#include "BinaryHolder.h"
#include "DebugMap.h"
#include "dsymutil.h"
+#include "llvm/ADT/IntervalMap.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/STLExtras.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/DIE.h"
#include "llvm/DebugInfo/DWARF/DWARFContext.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCCodeEmitter.h"
+#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCInstrInfo.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include <string>
+#include <tuple>
namespace llvm {
namespace dsymutil {
return false;
}
+template <typename KeyT, typename ValT>
+using HalfOpenIntervalMap =
+ IntervalMap<KeyT, ValT, IntervalMapImpl::NodeSizer<KeyT, ValT>::LeafSize,
+ IntervalMapHalfOpenInfo<KeyT>>;
+
+typedef HalfOpenIntervalMap<uint64_t, int64_t> FunctionIntervals;
+
/// \brief Stores all information relating to a compile unit, be it in
/// its original instance in the object file to its brand new cloned
/// and linked DIE tree.
public:
/// \brief Information gathered about a DIE in the object file.
struct DIEInfo {
- uint64_t Address; ///< Linked address of the described entity.
+ int64_t AddrAdjust; ///< Address offset to apply to the described entity.
DIE *Clone; ///< Cloned version of that DIE.
uint32_t ParentIdx; ///< The index of this DIE's parent.
bool Keep; ///< Is the DIE part of the linked output?
bool InDebugMap; ///< Was this DIE's entity found in the map?
};
- CompileUnit(DWARFUnit &OrigUnit) : OrigUnit(OrigUnit) {
+ CompileUnit(DWARFUnit &OrigUnit, unsigned ID)
+ : OrigUnit(OrigUnit), ID(ID), LowPc(UINT64_MAX), HighPc(0), RangeAlloc(),
+ Ranges(RangeAlloc), UnitRangeAttribute(nullptr) {
Info.resize(OrigUnit.getNumDIEs());
}
- // Workaround MSVC not supporting implicit move ops
CompileUnit(CompileUnit &&RHS)
: OrigUnit(RHS.OrigUnit), Info(std::move(RHS.Info)),
CUDie(std::move(RHS.CUDie)), StartOffset(RHS.StartOffset),
- NextUnitOffset(RHS.NextUnitOffset) {}
+ NextUnitOffset(RHS.NextUnitOffset), RangeAlloc(), Ranges(RangeAlloc) {
+ // The CompileUnit container has been 'reserve()'d with the right
+ // size. We cannot move the IntervalMap anyway.
+ llvm_unreachable("CompileUnits should not be moved.");
+ }
DWARFUnit &getOrigUnit() const { return OrigUnit; }
+ unsigned getUniqueID() const { return ID; }
+
DIE *getOutputUnitDIE() const { return CUDie.get(); }
void setOutputUnitDIE(DIE *Die) { CUDie.reset(Die); }
uint64_t getStartOffset() const { return StartOffset; }
uint64_t getNextUnitOffset() const { return NextUnitOffset; }
-
void setStartOffset(uint64_t DebugInfoSize) { StartOffset = DebugInfoSize; }
+ uint64_t getLowPc() const { return LowPc; }
+ uint64_t getHighPc() const { return HighPc; }
+
+ DIEInteger *getUnitRangesAttribute() const { return UnitRangeAttribute; }
+ const FunctionIntervals &getFunctionRanges() const { return Ranges; }
+ const std::vector<DIEInteger *> &getRangesAttributes() const {
+ return RangeAttributes;
+ }
+
+ const std::vector<std::pair<DIEInteger *, int64_t>> &
+ getLocationAttributes() const {
+ return LocationAttributes;
+ }
+
/// \brief Compute the end offset for this unit. Must be
/// called after the CU's DIEs have been cloned.
/// \returns the next unit offset (which is also the current
/// debug_info section size).
uint64_t computeNextUnitOffset();
- /// \brief Keep track of a forward reference to DIE \p Die by
- /// \p Attr. The attribute should be fixed up later to point to the
- /// absolute offset of \p Die in the debug_info section.
- void noteForwardReference(DIE *Die, DIEInteger *Attr);
+ /// \brief Keep track of a forward reference to DIE \p Die in \p
+ /// RefUnit by \p Attr. The attribute should be fixed up later to
+ /// point to the absolute offset of \p Die in the debug_info section.
+ void noteForwardReference(DIE *Die, const CompileUnit *RefUnit,
+ DIEInteger *Attr);
/// \brief Apply all fixups recored by noteForwardReference().
void fixupForwardReferences();
+ /// \brief Add a function range [\p LowPC, \p HighPC) that is
+ /// relocatad by applying offset \p PCOffset.
+ void addFunctionRange(uint64_t LowPC, uint64_t HighPC, int64_t PCOffset);
+
+ /// \brief Keep track of a DW_AT_range attribute that we will need to
+ /// patch up later.
+ void noteRangeAttribute(const DIE &Die, DIEInteger *Attr);
+
+ /// \brief Keep track of a location attribute pointing to a location
+ /// list in the debug_loc section.
+ void noteLocationAttribute(DIEInteger *Attr, int64_t PcOffset);
+
+ /// \brief Add a name accelerator entry for \p Die with \p Name
+ /// which is stored in the string table at \p Offset.
+ void addNameAccelerator(const DIE *Die, const char *Name, uint32_t Offset,
+ bool SkipPubnamesSection = false);
+
+ /// \brief Add a type accelerator entry for \p Die with \p Name
+ /// which is stored in the string table at \p Offset.
+ void addTypeAccelerator(const DIE *Die, const char *Name, uint32_t Offset);
+
+ struct AccelInfo {
+ StringRef Name; ///< Name of the entry.
+ const DIE *Die; ///< DIE this entry describes.
+ uint32_t NameOffset; ///< Offset of Name in the string pool.
+ bool SkipPubSection; ///< Emit this entry only in the apple_* sections.
+
+ AccelInfo(StringRef Name, const DIE *Die, uint32_t NameOffset,
+ bool SkipPubSection = false)
+ : Name(Name), Die(Die), NameOffset(NameOffset),
+ SkipPubSection(SkipPubSection) {}
+ };
+
+ const std::vector<AccelInfo> &getPubnames() const { return Pubnames; }
+ const std::vector<AccelInfo> &getPubtypes() const { return Pubtypes; }
+
private:
DWARFUnit &OrigUnit;
+ unsigned ID;
std::vector<DIEInfo> Info; ///< DIE info indexed by DIE index.
std::unique_ptr<DIE> CUDie; ///< Root of the linked DIE tree.
uint64_t StartOffset;
uint64_t NextUnitOffset;
+ uint64_t LowPc;
+ uint64_t HighPc;
+
/// \brief A list of attributes to fixup with the absolute offset of
/// a DIE in the debug_info section.
///
/// The offsets for the attributes in this array couldn't be set while
- /// cloning because for forward refences the target DIE's offset isn't
- /// known you emit the reference attribute.
- std::vector<std::pair<DIE *, DIEInteger *>> ForwardDIEReferences;
+ /// cloning because for cross-cu forward refences the target DIE's
+ /// offset isn't known you emit the reference attribute.
+ std::vector<std::tuple<DIE *, const CompileUnit *, DIEInteger *>>
+ ForwardDIEReferences;
+
+ FunctionIntervals::Allocator RangeAlloc;
+ /// \brief The ranges in that interval map are the PC ranges for
+ /// functions in this unit, associated with the PC offset to apply
+ /// to the addresses to get the linked address.
+ FunctionIntervals Ranges;
+
+ /// \brief DW_AT_ranges attributes to patch after we have gathered
+ /// all the unit's function addresses.
+ /// @{
+ std::vector<DIEInteger *> RangeAttributes;
+ DIEInteger *UnitRangeAttribute;
+ /// @}
+
+ /// \brief Location attributes that need to be transfered from th
+ /// original debug_loc section to the liked one. They are stored
+ /// along with the PC offset that is to be applied to their
+ /// function's address.
+ std::vector<std::pair<DIEInteger *, int64_t>> LocationAttributes;
+
+ /// \brief Accelerator entries for the unit, both for the pub*
+ /// sections and the apple* ones.
+ /// @{
+ std::vector<AccelInfo> Pubnames;
+ std::vector<AccelInfo> Pubtypes;
+ /// @}
};
uint64_t CompileUnit::computeNextUnitOffset() {
return NextUnitOffset;
}
-/// \brief Keep track of a forward reference to \p Die.
-void CompileUnit::noteForwardReference(DIE *Die, DIEInteger *Attr) {
- ForwardDIEReferences.emplace_back(Die, Attr);
+/// \brief Keep track of a forward cross-cu reference from this unit
+/// to \p Die that lives in \p RefUnit.
