C++ QualType::isObjCRetainableType方法代码示例

static bool rewriteToObjCProperty(const ObjCMethodDecl *Getter,
                                  const ObjCMethodDecl *Setter,
                                  const NSAPI &NS, edit::Commit &commit) {
  ASTContext &Context = NS.getASTContext();
  std::string PropertyString = "@property";
  const ParmVarDecl *argDecl = *Setter->param_begin();
  QualType ArgType = Context.getCanonicalType(argDecl->getType());
  Qualifiers::ObjCLifetime propertyLifetime = ArgType.getObjCLifetime();
  
  if (ArgType->isObjCRetainableType() &&
      propertyLifetime == Qualifiers::OCL_Strong) {
    if (const ObjCObjectPointerType *ObjPtrTy =
        ArgType->getAs<ObjCObjectPointerType>()) {
      ObjCInterfaceDecl *IDecl = ObjPtrTy->getObjectType()->getInterface();
      if (IDecl &&
          IDecl->lookupNestedProtocol(&Context.Idents.get("NSCopying")))
        PropertyString += "(copy)";
    }
  }
  else if (propertyLifetime == Qualifiers::OCL_Weak)
    // TODO. More precise determination of 'weak' attribute requires
    // looking into setter's implementation for backing weak ivar.
    PropertyString += "(weak)";
  else
    PropertyString += "(unsafe_unretained)";
  
  // strip off any ARC lifetime qualifier.
  QualType CanResultTy = Context.getCanonicalType(Getter->getResultType());
  if (CanResultTy.getQualifiers().hasObjCLifetime()) {
    Qualifiers Qs = CanResultTy.getQualifiers();
    Qs.removeObjCLifetime();
    CanResultTy = Context.getQualifiedType(CanResultTy.getUnqualifiedType(), Qs);
  }
  PropertyString += " ";
  PropertyString += CanResultTy.getAsString(Context.getPrintingPolicy());
  PropertyString += " ";
  PropertyString += Getter->getNameAsString();
  commit.replace(CharSourceRange::getCharRange(Getter->getLocStart(),
                                               Getter->getDeclaratorEndLoc()),
                 PropertyString);
  SourceLocation EndLoc = Setter->getDeclaratorEndLoc();
  // Get location past ';'
  EndLoc = EndLoc.getLocWithOffset(1);
  commit.remove(CharSourceRange::getCharRange(Setter->getLocStart(), EndLoc));
  return true;
}

/// Returns true if the property implementation is synthesized and the
/// type of the property is retainable.
static bool isSynthesizedRetainableProperty(const ObjCPropertyImplDecl *I,
                                            const ObjCIvarDecl **ID,
                                            const ObjCPropertyDecl **PD) {

  if (I->getPropertyImplementation() != ObjCPropertyImplDecl::Synthesize)
    return false;

  (*ID) = I->getPropertyIvarDecl();
  if (!(*ID))
    return false;

  QualType T = (*ID)->getType();
  if (!T->isObjCRetainableType())
    return false;

  (*PD) = I->getPropertyDecl();
  // Shouldn't be able to synthesize a property that doesn't exist.
  assert(*PD);

  return true;
}

bool PrintfSpecifier::fixType(QualType QT, const LangOptions &LangOpt,
                              ASTContext &Ctx, bool IsObjCLiteral) {
  // %n is different from other conversion specifiers; don't try to fix it.
  if (CS.getKind() == ConversionSpecifier::nArg)
    return false;

  // Handle Objective-C objects first. Note that while the '%@' specifier will
  // not warn for structure pointer or void pointer arguments (because that's
  // how CoreFoundation objects are implemented), we only show a fixit for '%@'
  // if we know it's an object (block, id, class, or __attribute__((NSObject))).
  if (QT->isObjCRetainableType()) {
    if (!IsObjCLiteral)
      return false;

    CS.setKind(ConversionSpecifier::ObjCObjArg);

