/DICK.B1/IronPython/Compiler/CollectableCompilationMode.cs

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 *

 * Copyright (c) Microsoft Corporation. 

 *

 * This source code is subject to terms and conditions of the Microsoft Public License. A 

 * copy of the license can be found in the License.html file at the root of this distribution. If 

 * you cannot locate the  Microsoft Public License, please send an email to 

 * dlr@microsoft.com. By using this source code in any fashion, you are agreeing to be bound 

 * by the terms of the Microsoft Public License.

 *

 * You must not remove this notice, or any other, from this software.

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#if !CLR2

using MSAst = System.Linq.Expressions;

#else

using MSAst = Microsoft.Scripting.Ast;

#endif



using System;

using System.Collections.Generic;

using System.Collections.ObjectModel;

using System.Runtime.CompilerServices;



using Microsoft.Scripting;

using Microsoft.Scripting.Ast;

using Microsoft.Scripting.Runtime;

using Microsoft.Scripting.Utils;



using IronPython.Runtime;



using AstUtils = Microsoft.Scripting.Ast.Utils;





namespace IronPython.Compiler.Ast {

    using Ast = MSAst.Expression;

    /// <summary>

    /// A global allocator that puts all of the globals into an array access.  The array is an

    /// array of PythonGlobal objects.  We then just close over the array for any inner functions.

    /// 

    /// Once compiled a RuntimeScriptCode is produced which is closed over the entire execution

    /// environment.

    /// </summary>

    class CollectableCompilationMode : CompilationMode {



        public override MSAst.LambdaExpression ReduceAst(PythonAst instance, string name) {

            return Ast.Lambda<Func<FunctionCode, object>>(

                    Ast.Block(

                        new[] { PythonAst._globalArray, PythonAst._globalContext },

                        Ast.Assign(PythonAst._globalArray, instance.GlobalArrayInstance),

                        Ast.Assign(PythonAst._globalContext, Ast.Constant(instance.ModuleContext.GlobalContext)),

                        AstUtils.Convert(instance.ReduceWorker(), typeof(object))

                    ),

                    name,

                    new[] { PythonAst._functionCode }

                );

        }



        public override void PrepareScope(PythonAst ast, ReadOnlyCollectionBuilder<MSAst.ParameterExpression> locals, List<MSAst.Expression> init) {

            locals.Add(PythonAst._globalArray);

            init.Add(Ast.Assign(PythonAst._globalArray, ast._arrayExpression));

        }





        public override MSAst.Expression GetGlobal(MSAst.Expression globalContext, int arrayIndex, PythonVariable variable, PythonGlobal global) {

            Assert.NotNull(global);



            return new PythonGlobalVariableExpression(

                Ast.ArrayIndex(

                    PythonAst._globalArray,

                    Ast.Constant(arrayIndex)

                ),

                variable,

                global

            );

        }



        public override Type DelegateType {

            get {

                return typeof(MSAst.Expression<Func<FunctionCode, object>>);

            }

        }

    }

}