ExecutionDriver.cpp revision 22ff748712b348300e51248339b6e8cf9b59e2c6 
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, RunLLCIA, 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(RunLLCIA, "run-llc-ia",
49                                  "Compile with LLC with integrated assembler"),
50                            clEnumValN(RunCBE, "run-cbe", "Compile with CBE"),
51                            clEnumValN(CBE_bug,"cbe-bug", "Find CBE bugs"),
52                            clEnumValN(LLC_Safe, "llc-safe", "Use LLC for all"),
53                            clEnumValN(Custom, "run-custom",
54                            "Use -exec-command to define a command to execute "
55                            "the bitcode. Useful for cross-compilation."),
56                            clEnumValEnd),
57                 cl::init(AutoPick));
58
59  cl::opt<OutputType>
60  SafeInterpreterSel(cl::desc("Specify \"safe\" i.e. known-good backend:"),
61              cl::values(clEnumValN(AutoPick, "safe-auto", "Use best guess"),
62                         clEnumValN(RunLLC, "safe-run-llc", "Compile with LLC"),
63                         clEnumValN(RunCBE, "safe-run-cbe", "Compile with CBE"),
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  CustomExecCommand("exec-command", cl::init("simulate"),
95      cl::desc("Command to execute the bitcode (use with -run-custom) "
96               "(default: simulate)"));
97}
98
99namespace llvm {
100  // Anything specified after the --args option are taken as arguments to the
101  // program being debugged.
102  cl::list<std::string>
103  InputArgv("args", cl::Positional, cl::desc("<program arguments>..."),
104            cl::ZeroOrMore, cl::PositionalEatsArgs);
105
106  cl::opt<std::string>
107  OutputPrefix("output-prefix", cl::init("bugpoint"),
108            cl::desc("Prefix to use for outputs (default: 'bugpoint')"));
109}
110
111namespace {
112  cl::list<std::string>
113  ToolArgv("tool-args", cl::Positional, cl::desc("<tool arguments>..."),
114           cl::ZeroOrMore, cl::PositionalEatsArgs);
115
116  cl::list<std::string>
117  SafeToolArgv("safe-tool-args", cl::Positional,
118               cl::desc("<safe-tool arguments>..."),
119               cl::ZeroOrMore, cl::PositionalEatsArgs);
120
121  cl::list<std::string>
122  GCCToolArgv("gcc-tool-args", cl::Positional,
123              cl::desc("<gcc-tool arguments>..."),
124              cl::ZeroOrMore, cl::PositionalEatsArgs);
125}
126
127//===----------------------------------------------------------------------===//
128// BugDriver method implementation
129//
130
131/// initializeExecutionEnvironment - This method is used to set up the
132/// environment for executing LLVM programs.
133///
134bool BugDriver::initializeExecutionEnvironment() {
135  outs() << "Initializing execution environment: ";
136
137  // Create an instance of the AbstractInterpreter interface as specified on
138  // the command line
139  SafeInterpreter = 0;
140  std::string Message;
141
142  switch (InterpreterSel) {
143  case AutoPick:
144    InterpreterSel = RunCBE;
145    Interpreter =
146      AbstractInterpreter::createCBE(getToolName(), Message, &ToolArgv,
147                                     &GCCToolArgv);
148    if (!Interpreter) {
149      InterpreterSel = RunJIT;
150      Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
151                                                   &ToolArgv);
152    }
153    if (!Interpreter) {
154      InterpreterSel = RunLLC;
155      Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
156                                                   &ToolArgv, &GCCToolArgv);
157    }
158    if (!Interpreter) {
159      InterpreterSel = RunLLI;
160      Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
161                                                   &ToolArgv);
162    }
163    if (!Interpreter) {
164      InterpreterSel = AutoPick;
165      Message = "Sorry, I can't automatically select an interpreter!\n";
166    }
167    break;
168  case RunLLI:
169    Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
170                                                 &ToolArgv);
171    break;
172  case RunLLC:
173  case RunLLCIA:
174  case LLC_Safe:
175    Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
176                                                 &ToolArgv, &GCCToolArgv,
177                                                 InterpreterSel == RunLLCIA);
178    break;
179  case RunJIT:
180    Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
181                                                 &ToolArgv);
182    break;
183  case RunCBE:
184  case CBE_bug:
185    Interpreter = AbstractInterpreter::createCBE(getToolName(), Message,
186                                                 &ToolArgv, &GCCToolArgv);
187    break;
188  case Custom:
189    Interpreter = AbstractInterpreter::createCustom(Message, CustomExecCommand);
190    break;
191  default:
192    Message = "Sorry, this back-end is not supported by bugpoint right now!\n";
193    break;
194  }
195  if (!Interpreter)
196    errs() << Message;
197  else // Display informational messages on stdout instead of stderr
198    outs() << Message;
199
200  std::string Path = SafeInterpreterPath;
201  if (Path.empty())
202    Path = getToolName();
203  std::vector<std::string> SafeToolArgs = SafeToolArgv;
204  switch (SafeInterpreterSel) {
205  case AutoPick:
206    // In "cbe-bug" mode, default to using LLC as the "safe" backend.
