1 //===---- ExecutionUtils.cpp - Utilities for executing functions in Orc ---===//
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/ExecutionUtils.h"
10
11 #include "llvm/ExecutionEngine/Orc/Layer.h"
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/Object/MachOUniversal.h"
17 #include "llvm/Support/FormatVariadic.h"
18 #include "llvm/Support/TargetRegistry.h"
19 #include "llvm/Target/TargetMachine.h"
20
21 namespace llvm {
22 namespace orc {
23
CtorDtorIterator(const GlobalVariable * GV,bool End)24 CtorDtorIterator::CtorDtorIterator(const GlobalVariable *GV, bool End)
25 : InitList(
26 GV ? dyn_cast_or_null<ConstantArray>(GV->getInitializer()) : nullptr),
27 I((InitList && End) ? InitList->getNumOperands() : 0) {
28 }
29
operator ==(const CtorDtorIterator & Other) const30 bool CtorDtorIterator::operator==(const CtorDtorIterator &Other) const {
31 assert(InitList == Other.InitList && "Incomparable iterators.");
32 return I == Other.I;
33 }
34
operator !=(const CtorDtorIterator & Other) const35 bool CtorDtorIterator::operator!=(const CtorDtorIterator &Other) const {
36 return !(*this == Other);
37 }
38
operator ++()39 CtorDtorIterator& CtorDtorIterator::operator++() {
40 ++I;
41 return *this;
42 }
43
operator ++(int)44 CtorDtorIterator CtorDtorIterator::operator++(int) {
45 CtorDtorIterator Temp = *this;
46 ++I;
47 return Temp;
48 }
49
operator *() const50 CtorDtorIterator::Element CtorDtorIterator::operator*() const {
51 ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(I));
52 assert(CS && "Unrecognized type in llvm.global_ctors/llvm.global_dtors");
53
54 Constant *FuncC = CS->getOperand(1);
55 Function *Func = nullptr;
56
57 // Extract function pointer, pulling off any casts.
58 while (FuncC) {
59 if (Function *F = dyn_cast_or_null<Function>(FuncC)) {
60 Func = F;
61 break;
62 } else if (ConstantExpr *CE = dyn_cast_or_null<ConstantExpr>(FuncC)) {
63 if (CE->isCast())
64 FuncC = dyn_cast_or_null<ConstantExpr>(CE->getOperand(0));
65 else
66 break;
67 } else {
68 // This isn't anything we recognize. Bail out with Func left set to null.
69 break;
70 }
71 }
72
73 auto *Priority = cast<ConstantInt>(CS->getOperand(0));
74 Value *Data = CS->getNumOperands() == 3 ? CS->getOperand(2) : nullptr;
75 if (Data && !isa<GlobalValue>(Data))
76 Data = nullptr;
77 return Element(Priority->getZExtValue(), Func, Data);
78 }
79
getConstructors(const Module & M)80 iterator_range<CtorDtorIterator> getConstructors(const Module &M) {
81 const GlobalVariable *CtorsList = M.getNamedGlobal("llvm.global_ctors");
82 return make_range(CtorDtorIterator(CtorsList, false),
83 CtorDtorIterator(CtorsList, true));
84 }
85
getDestructors(const Module & M)86 iterator_range<CtorDtorIterator> getDestructors(const Module &M) {
87 const GlobalVariable *DtorsList = M.getNamedGlobal("llvm.global_dtors");
88 return make_range(CtorDtorIterator(DtorsList, false),
89 CtorDtorIterator(DtorsList, true));
90 }
91
isStaticInitGlobal(GlobalValue & GV)92 bool StaticInitGVIterator::isStaticInitGlobal(GlobalValue &GV) {
93 if (GV.isDeclaration())
94 return false;
95
96 if (GV.hasName() && (GV.getName() == "llvm.global_ctors" ||
97 GV.getName() == "llvm.global_dtors"))
98 return true;
99
100 if (ObjFmt == Triple::MachO) {
101 // FIXME: These section checks are too strict: We should match first and
102 // second word split by comma.
