X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=tools%2Fdsymutil%2FDwarfLinker.cpp;h=b37e260e916b566ca276c888123fa6ad73f93a89;hb=0d68ddf6cecc75309dd6a9ee704acadec0b9e51e;hp=a6e62a83894590df764b53d9a3c118fb583e4dcc;hpb=3c41ae83f2938c231d9c05b28ee7e8a1fffcaa20;p=oota-llvm.git diff --git a/tools/dsymutil/DwarfLinker.cpp b/tools/dsymutil/DwarfLinker.cpp index a6e62a83894..b37e260e916 100644 --- a/tools/dsymutil/DwarfLinker.cpp +++ b/tools/dsymutil/DwarfLinker.cpp @@ -15,6 +15,7 @@ #include "llvm/ADT/STLExtras.h" #include "llvm/CodeGen/AsmPrinter.h" #include "llvm/CodeGen/DIE.h" +#include "llvm/Config/config.h" #include "llvm/DebugInfo/DWARF/DWARFContext.h" #include "llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h" #include "llvm/DebugInfo/DWARF/DWARFFormValue.h" @@ -60,6 +61,132 @@ using HalfOpenIntervalMap = typedef HalfOpenIntervalMap FunctionIntervals; +// FIXME: Delete this structure. +struct PatchLocation { + DIE::value_iterator I; + + PatchLocation() = default; + PatchLocation(DIE::value_iterator I) : I(I) {} + + void set(uint64_t New) const { + assert(I); + const auto &Old = *I; + assert(Old.getType() == DIEValue::isInteger); + *I = DIEValue(Old.getAttribute(), Old.getForm(), DIEInteger(New)); + } + + uint64_t get() const { + assert(I); + return I->getDIEInteger().getValue(); + } +}; + +class CompileUnit; +struct DeclMapInfo; +class NonRelocatableStringpool; + +/// A DeclContext is a named program scope that is used for ODR +/// uniquing of types. +/// The set of DeclContext for the ODR-subject parts of a Dwarf link +/// is expanded (and uniqued) with each new object file processed. We +/// need to determine the context of each DIE in an linked object file +/// to see if the corresponding type has already been emitted. +/// +/// The contexts are conceptually organised as a tree (eg. a function +/// scope is contained in a namespace scope that contains other +/// scopes), but storing/accessing them in an actual tree is too +/// inefficient: we need to be able to very quickly query a context +/// for a given child context by name. Storing a StringMap in each +/// DeclContext would be too space inefficient. +/// The solution here is to give each DeclContext a link to its parent +/// (this allows to walk up the tree), but to query the existance of a +/// specific DeclContext using a separate DenseMap keyed on the hash +/// of the fully qualified name of the context. +class DeclContext { + unsigned QualifiedNameHash; + uint32_t Line; + uint32_t ByteSize; + uint16_t Tag; + StringRef Name; + StringRef File; + const DeclContext &Parent; + const DWARFDebugInfoEntryMinimal *LastSeenDIE; + uint32_t LastSeenCompileUnitID; + uint32_t CanonicalDIEOffset; + + friend DeclMapInfo; + +public: + typedef DenseSet Map; + + DeclContext() + : QualifiedNameHash(0), Line(0), ByteSize(0), + Tag(dwarf::DW_TAG_compile_unit), Name(), File(), Parent(*this), + LastSeenDIE(nullptr), LastSeenCompileUnitID(0), CanonicalDIEOffset(0) {} + + DeclContext(unsigned Hash, uint32_t Line, uint32_t ByteSize, uint16_t Tag, + StringRef Name, StringRef File, const DeclContext &Parent, + const DWARFDebugInfoEntryMinimal *LastSeenDIE = nullptr, + unsigned CUId = 0) + : QualifiedNameHash(Hash), Line(Line), ByteSize(ByteSize), Tag(Tag), + Name(Name), File(File), Parent(Parent), LastSeenDIE(LastSeenDIE), + LastSeenCompileUnitID(CUId), CanonicalDIEOffset(0) {} + + uint32_t getQualifiedNameHash() const { return QualifiedNameHash; } + + bool setLastSeenDIE(CompileUnit &U, const DWARFDebugInfoEntryMinimal *Die); + + uint32_t getCanonicalDIEOffset() const { return CanonicalDIEOffset; } + void setCanonicalDIEOffset(uint32_t Offset) { CanonicalDIEOffset = Offset; } + + uint16_t getTag() const { return Tag; } + StringRef getName() const { return Name; } +}; + +/// Info type for the DenseMap storing the DeclContext pointers. +struct DeclMapInfo : private DenseMapInfo { + using DenseMapInfo::getEmptyKey; + using DenseMapInfo::getTombstoneKey; + + static unsigned getHashValue(const DeclContext *Ctxt) { + return Ctxt->QualifiedNameHash; + } + + static bool isEqual(const DeclContext *LHS, const DeclContext *RHS) { + if (RHS == getEmptyKey() || RHS == getTombstoneKey()) + return RHS == LHS; + return LHS->QualifiedNameHash == RHS->QualifiedNameHash && + LHS->Line == RHS->Line && LHS->ByteSize == RHS->ByteSize && + LHS->Name.data() == RHS->Name.data() && + LHS->File.data() == RHS->File.data() && + LHS->Parent.QualifiedNameHash == RHS->Parent.QualifiedNameHash; + } +}; + +/// This class gives a tree-like API to the DenseMap that stores the +/// DeclContext objects. It also holds the BumpPtrAllocator where +/// these objects will be allocated. +class DeclContextTree { + BumpPtrAllocator Allocator; + DeclContext Root; + DeclContext::Map Contexts; + +public: + /// Get the child of \a Context described by \a DIE in \a Unit. The + /// required strings will be interned in \a StringPool. + /// \returns The child DeclContext along with one bit that is set if + /// this context is invalid. + /// FIXME: the invalid bit along the return value is to emulate some + /// dsymutil-classic functionality. See the fucntion definition for + /// a more thorough discussion of its use. + PointerIntPair + getChildDeclContext(DeclContext &Context, + const DWARFDebugInfoEntryMinimal *DIE, CompileUnit &Unit, + NonRelocatableStringpool &StringPool); + + DeclContext &getRoot() { return Root; } +}; + /// \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. @@ -68,16 +195,26 @@ public: /// \brief Information gathered about a DIE in the object file. struct DIEInfo { int64_t AddrAdjust; ///< Address offset to apply to the described entity. + DeclContext *Ctxt; ///< ODR Declaration context. 