tools/bugpoint/OptimizerDriver.cpp

   1 //===- OptimizerDriver.cpp - Allow BugPoint to run passes safely ----------===//
   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-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file defines an interface that allows bugpoint to run various passes
  10 // without the threat of a buggy pass corrupting bugpoint (of course, bugpoint
  11 // may have its own bugs, but that's another story...).  It achieves this by
  12 // forking a copy of itself and having the child process do the optimizations.
  13 // If this client dies, we can always fork a new one.  :)
  14 //
  15 //===----------------------------------------------------------------------===//
  16
  17 #include "BugDriver.h"
  18 #include "ToolRunner.h"
  19 #include "llvm/Bitcode/BitcodeWriter.h"
  20 #include "llvm/IR/DataLayout.h"
  21 #include "llvm/IR/Module.h"
  22 #include "llvm/Support/CommandLine.h"
  23 #include "llvm/Support/Debug.h"
  24 #include "llvm/Support/FileUtilities.h"
  25 #include "llvm/Support/Path.h"
  26 #include "llvm/Support/Program.h"
  27 #include "llvm/Support/ToolOutputFile.h"
  28
  29 #define DONT_GET_PLUGIN_LOADER_OPTION
  30 #include "llvm/Support/PluginLoader.h"
  31
  32
  33 using namespace llvm;
  34
  35 #define DEBUG_TYPE "bugpoint"
  36
  37 namespace llvm {
  38 extern cl::opt<std::string> OutputPrefix;
  39 }
  40
  41 static cl::opt<bool> PreserveBitcodeUseListOrder(
  42     "preserve-bc-uselistorder",
  43     cl::desc("Preserve use-list order when writing LLVM bitcode."),
  44     cl::init(true), cl::Hidden);
  45
  46 static cl::opt<std::string>
  47     OptCmd("opt-command", cl::init(""),
  48            cl::desc("Path to opt. (default: search path "
  49                     "for 'opt'.)"));
  50
  51 /// This writes the current "Program" to the named bitcode file.  If an error
  52 /// occurs, true is returned.
  53 static bool writeProgramToFileAux(ToolOutputFile &Out, const Module &M) {
  54   WriteBitcodeToFile(M, Out.os(), PreserveBitcodeUseListOrder);
  55   Out.os().close();
  56   if (!Out.os().has_error()) {
  57     Out.keep();
  58     return false;
  59   }
  60   return true;
  61 }
  62
  63 bool BugDriver::writeProgramToFile(const std::string &Filename, int FD,
  64                                    const Module &M) const {
  65   ToolOutputFile Out(Filename, FD);
  66   return writeProgramToFileAux(Out, M);
  67 }
  68
  69 bool BugDriver::writeProgramToFile(int FD, const Module &M) const {
  70   raw_fd_ostream OS(FD, /*shouldClose*/ false);
  71   WriteBitcodeToFile(M, OS, PreserveBitcodeUseListOrder);
  72   OS.flush();
  73   if (!OS.has_error())
  74     return false;
  75   OS.clear_error();
  76   return true;
  77 }
  78
  79 bool BugDriver::writeProgramToFile(const std::string &Filename,
  80                                    const Module &M) const {
  81   std::error_code EC;
  82   ToolOutputFile Out(Filename, EC, sys::fs::OF_None);
  83   if (!EC)
  84     return writeProgramToFileAux(Out, M);
  85   return true;
  86 }
  87
  88 /// This function is used to output the current Program to a file named
  89 /// "bugpoint-ID.bc".
