RuntimeDyldELF.h revision 276479 
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 {
23namespace {
24// Helper for extensive error checking in debug builds.
25std::error_code Check(std::error_code Err) {
26  if (Err) {
27    report_fatal_error(Err.message());
28  }
29  return Err;
30}
31} // end anonymous namespace
32
33class RuntimeDyldELF : public RuntimeDyldImpl {
34  void resolveRelocation(const SectionEntry &Section, uint64_t Offset,
35                         uint64_t Value, uint32_t Type, int64_t Addend,
36                         uint64_t SymOffset = 0);
37
38  void resolveX86_64Relocation(const SectionEntry &Section, uint64_t Offset,
39                               uint64_t Value, uint32_t Type, int64_t Addend,
40                               uint64_t SymOffset);
41
42  void resolveX86Relocation(const SectionEntry &Section, uint64_t Offset,
43                            uint32_t Value, uint32_t Type, int32_t Addend);
44
45  void resolveAArch64Relocation(const SectionEntry &Section, uint64_t Offset,
46                                uint64_t Value, uint32_t Type, int64_t Addend);
47
48  void resolveARMRelocation(const SectionEntry &Section, uint64_t Offset,
49                            uint32_t Value, uint32_t Type, int32_t Addend);
50
51  void resolveMIPSRelocation(const SectionEntry &Section, uint64_t Offset,
52                             uint32_t Value, uint32_t Type, int32_t Addend);
53
54  void resolvePPC64Relocation(const SectionEntry &Section, uint64_t Offset,
55                              uint64_t Value, uint32_t Type, int64_t Addend);
56
57  void resolveSystemZRelocation(const SectionEntry &Section, uint64_t Offset,
58                                uint64_t Value, uint32_t Type, int64_t Addend);
59
60  unsigned getMaxStubSize() override {
61    if (Arch == Triple::aarch64 || Arch == Triple::arm64 ||
62        Arch == Triple::aarch64_be || Arch == Triple::arm64_be)
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  void findPPC64TOCSection(ObjectImage &Obj, ObjSectionToIDMap &LocalSections,
86                           RelocationValueRef &Rel);
87  void findOPDEntrySection(ObjectImage &Obj, ObjSectionToIDMap &LocalSections,
88                           RelocationValueRef &Rel);
89
90  uint64_t findGOTEntry(uint64_t LoadAddr, uint64_t Offset);
91  size_t getGOTEntrySize();
92
93  void updateGOTEntries(StringRef Name, uint64_t Addr) override;
94
95  // Relocation entries for symbols whose position-independent offset is
96  // updated in a global offset table.
97  typedef SmallVector<RelocationValueRef, 2> GOTRelocations;
98  GOTRelocations GOTEntries; // List of entries requiring finalization.
99  SmallVector<std::pair<SID, GOTRelocations>, 8> GOTs; // Allocated tables.
100
101  // When a module is loaded we save the SectionID of the EH frame section
102  // in a table until we receive a request to register all unregistered
103  // EH frame sections with the memory manager.
104  SmallVector<SID, 2> UnregisteredEHFrameSections;
105  SmallVector<SID, 2> RegisteredEHFrameSections;
106
107public:
108  RuntimeDyldELF(RTDyldMemoryManager *mm) : RuntimeDyldImpl(mm) {}
109
110  void resolveRelocation(const RelocationEntry &RE, uint64_t Value) override;
111  relocation_iterator
112  processRelocationRef(unsigned SectionID, relocation_iterator RelI,
113                       ObjectImage &Obj, ObjSectionToIDMap &ObjSectionToID,
114                       const SymbolTableMap &Symbols, StubMap &Stubs) override;
115  bool isCompatibleFormat(const ObjectBuffer *Buffer) const override;
116  bool isCompatibleFile(const object::ObjectFile *Buffer) const override;
117  void registerEHFrames() override;
118  void deregisterEHFrames() override;
119  void finalizeLoad(ObjectImage &ObjImg,
120                    ObjSectionToIDMap &SectionMap) override;
121  virtual ~RuntimeDyldELF();
122
123  static ObjectImage *createObjectImage(ObjectBuffer *InputBuffer);
124  static ObjectImage *createObjectImageFromFile(std::unique_ptr<object::ObjectFile> Obj);
125};
126
127} // end namespace llvm
128
129#endif
130