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(Triple T, TargetAddress ErrorHandlerAddress) {
27   switch (T.getArch()) {
28     default: return nullptr;
29 
30     case Triple::x86: {
31       typedef orc::LocalJITCompileCallbackManager<orc::OrcI386> CCMgrT;
32       return llvm::make_unique<CCMgrT>(ErrorHandlerAddress);
33     }
34 
35     case Triple::x86_64: {
36       if ( T.getOS() == Triple::OSType::Win32 ) {
37         typedef orc::LocalJITCompileCallbackManager<orc::OrcX86_64_Win32> CCMgrT;
38         return llvm::make_unique<CCMgrT>(ErrorHandlerAddress);
39       } else {
40         typedef orc::LocalJITCompileCallbackManager<orc::OrcX86_64_SysV> CCMgrT;
41         return llvm::make_unique<CCMgrT>(ErrorHandlerAddress);
42       }
43     }
44   }
45 }
46 
47 std::function<std::unique_ptr<IndirectStubsManager>()>
48 createLocalIndirectStubsManagerBuilder(Triple T) {
49   switch (T.getArch()) {
50     default: return nullptr;
51 
52     case Triple::x86:
53       return [](){
54         return llvm::make_unique<
55                        orc::LocalIndirectStubsManager<orc::OrcI386>>();
56       };
57 
58     case Triple::x86_64:
59       if (T.getOS() == Triple::OSType::Win32) {
60         return [](){
61           return llvm::make_unique<
62                      orc::LocalIndirectStubsManager<orc::OrcX86_64_Win32>>();
63         };
64       } else {
65         return [](){
66           return llvm::make_unique<
67                      orc::LocalIndirectStubsManager<orc::OrcX86_64_SysV>>();
68         };
69       }
70   }
71 }
72 
73 Constant* createIRTypedAddress(FunctionType &FT, TargetAddress Addr) {
74   Constant *AddrIntVal =
75     ConstantInt::get(Type::getInt64Ty(FT.getContext()), Addr);
76   Constant *AddrPtrVal =
77     ConstantExpr::getCast(Instruction::IntToPtr, AddrIntVal,
78                           PointerType::get(&FT, 0));
79   return AddrPtrVal;
80 }
81 
82 GlobalVariable* createImplPointer(PointerType &PT, Module &M,
83                                   const Twine &Name, Constant *Initializer) {
84   auto IP = new GlobalVariable(M, &PT, false, GlobalValue::ExternalLinkage,
85                                Initializer, Name, nullptr,
86                                GlobalValue::NotThreadLocal, 0, true);
87   IP->setVisibility(GlobalValue::HiddenVisibility);
88   return IP;
89 }
90 
91 void makeStub(Function &F, Value &ImplPointer) {
92   assert(F.isDeclaration() && "Can't turn a definition into a stub.");
93   assert(F.getParent() && "Function isn't in a module.");
94   Module &M = *F.getParent();
95   BasicBlock *EntryBlock = BasicBlock::Create(M.getContext(), "entry", &F);
96   IRBuilder<> Builder(EntryBlock);
97   LoadInst *ImplAddr = Builder.CreateLoad(&ImplPointer);
98   std::vector<Value*> CallArgs;
99   for (auto &A : F.args())
100     CallArgs.push_back(&A);
101   CallInst *Call = Builder.CreateCall(ImplAddr, CallArgs);
102   Call->setTailCall();
103   Call->setAttributes(F.getAttributes());
104   if (F.getReturnType()->isVoidTy())
105     Builder.CreateRetVoid();
106   else
107     Builder.CreateRet(Call);
108 }
109 
110 // Utility class for renaming global values and functions during partitioning.
111 class GlobalRenamer {
112 public:
113 
114   static bool needsRenaming(const Value &New) {
115     return !New.hasName() || New.getName().startswith("\01L");
116   }
117 
118   const std::string& getRename(const Value &Orig) {
119     // See if we have a name for this global.
120     {
121       auto I = Names.find(&Orig);
122       if (I != Names.end())
123         return I->second;
124     }
125 
126     // Nope. Create a new one.
127     // FIXME: Use a more robust uniquing scheme. (This may blow up if the user
128     //        writes a "__orc_anon[[:digit:]]* method).
