DwarfDebug.cpp

               unsigned Reg = *AI; ++AI) {
            const MDNode *Var = LiveUserVar[Reg];
            if (!Var)
              continue;
            // Reg is now clobbered.
            LiveUserVar[Reg] = 0;

            // Was MD last defined by a DBG_VALUE referring to Reg?
            DbgValueHistoryMap::iterator HistI = DbgValues.find(Var);
            if (HistI == DbgValues.end())
              continue;
            SmallVectorImpl<const MachineInstr*> &History = HistI->second;
            if (History.empty())
              continue;
            const MachineInstr *Prev = History.back();
            // Sanity-check: Register assignments are terminated at the end of
            // their block.
            if (!Prev->isDebugValue() || Prev->getParent() != MI->getParent())
              continue;
            // Is the variable still in Reg?
            if (!isDbgValueInDefinedReg(Prev) ||
                Prev->getOperand(0).getReg() != Reg)
              continue;
            // Var is clobbered. Make sure the next instruction gets a label.
            History.push_back(MI);
          }
        }
      }
    }
  }

  for (DbgValueHistoryMap::iterator I = DbgValues.begin(), E = DbgValues.end();
       I != E; ++I) {
    SmallVectorImpl<const MachineInstr*> &History = I->second;
    if (History.empty())
      continue;

    // Make sure the final register assignments are terminated.
    const MachineInstr *Prev = History.back();
    if (Prev->isDebugValue() && isDbgValueInDefinedReg(Prev)) {
      const MachineBasicBlock *PrevMBB = Prev->getParent();
      MachineBasicBlock::const_iterator LastMI = PrevMBB->getLastNonDebugInstr();
      if (LastMI == PrevMBB->end())
        // Drop DBG_VALUE for empty range.
        History.pop_back();
      else {
        // Terminate after LastMI.
        History.push_back(LastMI);
      }
    }
    // Request labels for the full history.
    for (unsigned i = 0, e = History.size(); i != e; ++i) {
      const MachineInstr *MI = History[i];
      if (MI->isDebugValue())
        requestLabelBeforeInsn(MI);
      else
        requestLabelAfterInsn(MI);
    }
  }

  PrevInstLoc = DebugLoc();
  PrevLabel = FunctionBeginSym;
}

/// endFunction - Gather and emit post-function debug information.
///
void DwarfDebug::endFunction(const MachineFunction *MF) {
  if (!MMI->hasDebugInfo() || DbgScopeMap.empty()) return;

  if (CurrentFnDbgScope) {

    // Define end label for subprogram.
    FunctionEndSym = Asm->GetTempSymbol("func_end",
                                        Asm->getFunctionNumber());
    // Assumes in correct section after the entry point.
    Asm->OutStreamer.EmitLabel(FunctionEndSym);

    SmallPtrSet<const MDNode *, 16> ProcessedVars;
    collectVariableInfo(MF, ProcessedVars);

    // Construct abstract scopes.
    for (SmallVector<DbgScope *, 4>::iterator AI = AbstractScopesList.begin(),
           AE = AbstractScopesList.end(); AI != AE; ++AI) {
      DISubprogram SP((*AI)->getScopeNode());
      if (SP.Verify()) {
        // Collect info for variables that were optimized out.
        StringRef FName = SP.getLinkageName();
        if (FName.empty())
          FName = SP.getName();
        if (NamedMDNode *NMD = 
            getFnSpecificMDNode(*(MF->getFunction()->getParent()), FName)) {
          for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
          DIVariable DV(cast<MDNode>(NMD->getOperand(i)));
          if (!DV || !ProcessedVars.insert(DV))
            continue;
          DbgScope *Scope = AbstractScopes.lookup(DV.getContext());
          if (Scope)
            Scope->addVariable(new DbgVariable(DV));
          }
        }
      }
      if (ProcessedSPNodes.count((*AI)->getScopeNode()) == 0)
        constructScopeDIE(*AI);
    }

    DIE *CurFnDIE = constructScopeDIE(CurrentFnDbgScope);

    if (!DisableFramePointerElim(*MF))
      addUInt(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr,
              dwarf::DW_FORM_flag, 1);


    DebugFrames.push_back(FunctionDebugFrameInfo(Asm->getFunctionNumber(),
                                                 MMI->getFrameMoves()));
  }

  // Clear debug info
  CurrentFnDbgScope = NULL;
  CurrentFnArguments.clear();
  DbgVariableToFrameIndexMap.clear();
  VarToAbstractVarMap.clear();
  DbgVariableToDbgInstMap.clear();
  DeleteContainerSeconds(DbgScopeMap);
  UserVariables.clear();
  DbgValues.clear();
  ConcreteScopes.clear();
  DeleteContainerSeconds(AbstractScopes);
  AbstractScopesList.clear();
  AbstractVariables.clear();
  LabelsBeforeInsn.clear();
  LabelsAfterInsn.clear();
  PrevLabel = NULL;
}

