C++ const_global_iterator::isDeclaration方法代码示例

bool X86IntelAsmPrinter::doInitialization(Module &M) {
  bool Result = AsmPrinter::doInitialization(M);

  Mang->markCharUnacceptable('.');

  O << "\t.686\n\t.model flat\n\n";

  // Emit declarations for external functions.
  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
    if (I->isDeclaration()) {
      std::string Name = Mang->getValueName(I);
      decorateName(Name, I);

      O << "\textern " ;
      if (I->hasDLLImportLinkage()) {
        O << "__imp_";
      }
      O << Name << ":near\n";
    }

  // Emit declarations for external globals.  Note that VC++ always declares
  // external globals to have type byte, and if that's good enough for VC++...
  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
       I != E; ++I) {
    if (I->isDeclaration()) {
      std::string Name = Mang->getValueName(I);

      O << "\textern " ;
      if (I->hasDLLImportLinkage()) {
        O << "__imp_";
      }
      O << Name << ":byte\n";
    }
  }

  return Result;
}

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";
  }
}

/// EmitGlobals - Emit all of the global variables to memory, storing their
/// addresses into GlobalAddress.  This must make sure to copy the contents of
/// their initializers into the memory.
///
void ExecutionEngine::emitGlobals() {

  // Loop over all of the global variables in the program, allocating the memory
  // to hold them.  If there is more than one module, do a prepass over globals
  // to figure out how the different modules should link together.
  //
  std::map<std::pair<std::string, const Type*>,
           const GlobalValue*> LinkedGlobalsMap;

  if (Modules.size() != 1) {
    for (unsigned m = 0, e = Modules.size(); m != e; ++m) {
      Module &M = *Modules[m]->getModule();
      for (Module::const_global_iterator I = M.global_begin(),
           E = M.global_end(); I != E; ++I) {
        const GlobalValue *GV = I;
        if (GV->hasLocalLinkage() || GV->isDeclaration() ||
            GV->hasAppendingLinkage() || !GV->hasName())
          continue;// Ignore external globals and globals with internal linkage.
          
        const GlobalValue *&GVEntry = 
          LinkedGlobalsMap[std::make_pair(GV->getName(), GV->getType())];

        // If this is the first time we've seen this global, it is the canonical
        // version.
        if (!GVEntry) {
          GVEntry = GV;
          continue;
        }
        
        // If the existing global is strong, never replace it.
        if (GVEntry->hasExternalLinkage() ||
            GVEntry->hasDLLImportLinkage() ||
            GVEntry->hasDLLExportLinkage())
          continue;
        
        // Otherwise, we know it's linkonce/weak, replace it if this is a strong
        // symbol.  FIXME is this right for common?
        if (GV->hasExternalLinkage() || GVEntry->hasExternalWeakLinkage())
          GVEntry = GV;
      }
    }
  }
  
  std::vector<const GlobalValue*> NonCanonicalGlobals;
  for (unsigned m = 0, e = Modules.size(); m != e; ++m) {
    Module &M = *Modules[m]->getModule();
    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
         I != E; ++I) {
      // In the multi-module case, see what this global maps to.
      if (!LinkedGlobalsMap.empty()) {
        if (const GlobalValue *GVEntry = 
              LinkedGlobalsMap[std::make_pair(I->getName(), I->getType())]) {
          // If something else is the canonical global, ignore this one.
          if (GVEntry != &*I) {
            NonCanonicalGlobals.push_back(I);
            continue;
          }
        }
      }
      
      if (!I->isDeclaration()) {
        addGlobalMapping(I, getMemoryForGV(I));
      } else {
        // External variable reference. Try to use the dynamic loader to
        // get a pointer to it.
        if (void *SymAddr =
            sys::DynamicLibrary::SearchForAddressOfSymbol(I->getName().c_str()))
          addGlobalMapping(I, SymAddr);
        else {
          cerr << "Could not resolve external global address: "
               << I->getName() << "\n";
          abort();
        }
      }
    }
    
