summaryrefslogtreecommitdiff
path: root/tools/bugpoint/ExecutionDriver.cpp
blob: 25813b34e62d2571c2587af9d6ecca1eee996716 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
//===- ExecutionDriver.cpp - Allow execution of LLVM program --------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains code used to execute the program utilizing one of the
// various ways of running LLVM bitcode.
//
//===----------------------------------------------------------------------===//

#include "BugDriver.h"
#include "ToolRunner.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/FileUtilities.h"
#include "llvm/Support/SystemUtils.h"
#include "llvm/Support/raw_ostream.h"
#include <fstream>

using namespace llvm;

namespace {
  // OutputType - Allow the user to specify the way code should be run, to test
  // for miscompilation.
  //
  enum OutputType {
    AutoPick, RunLLI, RunJIT, RunLLC, RunLLCIA, LLC_Safe, CompileCustom, Custom
  };

  cl::opt<double>
  AbsTolerance("abs-tolerance", cl::desc("Absolute error tolerated"),
               cl::init(0.0));
  cl::opt<double>
  RelTolerance("rel-tolerance", cl::desc("Relative error tolerated"),
               cl::init(0.0));

  cl::opt<OutputType>
  InterpreterSel(cl::desc("Specify the \"test\" i.e. suspect back-end:"),
                 cl::values(clEnumValN(AutoPick, "auto", "Use best guess"),
                            clEnumValN(RunLLI, "run-int",
                                       "Execute with the interpreter"),
                            clEnumValN(RunJIT, "run-jit", "Execute with JIT"),
                            clEnumValN(RunLLC, "run-llc", "Compile with LLC"),
                            clEnumValN(RunLLCIA, "run-llc-ia",
                                  "Compile with LLC with integrated assembler"),
                            clEnumValN(LLC_Safe, "llc-safe", "Use LLC for all"),
                            clEnumValN(CompileCustom, "compile-custom",
                            "Use -compile-command to define a command to "
                            "compile the bitcode. Useful to avoid linking."),
                            clEnumValN(Custom, "run-custom",
                            "Use -exec-command to define a command to execute "
                            "the bitcode. Useful for cross-compilation."),
                            clEnumValEnd),
                 cl::init(AutoPick));

  cl::opt<OutputType>
  SafeInterpreterSel(cl::desc("Specify \"safe\" i.e. known-good backend:"),
              cl::values(clEnumValN(AutoPick, "safe-auto", "Use best guess"),
                         clEnumValN(RunLLC, "safe-run-llc", "Compile with LLC"),
                         clEnumValN(Custom, "safe-run-custom",
                         "Use -exec-command to define a command to execute "
                         "the bitcode. Useful for cross-compilation."),
                         clEnumValEnd),
                     cl::init(AutoPick));

  cl::opt<std::string>
  SafeInterpreterPath("safe-path",
                   cl::desc("Specify the path to the \"safe\" backend program"),
                   cl::init(""));

  cl::opt<bool>
  AppendProgramExitCode("append-exit-code",
      cl::desc("Append the exit code to the output so it gets diff'd too"),
      cl::init(false));

  cl::opt<std::string>
  InputFile("input", cl::init("/dev/null"),
            cl::desc("Filename to pipe in as stdin (default: /dev/null)"));

  cl::list<std::string>
  AdditionalSOs("additional-so",
                cl::desc("Additional shared objects to load "
                         "into executing programs"));

  cl::list<std::string>
  AdditionalLinkerArgs("Xlinker",
      cl::desc("Additional arguments to pass to the linker"));

  cl::opt<std::string>
  CustomCompileCommand("compile-command", cl::init("llc"),
      cl::desc("Command to compile the bitcode (use with -compile-custom) "
               "(default: llc)"));

  cl::opt<std::string>
  CustomExecCommand("exec-command", cl::init("simulate"),
      cl::desc("Command to execute the bitcode (use with -run-custom) "
               "(default: simulate)"));
}

namespace llvm {
  // Anything specified after the --args option are taken as arguments to the
  // program being debugged.
  cl::list<std::string>
  InputArgv("args", cl::Positional, cl::desc("<program arguments>..."),
            cl::ZeroOrMore, cl::PositionalEatsArgs);

