llvm::Error DWARFDebugNames::Header::extract(const DWARFDataExtractor &AS,
uint32_t *Offset) {
// Check that we can read the fixed-size part.
if (!AS.isValidOffset(*Offset + sizeof(HeaderPOD) - 1))
return make_error<StringError>("Section too small: cannot read header.",
inconvertibleErrorCode());
UnitLength = AS.getU32(Offset);
Version = AS.getU16(Offset);
Padding = AS.getU16(Offset);
CompUnitCount = AS.getU32(Offset);
LocalTypeUnitCount = AS.getU32(Offset);
ForeignTypeUnitCount = AS.getU32(Offset);
BucketCount = AS.getU32(Offset);
NameCount = AS.getU32(Offset);
AbbrevTableSize = AS.getU32(Offset);
AugmentationStringSize = AS.getU32(Offset);
if (!AS.isValidOffsetForDataOfSize(*Offset, AugmentationStringSize))
return make_error<StringError>(
"Section too small: cannot read header augmentation.",
inconvertibleErrorCode());
AugmentationString.resize(AugmentationStringSize);
AS.getU8(Offset, reinterpret_cast<uint8_t *>(AugmentationString.data()),
AugmentationStringSize);
*Offset = alignTo(*Offset, 4);
return Error::success();
}
Optional<DWARFDebugLoc::LocationList>
DWARFDebugLoc::parseOneLocationList(DWARFDataExtractor Data, unsigned *Offset) {
LocationList LL;
LL.Offset = *Offset;
// 2.6.2 Location Lists
// A location list entry consists of:
while (true) {
Entry E;
if (!Data.isValidOffsetForDataOfSize(*Offset, 2 * Data.getAddressSize())) {
llvm::errs() << "Location list overflows the debug_loc section.\n";
return None;
}
// 1. A beginning address offset. ...
E.Begin = Data.getRelocatedAddress(Offset);
// 2. An ending address offset. ...
E.End = Data.getRelocatedAddress(Offset);
// 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)
return LL;
if (!Data.isValidOffsetForDataOfSize(*Offset, 2)) {
llvm::errs() << "Location list overflows the debug_loc section.\n";
return None;
}
unsigned Bytes = Data.getU16(Offset);
if (!Data.isValidOffsetForDataOfSize(*Offset, Bytes)) {
llvm::errs() << "Location list overflows the debug_loc section.\n";
return None;
}
// 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));
LL.Entries.push_back(std::move(E));
}
}
Optional<StrOffsetsContributionDescriptor>
StrOffsetsContributionDescriptor::validateContributionSize(
DWARFDataExtractor &DA) {
uint8_t EntrySize = getDwarfOffsetByteSize();
// In order to ensure that we don't read a partial record at the end of
// the section we validate for a multiple of the entry size.
uint64_t ValidationSize = alignTo(Size, EntrySize);
// Guard against overflow.
if (ValidationSize >= Size)
if (DA.isValidOffsetForDataOfSize((uint32_t)Base, ValidationSize))
return *this;
return Optional<StrOffsetsContributionDescriptor>();
}
// Look for a DWARF32-formatted contribution to the string offsets table
// starting at a given offset and record it in a descriptor.
static Optional<StrOffsetsContributionDescriptor>
parseDWARF32StringOffsetsTableHeader(DWARFDataExtractor &DA, uint32_t Offset) {
if (!DA.isValidOffsetForDataOfSize(Offset, 8))
return None;
uint32_t ContributionSize = DA.getU32(&Offset);
if (ContributionSize >= 0xfffffff0)
return None;
uint8_t Version = DA.getU16(&Offset);
(void)DA.getU16(&Offset); // padding
// The encoded length includes the 2-byte version field and the 2-byte
// padding, so we need to subtract them out when we populate the descriptor.
return {{Offset, ContributionSize - 4, Version, DWARF32}};
}
// Look for a DWARF64-formatted contribution to the string offsets table
// starting at a given offset and record it in a descriptor.
static Optional<StrOffsetsContributionDescriptor>
parseDWARF64StringOffsetsTableHeader(DWARFDataExtractor &DA, uint32_t Offset) {
if (!DA.isValidOffsetForDataOfSize(Offset, 16))
return Optional<StrOffsetsContributionDescriptor>();
if (DA.getU32(&Offset) != 0xffffffff)
return Optional<StrOffsetsContributionDescriptor>();
uint64_t Size = DA.getU64(&Offset);
uint8_t Version = DA.getU16(&Offset);
(void)DA.getU16(&Offset); // padding
// The encoded length includes the 2-byte version field and the 2-byte
// padding, so we need to subtract them out when we populate the descriptor.
return StrOffsetsContributionDescriptor(Offset, Size - 4, Version, DWARF64);
//return Optional<StrOffsetsContributionDescriptor>(Descriptor);
}
