Merge pull request #4579 from tmat/EncAssemblyDef

Do not emit AssemblyDef into EnC delta

src/Compilers/CSharp/Test/Emit/Emit/EditAndContinue/EditAndContinueTests.cs

@@ -7,6 +7,7 @@
 using System.Reflection;
 using System.Reflection.Metadata;
 using System.Reflection.Metadata.Ecma335;
+using System.Threading;
 using Microsoft.CodeAnalysis.CodeGen;
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.CSharp.Test.Utilities;
@@ -85,18 +86,9 @@ public void Delta_AssemblyDefTable()
                 generation0,
                 ImmutableArray.Create(new SemanticEdit(SemanticEditKind.Update, f0, f1, preserveLocalVariables: true)));
 
-            var reader1 = diff1.GetMetadata().Reader;
-
-            var assemblyDef = reader1.GetAssemblyDefinition();
-            Assert.False(assemblyDef.Name.IsNil);
-            Assert.Equal(0, assemblyDef.Version.Major);
-            Assert.Equal(0, assemblyDef.Version.Minor);
-            Assert.Equal(0, assemblyDef.Version.Revision);
-            Assert.Equal(0, assemblyDef.Version.Build);
-            Assert.True(assemblyDef.PublicKey.IsNil);
-            Assert.True(assemblyDef.Culture.IsNil);
-            Assert.Equal((AssemblyFlags)0, assemblyDef.Flags);
-            Assert.Equal(AssemblyHashAlgorithm.Sha1, assemblyDef.HashAlgorithm);
+            // AssemblyDef record is not emitted to delta since changes in assembly identity are not allowed:
+            Assert.True(md0.MetadataReader.IsAssembly);
+            Assert.False(diff1.GetMetadata().Reader.IsAssembly);
         }
 
         [Fact]
@@ -3931,7 +3923,7 @@ .maxstack  1
 ");
             // expect a single TypeRef for System.Object
             var md1 = diff1.GetMetadata();
-            AssertEx.Equal(new[] { "[0x23000002] 0x0000028b.0x00000298" }, DumpTypeRefs(md1.Reader));
+            AssertEx.Equal(new[] { "[0x23000002] 0x00000266.0x00000273" }, DumpTypeRefs(md1.Reader));
 
             var diff2 = compilation2.EmitDifference(
                 diff1.NextGeneration,
@@ -3954,7 +3946,7 @@ .maxstack  1
 ");
             // expect a single TypeRef for System.Object
             var md2 = diff2.GetMetadata();
-            AssertEx.Equal(new[] { "[0x23000003] 0x000002f9.0x00000306" }, DumpTypeRefs(md2.Reader));
+            AssertEx.Equal(new[] { "[0x23000003] 0x000002af.0x000002bc" }, DumpTypeRefs(md2.Reader));
         }
 
         [Fact]
@@ -4039,7 +4031,7 @@ .maxstack  1
 ");
             // expect a single TypeRef for System.Object
             var md2 = diff2.GetMetadata();
-            AssertEx.Equal(new[] { "[0x23000003] 0x0000032c.0x00000339" }, DumpTypeRefs(md2.Reader));
+            AssertEx.Equal(new[] { "[0x23000003] 0x000002e2.0x000002ef" }, DumpTypeRefs(md2.Reader));
         }
 
         private static IEnumerable<string> DumpTypeRefs(MetadataReader reader)

src/Compilers/Core/Portable/PEWriter/MetadataWriter.cs

@@ -119,6 +119,12 @@ private bool IsMinimalDelta
             get { return !IsFullMetadata; }
         }
 
