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/Debug.h"
  16 #include "llvm/Support/Dwarf.h"
  17 #include "llvm/Support/Format.h"
  18 #include "llvm/Support/raw_ostream.h"
  19 using namespace llvm;
  20 using namespace dwarf;
  21
  22 void DWARFDebugInfoEntryMinimal::dump(raw_ostream &OS,
  23                                       const DWARFCompileUnit *cu,
  24                                       unsigned recurseDepth,
  25                                       unsigned indent) const {
  26   DataExtractor debug_info_data = cu->getDebugInfoExtractor();
  27   uint32_t offset = Offset;
  28
  29   if (debug_info_data.isValidOffset(offset)) {
  30     uint32_t abbrCode = debug_info_data.getULEB128(&offset);
  31
  32     OS << format("\n0x%8.8x: ", Offset);
  33     if (abbrCode) {
  34       if (AbbrevDecl) {
  35         const char *tagString = TagString(getTag());
  36         if (tagString)
  37           OS.indent(indent) << tagString;
  38         else
  39           OS.indent(indent) << format("DW_TAG_Unknown_%x", getTag());
  40         OS << format(" [%u] %c\n", abbrCode,
  41                      AbbrevDecl->hasChildren() ? '*' : ' ');
  42
  43         // Dump all data in the DIE for the attributes.
  44         const uint32_t numAttributes = AbbrevDecl->getNumAttributes();
  45         for (uint32_t i = 0; i != numAttributes; ++i) {
  46           uint16_t attr = AbbrevDecl->getAttrByIndex(i);
  47           uint16_t form = AbbrevDecl->getFormByIndex(i);
  48           dumpAttribute(OS, cu, &offset, attr, form, indent);
  49         }
  50
  51         const DWARFDebugInfoEntryMinimal *child = getFirstChild();
  52         if (recurseDepth > 0 && child) {
  53           while (child) {
  54             child->dump(OS, cu, recurseDepth-1, indent+2);
  55             child = child->getSibling();
  56           }
  57         }
  58       } else {
  59         OS << "Abbreviation code not found in 'debug_abbrev' class for code: "
  60            << abbrCode << '\n';
  61       }
  62     } else {
  63       OS.indent(indent) << "NULL\n";
  64     }
  65   }
  66 }
  67
  68 void DWARFDebugInfoEntryMinimal::dumpAttribute(raw_ostream &OS,
  69                                                const DWARFCompileUnit *cu,
  70                                                uint32_t* offset_ptr,
  71                                                uint16_t attr,
  72                                                uint16_t form,
  73                                                unsigned indent) const {
  74   OS << format("0x%8.8x: ", *offset_ptr);
  75   OS.indent(indent+2);
  76   const char *attrString = AttributeString(attr);
  77   if (attrString)
  78     OS << attrString;
  79   else
  80     OS << format("DW_AT_Unknown_%x", attr);
  81   const char *formString = FormEncodingString(form);
  82   if (formString)
  83     OS << " [" << formString << ']';
  84   else
  85     OS << format(" [DW_FORM_Unknown_%x]", form);
  86
  87   DWARFFormValue formValue(form);
  88
  89   if (!formValue.extractValue(cu->getDebugInfoExtractor(), offset_ptr, cu))
  90     return;
  91
  92   OS << "\t(";
  93   formValue.dump(OS, cu);
  94   OS << ")\n";
  95 }
  96
  97 bool DWARFDebugInfoEntryMinimal::extractFast(const DWARFCompileUnit *cu,
  98                                              const uint8_t *fixed_form_sizes,
  99                                              uint32_t *offset_ptr) {
 100   Offset = *offset_ptr;
 101
 102   DataExtractor debug_info_data = cu->getDebugInfoExtractor();
 103   uint64_t abbrCode = debug_info_data.getULEB128(offset_ptr);
 104
 105   assert(fixed_form_sizes); // For best performance this should be specified!
 106
 107   if (abbrCode) {
 108     uint32_t offset = *offset_ptr;
 109
 110     AbbrevDecl = cu->getAbbreviations()->getAbbreviationDeclaration(abbrCode);
 111
 112     // Skip all data in the .debug_info for the attributes
 113     const uint32_t numAttributes = AbbrevDecl->getNumAttributes();
 114     uint32_t i;
 115     uint16_t form;
 116     for (i=0; i<numAttributes; ++i) {
 117
 118       form = AbbrevDecl->getFormByIndex(i);
 119
 120       // FIXME: Currently we're checking if this is less than the last
 121       // entry in the fixed_form_sizes table, but this should be changed
 122       // to use dynamic dispatch.
