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/Streams.h"
  31 #include "llvm/System/Path.h"
  32 #include "llvm/System/Program.h"
  33 #include "llvm/Config/alloca.h"
  34
  35 #define DONT_GET_PLUGIN_LOADER_OPTION
  36 #include "llvm/Support/PluginLoader.h"
  37
  38 #include <fstream>
  39 using namespace llvm;
  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   cl::opt<bool> UseValgrind("enable-valgrind",
  47                             cl::desc("Run optimizations through valgrind"));
  48 }
  49
  50 /// writeProgramToFile - This writes the current "Program" to the named bitcode
  51 /// file.  If an error occurs, true is returned.
  52 ///
  53 bool BugDriver::writeProgramToFile(const std::string &Filename,
  54                                    Module *M) const {
  55   std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
  56                                std::ios::binary;
  57   std::ofstream Out(Filename.c_str(), io_mode);
  58   if (!Out.good()) return true;
  59
  60   WriteBitcodeToFile(M ? M : Program, Out);
  61   return false;
  62 }
  63
  64
  65 /// EmitProgressBitcode - This function is used to output the current Program
  66 /// to a file named "bugpoint-ID.bc".
  67 ///
  68 void BugDriver::EmitProgressBitcode(const std::string &ID, bool NoFlyer) {
  69   // Output the input to the current pass to a bitcode file, emit a message
  70   // telling the user how to reproduce it: opt -foo blah.bc
  71   //
  72   std::string Filename = "bugpoint-" + ID + ".bc";
  73   if (writeProgramToFile(Filename)) {
  74     cerr <<  "Error opening file '" << Filename << "' for writing!\n";
  75     return;
  76   }
  77
  78   cout << "Emitted bitcode to '" << Filename << "'\n";
  79   if (NoFlyer || PassesToRun.empty()) return;
  80   cout << "\n*** You can reproduce the problem with: ";
  81   cout << "opt " << Filename << " ";
  82   cout << getPassesString(PassesToRun) << "\n";
  83 }
  84
  85 int BugDriver::runPassesAsChild(const std::vector<const PassInfo*> &Passes) {
  86
  87   std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
  88                                std::ios::binary;
  89   std::ofstream OutFile(ChildOutput.c_str(), io_mode);
  90   if (!OutFile.good()) {
  91     cerr << "Error opening bitcode file: " << ChildOutput << "\n";
  92     return 1;
  93   }
  94
  95   PassManager PM;
  96   // Make sure that the appropriate target data is always used...
  97   PM.add(new TargetData(Program));
  98
  99   for (unsigned i = 0, e = Passes.size(); i != e; ++i) {
 100     if (Passes[i]->getNormalCtor())
 101       PM.add(Passes[i]->getNormalCtor()());
 102     else
 103       cerr << "Cannot create pass yet: " << Passes[i]->getPassName() << "\n";
 104   }
 105   // Check that the module is well formed on completion of optimization
 106   PM.add(createVerifierPass());
 107
 108   // Write bitcode out to disk as the last step...
 109   PM.add(CreateBitcodeWriterPass(OutFile));
 110
 111   // Run all queued passes.
 112   PM.run(*Program);
 113
 114   return 0;
 115 }
 116
 117 cl::opt<bool> SilencePasses("silence-passes", cl::desc("Suppress output of running passes (both stdout and stderr)"));
 118
 119 /// runPasses - Run the specified passes on Program, outputting a bitcode file
 120 /// and writing the filename into OutputFile if successful.  If the
 121 /// optimizations fail for some reason (optimizer crashes), return true,
 122 /// otherwise return false.  If DeleteOutput is set to true, the bitcode is
 123 /// deleted on success, and the filename string is undefined.  This prints to
 124 /// cout a single line message indicating whether compilation was successful or
 125 /// failed.