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, unsigned ID) + CompileUnit(DWARFUnit &OrigUnit, unsigned ID, bool CanUseODR) : OrigUnit(OrigUnit), ID(ID), LowPc(UINT64_MAX), HighPc(0), RangeAlloc(), - Ranges(RangeAlloc), UnitRangeAttribute(nullptr) { + Ranges(RangeAlloc) { Info.resize(OrigUnit.getNumDIEs()); + + const auto *CUDie = OrigUnit.getUnitDIE(false); + unsigned Lang = CUDie->getAttributeValueAsUnsignedConstant( + &OrigUnit, dwarf::DW_AT_language, 0); + HasODR = CanUseODR && (Lang == dwarf::DW_LANG_C_plus_plus || + Lang == dwarf::DW_LANG_C_plus_plus_03 || + Lang == dwarf::DW_LANG_C_plus_plus_11 || + Lang == dwarf::DW_LANG_C_plus_plus_14 || + Lang == dwarf::DW_LANG_ObjC_plus_plus); } CompileUnit(CompileUnit &&RHS) @@ -93,8 +230,10 @@ public: unsigned getUniqueID() const { return ID; } - DIE *getOutputUnitDIE() const { return CUDie.get(); } - void setOutputUnitDIE(DIE *Die) { CUDie.reset(Die); } + DIE *getOutputUnitDIE() const { return CUDie; } + void setOutputUnitDIE(DIE *Die) { CUDie = Die; } + + bool hasODR() const { return HasODR; } DIEInfo &getInfo(unsigned Idx) { return Info[Idx]; } const DIEInfo &getInfo(unsigned Idx) const { return Info[Idx]; } @@ -106,13 +245,15 @@ public: uint64_t getLowPc() const { return LowPc; } uint64_t getHighPc() const { return HighPc; } - DIEInteger *getUnitRangesAttribute() const { return UnitRangeAttribute; } + Optional getUnitRangesAttribute() const { + return UnitRangeAttribute; + } const FunctionIntervals &getFunctionRanges() const { return Ranges; } - const std::vector &getRangesAttributes() const { + const std::vector &getRangesAttributes() const { return RangeAttributes; } - const std::vector> & + const std::vector> & getLocationAttributes() const { return LocationAttributes; } @@ -125,9 +266,10 @@ public: /// \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. + /// point to the absolute offset of \p Die in the debug_info section + /// or to the canonical offset of \p Ctxt if it is non-null. void noteForwardReference(DIE *Die, const CompileUnit *RefUnit, - DIEInteger *Attr); + DeclContext *Ctxt, PatchLocation Attr); /// \brief Apply all fixups recored by noteForwardReference(). void fixupForwardReferences(); @@ -138,11 +280,11 @@ public: /// \brief Keep track of a DW_AT_range attribute that we will need to /// patch up later. - void noteRangeAttribute(const DIE &Die, DIEInteger *Attr); + void noteRangeAttribute(const DIE &Die, PatchLocation 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); + void noteLocationAttribute(PatchLocation 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. @@ -154,8 +296,8 @@ public: 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. + 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. @@ -168,11 +310,27 @@ public: const std::vector &getPubnames() const { return Pubnames; } const std::vector &getPubtypes() const { return Pubtypes; } + /// Get the full path for file \a FileNum in the line table + const char *getResolvedPath(unsigned FileNum) { + if (FileNum >= ResolvedPaths.size()) + return nullptr; + return ResolvedPaths[FileNum].size() ? ResolvedPaths[FileNum].c_str() + : nullptr; + } + + /// Set the fully resolved path for the line-table's file \a FileNum + /// to \a Path. + void setResolvedPath(unsigned FileNum, const std::string &Path) { + if (ResolvedPaths.size() <= FileNum) + ResolvedPaths.resize(FileNum + 1); + ResolvedPaths[FileNum] = Path; + } + private: DWARFUnit &OrigUnit; unsigned ID; - std::vector Info; ///< DIE info indexed by DIE index. - std::unique_ptr CUDie; ///< Root of the linked DIE tree. + std::vector Info; ///< DIE info indexed by DIE index. + DIE *CUDie; ///< Root of the linked DIE tree. uint64_t StartOffset; uint64_t NextUnitOffset; @@ -186,8 +344,8 @@ private: /// The offsets for the attributes in this array couldn't be set while /// cloning because for cross-cu forward refences the target DIE's /// offset isn't known you emit the reference attribute. - std::vector> - ForwardDIEReferences; + std::vector> ForwardDIEReferences; FunctionIntervals::Allocator RangeAlloc; /// \brief The ranges in that interval map are the PC ranges for @@ -198,15 +356,15 @@ private: /// \brief DW_AT_ranges attributes to patch after we have gathered /// all the unit's function addresses. /// @{ - std::vector RangeAttributes; - DIEInteger *UnitRangeAttribute; + std::vector RangeAttributes; + Optional 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> LocationAttributes; + std::vector> LocationAttributes; /// \brief Accelerator entries for the unit, both for the pub* /// sections and the apple* ones. @@ -214,6 +372,12 @@ private: std::vector Pubnames; std::vector Pubtypes; /// @} + + /// Cached resolved paths from the line table. + std::vector ResolvedPaths; + + /// Is this unit subject to the ODR rule? + bool HasODR; }; uint64_t CompileUnit::computeNextUnitOffset() { @@ -229,8 +393,8 @@ uint64_t CompileUnit::computeNextUnitOffset() { /// \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); + DeclContext *Ctxt, PatchLocation Attr) { + ForwardDIEReferences.emplace_back(Die, RefUnit, Ctxt, Attr); } /// \brief Apply all fixups recorded by noteForwardReference(). @@ -238,9 +402,13 @@ void CompileUnit::fixupForwardReferences() { for (const auto &Ref : ForwardDIEReferences) { DIE *RefDie; const CompileUnit *RefUnit; - DIEInteger *Attr; - std::tie(RefDie, RefUnit, Attr) = Ref; - Attr->setValue(RefDie->getOffset() + RefUnit->getStartOffset()); + PatchLocation Attr; + DeclContext *Ctxt; + std::tie(RefDie, RefUnit, Ctxt, Attr) = Ref; + if (Ctxt && Ctxt->getCanonicalDIEOffset()) + Attr.set(Ctxt->getCanonicalDIEOffset()); + else + Attr.set(RefDie->getOffset() + RefUnit->getStartOffset()); } } @@ -251,14 +419,14 @@ void CompileUnit::addFunctionRange(uint64_t FuncLowPc, uint64_t FuncHighPc, this->HighPc = std::max(HighPc, FuncHighPc + PcOffset); } -void CompileUnit::noteRangeAttribute(const DIE &Die, DIEInteger *Attr) { +void CompileUnit::noteRangeAttribute(const DIE &Die, PatchLocation Attr) { if (Die.getTag() != dwarf::DW_TAG_compile_unit) RangeAttributes.push_back(Attr); else UnitRangeAttribute = Attr; } -void CompileUnit::noteLocationAttribute(DIEInteger *Attr, int64_t PcOffset) { +void CompileUnit::noteLocationAttribute(PatchLocation Attr, int64_t PcOffset) { LocationAttributes.emplace_back(Attr, PcOffset); } @@ -387,6 +555,7 @@ class DwarfStreamer { uint32_t RangesSectionSize; uint32_t LocSectionSize; uint32_t LineSectionSize; + uint32_t FrameSectionSize; /// \brief Emit the pubnames or pubtypes section contribution for \p /// Unit into \p Sec. The data is provided in \p Names. @@ -449,7 +618,8 @@ public: /// \brief Emit the line table described in \p Rows into the /// debug_line section. - void emitLineTableForUnit(StringRef PrologueBytes, unsigned MinInstLength, + void emitLineTableForUnit(MCDwarfLineTableParams Params, + StringRef PrologueBytes, unsigned MinInstLength, std::vector &Rows, unsigned AdddressSize); @@ -460,6 +630,15 @@ public: /// \brief Emit the .debug_pubtypes contribution for \p Unit. void emitPubTypesForUnit(const CompileUnit &Unit); + + /// \brief Emit a CIE. + void emitCIE(StringRef CIEBytes); + + /// \brief Emit an FDE with data \p Bytes. + void emitFDE(uint32_t CIEOffset, uint32_t AddreSize, uint32_t Address, + StringRef Bytes); + + uint32_t getFrameSectionSize() const { return FrameSectionSize; } }; bool DwarfStreamer::init(Triple TheTriple, StringRef OutputFilename) { @@ -485,7 +664,7 @@ bool DwarfStreamer::init(Triple TheTriple, StringRef OutputFilename) { MOFI.reset(new MCObjectFileInfo); MC.reset(new