 123       const uint8_t fixed_skip_size = (form < DW_FORM_ref_sig8) ?
 124                                        fixed_form_sizes[form] : 0;
 125       if (fixed_skip_size)
 126         offset += fixed_skip_size;
 127       else {
 128         bool form_is_indirect = false;
 129         do {
 130           form_is_indirect = false;
 131           uint32_t form_size = 0;
 132           switch (form) {
 133           // Blocks if inlined data that have a length field and the data bytes
 134           // inlined in the .debug_info.
 135           case DW_FORM_exprloc:
 136           case DW_FORM_block:
 137             form_size = debug_info_data.getULEB128(&offset);
 138             break;
 139           case DW_FORM_block1:
 140             form_size = debug_info_data.getU8(&offset);
 141             break;
 142           case DW_FORM_block2:
 143             form_size = debug_info_data.getU16(&offset);
 144             break;
 145           case DW_FORM_block4:
 146             form_size = debug_info_data.getU32(&offset);
 147             break;
 148
 149           // Inlined NULL terminated C-strings
 150           case DW_FORM_string:
 151             debug_info_data.getCStr(&offset);
 152             break;
 153
 154           // Compile unit address sized values
 155           case DW_FORM_addr:
 156           case DW_FORM_ref_addr:
 157             form_size = cu->getAddressByteSize();
 158             break;
 159
 160           // 0 sized form.
 161           case DW_FORM_flag_present:
 162             form_size = 0;
 163             break;
 164
 165           // 1 byte values
 166           case DW_FORM_data1:
 167           case DW_FORM_flag:
 168           case DW_FORM_ref1:
 169             form_size = 1;
 170             break;
 171
 172           // 2 byte values
 173           case DW_FORM_data2:
 174           case DW_FORM_ref2:
 175             form_size = 2;
 176             break;
 177
 178           // 4 byte values
 179           case DW_FORM_strp:
 180           case DW_FORM_data4:
 181           case DW_FORM_ref4:
 182             form_size = 4;
 183             break;
 184
 185           // 8 byte values
 186           case DW_FORM_data8:
 187           case DW_FORM_ref8:
 188           case DW_FORM_ref_sig8:
 189             form_size = 8;
 190             break;
 191
 192           // signed or unsigned LEB 128 values
 193           case DW_FORM_sdata:
 194           case DW_FORM_udata:
 195           case DW_FORM_ref_udata:
 196           case DW_FORM_GNU_str_index:
 197           case DW_FORM_GNU_addr_index:
 198             debug_info_data.getULEB128(&offset);
 199             break;
 200
 201           case DW_FORM_indirect:
 202             form_is_indirect = true;
 203             form = debug_info_data.getULEB128(&offset);
 204             break;
 205
 206             // FIXME: 64-bit for DWARF64
 207           case DW_FORM_sec_offset:
 208             debug_info_data.getU32(offset_ptr);
 209             break;
 210
 211           default:
 212             *offset_ptr = Offset;
 213             return false;
 214           }
 215           offset += form_size;
 216         } while (form_is_indirect);
 217       }
 218     }
 219     *offset_ptr = offset;
 220     return true;
 221   } else {
 222     AbbrevDecl = NULL;
 223     return true; // NULL debug tag entry
 224   }
 225 }
 226
 227 bool
 228 DWARFDebugInfoEntryMinimal::extract(const DWARFCompileUnit *cu,
 229                                     uint32_t *offset_ptr) {
 230   DataExtractor debug_info_data = cu->getDebugInfoExtractor();
 231   const uint32_t cu_end_offset = cu->getNextCompileUnitOffset();
 232   const uint8_t cu_addr_size = cu->getAddressByteSize();
 233   uint32_t offset = *offset_ptr;
 234   if ((offset < cu_end_offset) && debug_info_data.isValidOffset(offset)) {
 235     Offset = offset;
 236
 237     uint64_t abbrCode = debug_info_data.getULEB128(&offset);
 238
 239     if (abbrCode) {
 240       AbbrevDecl = cu->getAbbreviations()->getAbbreviationDeclaration(abbrCode);
 241
