1 //===-- DifferenceEngine.h - Module comparator ------------------*- C++ -*-===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This header defines the interface to the LLVM difference engine,
10 // which structurally compares functions within a module.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_TOOLS_LLVM_DIFF_DIFFERENCEENGINE_H
15 #define LLVM_TOOLS_LLVM_DIFF_DIFFERENCEENGINE_H
17 #include "DiffConsumer.h"
19 #include "llvm/ADT/StringRef.h"
31 /// A class for performing structural comparisons of LLVM assembly.
32 class DifferenceEngine {
34 /// A RAII object for recording the current context.
36 Context(DifferenceEngine &Engine, Value *L, Value *R) : Engine(Engine) {
37 Engine.consumer.enterContext(L, R);
41 Engine.consumer.exitContext();
45 DifferenceEngine &Engine;
48 /// An oracle for answering whether two values are equivalent as
51 virtual void anchor();
53 virtual bool operator()(Value *L, Value *R) = 0;
59 DifferenceEngine(Consumer &consumer)
60 : consumer(consumer), globalValueOracle(nullptr) {}
62 void diff(Module *L, Module *R);
63 void diff(Function *L, Function *R);
64 void log(StringRef text) {
67 LogBuilder logf(StringRef text) {
68 return LogBuilder(consumer, text);
70 Consumer& getConsumer() const { return consumer; }
72 /// Installs an oracle to decide whether two global values are
73 /// equivalent as operands. Without an oracle, global values are
74 /// considered equivalent as operands precisely when they have the
76 void setGlobalValueOracle(Oracle *oracle) {
77 globalValueOracle = oracle;
80 /// Determines whether two global values are equivalent.
81 bool equivalentAsOperands(GlobalValue *L, GlobalValue *R);
85 Oracle *globalValueOracle;