ExecutionDriver.cpp revision 8ff70c2635bfd4e02c0140a5dc9ca909fffba35a 
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 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
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                            clEnumValN(LLC_Safe, "llc-safe", "Use LLC for all"),
51                            clEnumValEnd),
52                 cl::init(AutoPick));
53
54  cl::opt<bool>
55  CheckProgramExitCode("check-exit-code",
56                   cl::desc("Assume nonzero exit code is failure (default on)"),
57                       cl::init(true));
58
59  cl::opt<bool>
60  AppendProgramExitCode("append-exit-code",
61      cl::desc("Append the exit code to the output so it gets diff'd too"),
62      cl::init(false));
63
64  cl::opt<std::string>
65  InputFile("input", cl::init("/dev/null"),
66            cl::desc("Filename to pipe in as stdin (default: /dev/null)"));
67
68  cl::list<std::string>
69  AdditionalSOs("additional-so",
70                cl::desc("Additional shared objects to load "
71                         "into executing programs"));
72
73  cl::list<std::string>
74    AdditionalLinkerArgs("Xlinker",
75      cl::desc("Additional arguments to pass to the linker"));
76}
77
78namespace llvm {
79  // Anything specified after the --args option are taken as arguments to the
80  // program being debugged.
81  cl::list<std::string>
82  InputArgv("args", cl::Positional, cl::desc("<program arguments>..."),
83            cl::ZeroOrMore, cl::PositionalEatsArgs);
84
85  cl::list<std::string>
86  ToolArgv("tool-args", cl::Positional, cl::desc("<tool arguments>..."),
87           cl::ZeroOrMore, cl::PositionalEatsArgs);
88}
89
90//===----------------------------------------------------------------------===//
91// BugDriver method implementation
92//
93
94/// initializeExecutionEnvironment - This method is used to set up the
95/// environment for executing LLVM programs.
96///
97bool BugDriver::initializeExecutionEnvironment() {
98  std::cout << "Initializing execution environment: ";
99
100  // Create an instance of the AbstractInterpreter interface as specified on
101  // the command line
102  cbe = 0;
103  std::string Message;
104
105  switch (InterpreterSel) {
106  case AutoPick:
107    InterpreterSel = RunCBE;
108    Interpreter = cbe = AbstractInterpreter::createCBE(getToolName(), Message,
109                                                       &ToolArgv);
110    if (!Interpreter) {
111      InterpreterSel = RunJIT;
112      Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
113                                                   &ToolArgv);
114    }
115    if (!Interpreter) {
116      InterpreterSel = RunLLC;
117      Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
118                                                   &ToolArgv);
119    }
120    if (!Interpreter) {
121      InterpreterSel = RunLLI;
122      Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
123                                                   &ToolArgv);
124    }
125    if (!Interpreter) {
126      InterpreterSel = AutoPick;
127      Message = "Sorry, I can't automatically select an interpreter!\n";
128    }
129    break;
130  case RunLLI:
131    Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
132                                                 &ToolArgv);
133    break;
134  case RunLLC:
135    Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
136                                                 &ToolArgv);
137    break;
138  case RunJIT:
139    Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
140                                                 &ToolArgv);
141    break;
142  case LLC_Safe:
143    Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
144                                                 &ToolArgv);
145    break;
146  case RunCBE:
147  case CBE_bug:
148    Interpreter = AbstractInterpreter::createCBE(getToolName(), Message,
149                                                 &ToolArgv);
150    break;
151  default:
152    Message = "Sorry, this back-end is not supported by bugpoint right now!\n";
153    break;
154  }
155  std::cerr << Message;
156
157  // Initialize auxiliary tools for debugging
158  if (InterpreterSel == RunCBE) {
159    // We already created a CBE, reuse it.
160    cbe = Interpreter;
161  } else if (InterpreterSel == CBE_bug || InterpreterSel == LLC_Safe) {
162    // We want to debug the CBE itself or LLC is known-good.  Use LLC as the
163    // 'known-good' compiler.
164    std::vector<std::string> ToolArgs;
165    ToolArgs.push_back("--relocation-model=pic");
166    cbe = AbstractInterpreter::createLLC(getToolName(), Message, &ToolArgs);
167  } else {
168    cbe = AbstractInterpreter::createCBE(getToolName(), Message, &ToolArgv);
169  }
170  if (!cbe) { std::cout << Message << "\nExiting.\n"; exit(1); }
171
172  gcc = GCC::create(getToolName(), Message);
173  if (!gcc) { std::cout << Message << "\nExiting.\n"; exit(1); }
174
175  // If there was an error creating the selected interpreter, quit with error.