 242       if (AbbrevDecl) {
 243         uint16_t tag = AbbrevDecl->getTag();
 244
 245         bool isCompileUnitTag = tag == DW_TAG_compile_unit;
 246         if(cu && isCompileUnitTag)
 247           const_cast<DWARFCompileUnit*>(cu)->setBaseAddress(0);
 248
 249         // Skip all data in the .debug_info for the attributes
 250         const uint32_t numAttributes = AbbrevDecl->getNumAttributes();
 251         for (uint32_t i = 0; i != numAttributes; ++i) {
 252           uint16_t attr = AbbrevDecl->getAttrByIndex(i);
 253           uint16_t form = AbbrevDecl->getFormByIndex(i);
 254
 255           if (isCompileUnitTag &&
 256               ((attr == DW_AT_entry_pc) || (attr == DW_AT_low_pc))) {
 257             DWARFFormValue form_value(form);
 258             if (form_value.extractValue(debug_info_data, &offset, cu)) {
 259               if (attr == DW_AT_low_pc || attr == DW_AT_entry_pc)
 260                 const_cast<DWARFCompileUnit*>(cu)
 261                   ->setBaseAddress(form_value.getUnsigned());
 262             }
 263           } else {
 264             bool form_is_indirect = false;
 265             do {
 266               form_is_indirect = false;
 267               register uint32_t form_size = 0;
 268               switch (form) {
 269               // Blocks if inlined data that have a length field and the data
 270               // bytes // inlined in the .debug_info
 271               case DW_FORM_exprloc:
 272               case DW_FORM_block:
 273                 form_size = debug_info_data.getULEB128(&offset);
 274                 break;
 275               case DW_FORM_block1:
 276                 form_size = debug_info_data.getU8(&offset);
 277                 break;
 278               case DW_FORM_block2:
 279                 form_size = debug_info_data.getU16(&offset);
 280                 break;
 281               case DW_FORM_block4:
 282                 form_size = debug_info_data.getU32(&offset);
 283                 break;
 284
 285               // Inlined NULL terminated C-strings
 286               case DW_FORM_string:
 287                 debug_info_data.getCStr(&offset);
 288                 break;
 289
 290               // Compile unit address sized values
 291               case DW_FORM_addr:
 292               case DW_FORM_ref_addr:
 293                 form_size = cu_addr_size;
 294                 break;
 295
 296               // 0 byte value
 297               case DW_FORM_flag_present:
 298                 form_size = 0;
 299                 break;
 300
 301               // 1 byte values
 302               case DW_FORM_data1:
 303               case DW_FORM_flag:
 304               case DW_FORM_ref1:
 305                 form_size = 1;
 306                 break;
 307
 308               // 2 byte values
 309               case DW_FORM_data2:
 310               case DW_FORM_ref2:
 311                 form_size = 2;
 312                 break;
 313
 314                 // 4 byte values
 315               case DW_FORM_strp:
 316                 form_size = 4;
 317                 break;
 318
 319               case DW_FORM_data4:
 320               case DW_FORM_ref4:
 321                 form_size = 4;
 322                 break;
 323
 324               // 8 byte values
 325               case DW_FORM_data8:
 326               case DW_FORM_ref8:
 327               case DW_FORM_ref_sig8:
 328                 form_size = 8;
 329                 break;
 330
 331               // signed or unsigned LEB 128 values
 332               case DW_FORM_sdata:
 333               case DW_FORM_udata:
 334               case DW_FORM_ref_udata:
 335               case DW_FORM_GNU_str_index:
 336               case DW_FORM_GNU_addr_index:
 337                 debug_info_data.getULEB128(&offset);
 338                 break;
 339
 340               case DW_FORM_indirect:
 341                 form = debug_info_data.getULEB128(&offset);
 342                 form_is_indirect = true;
 343                 break;
 344
 345                 // FIXME: 64-bit for DWARF64.
