tools/bugpoint/ExecutionDriver.cpp

   1 //===- ExecutionDriver.cpp - Allow execution of LLVM program --------------===//
   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 contains code used to execute the program utilizing one of the
  11 // various ways of running LLVM bitcode.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "BugDriver.h"
  16 #include "ToolRunner.h"
  17 #include "llvm/Support/CommandLine.h"
  18 #include "llvm/Support/Debug.h"
  19 #include "llvm/Support/FileUtilities.h"
  20 #include "llvm/Support/SystemUtils.h"
  21 #include "llvm/Support/raw_ostream.h"
  22 #include <fstream>
  23
  24 using namespace llvm;
  25
  26 namespace {
  27   // OutputType - Allow the user to specify the way code should be run, to test
  28   // for miscompilation.
  29   //
  30   enum OutputType {
  31     AutoPick, RunLLI, RunJIT, RunLLC, RunCBE, CBE_bug, LLC_Safe, Custom
  32   };
  33
  34   cl::opt<double>
  35   AbsTolerance("abs-tolerance", cl::desc("Absolute error tolerated"),
  36                cl::init(0.0));
  37   cl::opt<double>
  38   RelTolerance("rel-tolerance", cl::desc("Relative error tolerated"),
  39                cl::init(0.0));
  40
  41   cl::opt<OutputType>
  42   InterpreterSel(cl::desc("Specify the \"test\" i.e. suspect back-end:"),
  43                  cl::values(clEnumValN(AutoPick, "auto", "Use best guess"),
  44                             clEnumValN(RunLLI, "run-int",
  45                                        "Execute with the interpreter"),
  46                             clEnumValN(RunJIT, "run-jit", "Execute with JIT"),
  47                             clEnumValN(RunLLC, "run-llc", "Compile with LLC"),
  48                             clEnumValN(RunCBE, "run-cbe", "Compile with CBE"),
  49                             clEnumValN(CBE_bug,"cbe-bug", "Find CBE bugs"),
  50                             clEnumValN(LLC_Safe, "llc-safe", "Use LLC for all"),
  51                             clEnumValN(Custom, "run-custom",
  52                             "Use -exec-command to define a command to execute "
  53                             "the bitcode. Useful for cross-compilation."),
  54                             clEnumValEnd),
  55                  cl::init(AutoPick));
  56
  57   cl::opt<OutputType>
  58   SafeInterpreterSel(cl::desc("Specify \"safe\" i.e. known-good backend:"),
  59               cl::values(clEnumValN(AutoPick, "safe-auto", "Use best guess"),
  60                          clEnumValN(RunLLC, "safe-run-llc", "Compile with LLC"),
  61                          clEnumValN(RunCBE, "safe-run-cbe", "Compile with CBE"),
  62                          clEnumValN(Custom, "safe-run-custom",
  63                          "Use -exec-command to define a command to execute "
  64                          "the bitcode. Useful for cross-compilation."),
  65                          clEnumValEnd),
  66                      cl::init(AutoPick));
  67
  68   cl::opt<std::string>
  69   SafeInterpreterPath("safe-path",
  70                    cl::desc("Specify the path to the \"safe\" backend program"),
  71                    cl::init(""));
  72
  73   cl::opt<bool>
  74   AppendProgramExitCode("append-exit-code",
  75       cl::desc("Append the exit code to the output so it gets diff'd too"),
  76       cl::init(false));
  77
  78   cl::opt<std::string>
  79   InputFile("input", cl::init("/dev/null"),
  80             cl::desc("Filename to pipe in as stdin (default: /dev/null)"));
  81
  82   cl::list<std::string>
  83   AdditionalSOs("additional-so",
  84                 cl::desc("Additional shared objects to load "
  85                          "into executing programs"));
  86
  87   cl::list<std::string>
  88   AdditionalLinkerArgs("Xlinker",
  89       cl::desc("Additional arguments to pass to the linker"));
  90
  91   cl::opt<std::string>
  92   CustomExecCommand("exec-command", cl::init("simulate"),
  93       cl::desc("Command to execute the bitcode (use with -run-custom) "
  94                "(default: simulate)"));
  95 }
  96
  97 namespace llvm {
  98   // Anything specified after the --args option are taken as arguments to the
  99   // program being debugged.
