ExecutionDriver.cpp revision dd04df0ec33a903ee7fc747701bafde622f77d8b 
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 "llvm/Support/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>
22using namespace llvm;
23
24namespace {
25  // OutputType - Allow the user to specify the way code should be run, to test
26  // for miscompilation.
27  //
28  enum OutputType {
29    AutoPick, RunLLI, RunJIT, RunLLC, RunCBE
30  };
31
32  cl::opt<double>
33  AbsTolerance("abs-tolerance", cl::desc("Absolute error tolerated"),
34               cl::init(0.0));
35  cl::opt<double>
36  RelTolerance("rel-tolerance", cl::desc("Relative error tolerated"),
37               cl::init(0.0));
38
39  cl::opt<OutputType>
40  InterpreterSel(cl::desc("Specify how LLVM code should be executed:"),
41                 cl::values(clEnumValN(AutoPick, "auto", "Use best guess"),
42                            clEnumValN(RunLLI, "run-int",
43                                       "Execute with the interpreter"),
44                            clEnumValN(RunJIT, "run-jit", "Execute with JIT"),
45                            clEnumValN(RunLLC, "run-llc", "Compile with LLC"),
46                            clEnumValN(RunCBE, "run-cbe", "Compile with CBE"),
47                            clEnumValEnd),
48                 cl::init(AutoPick));
49
50  cl::opt<bool>
51  CheckProgramExitCode("check-exit-code",
52                   cl::desc("Assume nonzero exit code is failure (default on)"),
53                       cl::init(true));
54
55  cl::opt<std::string>
56  InputFile("input", cl::init("/dev/null"),
57            cl::desc("Filename to pipe in as stdin (default: /dev/null)"));
58
59  cl::list<std::string>
60  AdditionalSOs("additional-so",
61                cl::desc("Additional shared objects to load "
62                         "into executing programs"));
63
64  cl::opt<unsigned>
65  TimeoutValue("timeout", cl::init(300), cl::value_desc("seconds"),
66               cl::desc("Number of seconds program is allowed to run before it "
67                        "is killed (default is 300s), 0 disables timeout"));
68}
69
70namespace llvm {
71  // Anything specified after the --args option are taken as arguments to the
72  // program being debugged.
73  cl::list<std::string>
74  InputArgv("args", cl::Positional, cl::desc("<program arguments>..."),
75            cl::ZeroOrMore, cl::PositionalEatsArgs);
76
77  cl::list<std::string>
78  ToolArgv("tool-args", cl::Positional, cl::desc("<tool arguments>..."),
79           cl::ZeroOrMore, cl::PositionalEatsArgs);
80}
81
82//===----------------------------------------------------------------------===//
83// BugDriver method implementation
84//
85
86/// initializeExecutionEnvironment - This method is used to set up the
87/// environment for executing LLVM programs.
88///
89bool BugDriver::initializeExecutionEnvironment() {
90  std::cout << "Initializing execution environment: ";
91
92  // Create an instance of the AbstractInterpreter interface as specified on
93  // the command line
94  cbe = 0;
95  std::string Message;
96
97  switch (InterpreterSel) {
98  case AutoPick:
99    InterpreterSel = RunCBE;
100    Interpreter = cbe = AbstractInterpreter::createCBE(getToolName(), Message,
101                                                       &ToolArgv);
102    if (!Interpreter) {
103      InterpreterSel = RunJIT;
104      Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
105                                                   &ToolArgv);
106    }
107    if (!Interpreter) {
108      InterpreterSel = RunLLC;
109      Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
110                                                   &ToolArgv);
111    }
112    if (!Interpreter) {
113      InterpreterSel = RunLLI;
114      Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
115                                                   &ToolArgv);
116    }
117    if (!Interpreter) {
118      InterpreterSel = AutoPick;
119      Message = "Sorry, I can't automatically select an interpreter!\n";
120    }
121    break;
122  case RunLLI:
123    Interpreter = AbstractInterpreter::createLLI(getToolName(), Message,
124                                                 &ToolArgv);
125    break;
126  case RunLLC:
127    Interpreter = AbstractInterpreter::createLLC(getToolName(), Message,
128                                                 &ToolArgv);
129    break;
130  case RunJIT:
131    Interpreter = AbstractInterpreter::createJIT(getToolName(), Message,
132                                                 &ToolArgv);
133    break;
134  case RunCBE:
135    Interpreter = cbe = AbstractInterpreter::createCBE(getToolName(), Message,
136                                                       &ToolArgv);
137    break;
138  default:
139    Message = "Sorry, this back-end is not supported by bugpoint right now!\n";
140    break;
141  }
142  std::cerr << Message;
143
144  // Initialize auxiliary tools for debugging
145  if (!cbe) {
146    cbe = AbstractInterpreter::createCBE(getToolName(), Message, &ToolArgv);
147    if (!cbe) { std::cout << Message << "\nExiting.\n"; exit(1); }
148  }
149  gcc = GCC::create(getToolName(), Message);
150  if (!gcc) { std::cout << Message << "\nExiting.\n"; exit(1); }
151
152  // If there was an error creating the selected interpreter, quit with error.
