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 "llvm/ADT/SmallVector.h" 19 #include "llvm/ADT/StringRef.h" 20 #include "DiffLog.h" 21 #include "DiffConsumer.h" 22 23 #include <utility> 24 25 namespace llvm { 26 class Function; 27 class GlobalValue; 28 class Instruction; 29 class LLVMContext; 30 class Module; 31 class Twine; 32 class Value; 33 34 /// A class for performing structural comparisons of LLVM assembly. 35 class DifferenceEngine { 36 public: 37 /// A RAII object for recording the current context. 38 struct Context { 39 Context(DifferenceEngine &Engine, Value *L, Value *R) : Engine(Engine) { 40 Engine.consumer.enterContext(L, R); 41 } 42 43 ~Context() { 44 Engine.consumer.exitContext(); 45 } 46 47 private: 48 DifferenceEngine &Engine; 49 }; 50 51 /// An oracle for answering whether two values are equivalent as 52 /// operands. 53 class Oracle { 54 virtual void anchor(); 55 public: 56 virtual bool operator()(Value *L, Value *R) = 0; 57 58 protected: 59 virtual ~Oracle() {} 60 }; 61 62 DifferenceEngine(LLVMContext &context, Consumer &consumer) 63 : context(context), consumer(consumer), globalValueOracle(0) {} 64 65 void diff(Module *L, Module *R); 66 void diff(Function *L, Function *R); 67 void log(StringRef text) { 68 consumer.log(text); 69 } 70 LogBuilder logf(StringRef text) { 71 return LogBuilder(consumer, text); 72 } 73 Consumer& getConsumer() const { return consumer; } 74 75 /// Installs an oracle to decide whether two global values are 76 /// equivalent as operands. Without an oracle, global values are 77 /// considered equivalent as operands precisely when they have the 78 /// same name. 79 void setGlobalValueOracle(Oracle *oracle) { 80 globalValueOracle = oracle; 81 } 82 83 /// Determines whether two global values are equivalent. 84 bool equivalentAsOperands(GlobalValue *L, GlobalValue *R); 85 86 private: 87 LLVMContext &context; 88 Consumer &consumer; 89 Oracle *globalValueOracle; 90 }; 91 } 92 93 #endif 94
