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           case DW_FORM_sec_offset:
 207             if (cu->getAddressByteSize() == 4)
 208               debug_info_data.getU32(offset_ptr);
 209             else
 210               debug_info_data.getU64(offset_ptr);
 211             break;
 212
 213           default:
 214             *offset_ptr = Offset;
 215             return false;
 216           }
 217           offset += form_size;
 218         } while (form_is_indirect);
 219       }
 220     }
 221     *offset_ptr = offset;
 222     return true;
 223   } else {
 224     AbbrevDecl = NULL;
 225     return true; // NULL debug tag entry
 226   }
 227 }
 228
 229 bool
 230 DWARFDebugInfoEntryMinimal::extract(const DWARFCompileUnit *cu,
 231                                     uint32_t *offset_ptr) {
 232   DataExtractor debug_info_data = cu->getDebugInfoExtractor();
 233   const uint32_t cu_end_offset = cu->getNextCompileUnitOffset();
 234   const uint8_t cu_addr_size = cu->getAddressByteSize();
 235   uint32_t offset = *offset_ptr;
 236   if ((offset < cu_end_offset) && debug_info_data.isValidOffset(offset)) {
 237     Offset = offset;
 238
 239     uint64_t abbrCode = debug_info_data.getULEB128(&offset);
 240
 241     if (abbrCode) {
 242       AbbrevDecl = cu->getAbbreviations()->getAbbreviationDeclaration(abbrCode);
 243
 244       if (AbbrevDecl) {
 245         uint16_t tag = AbbrevDecl->getTag();
 246
 247         bool isCompileUnitTag = tag == DW_TAG_compile_unit;
 248         if(cu && isCompileUnitTag)
 249           const_cast<DWARFCompileUnit*>(cu)->setBaseAddress(0);
 250
 251         // Skip all data in the .debug_info for the attributes
 252         const uint32_t numAttributes = AbbrevDecl->getNumAttributes();
 253         for (uint32_t i = 0; i != numAttributes; ++i) {
 254           uint16_t attr = AbbrevDecl->getAttrByIndex(i);
 255           uint16_t form = AbbrevDecl->getFormByIndex(i);
 256
 257           if (isCompileUnitTag &&
 258               ((attr == DW_AT_entry_pc) || (attr == DW_AT_low_pc))) {
 259             DWARFFormValue form_value(form);
 260             if (form_value.extractValue(debug_info_data, &offset, cu)) {
 261               if (attr == DW_AT_low_pc || attr == DW_AT_entry_pc)
 262                 const_cast<DWARFCompileUnit*>(cu)
 263                   ->setBaseAddress(form_value.getUnsigned());
 264             }
 265           } else {
 266             bool form_is_indirect = false;
 267             do {
 268               form_is_indirect = false;
 269               register uint32_t form_size = 0;
 270               switch (form) {
 271               // Blocks if inlined data that have a length field and the data
 272               // bytes // inlined in the .debug_info
 273               case DW_FORM_exprloc:
 274               case DW_FORM_block:
 275                 form_size = debug_info_data.getULEB128(&offset);
 276                 break;
 277               case DW_FORM_block1:
 278                 form_size = debug_info_data.getU8(&offset);
 279                 break;
 280               case DW_FORM_block2:
 281                 form_size = debug_info_data.getU16(&offset);
 282                 break;
 283               case DW_FORM_block4:
 284                 form_size = debug_info_data.getU32(&offset);
 285                 break;
 286
 287               // Inlined NULL terminated C-strings
 288               case DW_FORM_string:
 289                 debug_info_data.getCStr(&offset);
 290                 break;
 291
 292               // Compile unit address sized values
 293               case DW_FORM_addr:
 294               case DW_FORM_ref_addr:
 295                 form_size = cu_addr_size;
 296                 break;
 297
 298               // 0 byte value
 299               case DW_FORM_flag_present:
 300                 form_size = 0;
 301                 break;
 302
 303               // 1 byte values