/// recordVariableFrameIndex - Record a variable's index.
void DwarfDebug::recordVariableFrameIndex(const DbgVariable *V, int Index) {
  assert (V && "Invalid DbgVariable!");
  DbgVariableToFrameIndexMap[V] = Index;
}

/// findVariableFrameIndex - Return true if frame index for the variable
/// is found. Update FI to hold value of the index.
bool DwarfDebug::findVariableFrameIndex(const DbgVariable *V, int *FI) {
  assert (V && "Invalid DbgVariable!");
  DenseMap<const DbgVariable *, int>::iterator I =
    DbgVariableToFrameIndexMap.find(V);
  if (I == DbgVariableToFrameIndexMap.end())
    return false;
  *FI = I->second;
  return true;
}

/// findDbgScope - Find DbgScope for the debug loc attached with an
/// instruction.
DbgScope *DwarfDebug::findDbgScope(const MachineInstr *MInsn) {
  DbgScope *Scope = NULL;
  LLVMContext &Ctx =
    MInsn->getParent()->getParent()->getFunction()->getContext();
  DebugLoc DL = MInsn->getDebugLoc();

  if (DL.isUnknown())
    return Scope;

  if (const MDNode *IA = DL.getInlinedAt(Ctx))
    Scope = ConcreteScopes.lookup(IA);
  if (Scope == 0)
    Scope = DbgScopeMap.lookup(DL.getScope(Ctx));

  return Scope;
}


/// recordSourceLine - Register a source line with debug info. Returns the
/// unique label that was emitted and which provides correspondence to
/// the source line list.
void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S){
  StringRef Fn;
  StringRef Dir;
  unsigned Src = 1;
  if (S) {
    DIDescriptor Scope(S);

    if (Scope.isCompileUnit()) {
      DICompileUnit CU(S);
      Fn = CU.getFilename();
      Dir = CU.getDirectory();
    } else if (Scope.isFile()) {
      DIFile F(S);
      Fn = F.getFilename();
      Dir = F.getDirectory();
    } else if (Scope.isSubprogram()) {
      DISubprogram SP(S);
      Fn = SP.getFilename();
      Dir = SP.getDirectory();
    } else if (Scope.isLexicalBlock()) {
      DILexicalBlock DB(S);
      Fn = DB.getFilename();
      Dir = DB.getDirectory();
    } else
      assert(0 && "Unexpected scope info");

    Src = GetOrCreateSourceID(Fn, Dir);
  }

  Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, DWARF2_FLAG_IS_STMT,
                                         0, 0);
}

//===----------------------------------------------------------------------===//
// Emit Methods
//===----------------------------------------------------------------------===//

/// computeSizeAndOffset - Compute the size and offset of a DIE.
///
unsigned
DwarfDebug::computeSizeAndOffset(DIE *Die, unsigned Offset, bool Last) {
  // Get the children.
  const std::vector<DIE *> &Children = Die->getChildren();

  // If not last sibling and has children then add sibling offset attribute.
  if (!Last && !Children.empty())
    Die->addSiblingOffset(DIEValueAllocator);

  // Record the abbreviation.
  assignAbbrevNumber(Die->getAbbrev());

  // Get the abbreviation for this DIE.
  unsigned AbbrevNumber = Die->getAbbrevNumber();
  const DIEAbbrev *Abbrev = Abbreviations[AbbrevNumber - 1];

  // Set DIE offset
  Die->setOffset(Offset);

  // Start the size with the size of abbreviation code.
  Offset += MCAsmInfo::getULEB128Size(AbbrevNumber);

  const SmallVector<DIEValue*, 32> &Values = Die->getValues();
  const SmallVector<DIEAbbrevData, 8> &AbbrevData = Abbrev->getData();

  // Size the DIE attribute values.
  for (unsigned i = 0, N = Values.size(); i < N; ++i)
    // Size attribute value.
    Offset += Values[i]->SizeOf(Asm, AbbrevData[i].getForm());

  // Size the DIE children if any.
  if (!Children.empty()) {
    assert(Abbrev->getChildrenFlag() == dwarf::DW_CHILDREN_yes &&
           "Children flag not set");

    for (unsigned j = 0, M = Children.size(); j < M; ++j)
      Offset = computeSizeAndOffset(Children[j], Offset, (j + 1) == M);

