1//===-- RuntimeDyldCOFF.cpp - 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// Implementation of COFF support for the MC-JIT runtime dynamic linker.
10//
11//===----------------------------------------------------------------------===//
12
13#include "RuntimeDyldCOFF.h"
14#include "Targets/RuntimeDyldCOFFAArch64.h"
15#include "Targets/RuntimeDyldCOFFI386.h"
16#include "Targets/RuntimeDyldCOFFThumb.h"
17#include "Targets/RuntimeDyldCOFFX86_64.h"
18#include "llvm/Object/ObjectFile.h"
19#include "llvm/Support/FormatVariadic.h"
20#include "llvm/TargetParser/Triple.h"
21
22using namespace llvm;
23using namespace llvm::object;
24
25#define DEBUG_TYPE "dyld"
26
27namespace {
28
29class LoadedCOFFObjectInfo final
30 : public LoadedObjectInfoHelper<LoadedCOFFObjectInfo,
31 RuntimeDyld::LoadedObjectInfo> {
32public:
33 LoadedCOFFObjectInfo(
34 RuntimeDyldImpl &RTDyld,
35 RuntimeDyld::LoadedObjectInfo::ObjSectionToIDMap ObjSecToIDMap)
36 : LoadedObjectInfoHelper(RTDyld, std::move(ObjSecToIDMap)) {}
37
38 OwningBinary<ObjectFile>
39 getObjectForDebug(const ObjectFile &Obj) const override {
40 return OwningBinary<ObjectFile>();
41 }
42};
43}
44
45namespace llvm {
46
47std::unique_ptr<RuntimeDyldCOFF>
48llvm::RuntimeDyldCOFF::create(Triple::ArchType Arch,
49 RuntimeDyld::MemoryManager &MemMgr,
50 JITSymbolResolver &Resolver) {
51 switch (Arch) {
52 default: llvm_unreachable("Unsupported target for RuntimeDyldCOFF.");
53 case Triple::x86:
54 return std::make_unique<RuntimeDyldCOFFI386>(args&: MemMgr, args&: Resolver);
55 case Triple::thumb:
56 return std::make_unique<RuntimeDyldCOFFThumb>(args&: MemMgr, args&: Resolver);
57 case Triple::x86_64:
58 return std::make_unique<RuntimeDyldCOFFX86_64>(args&: MemMgr, args&: Resolver);
59 case Triple::aarch64:
60 return std::make_unique<RuntimeDyldCOFFAArch64>(args&: MemMgr, args&: Resolver);
61 }
62}
63
64std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
65RuntimeDyldCOFF::loadObject(const object::ObjectFile &O) {
66 if (auto ObjSectionToIDOrErr = loadObjectImpl(Obj: O)) {
67 return std::make_unique<LoadedCOFFObjectInfo>(args&: *this, args&: *ObjSectionToIDOrErr);
68 } else {
69 HasError = true;
70 raw_string_ostream ErrStream(ErrorStr);
71 logAllUnhandledErrors(E: ObjSectionToIDOrErr.takeError(), OS&: ErrStream);
72 return nullptr;
73 }
74}
75
76uint64_t RuntimeDyldCOFF::getSymbolOffset(const SymbolRef &Sym) {
77 // The value in a relocatable COFF object is the offset.
78 return cantFail(ValOrErr: Sym.getValue());
79}
80
81uint64_t RuntimeDyldCOFF::getDLLImportOffset(unsigned SectionID, StubMap &Stubs,
82 StringRef Name,
83 bool SetSectionIDMinus1) {
84 LLVM_DEBUG(dbgs() << "Getting DLLImport entry for " << Name << "... ");
85 assert(Name.starts_with(getImportSymbolPrefix()) &&
86 "Not a DLLImport symbol?");
87 RelocationValueRef Reloc;
88 Reloc.SymbolName = Name.data();
89 auto [It, Inserted] = Stubs.try_emplace(k: Reloc);
90 if (!Inserted) {
91 LLVM_DEBUG(dbgs() << format("{0:x8}", It->second) << "\n");
92 return It->second;
93 }
94
95 assert(SectionID < Sections.size() && "SectionID out of range");
96 auto &Sec = Sections[SectionID];
97 auto EntryOffset = alignTo(Value: Sec.getStubOffset(), Align: PointerSize);
98 Sec.advanceStubOffset(StubSize: EntryOffset + PointerSize - Sec.getStubOffset());
99 It->second = EntryOffset;
100
101 RelocationEntry RE(SectionID, EntryOffset, PointerReloc, 0, false,
102 Log2_64(Value: PointerSize));
103 // Hack to tell I386/Thumb resolveRelocation that this isn't section relative.
104 if (SetSectionIDMinus1)
105 RE.Sections.SectionA = -1;
106 addRelocationForSymbol(RE, SymbolName: Name.drop_front(N: getImportSymbolPrefix().size()));
107
108 LLVM_DEBUG({
109 dbgs() << "Creating entry at "
110 << formatv("{0:x16} + {1:x8} ( {2:x16} )", Sec.getLoadAddress(),
111 EntryOffset, Sec.getLoadAddress() + EntryOffset)
112 << "\n";
113 });
114 return EntryOffset;
115}
116
117bool RuntimeDyldCOFF::isCompatibleFile(const object::ObjectFile &Obj) const {
118 return Obj.isCOFF();
119}
120
121bool RuntimeDyldCOFF::relocationNeedsDLLImportStub(
122 const RelocationRef &R) const {
123 object::symbol_iterator Symbol = R.getSymbol();
124 Expected<StringRef> TargetNameOrErr = Symbol->getName();
125 if (!TargetNameOrErr)
126 return false;
127
128 return TargetNameOrErr->starts_with(Prefix: getImportSymbolPrefix());
129}
130
131} // namespace llvm
132