OptimizerDriver.cpp revision 03b696376219945d67caffda1995d12e3410f05b 
1//===- OptimizerDriver.cpp - Allow BugPoint to run passes safely ----------===//
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 defines an interface that allows bugpoint to run various passes
11// without the threat of a buggy pass corrupting bugpoint (of course, bugpoint
12// may have its own bugs, but that's another story...).  It achieves this by
13// forking a copy of itself and having the child process do the optimizations.
14// If this client dies, we can always fork a new one.  :)
15//
16//===----------------------------------------------------------------------===//
17
18// Note: as a short term hack, the old Unix-specific code and platform-
19// independent code co-exist via conditional compilation until it is verified
20// that the new code works correctly on Unix.
21
22#include "BugDriver.h"
23#include "llvm/Module.h"
24#include "llvm/PassManager.h"
25#include "llvm/Analysis/Verifier.h"
26#include "llvm/Bytecode/WriteBytecodePass.h"
27#include "llvm/Bitcode/ReaderWriter.h"
28#include "llvm/Target/TargetData.h"
29#include "llvm/Support/FileUtilities.h"
30#include "llvm/Support/CommandLine.h"
31#include "llvm/Support/Streams.h"
32#include "llvm/System/Path.h"
33#include "llvm/System/Program.h"
34#include "llvm/Config/alloca.h"
35
36#define DONT_GET_PLUGIN_LOADER_OPTION
37#include "llvm/Support/PluginLoader.h"
38
39#include <fstream>
40using namespace llvm;
41
42static bool Bitcode = false;
43
44
45namespace {
46  // ChildOutput - This option captures the name of the child output file that
47  // is set up by the parent bugpoint process
48  cl::opt<std::string> ChildOutput("child-output", cl::ReallyHidden);
49  cl::opt<bool> UseValgrind("enable-valgrind",
50                            cl::desc("Run optimizations through valgrind"));
51}
52
53/// writeProgramToFile - This writes the current "Program" to the named bytecode
54/// file.  If an error occurs, true is returned.
55///
56bool BugDriver::writeProgramToFile(const std::string &Filename,
57                                   Module *M) const {
58  std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
59                               std::ios::binary;
60  std::ofstream Out(Filename.c_str(), io_mode);
61  if (!Out.good()) return true;
62  try {
63    OStream L(Out);
64    WriteBytecodeToFile(M ? M : Program, L, /*compression=*/false);
65  } catch (...) {
66    return true;
67  }
68  return false;
69}
70
71
72/// EmitProgressBytecode - This function is used to output the current Program
73/// to a file named "bugpoint-ID.bc".
74///
75void BugDriver::EmitProgressBytecode(const std::string &ID, bool NoFlyer) {
76  // Output the input to the current pass to a bytecode file, emit a message
77  // telling the user how to reproduce it: opt -foo blah.bc
78  //
79  std::string Filename = "bugpoint-" + ID + ".bc";
80  if (writeProgramToFile(Filename)) {
81    cerr <<  "Error opening file '" << Filename << "' for writing!\n";
82    return;
83  }
84
85  cout << "Emitted bytecode to '" << Filename << "'\n";
86  if (NoFlyer || PassesToRun.empty()) return;
87  cout << "\n*** You can reproduce the problem with: ";
88  cout << "opt " << Filename << " ";
89  cout << getPassesString(PassesToRun) << "\n";
90}
91
92int BugDriver::runPassesAsChild(const std::vector<const PassInfo*> &Passes) {
93
94  std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
95                               std::ios::binary;
96  std::ofstream OutFile(ChildOutput.c_str(), io_mode);
97  if (!OutFile.good()) {
98    cerr << "Error opening bytecode file: " << ChildOutput << "\n";
99    return 1;
100  }
101
102  PassManager PM;
103  // Make sure that the appropriate target data is always used...
104  PM.add(new TargetData(Program));
105
106  for (unsigned i = 0, e = Passes.size(); i != e; ++i) {
107    if (Passes[i]->getNormalCtor())
108      PM.add(Passes[i]->getNormalCtor()());
109    else
110      cerr << "Cannot create pass yet: " << Passes[i]->getPassName() << "\n";
111  }
112  // Check that the module is well formed on completion of optimization
113  PM.add(createVerifierPass());
114
115  // Write bytecode out to disk as the last step...
116  OStream L(OutFile);
117  if (Bitcode)
118    PM.add(CreateBitcodeWriterPass(OutFile));
119  else
120    PM.add(new WriteBytecodePass(&L));
121
122  // Run all queued passes.
123  PM.run(*Program);
124
125  return 0;
126}
127
128/// runPasses - Run the specified passes on Program, outputting a bytecode file
129/// and writing the filename into OutputFile if successful.  If the
130/// optimizations fail for some reason (optimizer crashes), return true,
131/// otherwise return false.  If DeleteOutput is set to true, the bytecode is
132/// deleted on success, and the filename string is undefined.  This prints to
133/// cout a single line message indicating whether compilation was successful or
134/// failed.