103 if (GV.hasSection() &&
104 (GV.getSection().startswith("__DATA,__objc_classlist") ||
105 GV.getSection().startswith("__DATA,__objc_selrefs")))
106 return true;
107 }
108
109 return false;
110 }
111
add(iterator_range<CtorDtorIterator> CtorDtors)112 void CtorDtorRunner::add(iterator_range<CtorDtorIterator> CtorDtors) {
113 if (CtorDtors.empty())
114 return;
115
116 MangleAndInterner Mangle(
117 JD.getExecutionSession(),
118 (*CtorDtors.begin()).Func->getParent()->getDataLayout());
119
120 for (auto CtorDtor : CtorDtors) {
121 assert(CtorDtor.Func && CtorDtor.Func->hasName() &&
122 "Ctor/Dtor function must be named to be runnable under the JIT");
123
124 // FIXME: Maybe use a symbol promoter here instead.
125 if (CtorDtor.Func->hasLocalLinkage()) {
126 CtorDtor.Func->setLinkage(GlobalValue::ExternalLinkage);
127 CtorDtor.Func->setVisibility(GlobalValue::HiddenVisibility);
128 }
129
130 if (CtorDtor.Data && cast<GlobalValue>(CtorDtor.Data)->isDeclaration()) {
131 dbgs() << " Skipping because why now?\n";
132 continue;
133 }
134
135 CtorDtorsByPriority[CtorDtor.Priority].push_back(
136 Mangle(CtorDtor.Func->getName()));
137 }
138 }
139
run()140 Error CtorDtorRunner::run() {
141 using CtorDtorTy = void (*)();
142
143 SymbolLookupSet LookupSet;
144 for (auto &KV : CtorDtorsByPriority)
145 for (auto &Name : KV.second)
146 LookupSet.add(Name);
147 assert(!LookupSet.containsDuplicates() &&
148 "Ctor/Dtor list contains duplicates");
149
150 auto &ES = JD.getExecutionSession();
151 if (auto CtorDtorMap = ES.lookup(
152 makeJITDylibSearchOrder(&JD, JITDylibLookupFlags::MatchAllSymbols),
153 std::move(LookupSet))) {
154 for (auto &KV : CtorDtorsByPriority) {
155 for (auto &Name : KV.second) {
156 assert(CtorDtorMap->count(Name) && "No entry for Name");
157 auto CtorDtor = reinterpret_cast<CtorDtorTy>(
158 static_cast<uintptr_t>((*CtorDtorMap)[Name].getAddress()));
159 CtorDtor();
160 }
161 }
162 CtorDtorsByPriority.clear();
163 return Error::success();
164 } else
165 return CtorDtorMap.takeError();
166 }
167
runDestructors()168 void LocalCXXRuntimeOverridesBase::runDestructors() {
169 auto& CXXDestructorDataPairs = DSOHandleOverride;
170 for (auto &P : CXXDestructorDataPairs)
171 P.first(P.second);
172 CXXDestructorDataPairs.clear();
173 }
174
CXAAtExitOverride(DestructorPtr Destructor,void * Arg,void * DSOHandle)175 int LocalCXXRuntimeOverridesBase::CXAAtExitOverride(DestructorPtr Destructor,
176 void *Arg,
177 void *DSOHandle) {
178 auto& CXXDestructorDataPairs =
179 *reinterpret_cast<CXXDestructorDataPairList*>(DSOHandle);
180 CXXDestructorDataPairs.push_back(std::make_pair(Destructor, Arg));
181 return 0;
182 }
183
enable(JITDylib & JD,MangleAndInterner & Mangle)184 Error LocalCXXRuntimeOverrides::enable(JITDylib &JD,
185 MangleAndInterner &Mangle) {
186 SymbolMap RuntimeInterposes;
187 RuntimeInterposes[Mangle("__dso_handle")] =
188 JITEvaluatedSymbol(toTargetAddress(&DSOHandleOverride),
189 JITSymbolFlags::Exported);
190 RuntimeInterposes[Mangle("__cxa_atexit")] =
191 JITEvaluatedSymbol(toTargetAddress(&CXAAtExitOverride),
192 JITSymbolFlags::Exported);
193
194 return JD.define(absoluteSymbols(std::move(RuntimeInterposes)));
195 }
196
registerAtExit(void (* F)(void *),void * Ctx,void * DSOHandle)197 void ItaniumCXAAtExitSupport::registerAtExit(void (*F)(void *), void *Ctx,
198 void *DSOHandle) {
199 std::lock_guard<std::mutex> Lock(AtExitsMutex);
200 AtExitRecords[DSOHandle].push_back({F, Ctx});
