ExecutionDriver.cpp revision 33b1c30b0be49d09e57630abd2535c9aaeaf8636 
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 <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, 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 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                            clEnumValN(Custom, "run-custom",
52                            "Use -exec-command to define a command to execute "
53                            "the bitcode. Useful for cross-compilation."),
54                            clEnumValEnd),
55                 cl::init(AutoPick));
56
57  cl::opt<bool>
58  AppendProgramExitCode("append-exit-code",
59      cl::desc("Append the exit code to the output so it gets diff'd too"),
60      cl::init(false));
61
62  cl::opt<std::string>
63  InputFile("input", cl::init("/dev/null"),
64            cl::desc("Filename to pipe in as stdin (default: /dev/null)"));
65
66  cl::list<std::string>
67  AdditionalSOs("additional-so",
68                cl::desc("Additional shared objects to load "
69                         "into executing programs"));
70
71  cl::list<std::string>
72  AdditionalLinkerArgs("Xlinker",
73      cl::desc("Additional arguments to pass to the linker"));
74
75  cl::opt<std::string>
76  CustomExecCommand("exec-command", cl::init("simulate"),
77      cl::desc("Command to execute the bitcode (use with -run-custom) "
78               "(default: simulate)"));
79}
80
81namespace llvm {
82  // Anything specified after the --args option are taken as arguments to the
83  // program being debugged.
84  cl::list<std::string>
85  InputArgv("args", cl::Positional, cl::desc("<program arguments>..."),
86            cl::ZeroOrMore, cl::PositionalEatsArgs);
87
88  cl::list<std::string>
89  ToolArgv("tool-args", cl::Positional, cl::desc("<tool arguments>..."),
90           cl::ZeroOrMore, cl::PositionalEatsArgs);
91}
92
93//===----------------------------------------------------------------------===//
94// BugDriver method implementation
95//
96
97/// initializeExecutionEnvironment - This method is used to set up the
98/// environment for executing LLVM programs.
99///
100bool BugDriver::initializeExecutionEnvironment() {
101  std::cout << "Initializing execution environment: ";
102
103  // Create an instance of the AbstractInterpreter interface as specified on
104  // the command line
105  cbe = 0;
106  std::string Message;
107
108  switch (InterpreterSel) {
109  case AutoPick:
110    InterpreterSel = RunCBE;
111    Interpreter = cbe = AbstractInterpreter::createCBE(getToolName(), Message,
112                                                       &ToolArgv);
113    if (!Interpreter) {
114      InterpreterSel = RunJIT;
115      Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
116                                                   &ToolArgv);
117    }
118    if (!Interpreter) {
119      InterpreterSel = RunLLC;
120      Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
121                                                   &ToolArgv);
122    }
123    if (!Interpreter) {
124      InterpreterSel = RunLLI;
125      Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
126                                                   &ToolArgv);
127    }
128    if (!Interpreter) {
129      InterpreterSel = AutoPick;
130      Message = "Sorry, I can't automatically select an interpreter!\n";
131    }
132    break;
133  case RunLLI:
134    Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
135                                                 &ToolArgv);
136    break;
137  case RunLLC:
138    Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
139                                                 &ToolArgv);
140    break;
141  case RunJIT:
142    Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
143                                                 &ToolArgv);
144    break;
145  case LLC_Safe:
146    Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
147                                                 &ToolArgv);
148    break;
149  case RunCBE:
150  case CBE_bug:
151    Interpreter = AbstractInterpreter::createCBE(getToolName(), Message,
152                                                 &ToolArgv);
153    break;
154  case Custom:
155    Interpreter = AbstractInterpreter::createCustom(getToolName(), Message,
156                                                    CustomExecCommand);
157    break;
158  default:
159    Message = "Sorry, this back-end is not supported by bugpoint right now!\n";
160    break;
161  }
162  if (!Interpreter)
163    std::cerr << Message;
164  else // Display informational messages on stdout instead of stderr
165    std::cout << Message;
166
167  // Initialize auxiliary tools for debugging
168  if (InterpreterSel == RunCBE) {
169    // We already created a CBE, reuse it.
170    cbe = Interpreter;
171  } else if (InterpreterSel == CBE_bug || InterpreterSel == LLC_Safe) {
172    // We want to debug the CBE itself or LLC is known-good.  Use LLC as the
173    // 'known-good' compiler.
