OptimizerDriver.cpp revision 8ee23f00c7e9343d09313051c318906558d6ad17 
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/Analysis/Verifier.h"
20#include "llvm/Bitcode/ReaderWriter.h"
21#include "llvm/IR/DataLayout.h"
22#include "llvm/IR/Module.h"
23#include "llvm/PassManager.h"
24#include "llvm/Support/CommandLine.h"
25#include "llvm/Support/Debug.h"
26#include "llvm/Support/FileUtilities.h"
27#include "llvm/Support/Path.h"
28#include "llvm/Support/Program.h"
29#include "llvm/Support/SystemUtils.h"
30#include "llvm/Support/ToolOutputFile.h"
31
32#define DONT_GET_PLUGIN_LOADER_OPTION
33#include "llvm/Support/PluginLoader.h"
34
35#include <fstream>
36
37using namespace llvm;
38
39namespace llvm {
40  extern cl::opt<std::string> OutputPrefix;
41}
42
43namespace {
44  // ChildOutput - This option captures the name of the child output file that
45  // is set up by the parent bugpoint process
46  cl::opt<std::string> ChildOutput("child-output", cl::ReallyHidden);
47}
48
49/// writeProgramToFile - This writes the current "Program" to the named bitcode
50/// file.  If an error occurs, true is returned.
51///
52static bool writeProgramToFileAux(tool_output_file &Out, const Module *M) {
53  WriteBitcodeToFile(M, Out.os());
54  Out.os().close();
55  if (!Out.os().has_error()) {
56    Out.keep();
57    return false;
58  }
59  return true;
60}
61
62bool BugDriver::writeProgramToFile(const std::string &Filename, int FD,
63                                   const Module *M) const {
64  tool_output_file Out(Filename.c_str(), FD);
65  return writeProgramToFileAux(Out, M);
66}
67
68bool BugDriver::writeProgramToFile(const std::string &Filename,
69                                   const Module *M) const {
70  std::string ErrInfo;
71  tool_output_file Out(Filename.c_str(), ErrInfo, raw_fd_ostream::F_Binary);
72  if (ErrInfo.empty())
73    return writeProgramToFileAux(Out, M);
74  return true;
75}
76
77
78/// EmitProgressBitcode - This function is used to output the current Program
79/// to a file named "bugpoint-ID.bc".
80///
81void BugDriver::EmitProgressBitcode(const Module *M,
82                                    const std::string &ID,
83                                    bool NoFlyer)  const {
84  // Output the input to the current pass to a bitcode file, emit a message
85  // telling the user how to reproduce it: opt -foo blah.bc
86  //
87  std::string Filename = OutputPrefix + "-" + ID + ".bc";
88  if (writeProgramToFile(Filename, M)) {
89    errs() <<  "Error opening file '" << Filename << "' for writing!\n";
90    return;
91  }
92
93  outs() << "Emitted bitcode to '" << Filename << "'\n";
94  if (NoFlyer || PassesToRun.empty()) return;
95  outs() << "\n*** You can reproduce the problem with: ";
96  if (UseValgrind) outs() << "valgrind ";
97  outs() << "opt " << Filename;
98  for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
99    outs() << " -load " << PluginLoader::getPlugin(i);
100  }
101  outs() << " " << getPassesString(PassesToRun) << "\n";
102}
103
104cl::opt<bool> SilencePasses("silence-passes",
105        cl::desc("Suppress output of running passes (both stdout and stderr)"));
106
107static cl::list<std::string> OptArgs("opt-args", cl::Positional,
108                                     cl::desc("<opt arguments>..."),
109                                     cl::ZeroOrMore, cl::PositionalEatsArgs);
110
111/// runPasses - Run the specified passes on Program, outputting a bitcode file
112/// and writing the filename into OutputFile if successful.  If the
113/// optimizations fail for some reason (optimizer crashes), return true,
114/// otherwise return false.  If DeleteOutput is set to true, the bitcode is
115/// deleted on success, and the filename string is undefined.  This prints to
116/// outs() a single line message indicating whether compilation was successful
117/// or failed.
