ExecutionDriver.cpp revision 70ef449741da8b1ef035e04a55958652a0200ba1 
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
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
116//===----------------------------------------------------------------------===//
117// BugDriver method implementation
118//
119
120/// initializeExecutionEnvironment - This method is used to set up the
121/// environment for executing LLVM programs.
122///
123bool BugDriver::initializeExecutionEnvironment() {
124  std::cout << "Initializing execution environment: ";
125
126  // Create an instance of the AbstractInterpreter interface as specified on
127  // the command line
128  SafeInterpreter = 0;
129  std::string Message;
130
131  switch (InterpreterSel) {
132  case AutoPick:
133    InterpreterSel = RunCBE;
134    Interpreter =
135      AbstractInterpreter::createCBE(getToolName(), Message, &ToolArgv);
136    if (!Interpreter) {
137      InterpreterSel = RunJIT;
138      Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
139                                                   &ToolArgv);
140    }
141    if (!Interpreter) {
142      InterpreterSel = RunLLC;
143      Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
144                                                   &ToolArgv);
145    }
146    if (!Interpreter) {
147      InterpreterSel = RunLLI;
148      Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
149                                                   &ToolArgv);
150    }
151    if (!Interpreter) {
152      InterpreterSel = AutoPick;
153      Message = "Sorry, I can't automatically select an interpreter!\n";
154    }
155    break;
156  case RunLLI:
157    Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
158                                                 &ToolArgv);
159    break;
160  case RunLLC:
161  case LLC_Safe:
162    Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
163                                                 &ToolArgv);
164    break;
165  case RunJIT:
166    Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
167                                                 &ToolArgv);
168    break;
169  case RunCBE:
170  case CBE_bug:
171    Interpreter = AbstractInterpreter::createCBE(getToolName(), Message,
172                                                 &ToolArgv);
173    break;
174  case Custom:
175    Interpreter = AbstractInterpreter::createCustom(getToolName(), Message,
176                                                    CustomExecCommand);
177    break;
178  default:
179    Message = "Sorry, this back-end is not supported by bugpoint right now!\n";
180    break;
181  }
182  if (!Interpreter)
183    std::cerr << Message;
184  else // Display informational messages on stdout instead of stderr
185    std::cout << Message;
186
187  std::string Path = SafeInterpreterPath;
188  if (Path.empty())
189    Path = getToolName();
190  std::vector<std::string> SafeToolArgs = SafeToolArgv;
191  switch (SafeInterpreterSel) {
192  case AutoPick:
193    // In "cbe-bug" mode, default to using LLC as the "safe" backend.
194    if (!SafeInterpreter &&
195        InterpreterSel == CBE_bug) {
196      SafeInterpreterSel = RunLLC;
197      SafeToolArgs.push_back("--relocation-model=pic");
198      SafeInterpreter = AbstractInterpreter::createLLC(Path, Message,
199                                                       &SafeToolArgs);
200    }
201
202    // In "llc-safe" mode, default to using LLC as the "safe" backend.
203    if (!SafeInterpreter &&
204        InterpreterSel == LLC_Safe) {
205      SafeInterpreterSel = RunLLC;
206      SafeToolArgs.push_back("--relocation-model=pic");
207      SafeInterpreter = AbstractInterpreter::createLLC(Path, Message,
208                                                       &SafeToolArgs);
209    }
210
211    // Pick a backend that's different from the test backend. The JIT and
212    // LLC backends share a lot of code, so prefer to use the CBE as the
213    // safe back-end when testing them.
214    if (!SafeInterpreter &&
215        InterpreterSel != RunCBE) {
216      SafeInterpreterSel = RunCBE;
217      SafeInterpreter = AbstractInterpreter::createCBE(Path, Message,
218                                                       &SafeToolArgs);
219    }
220    if (!SafeInterpreter &&
221        InterpreterSel != RunLLC &&
222        InterpreterSel != RunJIT) {
223      SafeInterpreterSel = RunLLC;
224      SafeToolArgs.push_back("--relocation-model=pic");
225      SafeInterpreter = AbstractInterpreter::createLLC(Path, Message,
226                                                       &SafeToolArgs);
227    }
228    if (!SafeInterpreter) {
229      SafeInterpreterSel = AutoPick;
230      Message = "Sorry, I can't automatically select an interpreter!\n";
231    }
232    break;
233  case RunLLC:
234    SafeToolArgs.push_back("--relocation-model=pic");
235    SafeInterpreter = AbstractInterpreter::createLLC(Path, Message,
236                                                     &SafeToolArgs);
237    break;
238  case RunCBE:
239    SafeInterpreter = AbstractInterpreter::createCBE(Path, Message,
240                                                     &SafeToolArgs);
241    break;
242  case Custom:
243    SafeInterpreter = AbstractInterpreter::createCustom(Path, Message,
244                                                        CustomExecCommand);
245    break;
246  default:
247    Message = "Sorry, this back-end is not supported by bugpoint as the "
248              "\"safe\" backend right now!\n";
249    break;
250  }
251  if (!SafeInterpreter) { std::cout << Message << "\nExiting.\n"; exit(1); }
252
253  gcc = GCC::create(getToolName(), Message);
254  if (!gcc) { std::cout << Message << "\nExiting.\n"; exit(1); }
255
256  // If there was an error creating the selected interpreter, quit with error.