 346               case DW_FORM_sec_offset:
 347                 debug_info_data.getU32(offset_ptr);
 348                 break;
 349
 350               default:
 351                 *offset_ptr = offset;
 352                 return false;
 353               }
 354
 355               offset += form_size;
 356             } while (form_is_indirect);
 357           }
 358         }
 359         *offset_ptr = offset;
 360         return true;
 361       }
 362     } else {
 363       AbbrevDecl = NULL;
 364       *offset_ptr = offset;
 365       return true;    // NULL debug tag entry
 366     }
 367   }
 368
 369   return false;
 370 }
 371
 372 bool DWARFDebugInfoEntryMinimal::isSubprogramDIE() const {
 373   return getTag() == DW_TAG_subprogram;
 374 }
 375
 376 bool DWARFDebugInfoEntryMinimal::isSubroutineDIE() const {
 377   uint32_t Tag = getTag();
 378   return Tag == DW_TAG_subprogram ||
 379          Tag == DW_TAG_inlined_subroutine;
 380 }
 381
 382 uint32_t
 383 DWARFDebugInfoEntryMinimal::getAttributeValue(const DWARFCompileUnit *cu,
 384                                               const uint16_t attr,
 385                                               DWARFFormValue &form_value,
 386                                               uint32_t *end_attr_offset_ptr)
 387                                               const {
 388   if (AbbrevDecl) {
 389     uint32_t attr_idx = AbbrevDecl->findAttributeIndex(attr);
 390
 391     if (attr_idx != -1U) {
 392       uint32_t offset = getOffset();
 393
 394       DataExtractor debug_info_data = cu->getDebugInfoExtractor();
 395
 396       // Skip the abbreviation code so we are at the data for the attributes
 397       debug_info_data.getULEB128(&offset);
 398
 399       uint32_t idx = 0;
 400       while (idx < attr_idx)
 401         DWARFFormValue::skipValue(AbbrevDecl->getFormByIndex(idx++),
 402                                   debug_info_data, &offset, cu);
 403
 404       const uint32_t attr_offset = offset;
 405       form_value = DWARFFormValue(AbbrevDecl->getFormByIndex(idx));
 406       if (form_value.extractValue(debug_info_data, &offset, cu)) {
 407         if (end_attr_offset_ptr)
 408           *end_attr_offset_ptr = offset;
 409         return attr_offset;
 410       }
 411     }
 412   }
 413
 414   return 0;
 415 }
 416
 417 const char*
 418 DWARFDebugInfoEntryMinimal::getAttributeValueAsString(
 419                                                      const DWARFCompileUnit* cu,
 420                                                      const uint16_t attr,
 421                                                      const char* fail_value)
 422                                                      const {
 423   DWARFFormValue form_value;
 424   if (getAttributeValue(cu, attr, form_value)) {
 425     DataExtractor stringExtractor(cu->getStringSection(), false, 0);
 426     return form_value.getAsCString(&stringExtractor);
 427   }
 428   return fail_value;
 429 }
 430
 431 uint64_t
 432 DWARFDebugInfoEntryMinimal::getAttributeValueAsUnsigned(
 433                                                     const DWARFCompileUnit* cu,
 434                                                     const uint16_t attr,
 435                                                     uint64_t fail_value) const {
 436   DWARFFormValue form_value;
 437   if (getAttributeValue(cu, attr, form_value))
 438       return form_value.getUnsigned();
 439   return fail_value;
 440 }
 441
 442 int64_t
 443 DWARFDebugInfoEntryMinimal::getAttributeValueAsSigned(
 444                                                      const DWARFCompileUnit* cu,
 445                                                      const uint16_t attr,
 446                                                      int64_t fail_value) const {
 447   DWARFFormValue form_value;
 448   if (getAttributeValue(cu, attr, form_value))
 449       return form_value.getSigned();
 450   return fail_value;
 451 }
 452
 453 uint64_t
 454 DWARFDebugInfoEntryMinimal::getAttributeValueAsReference(
 455                                                      const DWARFCompileUnit* cu,
 456                                                      const uint16_t attr,
 457                                                      uint64_t fail_value)
 458                                                      const {
 459   DWARFFormValue form_value;
 460   if (getAttributeValue(cu, attr, form_value))
 461       return form_value.getReference(cu);
 462   return fail_value;
 463 }
 464
 465 bool DWARFDebugInfoEntryMinimal::getLowAndHighPC(const DWARFCompileUnit *CU,
 466                                                  uint64_t &LowPC,
 467                                                  uint64_t &HighPC) const {
 468   HighPC = -1ULL;
 469   LowPC = getAttributeValueAsUnsigned(CU, DW_AT_low_pc, -1ULL);
 470   if (LowPC != -1ULL)
 471     HighPC = getAttributeValueAsUnsigned(CU, DW_AT_high_pc, -1ULL);
 472   return (HighPC != -1ULL);
 473 }
 474
 475 void
 476 DWARFDebugInfoEntryMinimal::buildAddressRangeTable(const DWARFCompileUnit *CU,
 477                                                DWARFDebugAranges *DebugAranges)
 478                                                    const {
 479   if (AbbrevDecl) {
 480     if (isSubprogramDIE()) {
 481       uint64_t LowPC, HighPC;
 482       if (getLowAndHighPC(CU, LowPC, HighPC)) {
 483         DebugAranges->appendRange(CU->getOffset(), LowPC, HighPC);
 484       }
 485       // FIXME: try to append ranges from .debug_ranges section.