176  return Interpreter == 0;
177}
178
179/// compileProgram - Try to compile the specified module, throwing an exception
180/// if an error occurs, or returning normally if not.  This is used for code
181/// generation crash testing.
182///
183void BugDriver::compileProgram(Module *M) {
184  // Emit the program to a bitcode file...
185  sys::Path BitcodeFile ("bugpoint-test-program.bc");
186  std::string ErrMsg;
187  if (BitcodeFile.makeUnique(true,&ErrMsg)) {
188    std::cerr << ToolName << ": Error making unique filename: " << ErrMsg
189              << "\n";
190    exit(1);
191  }
192  if (writeProgramToFile(BitcodeFile.toString(), M)) {
193    std::cerr << ToolName << ": Error emitting bitcode to file '"
194              << BitcodeFile << "'!\n";
195    exit(1);
196  }
197
198    // Remove the temporary bitcode file when we are done.
199  FileRemover BitcodeFileRemover(BitcodeFile);
200
201  // Actually compile the program!
202  Interpreter->compileProgram(BitcodeFile.toString());
203}
204
205
206/// executeProgram - This method runs "Program", capturing the output of the
207/// program to a file, returning the filename of the file.  A recommended
208/// filename may be optionally specified.
209///
210std::string BugDriver::executeProgram(std::string OutputFile,
211                                      std::string BitcodeFile,
212                                      const std::string &SharedObj,
213                                      AbstractInterpreter *AI,
214                                      bool *ProgramExitedNonzero) {
215  if (AI == 0) AI = Interpreter;
216  assert(AI && "Interpreter should have been created already!");
217  bool CreatedBitcode = false;
218  std::string ErrMsg;
219  if (BitcodeFile.empty()) {
220    // Emit the program to a bitcode file...
221    sys::Path uniqueFilename("bugpoint-test-program.bc");
222    if (uniqueFilename.makeUnique(true, &ErrMsg)) {
223      std::cerr << ToolName << ": Error making unique filename: "
224                << ErrMsg << "!\n";
225      exit(1);
226    }
227    BitcodeFile = uniqueFilename.toString();
228
229    if (writeProgramToFile(BitcodeFile, Program)) {
230      std::cerr << ToolName << ": Error emitting bitcode to file '"
231                << BitcodeFile << "'!\n";
232      exit(1);
233    }
234    CreatedBitcode = true;
235  }
236
237  // Remove the temporary bitcode file when we are done.
238  sys::Path BitcodePath (BitcodeFile);
239  FileRemover BitcodeFileRemover(BitcodePath, CreatedBitcode);
240
241  if (OutputFile.empty()) OutputFile = "bugpoint-execution-output";
242
243  // Check to see if this is a valid output filename...
244  sys::Path uniqueFile(OutputFile);
245  if (uniqueFile.makeUnique(true, &ErrMsg)) {
246    std::cerr << ToolName << ": Error making unique filename: "
247              << ErrMsg << "\n";
248    exit(1);
249  }
250  OutputFile = uniqueFile.toString();
251
252  // Figure out which shared objects to run, if any.
253  std::vector<std::string> SharedObjs(AdditionalSOs);
254  if (!SharedObj.empty())
255    SharedObjs.push_back(SharedObj);
256
257
258  // If this is an LLC or CBE run, then the GCC compiler might get run to
259  // compile the program. If so, we should pass the user's -Xlinker options
260  // as the GCCArgs.
261  int RetVal = 0;
262  if (InterpreterSel == RunLLC || InterpreterSel == RunCBE ||
263      InterpreterSel == CBE_bug || InterpreterSel == LLC_Safe)
264    RetVal = AI->ExecuteProgram(BitcodeFile, InputArgv, InputFile,
265                                OutputFile, AdditionalLinkerArgs, SharedObjs,
266                                Timeout, MemoryLimit);
267  else
268    RetVal = AI->ExecuteProgram(BitcodeFile, InputArgv, InputFile,
269                                OutputFile, std::vector<std::string>(),
270                                SharedObjs, Timeout, MemoryLimit);
271
272  if (RetVal == -1) {
273    std::cerr << "<timeout>";
274    static bool FirstTimeout = true;
275    if (FirstTimeout) {
276      std::cout << "\n"
277 "*** Program execution timed out!  This mechanism is designed to handle\n"
278 "    programs stuck in infinite loops gracefully.  The -timeout option\n"
279 "    can be used to change the timeout threshold or disable it completely\n"
280 "    (with -timeout=0).  This message is only displayed once.\n";
281      FirstTimeout = false;
282    }
283  }
284
285  if (AppendProgramExitCode) {
286    std::ofstream outFile(OutputFile.c_str(), std::ios_base::app);
287    outFile << "exit " << RetVal << '\n';
288    outFile.close();
289  }
290
291  if (ProgramExitedNonzero != 0)
292    *ProgramExitedNonzero = (RetVal != 0);
293
294  // Return the filename we captured the output to.
