OptimizerDriver.cpp revision 17be6791b8b22b36850340a44a6f05de5c3cbf85 
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/Target/TargetData.h"
28#include "llvm/Support/FileUtilities.h"
29#include "llvm/Support/CommandLine.h"
30#include "llvm/Support/Streams.h"
31#include "llvm/System/Path.h"
32#include "llvm/System/Program.h"
33#include "llvm/Config/alloca.h"
34
35#define DONT_GET_PLUGIN_LOADER_OPTION
36#include "llvm/Support/PluginLoader.h"
37
38#include <fstream>
39using namespace llvm;
40
41namespace {
42  // ChildOutput - This option captures the name of the child output file that
43  // is set up by the parent bugpoint process
44  cl::opt<std::string> ChildOutput("child-output", cl::ReallyHidden);
45  cl::opt<bool> UseValgrind("enable-valgrind",
46                            cl::desc("Run optimizations through valgrind"));
47}
48
49/// writeProgramToFile - This writes the current "Program" to the named bytecode
50/// file.  If an error occurs, true is returned.
51///
52bool BugDriver::writeProgramToFile(const std::string &Filename,
53                                   Module *M) const {
54  std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
55                               std::ios::binary;
56  std::ofstream Out(Filename.c_str(), io_mode);
57  if (!Out.good()) return true;
58  try {
59    OStream L(Out);
60    WriteBytecodeToFile(M ? M : Program, L, /*compression=*/false);
61  } catch (...) {
62    return true;
63  }
64  return false;
65}
66
67
68/// EmitProgressBytecode - This function is used to output the current Program
69/// to a file named "bugpoint-ID.bc".
70///
71void BugDriver::EmitProgressBytecode(const std::string &ID, bool NoFlyer) {
72  // Output the input to the current pass to a bytecode file, emit a message
73  // telling the user how to reproduce it: opt -foo blah.bc
74  //
75  std::string Filename = "bugpoint-" + ID + ".bc";
76  if (writeProgramToFile(Filename)) {
77    cerr <<  "Error opening file '" << Filename << "' for writing!\n";
78    return;
79  }
80
81  cout << "Emitted bytecode to '" << Filename << "'\n";
82  if (NoFlyer || PassesToRun.empty()) return;
83  cout << "\n*** You can reproduce the problem with: ";
84  cout << "opt " << Filename << " ";
85  cout << getPassesString(PassesToRun) << "\n";
86}
87
88int BugDriver::runPassesAsChild(const std::vector<const PassInfo*> &Passes) {
89
90  std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
91                               std::ios::binary;
92  std::ofstream OutFile(ChildOutput.c_str(), io_mode);
93  if (!OutFile.good()) {
94    cerr << "Error opening bytecode file: " << ChildOutput << "\n";
95    return 1;
96  }
97
98  PassManager PM;
99  // Make sure that the appropriate target data is always used...
100  PM.add(new TargetData(Program));
101
102  for (unsigned i = 0, e = Passes.size(); i != e; ++i) {
103    if (Passes[i]->getNormalCtor())
104      PM.add(Passes[i]->getNormalCtor()());
105    else
106      cerr << "Cannot create pass yet: " << Passes[i]->getPassName() << "\n";
107  }
108  // Check that the module is well formed on completion of optimization
109  PM.add(createVerifierPass());
110
111  // Write bytecode out to disk as the last step...
112  OStream L(OutFile);
113  PM.add(new WriteBytecodePass(&L));
114
115  // Run all queued passes.
116  PM.run(*Program);
117
118  return 0;
119}
120
121/// runPasses - Run the specified passes on Program, outputting a bytecode file
122/// and writing the filename into OutputFile if successful.  If the
123/// optimizations fail for some reason (optimizer crashes), return true,
124/// otherwise return false.  If DeleteOutput is set to true, the bytecode is
125/// deleted on success, and the filename string is undefined.  This prints to
126/// cout a single line message indicating whether compilation was successful or
127/// failed.
