OptimizerDriver.cpp revision b8be03b0e4275eca68f998baab47e66b8a091c05 
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/raw_ostream.h"
31#include "llvm/System/Path.h"
32#include "llvm/System/Program.h"
33
34#define DONT_GET_PLUGIN_LOADER_OPTION
35#include "llvm/Support/PluginLoader.h"
36
37#include <fstream>
38using namespace llvm;
39
40namespace llvm {
41  extern cl::opt<std::string> OutputPrefix;
42}
43
44namespace {
45  // ChildOutput - This option captures the name of the child output file that
46  // is set up by the parent bugpoint process
47  cl::opt<std::string> ChildOutput("child-output", cl::ReallyHidden);
48}
49
50/// writeProgramToFile - This writes the current "Program" to the named bitcode
51/// file.  If an error occurs, true is returned.
52///
53bool BugDriver::writeProgramToFile(const std::string &Filename,
54                                   const Module *M) const {
55  std::string ErrInfo;
56  raw_fd_ostream Out(Filename.c_str(), ErrInfo,
57                     raw_fd_ostream::F_Binary);
58  if (!ErrInfo.empty()) return true;
59
60  WriteBitcodeToFile(M, Out);
61  return false;
62}
63
64
65/// EmitProgressBitcode - This function is used to output the current Program
66/// to a file named "bugpoint-ID.bc".
67///
68void BugDriver::EmitProgressBitcode(const Module *M,
69                                    const std::string &ID,
70                                    bool NoFlyer)  const {
71  // Output the input to the current pass to a bitcode file, emit a message
72  // telling the user how to reproduce it: opt -foo blah.bc
73  //
74  std::string Filename = OutputPrefix + "-" + ID + ".bc";
75  if (writeProgramToFile(Filename, M)) {
76    errs() <<  "Error opening file '" << Filename << "' for writing!\n";
77    return;
78  }
79
80  outs() << "Emitted bitcode to '" << Filename << "'\n";
81  if (NoFlyer || PassesToRun.empty()) return;
82  outs() << "\n*** You can reproduce the problem with: ";
83  if (UseValgrind) outs() << "valgrind ";
84  outs() << "opt " << Filename << " ";
85  outs() << getPassesString(PassesToRun) << "\n";
86}
87
88int BugDriver::runPassesAsChild(const std::vector<const PassInfo*> &Passes) {
89  std::string ErrInfo;
90  raw_fd_ostream OutFile(ChildOutput.c_str(), ErrInfo,
91                         raw_fd_ostream::F_Binary);
92  if (!ErrInfo.empty()) {
93    errs() << "Error opening bitcode file: " << ChildOutput << "\n";
94    return 1;
95  }
96
97  PassManager PM;
98  // Make sure that the appropriate target data is always used...
99  PM.add(new TargetData(Program));
100
101  for (unsigned i = 0, e = Passes.size(); i != e; ++i) {
102    if (Passes[i]->getNormalCtor())
103      PM.add(Passes[i]->getNormalCtor()());
104    else
105      errs() << "Cannot create pass yet: " << Passes[i]->getPassName() << "\n";
106  }
107  // Check that the module is well formed on completion of optimization
108  PM.add(createVerifierPass());
109
110  // Write bitcode out to disk as the last step...
111  PM.add(createBitcodeWriterPass(OutFile));
112
113  // Run all queued passes.
114  PM.run(*Program);
115
116  return 0;
117}
118
119cl::opt<bool> SilencePasses("silence-passes", cl::desc("Suppress output of running passes (both stdout and stderr)"));
120
121/// runPasses - Run the specified passes on Program, outputting a bitcode 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 bitcode is
125/// deleted on success, and the filename string is undefined.  This prints to
126/// outs() a single line message indicating whether compilation was successful
127/// or failed.