201 }
202
runAtExits(void * DSOHandle)203 void ItaniumCXAAtExitSupport::runAtExits(void *DSOHandle) {
204 std::vector<AtExitRecord> AtExitsToRun;
205
206 {
207 std::lock_guard<std::mutex> Lock(AtExitsMutex);
208 auto I = AtExitRecords.find(DSOHandle);
209 if (I != AtExitRecords.end()) {
210 AtExitsToRun = std::move(I->second);
211 AtExitRecords.erase(I);
212 }
213 }
214
215 while (!AtExitsToRun.empty()) {
216 AtExitsToRun.back().F(AtExitsToRun.back().Ctx);
217 AtExitsToRun.pop_back();
218 }
219 }
220
DynamicLibrarySearchGenerator(sys::DynamicLibrary Dylib,char GlobalPrefix,SymbolPredicate Allow)221 DynamicLibrarySearchGenerator::DynamicLibrarySearchGenerator(
222 sys::DynamicLibrary Dylib, char GlobalPrefix, SymbolPredicate Allow)
223 : Dylib(std::move(Dylib)), Allow(std::move(Allow)),
224 GlobalPrefix(GlobalPrefix) {}
225
226 Expected<std::unique_ptr<DynamicLibrarySearchGenerator>>
Load(const char * FileName,char GlobalPrefix,SymbolPredicate Allow)227 DynamicLibrarySearchGenerator::Load(const char *FileName, char GlobalPrefix,
228 SymbolPredicate Allow) {
229 std::string ErrMsg;
230 auto Lib = sys::DynamicLibrary::getPermanentLibrary(FileName, &ErrMsg);
231 if (!Lib.isValid())
232 return make_error<StringError>(std::move(ErrMsg), inconvertibleErrorCode());
233 return std::make_unique<DynamicLibrarySearchGenerator>(
234 std::move(Lib), GlobalPrefix, std::move(Allow));
235 }
236
tryToGenerate(LookupState & LS,LookupKind K,JITDylib & JD,JITDylibLookupFlags JDLookupFlags,const SymbolLookupSet & Symbols)237 Error DynamicLibrarySearchGenerator::tryToGenerate(
238 LookupState &LS, LookupKind K, JITDylib &JD,
239 JITDylibLookupFlags JDLookupFlags, const SymbolLookupSet &Symbols) {
240 orc::SymbolMap NewSymbols;
241
242 bool HasGlobalPrefix = (GlobalPrefix != '\0');
243
244 for (auto &KV : Symbols) {
245 auto &Name = KV.first;
246
247 if ((*Name).empty())
248 continue;
249
250 if (Allow && !Allow(Name))
251 continue;
252
253 if (HasGlobalPrefix && (*Name).front() != GlobalPrefix)
254 continue;
255
256 std::string Tmp((*Name).data() + HasGlobalPrefix,
257 (*Name).size() - HasGlobalPrefix);
258 if (void *Addr = Dylib.getAddressOfSymbol(Tmp.c_str())) {
259 NewSymbols[Name] = JITEvaluatedSymbol(
260 static_cast<JITTargetAddress>(reinterpret_cast<uintptr_t>(Addr)),
261 JITSymbolFlags::Exported);
262 }
263 }
264
265 if (NewSymbols.empty())
266 return Error::success();
267
268 return JD.define(absoluteSymbols(std::move(NewSymbols)));
269 }
270
271 Expected<std::unique_ptr<StaticLibraryDefinitionGenerator>>
Load(ObjectLayer & L,const char * FileName)272 StaticLibraryDefinitionGenerator::Load(ObjectLayer &L, const char *FileName) {
273 auto ArchiveBuffer = errorOrToExpected(MemoryBuffer::getFile(FileName));
274
275 if (!ArchiveBuffer)
276 return ArchiveBuffer.takeError();
277
278 return Create(L, std::move(*ArchiveBuffer));
279 }
280
281 Expected<std::unique_ptr<StaticLibraryDefinitionGenerator>>
Load(ObjectLayer & L,const char * FileName,const Triple & TT)282 StaticLibraryDefinitionGenerator::Load(ObjectLayer &L, const char *FileName,
283 const Triple &TT) {
284 auto B = object::createBinary(FileName);
285 if (!B)
286 return B.takeError();
287
288 // If this is a regular archive then create an instance from it.
289 if (isa<object::Archive>(B->getBinary()))
290 return Create(L, std::move(B->takeBinary().second));
291
292 // If this is a universal binary then search for a slice matching the given
293 // Triple.