MCContext(MAI.get(), MRI.get(), MOFI.get())); - MOFI->InitMCObjectFileInfo(TripleName, Reloc::Default, CodeModel::Default, + MOFI->InitMCObjectFileInfo(TheTriple, Reloc::Default, CodeModel::Default, *MC); MAB = TheTarget->createMCAsmBackend(*MRI, TripleName, ""); @@ -529,6 +708,7 @@ bool DwarfStreamer::init(Triple TheTriple, StringRef OutputFilename) { RangesSectionSize = 0; LocSectionSize = 0; LineSectionSize = 0; + FrameSectionSize = 0; return true; } @@ -717,8 +897,7 @@ void DwarfStreamer::emitUnitRangesEntries(CompileUnit &Unit, /// point to the new entries. void DwarfStreamer::emitLocationsForUnit(const CompileUnit &Unit, DWARFContext &Dwarf) { - const std::vector> &Attributes = - Unit.getLocationAttributes(); + const auto &Attributes = Unit.getLocationAttributes(); if (Attributes.empty()) return; @@ -737,8 +916,8 @@ void DwarfStreamer::emitLocationsForUnit(const CompileUnit &Unit, UnitPcOffset = int64_t(OrigLowPc) - Unit.getLowPc(); for (const auto &Attr : Attributes) { - uint32_t Offset = Attr.first->getValue(); - Attr.first->setValue(LocSectionSize); + uint32_t Offset = Attr.first.get(); + Attr.first.set(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; @@ -764,7 +943,8 @@ void DwarfStreamer::emitLocationsForUnit(const CompileUnit &Unit, } } -void DwarfStreamer::emitLineTableForUnit(StringRef PrologueBytes, +void DwarfStreamer::emitLineTableForUnit(MCDwarfLineTableParams Params, + StringRef PrologueBytes, unsigned MinInstLength, std::vector &Rows, unsigned PointerSize) { @@ -787,7 +967,7 @@ void DwarfStreamer::emitLineTableForUnit(StringRef PrologueBytes, 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); + MCDwarfLineAddr::Encode(*MC, Params, INT64_MAX, 0, EncodingOS); MS->EmitBytes(EncodingOS.str()); LineSectionSize += EncodingBuffer.size(); MS->EmitLabel(LineEndSym); @@ -869,11 +1049,10 @@ void DwarfStreamer::emitLineTableForUnit(StringRef PrologueBytes, int64_t LineDelta = int64_t(Row.Line) - LastLine; if (!Row.EndSequence) { - MCDwarfLineAddr::Encode(*MC, LineDelta, AddressDelta, EncodingOS); + MCDwarfLineAddr::Encode(*MC, Params, LineDelta, AddressDelta, EncodingOS); MS->EmitBytes(EncodingOS.str()); LineSectionSize += EncodingBuffer.size(); EncodingBuffer.resize(0); - EncodingOS.resync(); Address = Row.Address; LastLine = Row.Line; RowsSinceLastSequence++; @@ -888,11 +1067,10 @@ void DwarfStreamer::emitLineTableForUnit(StringRef PrologueBytes, MS->EmitULEB128IntValue(AddressDelta); LineSectionSize += 1 + getULEB128Size(AddressDelta); } - MCDwarfLineAddr::Encode(*MC, INT64_MAX, 0, EncodingOS); + MCDwarfLineAddr::Encode(*MC, Params, 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; @@ -900,11 +1078,10 @@ void DwarfStreamer::emitLineTableForUnit(StringRef PrologueBytes, } if (RowsSinceLastSequence) { - MCDwarfLineAddr::Encode(*MC, INT64_MAX, 0, EncodingOS); + MCDwarfLineAddr::Encode(*MC, Params, INT64_MAX, 0, EncodingOS); MS->EmitBytes(EncodingOS.str()); LineSectionSize += EncodingBuffer.size(); EncodingBuffer.resize(0); - EncodingOS.resync(); } MS->EmitLabel(LineEndSym); @@ -934,7 +1111,7 @@ void DwarfStreamer::emitPubSectionForUnit( 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.getStartOffset()); // Unit offset Asm->EmitInt32(Unit.getNextUnitOffset() - Unit.getStartOffset()); // Size HeaderEmitted = true; } @@ -961,6 +1138,28 @@ void DwarfStreamer::emitPubTypesForUnit(const CompileUnit &Unit) { "types", Unit, Unit.getPubtypes()); } +/// \brief Emit a CIE into the debug_frame section. +void DwarfStreamer::emitCIE(StringRef CIEBytes) { + MS->SwitchSection(MC->getObjectFileInfo()->getDwarfFrameSection()); + + MS->EmitBytes(CIEBytes); + FrameSectionSize += CIEBytes.size(); +} + +/// \brief Emit a FDE into the debug_frame section. \p FDEBytes +/// contains the FDE data without the length, CIE offset and address +/// which will be replaced with the paramter values. +void DwarfStreamer::emitFDE(uint32_t CIEOffset, uint32_t AddrSize, + uint32_t Address, StringRef FDEBytes) { + MS->SwitchSection(MC->getObjectFileInfo()->getDwarfFrameSection()); + + MS->EmitIntValue(FDEBytes.size() + 4 + AddrSize, 4); + MS->EmitIntValue(CIEOffset, 4); + MS->EmitIntValue(Address, AddrSize); + MS->EmitBytes(FDEBytes); + FrameSectionSize += FDEBytes.size() + 8 + AddrSize; +} + /// \brief The core of the Dwarf linking logic. /// /// The link of the dwarf information from the object files will be @@ -979,7 +1178,7 @@ class DwarfLinker { public: DwarfLinker(StringRef OutputFilename, const LinkOptions &Options) : OutputFilename(OutputFilename), Options(Options), - BinHolder(Options.Verbose) {} + BinHolder(Options.Verbose), LastCIEOffset(0) {} ~DwarfLinker() { for (auto *Abbrev : Abbreviations) @@ -1051,6 +1250,7 @@ private: TF_InFunctionScope = 1 << 1, ///< Current scope is a fucntion scope. TF_DependencyWalk = 1 << 2, ///< Walking the dependencies of a kept DIE. TF_ParentWalk = 1 << 3, ///< Walking up the parents of a kept DIE. + TF_ODR = 1 << 4, ///< Use the ODR whhile keeping dependants. }; /// \brief Mark the passed DIE as well as all the ones it depends on @@ -1058,7 +1258,7 @@ private: void keepDIEAndDenpendencies(const DWARFDebugInfoEntryMinimal &DIE, CompileUnit::DIEInfo &MyInfo, const DebugMapObject &DMO, CompileUnit &CU, - unsigned Flags); + bool UseODR); unsigned shouldKeepDIE(const DWARFDebugInfoEntryMinimal &DIE, CompileUnit &Unit, CompileUnit::DIEInfo &MyInfo, @@ -1177,6 +1377,10 @@ private: /// \brief Emit the accelerator entries for \p Unit. void emitAcceleratorEntriesForUnit(CompileUnit &Unit); + /// \brief Patch the frame info for an object file and emit it. + void patchFrameInfoForObject(const DebugMapObject &, DWARFContext &, + unsigned AddressSize); + /// \brief DIELoc objects that need to be destructed (but not freed!). std::vector DIELocs; /// \brief DIEBlock objects that need to be destructed (but not freed!). @@ -1185,11 +1389,14 @@ private: BumpPtrAllocator DIEAlloc; /// @} + /// ODR Contexts for that link. + DeclContextTree ODRContexts; + /// \defgroup Helpers Various helper methods. /// /// @{ const DWARFDebugInfoEntryMinimal * - resolveDIEReference(DWARFFormValue &RefValue, const DWARFUnit &Unit, + resolveDIEReference(const DWARFFormValue &RefValue, const DWARFUnit &Unit, const DWARFDebugInfoEntryMinimal &DIE, CompileUnit *&ReferencedCU); @@ -1202,6 +1409,11 @@ private: const DWARFDebugInfoEntryMinimal *DIE = nullptr) const; bool createStreamer(Triple TheTriple, StringRef OutputFilename); + + /// \brief Attempt to load a debug object from disk. + ErrorOr loadObject(BinaryHolder &BinaryHolder, + DebugMapObject &Obj, + const DebugMap &Map); /// @} private: @@ -1226,6 +1438,16 @@ private: /// /// See startDebugObject() for a more complete