128///
129bool BugDriver::runPasses(Module *Program,
130                          const std::vector<const PassInfo*> &Passes,
131                          std::string &OutputFilename, bool DeleteOutput,
132                          bool Quiet, unsigned NumExtraArgs,
133                          const char * const *ExtraArgs) const {
134  // setup the output file name
135  outs().flush();
136  sys::Path uniqueFilename(OutputPrefix + "-output.bc");
137  std::string ErrMsg;
138  if (uniqueFilename.makeUnique(true, &ErrMsg)) {
139    errs() << getToolName() << ": Error making unique filename: "
140           << ErrMsg << "\n";
141    return(1);
142  }
143  OutputFilename = uniqueFilename.str();
144
145  // set up the input file name
146  sys::Path inputFilename(OutputPrefix + "-input.bc");
147  if (inputFilename.makeUnique(true, &ErrMsg)) {
148    errs() << getToolName() << ": Error making unique filename: "
149           << ErrMsg << "\n";
150    return(1);
151  }
152
153  std::string ErrInfo;
154  raw_fd_ostream InFile(inputFilename.c_str(), ErrInfo,
155                        raw_fd_ostream::F_Binary);
156
157
158  if (!ErrInfo.empty()) {
159    errs() << "Error opening bitcode file: " << inputFilename.str() << "\n";
160    return 1;
161  }
162  WriteBitcodeToFile(Program, InFile);
163  InFile.close();
164
165  // setup the child process' arguments
166  SmallVector<const char*, 8> Args;
167  sys::Path tool = sys::Program::FindProgramByName(ToolName);
168  if (UseValgrind) {
169    Args.push_back("valgrind");
170    Args.push_back("--error-exitcode=1");
171    Args.push_back("-q");
172    Args.push_back(tool.c_str());
173  } else
174    Args.push_back(ToolName);
175
176  Args.push_back("-as-child");
177  Args.push_back("-child-output");
178  Args.push_back(OutputFilename.c_str());
179  std::vector<std::string> pass_args;
180  for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
181    pass_args.push_back( std::string("-load"));
182    pass_args.push_back( PluginLoader::getPlugin(i));
183  }
184  for (std::vector<const PassInfo*>::const_iterator I = Passes.begin(),
185       E = Passes.end(); I != E; ++I )
186    pass_args.push_back( std::string("-") + (*I)->getPassArgument() );
187  for (std::vector<std::string>::const_iterator I = pass_args.begin(),
188       E = pass_args.end(); I != E; ++I )
189    Args.push_back(I->c_str());
190  Args.push_back(inputFilename.c_str());
191  for (unsigned i = 0; i < NumExtraArgs; ++i)
192    Args.push_back(*ExtraArgs);
193  Args.push_back(0);
194
195  sys::Path prog;
196  if (UseValgrind)
197    prog = sys::Program::FindProgramByName("valgrind");
198  else
199    prog = tool;
200
201  // Redirect stdout and stderr to nowhere if SilencePasses is given
202  sys::Path Nowhere;
203  const sys::Path *Redirects[3] = {0, &Nowhere, &Nowhere};
204
205  int result = sys::Program::ExecuteAndWait(prog, Args.data(), 0,
206                                            (SilencePasses ? Redirects : 0),
207                                            Timeout, MemoryLimit, &ErrMsg);
208
209  // If we are supposed to delete the bitcode file or if the passes crashed,
210  // remove it now.  This may fail if the file was never created, but that's ok.
211  if (DeleteOutput || result != 0)
212    sys::Path(OutputFilename).eraseFromDisk();
213
214  // Remove the temporary input file as well
215  inputFilename.eraseFromDisk();
216
217  if (!Quiet) {
218    if (result == 0)
219      outs() << "Success!\n";
220    else if (result > 0)
221      outs() << "Exited with error code '" << result << "'\n";
222    else if (result < 0) {
223      if (result == -1)
224        outs() << "Execute failed: " << ErrMsg << "\n";
225      else
226        outs() << "Crashed with signal #" << abs(result) << "\n";
227    }
228    if (result & 0x01000000)
229      outs() << "Dumped core\n";
230  }
231
232  // Was the child successful?
233  return result != 0;
234}
235
236
237/// runPassesOn - Carefully run the specified set of pass on the specified
238/// module, returning the transformed module on success, or a null pointer on
239/// failure.
240Module *BugDriver::runPassesOn(Module *M,
241                               const std::vector<const PassInfo*> &Passes,
242                               bool AutoDebugCrashes, unsigned NumExtraArgs,
243                               const char * const *ExtraArgs) {
244  std::string BitcodeResult;
245  if (runPasses(M, Passes, BitcodeResult, false/*delete*/, true/*quiet*/,
246                NumExtraArgs, ExtraArgs)) {
247    if (AutoDebugCrashes) {
248      errs() << " Error running this sequence of passes"
249             << " on the input program!\n";
250      delete swapProgramIn(M);
251      EmitProgressBitcode(M, "pass-error",  false);
252      exit(debugOptimizerCrash());
253    }
254    return 0;
255  }
256
257  Module *Ret = ParseInputFile(BitcodeResult, Context);
258  if (Ret == 0) {
259    errs() << getToolName() << ": Error reading bitcode file '"
260           << BitcodeResult << "'!\n";
261    exit(1);
262  }
263  sys::Path(BitcodeResult).eraseFromDisk();  // No longer need the file on disk
264  return Ret;
265}
266