source: stable/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory.CSharp-5.5.0/Analysis/SemanticHighlightingVisitor.cs @ 12515

// Copyright (c) 2010-2013 AlphaSierraPapa for the SharpDevelop Team
// 
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// 
// 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.Diagnostics;
using System.Linq;
using ICSharpCode.NRefactory.CSharp.Resolver;
using ICSharpCode.NRefactory.Semantics;
using ICSharpCode.NRefactory.TypeSystem;
using System.Threading;
using ICSharpCode.NRefactory.CSharp.Completion;
using System.Collections.ObjectModel;

namespace ICSharpCode.NRefactory.CSharp.Analysis
{
  /// <summary>
  /// C# Semantic highlighter.
  /// </summary>
  public abstract class SemanticHighlightingVisitor<TColor> : DepthFirstAstVisitor
  {
    protected CancellationToken cancellationToken = default (CancellationToken);
    
    protected TColor defaultTextColor;
    protected TColor referenceTypeColor;
    protected TColor valueTypeColor;
    protected TColor interfaceTypeColor;
    protected TColor enumerationTypeColor;
    protected TColor typeParameterTypeColor;
    protected TColor delegateTypeColor;
    
    protected TColor methodCallColor;
    protected TColor methodDeclarationColor;
    
    protected TColor eventDeclarationColor;
    protected TColor eventAccessColor;
    
    protected TColor propertyDeclarationColor;
    protected TColor propertyAccessColor;
    
    protected TColor fieldDeclarationColor;
    protected TColor fieldAccessColor;
    
    protected TColor variableDeclarationColor;
    protected TColor variableAccessColor;
    
    protected TColor parameterDeclarationColor;
    protected TColor parameterAccessColor;
    
    protected TColor valueKeywordColor;
    protected TColor externAliasKeywordColor;
    protected TColor varKeywordTypeColor;

    /// <summary>
    /// Used for 'in' modifiers on type parameters.
    /// </summary>
    /// <remarks>
    /// 'in' may have a different color when used with 'foreach'.
    /// 'out' is not colored by semantic highlighting, as syntax highlighting can already detect it as a parameter modifier.
    /// </remarks>
    protected TColor parameterModifierColor;
    
    /// <summary>
    /// Used for inactive code (excluded by preprocessor or ConditionalAttribute)
    /// </summary>
    protected TColor inactiveCodeColor;

    protected TColor stringFormatItemColor;


    protected TColor syntaxErrorColor;
    
    protected TextLocation regionStart;
    protected TextLocation regionEnd;
    
    protected CSharpAstResolver resolver;
    protected bool isInAccessorContainingValueParameter;
    
    protected abstract void Colorize(TextLocation start, TextLocation end, TColor color);
    
    #region Colorize helper methods
    protected void Colorize(Identifier identifier, ResolveResult rr)
    {
      if (identifier.IsNull)
        return;
      if (rr.IsError) {
        Colorize(identifier, syntaxErrorColor);
        return;
      }
      if (rr is TypeResolveResult) {
        if (blockDepth > 0 && identifier.Name == "var" && rr.Type.Kind != TypeKind.Null && rr.Type.Name != "var" ) {
          Colorize(identifier, varKeywordTypeColor);
          return;
        }

        TColor color;
        if (TryGetTypeHighlighting (rr.Type.Kind, out color)) {
          Colorize(identifier, color);
        }
        return;
      }
      var mrr = rr as MemberResolveResult;
      if (mrr != null) {
        TColor color;
        if (TryGetMemberColor (mrr.Member, out color)) {
          Colorize(identifier, color);
          return;
        }
      }
      
      if (rr is MethodGroupResolveResult) {
        Colorize (identifier, methodCallColor);
        return;
      }
      
      var localResult = rr as LocalResolveResult;
      if (localResult != null) {
        if (localResult.Variable is IParameter) {
          Colorize (identifier, parameterAccessColor);
        } else {
          Colorize (identifier, variableAccessColor);
        }
      }
      
