reference, declarationdefinition
definition → references, declarations, derived classes, virtual overrides
reference to multiple definitions → definitions
unreferenced
    1
    2
    3
    4
    5
    6
    7
    8
    9
   10
   11
   12
   13
   14
   15
   16
   17
   18
   19
   20
   21
   22
   23
   24
   25
   26
   27
   28
   29
   30
   31
   32
   33
   34
   35
   36
   37
   38
   39
   40
   41
   42
   43
   44
   45
   46
   47
   48
   49
   50
   51
   52
   53
   54
   55
   56
   57
   58
   59
   60
   61
   62
   63
   64
   65
   66
   67
   68
   69
   70
   71
   72
   73
   74
   75
   76
   77
   78
   79
   80
   81
   82
   83
   84
   85
   86
   87
   88
   89
   90
   91
   92
   93
   94
   95
   96
   97
   98
   99
  100
  101
  102
  103
  104
  105
  106
  107
  108
  109
  110
  111
  112
  113
  114
  115
  116
  117
  118
  119
  120
  121
  122
  123
  124
  125
  126
  127
  128
  129
  130
  131
  132
  133
  134
  135
  136
  137
  138
  139
  140
  141
  142
  143
  144
  145
  146
  147
  148
  149
  150
  151
  152
  153
  154
  155
  156
  157
  158
  159
  160
  161
  162
  163
  164
  165
  166
  167
  168
  169
  170
  171
  172
  173
  174
  175
  176
  177
  178
  179
  180
  181
  182
  183
  184
  185
  186
  187
  188
  189
  190
  191
  192
  193
  194
  195
  196
  197
  198
  199
  200
  201
  202
  203
  204
  205
  206
  207
  208
  209
  210
  211
  212
  213
  214
  215
  216
  217
  218
  219
  220
  221
  222
  223
  224
  225
  226
  227
  228
  229
  230
  231
  232
  233
  234
  235
  236
  237
  238
  239
  240
  241
  242
  243
  244
  245
  246
  247
  248
  249
  250
  251
  252
  253
  254
  255
  256
  257
  258
  259
  260
  261
  262
  263
  264
  265
  266
  267
  268
  269
  270
  271
  272
  273
  274
  275
  276
  277
  278
  279
  280
  281
  282
  283
  284
//===- OptimizerDriver.cpp - Allow BugPoint to run passes safely ----------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines an interface that allows bugpoint to run various passes
// without the threat of a buggy pass corrupting bugpoint (of course, bugpoint
// may have its own bugs, but that's another story...).  It achieves this by
// forking a copy of itself and having the child process do the optimizations.
// If this client dies, we can always fork a new one.  :)
//
//===----------------------------------------------------------------------===//

#include "BugDriver.h"
#include "ToolRunner.h"
#include "llvm/Bitcode/BitcodeWriter.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/FileUtilities.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/Program.h"
#include "llvm/Support/ToolOutputFile.h"

#define DONT_GET_PLUGIN_LOADER_OPTION
#include "llvm/Support/PluginLoader.h"


using namespace llvm;

#define DEBUG_TYPE "bugpoint"

namespace llvm {
extern cl::opt<std::string> OutputPrefix;
}

static cl::opt<bool> PreserveBitcodeUseListOrder(
    "preserve-bc-uselistorder",
    cl::desc("Preserve use-list order when writing LLVM bitcode."),
    cl::init(true), cl::Hidden);

static cl::opt<std::string>
    OptCmd("opt-command", cl::init(""),
           cl::desc("Path to opt. (default: search path "
                    "for 'opt'.)"));

