ExecutionEngine.h revision c1d035a8818058461d776fc0ffb9cdbfa4cfccd3
1//===- ExecutionEngine.h - Abstract Execution Engine Interface --*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file was developed by the LLVM research group and is distributed under 6// the University of Illinois Open Source License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file defines the abstract interface that implements execution support 11// for LLVM. 12// 13//===----------------------------------------------------------------------===// 14 15#ifndef EXECUTION_ENGINE_H 16#define EXECUTION_ENGINE_H 17 18#include <vector> 19#include <map> 20#include <cassert> 21#include <string> 22 23namespace llvm { 24 25union GenericValue; 26class Constant; 27class Function; 28class GlobalVariable; 29class GlobalValue; 30class Module; 31class ModuleProvider; 32class TargetData; 33class Type; 34class IntrinsicLowering; 35 36class ExecutionEngine { 37 Module &CurMod; 38 const TargetData *TD; 39 40 /// GlobalAddressMap - A mapping between LLVM global values and their 41 /// actualized version... 42 std::map<const GlobalValue*, void *> GlobalAddressMap; 43 44 /// GlobalAddressReverseMap - This is the reverse mapping of GlobalAddressMap, 45 /// used to convert raw addresses into the LLVM global value that is emitted 46 /// at the address. This map is not computed unless getGlobalValueAtAddress 47 /// is called at some point. 48 std::map<void *, const GlobalValue*> GlobalAddressReverseMap; 49protected: 50 ModuleProvider *MP; 51 52 void setTargetData(const TargetData &td) { 53 TD = &td; 54 } 55 56public: 57 ExecutionEngine(ModuleProvider *P); 58 ExecutionEngine(Module *M); 59 virtual ~ExecutionEngine(); 60 61 Module &getModule() const { return CurMod; } 62 const TargetData &getTargetData() const { return *TD; } 63 64 /// create - This is the factory method for creating an execution engine which 65 /// is appropriate for the current machine. If specified, the 66 /// IntrinsicLowering implementation should be allocated on the heap. 67 static ExecutionEngine *create(ModuleProvider *MP, bool ForceInterpreter, 68 IntrinsicLowering *IL = 0); 69 70 /// runFunction - Execute the specified function with the specified arguments, 71 /// and return the result. 72 /// 73 virtual GenericValue runFunction(Function *F, 74 const std::vector<GenericValue> &ArgValues) = 0; 75 76 /// runFunctionAsMain - This is a helper function which wraps runFunction to 77 /// handle the common task of starting up main with the specified argc, argv, 78 /// and envp parameters. 79 int runFunctionAsMain(Function *Fn, const std::vector<std::string> &argv, 80 const char * const * envp); 81 82 83 void addGlobalMapping(const GlobalValue *GV, void *Addr) { 84 void *&CurVal = GlobalAddressMap[GV]; 85 assert((CurVal == 0 || Addr == 0) && "GlobalMapping already established!"); 86 CurVal = Addr; 87 88 // If we are using the reverse mapping, add it too 89 if (!GlobalAddressReverseMap.empty()) { 90 const GlobalValue *&V = GlobalAddressReverseMap[Addr]; 91 assert((V == 0 || GV == 0) && "GlobalMapping already established!"); 92 V = GV; 93 } 94 } 95 96 /// FIXME: I have no idea if this is right, I just implemented it to get 97 /// the build to compile because it is called by JIT/Emitter.cpp. 98 void updateGlobalMapping(const GlobalValue *GV, void*Addr) { 99 GlobalAddressMap[GV] = Addr; 100 GlobalAddressReverseMap[Addr] = GV; 101 } 102 103 /// getPointerToGlobalIfAvailable - This returns the address of the specified 104 /// global value if it is available, otherwise it returns null. 105 /// 106 void *getPointerToGlobalIfAvailable(const GlobalValue *GV) { 107 std::map<const GlobalValue*, void*>::iterator I = GlobalAddressMap.find(GV); 108 return I != GlobalAddressMap.end() ? I->second : 0; 109 } 110 111 /// getPointerToGlobal - This returns the address of the specified global 112 /// value. This may involve code generation if it's a function. 113 /// 114 void *getPointerToGlobal(const GlobalValue *GV); 115 116 /// getPointerToFunction - The different EE's represent function bodies in 117 /// different ways. They should each implement this to say what a function 118 /// pointer should look like. 119 /// 120 virtual void *getPointerToFunction(Function *F) = 0; 121 122 /// getPointerToFunctionOrStub - If the specified function has been 123 /// code-gen'd, return a pointer to the function. If not, compile it, or use 124 /// a stub to implement lazy compilation if available. 125 /// 126 virtual void *getPointerToFunctionOrStub(Function *F) { 127 // Default implementation, just codegen the function. 128 return getPointerToFunction(F); 129 } 130 131 /// getGlobalValueAtAddress - Return the LLVM global value object that starts 132 /// at the specified address. 133 /// 134 const GlobalValue *getGlobalValueAtAddress(void *Addr); 135 136 137 void StoreValueToMemory(GenericValue Val, GenericValue *Ptr, const Type *Ty); 138 void InitializeMemory(const Constant *Init, void *Addr); 139 140 /// recompileAndRelinkFunction - This method is used to force a function 141 /// which has already been compiled to be compiled again, possibly 142 /// after it has been modified. Then the entry to the old copy is overwritten 143 /// with a branch to the new copy. If there was no old copy, this acts 144 /// just like VM::getPointerToFunction(). 145 /// 146 virtual void *recompileAndRelinkFunction(Function *F) = 0; 147 148 /// freeMachineCodeForFunction - Release memory in the ExecutionEngine 149 /// corresponding to the machine code emitted to execute this function, useful 150 /// for garbage-collecting generated code. 151 /// 152 virtual void freeMachineCodeForFunction(Function *F) = 0; 153 154 /// getOrEmitGlobalVariable - Return the address of the specified global 155 /// variable, possibly emitting it to memory if needed. This is used by the 156 /// Emitter. 157 virtual void *getOrEmitGlobalVariable(const GlobalVariable *GV) { 158 return getPointerToGlobal((GlobalValue*)GV); 159 } 160 161protected: 162 void emitGlobals(); 163 164 // EmitGlobalVariable - This method emits the specified global variable to the 165 // address specified in GlobalAddresses, or allocates new memory if it's not 166 // already in the map. 167 void EmitGlobalVariable(const GlobalVariable *GV); 168 169 GenericValue getConstantValue(const Constant *C); 170 GenericValue LoadValueFromMemory(GenericValue *Ptr, const Type *Ty); 171}; 172 173} // End llvm namespace 174 175#endif 176