1 //===---- IndirectionUtils.cpp - Utilities for call indirection 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/IndirectionUtils.h"
10 #include "llvm/ADT/STLExtras.h"
11 #include "llvm/ADT/Triple.h"
12 #include "llvm/ExecutionEngine/JITLink/x86_64.h"
13 #include "llvm/ExecutionEngine/Orc/OrcABISupport.h"
14 #include "llvm/IR/IRBuilder.h"
15 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
16 #include "llvm/MC/MCInstrAnalysis.h"
17 #include "llvm/Support/Format.h"
18 #include "llvm/Transforms/Utils/Cloning.h"
19 #include <sstream>
20
21 #define DEBUG_TYPE "orc"
22
23 using namespace llvm;
24 using namespace llvm::orc;
25
26 namespace {
27
28 class CompileCallbackMaterializationUnit : public orc::MaterializationUnit {
29 public:
30 using CompileFunction = JITCompileCallbackManager::CompileFunction;
31
CompileCallbackMaterializationUnit(SymbolStringPtr Name,CompileFunction Compile)32 CompileCallbackMaterializationUnit(SymbolStringPtr Name,
33 CompileFunction Compile)
34 : MaterializationUnit(Interface(
35 SymbolFlagsMap({{Name, JITSymbolFlags::Exported}}), nullptr)),
36 Name(std::move(Name)), Compile(std::move(Compile)) {}
37
getName() const38 StringRef getName() const override { return "<Compile Callbacks>"; }
39
40 private:
materialize(std::unique_ptr<MaterializationResponsibility> R)41 void materialize(std::unique_ptr<MaterializationResponsibility> R) override {
42 SymbolMap Result;
43 Result[Name] = JITEvaluatedSymbol(Compile(), JITSymbolFlags::Exported);
44 // No dependencies, so these calls cannot fail.
45 cantFail(R->notifyResolved(Result));
46 cantFail(R->notifyEmitted());
47 }
48
discard(const JITDylib & JD,const SymbolStringPtr & Name)49 void discard(const JITDylib &JD, const SymbolStringPtr &Name) override {
50 llvm_unreachable("Discard should never occur on a LMU?");
51 }
52
53 SymbolStringPtr Name;
54 CompileFunction Compile;
55 };
56
57 } // namespace
58
59 namespace llvm {
60 namespace orc {
61
62 TrampolinePool::~TrampolinePool() = default;
anchor()63 void IndirectStubsManager::anchor() {}
64
65 Expected<JITTargetAddress>
getCompileCallback(CompileFunction Compile)66 JITCompileCallbackManager::getCompileCallback(CompileFunction Compile) {
67 if (auto TrampolineAddr = TP->getTrampoline()) {
68 auto CallbackName =
69 ES.intern(std::string("cc") + std::to_string(++NextCallbackId));
70
71 std::lock_guard<std::mutex> Lock(CCMgrMutex);
72 AddrToSymbol[*TrampolineAddr] = CallbackName;
73 cantFail(
74 CallbacksJD.define(std::make_unique<CompileCallbackMaterializationUnit>(
75 std::move(CallbackName), std::move(Compile))));
76 return *TrampolineAddr;
77 } else
78 return TrampolineAddr.takeError();
79 }
80
executeCompileCallback(JITTargetAddress TrampolineAddr)81 JITTargetAddress JITCompileCallbackManager::executeCompileCallback(
82 JITTargetAddress TrampolineAddr) {
83 SymbolStringPtr Name;
84
85 {
86 std::unique_lock<std::mutex> Lock(CCMgrMutex);
87 auto I = AddrToSymbol.find(TrampolineAddr);
88
89 // If this address is not associated with a compile callback then report an
90 // error to the execution session and return ErrorHandlerAddress to the
91 // callee.