295  return OutputFile;
296}
297
298/// executeProgramWithCBE - Used to create reference output with the C
299/// backend, if reference output is not provided.
300///
301std::string BugDriver::executeProgramWithCBE(std::string OutputFile) {
302  bool ProgramExitedNonzero;
303  std::string outFN = executeProgram(OutputFile, "", "", cbe,
304                                     &ProgramExitedNonzero);
305  if (ProgramExitedNonzero) {
306    std::cerr
307      << "Warning: While generating reference output, program exited with\n"
308      << "non-zero exit code. This will NOT be treated as a failure.\n";
309    CheckProgramExitCode = false;
310  }
311  return outFN;
312}
313
314std::string BugDriver::compileSharedObject(const std::string &BitcodeFile) {
315  assert(Interpreter && "Interpreter should have been created already!");
316  sys::Path OutputFile;
317
318  // Using CBE
319  GCC::FileType FT = cbe->OutputCode(BitcodeFile, OutputFile);
320
321  std::string SharedObjectFile;
322  if (gcc->MakeSharedObject(OutputFile.toString(), FT,
323                            SharedObjectFile, AdditionalLinkerArgs))
324    exit(1);
325
326  // Remove the intermediate C file
327  OutputFile.eraseFromDisk();
328
329  return "./" + SharedObjectFile;
330}
331
332/// createReferenceFile - calls compileProgram and then records the output
333/// into ReferenceOutputFile. Returns true if reference file created, false
334/// otherwise. Note: initializeExecutionEnvironment should be called BEFORE
335/// this function.
336///
337bool BugDriver::createReferenceFile(Module *M, const std::string &Filename) {
338  try {
339    compileProgram(Program);
340  } catch (ToolExecutionError &) {
341    return false;
342  }
343  try {
344    ReferenceOutputFile = executeProgramWithCBE(Filename);
345    std::cout << "Reference output is: " << ReferenceOutputFile << "\n\n";
346  } catch (ToolExecutionError &TEE) {
347    std::cerr << TEE.what();
348    if (Interpreter != cbe) {
349      std::cerr << "*** There is a bug running the C backend.  Either debug"
350                << " it (use the -run-cbe bugpoint option), or fix the error"
351                << " some other way.\n";
352    }
353    return false;
354  }
355  return true;
356}
357
358/// diffProgram - This method executes the specified module and diffs the
359/// output against the file specified by ReferenceOutputFile.  If the output
360/// is different, true is returned.  If there is a problem with the code
361/// generator (e.g., llc crashes), this will throw an exception.
362///
363bool BugDriver::diffProgram(const std::string &BitcodeFile,
364                            const std::string &SharedObject,
365                            bool RemoveBitcode) {
366  bool ProgramExitedNonzero;
367
368  // Execute the program, generating an output file...
369  sys::Path Output(executeProgram("", BitcodeFile, SharedObject, 0,
370                                      &ProgramExitedNonzero));
371
372  // If we're checking the program exit code, assume anything nonzero is bad.
373  if (CheckProgramExitCode && ProgramExitedNonzero) {
374    Output.eraseFromDisk();
375    if (RemoveBitcode)
376      sys::Path(BitcodeFile).eraseFromDisk();
377    return true;
378  }
379
380  std::string Error;
381  bool FilesDifferent = false;
382  if (int Diff = DiffFilesWithTolerance(sys::Path(ReferenceOutputFile),
383                                        sys::Path(Output.toString()),
384                                        AbsTolerance, RelTolerance, &Error)) {
385    if (Diff == 2) {
386      std::cerr << "While diffing output: " << Error << '\n';
387      exit(1);
388    }
389    FilesDifferent = true;
390  }
391
392  // Remove the generated output.
393  Output.eraseFromDisk();
394
395  // Remove the bitcode file if we are supposed to.
396  if (RemoveBitcode)
397    sys::Path(BitcodeFile).eraseFromDisk();
398  return FilesDifferent;
399}
400
401bool BugDriver::isExecutingJIT() {
402  return InterpreterSel == RunJIT;
403}
404
405