+void CompileUnit::noteForwardReference(DIE *Die, const CompileUnit *RefUnit,
+ DIEInteger *Attr) {
+ ForwardDIEReferences.emplace_back(Die, RefUnit, Attr);
}
/// \brief Apply all fixups recorded by noteForwardReference().
void CompileUnit::fixupForwardReferences() {
- for (const auto &Ref : ForwardDIEReferences)
- Ref.second->setValue(Ref.first->getOffset() + getStartOffset());
+ for (const auto &Ref : ForwardDIEReferences) {
+ DIE *RefDie;
+ const CompileUnit *RefUnit;
+ DIEInteger *Attr;
+ std::tie(RefDie, RefUnit, Attr) = Ref;
+ Attr->setValue(RefDie->getOffset() + RefUnit->getStartOffset());
+ }
+}
+
+void CompileUnit::addFunctionRange(uint64_t FuncLowPc, uint64_t FuncHighPc,
+ int64_t PcOffset) {
+ Ranges.insert(FuncLowPc, FuncHighPc, PcOffset);
+ this->LowPc = std::min(LowPc, FuncLowPc + PcOffset);
+ this->HighPc = std::max(HighPc, FuncHighPc + PcOffset);
+}
+
+void CompileUnit::noteRangeAttribute(const DIE &Die, DIEInteger *Attr) {
+ if (Die.getTag() != dwarf::DW_TAG_compile_unit)
+ RangeAttributes.push_back(Attr);
+ else
+ UnitRangeAttribute = Attr;
+}
+
+void CompileUnit::noteLocationAttribute(DIEInteger *Attr, int64_t PcOffset) {
+ LocationAttributes.emplace_back(Attr, PcOffset);
+}
+
+/// \brief Add a name accelerator entry for \p Die with \p Name
+/// which is stored in the string table at \p Offset.
+void CompileUnit::addNameAccelerator(const DIE *Die, const char *Name,
+ uint32_t Offset, bool SkipPubSection) {
+ Pubnames.emplace_back(Name, Die, Offset, SkipPubSection);
+}
+
+/// \brief Add a type accelerator entry for \p Die with \p Name
+/// which is stored in the string table at \p Offset.
+void CompileUnit::addTypeAccelerator(const DIE *Die, const char *Name,
+ uint32_t Offset) {
+ Pubtypes.emplace_back(Name, Die, Offset, false);
}
/// \brief A string table that doesn't need relocations.
Last = &*It;
}
return It->getValue().first;
-};
+}
/// \brief Put \p S into the StringMap so that it gets permanent
/// storage, but do not actually link it in the chain of elements
std::pair<uint32_t, StringMapEntryBase *> Entry(0, nullptr);
auto InsertResult = Strings.insert(std::make_pair(S, Entry));
return InsertResult.first->getKey();
-};
+}
/// \brief The Dwarf streaming logic
///
/// \brief the file we stream the linked Dwarf to.
std::unique_ptr<raw_fd_ostream> OutFile;
+ uint32_t RangesSectionSize;
+ uint32_t LocSectionSize;
+ uint32_t LineSectionSize;
+
+ /// \brief Emit the pubnames or pubtypes section contribution for \p
+ /// Unit into \p Sec. The data is provided in \p Names.
+ void emitPubSectionForUnit(const MCSection *Sec, StringRef Name,
+ const CompileUnit &Unit,
+ const std::vector<CompileUnit::AccelInfo> &Names);
+
public:
/// \brief Actually create the streamer and the ouptut file.
///
/// \brief Emit the string table described by \p Pool.
void emitStrings(const NonRelocatableStringpool &Pool);
+
+ /// \brief Emit debug_ranges for \p FuncRange by translating the
+ /// original \p Entries.
+ void emitRangesEntries(
+ int64_t UnitPcOffset, uint64_t OrigLowPc,
+ FunctionIntervals::const_iterator FuncRange,
+ const std::vector<DWARFDebugRangeList::RangeListEntry> &Entries,
+ unsigned AddressSize);
+
+ /// \brief Emit debug_aranges entries for \p Unit and if \p
+ /// DoRangesSection is true, also emit the debug_ranges entries for
+ /// the DW_TAG_compile_unit's DW_AT_ranges attribute.
+ void emitUnitRangesEntries(CompileUnit &Unit, bool DoRangesSection);
+
+ uint32_t getRangesSectionSize() const { return RangesSectionSize; }
+
+ /// \brief Emit the debug_loc contribution for \p Unit by copying
+ /// the entries from \p Dwarf and offseting them. Update the
+ /// location attributes to point to the new entries.
+ void emitLocationsForUnit(const CompileUnit &Unit, DWARFContext &Dwarf);
+
+ /// \brief Emit the line table described in \p Rows into the
+ /// debug_line section.
+ void emitLineTableForUnit(StringRef PrologueBytes, unsigned MinInstLength,
+ std::vector<DWARFDebugLine::Row> &Rows,
+ unsigned AdddressSize);
+
+ uint32_t getLineSectionSize() const { return LineSectionSize; }
+
+ /// \brief Emit the .debug_pubnames contribution for \p Unit.
+ void emitPubNamesForUnit(const CompileUnit &Unit);
+
+ /// \brief Emit the .debug_pubtypes contribution for \p Unit.
+ void emitPubTypesForUnit(const CompileUnit &Unit);
};
bool DwarfStreamer::init(Triple TheTriple, StringRef OutputFilename) {
if (!MSTI)
return error("no subtarget info for target " + TripleName, Context);
- MCE = TheTarget->createMCCodeEmitter(*MII, *MRI, *MSTI, *MC);
+ MCE = TheTarget->createMCCodeEmitter(*MII, *MRI, *MC);
if (!MCE)
return error("no code emitter for target " + TripleName, Context);
if (EC)
return error(Twine(OutputFilename) + ": " + EC.message(), Context);
- MS = TheTarget->createMCObjectStreamer(TripleName, *MC, *MAB, *OutFile, MCE,
- *MSTI, false);
+ MS = TheTarget->createMCObjectStreamer(TheTriple, *MC, *MAB, *OutFile, MCE,
+ *MSTI, false,
+ /*DWARFMustBeAtTheEnd*/ false);
if (!MS)
return error("no object streamer for target " + TripleName, Context);
if (!Asm)
return error("no asm printer for target " + TripleName, Context);
+ RangesSectionSize = 0;
+ LocSectionSize = 0;
+ LineSectionSize = 0;
+
return true;
}
/// \brief Emit the debug_str section stored in \p Pool.
void DwarfStreamer::emitStrings(const NonRelocatableStringpool &Pool) {
- Asm->OutStreamer.SwitchSection(MOFI->getDwarfStrSection());
+ Asm->OutStreamer->SwitchSection(MOFI->getDwarfStrSection());
for (auto *Entry = Pool.getFirstEntry(); Entry;
Entry = Pool.getNextEntry(Entry))
- Asm->OutStreamer.EmitBytes(
+ Asm->OutStreamer->EmitBytes(
StringRef(Entry->getKey().data(), Entry->getKey().size() + 1));
}
+/// \brief Emit the debug_range section contents for \p FuncRange by
+/// translating the original \p Entries. The debug_range section
+/// format is totally trivial, consisting just of pairs of address
+/// sized addresses describing the ranges.
+void DwarfStreamer::emitRangesEntries(
+ int64_t UnitPcOffset, uint64_t OrigLowPc,
+ FunctionIntervals::const_iterator FuncRange,
+ const std::vector<DWARFDebugRangeList::RangeListEntry> &Entries,
+ unsigned AddressSize) {
+ MS->SwitchSection(MC->getObjectFileInfo()->getDwarfRangesSection());
+
+ // Offset each range by the right amount.
+ int64_t PcOffset = FuncRange.value() + UnitPcOffset;
+ for (const auto &Range : Entries) {
+ if (Range.isBaseAddressSelectionEntry(AddressSize)) {
+ warn("unsupported base address selection operation",
+ "emitting debug_ranges");
+ break;
+ }
+ // Do not emit empty ranges.
+ if (Range.StartAddress == Range.EndAddress)
+ continue;
+
+ // All range entries should lie in the function range.
+ if (!(Range.StartAddress + OrigLowPc >= FuncRange.start() &&
+ Range.EndAddress + OrigLowPc <= FuncRange.stop()))
+ warn("inconsistent range data.", "emitting debug_ranges");
+ MS->EmitIntValue(Range.StartAddress + PcOffset, AddressSize);
+ MS->EmitIntValue(Range.EndAddress + PcOffset, AddressSize);
+ RangesSectionSize += 2 * AddressSize;
+ }
+
+ // Add the terminator entry.
+ MS->EmitIntValue(0, AddressSize);
+ MS->EmitIntValue(0, AddressSize);
+ RangesSectionSize += 2 * AddressSize;
+}
+
+/// \brief Emit the debug_aranges contribution of a unit and
+/// if \p DoDebugRanges is true the debug_range contents for a
+/// compile_unit level DW_AT_ranges attribute (Which are basically the
+/// same thing with a different base address).
+/// Just aggregate all the ranges gathered inside that unit.
