ExecutionDriver.cpp revision 80becf194d56524e8c75618ac57a34520f87a684 
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  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  std::cout << "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(getToolName(), Message,
182                                                    CustomExecCommand);
183    break;
184  default:
185    Message = "Sorry, this back-end is not supported by bugpoint right now!\n";
186    break;
187  }
188  if (!Interpreter)
189    std::cerr << Message;
190  else // Display informational messages on stdout instead of stderr
191    std::cout << Message;
192
193  std::string Path = SafeInterpreterPath;
194  if (Path.empty())
195    Path = getToolName();
196  std::vector<std::string> SafeToolArgs = SafeToolArgv;
197  switch (SafeInterpreterSel) {
198  case AutoPick:
199    // In "cbe-bug" mode, default to using LLC as the "safe" backend.
200    if (!SafeInterpreter &&
201        InterpreterSel == CBE_bug) {
202      SafeInterpreterSel = RunLLC;
203      SafeToolArgs.push_back("--relocation-model=pic");
204      SafeInterpreter = AbstractInterpreter::createLLC(Path, Message,
205                                                       &SafeToolArgs,
206                                                       &GCCToolArgv);
207    }
208
209    // In "llc-safe" mode, default to using LLC as the "safe" backend.
210    if (!SafeInterpreter &&
211        InterpreterSel == LLC_Safe) {
212      SafeInterpreterSel = RunLLC;
213      SafeToolArgs.push_back("--relocation-model=pic");
214      SafeInterpreter = AbstractInterpreter::createLLC(Path, Message,
215                                                       &SafeToolArgs,
216                                                       &GCCToolArgv);
217    }
218
219    // Pick a backend that's different from the test backend. The JIT and
220    // LLC backends share a lot of code, so prefer to use the CBE as the
221    // safe back-end when testing them.
222    if (!SafeInterpreter &&
223        InterpreterSel != RunCBE) {
224      SafeInterpreterSel = RunCBE;
225      SafeInterpreter = AbstractInterpreter::createCBE(Path, Message,
226                                                       &SafeToolArgs,
227                                                       &GCCToolArgv);
228    }
229    if (!SafeInterpreter &&
230        InterpreterSel != RunLLC &&
231        InterpreterSel != RunJIT) {
232      SafeInterpreterSel = RunLLC;
233      SafeToolArgs.push_back("--relocation-model=pic");
234      SafeInterpreter = AbstractInterpreter::createLLC(Path, Message,
235                                                       &SafeToolArgs,
236                                                       &GCCToolArgv);
237    }
238    if (!SafeInterpreter) {
239      SafeInterpreterSel = AutoPick;
240      Message = "Sorry, I can't automatically select an interpreter!\n";
241    }
242    break;
243  case RunLLC:
244    SafeToolArgs.push_back("--relocation-model=pic");
245    SafeInterpreter = AbstractInterpreter::createLLC(Path, Message,
246                                                     &SafeToolArgs,
247                                                     &GCCToolArgv);
248    break;
249  case RunCBE:
250    SafeInterpreter = AbstractInterpreter::createCBE(Path, Message,
251                                                     &SafeToolArgs,
252                                                     &GCCToolArgv);
253    break;
254  case Custom:
255    SafeInterpreter = AbstractInterpreter::createCustom(Path, Message,
256                                                        CustomExecCommand);
257    break;
258  default:
259    Message = "Sorry, this back-end is not supported by bugpoint as the "
260              "\"safe\" backend right now!\n";
261    break;
262  }
263  if (!SafeInterpreter) { std::cout << Message << "\nExiting.\n"; exit(1); }
264
265  gcc = GCC::create(getToolName(), Message, &GCCToolArgv);
266  if (!gcc) { std::cout << Message << "\nExiting.\n"; exit(1); }
267
268  // If there was an error creating the selected interpreter, quit with error.
269  return Interpreter == 0;
270}
271
272/// compileProgram - Try to compile the specified module, throwing an exception
273/// if an error occurs, or returning normally if not.  This is used for code
274/// generation crash testing.
