tools/bugpoint/OptimizerDriver.cpp

   1 //===- OptimizerDriver.cpp - Allow BugPoint to run passes safely ----------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file defines an interface that allows bugpoint to run various passes
  11 // without the threat of a buggy pass corrupting bugpoint (of course, bugpoint
  12 // may have its own bugs, but that's another story...).  It achieves this by
  13 // forking a copy of itself and having the child process do the optimizations.
  14 // If this client dies, we can always fork a new one.  :)
  15 //
  16 //===----------------------------------------------------------------------===//
  17
  18 #include "BugDriver.h"
  19 #include "llvm/Bitcode/BitcodeWriter.h"
  20 #include "llvm/IR/DataLayout.h"
  21 #include "llvm/IR/LegacyPassManager.h"
  22 #include "llvm/IR/Module.h"
  23 #include "llvm/IR/Verifier.h"
  24 #include "llvm/Support/CommandLine.h"
  25 #include "llvm/Support/Debug.h"
  26 #include "llvm/Support/FileUtilities.h"
  27 #include "llvm/Support/Path.h"
  28 #include "llvm/Support/Program.h"
  29 #include "llvm/Support/SystemUtils.h"
  30 #include "llvm/Support/ToolOutputFile.h"
  31
  32 #define DONT_GET_PLUGIN_LOADER_OPTION
  33 #include "llvm/Support/PluginLoader.h"
  34
  35 #include <fstream>
  36
  37 using namespace llvm;
  38
  39 #define DEBUG_TYPE "bugpoint"
  40
  41 namespace llvm {
  42 extern cl::opt<std::string> OutputPrefix;
  43 }
  44
  45 static cl::opt<bool> PreserveBitcodeUseListOrder(
  46     "preserve-bc-uselistorder",
  47     cl::desc("Preserve use-list order when writing LLVM bitcode."),
  48     cl::init(true), cl::Hidden);
  49
  50 // ChildOutput - This option captures the name of the child output file that
  51 // is set up by the parent bugpoint process
  52 static cl::opt<std::string> ChildOutput("child-output", cl::ReallyHidden);
  53 static cl::opt<std::string>
  54     OptCmd("opt-command", cl::init(""),
  55            cl::desc("Path to opt. (default: search path "
  56                     "for 'opt'.)"));
  57
  58 /// writeProgramToFile - This writes the current "Program" to the named bitcode
  59 /// file.  If an error occurs, true is returned.
  60 ///
  61 static bool writeProgramToFileAux(tool_output_file &Out, const Module *M) {
  62   WriteBitcodeToFile(M, Out.os(), PreserveBitcodeUseListOrder);
  63   Out.os().close();
  64   if (!Out.os().has_error()) {
  65     Out.keep();
  66     return false;
  67   }
  68   return true;
  69 }
  70
  71 bool BugDriver::writeProgramToFile(const std::string &Filename, int FD,
  72                                    const Module *M) const {
  73   tool_output_file Out(Filename, FD);
  74   return writeProgramToFileAux(Out, M);
  75 }
  76
  77 bool BugDriver::writeProgramToFile(const std::string &Filename,
  78                                    const Module *M) const {
  79   std::error_code EC;
  80   tool_output_file Out(Filename, EC, sys::fs::F_None);
  81   if (!EC)
  82     return writeProgramToFileAux(Out, M);
  83   return true;
  84 }
  85
  86 /// EmitProgressBitcode - This function is used to output the current Program
  87 /// to a file named "bugpoint-ID.bc".
  88 ///
  89 void BugDriver::EmitProgressBitcode(const Module *M, const std::string &ID,
  90                                     bool NoFlyer) const {
  91   // Output the input to the current pass to a bitcode file, emit a message
  92   // telling the user how to reproduce it: opt -foo blah.bc
  93   //
  94   std::string Filename = OutputPrefix + "-" + ID + ".bc";
  95   if (writeProgramToFile(Filename, M)) {
  96     errs() << "Error opening file '" << Filename << "' for writing!\n";
  97     return;
  98   }
  99
 100   outs() << "Emitted bitcode to '" << Filename << "'\n";
 101   if (NoFlyer || PassesToRun.empty())
 102     return;
 103   outs() << "\n*** You can reproduce the problem with: ";
 104   if (UseValgrind)
 105     outs() << "valgrind ";
 106   outs() << "opt " << Filename;
 107   for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
 108     outs() << " -load " << PluginLoader::getPlugin(i);
 109   }
 110   outs() << " " << getPassesString(PassesToRun) << "\n";
 111 }
 112
 113 cl::opt<bool> SilencePasses(
 114     "silence-passes",
 115     cl::desc("Suppress output of running passes (both stdout and stderr)"));
 116
 117 static cl::list<std::string> OptArgs("opt-args", cl::Positional,
 118                                      cl::desc("<opt arguments>..."),
 119                                      cl::ZeroOrMore, cl::PositionalEatsArgs);
 120
 121 /// runPasses - Run the specified passes on Program, outputting a bitcode file
 122 /// and writing the filename into OutputFile if successful.  If the
 123 /// optimizations fail for some reason (optimizer crashes), return true,
 124 /// otherwise return false.  If DeleteOutput is set to true, the bitcode is
 125 /// deleted on success, and the filename string is undefined.  This prints to
 126 /// outs() a single line message indicating whether compilation was successful
 127 /// or failed.