      
      VisitIdentifier(identifier); // un-colorize contextual keywords
    }
    
    protected void Colorize(AstNode node, TColor color)
    {
      if (node.IsNull)
        return;
      Colorize(node.StartLocation, node.EndLocation, color);
    }
    #endregion
    
    protected override void VisitChildren(AstNode node)
    {
      for (var child = node.FirstChild; child != null; child = child.NextSibling) {
        if (child.StartLocation < regionEnd && child.EndLocation > regionStart)
          child.AcceptVisitor(this);
      }
    }
    
    /// <summary>
    /// Visit all children of <c>node</c> until (but excluding) <c>end</c>.
    /// If <c>end</c> is a null node, nothing will be visited.
    /// </summary>
    protected void VisitChildrenUntil(AstNode node, AstNode end)
    {
      if (end.IsNull)
        return;
      Debug.Assert(node == end.Parent);
      for (var child = node.FirstChild; child != end; child = child.NextSibling) {
        cancellationToken.ThrowIfCancellationRequested();
        if (child.StartLocation < regionEnd && child.EndLocation > regionStart)
          child.AcceptVisitor(this);
      }
    }
    
    /// <summary>
    /// Visit all children of <c>node</c> after (excluding) <c>start</c>.
    /// If <c>start</c> is a null node, all children will be visited.
    /// </summary>
    protected void VisitChildrenAfter(AstNode node, AstNode start)
    {
      Debug.Assert(start.IsNull || start.Parent == node);
      for (var child = (start.IsNull ? node.FirstChild : start.NextSibling); child != null; child = child.NextSibling) {
        cancellationToken.ThrowIfCancellationRequested();
        if (child.StartLocation < regionEnd && child.EndLocation > regionStart)
          child.AcceptVisitor(this);
      }
    }
    
    public override void VisitIdentifier(Identifier identifier)
    {
      switch (identifier.Name) {
        case "add":
        case "async":
        case "await":
        case "get":
        case "partial":
        case "remove":
        case "set":
        case "where":
        case "yield":
        case "from":
        case "select":
        case "group":
        case "into":
        case "orderby":
        case "join":
        case "let":
        case "on":
        case "equals":
        case "by":
        case "ascending":
        case "descending":
        case "dynamic":
        case "var":
          // Reset color of contextual keyword to default if it's used as an identifier.
          // Note that this method does not get called when 'var' or 'dynamic' is used as a type,
          // because types get highlighted with valueTypeColor/referenceTypeColor instead.
          Colorize(identifier, defaultTextColor);
          break;
        case "global":
          // Reset color of 'global' keyword to default unless its used as part of 'global::'.
          MemberType parentMemberType = identifier.Parent as MemberType;
          if (parentMemberType == null || !parentMemberType.IsDoubleColon)
            Colorize(identifier, defaultTextColor);
          break;
      }
      // "value" is handled in VisitIdentifierExpression()
      // "alias" is handled in VisitExternAliasDeclaration()
    }
    
    public override void VisitSimpleType(SimpleType simpleType)
    {
      var identifierToken = simpleType.IdentifierToken;
      VisitChildrenUntil(simpleType, identifierToken);
      Colorize(identifierToken, resolver.Resolve(simpleType, cancellationToken));
      VisitChildrenAfter(simpleType, identifierToken);
    }
    
    public override void VisitMemberType(MemberType memberType)
    {
      var memberNameToken = memberType.MemberNameToken;
      VisitChildrenUntil(memberType, memberNameToken);
      Colorize(memberNameToken, resolver.Resolve(memberType, cancellationToken));
      VisitChildrenAfter(memberType, memberNameToken);
    }
    
    public override void VisitIdentifierExpression(IdentifierExpression identifierExpression)
    {
      var identifier = identifierExpression.IdentifierToken;
      VisitChildrenUntil(identifierExpression, identifier);
      if (isInAccessorContainingValueParameter && identifierExpression.Identifier == "value") {
        Colorize(identifier, valueKeywordColor);
      } else {
        Colorize(identifier, resolver.Resolve(identifierExpression, cancellationToken));
      }
      VisitChildrenAfter(identifierExpression, identifier);
    }
    
