1 //===---- ExecutionUtils.cpp - Utilities for executing functions in Orc ---===//
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 #include "llvm/ExecutionEngine/Orc/ExecutionUtils.h"
11
12 #include "llvm/IR/Constants.h"
13 #include "llvm/IR/Function.h"
14 #include "llvm/IR/GlobalVariable.h"
15 #include "llvm/IR/Module.h"
16 #include "llvm/Support/TargetRegistry.h"
17 #include "llvm/Target/TargetMachine.h"
18
19 namespace llvm {
20 namespace orc {
21
JITTargetMachineBuilder(Triple TT)22 JITTargetMachineBuilder::JITTargetMachineBuilder(Triple TT)
23 : TT(std::move(TT)) {}
24
detectHost()25 Expected<JITTargetMachineBuilder> JITTargetMachineBuilder::detectHost() {
26 return JITTargetMachineBuilder(Triple(sys::getProcessTriple()));
27 }
28
29 Expected<std::unique_ptr<TargetMachine>>
createTargetMachine()30 JITTargetMachineBuilder::createTargetMachine() {
31 if (!Arch.empty()) {
32 Triple::ArchType Type = Triple::getArchTypeForLLVMName(Arch);
33
34 if (Type == Triple::UnknownArch)
35 return make_error<StringError>(std::string("Unknown arch: ") + Arch,
36 inconvertibleErrorCode());
37 }
38
39 std::string ErrMsg;
40 auto *TheTarget = TargetRegistry::lookupTarget(TT.getTriple(), ErrMsg);
41 if (!TheTarget)
42 return make_error<StringError>(std::move(ErrMsg), inconvertibleErrorCode());
43
44 auto *TM =
45 TheTarget->createTargetMachine(TT.getTriple(), CPU, Features.getString(),
46 Options, RM, CM, OptLevel, /*JIT*/ true);
47 if (!TM)
48 return make_error<StringError>("Could not allocate target machine",
49 inconvertibleErrorCode());
50
51 return std::unique_ptr<TargetMachine>(TM);
52 }
53
addFeatures(const std::vector<std::string> & FeatureVec)54 JITTargetMachineBuilder &JITTargetMachineBuilder::addFeatures(
55 const std::vector<std::string> &FeatureVec) {
56 for (const auto &F : FeatureVec)
57 Features.AddFeature(F);
58 return *this;
59 }
60
CtorDtorIterator(const GlobalVariable * GV,bool End)61 CtorDtorIterator::CtorDtorIterator(const GlobalVariable *GV, bool End)
62 : InitList(
63 GV ? dyn_cast_or_null<ConstantArray>(GV->getInitializer()) : nullptr),
64 I((InitList && End) ? InitList->getNumOperands() : 0) {
65 }
66
operator ==(const CtorDtorIterator & Other) const67 bool CtorDtorIterator::operator==(const CtorDtorIterator &Other) const {
68 assert(InitList == Other.InitList && "Incomparable iterators.");
69 return I == Other.I;
70 }
71
operator !=(const CtorDtorIterator & Other) const72 bool CtorDtorIterator::operator!=(const CtorDtorIterator &Other) const {
73 return !(*this == Other);
74 }
75
operator ++()76 CtorDtorIterator& CtorDtorIterator::operator++() {
77 ++I;
78 return *this;
79 }
80
operator ++(int)81 CtorDtorIterator CtorDtorIterator::operator++(int) {
82 CtorDtorIterator Temp = *this;
83 ++I;
84 return Temp;
85 }
86
operator *() const87 CtorDtorIterator::Element CtorDtorIterator::operator*() const {
88 ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(I));
89 assert(CS && "Unrecognized type in llvm.global_ctors/llvm.global_dtors");
90
91 Constant *FuncC = CS->getOperand(1);
92 Function *Func = nullptr;
93
94 // Extract function pointer, pulling off any casts.
95 while (FuncC) {
96 if (Function *F = dyn_cast_or_null<Function>(FuncC)) {
97 Func = F;
98 break;
99 } else if (ConstantExpr *CE = dyn_cast_or_null<ConstantExpr>(FuncC)) {
100 if (CE->isCast())
101 FuncC = dyn_cast_or_null<ConstantExpr>(CE->getOperand(0));
102 else
103 break;
104 } else {
105 // This isn't anything we recognize. Bail out with Func left set to null.