    // End of children marker.
    Offset += sizeof(int8_t);
  }

  Die->setSize(Offset - Die->getOffset());
  return Offset;
}

/// computeSizeAndOffsets - Compute the size and offset of all the DIEs.
///
void DwarfDebug::computeSizeAndOffsets() {
  unsigned PrevOffset = 0;
  for (DenseMap<const MDNode *, CompileUnit *>::iterator I = CUMap.begin(),
         E = CUMap.end(); I != E; ++I) {
    // Compute size of compile unit header.
    static unsigned Offset = PrevOffset +
      sizeof(int32_t) + // Length of Compilation Unit Info
      sizeof(int16_t) + // DWARF version number
      sizeof(int32_t) + // Offset Into Abbrev. Section
      sizeof(int8_t);   // Pointer Size (in bytes)
    computeSizeAndOffset(I->second->getCUDie(), Offset, true);
    PrevOffset = Offset;
  }
}

/// EmitSectionSym - Switch to the specified MCSection and emit an assembler
/// temporary label to it if SymbolStem is specified.
static MCSymbol *EmitSectionSym(AsmPrinter *Asm, const MCSection *Section,
                                const char *SymbolStem = 0) {
  Asm->OutStreamer.SwitchSection(Section);
  if (!SymbolStem) return 0;

  MCSymbol *TmpSym = Asm->GetTempSymbol(SymbolStem);
  Asm->OutStreamer.EmitLabel(TmpSym);
  return TmpSym;
}

/// EmitSectionLabels - Emit initial Dwarf sections with a label at
/// the start of each one.
void DwarfDebug::EmitSectionLabels() {
  const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();

  // Dwarf sections base addresses.
  if (Asm->MAI->doesDwarfRequireFrameSection()) {
    DwarfFrameSectionSym =
      EmitSectionSym(Asm, TLOF.getDwarfFrameSection(), "section_debug_frame");
   }

  DwarfInfoSectionSym =
    EmitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
  DwarfAbbrevSectionSym =
    EmitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
  EmitSectionSym(Asm, TLOF.getDwarfARangesSection());

  if (const MCSection *MacroInfo = TLOF.getDwarfMacroInfoSection())
    EmitSectionSym(Asm, MacroInfo);

  EmitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
  EmitSectionSym(Asm, TLOF.getDwarfLocSection());
  EmitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
  EmitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
  DwarfStrSectionSym =
    EmitSectionSym(Asm, TLOF.getDwarfStrSection(), "section_str");
  DwarfDebugRangeSectionSym = EmitSectionSym(Asm, TLOF.getDwarfRangesSection(),
                                             "debug_range");

  DwarfDebugLocSectionSym = EmitSectionSym(Asm, TLOF.getDwarfLocSection(),
                                           "section_debug_loc");

  TextSectionSym = EmitSectionSym(Asm, TLOF.getTextSection(), "text_begin");
  EmitSectionSym(Asm, TLOF.getDataSection());
}

/// emitDIE - Recusively Emits a debug information entry.
///
void DwarfDebug::emitDIE(DIE *Die) {
  // Get the abbreviation for this DIE.
  unsigned AbbrevNumber = Die->getAbbrevNumber();
  const DIEAbbrev *Abbrev = Abbreviations[AbbrevNumber - 1];

  // Emit the code (index) for the abbreviation.
  if (Asm->isVerbose())
    Asm->OutStreamer.AddComment("Abbrev [" + Twine(AbbrevNumber) + "] 0x" +
                                Twine::utohexstr(Die->getOffset()) + ":0x" +
                                Twine::utohexstr(Die->getSize()) + " " +
                                dwarf::TagString(Abbrev->getTag()));
  Asm->EmitULEB128(AbbrevNumber);

  const SmallVector<DIEValue*, 32> &Values = Die->getValues();
  const SmallVector<DIEAbbrevData, 8> &AbbrevData = Abbrev->getData();

  // Emit the DIE attribute values.
  for (unsigned i = 0, N = Values.size(); i < N; ++i) {
    unsigned Attr = AbbrevData[i].getAttribute();
    unsigned Form = AbbrevData[i].getForm();
    assert(Form && "Too many attributes for DIE (check abbreviation)");

    if (Asm->isVerbose())
      Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));

    switch (Attr) {
    case dwarf::DW_AT_sibling:
      Asm->EmitInt32(Die->getSiblingOffset());
      break;
    case dwarf::DW_AT_abstract_origin: {
      DIEEntry *E = cast<DIEEntry>(Values[i]);
      DIE *Origin = E->getEntry();
      unsigned Addr = Origin->getOffset();
      Asm->EmitInt32(Addr);
      break;
    }
    case dwarf::DW_AT_ranges: {
      // DW_AT_range Value encodes offset in debug_range section.
      DIEInteger *V = cast<DIEInteger>(Values[i]);

