314               case DW_FORM_data4:
 315               case DW_FORM_ref4:
 316                 form_size = 4;
 317                 break;
 318
 319               // 8 byte values
 320               case DW_FORM_data8:
 321               case DW_FORM_ref8:
 322               case DW_FORM_ref_sig8:
 323                 form_size = 8;
 324                 break;
 325
 326               // signed or unsigned LEB 128 values
 327               case DW_FORM_sdata:
 328               case DW_FORM_udata:
 329               case DW_FORM_ref_udata:
 330                 debug_info_data.getULEB128(&offset);
 331                 break;
 332
 333               case DW_FORM_indirect:
 334                 form = debug_info_data.getULEB128(&offset);
 335                 form_is_indirect = true;
 336                 break;
 337
 338               case DW_FORM_sec_offset:
 339                 if (cu->getAddressByteSize() == 4)
 340                   debug_info_data.getU32(offset_ptr);
 341                 else
 342                   debug_info_data.getU64(offset_ptr);
 343                 break;
 344
 345               default:
 346                 *offset_ptr = offset;
 347                 return false;
 348               }
 349
 350               offset += form_size;
 351             } while (form_is_indirect);
 352           }
 353         }
 354         *offset_ptr = offset;
 355         return true;
 356       }
 357     } else {
 358       AbbrevDecl = NULL;
 359       *offset_ptr = offset;
 360       return true;    // NULL debug tag entry
 361     }
 362   }
 363
 364   return false;
 365 }
 366
 367 bool DWARFDebugInfoEntryMinimal::isSubprogramDIE() const {
 368   return getTag() == DW_TAG_subprogram;
 369 }
 370
 371 bool DWARFDebugInfoEntryMinimal::isSubroutineDIE() const {
 372   uint32_t Tag = getTag();
 373   return Tag == DW_TAG_subprogram ||
 374          Tag == DW_TAG_inlined_subroutine;
 375 }
 376
 377 uint32_t
 378 DWARFDebugInfoEntryMinimal::getAttributeValue(const DWARFCompileUnit *cu,
 379                                               const uint16_t attr,
 380                                               DWARFFormValue &form_value,
 381                                               uint32_t *end_attr_offset_ptr)
 382                                               const {
 383   if (AbbrevDecl) {
 384     uint32_t attr_idx = AbbrevDecl->findAttributeIndex(attr);
 385
 386     if (attr_idx != -1U) {
 387       uint32_t offset = getOffset();
 388
 389       DataExtractor debug_info_data = cu->getDebugInfoExtractor();
 390
 391       // Skip the abbreviation code so we are at the data for the attributes
 392       debug_info_data.getULEB128(&offset);
 393
 394       uint32_t idx = 0;
 395       while (idx < attr_idx)
 396         DWARFFormValue::skipValue(AbbrevDecl->getFormByIndex(idx++),
 397                                   debug_info_data, &offset, cu);
 398
 399       const uint32_t attr_offset = offset;
 400       form_value = DWARFFormValue(AbbrevDecl->getFormByIndex(idx));
 401       if (form_value.extractValue(debug_info_data, &offset, cu)) {
 402         if (end_attr_offset_ptr)
 403           *end_attr_offset_ptr = offset;
 404         return attr_offset;
 405       }
 406     }
 407   }
 408
 409   return 0;
 410 }
 411
 412 const char*
 413 DWARFDebugInfoEntryMinimal::getAttributeValueAsString(
 414     const DWARFCompileUnit* cu,
 415     const uint16_t attr,
 416     const char* fail_value) const {
 417   DWARFFormValue form_value;
 418   if (getAttributeValue(cu, attr, form_value)) {
 419     DataExtractor stringExtractor(cu->getContext().getStringSection(),
 420         false, 0);
 421     return form_value.getAsCString(&stringExtractor);
 422   }
 423   return fail_value;
 424 }
 425
 426 uint64_t
 427 DWARFDebugInfoEntryMinimal::getAttributeValueAsUnsigned(
 428     const DWARFCompileUnit* cu,
 429     const uint16_t attr,
 430     uint64_t fail_value) const {
 431   DWARFFormValue form_value;
 432   if (getAttributeValue(cu, attr, form_value))
 433       return form_value.getUnsigned();
 434   return fail_value;
 435 }
 436
 437 int64_t
 438 DWARFDebugInfoEntryMinimal::getAttributeValueAsSigned(
 439     const DWARFCompileUnit* cu,
 440     const uint16_t attr,
 441     int64_t fail_value) const {
 442   DWARFFormValue form_value;
 443   if (getAttributeValue(cu, attr, form_value))
 444       return form_value.getSigned();
 445   return fail_value;
 446 }
 447
 448 uint64_t
 449 DWARFDebugInfoEntryMinimal::getAttributeValueAsReference(
 450                                                   const DWARFCompileUnit* cu,
 451                                                   const uint16_t attr,
 452                                                   uint64_t fail_value) const {
 453   DWARFFormValue form_value;
 454   if (getAttributeValue(cu, attr, form_value))
 455       return form_value.getReference(cu);
 456   return fail_value;
 457 }
 458
 459 bool DWARFDebugInfoEntryMinimal::getLowAndHighPC(const DWARFCompileUnit *CU,
 460     uint64_t &LowPC, uint64_t &HighPC) const {
 461   HighPC = -1ULL;
 462   LowPC = getAttributeValueAsUnsigned(CU, DW_AT_low_pc, -1ULL);
 463   if (LowPC != -1ULL)
 464     HighPC = getAttributeValueAsUnsigned(CU, DW_AT_high_pc, -1ULL);
 465   return (HighPC != -1ULL);
 466 }
 467
 468 void
 469 DWARFDebugInfoEntryMinimal::buildAddressRangeTable(const DWARFCompileUnit *CU,
 470                                                DWARFDebugAranges *DebugAranges)
 471                                                    const {
 472   if (AbbrevDecl) {
 473     if (isSubprogramDIE()) {
 474       uint64_t LowPC, HighPC;
 475       if (getLowAndHighPC(CU, LowPC, HighPC)) {
 476         DebugAranges->appendRange(CU->getOffset(), LowPC, HighPC);
 477       }
 478       // FIXME: try to append ranges from .debug_ranges section.