207    if (!SafeInterpreter &&
208        InterpreterSel == CBE_bug) {
209      SafeInterpreterSel = RunLLC;
210      SafeToolArgs.push_back("--relocation-model=pic");
211      SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
212                                                       &SafeToolArgs,
213                                                       &GCCToolArgv);
214    }
215
216    // In "llc-safe" mode, default to using LLC as the "safe" backend.
217    if (!SafeInterpreter &&
218        InterpreterSel == LLC_Safe) {
219      SafeInterpreterSel = RunLLC;
220      SafeToolArgs.push_back("--relocation-model=pic");
221      SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
222                                                       &SafeToolArgs,
223                                                       &GCCToolArgv);
224    }
225
226    // Pick a backend that's different from the test backend. The JIT and
227    // LLC backends share a lot of code, so prefer to use the CBE as the
228    // safe back-end when testing them.
229    if (!SafeInterpreter &&
230        InterpreterSel != RunCBE) {
231      SafeInterpreterSel = RunCBE;
232      SafeInterpreter = AbstractInterpreter::createCBE(Path.c_str(), Message,
233                                                       &SafeToolArgs,
234                                                       &GCCToolArgv);
235    }
236    if (!SafeInterpreter &&
237        InterpreterSel != RunLLC &&
238        InterpreterSel != RunJIT) {
239      SafeInterpreterSel = RunLLC;
240      SafeToolArgs.push_back("--relocation-model=pic");
241      SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
242                                                       &SafeToolArgs,
243                                                       &GCCToolArgv);
244    }
245    if (!SafeInterpreter) {
246      SafeInterpreterSel = AutoPick;
247      Message = "Sorry, I can't automatically select an interpreter!\n";
248    }
249    break;
250  case RunLLC:
251  case RunLLCIA:
252    SafeToolArgs.push_back("--relocation-model=pic");
253    SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
254                                                     &SafeToolArgs,
255                                                     &GCCToolArgv,
256                                                SafeInterpreterSel == RunLLCIA);
257    break;
258  case RunCBE:
259    SafeInterpreter = AbstractInterpreter::createCBE(Path.c_str(), Message,
260                                                     &SafeToolArgs,
261                                                     &GCCToolArgv);
262    break;
263  case Custom:
264    SafeInterpreter = AbstractInterpreter::createCustom(Message,
265                                                        CustomExecCommand);
266    break;
267  default:
268    Message = "Sorry, this back-end is not supported by bugpoint as the "
269              "\"safe\" backend right now!\n";
270    break;
271  }
272  if (!SafeInterpreter) { outs() << Message << "\nExiting.\n"; exit(1); }
273
274  gcc = GCC::create(Message, &GCCToolArgv);
275  if (!gcc) { outs() << Message << "\nExiting.\n"; exit(1); }
276
277  // If there was an error creating the selected interpreter, quit with error.
