bool DWARFCompileUnit::extract(DataExtractor debug_info, uint32_t *offset_ptr) {
clear();
Offset = *offset_ptr;
if (debug_info.isValidOffset(*offset_ptr)) {
uint64_t abbrOffset;
Length = debug_info.getU32(offset_ptr);
Version = debug_info.getU16(offset_ptr);
abbrOffset = debug_info.getU32(offset_ptr);
AddrSize = debug_info.getU8(offset_ptr);
bool lengthOK = debug_info.isValidOffset(getNextCompileUnitOffset()-1);
bool versionOK = DWARFContext::isSupportedVersion(Version);
bool abbrOffsetOK = AbbrevSection.size() > abbrOffset;
bool addrSizeOK = AddrSize == 4 || AddrSize == 8;
if (lengthOK && versionOK && addrSizeOK && abbrOffsetOK && Abbrev != NULL) {
Abbrevs = Abbrev->getAbbreviationDeclarationSet(abbrOffset);
return true;
}
// reset the offset to where we tried to parse from if anything went wrong
*offset_ptr = Offset;
}
return false;
}
bool DWARFUnit::extractImpl(DataExtractor debug_info, uint32_t *offset_ptr) {
Length = debug_info.getU32(offset_ptr);
Version = debug_info.getU16(offset_ptr);
uint64_t AbbrOffset = debug_info.getU32(offset_ptr);
if (IndexEntry) {
if (AbbrOffset)
return false;
auto *UnitContrib = IndexEntry->getOffset();
if (!UnitContrib || UnitContrib->Length != (Length + 4))
return false;
auto *AbbrEntry = IndexEntry->getOffset(DW_SECT_ABBREV);
if (!AbbrEntry)
return false;
AbbrOffset = AbbrEntry->Offset;
}
AddrSize = debug_info.getU8(offset_ptr);
bool LengthOK = debug_info.isValidOffset(getNextUnitOffset() - 1);
bool VersionOK = DWARFContext::isSupportedVersion(Version);
bool AddrSizeOK = AddrSize == 4 || AddrSize == 8;
if (!LengthOK || !VersionOK || !AddrSizeOK)
return false;
Abbrevs = Abbrev->getAbbreviationDeclarationSet(AbbrOffset);
return Abbrevs != nullptr;
}
bool DWARFDebugAranges::extract(DataExtractor debug_aranges_data) {
if (debug_aranges_data.isValidOffset(0)) {
uint32_t offset = 0;
typedef std::vector<DWARFDebugArangeSet> SetCollection;
typedef SetCollection::const_iterator SetCollectionIter;
SetCollection sets;
DWARFDebugArangeSet set;
Range range;
while (set.extract(debug_aranges_data, &offset))
sets.push_back(set);
uint32_t count = 0;
std::for_each(sets.begin(), sets.end(), CountArangeDescriptors(count));
if (count > 0) {
Aranges.reserve(count);
AddArangeDescriptors range_adder(Aranges);
std::for_each(sets.begin(), sets.end(), range_adder);
}
}
return false;
}
bool
DWARFAbbreviationDeclaration::extract(DataExtractor data, uint32_t* offset_ptr,
uint32_t code) {
Code = code;
Attribute.clear();
if (Code) {
Tag = data.getULEB128(offset_ptr);
HasChildren = data.getU8(offset_ptr);
while (data.isValidOffset(*offset_ptr)) {
uint16_t attr = data.getULEB128(offset_ptr);
uint16_t form = data.getULEB128(offset_ptr);
if (attr && form)
Attribute.push_back(DWARFAttribute(attr, form));
else
break;
}
return Tag != 0;
} else {
Tag = 0;
HasChildren = false;
}
return false;
}
void DWARFDebugLocDWO::parse(DataExtractor data) {
uint32_t Offset = 0;
while (data.isValidOffset(Offset)) {
Locations.resize(Locations.size() + 1);
LocationList &Loc = Locations.back();
Loc.Offset = Offset;
dwarf::LocationListEntry Kind;
while ((Kind = static_cast<dwarf::LocationListEntry>(
data.getU8(&Offset))) != dwarf::DW_LLE_end_of_list) {
if (Kind != dwarf::DW_LLE_startx_length) {
llvm::errs() << "error: dumping support for LLE of kind " << (int)Kind
<< " not implemented\n";
return;
}
Entry E;
E.Start = data.getULEB128(&Offset);
E.Length = data.getU32(&Offset);
unsigned Bytes = data.getU16(&Offset);
// A single location description describing the location of the object...
