src/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.h

   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(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.
  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
 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:
 138   Impl &impl() { return static_cast<Impl &>(*this); }
 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:
 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