      if (Asm->MAI->doesDwarfUsesLabelOffsetForRanges()) {
        Asm->EmitLabelPlusOffset(DwarfDebugRangeSectionSym,
                                 V->getValue(),
                                 4);
      } else {
        Asm->EmitLabelOffsetDifference(DwarfDebugRangeSectionSym,
                                       V->getValue(),
                                       DwarfDebugRangeSectionSym,
                                       4);
      }
      break;
    }
    case dwarf::DW_AT_location: {
      if (UseDotDebugLocEntry.count(Die) != 0) {
        DIELabel *L = cast<DIELabel>(Values[i]);
        Asm->EmitLabelDifference(L->getValue(), DwarfDebugLocSectionSym, 4);
      } else
        Values[i]->EmitValue(Asm, Form);
      break;
    }
    case dwarf::DW_AT_accessibility: {
      if (Asm->isVerbose()) {
        DIEInteger *V = cast<DIEInteger>(Values[i]);
        Asm->OutStreamer.AddComment(dwarf::AccessibilityString(V->getValue()));
      }
      Values[i]->EmitValue(Asm, Form);
      break;
    }
    default:
      // Emit an attribute using the defined form.
      Values[i]->EmitValue(Asm, Form);
      break;
    }
  }

  // Emit the DIE children if any.
  if (Abbrev->getChildrenFlag() == dwarf::DW_CHILDREN_yes) {
    const std::vector<DIE *> &Children = Die->getChildren();

    for (unsigned j = 0, M = Children.size(); j < M; ++j)
      emitDIE(Children[j]);

    if (Asm->isVerbose())
      Asm->OutStreamer.AddComment("End Of Children Mark");
    Asm->EmitInt8(0);
  }
}

/// emitDebugInfo - Emit the debug info section.
///
void DwarfDebug::emitDebugInfo() {
  // Start debug info section.
  Asm->OutStreamer.SwitchSection(
                            Asm->getObjFileLowering().getDwarfInfoSection());
  for (DenseMap<const MDNode *, CompileUnit *>::iterator I = CUMap.begin(),
         E = CUMap.end(); I != E; ++I) {
    CompileUnit *TheCU = I->second;
    DIE *Die = TheCU->getCUDie();

    // Emit the compile units header.
    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("info_begin",
                                                  TheCU->getID()));

    // Emit size of content not including length itself
    unsigned ContentSize = Die->getSize() +
      sizeof(int16_t) + // DWARF version number
      sizeof(int32_t) + // Offset Into Abbrev. Section
      sizeof(int8_t) +  // Pointer Size (in bytes)
      sizeof(int32_t);  // FIXME - extra pad for gdb bug.

    Asm->OutStreamer.AddComment("Length of Compilation Unit Info");
    Asm->EmitInt32(ContentSize);
    Asm->OutStreamer.AddComment("DWARF version number");
    Asm->EmitInt16(dwarf::DWARF_VERSION);
    Asm->OutStreamer.AddComment("Offset Into Abbrev. Section");
    Asm->EmitSectionOffset(Asm->GetTempSymbol("abbrev_begin"),
                           DwarfAbbrevSectionSym);
    Asm->OutStreamer.AddComment("Address Size (in bytes)");
    Asm->EmitInt8(Asm->getTargetData().getPointerSize());

    emitDIE(Die);
    // FIXME - extra padding for gdb bug.
    Asm->OutStreamer.AddComment("4 extra padding bytes for GDB");
    Asm->EmitInt8(0);
    Asm->EmitInt8(0);
    Asm->EmitInt8(0);
    Asm->EmitInt8(0);
    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("info_end", TheCU->getID()));
  }
}

/// emitAbbreviations - Emit the abbreviation section.
///
void DwarfDebug::emitAbbreviations() const {
  // Check to see if it is worth the effort.
  if (!Abbreviations.empty()) {
    // Start the debug abbrev section.
    Asm->OutStreamer.SwitchSection(
                            Asm->getObjFileLowering().getDwarfAbbrevSection());

    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("abbrev_begin"));

    // For each abbrevation.
    for (unsigned i = 0, N = Abbreviations.size(); i < N; ++i) {
      // Get abbreviation data
      const DIEAbbrev *Abbrev = Abbreviations[i];

      // Emit the abbrevations code (base 1 index.)
      Asm->EmitULEB128(Abbrev->getNumber(), "Abbreviation Code");

      // Emit the abbreviations data.
      Abbrev->Emit(Asm);
    }

    // Mark end of abbreviations.
    Asm->EmitULEB128(0, "EOM(3)");

