diff --git a/lib/Interpreter/IncrementalParser.cpp b/lib/Interpreter/IncrementalParser.cpp
index a4f23a7f..f95f6c24 100644
--- a/lib/Interpreter/IncrementalParser.cpp
+++ b/lib/Interpreter/IncrementalParser.cpp
@@ -820,7 +820,7 @@ namespace cling {
     }
   }
 
-  void IncrementalParser::setTransformers(bool isChildInterpreter) {
+  void IncrementalParser::SetTransformers(bool isChildInterpreter) {
     // Add transformers to the IncrementalParser, which owns them
     Sema* TheSema = &m_CI->getSema();
     // Register the AST Transformers
diff --git a/lib/Interpreter/IncrementalParser.h b/lib/Interpreter/IncrementalParser.h
index c23ef1b9..2124cc15 100644
--- a/lib/Interpreter/IncrementalParser.h
+++ b/lib/Interpreter/IncrementalParser.h
@@ -224,7 +224,7 @@ namespace cling {
 
     ///\brief Add the trnasformers to the Incremental Parser.
     ///
-    void setTransformers(bool isChildInterpreter);
+    void SetTransformers(bool isChildInterpreter);
 
   private:
     ///\brief Finalizes the consumers (e.g. CodeGen) on a transaction.
diff --git a/lib/Interpreter/Interpreter.cpp b/lib/Interpreter/Interpreter.cpp
index 81f37ae1..e087b5ee 100644
--- a/lib/Interpreter/Interpreter.cpp
+++ b/lib/Interpreter/Interpreter.cpp
@@ -230,7 +230,7 @@ namespace cling {
       setCallbacks(std::move(AutoLoadCB));
     }
 
-    m_IncrParser->setTransformers(isChildInterp);
+    m_IncrParser->SetTransformers(isChildInterp);
   }
 
   ///\brief Constructor for the child Interpreter.
diff --git a/lib/Interpreter/NullDerefProtectionTransformer.cpp b/lib/Interpreter/NullDerefProtectionTransformer.cpp
index 1672e001..e2837a32 100644
--- a/lib/Interpreter/NullDerefProtectionTransformer.cpp
+++ b/lib/Interpreter/NullDerefProtectionTransformer.cpp
@@ -50,28 +50,20 @@ namespace cling {
     PointerCheckInjector(Sema& S) : m_Sema(S), m_Context(S.getASTContext()),
     m_clingthrowIfInvalidPointerCache(0) {}
 
-    bool VisitStmt(Stmt* S) {
-      for (auto child: S->children()) {
-        if (child)
-            VisitStmt(child);
-      }
-      return true;
-    }
-
     bool VisitUnaryOperator(UnaryOperator* UnOp) {
-      VisitStmt(UnOp->getSubExpr());
-      if (UnOp->getOpcode() == UO_Deref)
-        if (UnOp->getSubExpr()->getType().getTypePtr()->isPointerType())
-          UnOp->setSubExpr(SynthesizeCheck(UnOp->getSubExpr()));
+      Expr* SubExpr = UnOp->getSubExpr();
+      VisitStmt(SubExpr);
+      if (UnOp->getOpcode() == UO_Deref
+          && SubExpr->getType().getTypePtr()->isPointerType())
+          UnOp->setSubExpr(SynthesizeCheck(SubExpr));
       return true;
     }
 
     bool VisitMemberExpr(MemberExpr* ME) {
-      if (!((VarDecl*)(ME->getMemberDecl()))->isStaticDataMember()) {
-        VisitStmt(ME->getBase());
-        if (ME->isArrow())
-          ME->setBase(SynthesizeCheck(ME->getBase()));
-      }
+      VisitStmt(ME->getBase());
+      if (ME->isArrow()
+          && ME->getMemberDecl()->isCXXInstanceMember())
+        ME->setBase(SynthesizeCheck(ME->getBase()));
       return true;
     }
 
@@ -94,45 +86,17 @@ namespace cling {
       return true;
     }
 
-    bool VisitDecl (Decl* D)
-    {
-      printf("%ld\n", *(long*)D);
-      return true;
-    }
-
-    bool VisitFunctionDecl(FunctionDecl* FD) {
-      if (!FD->isConstexpr()) {
-        CompoundStmt* CS = dyn_cast_or_null<CompoundStmt>(FD->getBody());
-        if (CS)
-          VisitStmt(CS);
-      }
-      return true;
-    }
-
-    bool VisitCXXMethodDecl(CXXMethodDecl* FD) {
-      if (!FD->isConstexpr()) {
-        CompoundStmt* CS = dyn_cast_or_null<CompoundStmt>(FD->getBody());
-        if (CS)
-        VisitStmt(CS);
-    }
-      return true;
-    }
-
     bool TraverseFunctionDecl(FunctionDecl* FD) {
-      if (!FD->isConstexpr()) {
-        CompoundStmt* CS = dyn_cast_or_null<CompoundStmt>(FD->getBody());
-        if (CS)
-          TraverseStmt(CS);
-      }
+      // We cannot synthesize when there is a const expr.
+      if (!FD->isConstexpr())
+        RecursiveASTVisitor::TraverseFunctionDecl(FD);
       return true;
     }
 
-    bool TraverseCXXMethodDecl(CXXMethodDecl* CMD) {
-      if (!CMD->isConstexpr()){
-        CompoundStmt* CS = dyn_cast_or_null<CompoundStmt>(CMD->getBody());
-        if (CS)
-        TraverseStmt(CS);
-    }
+    bool TraverseCXXMethodDecl(CXXMethodDecl* CXXMD) {
+      // We cannot synthesize when there is a const expr.
+      if (!CXXMD->isConstexpr())
+        RecursiveASTVisitor::TraverseCXXMethodDecl(CXXMD);
       return true;
     }
 
diff --git a/lib/Utils/Validation.cpp b/lib/Utils/Validation.cpp
index bd9e02b5..d0ae5dc7 100644
--- a/lib/Utils/Validation.cpp
+++ b/lib/Utils/Validation.cpp
@@ -23,10 +23,8 @@
 namespace cling {
   namespace utils {
 
+#ifndef LLVM_ON_WIN32
     static int getNullDevFileDescriptor() {
-#ifdef LLVM_ON_WIN32
-      return 0;
-#else
       struct FileDescriptor {
         int FD;
         const char* file = "/dev/null";
@@ -37,12 +35,10 @@ namespace cling {
       };
       static FileDescriptor nullDev;
       return nullDev.FD;
-#endif
     }
+#endif
 
     // Checking whether the pointer points to a valid memory location
-    // Used for checking of void* output
-    // Should be moved to earlier stages (ex. IR) in the future
     bool isAddressValid(const void *P) {
       if (!P || P == (void *) -1)
         return false;
@@ -55,11 +51,10 @@ namespace cling {
         return false;
       return true;
 #else
-      // There is a POSIX way of finding whether an address can be accessed for
-      // reading: write() will return EFAULT if not.
-      int NBytes = write(getNullDevFileDescriptor(), P, 1/*byte*/);
-      if (NBytes != 1) {
-        assert(errno == EFAULT && "unexpected pipe write error");
+      // There is a POSIX way of finding whether an address
+      // can be accessed for reading.
+      if (write(getNullDevFileDescriptor(), P, 1/*byte*/) != 1) {
+        assert(errno == EFAULT && "unexpected write error at address");
         return false;
       }
       return true;