219 lines · cpp
1//===- llvm-reduce.cpp - The LLVM Delta Reduction utility -----------------===//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 tries to reduce an IR test case for a given interesting-ness10// test. It runs multiple delta debugging passes in order to minimize the input11// file. It's worth noting that this is a part of the bugpoint redesign12// proposal, and thus a *temporary* tool that will eventually be integrated13// into the bugpoint tool itself.14//15//===----------------------------------------------------------------------===//16 17#include "DeltaManager.h"18#include "ReducerWorkItem.h"19#include "TestRunner.h"20#include "llvm/Bitcode/BitcodeReader.h"21#include "llvm/CodeGen/CommandFlags.h"22#include "llvm/Support/CommandLine.h"23#include "llvm/Support/InitLLVM.h"24#include "llvm/Support/Process.h"25#include "llvm/Support/WithColor.h"26#include "llvm/Support/raw_ostream.h"27 28#ifdef _WIN3229#include <windows.h>30#endif31 32using namespace llvm;33 34cl::OptionCategory LLVMReduceOptions("llvm-reduce options");35 36static cl::opt<bool> Help("h", cl::desc("Alias for -help"), cl::Hidden,37 cl::cat(LLVMReduceOptions));38static cl::opt<bool> Version("v", cl::desc("Alias for -version"), cl::Hidden,39 cl::cat(LLVMReduceOptions));40 41static cl::opt<bool> PreserveDebugEnvironment(42 "preserve-debug-environment",43 cl::desc("Don't disable features used for crash "44 "debugging (crash reports, llvm-symbolizer and core dumps)"),45 cl::cat(LLVMReduceOptions));46 47static cl::opt<bool>48 PrintDeltaPasses("print-delta-passes",49 cl::desc("Print list of delta passes, passable to "50 "--delta-passes as a comma separated list"),51 cl::cat(LLVMReduceOptions));52 53static cl::opt<std::string> InputFilename(cl::Positional,54 cl::desc("<input llvm ll/bc file>"),55 cl::cat(LLVMReduceOptions));56 57static cl::opt<std::string>58 TestFilename("test",59 cl::desc("Name of the interesting-ness test to be run"),60 cl::cat(LLVMReduceOptions));61 62static cl::list<std::string>63 TestArguments("test-arg",64 cl::desc("Arguments passed onto the interesting-ness test"),65 cl::cat(LLVMReduceOptions));66 67static cl::opt<std::string> OutputFilename(68 "output",69 cl::desc("Specify the output file. default: reduced.ll|.bc|.mir"));70static cl::alias OutputFileAlias("o", cl::desc("Alias for -output"),71 cl::aliasopt(OutputFilename),72 cl::cat(LLVMReduceOptions));73 74static cl::opt<bool>75 ReplaceInput("in-place",76 cl::desc("WARNING: This option will replace your input file "77 "with the reduced version!"),78 cl::cat(LLVMReduceOptions));79 80enum class InputLanguages { None, IR, MIR };81 82static cl::opt<InputLanguages>83 InputLanguage("x", cl::ValueOptional,84 cl::desc("Input language ('ir' or 'mir')"),85 cl::init(InputLanguages::None),86 cl::values(clEnumValN(InputLanguages::IR, "ir", ""),87 clEnumValN(InputLanguages::MIR, "mir", "")),88 cl::cat(LLVMReduceOptions));89 90static cl::opt<bool> ForceOutputBitcode(91 "output-bitcode",92 cl::desc("Emit final result as bitcode instead of text IR"), cl::Hidden,93 cl::cat(LLVMReduceOptions));94 95static cl::opt<int>96 MaxPassIterations("max-pass-iterations",97 cl::desc("Maximum number of times to run the full set "98 "of delta passes (default=5)"),99 cl::init(5), cl::cat(LLVMReduceOptions));100 101static codegen::RegisterCodeGenFlags CGF;102 103/// Turn off crash debugging features104///105/// Crash is expected, so disable crash reports and symbolization