    // If there are multiple modules, map the non-canonical globals to their
    // canonical location.
    if (!NonCanonicalGlobals.empty()) {
      for (unsigned i = 0, e = NonCanonicalGlobals.size(); i != e; ++i) {
        const GlobalValue *GV = NonCanonicalGlobals[i];
        const GlobalValue *CGV =
          LinkedGlobalsMap[std::make_pair(GV->getName(), GV->getType())];
        void *Ptr = getPointerToGlobalIfAvailable(CGV);
        assert(Ptr && "Canonical global wasn't codegen'd!");
        addGlobalMapping(GV, Ptr);
      }
    }
    
    // Now that all of the globals are set up in memory, loop through them all 
    // and initialize their contents.
    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
         I != E; ++I) {
      if (!I->isDeclaration()) {
        if (!LinkedGlobalsMap.empty()) {
          if (const GlobalValue *GVEntry = 
//.........这里部分代码省略.........

void externalsAndGlobalsCheck(const Module *m) {
  std::map<std::string, bool> externals;
  std::set<std::string> modelled(modelledExternals,
                                 modelledExternals+NELEMS(modelledExternals));
  std::set<std::string> dontCare(dontCareExternals,
                                 dontCareExternals+NELEMS(dontCareExternals));
  std::set<std::string> unsafe(unsafeExternals,
                               unsafeExternals+NELEMS(unsafeExternals));

  switch (Libc) {
  case KleeLibc:
    dontCare.insert(dontCareKlee, dontCareKlee+NELEMS(dontCareKlee));
    break;
  case UcLibc:
    dontCare.insert(dontCareUclibc,
                    dontCareUclibc+NELEMS(dontCareUclibc));
    break;
  case NoLibc: /* silence compiler warning */
    break;
  }

  if (WithPOSIXRuntime)
    dontCare.insert("syscall");

  for (Module::const_iterator fnIt = m->begin(), fn_ie = m->end();
       fnIt != fn_ie; ++fnIt) {
    if (fnIt->isDeclaration() && !fnIt->use_empty())
      externals.insert(std::make_pair(fnIt->getName(), false));
    for (Function::const_iterator bbIt = fnIt->begin(), bb_ie = fnIt->end();
         bbIt != bb_ie; ++bbIt) {
      for (BasicBlock::const_iterator it = bbIt->begin(), ie = bbIt->end();
           it != ie; ++it) {
        if (const CallInst *ci = dyn_cast<CallInst>(it)) {
          if (isa<InlineAsm>(ci->getCalledValue())) {
            klee_warning_once(&*fnIt,
                              "function \"%s\" has inline asm",
                              fnIt->getName().data());
          }
        }
      }
    }
  }
  for (Module::const_global_iterator
         it = m->global_begin(), ie = m->global_end();
       it != ie; ++it)
    if (it->isDeclaration() && !it->use_empty())
      externals.insert(std::make_pair(it->getName(), true));
  // and remove aliases (they define the symbol after global
  // initialization)
  for (Module::const_alias_iterator
         it = m->alias_begin(), ie = m->alias_end();
       it != ie; ++it) {
    std::map<std::string, bool>::iterator it2 =
      externals.find(it->getName());
    if (it2!=externals.end())
      externals.erase(it2);
  }

  std::map<std::string, bool> foundUnsafe;
  for (std::map<std::string, bool>::iterator
         it = externals.begin(), ie = externals.end();
       it != ie; ++it) {
    const std::string &ext = it->first;
    if (!modelled.count(ext) && (WarnAllExternals ||
                                 !dontCare.count(ext))) {
      if (unsafe.count(ext)) {
        foundUnsafe.insert(*it);
      } else {
        klee_warning("undefined reference to %s: %s",
                     it->second ? "variable" : "function",
                     ext.c_str());
      }
    }
  }

  for (std::map<std::string, bool>::iterator
         it = foundUnsafe.begin(), ie = foundUnsafe.end();
       it != ie; ++it) {
    const std::string &ext = it->first;
    klee_warning("undefined reference to %s: %s (UNSAFE)!",
                 it->second ? "variable" : "function",
                 ext.c_str());
  }
}

