示例#1
0
// dropAllReferences() - This function causes all the subelements to "let go"
// of all references that they are maintaining.  This allows one to 'delete' a
// whole module at a time, even though there may be circular references... first
// all references are dropped, and all use counts go to zero.  Then everything
// is deleted for real.  Note that no operations are valid on an object that
// has "dropped all references", except operator delete.
//
void Module::dropAllReferences() {
  for(Module::iterator I = begin(), E = end(); I != E; ++I)
    I->dropAllReferences();

  for(Module::global_iterator I = global_begin(), E = global_end(); I != E; ++I)
    I->dropAllReferences();

  for(Module::alias_iterator I = alias_begin(), E = alias_end(); I != E; ++I)
    I->dropAllReferences();
}
示例#2
0
void ModuleLinker::linkAliasBodies() {
  for (Module::alias_iterator I = SrcM->alias_begin(), E = SrcM->alias_end();
       I != E; ++I) {
    if (DoNotLinkFromSource.count(I))
      continue;
    if (Constant *Aliasee = I->getAliasee()) {
      GlobalAlias *DA = cast<GlobalAlias>(ValueMap[I]);
      DA->setAliasee(MapValue(Aliasee, ValueMap, RF_None, &TypeMap));
    }
  }
}
示例#3
0
/// GetAllUndefinedSymbols - calculates the set of undefined symbols that still
/// exist in an LLVM module. This is a bit tricky because there may be two
/// symbols with the same name but different LLVM types that will be resolved to
/// each other but aren't currently (thus we need to treat it as resolved).
///
/// Inputs:
///  M - The module in which to find undefined symbols.
///
/// Outputs:
///  UndefinedSymbols - A set of C++ strings containing the name of all
///                     undefined symbols.
///
static void
GetAllUndefinedSymbols(Module *M, std::set<std::string> &UndefinedSymbols) {
  std::set<std::string> DefinedSymbols;
  UndefinedSymbols.clear();

  // If the program doesn't define a main, try pulling one in from a .a file.
  // This is needed for programs where the main function is defined in an
  // archive, such f2c'd programs.
  Function *Main = M->getFunction("main");
  if (Main == 0 || Main->isDeclaration())
    UndefinedSymbols.insert("main");

  for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
    if (I->hasName()) {
      if (I->isDeclaration())
        UndefinedSymbols.insert(I->getName());
      else if (!I->hasLocalLinkage()) {
        assert(!I->hasDLLImportLinkage()
               && "Found dllimported non-external symbol!");
        DefinedSymbols.insert(I->getName());
      }      
    }

  for (Module::global_iterator I = M->global_begin(), E = M->global_end();
       I != E; ++I)
    if (I->hasName()) {
      if (I->isDeclaration())
        UndefinedSymbols.insert(I->getName());
      else if (!I->hasLocalLinkage()) {
        assert(!I->hasDLLImportLinkage()
               && "Found dllimported non-external symbol!");
        DefinedSymbols.insert(I->getName());
      }      
    }

  for (Module::alias_iterator I = M->alias_begin(), E = M->alias_end();
       I != E; ++I)
    if (I->hasName())
      DefinedSymbols.insert(I->getName());

  // Prune out any defined symbols from the undefined symbols set...
  for (std::set<std::string>::iterator I = UndefinedSymbols.begin();
       I != UndefinedSymbols.end(); )
    if (DefinedSymbols.count(*I))
      UndefinedSymbols.erase(I++);  // This symbol really is defined!
    else
      ++I; // Keep this symbol in the undefined symbols list
}
void
AndroidBitcodeLinker::GetAllSymbols(Module *M,
  std::set<std::string> &UndefinedSymbols,
  std::set<std::string> &DefinedSymbols) {

  UndefinedSymbols.clear();
  DefinedSymbols.clear();

  Function *Main = M->getFunction("main");
  if (Main == 0 || Main->isDeclaration())
    UndefinedSymbols.insert("main");

  for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
    if (I->hasName()) {
      if (I->isDeclaration())
        UndefinedSymbols.insert(I->getName());
      else if (!I->hasLocalLinkage()) {
        assert(!I->hasDLLImportStorageClass()
               && "Found dllimported non-external symbol!");
        DefinedSymbols.insert(I->getName());
      }
    }

  for (Module::global_iterator I = M->global_begin(), E = M->global_end();
       I != E; ++I)
    if (I->hasName()) {
      if (I->isDeclaration())
        UndefinedSymbols.insert(I->getName());
      else if (!I->hasLocalLinkage()) {
        assert(!I->hasDLLImportStorageClass()
               && "Found dllimported non-external symbol!");
        DefinedSymbols.insert(I->getName());
      }
    }

  for (Module::alias_iterator I = M->alias_begin(), E = M->alias_end();
       I != E; ++I)
    if (I->hasName())
      DefinedSymbols.insert(I->getName());

  for (std::set<std::string>::iterator I = UndefinedSymbols.begin();
       I != UndefinedSymbols.end(); )
    if (DefinedSymbols.count(*I))
      UndefinedSymbols.erase(I++);
    else
      ++I;
}
示例#5
0
/// parseSymbols - Parse the symbols from the module and model-level ASM and add
/// them to either the defined or undefined lists.
bool LTOModule::parseSymbols(std::string &errMsg) {
  // add functions
  for (Module::iterator f = _module->begin(), e = _module->end(); f != e; ++f) {
    if (isDeclaration(*f))
      addPotentialUndefinedSymbol(f, true);
    else
      addDefinedFunctionSymbol(f);
  }

  // add data
  for (Module::global_iterator v = _module->global_begin(),
         e = _module->global_end(); v !=  e; ++v) {
    if (isDeclaration(*v))
      addPotentialUndefinedSymbol(v, false);
    else
      addDefinedDataSymbol(v);
  }

  // add asm globals
  if (addAsmGlobalSymbols(errMsg))
    return true;

  // add aliases
  for (Module::alias_iterator a = _module->alias_begin(),
         e = _module->alias_end(); a != e; ++a) {
    if (isDeclaration(*a->getAliasedGlobal()))
      // Is an alias to a declaration.
      addPotentialUndefinedSymbol(a, false);
    else
      addDefinedDataSymbol(a);
  }

