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