ExecutionDriver.cpp revision ac95cc79ac0b899d566cc29c0f646f39c2fa35c0 
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
23using namespace llvm;
24
25namespace {
26  // OutputType - Allow the user to specify the way code should be run, to test
27  // for miscompilation.
28  //
29  enum OutputType {
30    AutoPick, RunLLI, RunJIT, RunLLC, RunCBE, CBE_bug, LLC_Safe, Custom
31  };
32
33  cl::opt<double>
34  AbsTolerance("abs-tolerance", cl::desc("Absolute error tolerated"),
35               cl::init(0.0));
36  cl::opt<double>
37  RelTolerance("rel-tolerance", cl::desc("Relative error tolerated"),
38               cl::init(0.0));
39
40  cl::opt<OutputType>
41  InterpreterSel(cl::desc("Specify the \"test\" i.e. suspect back-end:"),
42                 cl::values(clEnumValN(AutoPick, "auto", "Use best guess"),
43                            clEnumValN(RunLLI, "run-int",
44                                       "Execute with the interpreter"),
45                            clEnumValN(RunJIT, "run-jit", "Execute with JIT"),
46                            clEnumValN(RunLLC, "run-llc", "Compile with LLC"),
47                            clEnumValN(RunCBE, "run-cbe", "Compile with CBE"),
48                            clEnumValN(CBE_bug,"cbe-bug", "Find CBE bugs"),
49                            clEnumValN(LLC_Safe, "llc-safe", "Use LLC for all"),
50                            clEnumValN(Custom, "run-custom",
51                            "Use -exec-command to define a command to execute "
52                            "the bitcode. Useful for cross-compilation."),
53                            clEnumValEnd),
54                 cl::init(AutoPick));
55
56  cl::opt<OutputType>
57  SafeInterpreterSel(cl::desc("Specify \"safe\" i.e. known-good backend:"),
58                     cl::values(clEnumValN(AutoPick, "safe-auto", "Use best guess"),
59                                clEnumValN(RunLLC, "safe-run-llc", "Compile with LLC"),
60                                clEnumValN(RunCBE, "safe-run-cbe", "Compile with CBE"),
61                                clEnumValN(Custom, "safe-run-custom",
62                                "Use -exec-command to define a command to execute "
63                                "the bitcode. Useful for cross-compilation."),
64                                clEnumValEnd),
65                     cl::init(AutoPick));
66
67  cl::opt<std::string>
68  SafeInterpreterPath("safe-path",
69                      cl::desc("Specify the path to the \"safe\" backend program"),
70                      cl::init(""));
71
72  cl::opt<bool>
73  AppendProgramExitCode("append-exit-code",
74      cl::desc("Append the exit code to the output so it gets diff'd too"),
75      cl::init(false));
76
77  cl::opt<std::string>
78  InputFile("input", cl::init("/dev/null"),
79            cl::desc("Filename to pipe in as stdin (default: /dev/null)"));
80
81  cl::list<std::string>
82  AdditionalSOs("additional-so",
83                cl::desc("Additional shared objects to load "
84                         "into executing programs"));
85
86  cl::list<std::string>
87  AdditionalLinkerArgs("Xlinker",
88      cl::desc("Additional arguments to pass to the linker"));
89
90  cl::opt<std::string>
91  CustomExecCommand("exec-command", cl::init("simulate"),
92      cl::desc("Command to execute the bitcode (use with -run-custom) "
93               "(default: simulate)"));
94}
95
96namespace llvm {
97  // Anything specified after the --args option are taken as arguments to the
98  // program being debugged.
99  cl::list<std::string>
100  InputArgv("args", cl::Positional, cl::desc("<program arguments>..."),
101            cl::ZeroOrMore, cl::PositionalEatsArgs);
102}
103
104namespace {
105  cl::list<std::string>
106  ToolArgv("tool-args", cl::Positional, cl::desc("<tool arguments>..."),
107           cl::ZeroOrMore, cl::PositionalEatsArgs);
108
109  cl::list<std::string>
110  SafeToolArgv("safe-tool-args", cl::Positional,
111               cl::desc("<safe-tool arguments>..."),
112               cl::ZeroOrMore, cl::PositionalEatsArgs);
113
114  cl::list<std::string>
115  GCCToolArgv("gcc-tool-args", cl::Positional,
116              cl::desc("<gcc-tool arguments>..."),
117              cl::ZeroOrMore, cl::PositionalEatsArgs);
118}
119
120//===----------------------------------------------------------------------===//
121// BugDriver method implementation
122//
123
124/// initializeExecutionEnvironment - This method is used to set up the
125/// environment for executing LLVM programs.
126///
127bool BugDriver::initializeExecutionEnvironment() {
128  outs() << "Initializing execution environment: ";
129
130  // Create an instance of the AbstractInterpreter interface as specified on
131  // the command line
132  SafeInterpreter = 0;
133  std::string Message;
134
135  switch (InterpreterSel) {
136  case AutoPick:
137    InterpreterSel = RunCBE;
138    Interpreter =
139      AbstractInterpreter::createCBE(getToolName(), Message, &ToolArgv,
140                                     &GCCToolArgv);
141    if (!Interpreter) {
142      InterpreterSel = RunJIT;
143      Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
144                                                   &ToolArgv);
145    }
146    if (!Interpreter) {
147      InterpreterSel = RunLLC;
148      Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
149                                                   &ToolArgv, &GCCToolArgv);
150    }
151    if (!Interpreter) {
152      InterpreterSel = RunLLI;
153      Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
154                                                   &ToolArgv);
155    }
156    if (!Interpreter) {
157      InterpreterSel = AutoPick;
158      Message = "Sorry, I can't automatically select an interpreter!\n";
159    }
160    break;
161  case RunLLI:
162    Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
163                                                 &ToolArgv);
164    break;
165  case RunLLC:
166  case LLC_Safe:
167    Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
168                                                 &ToolArgv, &GCCToolArgv);
169    break;
170  case RunJIT:
171    Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
172                                                 &ToolArgv);
173    break;
174  case RunCBE:
175  case CBE_bug:
176    Interpreter = AbstractInterpreter::createCBE(getToolName(), Message,
177                                                 &ToolArgv, &GCCToolArgv);
178    break;
179  case Custom:
180    Interpreter = AbstractInterpreter::createCustom(getToolName(), Message,
181                                                    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, 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, 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, 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, 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, Message,
245                                                     &SafeToolArgs,
246                                                     &GCCToolArgv);
247    break;
248  case RunCBE:
249    SafeInterpreter = AbstractInterpreter::createCBE(Path, Message,
250                                                     &SafeToolArgs,
251                                                     &GCCToolArgv);
252    break;
253  case Custom:
254    SafeInterpreter = AbstractInterpreter::createCustom(Path, 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(getToolName(), 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.toString(), M)) {
285    errs() << ToolName << ": Error emitting bitcode to file '"
286           << BitcodeFile << "'!\n";
287    exit(1);
288  }
289
290    // Remove the temporary bitcode file when we are done.
291  FileRemover BitcodeFileRemover(BitcodeFile);
292
293  // Actually compile the program!
294  Interpreter->compileProgram(BitcodeFile.toString());
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.toString();
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);
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.toString();
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.toString(), 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.toString()),
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