294 lines · c
1//===- tools/dsymutil/DwarfLinkerForBinary.h --------------------*- C++ -*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef LLVM_TOOLS_DSYMUTIL_DWARFLINKER_H10#define LLVM_TOOLS_DSYMUTIL_DWARFLINKER_H11 12#include "BinaryHolder.h"13#include "DebugMap.h"14#include "LinkUtils.h"15#include "MachOUtils.h"16#include "RelocationMap.h"17#include "llvm/DebugInfo/DWARF/DWARFContext.h"18#include "llvm/Remarks/RemarkFormat.h"19#include "llvm/Remarks/RemarkLinker.h"20#include <mutex>21#include <optional>22 23namespace llvm {24using namespace dwarf_linker;25 26namespace dsymutil {27 28/// DwarfLinkerForBinaryRelocationMap contains the logic to handle the29/// relocations and to store them inside an associated RelocationMap.30class DwarfLinkerForBinaryRelocationMap {31public:32 void init(DWARFContext &Context);33 34 bool isInitialized() {35 return StoredValidDebugInfoRelocsMap.getMemorySize() != 0;36 }37 38 void addValidRelocs(RelocationMap &RM);39 40 void updateAndSaveValidRelocs(bool IsDWARF5,41 std::vector<ValidReloc> &InRelocs,42 uint64_t UnitOffset, int64_t LinkedOffset);43 44 void updateRelocationsWithUnitOffset(uint64_t OriginalUnitOffset,45 uint64_t OutputUnitOffset);46 47 /// Map compilation unit offset to the valid relocations to store48 /// @{49 DenseMap<uint64_t, std::vector<ValidReloc>> StoredValidDebugInfoRelocsMap;50 DenseMap<uint64_t, std::vector<ValidReloc>> StoredValidDebugAddrRelocsMap;51 /// @}52 53 DwarfLinkerForBinaryRelocationMap() = default;54};55 56struct ObjectWithRelocMap {57 ObjectWithRelocMap(58 std::unique_ptr<DWARFFile> Object,59 std::shared_ptr<DwarfLinkerForBinaryRelocationMap> OutRelocs)60 : Object(std::move(Object)), OutRelocs(OutRelocs) {}61 std::unique_ptr<DWARFFile> Object;62 std::shared_ptr<DwarfLinkerForBinaryRelocationMap> OutRelocs;63};64 65/// The core of the Dsymutil Dwarf linking logic.66///67/// The link of the dwarf information from the object files will be68/// driven by DWARFLinker. DwarfLinkerForBinary reads DebugMap objects69/// and pass information to the DWARFLinker. DWARFLinker70/// optimizes DWARF taking into account valid relocations.71/// Finally, optimized DWARF is passed to DwarfLinkerForBinary through72/// DWARFEmitter interface.73class DwarfLinkerForBinary {74public:75 DwarfLinkerForBinary(raw_fd_ostream &OutFile, BinaryHolder &BinHolder,76 LinkOptions Options, std::mutex &ErrorHandlerMutex)77 : OutFile(OutFile), BinHolder(BinHolder), Options(std::move(Options)),78 ErrorHandlerMutex(ErrorHandlerMutex) {}79 80 /// Link the contents of the DebugMap.81 bool link(const DebugMap &);82 83 void reportWarning(Twine Warning, Twine Context = {},84 const DWARFDie *DIE = nullptr) const;85 void reportError(Twine Error, Twine Context = {},86 const DWARFDie *DIE = nullptr) const;87 88 /// Returns true if input verification is enabled and verification errors were89 /// found.90 bool InputVerificationFailed() const { return HasVerificationErrors; }91 92 /// Flags passed to DwarfLinker::lookForDIEsToKeep93 enum TraversalFlags {94 TF_Keep = 1 << 0, ///< Mark the traversed DIEs as kept.95 TF_InFunctionScope = 1 << 1, ///< Current scope is a function scope.96 TF_DependencyWalk = 1 << 2, ///< Walking the dependencies of a kept DIE.97 TF_ParentWalk = 1 << 3, ///< Walking up the parents of a kept DIE.98 TF_ODR = 1 << 4, ///< Use the ODR while keeping dependents.99 TF_SkipPC = 1 << 5, ///< Skip all location attributes.100 };101 102private:103 104 /// Keeps track of relocations.105 class AddressManager : public dwarf_linker::AddressesMap {106 107 const DwarfLinkerForBinary &Linker;108 109 /// The valid relocations for the current DebugMapObject.110 /// These vectors are sorted by relocation offset.111 /// {112 std::vector<ValidReloc> ValidDebugInfoRelocs;113 std::vector<ValidReloc> ValidDebugAddrRelocs;114 /// }115 116 StringRef SrcFileName;117 118 uint8_t DebugMapObjectType;119 120 std::shared_ptr<DwarfLinkerForBinaryRelocationMap> DwarfLinkerRelocMap;121 122 std::optional<std::string> LibInstallName;123 124 /// Returns list of valid relocations from \p Relocs,125 /// between \p StartOffset and \p NextOffset.126 ///127 /// \returns true if any relocation is found.128 std::vector<ValidReloc>129 getRelocations(const std::vector<ValidReloc> &Relocs, uint64_t StartPos,130 uint64_t EndPos);131 132 /// Resolve specified relocation \p Reloc.133 ///134 /// \returns resolved value.135 uint64_t relocate(const ValidReloc &Reloc) const;136 137 /// \returns value for the specified \p Reloc.138 int64_t getRelocValue(const ValidReloc &Reloc);139 140 /// Print contents of debug map entry for the specified \p Reloc.141 void printReloc(const ValidReloc &Reloc);142 143 public:144 AddressManager(DwarfLinkerForBinary &Linker, const object::ObjectFile &Obj,145 const DebugMapObject &DMO,146 std::shared_ptr<DwarfLinkerForBinaryRelocationMap> DLBRM)147 : Linker(Linker), SrcFileName(DMO.getObjectFilename()),148 DebugMapObjectType(MachO::N_OSO), DwarfLinkerRelocMap(DLBRM) {149 if (DMO.getRelocationMap().has_value()) {150 DebugMapObjectType = MachO::N_LIB;151 LibInstallName.emplace(DMO.getInstallName().value());152 const RelocationMap &RM = DMO.getRelocationMap().value();153 for (const auto &Reloc : RM.relocations()) {154 const auto *DebugMapEntry = DMO.lookupSymbol(Reloc.SymbolName);155 if (!DebugMapEntry)156 continue;157 std::optional<uint64_t> ObjAddress;158 ObjAddress.emplace(DebugMapEntry->getValue().ObjectAddress.value());159 ValidDebugInfoRelocs.emplace_back(160 Reloc.Offset, Reloc.Size, Reloc.Addend, Reloc.SymbolName,161 SymbolMapping(ObjAddress, DebugMapEntry->getValue().BinaryAddress,162 DebugMapEntry->getValue().Size));163 // FIXME: Support relocations debug_addr.164 }165 } else {166 findValidRelocsInDebugSections(Obj, DMO);167 }168 }169 ~AddressManager() override { clear(); }170 171 bool hasValidRelocs() override {172 return !ValidDebugInfoRelocs.empty() || !ValidDebugAddrRelocs.empty();173 }174 175 /// \defgroup FindValidRelocations Translate debug map into a list176 /// of relevant relocations177 ///178 /// @{179 bool findValidRelocsInDebugSections(const object::ObjectFile &Obj,180 const DebugMapObject &DMO);181 182 bool findValidRelocs(const object::SectionRef &Section,183 const object::ObjectFile &Obj,184 const DebugMapObject &DMO,185 std::vector<ValidReloc> &ValidRelocs);186 187 void findValidRelocsMachO(const object::SectionRef &Section,188 const object::MachOObjectFile &Obj,189 const DebugMapObject &DMO,190 std::vector<ValidReloc> &ValidRelocs);191 /// @}192 193 /// Checks that there is a relocation in the \p Relocs array against a194 /// debug map entry between \p StartOffset and \p NextOffset.195 /// Print debug output if \p Verbose is set.196 ///197 /// \returns relocation value if relocation exist, otherwise