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 // Note: as a short term hack, the old Unix-specific code and platform-
  19 // independent code co-exist via conditional compilation until it is verified
  20 // that the new code works correctly on Unix.
  21
  22 #include "BugDriver.h"
  23 #include "llvm/Module.h"
  24 #include "llvm/PassManager.h"
  25 #include "llvm/Analysis/Verifier.h"
  26 #include "llvm/Bitcode/ReaderWriter.h"
  27 #include "llvm/Target/TargetData.h"
  28 #include "llvm/Support/FileUtilities.h"
  29 #include "llvm/Support/CommandLine.h"
  30 #include "llvm/Support/raw_ostream.h"
  31 #include "llvm/System/Path.h"
  32 #include "llvm/System/Program.h"
  33
  34 #define DONT_GET_PLUGIN_LOADER_OPTION
  35 #include "llvm/Support/PluginLoader.h"
  36
  37 #include <fstream>
  38 using namespace llvm;
  39
  40 namespace llvm {
  41   extern cl::opt<std::string> OutputPrefix;
  42 }
  43
  44 namespace {
  45   // ChildOutput - This option captures the name of the child output file that
  46   // is set up by the parent bugpoint process
  47   cl::opt<std::string> ChildOutput("child-output", cl::ReallyHidden);
  48   cl::opt<bool> UseValgrind("enable-valgrind",
  49                             cl::desc("Run optimizations through valgrind"));
  50 }
  51
  52 /// writeProgramToFile - This writes the current "Program" to the named bitcode
  53 /// file.  If an error occurs, true is returned.
  54 ///
  55 bool BugDriver::writeProgramToFile(const std::string &Filename,
  56                                    Module *M) const {
  57   std::string ErrInfo;
  58   raw_fd_ostream Out(Filename.c_str(), ErrInfo,
  59                      raw_fd_ostream::F_Binary);
  60   if (!ErrInfo.empty()) return true;
  61
  62   WriteBitcodeToFile(M ? M : Program, Out);
  63   return false;
  64 }
  65
  66
  67 /// EmitProgressBitcode - This function is used to output the current Program
  68 /// to a file named "bugpoint-ID.bc".
  69 ///
  70 void BugDriver::EmitProgressBitcode(const std::string &ID, bool NoFlyer) {
  71   // Output the input to the current pass to a bitcode file, emit a message
  72   // telling the user how to reproduce it: opt -foo blah.bc
  73   //
  74   std::string Filename = OutputPrefix + "-" + ID + ".bc";
  75   if (writeProgramToFile(Filename)) {
  76     errs() <<  "Error opening file '" << Filename << "' for writing!\n";
  77     return;
  78   }
  79
  80   outs() << "Emitted bitcode to '" << Filename << "'\n";
  81   if (NoFlyer || PassesToRun.empty()) return;
  82   outs() << "\n*** You can reproduce the problem with: ";
  83   if (UseValgrind) outs() << "valgrind ";
  84   outs() << "opt " << Filename << " ";
  85   outs() << getPassesString(PassesToRun) << "\n";
  86 }
  87
  88 int BugDriver::runPassesAsChild(const std::vector<const PassInfo*> &Passes) {
  89   std::string ErrInfo;
  90   raw_fd_ostream OutFile(ChildOutput.c_str(), ErrInfo,
  91                          raw_fd_ostream::F_Binary);
  92   if (!ErrInfo.empty()) {
  93     errs() << "Error opening bitcode file: " << ChildOutput << "\n";
  94     return 1;
  95   }
  96
  97   PassManager PM;
  98   // Make sure that the appropriate target data is always used...
  99   PM.add(new TargetData(Program));
 100
 101   for (unsigned i = 0, e = Passes.size(); i != e; ++i) {
 102     if (Passes[i]->getNormalCtor())
 103       PM.add(Passes[i]->getNormalCtor()());
 104     else
 105       errs() << "Cannot create pass yet: " << Passes[i]->getPassName() << "\n";
 106   }
 107   // Check that the module is well formed on completion of optimization
 108   PM.add(createVerifierPass());
 109
 110   // Write bitcode out to disk as the last step...
 111   PM.add(createBitcodeWriterPass(OutFile));
 112
 113   // Run all queued passes.
