llvm-mirror/tools/bugpoint/FindBugs.cpp
Chandler Carruth ae65e281f3 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00

100 lines
3.1 KiB
C++

//===-- 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.
}