 479     }
 480
 481     const DWARFDebugInfoEntryMinimal *child = getFirstChild();
 482     while (child) {
 483       child->buildAddressRangeTable(CU, DebugAranges);
 484       child = child->getSibling();
 485     }
 486   }
 487 }
 488
 489 bool
 490 DWARFDebugInfoEntryMinimal::addressRangeContainsAddress(
 491     const DWARFCompileUnit *CU, const uint64_t Address) const {
 492   if (isNULL())
 493     return false;
 494   uint64_t LowPC, HighPC;
 495   if (getLowAndHighPC(CU, LowPC, HighPC))
 496     return (LowPC <= Address && Address <= HighPC);
 497   // Try to get address ranges from .debug_ranges section.
 498   uint32_t RangesOffset = getAttributeValueAsReference(CU, DW_AT_ranges, -1U);
 499   if (RangesOffset != -1U) {
 500     DWARFDebugRangeList RangeList;
 501     if (CU->extractRangeList(RangesOffset, RangeList))
 502       return RangeList.containsAddress(CU->getBaseAddress(), Address);
 503   }
 504   return false;
 505 }
 506
 507 const char*
 508 DWARFDebugInfoEntryMinimal::getSubroutineName(
 509     const DWARFCompileUnit *CU) const {
 510   if (!isSubroutineDIE())
 511     return 0;
 512   // Try to get mangled name if possible.
 513   if (const char *name =
 514       getAttributeValueAsString(CU, DW_AT_MIPS_linkage_name, 0))
 515     return name;
 516   if (const char *name = getAttributeValueAsString(CU, DW_AT_linkage_name, 0))
 517     return name;
 518   if (const char *name = getAttributeValueAsString(CU, DW_AT_name, 0))
 519     return name;
 520   // Try to get name from specification DIE.
 521   uint32_t spec_ref =
 522       getAttributeValueAsReference(CU, DW_AT_specification, -1U);
 523   if (spec_ref != -1U) {
 524     DWARFDebugInfoEntryMinimal spec_die;
 525     if (spec_die.extract(CU, &spec_ref)) {
 526       if (const char *name = spec_die.getSubroutineName(CU))
 527         return name;
 528     }
 529   }
 530   // Try to get name from abstract origin DIE.
 531   uint32_t abs_origin_ref =
 532       getAttributeValueAsReference(CU, DW_AT_abstract_origin, -1U);
 533   if (abs_origin_ref != -1U) {
 534     DWARFDebugInfoEntryMinimal abs_origin_die;
 535     if (abs_origin_die.extract(CU, &abs_origin_ref)) {
 536       if (const char *name = abs_origin_die.getSubroutineName(CU))
 537         return name;
 538     }
 539   }
 540   return 0;
 541 }
 542
 543 void DWARFDebugInfoEntryMinimal::getCallerFrame(
 544     const DWARFCompileUnit *CU, uint32_t &CallFile, uint32_t &CallLine,
 545     uint32_t &CallColumn) const {
 546   CallFile = getAttributeValueAsUnsigned(CU, DW_AT_call_file, 0);
 547   CallLine = getAttributeValueAsUnsigned(CU, DW_AT_call_line, 0);
 548   CallColumn = getAttributeValueAsUnsigned(CU, DW_AT_call_column, 0);
 549 }
 550
 551 DWARFDebugInfoEntryMinimal::InlinedChain
 552 DWARFDebugInfoEntryMinimal::getInlinedChainForAddress(
 553     const DWARFCompileUnit *CU, const uint64_t Address) const {
 554   DWARFDebugInfoEntryMinimal::InlinedChain InlinedChain;
 555   if (isNULL())
 556     return InlinedChain;
 557   for (const DWARFDebugInfoEntryMinimal *DIE = this; DIE; ) {
 558     // Append current DIE to inlined chain only if it has correct tag
 559     // (e.g. it is not a lexical block).
 560     if (DIE->isSubroutineDIE()) {
 561       InlinedChain.push_back(*DIE);
 562     }
 563     // Try to get child which also contains provided address.
 564     const DWARFDebugInfoEntryMinimal *Child = DIE->getFirstChild();
 565     while (Child) {
 566       if (Child->addressRangeContainsAddress(CU, Address)) {
 567         // Assume there is only one such child.
 568         break;
 569       }
 570       Child = Child->getSibling();
 571     }
 572     DIE = Child;
 573   }
 574   // Reverse the obtained chain to make the root of inlined chain last.
 575   std::reverse(InlinedChain.begin(), InlinedChain.end());
 576   return InlinedChain;
 577 }