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, RunLLCIA, RunCBE, CBE_bug, LLC_Safe,
  32     CompileCustom, Custom
  33   };
  34
  35   cl::opt<double>
  36   AbsTolerance("abs-tolerance", cl::desc("Absolute error tolerated"),
  37                cl::init(0.0));
  38   cl::opt<double>
  39   RelTolerance("rel-tolerance", cl::desc("Relative error tolerated"),
  40                cl::init(0.0));
  41
  42   cl::opt<OutputType>
  43   InterpreterSel(cl::desc("Specify the \"test\" i.e. suspect back-end:"),
  44                  cl::values(clEnumValN(AutoPick, "auto", "Use best guess"),
  45                             clEnumValN(RunLLI, "run-int",
  46                                        "Execute with the interpreter"),
  47                             clEnumValN(RunJIT, "run-jit", "Execute with JIT"),
  48                             clEnumValN(RunLLC, "run-llc", "Compile with LLC"),
  49                             clEnumValN(RunLLCIA, "run-llc-ia",
  50                                   "Compile with LLC with integrated assembler"),
  51                             clEnumValN(RunCBE, "run-cbe", "Compile with CBE"),
  52                             clEnumValN(CBE_bug,"cbe-bug", "Find CBE bugs"),
  53                             clEnumValN(LLC_Safe, "llc-safe", "Use LLC for all"),
  54                             clEnumValN(CompileCustom, "compile-custom",
  55                             "Use -compile-command to define a command to "
  56                             "compile the bitcode. Useful to avoid linking."),
  57                             clEnumValN(Custom, "run-custom",
  58                             "Use -exec-command to define a command to execute "
  59                             "the bitcode. Useful for cross-compilation."),
  60                             clEnumValEnd),
  61                  cl::init(AutoPick));
  62
  63   cl::opt<OutputType>
  64   SafeInterpreterSel(cl::desc("Specify \"safe\" i.e. known-good backend:"),
  65               cl::values(clEnumValN(AutoPick, "safe-auto", "Use best guess"),
  66                          clEnumValN(RunLLC, "safe-run-llc", "Compile with LLC"),
  67                          clEnumValN(RunCBE, "safe-run-cbe", "Compile with CBE"),
  68                          clEnumValN(Custom, "safe-run-custom",
  69                          "Use -exec-command to define a command to execute "
  70                          "the bitcode. Useful for cross-compilation."),
  71                          clEnumValEnd),
  72                      cl::init(AutoPick));
  73
  74   cl::opt<std::string>
  75   SafeInterpreterPath("safe-path",
  76                    cl::desc("Specify the path to the \"safe\" backend program"),
  77                    cl::init(""));
  78
  79   cl::opt<bool>
  80   AppendProgramExitCode("append-exit-code",
  81       cl::desc("Append the exit code to the output so it gets diff'd too"),
  82       cl::init(false));
  83
  84   cl::opt<std::string>
  85   InputFile("input", cl::init("/dev/null"),
  86             cl::desc("Filename to pipe in as stdin (default: /dev/null)"));
  87
  88   cl::list<std::string>
  89   AdditionalSOs("additional-so",
  90                 cl::desc("Additional shared objects to load "
  91                          "into executing programs"));
  92
  93   cl::list<std::string>
  94   AdditionalLinkerArgs("Xlinker",
  95       cl::desc("Additional arguments to pass to the linker"));
  96
  97   cl::opt<std::string>
  98   CustomCompileCommand("compile-command", cl::init("llc"),
  99       cl::desc("Command to compile the bitcode (use with -compile-custom) "
 100                "(default: llc)"));
 101
 102   cl::opt<std::string>
 103   CustomExecCommand("exec-command", cl::init("simulate"),
 104       cl::desc("Command to execute the bitcode (use with -run-custom) "
 105                "(default: simulate)"));
 106 }
 107
 108 namespace llvm {
 109   // Anything specified after the --args option are taken as arguments to the
 110   // program being debugged.
