1 //===-- RuntimeDyldMachO.h - Run-time dynamic linker for MC-JIT ---*- C++ -*-=// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // MachO support for MC-JIT runtime dynamic linker. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_RUNTIMEDYLDMACHO_H 15 #define LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_RUNTIMEDYLDMACHO_H 16 17 #include "RuntimeDyldImpl.h" 18 #include "llvm/Object/MachO.h" 19 #include "llvm/Support/Format.h" 20 21 #define DEBUG_TYPE "dyld" 22 23 using namespace llvm; 24 using namespace llvm::object; 25 26 namespace llvm { 27 class RuntimeDyldMachO : public RuntimeDyldImpl { 28 protected: 29 struct SectionOffsetPair { 30 unsigned SectionID; 31 uint64_t Offset; 32 }; 33 34 struct EHFrameRelatedSections { 35 EHFrameRelatedSections() 36 : EHFrameSID(RTDYLD_INVALID_SECTION_ID), 37 TextSID(RTDYLD_INVALID_SECTION_ID), 38 ExceptTabSID(RTDYLD_INVALID_SECTION_ID) {} 39 40 EHFrameRelatedSections(SID EH, SID T, SID Ex) 41 : EHFrameSID(EH), TextSID(T), ExceptTabSID(Ex) {} 42 SID EHFrameSID; 43 SID TextSID; 44 SID ExceptTabSID; 45 }; 46 47 // When a module is loaded we save the SectionID of the EH frame section 48 // in a table until we receive a request to register all unregistered 49 // EH frame sections with the memory manager. 50 SmallVector<EHFrameRelatedSections, 2> UnregisteredEHFrameSections; 51 52 RuntimeDyldMachO(RuntimeDyld::MemoryManager &MemMgr, 53 RuntimeDyld::SymbolResolver &Resolver) 54 : RuntimeDyldImpl(MemMgr, Resolver) {} 55 56 /// This convenience method uses memcpy to extract a contiguous addend (the 57 /// addend size and offset are taken from the corresponding fields of the RE). 58 int64_t memcpyAddend(const RelocationEntry &RE) const; 59 60 /// Given a relocation_iterator for a non-scattered relocation, construct a 61 /// RelocationEntry and fill in the common fields. The 'Addend' field is *not* 62 /// filled in, since immediate encodings are highly target/opcode specific. 63 /// For targets/opcodes with simple, contiguous immediates (e.g. X86) the 64 /// memcpyAddend method can be used to read the immediate. 65 RelocationEntry getRelocationEntry(unsigned SectionID, 66 const ObjectFile &BaseTObj, 67 const relocation_iterator &RI) const { 68 const MachOObjectFile &Obj = 69 static_cast<const MachOObjectFile &>(BaseTObj); 70 MachO::any_relocation_info RelInfo = 71 Obj.getRelocation(RI->getRawDataRefImpl()); 72 73 bool IsPCRel = Obj.getAnyRelocationPCRel(RelInfo); 74 unsigned Size = Obj.getAnyRelocationLength(RelInfo); 75 uint64_t Offset = RI->getOffset(); 76 MachO::RelocationInfoType RelType = 77 static_cast<MachO::RelocationInfoType>(Obj.getAnyRelocationType(RelInfo)); 78 79 return RelocationEntry(SectionID, Offset, RelType, 0, IsPCRel, Size); 80 } 81 82 /// Process a scattered vanilla relocation. 83 Expected<relocation_iterator> 84 processScatteredVANILLA(unsigned SectionID, relocation_iterator RelI, 85 const ObjectFile &BaseObjT, 86 RuntimeDyldMachO::ObjSectionToIDMap &ObjSectionToID); 87 88 /// Construct a RelocationValueRef representing the relocation target. 89 /// For Symbols in known sections, this will return a RelocationValueRef 90 /// representing a (SectionID, Offset) pair. 91 /// For Symbols whose section is not known, this will return a 92 /// (SymbolName, Offset) pair, where the Offset is taken from the instruction 93 /// immediate (held in RE.Addend). 94 /// In both cases the Addend field is *NOT* fixed up to be PC-relative. That 95 /// should be done by the caller where appropriate by calling makePCRel on 96 /// the RelocationValueRef. 97 Expected<RelocationValueRef> 98 getRelocationValueRef(const ObjectFile &BaseTObj, 99 const relocation_iterator &RI, 100 const RelocationEntry &RE, 101 ObjSectionToIDMap &ObjSectionToID); 102 103 /// Make the RelocationValueRef addend PC-relative. 104 void makeValueAddendPCRel(RelocationValueRef &Value, 105 const relocation_iterator &RI, 106 unsigned OffsetToNextPC); 107 108 /// Dump information about the relocation entry (RE) and resolved value. 109 void dumpRelocationToResolve(const RelocationEntry &RE, uint64_t Value) const; 110 111 // Return a section iterator for the section containing the given address. 112 static section_iterator getSectionByAddress(const MachOObjectFile &Obj, 113 uint64_t Addr); 114 115 116 // Populate __pointers section. 117 Error populateIndirectSymbolPointersSection(const MachOObjectFile &Obj, 118 const SectionRef &PTSection, 119 unsigned PTSectionID); 120 121 public: 122 123 /// Create a RuntimeDyldMachO instance for the given target architecture. 124 static std::unique_ptr<RuntimeDyldMachO> 125 create(Triple::ArchType Arch, 126 RuntimeDyld::MemoryManager &MemMgr, 127 RuntimeDyld::SymbolResolver &Resolver); 128 129 std::unique_ptr<RuntimeDyld::LoadedObjectInfo> 130 loadObject(const object::ObjectFile &O) override; 131 132 SectionEntry &getSection(unsigned SectionID) { return Sections[SectionID]; } 133 134 bool isCompatibleFile(const object::ObjectFile &Obj) const override; 135 }; 136 137 /// RuntimeDyldMachOTarget - Templated base class for generic MachO linker 138 /// algorithms and data structures. 139 /// 140 /// Concrete, target specific sub-classes can be accessed via the impl() 141 /// methods. (i.e. the RuntimeDyldMachO hierarchy uses the Curiously 142 /// Recurring Template Idiom). Concrete subclasses for each target 143 /// can be found in ./Targets. 144 template <typename Impl> 145 class RuntimeDyldMachOCRTPBase : public RuntimeDyldMachO { 146 private: 147 Impl &impl() { return static_cast<Impl &>(*this); } 148 const Impl &impl() const { return static_cast<const Impl &>(*this); } 149 150 unsigned char *processFDE(uint8_t *P, int64_t DeltaForText, 151 int64_t DeltaForEH); 152 153 public: 154 RuntimeDyldMachOCRTPBase(RuntimeDyld::MemoryManager &MemMgr, 155 RuntimeDyld::SymbolResolver &Resolver) 156 : RuntimeDyldMachO(MemMgr, Resolver) {} 157 158 Error finalizeLoad(const ObjectFile &Obj, 159 ObjSectionToIDMap &SectionMap) override; 160 void registerEHFrames() override; 161 }; 162 163 } // end namespace llvm 164 165 #undef DEBUG_TYPE 166 167 #endif 168
