ExecutionDriver.cpp revision 9a23039e42ce494feaf4b5efa806494026329b9f 
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
24#if !defined(_MSC_VER) && !defined(__MINGW32__)
25#include <unistd.h>
26#else
27#include <io.h>
28#endif
29
30using namespace llvm;
31
32namespace {
33  // OutputType - Allow the user to specify the way code should be run, to test
34  // for miscompilation.
35  //
36  enum OutputType {
37    AutoPick, RunLLI, RunJIT, RunLLC, RunLLCIA, LLC_Safe, CompileCustom, Custom
38  };
39
40  cl::opt<double>
41  AbsTolerance("abs-tolerance", cl::desc("Absolute error tolerated"),
42               cl::init(0.0));
43  cl::opt<double>
44  RelTolerance("rel-tolerance", cl::desc("Relative error tolerated"),
45               cl::init(0.0));
46
47  cl::opt<OutputType>
48  InterpreterSel(cl::desc("Specify the \"test\" i.e. suspect back-end:"),
49                 cl::values(clEnumValN(AutoPick, "auto", "Use best guess"),
50                            clEnumValN(RunLLI, "run-int",
51                                       "Execute with the interpreter"),
52                            clEnumValN(RunJIT, "run-jit", "Execute with JIT"),
53                            clEnumValN(RunLLC, "run-llc", "Compile with LLC"),
54                            clEnumValN(RunLLCIA, "run-llc-ia",
55                                  "Compile with LLC with integrated assembler"),
56                            clEnumValN(LLC_Safe, "llc-safe", "Use LLC for all"),
57                            clEnumValN(CompileCustom, "compile-custom",
58                            "Use -compile-command to define a command to "
59                            "compile the bitcode. Useful to avoid linking."),
60                            clEnumValN(Custom, "run-custom",
61                            "Use -exec-command to define a command to execute "
62                            "the bitcode. Useful for cross-compilation."),
63                            clEnumValEnd),
64                 cl::init(AutoPick));
65
66  cl::opt<OutputType>
67  SafeInterpreterSel(cl::desc("Specify \"safe\" i.e. known-good backend:"),
68              cl::values(clEnumValN(AutoPick, "safe-auto", "Use best guess"),
69                         clEnumValN(RunLLC, "safe-run-llc", "Compile with LLC"),
70                         clEnumValN(Custom, "safe-run-custom",
71                         "Use -exec-command to define a command to execute "
72                         "the bitcode. Useful for cross-compilation."),
73                         clEnumValEnd),
74                     cl::init(AutoPick));
75
76  cl::opt<std::string>
77  SafeInterpreterPath("safe-path",
78                   cl::desc("Specify the path to the \"safe\" backend program"),
79                   cl::init(""));
80
81  cl::opt<bool>
82  AppendProgramExitCode("append-exit-code",
83      cl::desc("Append the exit code to the output so it gets diff'd too"),
84      cl::init(false));
85
86  cl::opt<std::string>
87  InputFile("input", cl::init("/dev/null"),
88            cl::desc("Filename to pipe in as stdin (default: /dev/null)"));
89
90  cl::list<std::string>
91  AdditionalSOs("additional-so",
92                cl::desc("Additional shared objects to load "
93                         "into executing programs"));
94
95  cl::list<std::string>
96  AdditionalLinkerArgs("Xlinker",
97      cl::desc("Additional arguments to pass to the linker"));
98
99  cl::opt<std::string>
100  CustomCompileCommand("compile-command", cl::init("llc"),
101      cl::desc("Command to compile the bitcode (use with -compile-custom) "
102               "(default: llc)"));
103
104  cl::opt<std::string>
105  CustomExecCommand("exec-command", cl::init("simulate"),
106      cl::desc("Command to execute the bitcode (use with -run-custom) "
107               "(default: simulate)"));
108}
109
110namespace llvm {
111  // Anything specified after the --args option are taken as arguments to the
112  // program being debugged.
