1//===-------------------- Layer.cpp - Layer interfaces --------------------===//
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#include "llvm/ExecutionEngine/Orc/Layer.h"
10
11#include "llvm/ExecutionEngine/Orc/DebugUtils.h"
12#include "llvm/ExecutionEngine/Orc/ExecutionUtils.h"
13#include "llvm/ExecutionEngine/Orc/ObjectFileInterface.h"
14#include "llvm/IR/Constants.h"
15#include "llvm/Support/Debug.h"
16
17#define DEBUG_TYPE "orc"
18
19namespace llvm {
20namespace orc {
21
22IRLayer::~IRLayer() = default;
23
24Error IRLayer::add(ResourceTrackerSP RT, ThreadSafeModule TSM) {
25 assert(RT && "RT can not be null");
26 auto &JD = RT->getJITDylib();
27 return JD.define(MU: std::make_unique<BasicIRLayerMaterializationUnit>(
28 args&: *this, args: *getManglingOptions(), args: std::move(TSM)),
29 RT: std::move(RT));
30}
31
32IRMaterializationUnit::IRMaterializationUnit(
33 ExecutionSession &ES, const IRSymbolMapper::ManglingOptions &MO,
34 ThreadSafeModule TSM)
35 : MaterializationUnit(Interface()), TSM(std::move(TSM)) {
36
37 assert(this->TSM && "Module must not be null");
38
39 MangleAndInterner Mangle(ES, this->TSM.getModuleUnlocked()->getDataLayout());
40 this->TSM.withModuleDo(F: [&](Module &M) {
41 for (auto &G : M.global_values()) {
42 // Skip globals that don't generate symbols.
43
44 if (!G.hasName() || G.isDeclaration() || G.hasLocalLinkage() ||
45 G.hasAvailableExternallyLinkage() || G.hasAppendingLinkage())
46 continue;
47
48 // thread locals generate different symbols depending on whether or not
49 // emulated TLS is enabled.
50 if (G.isThreadLocal() && MO.EmulatedTLS) {
51 auto &GV = cast<GlobalVariable>(Val&: G);
52
53 auto Flags = JITSymbolFlags::fromGlobalValue(GV);
54
55 auto EmuTLSV = Mangle(("__emutls_v." + GV.getName()).str());
56 SymbolFlags[EmuTLSV] = Flags;
57 SymbolToDefinition[EmuTLSV] = &GV;
58
59 // If this GV has a non-zero initializer we'll need to emit an
60 // __emutls.t symbol too.
61 if (GV.hasInitializer()) {
62 const auto *InitVal = GV.getInitializer();
63
64 // Skip zero-initializers.
65 if (isa<ConstantAggregateZero>(Val: InitVal))
66 continue;
67 const auto *InitIntValue = dyn_cast<ConstantInt>(Val: InitVal);
68 if (InitIntValue && InitIntValue->isZero())
69 continue;
70
71 auto EmuTLST = Mangle(("__emutls_t." + GV.getName()).str());
72 SymbolFlags[EmuTLST] = Flags;
73 }
74 continue;
75 }
76
77 // Otherwise we just need a normal linker mangling.
78 auto MangledName = Mangle(G.getName());
79 SymbolFlags[MangledName] = JITSymbolFlags::fromGlobalValue(GV: G);
80 if (G.getComdat() &&
81 G.getComdat()->getSelectionKind() != Comdat::NoDeduplicate)
82 SymbolFlags[MangledName] |= JITSymbolFlags::Weak;
83 SymbolToDefinition[MangledName] = &G;
84 }
85
86 // If we need an init symbol for this module then create one.
87 if (!getStaticInitGVs(M).empty()) {
88 size_t Counter = 0;
89
90 do {
91 std::string InitSymbolName;
92 raw_string_ostream(InitSymbolName)
93 << "$." << M.getModuleIdentifier() << ".__inits." << Counter++;
94 InitSymbol = ES.intern(SymName: InitSymbolName);
95 } while (SymbolFlags.count(Val: InitSymbol));
96
97 SymbolFlags[InitSymbol] = JITSymbolFlags::MaterializationSideEffectsOnly;
98 }
99 });
100}
101
102IRMaterializationUnit::IRMaterializationUnit(
103 ThreadSafeModule TSM, Interface I,
104 SymbolNameToDefinitionMap SymbolToDefinition)
105 : MaterializationUnit(std::move(I)), TSM(std::move(TSM)),
106 SymbolToDefinition(std::move(SymbolToDefinition)) {}
107
108StringRef IRMaterializationUnit::getName() const {
109 if (TSM)
110 return TSM.withModuleDo(
111 F: [](const Module &M) -> StringRef { return M.getModuleIdentifier(); });
112 return "<null module>";
113}
114
115void IRMaterializationUnit::discard(const JITDylib &JD,
116 const SymbolStringPtr &Name) {
117 LLVM_DEBUG(JD.getExecutionSession().runSessionLocked([&]() {
118 dbgs() << "In " << JD.getName() << " discarding " << *Name << " from MU@"
119 << this << " (" << getName() << ")\n";
120 }););
121
122 auto I = SymbolToDefinition.find(x: Name);
123 assert(I != SymbolToDefinition.end() &&
124 "Symbol not provided by this MU, or previously discarded");
125 assert(!I->second->isDeclaration() &&
126 "Discard should only apply to definitions");
127 I->second->setLinkage(GlobalValue::AvailableExternallyLinkage);
128 // According to the IR verifier, "Declaration[s] may not be in a Comdat!"
