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/System/Path.h"
  31 #include "llvm/System/Program.h"
  32 #include "llvm/Config/alloca.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
  41 namespace {
  42   // ChildOutput - This option captures the name of the child output file that
  43   // is set up by the parent bugpoint process
  44   cl::opt<std::string> ChildOutput("child-output", cl::ReallyHidden);
  45   cl::opt<bool> UseValgrind("enable-valgrind",
  46                             cl::desc("Run optimizations through valgrind"));
  47 }
  48
  49 /// writeProgramToFile - This writes the current "Program" to the named bitcode
  50 /// file.  If an error occurs, true is returned.
  51 ///
  52 bool BugDriver::writeProgramToFile(const std::string &Filename,
  53                                    Module *M) const {
  54   std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
  55                                std::ios::binary;
  56   std::ofstream Out(Filename.c_str(), io_mode);
  57   if (!Out.good()) return true;
  58
  59   WriteBitcodeToFile(M ? M : Program, Out);
  60   return false;
  61 }
  62
  63
  64 /// EmitProgressBitcode - This function is used to output the current Program
  65 /// to a file named "bugpoint-ID.bc".
  66 ///
  67 void BugDriver::EmitProgressBitcode(const std::string &ID, bool NoFlyer) {
  68   // Output the input to the current pass to a bitcode file, emit a message
  69   // telling the user how to reproduce it: opt -foo blah.bc
  70   //
  71   std::string Filename = "bugpoint-" + ID + ".bc";
  72   if (writeProgramToFile(Filename)) {
  73     errs() <<  "Error opening file '" << Filename << "' for writing!\n";
  74     return;
  75   }
  76
  77   outs() << "Emitted bitcode to '" << Filename << "'\n";
  78   if (NoFlyer || PassesToRun.empty()) return;
  79   outs() << "\n*** You can reproduce the problem with: ";
  80   outs() << "opt " << Filename << " ";
  81   outs() << getPassesString(PassesToRun) << "\n";
  82 }
  83
  84 int BugDriver::runPassesAsChild(const std::vector<const PassInfo*> &Passes) {
  85
  86   std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
  87                                std::ios::binary;
  88   std::ofstream OutFile(ChildOutput.c_str(), io_mode);
  89   if (!OutFile.good()) {
  90     errs() << "Error opening bitcode file: " << ChildOutput << "\n";
  91     return 1;
  92   }
  93
  94   PassManager PM;
  95   // Make sure that the appropriate target data is always used...
  96   PM.add(new TargetData(Program));
  97
  98   for (unsigned i = 0, e = Passes.size(); i != e; ++i) {
  99     if (Passes[i]->getNormalCtor())
 100       PM.add(Passes[i]->getNormalCtor()());
 101     else
 102       errs() << "Cannot create pass yet: " << Passes[i]->getPassName() << "\n";
 103   }
 104   // Check that the module is well formed on completion of optimization
 105   PM.add(createVerifierPass());
 106
 107   // Write bitcode out to disk as the last step...
 108   PM.add(CreateBitcodeWriterPass(OutFile));
 109
 110   // Run all queued passes.
 111   PM.run(*Program);
 112
 113   return 0;
 114 }
 115
 116 cl::opt<bool> SilencePasses("silence-passes", cl::desc("Suppress output of running passes (both stdout and stderr)"));
 117
 118 /// runPasses - Run the specified passes on Program, outputting a bitcode file
 119 /// and writing the filename into OutputFile if successful.  If the
 120 /// optimizations fail for some reason (optimizer crashes), return true,
 121 /// otherwise return false.  If DeleteOutput is set to true, the bitcode is
 122 /// deleted on success, and the filename string is undefined.  This prints to
 123 /// outs() a single line message indicating whether compilation was successful
 124 /// or failed.
