Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/System.Data.Entity.Design/System/Data/EntityModel/Emitters/Emitter.cs

@@ -0,0 +1,127 @@
+//---------------------------------------------------------------------
+// <copyright file="Emitter.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//
+// @owner       [....]
+// @backupOwner [....]
+//---------------------------------------------------------------------
+
+using System;
+using System.CodeDom;
+using System.Diagnostics;
+using System.Data.EntityModel.SchemaObjectModel;
+
+
+
+
+namespace System.Data.EntityModel.Emitters
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    internal abstract class Emitter
+    {
+        #region Instance Fields
+        private ClientApiGenerator _generator = null;
+        #endregion
+
+        #region Static Fields
+        private static CodeExpression _nullExpression = null;
+        private static CodeExpression _thisRef = null;
+
+        /// <summary>Name of property used to get StorageContext from an Entity</summary>
+        private const string EntityGetContextPropertyName = "Context";
+        /// <summary>Name of property used to get StorageContext from a StorageSearcher</summary>
+        protected const string SearcherGetContextPropertyName = "Context";
+        #endregion
+
+        #region Protected Methods
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="generator"></param>
+        protected Emitter(ClientApiGenerator generator)
+        {
+            Generator = generator;
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="expression"></param>
+        /// <returns></returns>
+        protected static CodeBinaryOperatorExpression EmitExpressionEqualsNull(CodeExpression expression)
+        {
+            return new CodeBinaryOperatorExpression(expression, CodeBinaryOperatorType.IdentityEquality, NullExpression);
+        }
+
+        protected static CodeBinaryOperatorExpression EmitExpressionDoesNotEqualNull(CodeExpression expression)
+        {
+            return new CodeBinaryOperatorExpression(expression, CodeBinaryOperatorType.IdentityInequality, NullExpression);
+        }
+
+        internal static CodeExpression EmitEnumMemberExpression(CodeTypeReference type, string member)
+        {
+            CodeTypeReferenceExpression typeref = new CodeTypeReferenceExpression(type);
+            return new CodeFieldReferenceExpression(typeref, member);
+        }
+        #endregion
+
+        #region Protected Properties
+        /// <summary>
+        /// 
+        /// </summary>
+        protected static CodeExpression ThisRef
+        {
+            get
+            {
+                if (_thisRef == null)
+                    _thisRef = new CodeThisReferenceExpression();
+                return _thisRef;
+            }
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        internal ClientApiGenerator Generator
+        {
+            get
+            {
+                return _generator;
+            }
+            private set
+            {
+                _generator = value;
+            }
+        }
+
+        protected TypeReference TypeReference
+        {
+            get
+            {
+                return _generator.TypeReference;
+            }
+        }
+
+        protected AttributeEmitter AttributeEmitter
+        {
+            get { return _generator.AttributeEmitter; }
+        }
+
+        protected static CodeExpression NullExpression
+        {
+            get
+            {
+                if (_nullExpression == null)
+                    _nullExpression = new CodePrimitiveExpression(null);
+
+                return _nullExpression;
+
+            }
+        }
+
+        #endregion
+    }
+}