mcs/class/Microsoft.CSharp/Microsoft.CSharp.RuntimeBinder/CSharpBinder.cs

   1 //
   2 // CSharpBinder.cs
   3 //
   4 // Authors:
   5 //      Marek Safar  <marek.safar@gmail.com>
   6 //
   7 // Copyright (C) 2009 Novell, Inc (http://www.novell.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 using System;
  30 using System.Dynamic;
  31 using System.Linq.Expressions;
  32 using Compiler = Mono.CSharp;
  33 using System.Reflection;
  34 using System.Collections.Generic;
  35
  36 namespace Microsoft.CSharp.RuntimeBinder
  37 {
  38         class CSharpBinder
  39         {
  40                 static ConstructorInfo binder_exception_ctor;
  41                 static object resolver = new object ();
  42
  43                 DynamicMetaObjectBinder binder;
  44                 Compiler.Expression expr;
  45                 BindingRestrictions restrictions;
  46                 DynamicMetaObject errorSuggestion;
  47
  48                 public CSharpBinder (DynamicMetaObjectBinder binder, Compiler.Expression expr, DynamicMetaObject errorSuggestion)
  49                 {
  50                         this.binder = binder;
  51                         this.expr = expr;
  52                         this.restrictions = BindingRestrictions.Empty;
  53                         this.errorSuggestion = errorSuggestion;
  54                 }
  55
  56                 public Compiler.ResolveContext.Options ResolveOptions { get; set; }
  57
  58                 public void AddRestrictions (DynamicMetaObject arg)
  59                 {
  60                         restrictions = restrictions.Merge (CreateRestrictionsOnTarget (arg));
  61                 }
  62
  63                 public void AddRestrictions (DynamicMetaObject[] args)
  64                 {
  65                         restrictions = restrictions.Merge (CreateRestrictionsOnTarget (args));
  66                 }
  67
  68                 public DynamicMetaObject Bind (DynamicContext ctx, Type callingType)
  69                 {
  70                         Expression res;
  71                         try {
  72                                 var rc = new Compiler.ResolveContext (new RuntimeBinderContext (ctx, callingType), ResolveOptions);
  73
  74                                 // Static typemanager and internal caches are not thread-safe
  75                                 lock (resolver) {
  76                                         expr = expr.Resolve (rc, Compiler.ResolveFlags.VariableOrValue);
  77                                 }
  78
  79                                 if (expr == null)
  80                                         throw new RuntimeBinderInternalCompilerException ("Expression resolved to null");
  81
  82                                 res = expr.MakeExpression (new Compiler.BuilderContext ());
  83                         } catch (RuntimeBinderException e) {
  84                                 if (errorSuggestion != null)
  85                                         return errorSuggestion;
  86
  87                                 res = CreateBinderException (e.Message);
  88                         } catch (Exception) {
  89                                 if (errorSuggestion != null)
  90                                         return errorSuggestion;
  91
  92                                 throw;
  93                         }
  94
  95                         return new DynamicMetaObject (res, restrictions);
  96                 }
  97
  98                 Expression CreateBinderException (string message)
  99                 {
 100                         if (binder_exception_ctor == null)
 101                                 binder_exception_ctor = typeof (RuntimeBinderException).GetConstructor (new[] { typeof (string) });
 102
 103                         //
 104                         // Uses target type to keep expressions composition working
 105                         //
 106                         return Expression.Throw (Expression.New (binder_exception_ctor, Expression.Constant (message)), binder.ReturnType);
 107                 }
 108
 109                 static BindingRestrictions CreateRestrictionsOnTarget (DynamicMetaObject arg)
 110                 {
 111                         return arg.HasValue && arg.Value == null ?
 112                                 BindingRestrictions.GetInstanceRestriction (arg.Expression, null) :
 113                                 BindingRestrictions.GetTypeRestriction (arg.Expression, arg.LimitType);
 114                 }
 115
 116                 public static BindingRestrictions CreateRestrictionsOnTarget (DynamicMetaObject[] args)
 117                 {
 118                         if (args.Length == 0)
 119                                 return BindingRestrictions.Empty;
 120
 121                         var res = CreateRestrictionsOnTarget (args[0]);
 122                         for (int i = 1; i < args.Length; ++i)
 123                                 res = res.Merge (CreateRestrictionsOnTarget (args[i]));
 124
 125                         return res;
 126                 }
 127         }
 128 }