to reduce106/// output clutter and avoid potentially slow symbolization.107static void disableEnvironmentDebugFeatures() {108 sys::Process::PreventCoreFiles();109 110 // TODO: Copied from not. Should have a wrapper around setenv.111#ifdef _WIN32112 SetEnvironmentVariableA("LLVM_DISABLE_CRASH_REPORT", "1");113 SetEnvironmentVariableA("LLVM_DISABLE_SYMBOLIZATION", "1");114#else115 setenv("LLVM_DISABLE_CRASH_REPORT", "1", /*overwrite=*/1);116 setenv("LLVM_DISABLE_SYMBOLIZATION", "1", /*overwrite=*/1);117#endif118}119 120static std::pair<StringRef, bool> determineOutputType(bool IsMIR,121 bool InputIsBitcode) {122 bool OutputBitcode = ForceOutputBitcode || InputIsBitcode;123 124 if (ReplaceInput) { // In-place125 OutputFilename = InputFilename.c_str();126 } else if (OutputFilename.empty()) {127 // Default to producing bitcode if the input was bitcode, if not explicitly128 // requested.129 130 OutputFilename =131 IsMIR ? "reduced.mir" : (OutputBitcode ? "reduced.bc" : "reduced.ll");132 }133 134 return {OutputFilename, OutputBitcode};135}136 137int main(int Argc, char **Argv) {138 InitLLVM X(Argc, Argv);139 const StringRef ToolName(Argv[0]);140 141 cl::HideUnrelatedOptions({&LLVMReduceOptions, &getColorCategory()});142 cl::ParseCommandLineOptions(143 Argc, Argv,144 "LLVM automatic testcase reducer.\n"145 "See https://llvm.org/docs/CommandGuide/llvm-reduce.html for more "146 "information.\n");147 148 if (Argc == 1) {149 cl::PrintHelpMessage();150 return 0;151 }152 153 if (PrintDeltaPasses) {154 printDeltaPasses(outs());155 return 0;156 }157 158 bool ReduceModeMIR = false;159 if (InputLanguage != InputLanguages::None) {160 if (InputLanguage == InputLanguages::MIR)161 ReduceModeMIR = true;162 } else if (StringRef(InputFilename).ends_with(".mir")) {163 ReduceModeMIR = true;164 }165 166 if (InputFilename.empty()) {167 WithColor::error(errs(), ToolName)168 << "reduction testcase positional argument must be specified\n";169 return 1;170 }171 172 if (TestFilename.empty()) {173 WithColor::error(errs(), ToolName) << "--test option must be specified\n";174 return 1;175 }176 177 if (!PreserveDebugEnvironment)178 disableEnvironmentDebugFeatures();179 180 LLVMContext Context;181 std::unique_ptr<TargetMachine> TM;182 183 auto [OriginalProgram, InputIsBitcode] =184 parseReducerWorkItem(ToolName, InputFilename, Context, TM, ReduceModeMIR);185 if (!OriginalProgram) {186 return 1;187 }188 189 StringRef OutputFilename;190 bool OutputBitcode;191 std::tie(OutputFilename, OutputBitcode) =192 determineOutputType(ReduceModeMIR, InputIsBitcode);193 194 // Initialize test environment195 TestRunner Tester(TestFilename, TestArguments, std::move(OriginalProgram),196 std::move(TM), ToolName, OutputFilename, InputIsBitcode,197 OutputBitcode);198 199 // This parses and writes out the testcase into a temporary file copy for the200 // test, rather than evaluating the source IR directly. This is for the201 // convenience of lit tests; the stripped out comments may have broken the202 // interestingness checks.203 if (!Tester.getProgram().isReduced(Tester)) {204 errs() << "\nInput isn't interesting! Verify interesting-ness test\n";205 return 2;206 }207 208 // Try to reduce code209 runDeltaPasses(Tester, MaxPassIterations);210 211 // Print reduced file to STDOUT212 if (OutputFilename == "-")213 Tester.getProgram().print(outs(), nullptr);214 else215 Tester.writeOutput("Done reducing! Reduced testcase: ");216 217 return 0;218}219