C++ QualType::isVoidType方法代码示例

void ObjCMigrateASTConsumer::migrateObjCInterfaceDecl(ASTContext &Ctx,
                                                      ObjCInterfaceDecl *D) {
  for (ObjCContainerDecl::method_iterator M = D->meth_begin(), MEnd = D->meth_end();
       M != MEnd; ++M) {
    ObjCMethodDecl *Method = (*M);
    if (Method->isPropertyAccessor() ||  Method->param_size() != 0)
      continue;
    // Is this method candidate to be a getter?
    QualType GRT = Method->getResultType();
    if (GRT->isVoidType())
      continue;
    Selector GetterSelector = Method->getSelector();
    IdentifierInfo *getterName = GetterSelector.getIdentifierInfoForSlot(0);
    Selector SetterSelector =
      SelectorTable::constructSetterSelector(PP.getIdentifierTable(),
                                             PP.getSelectorTable(),
                                             getterName);
    if (ObjCMethodDecl *SetterMethod = D->lookupMethod(SetterSelector, true)) {
      // Is this a valid setter, matching the target getter?
      QualType SRT = SetterMethod->getResultType();
      if (!SRT->isVoidType())
        continue;
      const ParmVarDecl *argDecl = *SetterMethod->param_begin();
      QualType ArgType = argDecl->getType();
      if (!Ctx.hasSameType(ArgType, GRT))
          continue;
        edit::Commit commit(*Editor);
        edit::rewriteToObjCProperty(Method, SetterMethod, *NSAPIObj, commit);
        Editor->commit(commit);
      }
  }
}

  void ReturnSynthesizer::Transform() {
    if (!getTransaction()->getCompilationOpts().ResultEvaluation)
      return;

    FunctionDecl* FD = getTransaction()->getWrapperFD();

    int foundAtPos = -1;
    Expr* lastExpr = utils::Analyze::GetOrCreateLastExpr(FD, &foundAtPos, 
                                                         /*omitDS*/false,
                                                         m_Sema);
    if (lastExpr) {
      QualType RetTy = lastExpr->getType();
      if (!RetTy->isVoidType() && RetTy.isTriviallyCopyableType(*m_Context)) {
        // Change the void function's return type
        // We can't PushDeclContext, because we don't have scope.
        Sema::ContextRAII pushedDC(*m_Sema, FD);
        FunctionProtoType::ExtProtoInfo EPI;
        QualType FnTy
          = m_Context->getFunctionType(RetTy, llvm::ArrayRef<QualType>(), EPI);
        FD->setType(FnTy);
        CompoundStmt* CS = cast<CompoundStmt>(FD->getBody());
        assert(CS && "Missing body?");
        // Change it to a return stmt (Avoid dealloc/alloc of all el.)
        *(CS->body_begin() + foundAtPos)
          = m_Sema->ActOnReturnStmt(lastExpr->getExprLoc(), 
                                    lastExpr).take();
      }
    } else if (foundAtPos >= 0) {
      // check for non-void return statement
      CompoundStmt* CS = cast<CompoundStmt>(FD->getBody());
      Stmt* CSS = *(CS->body_begin() + foundAtPos);
      if (ReturnStmt* RS = dyn_cast<ReturnStmt>(CSS)) {
        if (Expr* RetV = RS->getRetValue()) {
          QualType RetTy = RetV->getType();
          // Any return statement will have been "healed" by Sema
          // to correspond to the original void return type of the
          // wrapper, using a ImplicitCastExpr 'void' <ToVoid>.
          // Remove that.
          if (RetTy->isVoidType()) {
            ImplicitCastExpr* VoidCast = dyn_cast<ImplicitCastExpr>(RetV);
            if (VoidCast) {
              RS->setRetValue(VoidCast->getSubExpr());
              RetTy = VoidCast->getSubExpr()->getType();
            }
          }

          if (!RetTy->isVoidType()
              && RetTy.isTriviallyCopyableType(*m_Context)) {
            Sema::ContextRAII pushedDC(*m_Sema, FD);
            FunctionProtoType::ExtProtoInfo EPI;
            QualType FnTy
              = m_Context->getFunctionType(RetTy, llvm::ArrayRef<QualType>(),
                                           EPI);
            FD->setType(FnTy);
          } // not returning void
        } // have return value
      } // is a return statement
    } // have a statement
  }