  cl::opt<std::string>
  OutputPrefix("output-prefix", cl::init("bugpoint"),
            cl::desc("Prefix to use for outputs (default: 'bugpoint')"));
}

namespace {
  cl::list<std::string>
  ToolArgv("tool-args", cl::Positional, cl::desc("<tool arguments>..."),
           cl::ZeroOrMore, cl::PositionalEatsArgs);

  cl::list<std::string>
  SafeToolArgv("safe-tool-args", cl::Positional,
               cl::desc("<safe-tool arguments>..."),
               cl::ZeroOrMore, cl::PositionalEatsArgs);

  cl::opt<std::string>
  GCCBinary("gcc", cl::init("gcc"),
              cl::desc("The gcc binary to use. (default 'gcc')"));

  cl::list<std::string>
  GCCToolArgv("gcc-tool-args", cl::Positional,
              cl::desc("<gcc-tool arguments>..."),
              cl::ZeroOrMore, cl::PositionalEatsArgs);
}

//===----------------------------------------------------------------------===//
// BugDriver method implementation
//

/// initializeExecutionEnvironment - This method is used to set up the
/// environment for executing LLVM programs.
///
bool BugDriver::initializeExecutionEnvironment() {
  outs() << "Initializing execution environment: ";

  // Create an instance of the AbstractInterpreter interface as specified on
  // the command line
  SafeInterpreter = nullptr;
  std::string Message;

  switch (InterpreterSel) {
  case AutoPick:
    if (!Interpreter) {
      InterpreterSel = RunJIT;
      Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
                                                   &ToolArgv);
    }
    if (!Interpreter) {
      InterpreterSel = RunLLC;
      Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
                                                   GCCBinary, &ToolArgv,
                                                   &GCCToolArgv);
    }
    if (!Interpreter) {
      InterpreterSel = RunLLI;
      Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
                                                   &ToolArgv);
    }
    if (!Interpreter) {
      InterpreterSel = AutoPick;
      Message = "Sorry, I can't automatically select an interpreter!\n";
    }
    break;
  case RunLLI:
    Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
                                                 &ToolArgv);
    break;
  case RunLLC:
  case RunLLCIA:
  case LLC_Safe:
    Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
                                                 GCCBinary, &ToolArgv,
                                                 &GCCToolArgv,
                                                 InterpreterSel == RunLLCIA);
    break;
  case RunJIT:
    Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
                                                 &ToolArgv);
    break;
  case CompileCustom:
    Interpreter =
      AbstractInterpreter::createCustomCompiler(Message, CustomCompileCommand);
    break;
  case Custom:
    Interpreter =
      AbstractInterpreter::createCustomExecutor(Message, CustomExecCommand);
    break;
  }
  if (!Interpreter)
    errs() << Message;
  else // Display informational messages on stdout instead of stderr
    outs() << Message;

  std::string Path = SafeInterpreterPath;
  if (Path.empty())
    Path = getToolName();
  std::vector<std::string> SafeToolArgs = SafeToolArgv;
  switch (SafeInterpreterSel) {
  case AutoPick:
    // In "llc-safe" mode, default to using LLC as the "safe" backend.
    if (!SafeInterpreter &&
        InterpreterSel == LLC_Safe) {
      SafeInterpreterSel = RunLLC;
      SafeToolArgs.push_back("--relocation-model=pic");
      SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
                                                       GCCBinary,
                                                       &SafeToolArgs,
                                                       &GCCToolArgv);
    }

    if (!SafeInterpreter &&
        InterpreterSel != RunLLC &&
        InterpreterSel != RunJIT) {
      SafeInterpreterSel = RunLLC;
      SafeToolArgs.push_back("--relocation-model=pic");
      SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
                                                       GCCBinary,
                                                       &SafeToolArgs,
                                                       &GCCToolArgv);
    }
    if (!SafeInterpreter) {
      SafeInterpreterSel = AutoPick;
      Message = "Sorry, I can't automatically select a safe interpreter!\n";
    }
    break;
  case RunLLC:
  case RunLLCIA:
    SafeToolArgs.push_back("--relocation-model=pic");
    SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
                                                     GCCBinary, &SafeToolArgs,
                                                     &GCCToolArgv,
                                                SafeInterpreterSel == RunLLCIA);
    break;
  case Custom:
    SafeInterpreter =
      AbstractInterpreter::createCustomExecutor(Message, CustomExecCommand);
    break;
  default:
    Message = "Sorry, this back-end is not supported by bugpoint as the "
              "\"safe\" backend right now!\n";
    break;
  }
  if (!SafeInterpreter) { outs() << Message << "\nExiting.\n"; exit(1); }

  gcc = GCC::create(Message, GCCBinary, &GCCToolArgv);
  if (!gcc) { outs() << Message << "\nExiting.\n"; exit(1); }

