text: //===- BugDriver.cpp - Top-Level BugPoint class implementation ------------===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  //
  // This class contains all of the shared state and information that is used by
  // the BugPoint tool to track down errors in optimizations.  This class is the
  // main driver class that invokes all sub-functionality.
  //
  //===----------------------------------------------------------------------===//
  
  #include "BugDriver.h"
  #include "ToolRunner.h"
  #include "llvm/IR/Module.h"
  #include "llvm/IRReader/IRReader.h"
  #include "llvm/Linker.h"
  #include "llvm/Pass.h"
  #include "llvm/Support/CommandLine.h"
  #include "llvm/Support/FileUtilities.h"
  #include "llvm/Support/Host.h"
  #include "llvm/Support/SourceMgr.h"
  #include "llvm/Support/raw_ostream.h"
  #include <memory>
  using namespace llvm;
  
  namespace llvm {
    Triple TargetTriple;
  }
  
  // Anonymous namespace to define command line options for debugging.
  //
  namespace {
    // Output - The user can specify a file containing the expected output of the
    // program.  If this filename is set, it is used as the reference diff source,
    // otherwise the raw input run through an interpreter is used as the reference
    // source.
    //
    cl::opt<std::string>
    OutputFile("output", cl::desc("Specify a reference program output "
                                  "(for miscompilation detection)"));
  }
  
  /// setNewProgram - If we reduce or update the program somehow, call this method
  /// to update bugdriver with it.  This deletes the old module and sets the
  /// specified one as the current program.
  void BugDriver::setNewProgram(Module *M) {
    delete Program;
    Program = M;
  }
  
  
  /// getPassesString - Turn a list of passes into a string which indicates the
  /// command line options that must be passed to add the passes.
  ///
  std::string llvm::getPassesString(const std::vector<std::string> &Passes) {
    std::string Result;
    for (unsigned i = 0, e = Passes.size(); i != e; ++i) {
      if (i) Result += " ";
      Result += "-";
      Result += Passes[i];
    }
    return Result;
  }
  
  BugDriver::BugDriver(const char *toolname, bool find_bugs,
                       unsigned timeout, unsigned memlimit, bool use_valgrind,
                       LLVMContext& ctxt)
    : Context(ctxt), ToolName(toolname), ReferenceOutputFile(OutputFile),
      Program(0), Interpreter(0), SafeInterpreter(0), gcc(0),
      run_find_bugs(find_bugs), Timeout(timeout),
      MemoryLimit(memlimit), UseValgrind(use_valgrind) {}
  
  BugDriver::~BugDriver() {
    delete Program;
  }
  
  
  /// ParseInputFile - Given a bitcode or assembly input filename, parse and
  /// return it, or return null if not possible.
  ///
  Module *llvm::ParseInputFile(const std::string &Filename,
                               LLVMContext& Ctxt) {
    SMDiagnostic Err;
    Module *Result = ParseIRFile(Filename, Err, Ctxt);
    if (!Result)
      Err.print("bugpoint", errs());
  
    // If we don't have an override triple, use the first one to configure
    // bugpoint, or use the host triple if none provided.
    if (Result) {
      if (TargetTriple.getTriple().empty()) {
        Triple TheTriple(Result->getTargetTriple());
  
        if (TheTriple.getTriple().empty())
          TheTriple.setTriple(sys::getDefaultTargetTriple());
  
        TargetTriple.setTriple(TheTriple.getTriple());
      }
  
      Result->setTargetTriple(TargetTriple.getTriple());  // override the triple
    }
    return Result;
  }
  
  // This method takes the specified list of LLVM input files, attempts to load
  // them, either as assembly or bitcode, then link them together. It returns
  // true on failure (if, for example, an input bitcode file could not be
  // parsed), and false on success.
  //
  bool BugDriver::addSources(const std::vector<std::string> &Filenames) {
    assert(Program == 0 && "Cannot call addSources multiple times!");
    assert(!Filenames.empty() && "Must specify at least on input filename!");
  
    // Load the first input file.
    Program = ParseInputFile(Filenames[0], Context);
    if (Program == 0) return true;
  
    outs() << "Read input file      : '" << Filenames[0] << "'\n";
  
    for (unsigned i = 1, e = Filenames.size(); i != e; ++i) {
      OwningPtr<Module> M(ParseInputFile(Filenames[i], Context));
      if (M.get() == 0) return true;
  
      outs() << "Linking in input file: '" << Filenames[i] << "'\n";
      std::string ErrorMessage;
      if (Linker::LinkModules(Program, M.get(), Linker::DestroySource,
                              &ErrorMessage)) {
        errs() << ToolName << ": error linking in '" << Filenames[i] << "': "
               << ErrorMessage << '\n';
        return true;
      }
    }
  
    outs() << "*** All input ok\n";
  
