ExecutionDriver.cpp revision 248d1c65f1ce5bc04b892998b2c2061e6a5f8e1c 
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::opt<std::string>
122  GCCBinary("gcc", cl::init("gcc"),
123              cl::desc("The gcc binary to use. (default 'gcc')"));
124
125  cl::list<std::string>
126  GCCToolArgv("gcc-tool-args", cl::Positional,
127              cl::desc("<gcc-tool arguments>..."),
128              cl::ZeroOrMore, cl::PositionalEatsArgs);
129}
130
131//===----------------------------------------------------------------------===//
132// BugDriver method implementation
133//
134
135/// initializeExecutionEnvironment - This method is used to set up the
136/// environment for executing LLVM programs.
137///
138bool BugDriver::initializeExecutionEnvironment() {
139  outs() << "Initializing execution environment: ";
140
141  // Create an instance of the AbstractInterpreter interface as specified on
142  // the command line
143  SafeInterpreter = 0;
144  std::string Message;
145
146  switch (InterpreterSel) {
147  case AutoPick:
148    InterpreterSel = RunCBE;
149    Interpreter =
150      AbstractInterpreter::createCBE(getToolName(), Message, GCCBinary,
151                                     &ToolArgv, &GCCToolArgv);
152    if (!Interpreter) {
153      InterpreterSel = RunJIT;
154      Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
155                                                   &ToolArgv);
156    }
157    if (!Interpreter) {
158      InterpreterSel = RunLLC;
159      Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
160                                                   GCCBinary, &ToolArgv,
161                                                   &GCCToolArgv);
162    }
163    if (!Interpreter) {
164      InterpreterSel = RunLLI;
165      Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
166                                                   &ToolArgv);
167    }
168    if (!Interpreter) {
169      InterpreterSel = AutoPick;
170      Message = "Sorry, I can't automatically select an interpreter!\n";
171    }
172    break;
173  case RunLLI:
174    Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
175                                                 &ToolArgv);
176    break;
177  case RunLLC:
178  case RunLLCIA:
179  case LLC_Safe:
180    Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
181                                                 GCCBinary, &ToolArgv,
182                                                 &GCCToolArgv,
183                                                 InterpreterSel == RunLLCIA);
184    break;
185  case RunJIT:
186    Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
187                                                 &ToolArgv);
188    break;
189  case RunCBE:
190  case CBE_bug:
191    Interpreter = AbstractInterpreter::createCBE(getToolName(), Message,
192                                                 GCCBinary, &ToolArgv,
193                                                 &GCCToolArgv);
194    break;
195  case Custom:
196    Interpreter = AbstractInterpreter::createCustom(Message, CustomExecCommand);
197    break;
198  default:
199    Message = "Sorry, this back-end is not supported by bugpoint right now!\n";
200    break;
201  }
202  if (!Interpreter)
203    errs() << Message;
204  else // Display informational messages on stdout instead of stderr
205    outs() << Message;
206
207  std::string Path = SafeInterpreterPath;
208  if (Path.empty())
209    Path = getToolName();
210  std::vector<std::string> SafeToolArgs = SafeToolArgv;
211  switch (SafeInterpreterSel) {
212  case AutoPick:
213    // In "cbe-bug" mode, default to using LLC as the "safe" backend.
214    if (!SafeInterpreter &&
215        InterpreterSel == CBE_bug) {
216      SafeInterpreterSel = RunLLC;
217      SafeToolArgs.push_back("--relocation-model=pic");
218      SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
219                                                       GCCBinary,
220                                                       &SafeToolArgs,
221                                                       &GCCToolArgv);
222    }
223
224    // In "llc-safe" mode, default to using LLC as the "safe" backend.
225    if (!SafeInterpreter &&
226        InterpreterSel == LLC_Safe) {
227      SafeInterpreterSel = RunLLC;
228      SafeToolArgs.push_back("--relocation-model=pic");
229      SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
230                                                       GCCBinary,
231                                                       &SafeToolArgs,
232                                                       &GCCToolArgv);
233    }
234
235    // Pick a backend that's different from the test backend. The JIT and
236    // LLC backends share a lot of code, so prefer to use the CBE as the
237    // safe back-end when testing them.