  // If there was an error creating the selected interpreter, quit with error.
  return Interpreter == nullptr;
}

/// compileProgram - Try to compile the specified module, returning false and
/// setting Error if an error occurs.  This is used for code generation
/// crash testing.
///
void BugDriver::compileProgram(Module *M, std::string *Error) const {
  // Emit the program to a bitcode file...
  SmallString<128> BitcodeFile;
  int BitcodeFD;
  std::error_code EC = sys::fs::createUniqueFile(
      OutputPrefix + "-test-program-%%%%%%%.bc", BitcodeFD, BitcodeFile);
  if (EC) {
    errs() << ToolName << ": Error making unique filename: " << EC.message()
           << "\n";
    exit(1);
  }
  if (writeProgramToFile(BitcodeFile.str(), BitcodeFD, M)) {
    errs() << ToolName << ": Error emitting bitcode to file '" << BitcodeFile
           << "'!\n";
    exit(1);
  }

  // Remove the temporary bitcode file when we are done.
  FileRemover BitcodeFileRemover(BitcodeFile.str(), !SaveTemps);

  // Actually compile the program!
  Interpreter->compileProgram(BitcodeFile.str(), Error, Timeout, MemoryLimit);
}


/// executeProgram - This method runs "Program", capturing the output of the
/// program to a file, returning the filename of the file.  A recommended
/// filename may be optionally specified.
///
std::string BugDriver::executeProgram(const Module *Program,
                                      std::string OutputFile,
                                      std::string BitcodeFile,
                                      const std::string &SharedObj,
                                      AbstractInterpreter *AI,
                                      std::string *Error) const {
  if (!AI) AI = Interpreter;
  assert(AI && "Interpreter should have been created already!");
  bool CreatedBitcode = false;
  if (BitcodeFile.empty()) {
    // Emit the program to a bitcode file...
    SmallString<128> UniqueFilename;
    int UniqueFD;
    std::error_code EC = sys::fs::createUniqueFile(
        OutputPrefix + "-test-program-%%%%%%%.bc", UniqueFD, UniqueFilename);
    if (EC) {
      errs() << ToolName << ": Error making unique filename: "
             << EC.message() << "!\n";
      exit(1);
    }
    BitcodeFile = UniqueFilename.str();

    if (writeProgramToFile(BitcodeFile, UniqueFD, Program)) {
      errs() << ToolName << ": Error emitting bitcode to file '"
             << BitcodeFile << "'!\n";
      exit(1);
    }
    CreatedBitcode = true;
  }

  // Remove the temporary bitcode file when we are done.
  std::string BitcodePath(BitcodeFile);
  FileRemover BitcodeFileRemover(BitcodePath,
    CreatedBitcode && !SaveTemps);

  if (OutputFile.empty()) OutputFile = OutputPrefix + "-execution-output-%%%%%%%";

  // Check to see if this is a valid output filename...
  SmallString<128> UniqueFile;
  std::error_code EC = sys::fs::createUniqueFile(OutputFile, UniqueFile);
  if (EC) {
    errs() << ToolName << ": Error making unique filename: "
           << EC.message() << "\n";
    exit(1);
  }
  OutputFile = UniqueFile.str();