 114   PM.run(*Program);
 115
 116   return 0;
 117 }
 118
 119 cl::opt<bool> SilencePasses("silence-passes", cl::desc("Suppress output of running passes (both stdout and stderr)"));
 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(const std::vector<const PassInfo*> &Passes,
 130                           std::string &OutputFilename, bool DeleteOutput,
 131                           bool Quiet, unsigned NumExtraArgs,
 132                           const char * const *ExtraArgs) const {
 133   // setup the output file name
 134   outs().flush();
 135   sys::Path uniqueFilename(OutputPrefix + "-output.bc");
 136   std::string ErrMsg;
 137   if (uniqueFilename.makeUnique(true, &ErrMsg)) {
 138     errs() << getToolName() << ": Error making unique filename: "
 139            << ErrMsg << "\n";
 140     return(1);
 141   }
 142   OutputFilename = uniqueFilename.str();
 143
 144   // set up the input file name
 145   sys::Path inputFilename(OutputPrefix + "-input.bc");
 146   if (inputFilename.makeUnique(true, &ErrMsg)) {
 147     errs() << getToolName() << ": Error making unique filename: "
 148            << ErrMsg << "\n";
 149     return(1);
 150   }
 151
 152   std::string ErrInfo;
 153   raw_fd_ostream InFile(inputFilename.c_str(), ErrInfo,
 154                         raw_fd_ostream::F_Binary);
 155
 156
 157   if (!ErrInfo.empty()) {
 158     errs() << "Error opening bitcode file: " << inputFilename.str() << "\n";
 159     return 1;
 160   }
 161   WriteBitcodeToFile(Program, InFile);
 162   InFile.close();
 163
 164   // setup the child process' arguments
 165   SmallVector<const char*, 8> Args;
 166   sys::Path tool = sys::Program::FindProgramByName(ToolName);
 167   if (UseValgrind) {
 168     Args.push_back("valgrind");
 169     Args.push_back("--error-exitcode=1");
 170     Args.push_back("-q");
 171     Args.push_back(tool.c_str());
 172   } else
 173     Args.push_back(ToolName);
 174
 175   Args.push_back("-as-child");
 176   Args.push_back("-child-output");
 177   Args.push_back(OutputFilename.c_str());
 178   std::vector<std::string> pass_args;
 179   for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
 180     pass_args.push_back( std::string("-load"));
 181     pass_args.push_back( PluginLoader::getPlugin(i));
 182   }
 183   for (std::vector<const PassInfo*>::const_iterator I = Passes.begin(),
 184        E = Passes.end(); I != E; ++I )
 185     pass_args.push_back( std::string("-") + (*I)->getPassArgument() );
 186   for (std::vector<std::string>::const_iterator I = pass_args.begin(),
 187        E = pass_args.end(); I != E; ++I )
 188     Args.push_back(I->c_str());
 189   Args.push_back(inputFilename.c_str());
 190   for (unsigned i = 0; i < NumExtraArgs; ++i)
 191     Args.push_back(*ExtraArgs);
 192   Args.push_back(0);
 193
 194   sys::Path prog;
 195   if (UseValgrind)
 196     prog = sys::Program::FindProgramByName("valgrind");
 197   else
 198     prog = tool;
 199
 200   // Redirect stdout and stderr to nowhere if SilencePasses is given
 201   sys::Path Nowhere;
 202   const sys::Path *Redirects[3] = {0, &Nowhere, &Nowhere};
 203
 204   int result = sys::Program::ExecuteAndWait(prog, Args.data(), 0,
 205                                             (SilencePasses ? Redirects : 0),
 206                                             Timeout, MemoryLimit, &ErrMsg);
 207
 208   // If we are supposed to delete the bitcode file or if the passes crashed,
 209   // remove it now.  This may fail if the file was never created, but that's ok.
 210   if (DeleteOutput || result != 0)
 211     sys::Path(OutputFilename).eraseFromDisk();
 212
 213   // Remove the temporary input file as well
 214   inputFilename.eraseFromDisk();
 215
 216   if (!Quiet) {
 217     if (result == 0)
 218       outs() << "Success!\n";
 219     else if (result > 0)
 220       outs() << "Exited with error code '" << result << "'\n";
 221     else if (result < 0) {
 222       if (result == -1)
 223         outs() << "Execute failed: " << ErrMsg << "\n";
 224       else
 225         outs() << "Crashed with signal #" << abs(result) << "\n";
 226     }
 227     if (result & 0x01000000)
 228       outs() << "Dumped core\n";
 229   }
 230
 231   // Was the child successful?
 232   return result != 0;
 233 }
 234
 235
 236 /// runPassesOn - Carefully run the specified set of pass on the specified
 237 /// module, returning the transformed module on success, or a null pointer on
 238 /// failure.
 239 Module *BugDriver::runPassesOn(Module *M,
 240                                const std::vector<const PassInfo*> &Passes,
 241                                bool AutoDebugCrashes, unsigned NumExtraArgs,
 242                                const char * const *ExtraArgs) {
 243   Module *OldProgram = swapProgramIn(M);
 244   std::string BitcodeResult;
 245   if (runPasses(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 OldProgram;
 251       EmitProgressBitcode("pass-error",  false);
 252       exit(debugOptimizerCrash());
 253     }
 254     swapProgramIn(OldProgram);
 255     return 0;
 256   }
 257
 258   // Restore the current program.
 259   swapProgramIn(OldProgram);
 260
 261   Module *Ret = ParseInputFile(BitcodeResult, Context);
 262   if (Ret == 0) {
 263     errs() << getToolName() << ": Error reading bitcode file '"
 264            << BitcodeResult << "'!\n";
 265     exit(1);
 266   }
 267   sys::Path(BitcodeResult).eraseFromDisk();  // No longer need the file on disk
 268   return Ret;
 269 }