128///
129bool BugDriver::runPasses(const std::vector<const PassInfo*> &Passes,
130                          std::string &OutputFilename, bool DeleteOutput,
131                          bool Quiet) const {
132  // setup the output file name
133  cout << std::flush;
134  sys::Path uniqueFilename("bugpoint-output.bc");
135  std::string ErrMsg;
136  if (uniqueFilename.makeUnique(true, &ErrMsg)) {
137    cerr << getToolName() << ": Error making unique filename: "
138         << ErrMsg << "\n";
139    return(1);
140  }
141  OutputFilename = uniqueFilename.toString();
142
143  // set up the input file name
144  sys::Path inputFilename("bugpoint-input.bc");
145  if (inputFilename.makeUnique(true, &ErrMsg)) {
146    cerr << getToolName() << ": Error making unique filename: "
147         << ErrMsg << "\n";
148    return(1);
149  }
150  std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
151                               std::ios::binary;
152  std::ofstream InFile(inputFilename.c_str(), io_mode);
153  if (!InFile.good()) {
154    cerr << "Error opening bytecode file: " << inputFilename << "\n";
155    return(1);
156  }
157  OStream L(InFile);
158  WriteBytecodeToFile(Program,L,false);
159  InFile.close();
160
161  // setup the child process' arguments
162  const char** args = (const char**)
163    alloca(sizeof(const char*) *
164	   (Passes.size()+13+2*PluginLoader::getNumPlugins()));
165  int n = 0;
166  sys::Path tool = sys::Program::FindProgramByName(ToolName);
167  if (UseValgrind) {
168    args[n++] = "valgrind";
169    args[n++] = "--error-exitcode=1";
170    args[n++] = "-q";
171    args[n++] = tool.c_str();
172  } else
173    args[n++] = ToolName.c_str();
174
175  args[n++] = "-as-child";
176  args[n++] = "-child-output";
177  args[n++] = OutputFilename.c_str();
178  std::vector<std::string> pass_args;
179  for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
180    pass_args.push_back( std::string("-load"));
181    pass_args.push_back( PluginLoader::getPlugin(i));
182  }
183  for (std::vector<const PassInfo*>::const_iterator I = Passes.begin(),
184       E = Passes.end(); I != E; ++I )
185    pass_args.push_back( std::string("-") + (*I)->getPassArgument() );
186  for (std::vector<std::string>::const_iterator I = pass_args.begin(),
187       E = pass_args.end(); I != E; ++I )
188    args[n++] = I->c_str();
189  args[n++] = inputFilename.c_str();
190  args[n++] = 0;
191
192  sys::Path prog;
193  if (UseValgrind)
194    prog = sys::Program::FindProgramByName("valgrind");
195  else
196    prog = tool;
197  int result = sys::Program::ExecuteAndWait(prog,args,0,0,Timeout,&ErrMsg);
198
199  // If we are supposed to delete the bytecode file or if the passes crashed,
200  // remove it now.  This may fail if the file was never created, but that's ok.
201  if (DeleteOutput || result != 0)
202    sys::Path(OutputFilename).eraseFromDisk();
203
204  // Remove the temporary input file as well
205  inputFilename.eraseFromDisk();
206
207  if (!Quiet) {
208    if (result == 0)
209      cout << "Success!\n";
210    else if (result > 0)
211      cout << "Exited with error code '" << result << "'\n";
212    else if (result < 0) {
213      if (result == -1)
214        cout << "Execute failed: " << ErrMsg << "\n";
215      else
216        cout << "Crashed with signal #" << abs(result) << "\n";
217    }
218    if (result & 0x01000000)
219      cout << "Dumped core\n";
220  }
221
222  // Was the child successful?
223  return result != 0;
224}
225
226
227/// runPassesOn - Carefully run the specified set of pass on the specified
228/// module, returning the transformed module on success, or a null pointer on
229/// failure.
230Module *BugDriver::runPassesOn(Module *M,
231                               const std::vector<const PassInfo*> &Passes,
232                               bool AutoDebugCrashes) {
233  Module *OldProgram = swapProgramIn(M);
234  std::string BytecodeResult;
235  if (runPasses(Passes, BytecodeResult, false/*delete*/, true/*quiet*/)) {
236    if (AutoDebugCrashes) {
237      cerr << " Error running this sequence of passes"
238           << " on the input program!\n";
239      delete OldProgram;
240      EmitProgressBytecode("pass-error",  false);
241      exit(debugOptimizerCrash());
242    }
243    swapProgramIn(OldProgram);
244    return 0;
245  }
246
247  // Restore the current program.
248  swapProgramIn(OldProgram);
249
250  Module *Ret = ParseInputFile(BytecodeResult);
251  if (Ret == 0) {
252    cerr << getToolName() << ": Error reading bytecode file '"
253         << BytecodeResult << "'!\n";
254    exit(1);
255  }
256  sys::Path(BytecodeResult).eraseFromDisk();  // No longer need the file on disk
257  return Ret;
258}
259