 125 ///
 126 bool BugDriver::runPasses(const std::vector<const PassInfo*> &Passes,
 127                           std::string &OutputFilename, bool DeleteOutput,
 128                           bool Quiet, unsigned NumExtraArgs,
 129                           const char * const *ExtraArgs) const {
 130   // setup the output file name
 131   outs().flush();
 132   sys::Path uniqueFilename("bugpoint-output.bc");
 133   std::string ErrMsg;
 134   if (uniqueFilename.makeUnique(true, &ErrMsg)) {
 135     errs() << getToolName() << ": Error making unique filename: "
 136            << ErrMsg << "\n";
 137     return(1);
 138   }
 139   OutputFilename = uniqueFilename.toString();
 140
 141   // set up the input file name
 142   sys::Path inputFilename("bugpoint-input.bc");
 143   if (inputFilename.makeUnique(true, &ErrMsg)) {
 144     errs() << getToolName() << ": Error making unique filename: "
 145            << ErrMsg << "\n";
 146     return(1);
 147   }
 148   std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
 149                                std::ios::binary;
 150   std::ofstream InFile(inputFilename.c_str(), io_mode);
 151   if (!InFile.good()) {
 152     errs() << "Error opening bitcode file: " << inputFilename << "\n";
 153     return(1);
 154   }
 155   WriteBitcodeToFile(Program, InFile);
 156   InFile.close();
 157
 158   // setup the child process' arguments
 159   const char** args = (const char**)
 160     alloca(sizeof(const char*) *
 161            (Passes.size()+13+2*PluginLoader::getNumPlugins()+NumExtraArgs));
 162   int n = 0;
 163   sys::Path tool = sys::Program::FindProgramByName(ToolName);
 164   if (UseValgrind) {
 165     args[n++] = "valgrind";
 166     args[n++] = "--error-exitcode=1";
 167     args[n++] = "-q";
 168     args[n++] = tool.c_str();
 169   } else
 170     args[n++] = ToolName.c_str();
 171
 172   args[n++] = "-as-child";
 173   args[n++] = "-child-output";
 174   args[n++] = OutputFilename.c_str();
 175   std::vector<std::string> pass_args;
 176   for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
 177     pass_args.push_back( std::string("-load"));
 178     pass_args.push_back( PluginLoader::getPlugin(i));
 179   }
 180   for (std::vector<const PassInfo*>::const_iterator I = Passes.begin(),
 181        E = Passes.end(); I != E; ++I )
 182     pass_args.push_back( std::string("-") + (*I)->getPassArgument() );
 183   for (std::vector<std::string>::const_iterator I = pass_args.begin(),
 184        E = pass_args.end(); I != E; ++I )
 185     args[n++] = I->c_str();
 186   args[n++] = inputFilename.c_str();
 187   for (unsigned i = 0; i < NumExtraArgs; ++i)
 188     args[n++] = *ExtraArgs;
 189   args[n++] = 0;
 190
 191   sys::Path prog;
 192   if (UseValgrind)
 193     prog = sys::Program::FindProgramByName("valgrind");
 194   else
 195     prog = tool;
 196
 197   // Redirect stdout and stderr to nowhere if SilencePasses is given
 198   sys::Path Nowhere;
 199   const sys::Path *Redirects[3] = {0, &Nowhere, &Nowhere};
 200
 201   int result = sys::Program::ExecuteAndWait(prog, args, 0, (SilencePasses ? Redirects : 0),
 202                                             Timeout, MemoryLimit, &ErrMsg);
 203
 204   // If we are supposed to delete the bitcode file or if the passes crashed,
 205   // remove it now.  This may fail if the file was never created, but that's ok.
 206   if (DeleteOutput || result != 0)
 207     sys::Path(OutputFilename).eraseFromDisk();
 208
 209   // Remove the temporary input file as well
 210   inputFilename.eraseFromDisk();
 211
 212   if (!Quiet) {
 213     if (result == 0)
 214       outs() << "Success!\n";
 215     else if (result > 0)
 216       outs() << "Exited with error code '" << result << "'\n";
 217     else if (result < 0) {
 218       if (result == -1)
 219         outs() << "Execute failed: " << ErrMsg << "\n";
 220       else
 221         outs() << "Crashed with signal #" << abs(result) << "\n";
 222     }
 223     if (result & 0x01000000)
 224       outs() << "Dumped core\n";
 225   }
 226
 227   // Was the child successful?
 228   return result != 0;
 229 }
 230
 231
 232 /// runPassesOn - Carefully run the specified set of pass on the specified
 233 /// module, returning the transformed module on success, or a null pointer on
 234 /// failure.
 235 Module *BugDriver::runPassesOn(Module *M,
 236                                const std::vector<const PassInfo*> &Passes,
 237                                bool AutoDebugCrashes, unsigned NumExtraArgs,
 238                                const char * const *ExtraArgs) {
 239   Module *OldProgram = swapProgramIn(M);
 240   std::string BitcodeResult;
 241   if (runPasses(Passes, BitcodeResult, false/*delete*/, true/*quiet*/,
 242                 NumExtraArgs, ExtraArgs)) {
 243     if (AutoDebugCrashes) {
 244       errs() << " Error running this sequence of passes"
 245              << " on the input program!\n";
 246       delete OldProgram;
 247       EmitProgressBitcode("pass-error",  false);
 248       exit(debugOptimizerCrash());
 249     }
 250     swapProgramIn(OldProgram);
 251     return 0;
 252   }
 253
 254   // Restore the current program.
 255   swapProgramIn(OldProgram);
 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 }