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/Module.h"
  20 #include "llvm/PassManager.h"
  21 #include "llvm/Analysis/Verifier.h"
  22 #include "llvm/Bitcode/ReaderWriter.h"
  23 #include "llvm/Target/TargetData.h"
  24 #include "llvm/Support/FileUtilities.h"
  25 #include "llvm/Support/CommandLine.h"
  26 #include "llvm/Support/SystemUtils.h"
  27 #include "llvm/Support/Debug.h"
  28 #include "llvm/Support/ToolOutputFile.h"
  29 #include "llvm/Support/Path.h"
  30 #include "llvm/Support/Program.h"
  31
  32 #define DONT_GET_PLUGIN_LOADER_OPTION
  33 #include "llvm/Support/PluginLoader.h"
  34
  35 #include <fstream>
  36 using namespace llvm;
  37
  38 namespace llvm {
  39   extern cl::opt<std::string> OutputPrefix;
  40 }
  41
  42 namespace {
  43   // ChildOutput - This option captures the name of the child output file that
  44   // is set up by the parent bugpoint process
  45   cl::opt<std::string> ChildOutput("child-output", cl::ReallyHidden);
  46 }
  47
  48 /// writeProgramToFile - This writes the current "Program" to the named bitcode
  49 /// file.  If an error occurs, true is returned.
  50 ///
  51 bool BugDriver::writeProgramToFile(const std::string &Filename,
  52                                    const Module *M) const {
  53   std::string ErrInfo;
  54   tool_output_file Out(Filename.c_str(), ErrInfo,
  55                        raw_fd_ostream::F_Binary);
  56   if (ErrInfo.empty()) {
  57     WriteBitcodeToFile(M, Out.os());
  58     Out.os().close();
  59     if (!Out.os().has_error()) {
  60       Out.keep();
  61       return false;
  62     }
  63   }
  64   Out.os().clear_error();
  65   return true;
  66 }
  67
  68
  69 /// EmitProgressBitcode - This function is used to output the current Program
  70 /// to a file named "bugpoint-ID.bc".
  71 ///
  72 void BugDriver::EmitProgressBitcode(const Module *M,
  73                                     const std::string &ID,
  74                                     bool NoFlyer)  const {
  75   // Output the input to the current pass to a bitcode file, emit a message
  76   // telling the user how to reproduce it: opt -foo blah.bc
  77   //
  78   std::string Filename = OutputPrefix + "-" + ID + ".bc";
  79   if (writeProgramToFile(Filename, M)) {
  80     errs() <<  "Error opening file '" << Filename << "' for writing!\n";
  81     return;
  82   }
  83
  84   outs() << "Emitted bitcode to '" << Filename << "'\n";
  85   if (NoFlyer || PassesToRun.empty()) return;
  86   outs() << "\n*** You can reproduce the problem with: ";
  87   if (UseValgrind) outs() << "valgrind ";
  88   outs() << "opt " << Filename << " ";
  89   outs() << getPassesString(PassesToRun) << "\n";
  90 }
  91
  92 cl::opt<bool> SilencePasses("silence-passes",
  93         cl::desc("Suppress output of running passes (both stdout and stderr)"));
  94
  95 static cl::list<std::string> OptArgs("opt-args", cl::Positional,
  96                                      cl::desc("<opt arguments>..."),
  97                                      cl::ZeroOrMore, cl::PositionalEatsArgs);
  98
  99 /// runPasses - Run the specified passes on Program, outputting a bitcode file
 100 /// and writing the filename into OutputFile if successful.  If the
 101 /// optimizations fail for some reason (optimizer crashes), return true,
 102 /// otherwise return false.  If DeleteOutput is set to true, the bitcode is
 103 /// deleted on success, and the filename string is undefined.  This prints to
 104 /// outs() a single line message indicating whether compilation was successful
 105 /// or failed.
 106 ///
 107 bool BugDriver::runPasses(Module *Program,
 108                           const std::vector<std::string> &Passes,
 109                           std::string &OutputFilename, bool DeleteOutput,
 110                           bool Quiet, unsigned NumExtraArgs,
 111                           const char * const *ExtraArgs) const {
 112   // setup the output file name
 113   outs().flush();
 114   sys::Path uniqueFilename(OutputPrefix + "-output.bc");
 115   std::string ErrMsg;
 116   if (uniqueFilename.makeUnique(true, &ErrMsg)) {
 117     errs() << getToolName() << ": Error making unique filename: "
 118            << ErrMsg << "\n";
 119     return(1);
 120   }
 121   OutputFilename = uniqueFilename.str();
 122
 123   // set up the input file name
 124   sys::Path inputFilename(OutputPrefix + "-input.bc");
 125   if (inputFilename.makeUnique(true, &ErrMsg)) {
 126     errs() << getToolName() << ": Error making unique filename: "
 127            << ErrMsg << "\n";
 128     return(1);
 129   }
 130
 131   std::string ErrInfo;
 132   tool_output_file InFile(inputFilename.c_str(), ErrInfo,
 133                           raw_fd_ostream::F_Binary);
 134
 135
 136   if (!ErrInfo.empty()) {
 137     errs() << "Error opening bitcode file: " << inputFilename.str() << "\n";
 138     return 1;
 139   }
 140   WriteBitcodeToFile(Program, InFile.os());
 141   InFile.os().close();
 142   if (InFile.os().has_error()) {
 143     errs() << "Error writing bitcode file: " << inputFilename.str() << "\n";
 144     InFile.os().clear_error();
 145     return 1;
 146   }
 147
 148   sys::Path tool = PrependMainExecutablePath("opt", getToolName(),
 149                                              (void*)"opt");
 150   if (tool.empty()) {
 151     errs() << "Cannot find `opt' in executable directory!\n";
 152     return 1;
 153   }
 154
 155   // Ok, everything that could go wrong before running opt is done.