+void DwarfStreamer::emitUnitRangesEntries(CompileUnit &Unit,
+ bool DoDebugRanges) {
+ unsigned AddressSize = Unit.getOrigUnit().getAddressByteSize();
+ // Gather the ranges in a vector, so that we can simplify them. The
+ // IntervalMap will have coalesced the non-linked ranges, but here
+ // we want to coalesce the linked addresses.
+ std::vector<std::pair<uint64_t, uint64_t>> Ranges;
+ const auto &FunctionRanges = Unit.getFunctionRanges();
+ for (auto Range = FunctionRanges.begin(), End = FunctionRanges.end();
+ Range != End; ++Range)
+ Ranges.push_back(std::make_pair(Range.start() + Range.value(),
+ Range.stop() + Range.value()));
+
+ // The object addresses where sorted, but again, the linked
+ // addresses might end up in a different order.
+ std::sort(Ranges.begin(), Ranges.end());
+
+ if (!Ranges.empty()) {
+ MS->SwitchSection(MC->getObjectFileInfo()->getDwarfARangesSection());
+
+ MCSymbol *BeginLabel = Asm->createTempSymbol("Barange");
+ MCSymbol *EndLabel = Asm->createTempSymbol("Earange");
+
+ unsigned HeaderSize =
+ sizeof(int32_t) + // Size of contents (w/o this field
+ sizeof(int16_t) + // DWARF ARange version number
+ sizeof(int32_t) + // Offset of CU in the .debug_info section
+ sizeof(int8_t) + // Pointer Size (in bytes)
+ sizeof(int8_t); // Segment Size (in bytes)
+
+ unsigned TupleSize = AddressSize * 2;
+ unsigned Padding = OffsetToAlignment(HeaderSize, TupleSize);
+
+ Asm->EmitLabelDifference(EndLabel, BeginLabel, 4); // Arange length
+ Asm->OutStreamer->EmitLabel(BeginLabel);
+ Asm->EmitInt16(dwarf::DW_ARANGES_VERSION); // Version number
+ Asm->EmitInt32(Unit.getStartOffset()); // Corresponding unit's offset
+ Asm->EmitInt8(AddressSize); // Address size
+ Asm->EmitInt8(0); // Segment size
+
+ Asm->OutStreamer->EmitFill(Padding, 0x0);
+
+ for (auto Range = Ranges.begin(), End = Ranges.end(); Range != End;
+ ++Range) {
+ uint64_t RangeStart = Range->first;
+ MS->EmitIntValue(RangeStart, AddressSize);
+ while ((Range + 1) != End && Range->second == (Range + 1)->first)
+ ++Range;
+ MS->EmitIntValue(Range->second - RangeStart, AddressSize);
+ }
+
+ // Emit terminator
+ Asm->OutStreamer->EmitIntValue(0, AddressSize);
+ Asm->OutStreamer->EmitIntValue(0, AddressSize);
+ Asm->OutStreamer->EmitLabel(EndLabel);
+ }
+
+ if (!DoDebugRanges)
+ return;
+
+ MS->SwitchSection(MC->getObjectFileInfo()->getDwarfRangesSection());
+ // Offset each range by the right amount.
+ int64_t PcOffset = -Unit.getLowPc();
+ // Emit coalesced ranges.
+ for (auto Range = Ranges.begin(), End = Ranges.end(); Range != End; ++Range) {
+ MS->EmitIntValue(Range->first + PcOffset, AddressSize);
+ while (Range + 1 != End && Range->second == (Range + 1)->first)
+ ++Range;
+ MS->EmitIntValue(Range->second + PcOffset, AddressSize);
+ RangesSectionSize += 2 * AddressSize;
+ }
+
+ // Add the terminator entry.
+ MS->EmitIntValue(0, AddressSize);
+ MS->EmitIntValue(0, AddressSize);
+ RangesSectionSize += 2 * AddressSize;
+}
+
+/// \brief Emit location lists for \p Unit and update attribtues to
+/// point to the new entries.
+void DwarfStreamer::emitLocationsForUnit(const CompileUnit &Unit,
+ DWARFContext &Dwarf) {
+ const std::vector<std::pair<DIEInteger *, int64_t>> &Attributes =
+ Unit.getLocationAttributes();
+
+ if (Attributes.empty())
+ return;
+
+ MS->SwitchSection(MC->getObjectFileInfo()->getDwarfLocSection());
+
+ unsigned AddressSize = Unit.getOrigUnit().getAddressByteSize();
+ const DWARFSection &InputSec = Dwarf.getLocSection();
+ DataExtractor Data(InputSec.Data, Dwarf.isLittleEndian(), AddressSize);
+ DWARFUnit &OrigUnit = Unit.getOrigUnit();
+ const auto *OrigUnitDie = OrigUnit.getCompileUnitDIE(false);
+ int64_t UnitPcOffset = 0;
+ uint64_t OrigLowPc = OrigUnitDie->getAttributeValueAsAddress(
+ &OrigUnit, dwarf::DW_AT_low_pc, -1ULL);
+ if (OrigLowPc != -1ULL)
+ UnitPcOffset = int64_t(OrigLowPc) - Unit.getLowPc();
+
+ for (const auto &Attr : Attributes) {
+ uint32_t Offset = Attr.first->getValue();
+ Attr.first->setValue(LocSectionSize);
+ // This is the quantity to add to the old location address to get
+ // the correct address for the new one.
+ int64_t LocPcOffset = Attr.second + UnitPcOffset;
+ while (Data.isValidOffset(Offset)) {
+ uint64_t Low = Data.getUnsigned(&Offset, AddressSize);
+ uint64_t High = Data.getUnsigned(&Offset, AddressSize);
+ LocSectionSize += 2 * AddressSize;
+ if (Low == 0 && High == 0) {
+ Asm->OutStreamer->EmitIntValue(0, AddressSize);
+ Asm->OutStreamer->EmitIntValue(0, AddressSize);
+ break;
+ }
+ Asm->OutStreamer->EmitIntValue(Low + LocPcOffset, AddressSize);
+ Asm->OutStreamer->EmitIntValue(High + LocPcOffset, AddressSize);
+ uint64_t Length = Data.getU16(&Offset);
+ Asm->OutStreamer->EmitIntValue(Length, 2);
+ // Just copy the bytes over.
+ Asm->OutStreamer->EmitBytes(
+ StringRef(InputSec.Data.substr(Offset, Length)));
+ Offset += Length;
+ LocSectionSize += Length + 2;
+ }
+ }
+}
+
+void DwarfStreamer::emitLineTableForUnit(StringRef PrologueBytes,
+ unsigned MinInstLength,
+ std::vector<DWARFDebugLine::Row> &Rows,
+ unsigned PointerSize) {
+ // Switch to the section where the table will be emitted into.
+ MS->SwitchSection(MC->getObjectFileInfo()->getDwarfLineSection());
+ MCSymbol *LineStartSym = MC->CreateTempSymbol();
+ MCSymbol *LineEndSym = MC->CreateTempSymbol();
+
+ // The first 4 bytes is the total length of the information for this
+ // compilation unit (not including these 4 bytes for the length).
+ Asm->EmitLabelDifference(LineEndSym, LineStartSym, 4);
+ Asm->OutStreamer->EmitLabel(LineStartSym);
+ // Copy Prologue.
+ MS->EmitBytes(PrologueBytes);
+ LineSectionSize += PrologueBytes.size() + 4;
+
+ SmallString<128> EncodingBuffer;
+ raw_svector_ostream EncodingOS(EncodingBuffer);
+
+ if (Rows.empty()) {
+ // We only have the dummy entry, dsymutil emits an entry with a 0
+ // address in that case.
+ MCDwarfLineAddr::Encode(*MC, INT64_MAX, 0, EncodingOS);
+ MS->EmitBytes(EncodingOS.str());
+ LineSectionSize += EncodingBuffer.size();
+ MS->EmitLabel(LineEndSym);
+ return;
+ }
+
+ // Line table state machine fields
+ unsigned FileNum = 1;
+ unsigned LastLine = 1;
+ unsigned Column = 0;
+ unsigned IsStatement = 1;
+ unsigned Isa = 0;
+ uint64_t Address = -1ULL;
+
+ unsigned RowsSinceLastSequence = 0;
+
+ for (unsigned Idx = 0; Idx < Rows.size(); ++Idx) {
+ auto &Row = Rows[Idx];
+
+ int64_t AddressDelta;
+ if (Address == -1ULL) {
+ MS->EmitIntValue(dwarf::DW_LNS_extended_op, 1);
+ MS->EmitULEB128IntValue(PointerSize + 1);
+ MS->EmitIntValue(dwarf::DW_LNE_set_address, 1);
+ MS->EmitIntValue(Row.Address, PointerSize);
+ LineSectionSize += 2 + PointerSize + getULEB128Size(PointerSize + 1);
+ AddressDelta = 0;
+ } else {
+ AddressDelta = (Row.Address - Address) / MinInstLength;
+ }
+
+ // FIXME: code copied and transfromed from
+ // MCDwarf.cpp::EmitDwarfLineTable. We should find a way to share
+ // this code, but the current compatibility requirement with
+ // classic dsymutil makes it hard. Revisit that once this
+ // requirement is dropped.