    // Disable irrelevant flags
    HasThousandsGrouping = false;
    HasPlusPrefix = false;
    HasSpacePrefix = false;
    HasAlternativeForm = false;
    HasLeadingZeroes = false;
    Precision.setHowSpecified(OptionalAmount::NotSpecified);
    LM.setKind(LengthModifier::None);

    return true;
  }

  // Handle strings next (char *, wchar_t *)
  if (QT->isPointerType() && (QT->getPointeeType()->isAnyCharacterType())) {
    CS.setKind(ConversionSpecifier::sArg);

    // Disable irrelevant flags
    HasAlternativeForm = 0;
    HasLeadingZeroes = 0;

    // Set the long length modifier for wide characters
    if (QT->getPointeeType()->isWideCharType())
      LM.setKind(LengthModifier::AsWideChar);
    else
      LM.setKind(LengthModifier::None);

    return true;
  }

  // If it's an enum, get its underlying type.
  if (const EnumType *ETy = QT->getAs<EnumType>())
    QT = ETy->getDecl()->getIntegerType();

  // We can only work with builtin types.
  const BuiltinType *BT = QT->getAs<BuiltinType>();
  if (!BT)
    return false;

  // Set length modifier
  switch (BT->getKind()) {
  case BuiltinType::Bool:
  case BuiltinType::WChar_U:
  case BuiltinType::WChar_S:
  case BuiltinType::Char16:
  case BuiltinType::Char32:
  case BuiltinType::UInt128:
  case BuiltinType::Int128:
  case BuiltinType::Half:
  case BuiltinType::Float128:
    // Various types which are non-trivial to correct.
    return false;

#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
  case BuiltinType::Id:
#include "clang/Basic/OpenCLImageTypes.def"
#define SIGNED_TYPE(Id, SingletonId)
#define UNSIGNED_TYPE(Id, SingletonId)
#define FLOATING_TYPE(Id, SingletonId)
#define BUILTIN_TYPE(Id, SingletonId) \
  case BuiltinType::Id:
#include "clang/AST/BuiltinTypes.def"
    // Misc other stuff which doesn't make sense here.
    return false;

  case BuiltinType::UInt:
  case BuiltinType::Int:
  case BuiltinType::Float:
  case BuiltinType::Double:
    LM.setKind(LengthModifier::None);
    break;

  case BuiltinType::Char_U:
  case BuiltinType::UChar:
  case BuiltinType::Char_S:
  case BuiltinType::SChar:
    LM.setKind(LengthModifier::AsChar);
    break;

  case BuiltinType::Short:
  case BuiltinType::UShort:
    LM.setKind(LengthModifier::AsShort);
    break;

  case BuiltinType::Long:
//.........这里部分代码省略.........

static void checkAllAtProps(MigrationContext &MigrateCtx,
                            SourceLocation AtLoc,
                            IndivPropsTy &IndProps) {
  if (IndProps.empty())
    return;

  for (IndivPropsTy::iterator
         PI = IndProps.begin(), PE = IndProps.end(); PI != PE; ++PI) {
    QualType T = (*PI)->getType();
    if (T.isNull() || !T->isObjCRetainableType())
      return;
  }

  SmallVector<std::pair<AttributedTypeLoc, ObjCPropertyDecl *>, 4> ATLs;
  bool hasWeak = false, hasStrong = false;
  ObjCPropertyDecl::PropertyAttributeKind
    Attrs = ObjCPropertyDecl::OBJC_PR_noattr;
  for (IndivPropsTy::iterator
         PI = IndProps.begin(), PE = IndProps.end(); PI != PE; ++PI) {
    ObjCPropertyDecl *PD = *PI;
    Attrs = PD->getPropertyAttributesAsWritten();
    TypeSourceInfo *TInfo = PD->getTypeSourceInfo();
    if (!TInfo)
      return;
    TypeLoc TL = TInfo->getTypeLoc();
    if (AttributedTypeLoc ATL =
            TL.getAs<AttributedTypeLoc>()) {
      ATLs.push_back(std::make_pair(ATL, PD));
      if (TInfo->getType().getObjCLifetime() == Qualifiers::OCL_Weak) {
        hasWeak = true;
      } else if (TInfo->getType().getObjCLifetime() == Qualifiers::OCL_Strong)
        hasStrong = true;
      else
        return;
    }
  }
  if (ATLs.empty())
    return;
  if (hasWeak && hasStrong)
    return;