129     unsigned ID = Names.size();
130     std::ostringstream NameStream;
131     NameStream << "__orc_anon" << ID++;
132     auto I = Names.insert(std::make_pair(&Orig, NameStream.str()));
133     return I.first->second;
134   }
135 private:
136   DenseMap<const Value*, std::string> Names;
137 };
138 
139 static void raiseVisibilityOnValue(GlobalValue &V, GlobalRenamer &R) {
140   if (V.hasLocalLinkage()) {
141     if (R.needsRenaming(V))
142       V.setName(R.getRename(V));
143     V.setLinkage(GlobalValue::ExternalLinkage);
144     V.setVisibility(GlobalValue::HiddenVisibility);
145   }
146   V.setUnnamedAddr(false);
147   assert(!R.needsRenaming(V) && "Invalid global name.");
148 }
149 
150 void makeAllSymbolsExternallyAccessible(Module &M) {
151   GlobalRenamer Renamer;
152 
153   for (auto &F : M)
154     raiseVisibilityOnValue(F, Renamer);
155 
156   for (auto &GV : M.globals())
157     raiseVisibilityOnValue(GV, Renamer);
158 
159   for (auto &A : M.aliases())
160     raiseVisibilityOnValue(A, Renamer);
161 }
162 
163 Function* cloneFunctionDecl(Module &Dst, const Function &F,
164                             ValueToValueMapTy *VMap) {
165   assert(F.getParent() != &Dst && "Can't copy decl over existing function.");
166   Function *NewF =
167     Function::Create(cast<FunctionType>(F.getValueType()),
168                      F.getLinkage(), F.getName(), &Dst);
169   NewF->copyAttributesFrom(&F);
170 
171   if (VMap) {
172     (*VMap)[&F] = NewF;
173     auto NewArgI = NewF->arg_begin();
174     for (auto ArgI = F.arg_begin(), ArgE = F.arg_end(); ArgI != ArgE;
175          ++ArgI, ++NewArgI)
176       (*VMap)[&*ArgI] = &*NewArgI;
177   }
178 
179   return NewF;
180 }
181 
182 void moveFunctionBody(Function &OrigF, ValueToValueMapTy &VMap,
183                       ValueMaterializer *Materializer,
184                       Function *NewF) {
185   assert(!OrigF.isDeclaration() && "Nothing to move");
186   if (!NewF)
187     NewF = cast<Function>(VMap[&OrigF]);
188   else
189     assert(VMap[&OrigF] == NewF && "Incorrect function mapping in VMap.");
190   assert(NewF && "Function mapping missing from VMap.");
191   assert(NewF->getParent() != OrigF.getParent() &&
192          "moveFunctionBody should only be used to move bodies between "
193          "modules.");
194 
195   SmallVector<ReturnInst *, 8> Returns; // Ignore returns cloned.
196   CloneFunctionInto(NewF, &OrigF, VMap, /*ModuleLevelChanges=*/true, Returns,
197                     "", nullptr, nullptr, Materializer);
198   OrigF.deleteBody();
199 }
200 
201 GlobalVariable* cloneGlobalVariableDecl(Module &Dst, const GlobalVariable &GV,
202                                         ValueToValueMapTy *VMap) {
203   assert(GV.getParent() != &Dst && "Can't copy decl over existing global var.");
204   GlobalVariable *NewGV = new GlobalVariable(
205       Dst, GV.getValueType(), GV.isConstant(),
206       GV.getLinkage(), nullptr, GV.getName(), nullptr,
207       GV.getThreadLocalMode(), GV.getType()->getAddressSpace());
208   NewGV->copyAttributesFrom(&GV);
209   if (VMap)
210     (*VMap)[&GV] = NewGV;
211   return NewGV;
212 }
213 
214 void moveGlobalVariableInitializer(GlobalVariable &OrigGV,
215                                    ValueToValueMapTy &VMap,
216                                    ValueMaterializer *Materializer,
217                                    GlobalVariable *NewGV) {
218   assert(OrigGV.hasInitializer() && "Nothing to move");
219   if (!NewGV)
220     NewGV = cast<GlobalVariable>(VMap[&OrigGV]);
221   else
222     assert(VMap[&OrigGV] == NewGV &&
223            "Incorrect global variable mapping in VMap.");
224   assert(NewGV->getParent() != OrigGV.getParent() &&
225          "moveGlobalVariable should only be used to move initializers between "
226          "modules");
227 
228   NewGV->setInitializer(MapValue(OrigGV.getInitializer(), VMap, RF_None,
229                                  nullptr, Materializer));
230 }
231 
232 GlobalAlias* cloneGlobalAliasDecl(Module &Dst, const GlobalAlias &OrigA,
233                                   ValueToValueMapTy &VMap) {
234   assert(OrigA.getAliasee() && "Original alias doesn't have an aliasee?");
235   auto *NewA = GlobalAlias::create(OrigA.getValueType(),
236                                    OrigA.getType()->getPointerAddressSpace(),
237                                    OrigA.getLinkage(), OrigA.getName(), &Dst);
238   NewA->copyAttributesFrom(&OrigA);
239   VMap[&OrigA] = NewA;
240   return NewA;
241 }
242 
243 } // End namespace orc.
244 } // End namespace llvm.
245