129 // Remove it, if this is a GlobalObject.
130 if (auto *GO = dyn_cast<GlobalObject>(Val: I->second))
131 GO->setComdat(nullptr);
132 SymbolToDefinition.erase(position: I);
133}
134
135BasicIRLayerMaterializationUnit::BasicIRLayerMaterializationUnit(
136 IRLayer &L, const IRSymbolMapper::ManglingOptions &MO, ThreadSafeModule TSM)
137 : IRMaterializationUnit(L.getExecutionSession(), MO, std::move(TSM)), L(L) {
138}
139
140void BasicIRLayerMaterializationUnit::materialize(
141 std::unique_ptr<MaterializationResponsibility> R) {
142
143 // Throw away the SymbolToDefinition map: it's not usable after we hand
144 // off the module.
145 SymbolToDefinition.clear();
146
147 // If cloneToNewContextOnEmit is set, clone the module now.
148 if (L.getCloneToNewContextOnEmit())
149 TSM = cloneToNewContext(TSMW: TSM);
150
151#ifndef NDEBUG
152 auto &ES = R->getTargetJITDylib().getExecutionSession();
153 auto &N = R->getTargetJITDylib().getName();
154#endif // NDEBUG
155
156 LLVM_DEBUG(ES.runSessionLocked(
157 [&]() { dbgs() << "Emitting, for " << N << ", " << *this << "\n"; }););
158 L.emit(R: std::move(R), TSM: std::move(TSM));
159 LLVM_DEBUG(ES.runSessionLocked([&]() {
160 dbgs() << "Finished emitting, for " << N << ", " << *this << "\n";
161 }););
162}
163
164char ObjectLayer::ID;
165
166ObjectLayer::ObjectLayer(ExecutionSession &ES) : ES(ES) {}
167
168ObjectLayer::~ObjectLayer() = default;
169
170Error ObjectLayer::add(ResourceTrackerSP RT, std::unique_ptr<MemoryBuffer> O,
171 MaterializationUnit::Interface I) {
172 assert(RT && "RT can not be null");
173 auto &JD = RT->getJITDylib();
174 return JD.define(MU: std::make_unique<BasicObjectLayerMaterializationUnit>(
175 args&: *this, args: std::move(O), args: std::move(I)),
176 RT: std::move(RT));
177}
178
179Error ObjectLayer::add(ResourceTrackerSP RT, std::unique_ptr<MemoryBuffer> O) {
180 auto I = getObjectFileInterface(ES&: getExecutionSession(), ObjBuffer: O->getMemBufferRef());
181 if (!I)
182 return I.takeError();
183 return add(RT: std::move(RT), O: std::move(O), I: std::move(*I));
184}
185
186Error ObjectLayer::add(JITDylib &JD, std::unique_ptr<MemoryBuffer> O) {
187 auto I = getObjectFileInterface(ES&: getExecutionSession(), ObjBuffer: O->getMemBufferRef());
188 if (!I)
189 return I.takeError();
190 return add(JD, O: std::move(O), I: std::move(*I));
191}
192
193Expected<std::unique_ptr<BasicObjectLayerMaterializationUnit>>
194BasicObjectLayerMaterializationUnit::Create(ObjectLayer &L,
195 std::unique_ptr<MemoryBuffer> O) {
196
197 auto ObjInterface =
198 getObjectFileInterface(ES&: L.getExecutionSession(), ObjBuffer: O->getMemBufferRef());
199
200 if (!ObjInterface)
201 return ObjInterface.takeError();
202
203 return std::make_unique<BasicObjectLayerMaterializationUnit>(
204 args&: L, args: std::move(O), args: std::move(*ObjInterface));
205}
206
207BasicObjectLayerMaterializationUnit::BasicObjectLayerMaterializationUnit(
208 ObjectLayer &L, std::unique_ptr<MemoryBuffer> O, Interface I)
209 : MaterializationUnit(std::move(I)), L(L), O(std::move(O)) {}
210
211StringRef BasicObjectLayerMaterializationUnit::getName() const {
212 if (O)
213 return O->getBufferIdentifier();
214 return "<null object>";
215}
216
217void BasicObjectLayerMaterializationUnit::materialize(
218 std::unique_ptr<MaterializationResponsibility> R) {
219 L.emit(R: std::move(R), O: std::move(O));
220}
221
222void BasicObjectLayerMaterializationUnit::discard(const JITDylib &JD,
223 const SymbolStringPtr &Name) {
224 // This is a no-op for object files: Having removed 'Name' from SymbolFlags
225 // the symbol will be dead-stripped by the JIT linker.
226}
227
228} // End namespace orc.
229} // End namespace llvm.
230