 111   cl::list<std::string>
 112   InputArgv("args", cl::Positional, cl::desc("<program arguments>..."),
 113             cl::ZeroOrMore, cl::PositionalEatsArgs);
 114
 115   cl::opt<std::string>
 116   OutputPrefix("output-prefix", cl::init("bugpoint"),
 117             cl::desc("Prefix to use for outputs (default: 'bugpoint')"));
 118 }
 119
 120 namespace {
 121   cl::list<std::string>
 122   ToolArgv("tool-args", cl::Positional, cl::desc("<tool arguments>..."),
 123            cl::ZeroOrMore, cl::PositionalEatsArgs);
 124
 125   cl::list<std::string>
 126   SafeToolArgv("safe-tool-args", cl::Positional,
 127                cl::desc("<safe-tool arguments>..."),
 128                cl::ZeroOrMore, cl::PositionalEatsArgs);
 129
 130   cl::opt<std::string>
 131   GCCBinary("gcc", cl::init("gcc"),
 132               cl::desc("The gcc binary to use. (default 'gcc')"));
 133
 134   cl::list<std::string>
 135   GCCToolArgv("gcc-tool-args", cl::Positional,
 136               cl::desc("<gcc-tool arguments>..."),
 137               cl::ZeroOrMore, cl::PositionalEatsArgs);
 138 }
 139
 140 //===----------------------------------------------------------------------===//
 141 // BugDriver method implementation
 142 //
 143
 144 /// initializeExecutionEnvironment - This method is used to set up the
 145 /// environment for executing LLVM programs.
 146 ///
 147 bool BugDriver::initializeExecutionEnvironment() {
 148   outs() << "Initializing execution environment: ";
 149
 150   // Create an instance of the AbstractInterpreter interface as specified on
 151   // the command line
 152   SafeInterpreter = 0;
 153   std::string Message;
 154
 155   switch (InterpreterSel) {
 156   case AutoPick:
 157     InterpreterSel = RunCBE;
 158     Interpreter =
 159       AbstractInterpreter::createCBE(getToolName(), Message, GCCBinary,
 160                                      &ToolArgv, &GCCToolArgv);
 161     if (!Interpreter) {
 162       InterpreterSel = RunJIT;
 163       Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
 164                                                    &ToolArgv);
 165     }
 166     if (!Interpreter) {
 167       InterpreterSel = RunLLC;
 168       Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
 169                                                    GCCBinary, &ToolArgv,
 170                                                    &GCCToolArgv);
 171     }
 172     if (!Interpreter) {
 173       InterpreterSel = RunLLI;
 174       Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
 175                                                    &ToolArgv);
 176     }
 177     if (!Interpreter) {
 178       InterpreterSel = AutoPick;
 179       Message = "Sorry, I can't automatically select an interpreter!\n";
 180     }
 181     break;
 182   case RunLLI:
 183     Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
 184                                                  &ToolArgv);
 185     break;
 186   case RunLLC:
 187   case RunLLCIA:
 188   case LLC_Safe:
 189     Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
 190                                                  GCCBinary, &ToolArgv,
 191                                                  &GCCToolArgv,
 192                                                  InterpreterSel == RunLLCIA);
 193     break;
 194   case RunJIT:
 195     Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
 196                                                  &ToolArgv);
 197     break;
 198   case RunCBE:
 199   case CBE_bug:
 200     Interpreter = AbstractInterpreter::createCBE(getToolName(), Message,
 201                                                  GCCBinary, &ToolArgv,
 202                                                  &GCCToolArgv);
 203     break;
 204   case CompileCustom:
 205     Interpreter =
 206       AbstractInterpreter::createCustomCompiler(Message, CustomCompileCommand);
 207     break;
 208   case Custom:
 209     Interpreter =
 210       AbstractInterpreter::createCustomExecutor(Message, CustomExecCommand);
 211     break;
 212   default:
 213     Message = "Sorry, this back-end is not supported by bugpoint right now!\n";
 214     break;
 215   }
 216   if (!Interpreter)
 217     errs() << Message;
 218   else // Display informational messages on stdout instead of stderr
 219     outs() << Message;
 220
 221   std::string Path = SafeInterpreterPath;
 222   if (Path.empty())
 223     Path = getToolName();
 224   std::vector<std::string> SafeToolArgs = SafeToolArgv;
 225   switch (SafeInterpreterSel) {
 226   case AutoPick:
 227     // In "cbe-bug" mode, default to using LLC as the "safe" backend.