 100   cl::list<std::string>
 101   InputArgv("args", cl::Positional, cl::desc("<program arguments>..."),
 102             cl::ZeroOrMore, cl::PositionalEatsArgs);
 103
 104   cl::opt<std::string>
 105   OutputPrefix("output-prefix", cl::init("bugpoint"),
 106             cl::desc("Prefix to use for outputs (default: 'bugpoint')"));
 107 }
 108
 109 namespace {
 110   cl::list<std::string>
 111   ToolArgv("tool-args", cl::Positional, cl::desc("<tool arguments>..."),
 112            cl::ZeroOrMore, cl::PositionalEatsArgs);
 113
 114   cl::list<std::string>
 115   SafeToolArgv("safe-tool-args", cl::Positional,
 116                cl::desc("<safe-tool arguments>..."),
 117                cl::ZeroOrMore, cl::PositionalEatsArgs);
 118
 119   cl::list<std::string>
 120   GCCToolArgv("gcc-tool-args", cl::Positional,
 121               cl::desc("<gcc-tool arguments>..."),
 122               cl::ZeroOrMore, cl::PositionalEatsArgs);
 123 }
 124
 125 //===----------------------------------------------------------------------===//
 126 // BugDriver method implementation
 127 //
 128
 129 /// initializeExecutionEnvironment - This method is used to set up the
 130 /// environment for executing LLVM programs.
 131 ///
 132 bool BugDriver::initializeExecutionEnvironment() {
 133   outs() << "Initializing execution environment: ";
 134
 135   // Create an instance of the AbstractInterpreter interface as specified on
 136   // the command line
 137   SafeInterpreter = 0;
 138   std::string Message;
 139
 140   switch (InterpreterSel) {
 141   case AutoPick:
 142     InterpreterSel = RunCBE;
 143     Interpreter =
 144       AbstractInterpreter::createCBE(getToolName(), Message, &ToolArgv,
 145                                      &GCCToolArgv);
 146     if (!Interpreter) {
 147       InterpreterSel = RunJIT;
 148       Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
 149                                                    &ToolArgv);
 150     }
 151     if (!Interpreter) {
 152       InterpreterSel = RunLLC;
 153       Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
 154                                                    &ToolArgv, &GCCToolArgv);
 155     }
 156     if (!Interpreter) {
 157       InterpreterSel = RunLLI;
 158       Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
 159                                                    &ToolArgv);
 160     }
 161     if (!Interpreter) {
 162       InterpreterSel = AutoPick;
 163       Message = "Sorry, I can't automatically select an interpreter!\n";
 164     }
 165     break;
 166   case RunLLI:
 167     Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
 168                                                  &ToolArgv);
 169     break;
 170   case RunLLC:
 171   case LLC_Safe:
 172     Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
 173                                                  &ToolArgv, &GCCToolArgv);
 174     break;
 175   case RunJIT:
 176     Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
 177                                                  &ToolArgv);
 178     break;
 179   case RunCBE:
 180   case CBE_bug:
 181     Interpreter = AbstractInterpreter::createCBE(getToolName(), Message,
 182                                                  &ToolArgv, &GCCToolArgv);
 183     break;
 184   case Custom:
 185     Interpreter = AbstractInterpreter::createCustom(Message, CustomExecCommand);
 186     break;
 187   default:
 188     Message = "Sorry, this back-end is not supported by bugpoint right now!\n";
 189     break;
 190   }
 191   if (!Interpreter)
 192     errs() << Message;
 193   else // Display informational messages on stdout instead of stderr
 194     outs() << Message;
 195
 196   std::string Path = SafeInterpreterPath;
 197   if (Path.empty())
 198     Path = getToolName();
 199   std::vector<std::string> SafeToolArgs = SafeToolArgv;
 200   switch (SafeInterpreterSel) {
 201   case AutoPick:
 202     // In "cbe-bug" mode, default to using LLC as the "safe" backend.