153  return Interpreter == 0;
154}
155
156/// compileProgram - Try to compile the specified module, throwing an exception
157/// if an error occurs, or returning normally if not.  This is used for code
158/// generation crash testing.
159///
160void BugDriver::compileProgram(Module *M) {
161  // Emit the program to a bytecode file...
162  sys::Path BytecodeFile ("bugpoint-test-program.bc");
163  BytecodeFile.makeUnique();
164  if (writeProgramToFile(BytecodeFile.toString(), M)) {
165    std::cerr << ToolName << ": Error emitting bytecode to file '"
166              << BytecodeFile << "'!\n";
167    exit(1);
168  }
169
170    // Remove the temporary bytecode file when we are done.
171  FileRemover BytecodeFileRemover(BytecodeFile);
172
173  // Actually compile the program!
174  Interpreter->compileProgram(BytecodeFile.toString());
175}
176
177
178/// executeProgram - This method runs "Program", capturing the output of the
179/// program to a file, returning the filename of the file.  A recommended
180/// filename may be optionally specified.
181///
182std::string BugDriver::executeProgram(std::string OutputFile,
183                                      std::string BytecodeFile,
184                                      const std::string &SharedObj,
185                                      AbstractInterpreter *AI,
186                                      bool *ProgramExitedNonzero) {
187  if (AI == 0) AI = Interpreter;
188  assert(AI && "Interpreter should have been created already!");
189  bool CreatedBytecode = false;
190  if (BytecodeFile.empty()) {
191    // Emit the program to a bytecode file...
192    sys::Path uniqueFilename("bugpoint-test-program.bc");
193    uniqueFilename.makeUnique();
194    BytecodeFile = uniqueFilename.toString();
195
196    if (writeProgramToFile(BytecodeFile, Program)) {
197      std::cerr << ToolName << ": Error emitting bytecode to file '"
198                << BytecodeFile << "'!\n";
199      exit(1);
200    }
201    CreatedBytecode = true;
202  }
203
204  // Remove the temporary bytecode file when we are done.
205  sys::Path BytecodePath (BytecodeFile);
206  FileRemover BytecodeFileRemover(BytecodePath, CreatedBytecode);
207
208  if (OutputFile.empty()) OutputFile = "bugpoint-execution-output";
209
210  // Check to see if this is a valid output filename...
211  sys::Path uniqueFile(OutputFile);
212  uniqueFile.makeUnique();
213  OutputFile = uniqueFile.toString();
214
215  // Figure out which shared objects to run, if any.
216  std::vector<std::string> SharedObjs(AdditionalSOs);
217  if (!SharedObj.empty())
218    SharedObjs.push_back(SharedObj);
219
220  // Actually execute the program!
