OptimizerDriver.cpp revision d4c454317a38d65957edebe62bfc69fc8d9885e8 
1//===- OptimizerDriver.cpp - Allow BugPoint to run passes safely ----------===//
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 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/Bitcode/ReaderWriter.h"
27#include "llvm/Target/TargetData.h"
28#include "llvm/Support/FileUtilities.h"
29#include "llvm/Support/CommandLine.h"
30#include "llvm/Support/SystemUtils.h"
31#include "llvm/Support/Debug.h"
32#include "llvm/Support/raw_ostream.h"
33#include "llvm/System/Path.h"
34#include "llvm/System/Program.h"
35
36#define DONT_GET_PLUGIN_LOADER_OPTION
37#include "llvm/Support/PluginLoader.h"
38
39#include <fstream>
40using namespace llvm;
41
42namespace llvm {
43  extern cl::opt<std::string> OutputPrefix;
44}
45
46namespace {
47  // ChildOutput - This option captures the name of the child output file that
48  // is set up by the parent bugpoint process
49  cl::opt<std::string> ChildOutput("child-output", cl::ReallyHidden);
50}
51
52/// writeProgramToFile - This writes the current "Program" to the named bitcode
53/// file.  If an error occurs, true is returned.
54///
55bool BugDriver::writeProgramToFile(const std::string &Filename,
56                                   const Module *M) const {
57  std::string ErrInfo;
58  tool_output_file Out(Filename.c_str(), ErrInfo,
59                       raw_fd_ostream::F_Binary);
60  if (ErrInfo.empty()) {
61    WriteBitcodeToFile(M, Out.os());
62    Out.os().close();
63    if (!Out.os().has_error()) {
64      Out.keep();
65      return false;
66    }
67  }
68  Out.os().clear_error();
69  return true;
70}
71
72
73/// EmitProgressBitcode - This function is used to output the current Program
74/// to a file named "bugpoint-ID.bc".
75///
76void BugDriver::EmitProgressBitcode(const Module *M,
77                                    const std::string &ID,
78                                    bool NoFlyer)  const {
79  // Output the input to the current pass to a bitcode file, emit a message
80  // telling the user how to reproduce it: opt -foo blah.bc
81  //
82  std::string Filename = OutputPrefix + "-" + ID + ".bc";
83  if (writeProgramToFile(Filename, M)) {
84    errs() <<  "Error opening file '" << Filename << "' for writing!\n";
85    return;
86  }
87
88  outs() << "Emitted bitcode to '" << Filename << "'\n";
89  if (NoFlyer || PassesToRun.empty()) return;
90  outs() << "\n*** You can reproduce the problem with: ";
91  if (UseValgrind) outs() << "valgrind ";
92  outs() << "opt " << Filename << " ";
93  outs() << getPassesString(PassesToRun) << "\n";
94}
95
96cl::opt<bool> SilencePasses("silence-passes", cl::desc("Suppress output of running passes (both stdout and stderr)"));
97
98static cl::list<std::string> OptArgs("opt-args", cl::Positional,
99                                     cl::desc("<opt arguments>..."),
100                                     cl::ZeroOrMore, cl::PositionalEatsArgs);
101
102/// runPasses - Run the specified passes on Program, outputting a bitcode file
103/// and writing the filename into OutputFile if successful.  If the
104/// optimizations fail for some reason (optimizer crashes), return true,
105/// otherwise return false.  If DeleteOutput is set to true, the bitcode is
106/// deleted on success, and the filename string is undefined.  This prints to
107/// outs() a single line message indicating whether compilation was successful
108/// or failed.