    // All input files read successfully!
    return false;
  }
  
  
  
  /// run - The top level method that is invoked after all of the instance
  /// variables are set up from command line arguments.
  ///
  bool BugDriver::run(std::string &ErrMsg) {
    if (run_find_bugs) {
      // Rearrange the passes and apply them to the program. Repeat this process
      // until the user kills the program or we find a bug.
      return runManyPasses(PassesToRun, ErrMsg);
    }
  
    // If we're not running as a child, the first thing that we must do is
    // determine what the problem is. Does the optimization series crash the
    // compiler, or does it produce illegal code?  We make the top-level
    // decision by trying to run all of the passes on the input program,
    // which should generate a bitcode file.  If it does generate a bitcode
    // file, then we know the compiler didn't crash, so try to diagnose a
    // miscompilation.
    if (!PassesToRun.empty()) {
      outs() << "Running selected passes on program to test for crash: ";
      if (runPasses(Program, PassesToRun))
        return debugOptimizerCrash();
    }
  
    // Set up the execution environment, selecting a method to run LLVM bitcode.
    if (initializeExecutionEnvironment()) return true;
  
    // Test to see if we have a code generator crash.
    outs() << "Running the code generator to test for a crash: ";
    std::string Error;
    compileProgram(Program, &Error);
    if (!Error.empty()) {
      outs() << Error;
      return debugCodeGeneratorCrash(ErrMsg);
    }
    outs() << '\n';
  
    // Run the raw input to see where we are coming from.  If a reference output
    // was specified, make sure that the raw output matches it.  If not, it's a
    // problem in the front-end or the code generator.
    //
    bool CreatedOutput = false;
    if (ReferenceOutputFile.empty()) {
      outs() << "Generating reference output from raw program: ";
      if (!createReferenceFile(Program)) {
        return debugCodeGeneratorCrash(ErrMsg);
      }
      CreatedOutput = true;
    }
  
    // Make sure the reference output file gets deleted on exit from this
    // function, if appropriate.
    sys::Path ROF(ReferenceOutputFile);
    FileRemover RemoverInstance(ROF.str(), CreatedOutput && !SaveTemps);
  
    // Diff the output of the raw program against the reference output.  If it
    // matches, then we assume there is a miscompilation bug and try to
    // diagnose it.
    outs() << "*** Checking the code generator...\n";
    bool Diff = diffProgram(Program, "", "", false, &Error);
    if (!Error.empty()) {
      errs() << Error;
      return debugCodeGeneratorCrash(ErrMsg);
    }
    if (!Diff) {
      outs() << "\n*** Output matches: Debugging miscompilation!\n";
      debugMiscompilation(&Error);
      if (!Error.empty()) {
        errs() << Error;
        return debugCodeGeneratorCrash(ErrMsg);
      }
      return false;
    }
  
    outs() << "\n*** Input program does not match reference diff!\n";
    outs() << "Debugging code generator problem!\n";
    bool Failure = debugCodeGenerator(&Error);
    if (!Error.empty()) {
      errs() << Error;
      return debugCodeGeneratorCrash(ErrMsg);
    }
    return Failure;
  }
  
  void llvm::PrintFunctionList(const std::vector<Function*> &Funcs) {
    unsigned NumPrint = Funcs.size();
    if (NumPrint > 10) NumPrint = 10;
    for (unsigned i = 0; i != NumPrint; ++i)
      outs() << " " << Funcs[i]->getName();
    if (NumPrint < Funcs.size())
      outs() << "... <" << Funcs.size() << " total>";
    outs().flush();
  }
  
  void llvm::PrintGlobalVariableList(const std::vector<GlobalVariable*> &GVs) {
    unsigned NumPrint = GVs.size();
    if (NumPrint > 10) NumPrint = 10;
    for (unsigned i = 0; i != NumPrint; ++i)
      outs() << " " << GVs[i]->getName();
    if (NumPrint < GVs.size())
      outs() << "... <" << GVs.size() << " total>";
    outs().flush();
  }
  