/// This writes the current "Program" to the named bitcode file.  If an error
/// occurs, true is returned.
static bool writeProgramToFileAux(ToolOutputFile &Out, const Module &M) {
  WriteBitcodeToFile(M, Out.os(), PreserveBitcodeUseListOrder);
  Out.os().close();
  if (!Out.os().has_error()) {
    Out.keep();
    return false;
  }
  return true;
}

bool BugDriver::writeProgramToFile(const std::string &Filename, int FD,
                                   const Module &M) const {
  ToolOutputFile Out(Filename, FD);
  return writeProgramToFileAux(Out, M);
}

bool BugDriver::writeProgramToFile(int FD, const Module &M) const {
  raw_fd_ostream OS(FD, /*shouldClose*/ false);
  WriteBitcodeToFile(M, OS, PreserveBitcodeUseListOrder);
  OS.flush();
  if (!OS.has_error())
    return false;
  OS.clear_error();
  return true;
}

bool BugDriver::writeProgramToFile(const std::string &Filename,
                                   const Module &M) const {
  std::error_code EC;
  ToolOutputFile Out(Filename, EC, sys::fs::OF_None);
  if (!EC)
    return writeProgramToFileAux(Out, M);
  return true;
}

/// This function is used to output the current Program to a file named
/// "bugpoint-ID.bc".
void BugDriver::EmitProgressBitcode(const Module &M, const std::string &ID,
                                    bool NoFlyer) const {
  // Output the input to the current pass to a bitcode file, emit a message
  // telling the user how to reproduce it: opt -foo blah.bc
  //
  std::string Filename = OutputPrefix + "-" + ID + ".bc";
  if (writeProgramToFile(Filename, M)) {
    errs() << "Error opening file '" << Filename << "' for writing!\n";
    return;
  }

  outs() << "Emitted bitcode to '" << Filename << "'\n";
  if (NoFlyer || PassesToRun.empty())
    return;
  outs() << "\n*** You can reproduce the problem with: ";
  if (UseValgrind)
    outs() << "valgrind ";
  outs() << "opt " << Filename;
  for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
    outs() << " -load " << PluginLoader::getPlugin(i);
  }
  outs() << " " << getPassesString(PassesToRun) << "\n";
}

cl::opt<bool> SilencePasses(
    "silence-passes",
    cl::desc("Suppress output of running passes (both stdout and stderr)"));

static cl::list<std::string> OptArgs("opt-args", cl::Positional,
                                     cl::desc("<opt arguments>..."),
                                     cl::ZeroOrMore, cl::PositionalEatsArgs);

/// runPasses - Run the specified passes on Program, outputting a bitcode file
/// and writing the filename into OutputFile if successful.  If the
/// optimizations fail for some reason (optimizer crashes), return true,
/// otherwise return false.  If DeleteOutput is set to true, the bitcode is
/// deleted on success, and the filename string is undefined.  This prints to
/// outs() a single line message indicating whether compilation was successful
/// or failed.
///
bool BugDriver::runPasses(Module &Program,
                          const std::vector<std::string> &Passes,
                          std::string &OutputFilename, bool DeleteOutput,
                          bool Quiet, ArrayRef<std::string> ExtraArgs) const {
  // setup the output file name
  outs().flush();
  SmallString<128> UniqueFilename;
  std::error_code EC = sys::fs::createUniqueFile(
      OutputPrefix + "-output-%%%%%%%.bc", UniqueFilename);
  if (EC) {
    errs() << getToolName()
           << ": Error making unique filename: " << EC.message() << "\n";
    return 1;
  }
  OutputFilename = UniqueFilename.str();

  // set up the input file name
  Expected<sys::fs::TempFile> Temp =
      sys::fs::TempFile::create(OutputPrefix + "-input-%%%%%%%.bc");
  if (!Temp) {
    errs() << getToolName()
           << ": Error making unique filename: " << toString(Temp.takeError())
           << "\n";
    return 1;
  }
  DiscardTemp Discard{*Temp};
  raw_fd_ostream OS(Temp->FD, /*shouldClose*/ false);

