ExecutionDriver.cpp revision 74382b7c699120fbec5cb5603c9cf4212eb37f06 
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
24using namespace llvm;
25
26namespace {
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
97namespace 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
105namespace {
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///
128bool 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///
275void 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///
302std::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///
382std::string BugDriver::executeProgramSafely(std::string OutputFile) {
383  bool ProgramExitedNonzero;
384  std::string outFN = executeProgram(OutputFile, "", "", SafeInterpreter,
385                                     &ProgramExitedNonzero);
386  return outFN;
387}
388
389std::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///
412bool 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///
439bool 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
470bool BugDriver::isExecutingJIT() {
471  return InterpreterSel == RunJIT;
472}
473
474