1 //===-- DifferenceEngine.h - Module comparator ------------------*- C++ -*-===// 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 // This header defines the interface to the LLVM difference engine, 11 // which structurally compares functions within a module. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef _LLVM_DIFFERENCE_ENGINE_H_ 16 #define _LLVM_DIFFERENCE_ENGINE_H_ 17 18 #include "DiffConsumer.h" 19 #include "DiffLog.h" 20 #include "llvm/ADT/SmallVector.h" 21 #include "llvm/ADT/StringRef.h" 22 #include <utility> 23 24 namespace llvm { 25 class Function; 26 class GlobalValue; 27 class Instruction; 28 class LLVMContext; 29 class Module; 30 class Twine; 31 class Value; 32 33 /// A class for performing structural comparisons of LLVM assembly. 34 class DifferenceEngine { 35 public: 36 /// A RAII object for recording the current context. 37 struct Context { 38 Context(DifferenceEngine &Engine, Value *L, Value *R) : Engine(Engine) { 39 Engine.consumer.enterContext(L, R); 40 } 41 42 ~Context() { 43 Engine.consumer.exitContext(); 44 } 45 46 private: 47 DifferenceEngine &Engine; 48 }; 49 50 /// An oracle for answering whether two values are equivalent as 51 /// operands. 52 class Oracle { 53 virtual void anchor(); 54 public: 55 virtual bool operator()(Value *L, Value *R) = 0; 56 57 protected: 58 virtual ~Oracle() {} 59 }; 60 61 DifferenceEngine(Consumer &consumer) 62 : consumer(consumer), globalValueOracle(0) {} 63 64 void diff(Module *L, Module *R); 65 void diff(Function *L, Function *R); 66 void log(StringRef text) { 67 consumer.log(text); 68 } 69 LogBuilder logf(StringRef text) { 70 return LogBuilder(consumer, text); 71 } 72 Consumer& getConsumer() const { return consumer; } 73 74 /// Installs an oracle to decide whether two global values are 75 /// equivalent as operands. Without an oracle, global values are 76 /// considered equivalent as operands precisely when they have the 77 /// same name. 78 void setGlobalValueOracle(Oracle *oracle) { 79 globalValueOracle = oracle; 80 } 81 82 /// Determines whether two global values are equivalent. 83 bool equivalentAsOperands(GlobalValue *L, GlobalValue *R); 84 85 private: 86 Consumer &consumer; 87 Oracle *globalValueOracle; 88 }; 89 } 90 91 #endif 92
