Merge pull request dotnet#503 from gafter/fix40

Do not use declared constant's value inside a nameof() expression
gafter · Feb 16, 2015 · 08c5fbf · 08c5fbf
2 parents 0bf8a33 + 575e6a7
commit 08c5fbf
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Showing 5 changed files with 423 additions and 411 deletions.
diff --git a/src/Compilers/CSharp/Portable/Binder/Binder.cs b/src/Compilers/CSharp/Portable/Binder/Binder.cs
@@ -65,11 +65,8 @@ internal bool IsEarlyAttributeBinder
             }
         }
 
-        // Is the given node being bound as a nameof(...) operator?
-        protected virtual bool IsNameofArgument(SyntaxNode node)
-        {
-            return false;
-        }
+        // Return the nearest enclosing node being bound as a nameof(...) argument, if any, or null if none.
+        protected virtual SyntaxNode EnclosingNameofArgument => null;
 
         /// <summary>
         /// Get the next binder in which to look up a name, if not found by this binder.

diff --git a/src/Compilers/CSharp/Portable/Binder/Binder_Expressions.cs b/src/Compilers/CSharp/Portable/Binder/Binder_Expressions.cs
@@ -1052,7 +1052,8 @@ private BoundExpression BindNonMethod(SimpleNameSyntax node, Symbol symbol, Diag
                 case SymbolKind.Local:
                     {
                         var localSymbol = (LocalSymbol)symbol;
-                        var constantValueOpt = localSymbol.IsConst ? localSymbol.GetConstantValue(node, this.LocalInProgress, diagnostics) : null;
+                        var constantValueOpt = localSymbol.IsConst && this.EnclosingNameofArgument == null
+                            ? localSymbol.GetConstantValue(node, this.LocalInProgress, diagnostics) : null;
                         TypeSymbol type;
 
                         Location localSymbolLocation = localSymbol.Locations[0];
@@ -1277,7 +1278,7 @@ private BoundExpression SynthesizeReceiver(SimpleNameSyntax node, Symbol member,
             if (currentType.IsEqualToOrDerivedFrom(member.ContainingType, ignoreDynamic: false, useSiteDiagnostics: ref useSiteDiagnostics))
             {
                 bool hasErrors = false;
-                if (!IsNameofArgument(node))
+                if (EnclosingNameofArgument != node)
                 {
                     if (InFieldInitializer && !currentType.IsScriptClass)
                     {
@@ -4594,7 +4595,7 @@ private bool IsUsingAliasInScope(string name)
                                 Error(diagnostics, ErrorCode.ERR_BadSKunknown, boundLeft.Syntax, leftType, MessageID.IDS_SK_TYVAR.Localize());
                                 return BadExpression(node, LookupResultKind.NotAValue, boundLeft);
                             }
-                            else if (this.IsNameofArgument(node))
+                            else if (this.EnclosingNameofArgument == node)
                             {
                                 // Support selecing an extension method from a type name in nameof(.)
                                 return BindInstanceMemberAccess(node, right, boundLeft, rightName, rightArity, typeArgumentsSyntax, typeArguments, invoked, diagnostics);
@@ -5244,7 +5245,7 @@ private static void CombineExtensionMethodArguments(BoundExpression receiver, An
 
             ConstantValue constantValueOpt = null;
 
-            if (fieldSymbol.IsConst)
+            if (fieldSymbol.IsConst && this.EnclosingNameofArgument == null)
             {
                 constantValueOpt = fieldSymbol.GetConstantValue(this.ConstantFieldsInProgress, this.IsEarlyAttributeBinder);
                 if (constantValueOpt == ConstantValue.Unset)
@@ -5386,7 +5387,7 @@ private bool InEnumMemberInitializer()
             }
             else
             {
-                if (instanceReceiver == false && !IsNameofArgument(node))
+                if (instanceReceiver == false && EnclosingNameofArgument != node)
                 {
                     Error(diagnostics, ErrorCode.ERR_ObjectRequired, node, symbol);
                     resultKind = LookupResultKind.StaticInstanceMismatch;

diff --git a/src/Compilers/CSharp/Portable/Binder/NameofBinder.cs b/src/Compilers/CSharp/Portable/Binder/NameofBinder.cs
@@ -19,9 +19,6 @@ public NameofBinder(SyntaxNode nameofArgument, Binder next) : base(next)
             _nameofArgument = nameofArgument;
         }
 
-        protected override bool IsNameofArgument(SyntaxNode possibleNameofArgument)
-        {
-            return possibleNameofArgument == _nameofArgument;
-        }
+        protected override SyntaxNode EnclosingNameofArgument => _nameofArgument;
     }
 }