src/llvm/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/ReaderWriter.h"
  20 #include "llvm/IR/DataLayout.h"
  21 #include "llvm/IR/Module.h"
  22 #include "llvm/IR/Verifier.h"
  23 #include "llvm/PassManager.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 namespace {
  46   // ChildOutput - This option captures the name of the child output file that
  47   // is set up by the parent bugpoint process
  48   cl::opt<std::string> ChildOutput("child-output", cl::ReallyHidden);
  49   cl::opt<std::string> OptCmd("opt-command", cl::init(""),
  50                               cl::desc("Path to opt. (default: search path "
  51                                        "for 'opt'.)"));
  52 }
  53
  54 /// writeProgramToFile - This writes the current "Program" to the named bitcode
  55 /// file.  If an error occurs, true is returned.
  56 ///
  57 static bool writeProgramToFileAux(tool_output_file &Out, const Module *M) {
  58   WriteBitcodeToFile(M, Out.os());
  59   Out.os().close();
  60   if (!Out.os().has_error()) {
  61     Out.keep();
  62     return false;
  63   }
  64   return true;
  65 }
  66
  67 bool BugDriver::writeProgramToFile(const std::string &Filename, int FD,
  68                                    const Module *M) const {
  69   tool_output_file Out(Filename, FD);
  70   return writeProgramToFileAux(Out, M);
  71 }
  72
  73 bool BugDriver::writeProgramToFile(const std::string &Filename,
  74                                    const Module *M) const {
  75   std::error_code EC;
  76   tool_output_file Out(Filename, EC, sys::fs::F_None);
  77   if (!EC)
  78     return writeProgramToFileAux(Out, M);
  79   return true;
  80 }
  81
  82
  83 /// EmitProgressBitcode - This function is used to output the current Program
  84 /// to a file named "bugpoint-ID.bc".
  85 ///
  86 void BugDriver::EmitProgressBitcode(const Module *M,
  87                                     const std::string &ID,
  88                                     bool NoFlyer)  const {
  89   // Output the input to the current pass to a bitcode file, emit a message
  90   // telling the user how to reproduce it: opt -foo blah.bc
  91   //
  92   std::string Filename = OutputPrefix + "-" + ID + ".bc";
  93   if (writeProgramToFile(Filename, M)) {
  94     errs() <<  "Error opening file '" << Filename << "' for writing!\n";
  95     return;
  96   }
  97
  98   outs() << "Emitted bitcode to '" << Filename << "'\n";
  99   if (NoFlyer || PassesToRun.empty()) return;
 100   outs() << "\n*** You can reproduce the problem with: ";
 101   if (UseValgrind) outs() << "valgrind ";
 102   outs() << "opt " << Filename;
 103   for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
 104     outs() << " -load " << PluginLoader::getPlugin(i);
 105   }
 106   outs() << " " << getPassesString(PassesToRun) << "\n";
 107 }
 108
 109 cl::opt<bool> SilencePasses("silence-passes",
 110         cl::desc("Suppress output of running passes (both stdout and stderr)"));
 111
 112 static cl::list<std::string> OptArgs("opt-args", cl::Positional,
 113                                      cl::desc("<opt arguments>..."),
 114                                      cl::ZeroOrMore, cl::PositionalEatsArgs);
 115
 116 /// runPasses - Run the specified passes on Program, outputting a bitcode file
 117 /// and writing the filename into OutputFile if successful.  If the
 118 /// optimizations fail for some reason (optimizer crashes), return true,
 119 /// otherwise return false.  If DeleteOutput is set to true, the bitcode is
 120 /// deleted on success, and the filename string is undefined.  This prints to
 121 /// outs() a single line message indicating whether compilation was successful
 122 /// or failed.
 123 ///
 124 bool BugDriver::runPasses(Module *Program,
 125                           const std::vector<std::string> &Passes,
 126                           std::string &OutputFilename, bool DeleteOutput,
 127                           bool Quiet, unsigned NumExtraArgs,
 128                           const char * const *ExtraArgs) const {
 129   // setup the output file name
 130   outs().flush();
 131   SmallString<128> UniqueFilename;
 132   std::error_code EC = sys::fs::createUniqueFile(
 133       OutputPrefix + "-output-%%%%%%%.bc", UniqueFilename);
 134   if (EC) {
 135     errs() << getToolName() << ": Error making unique filename: "
 136            << EC.message() << "\n";
 137     return 1;
 138   }
 139   OutputFilename = UniqueFilename.str();
 140
 141   // set up the input file name
 142   SmallString<128> InputFilename;
 143   int InputFD;
 144   EC = sys::fs::createUniqueFile(OutputPrefix + "-input-%%%%%%%.bc", InputFD,
 145                                  InputFilename);
 146   if (EC) {
 147     errs() << getToolName() << ": Error making unique filename: "
 148            << EC.message() << "\n";
 149     return 1;
 150   }
 151
 152   tool_output_file InFile(InputFilename, InputFD);
 153
 154   WriteBitcodeToFile(Program, InFile.os());
 155   InFile.os().close();
 156   if (InFile.os().has_error()) {
 157     errs() << "Error writing bitcode file: " << InputFilename << "\n";
 158     InFile.os().clear_error();
 159     return 1;
 160   }
 161
 162   std::string tool = OptCmd;
 163   if (OptCmd.empty()) {
 164     if (ErrorOr<std::string> Path = sys::findProgramByName("opt"))
 165       tool = *Path;
 166     else
 167       errs() << Path.getError().message() << "\n";
 168   }
 169   if (tool.empty()) {
 170     errs() << "Cannot find `opt' in PATH!\n";
 171     return 1;
 172   }
 173
 174   std::string Prog;
 175   if (UseValgrind) {
 176     if (ErrorOr<std::string> Path = sys::findProgramByName("valgrind"))
 177       Prog = *Path;
 178     else
 179       errs() << Path.getError().message() << "\n";
 180   } else
 181     Prog = tool;
 182   if (Prog.empty()) {
 183     errs() << "Cannot find `valgrind' in PATH!\n";
 184     return 1;
 185   }
 186
 187   // Ok, everything that could go wrong before running opt is done.