 203     if (!SafeInterpreter &&
 204         InterpreterSel == CBE_bug) {
 205       SafeInterpreterSel = RunLLC;
 206       SafeToolArgs.push_back("--relocation-model=pic");
 207       SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
 208                                                        &SafeToolArgs,
 209                                                        &GCCToolArgv);
 210     }
 211
 212     // In "llc-safe" mode, default to using LLC as the "safe" backend.
 213     if (!SafeInterpreter &&
 214         InterpreterSel == LLC_Safe) {
 215       SafeInterpreterSel = RunLLC;
 216       SafeToolArgs.push_back("--relocation-model=pic");
 217       SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
 218                                                        &SafeToolArgs,
 219                                                        &GCCToolArgv);
 220     }
 221
 222     // Pick a backend that's different from the test backend. The JIT and
 223     // LLC backends share a lot of code, so prefer to use the CBE as the
 224     // safe back-end when testing them.
 225     if (!SafeInterpreter &&
 226         InterpreterSel != RunCBE) {
 227       SafeInterpreterSel = RunCBE;
 228       SafeInterpreter = AbstractInterpreter::createCBE(Path.c_str(), Message,
 229                                                        &SafeToolArgs,
 230                                                        &GCCToolArgv);
 231     }
 232     if (!SafeInterpreter &&
 233         InterpreterSel != RunLLC &&
 234         InterpreterSel != RunJIT) {
 235       SafeInterpreterSel = RunLLC;
 236       SafeToolArgs.push_back("--relocation-model=pic");
 237       SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
 238                                                        &SafeToolArgs,
 239                                                        &GCCToolArgv);
 240     }
 241     if (!SafeInterpreter) {
 242       SafeInterpreterSel = AutoPick;
 243       Message = "Sorry, I can't automatically select an interpreter!\n";
 244     }
 245     break;
 246   case RunLLC:
 247     SafeToolArgs.push_back("--relocation-model=pic");
 248     SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
 249                                                      &SafeToolArgs,
 250                                                      &GCCToolArgv);
 251     break;
 252   case RunCBE:
 253     SafeInterpreter = AbstractInterpreter::createCBE(Path.c_str(), Message,
 254                                                      &SafeToolArgs,
 255                                                      &GCCToolArgv);
 256     break;
 257   case Custom:
 258     SafeInterpreter = AbstractInterpreter::createCustom(Message,
 259                                                         CustomExecCommand);
 260     break;
 261   default:
 262     Message = "Sorry, this back-end is not supported by bugpoint as the "
 263               "\"safe\" backend right now!\n";
 264     break;
 265   }
 266   if (!SafeInterpreter) { outs() << Message << "\nExiting.\n"; exit(1); }
 267
 268   gcc = GCC::create(Message, &GCCToolArgv);
 269   if (!gcc) { outs() << Message << "\nExiting.\n"; exit(1); }
 270
 271   // If there was an error creating the selected interpreter, quit with error.
 272   return Interpreter == 0;
 273 }
 274
 275 /// compileProgram - Try to compile the specified module, throwing an exception
 276 /// if an error occurs, or returning normally if not.  This is used for code
 277 /// generation crash testing.
 278 ///
 279 void BugDriver::compileProgram(Module *M) {
 280   // Emit the program to a bitcode file...
 281   sys::Path BitcodeFile (OutputPrefix + "-test-program.bc");
 282   std::string ErrMsg;
 283   if (BitcodeFile.makeUnique(true,&ErrMsg)) {
 284     errs() << ToolName << ": Error making unique filename: " << ErrMsg
 285            << "\n";
 286     exit(1);
 287   }
 288   if (writeProgramToFile(BitcodeFile.str(), M)) {
 289     errs() << ToolName << ": Error emitting bitcode to file '"
 290            << BitcodeFile.str() << "'!\n";
 291     exit(1);
 292   }
 293
 294     // Remove the temporary bitcode file when we are done.
