Add TypeNameFuzzer (dotnet#107206)

Co-authored-by: Miha Zupan <mihazupan.zupan1@gmail.com>
Co-authored-by: Adam Sitnik <adam.sitnik@gmail.com>

eng/pipelines/libraries/fuzzing/deploy-to-onefuzz.yml

@@ -121,6 +121,14 @@ extends:
             SYSTEM_ACCESSTOKEN: $(System.AccessToken)
           displayName: Send TextEncodingFuzzer to OneFuzz
 
+        - task: onefuzz-task@0
+          inputs:
+            onefuzzOSes: 'Windows'
+          env:
+            onefuzzDropDirectory: $(fuzzerProject)/deployment/TypeNameFuzzer
+            SYSTEM_ACCESSTOKEN: $(System.AccessToken)
+          displayName: Send TypeNameFuzzer to OneFuzz
+
         - task: onefuzz-task@0
           inputs:
             onefuzzOSes: 'Windows'

src/libraries/Fuzzing/DotnetFuzzing/Dictionaries/typename.dict

@@ -0,0 +1,26 @@
+"	"
+"0"
+","
+"[*["
+" System.Int32  "
+"System.Int32&&"
+"System.Int32[,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,]"
+"System.Int32[*******************************]"
+"System.Int32[][][][][][][][][][][][][][][][][][][][]"
+".NoNamespace"
+"Namespace.Ko\xC5\x9B\xC4\x87" 
+"Declaring+Nested"
+"Declaring+Deep+Deeper+Nested"
+"Declaring+Deep+Deeper+Nested, Lib"
+"MyNamespace.MyType+NestedType"
+"Pointer*******"
+"Generic`1[[A]]"
+"Generic`2[[A],[B]]"
+"Generic`3[[A],[B],[C]]"
+"Generic`3[A,B,C]"
+"Generic`2[[System.Int32, mscorlib, Version=4.0.0, Culture=neutral, PublicKeyToken=b77a5c561934],[System.Boolean, mscorlib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]"
+"Generic`3[[System.Int32, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089], System.Boolean, [System.Byte, other, Version=, Culture=neutral, PublicKeyToken=b77a5c561934e089]]"
+"TypeNameWith\\TheEscapingCharacter"
+"TypeNameWith[[]]NestedSquareBrackets"
+"TypeNameWith\\[]+*&,AllSpecialCharacters"
+"System.Reflection.Metadata.Tests.TypeNameTests+NestedGeneric_0`1+NestedGeneric_1`2+NestedGeneric_2`3+NestedNonGeneric_3[[System.Int32, System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.String, System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.Boolean, System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.Int16, System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.Byte, System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e],[System.SByte, System.Private.CoreLib, Version=9.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], System.Reflection.Metadata.Tests, Version=9.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51"

src/libraries/Fuzzing/DotnetFuzzing/Fuzzers/TypeNameFuzzer.cs

@@ -0,0 +1,65 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Buffers;
+using System.Reflection.Metadata;
+using System.Runtime.InteropServices;
+using System.Runtime.InteropServices.Marshalling;
+using System.Text;
+
+namespace DotnetFuzzing.Fuzzers
+{
+    internal sealed class TypeNameFuzzer : IFuzzer
+    {
+        public string[] TargetAssemblies { get; } = ["System.Reflection.Metadata"];
+        public string[] TargetCoreLibPrefixes => [];
+        public string Dictionary => "typename.dict";
+
+        public void FuzzTarget(ReadOnlySpan<byte> bytes)
+        {
+            Span<char> charSpan = new char[Encoding.UTF8.GetCharCount(bytes)];
+            Encoding.UTF8.GetChars(bytes, charSpan);
+            using var poisonAfter = PooledBoundedMemory<char>.Rent(charSpan, PoisonPagePlacement.After);
+            using var poisonBefore = PooledBoundedMemory<char>.Rent(charSpan, PoisonPagePlacement.Before);
+
+            Test(poisonAfter.Span);
+            Test(poisonBefore.Span);
+        }
+
+        private static void Test(Span<char> testSpan)
+        {
+            if (TypeName.TryParse(testSpan, out TypeName? result1))
+            {
+                TypeName result2 = TypeName.Parse(testSpan);
+                Assert.Equal(result1.Name, result2.Name);
+                Assert.Equal(result1.FullName, result2.FullName);
+                Assert.Equal(result1.AssemblyQualifiedName, result2.AssemblyQualifiedName);
+                Assert.Equal(result1.IsSimple, result2.IsSimple);
+                Assert.Equal(result1.IsNested, result2.IsNested);
+                Assert.Equal(result1.IsArray, result2.IsArray);
+                Assert.Equal(result1.GetNodeCount(), result2.GetNodeCount());
+                if (result1.AssemblyName != null)
+                {
+                    Assert.Equal(result1.AssemblyName.Name, result2.AssemblyName!.Name);
+                    Assert.Equal(result1.AssemblyName.FullName, result2.AssemblyName.FullName);
+                    Assert.Equal(result1.AssemblyName.CultureName, result2.AssemblyName.CultureName);
+                    Assert.Equal(result1.AssemblyName.Version?.ToString(), result2.AssemblyName.Version?.ToString());
+                }
+                else
+                {
+                    Assert.Equal(result1.AssemblyName, result2.AssemblyName);
+                }
+            }
+            else
+            {
+                try
+                {
+                    TypeName.Parse(testSpan);
+                    Assert.Equal(true, false); // should never succeed
+                }
+                catch (ArgumentException) { }
+                catch (InvalidOperationException) { }
+            }
+        }
+    }
+}