C++ DWARFFormValue::getAsBlock方法代码示例

void ObjectLoadListener::extractLocalLocations(
    const DWARFUnit *CU, const DWARFDebugInfoEntryMinimal *DebugEntry,
    std::vector<uint64_t> &Offsets) {
  if (DebugEntry->isNULL())
    return;
  if (DebugEntry->getTag() == dwarf::DW_TAG_formal_parameter ||
      DebugEntry->getTag() == dwarf::DW_TAG_variable) {
    uint64_t Offset;

    // Extract offset for each local found
    DWARFFormValue FormValue;
    if (DebugEntry->getAttributeValue(CU, dwarf::DW_AT_location, FormValue)) {
      Optional<ArrayRef<uint8_t>> FormValues = FormValue.getAsBlock();
      Offset = FormValues->back();
    }

    Offsets.push_back(Offset);
  }

  const DWARFDebugInfoEntryMinimal *Child = DebugEntry->getFirstChild();

  // Extract info for DebugEntry's child and its child's siblings.
  while (Child) {
    extractLocalLocations(CU, Child, Offsets);
    Child = Child->getSibling();
  }
}

static void dumpLocation(raw_ostream &OS, DWARFFormValue &FormValue,
                         DWARFUnit *U, unsigned Indent,
                         DIDumpOptions DumpOpts) {
  DWARFContext &Ctx = U->getContext();
  const DWARFObject &Obj = Ctx.getDWARFObj();
  const MCRegisterInfo *MRI = Ctx.getRegisterInfo();
  if (FormValue.isFormClass(DWARFFormValue::FC_Block) ||
      FormValue.isFormClass(DWARFFormValue::FC_Exprloc)) {
    ArrayRef<uint8_t> Expr = *FormValue.getAsBlock();
    DataExtractor Data(StringRef((const char *)Expr.data(), Expr.size()),
                       Ctx.isLittleEndian(), 0);
    DWARFExpression(Data, U->getVersion(), U->getAddressByteSize())
        .print(OS, MRI);
    return;
  }

  FormValue.dump(OS, DumpOpts);
  if (FormValue.isFormClass(DWARFFormValue::FC_SectionOffset)) {
    const DWARFSection &LocSection = Obj.getLocSection();
    const DWARFSection &LocDWOSection = Obj.getLocDWOSection();
    uint32_t Offset = *FormValue.getAsSectionOffset();
    if (!LocSection.Data.empty()) {
      DWARFDebugLoc DebugLoc;
      DWARFDataExtractor Data(Obj, LocSection, Ctx.isLittleEndian(),
                              Obj.getAddressSize());
      auto LL = DebugLoc.parseOneLocationList(Data, &Offset);
      if (LL) {
        uint64_t BaseAddr = 0;
        if (Optional<BaseAddress> BA = U->getBaseAddress())
          BaseAddr = BA->Address;
        LL->dump(OS, Ctx.isLittleEndian(), Obj.getAddressSize(), MRI, BaseAddr,
                 Indent);
      } else
        OS << "error extracting location list.";
    } else if (!LocDWOSection.Data.empty()) {
      DataExtractor Data(LocDWOSection.Data, Ctx.isLittleEndian(), 0);
      auto LL = DWARFDebugLocDWO::parseOneLocationList(Data, &Offset);
      if (LL)
        LL->dump(OS, Ctx.isLittleEndian(), Obj.getAddressSize(), MRI, Indent);
      else
        OS << "error extracting location list.";
    }
  }
}

void ObjectLoadListener::getDebugInfoForLocals(
    DWARFContextInMemory &DwarfContext, uint64_t Addr, uint64_t Size) {
  for (const auto &CU : DwarfContext.compile_units()) {
    const DWARFDebugInfoEntryMinimal *UnitDIE = CU->getUnitDIE(false);
    const DWARFDebugInfoEntryMinimal *SubprogramDIE = getSubprogramDIE(UnitDIE);

    ICorDebugInfo::RegNum FrameBaseRegister = ICorDebugInfo::REGNUM_COUNT;
    DWARFFormValue FormValue;

    // Find the frame_base register value
    if (SubprogramDIE->getAttributeValue(CU.get(), dwarf::DW_AT_frame_base,
                                         FormValue)) {
      Optional<ArrayRef<uint8_t>> FormValues = FormValue.getAsBlock();
      FrameBaseRegister = mapDwarfRegisterToRegNum(FormValues->back());
    }

    if (SubprogramDIE->getAttributeValue(CU.get(), dwarf::DW_AT_low_pc,
                                         FormValue)) {
      Optional<uint64_t> FormAddress = FormValue.getAsAddress(CU.get());