StringRef str = data.getData().substr(Offset, Bytes);
Offset += Bytes;
E.Loc.resize(str.size());
std::copy(str.begin(), str.end(), E.Loc.begin());
Loc.Entries.push_back(std::move(E));
}
}
}
void DWARFDebugAranges::extract(DataExtractor DebugArangesData) {
if (!DebugArangesData.isValidOffset(0))
return;
uint32_t Offset = 0;
typedef std::vector<DWARFDebugArangeSet> RangeSetColl;
RangeSetColl Sets;
DWARFDebugArangeSet Set;
uint32_t TotalRanges = 0;
while (Set.extract(DebugArangesData, &Offset)) {
Sets.push_back(Set);
TotalRanges += Set.getNumDescriptors();
}
if (TotalRanges == 0)
return;
Aranges.reserve(TotalRanges);
for (RangeSetColl::const_iterator I = Sets.begin(), E = Sets.end(); I != E;
++I) {
uint32_t CUOffset = I->getCompileUnitDIEOffset();
for (uint32_t i = 0, n = I->getNumDescriptors(); i < n; ++i) {
const DWARFDebugArangeSet::Descriptor *ArangeDescPtr =
I->getDescriptor(i);
uint64_t LowPC = ArangeDescPtr->Address;
uint64_t HighPC = LowPC + ArangeDescPtr->Length;
appendRange(CUOffset, LowPC, HighPC);
}
}
}
void DWARFDebugAbbrev::extract(DataExtractor Data) {
clear();
uint32_t Offset = 0;
DWARFAbbreviationDeclarationSet AbbrDecls;
while (Data.isValidOffset(Offset)) {
uint32_t CUAbbrOffset = Offset;
if (!AbbrDecls.extract(Data, &Offset))
break;
AbbrDeclSets[CUAbbrOffset] = std::move(AbbrDecls);
}
}
void DWARFDebugLocDWO::parse(DataExtractor data) {
IsLittleEndian = data.isLittleEndian();
AddressSize = data.getAddressSize();
uint32_t Offset = 0;
while (data.isValidOffset(Offset)) {
if (auto LL = parseOneLocationList(data, &Offset))
Locations.push_back(std::move(*LL));
else
return;
}
}
void DWARFDebugLoc::parse(DataExtractor data, unsigned AddressSize) {
uint32_t Offset = 0;
while (data.isValidOffset(Offset+AddressSize-1)) {
Locations.resize(Locations.size() + 1);
LocationList &Loc = Locations.back();
Loc.Offset = Offset;
// 2.6.2 Location Lists
// A location list entry consists of:
while (true) {
Entry E;
RelocAddrMap::const_iterator AI = RelocMap.find(Offset);
// 1. A beginning address offset. ...
E.Begin = data.getUnsigned(&Offset, AddressSize);
if (AI != RelocMap.end())
E.Begin += AI->second.second;
AI = RelocMap.find(Offset);
// 2. An ending address offset. ...
E.End = data.getUnsigned(&Offset, AddressSize);
if (AI != RelocMap.end())
E.End += AI->second.second;
// The end of any given location list is marked by an end of list entry,
// which consists of a 0 for the beginning address offset and a 0 for the
// ending address offset.
if (E.Begin == 0 && E.End == 0)
break;
unsigned Bytes = data.getU16(&Offset);
// A single location description describing the location of the object...