  WriteBitcodeToFile(Program, OS, PreserveBitcodeUseListOrder);
  OS.flush();
  if (OS.has_error()) {
    errs() << "Error writing bitcode file: " << Temp->TmpName << "\n";
    OS.clear_error();
    return 1;
  }

  std::string tool = OptCmd;
  if (OptCmd.empty()) {
    if (ErrorOr<std::string> Path =
            FindProgramByName("opt", getToolName(), &OutputPrefix))
      tool = *Path;
    else
      errs() << Path.getError().message() << "\n";
  }
  if (tool.empty()) {
    errs() << "Cannot find `opt' in PATH!\n";
    return 1;
  }
  if (!sys::fs::exists(tool)) {
    errs() << "Specified `opt' binary does not exist: " << tool << "\n";
    return 1;
  }

  std::string Prog;
  if (UseValgrind) {
    if (ErrorOr<std::string> Path = sys::findProgramByName("valgrind"))
      Prog = *Path;
    else
      errs() << Path.getError().message() << "\n";
  } else
    Prog = tool;
  if (Prog.empty()) {
    errs() << "Cannot find `valgrind' in PATH!\n";
    return 1;
  }

  // setup the child process' arguments
  SmallVector<StringRef, 8> Args;
  if (UseValgrind) {
    Args.push_back("valgrind");
    Args.push_back("--error-exitcode=1");
    Args.push_back("-q");
    Args.push_back(tool);
  } else
    Args.push_back(tool);

  for (unsigned i = 0, e = OptArgs.size(); i != e; ++i)
    Args.push_back(OptArgs[i]);
  Args.push_back("-disable-symbolication");
  Args.push_back("-o");
  Args.push_back(OutputFilename);
  std::vector<std::string> pass_args;
  for (unsigned i = 0, e = PluginLoader::getNumPlugins(); i != e; ++i) {
    pass_args.push_back(std::string("-load"));
    pass_args.push_back(PluginLoader::getPlugin(i));
  }
  for (std::vector<std::string>::const_iterator I = Passes.begin(),
                                                E = Passes.end();
       I != E; ++I)
    pass_args.push_back(std::string("-") + (*I));
  for (std::vector<std::string>::const_iterator I = pass_args.begin(),
                                                E = pass_args.end();
       I != E; ++I)
    Args.push_back(I->c_str());
  Args.push_back(Temp->TmpName.c_str());
  Args.append(ExtraArgs.begin(), ExtraArgs.end());

  LLVM_DEBUG(errs() << "\nAbout to run:\t";
             for (unsigned i = 0, e = Args.size() - 1; i != e; ++i) errs()
             << " " << Args[i];
             errs() << "\n";);

  Optional<StringRef> Redirects[3] = {None, None, None};
  // Redirect stdout and stderr to nowhere if SilencePasses is given.
  if (SilencePasses) {
    Redirects[1] = "";
    Redirects[2] = "";
  }

  std::string ErrMsg;
  int result = sys::ExecuteAndWait(Prog, Args, None, Redirects, Timeout,
                                   MemoryLimit, &ErrMsg);

  // If we are supposed to delete the bitcode file or if the passes crashed,
  // remove it now.  This may fail if the file was never created, but that's ok.
  if (DeleteOutput || result != 0)
    sys::fs::remove(OutputFilename);

  if (!Quiet) {
    if (result == 0)
      outs() << "Success!\n";
    else if (result > 0)
      outs() << "Exited with error code '" << result << "'\n";
    else if (result < 0) {
      if (result == -1)
        outs() << "Execute failed: " << ErrMsg << "\n";
      else
        outs() << "Crashed: " << ErrMsg << "\n";
    }
    if (result & 0x01000000)
      outs() << "Dumped core\n";
  }

  // Was the child successful?
  return result != 0;
}

std::unique_ptr<Module>
BugDriver::runPassesOn(Module *M, const std::vector<std::string> &Passes,
                       ArrayRef<std::string> ExtraArgs) {
  std::string BitcodeResult;
  if (runPasses(*M, Passes, BitcodeResult, false /*delete*/, true /*quiet*/,
                ExtraArgs)) {
    return nullptr;
  }

  std::unique_ptr<Module> Ret = parseInputFile(BitcodeResult, Context);
  if (!Ret) {
    errs() << getToolName() << ": Error reading bitcode file '" << BitcodeResult
           << "'!\n";
    exit(1);
  }
  sys::fs::remove(BitcodeResult);
  return Ret;
}