113  cl::list<std::string>
114  InputArgv("args", cl::Positional, cl::desc("<program arguments>..."),
115            cl::ZeroOrMore, cl::PositionalEatsArgs);
116
117  cl::opt<std::string>
118  OutputPrefix("output-prefix", cl::init("bugpoint"),
119            cl::desc("Prefix to use for outputs (default: 'bugpoint')"));
120}
121
122namespace {
123  cl::list<std::string>
124  ToolArgv("tool-args", cl::Positional, cl::desc("<tool arguments>..."),
125           cl::ZeroOrMore, cl::PositionalEatsArgs);
126
127  cl::list<std::string>
128  SafeToolArgv("safe-tool-args", cl::Positional,
129               cl::desc("<safe-tool arguments>..."),
130               cl::ZeroOrMore, cl::PositionalEatsArgs);
131
132  cl::opt<std::string>
133  GCCBinary("gcc", cl::init("gcc"),
134              cl::desc("The gcc binary to use. (default 'gcc')"));
135
136  cl::list<std::string>
137  GCCToolArgv("gcc-tool-args", cl::Positional,
138              cl::desc("<gcc-tool arguments>..."),
139              cl::ZeroOrMore, cl::PositionalEatsArgs);
140}
141
142//===----------------------------------------------------------------------===//
143// BugDriver method implementation
144//
145
146/// initializeExecutionEnvironment - This method is used to set up the
147/// environment for executing LLVM programs.
148///
149bool BugDriver::initializeExecutionEnvironment() {
150  outs() << "Initializing execution environment: ";
151
152  // Create an instance of the AbstractInterpreter interface as specified on
153  // the command line
154  SafeInterpreter = 0;
155  std::string Message;
156
157  switch (InterpreterSel) {
158  case AutoPick:
159    if (!Interpreter) {
160      InterpreterSel = RunJIT;
161      Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
162                                                   &ToolArgv);
163    }
164    if (!Interpreter) {
165      InterpreterSel = RunLLC;
166      Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
167                                                   GCCBinary, &ToolArgv,
168                                                   &GCCToolArgv);
169    }
170    if (!Interpreter) {
171      InterpreterSel = RunLLI;
172      Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
173                                                   &ToolArgv);
174    }
175    if (!Interpreter) {
176      InterpreterSel = AutoPick;
177      Message = "Sorry, I can't automatically select an interpreter!\n";
178    }
179    break;
180  case RunLLI:
181    Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
182                                                 &ToolArgv);
183    break;
184  case RunLLC:
185  case RunLLCIA:
186  case LLC_Safe:
187    Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
188                                                 GCCBinary, &ToolArgv,
189                                                 &GCCToolArgv,
190                                                 InterpreterSel == RunLLCIA);
191    break;
192  case RunJIT:
193    Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
194                                                 &ToolArgv);
195    break;
196  case CompileCustom:
197    Interpreter =
198      AbstractInterpreter::createCustomCompiler(Message, CustomCompileCommand);
199    break;
200  case Custom:
201    Interpreter =
202      AbstractInterpreter::createCustomExecutor(Message, CustomExecCommand);
203    break;
204  }
205  if (!Interpreter)
206    errs() << Message;
207  else // Display informational messages on stdout instead of stderr
208    outs() << Message;
209
210  std::string Path = SafeInterpreterPath;
211  if (Path.empty())
212    Path = getToolName();
213  std::vector<std::string> SafeToolArgs = SafeToolArgv;
214  switch (SafeInterpreterSel) {
215  case AutoPick:
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                                                       GCCBinary,
223                                                       &SafeToolArgs,
224                                                       &GCCToolArgv);
225    }
226
227    if (!SafeInterpreter &&
228        InterpreterSel != RunLLC &&
229        InterpreterSel != RunJIT) {
230      SafeInterpreterSel = RunLLC;
231      SafeToolArgs.push_back("--relocation-model=pic");
232      SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
233                                                       GCCBinary,
234                                                       &SafeToolArgs,
235                                                       &GCCToolArgv);
236    }
237    if (!SafeInterpreter) {
238      SafeInterpreterSel = AutoPick;
239      Message = "Sorry, I can't automatically select a safe interpreter!\n";
240    }
241    break;
242  case RunLLC:
243  case RunLLCIA:
244    SafeToolArgs.push_back("--relocation-model=pic");
245    SafeInterpreter = AbstractInterpreter::createLLC(Path.c_str(), Message,
246                                                     GCCBinary, &SafeToolArgs,
247                                                     &GCCToolArgv,
248                                                SafeInterpreterSel == RunLLCIA);
249    break;
250  case Custom:
251    SafeInterpreter =
252      AbstractInterpreter::createCustomExecutor(Message, CustomExecCommand);
253    break;
254  default:
255    Message = "Sorry, this back-end is not supported by bugpoint as the "
256              "\"safe\" backend right now!\n";
257    break;
258  }
259  if (!SafeInterpreter) { outs() << Message << "\nExiting.\n"; exit(1); }
260
261  gcc = GCC::create(Message, GCCBinary, &GCCToolArgv);
262  if (!gcc) { outs() << Message << "\nExiting.\n"; exit(1); }
263
264  // If there was an error creating the selected interpreter, quit with error.
