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/ADT/STLExtras.h"
11 #include "llvm/ADT/Triple.h"
12 #include "llvm/ExecutionEngine/Orc/IndirectionUtils.h"
13 #include "llvm/ExecutionEngine/Orc/OrcABISupport.h"
14 #include "llvm/IR/CallSite.h"
15 #include "llvm/IR/IRBuilder.h"
16 #include "llvm/Transforms/Utils/Cloning.h"
17 #include <sstream>
18 
19 namespace llvm {
20 namespace orc {
21 
22 void JITCompileCallbackManager::anchor() {}
23 void IndirectStubsManager::anchor() {}
24 
25 std::unique_ptr<JITCompileCallbackManager>
26 createLocalCompileCallbackManager(const Triple &T,
27                                   JITTargetAddress ErrorHandlerAddress) {
28   switch (T.getArch()) {
29     default: return nullptr;
30 
31     case Triple::x86: {
32       typedef orc::LocalJITCompileCallbackManager<orc::OrcI386> CCMgrT;
33       return llvm::make_unique<CCMgrT>(ErrorHandlerAddress);
34     }
35 
36     case Triple::x86_64: {
37       if ( T.getOS() == Triple::OSType::Win32 ) {
38         typedef orc::LocalJITCompileCallbackManager<orc::OrcX86_64_Win32> CCMgrT;
39         return llvm::make_unique<CCMgrT>(ErrorHandlerAddress);
40       } else {
41         typedef orc::LocalJITCompileCallbackManager<orc::OrcX86_64_SysV> CCMgrT;
42         return llvm::make_unique<CCMgrT>(ErrorHandlerAddress);
43       }
44     }
45   }
46 }
47 
48 std::function<std::unique_ptr<IndirectStubsManager>()>
49 createLocalIndirectStubsManagerBuilder(const Triple &T) {
50   switch (T.getArch()) {
51     default: return nullptr;
52 
53     case Triple::x86:
54       return [](){
55         return llvm::make_unique<
56                        orc::LocalIndirectStubsManager<orc::OrcI386>>();
57       };
58 
59     case Triple::x86_64:
60       if (T.getOS() == Triple::OSType::Win32) {
61         return [](){
62           return llvm::make_unique<
63                      orc::LocalIndirectStubsManager<orc::OrcX86_64_Win32>>();
64         };
65       } else {
66         return [](){
67           return llvm::make_unique<
68                      orc::LocalIndirectStubsManager<orc::OrcX86_64_SysV>>();
69         };
70       }
71   }
72 }
73 
74 Constant* createIRTypedAddress(FunctionType &FT, JITTargetAddress Addr) {
75   Constant *AddrIntVal =
76     ConstantInt::get(Type::getInt64Ty(FT.getContext()), Addr);
77   Constant *AddrPtrVal =
78     ConstantExpr::getCast(Instruction::IntToPtr, AddrIntVal,
79                           PointerType::get(&FT, 0));
80   return AddrPtrVal;
81 }
82 
83 GlobalVariable* createImplPointer(PointerType &PT, Module &M,
84                                   const Twine &Name, Constant *Initializer) {
85   auto IP = new GlobalVariable(M, &PT, false, GlobalValue::ExternalLinkage,
86                                Initializer, Name, nullptr,
87                                GlobalValue::NotThreadLocal, 0, true);
88   IP->setVisibility(GlobalValue::HiddenVisibility);
89   return IP;
90 }
91 
92 void makeStub(Function &F, Value &ImplPointer) {
93   assert(F.isDeclaration() && "Can't turn a definition into a stub.");
94   assert(F.getParent() && "Function isn't in a module.");
95   Module &M = *F.getParent();
96   BasicBlock *EntryBlock = BasicBlock::Create(M.getContext(), "entry", &F);
97   IRBuilder<> Builder(EntryBlock);
98   LoadInst *ImplAddr = Builder.CreateLoad(&ImplPointer);
99   std::vector<Value*> CallArgs;
100   for (auto &A : F.args())
101     CallArgs.push_back(&A);
102   CallInst *Call = Builder.CreateCall(ImplAddr, CallArgs);
103   Call->setTailCall();
104   Call->setAttributes(F.getAttributes());
105   if (F.getReturnType()->isVoidTy())
106     Builder.CreateRetVoid();
107   else
108     Builder.CreateRet(Call);
109 }
110 
111 // Utility class for renaming global values and functions during partitioning.
112 class GlobalRenamer {
113 public:
114 
115   static bool needsRenaming(const Value &New) {
116     return !New.hasName() || New.getName().startswith("\01L");
117   }
118 
119   const std::string& getRename(const Value &Orig) {
120     // See if we have a name for this global.
121     {
122       auto I = Names.find(&Orig);
123       if (I != Names.end())
124         return I->second;
125     }
126 
127     // Nope. Create a new one.
128     // FIXME: Use a more robust uniquing scheme. (This may blow up if the user
129     //        writes a "__orc_anon[[:digit:]]* method).