    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("abbrev_end"));
  }
}

/// emitEndOfLineMatrix - Emit the last address of the section and the end of
/// the line matrix.
///
void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
  // Define last address of section.
  Asm->OutStreamer.AddComment("Extended Op");
  Asm->EmitInt8(0);

  Asm->OutStreamer.AddComment("Op size");
  Asm->EmitInt8(Asm->getTargetData().getPointerSize() + 1);
  Asm->OutStreamer.AddComment("DW_LNE_set_address");
  Asm->EmitInt8(dwarf::DW_LNE_set_address);

  Asm->OutStreamer.AddComment("Section end label");

  Asm->OutStreamer.EmitSymbolValue(Asm->GetTempSymbol("section_end",SectionEnd),
                                   Asm->getTargetData().getPointerSize(),
                                   0/*AddrSpace*/);

  // Mark end of matrix.
  Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
  Asm->EmitInt8(0);
  Asm->EmitInt8(1);
  Asm->EmitInt8(1);
}

/// emitCommonDebugFrame - Emit common frame info into a debug frame section.
///
void DwarfDebug::emitCommonDebugFrame() {
  if (!Asm->MAI->doesDwarfRequireFrameSection())
    return;

  int stackGrowth = Asm->getTargetData().getPointerSize();
  if (Asm->TM.getFrameLowering()->getStackGrowthDirection() ==
      TargetFrameLowering::StackGrowsDown)
    stackGrowth *= -1;

  // Start the dwarf frame section.
  Asm->OutStreamer.SwitchSection(
                              Asm->getObjFileLowering().getDwarfFrameSection());

  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("debug_frame_common"));
  Asm->OutStreamer.AddComment("Length of Common Information Entry");
  Asm->EmitLabelDifference(Asm->GetTempSymbol("debug_frame_common_end"),
                           Asm->GetTempSymbol("debug_frame_common_begin"), 4);

  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("debug_frame_common_begin"));
  Asm->OutStreamer.AddComment("CIE Identifier Tag");
  Asm->EmitInt32((int)dwarf::DW_CIE_ID);
  Asm->OutStreamer.AddComment("CIE Version");
  Asm->EmitInt8(dwarf::DW_CIE_VERSION);
  Asm->OutStreamer.AddComment("CIE Augmentation");
  Asm->OutStreamer.EmitIntValue(0, 1, /*addrspace*/0); // nul terminator.
  Asm->EmitULEB128(1, "CIE Code Alignment Factor");
  Asm->EmitSLEB128(stackGrowth, "CIE Data Alignment Factor");
  Asm->OutStreamer.AddComment("CIE RA Column");
  const TargetRegisterInfo *RI = Asm->TM.getRegisterInfo();
  const TargetFrameLowering *TFI = Asm->TM.getFrameLowering();
  Asm->EmitInt8(RI->getDwarfRegNum(RI->getRARegister(), false));

  std::vector<MachineMove> Moves;
  TFI->getInitialFrameState(Moves);

  Asm->EmitFrameMoves(Moves, 0, false);

  Asm->EmitAlignment(2);
  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("debug_frame_common_end"));
}

/// emitFunctionDebugFrame - Emit per function frame info into a debug frame
/// section.
void DwarfDebug::
emitFunctionDebugFrame(const FunctionDebugFrameInfo &DebugFrameInfo) {
  if (!Asm->MAI->doesDwarfRequireFrameSection())
    return;

  // Start the dwarf frame section.
  Asm->OutStreamer.SwitchSection(
                              Asm->getObjFileLowering().getDwarfFrameSection());

  Asm->OutStreamer.AddComment("Length of Frame Information Entry");
  MCSymbol *DebugFrameBegin =
    Asm->GetTempSymbol("debug_frame_begin", DebugFrameInfo.Number);
  MCSymbol *DebugFrameEnd =
    Asm->GetTempSymbol("debug_frame_end", DebugFrameInfo.Number);
  Asm->EmitLabelDifference(DebugFrameEnd, DebugFrameBegin, 4);

  Asm->OutStreamer.EmitLabel(DebugFrameBegin);

  Asm->OutStreamer.AddComment("FDE CIE offset");
  Asm->EmitSectionOffset(Asm->GetTempSymbol("debug_frame_common"),
                         DwarfFrameSectionSym);

  Asm->OutStreamer.AddComment("FDE initial location");
  MCSymbol *FuncBeginSym =
    Asm->GetTempSymbol("func_begin", DebugFrameInfo.Number);
  Asm->OutStreamer.EmitSymbolValue(FuncBeginSym,
                                   Asm->getTargetData().getPointerSize(),
                                   0/*AddrSpace*/);


