RuntimeDyldELF.h revision 36b56886974eae4f9c5ebc96befd3e7bfe5de338 
1//===-- RuntimeDyldELF.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// ELF support for MC-JIT runtime dynamic linker.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_RUNTIME_DYLD_ELF_H
15#define LLVM_RUNTIME_DYLD_ELF_H
16
17#include "RuntimeDyldImpl.h"
18#include "llvm/ADT/DenseMap.h"
19
20using namespace llvm;
21
22namespace llvm {
23
24namespace {
25// Helper for extensive error checking in debug builds.
26error_code Check(error_code Err) {
27  if (Err) {
28    report_fatal_error(Err.message());
29  }
30  return Err;
31}
32} // end anonymous namespace
33
34class RuntimeDyldELF : public RuntimeDyldImpl {
35  void resolveRelocation(const SectionEntry &Section, uint64_t Offset,
36                         uint64_t Value, uint32_t Type, int64_t Addend,
37                         uint64_t SymOffset = 0);
38
39  void resolveX86_64Relocation(const SectionEntry &Section, uint64_t Offset,
40                               uint64_t Value, uint32_t Type, int64_t Addend,
41                               uint64_t SymOffset);
42
43  void resolveX86Relocation(const SectionEntry &Section, uint64_t Offset,
44                            uint32_t Value, uint32_t Type, int32_t Addend);
45
46  void resolveAArch64Relocation(const SectionEntry &Section, uint64_t Offset,
47                                uint64_t Value, uint32_t Type, int64_t Addend);
48
49  void resolveARMRelocation(const SectionEntry &Section, uint64_t Offset,
50                            uint32_t Value, uint32_t Type, int32_t Addend);
51
52  void resolveMIPSRelocation(const SectionEntry &Section, uint64_t Offset,
53                             uint32_t Value, uint32_t Type, int32_t Addend);
54
55  void resolvePPC64Relocation(const SectionEntry &Section, uint64_t Offset,
56                              uint64_t Value, uint32_t Type, int64_t Addend);
57
58  void resolveSystemZRelocation(const SectionEntry &Section, uint64_t Offset,
59                                uint64_t Value, uint32_t Type, int64_t Addend);
60
61  unsigned getMaxStubSize() override {
62    if (Arch == Triple::aarch64)
63      return 20; // movz; movk; movk; movk; br
64    if (Arch == Triple::arm || Arch == Triple::thumb)
65      return 8; // 32-bit instruction and 32-bit address
66    else if (Arch == Triple::mipsel || Arch == Triple::mips)
67      return 16;
68    else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le)
69      return 44;
70    else if (Arch == Triple::x86_64)
71      return 6; // 2-byte jmp instruction + 32-bit relative address
72    else if (Arch == Triple::systemz)
73      return 16;
74    else
75      return 0;
76  }
77
78  unsigned getStubAlignment() override {
79    if (Arch == Triple::systemz)
80      return 8;
81    else
82      return 1;
83  }
84
85  uint64_t findPPC64TOC() const;
86  void findOPDEntrySection(ObjectImage &Obj, ObjSectionToIDMap &LocalSections,
87                           RelocationValueRef &Rel);
88
89  uint64_t findGOTEntry(uint64_t LoadAddr, uint64_t Offset);
90  size_t getGOTEntrySize();
91
92  void updateGOTEntries(StringRef Name, uint64_t Addr) override;
93
94  // Relocation entries for symbols whose position-independent offset is
95  // updated in a global offset table.
96  typedef SmallVector<RelocationValueRef, 2> GOTRelocations;
97  GOTRelocations GOTEntries; // List of entries requiring finalization.
98  SmallVector<std::pair<SID, GOTRelocations>, 8> GOTs; // Allocated tables.
99
100  // When a module is loaded we save the SectionID of the EH frame section
101  // in a table until we receive a request to register all unregistered
102  // EH frame sections with the memory manager.
103  SmallVector<SID, 2> UnregisteredEHFrameSections;
104  SmallVector<SID, 2> RegisteredEHFrameSections;
105
106public:
107  RuntimeDyldELF(RTDyldMemoryManager *mm) : RuntimeDyldImpl(mm) {}
108
109  void resolveRelocation(const RelocationEntry &RE, uint64_t Value) override;
110  relocation_iterator
111  processRelocationRef(unsigned SectionID, relocation_iterator RelI,
112                       ObjectImage &Obj, ObjSectionToIDMap &ObjSectionToID,
113                       const SymbolTableMap &Symbols, StubMap &Stubs) override;
114  bool isCompatibleFormat(const ObjectBuffer *Buffer) const override;
115  bool isCompatibleFile(const object::ObjectFile *Buffer) const override;
116  void registerEHFrames() override;
117  void deregisterEHFrames() override;
118  void finalizeLoad(ObjSectionToIDMap &SectionMap) override;
119  virtual ~RuntimeDyldELF();
120
121  static ObjectImage *createObjectImage(ObjectBuffer *InputBuffer);
122  static ObjectImage *createObjectImageFromFile(object::ObjectFile *Obj);
123};
124
125} // end namespace llvm
126
127#endif
128