174    std::vector<std::string> ToolArgs;
175    ToolArgs.push_back("--relocation-model=pic");
176    cbe = AbstractInterpreter::createLLC(getToolName(), Message, &ToolArgs);
177  } else {
178    cbe = AbstractInterpreter::createCBE(getToolName(), Message, &ToolArgv);
179  }
180  if (!cbe) { std::cout << Message << "\nExiting.\n"; exit(1); }
181
182  gcc = GCC::create(getToolName(), Message);
183  if (!gcc) { std::cout << Message << "\nExiting.\n"; exit(1); }
184
185  // If there was an error creating the selected interpreter, quit with error.
186  return Interpreter == 0;
187}
188
189/// compileProgram - Try to compile the specified module, throwing an exception
190/// if an error occurs, or returning normally if not.  This is used for code
191/// generation crash testing.
192///
193void BugDriver::compileProgram(Module *M) {
194  // Emit the program to a bitcode file...
195  sys::Path BitcodeFile ("bugpoint-test-program.bc");
196  std::string ErrMsg;
197  if (BitcodeFile.makeUnique(true,&ErrMsg)) {
198    std::cerr << ToolName << ": Error making unique filename: " << ErrMsg
199              << "\n";
200    exit(1);
201  }
202  if (writeProgramToFile(BitcodeFile.toString(), M)) {
203    std::cerr << ToolName << ": Error emitting bitcode to file '"
204              << BitcodeFile << "'!\n";
205    exit(1);
206  }
207
208    // Remove the temporary bitcode file when we are done.
209  FileRemover BitcodeFileRemover(BitcodeFile);
210
211  // Actually compile the program!
212  Interpreter->compileProgram(BitcodeFile.toString());
213}
214
215
216/// executeProgram - This method runs "Program", capturing the output of the
217/// program to a file, returning the filename of the file.  A recommended
218/// filename may be optionally specified.
219///
220std::string BugDriver::executeProgram(std::string OutputFile,
221                                      std::string BitcodeFile,
222                                      const std::string &SharedObj,
223                                      AbstractInterpreter *AI,
224                                      bool *ProgramExitedNonzero) {
225  if (AI == 0) AI = Interpreter;
226  assert(AI && "Interpreter should have been created already!");
227  bool CreatedBitcode = false;
228  std::string ErrMsg;
229  if (BitcodeFile.empty()) {
230    // Emit the program to a bitcode file...
231    sys::Path uniqueFilename("bugpoint-test-program.bc");
232    if (uniqueFilename.makeUnique(true, &ErrMsg)) {
233      std::cerr << ToolName << ": Error making unique filename: "
234                << ErrMsg << "!\n";
235      exit(1);
236    }
237    BitcodeFile = uniqueFilename.toString();
238
239    if (writeProgramToFile(BitcodeFile, Program)) {
240      std::cerr << ToolName << ": Error emitting bitcode to file '"
241                << BitcodeFile << "'!\n";
242      exit(1);
243    }
244    CreatedBitcode = true;
245  }
246
247  // Remove the temporary bitcode file when we are done.
248  sys::Path BitcodePath (BitcodeFile);
249  FileRemover BitcodeFileRemover(BitcodePath, CreatedBitcode);
250
251  if (OutputFile.empty()) OutputFile = "bugpoint-execution-output";
252
253  // Check to see if this is a valid output filename...
254  sys::Path uniqueFile(OutputFile);
255  if (uniqueFile.makeUnique(true, &ErrMsg)) {
256    std::cerr << ToolName << ": Error making unique filename: "
257              << ErrMsg << "\n";
258    exit(1);
259  }
260  OutputFile = uniqueFile.toString();
261
262  // Figure out which shared objects to run, if any.
263  std::vector<std::string> SharedObjs(AdditionalSOs);
264  if (!SharedObj.empty())
265    SharedObjs.push_back(SharedObj);
266
267
268  // If this is an LLC or CBE run, then the GCC compiler might get run to
269  // compile the program. If so, we should pass the user's -Xlinker options
270  // as the GCCArgs.
