OptimizerDriver.cpp revision 263508 
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  cl::opt<std::string> OptCmd("opt-command", cl::init(""),
48                              cl::desc("Path to opt. (default: search path "
49                                       "for 'opt'.)"));
50}
51
52/// writeProgramToFile - This writes the current "Program" to the named bitcode
53/// file.  If an error occurs, true is returned.
54///
55static bool writeProgramToFileAux(tool_output_file &Out, const Module *M) {
56  WriteBitcodeToFile(M, Out.os());
57  Out.os().close();
58  if (!Out.os().has_error()) {
59    Out.keep();
60    return false;
61  }
62  return true;
63}
64
65bool BugDriver::writeProgramToFile(const std::string &Filename, int FD,
66                                   const Module *M) const {
67  tool_output_file Out(Filename.c_str(), FD);
68  return writeProgramToFileAux(Out, M);
69}
70
71bool BugDriver::writeProgramToFile(const std::string &Filename,
72                                   const Module *M) const {
73  std::string ErrInfo;
74  tool_output_file Out(Filename.c_str(), ErrInfo, sys::fs::F_Binary);
75  if (ErrInfo.empty())
76    return writeProgramToFileAux(Out, M);
77  return true;
78}
79
80
81/// EmitProgressBitcode - This function is used to output the current Program
82/// to a file named "bugpoint-ID.bc".
83///
84void BugDriver::EmitProgressBitcode(const Module *M,
85                                    const std::string &ID,
86                                    bool NoFlyer)  const {
87  // Output the input to the current pass to a bitcode file, emit a message
88  // telling the user how to reproduce it: opt -foo blah.bc
89  //
90  std::string Filename = OutputPrefix + "-" + ID + ".bc";
91  if (writeProgramToFile(Filename, M)) {
92    errs() <<  "Error opening file '" << Filename << "' for writing!\n";
93    return;
94  }
95
96  outs() << "Emitted bitcode to '" << Filename << "'\n";
97  if (NoFlyer || PassesToRun.empty()) return;
98  outs() << "\n*** You can reproduce the problem with: ";
99  if (UseValgrind) outs() << "valgrind ";
100  outs() << "opt " << Filename;
101  for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
102    outs() << " -load " << PluginLoader::getPlugin(i);
103  }
104  outs() << " " << getPassesString(PassesToRun) << "\n";
105}
106
107cl::opt<bool> SilencePasses("silence-passes",
108        cl::desc("Suppress output of running passes (both stdout and stderr)"));
109
110static cl::list<std::string> OptArgs("opt-args", cl::Positional,
111                                     cl::desc("<opt arguments>..."),
112                                     cl::ZeroOrMore, cl::PositionalEatsArgs);
113
114/// runPasses - Run the specified passes on Program, outputting a bitcode file
115/// and writing the filename into OutputFile if successful.  If the
116/// optimizations fail for some reason (optimizer crashes), return true,
117/// otherwise return false.  If DeleteOutput is set to true, the bitcode is
118/// deleted on success, and the filename string is undefined.  This prints to
119/// outs() a single line message indicating whether compilation was successful
120/// or failed.
121///
122bool BugDriver::runPasses(Module *Program,
123                          const std::vector<std::string> &Passes,
124                          std::string &OutputFilename, bool DeleteOutput,
125                          bool Quiet, unsigned NumExtraArgs,
126                          const char * const *ExtraArgs) const {
127  // setup the output file name
128  outs().flush();
129  SmallString<128> UniqueFilename;
130  error_code EC = sys::fs::createUniqueFile(
131      OutputPrefix + "-output-%%%%%%%.bc", UniqueFilename);
132  if (EC) {
133    errs() << getToolName() << ": Error making unique filename: "
134           << EC.message() << "\n";
135    return 1;
136  }
137  OutputFilename = UniqueFilename.str();
138
139  // set up the input file name
140  SmallString<128> InputFilename;
141  int InputFD;
142  EC = sys::fs::createUniqueFile(OutputPrefix + "-input-%%%%%%%.bc", InputFD,
143                                 InputFilename);
144  if (EC) {
145    errs() << getToolName() << ": Error making unique filename: "
146           << EC.message() << "\n";
147    return 1;
148  }
149
150  tool_output_file InFile(InputFilename.c_str(), InputFD);
151
152  WriteBitcodeToFile(Program, InFile.os());
153  InFile.os().close();
154  if (InFile.os().has_error()) {
155    errs() << "Error writing bitcode file: " << InputFilename << "\n";
156    InFile.os().clear_error();
157    return 1;
158  }
159
160  std::string tool = OptCmd.empty()? sys::FindProgramByName("opt") : OptCmd;
161  if (tool.empty()) {
162    errs() << "Cannot find `opt' in PATH!\n";
163    return 1;
164  }
165
166  // Ok, everything that could go wrong before running opt is done.
