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