+
+ if (FileNum != Row.File) {
+ FileNum = Row.File;
+ MS->EmitIntValue(dwarf::DW_LNS_set_file, 1);
+ MS->EmitULEB128IntValue(FileNum);
+ LineSectionSize += 1 + getULEB128Size(FileNum);
+ }
+ if (Column != Row.Column) {
+ Column = Row.Column;
+ MS->EmitIntValue(dwarf::DW_LNS_set_column, 1);
+ MS->EmitULEB128IntValue(Column);
+ LineSectionSize += 1 + getULEB128Size(Column);
+ }
+
+ // FIXME: We should handle the discriminator here, but dsymutil
+ // doesn' consider it, thus ignore it for now.
+
+ if (Isa != Row.Isa) {
+ Isa = Row.Isa;
+ MS->EmitIntValue(dwarf::DW_LNS_set_isa, 1);
+ MS->EmitULEB128IntValue(Isa);
+ LineSectionSize += 1 + getULEB128Size(Isa);
+ }
+ if (IsStatement != Row.IsStmt) {
+ IsStatement = Row.IsStmt;
+ MS->EmitIntValue(dwarf::DW_LNS_negate_stmt, 1);
+ LineSectionSize += 1;
+ }
+ if (Row.BasicBlock) {
+ MS->EmitIntValue(dwarf::DW_LNS_set_basic_block, 1);
+ LineSectionSize += 1;
+ }
+
+ if (Row.PrologueEnd) {
+ MS->EmitIntValue(dwarf::DW_LNS_set_prologue_end, 1);
+ LineSectionSize += 1;
+ }
+
+ if (Row.EpilogueBegin) {
+ MS->EmitIntValue(dwarf::DW_LNS_set_epilogue_begin, 1);
+ LineSectionSize += 1;
+ }
+
+ int64_t LineDelta = int64_t(Row.Line) - LastLine;
+ if (!Row.EndSequence) {
+ MCDwarfLineAddr::Encode(*MC, LineDelta, AddressDelta, EncodingOS);
+ MS->EmitBytes(EncodingOS.str());
+ LineSectionSize += EncodingBuffer.size();
+ EncodingBuffer.resize(0);
+ EncodingOS.resync();
+ Address = Row.Address;
+ LastLine = Row.Line;
+ RowsSinceLastSequence++;
+ } else {
+ if (LineDelta) {
+ MS->EmitIntValue(dwarf::DW_LNS_advance_line, 1);
+ MS->EmitSLEB128IntValue(LineDelta);
+ LineSectionSize += 1 + getSLEB128Size(LineDelta);
+ }
+ if (AddressDelta) {
+ MS->EmitIntValue(dwarf::DW_LNS_advance_pc, 1);
+ MS->EmitULEB128IntValue(AddressDelta);
+ LineSectionSize += 1 + getULEB128Size(AddressDelta);
+ }
+ MCDwarfLineAddr::Encode(*MC, INT64_MAX, 0, EncodingOS);
+ MS->EmitBytes(EncodingOS.str());
+ LineSectionSize += EncodingBuffer.size();
+ EncodingBuffer.resize(0);
+ EncodingOS.resync();
+ Address = -1ULL;
+ LastLine = FileNum = IsStatement = 1;
+ RowsSinceLastSequence = Column = Isa = 0;
+ }
+ }
+
+ if (RowsSinceLastSequence) {
+ MCDwarfLineAddr::Encode(*MC, INT64_MAX, 0, EncodingOS);
+ MS->EmitBytes(EncodingOS.str());
+ LineSectionSize += EncodingBuffer.size();
+ EncodingBuffer.resize(0);
+ EncodingOS.resync();
+ }
+
+ MS->EmitLabel(LineEndSym);
+}
+
+/// \brief Emit the pubnames or pubtypes section contribution for \p
+/// Unit into \p Sec. The data is provided in \p Names.
+void DwarfStreamer::emitPubSectionForUnit(
+ const MCSection *Sec, StringRef SecName, const CompileUnit &Unit,
+ const std::vector<CompileUnit::AccelInfo> &Names) {
+ if (Names.empty())
+ return;
+
+ // Start the dwarf pubnames section.
+ Asm->OutStreamer->SwitchSection(Sec);
+ MCSymbol *BeginLabel = Asm->createTempSymbol("pub" + SecName + "_begin");
+ MCSymbol *EndLabel = Asm->createTempSymbol("pub" + SecName + "_end");
+
+ bool HeaderEmitted = false;
+ // Emit the pubnames for this compilation unit.
+ for (const auto &Name : Names) {
+ if (Name.SkipPubSection)
+ continue;
+
+ if (!HeaderEmitted) {
+ // Emit the header.
+ Asm->EmitLabelDifference(EndLabel, BeginLabel, 4); // Length
+ Asm->OutStreamer->EmitLabel(BeginLabel);
+ Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION); // Version
+ Asm->EmitInt32(Unit.getStartOffset()); // Unit offset
+ Asm->EmitInt32(Unit.getNextUnitOffset() - Unit.getStartOffset()); // Size
+ HeaderEmitted = true;
+ }
+ Asm->EmitInt32(Name.Die->getOffset());
+ Asm->OutStreamer->EmitBytes(
+ StringRef(Name.Name.data(), Name.Name.size() + 1));
+ }
+
+ if (!HeaderEmitted)
+ return;
+ Asm->EmitInt32(0); // End marker.
+ Asm->OutStreamer->EmitLabel(EndLabel);
+}
+
+/// \brief Emit .debug_pubnames for \p Unit.
+void DwarfStreamer::emitPubNamesForUnit(const CompileUnit &Unit) {
+ emitPubSectionForUnit(MC->getObjectFileInfo()->getDwarfPubNamesSection(),
+ "names", Unit, Unit.getPubnames());
+}
+
+/// \brief Emit .debug_pubtypes for \p Unit.
+void DwarfStreamer::emitPubTypesForUnit(const CompileUnit &Unit) {
+ emitPubSectionForUnit(MC->getObjectFileInfo()->getDwarfPubTypesSection(),
+ "types", Unit, Unit.getPubtypes());
+}
+
/// \brief The core of the Dwarf linking logic.
///
/// The link of the dwarf information from the object files will be
private:
/// \brief Called at the start of a debug object link.
- void startDebugObject(DWARFContext &);
+ void startDebugObject(DWARFContext &, DebugMapObject &);
/// \brief Called at the end of a debug object link.
void endDebugObject();
///
/// \param OutOffset is the offset the cloned DIE in the output
/// compile unit.
+ /// \param PCOffset (while cloning a function scope) is the offset
+ /// applied to the entry point of the function to get the linked address.
///
/// \returns the root of the cloned tree.
DIE *cloneDIE(const DWARFDebugInfoEntryMinimal &InputDIE, CompileUnit &U,
- uint32_t OutOffset);
+ int64_t PCOffset, uint32_t OutOffset);
typedef DWARFAbbreviationDeclaration::AttributeSpec AttributeSpec;
+ /// \brief Information gathered and exchanged between the various
+ /// clone*Attributes helpers about the attributes of a particular DIE.
+ struct AttributesInfo {
+ const char *Name, *MangledName; ///< Names.
+ uint32_t NameOffset, MangledNameOffset; ///< Offsets in the string pool.
+
+ uint64_t OrigHighPc; ///< Value of AT_high_pc in the input DIE
+ int64_t PCOffset; ///< Offset to apply to PC addresses inside a function.
+
+ bool HasLowPc; ///< Does the DIE have a low_pc attribute?
+ bool IsDeclaration; ///< Is this DIE only a declaration?
+
+ AttributesInfo()
+ : Name(nullptr), MangledName(nullptr), NameOffset(0),
+ MangledNameOffset(0), OrigHighPc(0), PCOffset(0), HasLowPc(false),
+ IsDeclaration(false) {}
+ };
+
/// \brief Helper for cloneDIE.
unsigned cloneAttribute(DIE &Die, const DWARFDebugInfoEntryMinimal &InputDIE,
CompileUnit &U, const DWARFFormValue &Val,
- const AttributeSpec AttrSpec, unsigned AttrSize);
+ const AttributeSpec AttrSpec, unsigned AttrSize,
+ AttributesInfo &AttrInfo);
/// \brief Helper for cloneDIE.
unsigned cloneStringAttribute(DIE &Die, AttributeSpec AttrSpec,
cloneDieReferenceAttribute(DIE &Die,
const DWARFDebugInfoEntryMinimal &InputDIE,
AttributeSpec AttrSpec, unsigned AttrSize,
- const DWARFFormValue &Val, const DWARFUnit &U);
+ const DWARFFormValue &Val, CompileUnit &Unit);
/// \brief Helper for cloneDIE.
unsigned cloneBlockAttribute(DIE &Die, AttributeSpec AttrSpec,
const DWARFFormValue &Val, unsigned AttrSize);
+ /// \brief Helper for cloneDIE.
