Implement Block.CheckInvariant for BlockKind.ArrayInitializer, BlockKind.CollectionInitializer and BlockKind.ObjectInitializer

ICSharpCode.Decompiler/IL/Instructions/Block.cs

@@ -21,6 +21,7 @@ using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
 using ICSharpCode.Decompiler.IL.Transforms;
+using ICSharpCode.Decompiler.TypeSystem;
 
 namespace ICSharpCode.Decompiler.IL
 {
@@ -131,6 +132,42 @@ namespace ICSharpCode.Decompiler.IL
 						Debug.Assert(call.Arguments[0].MatchLdLoc(v));
 					}
 					break;
+				case BlockKind.ArrayInitializer:
+					var final = finalInstruction as LdLoc;
+					Debug.Assert(final != null && final.Variable.Kind == VariableKind.InitializerTarget);
+					IType type = null;
+					Debug.Assert(Instructions[0].MatchStLoc(final.Variable, out var init) && init.MatchNewArr(out type));
+					for (int i = 1; i < Instructions.Count; i++) {
+						Debug.Assert(Instructions[i].MatchStObj(out ILInstruction target, out ILInstruction value, out var t) && type != null && type.Equals(t));
+						Debug.Assert(target.MatchLdElema(out t, out ILInstruction array) && type.Equals(t));
+						Debug.Assert(array.MatchLdLoc(out ILVariable v) && v == final.Variable);
+					}
+					break;
+				case BlockKind.CollectionInitializer:
+				case BlockKind.ObjectInitializer:
+					var final2 = finalInstruction as LdLoc;
+					Debug.Assert(final2 != null && final2.Variable.Kind == VariableKind.InitializerTarget);
+					IType type2 = null;
+					Debug.Assert(Instructions[0].MatchStLoc(final2.Variable, out var init2));
+					Debug.Assert(init2 is NewObj || init2 is DefaultValue || (init2 is Block named && named.Kind == BlockKind.CallWithNamedArgs));
+					switch (init2) {
+						case NewObj newObj:
+							type2 = newObj.Method.DeclaringType;
+							break;
+						case DefaultValue defaultValue:
+							type2 = defaultValue.Type;
+							break;
+						case Block callWithNamedArgs when callWithNamedArgs.Kind == BlockKind.CallWithNamedArgs:
+							type2 = ((CallInstruction)callWithNamedArgs.FinalInstruction).Method.ReturnType;
+							break;
+						default:
+							Debug.Assert(false);
+							break;
+					}
+					for (int i = 1; i < Instructions.Count; i++) {
+						Debug.Assert(Instructions[i] is StLoc || IL.Transforms.AccessPathElement.GetAccessPath(Instructions[i], type2).Kind != IL.Transforms.AccessPathKind.Invalid);
+					}
+					break;
 			}
 		}
 

ICSharpCode.Decompiler/IL/Transforms/TransformCollectionAndObjectInitializers.cs

@@ -260,7 +260,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 		public override string ToString() => $"[{Member}, {Indices}]";
 
 		public static (AccessPathKind Kind, List<AccessPathElement> Path, List<ILInstruction> Values, ILVariable Target) GetAccessPath(
-			ILInstruction instruction, IType rootType, DecompilerSettings settings,
+			ILInstruction instruction, IType rootType, DecompilerSettings settings = null,
 			CSharpTypeResolveContext resolveContext = null,
 			Dictionary<ILVariable, (int Index, ILInstruction Value)> possibleIndexVariables = null)
 		{
@@ -282,7 +282,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 							if (!CanBeUsedInInitializer(property, resolveContext, kind, path)) goto default;
 							var isGetter = method.Equals(property?.Getter);
 							var indices = call.Arguments.Skip(1).Take(call.Arguments.Count - (isGetter ? 1 : 2)).ToArray();
-							if (indices.Length > 0 && !settings.DictionaryInitializers) goto default;
+							if (indices.Length > 0 && settings?.DictionaryInitializers == false) goto default;
 							if (possibleIndexVariables != null) {
 								// Mark all index variables as used
 								foreach (var index in indices.OfType<IInstructionWithVariableOperand>()) {
@@ -373,7 +373,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 			if (!"Add".Equals(method.Name, StringComparison.Ordinal) || arguments.Count == 0)
 				return false;
 			if (method.IsExtensionMethod)
-				return settings.ExtensionMethodsInCollectionInitializers
+				return settings?.ExtensionMethodsInCollectionInitializers != false
 					&& CSharp.Transforms.IntroduceExtensionMethods.CanTransformToExtensionMethodCall(method, resolveContext, ignoreTypeArguments: true);
 			var targetType = GetReturnTypeFromInstruction(arguments[0]) ?? rootType;
 			if (targetType == null)