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  for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
90    outs() << " -load " << PluginLoader::getPlugin(i);
91  }
92  outs() << " " << getPassesString(PassesToRun) << "\n";
93}
94
95cl::opt<bool> SilencePasses("silence-passes",
96        cl::desc("Suppress output of running passes (both stdout and stderr)"));
97
98static cl::list<std::string> OptArgs("opt-args", cl::Positional,
99                                     cl::desc("<opt arguments>..."),
100                                     cl::ZeroOrMore, cl::PositionalEatsArgs);
101
102/// runPasses - Run the specified passes on Program, outputting a bitcode file
103/// and writing the filename into OutputFile if successful.  If the
104/// optimizations fail for some reason (optimizer crashes), return true,
105/// otherwise return false.  If DeleteOutput is set to true, the bitcode is
106/// deleted on success, and the filename string is undefined.  This prints to
107/// outs() a single line message indicating whether compilation was successful
108/// or failed.
109///
110bool BugDriver::runPasses(Module *Program,
111                          const std::vector<std::string> &Passes,
112                          std::string &OutputFilename, bool DeleteOutput,
113                          bool Quiet, unsigned NumExtraArgs,
114                          const char * const *ExtraArgs) const {
115  // setup the output file name
116  outs().flush();
117  sys::Path uniqueFilename(OutputPrefix + "-output.bc");
118  std::string ErrMsg;
119  if (uniqueFilename.makeUnique(true, &ErrMsg)) {
120    errs() << getToolName() << ": Error making unique filename: "
121           << ErrMsg << "\n";
122    return(1);
123  }
124  OutputFilename = uniqueFilename.str();
125
126  // set up the input file name
127  sys::Path inputFilename(OutputPrefix + "-input.bc");
128  if (inputFilename.makeUnique(true, &ErrMsg)) {
129    errs() << getToolName() << ": Error making unique filename: "
130           << ErrMsg << "\n";
131    return(1);
132  }
133
134  std::string ErrInfo;
135  tool_output_file InFile(inputFilename.c_str(), ErrInfo,
136                          raw_fd_ostream::F_Binary);
137
138
139  if (!ErrInfo.empty()) {
140    errs() << "Error opening bitcode file: " << inputFilename.str() << "\n";
141    return 1;
142  }
143  WriteBitcodeToFile(Program, InFile.os());
144  InFile.os().close();
145  if (InFile.os().has_error()) {
146    errs() << "Error writing bitcode file: " << inputFilename.str() << "\n";
147    InFile.os().clear_error();
148    return 1;
149  }
150
151  sys::Path tool = sys::Program::FindProgramByName("opt");
152  if (tool.empty()) {
153    errs() << "Cannot find `opt' in PATH!\n";
154    return 1;
155  }
156
157  // Ok, everything that could go wrong before running opt is done.
158  InFile.keep();
159
160  // setup the child process' arguments
161  SmallVector<const char*, 8> Args;
162  std::string Opt = tool.str();
163  if (UseValgrind) {
164    Args.push_back("valgrind");
165    Args.push_back("--error-exitcode=1");
166    Args.push_back("-q");
167    Args.push_back(tool.c_str());
168  } else
169    Args.push_back(Opt.c_str());
170
171  Args.push_back("-o");
172  Args.push_back(OutputFilename.c_str());
173  for (unsigned i = 0, e = OptArgs.size(); i != e; ++i)
174    Args.push_back(OptArgs[i].c_str());
175  std::vector<std::string> pass_args;
176  for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
177    pass_args.push_back( std::string("-load"));
178    pass_args.push_back( PluginLoader::getPlugin(i));
179  }
180  for (std::vector<std::string>::const_iterator I = Passes.begin(),
181       E = Passes.end(); I != E; ++I )
182    pass_args.push_back( std::string("-") + (*I) );
183  for (std::vector<std::string>::const_iterator I = pass_args.begin(),
184       E = pass_args.end(); I != E; ++I )
185    Args.push_back(I->c_str());
186  Args.push_back(inputFilename.c_str());
187  for (unsigned i = 0; i < NumExtraArgs; ++i)
188    Args.push_back(*ExtraArgs);
189  Args.push_back(0);
190
191  DEBUG(errs() << "\nAbout to run:\t";
192        for (unsigned i = 0, e = Args.size()-1; i != e; ++i)
193          errs() << " " << Args[i];
194        errs() << "\n";
195        );
196
197  sys::Path prog;
198  if (UseValgrind)
199    prog = sys::Program::FindProgramByName("valgrind");
200  else
201    prog = tool;
202
203  // Redirect stdout and stderr to nowhere if SilencePasses is given
204  sys::Path Nowhere;
205  const sys::Path *Redirects[3] = {0, &Nowhere, &Nowhere};
206
207  int result = sys::Program::ExecuteAndWait(prog, Args.data(), 0,
208                                            (SilencePasses ? Redirects : 0),
209                                            Timeout, MemoryLimit, &ErrMsg);
210
211  // If we are supposed to delete the bitcode file or if the passes crashed,
212  // remove it now.  This may fail if the file was never created, but that's ok.
213  if (DeleteOutput || result != 0)
214    sys::Path(OutputFilename).eraseFromDisk();
215
216  // Remove the temporary input file as well
217  inputFilename.eraseFromDisk();
218
219  if (!Quiet) {
220    if (result == 0)
221      outs() << "Success!\n";
222    else if (result > 0)
223      outs() << "Exited with error code '" << result << "'\n";
224    else if (result < 0) {
225      if (result == -1)
226        outs() << "Execute failed: " << ErrMsg << "\n";
227      else
228        outs() << "Crashed: " << ErrMsg << "\n";
229    }
230    if (result & 0x01000000)
231      outs() << "Dumped core\n";
232  }
233
234  // Was the child successful?
235  return result != 0;
236}
237
238
239/// runPassesOn - Carefully run the specified set of pass on the specified
240/// module, returning the transformed module on success, or a null pointer on
241/// failure.
242Module *BugDriver::runPassesOn(Module *M,
243                               const std::vector<std::string> &Passes,
244                               bool AutoDebugCrashes, unsigned NumExtraArgs,
245                               const char * const *ExtraArgs) {
246  std::string BitcodeResult;
247  if (runPasses(M, Passes, BitcodeResult, false/*delete*/, true/*quiet*/,
248                NumExtraArgs, ExtraArgs)) {
249    if (AutoDebugCrashes) {
250      errs() << " Error running this sequence of passes"
251             << " on the input program!\n";
252      delete swapProgramIn(M);
253      EmitProgressBitcode(M, "pass-error",  false);
254      exit(debugOptimizerCrash());
255    }
256    return 0;
257  }
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