LLVM  3.7.0
RuntimeDyldMachO.h
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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 {
28 protected:
30  unsigned SectionID;
31  uint64_t Offset;
32  };
33 
36  : EHFrameSID(RTDYLD_INVALID_SECTION_ID),
38  ExceptTabSID(RTDYLD_INVALID_SECTION_ID) {}
39 
41  : EHFrameSID(EH), TextSID(T), ExceptTabSID(Ex) {}
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.
51 
54  : RuntimeDyldImpl(MemMgr, Resolver) {}
55 
56  /// This convenience method uses memcpy to extract a contiguous addend (the
57  /// addend size and offset are taken from the corresponding fields of the RE).
58  int64_t memcpyAddend(const RelocationEntry &RE) const;
59 
60  /// Given a relocation_iterator for a non-scattered relocation, construct a
61  /// RelocationEntry and fill in the common fields. The 'Addend' field is *not*
62  /// filled in, since immediate encodings are highly target/opcode specific.
63  /// For targets/opcodes with simple, contiguous immediates (e.g. X86) the
64  /// memcpyAddend method can be used to read the immediate.
65  RelocationEntry getRelocationEntry(unsigned SectionID,
66  const ObjectFile &BaseTObj,
67  const relocation_iterator &RI) const {
68  const MachOObjectFile &Obj =
69  static_cast<const MachOObjectFile &>(BaseTObj);
71  Obj.getRelocation(RI->getRawDataRefImpl());
72 
73  bool IsPCRel = Obj.getAnyRelocationPCRel(RelInfo);
74  unsigned Size = Obj.getAnyRelocationLength(RelInfo);
75  uint64_t Offset = RI->getOffset();
77  static_cast<MachO::RelocationInfoType>(Obj.getAnyRelocationType(RelInfo));
78 
79  return RelocationEntry(SectionID, Offset, RelType, 0, IsPCRel, Size);
80  }
81 
82  /// Construct a RelocationValueRef representing the relocation target.
83  /// For Symbols in known sections, this will return a RelocationValueRef
84  /// representing a (SectionID, Offset) pair.
85  /// For Symbols whose section is not known, this will return a
86  /// (SymbolName, Offset) pair, where the Offset is taken from the instruction
87  /// immediate (held in RE.Addend).
88  /// In both cases the Addend field is *NOT* fixed up to be PC-relative. That
89  /// should be done by the caller where appropriate by calling makePCRel on
90  /// the RelocationValueRef.
91  RelocationValueRef getRelocationValueRef(const ObjectFile &BaseTObj,
92  const relocation_iterator &RI,
93  const RelocationEntry &RE,
94  ObjSectionToIDMap &ObjSectionToID);
95 
96  /// Make the RelocationValueRef addend PC-relative.
97  void makeValueAddendPCRel(RelocationValueRef &Value,
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>
118  create(Triple::ArchType Arch,
120  RuntimeDyld::SymbolResolver &Resolver);
121 
122  std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
123  loadObject(const object::ObjectFile &O) override;
124 
125  SectionEntry &getSection(unsigned SectionID) { return Sections[SectionID]; }
126 
127  bool isCompatibleFile(const object::ObjectFile &Obj) const override;
128 };
129 
130 /// RuntimeDyldMachOTarget - Templated base class for generic MachO linker
131 /// algorithms and data structures.
132 ///
133 /// Concrete, target specific sub-classes can be accessed via the impl()
134 /// methods. (i.e. the RuntimeDyldMachO hierarchy uses the Curiously
135 /// Recurring Template Idiom). Concrete subclasses for each target
136 /// can be found in ./Targets.
137 template <typename Impl>
139 private:
140  Impl &impl() { return static_cast<Impl &>(*this); }
141  const Impl &impl() const { return static_cast<const Impl &>(*this); }
142 
143  unsigned char *processFDE(unsigned char *P, int64_t DeltaForText,
144  int64_t DeltaForEH);
145 
146 public:
148  RuntimeDyld::SymbolResolver &Resolver)
149  : RuntimeDyldMachO(MemMgr, Resolver) {}
150 
151  void finalizeLoad(const ObjectFile &Obj,
152  ObjSectionToIDMap &SectionMap) override;
153  void registerEHFrames() override;
154 };
155 
156 } // end namespace llvm
157 
158 #undef DEBUG_TYPE
159 
160 #endif
RelocationEntry - used to represent relocations internally in the dynamic linker. ...
unsigned getAnyRelocationType(const MachO::any_relocation_info &RE) const
RuntimeDyldMachO(RuntimeDyld::MemoryManager &MemMgr, RuntimeDyld::SymbolResolver &Resolver)
This class is the base class for all object file types.
Definition: ObjectFile.h:176
RelocationEntry getRelocationEntry(unsigned SectionID, const ObjectFile &BaseTObj, const relocation_iterator &RI) const
Given a relocation_iterator for a non-scattered relocation, construct a RelocationEntry and fill in t...
place backedge safepoints impl
SectionEntry & getSection(unsigned SectionID)
RuntimeDyldMachOTarget - Templated base class for generic MachO linker algorithms and data structures...
#define P(N)
MachO::any_relocation_info getRelocation(DataRefImpl Rel) const
unsigned getAnyRelocationPCRel(const MachO::any_relocation_info &RE) const
unsigned getAnyRelocationLength(const MachO::any_relocation_info &RE) const
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:861
#define RTDYLD_INVALID_SECTION_ID
SmallVector< EHFrameRelatedSections, 2 > UnregisteredEHFrameSections
SectionEntry - represents a section emitted into memory by the dynamic linker.
LLVM Value Representation.
Definition: Value.h:69
This is a value type class that represents a single section in the list of sections in the object fil...
Definition: ObjectFile.h:69
RuntimeDyldMachOCRTPBase(RuntimeDyld::MemoryManager &MemMgr, RuntimeDyld::SymbolResolver &Resolver)