  // make symbols for all undefines
  for (StringMap<NameAndAttributes>::iterator u =_undefines.begin(),
         e = _undefines.end(); u != e; ++u) {
    // If this symbol also has a definition, then don't make an undefine because
    // it is a tentative definition.
    if (_defines.count(u->getKey())) continue;
    NameAndAttributes info = u->getValue();
    _symbols.push_back(info);
  }

  return false;
}
static void getSymbols(Module*M, std::vector<std::string>& symbols) {
    // Loop over global variables
    for (Module::global_iterator GI = M->global_begin(), GE=M->global_end(); GI != GE; ++GI)
        if (!GI->isDeclaration() && !GI->hasLocalLinkage())
            if (!GI->getName().empty())
                symbols.push_back(GI->getName());

    // Loop over functions
    for (Module::iterator FI = M->begin(), FE = M->end(); FI != FE; ++FI)
        if (!FI->isDeclaration() && !FI->hasLocalLinkage())
            if (!FI->getName().empty())
                symbols.push_back(FI->getName());

    // Loop over aliases
    for (Module::alias_iterator AI = M->alias_begin(), AE = M->alias_end();
            AI != AE; ++AI) {
        if (AI->hasName())
            symbols.push_back(AI->getName());
    }
}
示例#7
0
//
// Method: runOnModule()
//
// Description:
//  Entry point for this LLVM pass.
//  Replace all internal aliases with the
//  aliasee value
//
// Inputs:
//  M - A reference to the LLVM module to transform
//
// Outputs:
//  M - The transformed LLVM module.
//
// Return value:
//  true  - The module was modified.
//  false - The module was not modified.
//
bool FuncSimplify::runOnModule(Module& M) {

  std::vector<GlobalAlias*> toDelete;
  for (Module::alias_iterator I = M.alias_begin(); I != M.alias_end(); ++I) {
    if(!I->hasInternalLinkage())
      continue;
    I->replaceAllUsesWith(I->getAliasee());
    toDelete.push_back(I);
  }
  numChanged += toDelete.size();

  while(!toDelete.empty()) {
    GlobalAlias *I = toDelete.back();
    toDelete.pop_back();
    I->eraseFromParent();
  }


  return true;
}
示例#8
0
bool InternalizePass::runOnModule(Module &M) {
  CallGraph *CG = getAnalysisIfAvailable<CallGraph>();
  CallGraphNode *ExternalNode = CG ? CG->getExternalCallingNode() : 0;
  
  if (ExternalNames.empty()) {
    // Return if we're not in 'all but main' mode and have no external api
    if (!AllButMain)
      return false;
    // If no list or file of symbols was specified, check to see if there is a
    // "main" symbol defined in the module.  If so, use it, otherwise do not
    // internalize the module, it must be a library or something.
    //
    Function *MainFunc = M.getFunction("main");
    if (MainFunc == 0 || MainFunc->isDeclaration())
      return false;  // No main found, must be a library...

    // Preserve main, internalize all else.
    ExternalNames.insert(MainFunc->getName());
  }

  bool Changed = false;

  // Never internalize functions which code-gen might insert.
  ExternalNames.insert("__stack_chk_fail");

  // Mark all functions not in the api as internal.
  // FIXME: maybe use private linkage?
  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
    if (!I->isDeclaration() &&         // Function must be defined here
        // Available externally is really just a "declaration with a body".
        !I->hasAvailableExternallyLinkage() &&
        !I->hasLocalLinkage() &&  // Can't already have internal linkage
        !ExternalNames.count(I->getName())) {// Not marked to keep external?
      I->setLinkage(GlobalValue::InternalLinkage);
      // Remove a callgraph edge from the external node to this function.
      if (ExternalNode) ExternalNode->removeOneAbstractEdgeTo((*CG)[I]);
      Changed = true;
      ++NumFunctions;
      DEBUG(dbgs() << "Internalizing func " << I->getName() << "\n");
    }

  // Never internalize the llvm.used symbol.  It is used to implement
  // attribute((used)).
  // FIXME: Shouldn't this just filter on llvm.metadata section??
  ExternalNames.insert("llvm.used");
  ExternalNames.insert("llvm.compiler.used");

  // Never internalize anchors used by the machine module info, else the info
  // won't find them.  (see MachineModuleInfo.)
  ExternalNames.insert("llvm.global_ctors");
  ExternalNames.insert("llvm.global_dtors");
  ExternalNames.insert("llvm.global.annotations");

  // Never internalize symbols code-gen inserts.
  ExternalNames.insert("__stack_chk_guard");

  // Mark all global variables with initializers that are not in the api as
  // internal as well.
  // FIXME: maybe use private linkage?
  for (Module::global_iterator I = M.global_begin(), E = M.global_end();
       I != E; ++I)
    if (!I->isDeclaration() && !I->hasLocalLinkage() &&
        // Available externally is really just a "declaration with a body".
        !I->hasAvailableExternallyLinkage() &&
        !ExternalNames.count(I->getName())) {
      I->setLinkage(GlobalValue::InternalLinkage);
      Changed = true;
      ++NumGlobals;
      DEBUG(dbgs() << "Internalized gvar " << I->getName() << "\n");
    }

  // Mark all aliases that are not in the api as internal as well.
  for (Module::alias_iterator I = M.alias_begin(), E = M.alias_end();
       I != E; ++I)
    if (!I->isDeclaration() && !I->hasInternalLinkage() &&
        // Available externally is really just a "declaration with a body".
        !I->hasAvailableExternallyLinkage() &&
        !ExternalNames.count(I->getName())) {
      I->setLinkage(GlobalValue::InternalLinkage);
      Changed = true;
      ++NumAliases;
      DEBUG(dbgs() << "Internalized alias " << I->getName() << "\n");
    }

  return Changed;
}
bool PNaClABIVerifyModule::runOnModule(Module &M) {
  if (!M.getModuleInlineAsm().empty()) {
    Reporter->addError() <<
        "Module contains disallowed top-level inline assembly\n";
  }

  for (Module::const_global_iterator MI = M.global_begin(), ME = M.global_end();
       MI != ME; ++MI) {
    checkGlobalIsFlattened(MI);
    checkGlobalValueCommon(MI);

    if (MI->isThreadLocal()) {
      Reporter->addError() << "Variable " << MI->getName() <<
          " has disallowed \"thread_local\" attribute\n";
    }
  }

