UninitializedFieldRule::StringRefSet UninitializedFieldRule::GetCandidateFieldsList(const RecordDecl* recordDeclaration,
                                                                                    ASTContext* context)
{
    StringRefSet candidates;

    for (const FieldDecl* fieldDeclaration : recordDeclaration->fields())
    {
        if (fieldDeclaration->hasInClassInitializer())
            continue;

        QualType type = fieldDeclaration->getType();
        if (! type.isPODType(*context))
            continue;

        if (IsRecordTypeWithoutDataMembers(type))
            continue;

        if (fieldDeclaration->isAnonymousStructOrUnion())
            continue;

        candidates.insert(fieldDeclaration->getName());
    }

    return candidates;
}
Exemple #2
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unsigned clang_isPODType(CXType X) {
  QualType T = GetQualType(X);
  if (T.isNull())
    return 0;
  
  CXTranslationUnit TU = GetTU(X);

  return T.isPODType(cxtu::getASTUnit(TU)->getASTContext()) ? 1 : 0;
}
unsigned clang_isPODType(CXType X) {
  QualType T = GetQualType(X);
  if (!T.getTypePtrOrNull())
    return 0;
  
  CXTranslationUnit TU = GetTU(X);
  ASTUnit *AU = static_cast<ASTUnit*>(TU->TUData);

  return T.isPODType(AU->getASTContext()) ? 1 : 0;
}
Exemple #4
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bool IsUninitializedPodVariable(const VarDecl* variableDeclaration, ASTContext* context)
{
    QualType type = variableDeclaration->getType();
    if (! type.isPODType(*context))
        return false;

    if (IsRecordTypeWithoutDataMembers(type))
        return false;

    return (!variableDeclaration->hasInit()) ||
           (type->isRecordType() && HasImplicitInitialization(variableDeclaration));
}
Exemple #5
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/// EmitLocalBlockVarDecl - Emit code and set up an entry in LocalDeclMap for a
/// variable declaration with auto, register, or no storage class specifier.
/// These turn into simple stack objects, or GlobalValues depending on target.
void CodeGenFunction::EmitLocalBlockVarDecl(const VarDecl &D) {
  QualType Ty = D.getType();
  bool isByRef = D.hasAttr<BlocksAttr>();
  bool needsDispose = false;
  unsigned Align = 0;
  bool IsSimpleConstantInitializer = false;

  llvm::Value *DeclPtr;
  if (Ty->isConstantSizeType()) {
    if (!Target.useGlobalsForAutomaticVariables()) {
      
      // If this value is an array or struct, is POD, and if the initializer is
      // a staticly determinable constant, try to optimize it.
      if (D.getInit() && !isByRef &&
          (Ty->isArrayType() || Ty->isRecordType()) &&
          Ty->isPODType() &&
          D.getInit()->isConstantInitializer(getContext())) {
        // If this variable is marked 'const', emit the value as a global.
        if (CGM.getCodeGenOpts().MergeAllConstants &&
            Ty.isConstant(getContext())) {
          EmitStaticBlockVarDecl(D);
          return;
        }
        
        IsSimpleConstantInitializer = true;
      }
      
      // A normal fixed sized variable becomes an alloca in the entry block.
      const llvm::Type *LTy = ConvertTypeForMem(Ty);
      if (isByRef)
        LTy = BuildByRefType(&D);
      llvm::AllocaInst *Alloc = CreateTempAlloca(LTy);
      Alloc->setName(D.getNameAsString());

      Align = getContext().getDeclAlignInBytes(&D);
      if (isByRef)
        Align = std::max(Align, unsigned(Target.getPointerAlign(0) / 8));
      Alloc->setAlignment(Align);
      DeclPtr = Alloc;
    } else {
      // Targets that don't support recursion emit locals as globals.
      const char *Class =
        D.getStorageClass() == VarDecl::Register ? ".reg." : ".auto.";
      DeclPtr = CreateStaticBlockVarDecl(D, Class,
                                         llvm::GlobalValue
                                         ::InternalLinkage);
    }