 486     }
 487
 488     const DWARFDebugInfoEntryMinimal *child = getFirstChild();
 489     while (child) {
 490       child->buildAddressRangeTable(CU, DebugAranges);
 491       child = child->getSibling();
 492     }
 493   }
 494 }
 495
 496 bool
 497 DWARFDebugInfoEntryMinimal::addressRangeContainsAddress(
 498                                                      const DWARFCompileUnit *CU,
 499                                                      const uint64_t Address)
 500                                                      const {
 501   if (isNULL())
 502     return false;
 503   uint64_t LowPC, HighPC;
 504   if (getLowAndHighPC(CU, LowPC, HighPC))
 505     return (LowPC <= Address && Address <= HighPC);
 506   // Try to get address ranges from .debug_ranges section.
 507   uint32_t RangesOffset = getAttributeValueAsReference(CU, DW_AT_ranges, -1U);
 508   if (RangesOffset != -1U) {
 509     DWARFDebugRangeList RangeList;
 510     if (CU->extractRangeList(RangesOffset, RangeList))
 511       return RangeList.containsAddress(CU->getBaseAddress(), Address);
 512   }
 513   return false;
 514 }
 515
 516 const char*
 517 DWARFDebugInfoEntryMinimal::getSubroutineName(const DWARFCompileUnit *CU)
 518                                                                          const {
 519   if (!isSubroutineDIE())
 520     return 0;
 521   // Try to get mangled name if possible.
 522   if (const char *name =
 523       getAttributeValueAsString(CU, DW_AT_MIPS_linkage_name, 0))
 524     return name;
 525   if (const char *name = getAttributeValueAsString(CU, DW_AT_linkage_name, 0))
 526     return name;
 527   if (const char *name = getAttributeValueAsString(CU, DW_AT_name, 0))
 528     return name;
 529   // Try to get name from specification DIE.
 530   uint32_t spec_ref =
 531       getAttributeValueAsReference(CU, DW_AT_specification, -1U);
 532   if (spec_ref != -1U) {
 533     DWARFDebugInfoEntryMinimal spec_die;
 534     if (spec_die.extract(CU, &spec_ref)) {
 535       if (const char *name = spec_die.getSubroutineName(CU))
 536         return name;
 537     }
 538   }
 539   // Try to get name from abstract origin DIE.
 540   uint32_t abs_origin_ref =
 541       getAttributeValueAsReference(CU, DW_AT_abstract_origin, -1U);
 542   if (abs_origin_ref != -1U) {
 543     DWARFDebugInfoEntryMinimal abs_origin_die;
 544     if (abs_origin_die.extract(CU, &abs_origin_ref)) {
 545       if (const char *name = abs_origin_die.getSubroutineName(CU))
 546         return name;
 547     }
 548   }
 549   return 0;
 550 }
 551
 552 void DWARFDebugInfoEntryMinimal::getCallerFrame(const DWARFCompileUnit *CU,
 553                                                 uint32_t &CallFile,
 554                                                 uint32_t &CallLine,
 555                                                 uint32_t &CallColumn) const {
 556   CallFile = getAttributeValueAsUnsigned(CU, DW_AT_call_file, 0);
 557   CallLine = getAttributeValueAsUnsigned(CU, DW_AT_call_line, 0);
 558   CallColumn = getAttributeValueAsUnsigned(CU, DW_AT_call_column, 0);
 559 }
 560
 561 DWARFDebugInfoEntryMinimal::InlinedChain
 562 DWARFDebugInfoEntryMinimal::getInlinedChainForAddress(
 563                                                      const DWARFCompileUnit *CU,
 564                                                      const uint64_t Address)
 565                                                      const {
 566   DWARFDebugInfoEntryMinimal::InlinedChain InlinedChain;
 567   if (isNULL())
 568     return InlinedChain;
 569   for (const DWARFDebugInfoEntryMinimal *DIE = this; DIE; ) {
 570     // Append current DIE to inlined chain only if it has correct tag
 571     // (e.g. it is not a lexical block).
 572     if (DIE->isSubroutineDIE()) {
 573       InlinedChain.push_back(*DIE);
 574     }
 575     // Try to get child which also contains provided address.
 576     const DWARFDebugInfoEntryMinimal *Child = DIE->getFirstChild();
 577     while (Child) {
 578       if (Child->addressRangeContainsAddress(CU, Address)) {
 579         // Assume there is only one such child.
 580         break;
 581       }
 582       Child = Child->getSibling();
 583     }
 584     DIE = Child;
 585   }
 586   // Reverse the obtained chain to make the root of inlined chain last.
 587   std::reverse(InlinedChain.begin(), InlinedChain.end());
 588   return InlinedChain;
 589 }