271  int RetVal = 0;
272  if (InterpreterSel == RunLLC || InterpreterSel == RunCBE ||
273      InterpreterSel == CBE_bug || InterpreterSel == LLC_Safe)
274    RetVal = AI->ExecuteProgram(BitcodeFile, InputArgv, InputFile,
275                                OutputFile, AdditionalLinkerArgs, SharedObjs,
276                                Timeout, MemoryLimit);
277  else
278    RetVal = AI->ExecuteProgram(BitcodeFile, InputArgv, InputFile,
279                                OutputFile, std::vector<std::string>(),
280                                SharedObjs, Timeout, MemoryLimit);
281
282  if (RetVal == -1) {
283    std::cerr << "<timeout>";
284    static bool FirstTimeout = true;
285    if (FirstTimeout) {
286      std::cout << "\n"
287 "*** Program execution timed out!  This mechanism is designed to handle\n"
288 "    programs stuck in infinite loops gracefully.  The -timeout option\n"
289 "    can be used to change the timeout threshold or disable it completely\n"
290 "    (with -timeout=0).  This message is only displayed once.\n";
291      FirstTimeout = false;
292    }
293  }
294
295  if (AppendProgramExitCode) {
296    std::ofstream outFile(OutputFile.c_str(), std::ios_base::app);
297    outFile << "exit " << RetVal << '\n';
298    outFile.close();
299  }
300
301  if (ProgramExitedNonzero != 0)
302    *ProgramExitedNonzero = (RetVal != 0);
303
304  // Return the filename we captured the output to.
305  return OutputFile;
306}
307
308/// executeProgramWithCBE - Used to create reference output with the C
309/// backend, if reference output is not provided.
310///
311std::string BugDriver::executeProgramWithCBE(std::string OutputFile) {
312  bool ProgramExitedNonzero;
313  std::string outFN = executeProgram(OutputFile, "", "", cbe,
314                                     &ProgramExitedNonzero);
315  return outFN;
316}
317
318std::string BugDriver::compileSharedObject(const std::string &BitcodeFile) {
319  assert(Interpreter && "Interpreter should have been created already!");
320  sys::Path OutputFile;
321
322  // Using CBE
323  GCC::FileType FT = cbe->OutputCode(BitcodeFile, OutputFile);
324
325  std::string SharedObjectFile;
326  if (gcc->MakeSharedObject(OutputFile.toString(), FT,
327                            SharedObjectFile, AdditionalLinkerArgs))
328    exit(1);
329
330  // Remove the intermediate C file
331  OutputFile.eraseFromDisk();
332
333  return "./" + SharedObjectFile;
334}
335
336/// createReferenceFile - calls compileProgram and then records the output
337/// into ReferenceOutputFile. Returns true if reference file created, false
338/// otherwise. Note: initializeExecutionEnvironment should be called BEFORE
339/// this function.
340///
341bool BugDriver::createReferenceFile(Module *M, const std::string &Filename) {
342  try {
343    compileProgram(Program);
344  } catch (ToolExecutionError &) {
345    return false;
346  }
347  try {
348    ReferenceOutputFile = executeProgramWithCBE(Filename);
349    std::cout << "Reference output is: " << ReferenceOutputFile << "\n\n";
350  } catch (ToolExecutionError &TEE) {
351    std::cerr << TEE.what();
352    if (Interpreter != cbe) {
353      std::cerr << "*** There is a bug running the C backend.  Either debug"
354                << " it (use the -run-cbe bugpoint option), or fix the error"
355                << " some other way.\n";
356    }
357    return false;
358  }
359  return true;
360}
361
362/// diffProgram - This method executes the specified module and diffs the
363/// output against the file specified by ReferenceOutputFile.  If the output
364/// is different, true is returned.  If there is a problem with the code
365/// generator (e.g., llc crashes), this will throw an exception.
366///
367bool BugDriver::diffProgram(const std::string &BitcodeFile,
368                            const std::string &SharedObject,
369                            bool RemoveBitcode) {
370  bool ProgramExitedNonzero;
371
372  // Execute the program, generating an output file...
373  sys::Path Output(executeProgram("", BitcodeFile, SharedObject, 0,
374                                      &ProgramExitedNonzero));
375
376  std::string Error;
377  bool FilesDifferent = false;
378  if (int Diff = DiffFilesWithTolerance(sys::Path(ReferenceOutputFile),
379                                        sys::Path(Output.toString()),
380                                        AbsTolerance, RelTolerance, &Error)) {
381    if (Diff == 2) {
382      std::cerr << "While diffing output: " << Error << '\n';
383      exit(1);
384    }
385    FilesDifferent = true;
386  }
387
388  // Remove the generated output.
389  Output.eraseFromDisk();
390
391  // Remove the bitcode file if we are supposed to.
392  if (RemoveBitcode)
393    sys::Path(BitcodeFile).eraseFromDisk();
394  return FilesDifferent;
395}
396
397bool BugDriver::isExecutingJIT() {
398  return InterpreterSel == RunJIT;
399}
400
401