Merge pull request #3417 from icsharpcode/roslyn413

Roslyn 4.13

Author: siegfriedpammer

Diff for: Directory.Packages.props

@@ -15,8 +15,8 @@
     <PackageVersion Include="K4os.Compression.LZ4" Version="1.3.8" />
     <PackageVersion Include="McMaster.Extensions.CommandLineUtils" Version="4.1.1" />
     <PackageVersion Include="McMaster.Extensions.Hosting.CommandLine" Version="4.1.1" />
-    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="4.12.0" />
-    <PackageVersion Include="Microsoft.CodeAnalysis.VisualBasic" Version="4.12.0" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="4.13.0" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.VisualBasic" Version="4.13.0" />
     <PackageVersion Include="Microsoft.DiaSymReader.Converter.Xml" Version="1.1.0-beta2-22171-02" />
     <PackageVersion Include="Microsoft.DiaSymReader" Version="1.4.0" />
     <PackageVersion Include="Microsoft.DiaSymReader.Native" Version="17.0.0-beta1.21524.1" />

Diff for: ICSharpCode.Decompiler/IL/ControlFlow/StateRangeAnalysis.cs

@@ -21,11 +21,8 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
-using System.Diagnostics.CodeAnalysis;
 using System.Linq;
-using System.Text;
 using System.Threading;
-using System.Threading.Tasks;
 
 using ICSharpCode.Decompiler.TypeSystem;
 using ICSharpCode.Decompiler.Util;
@@ -225,6 +222,32 @@ public LongSet AssignStateRanges(ILInstruction inst, LongSet stateRange)
 						goto default;
 					}
 				}
+				case StObj stobj when mode == StateRangeAnalysisMode.IteratorDispose:
+				{
+					if (stobj.MatchStFld(out var target, out var field, out var value) && target.MatchLdThis())
+					{
+						if (field.MemberDefinition == stateField && value.MatchLdcI4(-2))
+						{
+							// Roslyn 4.13 sets the state field in Dispose() to mark the iterator as disposed,
+							// don't consider this user code.
+							return stateRange;
+						}
+						else if (value.MatchDefaultOrNullOrZero())
+						{
+							// Roslyn 4.13 clears any local hoisted local variables in Dispose(),
+							// don't consider this user code.
+							return stateRange;
+						}
+						else
+						{
+							goto default;
+						}
+					}
+					else
+					{
+						goto default;
+					}
+				}
 				default:
 					// User code - abort analysis
 					if (mode == StateRangeAnalysisMode.IteratorDispose && !(inst is Leave l && l.IsLeavingFunction))