  // No aliases allowed for now.
  for (Module::alias_iterator MI = M.alias_begin(),
           E = M.alias_end(); MI != E; ++MI) {
    Reporter->addError() << "Variable " << MI->getName() <<
        " is an alias (disallowed)\n";
  }

  for (Module::const_iterator MI = M.begin(), ME = M.end(); MI != ME; ++MI) {
    if (MI->isIntrinsic()) {
      // Check intrinsics.
      if (!isWhitelistedIntrinsic(MI, MI->getIntrinsicID())) {
        Reporter->addError() << "Function " << MI->getName()
                             << " is a disallowed LLVM intrinsic\n";
      }
    } else {
      // Check types of functions and their arguments.  Not necessary
      // for intrinsics, whose types are fixed anyway, and which have
      // argument types that we disallow such as i8.
      if (!PNaClABITypeChecker::isValidFunctionType(MI->getFunctionType())) {
        Reporter->addError() << "Function " << MI->getName()
            << " has disallowed type: "
            << PNaClABITypeChecker::getTypeName(MI->getFunctionType())
            << "\n";
      }
      // This check is disabled in streaming mode because it would
      // reject a function that is defined but not read in yet.
      // Unfortunately this means we simply don't check this property
      // when translating a pexe in the browser.
      // TODO(mseaborn): Enforce this property in the bitcode reader.
      if (!StreamingMode && MI->isDeclaration()) {
        Reporter->addError() << "Function " << MI->getName()
                             << " is declared but not defined (disallowed)\n";
      }
      if (!MI->getAttributes().isEmpty()) {
        Reporter->addError()
            << "Function " << MI->getName() << " has disallowed attributes:"
            << getAttributesAsString(MI->getAttributes()) << "\n";
      }
      if (MI->getCallingConv() != CallingConv::C) {
        Reporter->addError()
            << "Function " << MI->getName()
            << " has disallowed calling convention: "
            << MI->getCallingConv() << "\n";
      }
    }

    checkGlobalValueCommon(MI);

    if (MI->hasGC()) {
      Reporter->addError() << "Function " << MI->getName() <<
          " has disallowed \"gc\" attribute\n";
    }
    // Knowledge of what function alignments are useful is
    // architecture-specific and sandbox-specific, so PNaCl pexes
    // should not be able to specify function alignment.
    if (MI->getAlignment() != 0) {
      Reporter->addError() << "Function " << MI->getName() <<
          " has disallowed \"align\" attribute\n";
    }
  }

  // Check named metadata nodes
  for (Module::const_named_metadata_iterator I = M.named_metadata_begin(),
           E = M.named_metadata_end(); I != E; ++I) {
    if (!isWhitelistedMetadata(I)) {
      Reporter->addError() << "Named metadata node " << I->getName()
                           << " is disallowed\n";
    }
  }

  Reporter->checkForFatalErrors();
  return false;
}
示例#10
0
bool InternalizePass::runOnModule(Module &M) {
  CallGraph *CG = getAnalysisIfAvailable<CallGraph>();
  CallGraphNode *ExternalNode = CG ? CG->getExternalCallingNode() : 0;
  bool Changed = false;

  // Never internalize functions which code-gen might insert.
  // FIXME: We should probably add this (and the __stack_chk_guard) via some
  // type of call-back in CodeGen.
  ExternalNames.insert("__stack_chk_fail");

  // Mark all functions not in the api as internal.
  // FIXME: maybe use private linkage?
  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
    if (!I->isDeclaration() &&         // Function must be defined here
        // Available externally is really just a "declaration with a body".
        !I->hasAvailableExternallyLinkage() &&
        !I->hasLocalLinkage() &&  // Can't already have internal linkage
        !ExternalNames.count(I->getName())) {// Not marked to keep external?
      I->setLinkage(GlobalValue::InternalLinkage);
      // Remove a callgraph edge from the external node to this function.
      if (ExternalNode) ExternalNode->removeOneAbstractEdgeTo((*CG)[I]);
      Changed = true;
      ++NumFunctions;
      DEBUG(dbgs() << "Internalizing func " << I->getName() << "\n");
    }

  // Never internalize the llvm.used symbol.  It is used to implement
  // attribute((used)).
  // FIXME: Shouldn't this just filter on llvm.metadata section??
  ExternalNames.insert("llvm.used");
  ExternalNames.insert("llvm.compiler.used");

  // Never internalize anchors used by the machine module info, else the info
  // won't find them.  (see MachineModuleInfo.)
  ExternalNames.insert("llvm.global_ctors");
  ExternalNames.insert("llvm.global_dtors");
  ExternalNames.insert("llvm.global.annotations");

  // Never internalize symbols code-gen inserts.
  ExternalNames.insert("__stack_chk_guard");

  // Mark all global variables with initializers that are not in the api as
  // internal as well.
  // FIXME: maybe use private linkage?
  for (Module::global_iterator I = M.global_begin(), E = M.global_end();
       I != E; ++I)
    if (!I->isDeclaration() && !I->hasLocalLinkage() &&
        // Available externally is really just a "declaration with a body".
        !I->hasAvailableExternallyLinkage() &&
        !ExternalNames.count(I->getName())) {
      I->setLinkage(GlobalValue::InternalLinkage);
      Changed = true;
      ++NumGlobals;
      DEBUG(dbgs() << "Internalized gvar " << I->getName() << "\n");
    }

  // Mark all aliases that are not in the api as internal as well.
  for (Module::alias_iterator I = M.alias_begin(), E = M.alias_end();
       I != E; ++I)
    if (!I->isDeclaration() && !I->hasInternalLinkage() &&
        // Available externally is really just a "declaration with a body".
        !I->hasAvailableExternallyLinkage() &&
        !ExternalNames.count(I->getName())) {
      I->setLinkage(GlobalValue::InternalLinkage);
      Changed = true;
      ++NumAliases;
      DEBUG(dbgs() << "Internalized alias " << I->getName() << "\n");
    }

  return Changed;
}
示例#11
0
bool GlobalDCE::runOnModule(Module &M) {
  bool Changed = false;
  
  // Loop over the module, adding globals which are obviously necessary.
  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
    Changed |= RemoveUnusedGlobalValue(*I);
    // Functions with external linkage are needed if they have a body
    if (!I->isDiscardableIfUnused() &&
        !I->isDeclaration() && !I->hasAvailableExternallyLinkage())
      GlobalIsNeeded(I);
  }

  for (Module::global_iterator I = M.global_begin(), E = M.global_end();
       I != E; ++I) {
    Changed |= RemoveUnusedGlobalValue(*I);
    // Externally visible & appending globals are needed, if they have an
    // initializer.
    if (!I->isDiscardableIfUnused() &&
        !I->isDeclaration() && !I->hasAvailableExternallyLinkage())
      GlobalIsNeeded(I);
  }

  for (Module::alias_iterator I = M.alias_begin(), E = M.alias_end();
       I != E; ++I) {
    Changed |= RemoveUnusedGlobalValue(*I);
    // Externally visible aliases are needed.
    if (!I->isDiscardableIfUnused())
      GlobalIsNeeded(I);
  }

