LLVM  9.0.0svn
RuntimeDyldMachO.h
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1 //===-- RuntimeDyldMachO.h - Run-time dynamic linker for MC-JIT ---*- C++ -*-=//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // MachO support for MC-JIT runtime dynamic linker.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_RUNTIMEDYLDMACHO_H
14 #define LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_RUNTIMEDYLDMACHO_H
15 
16 #include "RuntimeDyldImpl.h"
17 #include "llvm/Object/MachO.h"
18 #include "llvm/Support/Format.h"
19 
20 #define DEBUG_TYPE "dyld"
21 
22 using namespace llvm;
23 using namespace llvm::object;
24 
25 namespace llvm {
27 protected:
29  unsigned SectionID;
30  uint64_t Offset;
31  };
32 
35  : EHFrameSID(RTDYLD_INVALID_SECTION_ID),
37  ExceptTabSID(RTDYLD_INVALID_SECTION_ID) {}
38 
40  : EHFrameSID(EH), TextSID(T), ExceptTabSID(Ex) {}
44  };
45 
46  // When a module is loaded we save the SectionID of the EH frame section
47  // in a table until we receive a request to register all unregistered
48  // EH frame sections with the memory manager.
50 
53  : RuntimeDyldImpl(MemMgr, Resolver) {}
54 
55  /// This convenience method uses memcpy to extract a contiguous addend (the
56  /// addend size and offset are taken from the corresponding fields of the RE).
57  int64_t memcpyAddend(const RelocationEntry &RE) const;
58 
59  /// Given a relocation_iterator for a non-scattered relocation, construct a
60  /// RelocationEntry and fill in the common fields. The 'Addend' field is *not*
61  /// filled in, since immediate encodings are highly target/opcode specific.
62  /// For targets/opcodes with simple, contiguous immediates (e.g. X86) the
63  /// memcpyAddend method can be used to read the immediate.
64  RelocationEntry getRelocationEntry(unsigned SectionID,
65  const ObjectFile &BaseTObj,
66  const relocation_iterator &RI) const {
67  const MachOObjectFile &Obj =
68  static_cast<const MachOObjectFile &>(BaseTObj);
70  Obj.getRelocation(RI->getRawDataRefImpl());
71 
72  bool IsPCRel = Obj.getAnyRelocationPCRel(RelInfo);
73  unsigned Size = Obj.getAnyRelocationLength(RelInfo);
74  uint64_t Offset = RI->getOffset();
76  static_cast<MachO::RelocationInfoType>(Obj.getAnyRelocationType(RelInfo));
77 
78  return RelocationEntry(SectionID, Offset, RelType, 0, IsPCRel, Size);
79  }
80 
81  /// Process a scattered vanilla relocation.
83  processScatteredVANILLA(unsigned SectionID, relocation_iterator RelI,
84  const ObjectFile &BaseObjT,
86  bool TargetIsLocalThumbFunc = false);
87 
88  /// Construct a RelocationValueRef representing the relocation target.
89  /// For Symbols in known sections, this will return a RelocationValueRef
90  /// representing a (SectionID, Offset) pair.
91  /// For Symbols whose section is not known, this will return a
92  /// (SymbolName, Offset) pair, where the Offset is taken from the instruction
93  /// immediate (held in RE.Addend).
94  /// In both cases the Addend field is *NOT* fixed up to be PC-relative. That
95  /// should be done by the caller where appropriate by calling makePCRel on
96  /// the RelocationValueRef.
98  getRelocationValueRef(const ObjectFile &BaseTObj,
99  const relocation_iterator &RI,
100  const RelocationEntry &RE,
101  ObjSectionToIDMap &ObjSectionToID);
102 
103  /// Make the RelocationValueRef addend PC-relative.
104  void makeValueAddendPCRel(RelocationValueRef &Value,
105  const relocation_iterator &RI,
106  unsigned OffsetToNextPC);
107 
108  /// Dump information about the relocation entry (RE) and resolved value.
