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/Bitcode/ReaderWriter.h"
20#include "llvm/IR/DataLayout.h"
21#include "llvm/IR/LegacyPassManager.h"
22#include "llvm/IR/Module.h"
23#include "llvm/IR/Verifier.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
39#define DEBUG_TYPE "bugpoint"
40
41namespace llvm {
42  extern cl::opt<std::string> OutputPrefix;
43}
44
45static cl::opt<bool> PreserveBitcodeUseListOrder(
46    "preserve-bc-uselistorder",
47    cl::desc("Preserve use-list order when writing LLVM bitcode."),
48    cl::init(true), cl::Hidden);
49
50namespace {
51  // ChildOutput - This option captures the name of the child output file that
52  // is set up by the parent bugpoint process
53  cl::opt<std::string> ChildOutput("child-output", cl::ReallyHidden);
54  cl::opt<std::string> OptCmd("opt-command", cl::init(""),
55                              cl::desc("Path to opt. (default: search path "
56                                       "for 'opt'.)"));
57}
58
59/// writeProgramToFile - This writes the current "Program" to the named bitcode
60/// file.  If an error occurs, true is returned.
61///
62static bool writeProgramToFileAux(tool_output_file &Out, const Module *M) {
63  WriteBitcodeToFile(M, Out.os(), PreserveBitcodeUseListOrder);
64  Out.os().close();
65  if (!Out.os().has_error()) {
66    Out.keep();
67    return false;
68  }
69  return true;
70}
71
72bool BugDriver::writeProgramToFile(const std::string &Filename, int FD,
73                                   const Module *M) const {
74  tool_output_file Out(Filename, FD);
75  return writeProgramToFileAux(Out, M);
76}
77
78bool BugDriver::writeProgramToFile(const std::string &Filename,
79                                   const Module *M) const {
80  std::error_code EC;
81  tool_output_file Out(Filename, EC, sys::fs::F_None);
82  if (!EC)
83    return writeProgramToFileAux(Out, M);
84  return true;
85}
86
87
88/// EmitProgressBitcode - This function is used to output the current Program
89/// to a file named "bugpoint-ID.bc".
90///
91void BugDriver::EmitProgressBitcode(const Module *M,
92                                    const std::string &ID,
93                                    bool NoFlyer)  const {
94  // Output the input to the current pass to a bitcode file, emit a message
95  // telling the user how to reproduce it: opt -foo blah.bc
96  //
97  std::string Filename = OutputPrefix + "-" + ID + ".bc";
98  if (writeProgramToFile(Filename, M)) {
99    errs() <<  "Error opening file '" << Filename << "' for writing!\n";
100    return;
101  }
102
103  outs() << "Emitted bitcode to '" << Filename << "'\n";
104  if (NoFlyer || PassesToRun.empty()) return;
105  outs() << "\n*** You can reproduce the problem with: ";
106  if (UseValgrind) outs() << "valgrind ";
107  outs() << "opt " << Filename;
108  for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
109    outs() << " -load " << PluginLoader::getPlugin(i);
110  }
111  outs() << " " << getPassesString(PassesToRun) << "\n";
112}
113
114cl::opt<bool> SilencePasses("silence-passes",
115        cl::desc("Suppress output of running passes (both stdout and stderr)"));
116
117static cl::list<std::string> OptArgs("opt-args", cl::Positional,
118                                     cl::desc("<opt arguments>..."),
119                                     cl::ZeroOrMore, cl::PositionalEatsArgs);
120
121/// runPasses - Run the specified passes on Program, outputting a bitcode file
122/// and writing the filename into OutputFile if successful.  If the
123/// optimizations fail for some reason (optimizer crashes), return true,
124/// otherwise return false.  If DeleteOutput is set to true, the bitcode is
125/// deleted on success, and the filename string is undefined.  This prints to
126/// outs() a single line message indicating whether compilation was successful
127/// or failed.
