LLVM  3.7.0
RuntimeDyldELF.h
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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_LIB_EXECUTIONENGINE_RUNTIMEDYLD_RUNTIMEDYLDELF_H
15 #define LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_RUNTIMEDYLDELF_H
16 
17 #include "RuntimeDyldImpl.h"
18 #include "llvm/ADT/DenseMap.h"
19 
20 using namespace llvm;
21 
22 namespace llvm {
23 
25 
26  void resolveRelocation(const SectionEntry &Section, uint64_t Offset,
27  uint64_t Value, uint32_t Type, int64_t Addend,
28  uint64_t SymOffset = 0, SID SectionID = 0);
29 
30  void resolveX86_64Relocation(const SectionEntry &Section, uint64_t Offset,
31  uint64_t Value, uint32_t Type, int64_t Addend,
32  uint64_t SymOffset);
33 
34  void resolveX86Relocation(const SectionEntry &Section, uint64_t Offset,
35  uint32_t Value, uint32_t Type, int32_t Addend);
36 
37  void resolveAArch64Relocation(const SectionEntry &Section, uint64_t Offset,
38  uint64_t Value, uint32_t Type, int64_t Addend);
39 
40  void resolveARMRelocation(const SectionEntry &Section, uint64_t Offset,
41  uint32_t Value, uint32_t Type, int32_t Addend);
42 
43  void resolveMIPSRelocation(const SectionEntry &Section, uint64_t Offset,
44  uint32_t Value, uint32_t Type, int32_t Addend);
45 
46  void resolvePPC64Relocation(const SectionEntry &Section, uint64_t Offset,
47  uint64_t Value, uint32_t Type, int64_t Addend);
48 
49  void resolveSystemZRelocation(const SectionEntry &Section, uint64_t Offset,
50  uint64_t Value, uint32_t Type, int64_t Addend);
51 
52  void resolveMIPS64Relocation(const SectionEntry &Section, uint64_t Offset,
53  uint64_t Value, uint32_t Type, int64_t Addend,
54  uint64_t SymOffset, SID SectionID);
55 
56  int64_t evaluateMIPS64Relocation(const SectionEntry &Section,
57  uint64_t Offset, uint64_t Value,
58  uint32_t Type, int64_t Addend,
59  uint64_t SymOffset, SID SectionID);
60 
61  void applyMIPS64Relocation(uint8_t *TargetPtr, int64_t CalculatedValue,
62  uint32_t Type);
63 
64  unsigned getMaxStubSize() override {
66  return 20; // movz; movk; movk; movk; br
67  if (Arch == Triple::arm || Arch == Triple::thumb)
68  return 8; // 32-bit instruction and 32-bit address
69  else if (IsMipsO32ABI)
70  return 16;
71  else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le)
72  return 44;
73  else if (Arch == Triple::x86_64)
74  return 6; // 2-byte jmp instruction + 32-bit relative address
75  else if (Arch == Triple::systemz)
76  return 16;
77  else
78  return 0;
79  }
80 
81  unsigned getStubAlignment() override {
82  if (Arch == Triple::systemz)
83  return 8;
84  else
85  return 1;
86  }
87 
88  void setMipsABI(const ObjectFile &Obj) override;
89 
90  void findPPC64TOCSection(const ELFObjectFileBase &Obj,
91  ObjSectionToIDMap &LocalSections,
92  RelocationValueRef &Rel);
93  void findOPDEntrySection(const ELFObjectFileBase &Obj,
94  ObjSectionToIDMap &LocalSections,
95  RelocationValueRef &Rel);
96 
97  size_t getGOTEntrySize();
98 
99  SectionEntry &getSection(unsigned SectionID) { return Sections[SectionID]; }
100 
101  // Allocate no GOT entries for use in the given section.
102  uint64_t allocateGOTEntries(unsigned SectionID, unsigned no);
103 
104  // Resolve the relvative address of GOTOffset in Section ID and place
105  // it at the given Offset
106  void resolveGOTOffsetRelocation(unsigned SectionID, uint64_t Offset,
107  uint64_t GOTOffset);
108 
109  // For a GOT entry referenced from SectionID, compute a relocation entry
110  // that will place the final resolved value in the GOT slot
111  RelocationEntry computeGOTOffsetRE(unsigned SectionID,
112  uint64_t GOTOffset,
113  uint64_t SymbolOffset,
114  unsigned Type);
115 
116  // Compute the address in memory where we can find the placeholder
117  void *computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const;
118 
119  // Split out common case for createing the RelocationEntry for when the relocation requires
120  // no particular advanced processing.
121  void processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value);
122 
123  // The tentative ID for the GOT section
124  unsigned GOTSectionID;
125 
126  // Records the current number of allocated slots in the GOT
127  // (This would be equivalent to GOTEntries.size() were it not for relocations
128  // that consume more than one slot)
129  unsigned CurrentGOTIndex;
130 
131  // A map from section to a GOT section that has entries for section's GOT
132  // relocations. (Mips64 specific)
133  DenseMap<SID, SID> SectionToGOTMap;
134 
135  // A map to avoid duplicate got entries (Mips64 specific)
136  StringMap<uint64_t> GOTSymbolOffsets;
137 
138  // When a module is loaded we save the SectionID of the EH frame section
139  // in a table until we receive a request to register all unregistered
140  // EH frame sections with the memory manager.
141  SmallVector<SID, 2> UnregisteredEHFrameSections;
142  SmallVector<SID, 2> RegisteredEHFrameSections;
143 
144 public:
147  ~RuntimeDyldELF() override;
148 
149  std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
150  loadObject(const object::ObjectFile &O) override;
151 
152  void resolveRelocation(const RelocationEntry &RE, uint64_t Value) override;
154  processRelocationRef(unsigned SectionID, relocation_iterator RelI,
155  const ObjectFile &Obj,
156  ObjSectionToIDMap &ObjSectionToID,
157  StubMap &Stubs) override;
158  bool isCompatibleFile(const object::ObjectFile &Obj) const override;
159  void registerEHFrames() override;
160  void deregisterEHFrames() override;
161  void finalizeLoad(const ObjectFile &Obj,
162  ObjSectionToIDMap &SectionMap) override;
163 };
164 
165 } // end namespace llvm
166 
167 #endif
RelocationEntry - used to represent relocations internally in the dynamic linker. ...
RuntimeDyld::MemoryManager & MemMgr
RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr, RuntimeDyld::SymbolResolver &Resolver)
This class is the base class for all object file types.
Definition: ObjectFile.h:176
std::unique_ptr< RuntimeDyld::LoadedObjectInfo > loadObject(const object::ObjectFile &O) override
std::map< RelocationValueRef, uintptr_t > StubMap
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:45
RuntimeDyld::SymbolResolver & Resolver
void registerEHFrames() override
bool isCompatibleFile(const object::ObjectFile &Obj) const override
void finalizeLoad(const ObjectFile &Obj, ObjSectionToIDMap &SectionMap) override
void deregisterEHFrames() override
Triple::ArchType Arch
relocation_iterator processRelocationRef(unsigned SectionID, relocation_iterator RelI, const ObjectFile &Obj, ObjSectionToIDMap &ObjSectionToID, StubMap &Stubs) override
Parses one or more object file relocations (some object files use relocation pairs) and stores it to ...
std::map< SectionRef, unsigned > ObjSectionToIDMap
SectionEntry - represents a section emitted into memory by the dynamic linker.
LLVM Value Representation.
Definition: Value.h:69