      // If the Form address doesn't match the address for the function passed
      // do not collect debug for locals since they do not go with the current
      // function being processed
      if (FormAddress.getValue() != Addr) {
        return;
      }
    }

    std::vector<uint64_t> Offsets;
    extractLocalLocations(CU.get(), SubprogramDIE, Offsets);

    // Allocate the array of NativeVarInfo objects that will be sent to the EE
    ICorDebugInfo::NativeVarInfo *LocalVars;
    unsigned SizeOfArray =
        Offsets.size() * sizeof(ICorDebugInfo::NativeVarInfo);
    if (SizeOfArray > 0) {
      LocalVars =
          (ICorDebugInfo::NativeVarInfo *)Context->JitInfo->allocateArray(
              SizeOfArray);

      unsigned CurrentDebugEntry = 0;

      for (auto &Offset : Offsets) {
        LocalVars[CurrentDebugEntry].startOffset = Addr;
        LocalVars[CurrentDebugEntry].endOffset = Addr + Size;
        LocalVars[CurrentDebugEntry].varNumber = CurrentDebugEntry;

        // Assume all locals are on the stack
        ICorDebugInfo::VarLoc VarLoc;
        VarLoc.vlType = ICorDebugInfo::VLT_STK;
        VarLoc.vlStk.vlsBaseReg = FrameBaseRegister;
        VarLoc.vlStk.vlsOffset = Offset;

        LocalVars[CurrentDebugEntry].loc = VarLoc;

        CurrentDebugEntry++;
      }

      CORINFO_METHOD_INFO *MethodInfo = Context->MethodInfo;
      CORINFO_METHOD_HANDLE MethodHandle = MethodInfo->ftn;

      Context->JitInfo->setVars(MethodHandle, Offsets.size(), LocalVars);
    }
  }
}

static void dumpLocation(raw_ostream &OS, DWARFFormValue &FormValue,
                         DWARFUnit *U, unsigned Indent,
                         DIDumpOptions DumpOpts) {
  DWARFContext &Ctx = U->getContext();
  const DWARFObject &Obj = Ctx.getDWARFObj();
  const MCRegisterInfo *MRI = Ctx.getRegisterInfo();
  if (FormValue.isFormClass(DWARFFormValue::FC_Block) ||
      FormValue.isFormClass(DWARFFormValue::FC_Exprloc)) {
    ArrayRef<uint8_t> Expr = *FormValue.getAsBlock();
    DataExtractor Data(StringRef((const char *)Expr.data(), Expr.size()),
                       Ctx.isLittleEndian(), 0);
    DWARFExpression(Data, U->getVersion(), U->getAddressByteSize())
        .print(OS, MRI, U);
    return;
  }

  FormValue.dump(OS, DumpOpts);
  if (FormValue.isFormClass(DWARFFormValue::FC_SectionOffset)) {
    uint32_t Offset = *FormValue.getAsSectionOffset();
    if (!U->isDWOUnit() && !U->getLocSection()->Data.empty()) {
      DWARFDebugLoc DebugLoc;
      DWARFDataExtractor Data(Obj, *U->getLocSection(), Ctx.isLittleEndian(),
                              Obj.getAddressSize());
      auto LL = DebugLoc.parseOneLocationList(Data, &Offset);
      if (LL) {
        uint64_t BaseAddr = 0;
        if (Optional<object::SectionedAddress> BA = U->getBaseAddress())
          BaseAddr = BA->Address;
        LL->dump(OS, Ctx.isLittleEndian(), Obj.getAddressSize(), MRI, U,
                 BaseAddr, Indent);
      } else
        OS << "error extracting location list.";
      return;
    }

    bool UseLocLists = !U->isDWOUnit();
    StringRef LoclistsSectionData =
        UseLocLists ? Obj.getLoclistsSection().Data : U->getLocSectionData();

    if (!LoclistsSectionData.empty()) {
      DataExtractor Data(LoclistsSectionData, Ctx.isLittleEndian(),
                         Obj.getAddressSize());

      // Old-style location list were used in DWARF v4 (.debug_loc.dwo section).
      // Modern locations list (.debug_loclists) are used starting from v5.
      // Ideally we should take the version from the .debug_loclists section
      // header, but using CU's version for simplicity.
      auto LL = DWARFDebugLoclists::parseOneLocationList(
          Data, &Offset, UseLocLists ? U->getVersion() : 4);

      uint64_t BaseAddr = 0;
      if (Optional<object::SectionedAddress> BA = U->getBaseAddress())
        BaseAddr = BA->Address;

      if (LL)
        LL->dump(OS, BaseAddr, Ctx.isLittleEndian(), Obj.getAddressSize(), MRI,
                 U, Indent);
      else
        OS << "error extracting location list.";
    }
  }
}