  // Now that all globals which are needed are in the AliveGlobals set, we loop
  // through the program, deleting those which are not alive.
  //

  // The first pass is to drop initializers of global variables which are dead.
  std::vector<GlobalVariable*> DeadGlobalVars;   // Keep track of dead globals
  for (Module::global_iterator I = M.global_begin(), E = M.global_end();
       I != E; ++I)
    if (!AliveGlobals.count(I)) {
      DeadGlobalVars.push_back(I);         // Keep track of dead globals
      I->setInitializer(0);
    }

  // The second pass drops the bodies of functions which are dead...
  std::vector<Function*> DeadFunctions;
  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
    if (!AliveGlobals.count(I)) {
      DeadFunctions.push_back(I);         // Keep track of dead globals
      if (!I->isDeclaration())
        I->deleteBody();
    }

  // The third pass drops targets of aliases which are dead...
  std::vector<GlobalAlias*> DeadAliases;
  for (Module::alias_iterator I = M.alias_begin(), E = M.alias_end(); I != E;
       ++I)
    if (!AliveGlobals.count(I)) {
      DeadAliases.push_back(I);
      I->setAliasee(0);
    }

  if (!DeadFunctions.empty()) {
    // Now that all interferences have been dropped, delete the actual objects
    // themselves.
    for (unsigned i = 0, e = DeadFunctions.size(); i != e; ++i) {
      RemoveUnusedGlobalValue(*DeadFunctions[i]);
      M.getFunctionList().erase(DeadFunctions[i]);
    }
    NumFunctions += DeadFunctions.size();
    Changed = true;
  }

  if (!DeadGlobalVars.empty()) {
    for (unsigned i = 0, e = DeadGlobalVars.size(); i != e; ++i) {
      RemoveUnusedGlobalValue(*DeadGlobalVars[i]);
      M.getGlobalList().erase(DeadGlobalVars[i]);
    }
    NumVariables += DeadGlobalVars.size();
    Changed = true;
  }

  // Now delete any dead aliases.
  if (!DeadAliases.empty()) {
    for (unsigned i = 0, e = DeadAliases.size(); i != e; ++i) {
      RemoveUnusedGlobalValue(*DeadAliases[i]);
      M.getAliasList().erase(DeadAliases[i]);
    }
    NumAliases += DeadAliases.size();
    Changed = true;
  }

  // Make sure that all memory is released
  AliveGlobals.clear();

  return Changed;
}
示例#12
0
int main(int argc, char **argv) {
  // Print a stack trace if we signal out.
  sys::PrintStackTraceOnErrorSignal(argv[0]);
  PrettyStackTraceProgram X(argc, argv);

  LLVMContext Context;
  llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
  cl::ParseCommandLineOptions(argc, argv, "llvm extractor\n");

  // Use lazy loading, since we only care about selected global values.
  SMDiagnostic Err;
  std::unique_ptr<Module> M = getLazyIRFileModule(InputFilename, Err, Context);

  if (!M.get()) {
    Err.print(argv[0], errs());
    return 1;
  }

  // Use SetVector to avoid duplicates.
  SetVector<GlobalValue *> GVs;

  // Figure out which aliases we should extract.
  for (size_t i = 0, e = ExtractAliases.size(); i != e; ++i) {
    GlobalAlias *GA = M->getNamedAlias(ExtractAliases[i]);
    if (!GA) {
      errs() << argv[0] << ": program doesn't contain alias named '"
             << ExtractAliases[i] << "'!\n";
      return 1;
    }
    GVs.insert(GA);
  }

  // Extract aliases via regular expression matching.
  for (size_t i = 0, e = ExtractRegExpAliases.size(); i != e; ++i) {
    std::string Error;
    Regex RegEx(ExtractRegExpAliases[i]);
    if (!RegEx.isValid(Error)) {
      errs() << argv[0] << ": '" << ExtractRegExpAliases[i] << "' "
        "invalid regex: " << Error;
    }
    bool match = false;
    for (Module::alias_iterator GA = M->alias_begin(), E = M->alias_end();
         GA != E; GA++) {
      if (RegEx.match(GA->getName())) {
        GVs.insert(&*GA);
        match = true;
      }
    }
    if (!match) {
      errs() << argv[0] << ": program doesn't contain global named '"
             << ExtractRegExpAliases[i] << "'!\n";
      return 1;
    }
  }

  // Figure out which globals we should extract.
  for (size_t i = 0, e = ExtractGlobals.size(); i != e; ++i) {
    GlobalValue *GV = M->getNamedGlobal(ExtractGlobals[i]);
    if (!GV) {
      errs() << argv[0] << ": program doesn't contain global named '"
             << ExtractGlobals[i] << "'!\n";
      return 1;
    }
    GVs.insert(GV);
  }

  // Extract globals via regular expression matching.
  for (size_t i = 0, e = ExtractRegExpGlobals.size(); i != e; ++i) {
    std::string Error;
    Regex RegEx(ExtractRegExpGlobals[i]);
    if (!RegEx.isValid(Error)) {
      errs() << argv[0] << ": '" << ExtractRegExpGlobals[i] << "' "
        "invalid regex: " << Error;
    }
    bool match = false;
    for (auto &GV : M->globals()) {
      if (RegEx.match(GV.getName())) {
        GVs.insert(&GV);
        match = true;
      }
    }
    if (!match) {
      errs() << argv[0] << ": program doesn't contain global named '"
             << ExtractRegExpGlobals[i] << "'!\n";
      return 1;
    }
  }

