Added a base class for all AST visitors.

src/Bridge/ASTVisitor.cs

@@ -0,0 +1,150 @@
+using System.Collections.Generic;
+
+namespace Cxxi
+{
+    /// <summary>
+    /// Base class for AST visitors.
+    /// You can override the methods to customize the behaviour, by default
+    /// this will visit all the nodes in a default way that should be useful
+    /// for a lot of applications.
+    /// </summary>
+    public abstract class AstVisitor : ITypeVisitor<bool>, IDeclVisitor<bool>
+    {
+        private readonly ISet<object> Visited;
+
+        protected AstVisitor()
+        {
+            Visited = new HashSet<object>();
+        }
+
+        public bool AlreadyVisited(Type type)
+        {
+            return !Visited.Add(type);
+        }
+
+        public bool AlreadyVisited(Declaration decl)
+        {
+            return  !Visited.Add(decl);
+        }
+
+        public virtual bool VisitTagType(TagType tag, TypeQualifiers quals)
+        {
+            return tag.Declaration.Visit(this);
+        }
+
+        public virtual bool VisitArrayType(ArrayType array, TypeQualifiers quals)
+        {
+            return array.Type.Visit(this, quals);
+        }
+
+        public virtual bool VisitFunctionType(FunctionType function, TypeQualifiers quals)
+        {
+            if (function.ReturnType != null)
+                function.ReturnType.Visit(this);
+
+            foreach (var param in function.Arguments)
+                param.Visit(this);
+
+            return true;
+        }
+
+        public virtual bool VisitPointerType(PointerType pointer, TypeQualifiers quals)
+        {
+            if (pointer.Pointee == null)
+                return false;
+
+            return pointer.Pointee.Visit(this, quals);
+        }
+
+        public virtual bool VisitMemberPointerType(MemberPointerType member, TypeQualifiers quals)
+        {
+            return member.Pointee.Visit(this, quals);
+        }
+
+        public virtual bool VisitBuiltinType(BuiltinType builtin, TypeQualifiers quals)
+        {
+            return true;
+        }
+
+        public virtual bool VisitTypedefType(TypedefType typedef, TypeQualifiers quals)
+        {
+            return typedef.Declaration.Visit(this);
+        }
+
+        public virtual bool VisitTemplateSpecializationType(TemplateSpecializationType template, TypeQualifiers quals)
+        {
+            return template.Template.Visit(this);
+        }
+
+        public virtual bool VisitDeclaration(Declaration decl, TypeQualifiers quals)
+        {
+            return VisitDeclaration(decl);
+        }
+
+        public virtual bool VisitDeclaration(Declaration decl)
+        {
+            return true;
+        }
+
+        public virtual bool VisitClassDecl(Class @class)
+        {
+            if (AlreadyVisited(@class))
+                return true;
+
+            return VisitDeclaration(@class);
+        }
+
+        public virtual bool VisitFieldDecl(Field field)
+        {
+            return field.Type.Visit(this);
+        }
+
+        public virtual bool VisitFunctionDecl(Function function)
+        {
+            if (function.ReturnType != null)
+                function.ReturnType.Visit(this);
+
+            foreach (var param in function.Parameters)
+                param.Visit(this);
+
+            return true;
+        }    
+
+        public virtual bool VisitMethodDecl(Method method)
+        {
+            return VisitFunctionDecl(method);
+        }
+
+        public virtual bool VisitParameterDecl(Parameter parameter)
+        {
+            return parameter.Type.Visit(this);
+        }
+
+        public virtual bool VisitTypedefDecl(TypedefDecl typedef)
+        {
+            if (typedef.Type == null)
+                return false;
+            return typedef.Type.Visit(this);
+        }
+
+        public virtual bool VisitEnumDecl(Enumeration @enum)
+        {
+            return VisitDeclaration(@enum);
+        }
+
+        public virtual bool VisitClassTemplateDecl(ClassTemplate template)
+        {
+            return template.TemplatedClass.Visit(this);
+        }
+
+        public virtual bool VisitFunctionTemplateDecl(FunctionTemplate template)
+        {
+            return template.TemplatedFunction.Visit(this);
+        }
+
+        public virtual bool VisitMacroDefinition(MacroDefinition macro)
+        {
+            return true;
+        }
+    }
+}