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/Orc/OrcABISupport.h"
13 #include "llvm/IR/CallSite.h"
14 #include "llvm/IR/IRBuilder.h"
15 #include "llvm/Support/Format.h"
16 #include "llvm/Transforms/Utils/Cloning.h"
17 #include <sstream>
18 
19 using namespace llvm;
20 using namespace llvm::orc;
21 
22 namespace {
23 
24 class CompileCallbackMaterializationUnit : public orc::MaterializationUnit {
25 public:
26   using CompileFunction = JITCompileCallbackManager::CompileFunction;
27 
28   CompileCallbackMaterializationUnit(SymbolStringPtr Name,
29                                      CompileFunction Compile, VModuleKey K)
30       : MaterializationUnit(SymbolFlagsMap({{Name, JITSymbolFlags::Exported}}),
31                             std::move(K)),
32         Name(std::move(Name)), Compile(std::move(Compile)) {}
33 
34   StringRef getName() const override { return "<Compile Callbacks>"; }
35 
36 private:
37   void materialize(MaterializationResponsibility R) override {
38     SymbolMap Result;
39     Result[Name] = JITEvaluatedSymbol(Compile(), JITSymbolFlags::Exported);
40     R.resolve(Result);
41     R.emit();
42   }
43 
44   void discard(const JITDylib &JD, const SymbolStringPtr &Name) override {
45     llvm_unreachable("Discard should never occur on a LMU?");
46   }
47 
48   SymbolStringPtr Name;
49   CompileFunction Compile;
50 };
51 
52 } // namespace
53 
54 namespace llvm {
55 namespace orc {
56 
57 void IndirectStubsManager::anchor() {}
58 void TrampolinePool::anchor() {}
59 
60 Expected<JITTargetAddress>
61 JITCompileCallbackManager::getCompileCallback(CompileFunction Compile) {
62   if (auto TrampolineAddr = TP->getTrampoline()) {
63     auto CallbackName =
64         ES.intern(std::string("cc") + std::to_string(++NextCallbackId));
65 
66     std::lock_guard<std::mutex> Lock(CCMgrMutex);
67     AddrToSymbol[*TrampolineAddr] = CallbackName;
68     cantFail(CallbacksJD.define(
69         llvm::make_unique<CompileCallbackMaterializationUnit>(
70             std::move(CallbackName), std::move(Compile),
71             ES.allocateVModule())));
72     return *TrampolineAddr;
73   } else
74     return TrampolineAddr.takeError();
75 }
76 
77 JITTargetAddress JITCompileCallbackManager::executeCompileCallback(
78     JITTargetAddress TrampolineAddr) {
79   SymbolStringPtr Name;
80 
81   {
82     std::unique_lock<std::mutex> Lock(CCMgrMutex);
83     auto I = AddrToSymbol.find(TrampolineAddr);
84 
85     // If this address is not associated with a compile callback then report an
86     // error to the execution session and return ErrorHandlerAddress to the
87     // callee.
88     if (I == AddrToSymbol.end()) {
89       Lock.unlock();
90       std::string ErrMsg;
91       {
92         raw_string_ostream ErrMsgStream(ErrMsg);
93         ErrMsgStream << "No compile callback for trampoline at "
94                      << format("0x%016" PRIx64, TrampolineAddr);
95       }
96       ES.reportError(
97           make_error<StringError>(std::move(ErrMsg), inconvertibleErrorCode()));
98       return ErrorHandlerAddress;
99     } else
100       Name = I->second;
101   }
102 
103   if (auto Sym = ES.lookup(JITDylibSearchList({{&CallbacksJD, true}}), Name))
104     return Sym->getAddress();
105   else {
106     llvm::dbgs() << "Didn't find callback.\n";
107     // If anything goes wrong materializing Sym then report it to the session
108     // and return the ErrorHandlerAddress;
109     ES.reportError(Sym.takeError());
110     return ErrorHandlerAddress;
111   }
112 }
113 
114 Expected<std::unique_ptr<JITCompileCallbackManager>>
115 createLocalCompileCallbackManager(const Triple &T, ExecutionSession &ES,
116                                   JITTargetAddress ErrorHandlerAddress) {
117   switch (T.getArch()) {
118   default:
119     return make_error<StringError>(
120         std::string("No callback manager available for ") + T.str(),
121         inconvertibleErrorCode());
122   case Triple::aarch64: {
123     typedef orc::LocalJITCompileCallbackManager<orc::OrcAArch64> CCMgrT;
124     return CCMgrT::Create(ES, ErrorHandlerAddress);
125     }
126 
127     case Triple::x86: {
128       typedef orc::LocalJITCompileCallbackManager<orc::OrcI386> CCMgrT;
129       return CCMgrT::Create(ES, ErrorHandlerAddress);
130     }
131 
132     case Triple::mips: {
133       typedef orc::LocalJITCompileCallbackManager<orc::OrcMips32Be> CCMgrT;
134       return CCMgrT::Create(ES, ErrorHandlerAddress);