  TransformActions &TA = MigrateCtx.Pass.TA;
  Transaction Trans(TA);

  if (GCAttrsCollector::hasObjCImpl(
                              cast<Decl>(IndProps.front()->getDeclContext()))) {
    if (hasWeak)
      MigrateCtx.AtPropsWeak.insert(AtLoc.getRawEncoding());

  } else {
    StringRef toAttr = "strong";
    if (hasWeak) {
      if (canApplyWeak(MigrateCtx.Pass.Ctx, IndProps.front()->getType(),
                       /*AllowOnUnkwownClass=*/true))
        toAttr = "weak";
      else
        toAttr = "unsafe_unretained";
    }
    if (Attrs & ObjCPropertyDecl::OBJC_PR_assign)
      MigrateCtx.rewritePropertyAttribute("assign", toAttr, AtLoc);
    else
      MigrateCtx.addPropertyAttribute(toAttr, AtLoc);
  }

  for (unsigned i = 0, e = ATLs.size(); i != e; ++i) {
    SourceLocation Loc = ATLs[i].first.getAttrNameLoc();
    if (Loc.isMacroID())
      Loc = MigrateCtx.Pass.Ctx.getSourceManager()
                                         .getImmediateExpansionRange(Loc).first;
    TA.remove(Loc);
    TA.clearDiagnostic(diag::err_objc_property_attr_mutually_exclusive, AtLoc);
    TA.clearDiagnostic(diag::err_arc_inconsistent_property_ownership,
                       ATLs[i].second->getLocation());
    MigrateCtx.RemovedAttrSet.insert(Loc.getRawEncoding());
  }
}

void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
                                    llvm::Function *Fn,
                                    const CGFunctionInfo &FnInfo,
                                    const FunctionArgList &Args,
                                    SourceLocation StartLoc) {
  const Decl *D = GD.getDecl();
  
  DidCallStackSave = false;
  CurCodeDecl = CurFuncDecl = D;
  FnRetTy = RetTy;
  CurFn = Fn;
  CurFnInfo = &FnInfo;
  assert(CurFn->isDeclaration() && "Function already has body?");

  // Pass inline keyword to optimizer if it appears explicitly on any
  // declaration.
  if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D))
    for (FunctionDecl::redecl_iterator RI = FD->redecls_begin(),
           RE = FD->redecls_end(); RI != RE; ++RI)
      if (RI->isInlineSpecified()) {
        Fn->addFnAttr(llvm::Attribute::InlineHint);
        break;
      }

  if (getContext().getLangOptions().OpenCL) {
    // Add metadata for a kernel function.
    if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D))
      if (FD->hasAttr<OpenCLKernelAttr>()) {
        llvm::LLVMContext &Context = getLLVMContext();
        llvm::NamedMDNode *OpenCLMetadata = 
          CGM.getModule().getOrInsertNamedMetadata("opencl.kernels");
          
        llvm::Value *Op = Fn;
        OpenCLMetadata->addOperand(llvm::MDNode::get(Context, Op));
      }
  }

  llvm::BasicBlock *EntryBB = createBasicBlock("entry", CurFn);

  // Create a marker to make it easy to insert allocas into the entryblock
  // later.  Don't create this with the builder, because we don't want it
  // folded.
  llvm::Value *Undef = llvm::UndefValue::get(Int32Ty);
  AllocaInsertPt = new llvm::BitCastInst(Undef, Int32Ty, "", EntryBB);
  if (Builder.isNamePreserving())
    AllocaInsertPt->setName("allocapt");

  ReturnBlock = getJumpDestInCurrentScope("return");

  Builder.SetInsertPoint(EntryBB);

  // Emit subprogram debug descriptor.
  if (CGDebugInfo *DI = getDebugInfo()) {
    // FIXME: what is going on here and why does it ignore all these
    // interesting type properties?
    QualType FnType =
      getContext().getFunctionType(RetTy, 0, 0,
                                   FunctionProtoType::ExtProtoInfo());