StringRef str = data.getData().substr(Offset, Bytes);
Offset += Bytes;
E.Loc.reserve(str.size());
std::copy(str.begin(), str.end(), std::back_inserter(E.Loc));
Loc.Entries.push_back(llvm_move(E));
}
}
if (data.isValidOffset(Offset))
llvm::errs() << "error: failed to consume entire .debug_loc section\n";
}
uint32_t
DWARFCompileUnit::extract(uint32_t offset, DataExtractor debug_info_data,
const DWARFAbbreviationDeclarationSet *abbrevs) {
clear();
Offset = offset;
if (debug_info_data.isValidOffset(offset)) {
Length = debug_info_data.getU32(&offset);
Version = debug_info_data.getU16(&offset);
bool abbrevsOK = debug_info_data.getU32(&offset) == abbrevs->getOffset();
Abbrevs = abbrevs;
AddrSize = debug_info_data.getU8(&offset);
bool versionOK = DWARFContext::isSupportedVersion(Version);
bool addrSizeOK = AddrSize == 4 || AddrSize == 8;
if (versionOK && addrSizeOK && abbrevsOK &&
debug_info_data.isValidOffset(offset))
return offset;
}
return 0;
}
bool DWARFUnit::extract(DataExtractor debug_info, uint32_t *offset_ptr) {
clear();
Offset = *offset_ptr;
if (debug_info.isValidOffset(*offset_ptr)) {
if (extractImpl(debug_info, offset_ptr))
return true;
// reset the offset to where we tried to parse from if anything went wrong
*offset_ptr = Offset;
}
return false;
}
void DWARFDebugAranges::extract(DataExtractor DebugArangesData) {
if (!DebugArangesData.isValidOffset(0))
return;
uint32_t Offset = 0;
DWARFDebugArangeSet Set;
while (Set.extract(DebugArangesData, &Offset)) {
uint32_t CUOffset = Set.getCompileUnitDIEOffset();
for (const auto &Desc : Set.descriptors()) {
uint64_t LowPC = Desc.Address;
uint64_t HighPC = Desc.getEndAddress();
appendRange(CUOffset, LowPC, HighPC);
}
ParsedCUOffsets.insert(CUOffset);
}
}
bool DWARFUnit::extractImpl(DataExtractor debug_info, uint32_t *offset_ptr) {
Length = debug_info.getU32(offset_ptr);
Version = debug_info.getU16(offset_ptr);
uint64_t abbrOffset = debug_info.getU32(offset_ptr);
AddrSize = debug_info.getU8(offset_ptr);
bool lengthOK = debug_info.isValidOffset(getNextUnitOffset() - 1);
bool versionOK = DWARFContext::isSupportedVersion(Version);
bool abbrOffsetOK = AbbrevSection.size() > abbrOffset;
bool addrSizeOK = AddrSize == 4 || AddrSize == 8;
if (!lengthOK || !versionOK || !addrSizeOK || !abbrOffsetOK)
return false;
Abbrevs = Abbrev->getAbbreviationDeclarationSet(abbrOffset);
return true;
}
void DWARFDebugMacro::parse(DataExtractor data) {
uint32_t Offset = 0;
while (data.isValidOffset(Offset)) {
// A macro list entry consists of:
Entry E;
// 1. Macinfo type
E.Type = data.getULEB128(&Offset);
if (E.Type == 0) {
// Reached end of ".debug_macinfo" section.
return;
}
switch (E.Type) {
default:
// Got a corrupted ".debug_macinfo" section (invalid macinfo type).
// Push the corrupted entry to the list and halt parsing.
E.Type = DW_MACINFO_invalid;
Macros.push_back(E);
return;
case DW_MACINFO_define:
case DW_MACINFO_undef:
// 2. Source line
E.Line = data.getULEB128(&Offset);
// 3. Macro string
E.MacroStr = data.getCStr(&Offset);
break;
case DW_MACINFO_start_file:
// 2. Source line
E.Line = data.getULEB128(&Offset);
// 3. Source file id
E.File = data.getULEB128(&Offset);
break;
case DW_MACINFO_end_file:
break;
case DW_MACINFO_vendor_ext:
// 2. Vendor extension constant
E.ExtConstant = data.getULEB128(&Offset);
// 3. Vendor extension string
E.ExtStr = data.getCStr(&Offset);
break;
}
Macros.push_back(E);
}
}
bool DWARFUnit::extractImpl(DataExtractor debug_info, uint32_t *offset_ptr) {
Length = debug_info.getU32(offset_ptr);
Version = debug_info.getU16(offset_ptr);
uint64_t AbbrOffset = debug_info.getU32(offset_ptr);
AddrSize = debug_info.getU8(offset_ptr);
bool LengthOK = debug_info.isValidOffset(getNextUnitOffset() - 1);
bool VersionOK = DWARFContext::isSupportedVersion(Version);
bool AddrSizeOK = AddrSize == 4 || AddrSize == 8;
if (!LengthOK || !VersionOK || !AddrSizeOK)
return false;
Abbrevs = Abbrev->getAbbreviationDeclarationSet(AbbrOffset);
if (Abbrevs == nullptr)
return false;
return true;
}
bool DWARFDebugInfoEntry::extractFast(const DWARFUnit &U, uint32_t *OffsetPtr,
const DataExtractor &DebugInfoData,
uint32_t UEndOffset, uint32_t D) {
Offset = *OffsetPtr;
Depth = D;
if (Offset >= UEndOffset || !DebugInfoData.isValidOffset(Offset))
return false;
uint64_t AbbrCode = DebugInfoData.getULEB128(OffsetPtr);
if (0 == AbbrCode) {
// NULL debug tag entry.
