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