275///
276void BugDriver::compileProgram(Module *M) {
277  // Emit the program to a bitcode file...
278  sys::Path BitcodeFile ("bugpoint-test-program.bc");
279  std::string ErrMsg;
280  if (BitcodeFile.makeUnique(true,&ErrMsg)) {
281    std::cerr << ToolName << ": Error making unique filename: " << ErrMsg
282              << "\n";
283    exit(1);
284  }
285  if (writeProgramToFile(BitcodeFile.toString(), M)) {
286    std::cerr << ToolName << ": Error emitting bitcode to file '"
287              << BitcodeFile << "'!\n";
288    exit(1);
289  }
290
291    // Remove the temporary bitcode file when we are done.
292  FileRemover BitcodeFileRemover(BitcodeFile);
293
294  // Actually compile the program!
295  Interpreter->compileProgram(BitcodeFile.toString());
296}
297
298
299/// executeProgram - This method runs "Program", capturing the output of the
300/// program to a file, returning the filename of the file.  A recommended
301/// filename may be optionally specified.
302///
303std::string BugDriver::executeProgram(std::string OutputFile,
304                                      std::string BitcodeFile,
305                                      const std::string &SharedObj,
306                                      AbstractInterpreter *AI,
307                                      bool *ProgramExitedNonzero) {
308  if (AI == 0) AI = Interpreter;
309  assert(AI && "Interpreter should have been created already!");
310  bool CreatedBitcode = false;
311  std::string ErrMsg;
312  if (BitcodeFile.empty()) {
313    // Emit the program to a bitcode file...
314    sys::Path uniqueFilename("bugpoint-test-program.bc");
315    if (uniqueFilename.makeUnique(true, &ErrMsg)) {
316      std::cerr << ToolName << ": Error making unique filename: "
317                << ErrMsg << "!\n";
318      exit(1);
319    }
320    BitcodeFile = uniqueFilename.toString();
321
322    if (writeProgramToFile(BitcodeFile, Program)) {
323      std::cerr << ToolName << ": Error emitting bitcode to file '"
324                << BitcodeFile << "'!\n";
325      exit(1);
326    }
327    CreatedBitcode = true;
328  }
329
330  // Remove the temporary bitcode file when we are done.
331  sys::Path BitcodePath (BitcodeFile);
332  FileRemover BitcodeFileRemover(BitcodePath, CreatedBitcode);
333
334  if (OutputFile.empty()) OutputFile = "bugpoint-execution-output";
335
336  // Check to see if this is a valid output filename...
337  sys::Path uniqueFile(OutputFile);
338  if (uniqueFile.makeUnique(true, &ErrMsg)) {
339    std::cerr << ToolName << ": Error making unique filename: "
340              << ErrMsg << "\n";
341    exit(1);
342  }
343  OutputFile = uniqueFile.toString();
344
345  // Figure out which shared objects to run, if any.
346  std::vector<std::string> SharedObjs(AdditionalSOs);
347  if (!SharedObj.empty())
348    SharedObjs.push_back(SharedObj);
349
350  int RetVal = AI->ExecuteProgram(BitcodeFile, InputArgv, InputFile,
351                                  OutputFile, AdditionalLinkerArgs, SharedObjs,
352                                  Timeout, MemoryLimit);
353
354  if (RetVal == -1) {
355    std::cerr << "<timeout>";
356    static bool FirstTimeout = true;
357    if (FirstTimeout) {
358      std::cout << "\n"
359 "*** Program execution timed out!  This mechanism is designed to handle\n"
360 "    programs stuck in infinite loops gracefully.  The -timeout option\n"
361 "    can be used to change the timeout threshold or disable it completely\n"
362 "    (with -timeout=0).  This message is only displayed once.\n";
363      FirstTimeout = false;
364    }
365  }
366
367  if (AppendProgramExitCode) {
368    std::ofstream outFile(OutputFile.c_str(), std::ios_base::app);
369    outFile << "exit " << RetVal << '\n';
370    outFile.close();
371  }
372
373  if (ProgramExitedNonzero != 0)
374    *ProgramExitedNonzero = (RetVal != 0);
375
376  // Return the filename we captured the output to.