 228     if (!SafeInterpreter &&
 229         InterpreterSel == CBE_bug) {
 230       SafeInterpreterSel = RunLLC;
 231       SafeToolArgs.push_back("--relocation-model=pic");
 232       SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
 233                                                        GCCBinary,
 234                                                        &SafeToolArgs,
 235                                                        &GCCToolArgv);
 236     }
 237
 238     // In "llc-safe" mode, default to using LLC as the "safe" backend.
 239     if (!SafeInterpreter &&
 240         InterpreterSel == LLC_Safe) {
 241       SafeInterpreterSel = RunLLC;
 242       SafeToolArgs.push_back("--relocation-model=pic");
 243       SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
 244                                                        GCCBinary,
 245                                                        &SafeToolArgs,
 246                                                        &GCCToolArgv);
 247     }
 248
 249     // Pick a backend that's different from the test backend. The JIT and
 250     // LLC backends share a lot of code, so prefer to use the CBE as the
 251     // safe back-end when testing them.
 252     if (!SafeInterpreter &&
 253         InterpreterSel != RunCBE) {
 254       SafeInterpreterSel = RunCBE;
 255       SafeInterpreter = AbstractInterpreter::createCBE(Path.c_str(), Message,
 256                                                        GCCBinary,
 257                                                        &SafeToolArgs,
 258                                                        &GCCToolArgv);
 259     }
 260     if (!SafeInterpreter &&
 261         InterpreterSel != RunLLC &&
 262         InterpreterSel != RunJIT) {
 263       SafeInterpreterSel = RunLLC;
 264       SafeToolArgs.push_back("--relocation-model=pic");
 265       SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
 266                                                        GCCBinary,
 267                                                        &SafeToolArgs,
 268                                                        &GCCToolArgv);
 269     }
 270     if (!SafeInterpreter) {
 271       SafeInterpreterSel = AutoPick;
 272       Message = "Sorry, I can't automatically select an interpreter!\n";
 273     }
 274     break;
 275   case RunLLC:
 276   case RunLLCIA:
 277     SafeToolArgs.push_back("--relocation-model=pic");
 278     SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
 279                                                      GCCBinary, &SafeToolArgs,
 280                                                      &GCCToolArgv,
 281                                                 SafeInterpreterSel == RunLLCIA);
 282     break;
 283   case RunCBE:
 284     SafeInterpreter = AbstractInterpreter::createCBE(Path.c_str(), Message,
 285                                                      GCCBinary, &SafeToolArgs,
 286                                                      &GCCToolArgv);
 287     break;
 288   case Custom:
 289     SafeInterpreter =
 290       AbstractInterpreter::createCustomExecutor(Message, CustomExecCommand);
 291     break;
 292   default:
 293     Message = "Sorry, this back-end is not supported by bugpoint as the "
 294               "\"safe\" backend right now!\n";
 295     break;
 296   }
 297   if (!SafeInterpreter) { outs() << Message << "\nExiting.\n"; exit(1); }
 298
 299   gcc = GCC::create(Message, GCCBinary, &GCCToolArgv);
 300   if (!gcc) { outs() << Message << "\nExiting.\n"; exit(1); }
 301
 302   // If there was an error creating the selected interpreter, quit with error.
 303   return Interpreter == 0;
 304 }
 305
 306 /// compileProgram - Try to compile the specified module, returning false and
 307 /// setting Error if an error occurs.  This is used for code generation
 308 /// crash testing.
 309 ///
 310 void BugDriver::compileProgram(Module *M, std::string *Error) const {
 311   // Emit the program to a bitcode file...
 312   sys::Path BitcodeFile (OutputPrefix + "-test-program.bc");
 313   std::string ErrMsg;
 314   if (BitcodeFile.makeUnique(true, &ErrMsg)) {
 315     errs() << ToolName << ": Error making unique filename: " << ErrMsg
 316            << "\n";
 317     exit(1);
 318   }
 319   if (writeProgramToFile(BitcodeFile.str(), M)) {
 320     errs() << ToolName << ": Error emitting bitcode to file '"
 321            << BitcodeFile.str() << "'!\n";
 322     exit(1);
 323   }
 324
 325   // Remove the temporary bitcode file when we are done.
