source: tags/3.3.11/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory.CSharp-5.5.0/TypeSystem/AttributeTypeReference.cs @ 12011

// Copyright (c) 2010-2013 AlphaSierraPapa for the SharpDevelop Team
// 
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// software and associated documentation files (the "Software"), to deal in the Software
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// 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.
// 
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// 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
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using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Diagnostics;
using System.Linq;

using ICSharpCode.NRefactory.Semantics;
using ICSharpCode.NRefactory.TypeSystem;
using ICSharpCode.NRefactory.TypeSystem.Implementation;

namespace ICSharpCode.NRefactory.CSharp.TypeSystem
{
  /// <summary>
  /// Type reference used within an attribute.
  /// Looks up both 'withoutSuffix' and 'withSuffix' and returns the type that exists.
  /// </summary>
  [Serializable]
  public sealed class AttributeTypeReference : ITypeReference, ISupportsInterning
  {
    readonly ITypeReference withoutSuffix, withSuffix;
    
    public AttributeTypeReference(ITypeReference withoutSuffix, ITypeReference withSuffix)
    {
      if (withoutSuffix == null)
        throw new ArgumentNullException("withoutSuffix");
      if (withSuffix == null)
        throw new ArgumentNullException("withSuffix");
      this.withoutSuffix = withoutSuffix;
      this.withSuffix = withSuffix;
    }
    
    public IType Resolve(ITypeResolveContext context)
    {
      IType t1 = withoutSuffix.Resolve(context);
      IType t2 = withSuffix.Resolve(context);
      return PreferAttributeTypeWithSuffix(t1, t2, context.Compilation) ? t2 : t1;
    }
    
    internal static bool PreferAttributeTypeWithSuffix(IType t1, IType t2, ICompilation compilation)
    {
      if (t2.Kind == TypeKind.Unknown) return false;
      if (t1.Kind == TypeKind.Unknown) return true;
      
      var attrTypeDef = compilation.FindType(KnownTypeCode.Attribute).GetDefinition();
      if (attrTypeDef != null) {
        bool t1IsAttribute = (t1.GetDefinition() != null && t1.GetDefinition().IsDerivedFrom(attrTypeDef));
        bool t2IsAttribute = (t2.GetDefinition() != null && t2.GetDefinition().IsDerivedFrom(attrTypeDef));
        if (t2IsAttribute && !t1IsAttribute)
          return true;
        // If both types exist and are attributes, C# considers that to be an ambiguity, but we are less strict.
      }
      return false;
    }
    
    public override string ToString()
    {
      return withoutSuffix.ToString() + "[Attribute]";
    }
    
    int ISupportsInterning.GetHashCodeForInterning()
    {
      unchecked {
        return withoutSuffix.GetHashCode() + 715613 * withSuffix.GetHashCode();
      }
    }
    
    bool ISupportsInterning.EqualsForInterning(ISupportsInterning other)
    {
      AttributeTypeReference atr = other as AttributeTypeReference;
      return atr != null && this.withoutSuffix == atr.withoutSuffix && this.withSuffix == atr.withSuffix;
    }
  }
}