135     }
136     case Triple::mipsel: {
137       typedef orc::LocalJITCompileCallbackManager<orc::OrcMips32Le> CCMgrT;
138       return CCMgrT::Create(ES, ErrorHandlerAddress);
139     }
140 
141     case Triple::mips64:
142     case Triple::mips64el: {
143       typedef orc::LocalJITCompileCallbackManager<orc::OrcMips64> CCMgrT;
144       return CCMgrT::Create(ES, ErrorHandlerAddress);
145     }
146 
147     case Triple::x86_64: {
148       if ( T.getOS() == Triple::OSType::Win32 ) {
149         typedef orc::LocalJITCompileCallbackManager<orc::OrcX86_64_Win32> CCMgrT;
150         return CCMgrT::Create(ES, ErrorHandlerAddress);
151       } else {
152         typedef orc::LocalJITCompileCallbackManager<orc::OrcX86_64_SysV> CCMgrT;
153         return CCMgrT::Create(ES, ErrorHandlerAddress);
154       }
155     }
156 
157   }
158 }
159 
160 std::function<std::unique_ptr<IndirectStubsManager>()>
161 createLocalIndirectStubsManagerBuilder(const Triple &T) {
162   switch (T.getArch()) {
163     default:
164       return [](){
165         return llvm::make_unique<
166                        orc::LocalIndirectStubsManager<orc::OrcGenericABI>>();
167       };
168 
169     case Triple::aarch64:
170       return [](){
171         return llvm::make_unique<
172                        orc::LocalIndirectStubsManager<orc::OrcAArch64>>();
173       };
174 
175     case Triple::x86:
176       return [](){
177         return llvm::make_unique<
178                        orc::LocalIndirectStubsManager<orc::OrcI386>>();
179       };
180 
181     case Triple::mips:
182       return [](){
183           return llvm::make_unique<
184                       orc::LocalIndirectStubsManager<orc::OrcMips32Be>>();
185       };
186 
187     case Triple::mipsel:
188       return [](){
189           return llvm::make_unique<
190                       orc::LocalIndirectStubsManager<orc::OrcMips32Le>>();
191       };
192 
193     case Triple::mips64:
194     case Triple::mips64el:
195       return [](){
196           return llvm::make_unique<
197                       orc::LocalIndirectStubsManager<orc::OrcMips64>>();
198       };
199 
200     case Triple::x86_64:
201       if (T.getOS() == Triple::OSType::Win32) {
202         return [](){
203           return llvm::make_unique<
204                      orc::LocalIndirectStubsManager<orc::OrcX86_64_Win32>>();
205         };
206       } else {
207         return [](){
208           return llvm::make_unique<
209                      orc::LocalIndirectStubsManager<orc::OrcX86_64_SysV>>();
210         };
211       }
212 
213   }
214 }
215 
216 Constant* createIRTypedAddress(FunctionType &FT, JITTargetAddress Addr) {
217   Constant *AddrIntVal =
218     ConstantInt::get(Type::getInt64Ty(FT.getContext()), Addr);
219   Constant *AddrPtrVal =
220     ConstantExpr::getCast(Instruction::IntToPtr, AddrIntVal,
221                           PointerType::get(&FT, 0));
222   return AddrPtrVal;
223 }
224 
225 GlobalVariable* createImplPointer(PointerType &PT, Module &M,
226                                   const Twine &Name, Constant *Initializer) {
227   auto IP = new GlobalVariable(M, &PT, false, GlobalValue::ExternalLinkage,
228                                Initializer, Name, nullptr,
229                                GlobalValue::NotThreadLocal, 0, true);
230   IP->setVisibility(GlobalValue::HiddenVisibility);
231   return IP;
232 }
233 
234 void makeStub(Function &F, Value &ImplPointer) {
235   assert(F.isDeclaration() && "Can't turn a definition into a stub.");
236   assert(F.getParent() && "Function isn't in a module.");
237   Module &M = *F.getParent();
238   FunctionType *FTy = F.getFunctionType();
239   BasicBlock *EntryBlock = BasicBlock::Create(M.getContext(), "entry", &F);
240   IRBuilder<> Builder(EntryBlock);
241   LoadInst *ImplAddr = Builder.CreateLoad(&ImplPointer);
242   std::vector<Value*> CallArgs;
243   for (auto &A : F.args())
244     CallArgs.push_back(&A);
245   CallInst *Call = Builder.CreateCall(FTy, ImplAddr, CallArgs);
246   Call->setTailCall();
247   Call->setAttributes(F.getAttributes());
248   if (F.getReturnType()->isVoidTy())
249     Builder.CreateRetVoid();
250   else
251     Builder.CreateRet(Call);
252 }
253 
254 std::vector<GlobalValue *> SymbolLinkagePromoter::operator()(Module &M) {
255   std::vector<GlobalValue *> PromotedGlobals;
256 
257   for (auto &GV : M.global_values()) {
258     bool Promoted = true;
259 
260     // Rename if necessary.