    // FIXME: Can this happen?
    if (Ty->isVariablyModifiedType())
      EmitVLASize(Ty);
  } else {
    EnsureInsertPoint();

    if (!DidCallStackSave) {
      // Save the stack.
      const llvm::Type *LTy = llvm::Type::getInt8PtrTy(VMContext);
      llvm::Value *Stack = CreateTempAlloca(LTy, "saved_stack");

      llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::stacksave);
      llvm::Value *V = Builder.CreateCall(F);

      Builder.CreateStore(V, Stack);

      DidCallStackSave = true;

      {
        // Push a cleanup block and restore the stack there.
        DelayedCleanupBlock scope(*this);

        V = Builder.CreateLoad(Stack, "tmp");
        llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::stackrestore);
        Builder.CreateCall(F, V);
      }
    }

    // Get the element type.
    const llvm::Type *LElemTy = ConvertTypeForMem(Ty);
    const llvm::Type *LElemPtrTy =
      llvm::PointerType::get(LElemTy, D.getType().getAddressSpace());

    llvm::Value *VLASize = EmitVLASize(Ty);

    // Downcast the VLA size expression
    VLASize = Builder.CreateIntCast(VLASize, llvm::Type::getInt32Ty(VMContext),
                                    false, "tmp");

    // Allocate memory for the array.
    llvm::AllocaInst *VLA = 
      Builder.CreateAlloca(llvm::Type::getInt8Ty(VMContext), VLASize, "vla");
    VLA->setAlignment(getContext().getDeclAlignInBytes(&D));

    DeclPtr = Builder.CreateBitCast(VLA, LElemPtrTy, "tmp");
  }

  llvm::Value *&DMEntry = LocalDeclMap[&D];
  assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
  DMEntry = DeclPtr;

  // Emit debug info for local var declaration.
  if (CGDebugInfo *DI = getDebugInfo()) {
    assert(HaveInsertPoint() && "Unexpected unreachable point!");

    DI->setLocation(D.getLocation());
    if (Target.useGlobalsForAutomaticVariables()) {
      DI->EmitGlobalVariable(static_cast<llvm::GlobalVariable *>(DeclPtr), &D);
    } else
      DI->EmitDeclareOfAutoVariable(&D, DeclPtr, Builder);
  }

  // If this local has an initializer, emit it now.
  const Expr *Init = D.getInit();

  // If we are at an unreachable point, we don't need to emit the initializer
  // unless it contains a label.
  if (!HaveInsertPoint()) {
    if (!ContainsLabel(Init))
      Init = 0;
    else
      EnsureInsertPoint();
  }

  if (Init) {
    llvm::Value *Loc = DeclPtr;
    if (isByRef)
      Loc = Builder.CreateStructGEP(DeclPtr, getByRefValueLLVMField(&D), 
                                    D.getNameAsString());

    bool isVolatile =
      getContext().getCanonicalType(D.getType()).isVolatileQualified();
    
    // If the initializer was a simple constant initializer, we can optimize it
    // in various ways.
    if (IsSimpleConstantInitializer) {
      llvm::Constant *Init = CGM.EmitConstantExpr(D.getInit(),D.getType(),this);
      assert(Init != 0 && "Wasn't a simple constant init?");
      
      llvm::Value *AlignVal = 
        llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Align);
      const llvm::Type *IntPtr =
        llvm::IntegerType::get(VMContext, LLVMPointerWidth);
      llvm::Value *SizeVal =
        llvm::ConstantInt::get(IntPtr, getContext().getTypeSizeInBytes(Ty));

      const llvm::Type *BP = llvm::Type::getInt8PtrTy(VMContext);
      if (Loc->getType() != BP)
        Loc = Builder.CreateBitCast(Loc, BP, "tmp");
      
      // If the initializer is all zeros, codegen with memset.
      if (isa<llvm::ConstantAggregateZero>(Init)) {
        llvm::Value *Zero =
          llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), 0);
        Builder.CreateCall4(CGM.getMemSetFn(), Loc, Zero, SizeVal, AlignVal);
      } else {
        // Otherwise, create a temporary global with the initializer then 
        // memcpy from the global to the alloca.
        std::string Name = GetStaticDeclName(*this, D, ".");
        llvm::GlobalVariable *GV =
          new llvm::GlobalVariable(CGM.getModule(), Init->getType(), true,
                                   llvm::GlobalValue::InternalLinkage,
                                   Init, Name, 0, false, 0);
        GV->setAlignment(Align);

        llvm::Value *SrcPtr = GV;
        if (SrcPtr->getType() != BP)
          SrcPtr = Builder.CreateBitCast(SrcPtr, BP, "tmp");
        
