commit baa7106219bac139a8f79d2255df6b18df1811e1
author Jooyung Han <jooyung@google.com> Wed Sep 29 09:06:03 2021 +0900
committer Jooyung Han <jooyung@google.com> Wed Sep 29 09:06:03 2021 +0900
tree a7f4bda2c965af9f034957d3df003d9a512086ef
parent 589cfb0c1244d87682b97c1262718b56c8b5d251

Adding AidlCast to replace downcasting methods

This change only replaces ones in AidlMember for now but AidlCast can
replace downcasting methods in AidlDefinedType as well.

Bug: n/a
Test: aidl_unittests
Change-Id: Ib51f994622f87d6442cf1491b02c71c1a305d627

aidl_language.h

diff --git a/aidl_language.h b/aidl_language.h
index 284e24f..59bd1cd 100644
--- a/aidl_language.h
+++ b/aidl_language.h
@@ -468,22 +468,6 @@
   AidlMember(AidlMember&&) = delete;
   AidlMember& operator=(const AidlMember&) = delete;
   AidlMember& operator=(AidlMember&&) = delete;
-
-  virtual const AidlMethod* AsMethod() const { return nullptr; }
-  virtual const AidlConstantDeclaration* AsConstantDeclaration() const { return nullptr; }
-  virtual const AidlVariableDeclaration* AsVariableDeclaration() const { return nullptr; }
-
-  AidlMethod* AsMethod() {
-    return const_cast<AidlMethod*>(const_cast<const AidlMember*>(this)->AsMethod());
-  }
-  AidlConstantDeclaration* AsConstantDeclaration() {
-    return const_cast<AidlConstantDeclaration*>(
-        const_cast<const AidlMember*>(this)->AsConstantDeclaration());
-  }
-  AidlVariableDeclaration* AsVariableDeclaration() {
-    return const_cast<AidlVariableDeclaration*>(
-        const_cast<const AidlMember*>(this)->AsVariableDeclaration());
-  }
 };
 
 // TODO: This class is used for method arguments and also parcelable fields,
@@ -503,8 +487,6 @@
   AidlVariableDeclaration& operator=(const AidlVariableDeclaration&) = delete;
   AidlVariableDeclaration& operator=(AidlVariableDeclaration&&) = delete;
 
-  const AidlVariableDeclaration* AsVariableDeclaration() const override { return this; }
-
   std::string GetName() const { return name_; }
   std::string GetCapitalizedName() const;
   const AidlTypeSpecifier& GetType() const { return *type_; }
@@ -825,8 +807,6 @@
     return value_->ValueString(GetType(), decorator);
   }
 
-  const AidlConstantDeclaration* AsConstantDeclaration() const override { return this; }
-
   void TraverseChildren(std::function<void(const AidlNode&)> traverse) const override {
     traverse(GetType());
     traverse(GetValue());
@@ -854,7 +834,6 @@
   AidlMethod& operator=(const AidlMethod&) = delete;
   AidlMethod& operator=(AidlMethod&&) = delete;
 
-  const AidlMethod* AsMethod() const override { return this; }
   const AidlTypeSpecifier& GetType() const { return *type_; }
   AidlTypeSpecifier* GetMutableType() { return type_.get(); }
 
@@ -1285,3 +1264,21 @@
   };
   bottom_up(node);
 }
+
+template <typename T>
+const T* AidlCast(const AidlNode& node) {
+  struct CastVisitor : AidlVisitor {
+    const T* cast = nullptr;
+    void Visit(const T& t) override { cast = &t; }
+  } visitor;
+  node.DispatchVisit(visitor);
+  return visitor.cast;
+}
+
+template <>
+const AidlDefinedType* AidlCast<AidlDefinedType>(const AidlNode& node);
+
+template <typename T>
+T* AidlCast(AidlNode& node) {
+  return const_cast<T*>(AidlCast<T>(const_cast<const AidlNode&>(node)));
+}