  Asm->OutStreamer.AddComment("FDE address range");
  Asm->EmitLabelDifference(Asm->GetTempSymbol("func_end",DebugFrameInfo.Number),
                           FuncBeginSym, Asm->getTargetData().getPointerSize());

  Asm->EmitFrameMoves(DebugFrameInfo.Moves, FuncBeginSym, false);

  Asm->EmitAlignment(2);
  Asm->OutStreamer.EmitLabel(DebugFrameEnd);
}

/// emitDebugPubNames - Emit visible names into a debug pubnames section.
///
void DwarfDebug::emitDebugPubNames() {
  for (DenseMap<const MDNode *, CompileUnit *>::iterator I = CUMap.begin(),
         E = CUMap.end(); I != E; ++I) {
    CompileUnit *TheCU = I->second;
    // Start the dwarf pubnames section.
    Asm->OutStreamer.SwitchSection(
      Asm->getObjFileLowering().getDwarfPubNamesSection());

    Asm->OutStreamer.AddComment("Length of Public Names Info");
    Asm->EmitLabelDifference(
      Asm->GetTempSymbol("pubnames_end", TheCU->getID()),
      Asm->GetTempSymbol("pubnames_begin", TheCU->getID()), 4);

    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("pubnames_begin",
                                                  TheCU->getID()));

    Asm->OutStreamer.AddComment("DWARF Version");
    Asm->EmitInt16(dwarf::DWARF_VERSION);

    Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
    Asm->EmitSectionOffset(Asm->GetTempSymbol("info_begin", TheCU->getID()),
                           DwarfInfoSectionSym);

    Asm->OutStreamer.AddComment("Compilation Unit Length");
    Asm->EmitLabelDifference(Asm->GetTempSymbol("info_end", TheCU->getID()),
                             Asm->GetTempSymbol("info_begin", TheCU->getID()),
                             4);

    const StringMap<DIE*> &Globals = TheCU->getGlobals();
    for (StringMap<DIE*>::const_iterator
           GI = Globals.begin(), GE = Globals.end(); GI != GE; ++GI) {
      const char *Name = GI->getKeyData();
      DIE *Entity = GI->second;

      Asm->OutStreamer.AddComment("DIE offset");
      Asm->EmitInt32(Entity->getOffset());

      if (Asm->isVerbose())
        Asm->OutStreamer.AddComment("External Name");
      Asm->OutStreamer.EmitBytes(StringRef(Name, strlen(Name)+1), 0);
    }

    Asm->OutStreamer.AddComment("End Mark");
    Asm->EmitInt32(0);
    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("pubnames_end",
                                                TheCU->getID()));
  }
}

void DwarfDebug::emitDebugPubTypes() {
  for (DenseMap<const MDNode *, CompileUnit *>::iterator I = CUMap.begin(),
         E = CUMap.end(); I != E; ++I) {
    CompileUnit *TheCU = I->second;
    // Start the dwarf pubnames section.
    Asm->OutStreamer.SwitchSection(
      Asm->getObjFileLowering().getDwarfPubTypesSection());
    Asm->OutStreamer.AddComment("Length of Public Types Info");
    Asm->EmitLabelDifference(
      Asm->GetTempSymbol("pubtypes_end", TheCU->getID()),
      Asm->GetTempSymbol("pubtypes_begin", TheCU->getID()), 4);

    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("pubtypes_begin",
                                                  TheCU->getID()));

    if (Asm->isVerbose()) Asm->OutStreamer.AddComment("DWARF Version");
    Asm->EmitInt16(dwarf::DWARF_VERSION);

    Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
    Asm->EmitSectionOffset(Asm->GetTempSymbol("info_begin", TheCU->getID()),
                           DwarfInfoSectionSym);

    Asm->OutStreamer.AddComment("Compilation Unit Length");
    Asm->EmitLabelDifference(Asm->GetTempSymbol("info_end", TheCU->getID()),
                             Asm->GetTempSymbol("info_begin", TheCU->getID()),
                             4);

    const StringMap<DIE*> &Globals = TheCU->getGlobalTypes();
    for (StringMap<DIE*>::const_iterator
           GI = Globals.begin(), GE = Globals.end(); GI != GE; ++GI) {
      const char *Name = GI->getKeyData();
      DIE * Entity = GI->second;

      if (Asm->isVerbose()) Asm->OutStreamer.AddComment("DIE offset");
      Asm->EmitInt32(Entity->getOffset());

      if (Asm->isVerbose()) Asm->OutStreamer.AddComment("External Name");
      Asm->OutStreamer.EmitBytes(StringRef(Name, GI->getKeyLength()+1), 0);
    }