std::nullopt.198 std::optional<int64_t>199 hasValidRelocationAt(const std::vector<ValidReloc> &Relocs,200 uint64_t StartOffset, uint64_t EndOffset,201 bool Verbose);202 203 std::optional<int64_t> getExprOpAddressRelocAdjustment(204 DWARFUnit &U, const DWARFExpression::Operation &Op,205 uint64_t StartOffset, uint64_t EndOffset, bool Verbose) override;206 207 std::optional<int64_t> getSubprogramRelocAdjustment(const DWARFDie &DIE,208 bool Verbose) override;209 210 std::optional<StringRef> getLibraryInstallName() override;211 212 bool applyValidRelocs(MutableArrayRef<char> Data, uint64_t BaseOffset,213 bool IsLittleEndian) override;214 215 bool needToSaveValidRelocs() override { return true; }216 217 void updateAndSaveValidRelocs(bool IsDWARF5, uint64_t OriginalUnitOffset,218 int64_t LinkedOffset, uint64_t StartOffset,219 uint64_t EndOffset) override;220 221 void updateRelocationsWithUnitOffset(uint64_t OriginalUnitOffset,222 uint64_t OutputUnitOffset) override;223 224 void clear() override {225 ValidDebugInfoRelocs.clear();226 ValidDebugAddrRelocs.clear();227 }228 };229 230private:231 /// \defgroup Helpers Various helper methods.232 ///233 /// @{234 template <typename OutStreamer>235 bool createStreamer(const Triple &TheTriple,236 typename OutStreamer::OutputFileType FileType,237 std::unique_ptr<OutStreamer> &Streamer,238 raw_fd_ostream &OutFile);239 240 /// Attempt to load a debug object from disk.241 ErrorOr<const object::ObjectFile &> loadObject(const DebugMapObject &Obj,242 const Triple &triple);243 ErrorOr<std::unique_ptr<dwarf_linker::DWARFFile>>244 loadObject(const DebugMapObject &Obj, const DebugMap &DebugMap,245 remarks::RemarkLinker &RL,246 std::shared_ptr<DwarfLinkerForBinaryRelocationMap> DLBRM);247 248 void collectRelocationsToApplyToSwiftReflectionSections(249 const object::SectionRef &Section, StringRef &Contents,250 const llvm::object::MachOObjectFile *MO,251 const std::vector<uint64_t> &SectionToOffsetInDwarf,252 const llvm::dsymutil::DebugMapObject *Obj,253 std::vector<MachOUtils::DwarfRelocationApplicationInfo>254 &RelocationsToApply) const;255 256 Error copySwiftInterfaces(StringRef Architecture) const;257 258 void copySwiftReflectionMetadata(259 const llvm::dsymutil::DebugMapObject *Obj,260 classic::DwarfStreamer *Streamer,261 std::vector<uint64_t> &SectionToOffsetInDwarf,262 std::vector<MachOUtils::DwarfRelocationApplicationInfo>263 &RelocationsToApply);264 265 template <typename Linker>266 bool linkImpl(const DebugMap &Map,267 typename Linker::OutputFileType ObjectType);268 269 Error emitRelocations(const DebugMap &DM,270 std::vector<ObjectWithRelocMap> &ObjectsForLinking);271 272 raw_fd_ostream &OutFile;273 BinaryHolder &BinHolder;274 LinkOptions Options;275 std::mutex &ErrorHandlerMutex;276 277 std::vector<std::string> EmptyWarnings;278 279 /// A list of all .swiftinterface files referenced by the debug280 /// info, mapping Module name to path on disk. The entries need to281 /// be uniqued and sorted and there are only few entries expected282 /// per compile unit, which is why this is a std::map.283 std::map<std::string, std::string> ParseableSwiftInterfaces;284 285 bool ModuleCacheHintDisplayed = false;286 bool ArchiveHintDisplayed = false;287 bool HasVerificationErrors = false;288};289 290} // end namespace dsymutil291} // end namespace llvm292 293#endif // LLVM_TOOLS_DSYMUTIL_DWARFLINKER_H294