EE: Fix portable imports grouping (dotnet#21863)

shawnro · Sep 7, 2017 · ca3f2f0 · ca3f2f0
1 parent bd0d7b7
commit ca3f2f0
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Showing 2 changed files with 47 additions and 3 deletions.
diff --git a/src/ExpressionEvaluator/CSharp/Test/ExpressionCompiler/UsingDebugInfoTests.cs b/src/ExpressionEvaluator/CSharp/Test/ExpressionCompiler/UsingDebugInfoTests.cs
@@ -50,6 +50,42 @@ void M()
             });
         }
 
+        [Fact, WorkItem(21386, "https://github.com/dotnet/roslyn/issues/21386")]
+        public void Gaps()
+        {
+            var source = @"
+using System;
+
+namespace N1
+{
+  namespace N2 
+  {
+    using System.Collections;
+
+    namespace N3 
+    {
+      class C { void M() { } }
+    }
+  }
+}
+";
+            var comp = CreateStandardCompilation(source);
+            WithRuntimeInstance(comp, runtime =>
+            {
+                GetMethodDebugInfo(runtime, "N1.N2.N3.C.M").ImportRecordGroups.Verify(@"
+                {
+                }
+                {
+                    Namespace: string='System.Collections'
+                }
+                {
+                }
+                {
+                    Namespace: string='System'
+                }");
+            });
+        }
+
         [Fact]
         public void NestedScopes()
         {

diff --git a/src/ExpressionEvaluator/Core/Source/ExpressionCompiler/PDB/MethodDebugInfo.Portable.cs b/src/ExpressionEvaluator/Core/Source/ExpressionCompiler/PDB/MethodDebugInfo.Portable.cs
@@ -2,6 +2,7 @@
 
 using System;
 using System.Collections.Immutable;
+using System.Diagnostics;
 using System.Linq;
 using System.Reflection.Metadata;
 using System.Reflection.Metadata.Ecma335;
@@ -258,13 +259,20 @@ private static void PopulateImports(
                     // ignore invalid imports
                 }
 
-                // VB always expects two import groups (even if they are empty).
-                // TODO: consider doing this for C# as well and handle empty groups in the binder.
-                if (isVisualBasicMethod || importGroupBuilder.Count > 0)
+                // Portable PDBs represent project-level scope as the root of the chain of scopes.
+                // This scope might contain aliases for assembly references, but is not considered 
+                // to be part of imports groups.
+                if (isVisualBasicMethod || !importScope.Parent.IsNil)
                 {
                     importGroupsBuilder.Add(importGroupBuilder.ToImmutable());
                     importGroupBuilder.Clear();
                 }
+                else
+                {
+                    // C# currently doesn't support global imports in PDBs
+                    // https://github.com/dotnet/roslyn/issues/21862
+                    Debug.Assert(importGroupBuilder.Count == 0);
+                }
 
                 handle = importScope.Parent;
             }