278  return Interpreter == 0;
279}
280
281/// compileProgram - Try to compile the specified module, returning false and
282/// setting Error if an error occurs.  This is used for code generation
283/// crash testing.
284///
285void BugDriver::compileProgram(Module *M, std::string *Error) {
286  // Emit the program to a bitcode file...
287  sys::Path BitcodeFile (OutputPrefix + "-test-program.bc");
288  std::string ErrMsg;
289  if (BitcodeFile.makeUnique(true, &ErrMsg)) {
290    errs() << ToolName << ": Error making unique filename: " << ErrMsg
291           << "\n";
292    exit(1);
293  }
294  if (writeProgramToFile(BitcodeFile.str(), M)) {
295    errs() << ToolName << ": Error emitting bitcode to file '"
296           << BitcodeFile.str() << "'!\n";
297    exit(1);
298  }
299
300  // Remove the temporary bitcode file when we are done.
301  FileRemover BitcodeFileRemover(BitcodeFile, !SaveTemps);
302
303  // Actually compile the program!
304  Interpreter->compileProgram(BitcodeFile.str(), Error);
305}
306
307
308/// executeProgram - This method runs "Program", capturing the output of the
309/// program to a file, returning the filename of the file.  A recommended
310/// filename may be optionally specified.
311///
312std::string BugDriver::executeProgram(std::string OutputFile,
313                                      std::string BitcodeFile,
314                                      const std::string &SharedObj,
315                                      AbstractInterpreter *AI,
316                                      std::string *Error) {
317  if (AI == 0) AI = Interpreter;
318  assert(AI && "Interpreter should have been created already!");
319  bool CreatedBitcode = false;
320  std::string ErrMsg;
321  if (BitcodeFile.empty()) {
322    // Emit the program to a bitcode file...
323    sys::Path uniqueFilename(OutputPrefix + "-test-program.bc");
324    if (uniqueFilename.makeUnique(true, &ErrMsg)) {
325      errs() << ToolName << ": Error making unique filename: "
326             << ErrMsg << "!\n";
327      exit(1);
328    }
329    BitcodeFile = uniqueFilename.str();
330
331    if (writeProgramToFile(BitcodeFile, Program)) {
332      errs() << ToolName << ": Error emitting bitcode to file '"
333             << BitcodeFile << "'!\n";
334      exit(1);
335    }
336    CreatedBitcode = true;
337  }
338
339  // Remove the temporary bitcode file when we are done.
340  sys::Path BitcodePath(BitcodeFile);
341  FileRemover BitcodeFileRemover(BitcodePath, CreatedBitcode && !SaveTemps);
342
343  if (OutputFile.empty()) OutputFile = OutputPrefix + "-execution-output";
344
345  // Check to see if this is a valid output filename...
346  sys::Path uniqueFile(OutputFile);
347  if (uniqueFile.makeUnique(true, &ErrMsg)) {
348    errs() << ToolName << ": Error making unique filename: "
349           << ErrMsg << "\n";
350    exit(1);
351  }
352  OutputFile = uniqueFile.str();
353
354  // Figure out which shared objects to run, if any.
355  std::vector<std::string> SharedObjs(AdditionalSOs);
356  if (!SharedObj.empty())
357    SharedObjs.push_back(SharedObj);
358
359  int RetVal = AI->ExecuteProgram(BitcodeFile, InputArgv, InputFile, OutputFile,
360                                  Error, AdditionalLinkerArgs, SharedObjs,
361                                  Timeout, MemoryLimit);
362  if (!Error->empty())
363    return OutputFile;
364
365  if (RetVal == -1) {
366    errs() << "<timeout>";
367    static bool FirstTimeout = true;
368    if (FirstTimeout) {
369      outs() << "\n"
370 "*** Program execution timed out!  This mechanism is designed to handle\n"
371 "    programs stuck in infinite loops gracefully.  The -timeout option\n"
372 "    can be used to change the timeout threshold or disable it completely\n"
373 "    (with -timeout=0).  This message is only displayed once.\n";
374      FirstTimeout = false;
375    }
376  }
377
378  if (AppendProgramExitCode) {
379    std::ofstream outFile(OutputFile.c_str(), std::ios_base::app);
380    outFile << "exit " << RetVal << '\n';
381    outFile.close();
382  }
383
384  // Return the filename we captured the output to.