    public override void VisitMemberReferenceExpression(MemberReferenceExpression memberReferenceExpression)
    {
      var memberNameToken = memberReferenceExpression.MemberNameToken;
      VisitChildrenUntil(memberReferenceExpression, memberNameToken);
      ResolveResult rr = resolver.Resolve(memberReferenceExpression, cancellationToken);
      Colorize(memberNameToken, rr);
      VisitChildrenAfter(memberReferenceExpression, memberNameToken);
    }

    void HighlightStringFormatItems(PrimitiveExpression expr)
    {
      if (!(expr.Value is string))
        return;
      int line = expr.StartLocation.Line;
      int col = expr.StartLocation.Column;
      TextLocation start = TextLocation.Empty;
      for (int i = 0; i < expr.LiteralValue.Length; i++) {
        char ch = expr.LiteralValue [i];

        if (NewLine.GetDelimiterType(ch, i + 1 < expr.LiteralValue.Length ? expr.LiteralValue [i + 1] : '\0') != UnicodeNewline.Unknown) {
          line++;
          col = 1;
          continue;
        }


        if (ch == '{' && start.IsEmpty) {
          char next = i + 1 < expr.LiteralValue.Length ? expr.LiteralValue [i + 1] : '\0';
          if (next == '{') {
            i++;
            col += 2;
            continue;
          }
          start = new TextLocation(line, col);
        }
        if (ch == '}' &&!start.IsEmpty) {
          Colorize(start, new TextLocation(line, col + 1), stringFormatItemColor);
          start = TextLocation.Empty;
        }
        col++;
      }

    }

    public override void VisitInvocationExpression(InvocationExpression invocationExpression)
    {
      Expression target = invocationExpression.Target;
      if (target is IdentifierExpression || target is MemberReferenceExpression || target is PointerReferenceExpression) {
        var invocationRR = resolver.Resolve(invocationExpression, cancellationToken) as CSharpInvocationResolveResult;
        if (invocationRR != null) {
          if (invocationExpression.Parent is ExpressionStatement && (IsInactiveConditionalMethod(invocationRR.Member) || IsEmptyPartialMethod(invocationRR.Member))) {
            // mark the whole invocation statement as inactive code
            Colorize(invocationExpression.Parent, inactiveCodeColor);
            return;
          }

          Expression fmtArgumets;
          IList<Expression> args;
          if (invocationRR.Arguments.Count > 1 && FormatStringHelper.TryGetFormattingParameters(invocationRR, invocationExpression, out fmtArgumets, out args, null)) {
            var expr = invocationExpression.Arguments.First() as PrimitiveExpression; 
            if (expr != null)
              HighlightStringFormatItems(expr);
          }
        }

        VisitChildrenUntil(invocationExpression, target);
        
        // highlight the method call
        var identifier = target.GetChildByRole(Roles.Identifier);
        VisitChildrenUntil(target, identifier);
        if (invocationRR != null && !invocationRR.IsDelegateInvocation) {
          Colorize(identifier, methodCallColor);
        } else {
          ResolveResult targetRR = resolver.Resolve(target, cancellationToken);
          Colorize(identifier, targetRR);
        }
        VisitChildrenAfter(target, identifier);
        VisitChildrenAfter(invocationExpression, target);
      } else {
        VisitChildren(invocationExpression);
      }
    }
    
    #region IsInactiveConditional helper methods
    bool IsInactiveConditionalMethod(IParameterizedMember member)
    {
      if (member.SymbolKind != SymbolKind.Method || member.ReturnType.Kind != TypeKind.Void)
        return false;
      foreach (var baseMember in InheritanceHelper.GetBaseMembers(member, false)) {
        if (IsInactiveConditional (baseMember.Attributes))
          return true;
      }
      return IsInactiveConditional(member.Attributes);
    }

    static bool IsEmptyPartialMethod(IParameterizedMember member)
    {
      if (member.SymbolKind != SymbolKind.Method || member.ReturnType.Kind != TypeKind.Void)
        return false;
      var method = (IMethod)member;
      return method.IsPartial && !method.HasBody;
    }

