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//===- DWARFListTable.h -----------------------------------------*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/DebugInfo/DIContext.h"
#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/raw_ostream.h"
#include <cstdint>
#include <map>
#include <vector>
namespace llvm {
/// A base class for DWARF list entries, such as range or location list
/// entries.
struct DWARFListEntryBase {
/// The offset at which the entry is located in the section.
uint64_t Offset;
/// The DWARF encoding (DW_RLE_* or DW_LLE_*).
uint8_t EntryKind;
/// The index of the section this entry belongs to.
uint64_t SectionIndex;
/// A base class for lists of entries that are extracted from a particular
/// section, such as range lists or location lists.
template <typename ListEntryType> class DWARFListType {
using EntryType = ListEntryType;
using ListEntries = std::vector<EntryType>;
ListEntries Entries;
const ListEntries &getEntries() const { return Entries; }
bool empty() const { return Entries.empty(); }
void clear() { Entries.clear(); }
Error extract(DWARFDataExtractor Data, uint64_t HeaderOffset,
uint64_t *OffsetPtr, StringRef SectionName,
StringRef ListStringName);
/// A class representing the header of a list table such as the range list
/// table in the .debug_rnglists section.
class DWARFListTableHeader {
struct Header {
/// The total length of the entries for this table, not including the length
/// field itself.
uint64_t Length = 0;
/// The DWARF version number.
uint16_t Version;
/// The size in bytes of an address on the target architecture. For
/// segmented addressing, this is the size of the offset portion of the
/// address.
uint8_t AddrSize;
/// The size in bytes of a segment selector on the target architecture.
/// If the target system uses a flat address space, this value is 0.
uint8_t SegSize;
/// The number of offsets that follow the header before the range lists.
uint32_t OffsetEntryCount;
Header HeaderData;
/// The table's format, either DWARF32 or DWARF64.
dwarf::DwarfFormat Format;
/// The offset at which the header (and hence the table) is located within
/// its section.
uint64_t HeaderOffset;
/// The name of the section the list is located in.
StringRef SectionName;
/// A characterization of the list for dumping purposes, e.g. "range" or
/// "location".
StringRef ListTypeString;
DWARFListTableHeader(StringRef SectionName, StringRef ListTypeString)
: SectionName(SectionName), ListTypeString(ListTypeString) {}
void clear() {
HeaderData = {};
uint64_t getHeaderOffset() const { return HeaderOffset; }
uint8_t getAddrSize() const { return HeaderData.AddrSize; }
uint64_t getLength() const { return HeaderData.Length; }
uint16_t getVersion() const { return HeaderData.Version; }
uint32_t getOffsetEntryCount() const { return HeaderData.OffsetEntryCount; }
StringRef getSectionName() const { return SectionName; }
StringRef getListTypeString() const { return ListTypeString; }
dwarf::DwarfFormat getFormat() const { return Format; }
/// Return the size of the table header including the length but not including
/// the offsets.
static uint8_t getHeaderSize(dwarf::DwarfFormat Format) {
switch (Format) {
case dwarf::DwarfFormat::DWARF32:
return 12;
case dwarf::DwarfFormat::DWARF64:
return 20;
llvm_unreachable("Invalid DWARF format (expected DWARF32 or DWARF64");
void dump(DataExtractor Data, raw_ostream &OS,
DIDumpOptions DumpOpts = {}) const;
std::optional<uint64_t> getOffsetEntry(DataExtractor Data,
uint32_t Index) const {
if (Index >= HeaderData.OffsetEntryCount)
return std::nullopt;
return getOffsetEntry(Data, getHeaderOffset() + getHeaderSize(Format), Format, Index);
static std::optional<uint64_t> getOffsetEntry(DataExtractor Data,
uint64_t OffsetTableOffset,
dwarf::DwarfFormat Format,
uint32_t Index) {
uint8_t OffsetByteSize = Format == dwarf::DWARF64 ? 8 : 4;
uint64_t Offset = OffsetTableOffset + OffsetByteSize * Index;
auto R = Data.getUnsigned(&Offset, OffsetByteSize);
return R;
/// Extract the table header and the array of offsets.
Error extract(DWARFDataExtractor Data, uint64_t *OffsetPtr);
/// Returns the length of the table, including the length field, or 0 if the
/// length has not been determined (e.g. because the table has not yet been
/// parsed, or there was a problem in parsing).
uint64_t length() const;
/// A class representing a table of lists as specified in the DWARF v5
/// standard for location lists and range lists. The table consists of a header
/// followed by an array of offsets into a DWARF section, followed by zero or
/// more list entries. The list entries are kept in a map where the keys are
/// the lists' section offsets.
template <typename DWARFListType> class DWARFListTableBase {
DWARFListTableHeader Header;
/// A mapping between file offsets and lists. It is used to find a particular
/// list based on an offset (obtained from DW_AT_ranges, for example).
std::map<uint64_t, DWARFListType> ListMap;
/// This string is displayed as a heading before the list is dumped
/// (e.g. "ranges:").