+ unsigned cloneAddressAttribute(DIE &Die, AttributeSpec AttrSpec,
+ const DWARFFormValue &Val,
+ const CompileUnit &Unit, AttributesInfo &Info);
+
/// \brief Helper for cloneDIE.
unsigned cloneScalarAttribute(DIE &Die,
const DWARFDebugInfoEntryMinimal &InputDIE,
- const DWARFUnit &U, AttributeSpec AttrSpec,
- const DWARFFormValue &Val, unsigned AttrSize);
+ CompileUnit &U, AttributeSpec AttrSpec,
+ const DWARFFormValue &Val, unsigned AttrSize,
+ AttributesInfo &Info);
/// \brief Helper for cloneDIE.
bool applyValidRelocs(MutableArrayRef<char> Data, uint32_t BaseOffset,
/// be changed to a vecot of unique_ptrs.
std::vector<DIEAbbrev *> Abbreviations;
+ /// \brief Compute and emit debug_ranges section for \p Unit, and
+ /// patch the attributes referencing it.
+ void patchRangesForUnit(const CompileUnit &Unit, DWARFContext &Dwarf) const;
+
+ /// \brief Generate and emit the DW_AT_ranges attribute for a
+ /// compile_unit if it had one.
+ void generateUnitRanges(CompileUnit &Unit) const;
+
+ /// \brief Extract the line tables fromt he original dwarf, extract
+ /// the relevant parts according to the linked function ranges and
+ /// emit the result in the debug_line section.
+ void patchLineTableForUnit(CompileUnit &Unit, DWARFContext &OrigDwarf);
+
+ /// \brief Emit the accelerator entries for \p Unit.
+ void emitAcceleratorEntriesForUnit(CompileUnit &Unit);
+
/// \brief DIELoc objects that need to be destructed (but not freed!).
std::vector<DIELoc *> DIELocs;
/// \brief DIEBlock objects that need to be destructed (but not freed!).
CompileUnit *getUnitForOffset(unsigned Offset);
+ bool getDIENames(const DWARFDebugInfoEntryMinimal &Die, DWARFUnit &U,
+ AttributesInfo &Info);
+
void reportWarning(const Twine &Warning, const DWARFUnit *Unit = nullptr,
- const DWARFDebugInfoEntryMinimal *DIE = nullptr);
+ const DWARFDebugInfoEntryMinimal *DIE = nullptr) const;
bool createStreamer(Triple TheTriple, StringRef OutputFilename);
/// @}
/// \brief The Dwarf string pool
NonRelocatableStringpool StringPool;
+
+ /// \brief This map is keyed by the entry PC of functions in that
+ /// debug object and the associated value is a pair storing the
+ /// corresponding end PC and the offset to apply to get the linked
+ /// address.
+ ///
+ /// See startDebugObject() for a more complete description of its use.
+ std::map<uint64_t, std::pair<uint64_t, int64_t>> Ranges;
};
/// \brief Similar to DWARFUnitSection::getUnitForOffset(), but
return nullptr;
}
+/// \brief Get the potential name and mangled name for the entity
+/// described by \p Die and store them in \Info if they are not
+/// already there.
+/// \returns is a name was found.
+bool DwarfLinker::getDIENames(const DWARFDebugInfoEntryMinimal &Die,
+ DWARFUnit &U, AttributesInfo &Info) {
+ // FIXME: a bit wastefull as the first getName might return the
+ // short name.
+ if (!Info.MangledName &&
+ (Info.MangledName = Die.getName(&U, DINameKind::LinkageName)))
+ Info.MangledNameOffset = StringPool.getStringOffset(Info.MangledName);
+
+ if (!Info.Name && (Info.Name = Die.getName(&U, DINameKind::ShortName)))
+ Info.NameOffset = StringPool.getStringOffset(Info.Name);
+
+ return Info.Name || Info.MangledName;
+}
+
/// \brief Report a warning to the user, optionaly including
/// information about a specific \p DIE related to the warning.
void DwarfLinker::reportWarning(const Twine &Warning, const DWARFUnit *Unit,
- const DWARFDebugInfoEntryMinimal *DIE) {
+ const DWARFDebugInfoEntryMinimal *DIE) const {
StringRef Context = "<debug map>";
if (CurrentDebugObject)
Context = CurrentDebugObject->getObjectFilename();
llvm_unreachable("Invalid Tag");
}
-void DwarfLinker::startDebugObject(DWARFContext &Dwarf) {
+void DwarfLinker::startDebugObject(DWARFContext &Dwarf, DebugMapObject &Obj) {
Units.reserve(Dwarf.getNumCompileUnits());
NextValidReloc = 0;
+ // Iterate over the debug map entries and put all the ones that are
+ // functions (because they have a size) into the Ranges map. This
+ // map is very similar to the FunctionRanges that are stored in each
+ // unit, with 2 notable differences:
+ // - obviously this one is global, while the other ones are per-unit.
+ // - this one contains not only the functions described in the DIE
+ // tree, but also the ones that are only in the debug map.
+ // The latter information is required to reproduce dsymutil's logic
+ // while linking line tables. The cases where this information
+ // matters look like bugs that need to be investigated, but for now
+ // we need to reproduce dsymutil's behavior.
+ // FIXME: Once we understood exactly if that information is needed,
+ // maybe totally remove this (or try to use it to do a real
+ // -gline-tables-only on Darwin.
+ for (const auto &Entry : Obj.symbols()) {
+ const auto &Mapping = Entry.getValue();
+ if (Mapping.Size)
+ Ranges[Mapping.ObjectAddress] = std::make_pair(
+ Mapping.ObjectAddress + Mapping.Size,
+ int64_t(Mapping.BinaryAddress) - Mapping.ObjectAddress);
+ }
}
void DwarfLinker::endDebugObject() {
Units.clear();
ValidRelocs.clear();
+ Ranges.clear();
for (auto *Block : DIEBlocks)
Block->~DIEBlock();
ValidReloc.Mapping->getValue().ObjectAddress,
ValidReloc.Mapping->getValue().BinaryAddress);
- Info.Address =
- ValidReloc.Mapping->getValue().BinaryAddress + ValidReloc.Addend;
+ Info.AddrAdjust = int64_t(ValidReloc.Mapping->getValue().BinaryAddress) +
+ ValidReloc.Addend -
+ ValidReloc.Mapping->getValue().ObjectAddress;
Info.InDebugMap = true;
return true;
}
if (Options.Verbose)
DIE.dump(outs(), const_cast<DWARFUnit *>(&OrigUnit), 0, 8 /* Indent */);
- return Flags | TF_Keep;
+ Flags |= TF_Keep;
+
+ DWARFFormValue HighPcValue;
+ if (!DIE.getAttributeValue(&OrigUnit, dwarf::DW_AT_high_pc, HighPcValue)) {
+ reportWarning("Function without high_pc. Range will be discarded.\n",
+ &OrigUnit, &DIE);
+ return Flags;
+ }
+
+ uint64_t HighPc;
+ if (HighPcValue.isFormClass(DWARFFormValue::FC_Address)) {
+ HighPc = *HighPcValue.getAsAddress(&OrigUnit);
+ } else {
+ assert(HighPcValue.isFormClass(DWARFFormValue::FC_Constant));
+ HighPc = LowPc + *HighPcValue.getAsUnsignedConstant();
+ }
+
+ // Replace the debug map range with a more accurate one.
+ Ranges[LowPc] = std::make_pair(HighPc, MyInfo.AddrAdjust);
+ Unit.addFunctionRange(LowPc, HighPc, MyInfo.AddrAdjust);
+ return Flags;
}
/// \brief Check if a DIE should be kept.
unsigned DwarfLinker::cloneDieReferenceAttribute(
DIE &Die, const DWARFDebugInfoEntryMinimal &InputDIE,
AttributeSpec AttrSpec, unsigned AttrSize, const DWARFFormValue &Val,
- const DWARFUnit &U) {
- uint32_t Ref = *Val.getAsReference(&U);
+ CompileUnit &Unit) {
+ uint32_t Ref = *Val.getAsReference(&Unit.getOrigUnit());
DIE *NewRefDie = nullptr;
CompileUnit *RefUnit = nullptr;
const DWARFDebugInfoEntryMinimal *RefDie = nullptr;
AttributeString = "DW_AT_???";
reportWarning(Twine("Missing DIE for ref in attribute ") + AttributeString +
". Dropping.",
- &U, &InputDIE);
+ &Unit.getOrigUnit(), &InputDIE);
return 0;
}
} else {
// A forward reference. Note and fixup later.
Attr = new (DIEAlloc) DIEInteger(0xBADDEF);
- RefUnit->noteForwardReference(NewRefDie, Attr);
+ Unit.noteForwardReference(NewRefDie, RefUnit, Attr);
}
Die.addValue(dwarf::Attribute(AttrSpec.Attr), dwarf::DW_FORM_ref_addr,
Attr);
DIELoc *Loc = nullptr;
DIEBlock *Block = nullptr;
// Just copy the block data over.