  90 void BugDriver::EmitProgressBitcode(const Module &M, const std::string &ID,
  91                                     bool NoFlyer) const {
  92   // Output the input to the current pass to a bitcode file, emit a message
  93   // telling the user how to reproduce it: opt -foo blah.bc
  94   //
  95   std::string Filename = OutputPrefix + "-" + ID + ".bc";
  96   if (writeProgramToFile(Filename, M)) {
  97     errs() << "Error opening file '" << Filename << "' for writing!\n";
  98     return;
  99   }
 100
 101   outs() << "Emitted bitcode to '" << Filename << "'\n";
 102   if (NoFlyer || PassesToRun.empty())
 103     return;
 104   outs() << "\n*** You can reproduce the problem with: ";
 105   if (UseValgrind)
 106     outs() << "valgrind ";
 107   outs() << "opt " << Filename;
 108   for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
 109     outs() << " -load " << PluginLoader::getPlugin(i);
 110   }
 111   outs() << " " << getPassesString(PassesToRun) << "\n";
 112 }
 113
 114 cl::opt<bool> SilencePasses(
 115     "silence-passes",
 116     cl::desc("Suppress output of running passes (both stdout and stderr)"));
 117
 118 static cl::list<std::string> OptArgs("opt-args", cl::Positional,
 119                                      cl::desc("<opt arguments>..."),
 120                                      cl::ZeroOrMore, cl::PositionalEatsArgs);
 121
 122 /// runPasses - Run the specified passes on Program, outputting a bitcode file
 123 /// and writing the filename into OutputFile if successful.  If the
 124 /// optimizations fail for some reason (optimizer crashes), return true,
 125 /// otherwise return false.  If DeleteOutput is set to true, the bitcode is
 126 /// deleted on success, and the filename string is undefined.  This prints to
 127 /// outs() a single line message indicating whether compilation was successful
 128 /// or failed.
 129 ///
 130 bool BugDriver::runPasses(Module &Program,
 131                           const std::vector<std::string> &Passes,
 132                           std::string &OutputFilename, bool DeleteOutput,
 133                           bool Quiet, ArrayRef<std::string> ExtraArgs) const {
 134   // setup the output file name
 135   outs().flush();
 136   SmallString<128> UniqueFilename;
 137   std::error_code EC = sys::fs::createUniqueFile(
 138       OutputPrefix + "-output-%%%%%%%.bc", UniqueFilename);
 139   if (EC) {
 140     errs() << getToolName()
 141            << ": Error making unique filename: " << EC.message() << "\n";
 142     return 1;
 143   }
 144   OutputFilename = UniqueFilename.str();
 145
 146   // set up the input file name
 147   Expected<sys::fs::TempFile> Temp =
 148       sys::fs::TempFile::create(OutputPrefix + "-input-%%%%%%%.bc");
 149   if (!Temp) {
 150     errs() << getToolName()
 151            << ": Error making unique filename: " << toString(Temp.takeError())
 152            << "\n";
 153     return 1;
 154   }
 155   DiscardTemp Discard{*Temp};
 156   raw_fd_ostream OS(Temp->FD, /*shouldClose*/ false);
 157
 158   WriteBitcodeToFile(Program, OS, PreserveBitcodeUseListOrder);
 159   OS.flush();
 160   if (OS.has_error()) {
 161     errs() << "Error writing bitcode file: " << Temp->TmpName << "\n";
 162     OS.clear_error();
 163     return 1;
 164   }
 165
 166   std::string tool = OptCmd;
 167   if (OptCmd.empty()) {
 168     if (ErrorOr<std::string> Path =
 169             FindProgramByName("opt", getToolName(), &OutputPrefix))
 170       tool = *Path;
 171     else
 172       errs() << Path.getError().message() << "\n";
 173   }
 174   if (tool.empty()) {
 175     errs() << "Cannot find `opt' in PATH!\n";
 176     return 1;
 177   }
 178   if (!sys::fs::exists(tool)) {
 179     errs() << "Specified `opt' binary does not exist: " << tool << "\n";
