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_RUNTIME_DYLD_MACHO_H
  15 #define LLVM_RUNTIME_DYLD_MACHO_H
  16
  17 #include "llvm/ADT/IndexedMap.h"
  18 #include "llvm/Object/MachOObject.h"
  19 #include "llvm/Support/Format.h"
  20 #include "RuntimeDyldImpl.h"
  21
  22 using namespace llvm;
  23 using namespace llvm::object;
  24
  25
  26 namespace llvm {
  27 class RuntimeDyldMachO : public RuntimeDyldImpl {
  28
  29   // For each symbol, keep a list of relocations based on it. Anytime
  30   // its address is reassigned (the JIT re-compiled the function, e.g.),
  31   // the relocations get re-resolved.
  32   // The symbol (or section) the relocation is sourced from is the Key
  33   // in the relocation list where it's stored.
  34   struct RelocationEntry {
  35     unsigned    SectionID;  // Section the relocation is contained in.
  36     uint64_t    Offset;     // Offset into the section for the relocation.
  37     uint32_t    Data;       // Second word of the raw macho relocation entry.
  38     int64_t     Addend;     // Addend encoded in the instruction itself, if any,
  39                             // plus the offset into the source section for
  40                             // the symbol once the relocation is resolvable.
  41
  42     RelocationEntry(unsigned id, uint64_t offset, uint32_t data, int64_t addend)
  43       : SectionID(id), Offset(offset), Data(data), Addend(addend) {}
  44   };
  45   typedef SmallVector<RelocationEntry, 4> RelocationList;
  46   // Relocations to sections already loaded. Indexed by SectionID which is the
  47   // source of the address. The target where the address will be writen is
  48   // SectionID/Offset in the relocation itself.
  49   IndexedMap<RelocationList> Relocations;
  50   // Relocations to symbols that are not yet resolved. Must be external
  51   // relocations by definition. Indexed by symbol name.
  52   StringMap<RelocationList> UnresolvedRelocations;
  53
  54   bool resolveRelocation(uint8_t *LocalAddress,
  55                          uint64_t FinalAddress,
  56                          uint64_t Value,
  57                          bool isPCRel,
  58                          unsigned Type,
  59                          unsigned Size,
  60                          int64_t Addend);
  61   bool resolveX86_64Relocation(uint8_t *LocalAddress,
  62                                uint64_t FinalAddress,
  63                                uint64_t Value,
  64                                bool isPCRel,
  65                                unsigned Type,
  66                                unsigned Size,
  67                                int64_t Addend);
  68   bool resolveARMRelocation(uint8_t *LocalAddress,
  69                             uint64_t FinalAddress,
  70                             uint64_t Value,
  71                             bool isPCRel,
  72                             unsigned Type,
  73                             unsigned Size,
  74                             int64_t Addend);
  75
  76   bool loadSegment32(const MachOObject *Obj,
  77                      const MachOObject::LoadCommandInfo *SegmentLCI,
  78                      const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC);
  79   bool loadSegment64(const MachOObject *Obj,
  80                      const MachOObject::LoadCommandInfo *SegmentLCI,
  81                      const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC);
  82   bool processSymbols32(const MachOObject *Obj,
  83                       SmallVectorImpl<unsigned> &SectionMap,
  84                       SmallVectorImpl<StringRef> &SymbolNames,
  85                       const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC);
  86   bool processSymbols64(const MachOObject *Obj,
  87                       SmallVectorImpl<unsigned> &SectionMap,
  88                       SmallVectorImpl<StringRef> &SymbolNames,
  89                       const InMemoryStruct<macho::SymtabLoadCommand> &SymtabLC);
  90
  91   void resolveSymbol(StringRef Name);
  92
  93 public:
  94   RuntimeDyldMachO(RTDyldMemoryManager *mm) : RuntimeDyldImpl(mm) {}
  95
  96   bool loadObject(MemoryBuffer *InputBuffer);
  97
  98   void reassignSectionAddress(unsigned SectionID, uint64_t Addr);
  99
 100   static bool isKnownFormat(const MemoryBuffer *InputBuffer);
 101
 102   bool isCompatibleFormat(const MemoryBuffer *InputBuffer) const {
 103     return isKnownFormat(InputBuffer);
 104   }
 105 };
 106
 107 } // end namespace llvm
 108
 109 #endif