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1//===-- RuntimeDyldMachO.h - Run-time dynamic linker for MC-JIT ---*- 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// MachO support for MC-JIT runtime dynamic linker.10//11//===----------------------------------------------------------------------===//12 13#ifndef LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_RUNTIMEDYLDMACHO_H14#define LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_RUNTIMEDYLDMACHO_H15 16#include "RuntimeDyldImpl.h"17#include "llvm/Object/MachO.h"18#include "llvm/Support/Format.h"19 20namespace llvm {21class RuntimeDyldMachO : public RuntimeDyldImpl {22protected:23 struct SectionOffsetPair {24 unsigned SectionID;25 uint64_t Offset;26 };27 28 struct EHFrameRelatedSections {29 EHFrameRelatedSections()30 : EHFrameSID(RTDYLD_INVALID_SECTION_ID),31 TextSID(RTDYLD_INVALID_SECTION_ID),32 ExceptTabSID(RTDYLD_INVALID_SECTION_ID) {}33 34 EHFrameRelatedSections(SID EH, SID T, SID Ex)35 : EHFrameSID(EH), TextSID(T), ExceptTabSID(Ex) {}36 SID EHFrameSID;37 SID TextSID;38 SID ExceptTabSID;39 };40 41 // When a module is loaded we save the SectionID of the EH frame section42 // in a table until we receive a request to register all unregistered43 // EH frame sections with the memory manager.44 SmallVector<EHFrameRelatedSections, 2> UnregisteredEHFrameSections;45 46 RuntimeDyldMachO(RuntimeDyld::MemoryManager &MemMgr,47 JITSymbolResolver &Resolver)48 : RuntimeDyldImpl(MemMgr, Resolver) {}49 50 /// This convenience method uses memcpy to extract a contiguous addend (the51 /// addend size and offset are taken from the corresponding fields of the RE).52 int64_t memcpyAddend(const RelocationEntry &RE) const;53 54 /// Given a relocation_iterator for a non-scattered relocation, construct a55 /// RelocationEntry and fill in the common fields. The 'Addend' field is *not*56 /// filled in, since immediate encodings are highly target/opcode specific.57 /// For targets/opcodes with simple, contiguous immediates (e.g. X86) the58 /// memcpyAddend method can be used to read the immediate.59 RelocationEntry getRelocationEntry(unsigned SectionID,60 const ObjectFile &BaseTObj,61 const relocation_iterator &RI) const {62 const MachOObjectFile &Obj =63 static_cast<const MachOObjectFile &>(BaseTObj);64 MachO::any_relocation_info RelInfo =65 Obj.getRelocation(RI->getRawDataRefImpl());66 67 bool IsPCRel = Obj.getAnyRelocationPCRel(RelInfo);68 unsigned Size = Obj.getAnyRelocationLength(RelInfo);69 uint64_t Offset = RI->getOffset();70 MachO::RelocationInfoType RelType =71 static_cast<MachO::RelocationInfoType>(Obj.getAnyRelocationType(RelInfo));72 73 return RelocationEntry(SectionID, Offset, RelType, 0, IsPCRel, Size);74 }75 76 /// Process a scattered vanilla relocation.77 Expected<relocation_iterator>78 processScatteredVANILLA(unsigned SectionID, relocation_iterator RelI,79 const ObjectFile &BaseObjT,80 RuntimeDyldMachO::ObjSectionToIDMap &ObjSectionToID,81 bool TargetIsLocalThumbFunc = false);82 83 /// Construct a RelocationValueRef representing the relocation target.84 /// For Symbols in known sections, this will return a RelocationValueRef85 /// representing a (SectionID, Offset) pair.86 /// For Symbols whose section is not known, this will return a87 /// (SymbolName, Offset) pair, where the Offset is taken from the instruction88 /// immediate (held in RE.Addend).89 /// In both cases the Addend field is *NOT* fixed up to be PC-relative. That90 /// should be done by the caller where appropriate by calling makePCRel on91 /// the RelocationValueRef.92 Expected<RelocationValueRef>93 getRelocationValueRef(const ObjectFile &BaseTObj,94 const relocation_iterator &RI,95 const RelocationEntry &RE,96 ObjSectionToIDMap &ObjSectionToID);97 98 /// Make the RelocationValueRef addend PC-relative.99 void makeValueAddendPCRel(RelocationValueRef &Value,100 const relocation_iterator &RI,101 unsigned OffsetToNextPC);102 103 /// Dump information about the relocation entry (RE) and resolved value.104 void dumpRelocationToResolve(const RelocationEntry &RE, uint64_t Value) const;105 106 // Return a section iterator for the section containing the given address.107 static section_iterator getSectionByAddress(const MachOObjectFile &Obj,108 uint64_t Addr);109 110 111 // Populate __pointers section.112 Error populateIndirectSymbolPointersSection(const MachOObjectFile &Obj,113 const SectionRef &PTSection,114 unsigned PTSectionID);115 116public:117 118 /// Create a RuntimeDyldMachO instance for the given target architecture.119 static std::unique_ptr<RuntimeDyldMachO>120 create(Triple::ArchType Arch,121 RuntimeDyld::MemoryManager &MemMgr,122 JITSymbolResolver &Resolver);123 124 std::unique_ptr<RuntimeDyld::LoadedObjectInfo>125 loadObject(const object::ObjectFile &O) override;126 127 SectionEntry &getSection(unsigned SectionID) { return Sections[SectionID]; }128 129 bool isCompatibleFile(const object::ObjectFile &Obj) const override;130};131 132/// RuntimeDyldMachOTarget - Templated base class for generic MachO linker133/// algorithms and data structures.134///135/// Concrete, target specific sub-classes can be accessed via the impl()136/// methods. (i.e. the RuntimeDyldMachO hierarchy uses the Curiously137/// Recurring Template Idiom). Concrete subclasses for each target138/// can be found in ./Targets.139template <typename Impl>140class RuntimeDyldMachOCRTPBase : public RuntimeDyldMachO {141private:142 Impl &impl() { return static_cast<Impl &>(*this); }143 const Impl &impl() const { return static_cast<const Impl &>(*this); }144 145 unsigned char *processFDE(uint8_t *P, int64_t DeltaForText,146 int64_t DeltaForEH);147 148public:149 RuntimeDyldMachOCRTPBase(RuntimeDyld::MemoryManager &MemMgr,150 JITSymbolResolver &Resolver)151 : RuntimeDyldMachO(MemMgr, Resolver) {}152 153 Error finalizeLoad(const ObjectFile &Obj,154 ObjSectionToIDMap &SectionMap) override;155 void registerEHFrames() override;156};157 158} // end namespace llvm159 160#endif // LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_RUNTIMEDYLDMACHO_H161