+        /// <summary>
+        /// NetModules and EnC deltas don't have AssemblyDef record.
+        /// We don't emit it for EnC deltas since assembly identity has to be preserved across generations (CLR/debugger get confused otherwise).
+        /// </summary>
+        private bool EmitAssemblyDefinition => module.AsAssembly != null && !IsMinimalDelta;
+
         /// <summary>
         /// Returns metadata generation ordinal. Zero for
         /// full metadata and non-zero for delta.
@@ -459,7 +465,7 @@ private ImmutableArray<int> GetRowCounts()
         {
             var rowCounts = new int[MetadataTokens.TableCount];
 
-            rowCounts[(int)TableIndex.Assembly] = (this.module.AsAssembly != null) ? 1 : 0;
+            rowCounts[(int)TableIndex.Assembly] = EmitAssemblyDefinition ? 1 : 0;
             rowCounts[(int)TableIndex.AssemblyRef] = _assemblyRefTable.Count;
             rowCounts[(int)TableIndex.ClassLayout] = _classLayoutTable.Count;
             rowCounts[(int)TableIndex.Constant] = _constantTable.Count;
@@ -2584,12 +2590,12 @@ public int GetHashCode(IAssemblyReference reference)
 
         private void PopulateAssemblyTableRows()
         {
-            IAssembly assembly = this.module.AsAssembly;
-            if (assembly == null)
+            if (!EmitAssemblyDefinition)
             {
                 return;
             }
 
+            IAssembly assembly = this.module.AsAssembly;
             _assemblyKey = heaps.GetBlobIndex(assembly.PublicKey);
             _assemblyName = this.GetStringIndexForPathAndCheckLength(assembly.Name, assembly);
             _assemblyCulture = heaps.GetStringIndex(assembly.Culture);
@@ -4070,12 +4076,12 @@ private void SerializeFieldRvaTable(BlobBuilder writer, MetadataSizes metadataSi
 
         private void SerializeAssemblyTable(BlobBuilder writer, MetadataSizes metadataSizes)
         {
-            IAssembly assembly = this.module.AsAssembly;
-            if (assembly == null)
+            if (!EmitAssemblyDefinition)
             {
                 return;
             }
 
+            IAssembly assembly = this.module.AsAssembly;
             writer.WriteUInt32((uint)assembly.HashAlgorithm);
             writer.WriteUInt16((ushort)assembly.Version.Major);
             writer.WriteUInt16((ushort)assembly.Version.Minor);

src/Compilers/VisualBasic/Test/Emit/Emit/EditAndContinue/EditAndContinueTests.vb

@@ -3488,7 +3488,7 @@ End Class
 ")
             ' expect a single TypeRef for System.Object
             Dim md1 = diff1.GetMetadata()
-            AssertEx.Equal({"[0x23000002] 0x00000232.0x0000023f"}, DumpTypeRefs(md1.Reader))
+            AssertEx.Equal({"[0x23000002] 0x0000020d.0x0000021a"}, DumpTypeRefs(md1.Reader))
 
             Dim diff2 = compilation2.EmitDifference(diff1.NextGeneration,
                 ImmutableArray.Create(
@@ -3508,7 +3508,7 @@ End Class
 ")
             ' expect a single TypeRef for System.Object
             Dim md2 = diff2.GetMetadata()
-            AssertEx.Equal({"[0x23000003] 0x000002a0.0x000002ad"}, DumpTypeRefs(md2.Reader))
+            AssertEx.Equal({"[0x23000003] 0x00000256.0x00000263"}, DumpTypeRefs(md2.Reader))
         End Sub
 
         <Fact>
@@ -3580,7 +3580,7 @@ End Class
 ")
             ' expect a single TypeRef for System.Object
             Dim md2 = diff2.GetMetadata()
-            AssertEx.Equal({"[0x23000003] 0x000002d3.0x000002e0"}, DumpTypeRefs(md2.Reader))
+            AssertEx.Equal({"[0x23000003] 0x00000289.0x00000296"}, DumpTypeRefs(md2.Reader))
         End Sub
 
         Private Shared Iterator Function DumpTypeRefs(reader As MetadataReader) As IEnumerable(Of String)