  // Figure out which functions we should extract.
  for (size_t i = 0, e = ExtractFuncs.size(); i != e; ++i) {
    GlobalValue *GV = M->getFunction(ExtractFuncs[i]);
    if (!GV) {
      errs() << argv[0] << ": program doesn't contain function named '"
             << ExtractFuncs[i] << "'!\n";
      return 1;
    }
    GVs.insert(GV);
  }
  // Extract functions via regular expression matching.
  for (size_t i = 0, e = ExtractRegExpFuncs.size(); i != e; ++i) {
    std::string Error;
    StringRef RegExStr = ExtractRegExpFuncs[i];
    Regex RegEx(RegExStr);
    if (!RegEx.isValid(Error)) {
      errs() << argv[0] << ": '" << ExtractRegExpFuncs[i] << "' "
        "invalid regex: " << Error;
    }
    bool match = false;
    for (Module::iterator F = M->begin(), E = M->end(); F != E;
         F++) {
      if (RegEx.match(F->getName())) {
        GVs.insert(&*F);
        match = true;
      }
    }
    if (!match) {
      errs() << argv[0] << ": program doesn't contain global named '"
             << ExtractRegExpFuncs[i] << "'!\n";
      return 1;
    }
  }

  auto Materialize = [&](GlobalValue &GV) {
    if (std::error_code EC = GV.materialize()) {
      errs() << argv[0] << ": error reading input: " << EC.message() << "\n";
      exit(1);
    }
  };

  // Materialize requisite global values.
  if (!DeleteFn) {
    for (size_t i = 0, e = GVs.size(); i != e; ++i)
      Materialize(*GVs[i]);
  } else {
    // Deleting. Materialize every GV that's *not* in GVs.
    SmallPtrSet<GlobalValue *, 8> GVSet(GVs.begin(), GVs.end());
    for (auto &F : *M) {
      if (!GVSet.count(&F))
        Materialize(F);
    }
  }

  {
    std::vector<GlobalValue *> Gvs(GVs.begin(), GVs.end());
    legacy::PassManager Extract;
    Extract.add(createGVExtractionPass(Gvs, DeleteFn));
    Extract.run(*M);

    // Now that we have all the GVs we want, mark the module as fully
    // materialized.
    // FIXME: should the GVExtractionPass handle this?
    M->materializeAll();
  }

  // In addition to deleting all other functions, we also want to spiff it
  // up a little bit.  Do this now.
  legacy::PassManager Passes;

  if (!DeleteFn)
    Passes.add(createGlobalDCEPass());           // Delete unreachable globals
  Passes.add(createStripDeadDebugInfoPass());    // Remove dead debug info
  Passes.add(createStripDeadPrototypesPass());   // Remove dead func decls

  std::error_code EC;
  tool_output_file Out(OutputFilename, EC, sys::fs::F_None);
  if (EC) {
    errs() << EC.message() << '\n';
    return 1;
  }

  if (OutputAssembly)
    Passes.add(
        createPrintModulePass(Out.os(), "", PreserveAssemblyUseListOrder));
  else if (Force || !CheckBitcodeOutputToConsole(Out.os(), true))
    Passes.add(createBitcodeWriterPass(Out.os(), PreserveBitcodeUseListOrder));

  Passes.run(*M.get());

  // Declare success.
  Out.keep();

  return 0;
}
示例#13
0
int main(int argc, char **argv) {
  InitLLVM X(argc, argv);

  LLVMContext Context;
  cl::ParseCommandLineOptions(argc, argv, "llvm extractor\n");

  // Use lazy loading, since we only care about selected global values.
  SMDiagnostic Err;
  std::unique_ptr<Module> M = getLazyIRFileModule(InputFilename, Err, Context);

  if (!M.get()) {
    Err.print(argv[0], errs());
    return 1;
  }

  // Use SetVector to avoid duplicates.
  SetVector<GlobalValue *> GVs;

  // Figure out which aliases we should extract.
  for (size_t i = 0, e = ExtractAliases.size(); i != e; ++i) {
    GlobalAlias *GA = M->getNamedAlias(ExtractAliases[i]);
    if (!GA) {
      errs() << argv[0] << ": program doesn't contain alias named '"
             << ExtractAliases[i] << "'!\n";
      return 1;
    }
    GVs.insert(GA);
  }

  // Extract aliases via regular expression matching.
  for (size_t i = 0, e = ExtractRegExpAliases.size(); i != e; ++i) {
    std::string Error;
    Regex RegEx(ExtractRegExpAliases[i]);
    if (!RegEx.isValid(Error)) {
      errs() << argv[0] << ": '" << ExtractRegExpAliases[i] << "' "
        "invalid regex: " << Error;
    }
    bool match = false;
    for (Module::alias_iterator GA = M->alias_begin(), E = M->alias_end();
         GA != E; GA++) {
      if (RegEx.match(GA->getName())) {
        GVs.insert(&*GA);
        match = true;
      }
    }
    if (!match) {
      errs() << argv[0] << ": program doesn't contain global named '"
             << ExtractRegExpAliases[i] << "'!\n";
      return 1;
    }
  }

  // Figure out which globals we should extract.
  for (size_t i = 0, e = ExtractGlobals.size(); i != e; ++i) {
    GlobalValue *GV = M->getNamedGlobal(ExtractGlobals[i]);
    if (!GV) {
      errs() << argv[0] << ": program doesn't contain global named '"
             << ExtractGlobals[i] << "'!\n";
      return 1;
    }
    GVs.insert(GV);
  }

  // Extract globals via regular expression matching.
  for (size_t i = 0, e = ExtractRegExpGlobals.size(); i != e; ++i) {
    std::string Error;
    Regex RegEx(ExtractRegExpGlobals[i]);
    if (!RegEx.isValid(Error)) {
      errs() << argv[0] << ": '" << ExtractRegExpGlobals[i] << "' "
        "invalid regex: " << Error;
    }
    bool match = false;
    for (auto &GV : M->globals()) {
      if (RegEx.match(GV.getName())) {
        GVs.insert(&GV);
        match = true;
      }
    }
    if (!match) {
      errs() << argv[0] << ": program doesn't contain global named '"
             << ExtractRegExpGlobals[i] << "'!\n";
      return 1;
    }
  }

  // Figure out which functions we should extract.
  for (size_t i = 0, e = ExtractFuncs.size(); i != e; ++i) {
    GlobalValue *GV = M->getFunction(ExtractFuncs[i]);
    if (!GV) {
      errs() << argv[0] << ": program doesn't contain function named '"
             << ExtractFuncs[i] << "'!\n";
      return 1;
    }
    GVs.insert(GV);
  }
  // Extract functions via regular expression matching.
  for (size_t i = 0, e = ExtractRegExpFuncs.size(); i != e; ++i) {
    std::string Error;
    StringRef RegExStr = ExtractRegExpFuncs[i];
    Regex RegEx(RegExStr);
    if (!RegEx.isValid(Error)) {
      errs() << argv[0] << ": '" << ExtractRegExpFuncs[i] << "' "
        "invalid regex: " << Error;
    }
    bool match = false;
    for (Module::iterator F = M->begin(), E = M->end(); F != E;
         F++) {
      if (RegEx.match(F->getName())) {
        GVs.insert(&*F);
        match = true;
      }
    }
    if (!match) {
      errs() << argv[0] << ": program doesn't contain global named '"
             << ExtractRegExpFuncs[i] << "'!\n";
      return 1;
    }
  }

