ExecutionDriver.cpp revision d41b30def3181bce4bf87e8bde664d15663165d0 
1//===- ExecutionDriver.cpp - Allow execution of LLVM program --------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by the LLVM research group and is distributed under
6// the University of Illinois Open Source 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 bytecode.
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
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 how LLVM code should be executed:"),
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                            clEnumValEnd),
51                 cl::init(AutoPick));
52
53  cl::opt<bool>
54  CheckProgramExitCode("check-exit-code",
55                   cl::desc("Assume nonzero exit code is failure (default on)"),
56                       cl::init(true));
57
58  cl::opt<std::string>
59  InputFile("input", cl::init("/dev/null"),
60            cl::desc("Filename to pipe in as stdin (default: /dev/null)"));
61
62  cl::list<std::string>
63  AdditionalSOs("additional-so",
64                cl::desc("Additional shared objects to load "
65                         "into executing programs"));
66
67  cl::list<std::string>
68    AdditionalLinkerArgs("Xlinker",
69      cl::desc("Additional arguments to pass to the linker"));
70}
71
72namespace llvm {
73  // Anything specified after the --args option are taken as arguments to the
74  // program being debugged.
75  cl::list<std::string>
76  InputArgv("args", cl::Positional, cl::desc("<program arguments>..."),
77            cl::ZeroOrMore, cl::PositionalEatsArgs);
78
79  cl::list<std::string>
80  ToolArgv("tool-args", cl::Positional, cl::desc("<tool arguments>..."),
81           cl::ZeroOrMore, cl::PositionalEatsArgs);
82}
83
84//===----------------------------------------------------------------------===//
85// BugDriver method implementation
86//
87
88/// initializeExecutionEnvironment - This method is used to set up the
89/// environment for executing LLVM programs.
90///
91bool BugDriver::initializeExecutionEnvironment() {
92  std::cout << "Initializing execution environment: ";
93
94  // Create an instance of the AbstractInterpreter interface as specified on
95  // the command line
96  cbe = 0;
97  std::string Message;
98
99  switch (InterpreterSel) {
100  case AutoPick:
101    InterpreterSel = RunCBE;
102    Interpreter = cbe = AbstractInterpreter::createCBE(getToolName(), Message,
103                                                       &ToolArgv);
104    if (!Interpreter) {
105      InterpreterSel = RunJIT;
106      Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
107                                                   &ToolArgv);
108    }
109    if (!Interpreter) {
110      InterpreterSel = RunLLC;
111      Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
112                                                   &ToolArgv);
113    }
114    if (!Interpreter) {
115      InterpreterSel = RunLLI;
116      Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
117                                                   &ToolArgv);
118    }
119    if (!Interpreter) {
120      InterpreterSel = AutoPick;
121      Message = "Sorry, I can't automatically select an interpreter!\n";
122    }
123    break;
124  case RunLLI:
125    Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
126                                                 &ToolArgv);
127    break;
128  case RunLLC:
129    Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
130                                                 &ToolArgv);
131    break;
132  case RunJIT:
133    Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
134                                                 &ToolArgv);
135    break;
136  case RunCBE:
137  case CBE_bug:
138    Interpreter = AbstractInterpreter::createCBE(getToolName(), Message,
139                                                 &ToolArgv);
140    break;
141  default:
142    Message = "Sorry, this back-end is not supported by bugpoint right now!\n";
143    break;
144  }
145  std::cerr << Message;
146
147  // Initialize auxiliary tools for debugging
148  if (InterpreterSel == RunCBE) {
149    // We already created a CBE, reuse it.
150    cbe = Interpreter;
151  } else if (InterpreterSel == CBE_bug) {
152    // We want to debug the CBE itself.  Use LLC as the 'known-good' compiler.
153    std::vector<std::string> ToolArgs;
154    ToolArgs.push_back("--relocation-model=pic");
155    cbe = AbstractInterpreter::createLLC(getToolName(), Message, &ToolArgs);
156  } else {
157    cbe = AbstractInterpreter::createCBE(getToolName(), Message, &ToolArgv);
158  }
159  if (!cbe) { std::cout << Message << "\nExiting.\n"; exit(1); }
160
161  gcc = GCC::create(getToolName(), Message);
162  if (!gcc) { std::cout << Message << "\nExiting.\n"; exit(1); }
163
164  // If there was an error creating the selected interpreter, quit with error.