    bool IsInactiveConditional(IList<IAttribute> attributes)
    {
      bool hasConditionalAttribute = false;
      foreach (var attr in attributes) {
        if (attr.AttributeType.Name == "ConditionalAttribute" && attr.AttributeType.Namespace == "System.Diagnostics" && attr.PositionalArguments.Count == 1) {
          string symbol = attr.PositionalArguments[0].ConstantValue as string;
          if (symbol != null) {
            hasConditionalAttribute = true;
            var cu = this.resolver.RootNode as SyntaxTree;
            if (cu != null) {
              if (cu.ConditionalSymbols.Contains(symbol))
                return false; // conditional is active
            }
          }
        }
      }

      return hasConditionalAttribute;
    }
    #endregion
    
    public override void VisitExternAliasDeclaration (ExternAliasDeclaration externAliasDeclaration)
    {
      var aliasToken = externAliasDeclaration.AliasToken;
      VisitChildrenUntil(externAliasDeclaration, aliasToken);
      Colorize (aliasToken, externAliasKeywordColor);
      VisitChildrenAfter(externAliasDeclaration, aliasToken);
    }
    
    public override void VisitAccessor(Accessor accessor)
    {
      isInAccessorContainingValueParameter = accessor.Role != PropertyDeclaration.GetterRole;
      try {
        VisitChildren(accessor);
      } finally {
        isInAccessorContainingValueParameter = false;
      }
    }
    
    bool CheckInterfaceImplementation (EntityDeclaration entityDeclaration)
    {
      var result = resolver.Resolve (entityDeclaration, cancellationToken) as MemberResolveResult;
      if (result == null)
        return false;
      if (result.Member.ImplementedInterfaceMembers.Count == 0) {
        Colorize (entityDeclaration.NameToken, syntaxErrorColor);
        return false;
      }
      return true;
    }
    
    public override void VisitMethodDeclaration(MethodDeclaration methodDeclaration)
    {
      var nameToken = methodDeclaration.NameToken;
      VisitChildrenUntil(methodDeclaration, nameToken);
      if (!methodDeclaration.PrivateImplementationType.IsNull) {
        if (!CheckInterfaceImplementation (methodDeclaration)) {
          VisitChildrenAfter(methodDeclaration, nameToken);
          return;
        }
      }
      Colorize(nameToken, methodDeclarationColor);
      VisitChildrenAfter(methodDeclaration, nameToken);
    }
    
    public override void VisitParameterDeclaration(ParameterDeclaration parameterDeclaration)
    {
      var nameToken = parameterDeclaration.NameToken;
      VisitChildrenUntil(parameterDeclaration, nameToken);
      Colorize(nameToken, parameterDeclarationColor);
      VisitChildrenAfter(parameterDeclaration, nameToken);
    }
    
    public override void VisitEventDeclaration(EventDeclaration eventDeclaration)
    {
      var nameToken = eventDeclaration.NameToken;
      VisitChildrenUntil(eventDeclaration, nameToken);
      Colorize(nameToken, eventDeclarationColor);
      VisitChildrenAfter(eventDeclaration, nameToken);
    }
    
    public override void VisitCustomEventDeclaration(CustomEventDeclaration eventDeclaration)
    {
      var nameToken = eventDeclaration.NameToken;
      VisitChildrenUntil(eventDeclaration, nameToken);
      if (!eventDeclaration.PrivateImplementationType.IsNull) {
        if (!CheckInterfaceImplementation (eventDeclaration)) {
          VisitChildrenAfter(eventDeclaration, nameToken);
          return;
        }
      }
      Colorize(nameToken, eventDeclarationColor);
      VisitChildrenAfter(eventDeclaration, nameToken);
    }
    
    public override void VisitPropertyDeclaration(PropertyDeclaration propertyDeclaration)
    {
      var nameToken = propertyDeclaration.NameToken;
      VisitChildrenUntil(propertyDeclaration, nameToken);
      if (!propertyDeclaration.PrivateImplementationType.IsNull) {
        if (!CheckInterfaceImplementation (propertyDeclaration)) {
          VisitChildrenAfter(propertyDeclaration, nameToken);
          return;
        }
      }
      Colorize(nameToken, propertyDeclarationColor);
      VisitChildrenAfter(propertyDeclaration, nameToken);
    }
    