description of its use. std::map> Ranges; + + /// \brief The CIEs that have been emitted in the output + /// section. The actual CIE data serves a the key to this StringMap, + /// this takes care of comparing the semantics of CIEs defined in + /// different object files. + StringMap EmittedCIEs; + + /// Offset of the last CIE that has been emitted in the output + /// debug_frame section. + uint32_t LastCIEOffset; }; /// \brief Similar to DWARFUnitSection::getUnitForOffset(), but @@ -1244,7 +1466,7 @@ CompileUnit *DwarfLinker::getUnitForOffset(unsigned Offset) { /// CompileUnit which is stored into \p ReferencedCU. /// \returns null if resolving fails for any reason. const DWARFDebugInfoEntryMinimal *DwarfLinker::resolveDIEReference( - DWARFFormValue &RefValue, const DWARFUnit &Unit, + const DWARFFormValue &RefValue, const DWARFUnit &Unit, const DWARFDebugInfoEntryMinimal &DIE, CompileUnit *&RefCU) { assert(RefValue.isFormClass(DWARFFormValue::FC_Reference)); uint64_t RefOffset = *RefValue.getAsReference(&Unit); @@ -1257,6 +1479,220 @@ const DWARFDebugInfoEntryMinimal *DwarfLinker::resolveDIEReference( return nullptr; } +/// \returns whether the passed \a Attr type might contain a DIE +/// reference suitable for ODR uniquing. +static bool isODRAttribute(uint16_t Attr) { + switch (Attr) { + default: + return false; + case dwarf::DW_AT_type: + case dwarf::DW_AT_containing_type: + case dwarf::DW_AT_specification: + case dwarf::DW_AT_abstract_origin: + case dwarf::DW_AT_import: + return true; + } + llvm_unreachable("Improper attribute."); +} + +/// Set the last DIE/CU a context was seen in and, possibly invalidate +/// the context if it is ambiguous. +/// +/// In the current implementation, we don't handle overloaded +/// functions well, because the argument types are not taken into +/// account when computing the DeclContext tree. +/// +/// Some of this is mitigated byt using mangled names that do contain +/// the arguments types, but sometimes (eg. with function templates) +/// we don't have that. In that case, just do not unique anything that +/// refers to the contexts we are not able to distinguish. +/// +/// If a context that is not a namespace appears twice in the same CU, +/// we know it is ambiguous. Make it invalid. +bool DeclContext::setLastSeenDIE(CompileUnit &U, + const DWARFDebugInfoEntryMinimal *Die) { + if (LastSeenCompileUnitID == U.getUniqueID()) { + DWARFUnit &OrigUnit = U.getOrigUnit(); + uint32_t FirstIdx = OrigUnit.getDIEIndex(LastSeenDIE); + U.getInfo(FirstIdx).Ctxt = nullptr; + return false; + } + + LastSeenCompileUnitID = U.getUniqueID(); + LastSeenDIE = Die; + return true; +} + +/// Get the child context of \a Context corresponding to \a DIE. +/// +/// \returns the child context or null if we shouldn't track children +/// contexts. It also returns an additional bit meaning 'invalid'. An +/// invalid context means it shouldn't be considered for uniquing, but +/// its not returning null, because some children of that context +/// might be uniquing candidates. +/// FIXME: this is for dsymutil-classic compatibility, I don't think +/// it buys us much. +PointerIntPair DeclContextTree::getChildDeclContext( + DeclContext &Context, const DWARFDebugInfoEntryMinimal *DIE, CompileUnit &U, + NonRelocatableStringpool &StringPool) { + unsigned Tag = DIE->getTag(); + + // FIXME: dsymutil-classic compat: We should bail out here if we + // have a specification or an abstract_origin. We will get the + // parent context wrong here. + + switch (Tag) { + default: + // By default stop gathering child contexts. + return PointerIntPair(nullptr); + case dwarf::DW_TAG_compile_unit: + // FIXME: Add support for DW_TAG_module. + return PointerIntPair(&Context); + case dwarf::DW_TAG_subprogram: + // Do not unique anything inside CU local functions. + if ((Context.getTag() == dwarf::DW_TAG_namespace || + Context.getTag() == dwarf::DW_TAG_compile_unit) && + !DIE->getAttributeValueAsUnsignedConstant(&U.getOrigUnit(), + dwarf::DW_AT_external, 0)) + return PointerIntPair(nullptr); + // Fallthrough + case dwarf::DW_TAG_member: + case dwarf::DW_TAG_namespace: + case dwarf::DW_TAG_structure_type: + case dwarf::DW_TAG_class_type: + case dwarf::DW_TAG_union_type: + case dwarf::DW_TAG_enumeration_type: + case dwarf::DW_TAG_typedef: + // Artificial things might be ambiguous, because they might be + // created on demand. For example implicitely defined constructors + // are ambiguous because of the way we identify contexts, and they + // won't be generated everytime everywhere. + if (DIE->getAttributeValueAsUnsignedConstant(&U.getOrigUnit(), + dwarf::DW_AT_artificial, 0)) + return PointerIntPair(nullptr); + break; + } + + const char *Name = DIE->getName(&U.getOrigUnit(), DINameKind::LinkageName); + const char *ShortName = DIE->getName(&U.getOrigUnit(), DINameKind::ShortName); + StringRef NameRef; + StringRef ShortNameRef; + StringRef FileRef; + + if (Name) + NameRef = StringPool.internString(Name); + else if (Tag == dwarf::DW_TAG_namespace) + // FIXME: For dsymutil-classic compatibility. I think uniquing + // within anonymous namespaces is wrong. There is no ODR guarantee + // there. + NameRef = StringPool.internString("(anonymous namespace)"); + + if (ShortName && ShortName != Name) + ShortNameRef = StringPool.internString(ShortName); + else + ShortNameRef = NameRef; + + if (Tag != dwarf::DW_TAG_class_type && Tag != dwarf::DW_TAG_structure_type && + Tag != dwarf::DW_TAG_union_type && + Tag != dwarf::DW_TAG_enumeration_type && NameRef.empty()) + return PointerIntPair(nullptr); + + std::string File; + unsigned Line = 0; + unsigned ByteSize = 0; + + // Gather some discriminating data about the DeclContext we will be + // creating: File, line number and byte size. This shouldn't be + // necessary, because the ODR is just about names, but given that we + // do some approximations with overloaded functions and anonymous + // namespaces, use these additional data points to make the process safer. + ByteSize = DIE->getAttributeValueAsUnsignedConstant( + &U.getOrigUnit(), dwarf::DW_AT_byte_size, UINT64_MAX); + if (Tag != dwarf::DW_TAG_namespace || !Name) { + if (unsigned FileNum = DIE->getAttributeValueAsUnsignedConstant( + &U.getOrigUnit(), dwarf::DW_AT_decl_file, 0)) { + if (const auto *LT = U.getOrigUnit().getContext().getLineTableForUnit( + &U.getOrigUnit())) { + // FIXME: dsymutil-classic compatibility. I'd rather not + // unique anything in anonymous namespaces, but if we do, then + // verify that the file and line correspond. + if (!Name && Tag == dwarf::DW_TAG_namespace) + FileNum = 1; + + // FIXME: Passing U.getOrigUnit().getCompilationDir() + // instead of "" would