/// 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 for "
                              << M->getModuleIdentifier() << " ***\n");

  for (auto const &Function : *M) {
    if (Function.hasName()) {
      if (Function.isDeclaration())
        UndefinedSymbols.insert(Function.getName());
      else if (!Function.hasLocalLinkage()) {
#if LLVM_VERSION_CODE < LLVM_VERSION(3, 5)
        assert(!Function.hasDLLImportLinkage() &&
               "Found dllimported non-external symbol!");
#else
        assert(!Function.hasDLLImportStorageClass() &&
               "Found dllimported non-external symbol!");
#endif
        DefinedSymbols.insert(Function.getName());
      }
    }
  }

  for (Module::const_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::const_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.find(*I) != DefinedSymbols.end()) {
      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");
  }

  // Now remove the symbols from undefined set.
  for (auto const &symbol : SymbolsToRemove)
    UndefinedSymbols.erase(symbol);

  KLEE_DEBUG_WITH_TYPE("klee_linker",
                       dbgs() << "*** Finished computing undefined symbols ***\n");
}

bool X86IntelAsmPrinter::doFinalization(Module &M) {
  const TargetData *TD = TM.getTargetData();

  // Print out module-level global variables here.
  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
       I != E; ++I) {
    if (I->isDeclaration()) continue;   // External global require no code

    // Check to see if this is a special global used by LLVM, if so, emit it.
    if (EmitSpecialLLVMGlobal(I))
      continue;

    std::string name = Mang->getValueName(I);
    Constant *C = I->getInitializer();
    unsigned Align = TD->getPreferredAlignmentLog(I);
    bool bCustomSegment = false;

    switch (I->getLinkage()) {
    case GlobalValue::CommonLinkage:
    case GlobalValue::LinkOnceLinkage:
    case GlobalValue::WeakLinkage:
      SwitchToDataSection("");
      O << name << "?\tsegment common 'COMMON'\n";
      bCustomSegment = true;
      // FIXME: the default alignment is 16 bytes, but 1, 2, 4, and 256
      // are also available.
      break;
    case GlobalValue::AppendingLinkage:
      SwitchToDataSection("");
      O << name << "?\tsegment public 'DATA'\n";
      bCustomSegment = true;
      // FIXME: the default alignment is 16 bytes, but 1, 2, 4, and 256
      // are also available.
      break;
    case GlobalValue::DLLExportLinkage:
      DLLExportedGVs.insert(name);
      // FALL THROUGH
    case GlobalValue::ExternalLinkage:
      O << "\tpublic " << name << "\n";
      // FALL THROUGH
    case GlobalValue::InternalLinkage:
      SwitchToSection(TAI->getDataSection());
      break;
    default:
      assert(0 && "Unknown linkage type!");
    }

    if (!bCustomSegment)
      EmitAlignment(Align, I);

    O << name << ":\t\t\t\t" << TAI->getCommentString()
      << " " << I->getName() << '\n';

    EmitGlobalConstant(C);

    if (bCustomSegment)
      O << name << "?\tends\n";
  }

    // Output linker support code for dllexported globals
  if (!DLLExportedGVs.empty() || !DLLExportedFns.empty()) {
    SwitchToDataSection("");
    O << "; WARNING: The following code is valid only with MASM v8.x"
      << "and (possible) higher\n"
      << "; This version of MASM is usually shipped with Microsoft "
      << "Visual Studio 2005\n"
      << "; or (possible) further versions. Unfortunately, there is no "
      << "way to support\n"
      << "; dllexported symbols in the earlier versions of MASM in fully "
      << "automatic way\n\n";
    O << "_drectve\t segment info alias('.drectve')\n";
  }

  for (StringSet<>::iterator i = DLLExportedGVs.begin(),
         e = DLLExportedGVs.end();
         i != e; ++i)
    O << "\t db ' /EXPORT:" << i->getKeyData() << ",data'\n";

  for (StringSet<>::iterator i = DLLExportedFns.begin(),
         e = DLLExportedFns.end();
         i != e; ++i)
    O << "\t db ' /EXPORT:" << i->getKeyData() << "'\n";

  if (!DLLExportedGVs.empty() || !DLLExportedFns.empty())
    O << "_drectve\t ends\n";

