blob: 83dcf980a7860640d389f63d57249c09d586dbea [file] [log] [blame]
//===- llvm-reduce.cpp - The LLVM Delta Reduction utility -----------------===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// This program tries to reduce an IR test case for a given interesting-ness
// test. It runs multiple delta debugging passes in order to minimize the input
// file. It's worth noting that this is a part of the bugpoint redesign
// proposal, and thus a *temporary* tool that will eventually be integrated
// into the bugpoint tool itself.
#include "DeltaManager.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Verifier.h"
#include "llvm/IRReader/IRReader.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/InitLLVM.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/raw_ostream.h"
#include <system_error>
#include <vector>
using namespace llvm;
static cl::opt<bool> Help("h", cl::desc("Alias for -help"), cl::Hidden);
static cl::opt<bool> Version("v", cl::desc("Alias for -version"), cl::Hidden);
static cl::opt<std::string> InputFilename(cl::Positional, cl::Required,
cl::desc("<input llvm ll/bc file>"));
static cl::opt<std::string>
TestFilename("test", cl::Required,
cl::desc("Name of the interesting-ness test to be run"));
static cl::list<std::string>
TestArguments("test-arg", cl::ZeroOrMore,
cl::desc("Arguments passed onto the interesting-ness test"));
static cl::opt<std::string>
cl::desc("Specify the output file. default: reduced.ll"));
static cl::alias OutputFileAlias("o", cl::desc("Alias for -output"),
static cl::opt<bool>
cl::desc("WARNING: This option will replace your input file"
"with the reduced version!"));
// Parses IR into a Module and verifies it
static std::unique_ptr<Module> parseInputFile(StringRef Filename,
LLVMContext &Ctxt) {
SMDiagnostic Err;
std::unique_ptr<Module> Result = parseIRFile(Filename, Err, Ctxt);
if (!Result) {
Err.print("llvm-reduce", errs());
return Result;
if (verifyModule(*Result, &errs())) {
errs() << "Error: " << Filename << " - input module is broken!\n";
return std::unique_ptr<Module>();
return Result;
int main(int argc, char **argv) {
InitLLVM X(argc, argv);
cl::ParseCommandLineOptions(argc, argv, "LLVM automatic testcase reducer.\n");
LLVMContext Context;
std::unique_ptr<Module> OriginalProgram =
parseInputFile(InputFilename, Context);
// Initialize test environment
TestRunner Tester(TestFilename, TestArguments);
// Try to reduce code
if (!Tester.getProgram()) {
errs() << "\nCouldnt reduce input :/\n";
} else {
// Print reduced file to STDOUT
if (OutputFilename == "-")
Tester.getProgram()->print(outs(), nullptr);
else {
if (ReplaceInput) // In-place
OutputFilename = InputFilename.c_str();
else if (OutputFilename.empty())
OutputFilename = "reduced.ll";
std::error_code EC;
raw_fd_ostream Out(OutputFilename, EC);
if (EC) {
errs() << "Error opening output file: " << EC.message() << "!\n";
Tester.getProgram()->print(Out, /*AnnotationWriter=*/nullptr);
errs() << "\nDone reducing! Reduced testcase: " << OutputFilename << "\n";
return 0;