allow more uniquing, but for now, do + // it this way to match dsymutil-classic. + if (LT->getFileNameByIndex( + FileNum, "", + DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath, + File)) { + Line = DIE->getAttributeValueAsUnsignedConstant( + &U.getOrigUnit(), dwarf::DW_AT_decl_line, 0); +#ifdef HAVE_REALPATH + // Cache the resolved paths, because calling realpath is expansive. + if (const char *ResolvedPath = U.getResolvedPath(FileNum)) { + File = ResolvedPath; + } else { + char RealPath[PATH_MAX + 1]; + RealPath[PATH_MAX] = 0; + if (::realpath(File.c_str(), RealPath)) + File = RealPath; + U.setResolvedPath(FileNum, File); + } +#endif + FileRef = StringPool.internString(File); + } + } + } + } + + if (!Line && NameRef.empty()) + return PointerIntPair(nullptr); + + // FIXME: dsymutil-classic compat won't unique the same type + // presented once as a struct and once as a class. Use the Tag in + // the fully qualified name hash to get the same effect. + // We hash NameRef, which is the mangled name, in order to get most + // overloaded functions resolvec correctly. + unsigned Hash = hash_combine(Context.getQualifiedNameHash(), Tag, NameRef); + + // FIXME: dsymutil-classic compatibility: when we don't have a name, + // use the filename. + if (Tag == dwarf::DW_TAG_namespace && NameRef == "(anonymous namespace)") + Hash = hash_combine(Hash, FileRef); + + // Now look if this context already exists. + DeclContext Key(Hash, Line, ByteSize, Tag, NameRef, FileRef, Context); + auto ContextIter = Contexts.find(&Key); + + if (ContextIter == Contexts.end()) { + // The context wasn't found. + bool Inserted; + DeclContext *NewContext = + new (Allocator) DeclContext(Hash, Line, ByteSize, Tag, NameRef, FileRef, + Context, DIE, U.getUniqueID()); + std::tie(ContextIter, Inserted) = Contexts.insert(NewContext); + assert(Inserted && "Failed to insert DeclContext"); + (void)Inserted; + } else if (Tag != dwarf::DW_TAG_namespace && + !(*ContextIter)->setLastSeenDIE(U, DIE)) { + // The context was found, but it is ambiguous with another context + // in the same file. Mark it invalid. + return PointerIntPair(*ContextIter, /* Invalid= */ 1); + } + + assert(ContextIter != Contexts.end()); + // FIXME: dsymutil-classic compatibility. Union types aren't + // uniques, but their children might be. + if ((Tag == dwarf::DW_TAG_subprogram && + Context.getTag() != dwarf::DW_TAG_structure_type && + Context.getTag() != dwarf::DW_TAG_class_type) || + (Tag == dwarf::DW_TAG_union_type)) + return PointerIntPair(*ContextIter, /* Invalid= */ 1); + + return PointerIntPair(*ContextIter); +} + /// \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. @@ -1303,14 +1739,30 @@ bool DwarfLinker::createStreamer(Triple TheTriple, StringRef OutputFilename) { /// \brief Recursive helper to gather the child->parent relationships in the /// original compile unit. static void gatherDIEParents(const DWARFDebugInfoEntryMinimal *DIE, - unsigned ParentIdx, CompileUnit &CU) { + unsigned ParentIdx, CompileUnit &CU, + DeclContext *CurrentDeclContext, + NonRelocatableStringpool &StringPool, + DeclContextTree &Contexts) { unsigned MyIdx = CU.getOrigUnit().getDIEIndex(DIE); - CU.getInfo(MyIdx).ParentIdx = ParentIdx; + CompileUnit::DIEInfo &Info = CU.getInfo(MyIdx); + + Info.ParentIdx = ParentIdx; + if (CU.hasODR()) { + if (CurrentDeclContext) { + auto PtrInvalidPair = Contexts.getChildDeclContext(*CurrentDeclContext, + DIE, CU, StringPool); + CurrentDeclContext = PtrInvalidPair.getPointer(); + Info.Ctxt = + PtrInvalidPair.getInt() ? nullptr : PtrInvalidPair.getPointer(); + } else + Info.Ctxt = CurrentDeclContext = nullptr; + } if (DIE->hasChildren()) for (auto *Child = DIE->getFirstChild(); Child && !Child->isNULL(); Child = Child->getSibling()) - gatherDIEParents(Child, MyIdx, CU); + gatherDIEParents(Child, MyIdx, CU, CurrentDeclContext, StringPool, + Contexts); } static bool dieNeedsChildrenToBeMeaningful(uint32_t Tag) { @@ -1328,6 +1780,12 @@ static bool dieNeedsChildrenToBeMeaningful(uint32_t Tag) { llvm_unreachable("Invalid Tag"); } +static unsigned getRefAddrSize(const DWARFUnit &U) { + if (U.getVersion() == 2) + return U.getAddressByteSize(); + return 4; +} + void DwarfLinker::startDebugObject(DWARFContext &Dwarf, DebugMapObject &Obj) { Units.reserve(Dwarf.getNumCompileUnits()); NextValidReloc = 0; @@ -1359,10 +1817,10 @@ void DwarfLinker::endDebugObject() { ValidRelocs.clear(); Ranges.clear(); - for (auto *Block : DIEBlocks) - Block->~DIEBlock(); - for (auto *Loc : DIELocs) - Loc->~DIELoc(); + for (auto I = DIEBlocks.begin(), E = DIEBlocks.end(); I != E; ++I) + (*I)->~DIEBlock(); + for (auto I = DIELocs.begin(), E = DIELocs.end(); I != E; ++I) + (*I)->~DIELoc(); DIEBlocks.clear(); DIELocs.clear(); @@ -1383,8 +1841,8 @@ void DwarfLinker::findValidRelocsMachO(const object::SectionRef &Section, object::DataRefImpl RelocDataRef = Reloc.getRawDataRefImpl(); MachO::any_relocation_info MachOReloc = Obj.getRelocation(RelocDataRef); unsigned RelocSize = 1 << Obj.getAnyRelocationLength(MachOReloc); - uint64_t Offset64; - if ((RelocSize != 4 && RelocSize != 8) || Reloc.getOffset(Offset64)) { + uint64_t Offset64 = Reloc.getOffset(); + if ((RelocSize != 4 && RelocSize != 8)) { reportWarning(" unsupported relocation in debug_info section."); continue; } @@ -1394,12 +1852,12 @@ void DwarfLinker::findValidRelocsMachO(const object::SectionRef &Section, auto Sym = Reloc.getSymbol(); if (Sym != Obj.symbol_end()) { - StringRef SymbolName; - if (Sym->getName(SymbolName)) { + ErrorOr SymbolName = Sym->getName(); + if (!SymbolName) { reportWarning("error getting relocation symbol name."); continue; } - if (const auto *Mapping = DMO.lookupSymbol(SymbolName)) + if (const auto *Mapping = DMO.lookupSymbol(*SymbolName)) ValidRelocs.emplace_back(Offset64, RelocSize, Addend, Mapping); } else if (const auto *Mapping = DMO.lookupObjectAddress(Addend)) { // Do not store the addend. The addend was the address of the @@ -1477,15 +1935,15 @@ bool DwarfLinker::hasValidRelocation(uint32_t StartOffset, uint32_t EndOffset, return false; const auto &ValidReloc = ValidRelocs[NextValidReloc++]; + const auto &Mapping = ValidReloc.Mapping->getValue(); if (Options.Verbose) outs() << "Found valid debug map entry: " << ValidReloc.Mapping->getKey() << " " << format("\t%016" PRIx64 " => %016" PRIx64, - ValidReloc.Mapping->getValue().ObjectAddress, - ValidReloc.Mapping->getValue().BinaryAddress); + uint64_t(Mapping.ObjectAddress), + uint64_t(Mapping.BinaryAddress)); - Info.AddrAdjust = int64_t(ValidReloc.Mapping->getValue().BinaryAddress) + - ValidReloc.Addend - - ValidReloc.Mapping->getValue().ObjectAddress; + Info.AddrAdjust = int64_t(Mapping.BinaryAddress) + ValidReloc.Addend - + Mapping.ObjectAddress; Info.InDebugMap = true; return true; } @@ -1634,15 +2092,16 @@ unsigned DwarfLinker::shouldKeepDIE(const DWARFDebugInfoEntryMinimal &DIE, void DwarfLinker::keepDIEAndDenpendencies(const DWARFDebugInfoEntryMinimal &DIE, CompileUnit::DIEInfo &MyInfo, const DebugMapObject &DMO, - CompileUnit &CU, unsigned Flags) { + CompileUnit &CU, bool UseODR) { const DWARFUnit &Unit = CU.getOrigUnit(); MyInfo.Keep = true; // First mark all the parent chain as kept. unsigned AncestorIdx = MyInfo.ParentIdx; while (!CU.getInfo(AncestorIdx).Keep) { + unsigned ODRFlag = UseODR ? TF_ODR : 0; lookForDIEsToKeep(*Unit.getDIEAtIndex(AncestorIdx), DMO, CU, - TF_ParentWalk | TF_Keep | TF_DependencyWalk); + TF_ParentWalk | TF_Keep | TF_DependencyWalk | ODRFlag); AncestorIdx = CU.getInfo(AncestorIdx).ParentIdx; } @@ -1663,9 +2122,27 @@ void DwarfLinker::keepDIEAndDenpendencies(const DWARFDebugInfoEntryMinimal &DIE, Val.extractValue(Data, &Offset, &Unit); CompileUnit *ReferencedCU; - if (const auto *RefDIE = resolveDIEReference(Val, Unit, DIE, ReferencedCU)) + if (const auto *RefDIE = + resolveDIEReference(Val, Unit, DIE, ReferencedCU)) { + uint32_t RefIdx = ReferencedCU->getOrigUnit().getDIEIndex(RefDIE); + CompileUnit::DIEInfo &Info = ReferencedCU->getInfo(RefIdx); + // If the referenced DIE has a DeclContext that has already been + // emitted, then do not keep the one in this CU. We'll link to + // the canonical DIE in cloneDieReferenceAttribute. + // FIXME: compatibility with dsymutil-classic. UseODR shouldn't + // be necessary and could be advantageously replaced by + // ReferencedCU->hasODR() && CU.hasODR(). + // FIXME: compatibility with dsymutil-classic. There is no + // reason not to unique ref_addr references. + if (AttrSpec.Form != dwarf::DW_FORM_ref_addr && UseODR && Info.Ctxt && + Info.Ctxt != ReferencedCU->getInfo(Info.ParentIdx).Ctxt && + Info.Ctxt->getCanonicalDIEOffset() && isODRAttribute(AttrSpec.Attr)) + continue; + + unsigned ODRFlag = UseODR ? TF_ODR : 0; lookForDIEsToKeep(*RefDIE, DMO, *ReferencedCU, - TF_Keep | TF_DependencyWalk); + TF_Keep | TF_DependencyWalk | ODRFlag); + } } } @@ -1700,9 +2177,10 @@ void DwarfLinker::lookForDIEsToKeep(const DWARFDebugInfoEntryMinimal &DIE, Flags = shouldKeepDIE(DIE, CU, MyInfo, Flags); // If it is a newly kept DIE mark it as well as all its dependencies as kept. - if (!AlreadyKept && (Flags & TF_Keep)) - keepDIEAndDenpendencies(DIE, MyInfo, DMO, CU, Flags); - + if (!AlreadyKept && (Flags & TF_Keep)) { + bool UseOdr = (Flags & TF_DependencyWalk) ? (Flags & TF_ODR) : CU.hasODR(); + keepDIEAndDenpendencies(DIE, MyInfo, DMO, CU, UseOdr); + } // The TF_ParentWalk flag tells us that we are currently walking up // the parent chain of a required DIE, and we don't want to mark all // the children of the parents as kept (consider for example a @@ -1759,8 +2237,8 @@ unsigned DwarfLinker::cloneStringAttribute(DIE &Die, AttributeSpec AttrSpec, // Switch everything to out of line strings. const char *String = *Val.getAsCString(&U); unsigned Offset = StringPool.getStringOffset(String); - Die.addValue(dwarf::Attribute(AttrSpec.Attr), dwarf::DW_FORM_strp, - new (DIEAlloc) DIEInteger(Offset)); + Die.addValue(DIEAlloc, dwarf::Attribute(AttrSpec.Attr), dwarf::DW_FORM_strp, + DIEInteger(Offset)); return 4; } @@ -1771,56 +2249,70 @@ unsigned DwarfLinker::cloneDieReferenceAttribute( DIE &Die, const DWARFDebugInfoEntryMinimal &InputDIE, AttributeSpec AttrSpec, unsigned AttrSize, const DWARFFormValue &Val, CompileUnit &Unit) { - uint32_t Ref = *Val.getAsReference(&Unit.getOrigUnit()); + const DWARFUnit &U = Unit.getOrigUnit(); + uint32_t Ref = *Val.getAsReference(&U); DIE *NewRefDie = nullptr; CompileUnit *RefUnit = nullptr; - const DWARFDebugInfoEntryMinimal *RefDie = nullptr; - - if (!(RefUnit = getUnitForOffset(Ref)) || - !(RefDie = RefUnit->getOrigUnit().getDIEForOffset(Ref))) { - const char *AttributeString = dwarf::AttributeString(AttrSpec.Attr); - if (!AttributeString) - AttributeString = "DW_AT_???"; - reportWarning(Twine("Missing DIE for ref in attribute ") + AttributeString + - ". Dropping.", - &Unit.getOrigUnit(), &InputDIE); + DeclContext *Ctxt = nullptr; + + const DWARFDebugInfoEntryMinimal *RefDie = + resolveDIEReference(Val, U, InputDIE, RefUnit); + + // If the referenced DIE is not found, drop the attribute. + if (!RefDie) return 0; - } unsigned Idx = RefUnit->getOrigUnit().getDIEIndex(RefDie); CompileUnit::DIEInfo &RefInfo = RefUnit->getInfo(Idx); + + // If we already have emitted an equivalent DeclContext, just point + // at it. + if (isODRAttribute(AttrSpec.Attr)) { + Ctxt = RefInfo.Ctxt; + if (Ctxt && Ctxt->getCanonicalDIEOffset()) { + DIEInteger Attr(Ctxt->getCanonicalDIEOffset()); + Die.addValue(DIEAlloc, dwarf::Attribute(AttrSpec.Attr), + dwarf::DW_FORM_ref_addr, Attr); + return getRefAddrSize(U); + } + } + if (!RefInfo.Clone) { assert(Ref > InputDIE.getOffset()); // We haven't cloned this DIE yet. Just create an empty one and // store it. It'll get really cloned when we process it. - RefInfo.Clone = new DIE(dwarf::Tag(RefDie->getTag())); + RefInfo.Clone = DIE::get(DIEAlloc, dwarf::Tag(RefDie->getTag())); } NewRefDie = RefInfo.Clone; - if (AttrSpec.Form == dwarf::DW_FORM_ref_addr) { + if (AttrSpec.Form == dwarf::DW_FORM_ref_addr || + (Unit.hasODR() && isODRAttribute(AttrSpec.Attr))) { // We cannot currently rely on a DIEEntry to emit ref_addr // references, because the implementation calls back to DwarfDebug // to find the unit offset. (We don't have a DwarfDebug) // FIXME: we should be able to design DIEEntry reliance on // DwarfDebug away. - DIEInteger *Attr; + uint64_t Attr; if (Ref < InputDIE.getOffset()) { // We must have already cloned that DIE. uint32_t NewRefOffset = RefUnit->getStartOffset() + NewRefDie->getOffset(); - Attr = new (DIEAlloc) DIEInteger(NewRefOffset); + Attr = NewRefOffset; + Die.addValue(DIEAlloc, dwarf::Attribute(AttrSpec.Attr), + dwarf::DW_FORM_ref_addr, DIEInteger(Attr)); } else { // A forward reference. Note and fixup later. - Attr = new (DIEAlloc) DIEInteger(0xBADDEF); - Unit.noteForwardReference(NewRefDie, RefUnit, Attr); + Attr = 0xBADDEF; + Unit.noteForwardReference( + NewRefDie, RefUnit, Ctxt, + Die.addValue(DIEAlloc, dwarf::Attribute(AttrSpec.Attr), + dwarf::DW_FORM_ref_addr, DIEInteger(Attr))); } - Die.addValue(dwarf::Attribute(AttrSpec.Attr), dwarf::DW_FORM_ref_addr, - Attr); - return AttrSize; + return getRefAddrSize(U); } - Die.addValue(dwarf::Attribute(AttrSpec.Attr), dwarf::Form(AttrSpec.Form), - new (DIEAlloc) DIEEntry(*NewRefDie)); + Die.addValue(DIEAlloc, dwarf::Attribute(AttrSpec.Attr), + dwarf::Form(AttrSpec.Form), DIEEntry(*NewRefDie)); return