Merge pull request #4158 from icsharpcode/ldmembertoken

Invent a syntax for `ldtoken`.

ICSharpCode.Decompiler.Tests/TestCases/Ugly/NoArrayInitializers.Expected.cs

@@ -1,4 +1,3 @@
-using System;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
@@ -19,7 +18,7 @@ namespace ICSharpCode.Decompiler.Tests.TestCases.Ugly
 		public int[] LiteralArray()
 		{
 			int[] array = new int[3];
-			RuntimeHelpers.InitializeArray(array, (RuntimeFieldHandle)/*OpCode not supported: LdMemberToken*/);
+			RuntimeHelpers.InitializeArray(array, __ldtoken(_003CPrivateImplementationDetails_003E._4636993D3E1DA4E9D6B8F87B79E8F7C6D018580D52661950EABC3845C5897A4D));
 			return array;
 		}
 

ICSharpCode.Decompiler/CSharp/ExpressionBuilder.cs

@@ -5132,6 +5132,36 @@ namespace ICSharpCode.Decompiler.CSharp
 				.WithILInstruction(inst);
 		}
 
+		protected internal override TranslatedExpression VisitLdMemberToken(LdMemberToken inst, TranslationContext context)
+		{
+			// C# does not have syntax for obtaining a member token; so we emit pseudo-syntax:
+			// fields: __ldtoken(DeclaringType.Member)
+			// methods: __ldtoken(DeclaringType.Member(parameter-types))
+			var classType = astBuilder.ConvertType(inst.Member.DeclaringType);
+			var mre = new MemberReferenceExpression(
+				new TypeReferenceExpression(classType),
+				inst.Member.Name
+			);
+			Expression memberExpr = mre.WithRR(new MemberResolveResult(null, inst.Member));
+			if (inst.Member is IMethod method)
+			{
+				foreach (var t in method.TypeArguments)
+				{
+					mre.TypeArguments.Add(astBuilder.ConvertType(t));
+				}
+				var inv = new InvocationExpression(memberExpr);
+				foreach (var param in method.Parameters)
+				{
+					inv.Arguments.Add(new TypeReferenceExpression(astBuilder.ConvertType(param.Type)));
+				}
+				memberExpr = inv;
+			}
+			var tokenType = inst.Member is IField ? KnownTypeCode.RuntimeFieldHandle : KnownTypeCode.RuntimeMethodHandle;
+			return new InvocationExpression(new IdentifierExpression("__ldtoken"), memberExpr)
+				.WithRR(new ResolveResult(compilation.FindType(tokenType)))
+				.WithILInstruction(inst);
+		}
+
 		protected internal override TranslatedExpression VisitCallIndirect(CallIndirect inst, TranslationContext context)
 		{
 			if (inst.IsInstance)

ICSharpCode.Decompiler/TypeSystem/Implementation/MergedNamespace.cs

@@ -152,7 +152,10 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 						// and using the main assembly can cause a stack overflow if there
 						// are internal assembly attributes.
 					}
-					anyTypeDef = typeDef;
+					// If there's multiple possible matches prefer the first one -- we most likely are
+					// in the context of the assembly being decompiled, which usually is the first in the list,
+					// so this increases the odds of picking the correct type.
+					anyTypeDef ??= typeDef;
 				}
 			}
 			return anyTypeDef;