109  void dumpRelocationToResolve(const RelocationEntry &RE, uint64_t Value) const;
110 
111  // Return a section iterator for the section containing the given address.
112  static section_iterator getSectionByAddress(const MachOObjectFile &Obj,
113  uint64_t Addr);
114 
115 
116  // Populate __pointers section.
117  Error populateIndirectSymbolPointersSection(const MachOObjectFile &Obj,
118  const SectionRef &PTSection,
119  unsigned PTSectionID);
120 
121 public:
122 
123  /// Create a RuntimeDyldMachO instance for the given target architecture.
124  static std::unique_ptr<RuntimeDyldMachO>
125  create(Triple::ArchType Arch,
128 
129  std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
130  loadObject(const object::ObjectFile &O) override;
131 
132  SectionEntry &getSection(unsigned SectionID) { return Sections[SectionID]; }
133 
134  bool isCompatibleFile(const object::ObjectFile &Obj) const override;
135 };
136 
137 /// RuntimeDyldMachOTarget - Templated base class for generic MachO linker
138 /// algorithms and data structures.
139 ///
140 /// Concrete, target specific sub-classes can be accessed via the impl()
141 /// methods. (i.e. the RuntimeDyldMachO hierarchy uses the Curiously
142 /// Recurring Template Idiom). Concrete subclasses for each target
143 /// can be found in ./Targets.
144 template <typename Impl>
146 private:
147  Impl &impl() { return static_cast<Impl &>(*this); }
148  const Impl &impl() const { return static_cast<const Impl &>(*this); }
149 
150  unsigned char *processFDE(uint8_t *P, int64_t DeltaForText,
151  int64_t DeltaForEH);
152 
153 public:
156  : RuntimeDyldMachO(MemMgr, Resolver) {}
157 
158  Error finalizeLoad(const ObjectFile &Obj,
159  ObjSectionToIDMap &SectionMap) override;
160  void registerEHFrames() override;
161 };
162 
163 } // end namespace llvm
164 
165 #undef DEBUG_TYPE
166 
167 #endif
RelocationEntry - used to represent relocations internally in the dynamic linker. ...
This class represents lattice values for constants.
Definition: AllocatorList.h:23
unsigned getAnyRelocationPCRel(const MachO::any_relocation_info &RE) const
This class is the base class for all object file types.
Definition: ObjectFile.h:225
Tagged union holding either a T or a Error.
Definition: CachePruning.h:22
place backedge safepoints impl
SectionEntry & getSection(unsigned SectionID)
unsigned getAnyRelocationType(const MachO::any_relocation_info &RE) const
RuntimeDyldMachOTarget - Templated base class for generic MachO linker algorithms and data structures...
#define P(N)
RuntimeDyldMachO(RuntimeDyld::MemoryManager &MemMgr, JITSymbolResolver &Resolver)
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...
MachO::any_relocation_info getRelocation(DataRefImpl Rel) const
Interface for looking up the initializer for a variable name, used by Init::resolveReferences.
Definition: Record.h:1854
Symbol resolution interface.
Definition: JITSymbol.h:343
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:841
#define RTDYLD_INVALID_SECTION_ID
unsigned getAnyRelocationLength(const MachO::any_relocation_info &RE) const
std::map< SectionRef, unsigned > ObjSectionToIDMap
SmallVector< EHFrameRelatedSections, 2 > UnregisteredEHFrameSections
uint32_t Size
Definition: Profile.cpp:46
RuntimeDyldMachOCRTPBase(RuntimeDyld::MemoryManager &MemMgr, JITSymbolResolver &Resolver)
SectionEntry - represents a section emitted into memory by the dynamic linker.
RelocationInfoType
Definition: MachO.h:392
LLVM Value Representation.
Definition: Value.h:72
Lightweight error class with error context and mandatory checking.
Definition: Error.h:157
This is a value type class that represents a single section in the list of sections in the object fil...
Definition: ObjectFile.h:80