- if (AttrSpec.Attr == dwarf::DW_FORM_exprloc) {
+ if (AttrSpec.Form == dwarf::DW_FORM_exprloc) {
Loc = new (DIEAlloc) DIELoc();
DIELocs.push_back(Loc);
} else {
return AttrSize;
}
+/// \brief Clone an address attribute and add it to \p Die.
+/// \returns the size of the new attribute.
+unsigned DwarfLinker::cloneAddressAttribute(DIE &Die, AttributeSpec AttrSpec,
+ const DWARFFormValue &Val,
+ const CompileUnit &Unit,
+ AttributesInfo &Info) {
+ uint64_t Addr = *Val.getAsAddress(&Unit.getOrigUnit());
+ if (AttrSpec.Attr == dwarf::DW_AT_low_pc) {
+ if (Die.getTag() == dwarf::DW_TAG_inlined_subroutine ||
+ Die.getTag() == dwarf::DW_TAG_lexical_block)
+ Addr += Info.PCOffset;
+ else if (Die.getTag() == dwarf::DW_TAG_compile_unit) {
+ Addr = Unit.getLowPc();
+ if (Addr == UINT64_MAX)
+ return 0;
+ }
+ Info.HasLowPc = true;
+ } else if (AttrSpec.Attr == dwarf::DW_AT_high_pc) {
+ if (Die.getTag() == dwarf::DW_TAG_compile_unit) {
+ if (uint64_t HighPc = Unit.getHighPc())
+ Addr = HighPc;
+ else
+ return 0;
+ } else
+ // If we have a high_pc recorded for the input DIE, use
+ // it. Otherwise (when no relocations where applied) just use the
+ // one we just decoded.
+ Addr = (Info.OrigHighPc ? Info.OrigHighPc : Addr) + Info.PCOffset;
+ }
+
+ Die.addValue(static_cast<dwarf::Attribute>(AttrSpec.Attr),
+ static_cast<dwarf::Form>(AttrSpec.Form),
+ new (DIEAlloc) DIEInteger(Addr));
+ return Unit.getOrigUnit().getAddressByteSize();
+}
+
/// \brief Clone a scalar attribute and add it to \p Die.
/// \returns the size of the new attribute.
unsigned DwarfLinker::cloneScalarAttribute(
- DIE &Die, const DWARFDebugInfoEntryMinimal &InputDIE, const DWARFUnit &U,
- AttributeSpec AttrSpec, const DWARFFormValue &Val, unsigned AttrSize) {
+ DIE &Die, const DWARFDebugInfoEntryMinimal &InputDIE, CompileUnit &Unit,
+ AttributeSpec AttrSpec, const DWARFFormValue &Val, unsigned AttrSize,
+ AttributesInfo &Info) {
uint64_t Value;
- if (AttrSpec.Form == dwarf::DW_FORM_sec_offset)
+ if (AttrSpec.Attr == dwarf::DW_AT_high_pc &&
+ Die.getTag() == dwarf::DW_TAG_compile_unit) {
+ if (Unit.getLowPc() == -1ULL)
+ return 0;
+ // Dwarf >= 4 high_pc is an size, not an address.
+ Value = Unit.getHighPc() - Unit.getLowPc();
+ } else if (AttrSpec.Form == dwarf::DW_FORM_sec_offset)
Value = *Val.getAsSectionOffset();
else if (AttrSpec.Form == dwarf::DW_FORM_sdata)
Value = *Val.getAsSignedConstant();
- else if (AttrSpec.Form == dwarf::DW_FORM_addr)
- Value = *Val.getAsAddress(&U);
else if (auto OptionalValue = Val.getAsUnsignedConstant())
Value = *OptionalValue;
else {
- reportWarning("Unsupported scalar attribute form. Dropping attribute.", &U,
- &InputDIE);
+ reportWarning("Unsupported scalar attribute form. Dropping attribute.",
+ &Unit.getOrigUnit(), &InputDIE);
return 0;
}
+ DIEInteger *Attr = new (DIEAlloc) DIEInteger(Value);
+ if (AttrSpec.Attr == dwarf::DW_AT_ranges)
+ Unit.noteRangeAttribute(Die, Attr);
+ // A more generic way to check for location attributes would be
+ // nice, but it's very unlikely that any other attribute needs a
+ // location list.
+ else if (AttrSpec.Attr == dwarf::DW_AT_location ||
+ AttrSpec.Attr == dwarf::DW_AT_frame_base)
+ Unit.noteLocationAttribute(Attr, Info.PCOffset);
+ else if (AttrSpec.Attr == dwarf::DW_AT_declaration && Value)
+ Info.IsDeclaration = true;
+
Die.addValue(dwarf::Attribute(AttrSpec.Attr), dwarf::Form(AttrSpec.Form),
- new (DIEAlloc) DIEInteger(Value));
+ Attr);
return AttrSize;
}
CompileUnit &Unit,
const DWARFFormValue &Val,
const AttributeSpec AttrSpec,
- unsigned AttrSize) {
+ unsigned AttrSize, AttributesInfo &Info) {
const DWARFUnit &U = Unit.getOrigUnit();
switch (AttrSpec.Form) {
case dwarf::DW_FORM_ref4:
case dwarf::DW_FORM_ref8:
return cloneDieReferenceAttribute(Die, InputDIE, AttrSpec, AttrSize, Val,
- U);
+ Unit);
case dwarf::DW_FORM_block:
case dwarf::DW_FORM_block1:
case dwarf::DW_FORM_block2:
case dwarf::DW_FORM_exprloc:
return cloneBlockAttribute(Die, AttrSpec, Val, AttrSize);
case dwarf::DW_FORM_addr:
+ return cloneAddressAttribute(Die, AttrSpec, Val, Unit, Info);
case dwarf::DW_FORM_data1:
case dwarf::DW_FORM_data2:
case dwarf::DW_FORM_data4:
case dwarf::DW_FORM_sec_offset:
case dwarf::DW_FORM_flag:
case dwarf::DW_FORM_flag_present:
- return cloneScalarAttribute(Die, InputDIE, U, AttrSpec, Val, AttrSize);
+ return cloneScalarAttribute(Die, InputDIE, Unit, AttrSpec, Val, AttrSize,
+ Info);
default:
reportWarning("Unsupported attribute form in cloneAttribute. Dropping.", &U,
&InputDIE);
/// \returns wether any reloc has been applied.
bool DwarfLinker::applyValidRelocs(MutableArrayRef<char> Data,
uint32_t BaseOffset, bool isLittleEndian) {
- assert(NextValidReloc == 0 ||
- BaseOffset > ValidRelocs[NextValidReloc - 1].Offset &&
- "BaseOffset should only be increasing.");
+ assert((NextValidReloc == 0 ||
+ BaseOffset > ValidRelocs[NextValidReloc - 1].Offset) &&
+ "BaseOffset should only be increasing.");
if (NextValidReloc >= ValidRelocs.size())
return false;
return Applied;
}
+static bool isTypeTag(uint16_t Tag) {
+ switch (Tag) {
+ case dwarf::DW_TAG_array_type:
+ case dwarf::DW_TAG_class_type:
+ case dwarf::DW_TAG_enumeration_type:
+ case dwarf::DW_TAG_pointer_type:
+ case dwarf::DW_TAG_reference_type:
+ case dwarf::DW_TAG_string_type:
+ case dwarf::DW_TAG_structure_type:
+ case dwarf::DW_TAG_subroutine_type:
+ case dwarf::DW_TAG_typedef:
+ case dwarf::DW_TAG_union_type:
+ case dwarf::DW_TAG_ptr_to_member_type:
+ case dwarf::DW_TAG_set_type:
+ case dwarf::DW_TAG_subrange_type:
+ case dwarf::DW_TAG_base_type:
+ case dwarf::DW_TAG_const_type:
+ case dwarf::DW_TAG_constant:
+ case dwarf::DW_TAG_file_type:
+ case dwarf::DW_TAG_namelist:
+ case dwarf::DW_TAG_packed_type:
+ case dwarf::DW_TAG_volatile_type:
+ case dwarf::DW_TAG_restrict_type:
+ case dwarf::DW_TAG_interface_type:
+ case dwarf::DW_TAG_unspecified_type:
+ case dwarf::DW_TAG_shared_type:
+ return true;
+ default:
+ break;
+ }
+ return false;
+}
+
/// \brief Recursively clone \p InputDIE's subtrees that have been
/// selected to appear in the linked output.
///
///
/// \returns the cloned DIE object or null if nothing was selected.
DIE *DwarfLinker::cloneDIE(const DWARFDebugInfoEntryMinimal &InputDIE,
- CompileUnit &Unit, uint32_t OutOffset) {
+ CompileUnit &Unit, int64_t PCOffset,
+ uint32_t OutOffset) {
DWARFUnit &U = Unit.getOrigUnit();
unsigned Idx = U.getDIEIndex(&InputDIE);
CompileUnit::DIEInfo &Info = Unit.getInfo(Idx);
// Extract and clone every attribute.
