OptimizerDriver.cpp revision ca005120082385026fd80fe76946fc446d3c9d33 
1//===- OptimizerDriver.cpp - Allow BugPoint to run passes safely ----------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by the LLVM research group and is distributed under
6// the University of Illinois Open Source 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/PassManager.h"
20#include "llvm/Analysis/Verifier.h"
21#include "llvm/Bytecode/WriteBytecodePass.h"
22#include "llvm/Target/TargetData.h"
23#include "Support/FileUtilities.h"
24#include <fstream>
25#include <unistd.h>
26#include <sys/types.h>
27#include <sys/wait.h>
28using namespace llvm;
29
30/// writeProgramToFile - This writes the current "Program" to the named bytecode
31/// file.  If an error occurs, true is returned.
32///
33bool BugDriver::writeProgramToFile(const std::string &Filename,
34				   Module *M) const {
35  std::ofstream Out(Filename.c_str());
36  if (!Out.good()) return true;
37  WriteBytecodeToFile(M ? M : Program, Out);
38  return false;
39}
40
41
42/// EmitProgressBytecode - This function is used to output the current Program
43/// to a file named "bugpoint-ID.bc".
44///
45void BugDriver::EmitProgressBytecode(const std::string &ID, bool NoFlyer) {
46  // Output the input to the current pass to a bytecode file, emit a message
47  // telling the user how to reproduce it: opt -foo blah.bc
48  //
49  std::string Filename = "bugpoint-" + ID + ".bc";
50  if (writeProgramToFile(Filename)) {
51    std::cerr <<  "Error opening file '" << Filename << "' for writing!\n";
52    return;
53  }
54
55  std::cout << "Emitted bytecode to '" << Filename << "'\n";
56  if (NoFlyer || PassesToRun.empty()) return;
57  std::cout << "\n*** You can reproduce the problem with: ";
58
59  unsigned PassType = PassesToRun[0]->getPassType();
60  for (unsigned i = 1, e = PassesToRun.size(); i != e; ++i)
61    PassType &= PassesToRun[i]->getPassType();
62
63  if (PassType & PassInfo::Analysis)
64    std::cout << "analyze";
65  else if (PassType & PassInfo::Optimization)
66    std::cout << "opt";
67  else if (PassType & PassInfo::LLC)
68    std::cout << "llc";
69  else
70    std::cout << "bugpoint";
71  std::cout << " " << Filename << " ";
72  std::cout << getPassesString(PassesToRun) << "\n";
73}
74
75static void RunChild(Module *Program,const std::vector<const PassInfo*> &Passes,
76                     const std::string &OutFilename) {
77  std::ofstream OutFile(OutFilename.c_str());
78  if (!OutFile.good()) {
79    std::cerr << "Error opening bytecode file: " << OutFilename << "\n";
80    exit(1);
81  }
82
83  PassManager PM;
84  // Make sure that the appropriate target data is always used...
85  PM.add(new TargetData("bugpoint", Program));
86
87  for (unsigned i = 0, e = Passes.size(); i != e; ++i) {
88    if (Passes[i]->getNormalCtor())
89      PM.add(Passes[i]->getNormalCtor()());
90    else
91      std::cerr << "Cannot create pass yet: " << Passes[i]->getPassName()
92                << "\n";
93  }
94  // Check that the module is well formed on completion of optimization
95  PM.add(createVerifierPass());
96
97  // Write bytecode out to disk as the last step...
98  PM.add(new WriteBytecodePass(&OutFile));
99
100  // Run all queued passes.
101  PM.run(*Program);
102}
103
104/// runPasses - Run the specified passes on Program, outputting a bytecode file
105/// and writing the filename into OutputFile if successful.  If the
106/// optimizations fail for some reason (optimizer crashes), return true,
107/// otherwise return false.  If DeleteOutput is set to true, the bytecode is
108/// deleted on success, and the filename string is undefined.  This prints to
109/// cout a single line message indicating whether compilation was successful or
110/// failed.
111///
112bool BugDriver::runPasses(const std::vector<const PassInfo*> &Passes,
113                          std::string &OutputFilename, bool DeleteOutput,
114			  bool Quiet) const{
115  std::cout << std::flush;
116  OutputFilename = getUniqueFilename("bugpoint-output.bc");
117
118  pid_t child_pid;
119  switch (child_pid = fork()) {
120  case -1:    // Error occurred
121    std::cerr << ToolName << ": Error forking!\n";
122    exit(1);
123  case 0:     // Child process runs passes.
124    RunChild(Program, Passes, OutputFilename);
125    exit(0);  // If we finish successfully, return 0!
126  default:    // Parent continues...
127    break;
128  }
129
130  // Wait for the child process to get done.
131  int Status;
132  if (wait(&Status) != child_pid) {
133    std::cerr << "Error waiting for child process!\n";
134    exit(1);
135  }
136
137  // If we are supposed to delete the bytecode file, remove it now
138  // unconditionally...  this may fail if the file was never created, but that's
139  // ok.
140  if (DeleteOutput)
141    removeFile(OutputFilename);
142
143  bool ExitedOK = WIFEXITED(Status) && WEXITSTATUS(Status) == 0;
144
145  if (!Quiet) {
146    if (ExitedOK)
147      std::cout << "Success!\n";
148    else if (WIFEXITED(Status))
149      std::cout << "Exited with error code '" << WEXITSTATUS(Status) << "'\n";
150    else if (WIFSIGNALED(Status))
151      std::cout << "Crashed with signal #" << WTERMSIG(Status) << "\n";
152#ifdef WCOREDUMP
153    else if (WCOREDUMP(Status))
154      std::cout << "Dumped core\n";
155#endif
156    else
157      std::cout << "Failed for unknown reason!\n";
158  }
159
160  // Was the child successful?
161  return !ExitedOK;
162}
163
164