C++ iterator::hasExternalLinkage方法代码示例

/// Emit extern decls for functions imported from other modules, and emit
/// global declarations for function defined in this module and which are
/// available to other modules.
///
void PIC16AsmPrinter::EmitFunctionDecls(Module &M) {
 // Emit declarations for external functions.
  O <<"\n"<<TAI->getCommentString() << "Function Declarations - BEGIN." <<"\n";
  for (Module::iterator I = M.begin(), E = M.end(); I != E; I++) {
    if (I->isIntrinsic())
      continue;

    std::string Name = Mang->getMangledName(I);
    if (Name.compare("@abort") == 0)
      continue;
    
    if (!I->isDeclaration() && !I->hasExternalLinkage())
      continue;

    // Do not emit memcpy, memset, and memmove here.
    // Calls to these routines can be generated in two ways,
    // 1. User calling the standard lib function
    // 2. Codegen generating these calls for llvm intrinsics.
    // In the first case a prototype is alread availale, while in
    // second case the call is via and externalsym and the prototype is missing.
    // So declarations for these are currently always getting printing by
    // tracking both kind of references in printInstrunction.
    if (I->isDeclaration() && PAN::isMemIntrinsic(Name)) continue;

    const char *directive = I->isDeclaration() ? TAI->getExternDirective() :
                                                 TAI->getGlobalDirective();
      
    O << directive << Name << "\n";
    O << directive << PAN::getRetvalLabel(Name) << "\n";
    O << directive << PAN::getArgsLabel(Name) << "\n";
  }

  O << TAI->getCommentString() << "Function Declarations - END." <<"\n";
}

// Emit extern decls for functions imported from other modules, and emit
// global declarations for function defined in this module and which are
// available to other modules.
void PIC16AsmPrinter::EmitFunctionDecls (Module &M) {
 // Emit declarations for external functions.
  O << TAI->getCommentString() << "Function Declarations - BEGIN." <<"\n";
  for (Module::iterator I = M.begin(), E = M.end(); I != E; I++) {
    std::string Name = Mang->getValueName(I);
    if (Name.compare("@abort") == 0)
      continue;
    
    // If it is llvm intrinsic call then don't emit
    if (Name.find("llvm.") != std::string::npos)
      continue;

    if (! (I->isDeclaration() || I->hasExternalLinkage()))
      continue;

    const char *directive = I->isDeclaration() ? TAI->getExternDirective() :
                                                 TAI->getGlobalDirective();
      
    O << directive << Name << "\n";
    O << directive << PAN::getRetvalLabel(Name) << "\n";
    O << directive << PAN::getArgsLabel(Name) << "\n";
  }

  O << TAI->getCommentString() << "Function Declarations - END." <<"\n";
}

bool MergeFunctions::runOnModule(Module &M) {
  bool Changed = false;

  std::map<unsigned long, std::vector<Function *> > FnMap;

  for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
    if (F->isDeclaration() || F->isIntrinsic())
      continue;

    if (!F->hasLocalLinkage() && !F->hasExternalLinkage() &&
        !F->hasWeakLinkage())
      continue;

    if (hasAddressTaken(F))
      continue;

    FnMap[hash(F)].push_back(F);
  }

  // TODO: instead of running in a loop, we could also fold functions in callgraph
  // order. Constructing the CFG probably isn't cheaper than just running in a loop.

  bool LocalChanged;
  do {
    LocalChanged = false;
    for (std::map<unsigned long, std::vector<Function *> >::iterator
         I = FnMap.begin(), E = FnMap.end(); I != E; ++I) {
      DOUT << "size: " << FnMap.size() << "\n";
      std::vector<Function *> &FnVec = I->second;
      DOUT << "hash (" << I->first << "): " << FnVec.size() << "\n";

      for (int i = 0, e = FnVec.size(); i != e; ++i) {
        for (int j = i + 1; j != e; ++j) {
          bool isEqual = equals(FnVec[i], FnVec[j]);

          DOUT << "  " << FnVec[i]->getName()
               << (isEqual ? " == " : " != ")
               << FnVec[j]->getName() << "\n";

          if (isEqual) {
            if (fold(FnVec, i, j)) {
              LocalChanged = true;
              FnVec.erase(FnVec.begin() + j);
              --j, --e;
            }
          }
        }
      }

    }
    Changed |= LocalChanged;
  } while (LocalChanged);

  return Changed;
}

/* Change linkages of global values, in order to
 * improve alias analysis.
 */
bool DeadStoreEliminationPass::changeLinkageTypes(Module &M) {
  DEBUG(errs() << "Changing linkages to private...\n");
  for (Module::global_iterator git = M.global_begin(), gitE = M.global_end();
        git != gitE; ++git) {
    DEBUG(errs() << "  " << *git << "\n");
    if (!git->hasExternalLinkage() && !git->hasAppendingLinkage()) git->setLinkage(GlobalValue::PrivateLinkage);
  }
  for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
    if (!F->isDeclaration()) {
     if (!F->hasExternalLinkage() && !F->hasAppendingLinkage()) F->setLinkage(GlobalValue::PrivateLinkage);
      DEBUG(errs() << "  " << F->getName() << "\n");
    }
  }
  DEBUG(errs() << "\n");
  return true;
}

void PIC16AsmPrinter::EmitExternsAndGlobals (Module &M) {
 // Emit declarations for external functions.
  O << "section.0" <<"\n";
  for (Module::iterator I = M.begin(), E = M.end(); I != E; I++) {
    std::string Name = Mang->getValueName(I);
    if (Name.compare("abort") == 0)
      continue;
    if (I->isDeclaration()) {
      O << "\textern " <<Name << "\n";
      O << "\textern " << Name << ".retval\n";
      O << "\textern " << Name << ".args\n";
    }
    else if (I->hasExternalLinkage()) {
      O << "\tglobal " << Name << "\n";
      O << "\tglobal " << Name << ".retval\n";
      O << "\tglobal " << Name << ".args\n";
    }
  }

  // Emit header file to include declaration of library functions
  O << "\t#include C16IntrinsicCalls.INC\n";

  // Emit declarations for external globals.
  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
       I != E; I++) {
    // Any variables reaching here with ".auto." in its name is a local scope
    // variable and should not be printed in global data section.
    std::string Name = Mang->getValueName(I);
    if (isLocalName (Name))
      continue;

    if (I->isDeclaration())
      O << "\textern "<< Name << "\n";
    else if (I->hasCommonLinkage() || I->hasExternalLinkage())
      O << "\tglobal "<< Name << "\n";
  }
}