OptimizerDriver.cpp revision 24271cf8d78ee4ad181ac0168cf7c2590d40502e 
1//===- OptimizerDriver.cpp - Allow BugPoint to run passes safely ----------===//
2//
3// This file defines an interface that allows bugpoint to run various passes
4// without the threat of a buggy pass corrupting bugpoint (of course bugpoint
5// may have it's own bugs, but that's another story...).  It acheives this by
6// forking a copy of itself and having the child process do the optimizations.
7// If this client dies, we can always fork a new one.  :)
8//
9//===----------------------------------------------------------------------===//
10
11#include "BugDriver.h"
12#include "SystemUtils.h"
13#include "llvm/PassManager.h"
14#include "llvm/Analysis/Verifier.h"
15#include "llvm/Bytecode/WriteBytecodePass.h"
16#include "llvm/Target/TargetData.h"
17#include <sys/types.h>
18#include <sys/wait.h>
19#include <unistd.h>
20#include <stdlib.h>
21#include <fstream>
22
23/// writeProgramToFile - This writes the current "Program" to the named bytecode
24/// file.  If an error occurs, true is returned.
25///
26bool BugDriver::writeProgramToFile(const std::string &Filename,
27				   Module *M) const {
28  std::ofstream Out(Filename.c_str());
29  if (!Out.good()) return true;
30  WriteBytecodeToFile(M ? M : Program, Out);
31  return false;
32}
33
34
35/// EmitProgressBytecode - This function is used to output the current Program
36/// to a file named "bugpoing-ID.bc".
37///
38void BugDriver::EmitProgressBytecode(const std::string &ID, bool NoFlyer) {
39  // Output the input to the current pass to a bytecode file, emit a message
40  // telling the user how to reproduce it: opt -foo blah.bc
41  //
42  std::string Filename = "bugpoint-" + ID + ".bc";
43  if (writeProgramToFile(Filename)) {
44    std::cerr <<  "Error opening file '" << Filename << "' for writing!\n";
45    return;
46  }
47
48  std::cout << "Emitted bytecode to '" << Filename << "'\n";
49  if (NoFlyer) return;
50  std::cout << "\n*** You can reproduce the problem with: ";
51
52  unsigned PassType = PassesToRun[0]->getPassType();
53  for (unsigned i = 1, e = PassesToRun.size(); i != e; ++i)
54    PassType &= PassesToRun[i]->getPassType();
55
56  if (PassType & PassInfo::Analysis)
57    std::cout << "analyze";
58  else if (PassType & PassInfo::Optimization)
59    std::cout << "opt";
60  else if (PassType & PassInfo::LLC)
61    std::cout << "llc";
62  else
63    std::cout << "bugpoint";
64  std::cout << " " << Filename << " ";
65  std::cout << getPassesString(PassesToRun) << "\n";
66}
67
68static void RunChild(Module *Program,const std::vector<const PassInfo*> &Passes,
69                     const std::string &OutFilename) {
70  std::ofstream OutFile(OutFilename.c_str());
71  if (!OutFile.good()) {
72    std::cerr << "Error opening bytecode file: " << OutFilename << "\n";
73    exit(1);
74  }
75
76  PassManager PM;
77  // Make sure that the appropriate target data is always used...
78  PM.add(new TargetData("bugpoint", Program));
79
80  for (unsigned i = 0, e = Passes.size(); i != e; ++i) {
81    if (Passes[i]->getNormalCtor())
82      PM.add(Passes[i]->getNormalCtor()());
83    else
84      std::cerr << "Cannot create pass yet: " << Passes[i]->getPassName()
85                << "\n";
86  }
87  // Check that the module is well formed on completion of optimization
88  PM.add(createVerifierPass());
89
90  // Write bytecode out to disk as the last step...
91  PM.add(new WriteBytecodePass(&OutFile));
92
93  // Run all queued passes.
94  PM.run(*Program);
95}
96
97/// runPasses - Run the specified passes on Program, outputting a bytecode file
98/// and writting the filename into OutputFile if successful.  If the
99/// optimizations fail for some reason (optimizer crashes), return true,
100/// otherwise return false.  If DeleteOutput is set to true, the bytecode is
101/// deleted on success, and the filename string is undefined.  This prints to
102/// cout a single line message indicating whether compilation was successful or
103/// failed.
104///
105bool BugDriver::runPasses(const std::vector<const PassInfo*> &Passes,
106                          std::string &OutputFilename, bool DeleteOutput,
107			  bool Quiet) const{
108  std::cout << std::flush;
109  OutputFilename = getUniqueFilename("bugpoint-output.bc");
110
111  pid_t child_pid;
112  switch (child_pid = fork()) {
113  case -1:    // Error occurred
114    std::cerr << ToolName << ": Error forking!\n";
115    exit(1);
116  case 0:     // Child process runs passes.
117    RunChild(Program, Passes, OutputFilename);
118    exit(0);  // If we finish successfully, return 0!
119  default:    // Parent continues...
120    break;
121  }
122
123  // Wait for the child process to get done.
124  int Status;
125  if (wait(&Status) != child_pid) {
126    std::cerr << "Error waiting for child process!\n";
127    exit(1);
128  }
129
130  // If we are supposed to delete the bytecode file, remove it now
131  // unconditionally...  this may fail if the file was never created, but that's
132  // ok.
133  if (DeleteOutput)
134    removeFile(OutputFilename);
135
136  bool ExitedOK = WIFEXITED(Status) && WEXITSTATUS(Status) == 0;
137
138  if (!Quiet) {
139    if (ExitedOK)
140      std::cout << "Success!\n";
141    else if (WIFEXITED(Status))
142      std::cout << "Exited with error code '" << WEXITSTATUS(Status) << "'\n";
143    else if (WIFSIGNALED(Status))
144      std::cout << "Crashed with signal #" << WTERMSIG(Status) << "\n";
145#ifdef WCOREDUMP
146    else if (WCOREDUMP(Status))
147      std::cout << "Dumped core\n";
148#endif
149    else
150      std::cout << "Failed for unknown reason!\n";
151  }
152
153  // Was the child successful?
154  return !ExitedOK;
155}
156