AttrSize; } @@ -1830,24 +2322,31 @@ unsigned DwarfLinker::cloneDieReferenceAttribute( unsigned DwarfLinker::cloneBlockAttribute(DIE &Die, AttributeSpec AttrSpec, const DWARFFormValue &Val, unsigned AttrSize) { - DIE *Attr; - DIEValue *Value; + DIEValueList *Attr; + DIEValue Value; DIELoc *Loc = nullptr; DIEBlock *Block = nullptr; // Just copy the block data over. if (AttrSpec.Form == dwarf::DW_FORM_exprloc) { - Loc = new (DIEAlloc) DIELoc(); + Loc = new (DIEAlloc) DIELoc; DIELocs.push_back(Loc); } else { - Block = new (DIEAlloc) DIEBlock(); + Block = new (DIEAlloc) DIEBlock; DIEBlocks.push_back(Block); } - Attr = Loc ? static_cast(Loc) : static_cast(Block); - Value = Loc ? static_cast(Loc) : static_cast(Block); + Attr = Loc ? static_cast(Loc) + : static_cast(Block); + + if (Loc) + Value = DIEValue(dwarf::Attribute(AttrSpec.Attr), + dwarf::Form(AttrSpec.Form), Loc); + else + Value = DIEValue(dwarf::Attribute(AttrSpec.Attr), + dwarf::Form(AttrSpec.Form), Block); ArrayRef Bytes = *Val.getAsBlock(); for (auto Byte : Bytes) - Attr->addValue(static_cast(0), dwarf::DW_FORM_data1, - new (DIEAlloc) DIEInteger(Byte)); + Attr->addValue(DIEAlloc, static_cast(0), + dwarf::DW_FORM_data1, DIEInteger(Byte)); // FIXME: If DIEBlock and DIELoc just reuses the Size field of // the DIE class, this if could be replaced by // Attr->setSize(Bytes.size()). @@ -1857,8 +2356,7 @@ unsigned DwarfLinker::cloneBlockAttribute(DIE &Die, AttributeSpec AttrSpec, else Block->ComputeSize(&Streamer->getAsmPrinter()); } - Die.addValue(dwarf::Attribute(AttrSpec.Attr), dwarf::Form(AttrSpec.Form), - Value); + Die.addValue(DIEAlloc, Value); return AttrSize; } @@ -1892,9 +2390,8 @@ unsigned DwarfLinker::cloneAddressAttribute(DIE &Die, AttributeSpec AttrSpec, Addr = (Info.OrigHighPc ? Info.OrigHighPc : Addr) + Info.PCOffset; } - Die.addValue(static_cast(AttrSpec.Attr), - static_cast(AttrSpec.Form), - new (DIEAlloc) DIEInteger(Addr)); + Die.addValue(DIEAlloc, static_cast(AttrSpec.Attr), + static_cast(AttrSpec.Form), DIEInteger(Addr)); return Unit.getOrigUnit().getAddressByteSize(); } @@ -1922,20 +2419,20 @@ unsigned DwarfLinker::cloneScalarAttribute( &Unit.getOrigUnit(), &InputDIE); return 0; } - DIEInteger *Attr = new (DIEAlloc) DIEInteger(Value); + PatchLocation Patch = + Die.addValue(DIEAlloc, dwarf::Attribute(AttrSpec.Attr), + dwarf::Form(AttrSpec.Form), DIEInteger(Value)); if (AttrSpec.Attr == dwarf::DW_AT_ranges) - Unit.noteRangeAttribute(Die, Attr); + Unit.noteRangeAttribute(Die, Patch); // 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); + Unit.noteLocationAttribute(Patch, Info.PCOffset); else if (AttrSpec.Attr == dwarf::DW_AT_declaration && Value) Info.IsDeclaration = true; - Die.addValue(dwarf::Attribute(AttrSpec.Attr), dwarf::Form(AttrSpec.Form), - Attr); return AttrSize; } @@ -2088,9 +2585,17 @@ DIE *DwarfLinker::cloneDIE(const DWARFDebugInfoEntryMinimal &InputDIE, // (see cloneDieReferenceAttribute()). DIE *Die = Info.Clone; if (!Die) - Die = Info.Clone = new DIE(dwarf::Tag(InputDIE.getTag())); + Die = Info.Clone = DIE::get(DIEAlloc, dwarf::Tag(InputDIE.getTag())); assert(Die->getTag() == InputDIE.getTag()); Die->setOffset(OutOffset); + if (Unit.hasODR() && Die->getTag() != dwarf::DW_TAG_namespace && Info.Ctxt && + Info.Ctxt != Unit.getInfo(Info.ParentIdx).Ctxt && + !Info.Ctxt->getCanonicalDIEOffset()) { + // We are about to emit a DIE that is the root of its own valid + // DeclContext tree. Make the current offset the canonical offset + // for this context. + Info.Ctxt->setCanonicalDIEOffset(OutOffset + Unit.getStartOffset()); + } // Extract and clone every attribute. DataExtractor Data = U.getDebugInfoExtractor(); @@ -2157,14 +2662,15 @@ DIE *DwarfLinker::cloneDIE(const DWARFDebugInfoEntryMinimal &InputDIE, Unit.addTypeAccelerator(Die, AttrInfo.Name, AttrInfo.NameOffset); } - DIEAbbrev &NewAbbrev = Die->getAbbrev(); + DIEAbbrev NewAbbrev = Die->generateAbbrev(); // If a scope DIE is kept, we must have kept at least one child. If // it's not the case, we'll just be emitting one wasteful end of // children marker, but things won't break. if (InputDIE.hasChildren()) NewAbbrev.setChildrenFlag(dwarf::DW_CHILDREN_yes); // Assign a permanent abbrev number - AssignAbbrev(Die->getAbbrev()); + AssignAbbrev(NewAbbrev); + Die->setAbbrevNumber(NewAbbrev.getNumber()); // Add the size of the abbreviation number to the output offset. OutOffset += getULEB128Size(Die->getAbbrevNumber()); @@ -2179,7 +2685,7 @@ DIE *DwarfLinker::cloneDIE(const DWARFDebugInfoEntryMinimal &InputDIE, for (auto *Child = InputDIE.getFirstChild(); Child && !Child->isNULL(); Child = Child->getSibling()) { if (DIE *Clone = cloneDIE(*Child, Unit, PCOffset, OutOffset)) { - Die->addChild(std::unique_ptr(Clone)); + Die->addChild(Clone); OutOffset = Clone->getOffset() + Clone->getSize(); } } @@ -2213,8 +2719,8 @@ void DwarfLinker::patchRangesForUnit(const CompileUnit &Unit, UnitPcOffset = int64_t(OrigLowPc) - Unit.getLowPc(); for (const auto &RangeAttribute : Unit.getRangesAttributes()) { - uint32_t Offset = RangeAttribute->getValue(); - RangeAttribute->setValue(Streamer->getRangesSectionSize()); + uint32_t Offset = RangeAttribute.get(); + RangeAttribute.set(Streamer->getRangesSectionSize()); RangeList.extract(RangeExtractor, &Offset); const auto &Entries = RangeList.getEntries(); const DWARFDebugRangeList::RangeListEntry &First = Entries.front(); @@ -2241,10 +2747,10 @@ void DwarfLinker::patchRangesForUnit(const CompileUnit &Unit, /// 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(); + auto Attr = Unit.getUnitRangesAttribute(); if (Attr) - Attr->setValue(Streamer->getRangesSectionSize()); - Streamer->emitUnitRangesEntries(Unit, Attr != nullptr); + Attr->set(Streamer->getRangesSectionSize()); + Streamer->emitUnitRangesEntries(Unit, static_cast(Attr)); } /// \brief Insert the new line info sequence \p Seq into the current @@ -2281,30 +2787,30 @@ static void insertLineSequence(std::vector &Seq, Seq.clear(); } +static void patchStmtList(DIE &Die, DIEInteger Offset) { + for (auto &V : Die.values()) + if (V.getAttribute() == dwarf::DW_AT_stmt_list) { + V = DIEValue(V.getAttribute(), V.getForm(), Offset); + return; + } + + llvm_unreachable("Didn't find DW_AT_stmt_list in cloned DIE!"); +} + /// \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().getUnitDIE(); + const DWARFDebugInfoEntryMinimal *CUDie = Unit.getOrigUnit().getUnitDIE(); 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(OutputDIE->getValues()[Stmt - Abbrev.begin()]); - StmtAttr->setValue(Streamer->getLineSectionSize()); - } + if (auto *OutputDIE = Unit.getOutputUnitDIE()) + patchStmtList(*OutputDIE, DIEInteger(Streamer->getLineSectionSize())); // Parse the original line info for the unit. DWARFDebugLine::LineTable LineTable; @@ -2375,12 +2881,13 @@ void DwarfLinker::patchLineTableForUnit(CompileUnit &Unit, 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; + auto NextLine = Seq.back(); + NextLine.Address = StopAddress; + NextLine.EndSequence = 1; + NextLine.PrologueEnd = 0; + NextLine.BasicBlock = 0; + NextLine.EpilogueBegin = 0; + Seq.push_back(NextLine); insertLineSequence(Seq, NewRows); } @@ -2408,13 +2915,18 @@ void DwarfLinker::patchLineTableForUnit(CompileUnit &Unit, // 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) + LineTable.Prologue.OpcodeBase > 13) reportWarning("line table paramters mismatch. Cannot emit."); - else - Streamer->emitLineTableForUnit(LineData.slice(StmtList + 4, PrologueEnd), + else { + MCDwarfLineTableParams Params; + Params.DWARF2LineOpcodeBase = LineTable.Prologue.OpcodeBase; + Params.DWARF2LineBase = LineTable.Prologue.LineBase; + Params.DWARF2LineRange = LineTable.Prologue.LineRange; + Streamer->emitLineTableForUnit(Params, + LineData.slice(StmtList + 4, PrologueEnd), LineTable.Prologue.MinInstLength, NewRows, Unit.getOrigUnit().getAddressByteSize()); + } } void DwarfLinker::emitAcceleratorEntriesForUnit(CompileUnit &Unit) { @@ -2422,6 +2934,104 @@ void DwarfLinker::emitAcceleratorEntriesForUnit(CompileUnit &Unit) { Streamer->emitPubTypesForUnit(Unit); } +/// \brief Read the frame info stored in the object, and emit the +/// patched frame descriptions for the linked binary. +/// +/// This is actually pretty easy as the data of the CIEs and FDEs can +/// be considered as black boxes and moved as is. The only thing to do +/// is to patch the addresses in the headers. +void DwarfLinker::patchFrameInfoForObject(const DebugMapObject &DMO, + DWARFContext &OrigDwarf, + unsigned AddrSize) { + StringRef FrameData = OrigDwarf.getDebugFrameSection(); + if (FrameData.empty()) + return; + + DataExtractor Data(FrameData, OrigDwarf.isLittleEndian(), 0); + uint32_t InputOffset = 0; + + // Store the data of the CIEs defined in this object, keyed by their + // offsets. + DenseMap LocalCIES; + + while (Data.isValidOffset(InputOffset)) { + uint32_t EntryOffset = InputOffset; + uint32_t InitialLength = Data.getU32(&InputOffset); + if (InitialLength == 0xFFFFFFFF) + return reportWarning("Dwarf64 bits no supported"); + + uint32_t CIEId = Data.getU32(&InputOffset); + if (CIEId == 0xFFFFFFFF) { + // This is a CIE, store it. + StringRef CIEData = FrameData.substr(EntryOffset, InitialLength + 4); + LocalCIES[EntryOffset] = CIEData; + // The -4 is to account for the CIEId we just read. + InputOffset += InitialLength - 4; + continue; + } + + uint32_t Loc = Data.getUnsigned(&InputOffset, AddrSize); + + // Some compilers seem to emit frame info that doesn't start at + // the function entry point, thus we can't just lookup the address + // in the debug map. Use the linker's range map to see if the FDE + // describes something that we can relocate. + auto Range = Ranges.upper_bound(Loc); + if (Range != Ranges.begin()) + --Range; + if (Range == Ranges.end() || Range->first > Loc || + Range->second.first <= Loc) { + // The +4 is to account for the size of the InitialLength field itself. + InputOffset = EntryOffset + InitialLength + 4; + continue; + } + + // This is an FDE, and we have a mapping. + // Have we already emitted a corresponding CIE? + StringRef CIEData = LocalCIES[CIEId]; + if (CIEData.empty()) + return reportWarning("Inconsistent debug_frame content. Dropping."); + + // Look if we already emitted a CIE that corresponds to the + // referenced one (the CIE data is the key of that lookup). + auto IteratorInserted = EmittedCIEs.insert( + std::make_pair(CIEData, Streamer->getFrameSectionSize())); + // If there is no CIE yet for this ID, emit it. + if (IteratorInserted.second || + // FIXME: dsymutil-classic only caches the last used CIE for + // reuse. Mimic that behavior for now. Just removing that + // second half of the condition and the LastCIEOffset variable + // makes the code DTRT. + LastCIEOffset != IteratorInserted.first->getValue()) { + LastCIEOffset = Streamer->getFrameSectionSize(); + IteratorInserted.first->getValue() = LastCIEOffset; + Streamer->emitCIE(CIEData); + } + + // Emit the FDE with updated address and CIE pointer. + // (4 + AddrSize) is the size of the CIEId + initial_location + // fields that will get reconstructed by emitFDE(). + unsigned FDERemainingBytes = InitialLength - (4 + AddrSize); + Streamer->emitFDE(IteratorInserted.first->getValue(), AddrSize, + Loc + Range->second.second, + FrameData.substr(InputOffset, FDERemainingBytes)); + InputOffset += FDERemainingBytes; + } +} + +ErrorOr +DwarfLinker::loadObject(BinaryHolder &BinaryHolder, DebugMapObject &Obj, + const DebugMap &Map) { + auto ErrOrObjs = + BinaryHolder.GetObjectFiles(Obj.getObjectFilename(), Obj.getTimestamp()); + if (std::error_code EC = ErrOrObjs.getError()) + reportWarning(Twine(Obj.getObjectFilename()) + ": " + EC.message()); + auto ErrOrObj = BinaryHolder.Get(Map.getTriple()); + if (std::error_code EC = ErrOrObj.getError()) + reportWarning(Twine(Obj.getObjectFilename()) + ": " + EC.message()); + return ErrOrObj; +} + bool DwarfLinker::link(const DebugMap &Map) { if (Map.begin() == Map.end()) { @@ -2441,11 +3051,9 @@ bool DwarfLinker::link(const DebugMap &Map) { if (Options.Verbose) outs() << "DEBUG MAP OBJECT: " << Obj->getObjectFilename() << "\n"; - auto ErrOrObj = BinHolder.GetObjectFile(Obj->getObjectFilename()); - if (std::error_code EC = ErrOrObj.getError()) { - reportWarning(Twine(Obj->getObjectFilename()) + ": " + EC.message()); + auto ErrOrObj = loadObject(BinHolder, *Obj, Map); + if (!ErrOrObj) continue; - } // Look for relocations that correspond to debug map entries. if (!findValidRelocsInDebugInfo(*ErrOrObj, *Obj)) { @@ -2466,8 +3074,9 @@ bool DwarfLinker::link(const DebugMap &Map) { outs() << "Input compilation unit:"; CUDie->dump(outs(), CU.get(), 0); } - Units.emplace_back(*CU, UnitID++); - gatherDIEParents(CUDie, 0, Units.back()); + Units.emplace_back(*CU, UnitID++, !Options.NoODR); + gatherDIEParents(CUDie, 0, Units.back(), &ODRContexts.getRoot(), + StringPool, ODRContexts); } // Then mark all the DIEs that need to be present in the linked @@ -2519,6 +3128,10 @@ bool DwarfLinker::link(const DebugMap &Map) { Streamer->emitDIE(*CurrentUnit.getOutputUnitDIE()); } + if (!ValidRelocs.empty() && !Options.NoOutput && !Units.empty()) + patchFrameInfoForObject(*Obj, DwarfContext, + Units[0].getOrigUnit().getAddressByteSize()); + // Clean-up before starting working on the next object. endDebugObject(); }