 304               case DW_FORM_data1:
 305               case DW_FORM_flag:
 306               case DW_FORM_ref1:
 307                 form_size = 1;
 308                 break;
 309
 310               // 2 byte values
 311               case DW_FORM_data2:
 312               case DW_FORM_ref2:
 313                 form_size = 2;
 314                 break;
 315
 316                 // 4 byte values
 317               case DW_FORM_strp:
 318                 form_size = 4;
 319                 break;
 320
 321               case DW_FORM_data4:
 322               case DW_FORM_ref4:
 323                 form_size = 4;
 324                 break;
 325
 326               // 8 byte values
 327               case DW_FORM_data8:
 328               case DW_FORM_ref8:
 329               case DW_FORM_ref_sig8:
 330                 form_size = 8;
 331                 break;
 332
 333               // signed or unsigned LEB 128 values
 334               case DW_FORM_sdata:
 335               case DW_FORM_udata:
 336               case DW_FORM_ref_udata:
 337               case DW_FORM_GNU_str_index:
 338               case DW_FORM_GNU_addr_index:
 339                 debug_info_data.getULEB128(&offset);
 340                 break;
 341
 342               case DW_FORM_indirect:
 343                 form = debug_info_data.getULEB128(&offset);
 344                 form_is_indirect = true;
 345                 break;
 346
 347               case DW_FORM_sec_offset:
 348                 if (cu->getAddressByteSize() == 4)
 349                   debug_info_data.getU32(offset_ptr);
 350                 else
 351                   debug_info_data.getU64(offset_ptr);
 352                 break;
 353
 354               default:
 355                 *offset_ptr = offset;
 356                 return false;
 357               }
 358
 359               offset += form_size;
 360             } while (form_is_indirect);
 361           }
 362         }
 363         *offset_ptr = offset;
 364         return true;
 365       }
 366     } else {
 367       AbbrevDecl = NULL;
 368       *offset_ptr = offset;
 369       return true;    // NULL debug tag entry
 370     }
 371   }
 372
 373   return false;
 374 }
 375
 376 bool DWARFDebugInfoEntryMinimal::isSubprogramDIE() const {
 377   return getTag() == DW_TAG_subprogram;
 378 }
 379
 380 bool DWARFDebugInfoEntryMinimal::isSubroutineDIE() const {
 381   uint32_t Tag = getTag();
 382   return Tag == DW_TAG_subprogram ||
 383          Tag == DW_TAG_inlined_subroutine;
 384 }
 385
 386 uint32_t
 387 DWARFDebugInfoEntryMinimal::getAttributeValue(const DWARFCompileUnit *cu,
 388                                               const uint16_t attr,
 389                                               DWARFFormValue &form_value,
 390                                               uint32_t *end_attr_offset_ptr)
 391                                               const {
 392   if (AbbrevDecl) {
 393     uint32_t attr_idx = AbbrevDecl->findAttributeIndex(attr);
 394
 395     if (attr_idx != -1U) {
 396       uint32_t offset = getOffset();
 397
 398       DataExtractor debug_info_data = cu->getDebugInfoExtractor();
 399
 400       // Skip the abbreviation code so we are at the data for the attributes
 401       debug_info_data.getULEB128(&offset);
 402
 403       uint32_t idx = 0;
 404       while (idx < attr_idx)
 405         DWARFFormValue::skipValue(AbbrevDecl->getFormByIndex(idx++),
 406                                   debug_info_data, &offset, cu);
 407
 408       const uint32_t attr_offset = offset;
 409       form_value = DWARFFormValue(AbbrevDecl->getFormByIndex(idx));
 410       if (form_value.extractValue(debug_info_data, &offset, cu)) {
 411         if (end_attr_offset_ptr)
 412           *end_attr_offset_ptr = offset;
 413         return attr_offset;
 414       }
 415     }
 416   }
 417
 418   return 0;
 419 }
 420
 421 const char*
 422 DWARFDebugInfoEntryMinimal::getAttributeValueAsString(