StringRef HeaderString;
DWARFListTableBase(StringRef SectionName, StringRef HeaderString,
StringRef ListTypeString)
: Header(SectionName, ListTypeString), HeaderString(HeaderString) {}
void clear() {
/// Extract the table header and the array of offsets.
Error extractHeaderAndOffsets(DWARFDataExtractor Data, uint64_t *OffsetPtr) {
return Header.extract(Data, OffsetPtr);
/// Extract an entire table, including all list entries.
Error extract(DWARFDataExtractor Data, uint64_t *OffsetPtr);
/// Look up a list based on a given offset. Extract it and enter it into the
/// list map if necessary.
Expected<DWARFListType> findList(DWARFDataExtractor Data,
uint64_t Offset) const;
uint64_t getHeaderOffset() const { return Header.getHeaderOffset(); }
uint8_t getAddrSize() const { return Header.getAddrSize(); }
uint32_t getOffsetEntryCount() const { return Header.getOffsetEntryCount(); }
dwarf::DwarfFormat getFormat() const { return Header.getFormat(); }
dump(DWARFDataExtractor Data, raw_ostream &OS,
DIDumpOptions DumpOpts = {}) const;
/// Return the contents of the offset entry designated by a given index.
std::optional<uint64_t> getOffsetEntry(DataExtractor Data,
uint32_t Index) const {
return Header.getOffsetEntry(Data, Index);
/// Return the size of the table header including the length but not including
/// the offsets. This is dependent on the table format, which is unambiguously
/// derived from parsing the table.
uint8_t getHeaderSize() const {
return DWARFListTableHeader::getHeaderSize(getFormat());
uint64_t length() { return Header.length(); }
template <typename DWARFListType>
Error DWARFListTableBase<DWARFListType>::extract(DWARFDataExtractor Data,
uint64_t *OffsetPtr) {
if (Error E = extractHeaderAndOffsets(Data, OffsetPtr))
return E;
Data = DWARFDataExtractor(Data, getHeaderOffset() + Header.length());
while (Data.isValidOffset(*OffsetPtr)) {
DWARFListType CurrentList;
uint64_t Off = *OffsetPtr;
if (Error E = CurrentList.extract(Data, getHeaderOffset(), OffsetPtr,
return E;
ListMap[Off] = CurrentList;
assert(*OffsetPtr == Data.size() &&
"mismatch between expected length of table and length "
"of extracted data");
return Error::success();
template <typename ListEntryType>
Error DWARFListType<ListEntryType>::extract(DWARFDataExtractor Data,
uint64_t HeaderOffset,
uint64_t *OffsetPtr,
StringRef SectionName,
StringRef ListTypeString) {
if (*OffsetPtr < HeaderOffset || *OffsetPtr >= Data.size())
return createStringError(errc::invalid_argument,
"invalid %s list offset 0x%" PRIx64,, *OffsetPtr);
while (Data.isValidOffset(*OffsetPtr)) {
ListEntryType Entry;
if (Error E = Entry.extract(Data, OffsetPtr))
return E;
if (Entry.isSentinel())
return Error::success();
return createStringError(errc::illegal_byte_sequence,
"no end of list marker detected at end of %s table "
"starting at offset 0x%" PRIx64,, HeaderOffset);
template <typename DWARFListType>
void DWARFListTableBase<DWARFListType>::dump(
DWARFDataExtractor Data, raw_ostream &OS,
DIDumpOptions DumpOpts) const {
Header.dump(Data, OS, DumpOpts);
OS << HeaderString << "\n";
// Determine the length of the longest encoding string we have in the table,
// so we can align the output properly. We only need this in verbose mode.
size_t MaxEncodingStringLength = 0;
if (DumpOpts.Verbose) {
for (const auto &List : ListMap)
for (const auto &Entry : List.second.getEntries())
MaxEncodingStringLength =
uint64_t CurrentBase = 0;
for (const auto &List : ListMap)
for (const auto &Entry : List.second.getEntries())
Entry.dump(OS, getAddrSize(), MaxEncodingStringLength, CurrentBase,
DumpOpts, LookupPooledAddress);
template <typename DWARFListType>
DWARFListTableBase<DWARFListType>::findList(DWARFDataExtractor Data,
uint64_t Offset) const {
// Extract the list from the section and enter it into the list map.
DWARFListType List;
if (Header.length())
Data = DWARFDataExtractor(Data, getHeaderOffset() + Header.length());
if (Error E =
List.extract(Data, Header.length() ? getHeaderOffset() : 0, &Offset,
Header.getSectionName(), Header.getListTypeString()))
return std::move(E);
return List;
} // end namespace llvm