106 break;
107 }
108 }
109
110 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
111 Value *Data = CS->getNumOperands() == 3 ? CS->getOperand(2) : nullptr;
112 if (Data && !isa<GlobalValue>(Data))
113 Data = nullptr;
114 return Element(Priority->getZExtValue(), Func, Data);
115 }
116
getConstructors(const Module & M)117 iterator_range<CtorDtorIterator> getConstructors(const Module &M) {
118 const GlobalVariable *CtorsList = M.getNamedGlobal("llvm.global_ctors");
119 return make_range(CtorDtorIterator(CtorsList, false),
120 CtorDtorIterator(CtorsList, true));
121 }
122
getDestructors(const Module & M)123 iterator_range<CtorDtorIterator> getDestructors(const Module &M) {
124 const GlobalVariable *DtorsList = M.getNamedGlobal("llvm.global_dtors");
125 return make_range(CtorDtorIterator(DtorsList, false),
126 CtorDtorIterator(DtorsList, true));
127 }
128
add(iterator_range<CtorDtorIterator> CtorDtors)129 void CtorDtorRunner2::add(iterator_range<CtorDtorIterator> CtorDtors) {
130 if (CtorDtors.begin() == CtorDtors.end())
131 return;
132
133 MangleAndInterner Mangle(
134 V.getExecutionSession(),
135 (*CtorDtors.begin()).Func->getParent()->getDataLayout());
136
137 for (const auto &CtorDtor : CtorDtors) {
138 assert(CtorDtor.Func && CtorDtor.Func->hasName() &&
139 "Ctor/Dtor function must be named to be runnable under the JIT");
140
141 if (CtorDtor.Data && cast<GlobalValue>(CtorDtor.Data)->isDeclaration()) {
142 dbgs() << " Skipping because why now?\n";
143 continue;
144 }
145
146 CtorDtorsByPriority[CtorDtor.Priority].push_back(
147 Mangle(CtorDtor.Func->getName()));
148 }
149 }
150
run()151 Error CtorDtorRunner2::run() {
152 using CtorDtorTy = void (*)();
153
154 SymbolNameSet Names;
155
156 for (auto &KV : CtorDtorsByPriority) {
157 for (auto &Name : KV.second) {
158 auto Added = Names.insert(Name).second;
159 (void)Added;
160 assert(Added && "Ctor/Dtor names clashed");
161 }
162 }
163
164 if (auto CtorDtorMap = lookup({&V}, std::move(Names))) {
165 for (auto &KV : CtorDtorsByPriority) {
166 for (auto &Name : KV.second) {
167 assert(CtorDtorMap->count(Name) && "No entry for Name");
168 auto CtorDtor = reinterpret_cast<CtorDtorTy>(
169 static_cast<uintptr_t>((*CtorDtorMap)[Name].getAddress()));
170 CtorDtor();
171 }
172 }
173 return Error::success();
174 } else
175 return CtorDtorMap.takeError();
176
177 CtorDtorsByPriority.clear();
178
179 return Error::success();
180 }
181
runDestructors()182 void LocalCXXRuntimeOverridesBase::runDestructors() {
183 auto& CXXDestructorDataPairs = DSOHandleOverride;
184 for (auto &P : CXXDestructorDataPairs)
185 P.first(P.second);
186 CXXDestructorDataPairs.clear();
187 }
188
CXAAtExitOverride(DestructorPtr Destructor,void * Arg,void * DSOHandle)189 int LocalCXXRuntimeOverridesBase::CXAAtExitOverride(DestructorPtr Destructor,
190 void *Arg,
191 void *DSOHandle) {
192 auto& CXXDestructorDataPairs =
193 *reinterpret_cast<CXXDestructorDataPairList*>(DSOHandle);
194 CXXDestructorDataPairs.push_back(std::make_pair(Destructor, Arg));
195 return 0;
196 }
197
enable(VSO & V,MangleAndInterner & Mangle)198 Error LocalCXXRuntimeOverrides2::enable(VSO &V, MangleAndInterner &Mangle) {
199 SymbolMap RuntimeInterposes(
200 {{Mangle("__dso_handle"),
201 JITEvaluatedSymbol(toTargetAddress(&DSOHandleOverride),
202 JITSymbolFlags::Exported)},
203 {Mangle("__cxa_atexit"),
204 JITEvaluatedSymbol(toTargetAddress(&CXAAtExitOverride),
205 JITSymbolFlags::Exported)}});
206
207 return V.define(absoluteSymbols(std::move(RuntimeInterposes)));
208 }
209
DynamicLibraryFallbackGenerator(sys::DynamicLibrary Dylib,const DataLayout & DL,SymbolPredicate Allow)210 DynamicLibraryFallbackGenerator::DynamicLibraryFallbackGenerator(
211 sys::DynamicLibrary Dylib, const DataLayout &DL, SymbolPredicate Allow)
212 : Dylib(std::move(Dylib)), Allow(std::move(Allow)),
213 GlobalPrefix(DL.getGlobalPrefix()) {}
214
215 SymbolNameSet DynamicLibraryFallbackGenerator::
operator ()(VSO & V,const SymbolNameSet & Names)216 operator()(VSO &V, const SymbolNameSet &Names) {
217 orc::SymbolNameSet Added;
218 orc::SymbolMap NewSymbols;
219
220 bool HasGlobalPrefix = (GlobalPrefix != '\0');
221
222 for (auto &Name : Names) {
223 if (!Allow(Name) || (*Name).empty())
224 continue;
225
226 if (HasGlobalPrefix && (*Name).front() != GlobalPrefix)
227 continue;
228
229 std::string Tmp((*Name).data() + (HasGlobalPrefix ? 1 : 0), (*Name).size());
230 if (void *Addr = Dylib.getAddressOfSymbol(Tmp.c_str())) {
231 Added.insert(Name);
232 NewSymbols[Name] = JITEvaluatedSymbol(
233 static_cast<JITTargetAddress>(reinterpret_cast<uintptr_t>(Addr)),
234 JITSymbolFlags::Exported);
235 }
236 }
237
238 // Add any new symbols to V. Since the fallback generator is only called for
239 // symbols that are not already defined, this will never trigger a duplicate
240 // definition error, so we can wrap this call in a 'cantFail'.
241 if (!NewSymbols.empty())
242 cantFail(V.define(absoluteSymbols(std::move(NewSymbols))));
243
244 return Added;
245 }
246
247 } // End namespace orc.
248 } // End namespace llvm.
249