92 if (I == AddrToSymbol.end()) {
93 Lock.unlock();
94 std::string ErrMsg;
95 {
96 raw_string_ostream ErrMsgStream(ErrMsg);
97 ErrMsgStream << "No compile callback for trampoline at "
98 << format("0x%016" PRIx64, TrampolineAddr);
99 }
100 ES.reportError(
101 make_error<StringError>(std::move(ErrMsg), inconvertibleErrorCode()));
102 return ErrorHandlerAddress;
103 } else
104 Name = I->second;
105 }
106
107 if (auto Sym =
108 ES.lookup(makeJITDylibSearchOrder(
109 &CallbacksJD, JITDylibLookupFlags::MatchAllSymbols),
110 Name))
111 return Sym->getAddress();
112 else {
113 llvm::dbgs() << "Didn't find callback.\n";
114 // If anything goes wrong materializing Sym then report it to the session
115 // and return the ErrorHandlerAddress;
116 ES.reportError(Sym.takeError());
117 return ErrorHandlerAddress;
118 }
119 }
120
121 Expected<std::unique_ptr<JITCompileCallbackManager>>
createLocalCompileCallbackManager(const Triple & T,ExecutionSession & ES,JITTargetAddress ErrorHandlerAddress)122 createLocalCompileCallbackManager(const Triple &T, ExecutionSession &ES,
123 JITTargetAddress ErrorHandlerAddress) {
124 switch (T.getArch()) {
125 default:
126 return make_error<StringError>(
127 std::string("No callback manager available for ") + T.str(),
128 inconvertibleErrorCode());
129 case Triple::aarch64:
130 case Triple::aarch64_32: {
131 typedef orc::LocalJITCompileCallbackManager<orc::OrcAArch64> CCMgrT;
132 return CCMgrT::Create(ES, ErrorHandlerAddress);
133 }
134
135 case Triple::x86: {
136 typedef orc::LocalJITCompileCallbackManager<orc::OrcI386> CCMgrT;
137 return CCMgrT::Create(ES, ErrorHandlerAddress);
138 }
139
140 case Triple::mips: {
141 typedef orc::LocalJITCompileCallbackManager<orc::OrcMips32Be> CCMgrT;
142 return CCMgrT::Create(ES, ErrorHandlerAddress);
143 }
144 case Triple::mipsel: {
145 typedef orc::LocalJITCompileCallbackManager<orc::OrcMips32Le> CCMgrT;
146 return CCMgrT::Create(ES, ErrorHandlerAddress);
147 }
148
149 case Triple::mips64:
150 case Triple::mips64el: {
151 typedef orc::LocalJITCompileCallbackManager<orc::OrcMips64> CCMgrT;
152 return CCMgrT::Create(ES, ErrorHandlerAddress);
153 }
154
155 case Triple::riscv64: {
156 typedef orc::LocalJITCompileCallbackManager<orc::OrcRiscv64> CCMgrT;
157 return CCMgrT::Create(ES, ErrorHandlerAddress);
158 }
159
160 case Triple::x86_64: {
161 if (T.getOS() == Triple::OSType::Win32) {
162 typedef orc::LocalJITCompileCallbackManager<orc::OrcX86_64_Win32> CCMgrT;
163 return CCMgrT::Create(ES, ErrorHandlerAddress);
164 } else {
165 typedef orc::LocalJITCompileCallbackManager<orc::OrcX86_64_SysV> CCMgrT;
166 return CCMgrT::Create(ES, ErrorHandlerAddress);
167 }
168 }
169
170 }
171 }
172
173 std::function<std::unique_ptr<IndirectStubsManager>()>
createLocalIndirectStubsManagerBuilder(const Triple & T)174 createLocalIndirectStubsManagerBuilder(const Triple &T) {
175 switch (T.getArch()) {
176 default:
177 return [](){
178 return std::make_unique<
179 orc::LocalIndirectStubsManager<orc::OrcGenericABI>>();
180 };
181
182 case Triple::aarch64:
