Fix CA1825:AvoidZeroLengthArrayAllocations, use Empty<T>.Array consistently.

ICSharpCode.Decompiler/CSharp/ExpressionBuilder.cs

@@ -369,7 +369,7 @@ namespace ICSharpCode.Decompiler.CSharp
 			}
 			expr.Arguments.AddRange(args.Select(arg => arg.Expression));
 			return expr.WithILInstruction(inst)
-				.WithRR(new ArrayCreateResolveResult(new ArrayType(compilation, inst.Type, dimensions), args.Select(a => a.ResolveResult).ToList(), new ResolveResult[0]));
+				.WithRR(new ArrayCreateResolveResult(new ArrayType(compilation, inst.Type, dimensions), args.Select(a => a.ResolveResult).ToList(), Empty<ResolveResult>.Array));
 		}
 
 		protected internal override TranslatedExpression VisitLocAlloc(LocAlloc inst, TranslationContext context)

ICSharpCode.Decompiler/CSharp/Resolver/CSharpResolver.cs

@@ -379,14 +379,14 @@ namespace ICSharpCode.Decompiler.CSharp.Resolver
 						return UnaryOperatorResolveResult(new PointerType(expression.Type), op, expression);
 					case UnaryOperatorType.Await: {
 						ResolveResult getAwaiterMethodGroup = ResolveMemberAccess(expression, "GetAwaiter", EmptyList<IType>.Instance, NameLookupMode.InvocationTarget);
-						ResolveResult getAwaiterInvocation = ResolveInvocation(getAwaiterMethodGroup, new ResolveResult[0], argumentNames: null, allowOptionalParameters: false);
+						ResolveResult getAwaiterInvocation = ResolveInvocation(getAwaiterMethodGroup, Empty<ResolveResult>.Array, argumentNames: null, allowOptionalParameters: false);
 
 						var lookup = CreateMemberLookup();
 						IMethod getResultMethod;
 						IType awaitResultType;
 						var getResultMethodGroup = lookup.Lookup(getAwaiterInvocation, "GetResult", EmptyList<IType>.Instance, true) as MethodGroupResolveResult;
 						if (getResultMethodGroup != null) {
-							var getResultOR = getResultMethodGroup.PerformOverloadResolution(compilation, new ResolveResult[0], allowExtensionMethods: false, conversions: conversions);
+							var getResultOR = getResultMethodGroup.PerformOverloadResolution(compilation, Empty<ResolveResult>.Array, allowExtensionMethods: false, conversions: conversions);
 							getResultMethod = getResultOR.FoundApplicableCandidate ? getResultOR.GetBestCandidateWithSubstitutedTypeArguments() as IMethod : null;
 							awaitResultType = getResultMethod != null ? getResultMethod.ReturnType : SpecialType.UnknownType;
 						}
@@ -1698,12 +1698,12 @@ namespace ICSharpCode.Decompiler.CSharp.Resolver
 				}
 				getEnumeratorInvocation = ResolveCast(collectionType, expression);
 				getEnumeratorInvocation = ResolveMemberAccess(getEnumeratorInvocation, "GetEnumerator", EmptyList<IType>.Instance, NameLookupMode.InvocationTarget);
-				getEnumeratorInvocation = ResolveInvocation(getEnumeratorInvocation, new ResolveResult[0]);
+				getEnumeratorInvocation = ResolveInvocation(getEnumeratorInvocation, Empty<ResolveResult>.Array);
 			} else {
 				var getEnumeratorMethodGroup = memberLookup.Lookup(expression, "GetEnumerator", EmptyList<IType>.Instance, true) as MethodGroupResolveResult;
 				if (getEnumeratorMethodGroup != null) {
 					var or = getEnumeratorMethodGroup.PerformOverloadResolution(
-						compilation, new ResolveResult[0],
+						compilation, Empty<ResolveResult>.Array,
 						allowExtensionMethods: false, allowExpandingParams: false, allowOptionalParameters: false);
 					if (or.FoundApplicableCandidate && !or.IsAmbiguous && !or.BestCandidate.IsStatic && or.BestCandidate.Accessibility == Accessibility.Public) {
 						collectionType = expression.Type;
@@ -1722,7 +1722,7 @@ namespace ICSharpCode.Decompiler.CSharp.Resolver
 			var moveNextMethodGroup = memberLookup.Lookup(new ResolveResult(enumeratorType), "MoveNext", EmptyList<IType>.Instance, false) as MethodGroupResolveResult;
 			if (moveNextMethodGroup != null) {
 				var or = moveNextMethodGroup.PerformOverloadResolution(
-					compilation, new ResolveResult[0],
+					compilation, Empty<ResolveResult>.Array,
 					allowExtensionMethods: false, allowExpandingParams: false, allowOptionalParameters: false);
 				moveNextMethod = or.GetBestCandidateWithSubstitutedTypeArguments() as IMethod;
 			}
@@ -1763,7 +1763,7 @@ namespace ICSharpCode.Decompiler.CSharp.Resolver
 			}
 			getEnumeratorInvocation = ResolveCast(collectionType, expression);
 			getEnumeratorInvocation = ResolveMemberAccess(getEnumeratorInvocation, "GetEnumerator", EmptyList<IType>.Instance, NameLookupMode.InvocationTarget);
-			getEnumeratorInvocation = ResolveInvocation(getEnumeratorInvocation, new ResolveResult[0]);
+			getEnumeratorInvocation = ResolveInvocation(getEnumeratorInvocation, Empty<ResolveResult>.Array);
 		}
 		#endregion
 