 295   FileRemover BitcodeFileRemover(BitcodeFile, !SaveTemps);
 296
 297   // Actually compile the program!
 298   Interpreter->compileProgram(BitcodeFile.str());
 299 }
 300
 301
 302 /// executeProgram - This method runs "Program", capturing the output of the
 303 /// program to a file, returning the filename of the file.  A recommended
 304 /// filename may be optionally specified.
 305 ///
 306 std::string BugDriver::executeProgram(std::string OutputFile,
 307                                       std::string BitcodeFile,
 308                                       const std::string &SharedObj,
 309                                       AbstractInterpreter *AI,
 310                                       bool *ProgramExitedNonzero) {
 311   if (AI == 0) AI = Interpreter;
 312   assert(AI && "Interpreter should have been created already!");
 313   bool CreatedBitcode = false;
 314   std::string ErrMsg;
 315   if (BitcodeFile.empty()) {
 316     // Emit the program to a bitcode file...
 317     sys::Path uniqueFilename(OutputPrefix + "-test-program.bc");
 318     if (uniqueFilename.makeUnique(true, &ErrMsg)) {
 319       errs() << ToolName << ": Error making unique filename: "
 320              << ErrMsg << "!\n";
 321       exit(1);
 322     }
 323     BitcodeFile = uniqueFilename.str();
 324
 325     if (writeProgramToFile(BitcodeFile, Program)) {
 326       errs() << ToolName << ": Error emitting bitcode to file '"
 327              << BitcodeFile << "'!\n";
 328       exit(1);
 329     }
 330     CreatedBitcode = true;
 331   }
 332
 333   // Remove the temporary bitcode file when we are done.
 334   sys::Path BitcodePath (BitcodeFile);
 335   FileRemover BitcodeFileRemover(BitcodePath, CreatedBitcode && !SaveTemps);
 336
 337   if (OutputFile.empty()) OutputFile = OutputPrefix + "-execution-output";
 338
 339   // Check to see if this is a valid output filename...
 340   sys::Path uniqueFile(OutputFile);
 341   if (uniqueFile.makeUnique(true, &ErrMsg)) {
 342     errs() << ToolName << ": Error making unique filename: "
 343            << ErrMsg << "\n";
 344     exit(1);
 345   }
 346   OutputFile = uniqueFile.str();
 347
 348   // Figure out which shared objects to run, if any.
 349   std::vector<std::string> SharedObjs(AdditionalSOs);
 350   if (!SharedObj.empty())
 351     SharedObjs.push_back(SharedObj);
 352
 353   int RetVal = AI->ExecuteProgram(BitcodeFile, InputArgv, InputFile,
 354                                   OutputFile, AdditionalLinkerArgs, SharedObjs,
 355                                   Timeout, MemoryLimit);
 356
 357   if (RetVal == -1) {
 358     errs() << "<timeout>";
 359     static bool FirstTimeout = true;
 360     if (FirstTimeout) {
 361       outs() << "\n"
 362  "*** Program execution timed out!  This mechanism is designed to handle\n"
 363  "    programs stuck in infinite loops gracefully.  The -timeout option\n"
 364  "    can be used to change the timeout threshold or disable it completely\n"
 365  "    (with -timeout=0).  This message is only displayed once.\n";
 366       FirstTimeout = false;
 367     }
 368   }
 369
 370   if (AppendProgramExitCode) {
 371     std::ofstream outFile(OutputFile.c_str(), std::ios_base::app);
 372     outFile << "exit " << RetVal << '\n';
 373     outFile.close();
 374   }
 375
 376   if (ProgramExitedNonzero != 0)
 377     *ProgramExitedNonzero = (RetVal != 0);
 378
 379   // Return the filename we captured the output to.