183 case Triple::aarch64_32:
184 return [](){
185 return std::make_unique<
186 orc::LocalIndirectStubsManager<orc::OrcAArch64>>();
187 };
188
189 case Triple::x86:
190 return [](){
191 return std::make_unique<
192 orc::LocalIndirectStubsManager<orc::OrcI386>>();
193 };
194
195 case Triple::mips:
196 return [](){
197 return std::make_unique<
198 orc::LocalIndirectStubsManager<orc::OrcMips32Be>>();
199 };
200
201 case Triple::mipsel:
202 return [](){
203 return std::make_unique<
204 orc::LocalIndirectStubsManager<orc::OrcMips32Le>>();
205 };
206
207 case Triple::mips64:
208 case Triple::mips64el:
209 return [](){
210 return std::make_unique<
211 orc::LocalIndirectStubsManager<orc::OrcMips64>>();
212 };
213
214 case Triple::riscv64:
215 return []() {
216 return std::make_unique<
217 orc::LocalIndirectStubsManager<orc::OrcRiscv64>>();
218 };
219
220 case Triple::x86_64:
221 if (T.getOS() == Triple::OSType::Win32) {
222 return [](){
223 return std::make_unique<
224 orc::LocalIndirectStubsManager<orc::OrcX86_64_Win32>>();
225 };
226 } else {
227 return [](){
228 return std::make_unique<
229 orc::LocalIndirectStubsManager<orc::OrcX86_64_SysV>>();
230 };
231 }
232
233 }
234 }
235
createIRTypedAddress(FunctionType & FT,JITTargetAddress Addr)236 Constant* createIRTypedAddress(FunctionType &FT, JITTargetAddress Addr) {
237 Constant *AddrIntVal =
238 ConstantInt::get(Type::getInt64Ty(FT.getContext()), Addr);
239 Constant *AddrPtrVal =
240 ConstantExpr::getCast(Instruction::IntToPtr, AddrIntVal,
241 PointerType::get(&FT, 0));
242 return AddrPtrVal;
243 }
244
createImplPointer(PointerType & PT,Module & M,const Twine & Name,Constant * Initializer)245 GlobalVariable* createImplPointer(PointerType &PT, Module &M,
246 const Twine &Name, Constant *Initializer) {
247 auto IP = new GlobalVariable(M, &PT, false, GlobalValue::ExternalLinkage,
248 Initializer, Name, nullptr,
249 GlobalValue::NotThreadLocal, 0, true);
250 IP->setVisibility(GlobalValue::HiddenVisibility);
251 return IP;
252 }
253
makeStub(Function & F,Value & ImplPointer)254 void makeStub(Function &F, Value &ImplPointer) {
255 assert(F.isDeclaration() && "Can't turn a definition into a stub.");
256 assert(F.getParent() && "Function isn't in a module.");
257 Module &M = *F.getParent();
258 BasicBlock *EntryBlock = BasicBlock::Create(M.getContext(), "entry", &F);
259 IRBuilder<> Builder(EntryBlock);
260 LoadInst *ImplAddr = Builder.CreateLoad(F.getType(), &ImplPointer);
261 std::vector<Value*> CallArgs;
262 for (auto &A : F.args())
263 CallArgs.push_back(&A);
264 CallInst *Call = Builder.CreateCall(F.getFunctionType(), ImplAddr, CallArgs);
265 Call->setTailCall();
266 Call->setAttributes(F.getAttributes());
267 if (F.getReturnType()->isVoidTy())
268 Builder.CreateRetVoid();
269 else
270 Builder.CreateRet(Call);
271 }
272
operator ()(Module & M)273 std::vector<GlobalValue *> SymbolLinkagePromoter::operator()(Module &M) {
274 std::vector<GlobalValue *> PromotedGlobals;
275
276 for (auto &GV : M.global_values()) {
277 bool Promoted = true;
278
279 // Rename if necessary.
