DeclBase/DeclCXX/DeclTemplate - silence static analyzer getAs<> null dereference warnings. NFCI.

The static analyzer is warning about potential null dereferences, but in these cases we should be able to use castAs<> directly and if not assert will fire for us.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@373626 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AST/DeclBase.cpp

@@ -959,11 +959,11 @@ const FunctionType *Decl::getFunctionType(bool BlocksToo) const {
     return nullptr;
 
   if (Ty->isFunctionPointerType())
-    Ty = Ty->getAs<PointerType>()->getPointeeType();
+    Ty = Ty->castAs<PointerType>()->getPointeeType();
   else if (Ty->isFunctionReferenceType())
-    Ty = Ty->getAs<ReferenceType>()->getPointeeType();
+    Ty = Ty->castAs<ReferenceType>()->getPointeeType();
   else if (BlocksToo && Ty->isBlockPointerType())
-    Ty = Ty->getAs<BlockPointerType>()->getPointeeType();
+    Ty = Ty->castAs<BlockPointerType>()->getPointeeType();
 
   return Ty->getAs<FunctionType>();
 }

lib/AST/DeclCXX.cpp

@@ -2566,7 +2566,7 @@ bool CXXConstructorDecl::isConvertingConstructor(bool AllowExplicit) const {
     return false;
 
   return (getNumParams() == 0 &&
-          getType()->getAs<FunctionProtoType>()->isVariadic()) ||
+          getType()->castAs<FunctionProtoType>()->isVariadic()) ||
          (getNumParams() == 1) ||
          (getNumParams() > 1 &&
           (getParamDecl(1)->hasDefaultArg() ||

lib/AST/DeclTemplate.cpp

@@ -519,15 +519,15 @@ SourceRange TemplateTypeParmDecl::getSourceRange() const {
 }
 
 unsigned TemplateTypeParmDecl::getDepth() const {
-  return getTypeForDecl()->getAs<TemplateTypeParmType>()->getDepth();
+  return getTypeForDecl()->castAs<TemplateTypeParmType>()->getDepth();
 }
 
 unsigned TemplateTypeParmDecl::getIndex() const {
-  return getTypeForDecl()->getAs<TemplateTypeParmType>()->getIndex();
+  return getTypeForDecl()->castAs<TemplateTypeParmType>()->getIndex();
 }
 
 bool TemplateTypeParmDecl::isParameterPack() const {
-  return getTypeForDecl()->getAs<TemplateTypeParmType>()->isParameterPack();
+  return getTypeForDecl()->castAs<TemplateTypeParmType>()->isParameterPack();
 }
 
 //===----------------------------------------------------------------------===//