385  return OutputFile;
386}
387
388/// executeProgramSafely - Used to create reference output with the "safe"
389/// backend, if reference output is not provided.
390///
391std::string BugDriver::executeProgramSafely(std::string OutputFile,
392                                            std::string *Error) {
393  return executeProgram(OutputFile, "", "", SafeInterpreter, Error);
394}
395
396std::string BugDriver::compileSharedObject(const std::string &BitcodeFile,
397                                           std::string &Error) {
398  assert(Interpreter && "Interpreter should have been created already!");
399  sys::Path OutputFile;
400
401  // Using the known-good backend.
402  GCC::FileType FT = SafeInterpreter->OutputCode(BitcodeFile, OutputFile,
403                                                 Error);
404  if (!Error.empty())
405    return "";
406
407  std::string SharedObjectFile;
408  bool Failure = gcc->MakeSharedObject(OutputFile.str(), FT, SharedObjectFile,
409                                       AdditionalLinkerArgs, Error);
410  if (!Error.empty())
411    return "";
412  if (Failure)
413    exit(1);
414
415  // Remove the intermediate C file
416  OutputFile.eraseFromDisk();
417
418  return "./" + SharedObjectFile;
419}
420
421/// createReferenceFile - calls compileProgram and then records the output
422/// into ReferenceOutputFile. Returns true if reference file created, false
423/// otherwise. Note: initializeExecutionEnvironment should be called BEFORE
424/// this function.
425///
426bool BugDriver::createReferenceFile(Module *M, const std::string &Filename) {
427  std::string Error;
428  compileProgram(Program, &Error);
429  if (!Error.empty())
430    return false;
431
432  ReferenceOutputFile = executeProgramSafely(Filename, &Error);
433  if (!Error.empty()) {
434    errs() << Error;
435    if (Interpreter != SafeInterpreter) {
436      errs() << "*** There is a bug running the \"safe\" backend.  Either"
437             << " debug it (for example with the -run-cbe bugpoint option,"
438             << " if CBE is being used as the \"safe\" backend), or fix the"
439             << " error some other way.\n";
440    }
441    return false;
442  }
443  outs() << "\nReference output is: " << ReferenceOutputFile << "\n\n";
444  return true;
445}
446
447/// diffProgram - This method executes the specified module and diffs the
448/// output against the file specified by ReferenceOutputFile.  If the output
449/// is different, 1 is returned.  If there is a problem with the code
450/// generator (e.g., llc crashes), this will return -1 and set Error.
451///
452bool BugDriver::diffProgram(const std::string &BitcodeFile,
453                            const std::string &SharedObject,
454                            bool RemoveBitcode,
455                            std::string *ErrMsg) {
456  // Execute the program, generating an output file...
457  sys::Path Output(executeProgram("", BitcodeFile, SharedObject, 0, ErrMsg));
458  if (!ErrMsg->empty())
459    return false;
460
461  std::string Error;
462  bool FilesDifferent = false;
463  if (int Diff = DiffFilesWithTolerance(sys::Path(ReferenceOutputFile),
464                                        sys::Path(Output.str()),
465                                        AbsTolerance, RelTolerance, &Error)) {
466    if (Diff == 2) {
467      errs() << "While diffing output: " << Error << '\n';
468      exit(1);
469    }
470    FilesDifferent = true;
471  }
472  else {
473    // Remove the generated output if there are no differences.
474    Output.eraseFromDisk();
475  }
476
477  // Remove the bitcode file if we are supposed to.
478  if (RemoveBitcode)
479    sys::Path(BitcodeFile).eraseFromDisk();
480  return FilesDifferent;
481}
482
483bool BugDriver::isExecutingJIT() {
484  return InterpreterSel == RunJIT;
485}
486
487