165  return Interpreter == 0;
166}
167
168/// compileProgram - Try to compile the specified module, throwing an exception
169/// if an error occurs, or returning normally if not.  This is used for code
170/// generation crash testing.
171///
172void BugDriver::compileProgram(Module *M) {
173  // Emit the program to a bytecode file...
174  sys::Path BytecodeFile ("bugpoint-test-program.bc");
175  std::string ErrMsg;
176  if (BytecodeFile.makeUnique(true,&ErrMsg)) {
177    std::cerr << ToolName << ": Error making unique filename: " << ErrMsg
178              << "\n";
179    exit(1);
180  }
181  if (writeProgramToFile(BytecodeFile.toString(), M)) {
182    std::cerr << ToolName << ": Error emitting bytecode to file '"
183              << BytecodeFile << "'!\n";
184    exit(1);
185  }
186
187    // Remove the temporary bytecode file when we are done.
188  FileRemover BytecodeFileRemover(BytecodeFile);
189
190  // Actually compile the program!
191  Interpreter->compileProgram(BytecodeFile.toString());
192}
193
194
195/// executeProgram - This method runs "Program", capturing the output of the
196/// program to a file, returning the filename of the file.  A recommended
197/// filename may be optionally specified.
198///
199std::string BugDriver::executeProgram(std::string OutputFile,
200                                      std::string BytecodeFile,
201                                      const std::string &SharedObj,
202                                      AbstractInterpreter *AI,
203                                      bool *ProgramExitedNonzero) {
204  if (AI == 0) AI = Interpreter;
205  assert(AI && "Interpreter should have been created already!");
206  bool CreatedBytecode = false;
207  std::string ErrMsg;
208  if (BytecodeFile.empty()) {
209    // Emit the program to a bytecode file...
210    sys::Path uniqueFilename("bugpoint-test-program.bc");
211    if (uniqueFilename.makeUnique(true, &ErrMsg)) {
212      std::cerr << ToolName << ": Error making unique filename: "
213                << ErrMsg << "!\n";
214      exit(1);
215    }
216    BytecodeFile = uniqueFilename.toString();
217
218    if (writeProgramToFile(BytecodeFile, Program)) {
219      std::cerr << ToolName << ": Error emitting bytecode to file '"
220                << BytecodeFile << "'!\n";
221      exit(1);
222    }
223    CreatedBytecode = true;
224  }
225
226  // Remove the temporary bytecode file when we are done.
227  sys::Path BytecodePath (BytecodeFile);
228  FileRemover BytecodeFileRemover(BytecodePath, CreatedBytecode);
229
230  if (OutputFile.empty()) OutputFile = "bugpoint-execution-output";
231
232  // Check to see if this is a valid output filename...
233  sys::Path uniqueFile(OutputFile);
234  if (uniqueFile.makeUnique(true, &ErrMsg)) {
235    std::cerr << ToolName << ": Error making unique filename: "
236              << ErrMsg << "\n";
237    exit(1);
238  }
239  OutputFile = uniqueFile.toString();
240
241  // Figure out which shared objects to run, if any.
242  std::vector<std::string> SharedObjs(AdditionalSOs);
243  if (!SharedObj.empty())
244    SharedObjs.push_back(SharedObj);
245
246
247  // If this is an LLC or CBE run, then the GCC compiler might get run to
248  // compile the program. If so, we should pass the user's -Xlinker options
249  // as the GCCArgs.
250  int RetVal = 0;
251  if (InterpreterSel == RunLLC || InterpreterSel == RunCBE ||
252      InterpreterSel == CBE_bug)
253    RetVal = AI->ExecuteProgram(BytecodeFile, InputArgv, InputFile,
254                                OutputFile, AdditionalLinkerArgs, SharedObjs,
255                                Timeout);
256  else
257    RetVal = AI->ExecuteProgram(BytecodeFile, InputArgv, InputFile,
258                                OutputFile, std::vector<std::string>(),
259                                SharedObjs, Timeout);
260
261  if (RetVal == -1) {
262    std::cerr << "<timeout>";
263    static bool FirstTimeout = true;
264    if (FirstTimeout) {
265      std::cout << "\n"
266 "*** Program execution timed out!  This mechanism is designed to handle\n"
267 "    programs stuck in infinite loops gracefully.  The -timeout option\n"
268 "    can be used to change the timeout threshold or disable it completely\n"
269 "    (with -timeout=0).  This message is only displayed once.\n";
270      FirstTimeout = false;
271    }
272  }
273
274  if (ProgramExitedNonzero != 0)
275    *ProgramExitedNonzero = (RetVal != 0);
276
277  // Return the filename we captured the output to.