128///
129bool BugDriver::runPasses(Module *Program,
130                          const std::vector<std::string> &Passes,
131                          std::string &OutputFilename, bool DeleteOutput,
132                          bool Quiet, unsigned NumExtraArgs,
133                          const char * const *ExtraArgs) const {
134  // setup the output file name
135  outs().flush();
136  SmallString<128> UniqueFilename;
137  std::error_code EC = sys::fs::createUniqueFile(
138      OutputPrefix + "-output-%%%%%%%.bc", UniqueFilename);
139  if (EC) {
140    errs() << getToolName() << ": Error making unique filename: "
141           << EC.message() << "\n";
142    return 1;
143  }
144  OutputFilename = UniqueFilename.str();
145
146  // set up the input file name
147  SmallString<128> InputFilename;
148  int InputFD;
149  EC = sys::fs::createUniqueFile(OutputPrefix + "-input-%%%%%%%.bc", InputFD,
150                                 InputFilename);
151  if (EC) {
152    errs() << getToolName() << ": Error making unique filename: "
153           << EC.message() << "\n";
154    return 1;
155  }
156
157  tool_output_file InFile(InputFilename, InputFD);
158
159  WriteBitcodeToFile(Program, InFile.os(), PreserveBitcodeUseListOrder);
160  InFile.os().close();
161  if (InFile.os().has_error()) {
162    errs() << "Error writing bitcode file: " << InputFilename << "\n";
163    InFile.os().clear_error();
164    return 1;
165  }
166
167  std::string tool = OptCmd;
168  if (OptCmd.empty()) {
169    if (ErrorOr<std::string> Path = sys::findProgramByName("opt"))
170      tool = *Path;
171    else
172      errs() << Path.getError().message() << "\n";
173  }
174  if (tool.empty()) {
175    errs() << "Cannot find `opt' in PATH!\n";
176    return 1;
177  }
178
179  std::string Prog;
180  if (UseValgrind) {
181    if (ErrorOr<std::string> Path = sys::findProgramByName("valgrind"))
182      Prog = *Path;
183    else
184      errs() << Path.getError().message() << "\n";
185  } else
186    Prog = tool;
187  if (Prog.empty()) {
188    errs() << "Cannot find `valgrind' in PATH!\n";
189    return 1;
190  }
191
192  // Ok, everything that could go wrong before running opt is done.
193  InFile.keep();
194
195  // setup the child process' arguments
196  SmallVector<const char*, 8> Args;
197  if (UseValgrind) {
198    Args.push_back("valgrind");
199    Args.push_back("--error-exitcode=1");
200    Args.push_back("-q");
201    Args.push_back(tool.c_str());
202  } else
203    Args.push_back(tool.c_str());
204
205  Args.push_back("-o");
206  Args.push_back(OutputFilename.c_str());
207  for (unsigned i = 0, e = OptArgs.size(); i != e; ++i)
208    Args.push_back(OptArgs[i].c_str());
209  std::vector<std::string> pass_args;
210  for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
211    pass_args.push_back( std::string("-load"));
212    pass_args.push_back( PluginLoader::getPlugin(i));
213  }
214  for (std::vector<std::string>::const_iterator I = Passes.begin(),
215       E = Passes.end(); I != E; ++I )
216    pass_args.push_back( std::string("-") + (*I) );
217  for (std::vector<std::string>::const_iterator I = pass_args.begin(),
218       E = pass_args.end(); I != E; ++I )
219    Args.push_back(I->c_str());
220  Args.push_back(InputFilename.c_str());
221  for (unsigned i = 0; i < NumExtraArgs; ++i)
222    Args.push_back(*ExtraArgs);
223  Args.push_back(nullptr);
224
225  DEBUG(errs() << "\nAbout to run:\t";
226        for (unsigned i = 0, e = Args.size()-1; i != e; ++i)
227          errs() << " " << Args[i];
228        errs() << "\n";
229        );
230
231  // Redirect stdout and stderr to nowhere if SilencePasses is given
232  StringRef Nowhere;
233  const StringRef *Redirects[3] = {nullptr, &Nowhere, &Nowhere};
234
235  std::string ErrMsg;
236  int result = sys::ExecuteAndWait(Prog, Args.data(), nullptr,
237                                   (SilencePasses ? Redirects : nullptr),
238                                   Timeout, MemoryLimit, &ErrMsg);
239
240  // If we are supposed to delete the bitcode file or if the passes crashed,
241  // remove it now.  This may fail if the file was never created, but that's ok.
242  if (DeleteOutput || result != 0)
243    sys::fs::remove(OutputFilename);
244
245  // Remove the temporary input file as well
246  sys::fs::remove(InputFilename.c_str());
247
248  if (!Quiet) {
249    if (result == 0)
250      outs() << "Success!\n";
251    else if (result > 0)
252      outs() << "Exited with error code '" << result << "'\n";
253    else if (result < 0) {
254      if (result == -1)
255        outs() << "Execute failed: " << ErrMsg << "\n";
256      else
257        outs() << "Crashed: " << ErrMsg << "\n";
258    }
259    if (result & 0x01000000)
260      outs() << "Dumped core\n";
261  }
262
263  // Was the child successful?
264  return result != 0;
265}
266
267
268std::unique_ptr<Module>
269BugDriver::runPassesOn(Module *M, const std::vector<std::string> &Passes,
270                       unsigned NumExtraArgs,
271                       const char *const *ExtraArgs) {
272  std::string BitcodeResult;
273  if (runPasses(M, Passes, BitcodeResult, false/*delete*/, true/*quiet*/,
274                NumExtraArgs, ExtraArgs)) {
275    return nullptr;
276  }
277
278  std::unique_ptr<Module> Ret = parseInputFile(BitcodeResult, Context);
279  if (!Ret) {
280    errs() << getToolName() << ": Error reading bitcode file '"
281           << BitcodeResult << "'!\n";
282    exit(1);
283  }
284  sys::fs::remove(BitcodeResult);
285  return Ret;
286}
287