        Builder.CreateCall4(CGM.getMemCpyFn(), Loc, SrcPtr, SizeVal, AlignVal);
      }
    } else if (Ty->isReferenceType()) {
      RValue RV = EmitReferenceBindingToExpr(Init, Ty, /*IsInitializer=*/true);
      EmitStoreOfScalar(RV.getScalarVal(), Loc, false, Ty);
    } else if (!hasAggregateLLVMType(Init->getType())) {
      llvm::Value *V = EmitScalarExpr(Init);
      EmitStoreOfScalar(V, Loc, isVolatile, D.getType());
    } else if (Init->getType()->isAnyComplexType()) {
      EmitComplexExprIntoAddr(Init, Loc, isVolatile);
    } else {
      EmitAggExpr(Init, Loc, isVolatile);
    }
  }

  if (isByRef) {
    const llvm::PointerType *PtrToInt8Ty = llvm::Type::getInt8PtrTy(VMContext);

    EnsureInsertPoint();
    llvm::Value *isa_field = Builder.CreateStructGEP(DeclPtr, 0);
    llvm::Value *forwarding_field = Builder.CreateStructGEP(DeclPtr, 1);
    llvm::Value *flags_field = Builder.CreateStructGEP(DeclPtr, 2);
    llvm::Value *size_field = Builder.CreateStructGEP(DeclPtr, 3);
    llvm::Value *V;
    int flag = 0;
    int flags = 0;

    needsDispose = true;

    if (Ty->isBlockPointerType()) {
      flag |= BLOCK_FIELD_IS_BLOCK;
      flags |= BLOCK_HAS_COPY_DISPOSE;
    } else if (BlockRequiresCopying(Ty)) {
      flag |= BLOCK_FIELD_IS_OBJECT;
      flags |= BLOCK_HAS_COPY_DISPOSE;
    }

    // FIXME: Someone double check this.
    if (Ty.isObjCGCWeak())
      flag |= BLOCK_FIELD_IS_WEAK;

    int isa = 0;
    if (flag&BLOCK_FIELD_IS_WEAK)
      isa = 1;
    V = llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), isa);
    V = Builder.CreateIntToPtr(V, PtrToInt8Ty, "isa");
    Builder.CreateStore(V, isa_field);

    Builder.CreateStore(DeclPtr, forwarding_field);

    V = llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), flags);
    Builder.CreateStore(V, flags_field);

    const llvm::Type *V1;
    V1 = cast<llvm::PointerType>(DeclPtr->getType())->getElementType();
    V = llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
                               (CGM.getTargetData().getTypeStoreSizeInBits(V1)
                                / 8));
    Builder.CreateStore(V, size_field);

    if (flags & BLOCK_HAS_COPY_DISPOSE) {
      BlockHasCopyDispose = true;
      llvm::Value *copy_helper = Builder.CreateStructGEP(DeclPtr, 4);
      Builder.CreateStore(BuildbyrefCopyHelper(DeclPtr->getType(), flag, Align),
                          copy_helper);

      llvm::Value *destroy_helper = Builder.CreateStructGEP(DeclPtr, 5);
      Builder.CreateStore(BuildbyrefDestroyHelper(DeclPtr->getType(), flag,
                                                  Align),
                          destroy_helper);
    }
  }

  // Handle CXX destruction of variables.
  QualType DtorTy(Ty);
  while (const ArrayType *Array = getContext().getAsArrayType(DtorTy))
    DtorTy = getContext().getBaseElementType(Array);
  if (const RecordType *RT = DtorTy->getAs<RecordType>())
    if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
      if (!ClassDecl->hasTrivialDestructor()) {
        const CXXDestructorDecl *D = ClassDecl->getDestructor(getContext());
        assert(D && "EmitLocalBlockVarDecl - destructor is nul");
        
        if (const ConstantArrayType *Array = 
              getContext().getAsConstantArrayType(Ty)) {
          {
            DelayedCleanupBlock Scope(*this);
            QualType BaseElementTy = getContext().getBaseElementType(Array);
            const llvm::Type *BasePtr = ConvertType(BaseElementTy);
            BasePtr = llvm::PointerType::getUnqual(BasePtr);
            llvm::Value *BaseAddrPtr =
              Builder.CreateBitCast(DeclPtr, BasePtr);
            EmitCXXAggrDestructorCall(D, Array, BaseAddrPtr);
          
