Add custom attribute type name formatter (#4367)

2 files changed, 58 insertions, 0 deletions

diff --git a/src/ILCompiler.TypeSystem/src/ILCompiler.TypeSystem.csproj b/src/ILCompiler.TypeSystem/src/ILCompiler.TypeSystem.csproj
index 67bbb498f..d68cff2c9 100644
--- a/src/ILCompiler.TypeSystem/src/ILCompiler.TypeSystem.csproj
+++ b/src/ILCompiler.TypeSystem/src/ILCompiler.TypeSystem.csproj
@@ -112,6 +112,9 @@
     <Compile Include="..\..\Common\src\TypeSystem\Common\ThrowHelper.Common.cs">
       <Link>TypeSystem\Common\ThrowHelper.Common.cs</Link>
     </Compile>
+    <Compile Include="..\..\Common\src\TypeSystem\Common\Utilities\CustomAttributeTypeNameFormatter.cs">
+      <Link>Utilities\CustomAttributeTypeNameFormatter.cs</Link>
+    </Compile>
     <Compile Include="..\..\Common\src\TypeSystem\Common\Utilities\CustomAttributeTypeNameParser.cs">
       <Link>Utilities\CustomAttributeTypeNameParser.cs</Link>
     </Compile>
diff --git a/src/ILCompiler.TypeSystem/tests/TypeNameParsingTests.cs b/src/ILCompiler.TypeSystem/tests/TypeNameParsingTests.cs
index b6cd357b4..e366f0744 100644
--- a/src/ILCompiler.TypeSystem/tests/TypeNameParsingTests.cs
+++ b/src/ILCompiler.TypeSystem/tests/TypeNameParsingTests.cs
@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
+using System.Collections.Generic;
 
 using Internal.TypeSystem;
 
@@ -240,5 +241,59 @@ namespace TypeSystemTests
             Assert.Null(_testModule.GetTypeByCustomAttributeTypeName("TypeNameParsing.Simple+Nested+NonNamespaceQualifiedType", throwIfNotFound: false));
             Assert.Null(_testModule.GetTypeByCustomAttributeTypeName("TypeNameParsing.Generic`1[TypeNameParsing.SimpleButNotThere]", throwIfNotFound: false));
         }
+
+        public IEnumerable<TypeDesc> GetTypesForRoundtripTest()
+        {
+            yield return _simpleType;
+            yield return _nestedType;
+            yield return _nestedTwiceType;
+            yield return _context.GetWellKnownType(WellKnownType.Int32);
+            yield return _veryGenericType;
+            yield return _simpleType.MakeArrayType();
+            yield return _simpleType.MakeArrayType().MakeArrayType();
+            yield return _simpleType.MakeArrayType(2).MakeArrayType(3);
+            yield return _context.GetWellKnownType(WellKnownType.Int32).MakeArrayType();
+            yield return _structType.MakePointerType();
+            yield return _context.GetWellKnownType(WellKnownType.Int32).MakePointerType().MakePointerType();
+            yield return _genericType.MakeInstantiatedType(_simpleType);
+            yield return _veryGenericType.MakeInstantiatedType(
+                    _simpleType,
+                    _genericType.MakeInstantiatedType(_simpleType),
+                    _structType
+                );
+            yield return _genericType.MakeInstantiatedType(_context.GetWellKnownType(WellKnownType.Object));
+            yield return _veryGenericType.MakeInstantiatedType(
+                    _context.GetWellKnownType(WellKnownType.Object),
+                    _simpleType,
+                    _context.GetWellKnownType(WellKnownType.Int32)
+                );
+            yield return ((MetadataType)_context.GetWellKnownType(WellKnownType.Nullable)).MakeInstantiatedType(_structType);
+            yield return _genericType.MakeInstantiatedType(_structType.MakePointerType().MakeArrayType());
+            yield return _nestedGenericType.MakeInstantiatedType(
+                    ((MetadataType)_context.GetWellKnownType(WellKnownType.Nullable)).MakeInstantiatedType(_context.GetWellKnownType(WellKnownType.Int32)),
+                    _nestedType.MakeArrayType()
+                );
+        }
+
+        [Fact]
+        public void TestRoundtripping()
+        {
+            foreach (TypeDesc type in GetTypesForRoundtripTest())
+            {
+                {
+                    var fmt = new CustomAttributeTypeNameFormatter((IAssemblyDesc)_testModule);
+                    string formatted = fmt.FormatName(type);
+                    TypeDesc roundTripped = _testModule.GetTypeByCustomAttributeTypeName(formatted);
+                    Assert.Equal(type, roundTripped);
+                }
+
+                {
+                    var fmt = new CustomAttributeTypeNameFormatter();
+                    string formatted = fmt.FormatName(type);
+                    TypeDesc roundTripped = _testModule.GetTypeByCustomAttributeTypeName(formatted);
+                    Assert.Equal(type, roundTripped);
+                }
+            }
+        }
     }
 }