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