            // Make sure to jump to the exit block.
            EmitBranch(Scope.getCleanupExitBlock());
          }
          if (Exceptions) {
            EHCleanupBlock Cleanup(*this);
            QualType BaseElementTy = getContext().getBaseElementType(Array);
            const llvm::Type *BasePtr = ConvertType(BaseElementTy);
            BasePtr = llvm::PointerType::getUnqual(BasePtr);
            llvm::Value *BaseAddrPtr =
              Builder.CreateBitCast(DeclPtr, BasePtr);
            EmitCXXAggrDestructorCall(D, Array, BaseAddrPtr);
          }
        } else {
          {
            DelayedCleanupBlock Scope(*this);
            EmitCXXDestructorCall(D, Dtor_Complete, DeclPtr);

            // Make sure to jump to the exit block.
            EmitBranch(Scope.getCleanupExitBlock());
          }
          if (Exceptions) {
            EHCleanupBlock Cleanup(*this);
            EmitCXXDestructorCall(D, Dtor_Complete, DeclPtr);
          }
        }
      }
  }

  // Handle the cleanup attribute
  if (const CleanupAttr *CA = D.getAttr<CleanupAttr>()) {
    const FunctionDecl *FD = CA->getFunctionDecl();

    llvm::Constant* F = CGM.GetAddrOfFunction(FD);
    assert(F && "Could not find function!");

    const CGFunctionInfo &Info = CGM.getTypes().getFunctionInfo(FD);

    // In some cases, the type of the function argument will be different from
    // the type of the pointer. An example of this is
    // void f(void* arg);
    // __attribute__((cleanup(f))) void *g;
    //
    // To fix this we insert a bitcast here.
    QualType ArgTy = Info.arg_begin()->type;
    {
      DelayedCleanupBlock scope(*this);

      CallArgList Args;
      Args.push_back(std::make_pair(RValue::get(Builder.CreateBitCast(DeclPtr,
                                                           ConvertType(ArgTy))),
                                    getContext().getPointerType(D.getType())));
      EmitCall(Info, F, Args);
    }
    if (Exceptions) {
      EHCleanupBlock Cleanup(*this);

      CallArgList Args;
      Args.push_back(std::make_pair(RValue::get(Builder.CreateBitCast(DeclPtr,
                                                           ConvertType(ArgTy))),
                                    getContext().getPointerType(D.getType())));
      EmitCall(Info, F, Args);
    }
  }

  if (needsDispose && CGM.getLangOptions().getGCMode() != LangOptions::GCOnly) {
    {
      DelayedCleanupBlock scope(*this);
      llvm::Value *V = Builder.CreateStructGEP(DeclPtr, 1, "forwarding");
      V = Builder.CreateLoad(V);
      BuildBlockRelease(V);
    }
    // FIXME: Turn this on and audit the codegen
    if (0 && Exceptions) {
      EHCleanupBlock Cleanup(*this);
      llvm::Value *V = Builder.CreateStructGEP(DeclPtr, 1, "forwarding");
      V = Builder.CreateLoad(V);
      BuildBlockRelease(V);
    }
  }
}
Exemple #6
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llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) {
  QualType AllocType = E->getAllocatedType();
  FunctionDecl *NewFD = E->getOperatorNew();
  const FunctionProtoType *NewFTy = NewFD->getType()->getAs<FunctionProtoType>();

  CallArgList NewArgs;

  // The allocation size is the first argument.
  QualType SizeTy = getContext().getSizeType();

  llvm::Value *NumElements = 0;
  llvm::Value *AllocSize = EmitCXXNewAllocSize(*this, E, NumElements);
  
  NewArgs.push_back(std::make_pair(RValue::get(AllocSize), SizeTy));

