OptimizerDriver.cpp revision 218885 
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#include "BugDriver.h"
19#include "llvm/Module.h"
20#include "llvm/PassManager.h"
21#include "llvm/Analysis/Verifier.h"
22#include "llvm/Bitcode/ReaderWriter.h"
23#include "llvm/Target/TargetData.h"
24#include "llvm/Support/FileUtilities.h"
25#include "llvm/Support/CommandLine.h"
26#include "llvm/Support/SystemUtils.h"
27#include "llvm/Support/Debug.h"
28#include "llvm/Support/ToolOutputFile.h"
29#include "llvm/Support/Path.h"
30#include "llvm/Support/Program.h"
31
32#define DONT_GET_PLUGIN_LOADER_OPTION
33#include "llvm/Support/PluginLoader.h"
34
35#include <fstream>
36using namespace llvm;
37
38namespace llvm {
39  extern cl::opt<std::string> OutputPrefix;
40}
41
42namespace {
43  // ChildOutput - This option captures the name of the child output file that
44  // is set up by the parent bugpoint process
45  cl::opt<std::string> ChildOutput("child-output", cl::ReallyHidden);
46}
47
48/// writeProgramToFile - This writes the current "Program" to the named bitcode
49/// file.  If an error occurs, true is returned.
50///
51bool BugDriver::writeProgramToFile(const std::string &Filename,
52                                   const Module *M) const {
53  std::string ErrInfo;
54  tool_output_file Out(Filename.c_str(), ErrInfo,
55                       raw_fd_ostream::F_Binary);
56  if (ErrInfo.empty()) {
57    WriteBitcodeToFile(M, Out.os());
58    Out.os().close();
59    if (!Out.os().has_error()) {
60      Out.keep();
61      return false;
62    }
63  }
64  Out.os().clear_error();
65  return true;
66}
67
68
69/// EmitProgressBitcode - This function is used to output the current Program
70/// to a file named "bugpoint-ID.bc".
71///
72void BugDriver::EmitProgressBitcode(const Module *M,
73                                    const std::string &ID,
74                                    bool NoFlyer)  const {
75  // Output the input to the current pass to a bitcode file, emit a message
76  // telling the user how to reproduce it: opt -foo blah.bc
77  //
78  std::string Filename = OutputPrefix + "-" + ID + ".bc";
79  if (writeProgramToFile(Filename, M)) {
80    errs() <<  "Error opening file '" << Filename << "' for writing!\n";
81    return;
82  }
83
84  outs() << "Emitted bitcode to '" << Filename << "'\n";
85  if (NoFlyer || PassesToRun.empty()) return;
86  outs() << "\n*** You can reproduce the problem with: ";
87  if (UseValgrind) outs() << "valgrind ";
88  outs() << "opt " << Filename << " ";
89  outs() << getPassesString(PassesToRun) << "\n";
90}
91
92cl::opt<bool> SilencePasses("silence-passes", cl::desc("Suppress output of running passes (both stdout and stderr)"));
93
94static cl::list<std::string> OptArgs("opt-args", cl::Positional,
95                                     cl::desc("<opt arguments>..."),
96                                     cl::ZeroOrMore, cl::PositionalEatsArgs);
97
98/// runPasses - Run the specified passes on Program, outputting a bitcode file
99/// and writing the filename into OutputFile if successful.  If the
100/// optimizations fail for some reason (optimizer crashes), return true,
101/// otherwise return false.  If DeleteOutput is set to true, the bitcode is
102/// deleted on success, and the filename string is undefined.  This prints to
103/// outs() a single line message indicating whether compilation was successful
104/// or failed.
105///
106bool BugDriver::runPasses(Module *Program,
107                          const std::vector<std::string> &Passes,
108                          std::string &OutputFilename, bool DeleteOutput,
109                          bool Quiet, unsigned NumExtraArgs,
110                          const char * const *ExtraArgs) const {
111  // setup the output file name
112  outs().flush();
113  sys::Path uniqueFilename(OutputPrefix + "-output.bc");
114  std::string ErrMsg;
115  if (uniqueFilename.makeUnique(true, &ErrMsg)) {
116    errs() << getToolName() << ": Error making unique filename: "
117           << ErrMsg << "\n";
118    return(1);
119  }
120  OutputFilename = uniqueFilename.str();
121
122  // set up the input file name
123  sys::Path inputFilename(OutputPrefix + "-input.bc");
124  if (inputFilename.makeUnique(true, &ErrMsg)) {
125    errs() << getToolName() << ": Error making unique filename: "
126           << ErrMsg << "\n";
127    return(1);
128  }
129
130  std::string ErrInfo;
131  tool_output_file InFile(inputFilename.c_str(), ErrInfo,
132                          raw_fd_ostream::F_Binary);
133
134
135  if (!ErrInfo.empty()) {
136    errs() << "Error opening bitcode file: " << inputFilename.str() << "\n";
137    return 1;
138  }
139  WriteBitcodeToFile(Program, InFile.os());
140  InFile.os().close();
141  if (InFile.os().has_error()) {
142    errs() << "Error writing bitcode file: " << inputFilename.str() << "\n";
143    InFile.os().clear_error();
144    return 1;
145  }
146
147  sys::Path tool = PrependMainExecutablePath("opt", getToolName(),
148                                             (void*)"opt");
149  if (tool.empty()) {
150    errs() << "Cannot find `opt' in executable directory!\n";
151    return 1;
152  }
153
154  // Ok, everything that could go wrong before running opt is done.