    public override void VisitIndexerDeclaration(IndexerDeclaration indexerDeclaration)
    {
      base.VisitIndexerDeclaration(indexerDeclaration);
      if (!indexerDeclaration.PrivateImplementationType.IsNull) {
        CheckInterfaceImplementation (indexerDeclaration);
      }
    }
    
    public override void VisitFieldDeclaration(FieldDeclaration fieldDeclaration)
    {
      fieldDeclaration.ReturnType.AcceptVisitor (this);
      foreach (var init in fieldDeclaration.Variables) {
        Colorize (init.NameToken, fieldDeclarationColor);
        init.Initializer.AcceptVisitor (this);
      }
    }
    
    public override void VisitFixedFieldDeclaration(FixedFieldDeclaration fixedFieldDeclaration)
    {
      fixedFieldDeclaration.ReturnType.AcceptVisitor (this);
      foreach (var init in fixedFieldDeclaration.Variables) {
        Colorize (init.NameToken, fieldDeclarationColor);
        init.CountExpression.AcceptVisitor (this);
      }
    }
    
    public override void VisitConstructorDeclaration(ConstructorDeclaration constructorDeclaration)
    {
      HandleConstructorOrDestructor(constructorDeclaration);
    }
    
    public override void VisitDestructorDeclaration(DestructorDeclaration destructorDeclaration)
    {
      HandleConstructorOrDestructor(destructorDeclaration);
    }
    
    void HandleConstructorOrDestructor(AstNode constructorDeclaration)
    {
      Identifier nameToken = constructorDeclaration.GetChildByRole(Roles.Identifier);
      VisitChildrenUntil(constructorDeclaration, nameToken);
      var currentTypeDef = resolver.GetResolverStateBefore(constructorDeclaration).CurrentTypeDefinition;
      if (currentTypeDef != null && nameToken.Name == currentTypeDef.Name) {
        TColor color;
        if (TryGetTypeHighlighting (currentTypeDef.Kind, out color))
          Colorize(nameToken, color);
      }
      VisitChildrenAfter(constructorDeclaration, nameToken);
    }
    
    bool TryGetMemberColor(IMember member, out TColor color)
    {
      switch (member.SymbolKind) {
        case SymbolKind.Field:
          color = fieldAccessColor;
          return true;
        case SymbolKind.Property:
          color = propertyAccessColor;
          return true;
        case SymbolKind.Event:
          color = eventAccessColor;
          return true;
        case SymbolKind.Method:
          color = methodCallColor;
          return true;
        case SymbolKind.Constructor:
        case SymbolKind.Destructor:
          return TryGetTypeHighlighting (member.DeclaringType.Kind, out color);
        default:
          color = default (TColor);
          return false;
      }
    }
    
    TColor GetTypeHighlighting (ClassType classType)
    {
      switch (classType) {
        case ClassType.Class:
          return referenceTypeColor;
        case ClassType.Struct:
          return valueTypeColor;
        case ClassType.Interface:
          return interfaceTypeColor;
        case ClassType.Enum:
          return enumerationTypeColor;
        default:
          throw new InvalidOperationException ("Unknown class type :" + classType);
      }
    }
    
    bool TryGetTypeHighlighting (TypeKind kind, out TColor color)
    {
      switch (kind) {
        case TypeKind.Class:
          color = referenceTypeColor;
          return true;
        case TypeKind.Struct:
          color = valueTypeColor;
          return true;
        case TypeKind.Interface:
          color = interfaceTypeColor;
          return true;
        case TypeKind.Enum:
          color = enumerationTypeColor;
          return true;
        case TypeKind.TypeParameter:
          color = typeParameterTypeColor;
          return true;
        case TypeKind.Delegate:
          color = delegateTypeColor;
          return true;
        case TypeKind.Unknown:
        case TypeKind.Null:
          color = syntaxErrorColor;
          return true;
        default:
          color = default (TColor);
          return false;
      }
    }
    