278  return OutputFile;
279}
280
281/// executeProgramWithCBE - Used to create reference output with the C
282/// backend, if reference output is not provided.
283///
284std::string BugDriver::executeProgramWithCBE(std::string OutputFile) {
285  bool ProgramExitedNonzero;
286  std::string outFN = executeProgram(OutputFile, "", "", cbe,
287                                     &ProgramExitedNonzero);
288  if (ProgramExitedNonzero) {
289    std::cerr
290      << "Warning: While generating reference output, program exited with\n"
291      << "non-zero exit code. This will NOT be treated as a failure.\n";
292    CheckProgramExitCode = false;
293  }
294  return outFN;
295}
296
297std::string BugDriver::compileSharedObject(const std::string &BytecodeFile) {
298  assert(Interpreter && "Interpreter should have been created already!");
299  sys::Path OutputFile;
300
301  // Using CBE
302  GCC::FileType FT = cbe->OutputCode(BytecodeFile, OutputFile);
303
304  std::string SharedObjectFile;
305  if (gcc->MakeSharedObject(OutputFile.toString(), FT,
306                            SharedObjectFile, AdditionalLinkerArgs))
307    exit(1);
308
309  // Remove the intermediate C file
310  OutputFile.eraseFromDisk();
311
312  return "./" + SharedObjectFile;
313}
314
315/// createReferenceFile - calls compileProgram and then records the output
316/// into ReferenceOutputFile. Returns true if reference file created, false
317/// otherwise. Note: initializeExecutionEnvironment should be called BEFORE
318/// this function.
319///
320bool BugDriver::createReferenceFile(Module *M, const std::string &Filename) {
321  try {
322    compileProgram(Program);
323  } catch (ToolExecutionError &) {
324    return false;
325  }
326  try {
327    ReferenceOutputFile = executeProgramWithCBE(Filename);
328    std::cout << "Reference output is: " << ReferenceOutputFile << "\n\n";
329  } catch (ToolExecutionError &TEE) {
330    std::cerr << TEE.what();
331    if (Interpreter != cbe) {
332      std::cerr << "*** There is a bug running the C backend.  Either debug"
333                << " it (use the -run-cbe bugpoint option), or fix the error"
334                << " some other way.\n";
335    }
336    return false;
337  }
338  return true;
339}
340
341/// diffProgram - This method executes the specified module and diffs the
342/// output against the file specified by ReferenceOutputFile.  If the output
343/// is different, true is returned.  If there is a problem with the code
344/// generator (e.g., llc crashes), this will throw an exception.
345///
346bool BugDriver::diffProgram(const std::string &BytecodeFile,
347                            const std::string &SharedObject,
348                            bool RemoveBytecode) {
349  bool ProgramExitedNonzero;
350
351  // Execute the program, generating an output file...
352  sys::Path Output(executeProgram("", BytecodeFile, SharedObject, 0,
353                                      &ProgramExitedNonzero));
354
355  // If we're checking the program exit code, assume anything nonzero is bad.
356  if (CheckProgramExitCode && ProgramExitedNonzero) {
357    Output.eraseFromDisk();
358    if (RemoveBytecode)
359      sys::Path(BytecodeFile).eraseFromDisk();
360    return true;
361  }
362
363  std::string Error;
364  bool FilesDifferent = false;
365  if (int Diff = DiffFilesWithTolerance(sys::Path(ReferenceOutputFile),
366                                        sys::Path(Output.toString()),
367                                        AbsTolerance, RelTolerance, &Error)) {
368    if (Diff == 2) {
369      std::cerr << "While diffing output: " << Error << '\n';
370      exit(1);
371    }
372    FilesDifferent = true;
373  }
374
375  // Remove the generated output.
376  Output.eraseFromDisk();
377
378  // Remove the bytecode file if we are supposed to.
379  if (RemoveBytecode)
380    sys::Path(BytecodeFile).eraseFromDisk();
381  return FilesDifferent;
382}
383
384bool BugDriver::isExecutingJIT() {
385  return InterpreterSel == RunJIT;
386}
387
388