257  return Interpreter == 0;
258}
259
260/// compileProgram - Try to compile the specified module, throwing an exception
261/// if an error occurs, or returning normally if not.  This is used for code
262/// generation crash testing.
263///
264void BugDriver::compileProgram(Module *M) {
265  // Emit the program to a bitcode file...
266  sys::Path BitcodeFile ("bugpoint-test-program.bc");
267  std::string ErrMsg;
268  if (BitcodeFile.makeUnique(true,&ErrMsg)) {
269    std::cerr << ToolName << ": Error making unique filename: " << ErrMsg
270              << "\n";
271    exit(1);
272  }
273  if (writeProgramToFile(BitcodeFile.toString(), M)) {
274    std::cerr << ToolName << ": Error emitting bitcode to file '"
275              << BitcodeFile << "'!\n";
276    exit(1);
277  }
278
279    // Remove the temporary bitcode file when we are done.
280  FileRemover BitcodeFileRemover(BitcodeFile);
281
282  // Actually compile the program!
283  Interpreter->compileProgram(BitcodeFile.toString());
284}
285
286
287/// executeProgram - This method runs "Program", capturing the output of the
288/// program to a file, returning the filename of the file.  A recommended
289/// filename may be optionally specified.
290///
291std::string BugDriver::executeProgram(std::string OutputFile,
292                                      std::string BitcodeFile,
293                                      const std::string &SharedObj,
294                                      AbstractInterpreter *AI,
295                                      bool *ProgramExitedNonzero) {
296  if (AI == 0) AI = Interpreter;
297  assert(AI && "Interpreter should have been created already!");
298  bool CreatedBitcode = false;
299  std::string ErrMsg;
300  if (BitcodeFile.empty()) {
301    // Emit the program to a bitcode file...
302    sys::Path uniqueFilename("bugpoint-test-program.bc");
303    if (uniqueFilename.makeUnique(true, &ErrMsg)) {
304      std::cerr << ToolName << ": Error making unique filename: "
305                << ErrMsg << "!\n";
306      exit(1);
307    }
308    BitcodeFile = uniqueFilename.toString();
309
310    if (writeProgramToFile(BitcodeFile, Program)) {
311      std::cerr << ToolName << ": Error emitting bitcode to file '"
312                << BitcodeFile << "'!\n";
313      exit(1);
314    }
315    CreatedBitcode = true;
316  }
317
318  // Remove the temporary bitcode file when we are done.
319  sys::Path BitcodePath (BitcodeFile);
320  FileRemover BitcodeFileRemover(BitcodePath, CreatedBitcode);
321
322  if (OutputFile.empty()) OutputFile = "bugpoint-execution-output";
323
324  // Check to see if this is a valid output filename...
325  sys::Path uniqueFile(OutputFile);
326  if (uniqueFile.makeUnique(true, &ErrMsg)) {
327    std::cerr << ToolName << ": Error making unique filename: "
328              << ErrMsg << "\n";
329    exit(1);
330  }
331  OutputFile = uniqueFile.toString();
332
333  // Figure out which shared objects to run, if any.
