| //===-- FindBugs.cpp - Run Many Different Optimizations -------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines an interface that allows bugpoint to choose different |
| // combinations of optimizations to run on the selected input. Bugpoint will |
| // run these optimizations and record the success/failure of each. This way |
| // we can hopefully spot bugs in the optimizations. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "BugDriver.h" |
| #include "llvm/Support/FileSystem.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include <random> |
| using namespace llvm; |
| |
| Error |
| BugDriver::runManyPasses(const std::vector<std::string> &AllPasses) { |
| setPassesToRun(AllPasses); |
| outs() << "Starting bug finding procedure...\n\n"; |
| |
| // Creating a reference output if necessary |
| if (Error E = initializeExecutionEnvironment()) |
| return E; |
| |
| outs() << "\n"; |
| if (ReferenceOutputFile.empty()) { |
| outs() << "Generating reference output from raw program: \n"; |
| if (Error E = createReferenceFile(*Program)) |
| return E; |
| } |
| |
| std::mt19937 randomness(std::random_device{}()); |
| unsigned num = 1; |
| while (1) { |
| // |
| // Step 1: Randomize the order of the optimizer passes. |
| // |
| std::shuffle(PassesToRun.begin(), PassesToRun.end(), randomness); |
| |
| // |
| // Step 2: Run optimizer passes on the program and check for success. |
| // |
| outs() << "Running selected passes on program to test for crash: "; |
| for (int i = 0, e = PassesToRun.size(); i != e; i++) { |
| outs() << "-" << PassesToRun[i] << " "; |
| } |
| |
| std::string Filename; |
| if (runPasses(*Program, PassesToRun, Filename, false)) { |
| outs() << "\n"; |
| outs() << "Optimizer passes caused failure!\n\n"; |
| return debugOptimizerCrash(); |
| } else { |
| outs() << "Combination " << num << " optimized successfully!\n"; |
| } |
| |
| // |
| // Step 3: Compile the optimized code. |
| // |
| outs() << "Running the code generator to test for a crash: "; |
| if (Error E = compileProgram(*Program)) { |
| outs() << "\n*** compileProgram threw an exception: "; |
| outs() << toString(std::move(E)); |
| return debugCodeGeneratorCrash(); |
| } |
| outs() << '\n'; |
| |
| // |
| // Step 4: Run the program and compare its output to the reference |
| // output (created above). |
| // |
| outs() << "*** Checking if passes caused miscompliation:\n"; |
| Expected<bool> Diff = diffProgram(*Program, Filename, "", false); |
| if (Error E = Diff.takeError()) { |
| errs() << toString(std::move(E)); |
| return debugCodeGeneratorCrash(); |
| } |
| if (*Diff) { |
| outs() << "\n*** diffProgram returned true!\n"; |
| Error E = debugMiscompilation(); |
| if (!E) |
| return Error::success(); |
| } |
| outs() << "\n*** diff'd output matches!\n"; |
| |
| sys::fs::remove(Filename); |
| |
| outs() << "\n\n"; |
| num++; |
| } // end while |
| |
| // Unreachable. |
| } |