  // Figure out which BasicBlocks we should extract.
  SmallVector<BasicBlock *, 4> BBs;
  for (StringRef StrPair : ExtractBlocks) {
    auto BBInfo = StrPair.split(':');
    // Get the function.
    Function *F = M->getFunction(BBInfo.first);
    if (!F) {
      errs() << argv[0] << ": program doesn't contain a function named '"
             << BBInfo.first << "'!\n";
      return 1;
    }
    // Do not materialize this function.
    GVs.insert(F);
    // Get the basic block.
    auto Res = llvm::find_if(*F, [&](const BasicBlock &BB) {
      return BB.getName().equals(BBInfo.second);
    });
    if (Res == F->end()) {
      errs() << argv[0] << ": function " << F->getName()
             << " doesn't contain a basic block named '" << BBInfo.second
             << "'!\n";
      return 1;
    }
    BBs.push_back(&*Res);
  }

  // Use *argv instead of argv[0] to work around a wrong GCC warning.
  ExitOnError ExitOnErr(std::string(*argv) + ": error reading input: ");

  if (Recursive) {
    std::vector<llvm::Function *> Workqueue;
    for (GlobalValue *GV : GVs) {
      if (auto *F = dyn_cast<Function>(GV)) {
        Workqueue.push_back(F);
      }
    }
    while (!Workqueue.empty()) {
      Function *F = &*Workqueue.back();
      Workqueue.pop_back();
      ExitOnErr(F->materialize());
      for (auto &BB : *F) {
        for (auto &I : BB) {
          auto *CI = dyn_cast<CallInst>(&I);
          if (!CI)
            continue;
          Function *CF = CI->getCalledFunction();
          if (!CF)
            continue;
          if (CF->isDeclaration() || GVs.count(CF))
            continue;
          GVs.insert(CF);
          Workqueue.push_back(CF);
        }
      }
    }
  }

  auto Materialize = [&](GlobalValue &GV) { ExitOnErr(GV.materialize()); };

  // Materialize requisite global values.
  if (!DeleteFn) {
    for (size_t i = 0, e = GVs.size(); i != e; ++i)
      Materialize(*GVs[i]);
  } else {
    // Deleting. Materialize every GV that's *not* in GVs.
    SmallPtrSet<GlobalValue *, 8> GVSet(GVs.begin(), GVs.end());
    for (auto &F : *M) {
      if (!GVSet.count(&F))
        Materialize(F);
    }
  }

  {
    std::vector<GlobalValue *> Gvs(GVs.begin(), GVs.end());
    legacy::PassManager Extract;
    Extract.add(createGVExtractionPass(Gvs, DeleteFn));
    Extract.run(*M);

    // Now that we have all the GVs we want, mark the module as fully
    // materialized.
    // FIXME: should the GVExtractionPass handle this?
    ExitOnErr(M->materializeAll());
  }

  // Extract the specified basic blocks from the module and erase the existing
  // functions.
  if (!ExtractBlocks.empty()) {
    legacy::PassManager PM;
    PM.add(createBlockExtractorPass(BBs, true));
    PM.run(*M);
  }

  // In addition to deleting all other functions, we also want to spiff it
  // up a little bit.  Do this now.
  legacy::PassManager Passes;

  if (!DeleteFn)
    Passes.add(createGlobalDCEPass());           // Delete unreachable globals
  Passes.add(createStripDeadDebugInfoPass());    // Remove dead debug info
  Passes.add(createStripDeadPrototypesPass());   // Remove dead func decls

  std::error_code EC;
  ToolOutputFile Out(OutputFilename, EC, sys::fs::F_None);
  if (EC) {
    errs() << EC.message() << '\n';
    return 1;
  }

  if (OutputAssembly)
    Passes.add(
        createPrintModulePass(Out.os(), "", PreserveAssemblyUseListOrder));
  else if (Force || !CheckBitcodeOutputToConsole(Out.os(), true))
    Passes.add(createBitcodeWriterPass(Out.os(), PreserveBitcodeUseListOrder));

  Passes.run(*M.get());

  // Declare success.
  Out.keep();

  return 0;
}
示例#14
0
bool InternalizePass::runOnModule(Module &M) {
  CallGraphWrapperPass *CGPass = getAnalysisIfAvailable<CallGraphWrapperPass>();
  CallGraph *CG = CGPass ? &CGPass->getCallGraph() : 0;
  CallGraphNode *ExternalNode = CG ? CG->getExternalCallingNode() : 0;
  bool Changed = false;

  SmallPtrSet<GlobalValue *, 8> Used;
  collectUsedGlobalVariables(M, Used, false);

  // We must assume that globals in llvm.used have a reference that not even
  // the linker can see, so we don't internalize them.
  // For llvm.compiler.used the situation is a bit fuzzy. The assembler and
  // linker can drop those symbols. If this pass is running as part of LTO,
  // one might think that it could just drop llvm.compiler.used. The problem
  // is that even in LTO llvm doesn't see every reference. For example,
  // we don't see references from function local inline assembly. To be
  // conservative, we internalize symbols in llvm.compiler.used, but we
  // keep llvm.compiler.used so that the symbol is not deleted by llvm.
  for (SmallPtrSet<GlobalValue *, 8>::iterator I = Used.begin(), E = Used.end();
       I != E; ++I) {
    GlobalValue *V = *I;
    ExternalNames.insert(V->getName());
  }

  // Mark all functions not in the api as internal.
  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
    if (!shouldInternalize(*I, ExternalNames, OnlyHidden))
      continue;

    I->setLinkage(GlobalValue::InternalLinkage);

    if (ExternalNode)
      // Remove a callgraph edge from the external node to this function.
      ExternalNode->removeOneAbstractEdgeTo((*CG)[I]);

    Changed = true;
    ++NumFunctions;
    DEBUG(dbgs() << "Internalizing func " << I->getName() << "\n");
  }