 326   FileRemover BitcodeFileRemover(BitcodeFile.str(), !SaveTemps);
 327
 328   // Actually compile the program!
 329   Interpreter->compileProgram(BitcodeFile.str(), Error, Timeout, MemoryLimit);
 330 }
 331
 332
 333 /// executeProgram - This method runs "Program", capturing the output of the
 334 /// program to a file, returning the filename of the file.  A recommended
 335 /// filename may be optionally specified.
 336 ///
 337 std::string BugDriver::executeProgram(const Module *Program,
 338                                       std::string OutputFile,
 339                                       std::string BitcodeFile,
 340                                       const std::string &SharedObj,
 341                                       AbstractInterpreter *AI,
 342                                       std::string *Error) const {
 343   if (AI == 0) AI = Interpreter;
 344   assert(AI && "Interpreter should have been created already!");
 345   bool CreatedBitcode = false;
 346   std::string ErrMsg;
 347   if (BitcodeFile.empty()) {
 348     // Emit the program to a bitcode file...
 349     sys::Path uniqueFilename(OutputPrefix + "-test-program.bc");
 350     if (uniqueFilename.makeUnique(true, &ErrMsg)) {
 351       errs() << ToolName << ": Error making unique filename: "
 352              << ErrMsg << "!\n";
 353       exit(1);
 354     }
 355     BitcodeFile = uniqueFilename.str();
 356
 357     if (writeProgramToFile(BitcodeFile, Program)) {
 358       errs() << ToolName << ": Error emitting bitcode to file '"
 359              << BitcodeFile << "'!\n";
 360       exit(1);
 361     }
 362     CreatedBitcode = true;
 363   }
 364
 365   // Remove the temporary bitcode file when we are done.
 366   sys::Path BitcodePath(BitcodeFile);
 367   FileRemover BitcodeFileRemover(BitcodePath.str(),
 368     CreatedBitcode && !SaveTemps);
 369
 370   if (OutputFile.empty()) OutputFile = OutputPrefix + "-execution-output";
 371
 372   // Check to see if this is a valid output filename...
 373   sys::Path uniqueFile(OutputFile);
 374   if (uniqueFile.makeUnique(true, &ErrMsg)) {
 375     errs() << ToolName << ": Error making unique filename: "
 376            << ErrMsg << "\n";
 377     exit(1);
 378   }
 379   OutputFile = uniqueFile.str();
 380
 381   // Figure out which shared objects to run, if any.
 382   std::vector<std::string> SharedObjs(AdditionalSOs);
 383   if (!SharedObj.empty())
 384     SharedObjs.push_back(SharedObj);
 385
 386   int RetVal = AI->ExecuteProgram(BitcodeFile, InputArgv, InputFile, OutputFile,
 387                                   Error, AdditionalLinkerArgs, SharedObjs,
 388                                   Timeout, MemoryLimit);
 389   if (!Error->empty())
 390     return OutputFile;
 391
 392   if (RetVal == -1) {
 393     errs() << "<timeout>";
 394     static bool FirstTimeout = true;
 395     if (FirstTimeout) {
 396       outs() << "\n"
 397  "*** Program execution timed out!  This mechanism is designed to handle\n"
 398  "    programs stuck in infinite loops gracefully.  The -timeout option\n"
 399  "    can be used to change the timeout threshold or disable it completely\n"
 400  "    (with -timeout=0).  This message is only displayed once.\n";
 401       FirstTimeout = false;
 402     }
 403   }
 404
 405   if (AppendProgramExitCode) {
 406     std::ofstream outFile(OutputFile.c_str(), std::ios_base::app);
 407     outFile << "exit " << RetVal << '\n';
 408     outFile.close();
 409   }
 410
 411   // Return the filename we captured the output to.