238    if (!SafeInterpreter &&
239        InterpreterSel != RunCBE) {
240      SafeInterpreterSel = RunCBE;
241      SafeInterpreter = AbstractInterpreter::createCBE(Path.c_str(), Message,
242                                                       GCCBinary,
243                                                       &SafeToolArgs,
244                                                       &GCCToolArgv);
245    }
246    if (!SafeInterpreter &&
247        InterpreterSel != RunLLC &&
248        InterpreterSel != RunJIT) {
249      SafeInterpreterSel = RunLLC;
250      SafeToolArgs.push_back("--relocation-model=pic");
251      SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
252                                                       GCCBinary,
253                                                       &SafeToolArgs,
254                                                       &GCCToolArgv);
255    }
256    if (!SafeInterpreter) {
257      SafeInterpreterSel = AutoPick;
258      Message = "Sorry, I can't automatically select an interpreter!\n";
259    }
260    break;
261  case RunLLC:
262  case RunLLCIA:
263    SafeToolArgs.push_back("--relocation-model=pic");
264    SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
265                                                     GCCBinary, &SafeToolArgs,
266                                                     &GCCToolArgv,
267                                                SafeInterpreterSel == RunLLCIA);
268    break;
269  case RunCBE:
270    SafeInterpreter = AbstractInterpreter::createCBE(Path.c_str(), Message,
271                                                     GCCBinary, &SafeToolArgs,
272                                                     &GCCToolArgv);
273    break;
274  case Custom:
275    SafeInterpreter = AbstractInterpreter::createCustom(Message,
276                                                        CustomExecCommand);
277    break;
278  default:
279    Message = "Sorry, this back-end is not supported by bugpoint as the "
280              "\"safe\" backend right now!\n";
281    break;
282  }
283  if (!SafeInterpreter) { outs() << Message << "\nExiting.\n"; exit(1); }
284
285  gcc = GCC::create(Message, GCCBinary, &GCCToolArgv);
286  if (!gcc) { outs() << Message << "\nExiting.\n"; exit(1); }
287
288  // If there was an error creating the selected interpreter, quit with error.
289  return Interpreter == 0;
290}
291
292/// compileProgram - Try to compile the specified module, returning false and
293/// setting Error if an error occurs.  This is used for code generation
294/// crash testing.
295///
296void BugDriver::compileProgram(Module *M, std::string *Error) const {
297  // Emit the program to a bitcode file...
298  sys::Path BitcodeFile (OutputPrefix + "-test-program.bc");
299  std::string ErrMsg;
300  if (BitcodeFile.makeUnique(true, &ErrMsg)) {
301    errs() << ToolName << ": Error making unique filename: " << ErrMsg
302           << "\n";
303    exit(1);
304  }
305  if (writeProgramToFile(BitcodeFile.str(), M)) {
306    errs() << ToolName << ": Error emitting bitcode to file '"
307           << BitcodeFile.str() << "'!\n";
308    exit(1);
309  }
310
311  // Remove the temporary bitcode file when we are done.
312  FileRemover BitcodeFileRemover(BitcodeFile, !SaveTemps);
313
314  // Actually compile the program!
315  Interpreter->compileProgram(BitcodeFile.str(), Error, Timeout, MemoryLimit);
316}
317
318
319/// executeProgram - This method runs "Program", capturing the output of the
320/// program to a file, returning the filename of the file.  A recommended
321/// filename may be optionally specified.
322///
323std::string BugDriver::executeProgram(const Module *Program,
324                                      std::string OutputFile,
325                                      std::string BitcodeFile,
326                                      const std::string &SharedObj,
327                                      AbstractInterpreter *AI,
328                                      std::string *Error) const {
329  if (AI == 0) AI = Interpreter;
330  assert(AI && "Interpreter should have been created already!");
331  bool CreatedBitcode = false;
332  std::string ErrMsg;
333  if (BitcodeFile.empty()) {
334    // Emit the program to a bitcode file...
335    sys::Path uniqueFilename(OutputPrefix + "-test-program.bc");
336    if (uniqueFilename.makeUnique(true, &ErrMsg)) {
337      errs() << ToolName << ": Error making unique filename: "
338             << ErrMsg << "!\n";
339      exit(1);
340    }
341    BitcodeFile = uniqueFilename.str();
342
343    if (writeProgramToFile(BitcodeFile, Program)) {
344      errs() << ToolName << ": Error emitting bitcode to file '"
345             << BitcodeFile << "'!\n";
346      exit(1);
347    }
348    CreatedBitcode = true;
349  }
350
351  // Remove the temporary bitcode file when we are done.
352  sys::Path BitcodePath(BitcodeFile);
353  FileRemover BitcodeFileRemover(BitcodePath, CreatedBitcode && !SaveTemps);
354
355  if (OutputFile.empty()) OutputFile = OutputPrefix + "-execution-output";
356
357  // Check to see if this is a valid output filename...
358  sys::Path uniqueFile(OutputFile);
359  if (uniqueFile.makeUnique(true, &ErrMsg)) {
360    errs() << ToolName << ": Error making unique filename: "
361           << ErrMsg << "\n";
362    exit(1);
363  }
364  OutputFile = uniqueFile.str();
365
366  // Figure out which shared objects to run, if any.