 380   return OutputFile;
 381 }
 382
 383 /// executeProgramSafely - Used to create reference output with the "safe"
 384 /// backend, if reference output is not provided.
 385 ///
 386 std::string BugDriver::executeProgramSafely(std::string OutputFile) {
 387   bool ProgramExitedNonzero;
 388   std::string outFN = executeProgram(OutputFile, "", "", SafeInterpreter,
 389                                      &ProgramExitedNonzero);
 390   return outFN;
 391 }
 392
 393 std::string BugDriver::compileSharedObject(const std::string &BitcodeFile) {
 394   assert(Interpreter && "Interpreter should have been created already!");
 395   sys::Path OutputFile;
 396
 397   // Using the known-good backend.
 398   GCC::FileType FT = SafeInterpreter->OutputCode(BitcodeFile, OutputFile);
 399
 400   std::string SharedObjectFile;
 401   if (gcc->MakeSharedObject(OutputFile.str(), FT,
 402                             SharedObjectFile, AdditionalLinkerArgs))
 403     exit(1);
 404
 405   // Remove the intermediate C file
 406   OutputFile.eraseFromDisk();
 407
 408   return "./" + SharedObjectFile;
 409 }
 410
 411 /// createReferenceFile - calls compileProgram and then records the output
 412 /// into ReferenceOutputFile. Returns true if reference file created, false
 413 /// otherwise. Note: initializeExecutionEnvironment should be called BEFORE
 414 /// this function.
 415 ///
 416 bool BugDriver::createReferenceFile(Module *M, const std::string &Filename) {
 417   try {
 418     compileProgram(Program);
 419   } catch (ToolExecutionError &) {
 420     return false;
 421   }
 422   try {
 423     ReferenceOutputFile = executeProgramSafely(Filename);
 424     outs() << "\nReference output is: " << ReferenceOutputFile << "\n\n";
 425   } catch (ToolExecutionError &TEE) {
 426     errs() << TEE.what();
 427     if (Interpreter != SafeInterpreter) {
 428       errs() << "*** There is a bug running the \"safe\" backend.  Either"
 429              << " debug it (for example with the -run-cbe bugpoint option,"
 430              << " if CBE is being used as the \"safe\" backend), or fix the"
 431              << " error some other way.\n";
 432     }
 433     return false;
 434   }
 435   return true;
 436 }
 437
 438 /// diffProgram - This method executes the specified module and diffs the
 439 /// output against the file specified by ReferenceOutputFile.  If the output
 440 /// is different, true is returned.  If there is a problem with the code
 441 /// generator (e.g., llc crashes), this will throw an exception.
 442 ///
 443 bool BugDriver::diffProgram(const std::string &BitcodeFile,
 444                             const std::string &SharedObject,
 445                             bool RemoveBitcode) {
 446   bool ProgramExitedNonzero;
 447
 448   // Execute the program, generating an output file...
 449   sys::Path Output(executeProgram("", BitcodeFile, SharedObject, 0,
 450                                       &ProgramExitedNonzero));
 451
 452   std::string Error;
 453   bool FilesDifferent = false;
 454   if (int Diff = DiffFilesWithTolerance(sys::Path(ReferenceOutputFile),
 455                                         sys::Path(Output.str()),
 456                                         AbsTolerance, RelTolerance, &Error)) {
 457     if (Diff == 2) {
 458       errs() << "While diffing output: " << Error << '\n';
 459       exit(1);
 460     }
 461     FilesDifferent = true;
 462   }
 463   else {
 464     // Remove the generated output if there are no differences.
 465     Output.eraseFromDisk();
 466   }
 467
 468   // Remove the bitcode file if we are supposed to.
 469   if (RemoveBitcode)
 470     sys::Path(BitcodeFile).eraseFromDisk();
 471   return FilesDifferent;
 472 }
 473
 474 bool BugDriver::isExecutingJIT() {
 475   return InterpreterSel == RunJIT;
 476 }
 477