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 { EHFrameRelatedSectionsEHFrameRelatedSections35 EHFrameRelatedSections() 36 : EHFrameSID(RTDYLD_INVALID_SECTION_ID), 37 TextSID(RTDYLD_INVALID_SECTION_ID), 38 ExceptTabSID(RTDYLD_INVALID_SECTION_ID) {} 39 EHFrameRelatedSectionsEHFrameRelatedSections40 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 RuntimeDyldMachO(RTDyldMemoryManager * mm)52 RuntimeDyldMachO(RTDyldMemoryManager *mm) : RuntimeDyldImpl(mm) {} 53 54 /// This convenience method uses memcpy to extract a contiguous addend (the 55 /// addend size and offset are taken from the corresponding fields of the RE). 56 int64_t memcpyAddend(const RelocationEntry &RE) const; 57 58 /// Given a relocation_iterator for a non-scattered relocation, construct a 59 /// RelocationEntry and fill in the common fields. The 'Addend' field is *not* 60 /// filled in, since immediate encodings are highly target/opcode specific. 61 /// For targets/opcodes with simple, contiguous immediates (e.g. X86) the 62 /// memcpyAddend method can be used to read the immediate. getRelocationEntry(unsigned SectionID,const ObjectFile & BaseTObj,const relocation_iterator & RI)63 RelocationEntry getRelocationEntry(unsigned SectionID, 64 const ObjectFile &BaseTObj, 65 const relocation_iterator &RI) const { 66 const MachOObjectFile &Obj = 67 static_cast<const MachOObjectFile &>(BaseTObj); 68 MachO::any_relocation_info RelInfo = 69 Obj.getRelocation(RI->getRawDataRefImpl()); 70 71 bool IsPCRel = Obj.getAnyRelocationPCRel(RelInfo); 72 unsigned Size = Obj.getAnyRelocationLength(RelInfo); 73 uint64_t Offset; 74 RI->getOffset(Offset); 75 MachO::RelocationInfoType RelType = 76 static_cast<MachO::RelocationInfoType>(Obj.getAnyRelocationType(RelInfo)); 77 78 return RelocationEntry(SectionID, Offset, RelType, 0, IsPCRel, Size); 79 } 80 81 /// Construct a RelocationValueRef representing the relocation target. 82 /// For Symbols in known sections, this will return a RelocationValueRef 83 /// representing a (SectionID, Offset) pair. 84 /// For Symbols whose section is not known, this will return a 85 /// (SymbolName, Offset) pair, where the Offset is taken from the instruction 86 /// immediate (held in RE.Addend). 87 /// In both cases the Addend field is *NOT* fixed up to be PC-relative. That 88 /// should be done by the caller where appropriate by calling makePCRel on 89 /// the RelocationValueRef. 90 RelocationValueRef getRelocationValueRef(const ObjectFile &BaseTObj, 91 const relocation_iterator &RI, 92 const RelocationEntry &RE, 93 ObjSectionToIDMap &ObjSectionToID); 94 95 /// Make the RelocationValueRef addend PC-relative. 96 void makeValueAddendPCRel(RelocationValueRef &Value, 97 const ObjectFile &BaseTObj, 98 const relocation_iterator &RI, 99 unsigned OffsetToNextPC); 100 101 /// Dump information about the relocation entry (RE) and resolved value. 102 void dumpRelocationToResolve(const RelocationEntry &RE, uint64_t Value) const; 103 104 // Return a section iterator for the section containing the given address. 105 static section_iterator getSectionByAddress(const MachOObjectFile &Obj, 106 uint64_t Addr); 107 108 109 // Populate __pointers section. 110 void populateIndirectSymbolPointersSection(const MachOObjectFile &Obj, 111 const SectionRef &PTSection, 112 unsigned PTSectionID); 113 114 public: 115 116 /// Create a RuntimeDyldMachO instance for the given target architecture. 117 static std::unique_ptr<RuntimeDyldMachO> create(Triple::ArchType Arch, 118 RTDyldMemoryManager *mm); 119 120 std::unique_ptr<RuntimeDyld::LoadedObjectInfo> 121 loadObject(const object::ObjectFile &O) override; 122 getSection(unsigned SectionID)123 SectionEntry &getSection(unsigned SectionID) { return Sections[SectionID]; } 124 125 bool isCompatibleFile(const object::ObjectFile &Obj) const override; 126 }; 127 128 /// RuntimeDyldMachOTarget - Templated base class for generic MachO linker 129 /// algorithms and data structures. 130 /// 131 /// Concrete, target specific sub-classes can be accessed via the impl() 132 /// methods. (i.e. the RuntimeDyldMachO hierarchy uses the Curiously 133 /// Recurring Template Idiom). Concrete subclasses for each target 134 /// can be found in ./Targets. 135 template <typename Impl> 136 class RuntimeDyldMachOCRTPBase : public RuntimeDyldMachO { 137 private: impl()138 Impl &impl() { return static_cast<Impl &>(*this); } impl()139 const Impl &impl() const { return static_cast<const Impl &>(*this); } 140 141 unsigned char *processFDE(unsigned char *P, int64_t DeltaForText, 142 int64_t DeltaForEH); 143 144 public: RuntimeDyldMachOCRTPBase(RTDyldMemoryManager * mm)145 RuntimeDyldMachOCRTPBase(RTDyldMemoryManager *mm) : RuntimeDyldMachO(mm) {} 146 147 void finalizeLoad(const ObjectFile &Obj, 148 ObjSectionToIDMap &SectionMap) override; 149 void registerEHFrames() override; 150 }; 151 152 } // end namespace llvm 153 154 #undef DEBUG_TYPE 155 156 #endif 157