294 if (auto *UB = cast<object::MachOUniversalBinary>(B->getBinary())) {
295 for (const auto &Obj : UB->objects()) {
296 auto ObjTT = Obj.getTriple();
297 if (ObjTT.getArch() == TT.getArch() &&
298 ObjTT.getSubArch() == TT.getSubArch() &&
299 (TT.getVendor() == Triple::UnknownVendor ||
300 ObjTT.getVendor() == TT.getVendor())) {
301 // We found a match. Create an instance from a buffer covering this
302 // slice.
303 auto SliceBuffer = MemoryBuffer::getFileSlice(FileName, Obj.getSize(),
304 Obj.getOffset());
305 if (!SliceBuffer)
306 return make_error<StringError>(
307 Twine("Could not create buffer for ") + TT.str() + " slice of " +
308 FileName + ": [ " + formatv("{0:x}", Obj.getOffset()) +
309 " .. " + formatv("{0:x}", Obj.getOffset() + Obj.getSize()) +
310 ": " + SliceBuffer.getError().message(),
311 SliceBuffer.getError());
312 return Create(L, std::move(*SliceBuffer));
313 }
314 }
315
316 return make_error<StringError>(Twine("Universal binary ") + FileName +
317 " does not contain a slice for " +
318 TT.str(),
319 inconvertibleErrorCode());
320 }
321
322 return make_error<StringError>(Twine("Unrecognized file type for ") +
323 FileName,
324 inconvertibleErrorCode());
325 }
326
327 Expected<std::unique_ptr<StaticLibraryDefinitionGenerator>>
Create(ObjectLayer & L,std::unique_ptr<MemoryBuffer> ArchiveBuffer)328 StaticLibraryDefinitionGenerator::Create(
329 ObjectLayer &L, std::unique_ptr<MemoryBuffer> ArchiveBuffer) {
330 Error Err = Error::success();
331
332 std::unique_ptr<StaticLibraryDefinitionGenerator> ADG(
333 new StaticLibraryDefinitionGenerator(L, std::move(ArchiveBuffer), Err));
334
335 if (Err)
336 return std::move(Err);
337
338 return std::move(ADG);
339 }
340
tryToGenerate(LookupState & LS,LookupKind K,JITDylib & JD,JITDylibLookupFlags JDLookupFlags,const SymbolLookupSet & Symbols)341 Error StaticLibraryDefinitionGenerator::tryToGenerate(
342 LookupState &LS, LookupKind K, JITDylib &JD,
343 JITDylibLookupFlags JDLookupFlags, const SymbolLookupSet &Symbols) {
344
345 // Don't materialize symbols from static archives unless this is a static
346 // lookup.
347 if (K != LookupKind::Static)
348 return Error::success();
349
350 // Bail out early if we've already freed the archive.
351 if (!Archive)
352 return Error::success();
353
354 DenseSet<std::pair<StringRef, StringRef>> ChildBufferInfos;
355
356 for (const auto &KV : Symbols) {
357 const auto &Name = KV.first;
358 auto Child = Archive->findSym(*Name);
359 if (!Child)
360 return Child.takeError();
361 if (*Child == None)
362 continue;
363 auto ChildBuffer = (*Child)->getMemoryBufferRef();
364 if (!ChildBuffer)
365 return ChildBuffer.takeError();
366 ChildBufferInfos.insert(
367 {ChildBuffer->getBuffer(), ChildBuffer->getBufferIdentifier()});
368 }
369
370 for (auto ChildBufferInfo : ChildBufferInfos) {
371 MemoryBufferRef ChildBufferRef(ChildBufferInfo.first,
372 ChildBufferInfo.second);
373
374 if (auto Err = L.add(JD, MemoryBuffer::getMemBuffer(ChildBufferRef, false)))
375 return Err;
376 }
377
378 return Error::success();
379 }
380
StaticLibraryDefinitionGenerator(ObjectLayer & L,std::unique_ptr<MemoryBuffer> ArchiveBuffer,Error & Err)381 StaticLibraryDefinitionGenerator::StaticLibraryDefinitionGenerator(
382 ObjectLayer &L, std::unique_ptr<MemoryBuffer> ArchiveBuffer, Error &Err)
383 : L(L), ArchiveBuffer(std::move(ArchiveBuffer)),
384 Archive(std::make_unique<object::Archive>(*this->ArchiveBuffer, Err)) {}
385
386 } // End namespace orc.
387 } // End namespace llvm.
388