 180     return 1;
 181   }
 182
 183   std::string Prog;
 184   if (UseValgrind) {
 185     if (ErrorOr<std::string> Path = sys::findProgramByName("valgrind"))
 186       Prog = *Path;
 187     else
 188       errs() << Path.getError().message() << "\n";
 189   } else
 190     Prog = tool;
 191   if (Prog.empty()) {
 192     errs() << "Cannot find `valgrind' in PATH!\n";
 193     return 1;
 194   }
 195
 196   // setup the child process' arguments
 197   SmallVector<StringRef, 8> Args;
 198   if (UseValgrind) {
 199     Args.push_back("valgrind");
 200     Args.push_back("--error-exitcode=1");
 201     Args.push_back("-q");
 202     Args.push_back(tool);
 203   } else
 204     Args.push_back(tool);
 205
 206   for (unsigned i = 0, e = OptArgs.size(); i != e; ++i)
 207     Args.push_back(OptArgs[i]);
 208   Args.push_back("-disable-symbolication");
 209   Args.push_back("-o");
 210   Args.push_back(OutputFilename);
 211   std::vector<std::string> pass_args;
 212   for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
 213     pass_args.push_back(std::string("-load"));
 214     pass_args.push_back(PluginLoader::getPlugin(i));
 215   }
 216   for (std::vector<std::string>::const_iterator I = Passes.begin(),
 217                                                 E = Passes.end();
 218        I != E; ++I)
 219     pass_args.push_back(std::string("-") + (*I));
 220   for (std::vector<std::string>::const_iterator I = pass_args.begin(),
 221                                                 E = pass_args.end();
 222        I != E; ++I)
 223     Args.push_back(I->c_str());
 224   Args.push_back(Temp->TmpName.c_str());
 225   Args.append(ExtraArgs.begin(), ExtraArgs.end());
 226
 227   LLVM_DEBUG(errs() << "\nAbout to run:\t";
 228              for (unsigned i = 0, e = Args.size() - 1; i != e; ++i) errs()
 229              << " " << Args[i];
 230              errs() << "\n";);
 231
 232   Optional<StringRef> Redirects[3] = {None, None, None};
 233   // Redirect stdout and stderr to nowhere if SilencePasses is given.
 234   if (SilencePasses) {
 235     Redirects[1] = "";
 236     Redirects[2] = "";
 237   }
 238
 239   std::string ErrMsg;
 240   int result = sys::ExecuteAndWait(Prog, Args, None, Redirects, Timeout,
 241                                    MemoryLimit, &ErrMsg);
 242
 243   // If we are supposed to delete the bitcode file or if the passes crashed,
 244   // remove it now.  This may fail if the file was never created, but that's ok.
 245   if (DeleteOutput || result != 0)
 246     sys::fs::remove(OutputFilename);
 247
 248   if (!Quiet) {
 249     if (result == 0)
 250       outs() << "Success!\n";
 251     else if (result > 0)
 252       outs() << "Exited with error code '" << result << "'\n";
 253     else if (result < 0) {
 254       if (result == -1)
 255         outs() << "Execute failed: " << ErrMsg << "\n";
 256       else
 257         outs() << "Crashed: " << ErrMsg << "\n";
 258     }
 259     if (result & 0x01000000)
 260       outs() << "Dumped core\n";
 261   }
 262
 263   // Was the child successful?
 264   return result != 0;
 265 }
 266
 267 std::unique_ptr<Module>
 268 BugDriver::runPassesOn(Module *M, const std::vector<std::string> &Passes,
 269                        ArrayRef<std::string> ExtraArgs) {
 270   std::string BitcodeResult;
 271   if (runPasses(*M, Passes, BitcodeResult, false /*delete*/, true /*quiet*/,
 272                 ExtraArgs)) {
 273     return nullptr;
 274   }
 275
 276   std::unique_ptr<Module> Ret = parseInputFile(BitcodeResult, Context);
 277   if (!Ret) {
 278     errs() << getToolName() << ": Error reading bitcode file '" << BitcodeResult
 279            << "'!\n";
 280     exit(1);
 281   }
 282   sys::fs::remove(BitcodeResult);
 283   return Ret;
 284 }