DataExtractor Data = U.getDebugInfoExtractor();
uint32_t NextOffset = U.getDIEAtIndex(Idx + 1)->getOffset();
+ AttributesInfo AttrInfo;
// We could copy the data only if we need to aply a relocation to
// it. After testing, it seems there is no performance downside to
SmallString<40> DIECopy(Data.getData().substr(Offset, NextOffset - Offset));
Data = DataExtractor(DIECopy, Data.isLittleEndian(), Data.getAddressSize());
// Modify the copy with relocated addresses.
- applyValidRelocs(DIECopy, Offset, Data.isLittleEndian());
+ if (applyValidRelocs(DIECopy, Offset, Data.isLittleEndian())) {
+ // If we applied relocations, we store the value of high_pc that was
+ // potentially stored in the input DIE. If high_pc is an address
+ // (Dwarf version == 2), then it might have been relocated to a
+ // totally unrelated value (because the end address in the object
+ // file might be start address of another function which got moved
+ // independantly by the linker). The computation of the actual
+ // high_pc value is done in cloneAddressAttribute().
+ AttrInfo.OrigHighPc =
+ InputDIE.getAttributeValueAsAddress(&U, dwarf::DW_AT_high_pc, 0);
+ }
// Reset the Offset to 0 as we will be working on the local copy of
// the data.
const auto *Abbrev = InputDIE.getAbbreviationDeclarationPtr();
Offset += getULEB128Size(Abbrev->getCode());
+ // We are entering a subprogram. Get and propagate the PCOffset.
+ if (Die->getTag() == dwarf::DW_TAG_subprogram)
+ PCOffset = Info.AddrAdjust;
+ AttrInfo.PCOffset = PCOffset;
+
for (const auto &AttrSpec : Abbrev->attributes()) {
DWARFFormValue Val(AttrSpec.Form);
uint32_t AttrSize = Offset;
Val.extractValue(Data, &Offset, &U);
AttrSize = Offset - AttrSize;
- OutOffset += cloneAttribute(*Die, InputDIE, Unit, Val, AttrSpec, AttrSize);
+ OutOffset +=
+ cloneAttribute(*Die, InputDIE, Unit, Val, AttrSpec, AttrSize, AttrInfo);
+ }
+
+ // Look for accelerator entries.
+ uint16_t Tag = InputDIE.getTag();
+ // FIXME: This is slightly wrong. An inline_subroutine without a
+ // low_pc, but with AT_ranges might be interesting to get into the
+ // accelerator tables too. For now stick with dsymutil's behavior.
+ if ((Info.InDebugMap || AttrInfo.HasLowPc) &&
+ Tag != dwarf::DW_TAG_compile_unit &&
+ getDIENames(InputDIE, Unit.getOrigUnit(), AttrInfo)) {
+ if (AttrInfo.MangledName && AttrInfo.MangledName != AttrInfo.Name)
+ Unit.addNameAccelerator(Die, AttrInfo.MangledName,
+ AttrInfo.MangledNameOffset,
+ Tag == dwarf::DW_TAG_inlined_subroutine);
+ if (AttrInfo.Name)
+ Unit.addNameAccelerator(Die, AttrInfo.Name, AttrInfo.NameOffset,
+ Tag == dwarf::DW_TAG_inlined_subroutine);
+ } else if (isTypeTag(Tag) && !AttrInfo.IsDeclaration &&
+ getDIENames(InputDIE, Unit.getOrigUnit(), AttrInfo)) {
+ Unit.addTypeAccelerator(Die, AttrInfo.Name, AttrInfo.NameOffset);
}
DIEAbbrev &NewAbbrev = Die->getAbbrev();
// Recursively clone children.
for (auto *Child = InputDIE.getFirstChild(); Child && !Child->isNULL();
Child = Child->getSibling()) {
- if (DIE *Clone = cloneDIE(*Child, Unit, OutOffset)) {
+ if (DIE *Clone = cloneDIE(*Child, Unit, PCOffset, OutOffset)) {
Die->addChild(std::unique_ptr<DIE>(Clone));
OutOffset = Clone->getOffset() + Clone->getSize();
}
return Die;
}
+/// \brief Patch the input object file relevant debug_ranges entries
+/// and emit them in the output file. Update the relevant attributes
+/// to point at the new entries.
+void DwarfLinker::patchRangesForUnit(const CompileUnit &Unit,
+ DWARFContext &OrigDwarf) const {
+ DWARFDebugRangeList RangeList;
+ const auto &FunctionRanges = Unit.getFunctionRanges();
+ unsigned AddressSize = Unit.getOrigUnit().getAddressByteSize();
+ DataExtractor RangeExtractor(OrigDwarf.getRangeSection(),
+ OrigDwarf.isLittleEndian(), AddressSize);
+ auto InvalidRange = FunctionRanges.end(), CurrRange = InvalidRange;
+ DWARFUnit &OrigUnit = Unit.getOrigUnit();
+ const auto *OrigUnitDie = OrigUnit.getCompileUnitDIE(false);
+ uint64_t OrigLowPc = OrigUnitDie->getAttributeValueAsAddress(
+ &OrigUnit, dwarf::DW_AT_low_pc, -1ULL);
+ // Ranges addresses are based on the unit's low_pc. Compute the
+ // offset we need to apply to adapt to the the new unit's low_pc.
+ int64_t UnitPcOffset = 0;
+ if (OrigLowPc != -1ULL)
+ UnitPcOffset = int64_t(OrigLowPc) - Unit.getLowPc();
+
+ for (const auto &RangeAttribute : Unit.getRangesAttributes()) {
+ uint32_t Offset = RangeAttribute->getValue();
+ RangeAttribute->setValue(Streamer->getRangesSectionSize());
+ RangeList.extract(RangeExtractor, &Offset);
+ const auto &Entries = RangeList.getEntries();
+ const DWARFDebugRangeList::RangeListEntry &First = Entries.front();
+
+ if (CurrRange == InvalidRange || First.StartAddress < CurrRange.start() ||
+ First.StartAddress >= CurrRange.stop()) {
+ CurrRange = FunctionRanges.find(First.StartAddress + OrigLowPc);
+ if (CurrRange == InvalidRange ||
+ CurrRange.start() > First.StartAddress + OrigLowPc) {
+ reportWarning("no mapping for range.");
+ continue;
+ }
+ }
+
+ Streamer->emitRangesEntries(UnitPcOffset, OrigLowPc, CurrRange, Entries,
+ AddressSize);
+ }
+}
+
+/// \brief Generate the debug_aranges entries for \p Unit and if the
+/// unit has a DW_AT_ranges attribute, also emit the debug_ranges
+/// contribution for this attribute.
+/// FIXME: this could actually be done right in patchRangesForUnit,
+/// but for the sake of initial bit-for-bit compatibility with legacy
+/// dsymutil, we have to do it in a delayed pass.
+void DwarfLinker::generateUnitRanges(CompileUnit &Unit) const {
+ DIEInteger *Attr = Unit.getUnitRangesAttribute();
+ if (Attr)
+ Attr->setValue(Streamer->getRangesSectionSize());
+ Streamer->emitUnitRangesEntries(Unit, Attr != nullptr);
+}
+
+/// \brief Insert the new line info sequence \p Seq into the current
+/// set of already linked line info \p Rows.
+static void insertLineSequence(std::vector<DWARFDebugLine::Row> &Seq,
+ std::vector<DWARFDebugLine::Row> &Rows) {
+ if (Seq.empty())
+ return;
+
+ if (!Rows.empty() && Rows.back().Address < Seq.front().Address) {
+ Rows.insert(Rows.end(), Seq.begin(), Seq.end());
+ Seq.clear();
+ return;
+ }
+
+ auto InsertPoint = std::lower_bound(
+ Rows.begin(), Rows.end(), Seq.front(),
+ [](const DWARFDebugLine::Row &LHS, const DWARFDebugLine::Row &RHS) {
+ return LHS.Address < RHS.Address;
+ });
+
+ // FIXME: this only removes the unneeded end_sequence if the
+ // sequences have been inserted in order. using a global sort like
+ // described in patchLineTableForUnit() and delaying the end_sequene
+ // elimination to emitLineTableForUnit() we can get rid of all of them.
+ if (InsertPoint != Rows.end() &&
+ InsertPoint->Address == Seq.front().Address && InsertPoint->EndSequence) {
+ *InsertPoint = Seq.front();
+ Rows.insert(InsertPoint + 1, Seq.begin() + 1, Seq.end());
+ } else {
+ Rows.insert(InsertPoint, Seq.begin(), Seq.end());
+ }
+
+ Seq.clear();
+}
+
+/// \brief Extract the line table for \p Unit from \p OrigDwarf, and
+/// recreate a relocated version of these for the address ranges that
+/// are present in the binary.
