149 lines · cpp
1//===-- llvm-sim.cpp - Find similar sections of programs -------*- C++ -*-===//2//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-exception6//7//===----------------------------------------------------------------------===//8//9// This program finds similar sections of a Module, and exports them as a JSON10// file.11//12// To find similarities contained across multiple modules, please use llvm-link13// first to merge the modules.14//15//===----------------------------------------------------------------------===//16 17#include "llvm/Analysis/IRSimilarityIdentifier.h"18#include "llvm/IRReader/IRReader.h"19#include "llvm/Support/CommandLine.h"20#include "llvm/Support/FileSystem.h"21#include "llvm/Support/InitLLVM.h"22#include "llvm/Support/JSON.h"23#include "llvm/Support/SourceMgr.h"24#include "llvm/Support/ToolOutputFile.h"25 26using namespace llvm;27using namespace IRSimilarity;28 29static cl::opt<std::string> OutputFilename("o", cl::desc("Output Filename"),30 cl::init("-"),31 cl::value_desc("filename"));32 33static cl::opt<std::string> InputSourceFile(cl::Positional,34 cl::desc("<Source file>"),35 cl::init("-"),36 cl::value_desc("filename"));37 38/// Retrieve the unique number \p I was mapped to in parseBitcodeFile.39///40/// \param I - The Instruction to find the instruction number for.41/// \param LLVMInstNum - The mapping of Instructions to their location in the42/// module represented by an unsigned integer.43/// \returns The instruction number for \p I if it exists.44std::optional<unsigned>45getPositionInModule(const Instruction *I,46 const DenseMap<Instruction *, unsigned> &LLVMInstNum) {47 assert(I && "Instruction is nullptr!");48 DenseMap<Instruction *, unsigned>::const_iterator It = LLVMInstNum.find(I);49 if (It == LLVMInstNum.end())50 return std::nullopt;51 return It->second;52}53 54/// Exports the given SimilarityGroups to a JSON file at \p FilePath.55///56/// \param FilePath - The path to the output location.57/// \param SimSections - The similarity groups to process.58/// \param LLVMInstNum - The mapping of Instructions to their location in the59/// module represented by an unsigned integer.60/// \returns A nonzero error code if there was a failure creating the file.61std::error_code62exportToFile(const StringRef FilePath,63 const SimilarityGroupList &SimSections,64 const DenseMap<Instruction *, unsigned> &LLVMInstNum) {65 std::error_code EC;66 std::unique_ptr<ToolOutputFile> Out(67 new ToolOutputFile(FilePath, EC, sys::fs::OF_None));68 if (EC)69 return EC;70 71 json::OStream J(Out->os(), 1);72 J.objectBegin();73 74 unsigned SimOption = 1;75 // Process each list of SimilarityGroups organized by the Module.76 for (const SimilarityGroup &G : SimSections) {77 std::string SimOptionStr = std::to_string(SimOption);78 J.attributeBegin(SimOptionStr);79 J.arrayBegin();80 // For each file there is a list of the range where the similarity81 // exists.82 for (const IRSimilarityCandidate &C : G) {83 std::optional<unsigned> Start =84 getPositionInModule((*C.front()).Inst, LLVMInstNum);85 std::optional<unsigned> End =86 getPositionInModule((*C.back()).Inst, LLVMInstNum);87 88 assert(Start &&89 "Could not find instruction number for first instruction");90 assert(End && "Could not find instruction number for last instruction");91 92 J.object([&] {93 J.attribute("start", *Start);94 J.attribute("end", *End);95 });96 }97 J.arrayEnd();98 J.attributeEnd();99 SimOption++;100 }101 J.objectEnd();102 103 Out->keep();104 105 return EC;106}107 108int main(int argc, const char *argv[]) {109 InitLLVM X(argc, argv);110 111 cl::ParseCommandLineOptions(argc, argv, "LLVM IR Similarity Visualizer\n");112 113 LLVMContext CurrContext;114 SMDiagnostic Err;115 std::unique_ptr<Module> ModuleToAnalyze =116 parseIRFile(InputSourceFile, Err, CurrContext);117 118 if (!ModuleToAnalyze) {119 Err.print(argv[0], errs());120 return 1;121 }122 123 // Mapping from an Instruction pointer to its occurrence in a sequential124 // list of all the Instructions in a Module.125 DenseMap<Instruction *, unsigned> LLVMInstNum;126 127 // We give each instruction a number, which gives us a start and end value128 // for the beginning and end of each IRSimilarityCandidate.129 unsigned InstructionNumber = 1;130 for (Function &F : *ModuleToAnalyze)131 for (BasicBlock &BB : F)132 for (Instruction &I : BB.instructionsWithoutDebug())133 LLVMInstNum[&I]= InstructionNumber++;134 135 // The similarity identifier we will use to find the similar sections.136 IRSimilarityIdentifier SimIdent;137 SimilarityGroupList SimilaritySections =138 SimIdent.findSimilarity(*ModuleToAnalyze);139 140 std::error_code E =141 exportToFile(OutputFilename, SimilaritySections, LLVMInstNum);142 if (E) {143 errs() << argv[0] << ": " << E.message() << '\n';144 return 2;145 }146 147 return 0;148}149