280 if (!GV.hasName())
281 GV.setName("__orc_anon." + Twine(NextId++));
282 else if (GV.getName().startswith("\01L"))
283 GV.setName("__" + GV.getName().substr(1) + "." + Twine(NextId++));
284 else if (GV.hasLocalLinkage())
285 GV.setName("__orc_lcl." + GV.getName() + "." + Twine(NextId++));
286 else
287 Promoted = false;
288
289 if (GV.hasLocalLinkage()) {
290 GV.setLinkage(GlobalValue::ExternalLinkage);
291 GV.setVisibility(GlobalValue::HiddenVisibility);
292 Promoted = true;
293 }
294 GV.setUnnamedAddr(GlobalValue::UnnamedAddr::None);
295
296 if (Promoted)
297 PromotedGlobals.push_back(&GV);
298 }
299
300 return PromotedGlobals;
301 }
302
cloneFunctionDecl(Module & Dst,const Function & F,ValueToValueMapTy * VMap)303 Function* cloneFunctionDecl(Module &Dst, const Function &F,
304 ValueToValueMapTy *VMap) {
305 Function *NewF =
306 Function::Create(cast<FunctionType>(F.getValueType()),
307 F.getLinkage(), F.getName(), &Dst);
308 NewF->copyAttributesFrom(&F);
309
310 if (VMap) {
311 (*VMap)[&F] = NewF;
312 auto NewArgI = NewF->arg_begin();
313 for (auto ArgI = F.arg_begin(), ArgE = F.arg_end(); ArgI != ArgE;
314 ++ArgI, ++NewArgI)
315 (*VMap)[&*ArgI] = &*NewArgI;
316 }
317
318 return NewF;
319 }
320
moveFunctionBody(Function & OrigF,ValueToValueMapTy & VMap,ValueMaterializer * Materializer,Function * NewF)321 void moveFunctionBody(Function &OrigF, ValueToValueMapTy &VMap,
322 ValueMaterializer *Materializer,
323 Function *NewF) {
324 assert(!OrigF.isDeclaration() && "Nothing to move");
325 if (!NewF)
326 NewF = cast<Function>(VMap[&OrigF]);
327 else
328 assert(VMap[&OrigF] == NewF && "Incorrect function mapping in VMap.");
329 assert(NewF && "Function mapping missing from VMap.");
330 assert(NewF->getParent() != OrigF.getParent() &&
331 "moveFunctionBody should only be used to move bodies between "
332 "modules.");
333
334 SmallVector<ReturnInst *, 8> Returns; // Ignore returns cloned.
335 CloneFunctionInto(NewF, &OrigF, VMap,
336 CloneFunctionChangeType::DifferentModule, Returns, "",
337 nullptr, nullptr, Materializer);
338 OrigF.deleteBody();
339 }
340
cloneGlobalVariableDecl(Module & Dst,const GlobalVariable & GV,ValueToValueMapTy * VMap)341 GlobalVariable* cloneGlobalVariableDecl(Module &Dst, const GlobalVariable &GV,
342 ValueToValueMapTy *VMap) {
343 GlobalVariable *NewGV = new GlobalVariable(
344 Dst, GV.getValueType(), GV.isConstant(),
345 GV.getLinkage(), nullptr, GV.getName(), nullptr,
346 GV.getThreadLocalMode(), GV.getType()->getAddressSpace());
347 NewGV->copyAttributesFrom(&GV);
348 if (VMap)
349 (*VMap)[&GV] = NewGV;
350 return NewGV;
351 }
352
moveGlobalVariableInitializer(GlobalVariable & OrigGV,ValueToValueMapTy & VMap,ValueMaterializer * Materializer,GlobalVariable * NewGV)353 void moveGlobalVariableInitializer(GlobalVariable &OrigGV,
354 ValueToValueMapTy &VMap,
355 ValueMaterializer *Materializer,
356 GlobalVariable *NewGV) {
357 assert(OrigGV.hasInitializer() && "Nothing to move");
358 if (!NewGV)
359 NewGV = cast<GlobalVariable>(VMap[&OrigGV]);
360 else
361 assert(VMap[&OrigGV] == NewGV &&
362 "Incorrect global variable mapping in VMap.");
363 assert(NewGV->getParent() != OrigGV.getParent() &&
364 "moveGlobalVariableInitializer should only be used to move "
365 "initializers between modules");
366
367 NewGV->setInitializer(MapValue(OrigGV.getInitializer(), VMap, RF_None,
368 nullptr, Materializer));
369 }
370
cloneGlobalAliasDecl(Module & Dst,const GlobalAlias & OrigA,ValueToValueMapTy & VMap)371 GlobalAlias* cloneGlobalAliasDecl(Module &Dst, const GlobalAlias &OrigA,
372 ValueToValueMapTy &VMap) {
373 assert(OrigA.getAliasee() && "Original alias doesn't have an aliasee?");
374 auto *NewA = GlobalAlias::create(OrigA.getValueType(),
375 OrigA.getType()->getPointerAddressSpace(),
376 OrigA.getLinkage(), OrigA.getName(), &Dst);
377 NewA->copyAttributesFrom(&OrigA);
378 VMap[&OrigA] = NewA;
379 return NewA;
380 }
381
cloneModuleFlagsMetadata(Module & Dst,const Module & Src,ValueToValueMapTy & VMap)382 void cloneModuleFlagsMetadata(Module &Dst, const Module &Src,
383 ValueToValueMapTy &VMap) {
384 auto *MFs = Src.getModuleFlagsMetadata();
385 if (!MFs)
386 return;
387 for (auto *MF : MFs->operands())
388 Dst.addModuleFlag(MapMetadata(MF, VMap));
389 }
390
addFunctionPointerRelocationsToCurrentSymbol(jitlink::Symbol & Sym,jitlink::LinkGraph & G,MCDisassembler & Disassembler,MCInstrAnalysis & MIA)391 Error addFunctionPointerRelocationsToCurrentSymbol(jitlink::Symbol &Sym,
392 jitlink::LinkGraph &G,
393 MCDisassembler &Disassembler,
394 MCInstrAnalysis &MIA) {
395 // AArch64 appears to already come with the necessary relocations. Among other
396 // architectures, only x86_64 is currently implemented here.