265  return Interpreter == 0;
266}
267
268/// compileProgram - Try to compile the specified module, returning false and
269/// setting Error if an error occurs.  This is used for code generation
270/// crash testing.
271///
272void BugDriver::compileProgram(Module *M, std::string *Error) const {
273  // Emit the program to a bitcode file...
274  SmallString<128> BitcodeFile;
275  int BitcodeFD;
276  error_code EC = sys::fs::unique_file(
277      OutputPrefix + "-test-program-%%%%%%%.bc", BitcodeFD, BitcodeFile);
278  if (EC) {
279    errs() << ToolName << ": Error making unique filename: " << EC.message()
280           << "\n";
281    exit(1);
282  }
283  if (writeProgramToFile(BitcodeFile.str(), BitcodeFD, M)) {
284    errs() << ToolName << ": Error emitting bitcode to file '" << BitcodeFile
285           << "'!\n";
286    exit(1);
287  }
288
289  // Remove the temporary bitcode file when we are done.
290  FileRemover BitcodeFileRemover(BitcodeFile.str(), !SaveTemps);
291
292  // Actually compile the program!
293  Interpreter->compileProgram(BitcodeFile.str(), Error, Timeout, MemoryLimit);
294}
295
296
297/// executeProgram - This method runs "Program", capturing the output of the
298/// program to a file, returning the filename of the file.  A recommended
299/// filename may be optionally specified.
300///
301std::string BugDriver::executeProgram(const Module *Program,
302                                      std::string OutputFile,
303                                      std::string BitcodeFile,
304                                      const std::string &SharedObj,
305                                      AbstractInterpreter *AI,
306                                      std::string *Error) const {
307  if (AI == 0) AI = Interpreter;
308  assert(AI && "Interpreter should have been created already!");
309  bool CreatedBitcode = false;
310  std::string ErrMsg;
311  if (BitcodeFile.empty()) {
312    // Emit the program to a bitcode file...
313    SmallString<128> UniqueFilename;
314    int UniqueFD;
315    error_code EC = sys::fs::unique_file(
316        OutputPrefix + "-test-program-%%%%%%%.bc", UniqueFD, UniqueFilename);
317    if (EC) {
318      errs() << ToolName << ": Error making unique filename: "
319             << EC.message() << "!\n";
320      exit(1);
321    }
322    BitcodeFile = UniqueFilename.str();
323
324    if (writeProgramToFile(BitcodeFile, UniqueFD, Program)) {
325      errs() << ToolName << ": Error emitting bitcode to file '"
326             << BitcodeFile << "'!\n";
327      exit(1);
328    }
329    CreatedBitcode = true;
330  }
331
332  // Remove the temporary bitcode file when we are done.
333  std::string BitcodePath(BitcodeFile);
334  FileRemover BitcodeFileRemover(BitcodePath,
335    CreatedBitcode && !SaveTemps);
336
337  if (OutputFile.empty()) OutputFile = OutputPrefix + "-execution-output";
338
339  // Check to see if this is a valid output filename...
340  SmallString<128> UniqueFile;
341  int UniqueFD;
342  error_code EC = sys::fs::unique_file(OutputFile, UniqueFD, UniqueFile);
343  if (EC) {
344    errs() << ToolName << ": Error making unique filename: "
345           << EC.message() << "\n";
346    exit(1);
347  }
348  OutputFile = UniqueFile.str();
349  close(UniqueFD);
350
351  // Figure out which shared objects to run, if any.