SVal StoreManager::evalDynamicCast(SVal Base, QualType DerivedType,
                                   bool &Failed) {
  Failed = false;

  loc::MemRegionVal *BaseRegVal = dyn_cast<loc::MemRegionVal>(&Base);
  if (!BaseRegVal)
    return UnknownVal();
  const MemRegion *BaseRegion = BaseRegVal->stripCasts(/*StripBases=*/false);

  // Assume the derived class is a pointer or a reference to a CXX record.
  DerivedType = DerivedType->getPointeeType();
  assert(!DerivedType.isNull());
  const CXXRecordDecl *DerivedDecl = DerivedType->getAsCXXRecordDecl();
  if (!DerivedDecl && !DerivedType->isVoidType())
    return UnknownVal();

  // Drill down the CXXBaseObject chains, which represent upcasts (casts from
  // derived to base).
  const MemRegion *SR = BaseRegion;
  while (const TypedRegion *TSR = dyn_cast_or_null<TypedRegion>(SR)) {
    QualType BaseType = TSR->getLocationType()->getPointeeType();
    assert(!BaseType.isNull());
    const CXXRecordDecl *SRDecl = BaseType->getAsCXXRecordDecl();
    if (!SRDecl)
      return UnknownVal();

    // If found the derived class, the cast succeeds.
    if (SRDecl == DerivedDecl)
      return loc::MemRegionVal(TSR);

    if (!DerivedType->isVoidType()) {
      // Static upcasts are marked as DerivedToBase casts by Sema, so this will
      // only happen when multiple or virtual inheritance is involved.
      CXXBasePaths Paths(/*FindAmbiguities=*/false, /*RecordPaths=*/true,
                         /*DetectVirtual=*/false);
      if (SRDecl->isDerivedFrom(DerivedDecl, Paths))
        return evalDerivedToBase(loc::MemRegionVal(TSR), Paths.front());
    }

    if (const CXXBaseObjectRegion *R = dyn_cast<CXXBaseObjectRegion>(TSR))
      // Drill down the chain to get the derived classes.
      SR = R->getSuperRegion();
    else {
      // We reached the bottom of the hierarchy.

      // If this is a cast to void*, return the region.
      if (DerivedType->isVoidType())
        return loc::MemRegionVal(TSR);

      // We did not find the derived class. We we must be casting the base to
      // derived, so the cast should fail.
      Failed = true;
      return UnknownVal();
    }
  }
  
  return UnknownVal();
}

void ReturnUndefChecker::checkPreStmt(const ReturnStmt *RS,
                                      CheckerContext &C) const {
  const Expr *RetE = RS->getRetValue();
  if (!RetE)
    return;
  SVal RetVal = C.getSVal(RetE);

  const StackFrameContext *SFC = C.getStackFrame();
  QualType RT = CallEvent::getDeclaredResultType(SFC->getDecl());

  if (RetVal.isUndef()) {
    // "return;" is modeled to evaluate to an UndefinedVal. Allow UndefinedVal
    // to be returned in functions returning void to support this pattern:
    //   void foo() {
    //     return;
    //   }
    //   void test() {
    //     return foo();
    //   }
    if (RT.isNull() || !RT->isVoidType())
      emitUndef(C, RetE);
    return;
  }

  if (RT.isNull())
    return;

  if (RT->isReferenceType()) {
    checkReference(C, RetE, RetVal.castAs<DefinedOrUnknownSVal>());
    return;
  }
}