    Asm->OutStreamer.AddComment("End Mark");
    Asm->EmitInt32(0);
    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("pubtypes_end",
                                                  TheCU->getID()));
  }
}

/// emitDebugStr - Emit visible names into a debug str section.
///
void DwarfDebug::emitDebugStr() {
  // Check to see if it is worth the effort.
  if (StringPool.empty()) return;

  // Start the dwarf str section.
  Asm->OutStreamer.SwitchSection(
                                Asm->getObjFileLowering().getDwarfStrSection());

  // Get all of the string pool entries and put them in an array by their ID so
  // we can sort them.
  SmallVector<std::pair<unsigned,
      StringMapEntry<std::pair<MCSymbol*, unsigned> >*>, 64> Entries;

  for (StringMap<std::pair<MCSymbol*, unsigned> >::iterator
       I = StringPool.begin(), E = StringPool.end(); I != E; ++I)
    Entries.push_back(std::make_pair(I->second.second, &*I));

  array_pod_sort(Entries.begin(), Entries.end());

  for (unsigned i = 0, e = Entries.size(); i != e; ++i) {
    // Emit a label for reference from debug information entries.
    Asm->OutStreamer.EmitLabel(Entries[i].second->getValue().first);

    // Emit the string itself.
    Asm->OutStreamer.EmitBytes(Entries[i].second->getKey(), 0/*addrspace*/);
  }
}

/// emitDebugLoc - Emit visible names into a debug loc section.
///
void DwarfDebug::emitDebugLoc() {
  if (DotDebugLocEntries.empty())
    return;

  for (SmallVector<DotDebugLocEntry, 4>::iterator
         I = DotDebugLocEntries.begin(), E = DotDebugLocEntries.end();
       I != E; ++I) {
    DotDebugLocEntry &Entry = *I;
    if (I + 1 != DotDebugLocEntries.end())
      Entry.Merge(I+1);
  }

  // Start the dwarf loc section.
  Asm->OutStreamer.SwitchSection(
    Asm->getObjFileLowering().getDwarfLocSection());
  unsigned char Size = Asm->getTargetData().getPointerSize();
  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("debug_loc", 0));
  unsigned index = 1;
  for (SmallVector<DotDebugLocEntry, 4>::iterator
         I = DotDebugLocEntries.begin(), E = DotDebugLocEntries.end();
       I != E; ++I, ++index) {
    DotDebugLocEntry &Entry = *I;
    if (Entry.isMerged()) continue;
    if (Entry.isEmpty()) {
      Asm->OutStreamer.EmitIntValue(0, Size, /*addrspace*/0);
      Asm->OutStreamer.EmitIntValue(0, Size, /*addrspace*/0);
      Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("debug_loc", index));
    } else {
      Asm->OutStreamer.EmitSymbolValue(Entry.Begin, Size, 0);
      Asm->OutStreamer.EmitSymbolValue(Entry.End, Size, 0);
      const TargetRegisterInfo *RI = Asm->TM.getRegisterInfo();
      unsigned Reg = RI->getDwarfRegNum(Entry.Loc.getReg(), false);
      if (int Offset =  Entry.Loc.getOffset()) {
        // If the value is at a certain offset from frame register then
        // use DW_OP_fbreg.
        unsigned OffsetSize = Offset ? MCAsmInfo::getSLEB128Size(Offset) : 1;
        Asm->OutStreamer.AddComment("Loc expr size");
        Asm->EmitInt16(1 + OffsetSize);
        Asm->OutStreamer.AddComment(
          dwarf::OperationEncodingString(dwarf::DW_OP_fbreg));
        Asm->EmitInt8(dwarf::DW_OP_fbreg);
        Asm->OutStreamer.AddComment("Offset");
        Asm->EmitSLEB128(Offset);
      } else {
        if (Reg < 32) {
          Asm->OutStreamer.AddComment("Loc expr size");
          Asm->EmitInt16(1);
          Asm->OutStreamer.AddComment(
            dwarf::OperationEncodingString(dwarf::DW_OP_reg0 + Reg));
          Asm->EmitInt8(dwarf::DW_OP_reg0 + Reg);
        } else {
          Asm->OutStreamer.AddComment("Loc expr size");
          Asm->EmitInt16(1 + MCAsmInfo::getULEB128Size(Reg));
          Asm->EmitInt8(dwarf::DW_OP_regx);
          Asm->EmitULEB128(Reg);
        }
      }
    }
  }
}

/// EmitDebugARanges - Emit visible names into a debug aranges section.
///
void DwarfDebug::EmitDebugARanges() {
  // Start the dwarf aranges section.
  Asm->OutStreamer.SwitchSection(
                          Asm->getObjFileLowering().getDwarfARangesSection());
}