118///
119bool BugDriver::runPasses(Module *Program,
120                          const std::vector<std::string> &Passes,
121                          std::string &OutputFilename, bool DeleteOutput,
122                          bool Quiet, unsigned NumExtraArgs,
123                          const char * const *ExtraArgs) const {
124  // setup the output file name
125  outs().flush();
126  SmallString<128> UniqueFilename;
127  error_code EC =
128      sys::fs::unique_file(OutputPrefix + "-output-%%%%%%%.bc", UniqueFilename);
129  if (EC) {
130    errs() << getToolName() << ": Error making unique filename: "
131           << EC.message() << "\n";
132    return 1;
133  }
134  OutputFilename = UniqueFilename.str();
135
136  // set up the input file name
137  SmallString<128> InputFilename;
138  int InputFD;
139  EC = sys::fs::unique_file(OutputPrefix + "-input-%%%%%%%.bc", InputFD,
140                            InputFilename);
141  if (EC) {
142    errs() << getToolName() << ": Error making unique filename: "
143           << EC.message() << "\n";
144    return 1;
145  }
146
147  tool_output_file InFile(InputFilename.c_str(), InputFD);
148
149  WriteBitcodeToFile(Program, InFile.os());
150  InFile.os().close();
151  if (InFile.os().has_error()) {
152    errs() << "Error writing bitcode file: " << InputFilename << "\n";
153    InFile.os().clear_error();
154    return 1;
155  }
156
157  std::string tool = sys::FindProgramByName("opt");
158  if (tool.empty()) {
159    errs() << "Cannot find `opt' in PATH!\n";
160    return 1;
161  }
162
163  // Ok, everything that could go wrong before running opt is done.
164  InFile.keep();
165
166  // setup the child process' arguments
167  SmallVector<const char*, 8> Args;
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(tool.c_str());
175
176  Args.push_back("-o");
177  Args.push_back(OutputFilename.c_str());
178  for (unsigned i = 0, e = OptArgs.size(); i != e; ++i)
179    Args.push_back(OptArgs[i].c_str());
180  std::vector<std::string> pass_args;
181  for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
182    pass_args.push_back( std::string("-load"));
183    pass_args.push_back( PluginLoader::getPlugin(i));
184  }
185  for (std::vector<std::string>::const_iterator I = Passes.begin(),
186       E = Passes.end(); I != E; ++I )
187    pass_args.push_back( std::string("-") + (*I) );
188  for (std::vector<std::string>::const_iterator I = pass_args.begin(),
189       E = pass_args.end(); I != E; ++I )
190    Args.push_back(I->c_str());
191  Args.push_back(InputFilename.c_str());
192  for (unsigned i = 0; i < NumExtraArgs; ++i)
193    Args.push_back(*ExtraArgs);
194  Args.push_back(0);
195
196  DEBUG(errs() << "\nAbout to run:\t";
197        for (unsigned i = 0, e = Args.size()-1; i != e; ++i)
198          errs() << " " << Args[i];
199        errs() << "\n";
200        );
201
202  std::string Prog;
203  if (UseValgrind)
204    Prog = sys::FindProgramByName("valgrind");
205  else
206    Prog = tool;
207
208  // Redirect stdout and stderr to nowhere if SilencePasses is given
209  StringRef Nowhere;
210  const StringRef *Redirects[3] = {0, &Nowhere, &Nowhere};
211
212  std::string ErrMsg;
213  int result = sys::ExecuteAndWait(Prog, Args.data(), 0,
214                                   (SilencePasses ? Redirects : 0), Timeout,
215                                   MemoryLimit, &ErrMsg);
216
217  // If we are supposed to delete the bitcode file or if the passes crashed,
218  // remove it now.  This may fail if the file was never created, but that's ok.
219  if (DeleteOutput || result != 0)
220    sys::fs::remove(OutputFilename);
221
222  // Remove the temporary input file as well
223  sys::fs::remove(InputFilename.c_str());
224
225  if (!Quiet) {
226    if (result == 0)
227      outs() << "Success!\n";
228    else if (result > 0)
229      outs() << "Exited with error code '" << result << "'\n";
230    else if (result < 0) {
231      if (result == -1)
232        outs() << "Execute failed: " << ErrMsg << "\n";
233      else
234        outs() << "Crashed: " << ErrMsg << "\n";
235    }
236    if (result & 0x01000000)
237      outs() << "Dumped core\n";
238  }
239
240  // Was the child successful?
241  return result != 0;
242}
243
244
245/// runPassesOn - Carefully run the specified set of pass on the specified
246/// module, returning the transformed module on success, or a null pointer on
247/// failure.
248Module *BugDriver::runPassesOn(Module *M,
249                               const std::vector<std::string> &Passes,
250                               bool AutoDebugCrashes, unsigned NumExtraArgs,
251                               const char * const *ExtraArgs) {
252  std::string BitcodeResult;
253  if (runPasses(M, Passes, BitcodeResult, false/*delete*/, true/*quiet*/,
254                NumExtraArgs, ExtraArgs)) {
255    if (AutoDebugCrashes) {
256      errs() << " Error running this sequence of passes"
257             << " on the input program!\n";
258      delete swapProgramIn(M);
259      EmitProgressBitcode(M, "pass-error",  false);
260      exit(debugOptimizerCrash());
261    }
262    return 0;
263  }
264
265  Module *Ret = ParseInputFile(BitcodeResult, Context);
266  if (Ret == 0) {
267    errs() << getToolName() << ": Error reading bitcode file '"
268           << BitcodeResult << "'!\n";
269    exit(1);
270  }
271  sys::fs::remove(BitcodeResult);
272  return Ret;
273}
274