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
22using namespace llvm;
23using namespace llvm::object;
24
25namespace llvm {
26class RuntimeDyldMachO : public RuntimeDyldImpl {
27protected:
28 struct SectionOffsetPair {
29 unsigned SectionID;
30 uint64_t Offset;
31 };
32
33 struct EHFrameRelatedSections {
34 EHFrameRelatedSections()
35 : EHFrameSID(RTDYLD_INVALID_SECTION_ID),
36 TextSID(RTDYLD_INVALID_SECTION_ID),
37 ExceptTabSID(RTDYLD_INVALID_SECTION_ID) {}
38
39 EHFrameRelatedSections(SID EH, SID T, SID Ex)
40 : EHFrameSID(EH), TextSID(T), ExceptTabSID(Ex) {}
41 SID EHFrameSID;
42 SID TextSID;
43 SID ExceptTabSID;
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.
49 SmallVector<EHFrameRelatedSections, 2> UnregisteredEHFrameSections;
50
51 RuntimeDyldMachO(RuntimeDyld::MemoryManager &MemMgr,
52 JITSymbolResolver &Resolver)
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);
69 MachO::any_relocation_info RelInfo =
70 Obj.getRelocation(RI->getRawDataRefImpl());
71
72 bool IsPCRel = Obj.getAnyRelocationPCRel(RelInfo);
73 unsigned Size = Obj.getAnyRelocationLength(RelInfo);
74 uint64_t Offset = RI->getOffset();
75 MachO::RelocationInfoType RelType =
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.
82 Expected<relocation_iterator>
83 processScatteredVANILLA(unsigned SectionID, relocation_iterator RelI,
84 const ObjectFile &BaseObjT,
85 RuntimeDyldMachO::ObjSectionToIDMap &ObjSectionToID,
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.
97 Expected<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
121public:
122
123 /// Create a RuntimeDyldMachO instance for the given target architecture.
124 static std::unique_ptr<RuntimeDyldMachO>
125 create(Triple::ArchType Arch,
126 RuntimeDyld::MemoryManager &MemMgr,
127 JITSymbolResolver &Resolver);
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.
144template <typename Impl>
145class RuntimeDyldMachOCRTPBase : public RuntimeDyldMachO {
146private:
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
153public:
154 RuntimeDyldMachOCRTPBase(RuntimeDyld::MemoryManager &MemMgr,
155 JITSymbolResolver &Resolver)
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
168