 156   InFile.keep();
 157
 158   // setup the child process' arguments
 159   SmallVector<const char*, 8> Args;
 160   std::string Opt = tool.str();
 161   if (UseValgrind) {
 162     Args.push_back("valgrind");
 163     Args.push_back("--error-exitcode=1");
 164     Args.push_back("-q");
 165     Args.push_back(tool.c_str());
 166   } else
 167     Args.push_back(Opt.c_str());
 168
 169   Args.push_back("-o");
 170   Args.push_back(OutputFilename.c_str());
 171   for (unsigned i = 0, e = OptArgs.size(); i != e; ++i)
 172     Args.push_back(OptArgs[i].c_str());
 173   std::vector<std::string> pass_args;
 174   for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
 175     pass_args.push_back( std::string("-load"));
 176     pass_args.push_back( PluginLoader::getPlugin(i));
 177   }
 178   for (std::vector<std::string>::const_iterator I = Passes.begin(),
 179        E = Passes.end(); I != E; ++I )
 180     pass_args.push_back( std::string("-") + (*I) );
 181   for (std::vector<std::string>::const_iterator I = pass_args.begin(),
 182        E = pass_args.end(); I != E; ++I )
 183     Args.push_back(I->c_str());
 184   Args.push_back(inputFilename.c_str());
 185   for (unsigned i = 0; i < NumExtraArgs; ++i)
 186     Args.push_back(*ExtraArgs);
 187   Args.push_back(0);
 188
 189   DEBUG(errs() << "\nAbout to run:\t";
 190         for (unsigned i = 0, e = Args.size()-1; i != e; ++i)
 191           errs() << " " << Args[i];
 192         errs() << "\n";
 193         );
 194
 195   sys::Path prog;
 196   if (UseValgrind)
 197     prog = sys::Program::FindProgramByName("valgrind");
 198   else
 199     prog = tool;
 200
 201   // Redirect stdout and stderr to nowhere if SilencePasses is given
 202   sys::Path Nowhere;
 203   const sys::Path *Redirects[3] = {0, &Nowhere, &Nowhere};
 204
 205   int result = sys::Program::ExecuteAndWait(prog, Args.data(), 0,
 206                                             (SilencePasses ? Redirects : 0),
 207                                             Timeout, MemoryLimit, &ErrMsg);
 208
 209   // If we are supposed to delete the bitcode file or if the passes crashed,
 210   // remove it now.  This may fail if the file was never created, but that's ok.
 211   if (DeleteOutput || result != 0)
 212     sys::Path(OutputFilename).eraseFromDisk();
 213
 214   // Remove the temporary input file as well
 215   inputFilename.eraseFromDisk();
 216
 217   if (!Quiet) {
 218     if (result == 0)
 219       outs() << "Success!\n";
 220     else if (result > 0)
 221       outs() << "Exited with error code '" << result << "'\n";
 222     else if (result < 0) {
 223       if (result == -1)
 224         outs() << "Execute failed: " << ErrMsg << "\n";
 225       else
 226         outs() << "Crashed: " << ErrMsg << "\n";
 227     }
 228     if (result & 0x01000000)
 229       outs() << "Dumped core\n";
 230   }
 231
 232   // Was the child successful?
 233   return result != 0;
 234 }
 235
 236
 237 /// runPassesOn - Carefully run the specified set of pass on the specified
 238 /// module, returning the transformed module on success, or a null pointer on
 239 /// failure.
 240 Module *BugDriver::runPassesOn(Module *M,
 241                                const std::vector<std::string> &Passes,
 242                                bool AutoDebugCrashes, unsigned NumExtraArgs,
 243                                const char * const *ExtraArgs) {
 244   std::string BitcodeResult;
 245   if (runPasses(M, Passes, BitcodeResult, false/*delete*/, true/*quiet*/,
 246                 NumExtraArgs, ExtraArgs)) {
 247     if (AutoDebugCrashes) {
 248       errs() << " Error running this sequence of passes"
 249              << " on the input program!\n";
 250       delete swapProgramIn(M);
 251       EmitProgressBitcode(M, "pass-error",  false);
 252       exit(debugOptimizerCrash());
 253     }
 254     return 0;
 255   }
 256
 257   Module *Ret = ParseInputFile(BitcodeResult, Context);
 258   if (Ret == 0) {
 259     errs() << getToolName() << ": Error reading bitcode file '"
 260            << BitcodeResult << "'!\n";
 261     exit(1);
 262   }
 263   sys::Path(BitcodeResult).eraseFromDisk();  // No longer need the file on disk
 264   return Ret;
 265 }