 188   InFile.keep();
 189
 190   // setup the child process' arguments
 191   SmallVector<const char*, 8> Args;
 192   if (UseValgrind) {
 193     Args.push_back("valgrind");
 194     Args.push_back("--error-exitcode=1");
 195     Args.push_back("-q");
 196     Args.push_back(tool.c_str());
 197   } else
 198     Args.push_back(tool.c_str());
 199
 200   Args.push_back("-o");
 201   Args.push_back(OutputFilename.c_str());
 202   for (unsigned i = 0, e = OptArgs.size(); i != e; ++i)
 203     Args.push_back(OptArgs[i].c_str());
 204   std::vector<std::string> pass_args;
 205   for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
 206     pass_args.push_back( std::string("-load"));
 207     pass_args.push_back( PluginLoader::getPlugin(i));
 208   }
 209   for (std::vector<std::string>::const_iterator I = Passes.begin(),
 210        E = Passes.end(); I != E; ++I )
 211     pass_args.push_back( std::string("-") + (*I) );
 212   for (std::vector<std::string>::const_iterator I = pass_args.begin(),
 213        E = pass_args.end(); I != E; ++I )
 214     Args.push_back(I->c_str());
 215   Args.push_back(InputFilename.c_str());
 216   for (unsigned i = 0; i < NumExtraArgs; ++i)
 217     Args.push_back(*ExtraArgs);
 218   Args.push_back(nullptr);
 219
 220   DEBUG(errs() << "\nAbout to run:\t";
 221         for (unsigned i = 0, e = Args.size()-1; i != e; ++i)
 222           errs() << " " << Args[i];
 223         errs() << "\n";
 224         );
 225
 226   // Redirect stdout and stderr to nowhere if SilencePasses is given
 227   StringRef Nowhere;
 228   const StringRef *Redirects[3] = {nullptr, &Nowhere, &Nowhere};
 229
 230   std::string ErrMsg;
 231   int result = sys::ExecuteAndWait(Prog, Args.data(), nullptr,
 232                                    (SilencePasses ? Redirects : nullptr),
 233                                    Timeout, MemoryLimit, &ErrMsg);
 234
 235   // If we are supposed to delete the bitcode file or if the passes crashed,
 236   // remove it now.  This may fail if the file was never created, but that's ok.
 237   if (DeleteOutput || result != 0)
 238     sys::fs::remove(OutputFilename);
 239
 240   // Remove the temporary input file as well
 241   sys::fs::remove(InputFilename.c_str());
 242
 243   if (!Quiet) {
 244     if (result == 0)
 245       outs() << "Success!\n";
 246     else if (result > 0)
 247       outs() << "Exited with error code '" << result << "'\n";
 248     else if (result < 0) {
 249       if (result == -1)
 250         outs() << "Execute failed: " << ErrMsg << "\n";
 251       else
 252         outs() << "Crashed: " << ErrMsg << "\n";
 253     }
 254     if (result & 0x01000000)
 255       outs() << "Dumped core\n";
 256   }
 257
 258   // Was the child successful?
 259   return result != 0;
 260 }
 261
 262
 263 std::unique_ptr<Module>
 264 BugDriver::runPassesOn(Module *M, const std::vector<std::string> &Passes,
 265                        bool AutoDebugCrashes, unsigned NumExtraArgs,
 266                        const char *const *ExtraArgs) {
 267   std::string BitcodeResult;
 268   if (runPasses(M, Passes, BitcodeResult, false/*delete*/, true/*quiet*/,
 269                 NumExtraArgs, ExtraArgs)) {
 270     if (AutoDebugCrashes) {
 271       errs() << " Error running this sequence of passes"
 272              << " on the input program!\n";
 273       delete swapProgramIn(M);
 274       EmitProgressBitcode(M, "pass-error",  false);
 275       exit(debugOptimizerCrash());
 276     }
 277     return nullptr;
 278   }
 279
 280   std::unique_ptr<Module> Ret = parseInputFile(BitcodeResult, Context);
 281   if (!Ret) {
 282     errs() << getToolName() << ": Error reading bitcode file '"
 283            << BitcodeResult << "'!\n";
 284     exit(1);
 285   }
 286   sys::fs::remove(BitcodeResult);
 287   return Ret;
 288 }