Add method to get qualified name of CIL extraction types

Author: tamasvajk

csharp/extractor/Semmle.Extraction.CIL/Context.cs

@@ -1,6 +1,5 @@
 using System;
 using System.IO;
-using System.Linq;
 using System.Reflection.Metadata;
 using System.Reflection.PortableExecutable;
 
@@ -83,7 +82,7 @@ public void WriteAssemblyPrefix(TextWriter trapFile)
             trapFile.Write(GetString(def.Name));
             trapFile.Write('_');
             trapFile.Write(def.Version.ToString());
-            trapFile.Write("::");
+            trapFile.Write(Entities.Type.AssemblyTypeNameSeparator);
         }
 
         public Entities.TypeSignatureDecoder TypeSignatureDecoder { get; }

csharp/extractor/Semmle.Extraction.CIL/Entities/Type.cs

@@ -12,7 +12,8 @@ namespace Semmle.Extraction.CIL.Entities
     public abstract class Type : TypeContainer, IMember
     {
         public override string IdSuffix => ";cil-type";
-        internal const string PrimitiveTypePrefix = "builtin:";
+        internal const string AssemblyTypeNameSeparator = "::";
+        internal const string PrimitiveTypePrefix = "builtin" + AssemblyTypeNameSeparator + "System.";
 
         protected Type(Context cx) : base(cx) { }
 
@@ -72,6 +73,21 @@ public virtual IEnumerable<Type> ThisTypeArguments
 
         public void GetId(TextWriter trapFile, bool inContext) => WriteId(trapFile, inContext);
 
+        /// <summary>
+        /// Returns the friendly qualified name of types, such as
+        /// ``"System.Collection.Generic.List`1"`` or
+        /// ``"System.Collection.Generic.List<System.Int32>"``.
+        ///
+        /// Note that method/type generic type parameters never show up in the returned name.
+        /// </summary>
+        public string GetQualifiedName()
+        {
+            using var writer = new StringWriter();
+            GetId(writer, false);
+            var name = writer.ToString();
+            return name.Substring(name.IndexOf(AssemblyTypeNameSeparator) + 2);
+        }
+
         public abstract CilTypeKind Kind { get; }
 
         public override IEnumerable<IExtractionProduct> Contents

csharp/extractor/Semmle.Extraction.CIL/Entities/TypeReferenceType.cs

@@ -114,7 +114,7 @@ public override void WriteAssemblyPrefix(TextWriter trapFile)
                     trapFile.Write(Cx.GetString(assemblyDef.Name));
                     trapFile.Write('_');
                     trapFile.Write(assemblyDef.Version.ToString());
-                    trapFile.Write("::");
+                    trapFile.Write(Entities.Type.AssemblyTypeNameSeparator);
                     break;
                 default:
                     Cx.WriteAssemblyPrefix(trapFile);