  // Bypass X86SharedAsmPrinter::doFinalization().
  bool Result = AsmPrinter::doFinalization(M);
  SwitchToDataSection("");
  O << "\tend\n";
  return Result;
}

std::unique_ptr<Module> llvm::CloneModule(
    const Module *M, ValueToValueMapTy &VMap,
    function_ref<bool(const GlobalValue *)> ShouldCloneDefinition) {
  // First off, we need to create the new module.
  std::unique_ptr<Module> New =
      llvm::make_unique<Module>(M->getModuleIdentifier(), M->getContext());
  New->setDataLayout(M->getDataLayout());
  New->setTargetTriple(M->getTargetTriple());
  New->setModuleInlineAsm(M->getModuleInlineAsm());
   
  // Loop over all of the global variables, making corresponding globals in the
  // new module.  Here we add them to the VMap and to the new Module.  We
  // don't worry about attributes or initializers, they will come later.
  //
  for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
       I != E; ++I) {
    GlobalVariable *GV = new GlobalVariable(*New, 
                                            I->getValueType(),
                                            I->isConstant(), I->getLinkage(),
                                            (Constant*) nullptr, I->getName(),
                                            (GlobalVariable*) nullptr,
                                            I->getThreadLocalMode(),
                                            I->getType()->getAddressSpace());
    GV->copyAttributesFrom(&*I);
    VMap[&*I] = GV;
  }

  // Loop over the functions in the module, making external functions as before
  for (const Function &I : *M) {
    Function *NF = Function::Create(cast<FunctionType>(I.getValueType()),
                                    I.getLinkage(), I.getName(), New.get());
    NF->copyAttributesFrom(&I);
    VMap[&I] = NF;
  }

  // Loop over the aliases in the module
  for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
       I != E; ++I) {
    if (!ShouldCloneDefinition(&*I)) {
      // An alias cannot act as an external reference, so we need to create
      // either a function or a global variable depending on the value type.
      // FIXME: Once pointee types are gone we can probably pick one or the
      // other.
      GlobalValue *GV;
      if (I->getValueType()->isFunctionTy())
        GV = Function::Create(cast<FunctionType>(I->getValueType()),
                              GlobalValue::ExternalLinkage, I->getName(),
                              New.get());
      else
        GV = new GlobalVariable(
            *New, I->getValueType(), false, GlobalValue::ExternalLinkage,
            (Constant *)nullptr, I->getName(), (GlobalVariable *)nullptr,
            I->getThreadLocalMode(), I->getType()->getAddressSpace());
      VMap[&*I] = GV;
      // We do not copy attributes (mainly because copying between different
      // kinds of globals is forbidden), but this is generally not required for
      // correctness.
      continue;
    }
    auto *GA = GlobalAlias::create(I->getValueType(),
                                   I->getType()->getPointerAddressSpace(),
                                   I->getLinkage(), I->getName(), New.get());
    GA->copyAttributesFrom(&*I);
    VMap[&*I] = GA;
  }
  
  // Now that all of the things that global variable initializer can refer to
  // have been created, loop through and copy the global variable referrers
  // over...  We also set the attributes on the global now.
  //
  for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
       I != E; ++I) {
    if (I->isDeclaration())
      continue;

    GlobalVariable *GV = cast<GlobalVariable>(VMap[&*I]);
    if (!ShouldCloneDefinition(&*I)) {
      // Skip after setting the correct linkage for an external reference.
      GV->setLinkage(GlobalValue::ExternalLinkage);
      continue;
    }
    if (I->hasInitializer())
      GV->setInitializer(MapValue(I->getInitializer(), VMap));

    SmallVector<std::pair<unsigned, MDNode *>, 1> MDs;
    I->getAllMetadata(MDs);
    for (auto MD : MDs)
      GV->addMetadata(MD.first, *MapMetadata(MD.second, VMap));
  }

  // Similarly, copy over function bodies now...
  //
  for (const Function &I : *M) {
    if (I.isDeclaration())
      continue;

    Function *F = cast<Function>(VMap[&I]);
    if (!ShouldCloneDefinition(&I)) {
      // Skip after setting the correct linkage for an external reference.
      F->setLinkage(GlobalValue::ExternalLinkage);
//.........这里部分代码省略.........