long long clang_Type_getSizeOf(CXType T) {
  if (T.kind == CXType_Invalid)
    return CXTypeLayoutError_Invalid;
  ASTContext &Ctx = cxtu::getASTUnit(GetTU(T))->getASTContext();
  QualType QT = GetQualType(T);
  // [expr.sizeof] p2: if reference type, return size of referenced type
  if (QT->isReferenceType())
    QT = QT.getNonReferenceType();
  // [expr.sizeof] p1: return -1 on: func, incomplete, bitfield, incomplete
  //                   enumeration
  // Note: We get the cxtype, not the cxcursor, so we can't call
  //       FieldDecl->isBitField()
  // [expr.sizeof] p3: pointer ok, function not ok.
  // [gcc extension] lib/AST/ExprConstant.cpp:1372 HandleSizeof : vla == error
  if (QT->isIncompleteType())
    return CXTypeLayoutError_Incomplete;
  if (QT->isDependentType())
    return CXTypeLayoutError_Dependent;
  if (!QT->isConstantSizeType())
    return CXTypeLayoutError_NotConstantSize;
  // [gcc extension] lib/AST/ExprConstant.cpp:1372
  //                 HandleSizeof : {voidtype,functype} == 1
  // not handled by ASTContext.cpp:1313 getTypeInfoImpl
  if (QT->isVoidType() || QT->isFunctionType())
    return 1;
  return Ctx.getTypeSizeInChars(QT).getQuantity();
}

/// Recursively check if the pointer types are equal modulo const, volatile,
/// and restrict qualifiers. Also, assume that all types are similar to 'void'.
/// Assumes the input types are canonical.
static bool shouldBeModeledWithNoOp(ASTContext &Context, QualType ToTy,
                                                         QualType FromTy) {
  while (Context.UnwrapSimilarPointerTypes(ToTy, FromTy)) {
    Qualifiers Quals1, Quals2;
    ToTy = Context.getUnqualifiedArrayType(ToTy, Quals1);
    FromTy = Context.getUnqualifiedArrayType(FromTy, Quals2);

    // Make sure that non-cvr-qualifiers the other qualifiers (e.g., address
    // spaces) are identical.
    Quals1.removeCVRQualifiers();
    Quals2.removeCVRQualifiers();
    if (Quals1 != Quals2)
      return false;
  }

  // If we are casting to void, the 'From' value can be used to represent the
  // 'To' value.
  if (ToTy->isVoidType())
    return true;

  if (ToTy != FromTy)
    return false;

  return true;
}

/// Recursively check if the pointer types are equal modulo const, volatile,
/// and restrict qualifiers. Also, assume that all types are similar to 'void'.
/// Assumes the input types are canonical.
static bool shouldBeModeledWithNoOp(ASTContext &Context, QualType ToTy,
                                                         QualType FromTy) {
  while (Context.UnwrapSimilarTypes(ToTy, FromTy)) {
    Qualifiers Quals1, Quals2;
    ToTy = Context.getUnqualifiedArrayType(ToTy, Quals1);
    FromTy = Context.getUnqualifiedArrayType(FromTy, Quals2);

    // Make sure that non-cvr-qualifiers the other qualifiers (e.g., address
    // spaces) are identical.
    Quals1.removeCVRQualifiers();
    Quals2.removeCVRQualifiers();
    if (Quals1 != Quals2)
      return false;
  }

  // If we are casting to void, the 'From' value can be used to represent the
  // 'To' value.
  //
  // FIXME: Doing this after unwrapping the types doesn't make any sense. A
  // cast from 'int**' to 'void**' is not special in the way that a cast from
  // 'int*' to 'void*' is.
  if (ToTy->isVoidType())
    return true;

  if (ToTy != FromTy)
    return false;

  return true;
}

static bool isVoidPointerToNonConst(QualType T) {
  if (const PointerType *PT = T->getAs<PointerType>()) {
    QualType PointeeTy = PT->getPointeeType();
    if (PointeeTy.isConstQualified())
      return false;
    return PointeeTy->isVoidType();
  } else
    return false;
}

void AdjustedReturnValueChecker::checkPostStmt(const CallExpr *CE,
                                               CheckerContext &C) const {
  