 128 ///
 129 bool BugDriver::runPasses(Module *Program,
 130                           const std::vector<std::string> &Passes,
 131                           std::string &OutputFilename, bool DeleteOutput,
 132                           bool Quiet, unsigned NumExtraArgs,
 133                           const char *const *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   SmallString<128> InputFilename;
 148   int InputFD;
 149   EC = sys::fs::createUniqueFile(OutputPrefix + "-input-%%%%%%%.bc", InputFD,
 150                                  InputFilename);
 151   if (EC) {
 152     errs() << getToolName()
 153            << ": Error making unique filename: " << EC.message() << "\n";
 154     return 1;
 155   }
 156
 157   tool_output_file InFile(InputFilename, InputFD);
 158
 159   WriteBitcodeToFile(Program, InFile.os(), PreserveBitcodeUseListOrder);
 160   InFile.os().close();
 161   if (InFile.os().has_error()) {
 162     errs() << "Error writing bitcode file: " << InputFilename << "\n";
 163     InFile.os().clear_error();
 164     return 1;
 165   }
 166
 167   std::string tool = OptCmd;
 168   if (OptCmd.empty()) {
 169     if (ErrorOr<std::string> Path = sys::findProgramByName("opt"))
 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
 179   std::string Prog;
 180   if (UseValgrind) {
 181     if (ErrorOr<std::string> Path = sys::findProgramByName("valgrind"))
 182       Prog = *Path;
 183     else
 184       errs() << Path.getError().message() << "\n";
 185   } else
 186     Prog = tool;
 187   if (Prog.empty()) {
 188     errs() << "Cannot find `valgrind' in PATH!\n";
 189     return 1;
 190   }
 191
 192   // Ok, everything that could go wrong before running opt is done.
 193   InFile.keep();
 194
 195   // setup the child process' arguments
 196   SmallVector<const char *, 8> Args;
 197   if (UseValgrind) {
 198     Args.push_back("valgrind");
 199     Args.push_back("--error-exitcode=1");
 200     Args.push_back("-q");
 201     Args.push_back(tool.c_str());
 202   } else
 203     Args.push_back(tool.c_str());
 204
 205   for (unsigned i = 0, e = OptArgs.size(); i != e; ++i)
 206     Args.push_back(OptArgs[i].c_str());
 207   Args.push_back("-disable-symbolication");
 208   Args.push_back("-o");
 209   Args.push_back(OutputFilename.c_str());
 210   std::vector<std::string> pass_args;
 211   for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
 212     pass_args.push_back(std::string("-load"));
 213     pass_args.push_back(PluginLoader::getPlugin(i));
 214   }
 215   for (std::vector<std::string>::const_iterator I = Passes.begin(),
 216                                                 E = Passes.end();
 217        I != E; ++I)
 218     pass_args.push_back(std::string("-") + (*I));
 219   for (std::vector<std::string>::const_iterator I = pass_args.begin(),
 220                                                 E = pass_args.end();
 221        I != E; ++I)
 222     Args.push_back(I->c_str());
 223   Args.push_back(InputFilename.c_str());
 224   for (unsigned i = 0; i < NumExtraArgs; ++i)
 225     Args.push_back(*ExtraArgs);
 226   Args.push_back(nullptr);
 227
 228   DEBUG(errs() << "\nAbout to run:\t";
 229         for (unsigned i = 0, e = Args.size() - 1; i != e; ++i) errs()
 230         << " " << Args[i];
 231         errs() << "\n";);
 232
 233   // Redirect stdout and stderr to nowhere if SilencePasses is given
 234   StringRef Nowhere;
 235   const StringRef *Redirects[3] = {nullptr, &Nowhere, &Nowhere};
 236
 237   std::string ErrMsg;
 238   int result = sys::ExecuteAndWait(Prog, Args.data(), nullptr,
 239                                    (SilencePasses ? Redirects : nullptr),
 240                                    Timeout, MemoryLimit, &ErrMsg);
 241
 242   // If we are supposed to delete the bitcode file or if the passes crashed,
 243   // remove it now.  This may fail if the file was never created, but that's ok.
 244   if (DeleteOutput || result != 0)
 245     sys::fs::remove(OutputFilename);
 246
 247   // Remove the temporary input file as well
 248   sys::fs::remove(InputFilename.c_str());
 249
 250   if (!Quiet) {
 251     if (result == 0)
 252       outs() << "Success!\n";
 253     else if (result > 0)
 254       outs() << "Exited with error code '" << result << "'\n";
 255     else if (result < 0) {
 256       if (result == -1)
 257         outs() << "Execute failed: " << ErrMsg << "\n";
 258       else
 259         outs() << "Crashed: " << ErrMsg << "\n";
 260     }
 261     if (result & 0x01000000)
 262       outs() << "Dumped core\n";
 263   }
 264
 265   // Was the child successful?
 266   return result != 0;
 267 }
 268
 269 std::unique_ptr<Module>
 270 BugDriver::runPassesOn(Module *M, const std::vector<std::string> &Passes,
 271                        unsigned NumExtraArgs, const char *const *ExtraArgs) {
 272   std::string BitcodeResult;
 273   if (runPasses(M, Passes, BitcodeResult, false /*delete*/, true /*quiet*/,
 274                 NumExtraArgs, ExtraArgs)) {
 275     return nullptr;
 276   }
 277
 278   std::unique_ptr<Module> Ret = parseInputFile(BitcodeResult, Context);
 279   if (!Ret) {
 280     errs() << getToolName() << ": Error reading bitcode file '" << BitcodeResult
 281            << "'!\n";
 282     exit(1);
 283   }
 284   sys::fs::remove(BitcodeResult);
 285   return Ret;
 286 }