352  std::vector<std::string> SharedObjs(AdditionalSOs);
353  if (!SharedObj.empty())
354    SharedObjs.push_back(SharedObj);
355
356  int RetVal = AI->ExecuteProgram(BitcodeFile, InputArgv, InputFile, OutputFile,
357                                  Error, AdditionalLinkerArgs, SharedObjs,
358                                  Timeout, MemoryLimit);
359  if (!Error->empty())
360    return OutputFile;
361
362  if (RetVal == -1) {
363    errs() << "<timeout>";
364    static bool FirstTimeout = true;
365    if (FirstTimeout) {
366      outs() << "\n"
367 "*** Program execution timed out!  This mechanism is designed to handle\n"
368 "    programs stuck in infinite loops gracefully.  The -timeout option\n"
369 "    can be used to change the timeout threshold or disable it completely\n"
370 "    (with -timeout=0).  This message is only displayed once.\n";
371      FirstTimeout = false;
372    }
373  }
374
375  if (AppendProgramExitCode) {
376    std::ofstream outFile(OutputFile.c_str(), std::ios_base::app);
377    outFile << "exit " << RetVal << '\n';
378    outFile.close();
379  }
380
381  // Return the filename we captured the output to.
382  return OutputFile;
383}
384
385/// executeProgramSafely - Used to create reference output with the "safe"
386/// backend, if reference output is not provided.
387///
388std::string BugDriver::executeProgramSafely(const Module *Program,
389                                            std::string OutputFile,
390                                            std::string *Error) const {
391  return executeProgram(Program, OutputFile, "", "", SafeInterpreter, Error);
392}
393
394std::string BugDriver::compileSharedObject(const std::string &BitcodeFile,
395                                           std::string &Error) {
396  assert(Interpreter && "Interpreter should have been created already!");
397  std::string OutputFile;
398
399  // Using the known-good backend.
400  GCC::FileType FT = SafeInterpreter->OutputCode(BitcodeFile, OutputFile,
401                                                 Error);
402  if (!Error.empty())
403    return "";
404
405  std::string SharedObjectFile;
406  bool Failure = gcc->MakeSharedObject(OutputFile, FT, SharedObjectFile,
407                                       AdditionalLinkerArgs, Error);
408  if (!Error.empty())
409    return "";
410  if (Failure)
411    exit(1);
412
413  // Remove the intermediate C file
414  sys::fs::remove(OutputFile);
415
416  return "./" + SharedObjectFile;
417}
418
419/// createReferenceFile - calls compileProgram and then records the output
420/// into ReferenceOutputFile. Returns true if reference file created, false
421/// otherwise. Note: initializeExecutionEnvironment should be called BEFORE
422/// this function.
423///
424bool BugDriver::createReferenceFile(Module *M, const std::string &Filename) {
425  std::string Error;
426  compileProgram(Program, &Error);
427  if (!Error.empty())
428    return false;
429
430  ReferenceOutputFile = executeProgramSafely(Program, Filename, &Error);
431  if (!Error.empty()) {
432    errs() << Error;
433    if (Interpreter != SafeInterpreter) {
434      errs() << "*** There is a bug running the \"safe\" backend.  Either"
435             << " debug it (for example with the -run-jit bugpoint option,"
436             << " if JIT is being used as the \"safe\" backend), or fix the"
437             << " error some other way.\n";
438    }
439    return false;
440  }
441  outs() << "\nReference output is: " << ReferenceOutputFile << "\n\n";
442  return true;
443}
444
445/// diffProgram - This method executes the specified module and diffs the
446/// output against the file specified by ReferenceOutputFile.  If the output
447/// is different, 1 is returned.  If there is a problem with the code
448/// generator (e.g., llc crashes), this will set ErrMsg.
449///
450bool BugDriver::diffProgram(const Module *Program,
451                            const std::string &BitcodeFile,
452                            const std::string &SharedObject,
453                            bool RemoveBitcode,
454                            std::string *ErrMsg) const {
455  // Execute the program, generating an output file...
456  std::string Output(
457      executeProgram(Program, "", 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(ReferenceOutputFile,
464                                        Output,
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    sys::fs::remove(Output);
475  }
476
477  // Remove the bitcode file if we are supposed to.
478  if (RemoveBitcode)
479    sys::fs::remove(BitcodeFile);
480  return FilesDifferent;
481}
482
483bool BugDriver::isExecutingJIT() {
484  return InterpreterSel == RunJIT;
485}
486
487