AbbrevDecl = nullptr;
return true;
}
AbbrevDecl = U.getAbbreviations()->getAbbreviationDeclaration(AbbrCode);
if (nullptr == AbbrevDecl) {
// Restore the original offset.
*OffsetPtr = Offset;
return false;
}
// See if all attributes in this DIE have fixed byte sizes. If so, we can
// just add this size to the offset to skip to the next DIE.
if (Optional<size_t> FixedSize = AbbrevDecl->getFixedAttributesByteSize(U)) {
*OffsetPtr += *FixedSize;
return true;
}
// Skip all data in the .debug_info for the attributes
for (const auto &AttrSpec : AbbrevDecl->attributes()) {
// Check if this attribute has a fixed byte size.
if (auto FixedSize = AttrSpec.getByteSize(U)) {
// Attribute byte size if fixed, just add the size to the offset.
*OffsetPtr += *FixedSize;
} else if (!DWARFFormValue::skipValue(AttrSpec.Form, DebugInfoData,
OffsetPtr, &U)) {
// We failed to skip this attribute's value, restore the original offset
// and return the failure status.
*OffsetPtr = Offset;
return false;
}
}
return true;
}
bool DWARFDebugInfoEntryMinimal::extractFast(const DWARFUnit *U,
uint32_t *OffsetPtr) {
Offset = *OffsetPtr;
DataExtractor DebugInfoData = U->getDebugInfoExtractor();
uint32_t UEndOffset = U->getNextUnitOffset();
if (Offset >= UEndOffset || !DebugInfoData.isValidOffset(Offset))
return false;
uint64_t AbbrCode = DebugInfoData.getULEB128(OffsetPtr);
if (0 == AbbrCode) {
// NULL debug tag entry.
AbbrevDecl = nullptr;
return true;
}
AbbrevDecl = U->getAbbreviations()->getAbbreviationDeclaration(AbbrCode);
if (nullptr == AbbrevDecl) {
// Restore the original offset.
*OffsetPtr = Offset;
return false;
}
ArrayRef<uint8_t> FixedFormSizes = DWARFFormValue::getFixedFormSizes(
U->getAddressByteSize(), U->getVersion());
assert(FixedFormSizes.size() > 0);
// Skip all data in the .debug_info for the attributes
for (const auto &AttrSpec : AbbrevDecl->attributes()) {
uint16_t Form = AttrSpec.Form;
uint8_t FixedFormSize =
(Form < FixedFormSizes.size()) ? FixedFormSizes[Form] : 0;
if (FixedFormSize)
*OffsetPtr += FixedFormSize;
else if (!DWARFFormValue::skipValue(Form, DebugInfoData, OffsetPtr, U)) {
// Restore the original offset.
*OffsetPtr = Offset;
return false;
}
}
return true;
}
bool DWARFUnit::extractImpl(DataExtractor debug_info, uint32_t *offset_ptr) {
Length = debug_info.getU32(offset_ptr);
// FIXME: Support DWARF64.
