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