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