FormParams.Format = DWARF32;
FormParams.Version = debug_info.getU16(offset_ptr);
if (FormParams.Version >= 5) {
UnitType = debug_info.getU8(offset_ptr);
FormParams.AddrSize = debug_info.getU8(offset_ptr);
AbbrOffset = debug_info.getU32(offset_ptr);
} else {
AbbrOffset = debug_info.getU32(offset_ptr);
FormParams.AddrSize = debug_info.getU8(offset_ptr);
}
if (IndexEntry) {
if (AbbrOffset)
return false;
auto *UnitContrib = IndexEntry->getOffset();
if (!UnitContrib || UnitContrib->Length != (Length + 4))
return false;
auto *AbbrEntry = IndexEntry->getOffset(DW_SECT_ABBREV);
if (!AbbrEntry)
return false;
AbbrOffset = AbbrEntry->Offset;
}
bool LengthOK = debug_info.isValidOffset(getNextUnitOffset() - 1);
bool VersionOK = DWARFContext::isSupportedVersion(getVersion());
bool AddrSizeOK = getAddressByteSize() == 4 || getAddressByteSize() == 8;
if (!LengthOK || !VersionOK || !AddrSizeOK)
return false;
// Keep track of the highest DWARF version we encounter across all units.
Context.setMaxVersionIfGreater(getVersion());
return true;
}
bool DWARFDebugRangeList::extract(DataExtractor data, uint32_t *offset_ptr) {
clear();
if (!data.isValidOffset(*offset_ptr))
return false;
AddressSize = data.getAddressSize();
if (AddressSize != 4 && AddressSize != 8)
return false;
Offset = *offset_ptr;
while (true) {
RangeListEntry entry;
uint32_t prev_offset = *offset_ptr;
entry.StartAddress = data.getAddress(offset_ptr);
entry.EndAddress = data.getAddress(offset_ptr);
// Check that both values were extracted correctly.
if (*offset_ptr != prev_offset + 2 * AddressSize) {
clear();
return false;
}
if (entry.isEndOfListEntry())
break;
Entries.push_back(entry);
}
return true;
}
void DWARFDebugFrame::parse(DataExtractor Data) {
uint32_t Offset = 0;
DenseMap<uint32_t, CIE *> CIEs;
while (Data.isValidOffset(Offset)) {
uint32_t StartOffset = Offset;
bool IsDWARF64 = false;
uint64_t Length = Data.getU32(&Offset);
uint64_t Id;
if (Length == UINT32_MAX) {
// DWARF-64 is distinguished by the first 32 bits of the initial length
// field being 0xffffffff. Then, the next 64 bits are the actual entry
// length.
IsDWARF64 = true;
Length = Data.getU64(&Offset);
}
// At this point, Offset points to the next field after Length.
// Length is the structure size excluding itself. Compute an offset one
// past the end of the structure (needed to know how many instructions to
// read).
// TODO: For honest DWARF64 support, DataExtractor will have to treat
// offset_ptr as uint64_t*
uint32_t EndStructureOffset = Offset + static_cast<uint32_t>(Length);
// The Id field's size depends on the DWARF format
Id = Data.getUnsigned(&Offset, IsDWARF64 ? 8 : 4);
bool IsCIE = ((IsDWARF64 && Id == DW64_CIE_ID) || Id == DW_CIE_ID);
if (IsCIE) {
uint8_t Version = Data.getU8(&Offset);
const char *Augmentation = Data.getCStr(&Offset);
uint8_t AddressSize = Version < 4 ? Data.getAddressSize() : Data.getU8(&Offset);
Data.setAddressSize(AddressSize);
uint8_t SegmentDescriptorSize = Version < 4 ? 0 : Data.getU8(&Offset);
uint64_t CodeAlignmentFactor = Data.getULEB128(&Offset);
int64_t DataAlignmentFactor = Data.getSLEB128(&Offset);
uint64_t ReturnAddressRegister = Data.getULEB128(&Offset);
auto Cie = make_unique<CIE>(StartOffset, Length, Version,
StringRef(Augmentation), AddressSize,
SegmentDescriptorSize, CodeAlignmentFactor,
DataAlignmentFactor, ReturnAddressRegister);
CIEs[StartOffset] = Cie.get();
Entries.emplace_back(std::move(Cie));
} else {
// FDE
uint64_t CIEPointer = Id;
uint64_t InitialLocation = Data.getAddress(&Offset);
uint64_t AddressRange = Data.getAddress(&Offset);
Entries.emplace_back(new FDE(StartOffset, Length, CIEPointer,
InitialLocation, AddressRange,
CIEs[CIEPointer]));
}
Entries.back()->parseInstructions(Data, &Offset, EndStructureOffset);
if (Offset != EndStructureOffset) {
std::string Str;
raw_string_ostream OS(Str);
OS << format("Parsing entry instructions at %lx failed", StartOffset);
report_fatal_error(Str);
}
}
}
void DWARFDebugFrame::parse(DataExtractor Data) {
uint32_t Offset = 0;
DenseMap<uint32_t, CIE *> CIEs;
while (Data.isValidOffset(Offset)) {
uint32_t StartOffset = Offset;
auto ReportError = [StartOffset](const char *ErrorMsg) {
std::string Str;
raw_string_ostream OS(Str);
OS << format(ErrorMsg, StartOffset);
OS.flush();
report_fatal_error(Str);
};
bool IsDWARF64 = false;
uint64_t Length = Data.getU32(&Offset);
uint64_t Id;
if (Length == UINT32_MAX) {
// DWARF-64 is distinguished by the first 32 bits of the initial length
// field being 0xffffffff. Then, the next 64 bits are the actual entry
// length.