  // Get the result type of the call.
  QualType expectedResultTy = CE->getType();

  // Fetch the signature of the called function.
  const ProgramState *state = C.getState();
  const LocationContext *LCtx = C.getLocationContext();

  SVal V = state->getSVal(CE, LCtx);
  
  if (V.isUnknown())
    return;
  
  // Casting to void?  Discard the value.
  if (expectedResultTy->isVoidType()) {
    C.addTransition(state->BindExpr(CE, LCtx, UnknownVal()));
    return;
  }                   

  const MemRegion *callee = state->getSVal(CE->getCallee(), LCtx).getAsRegion();
  if (!callee)
    return;

  QualType actualResultTy;
  
  if (const FunctionTextRegion *FT = dyn_cast<FunctionTextRegion>(callee)) {
    const FunctionDecl *FD = FT->getDecl();
    actualResultTy = FD->getResultType();
  }
  else if (const BlockDataRegion *BD = dyn_cast<BlockDataRegion>(callee)) {
    const BlockTextRegion *BR = BD->getCodeRegion();
    const BlockPointerType *BT=BR->getLocationType()->getAs<BlockPointerType>();
    const FunctionType *FT = BT->getPointeeType()->getAs<FunctionType>();
    actualResultTy = FT->getResultType();
  }

  // Can this happen?
  if (actualResultTy.isNull())
    return;

  // For now, ignore references.
  if (actualResultTy->getAs<ReferenceType>())
    return;
  

  // Are they the same?
  if (expectedResultTy != actualResultTy) {
    // FIXME: Do more checking and actual emit an error. At least performing
    // the cast avoids some assertion failures elsewhere.
    SValBuilder &svalBuilder = C.getSValBuilder();
    V = svalBuilder.evalCast(V, expectedResultTy, actualResultTy);
    C.addTransition(state->BindExpr(CE, LCtx, V));
  }
}

SVal Environment::GetSVal(const Stmt *E, ValueManager& ValMgr) const {

  for (;;) {

    switch (E->getStmtClass()) {

      case Stmt::AddrLabelExprClass:
        return ValMgr.makeLoc(cast<AddrLabelExpr>(E));

        // ParenExprs are no-ops.

      case Stmt::ParenExprClass:
        E = cast<ParenExpr>(E)->getSubExpr();
        continue;

      case Stmt::CharacterLiteralClass: {
        const CharacterLiteral* C = cast<CharacterLiteral>(E);
        return ValMgr.makeIntVal(C->getValue(), C->getType());
      }

      case Stmt::IntegerLiteralClass: {
        return ValMgr.makeIntVal(cast<IntegerLiteral>(E));
      }

      // Casts where the source and target type are the same
      // are no-ops.  We blast through these to get the descendant
      // subexpression that has a value.

      case Stmt::ImplicitCastExprClass:
      case Stmt::CStyleCastExprClass: {
        const CastExpr* C = cast<CastExpr>(E);
        QualType CT = C->getType();

        if (CT->isVoidType())
          return UnknownVal();

        break;
      }

        // Handle all other Stmt* using a lookup.

      default:
        break;
    };

    break;
  }

  return LookupExpr(E);
}

  // We need to artificially create:
  // cling_PrintValue(void* (ASTContext)C, void* (Expr)E, const void* (&i)
  Expr* ValuePrinterSynthesizer::SynthesizeVP(Expr* E) {
    QualType QT = E->getType();
    // For now we skip void and function pointer types.
    if (!QT.isNull() && (QT->isVoidType() || QT->isFunctionType()))
      return 0;

    // Find cling_PrintValue
    SourceLocation NoSLoc = SourceLocation();
    DeclarationName PVName = &m_Context->Idents.get("cling_PrintValue");
    LookupResult R(*m_Sema, PVName, NoSLoc, Sema::LookupOrdinaryName,
                   Sema::ForRedeclaration);

    Scope* S = m_Sema->getScopeForContext(m_Sema->CurContext);
    m_Sema->LookupName(R, S);
    assert(!R.empty() && "Cannot find cling_PrintValue(...)");