  // Figure out which shared objects to run, if any.
  std::vector<std::string> SharedObjs(AdditionalSOs);
  if (!SharedObj.empty())
    SharedObjs.push_back(SharedObj);

  int RetVal = AI->ExecuteProgram(BitcodeFile, InputArgv, InputFile, OutputFile,
                                  Error, AdditionalLinkerArgs, SharedObjs,
                                  Timeout, MemoryLimit);
  if (!Error->empty())
    return OutputFile;

  if (RetVal == -1) {
    errs() << "<timeout>";
    static bool FirstTimeout = true;
    if (FirstTimeout) {
      outs() << "\n"
 "*** Program execution timed out!  This mechanism is designed to handle\n"
 "    programs stuck in infinite loops gracefully.  The -timeout option\n"
 "    can be used to change the timeout threshold or disable it completely\n"
 "    (with -timeout=0).  This message is only displayed once.\n";
      FirstTimeout = false;
    }
  }

  if (AppendProgramExitCode) {
    std::ofstream outFile(OutputFile.c_str(), std::ios_base::app);
    outFile << "exit " << RetVal << '\n';
    outFile.close();
  }

  // Return the filename we captured the output to.
  return OutputFile;
}

/// executeProgramSafely - Used to create reference output with the "safe"
/// backend, if reference output is not provided.
///
std::string BugDriver::executeProgramSafely(const Module *Program,
                                            std::string OutputFile,
                                            std::string *Error) const {
  return executeProgram(Program, OutputFile, "", "", SafeInterpreter, Error);
}

std::string BugDriver::compileSharedObject(const std::string &BitcodeFile,
                                           std::string &Error) {
  assert(Interpreter && "Interpreter should have been created already!");
  std::string OutputFile;

  // Using the known-good backend.
  GCC::FileType FT = SafeInterpreter->OutputCode(BitcodeFile, OutputFile,
                                                 Error);
  if (!Error.empty())
    return "";

  std::string SharedObjectFile;
  bool Failure = gcc->MakeSharedObject(OutputFile, FT, SharedObjectFile,
                                       AdditionalLinkerArgs, Error);
  if (!Error.empty())
    return "";
  if (Failure)
    exit(1);

  // Remove the intermediate C file
  sys::fs::remove(OutputFile);

  return SharedObjectFile;
}

/// createReferenceFile - calls compileProgram and then records the output
/// into ReferenceOutputFile. Returns true if reference file created, false
/// otherwise. Note: initializeExecutionEnvironment should be called BEFORE
/// this function.
///
bool BugDriver::createReferenceFile(Module *M, const std::string &Filename) {
  std::string Error;
  compileProgram(Program, &Error);
  if (!Error.empty())
    return false;

  ReferenceOutputFile = executeProgramSafely(Program, Filename, &Error);
  if (!Error.empty()) {
    errs() << Error;
    if (Interpreter != SafeInterpreter) {
      errs() << "*** There is a bug running the \"safe\" backend.  Either"
             << " debug it (for example with the -run-jit bugpoint option,"
             << " if JIT is being used as the \"safe\" backend), or fix the"
             << " error some other way.\n";
    }
    return false;
  }
  outs() << "\nReference output is: " << ReferenceOutputFile << "\n\n";
  return true;
}

/// diffProgram - This method executes the specified module and diffs the
/// output against the file specified by ReferenceOutputFile.  If the output
/// is different, 1 is returned.  If there is a problem with the code
/// generator (e.g., llc crashes), this will set ErrMsg.
///
bool BugDriver::diffProgram(const Module *Program,
                            const std::string &BitcodeFile,
                            const std::string &SharedObject,
                            bool RemoveBitcode,
                            std::string *ErrMsg) const {
  // Execute the program, generating an output file...
  std::string Output(
      executeProgram(Program, "", BitcodeFile, SharedObject, nullptr, ErrMsg));
  if (!ErrMsg->empty())
    return false;

  std::string Error;
  bool FilesDifferent = false;
  if (int Diff = DiffFilesWithTolerance(ReferenceOutputFile,
                                        Output,
                                        AbsTolerance, RelTolerance, &Error)) {
    if (Diff == 2) {
      errs() << "While diffing output: " << Error << '\n';
      exit(1);
    }
    FilesDifferent = true;
  }
  else {
    // Remove the generated output if there are no differences.
    sys::fs::remove(Output);
  }

  // Remove the bitcode file if we are supposed to.
  if (RemoveBitcode)
    sys::fs::remove(BitcodeFile);
  return FilesDifferent;
}

bool BugDriver::isExecutingJIT() {
  return InterpreterSel == RunJIT;
}