IsDWARF64 = true;
Length = Data.getU64(&Offset);
}
// At this point, Offset points to the next field after Length.
// Length is the structure size excluding itself. Compute an offset one
// past the end of the structure (needed to know how many instructions to
// read).
// TODO: For honest DWARF64 support, DataExtractor will have to treat
// offset_ptr as uint64_t*
uint32_t StartStructureOffset = Offset;
uint32_t EndStructureOffset = Offset + static_cast<uint32_t>(Length);
// The Id field's size depends on the DWARF format
Id = Data.getUnsigned(&Offset, (IsDWARF64 && !IsEH) ? 8 : 4);
bool IsCIE = ((IsDWARF64 && Id == DW64_CIE_ID) ||
Id == DW_CIE_ID ||
(IsEH && !Id));
if (IsCIE) {
uint8_t Version = Data.getU8(&Offset);
const char *Augmentation = Data.getCStr(&Offset);
StringRef AugmentationString(Augmentation ? Augmentation : "");
uint8_t AddressSize = Version < 4 ? Data.getAddressSize() :
Data.getU8(&Offset);
Data.setAddressSize(AddressSize);
uint8_t SegmentDescriptorSize = Version < 4 ? 0 : Data.getU8(&Offset);
uint64_t CodeAlignmentFactor = Data.getULEB128(&Offset);
int64_t DataAlignmentFactor = Data.getSLEB128(&Offset);
uint64_t ReturnAddressRegister = Data.getULEB128(&Offset);
// Parse the augmentation data for EH CIEs
StringRef AugmentationData("");
uint32_t FDEPointerEncoding = DW_EH_PE_omit;
uint32_t LSDAPointerEncoding = DW_EH_PE_omit;
if (IsEH) {
Optional<uint32_t> PersonalityEncoding;
Optional<uint64_t> Personality;
Optional<uint64_t> AugmentationLength;
uint32_t StartAugmentationOffset;
uint32_t EndAugmentationOffset;
// Walk the augmentation string to get all the augmentation data.
for (unsigned i = 0, e = AugmentationString.size(); i != e; ++i) {
switch (AugmentationString[i]) {
default:
ReportError("Unknown augmentation character in entry at %lx");
case 'L':
LSDAPointerEncoding = Data.getU8(&Offset);
break;
case 'P': {
if (Personality)
ReportError("Duplicate personality in entry at %lx");
PersonalityEncoding = Data.getU8(&Offset);
Personality = readPointer(Data, Offset, *PersonalityEncoding);
break;
}
case 'R':
FDEPointerEncoding = Data.getU8(&Offset);
break;
case 'z':
if (i)
ReportError("'z' must be the first character at %lx");
// Parse the augmentation length first. We only parse it if
// the string contains a 'z'.
AugmentationLength = Data.getULEB128(&Offset);
StartAugmentationOffset = Offset;
EndAugmentationOffset = Offset +
static_cast<uint32_t>(*AugmentationLength);
}
}
if (AugmentationLength.hasValue()) {
if (Offset != EndAugmentationOffset)
ReportError("Parsing augmentation data at %lx failed");
AugmentationData = Data.getData().slice(StartAugmentationOffset,
EndAugmentationOffset);
}
}
auto Cie = make_unique<CIE>(StartOffset, Length, Version,
AugmentationString, AddressSize,
SegmentDescriptorSize, CodeAlignmentFactor,
DataAlignmentFactor, ReturnAddressRegister,
AugmentationData, FDEPointerEncoding,
LSDAPointerEncoding);
CIEs[StartOffset] = Cie.get();
Entries.emplace_back(std::move(Cie));
} else {
// FDE
uint64_t CIEPointer = Id;
uint64_t InitialLocation = 0;
uint64_t AddressRange = 0;
CIE *Cie = CIEs[IsEH ? (StartStructureOffset - CIEPointer) : CIEPointer];
if (IsEH) {
// The address size is encoded in the CIE we reference.