221  int RetVal = AI->ExecuteProgram(BytecodeFile, InputArgv, InputFile,
222                                  OutputFile, SharedObjs, TimeoutValue);
223
224  if (RetVal == -1) {
225    std::cerr << "<timeout>";
226    static bool FirstTimeout = true;
227    if (FirstTimeout) {
228      std::cout << "\n"
229 "*** Program execution timed out!  This mechanism is designed to handle\n"
230 "    programs stuck in infinite loops gracefully.  The -timeout option\n"
231 "    can be used to change the timeout threshold or disable it completely\n"
232 "    (with -timeout=0).  This message is only displayed once.\n";
233      FirstTimeout = false;
234    }
235  }
236
237  if (ProgramExitedNonzero != 0)
238    *ProgramExitedNonzero = (RetVal != 0);
239
240  // Return the filename we captured the output to.
241  return OutputFile;
242}
243
244/// executeProgramWithCBE - Used to create reference output with the C
245/// backend, if reference output is not provided.
246///
247std::string BugDriver::executeProgramWithCBE(std::string OutputFile) {
248  bool ProgramExitedNonzero;
249  std::string outFN = executeProgram(OutputFile, "", "",
250                                     (AbstractInterpreter*)cbe,
251                                     &ProgramExitedNonzero);
252  if (ProgramExitedNonzero) {
253    std::cerr
254      << "Warning: While generating reference output, program exited with\n"
255      << "non-zero exit code. This will NOT be treated as a failure.\n";
256    CheckProgramExitCode = false;
257  }
258  return outFN;
259}
260
261std::string BugDriver::compileSharedObject(const std::string &BytecodeFile) {
262  assert(Interpreter && "Interpreter should have been created already!");
263  sys::Path OutputCFile;
264
265  // Using CBE
266  cbe->OutputC(BytecodeFile, OutputCFile);
267
268#if 0 /* This is an alternative, as yet unimplemented */
269  // Using LLC
270  std::string Message;
271  LLC *llc = createLLCtool(Message);
272  if (llc->OutputAsm(BytecodeFile, OutputFile)) {
273    std::cerr << "Could not generate asm code with `llc', exiting.\n";
274    exit(1);
275  }
276#endif
277
278  std::string SharedObjectFile;
279  if (gcc->MakeSharedObject(OutputCFile.toString(), GCC::CFile,
280                            SharedObjectFile))
281    exit(1);
282
283  // Remove the intermediate C file
284  OutputCFile.destroy();
285
286  return "./" + SharedObjectFile;
287}
288
289
290/// diffProgram - This method executes the specified module and diffs the output
291/// against the file specified by ReferenceOutputFile.  If the output is
292/// different, true is returned.
293///
294bool BugDriver::diffProgram(const std::string &BytecodeFile,
295                            const std::string &SharedObject,
296                            bool RemoveBytecode) {
297  bool ProgramExitedNonzero;
298
299  // Execute the program, generating an output file...
300  sys::Path Output (executeProgram("", BytecodeFile, SharedObject, 0,
301                                      &ProgramExitedNonzero));
302
303  // If we're checking the program exit code, assume anything nonzero is bad.
304  if (CheckProgramExitCode && ProgramExitedNonzero) {
305    Output.destroy();
306    if (RemoveBytecode)
307      sys::Path(BytecodeFile).destroy();
308    return true;
309  }
310
311  std::string Error;
312  bool FilesDifferent = false;
313  if (int Diff = DiffFilesWithTolerance(sys::Path(ReferenceOutputFile),
314                                        sys::Path(Output.toString()),
315                                        AbsTolerance, RelTolerance, &Error)) {
316    if (Diff == 2) {
317      std::cerr << "While diffing output: " << Error << '\n';
318      exit(1);
319    }
320    FilesDifferent = true;
321  }
322
323  // Remove the generated output.
324  Output.destroy();
325
326  // Remove the bytecode file if we are supposed to.
327  if (RemoveBytecode)
328    sys::Path(BytecodeFile).destroy();
329  return FilesDifferent;
330}
331
332bool BugDriver::isExecutingJIT() {
333  return InterpreterSel == RunJIT;
334}
335
336