  // Emit the rest of the arguments.
  // FIXME: Ideally, this should just use EmitCallArgs.
  CXXNewExpr::const_arg_iterator NewArg = E->placement_arg_begin();

  // First, use the types from the function type.
  // We start at 1 here because the first argument (the allocation size)
  // has already been emitted.
  for (unsigned i = 1, e = NewFTy->getNumArgs(); i != e; ++i, ++NewArg) {
    QualType ArgType = NewFTy->getArgType(i);

    assert(getContext().getCanonicalType(ArgType.getNonReferenceType()).
           getTypePtr() ==
           getContext().getCanonicalType(NewArg->getType()).getTypePtr() &&
           "type mismatch in call argument!");

    NewArgs.push_back(std::make_pair(EmitCallArg(*NewArg, ArgType),
                                     ArgType));

  }

  // Either we've emitted all the call args, or we have a call to a
  // variadic function.
  assert((NewArg == E->placement_arg_end() || NewFTy->isVariadic()) &&
         "Extra arguments in non-variadic function!");

  // If we still have any arguments, emit them using the type of the argument.
  for (CXXNewExpr::const_arg_iterator NewArgEnd = E->placement_arg_end();
       NewArg != NewArgEnd; ++NewArg) {
    QualType ArgType = NewArg->getType();
    NewArgs.push_back(std::make_pair(EmitCallArg(*NewArg, ArgType),
                                     ArgType));
  }

  // Emit the call to new.
  RValue RV =
    EmitCall(CGM.getTypes().getFunctionInfo(NewFTy->getResultType(), NewArgs),
             CGM.GetAddrOfFunction(NewFD), NewArgs, NewFD);

  // If an allocation function is declared with an empty exception specification
  // it returns null to indicate failure to allocate storage. [expr.new]p13.
  // (We don't need to check for null when there's no new initializer and
  // we're allocating a POD type).
  bool NullCheckResult = NewFTy->hasEmptyExceptionSpec() &&
    !(AllocType->isPODType() && !E->hasInitializer());

  llvm::BasicBlock *NewNull = 0;
  llvm::BasicBlock *NewNotNull = 0;
  llvm::BasicBlock *NewEnd = 0;

  llvm::Value *NewPtr = RV.getScalarVal();

  if (NullCheckResult) {
    NewNull = createBasicBlock("new.null");
    NewNotNull = createBasicBlock("new.notnull");
    NewEnd = createBasicBlock("new.end");

    llvm::Value *IsNull =
      Builder.CreateICmpEQ(NewPtr,
                           llvm::Constant::getNullValue(NewPtr->getType()),
                           "isnull");

    Builder.CreateCondBr(IsNull, NewNull, NewNotNull);
    EmitBlock(NewNotNull);
  }

  if (uint64_t CookiePadding = CalculateCookiePadding(getContext(), E)) {
    uint64_t CookieOffset = 
      CookiePadding - getContext().getTypeSize(SizeTy) / 8;
    
    llvm::Value *NumElementsPtr = 
      Builder.CreateConstInBoundsGEP1_64(NewPtr, CookieOffset);
    
    NumElementsPtr = Builder.CreateBitCast(NumElementsPtr, 
                                           ConvertType(SizeTy)->getPointerTo());
    Builder.CreateStore(NumElements, NumElementsPtr);

    // Now add the padding to the new ptr.
    NewPtr = Builder.CreateConstInBoundsGEP1_64(NewPtr, CookiePadding);
  }
  
  NewPtr = Builder.CreateBitCast(NewPtr, ConvertType(E->getType()));

  EmitNewInitializer(*this, E, NewPtr, NumElements);

  if (NullCheckResult) {
    Builder.CreateBr(NewEnd);
    NewNotNull = Builder.GetInsertBlock();
    EmitBlock(NewNull);
    Builder.CreateBr(NewEnd);
    EmitBlock(NewEnd);

    llvm::PHINode *PHI = Builder.CreatePHI(NewPtr->getType());
    PHI->reserveOperandSpace(2);
    PHI->addIncoming(NewPtr, NewNotNull);
    PHI->addIncoming(llvm::Constant::getNullValue(NewPtr->getType()), NewNull);

    NewPtr = PHI;
  }

  return NewPtr;
}