OptimizerDriver.cpp revision e8a469cdb400249ec263c79d1021f953f42f2760 
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                                   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 ? M : Program, 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 std::string &ID, bool NoFlyer) {
69  // Output the input to the current pass to a bitcode file, emit a message
70  // telling the user how to reproduce it: opt -foo blah.bc
71  //
72  std::string Filename = OutputPrefix + "-" + ID + ".bc";
73  if (writeProgramToFile(Filename)) {
74    errs() <<  "Error opening file '" << Filename << "' for writing!\n";
75    return;
76  }
77
78  outs() << "Emitted bitcode to '" << Filename << "'\n";
79  if (NoFlyer || PassesToRun.empty()) return;
80  outs() << "\n*** You can reproduce the problem with: ";
81  if (UseValgrind) outs() << "valgrind ";
82  outs() << "opt " << Filename << " ";
83  outs() << getPassesString(PassesToRun) << "\n";
84}
85
86int BugDriver::runPassesAsChild(const std::vector<const PassInfo*> &Passes) {
87  std::string ErrInfo;
88  raw_fd_ostream OutFile(ChildOutput.c_str(), ErrInfo,
89                         raw_fd_ostream::F_Binary);
90  if (!ErrInfo.empty()) {
91    errs() << "Error opening bitcode file: " << ChildOutput << "\n";
92    return 1;
93  }
94
95  PassManager PM;
96  // Make sure that the appropriate target data is always used...
97  PM.add(new TargetData(Program));
98
99  for (unsigned i = 0, e = Passes.size(); i != e; ++i) {
100    if (Passes[i]->getNormalCtor())
101      PM.add(Passes[i]->getNormalCtor()());
102    else
103      errs() << "Cannot create pass yet: " << Passes[i]->getPassName() << "\n";
104  }
105  // Check that the module is well formed on completion of optimization
106  PM.add(createVerifierPass());
107
108  // Write bitcode out to disk as the last step...
109  PM.add(createBitcodeWriterPass(OutFile));
110
111  // Run all queued passes.
112  PM.run(*Program);
113
114  return 0;
115}
116
117cl::opt<bool> SilencePasses("silence-passes", cl::desc("Suppress output of running passes (both stdout and stderr)"));
118
119/// runPasses - Run the specified passes on Program, outputting a bitcode file
120/// and writing the filename into OutputFile if successful.  If the
121/// optimizations fail for some reason (optimizer crashes), return true,
122/// otherwise return false.  If DeleteOutput is set to true, the bitcode is
123/// deleted on success, and the filename string is undefined.  This prints to
124/// outs() a single line message indicating whether compilation was successful
125/// or failed.
126///
127bool BugDriver::runPasses(const std::vector<const PassInfo*> &Passes,
128                          std::string &OutputFilename, bool DeleteOutput,
129                          bool Quiet, unsigned NumExtraArgs,
130                          const char * const *ExtraArgs) const {
131  // setup the output file name
132  outs().flush();
133  sys::Path uniqueFilename(OutputPrefix + "-output.bc");
134  std::string ErrMsg;
135  if (uniqueFilename.makeUnique(true, &ErrMsg)) {
136    errs() << getToolName() << ": Error making unique filename: "
137           << ErrMsg << "\n";
138    return(1);
139  }
140  OutputFilename = uniqueFilename.str();
141
142  // set up the input file name
143  sys::Path inputFilename(OutputPrefix + "-input.bc");
144  if (inputFilename.makeUnique(true, &ErrMsg)) {
145    errs() << getToolName() << ": Error making unique filename: "
146           << ErrMsg << "\n";
147    return(1);
148  }
149
150  std::string ErrInfo;
151  raw_fd_ostream InFile(inputFilename.c_str(), ErrInfo,
152                        raw_fd_ostream::F_Binary);
153
154
155  if (!ErrInfo.empty()) {
156    errs() << "Error opening bitcode file: " << inputFilename.str() << "\n";
157    return 1;
158  }
159  WriteBitcodeToFile(Program, InFile);
160  InFile.close();
161
162  // setup the child process' arguments