397 if (G.getTargetTriple().getArch() != Triple::x86_64)
398 return Error::success();
399
400 raw_null_ostream CommentStream;
401 auto &STI = Disassembler.getSubtargetInfo();
402
403 // Determine the function bounds
404 auto &B = Sym.getBlock();
405 assert(!B.isZeroFill() && "expected content block");
406 auto SymAddress = Sym.getAddress();
407 auto SymStartInBlock =
408 (const uint8_t *)B.getContent().data() + Sym.getOffset();
409 auto SymSize = Sym.getSize() ? Sym.getSize() : B.getSize() - Sym.getOffset();
410 auto Content = makeArrayRef(SymStartInBlock, SymSize);
411
412 LLVM_DEBUG(dbgs() << "Adding self-relocations to " << Sym.getName() << "\n");
413
414 SmallDenseSet<uintptr_t, 8> ExistingRelocations;
415 for (auto &E : B.edges()) {
416 if (E.isRelocation())
417 ExistingRelocations.insert(E.getOffset());
418 }
419
420 size_t I = 0;
421 while (I < Content.size()) {
422 MCInst Instr;
423 uint64_t InstrSize = 0;
424 uint64_t InstrStart = SymAddress.getValue() + I;
425 auto DecodeStatus = Disassembler.getInstruction(
426 Instr, InstrSize, Content.drop_front(I), InstrStart, CommentStream);
427 if (DecodeStatus != MCDisassembler::Success) {
428 LLVM_DEBUG(dbgs() << "Aborting due to disassembly failure at address "
429 << InstrStart);
430 return make_error<StringError>(
431 formatv("failed to disassemble at address {0:x16}", InstrStart),
432 inconvertibleErrorCode());
433 }
434 // Advance to the next instruction.
435 I += InstrSize;
436
437 // Check for a PC-relative address equal to the symbol itself.
438 auto PCRelAddr =
439 MIA.evaluateMemoryOperandAddress(Instr, &STI, InstrStart, InstrSize);
440 if (!PCRelAddr || *PCRelAddr != SymAddress.getValue())
441 continue;
442
443 auto RelocOffInInstr =
444 MIA.getMemoryOperandRelocationOffset(Instr, InstrSize);
445 if (!RelocOffInInstr || InstrSize - *RelocOffInInstr != 4) {
446 LLVM_DEBUG(dbgs() << "Skipping unknown self-relocation at "
447 << InstrStart);
448 continue;
449 }
450
451 auto RelocOffInBlock = orc::ExecutorAddr(InstrStart) + *RelocOffInInstr -
452 SymAddress + Sym.getOffset();
453 if (ExistingRelocations.contains(RelocOffInBlock))
454 continue;
455
456 LLVM_DEBUG(dbgs() << "Adding delta32 self-relocation at " << InstrStart);
457 B.addEdge(jitlink::x86_64::Delta32, RelocOffInBlock, Sym, /*Addend=*/-4);
458 }
459 return Error::success();
460 }
461
462 } // End namespace orc.
463 } // End namespace llvm.
464