109///
110bool BugDriver::runPasses(Module *Program,
111                          const std::vector<std::string> &Passes,
112                          std::string &OutputFilename, bool DeleteOutput,
113                          bool Quiet, unsigned NumExtraArgs,
114                          const char * const *ExtraArgs) const {
115  // setup the output file name
116  outs().flush();
117  sys::Path uniqueFilename(OutputPrefix + "-output.bc");
118  std::string ErrMsg;
119  if (uniqueFilename.makeUnique(true, &ErrMsg)) {
120    errs() << getToolName() << ": Error making unique filename: "
121           << ErrMsg << "\n";
122    return(1);
123  }
124  OutputFilename = uniqueFilename.str();
125
126  // set up the input file name
127  sys::Path inputFilename(OutputPrefix + "-input.bc");
128  if (inputFilename.makeUnique(true, &ErrMsg)) {
129    errs() << getToolName() << ": Error making unique filename: "
130           << ErrMsg << "\n";
131    return(1);
132  }
133
134  std::string ErrInfo;
135  tool_output_file InFile(inputFilename.c_str(), ErrInfo,
136                          raw_fd_ostream::F_Binary);
137
138
139  if (!ErrInfo.empty()) {
140    errs() << "Error opening bitcode file: " << inputFilename.str() << "\n";
141    return 1;
142  }
143  WriteBitcodeToFile(Program, InFile.os());
144  InFile.os().close();
145  if (InFile.os().has_error()) {
146    errs() << "Error writing bitcode file: " << inputFilename.str() << "\n";
147    InFile.os().clear_error();
148    return 1;
149  }
150  InFile.keep();
151
152  // setup the child process' arguments
153  SmallVector<const char*, 8> Args;
154  sys::Path tool = FindExecutable("opt", getToolName(), (void*)"opt");
155  std::string Opt = tool.str();
156  if (UseValgrind) {
157    Args.push_back("valgrind");
158    Args.push_back("--error-exitcode=1");
159    Args.push_back("-q");
160    Args.push_back(tool.c_str());
161  } else
162    Args.push_back(Opt.c_str());
163
164  Args.push_back("-o");
165  Args.push_back(OutputFilename.c_str());
166  for (unsigned i = 0, e = OptArgs.size(); i != e; ++i)
167    Args.push_back(OptArgs[i].c_str());
168  std::vector<std::string> pass_args;
169  for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
170    pass_args.push_back( std::string("-load"));
171    pass_args.push_back( PluginLoader::getPlugin(i));
172  }
173  for (std::vector<std::string>::const_iterator I = Passes.begin(),
174       E = Passes.end(); I != E; ++I )
175    pass_args.push_back( std::string("-") + (*I) );
176  for (std::vector<std::string>::const_iterator I = pass_args.begin(),
177       E = pass_args.end(); I != E; ++I )
178    Args.push_back(I->c_str());
179  Args.push_back(inputFilename.c_str());
180  for (unsigned i = 0; i < NumExtraArgs; ++i)
181    Args.push_back(*ExtraArgs);
182  Args.push_back(0);
183
184  DEBUG(errs() << "\nAbout to run:\t";
185        for (unsigned i = 0, e = Args.size()-1; i != e; ++i)
186          errs() << " " << Args[i];
187        errs() << "\n";
188        );
189
190  sys::Path prog;
191  if (UseValgrind)
192    prog = sys::Program::FindProgramByName("valgrind");
193  else
194    prog = tool;
195
196  // Redirect stdout and stderr to nowhere if SilencePasses is given
197  sys::Path Nowhere;
198  const sys::Path *Redirects[3] = {0, &Nowhere, &Nowhere};
199
200  int result = sys::Program::ExecuteAndWait(prog, Args.data(), 0,
201                                            (SilencePasses ? Redirects : 0),
202                                            Timeout, MemoryLimit, &ErrMsg);
203
204  // If we are supposed to delete the bitcode file or if the passes crashed,
205  // remove it now.  This may fail if the file was never created, but that's ok.
206  if (DeleteOutput || result != 0)
207    sys::Path(OutputFilename).eraseFromDisk();
208
209  // Remove the temporary input file as well
210  inputFilename.eraseFromDisk();
211
212  if (!Quiet) {
213    if (result == 0)
214      outs() << "Success!\n";
215    else if (result > 0)
216      outs() << "Exited with error code '" << result << "'\n";
217    else if (result < 0) {
218      if (result == -1)
219        outs() << "Execute failed: " << ErrMsg << "\n";
220      else
221        outs() << "Crashed with signal #" << abs(result) << "\n";
222    }
223    if (result & 0x01000000)
224      outs() << "Dumped core\n";
225  }
226
227  // Was the child successful?
228  return result != 0;
229}
230
231
232/// runPassesOn - Carefully run the specified set of pass on the specified
233/// module, returning the transformed module on success, or a null pointer on
234/// failure.
235Module *BugDriver::runPassesOn(Module *M,
236                               const std::vector<std::string> &Passes,
237                               bool AutoDebugCrashes, unsigned NumExtraArgs,
238                               const char * const *ExtraArgs) {
239  std::string BitcodeResult;
240  if (runPasses(M, Passes, BitcodeResult, false/*delete*/, true/*quiet*/,
241                NumExtraArgs, ExtraArgs)) {
242    if (AutoDebugCrashes) {
243      errs() << " Error running this sequence of passes"
244             << " on the input program!\n";
245      delete swapProgramIn(M);
246      EmitProgressBitcode(M, "pass-error",  false);
247      exit(debugOptimizerCrash());
248    }
249    return 0;
250  }
251
252  Module *Ret = ParseInputFile(BitcodeResult, Context);
253  if (Ret == 0) {
254    errs() << getToolName() << ": Error reading bitcode file '"
255           << BitcodeResult << "'!\n";
256    exit(1);
257  }
258  sys::Path(BitcodeResult).eraseFromDisk();  // No longer need the file on disk
259  return Ret;
260}
261