163  SmallVector<const char*, 8> Args;
164  sys::Path tool = sys::Program::FindProgramByName(ToolName);
165  if (UseValgrind) {
166    Args.push_back("valgrind");
167    Args.push_back("--error-exitcode=1");
168    Args.push_back("-q");
169    Args.push_back(tool.c_str());
170  } else
171    Args.push_back(ToolName);
172
173  Args.push_back("-as-child");
174  Args.push_back("-child-output");
175  Args.push_back(OutputFilename.c_str());
176  std::vector<std::string> pass_args;
177  for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
178    pass_args.push_back( std::string("-load"));
179    pass_args.push_back( PluginLoader::getPlugin(i));
180  }
181  for (std::vector<const PassInfo*>::const_iterator I = Passes.begin(),
182       E = Passes.end(); I != E; ++I )
183    pass_args.push_back( std::string("-") + (*I)->getPassArgument() );
184  for (std::vector<std::string>::const_iterator I = pass_args.begin(),
185       E = pass_args.end(); I != E; ++I )
186    Args.push_back(I->c_str());
187  Args.push_back(inputFilename.c_str());
188  for (unsigned i = 0; i < NumExtraArgs; ++i)
189    Args.push_back(*ExtraArgs);
190  Args.push_back(0);
191
192  sys::Path prog;
193  if (UseValgrind)
194    prog = sys::Program::FindProgramByName("valgrind");
195  else
196    prog = tool;
197
198  // Redirect stdout and stderr to nowhere if SilencePasses is given
199  sys::Path Nowhere;
200  const sys::Path *Redirects[3] = {0, &Nowhere, &Nowhere};
201
202  int result = sys::Program::ExecuteAndWait(prog, Args.data(), 0,
203                                            (SilencePasses ? Redirects : 0),
204                                            Timeout, MemoryLimit, &ErrMsg);
205
206  // If we are supposed to delete the bitcode file or if the passes crashed,
207  // remove it now.  This may fail if the file was never created, but that's ok.
208  if (DeleteOutput || result != 0)
209    sys::Path(OutputFilename).eraseFromDisk();
210
211  // Remove the temporary input file as well
212  inputFilename.eraseFromDisk();
213
214  if (!Quiet) {
215    if (result == 0)
216      outs() << "Success!\n";
217    else if (result > 0)
218      outs() << "Exited with error code '" << result << "'\n";
219    else if (result < 0) {
220      if (result == -1)
221        outs() << "Execute failed: " << ErrMsg << "\n";
222      else
223        outs() << "Crashed with signal #" << abs(result) << "\n";
224    }
225    if (result & 0x01000000)
226      outs() << "Dumped core\n";
227  }
228
229  // Was the child successful?
230  return result != 0;
231}
232
233
234/// runPassesOn - Carefully run the specified set of pass on the specified
235/// module, returning the transformed module on success, or a null pointer on
236/// failure.
237Module *BugDriver::runPassesOn(Module *M,
238                               const std::vector<const PassInfo*> &Passes,
239                               bool AutoDebugCrashes, unsigned NumExtraArgs,
240                               const char * const *ExtraArgs) {
241  Module *OldProgram = swapProgramIn(M);
242  std::string BitcodeResult;
243  if (runPasses(Passes, BitcodeResult, false/*delete*/, true/*quiet*/,
244                NumExtraArgs, ExtraArgs)) {
245    if (AutoDebugCrashes) {
246      errs() << " Error running this sequence of passes"
247             << " on the input program!\n";
248      delete OldProgram;
249      EmitProgressBitcode("pass-error",  false);
250      exit(debugOptimizerCrash());
251    }
252    swapProgramIn(OldProgram);
253    return 0;
254  }
255
256  // Restore the current program.
257  swapProgramIn(OldProgram);
258
259  Module *Ret = ParseInputFile(BitcodeResult, Context);
260  if (Ret == 0) {
261    errs() << getToolName() << ": Error reading bitcode file '"
262           << BitcodeResult << "'!\n";
263    exit(1);
264  }
265  sys::Path(BitcodeResult).eraseFromDisk();  // No longer need the file on disk
266  return Ret;
267}
268