  // Never internalize the llvm.used symbol.  It is used to implement
  // attribute((used)).
  // FIXME: Shouldn't this just filter on llvm.metadata section??
  ExternalNames.insert("llvm.used");
  ExternalNames.insert("llvm.compiler.used");

  // Never internalize anchors used by the machine module info, else the info
  // won't find them.  (see MachineModuleInfo.)
  ExternalNames.insert("llvm.global_ctors");
  ExternalNames.insert("llvm.global_dtors");
  ExternalNames.insert("llvm.global.annotations");

  // Never internalize symbols code-gen inserts.
  // FIXME: We should probably add this (and the __stack_chk_guard) via some
  // type of call-back in CodeGen.
  ExternalNames.insert("__stack_chk_fail");
  ExternalNames.insert("__stack_chk_guard");

  // Mark all global variables with initializers that are not in the api as
  // internal as well.
  for (Module::global_iterator I = M.global_begin(), E = M.global_end();
       I != E; ++I) {
    if (!shouldInternalize(*I, ExternalNames, OnlyHidden))
      continue;

    I->setLinkage(GlobalValue::InternalLinkage);
    Changed = true;
    ++NumGlobals;
    DEBUG(dbgs() << "Internalized gvar " << I->getName() << "\n");
  }

  // Mark all aliases that are not in the api as internal as well.
  for (Module::alias_iterator I = M.alias_begin(), E = M.alias_end();
       I != E; ++I) {
    if (!shouldInternalize(*I, ExternalNames, OnlyHidden))
      continue;

    I->setLinkage(GlobalValue::InternalLinkage);
    Changed = true;
    ++NumAliases;
    DEBUG(dbgs() << "Internalized alias " << I->getName() << "\n");
  }

  return Changed;
}
示例#15
0
/// Based on GetAllUndefinedSymbols() from LLVM3.2
///
/// GetAllUndefinedSymbols - calculates the set of undefined symbols that still
/// exist in an LLVM module. This is a bit tricky because there may be two
/// symbols with the same name but different LLVM types that will be resolved to
/// each other but aren't currently (thus we need to treat it as resolved).
///
/// Inputs:
///  M - The module in which to find undefined symbols.
///
/// Outputs:
///  UndefinedSymbols - A set of C++ strings containing the name of all
///                     undefined symbols.
///
static void
GetAllUndefinedSymbols(Module *M, std::set<std::string> &UndefinedSymbols) {
    static const std::string llvmIntrinsicPrefix="llvm.";
    std::set<std::string> DefinedSymbols;
    UndefinedSymbols.clear();
    KLEE_DEBUG_WITH_TYPE("klee_linker",
                         dbgs() << "*** Computing undefined symbols ***\n");

    for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I)
        if (I->hasName()) {
            if (I->isDeclaration())
                UndefinedSymbols.insert(I->getName());
            else if (!I->hasLocalLinkage()) {
#if LLVM_VERSION_CODE < LLVM_VERSION(3, 5)
                assert(!I->hasDLLImportLinkage() && "Found dllimported non-external symbol!");
#else
                assert(!I->hasDLLImportStorageClass() && "Found dllimported non-external symbol!");
#endif
                DefinedSymbols.insert(I->getName());
            }
        }

    for (Module::global_iterator I = M->global_begin(), E = M->global_end();
            I != E; ++I)
        if (I->hasName()) {
            if (I->isDeclaration())
                UndefinedSymbols.insert(I->getName());
            else if (!I->hasLocalLinkage()) {
#if LLVM_VERSION_CODE < LLVM_VERSION(3, 5)
                assert(!I->hasDLLImportLinkage() && "Found dllimported non-external symbol!");
#else
                assert(!I->hasDLLImportStorageClass() && "Found dllimported non-external symbol!");
#endif
                DefinedSymbols.insert(I->getName());
            }
        }

    for (Module::alias_iterator I = M->alias_begin(), E = M->alias_end();
            I != E; ++I)
        if (I->hasName())
            DefinedSymbols.insert(I->getName());


    // Prune out any defined symbols from the undefined symbols set
    // and other symbols we don't want to treat as an undefined symbol
    std::vector<std::string> SymbolsToRemove;
    for (std::set<std::string>::iterator I = UndefinedSymbols.begin();
            I != UndefinedSymbols.end(); ++I )
    {
        if (DefinedSymbols.count(*I))
        {
            SymbolsToRemove.push_back(*I);
            continue;
        }

        // Strip out llvm intrinsics
        if ( (I->size() >= llvmIntrinsicPrefix.size() ) &&
                (I->compare(0, llvmIntrinsicPrefix.size(), llvmIntrinsicPrefix) == 0) )
        {
            KLEE_DEBUG_WITH_TYPE("klee_linker", dbgs() << "LLVM intrinsic " << *I <<
                                 " has will be removed from undefined symbols"<< "\n");
            SymbolsToRemove.push_back(*I);
            continue;
        }

        // Symbol really is undefined
        KLEE_DEBUG_WITH_TYPE("klee_linker",
                             dbgs() << "Symbol " << *I << " is undefined.\n");
    }

    // Remove KLEE intrinsics from set of undefined symbols
    for (SpecialFunctionHandler::const_iterator sf = SpecialFunctionHandler::begin(),
            se = SpecialFunctionHandler::end(); sf != se; ++sf)
    {
        if (UndefinedSymbols.find(sf->name) == UndefinedSymbols.end())
            continue;

        SymbolsToRemove.push_back(sf->name);
        KLEE_DEBUG_WITH_TYPE("klee_linker",
                             dbgs() << "KLEE intrinsic " << sf->name <<
                             " has will be removed from undefined symbols"<< "\n");
    }

    // Now remove the symbols from undefined set.
    for (size_t i = 0, j = SymbolsToRemove.size(); i < j; ++i )
        UndefinedSymbols.erase(SymbolsToRemove[i]);

    KLEE_DEBUG_WITH_TYPE("klee_linker",
                         dbgs() << "*** Finished computing undefined symbols ***\n");
}
示例#16
0
int main(int argc, char **argv) {
  // Print a stack trace if we signal out.
  sys::PrintStackTraceOnErrorSignal();
  PrettyStackTraceProgram X(argc, argv);

  LLVMContext &Context = getGlobalContext();
  llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
  cl::ParseCommandLineOptions(argc, argv, "llvm extractor\n");

