Fixed 'Bug 42591 - XS generates documentation for preprocessor

directives.'.

Note that WithFrozenPartialSemanticAsync is a < 5ms operation which
gives the current, but maybe not 100% correct semantic. So it's not
blocking the UI thread.
(Which isn't needed since it's more or less an AST operation and the
AST is always up2date there)

2 files changed, 17 insertions, 9 deletions

diff --git a/main/src/addins/MonoDevelop.DocFood/MonoDevelop.DocFood.csproj b/main/src/addins/MonoDevelop.DocFood/MonoDevelop.DocFood.csproj
index 89dad2b139..46e82424b6 100644
--- a/main/src/addins/MonoDevelop.DocFood/MonoDevelop.DocFood.csproj
+++ b/main/src/addins/MonoDevelop.DocFood/MonoDevelop.DocFood.csproj
@@ -20,11 +20,6 @@
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
     <Externalconsole>True</Externalconsole>
-    <CustomCommands>
-      <CustomCommands>
-        <Command type="Execute" command="../../../main/build/bin/MonoDevelop.exe" />
-      </CustomCommands>
-    </CustomCommands>
     <NoWarn>1591;1573</NoWarn>
     <DocumentationFile>..\..\..\build\AddIns\BackendBindings\MonoDevelop.DocFood.xml</DocumentationFile>
   </PropertyGroup>
@@ -69,6 +64,9 @@
       <HintPath>..\..\..\external\roslyn\Binaries\Release\Microsoft.CodeAnalysis.CSharp.dll</HintPath>
       <Private>False</Private>
     </Reference>
+    <Reference Include="Microsoft.CodeAnalysis.Workspaces">
+      <HintPath>..\..\..\build\bin\Microsoft.CodeAnalysis.Workspaces.dll</HintPath>
+    </Reference>
   </ItemGroup>
   <ItemGroup>
     <Compile Include="AssemblyInfo.cs" />
diff --git a/main/src/addins/MonoDevelop.DocFood/MonoDevelop.DocFood/DocFoodTextEditorExtension.cs b/main/src/addins/MonoDevelop.DocFood/MonoDevelop.DocFood/DocFoodTextEditorExtension.cs
index 7ccb5b775d..16a4d01097 100644
--- a/main/src/addins/MonoDevelop.DocFood/MonoDevelop.DocFood/DocFoodTextEditorExtension.cs
+++ b/main/src/addins/MonoDevelop.DocFood/MonoDevelop.DocFood/DocFoodTextEditorExtension.cs
@@ -24,11 +24,14 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 using System;
+using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Text;
+using MonoDevelop.CSharp.Completion;
 using MonoDevelop.Ide.Editor;
 using MonoDevelop.Ide.Editor.Extension;
+using System.Threading;
 
 namespace MonoDevelop.DocFood
 {
@@ -72,9 +75,10 @@ namespace MonoDevelop.DocFood
 			if (l != null && Editor.GetTextAt (l).TrimStart ().StartsWith ("///", StringComparison.Ordinal))
 				return base.KeyPress (descriptor);
 
-			var member = GetMemberToDocument ();
-			if (member == null)
+			var memberTask = GetMemberToDocument ();
+			if (!memberTask.Wait (250) || memberTask.Result == null)
 				return base.KeyPress (descriptor);
+			var member = memberTask.Result;
 			
 			string documentation = GenerateDocumentation (member, Editor.GetLineIndent (line));
 			if (string.IsNullOrEmpty (documentation))
@@ -156,12 +160,14 @@ namespace MonoDevelop.DocFood
 			return true;
 		}	
 		
-		ISymbol GetMemberToDocument ()
+		async Task<ISymbol> GetMemberToDocument (CancellationToken cancellationToken = default(CancellationToken))
 		{
 			var parsedDocument = DocumentContext.ParsedDocument;
 			if (parsedDocument == null)
 				return null;
-			var semanticModel = parsedDocument.GetAst<SemanticModel> ();
+
+			var partialDoc = await CSharpCompletionTextEditorExtension.WithFrozenPartialSemanticsAsync (DocumentContext.AnalysisDocument, cancellationToken).ConfigureAwait (false);
+			var semanticModel = await partialDoc.GetSemanticModelAsync ();
 			if (semanticModel == null)
 				return null;
 			var caretOffset = Editor.CaretOffset;
@@ -182,6 +188,10 @@ namespace MonoDevelop.DocFood
 				if (eventDeclaration != null) {
 					node = eventDeclaration.Declaration.Variables.First ();
 				}
+
+				if (node.Span.Contains (caretOffset))
+					return null;
+
 				var declaredSymbol = semanticModel.GetDeclaredSymbol (node); 
 				if (declaredSymbol != null)
 					return declaredSymbol;