GenericParameter.cs: override Module properly

[mcs.git] / class / Microsoft.CSharp / Microsoft.CSharp.RuntimeBinder / CSharpBinder.cs

//
// CSharpBinder.cs
//
// Authors:
//      Marek Safar  <marek.safar@gmail.com>
//
// Copyright (C) 2009 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System;
using System.Dynamic;
using System.Linq.Expressions;
using Compiler = Mono.CSharp;
using System.Reflection;
using System.Collections.Generic;

namespace Microsoft.CSharp.RuntimeBinder
{
        class CSharpBinder
        {
                static ConstructorInfo binder_exception_ctor;
                static object compiler_initializer = new object ();
                static object resolver = new object ();

                DynamicMetaObjectBinder binder;
                Compiler.Expression expr;
                BindingRestrictions restrictions;
                DynamicMetaObject errorSuggestion;

                public CSharpBinder (DynamicMetaObjectBinder binder, Compiler.Expression expr, DynamicMetaObject errorSuggestion)
                {
                        this.binder = binder;
                        this.expr = expr;
                        this.restrictions = BindingRestrictions.Empty;
                        this.errorSuggestion = errorSuggestion;
                }

                public Compiler.ResolveContext.Options ResolveOptions { get; set; }

                public void AddRestrictions (DynamicMetaObject arg)
                {
                        restrictions = restrictions.Merge (CreateRestrictionsOnTarget (arg));
                }

                public void AddRestrictions (DynamicMetaObject[] args)
                {
                        restrictions = restrictions.Merge (CreateRestrictionsOnTarget (args));
                }

                public DynamicMetaObject Bind (Type callingType, DynamicMetaObject target)
                {
                        if (target.Value == null) {
                                if (errorSuggestion != null)
                                        return errorSuggestion;

                                var ex = CreateBinderException ("Cannot perform member binding on `null' value");
                                return new DynamicMetaObject (ex, restrictions);
                        }

                        return Bind (callingType);
                }

                public DynamicMetaObject Bind (Type callingType)
                {
                        var ctx = CreateDefaultCompilerContext ();

                        InitializeCompiler (ctx);

                        Expression res;
                        try {
                                var rc = new Compiler.ResolveContext (new RuntimeBinderContext (ctx, callingType), ResolveOptions);

                                // Static typemanager and internal caches are not thread-safe
                                lock (resolver) {
                                        expr = expr.Resolve (rc, Compiler.ResolveFlags.VariableOrValue);
                                }

                                if (expr == null)
                                        throw new RuntimeBinderInternalCompilerException ("Expression resolved to null");

                                res = expr.MakeExpression (new Compiler.BuilderContext ());
                        } catch (RuntimeBinderException e) {
                                if (errorSuggestion != null)
                                        return errorSuggestion;

                                res = CreateBinderException (e.Message);
                        } catch (Exception) {
                                if (errorSuggestion != null)
                                        return errorSuggestion;

                                throw;
                        }

                        return new DynamicMetaObject (res, restrictions);
                }

                Expression CreateBinderException (string message)
                {
                        if (binder_exception_ctor == null)
                                binder_exception_ctor = typeof (RuntimeBinderException).GetConstructor (new[] { typeof (string) });

                        //
                        // Uses target type to keep expressions composition working
                        //
                        return Expression.Throw (Expression.New (binder_exception_ctor, Expression.Constant (message)), binder.ReturnType);
                }

                //
                // Creates mcs expression from dynamic method object
                //
                public static Compiler.Expression CreateCompilerExpression (CSharpArgumentInfo info, DynamicMetaObject value)
                {
                        if (value.Value == null) {
                                if (value.LimitType == typeof (object))
                                        return new Compiler.NullLiteral (Compiler.Location.Null);

                                InitializeCompiler (null);
                                return Compiler.Constant.CreateConstantFromValue (value.LimitType, null, Compiler.Location.Null);
                        }

                        bool is_compile_time;

                        if (info != null) {
                                if ((info.Flags & CSharpArgumentInfoFlags.Constant) != 0) {
                                        InitializeCompiler (null);
                                        return Compiler.Constant.CreateConstantFromValue (value.LimitType, value.Value, Compiler.Location.Null);
                                }

                                if ((info.Flags & CSharpArgumentInfoFlags.IsStaticType) != 0)
                                        return new Compiler.TypeExpression ((Type) value.Value, Compiler.Location.Null);

                                is_compile_time = (info.Flags & CSharpArgumentInfoFlags.UseCompileTimeType) != 0;
                        } else {
                                is_compile_time = false;
                        }

                        return new Compiler.RuntimeValueExpression (value, is_compile_time);
                }

                public static Compiler.Arguments CreateCompilerArguments (IEnumerable<CSharpArgumentInfo> info, DynamicMetaObject[] args)
                {
                        var res = new Compiler.Arguments (args.Length);
                        int pos = 0;

                        // enumerates over args
                        foreach (var item in info) {
                                var expr = CreateCompilerExpression (item, args [pos++]);
                                if (item.IsNamed) {
                                        res.Add (new Compiler.NamedArgument (item.Name, Compiler.Location.Null, expr));
                                } else {
                                        res.Add (new Compiler.Argument (expr, item.ArgumentModifier));
                                }

                                if (pos == args.Length)
                                        break;
                        }

                        return res;
                }

                public static Compiler.CompilerContext CreateDefaultCompilerContext ()
                {
                        return new Compiler.CompilerContext (
                                new Compiler.Report (ErrorPrinter.Instance) {
                                        WarningLevel = 0
                                }) {
                                        IsRuntimeBinder = true
                                };
                }

                static BindingRestrictions CreateRestrictionsOnTarget (DynamicMetaObject arg)
                {
                        return arg.HasValue && arg.Value == null ?
                                BindingRestrictions.GetInstanceRestriction (arg.Expression, null) :
                                BindingRestrictions.GetTypeRestriction (arg.Expression, arg.LimitType);
                }

                public static BindingRestrictions CreateRestrictionsOnTarget (DynamicMetaObject[] args)
                {
                        if (args.Length == 0)
                                return BindingRestrictions.Empty;

                        var res = CreateRestrictionsOnTarget (args[0]);
                        for (int i = 1; i < args.Length; ++i)
                                res = res.Merge (CreateRestrictionsOnTarget (args[i]));

                        return res;
                }

                public static void InitializeCompiler (Compiler.CompilerContext ctx)
                {
                        if (Compiler.TypeManager.object_type != null)
                                return;

                        lock (compiler_initializer) {
                                if (Compiler.TypeManager.object_type != null)
                                        return;

                                // I don't think dynamically loaded assemblies can be used as dynamic
                                // expression without static type be loaded first
                                // AppDomain.CurrentDomain.AssemblyLoad += (sender, e) => { throw new NotImplementedException (); };

                                // Import all currently loaded assemblies
                                foreach (System.Reflection.Assembly a in AppDomain.CurrentDomain.GetAssemblies ())
                                        Compiler.GlobalRootNamespace.Instance.AddAssemblyReference (a);

                                if (ctx == null)
                                        ctx = CreateDefaultCompilerContext ();

                                Compiler.TypeManager.InitCoreTypes (ctx);
                                Compiler.TypeManager.InitOptionalCoreTypes (ctx);
                        }
                }
        }
}