if (!Cie)
ReportError("Parsing FDE data at %lx failed due to missing CIE");
InitialLocation = readPointer(Data, Offset,
Cie->getFDEPointerEncoding());
AddressRange = readPointer(Data, Offset,
Cie->getFDEPointerEncoding());
StringRef AugmentationString = Cie->getAugmentationString();
if (!AugmentationString.empty()) {
// Parse the augmentation length and data for this FDE.
uint64_t AugmentationLength = Data.getULEB128(&Offset);
uint32_t EndAugmentationOffset =
Offset + static_cast<uint32_t>(AugmentationLength);
// Decode the LSDA if the CIE augmentation string said we should.
if (Cie->getLSDAPointerEncoding() != DW_EH_PE_omit)
readPointer(Data, Offset, Cie->getLSDAPointerEncoding());
if (Offset != EndAugmentationOffset)
ReportError("Parsing augmentation data at %lx failed");
}
} else {
InitialLocation = Data.getAddress(&Offset);
AddressRange = Data.getAddress(&Offset);
}
Entries.emplace_back(new FDE(StartOffset, Length, CIEPointer,
InitialLocation, AddressRange,
Cie));
}
Entries.back()->parseInstructions(Data, &Offset, EndStructureOffset);
if (Offset != EndStructureOffset)
ReportError("Parsing entry instructions at %lx failed");
}
}
void DWARFDebugFrame::parse(DataExtractor Data) {
uint32_t Offset = 0;
while (Data.isValidOffset(Offset)) {
uint32_t StartOffset = Offset;
bool IsDWARF64 = false;
uint64_t Length = Data.getU32(&Offset);
uint64_t Id;
if (Length == UINT32_MAX) {
// DWARF-64 is distinguished by the first 32 bits of the initial length
// field being 0xffffffff. Then, the next 64 bits are the actual entry
// length.
IsDWARF64 = true;
Length = Data.getU64(&Offset);
}
// At this point, Offset points to the next field after Length.
// Length is the structure size excluding itself. Compute an offset one
// past the end of the structure (needed to know how many instructions to
// read).
// TODO: For honest DWARF64 support, DataExtractor will have to treat
// offset_ptr as uint64_t*
uint32_t EndStructureOffset = Offset + static_cast<uint32_t>(Length);
// The Id field's size depends on the DWARF format
Id = Data.getUnsigned(&Offset, IsDWARF64 ? 8 : 4);
bool IsCIE = ((IsDWARF64 && Id == DW64_CIE_ID) || Id == DW_CIE_ID);
if (IsCIE) {
// Note: this is specifically DWARFv3 CIE header structure. It was
// changed in DWARFv4. We currently don't support reading DWARFv4
// here because LLVM itself does not emit it (and LLDB doesn't
// support it either).
uint8_t Version = Data.getU8(&Offset);
const char *Augmentation = Data.getCStr(&Offset);
uint64_t CodeAlignmentFactor = Data.getULEB128(&Offset);
int64_t DataAlignmentFactor = Data.getSLEB128(&Offset);
uint64_t ReturnAddressRegister = Data.getULEB128(&Offset);
Entries.emplace_back(new CIE(StartOffset, Length, Version,
StringRef(Augmentation), CodeAlignmentFactor,
DataAlignmentFactor, ReturnAddressRegister));
} else {
// FDE
uint64_t CIEPointer = Id;
uint64_t InitialLocation = Data.getAddress(&Offset);
uint64_t AddressRange = Data.getAddress(&Offset);
Entries.emplace_back(new FDE(StartOffset, Length, CIEPointer,
InitialLocation, AddressRange));
}
Entries.back()->parseInstructions(Data, &Offset, EndStructureOffset);
if (Offset != EndStructureOffset) {
string_ostream Str;
Str << format("Parsing entry instructions at %lx failed", StartOffset);
report_fatal_error(Str.str());
}
}
}