    DI->setLocation(StartLoc);
    DI->EmitFunctionStart(GD, FnType, CurFn, Builder);
  }

  if (ShouldInstrumentFunction())
    EmitFunctionInstrumentation("__cyg_profile_func_enter");

  if (CGM.getCodeGenOpts().InstrumentForProfiling)
    EmitMCountInstrumentation();

  if (RetTy->isVoidType()) {
    // Void type; nothing to return.
    ReturnValue = 0;
  } else if (CurFnInfo->getReturnInfo().getKind() == ABIArgInfo::Indirect &&
             hasAggregateLLVMType(CurFnInfo->getReturnType())) {
    // Indirect aggregate return; emit returned value directly into sret slot.
    // This reduces code size, and affects correctness in C++.
    ReturnValue = CurFn->arg_begin();
  } else {
    ReturnValue = CreateIRTemp(RetTy, "retval");

    // Tell the epilog emitter to autorelease the result.  We do this
    // now so that various specialized functions can suppress it
    // during their IR-generation.
    if (getLangOptions().ObjCAutoRefCount &&
        !CurFnInfo->isReturnsRetained() &&
        RetTy->isObjCRetainableType())
      AutoreleaseResult = true;
  }

  EmitStartEHSpec(CurCodeDecl);

  PrologueCleanupDepth = EHStack.stable_begin();
  EmitFunctionProlog(*CurFnInfo, CurFn, Args);

  if (D && isa<CXXMethodDecl>(D) && cast<CXXMethodDecl>(D)->isInstance())
    CGM.getCXXABI().EmitInstanceFunctionProlog(*this);

  // If any of the arguments have a variably modified type, make sure to
  // emit the type size.
  for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end();
//.........这里部分代码省略.........

void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
                                    llvm::Function *Fn,
                                    const CGFunctionInfo &FnInfo,
                                    const FunctionArgList &Args,
                                    SourceLocation StartLoc) {
  const Decl *D = GD.getDecl();
  
  DidCallStackSave = false;
  CurCodeDecl = CurFuncDecl = D;
  FnRetTy = RetTy;
  CurFn = Fn;
  CurFnInfo = &FnInfo;
  assert(CurFn->isDeclaration() && "Function already has body?");

  // Pass inline keyword to optimizer if it appears explicitly on any
  // declaration.
  if (!CGM.getCodeGenOpts().NoInline) 
    if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D))
      for (FunctionDecl::redecl_iterator RI = FD->redecls_begin(),
             RE = FD->redecls_end(); RI != RE; ++RI)
        if (RI->isInlineSpecified()) {
          Fn->addFnAttr(llvm::Attribute::InlineHint);
          break;
        }

  if (getContext().getLangOpts().OpenCL) {
    // Add metadata for a kernel function.
    if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D))
      EmitOpenCLKernelMetadata(FD, Fn);
  }

  llvm::BasicBlock *EntryBB = createBasicBlock("entry", CurFn);

  // Create a marker to make it easy to insert allocas into the entryblock
  // later.  Don't create this with the builder, because we don't want it
  // folded.
  llvm::Value *Undef = llvm::UndefValue::get(Int32Ty);
  AllocaInsertPt = new llvm::BitCastInst(Undef, Int32Ty, "", EntryBB);
  if (Builder.isNamePreserving())
    AllocaInsertPt->setName("allocapt");

  ReturnBlock = getJumpDestInCurrentScope("return");

  Builder.SetInsertPoint(EntryBB);

  // Emit subprogram debug descriptor.
  if (CGDebugInfo *DI = getDebugInfo()) {
    unsigned NumArgs = 0;
    QualType *ArgsArray = new QualType[Args.size()];
    for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end();
	 i != e; ++i) {
      ArgsArray[NumArgs++] = (*i)->getType();
    }

    QualType FnType =
      getContext().getFunctionType(RetTy, ArgsArray, NumArgs,
                                   FunctionProtoType::ExtProtoInfo());

    delete[] ArgsArray;