  // Use lazy loading, since we only care about selected global values.
  SMDiagnostic Err;
  std::unique_ptr<Module> M;
  M.reset(getLazyIRFileModule(InputFilename, Err, Context));

  if (!M.get()) {
    Err.print(argv[0], errs());
    return 1;
  }

  // Use SetVector to avoid duplicates.
  SetVector<GlobalValue *> GVs;

  // Figure out which aliases we should extract.
  for (size_t i = 0, e = ExtractAliases.size(); i != e; ++i) {
    GlobalAlias *GA = M->getNamedAlias(ExtractAliases[i]);
    if (!GA) {
      errs() << argv[0] << ": program doesn't contain alias named '"
             << ExtractAliases[i] << "'!\n";
      return 1;
    }
    GVs.insert(GA);
  }

  // Extract aliases via regular expression matching.
  for (size_t i = 0, e = ExtractRegExpAliases.size(); i != e; ++i) {
    std::string Error;
    Regex RegEx(ExtractRegExpAliases[i]);
    if (!RegEx.isValid(Error)) {
      errs() << argv[0] << ": '" << ExtractRegExpAliases[i] << "' "
        "invalid regex: " << Error;
    }
    bool match = false;
    for (Module::alias_iterator GA = M->alias_begin(), E = M->alias_end();
         GA != E; GA++) {
      if (RegEx.match(GA->getName())) {
        GVs.insert(&*GA);
        match = true;
      }
    }
    if (!match) {
      errs() << argv[0] << ": program doesn't contain global named '"
             << ExtractRegExpAliases[i] << "'!\n";
      return 1;
    }
  }

  // Figure out which globals we should extract.
  for (size_t i = 0, e = ExtractGlobals.size(); i != e; ++i) {
    GlobalValue *GV = M->getNamedGlobal(ExtractGlobals[i]);
    if (!GV) {
      errs() << argv[0] << ": program doesn't contain global named '"
             << ExtractGlobals[i] << "'!\n";
      return 1;
    }
    GVs.insert(GV);
  }

  // Extract globals via regular expression matching.
  for (size_t i = 0, e = ExtractRegExpGlobals.size(); i != e; ++i) {
    std::string Error;
    Regex RegEx(ExtractRegExpGlobals[i]);
    if (!RegEx.isValid(Error)) {
      errs() << argv[0] << ": '" << ExtractRegExpGlobals[i] << "' "
        "invalid regex: " << Error;
    }
    bool match = false;
    for (Module::global_iterator GV = M->global_begin(),
           E = M->global_end(); GV != E; GV++) {
      if (RegEx.match(GV->getName())) {
        GVs.insert(&*GV);
        match = true;
      }
    }
    if (!match) {
      errs() << argv[0] << ": program doesn't contain global named '"
             << ExtractRegExpGlobals[i] << "'!\n";
      return 1;
    }
  }

  // Figure out which functions we should extract.
  for (size_t i = 0, e = ExtractFuncs.size(); i != e; ++i) {
    GlobalValue *GV = M->getFunction(ExtractFuncs[i]);
    if (!GV) {
      errs() << argv[0] << ": program doesn't contain function named '"
             << ExtractFuncs[i] << "'!\n";
      return 1;
    }
    GVs.insert(GV);
  }
  // Extract functions via regular expression matching.
  for (size_t i = 0, e = ExtractRegExpFuncs.size(); i != e; ++i) {
    std::string Error;
    StringRef RegExStr = ExtractRegExpFuncs[i];
    Regex RegEx(RegExStr);
    if (!RegEx.isValid(Error)) {
      errs() << argv[0] << ": '" << ExtractRegExpFuncs[i] << "' "
        "invalid regex: " << Error;
    }
    bool match = false;
    for (Module::iterator F = M->begin(), E = M->end(); F != E;
         F++) {
      if (RegEx.match(F->getName())) {
        GVs.insert(&*F);
        match = true;
      }
    }
    if (!match) {
      errs() << argv[0] << ": program doesn't contain global named '"
             << ExtractRegExpFuncs[i] << "'!\n";
      return 1;
    }
  }

  // Materialize requisite global values.
  if (!DeleteFn)
    for (size_t i = 0, e = GVs.size(); i != e; ++i) {
      GlobalValue *GV = GVs[i];
      if (GV->isMaterializable()) {
        std::string ErrInfo;
        if (GV->Materialize(&ErrInfo)) {
          errs() << argv[0] << ": error reading input: " << ErrInfo << "\n";
          return 1;
        }
      }
    }
  else {
    // Deleting. Materialize every GV that's *not* in GVs.
    SmallPtrSet<GlobalValue *, 8> GVSet(GVs.begin(), GVs.end());
    for (Module::global_iterator I = M->global_begin(), E = M->global_end();
         I != E; ++I) {
      GlobalVariable *G = I;
      if (!GVSet.count(G) && G->isMaterializable()) {
        std::string ErrInfo;
        if (G->Materialize(&ErrInfo)) {
          errs() << argv[0] << ": error reading input: " << ErrInfo << "\n";
          return 1;
        }
      }
    }
    for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I) {
      Function *F = I;
      if (!GVSet.count(F) && F->isMaterializable()) {
        std::string ErrInfo;
        if (F->Materialize(&ErrInfo)) {
          errs() << argv[0] << ": error reading input: " << ErrInfo << "\n";
          return 1;
        }
      }
    }
  }

  // In addition to deleting all other functions, we also want to spiff it
  // up a little bit.  Do this now.
  PassManager Passes;
  Passes.add(new DataLayoutPass(M.get())); // Use correct DataLayout

  std::vector<GlobalValue*> Gvs(GVs.begin(), GVs.end());

  Passes.add(createGVExtractionPass(Gvs, DeleteFn));
  if (!DeleteFn)
    Passes.add(createGlobalDCEPass());           // Delete unreachable globals
  Passes.add(createStripDeadDebugInfoPass());    // Remove dead debug info
  Passes.add(createStripDeadPrototypesPass());   // Remove dead func decls

  std::string ErrorInfo;
  tool_output_file Out(OutputFilename.c_str(), ErrorInfo, sys::fs::F_None);
  if (!ErrorInfo.empty()) {
    errs() << ErrorInfo << '\n';
    return 1;
  }

  if (OutputAssembly)
    Passes.add(createPrintModulePass(Out.os()));
  else if (Force || !CheckBitcodeOutputToConsole(Out.os(), true))
    Passes.add(createBitcodeWriterPass(Out.os()));

  Passes.run(*M.get());

  // Declare success.
  Out.keep();

  return 0;
}