155  InFile.keep();
156
157  // setup the child process' arguments
158  SmallVector<const char*, 8> Args;
159  std::string Opt = tool.str();
160  if (UseValgrind) {
161    Args.push_back("valgrind");
162    Args.push_back("--error-exitcode=1");
163    Args.push_back("-q");
164    Args.push_back(tool.c_str());
165  } else
166    Args.push_back(Opt.c_str());
167
168  Args.push_back("-o");
169  Args.push_back(OutputFilename.c_str());
170  for (unsigned i = 0, e = OptArgs.size(); i != e; ++i)
171    Args.push_back(OptArgs[i].c_str());
172  std::vector<std::string> pass_args;
173  for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
174    pass_args.push_back( std::string("-load"));
175    pass_args.push_back( PluginLoader::getPlugin(i));
176  }
177  for (std::vector<std::string>::const_iterator I = Passes.begin(),
178       E = Passes.end(); I != E; ++I )
179    pass_args.push_back( std::string("-") + (*I) );
180  for (std::vector<std::string>::const_iterator I = pass_args.begin(),
181       E = pass_args.end(); I != E; ++I )
182    Args.push_back(I->c_str());
183  Args.push_back(inputFilename.c_str());
184  for (unsigned i = 0; i < NumExtraArgs; ++i)
185    Args.push_back(*ExtraArgs);
186  Args.push_back(0);
187
188  DEBUG(errs() << "\nAbout to run:\t";
189        for (unsigned i = 0, e = Args.size()-1; i != e; ++i)
190          errs() << " " << Args[i];
191        errs() << "\n";
192        );
193
194  sys::Path prog;
195  if (UseValgrind)
196    prog = sys::Program::FindProgramByName("valgrind");
197  else
198    prog = tool;
199
200  // Redirect stdout and stderr to nowhere if SilencePasses is given
201  sys::Path Nowhere;
202  const sys::Path *Redirects[3] = {0, &Nowhere, &Nowhere};
203
204  int result = sys::Program::ExecuteAndWait(prog, Args.data(), 0,
205                                            (SilencePasses ? Redirects : 0),
206                                            Timeout, MemoryLimit, &ErrMsg);
207
208  // If we are supposed to delete the bitcode file or if the passes crashed,
209  // remove it now.  This may fail if the file was never created, but that's ok.
210  if (DeleteOutput || result != 0)
211    sys::Path(OutputFilename).eraseFromDisk();
212
213  // Remove the temporary input file as well
214  inputFilename.eraseFromDisk();
215
216  if (!Quiet) {
217    if (result == 0)
218      outs() << "Success!\n";
219    else if (result > 0)
220      outs() << "Exited with error code '" << result << "'\n";
221    else if (result < 0) {
222      if (result == -1)
223        outs() << "Execute failed: " << ErrMsg << "\n";
224      else
225        outs() << "Crashed with signal #" << abs(result) << "\n";
226    }
227    if (result & 0x01000000)
228      outs() << "Dumped core\n";
229  }
230
231  // Was the child successful?
232  return result != 0;
233}
234
235
236/// runPassesOn - Carefully run the specified set of pass on the specified
237/// module, returning the transformed module on success, or a null pointer on
238/// failure.
239Module *BugDriver::runPassesOn(Module *M,
240                               const std::vector<std::string> &Passes,
241                               bool AutoDebugCrashes, unsigned NumExtraArgs,
242                               const char * const *ExtraArgs) {
243  std::string BitcodeResult;
244  if (runPasses(M, Passes, BitcodeResult, false/*delete*/, true/*quiet*/,
245                NumExtraArgs, ExtraArgs)) {
246    if (AutoDebugCrashes) {
247      errs() << " Error running this sequence of passes"
248             << " on the input program!\n";
249      delete swapProgramIn(M);
250      EmitProgressBitcode(M, "pass-error",  false);
251      exit(debugOptimizerCrash());
252    }
253    return 0;
254  }
255
256  Module *Ret = ParseInputFile(BitcodeResult, Context);
257  if (Ret == 0) {
258    errs() << getToolName() << ": Error reading bitcode file '"
259           << BitcodeResult << "'!\n";
260    exit(1);
261  }
262  sys::Path(BitcodeResult).eraseFromDisk();  // No longer need the file on disk
263  return Ret;
264}
265