/// emitDebugRanges - Emit visible names into a debug ranges section.
///
void DwarfDebug::emitDebugRanges() {
  // Start the dwarf ranges section.
  Asm->OutStreamer.SwitchSection(
    Asm->getObjFileLowering().getDwarfRangesSection());
  unsigned char Size = Asm->getTargetData().getPointerSize();
  for (SmallVector<const MCSymbol *, 8>::iterator
         I = DebugRangeSymbols.begin(), E = DebugRangeSymbols.end();
       I != E; ++I) {
    if (*I)
      Asm->OutStreamer.EmitSymbolValue(const_cast<MCSymbol*>(*I), Size, 0);
    else
      Asm->OutStreamer.EmitIntValue(0, Size, /*addrspace*/0);
  }
}

/// emitDebugMacInfo - Emit visible names into a debug macinfo section.
///
void DwarfDebug::emitDebugMacInfo() {
  if (const MCSection *LineInfo =
      Asm->getObjFileLowering().getDwarfMacroInfoSection()) {
    // Start the dwarf macinfo section.
    Asm->OutStreamer.SwitchSection(LineInfo);
  }
}

/// emitDebugInlineInfo - Emit inline info using following format.
/// Section Header:
/// 1. length of section
/// 2. Dwarf version number
/// 3. address size.
///
/// Entries (one "entry" for each function that was inlined):
///
/// 1. offset into __debug_str section for MIPS linkage name, if exists;
///   otherwise offset into __debug_str for regular function name.
/// 2. offset into __debug_str section for regular function name.
/// 3. an unsigned LEB128 number indicating the number of distinct inlining
/// instances for the function.
///
/// The rest of the entry consists of a {die_offset, low_pc} pair for each
/// inlined instance; the die_offset points to the inlined_subroutine die in the
/// __debug_info section, and the low_pc is the starting address for the
/// inlining instance.
void DwarfDebug::emitDebugInlineInfo() {
  if (!Asm->MAI->doesDwarfUsesInlineInfoSection())
    return;

  if (!FirstCU)
    return;

  Asm->OutStreamer.SwitchSection(
                        Asm->getObjFileLowering().getDwarfDebugInlineSection());

  Asm->OutStreamer.AddComment("Length of Debug Inlined Information Entry");
  Asm->EmitLabelDifference(Asm->GetTempSymbol("debug_inlined_end", 1),
                           Asm->GetTempSymbol("debug_inlined_begin", 1), 4);

  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("debug_inlined_begin", 1));

  Asm->OutStreamer.AddComment("Dwarf Version");
  Asm->EmitInt16(dwarf::DWARF_VERSION);
  Asm->OutStreamer.AddComment("Address Size (in bytes)");
  Asm->EmitInt8(Asm->getTargetData().getPointerSize());

  for (SmallVector<const MDNode *, 4>::iterator I = InlinedSPNodes.begin(),
         E = InlinedSPNodes.end(); I != E; ++I) {

    const MDNode *Node = *I;
    DenseMap<const MDNode *, SmallVector<InlineInfoLabels, 4> >::iterator II
      = InlineInfo.find(Node);
    SmallVector<InlineInfoLabels, 4> &Labels = II->second;
    DISubprogram SP(Node);
    StringRef LName = SP.getLinkageName();
    StringRef Name = SP.getName();

    Asm->OutStreamer.AddComment("MIPS linkage name");
    if (LName.empty()) {
      Asm->OutStreamer.EmitBytes(Name, 0);
      Asm->OutStreamer.EmitIntValue(0, 1, 0); // nul terminator.
    } else
      Asm->EmitSectionOffset(getStringPoolEntry(getRealLinkageName(LName)),
                             DwarfStrSectionSym);

    Asm->OutStreamer.AddComment("Function name");
    Asm->EmitSectionOffset(getStringPoolEntry(Name), DwarfStrSectionSym);
    Asm->EmitULEB128(Labels.size(), "Inline count");

    for (SmallVector<InlineInfoLabels, 4>::iterator LI = Labels.begin(),
           LE = Labels.end(); LI != LE; ++LI) {
      if (Asm->isVerbose()) Asm->OutStreamer.AddComment("DIE offset");
      Asm->EmitInt32(LI->second->getOffset());

      if (Asm->isVerbose()) Asm->OutStreamer.AddComment("low_pc");
      Asm->OutStreamer.EmitSymbolValue(LI->first,
                                       Asm->getTargetData().getPointerSize(),0);
    }
  }

  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("debug_inlined_end", 1));
}