 126 ///
 127 bool BugDriver::runPasses(const std::vector<const PassInfo*> &Passes,
 128                           std::string &OutputFilename, bool DeleteOutput,
 129                           bool Quiet, unsigned NumExtraArgs,
 130                           const char * const *ExtraArgs) const {
 131   // setup the output file name
 132   cout << std::flush;
 133   sys::Path uniqueFilename("bugpoint-output.bc");
 134   std::string ErrMsg;
 135   if (uniqueFilename.makeUnique(true, &ErrMsg)) {
 136     cerr << getToolName() << ": Error making unique filename: "
 137          << ErrMsg << "\n";
 138     return(1);
 139   }
 140   OutputFilename = uniqueFilename.toString();
 141
 142   // set up the input file name
 143   sys::Path inputFilename("bugpoint-input.bc");
 144   if (inputFilename.makeUnique(true, &ErrMsg)) {
 145     cerr << getToolName() << ": Error making unique filename: "
 146          << ErrMsg << "\n";
 147     return(1);
 148   }
 149   std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
 150                                std::ios::binary;
 151   std::ofstream InFile(inputFilename.c_str(), io_mode);
 152   if (!InFile.good()) {
 153     cerr << "Error opening bitcode file: " << inputFilename << "\n";
 154     return(1);
 155   }
 156   WriteBitcodeToFile(Program, InFile);
 157   InFile.close();
 158
 159   // setup the child process' arguments
 160   const char** args = (const char**)
 161     alloca(sizeof(const char*) *
 162            (Passes.size()+13+2*PluginLoader::getNumPlugins()+NumExtraArgs));
 163   int n = 0;
 164   sys::Path tool = sys::Program::FindProgramByName(ToolName);
 165   if (UseValgrind) {
 166     args[n++] = "valgrind";
 167     args[n++] = "--error-exitcode=1";
 168     args[n++] = "-q";
 169     args[n++] = tool.c_str();
 170   } else
 171     args[n++] = ToolName.c_str();
 172
 173   args[n++] = "-as-child";
 174   args[n++] = "-child-output";
 175   args[n++] = OutputFilename.c_str();
 176   std::vector<std::string> pass_args;
 177   for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
 178     pass_args.push_back( std::string("-load"));
 179     pass_args.push_back( PluginLoader::getPlugin(i));
 180   }
 181   for (std::vector<const PassInfo*>::const_iterator I = Passes.begin(),
 182        E = Passes.end(); I != E; ++I )
 183     pass_args.push_back( std::string("-") + (*I)->getPassArgument() );
 184   for (std::vector<std::string>::const_iterator I = pass_args.begin(),
 185        E = pass_args.end(); I != E; ++I )
 186     args[n++] = I->c_str();
 187   args[n++] = inputFilename.c_str();
 188   for (unsigned i = 0; i < NumExtraArgs; ++i)
 189     args[n++] = *ExtraArgs;
 190   args[n++] = 0;
 191
 192   sys::Path prog;
 193   if (UseValgrind)
 194     prog = sys::Program::FindProgramByName("valgrind");
 195   else
 196     prog = tool;
 197
 198   // Redirect stdout and stderr to nowhere if SilencePasses is given
 199   sys::Path Nowhere;
 200   const sys::Path *Redirects[3] = {0, &Nowhere, &Nowhere};
 201
 202   int result = sys::Program::ExecuteAndWait(prog, args, 0, (SilencePasses ? Redirects : 0),
 203                                             Timeout, MemoryLimit, &ErrMsg);
 204
 205   // If we are supposed to delete the bitcode file or if the passes crashed,
 206   // remove it now.  This may fail if the file was never created, but that's ok.
 207   if (DeleteOutput || result != 0)
 208     sys::Path(OutputFilename).eraseFromDisk();
 209
 210   // Remove the temporary input file as well
 211   inputFilename.eraseFromDisk();
 212
 213   if (!Quiet) {
 214     if (result == 0)
 215       cout << "Success!\n";
 216     else if (result > 0)
 217       cout << "Exited with error code '" << result << "'\n";
 218     else if (result < 0) {
 219       if (result == -1)
 220         cout << "Execute failed: " << ErrMsg << "\n";
 221       else
 222         cout << "Crashed with signal #" << abs(result) << "\n";
 223     }
 224     if (result & 0x01000000)
 225       cout << "Dumped core\n";
 226   }
 227
 228   // Was the child successful?
 229   return result != 0;
 230 }
 231
 232
 233 /// runPassesOn - Carefully run the specified set of pass on the specified
 234 /// module, returning the transformed module on success, or a null pointer on
 235 /// failure.
 236 Module *BugDriver::runPassesOn(Module *M,
 237                                const std::vector<const PassInfo*> &Passes,
 238                                bool AutoDebugCrashes, unsigned NumExtraArgs,
 239                                const char * const *ExtraArgs) {
 240   Module *OldProgram = swapProgramIn(M);
 241   std::string BitcodeResult;
 242   if (runPasses(Passes, BitcodeResult, false/*delete*/, true/*quiet*/,
 243                 NumExtraArgs, ExtraArgs)) {
 244     if (AutoDebugCrashes) {
 245       cerr << " Error running this sequence of passes"
 246            << " on the input program!\n";
 247       delete OldProgram;
 248       EmitProgressBitcode("pass-error",  false);
 249       exit(debugOptimizerCrash());
 250     }
 251     swapProgramIn(OldProgram);
 252     return 0;
 253   }
 254
 255   // Restore the current program.
 256   swapProgramIn(OldProgram);
 257
 258   Module *Ret = ParseInputFile(BitcodeResult);
 259   if (Ret == 0) {
 260     cerr << getToolName() << ": Error reading bitcode file '"
 261          << BitcodeResult << "'!\n";
 262     exit(1);
 263   }
 264   sys::Path(BitcodeResult).eraseFromDisk();  // No longer need the file on disk
 265   return Ret;
 266 }