    CXXScopeSpec CSS;
    Expr* UnresolvedLookup
      = m_Sema->BuildDeclarationNameExpr(CSS, R, /*ADL*/ false).take();


    Expr* VoidEArg = utils::Synthesize::CStyleCastPtrExpr(m_Sema, 
                                                          m_Context->VoidPtrTy,
                                                          (uint64_t)E);
    Expr* VoidCArg = utils::Synthesize::CStyleCastPtrExpr(m_Sema, 
                                                          m_Context->VoidPtrTy,
                                                          (uint64_t)m_Context);

    if (!QT->isPointerType()) {
      while(ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(E))
        E = ICE->getSubExpr();
      E = m_Sema->BuildUnaryOp(S, NoSLoc, UO_AddrOf, E).take();
    }

    llvm::SmallVector<Expr*, 4> CallArgs;
    CallArgs.push_back(VoidEArg);
    CallArgs.push_back(VoidCArg);
    CallArgs.push_back(E);

    Expr* Result = m_Sema->ActOnCallExpr(S, UnresolvedLookup, NoSLoc,
                                         CallArgs, NoSLoc).take();
    assert(Result && "Cannot create value printer!");

    return Result;
  }

 bool GetFuncType(const FunctionType * f, Obj * typ) {
     Obj returns,parameters;
     resulttable->newlist(&returns);
     resulttable->newlist(&parameters);
     
     bool valid = true; //decisions about whether this function can be exported or not are delayed until we have seen all the potential problems
     QualType RT = f->getResultType();
     if(!RT->isVoidType()) {
         Obj rt;
         if(!GetType(RT,&rt)) {
             valid = false;
         } else {
             rt.push();
             returns.addentry();
         }
     }
    
     
     const FunctionProtoType * proto = f->getAs<FunctionProtoType>();
     //proto is null if the function was declared without an argument list (e.g. void foo() and not void foo(void))
     //we don't support old-style C parameter lists, we just treat them as empty
     if(proto) {
         for(size_t i = 0; i < proto->getNumArgs(); i++) {
             QualType PT = proto->getArgType(i);
             Obj pt;
             if(!GetType(PT,&pt)) {
                 valid = false; //keep going with attempting to parse type to make sure we see all the reasons why we cannot support this function
             } else if(valid) {
                 pt.push();
                 parameters.addentry();
             }
         }
     }
     
     if(valid) {
         PushTypeFunction("functype");
         parameters.push();
         returns.push();
         lua_pushboolean(L, proto ? proto->isVariadic() : false);
         lua_call(L, 3, 1);
         typ->initFromStack(L,ref_table);
     }
     
     return valid;
 }

bool Sema::CXXCheckCStyleCast(SourceRange R, QualType CastTy, Expr *&CastExpr,
                              CastExpr::CastKind &Kind, bool FunctionalStyle)
{
  // This test is outside everything else because it's the only case where
  // a non-lvalue-reference target type does not lead to decay.
  // C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
  if (CastTy->isVoidType())
    return false;

  // If the type is dependent, we won't do any other semantic analysis now.
  if (CastTy->isDependentType() || CastExpr->isTypeDependent())
    return false;

  if (!CastTy->isLValueReferenceType())
    DefaultFunctionArrayConversion(CastExpr);

  // C++ [expr.cast]p5: The conversions performed by
  //   - a const_cast,
  //   - a static_cast,
  //   - a static_cast followed by a const_cast,
  //   - a reinterpret_cast, or
  //   - a reinterpret_cast followed by a const_cast,
  //   can be performed using the cast notation of explicit type conversion.
  //   [...] If a conversion can be interpreted in more than one of the ways
  //   listed above, the interpretation that appears first in the list is used,
  //   even if a cast resulting from that interpretation is ill-formed.
  // In plain language, this means trying a const_cast ...
  unsigned msg = diag::err_bad_cxx_cast_generic;
  TryCastResult tcr = TryConstCast(*this, CastExpr, CastTy, /*CStyle*/true,msg);
  if (tcr == TC_NotApplicable) {
    // ... or if that is not possible, a static_cast, ignoring const, ...
    tcr = TryStaticCast(*this, CastExpr, CastTy, /*CStyle*/true, R, Kind, msg);
    if (tcr == TC_NotApplicable) {
      // ... and finally a reinterpret_cast, ignoring const.
      tcr = TryReinterpretCast(*this, CastExpr, CastTy, /*CStyle*/true, R, msg);
    }
  }

