Resolve rename conflicts in nameof in attributes

The expander can operate on a specific set of known nodes, so when
rename finds a conflict in a particular node, it uses the span of a
parent that the expander knows how to handle. For normal
ArgumentSyntaxes, this is covered by being within a StatementSyntax.
However, nameof within an attribute constructor isn't in a statement, so
rename needs to expand to the span of the attribute.

src/EditorFeatures/Test2/Rename/CSharp/AliasTests.vb

@@ -700,8 +700,8 @@ class Program
                     </Project>
                 </Workspace>, renameTo:="BarAttribute")
 
-                result.AssertLabeledSpansAre("short", "BarAttribute", RelatedLocationType.ResolvedReferenceConflict)
-                result.AssertLabeledSpansAre("long", "BarAttribute", RelatedLocationType.NoConflict)
+                result.AssertLabeledSpansAre("short", "BarAttribute()", RelatedLocationType.ResolvedReferenceConflict)
+                result.AssertLabeledSpansAre("long", "BarAttributeAttribute()", RelatedLocationType.NoConflict)
             End Using
         End Sub
 

src/EditorFeatures/Test2/Rename/CSharp/DeclarationConflictTests.vb

@@ -543,7 +543,7 @@ class C
                 </Workspace>, renameTo:="Method")
 
                 result.AssertLabeledSpansAre("first", "Method", RelatedLocationType.NoConflict)
-                result.AssertLabeledSpansAre("second", "C.Method", type:=RelatedLocationType.ResolvedReferenceConflict)
+                result.AssertLabeledSpansAre("second", "DefaultValue(C.Method)", type:=RelatedLocationType.ResolvedReferenceConflict)
             End Using
         End Sub
     End Class

src/EditorFeatures/Test2/Rename/CSharp/EscapingTests.vb

@@ -63,7 +63,7 @@ class [|$$MainAttribute|] : System.Attribute
                     </Project>
                 </Workspace>, renameTo:="ifAttribute")
 
-                result.AssertLabeledSpecialSpansAre("resolved", "ifAttribute", RelatedLocationType.ResolvedReferenceConflict)
+                result.AssertLabeledSpecialSpansAre("resolved", "ifAttribute()", RelatedLocationType.ResolvedReferenceConflict)
             End Using
         End Sub
 

src/EditorFeatures/Test2/Rename/RenameEngineTests.vb

@@ -6770,6 +6770,28 @@ class C
             End Using
         End Sub
 
+        <WorkItem(446, "https://github.com/dotnet/roslyn/issues/446")>
+        <Fact>
+        <Trait(Traits.Feature, Traits.Features.Rename)>
+        Public Sub RenameWithNameOfInAttribute()
+            Using result = RenameEngineResult.Create(
+                   <Workspace>
+                       <Project Language="C#" CommonReferences="true">
+                           <Document>
+class C
+{
+    // Rename F to Fail
+    static void [|F|]$$(int x) { }
+
+    [System.Obsolete(nameof({|conflict:Fail|}))]
+    static void Fail() { }
+}
+                            </Document>
+                       </Project>
+                   </Workspace>, renameTo:="Fail")
+                result.AssertLabeledSpansAre("conflict", type:=RelatedLocationType.UnresolvedConflict)
+            End Using
+        End Sub
 #End Region
 
     End Class

src/Workspaces/CSharp/Portable/Rename/CSharpRenameRewriterLanguageService.cs

@@ -1096,6 +1096,12 @@ private static SyntaxNode GetExpansionTarget(SyntaxToken token)
                 return enclosingInitializer.Value;
             }
 
+            var attributeSyntax = token.GetAncestor<AttributeSyntax>();
+            if (attributeSyntax != null)
+            {
+                return attributeSyntax;
+            }
+
             // there seems to be no statement above this one. Let's see if we can at least get an SimpleNameSyntax
             return enclosingStatement ?? enclosingNameMemberCrefOrnull ?? token.GetAncestors(n => n is SimpleNameSyntax).FirstOrDefault();
         }