 412   return OutputFile;
 413 }
 414
 415 /// executeProgramSafely - Used to create reference output with the "safe"
 416 /// backend, if reference output is not provided.
 417 ///
 418 std::string BugDriver::executeProgramSafely(const Module *Program,
 419                                             std::string OutputFile,
 420                                             std::string *Error) const {
 421   return executeProgram(Program, OutputFile, "", "", SafeInterpreter, Error);
 422 }
 423
 424 std::string BugDriver::compileSharedObject(const std::string &BitcodeFile,
 425                                            std::string &Error) {
 426   assert(Interpreter && "Interpreter should have been created already!");
 427   sys::Path OutputFile;
 428
 429   // Using the known-good backend.
 430   GCC::FileType FT = SafeInterpreter->OutputCode(BitcodeFile, OutputFile,
 431                                                  Error);
 432   if (!Error.empty())
 433     return "";
 434
 435   std::string SharedObjectFile;
 436   bool Failure = gcc->MakeSharedObject(OutputFile.str(), FT, SharedObjectFile,
 437                                        AdditionalLinkerArgs, Error);
 438   if (!Error.empty())
 439     return "";
 440   if (Failure)
 441     exit(1);
 442
 443   // Remove the intermediate C file
 444   OutputFile.eraseFromDisk();
 445
 446   return "./" + SharedObjectFile;
 447 }
 448
 449 /// createReferenceFile - calls compileProgram and then records the output
 450 /// into ReferenceOutputFile. Returns true if reference file created, false
 451 /// otherwise. Note: initializeExecutionEnvironment should be called BEFORE
 452 /// this function.
 453 ///
 454 bool BugDriver::createReferenceFile(Module *M, const std::string &Filename) {
 455   std::string Error;
 456   compileProgram(Program, &Error);
 457   if (!Error.empty())
 458     return false;
 459
 460   ReferenceOutputFile = executeProgramSafely(Program, Filename, &Error);
 461   if (!Error.empty()) {
 462     errs() << Error;
 463     if (Interpreter != SafeInterpreter) {
 464       errs() << "*** There is a bug running the \"safe\" backend.  Either"
 465              << " debug it (for example with the -run-cbe bugpoint option,"
 466              << " if CBE is being used as the \"safe\" backend), or fix the"
 467              << " error some other way.\n";
 468     }
 469     return false;
 470   }
 471   outs() << "\nReference output is: " << ReferenceOutputFile << "\n\n";
 472   return true;
 473 }
 474
 475 /// diffProgram - This method executes the specified module and diffs the
 476 /// output against the file specified by ReferenceOutputFile.  If the output
 477 /// is different, 1 is returned.  If there is a problem with the code
 478 /// generator (e.g., llc crashes), this will set ErrMsg.
 479 ///
 480 bool BugDriver::diffProgram(const Module *Program,
 481                             const std::string &BitcodeFile,
 482                             const std::string &SharedObject,
 483                             bool RemoveBitcode,
 484                             std::string *ErrMsg) const {
 485   // Execute the program, generating an output file...
 486   sys::Path Output(executeProgram(Program, "", BitcodeFile, SharedObject, 0,
 487                                   ErrMsg));
 488   if (!ErrMsg->empty())
 489     return false;
 490
 491   std::string Error;
 492   bool FilesDifferent = false;
 493   if (int Diff = DiffFilesWithTolerance(sys::Path(ReferenceOutputFile),
 494                                         sys::Path(Output.str()),
 495                                         AbsTolerance, RelTolerance, &Error)) {
 496     if (Diff == 2) {
 497       errs() << "While diffing output: " << Error << '\n';
 498       exit(1);
 499     }
 500     FilesDifferent = true;
 501   }
 502   else {
 503     // Remove the generated output if there are no differences.
 504     Output.eraseFromDisk();
 505   }
 506
 507   // Remove the bitcode file if we are supposed to.
 508   if (RemoveBitcode)
 509     sys::Path(BitcodeFile).eraseFromDisk();
 510   return FilesDifferent;
 511 }
 512
 513 bool BugDriver::isExecutingJIT() {
 514   return InterpreterSel == RunJIT;
 515 }
 516