ICSharpCode.Decompiler/CSharp/Resolver/TypeInference.cs

@@ -361,8 +361,6 @@ namespace ICSharpCode.Decompiler.CSharp.Resolver
 		#endregion
 		
 		#region Input Types / Output Types (§7.5.2.3 + §7.5.2.4)
-		static readonly IType[] emptyTypeArray = new IType[0];
-		
 		IType[] InputTypes(ResolveResult e, IType t)
 		{
 			// C# 4.0 spec: §7.5.2.3 Input types
@@ -377,7 +375,7 @@ namespace ICSharpCode.Decompiler.CSharp.Resolver
 					return inputTypes;
 				}
 			}
-			return emptyTypeArray;
+			return Empty<IType>.Array;
 		}
 		
 		IType[] OutputTypes(ResolveResult e, IType t)
@@ -390,7 +388,7 @@ namespace ICSharpCode.Decompiler.CSharp.Resolver
 					return new[] { m.ReturnType };
 				}
 			}
-			return emptyTypeArray;
+			return Empty<IType>.Array;
 		}
 		
 		static IMethod GetDelegateOrExpressionTreeSignature(IType t)

ICSharpCode.Decompiler/Documentation/XmlDocumentationProvider.cs

@@ -24,6 +24,7 @@ using System.Runtime.Serialization;
 using System.Text;
 using System.Xml;
 using ICSharpCode.Decompiler.TypeSystem;
+using ICSharpCode.Decompiler.Util;
 
 namespace ICSharpCode.Decompiler.Documentation
 {
@@ -392,11 +393,11 @@ namespace ICSharpCode.Decompiler.Documentation
 				}
 			} catch (IOException) {
 				// Ignore errors on reload; IEntity.Documentation callers aren't prepared to handle exceptions
-				this.index = new IndexEntry[0]; // clear index to avoid future load attempts
+				this.index = Empty<IndexEntry>.Array; // clear index to avoid future load attempts
 				return null;
 			} catch (XmlException) {
-				this.index = new IndexEntry[0]; // clear index to avoid future load attempts
+				this.index = Empty<IndexEntry>.Array; // clear index to avoid future load attempts
-				return null;				
+				return null;
 			}
 			return GetDocumentation(key, allowReload: false); // prevent infinite reload loops
 		}

ICSharpCode.Decompiler/Util/EmptyList.cs

@@ -114,7 +114,7 @@ namespace ICSharpCode.Decompiler.Util
 
 	public static class Empty<T>
 	{
-		public static readonly T[] Array = new T[0];
+		public static readonly T[] Array = System.Array.Empty<T>();
 	}
 
 	public struct Unit { }

ILSpy/Analyzers/Builtin/AttributeAppliedToAnalyzer.cs

@@ -24,6 +24,7 @@ using System.Reflection.Metadata;
 using System.Runtime.InteropServices;
 using ICSharpCode.Decompiler;
 using ICSharpCode.Decompiler.TypeSystem;
+using ICSharpCode.Decompiler.Util;
 
 namespace ICSharpCode.ILSpy.Analyzers.Builtin
 {
@@ -33,7 +34,7 @@ namespace ICSharpCode.ILSpy.Analyzers.Builtin
 		public IEnumerable<ISymbol> Analyze(ISymbol analyzedSymbol, AnalyzerContext context)
 		{
 			if (!(analyzedSymbol is ITypeDefinition attributeType))
-				return Array.Empty<ISymbol>();
+				return Empty<ISymbol>.Array;
 
 			var scope = context.GetScopeOf(attributeType);
 			// TODO: DeclSecurity attributes are not supported.