    DI->setLocation(StartLoc);
    DI->EmitFunctionStart(GD, FnType, CurFn, Builder);
  }

  if (ShouldInstrumentFunction())
    EmitFunctionInstrumentation("__cyg_profile_func_enter");

  if (CGM.getCodeGenOpts().InstrumentForProfiling)
    EmitMCountInstrumentation();

  if (RetTy->isVoidType()) {
    // Void type; nothing to return.
    ReturnValue = 0;
  } else if (CurFnInfo->getReturnInfo().getKind() == ABIArgInfo::Indirect &&
             hasAggregateLLVMType(CurFnInfo->getReturnType())) {
    // Indirect aggregate return; emit returned value directly into sret slot.
    // This reduces code size, and affects correctness in C++.
    ReturnValue = CurFn->arg_begin();
  } else {
    ReturnValue = CreateIRTemp(RetTy, "retval");

    // Tell the epilog emitter to autorelease the result.  We do this
    // now so that various specialized functions can suppress it
    // during their IR-generation.
    if (getLangOpts().ObjCAutoRefCount &&
        !CurFnInfo->isReturnsRetained() &&
        RetTy->isObjCRetainableType())
      AutoreleaseResult = true;
  }

  EmitStartEHSpec(CurCodeDecl);

  PrologueCleanupDepth = EHStack.stable_begin();
  EmitFunctionProlog(*CurFnInfo, CurFn, Args);

  if (D && isa<CXXMethodDecl>(D) && cast<CXXMethodDecl>(D)->isInstance()) {
    CGM.getCXXABI().EmitInstanceFunctionProlog(*this);
    const CXXMethodDecl *MD = cast<CXXMethodDecl>(D);
    if (MD->getParent()->isLambda() &&
        MD->getOverloadedOperator() == OO_Call) {
//.........这里部分代码省略.........

void WalkAST::VisitObjCMessageExpr(const ObjCMessageExpr *ME) {
  if (!ME) {
    return;
  }

  const ObjCInterfaceDecl *ID = ME->getReceiverInterface();

  if (ID) {
    StringRef receiverClassName = ID->getIdentifier()->getName();
    Selector sel = ME->getSelector();

    if (receiverClassName == "NSInvocation" &&
        (sel.getAsString() == "getArgument:atIndex:" ||
        sel.getAsString() == "getReturnValue:")) {

      const Expr *Arg = ME->getArg(0);
      if (!Arg) {
        VisitChildren(ME);
        return;
      }

      QualType T = Arg->IgnoreParenImpCasts()->getType();
      const PointerType *PT = T->getAs<PointerType>();
      if (!PT) {
        // there appears to be a type error anyway...
        VisitChildren(ME);
        return;
      }
      T = PT->getPointeeType();
      if (!T->isObjCRetainableType()) {
        VisitChildren(ME);
        return;
      }
      const AttributedType *AttrType = T->getAs<AttributedType>();
      bool passed = false;
      if (AttrType) {
        Qualifiers::ObjCLifetime argLifetime = AttrType->getModifiedType().getObjCLifetime();
        passed = argLifetime == Qualifiers::OCL_None || argLifetime == Qualifiers::OCL_ExplicitNone;
      }

      if (!passed) {
        SmallString<64> BufName, Buf;
        llvm::raw_svector_ostream OsName(BufName), Os(Buf);

        OsName << "Invalid use of '" << receiverClassName << "'" ;        
        Os << "In ARC mode, the first argument to '-["
           << receiverClassName
           << " " << sel.getAsString()
           << "]' must be declared with __unsafe_unretained to avoid over-release.";

        PathDiagnosticLocation MELoc =
        PathDiagnosticLocation::createBegin(ME, BR.getSourceManager(), AC);
        BR.EmitBasicReport(AC->getDecl(),
                           &Checker,
                           OsName.str(),
                           "Memory error (Facebook)",
                           Os.str(),
                           MELoc);
      }
    }
  }
  VisitChildren(ME);
}