+void DwarfLinker::patchLineTableForUnit(CompileUnit &Unit,
+ DWARFContext &OrigDwarf) {
+ const DWARFDebugInfoEntryMinimal *CUDie =
+ Unit.getOrigUnit().getCompileUnitDIE();
+ uint64_t StmtList = CUDie->getAttributeValueAsSectionOffset(
+ &Unit.getOrigUnit(), dwarf::DW_AT_stmt_list, -1ULL);
+ if (StmtList == -1ULL)
+ return;
+
+ // Update the cloned DW_AT_stmt_list with the correct debug_line offset.
+ if (auto *OutputDIE = Unit.getOutputUnitDIE()) {
+ const auto &Abbrev = OutputDIE->getAbbrev().getData();
+ auto Stmt = std::find_if(
+ Abbrev.begin(), Abbrev.end(), [](const DIEAbbrevData &AbbrevData) {
+ return AbbrevData.getAttribute() == dwarf::DW_AT_stmt_list;
+ });
+ assert(Stmt < Abbrev.end() && "Didn't find DW_AT_stmt_list in cloned DIE!");
+ DIEInteger *StmtAttr =
+ cast<DIEInteger>(OutputDIE->getValues()[Stmt - Abbrev.begin()]);
+ StmtAttr->setValue(Streamer->getLineSectionSize());
+ }
+
+ // Parse the original line info for the unit.
+ DWARFDebugLine::LineTable LineTable;
+ uint32_t StmtOffset = StmtList;
+ StringRef LineData = OrigDwarf.getLineSection().Data;
+ DataExtractor LineExtractor(LineData, OrigDwarf.isLittleEndian(),
+ Unit.getOrigUnit().getAddressByteSize());
+ LineTable.parse(LineExtractor, &OrigDwarf.getLineSection().Relocs,
+ &StmtOffset);
+
+ // This vector is the output line table.
+ std::vector<DWARFDebugLine::Row> NewRows;
+ NewRows.reserve(LineTable.Rows.size());
+
+ // Current sequence of rows being extracted, before being inserted
+ // in NewRows.
+ std::vector<DWARFDebugLine::Row> Seq;
+ const auto &FunctionRanges = Unit.getFunctionRanges();
+ auto InvalidRange = FunctionRanges.end(), CurrRange = InvalidRange;
+
+ // FIXME: This logic is meant to generate exactly the same output as
+ // Darwin's classic dsynutil. There is a nicer way to implement this
+ // by simply putting all the relocated line info in NewRows and simply
+ // sorting NewRows before passing it to emitLineTableForUnit. This
+ // should be correct as sequences for a function should stay
+ // together in the sorted output. There are a few corner cases that
+ // look suspicious though, and that required to implement the logic
+ // this way. Revisit that once initial validation is finished.
+
+ // Iterate over the object file line info and extract the sequences
+ // that correspond to linked functions.
+ for (auto &Row : LineTable.Rows) {
+ // Check wether we stepped out of the range. The range is
+ // half-open, but consider accept the end address of the range if
+ // it is marked as end_sequence in the input (because in that
+ // case, the relocation offset is accurate and that entry won't
+ // serve as the start of another function).
+ if (CurrRange == InvalidRange || Row.Address < CurrRange.start() ||
+ Row.Address > CurrRange.stop() ||
+ (Row.Address == CurrRange.stop() && !Row.EndSequence)) {
+ // We just stepped out of a known range. Insert a end_sequence
+ // corresponding to the end of the range.
+ uint64_t StopAddress = CurrRange != InvalidRange
+ ? CurrRange.stop() + CurrRange.value()
+ : -1ULL;
+ CurrRange = FunctionRanges.find(Row.Address);
+ bool CurrRangeValid =
+ CurrRange != InvalidRange && CurrRange.start() <= Row.Address;
+ if (!CurrRangeValid) {
+ CurrRange = InvalidRange;
+ if (StopAddress != -1ULL) {
+ // Try harder by looking in the DebugMapObject function
+ // ranges map. There are corner cases where this finds a
+ // valid entry. It's unclear if this is right or wrong, but
+ // for now do as dsymutil.
+ // FIXME: Understand exactly what cases this addresses and
+ // potentially remove it along with the Ranges map.
+ auto Range = Ranges.lower_bound(Row.Address);
+ if (Range != Ranges.begin() && Range != Ranges.end())
+ --Range;
+
+ if (Range != Ranges.end() && Range->first <= Row.Address &&
+ Range->second.first >= Row.Address) {
+ StopAddress = Row.Address + Range->second.second;
+ }
+ }
+ }
+ if (StopAddress != -1ULL && !Seq.empty()) {
+ // Insert end sequence row with the computed end address, but
+ // the same line as the previous one.
+ Seq.emplace_back(Seq.back());
+ Seq.back().Address = StopAddress;
+ Seq.back().EndSequence = 1;
+ Seq.back().PrologueEnd = 0;
+ Seq.back().BasicBlock = 0;
+ Seq.back().EpilogueBegin = 0;
+ insertLineSequence(Seq, NewRows);
+ }
+
+ if (!CurrRangeValid)
+ continue;
+ }
+
+ // Ignore empty sequences.
+ if (Row.EndSequence && Seq.empty())
+ continue;
+
+ // Relocate row address and add it to the current sequence.
+ Row.Address += CurrRange.value();
+ Seq.emplace_back(Row);
+
+ if (Row.EndSequence)
+ insertLineSequence(Seq, NewRows);
+ }
+
+ // Finished extracting, now emit the line tables.
+ uint32_t PrologueEnd = StmtList + 10 + LineTable.Prologue.PrologueLength;
+ // FIXME: LLVM hardcodes it's prologue values. We just copy the
+ // prologue over and that works because we act as both producer and
+ // consumer. It would be nicer to have a real configurable line
+ // table emitter.
+ if (LineTable.Prologue.Version != 2 ||
+ LineTable.Prologue.DefaultIsStmt != DWARF2_LINE_DEFAULT_IS_STMT ||
+ LineTable.Prologue.LineBase != -5 || LineTable.Prologue.LineRange != 14 ||
+ LineTable.Prologue.OpcodeBase != 13)
+ reportWarning("line table paramters mismatch. Cannot emit.");
+ else
+ Streamer->emitLineTableForUnit(LineData.slice(StmtList + 4, PrologueEnd),
+ LineTable.Prologue.MinInstLength, NewRows,
+ Unit.getOrigUnit().getAddressByteSize());
+}
+
+void DwarfLinker::emitAcceleratorEntriesForUnit(CompileUnit &Unit) {
+ Streamer->emitPubNamesForUnit(Unit);
+ Streamer->emitPubTypesForUnit(Unit);
+}
+
bool DwarfLinker::link(const DebugMap &Map) {
if (Map.begin() == Map.end()) {
// Size of the DIEs (and headers) generated for the linked output.
uint64_t OutputDebugInfoSize = 0;
-
+ // A unique ID that identifies each compile unit.
+ unsigned UnitID = 0;
for (const auto &Obj : Map.objects()) {
CurrentDebugObject = Obj.get();
// Setup access to the debug info.
DWARFContextInMemory DwarfContext(*ErrOrObj);
- startDebugObject(DwarfContext);
+ startDebugObject(DwarfContext, *Obj);
// In a first phase, just read in the debug info and store the DIE
// parent links that we will use during the next phase.
outs() << "Input compilation unit:";
CUDie->dump(outs(), CU.get(), 0);
}
- Units.emplace_back(*CU);
+ Units.emplace_back(*CU, UnitID++);
gatherDIEParents(CUDie, 0, Units.back());
}
for (auto &CurrentUnit : Units) {
const auto *InputDIE = CurrentUnit.getOrigUnit().getCompileUnitDIE();
CurrentUnit.setStartOffset(OutputDebugInfoSize);
- DIE *OutputDIE =
- cloneDIE(*InputDIE, CurrentUnit, 11 /* Unit Header size */);
+ DIE *OutputDIE = cloneDIE(*InputDIE, CurrentUnit, 0 /* PCOffset */,
+ 11 /* Unit Header size */);
CurrentUnit.setOutputUnitDIE(OutputDIE);
OutputDebugInfoSize = CurrentUnit.computeNextUnitOffset();
+ if (Options.NoOutput)
+ continue;
+ // FIXME: for compatibility with the classic dsymutil, we emit
+ // an empty line table for the unit, even if the unit doesn't
+ // actually exist in the DIE tree.
+ patchLineTableForUnit(CurrentUnit, DwarfContext);
+ if (!OutputDIE)
+ continue;
+ patchRangesForUnit(CurrentUnit, DwarfContext);
+ Streamer->emitLocationsForUnit(CurrentUnit, DwarfContext);
+ emitAcceleratorEntriesForUnit(CurrentUnit);
}
// Emit all the compile unit's debug information.
if (!ValidRelocs.empty() && !Options.NoOutput)
for (auto &CurrentUnit : Units) {
+ generateUnitRanges(CurrentUnit);
CurrentUnit.fixupForwardReferences();
Streamer->emitCompileUnitHeader(CurrentUnit);
if (!CurrentUnit.getOutputUnitDIE())
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