chore: upgrade dnlib from 3.6.0 to 4.5.0 (#70) (#87)

* chore: upgrade dnlib from 3.6.0 to 4.5.0 (#70)

Evaluated and upgraded dnlib to the latest 4.x. The only breaking API
change affecting ConfuserEx: dnlib 4.x added IChunk.CalculateAlignment().
Implemented it on the two custom chunk classes in the AntiTamper JIT mode
(JITMethodBody, JITBodyIndex), returning 0 (default/no alignment) to
preserve the pre-4.x behaviour.

Evaluation notes:
- netstandard2.0 target preserved (dnlib 4.5.0 still ships net35/net45/
  netstandard2.0/net6.0) — Confuser.Core net48+netstandard2.0 unaffected
- DnlibUtils extension methods compile unchanged
- Resolve/ResolveThrow, ModuleWriter events, AssemblyResolver: no API
  changes affecting us
- Full suite green: 144 passed, 0 failed (incl. AntiTamper, Compressor,
  packer, and all cross-framework obfuscation tests)

Fixes #70

* perf: route HasAttribute through dnlib IsDefined; test ref-struct generics (#70)

Two low-risk wins enabled by the dnlib 4.5 upgrade:

- HasAttribute now calls CustomAttributeCollection.IsDefined(fullName)
  instead of a manual LINQ scan over CustomAttributes. This is the
  by-full-name lookup dnlib 4.2 optimized, and it benefits all 10 callers
  (including the per-definition renamer analysis path). Behaviour is
  identical — full suite stays green.

- Add a regression test locking in that obfuscation preserves the
  'allows ref struct' generic constraint (GenericParamAttributes.
  AllowByRefLike, named by dnlib 4.x). The net10 library subject now
  carries such a constraint, and Library_Net10_PreservesAllowByRefLike
  loads the obfuscated output and asserts the flag survives. ConfuserEx
  only renames generic parameters, so the attribute bits are preserved —
  this guards against a future change silently dropping them.

145 tests pass (was 144).

---------

Co-authored-by: RandomCrocodile <mawi@polosab.com>

Author: mcpolo99

Confuser.Core/Confuser.Core.csproj

@@ -15,7 +15,7 @@
   </PropertyGroup>
 
   <ItemGroup Label="Nuget Dependencies">
-    <PackageReference Include="dnlib" Version="3.6.0" />
+    <PackageReference Include="dnlib" Version="4.5.0" />
     <PackageReference Include="Microsoft.DiaSymReader.Native" Version="1.7.0" />
     <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="9.*" />
     <PackageReference Include="Microsoft.Win32.Registry" Version="5.0.0" />

Confuser.Core/DnlibUtils.cs

@@ -166,7 +166,9 @@ public static bool IsVisibleOutside(this TypeDef typeDef, bool exeNonPublic = tr
 		/// <param name="fullName">The full name of the type of custom attribute.</param>
 		/// <returns><c>true</c> if the specified object has custom attribute; otherwise, <c>false</c>.</returns>
 		public static bool HasAttribute(this IHasCustomAttribute obj, string fullName) {
-			return obj.CustomAttributes.Any(attr => attr.TypeFullName == fullName);
+			// dnlib's CustomAttributeCollection.IsDefined is the by-full-name lookup that dnlib
+			// 4.2 optimized — prefer it over a manual LINQ scan.
+			return obj.CustomAttributes.IsDefined(fullName);
 		}
 
 		/// <summary>

Confuser.Protections/AntiTamper/JITBody.cs

@@ -47,6 +47,12 @@ public uint GetVirtualSize() {
 			return GetFileLength();
 		}
 
+		// dnlib 4.x added IChunk.CalculateAlignment. Return 0 for default/no alignment,
+		// matching the implicit behaviour before the method existed in 3.x.
+		public uint CalculateAlignment() {
+			return 0;
+		}
+
 		public void WriteTo(DataWriter writer) {
 			writer.WriteUInt32((uint)(Body.Length >> 2));
 			writer.WriteBytes(Body);
@@ -224,6 +230,12 @@ public uint GetVirtualSize() {
 			return GetFileLength();
 		}
 
+		// dnlib 4.x added IChunk.CalculateAlignment. Return 0 for default/no alignment,
+		// matching the implicit behaviour before the method existed in 3.x.
+		public uint CalculateAlignment() {
+			return 0;
+		}
+
 		public void WriteTo(DataWriter writer) {
 			uint length = GetFileLength() - 4; // minus length field
 			writer.WriteUInt32((uint)bodies.Count);

Tests/CrossFramework.Library.Net10/SampleService.cs

@@ -40,4 +40,12 @@ public string Process(string data) {
 			return new string(chars);
 		}
 	}
+
+	// Carries a C# 13+ 'allows ref struct' generic constraint, which the compiler emits as
+	// the GenericParamAttributes.AllowByRefLike flag. Used to verify obfuscation preserves it.
+	public static class RefStructConsumer {
+		public static void Consume<T>(T value) where T : allows ref struct {
+			// Intentionally empty — the 'allows ref struct' constraint is what this exercises.
+		}
+	}
 }

Tests/CrossFramework.Test/LibraryFrameworkTest.cs

@@ -1,8 +1,10 @@
 using System.IO;
+using System.Linq;
 using System.Threading.Tasks;
 using Confuser.Core;
 using Confuser.Core.Project;
 using Confuser.UnitTest;
+using dnlib.DotNet;
 using Xunit;
 using Xunit.Abstractions;
 
@@ -64,5 +66,31 @@ public Task Library_Net10_RenameProtection() =>
 				new SettingItem<Protection>("rename"),
 				outputDirSuffix: "-lib-net10",
 				checkOutput: false);
+
+		// Regression guard: the subject has a 'allows ref struct' generic constraint
+		// (GenericParamAttributes.AllowByRefLike). Renaming must not drop it — verify the flag
+		// survives obfuscation on the output assembly. (dnlib 4.x names this flag; ConfuserEx
+		// only renames generic parameters, so the attribute bits must be preserved.)
+		[Fact]
+		[Trait("Category", "CrossFramework")]
+		[Trait("AppType", "Library")]
+		[Trait("TFM", "net10.0")]
+		public Task Library_Net10_PreservesAllowByRefLike() =>
+			Run("CrossFramework.Library.Net10.dll",
+				null,
+				new SettingItem<Protection>("rename"),
+				outputDirSuffix: "-lib-net10-refstruct",
+				checkOutput: false,
+				postProcessAction: outputPath => {
+					var modulePath = Path.Combine(outputPath, "CrossFramework.Library.Net10.dll");
+					using var module = ModuleDefMD.Load(modulePath);
+					var genericParams = module.GetTypes()
+						.SelectMany(type => type.Methods)
+						.SelectMany(method => method.GenericParameters)
+						.Concat(module.GetTypes().SelectMany(type => type.GenericParameters));
+					Assert.Contains(genericParams,
+						gp => (gp.Flags & GenericParamAttributes.AllowByRefLike) != 0);
+					return Task.CompletedTask;
+				});
 	}
 }