377  return OutputFile;
378}
379
380/// executeProgramSafely - Used to create reference output with the "safe"
381/// backend, if reference output is not provided.
382///
383std::string BugDriver::executeProgramSafely(std::string OutputFile) {
384  bool ProgramExitedNonzero;
385  std::string outFN = executeProgram(OutputFile, "", "", SafeInterpreter,
386                                     &ProgramExitedNonzero);
387  return outFN;
388}
389
390std::string BugDriver::compileSharedObject(const std::string &BitcodeFile) {
391  assert(Interpreter && "Interpreter should have been created already!");
392  sys::Path OutputFile;
393
394  // Using the known-good backend.
395  GCC::FileType FT = SafeInterpreter->OutputCode(BitcodeFile, OutputFile);
396
397  std::string SharedObjectFile;
398  if (gcc->MakeSharedObject(OutputFile.toString(), FT,
399                            SharedObjectFile, AdditionalLinkerArgs))
400    exit(1);
401
402  // Remove the intermediate C file
403  OutputFile.eraseFromDisk();
404
405  return "./" + SharedObjectFile;
406}
407
408/// createReferenceFile - calls compileProgram and then records the output
409/// into ReferenceOutputFile. Returns true if reference file created, false
410/// otherwise. Note: initializeExecutionEnvironment should be called BEFORE
411/// this function.
412///
413bool BugDriver::createReferenceFile(Module *M, const std::string &Filename) {
414  try {
415    compileProgram(Program);
416  } catch (ToolExecutionError &) {
417    return false;
418  }
419  try {
420    ReferenceOutputFile = executeProgramSafely(Filename);
421    std::cout << "\nReference output is: " << ReferenceOutputFile << "\n\n";
422  } catch (ToolExecutionError &TEE) {
423    std::cerr << TEE.what();
424    if (Interpreter != SafeInterpreter) {
425      std::cerr << "*** There is a bug running the \"safe\" backend.  Either"
426                << " debug it (for example with the -run-cbe bugpoint option,"
427                << " if CBE is being used as the \"safe\" backend), or fix the"
428                << " error some other way.\n";
429    }
430    return false;
431  }
432  return true;
433}
434
435/// diffProgram - This method executes the specified module and diffs the
436/// output against the file specified by ReferenceOutputFile.  If the output
437/// is different, true is returned.  If there is a problem with the code
438/// generator (e.g., llc crashes), this will throw an exception.
439///
440bool BugDriver::diffProgram(const std::string &BitcodeFile,
441                            const std::string &SharedObject,
442                            bool RemoveBitcode) {
443  bool ProgramExitedNonzero;
444
445  // Execute the program, generating an output file...
446  sys::Path Output(executeProgram("", BitcodeFile, SharedObject, 0,
447                                      &ProgramExitedNonzero));
448
449  std::string Error;
450  bool FilesDifferent = false;
451  if (int Diff = DiffFilesWithTolerance(sys::Path(ReferenceOutputFile),
452                                        sys::Path(Output.toString()),
453                                        AbsTolerance, RelTolerance, &Error)) {
454    if (Diff == 2) {
455      std::cerr << "While diffing output: " << Error << '\n';
456      exit(1);
457    }
458    FilesDifferent = true;
459  }
460  else {
461    // Remove the generated output if there are no differences.
462    Output.eraseFromDisk();
463  }
464
465  // Remove the bitcode file if we are supposed to.
466  if (RemoveBitcode)
467    sys::Path(BitcodeFile).eraseFromDisk();
468  return FilesDifferent;
469}
470
471bool BugDriver::isExecutingJIT() {
472  return InterpreterSel == RunJIT;
473}
474
475