 423                                                      const DWARFCompileUnit* cu,
 424                                                      const uint16_t attr,
 425                                                      const char* fail_value)
 426                                                      const {
 427   DWARFFormValue form_value;
 428   if (getAttributeValue(cu, attr, form_value)) {
 429     DataExtractor stringExtractor(cu->getStringSection(), false, 0);
 430     return form_value.getAsCString(&stringExtractor);
 431   }
 432   return fail_value;
 433 }
 434
 435 uint64_t
 436 DWARFDebugInfoEntryMinimal::getAttributeValueAsUnsigned(
 437                                                     const DWARFCompileUnit* cu,
 438                                                     const uint16_t attr,
 439                                                     uint64_t fail_value) const {
 440   DWARFFormValue form_value;
 441   if (getAttributeValue(cu, attr, form_value))
 442       return form_value.getUnsigned();
 443   return fail_value;
 444 }
 445
 446 int64_t
 447 DWARFDebugInfoEntryMinimal::getAttributeValueAsSigned(
 448                                                      const DWARFCompileUnit* cu,
 449                                                      const uint16_t attr,
 450                                                      int64_t fail_value) const {
 451   DWARFFormValue form_value;
 452   if (getAttributeValue(cu, attr, form_value))
 453       return form_value.getSigned();
 454   return fail_value;
 455 }
 456
 457 uint64_t
 458 DWARFDebugInfoEntryMinimal::getAttributeValueAsReference(
 459                                                      const DWARFCompileUnit* cu,
 460                                                      const uint16_t attr,
 461                                                      uint64_t fail_value)
 462                                                      const {
 463   DWARFFormValue form_value;
 464   if (getAttributeValue(cu, attr, form_value))
 465       return form_value.getReference(cu);
 466   return fail_value;
 467 }
 468
 469 bool DWARFDebugInfoEntryMinimal::getLowAndHighPC(const DWARFCompileUnit *CU,
 470                                                  uint64_t &LowPC,
 471                                                  uint64_t &HighPC) const {
 472   HighPC = -1ULL;
 473   LowPC = getAttributeValueAsUnsigned(CU, DW_AT_low_pc, -1ULL);
 474   if (LowPC != -1ULL)
 475     HighPC = getAttributeValueAsUnsigned(CU, DW_AT_high_pc, -1ULL);
 476   return (HighPC != -1ULL);
 477 }
 478
 479 void
 480 DWARFDebugInfoEntryMinimal::buildAddressRangeTable(const DWARFCompileUnit *CU,
 481                                                DWARFDebugAranges *DebugAranges)
 482                                                    const {
 483   if (AbbrevDecl) {
 484     if (isSubprogramDIE()) {
 485       uint64_t LowPC, HighPC;
 486       if (getLowAndHighPC(CU, LowPC, HighPC)) {
 487         DebugAranges->appendRange(CU->getOffset(), LowPC, HighPC);
 488       }
 489       // FIXME: try to append ranges from .debug_ranges section.
 490     }
 491
 492     const DWARFDebugInfoEntryMinimal *child = getFirstChild();
 493     while (child) {
 494       child->buildAddressRangeTable(CU, DebugAranges);
 495       child = child->getSibling();
 496     }
 497   }
 498 }
 499
 500 bool
 501 DWARFDebugInfoEntryMinimal::addressRangeContainsAddress(
 502                                                      const DWARFCompileUnit *CU,
 503                                                      const uint64_t Address)
 504                                                      const {
 505   if (isNULL())
 506     return false;
 507   uint64_t LowPC, HighPC;
 508   if (getLowAndHighPC(CU, LowPC, HighPC))
 509     return (LowPC <= Address && Address <= HighPC);
 510   // Try to get address ranges from .debug_ranges section.