367  std::vector<std::string> SharedObjs(AdditionalSOs);
368  if (!SharedObj.empty())
369    SharedObjs.push_back(SharedObj);
370
371  int RetVal = AI->ExecuteProgram(BitcodeFile, InputArgv, InputFile, OutputFile,
372                                  Error, AdditionalLinkerArgs, SharedObjs,
373                                  Timeout, MemoryLimit);
374  if (!Error->empty())
375    return OutputFile;
376
377  if (RetVal == -1) {
378    errs() << "<timeout>";
379    static bool FirstTimeout = true;
380    if (FirstTimeout) {
381      outs() << "\n"
382 "*** Program execution timed out!  This mechanism is designed to handle\n"
383 "    programs stuck in infinite loops gracefully.  The -timeout option\n"
384 "    can be used to change the timeout threshold or disable it completely\n"
385 "    (with -timeout=0).  This message is only displayed once.\n";
386      FirstTimeout = false;
387    }
388  }
389
390  if (AppendProgramExitCode) {
391    std::ofstream outFile(OutputFile.c_str(), std::ios_base::app);
392    outFile << "exit " << RetVal << '\n';
393    outFile.close();
394  }
395
396  // Return the filename we captured the output to.
397  return OutputFile;
398}
399
400/// executeProgramSafely - Used to create reference output with the "safe"
401/// backend, if reference output is not provided.
402///
403std::string BugDriver::executeProgramSafely(const Module *Program,
404                                            std::string OutputFile,
405                                            std::string *Error) const {
406  return executeProgram(Program, OutputFile, "", "", SafeInterpreter, Error);
407}
408
409std::string BugDriver::compileSharedObject(const std::string &BitcodeFile,
410                                           std::string &Error) {
411  assert(Interpreter && "Interpreter should have been created already!");
412  sys::Path OutputFile;
413
414  // Using the known-good backend.
415  GCC::FileType FT = SafeInterpreter->OutputCode(BitcodeFile, OutputFile,
416                                                 Error);
417  if (!Error.empty())
418    return "";
419
420  std::string SharedObjectFile;
421  bool Failure = gcc->MakeSharedObject(OutputFile.str(), FT, SharedObjectFile,
422                                       AdditionalLinkerArgs, Error);
423  if (!Error.empty())
424    return "";
425  if (Failure)
426    exit(1);
427
428  // Remove the intermediate C file
429  OutputFile.eraseFromDisk();
430
431  return "./" + SharedObjectFile;
432}
433
434/// createReferenceFile - calls compileProgram and then records the output
435/// into ReferenceOutputFile. Returns true if reference file created, false
436/// otherwise. Note: initializeExecutionEnvironment should be called BEFORE
437/// this function.
438///
439bool BugDriver::createReferenceFile(Module *M, const std::string &Filename) {
440  std::string Error;
441  compileProgram(Program, &Error);
442  if (!Error.empty())
443    return false;
444
445  ReferenceOutputFile = executeProgramSafely(Program, Filename, &Error);
446  if (!Error.empty()) {
447    errs() << Error;
448    if (Interpreter != SafeInterpreter) {
449      errs() << "*** There is a bug running the \"safe\" backend.  Either"
450             << " debug it (for example with the -run-cbe bugpoint option,"
451             << " if CBE is being used as the \"safe\" backend), or fix the"
452             << " error some other way.\n";
453    }
454    return false;
455  }
456  outs() << "\nReference output is: " << ReferenceOutputFile << "\n\n";
457  return true;
458}
459
460/// diffProgram - This method executes the specified module and diffs the
461/// output against the file specified by ReferenceOutputFile.  If the output
462/// is different, 1 is returned.  If there is a problem with the code
463/// generator (e.g., llc crashes), this will return -1 and set Error.
464///
465bool BugDriver::diffProgram(const Module *Program,
466                            const std::string &BitcodeFile,
467                            const std::string &SharedObject,
468                            bool RemoveBitcode,
469                            std::string *ErrMsg) const {
470  // Execute the program, generating an output file...
471  sys::Path Output(executeProgram(Program, "", BitcodeFile, SharedObject, 0,
472                                  ErrMsg));
473  if (!ErrMsg->empty())
474    return false;
475
476  std::string Error;
477  bool FilesDifferent = false;
478  if (int Diff = DiffFilesWithTolerance(sys::Path(ReferenceOutputFile),
479                                        sys::Path(Output.str()),
480                                        AbsTolerance, RelTolerance, &Error)) {
481    if (Diff == 2) {
482      errs() << "While diffing output: " << Error << '\n';
483      exit(1);
484    }
485    FilesDifferent = true;
486  }
487  else {
488    // Remove the generated output if there are no differences.
489    Output.eraseFromDisk();
490  }
491
492  // Remove the bitcode file if we are supposed to.
493  if (RemoveBitcode)
494    sys::Path(BitcodeFile).eraseFromDisk();
495  return FilesDifferent;
496}
497
498bool BugDriver::isExecutingJIT() {
499  return InterpreterSel == RunJIT;
500}
501
502