135///
136bool BugDriver::runPasses(const std::vector<const PassInfo*> &Passes,
137                          std::string &OutputFilename, bool DeleteOutput,
138                          bool Quiet) const {
139  // setup the output file name
140  cout << std::flush;
141  sys::Path uniqueFilename("bugpoint-output.bc");
142  std::string ErrMsg;
143  if (uniqueFilename.makeUnique(true, &ErrMsg)) {
144    cerr << getToolName() << ": Error making unique filename: "
145         << ErrMsg << "\n";
146    return(1);
147  }
148  OutputFilename = uniqueFilename.toString();
149
150  // set up the input file name
151  sys::Path inputFilename("bugpoint-input.bc");
152  if (inputFilename.makeUnique(true, &ErrMsg)) {
153    cerr << getToolName() << ": Error making unique filename: "
154         << ErrMsg << "\n";
155    return(1);
156  }
157  std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
158                               std::ios::binary;
159  std::ofstream InFile(inputFilename.c_str(), io_mode);
160  if (!InFile.good()) {
161    cerr << "Error opening bytecode file: " << inputFilename << "\n";
162    return(1);
163  }
164  OStream L(InFile);
165  WriteBytecodeToFile(Program,L,false);
166  InFile.close();
167
168  // setup the child process' arguments
169  const char** args = (const char**)
170    alloca(sizeof(const char*) *
171	   (Passes.size()+13+2*PluginLoader::getNumPlugins()));
172  int n = 0;
173  sys::Path tool = sys::Program::FindProgramByName(ToolName);
174  if (UseValgrind) {
175    args[n++] = "valgrind";
176    args[n++] = "--error-exitcode=1";
177    args[n++] = "-q";
178    args[n++] = tool.c_str();
179  } else
180    args[n++] = ToolName.c_str();
181
182  args[n++] = "-as-child";
183  args[n++] = "-child-output";
184  args[n++] = OutputFilename.c_str();
185  std::vector<std::string> pass_args;
186  for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
187    pass_args.push_back( std::string("-load"));
188    pass_args.push_back( PluginLoader::getPlugin(i));
189  }
190  for (std::vector<const PassInfo*>::const_iterator I = Passes.begin(),
191       E = Passes.end(); I != E; ++I )
192    pass_args.push_back( std::string("-") + (*I)->getPassArgument() );
193  for (std::vector<std::string>::const_iterator I = pass_args.begin(),
194       E = pass_args.end(); I != E; ++I )
195    args[n++] = I->c_str();
196  args[n++] = inputFilename.c_str();
197  args[n++] = 0;
198
199  sys::Path prog;
200  if (UseValgrind)
201    prog = sys::Program::FindProgramByName("valgrind");
202  else
203    prog = tool;
204  int result = sys::Program::ExecuteAndWait(prog, args, 0, 0,
205                                            Timeout, MemoryLimit, &ErrMsg);
206
207  // If we are supposed to delete the bytecode file or if the passes crashed,
208  // remove it now.  This may fail if the file was never created, but that's ok.
209  if (DeleteOutput || result != 0)
210    sys::Path(OutputFilename).eraseFromDisk();
211
212  // Remove the temporary input file as well
213  inputFilename.eraseFromDisk();
214
215  if (!Quiet) {
216    if (result == 0)
217      cout << "Success!\n";
218    else if (result > 0)
219      cout << "Exited with error code '" << result << "'\n";
220    else if (result < 0) {
221      if (result == -1)
222        cout << "Execute failed: " << ErrMsg << "\n";
223      else
224        cout << "Crashed with signal #" << abs(result) << "\n";
225    }
226    if (result & 0x01000000)
227      cout << "Dumped core\n";
228  }
229
230  // Was the child successful?
231  return result != 0;
232}
233
234
235/// runPassesOn - Carefully run the specified set of pass on the specified
236/// module, returning the transformed module on success, or a null pointer on
237/// failure.
238Module *BugDriver::runPassesOn(Module *M,
239                               const std::vector<const PassInfo*> &Passes,
240                               bool AutoDebugCrashes) {
241  Module *OldProgram = swapProgramIn(M);
242  std::string BytecodeResult;
243  if (runPasses(Passes, BytecodeResult, false/*delete*/, true/*quiet*/)) {
244    if (AutoDebugCrashes) {
245      cerr << " Error running this sequence of passes"
246           << " on the input program!\n";
247      delete OldProgram;
248      EmitProgressBytecode("pass-error",  false);
249      exit(debugOptimizerCrash());
250    }
251    swapProgramIn(OldProgram);
252    return 0;
253  }
254
255  // Restore the current program.
256  swapProgramIn(OldProgram);
257
258  Module *Ret = ParseInputFile(BytecodeResult);
259  if (Ret == 0) {
260    cerr << getToolName() << ": Error reading bytecode file '"
261         << BytecodeResult << "'!\n";
262    exit(1);
263  }
264  sys::Path(BytecodeResult).eraseFromDisk();  // No longer need the file on disk
265  return Ret;
266}
267