 511   uint32_t RangesOffset = getAttributeValueAsReference(CU, DW_AT_ranges, -1U);
 512   if (RangesOffset != -1U) {
 513     DWARFDebugRangeList RangeList;
 514     if (CU->extractRangeList(RangesOffset, RangeList))
 515       return RangeList.containsAddress(CU->getBaseAddress(), Address);
 516   }
 517   return false;
 518 }
 519
 520 const char*
 521 DWARFDebugInfoEntryMinimal::getSubroutineName(const DWARFCompileUnit *CU)
 522                                                                          const {
 523   if (!isSubroutineDIE())
 524     return 0;
 525   // Try to get mangled name if possible.
 526   if (const char *name =
 527       getAttributeValueAsString(CU, DW_AT_MIPS_linkage_name, 0))
 528     return name;
 529   if (const char *name = getAttributeValueAsString(CU, DW_AT_linkage_name, 0))
 530     return name;
 531   if (const char *name = getAttributeValueAsString(CU, DW_AT_name, 0))
 532     return name;
 533   // Try to get name from specification DIE.
 534   uint32_t spec_ref =
 535       getAttributeValueAsReference(CU, DW_AT_specification, -1U);
 536   if (spec_ref != -1U) {
 537     DWARFDebugInfoEntryMinimal spec_die;
 538     if (spec_die.extract(CU, &spec_ref)) {
 539       if (const char *name = spec_die.getSubroutineName(CU))
 540         return name;
 541     }
 542   }
 543   // Try to get name from abstract origin DIE.
 544   uint32_t abs_origin_ref =
 545       getAttributeValueAsReference(CU, DW_AT_abstract_origin, -1U);
 546   if (abs_origin_ref != -1U) {
 547     DWARFDebugInfoEntryMinimal abs_origin_die;
 548     if (abs_origin_die.extract(CU, &abs_origin_ref)) {
 549       if (const char *name = abs_origin_die.getSubroutineName(CU))
 550         return name;
 551     }
 552   }
 553   return 0;
 554 }
 555
 556 void DWARFDebugInfoEntryMinimal::getCallerFrame(const DWARFCompileUnit *CU,
 557                                                 uint32_t &CallFile,
 558                                                 uint32_t &CallLine,
 559                                                 uint32_t &CallColumn) const {
 560   CallFile = getAttributeValueAsUnsigned(CU, DW_AT_call_file, 0);
 561   CallLine = getAttributeValueAsUnsigned(CU, DW_AT_call_line, 0);
 562   CallColumn = getAttributeValueAsUnsigned(CU, DW_AT_call_column, 0);
 563 }
 564
 565 DWARFDebugInfoEntryMinimal::InlinedChain
 566 DWARFDebugInfoEntryMinimal::getInlinedChainForAddress(
 567                                                      const DWARFCompileUnit *CU,
 568                                                      const uint64_t Address)
 569                                                      const {
 570   DWARFDebugInfoEntryMinimal::InlinedChain InlinedChain;
 571   if (isNULL())
 572     return InlinedChain;
 573   for (const DWARFDebugInfoEntryMinimal *DIE = this; DIE; ) {
 574     // Append current DIE to inlined chain only if it has correct tag
 575     // (e.g. it is not a lexical block).
 576     if (DIE->isSubroutineDIE()) {
 577       InlinedChain.push_back(*DIE);
 578     }
 579     // Try to get child which also contains provided address.
 580     const DWARFDebugInfoEntryMinimal *Child = DIE->getFirstChild();
 581     while (Child) {
 582       if (Child->addressRangeContainsAddress(CU, Address)) {
 583         // Assume there is only one such child.
 584         break;
 585       }
 586       Child = Child->getSibling();
 587     }
 588     DIE = Child;
 589   }
 590   // Reverse the obtained chain to make the root of inlined chain last.
 591   std::reverse(InlinedChain.begin(), InlinedChain.end());
 592   return InlinedChain;
 593 }