167  InFile.keep();
168
169  // setup the child process' arguments
170  SmallVector<const char*, 8> Args;
171  if (UseValgrind) {
172    Args.push_back("valgrind");
173    Args.push_back("--error-exitcode=1");
174    Args.push_back("-q");
175    Args.push_back(tool.c_str());
176  } else
177    Args.push_back(tool.c_str());
178
179  Args.push_back("-o");
180  Args.push_back(OutputFilename.c_str());
181  for (unsigned i = 0, e = OptArgs.size(); i != e; ++i)
182    Args.push_back(OptArgs[i].c_str());
183  std::vector<std::string> pass_args;
184  for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
185    pass_args.push_back( std::string("-load"));
186    pass_args.push_back( PluginLoader::getPlugin(i));
187  }
188  for (std::vector<std::string>::const_iterator I = Passes.begin(),
189       E = Passes.end(); I != E; ++I )
190    pass_args.push_back( std::string("-") + (*I) );
191  for (std::vector<std::string>::const_iterator I = pass_args.begin(),
192       E = pass_args.end(); I != E; ++I )
193    Args.push_back(I->c_str());
194  Args.push_back(InputFilename.c_str());
195  for (unsigned i = 0; i < NumExtraArgs; ++i)
196    Args.push_back(*ExtraArgs);
197  Args.push_back(0);
198
199  DEBUG(errs() << "\nAbout to run:\t";
200        for (unsigned i = 0, e = Args.size()-1; i != e; ++i)
201          errs() << " " << Args[i];
202        errs() << "\n";
203        );
204
205  std::string Prog;
206  if (UseValgrind)
207    Prog = sys::FindProgramByName("valgrind");
208  else
209    Prog = tool;
210
211  // Redirect stdout and stderr to nowhere if SilencePasses is given
212  StringRef Nowhere;
213  const StringRef *Redirects[3] = {0, &Nowhere, &Nowhere};
214
215  std::string ErrMsg;
216  int result = sys::ExecuteAndWait(Prog, Args.data(), 0,
217                                   (SilencePasses ? Redirects : 0), Timeout,
218                                   MemoryLimit, &ErrMsg);
219
220  // If we are supposed to delete the bitcode file or if the passes crashed,
221  // remove it now.  This may fail if the file was never created, but that's ok.
222  if (DeleteOutput || result != 0)
223    sys::fs::remove(OutputFilename);
224
225  // Remove the temporary input file as well
226  sys::fs::remove(InputFilename.c_str());
227
228  if (!Quiet) {
229    if (result == 0)
230      outs() << "Success!\n";
231    else if (result > 0)
232      outs() << "Exited with error code '" << result << "'\n";
233    else if (result < 0) {
234      if (result == -1)
235        outs() << "Execute failed: " << ErrMsg << "\n";
236      else
237        outs() << "Crashed: " << ErrMsg << "\n";
238    }
239    if (result & 0x01000000)
240      outs() << "Dumped core\n";
241  }
242
243  // Was the child successful?
244  return result != 0;
245}
246
247
248/// runPassesOn - Carefully run the specified set of pass on the specified
249/// module, returning the transformed module on success, or a null pointer on
250/// failure.
251Module *BugDriver::runPassesOn(Module *M,
252                               const std::vector<std::string> &Passes,
253                               bool AutoDebugCrashes, unsigned NumExtraArgs,
254                               const char * const *ExtraArgs) {
255  std::string BitcodeResult;
256  if (runPasses(M, Passes, BitcodeResult, false/*delete*/, true/*quiet*/,
257                NumExtraArgs, ExtraArgs)) {
258    if (AutoDebugCrashes) {
259      errs() << " Error running this sequence of passes"
260             << " on the input program!\n";
261      delete swapProgramIn(M);
262      EmitProgressBitcode(M, "pass-error",  false);
263      exit(debugOptimizerCrash());
264    }
265    return 0;
266  }
267
268  Module *Ret = ParseInputFile(BitcodeResult, Context);
269  if (Ret == 0) {
270    errs() << getToolName() << ": Error reading bitcode file '"
271           << BitcodeResult << "'!\n";
272    exit(1);
273  }
274  sys::fs::remove(BitcodeResult);
275  return Ret;
276}
277