130     unsigned ID = Names.size();
131     std::ostringstream NameStream;
132     NameStream << "__orc_anon" << ID++;
133     auto I = Names.insert(std::make_pair(&Orig, NameStream.str()));
134     return I.first->second;
135   }
136 private:
137   DenseMap<const Value*, std::string> Names;
138 };
139 
140 static void raiseVisibilityOnValue(GlobalValue &V, GlobalRenamer &R) {
141   if (V.hasLocalLinkage()) {
142     if (R.needsRenaming(V))
143       V.setName(R.getRename(V));
144     V.setLinkage(GlobalValue::ExternalLinkage);
145     V.setVisibility(GlobalValue::HiddenVisibility);
146   }
147   V.setUnnamedAddr(GlobalValue::UnnamedAddr::None);
148   assert(!R.needsRenaming(V) && "Invalid global name.");
149 }
150 
151 void makeAllSymbolsExternallyAccessible(Module &M) {
152   GlobalRenamer Renamer;
153 
154   for (auto &F : M)
155     raiseVisibilityOnValue(F, Renamer);
156 
157   for (auto &GV : M.globals())
158     raiseVisibilityOnValue(GV, Renamer);
159 
160   for (auto &A : M.aliases())
161     raiseVisibilityOnValue(A, Renamer);
162 }
163 
164 Function* cloneFunctionDecl(Module &Dst, const Function &F,
165                             ValueToValueMapTy *VMap) {
166   assert(F.getParent() != &Dst && "Can't copy decl over existing function.");
167   Function *NewF =
168     Function::Create(cast<FunctionType>(F.getValueType()),
169                      F.getLinkage(), F.getName(), &Dst);
170   NewF->copyAttributesFrom(&F);
171 
172   if (VMap) {
173     (*VMap)[&F] = NewF;
174     auto NewArgI = NewF->arg_begin();
175     for (auto ArgI = F.arg_begin(), ArgE = F.arg_end(); ArgI != ArgE;
176          ++ArgI, ++NewArgI)
177       (*VMap)[&*ArgI] = &*NewArgI;
178   }
179 
180   return NewF;
181 }
182 
183 void moveFunctionBody(Function &OrigF, ValueToValueMapTy &VMap,
184                       ValueMaterializer *Materializer,
185                       Function *NewF) {
186   assert(!OrigF.isDeclaration() && "Nothing to move");
187   if (!NewF)
188     NewF = cast<Function>(VMap[&OrigF]);
189   else
190     assert(VMap[&OrigF] == NewF && "Incorrect function mapping in VMap.");
191   assert(NewF && "Function mapping missing from VMap.");
192   assert(NewF->getParent() != OrigF.getParent() &&
193          "moveFunctionBody should only be used to move bodies between "
194          "modules.");
195 
196   SmallVector<ReturnInst *, 8> Returns; // Ignore returns cloned.
197   CloneFunctionInto(NewF, &OrigF, VMap, /*ModuleLevelChanges=*/true, Returns,
198                     "", nullptr, nullptr, Materializer);
199   OrigF.deleteBody();
200 }
201 
202 GlobalVariable* cloneGlobalVariableDecl(Module &Dst, const GlobalVariable &GV,
203                                         ValueToValueMapTy *VMap) {
204   assert(GV.getParent() != &Dst && "Can't copy decl over existing global var.");
205   GlobalVariable *NewGV = new GlobalVariable(
206       Dst, GV.getValueType(), GV.isConstant(),
207       GV.getLinkage(), nullptr, GV.getName(), nullptr,
208       GV.getThreadLocalMode(), GV.getType()->getAddressSpace());
209   NewGV->copyAttributesFrom(&GV);
210   if (VMap)
211     (*VMap)[&GV] = NewGV;
212   return NewGV;
213 }
214 
215 void moveGlobalVariableInitializer(GlobalVariable &OrigGV,
216                                    ValueToValueMapTy &VMap,
217                                    ValueMaterializer *Materializer,
218                                    GlobalVariable *NewGV) {
219   assert(OrigGV.hasInitializer() && "Nothing to move");
220   if (!NewGV)
221     NewGV = cast<GlobalVariable>(VMap[&OrigGV]);
222   else
223     assert(VMap[&OrigGV] == NewGV &&
224            "Incorrect global variable mapping in VMap.");
225   assert(NewGV->getParent() != OrigGV.getParent() &&
226          "moveGlobalVariable should only be used to move initializers between "
227          "modules");
228 
229   NewGV->setInitializer(MapValue(OrigGV.getInitializer(), VMap, RF_None,
230                                  nullptr, Materializer));
231 }
232 
233 GlobalAlias* cloneGlobalAliasDecl(Module &Dst, const GlobalAlias &OrigA,
234                                   ValueToValueMapTy &VMap) {
235   assert(OrigA.getAliasee() && "Original alias doesn't have an aliasee?");
236   auto *NewA = GlobalAlias::create(OrigA.getValueType(),
237                                    OrigA.getType()->getPointerAddressSpace(),
238                                    OrigA.getLinkage(), OrigA.getName(), &Dst);
239   NewA->copyAttributesFrom(&OrigA);
240   VMap[&OrigA] = NewA;
241   return NewA;
242 }
243 
244 void cloneModuleFlagsMetadata(Module &Dst, const Module &Src,
245                               ValueToValueMapTy &VMap) {
246   auto *MFs = Src.getModuleFlagsMetadata();
247   if (!MFs)
248     return;
249   for (auto *MF : MFs->operands())
250     Dst.addModuleFlag(MapMetadata(MF, VMap));
251 }
252 
253 } // End namespace orc.
254 } // End namespace llvm.
255