334  std::vector<std::string> SharedObjs(AdditionalSOs);
335  if (!SharedObj.empty())
336    SharedObjs.push_back(SharedObj);
337
338  int RetVal = AI->ExecuteProgram(BitcodeFile, InputArgv, InputFile,
339                                  OutputFile, AdditionalLinkerArgs, SharedObjs,
340                                  Timeout, MemoryLimit);
341
342  if (RetVal == -1) {
343    std::cerr << "<timeout>";
344    static bool FirstTimeout = true;
345    if (FirstTimeout) {
346      std::cout << "\n"
347 "*** Program execution timed out!  This mechanism is designed to handle\n"
348 "    programs stuck in infinite loops gracefully.  The -timeout option\n"
349 "    can be used to change the timeout threshold or disable it completely\n"
350 "    (with -timeout=0).  This message is only displayed once.\n";
351      FirstTimeout = false;
352    }
353  }
354
355  if (AppendProgramExitCode) {
356    std::ofstream outFile(OutputFile.c_str(), std::ios_base::app);
357    outFile << "exit " << RetVal << '\n';
358    outFile.close();
359  }
360
361  if (ProgramExitedNonzero != 0)
362    *ProgramExitedNonzero = (RetVal != 0);
363
364  // Return the filename we captured the output to.
365  return OutputFile;
366}
367
368/// executeProgramSafely - Used to create reference output with the "safe"
369/// backend, if reference output is not provided.
370///
371std::string BugDriver::executeProgramSafely(std::string OutputFile) {
372  bool ProgramExitedNonzero;
373  std::string outFN = executeProgram(OutputFile, "", "", SafeInterpreter,
374                                     &ProgramExitedNonzero);
375  return outFN;
376}
377
378std::string BugDriver::compileSharedObject(const std::string &BitcodeFile) {
379  assert(Interpreter && "Interpreter should have been created already!");
380  sys::Path OutputFile;
381
382  // Using the known-good backend.
383  GCC::FileType FT = SafeInterpreter->OutputCode(BitcodeFile, OutputFile);
384
385  std::string SharedObjectFile;
386  if (gcc->MakeSharedObject(OutputFile.toString(), FT,
387                            SharedObjectFile, AdditionalLinkerArgs))
388    exit(1);
389
390  // Remove the intermediate C file
391  OutputFile.eraseFromDisk();
392
393  return "./" + SharedObjectFile;
394}
395
396/// createReferenceFile - calls compileProgram and then records the output
397/// into ReferenceOutputFile. Returns true if reference file created, false
398/// otherwise. Note: initializeExecutionEnvironment should be called BEFORE
399/// this function.
400///
401bool BugDriver::createReferenceFile(Module *M, const std::string &Filename) {
402  try {
403    compileProgram(Program);
404  } catch (ToolExecutionError &) {
405    return false;
406  }
407  try {
408    ReferenceOutputFile = executeProgramSafely(Filename);
409    std::cout << "Reference output is: " << ReferenceOutputFile << "\n\n";
410  } catch (ToolExecutionError &TEE) {
411    std::cerr << TEE.what();
412    if (Interpreter != SafeInterpreter) {
413      std::cerr << "*** There is a bug running the \"safe\" backend.  Either"
414                << " debug it (for example with the -run-cbe bugpoint option,"
415                << " if CBE is being used as the \"safe\" backend), or fix the"
416                << " error some other way.\n";
417    }
418    return false;
419  }
420  return true;
421}
422
423/// diffProgram - This method executes the specified module and diffs the
424/// output against the file specified by ReferenceOutputFile.  If the output
425/// is different, true is returned.  If there is a problem with the code
426/// generator (e.g., llc crashes), this will throw an exception.
427///
428bool BugDriver::diffProgram(const std::string &BitcodeFile,
429                            const std::string &SharedObject,
430                            bool RemoveBitcode) {
431  bool ProgramExitedNonzero;
432
433  // Execute the program, generating an output file...
434  sys::Path Output(executeProgram("", BitcodeFile, SharedObject, 0,
435                                      &ProgramExitedNonzero));
436
437  std::string Error;
438  bool FilesDifferent = false;
439  if (int Diff = DiffFilesWithTolerance(sys::Path(ReferenceOutputFile),
440                                        sys::Path(Output.toString()),
441                                        AbsTolerance, RelTolerance, &Error)) {
442    if (Diff == 2) {
443      std::cerr << "While diffing output: " << Error << '\n';
444      exit(1);
445    }
446    FilesDifferent = true;
447  }
448
449  // Remove the generated output.
450  Output.eraseFromDisk();
451
452  // Remove the bitcode file if we are supposed to.
453  if (RemoveBitcode)
454    sys::Path(BitcodeFile).eraseFromDisk();
455  return FilesDifferent;
456}
457
458bool BugDriver::isExecutingJIT() {
459  return InterpreterSel == RunJIT;
460}
461
462