261     if (!GV.hasName())
262       GV.setName("__orc_anon." + Twine(NextId++));
263     else if (GV.getName().startswith("\01L"))
264       GV.setName("__" + GV.getName().substr(1) + "." + Twine(NextId++));
265     else if (GV.hasLocalLinkage())
266       GV.setName("__orc_lcl." + GV.getName() + "." + Twine(NextId++));
267     else
268       Promoted = false;
269 
270     if (GV.hasLocalLinkage()) {
271       GV.setLinkage(GlobalValue::ExternalLinkage);
272       GV.setVisibility(GlobalValue::HiddenVisibility);
273       Promoted = true;
274     }
275     GV.setUnnamedAddr(GlobalValue::UnnamedAddr::None);
276 
277     if (Promoted)
278       PromotedGlobals.push_back(&GV);
279   }
280 
281   return PromotedGlobals;
282 }
283 
284 Function* cloneFunctionDecl(Module &Dst, const Function &F,
285                             ValueToValueMapTy *VMap) {
286   Function *NewF =
287     Function::Create(cast<FunctionType>(F.getValueType()),
288                      F.getLinkage(), F.getName(), &Dst);
289   NewF->copyAttributesFrom(&F);
290 
291   if (VMap) {
292     (*VMap)[&F] = NewF;
293     auto NewArgI = NewF->arg_begin();
294     for (auto ArgI = F.arg_begin(), ArgE = F.arg_end(); ArgI != ArgE;
295          ++ArgI, ++NewArgI)
296       (*VMap)[&*ArgI] = &*NewArgI;
297   }
298 
299   return NewF;
300 }
301 
302 void moveFunctionBody(Function &OrigF, ValueToValueMapTy &VMap,
303                       ValueMaterializer *Materializer,
304                       Function *NewF) {
305   assert(!OrigF.isDeclaration() && "Nothing to move");
306   if (!NewF)
307     NewF = cast<Function>(VMap[&OrigF]);
308   else
309     assert(VMap[&OrigF] == NewF && "Incorrect function mapping in VMap.");
310   assert(NewF && "Function mapping missing from VMap.");
311   assert(NewF->getParent() != OrigF.getParent() &&
312          "moveFunctionBody should only be used to move bodies between "
313          "modules.");
314 
315   SmallVector<ReturnInst *, 8> Returns; // Ignore returns cloned.
316   CloneFunctionInto(NewF, &OrigF, VMap, /*ModuleLevelChanges=*/true, Returns,
317                     "", nullptr, nullptr, Materializer);
318   OrigF.deleteBody();
319 }
320 
321 GlobalVariable* cloneGlobalVariableDecl(Module &Dst, const GlobalVariable &GV,
322                                         ValueToValueMapTy *VMap) {
323   GlobalVariable *NewGV = new GlobalVariable(
324       Dst, GV.getValueType(), GV.isConstant(),
325       GV.getLinkage(), nullptr, GV.getName(), nullptr,
326       GV.getThreadLocalMode(), GV.getType()->getAddressSpace());
327   NewGV->copyAttributesFrom(&GV);
328   if (VMap)
329     (*VMap)[&GV] = NewGV;
330   return NewGV;
331 }
332 
333 void moveGlobalVariableInitializer(GlobalVariable &OrigGV,
334                                    ValueToValueMapTy &VMap,
335                                    ValueMaterializer *Materializer,
336                                    GlobalVariable *NewGV) {
337   assert(OrigGV.hasInitializer() && "Nothing to move");
338   if (!NewGV)
339     NewGV = cast<GlobalVariable>(VMap[&OrigGV]);
340   else
341     assert(VMap[&OrigGV] == NewGV &&
342            "Incorrect global variable mapping in VMap.");
343   assert(NewGV->getParent() != OrigGV.getParent() &&
344          "moveGlobalVariableInitializer should only be used to move "
345          "initializers between modules");
346 
347   NewGV->setInitializer(MapValue(OrigGV.getInitializer(), VMap, RF_None,
348                                  nullptr, Materializer));
349 }
350 
351 GlobalAlias* cloneGlobalAliasDecl(Module &Dst, const GlobalAlias &OrigA,
352                                   ValueToValueMapTy &VMap) {
353   assert(OrigA.getAliasee() && "Original alias doesn't have an aliasee?");
354   auto *NewA = GlobalAlias::create(OrigA.getValueType(),
355                                    OrigA.getType()->getPointerAddressSpace(),
356                                    OrigA.getLinkage(), OrigA.getName(), &Dst);
357   NewA->copyAttributesFrom(&OrigA);
358   VMap[&OrigA] = NewA;
359   return NewA;
360 }
361 
362 void cloneModuleFlagsMetadata(Module &Dst, const Module &Src,
363                               ValueToValueMapTy &VMap) {
364   auto *MFs = Src.getModuleFlagsMetadata();
365   if (!MFs)
366     return;
367   for (auto *MF : MFs->operands())
368     Dst.addModuleFlag(MapMetadata(MF, VMap));
369 }
370 
371 } // End namespace orc.
372 } // End namespace llvm.
373