    public override void VisitTypeDeclaration(TypeDeclaration typeDeclaration)
    {
      var nameToken = typeDeclaration.NameToken;
      VisitChildrenUntil(typeDeclaration, nameToken);
      Colorize(nameToken, GetTypeHighlighting (typeDeclaration.ClassType));
      VisitChildrenAfter(typeDeclaration, nameToken);
    }
    
    public override void VisitTypeParameterDeclaration(TypeParameterDeclaration typeParameterDeclaration)
    {
      if (typeParameterDeclaration.Variance == VarianceModifier.Contravariant)
        Colorize(typeParameterDeclaration.VarianceToken, parameterModifierColor);
      
      //      bool isValueType = false;
      //      if (typeParameterDeclaration.Parent != null) {
      //        foreach (var constraint in typeParameterDeclaration.Parent.GetChildrenByRole(Roles.Constraint)) {
      //          if (constraint.TypeParameter.Identifier == typeParameterDeclaration.Name) {
      //            isValueType = constraint.BaseTypes.OfType<PrimitiveType>().Any(p => p.Keyword == "struct");
      //          }
      //        }
      //      }
      var nameToken = typeParameterDeclaration.NameToken;
      VisitChildrenUntil(typeParameterDeclaration, nameToken);
      Colorize(nameToken, typeParameterTypeColor);  /*isValueType ? valueTypeColor : referenceTypeColor*/
      VisitChildrenAfter(typeParameterDeclaration, nameToken);
    }
    
    public override void VisitDelegateDeclaration(DelegateDeclaration delegateDeclaration)
    {
      var nameToken = delegateDeclaration.NameToken;
      VisitChildrenUntil(delegateDeclaration, nameToken);
      Colorize(nameToken, delegateTypeColor);
      VisitChildrenAfter(delegateDeclaration, nameToken);
    }
    
    public override void VisitVariableInitializer(VariableInitializer variableInitializer)
    {
      var nameToken = variableInitializer.NameToken;
      VisitChildrenUntil(variableInitializer, nameToken);
      if (variableInitializer.Parent is FieldDeclaration) {
        Colorize(nameToken, fieldDeclarationColor);
      } else if (variableInitializer.Parent is EventDeclaration) {
        Colorize(nameToken, eventDeclarationColor);
      } else {
        Colorize(nameToken, variableDeclarationColor);
      }
      VisitChildrenAfter(variableInitializer, nameToken);
    }
    
    public override void VisitComment(Comment comment)
    {
      if (comment.CommentType == CommentType.InactiveCode) {
        Colorize(comment, inactiveCodeColor);
      }
    }

    public override void VisitPreProcessorDirective(PreProcessorDirective preProcessorDirective)
    {
    }
    
    public override void VisitAttribute(ICSharpCode.NRefactory.CSharp.Attribute attribute)
    {
      ITypeDefinition attrDef = resolver.Resolve(attribute.Type, cancellationToken).Type.GetDefinition();
      if (attrDef != null && IsInactiveConditional(attrDef.Attributes)) {
        Colorize(attribute, inactiveCodeColor);
      } else {
        VisitChildren(attribute);
      }
    }
    
    public override void VisitArrayInitializerExpression (ArrayInitializerExpression arrayInitializerExpression)
    {
      foreach (var a in arrayInitializerExpression.Elements) {
        var namedElement = a as NamedExpression;
        if (namedElement != null) {
          var result = resolver.Resolve (namedElement, cancellationToken);
          if (result.IsError)
            Colorize (namedElement.NameToken, syntaxErrorColor);
          namedElement.Expression.AcceptVisitor (this);
        } else {
          a.AcceptVisitor (this);
        }
      }
    }

    int blockDepth;
    public override void VisitBlockStatement(BlockStatement blockStatement)
    {
      blockDepth++;
      base.VisitBlockStatement(blockStatement);
      blockDepth--;
    }
  }
}