  if (tcr != TC_Success && msg != 0)
    Diag(R.getBegin(), msg) << (FunctionalStyle ? CT_Functional : CT_CStyle)
      << CastExpr->getType() << CastTy << R;

  return tcr != TC_Success;
}

  // We need to artificially create:
  // cling_PrintValue(void* (ASTContext)C, void* (Expr)E, const void* (&i)
  Expr* ValuePrinterSynthesizer::SynthesizeVP(Expr* E) {
    QualType QT = E->getType();
    // For now we skip void and function pointer types.
    if (!QT.isNull() && (QT->isVoidType() || QT->isFunctionType()))
      return 0;

    // Find cling_PrintValue
    if (!m_LookupResult)
      FindAndCacheRuntimeLookupResult(E->getLocStart());


    Expr* VoidEArg = utils::Synthesize::CStyleCastPtrExpr(m_Sema,
                                                          m_Context->VoidPtrTy,
                                                          (uint64_t)E);
    Expr* VoidCArg = utils::Synthesize::CStyleCastPtrExpr(m_Sema,
                                                          m_Context->VoidPtrTy,
                                                          (uint64_t)m_Context);

    SourceLocation NoSLoc = SourceLocation();
    Scope* S = m_Sema->getScopeForContext(m_Sema->CurContext);
    if (!QT->isPointerType()) {
      while(ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(E))
        E = ICE->getSubExpr();
      E = m_Sema->BuildUnaryOp(S, NoSLoc, UO_AddrOf, E).get();
    }

    llvm::SmallVector<Expr*, 4> CallArgs;
    CallArgs.push_back(VoidEArg);
    CallArgs.push_back(VoidCArg);
    CallArgs.push_back(E);

    CXXScopeSpec CSS;
    Expr* unresolvedLookup
      = m_Sema->BuildDeclarationNameExpr(CSS, *m_LookupResult,
                                         /*ADL*/ false).get();

    Expr* Result = m_Sema->ActOnCallExpr(S, unresolvedLookup, E->getLocStart(),
                                         CallArgs, E->getLocEnd()).get();
    assert(Result && "Cannot create value printer!");

    return Result;
  }

void ReturnUndefChecker::checkPreStmt(const ReturnStmt *RS,
                                      CheckerContext &C) const {
  const Expr *RetE = RS->getRetValue();
  if (!RetE)
    return;
  SVal RetVal = C.getSVal(RetE);

  const StackFrameContext *SFC = C.getStackFrame();
  QualType RT = CallEvent::getDeclaredResultType(SFC->getDecl());

  if (RetVal.isUndef()) {
    // "return;" is modeled to evaluate to an UndefinedVal. Allow UndefinedVal
    // to be returned in functions returning void to support this pattern:
    //   void foo() {
    //     return;
    //   }
    //   void test() {
    //     return foo();
    //   }
    if (!RT.isNull() && RT->isVoidType())
      return;

    // Not all blocks have explicitly-specified return types; if the return type
    // is not available, but the return value expression has 'void' type, assume
    // Sema already checked it.
    if (RT.isNull() && isa<BlockDecl>(SFC->getDecl()) &&
        RetE->getType()->isVoidType())
      return;

    emitUndef(C, RetE);
    return;
  }

  if (RT.isNull())
    return;

  if (RT->isReferenceType()) {
    checkReference(C, RetE, RetVal.castAs<DefinedOrUnknownSVal>());
    return;
  }
}