diff --git a/Editor/Emit/EvalStackCalculator.cs b/Editor/Emit/EvalStackCalculator.cs
index 55b608d..8ab3c87 100644
--- a/Editor/Emit/EvalStackCalculator.cs
+++ b/Editor/Emit/EvalStackCalculator.cs
@@ -39,6 +39,7 @@ namespace Obfuz.Emit
         private readonly MethodDef _method;
         private readonly BasicBlockCollection _basicBlocks;
         private readonly Dictionary<Instruction, InstructionParameterInfo> _instructionParameterInfos = new Dictionary<Instruction, InstructionParameterInfo>();
+        private readonly Dictionary<Instruction, EvalDataType> _evalStackTopDataTypeAfterInstructions = new Dictionary<Instruction, EvalDataType>();
 
         public EvalStackCalculator(MethodDef method)
         {
@@ -53,6 +54,11 @@ namespace Obfuz.Emit
             return _instructionParameterInfos.TryGetValue(inst, out info);
         }
 
+        public bool TryGetPushResult(Instruction inst, out EvalDataType result)
+        {
+            return _evalStackTopDataTypeAfterInstructions.TryGetValue(inst, out result);
+        }
+
         class EvalStackState
         {
             public bool visited;
@@ -861,6 +867,10 @@ namespace Obfuz.Emit
                         stackDatas.AddRange(newPushedDatas);
                         Assert.AreEqual(stackSize + pushed - pops, stackDatas.Count);
                     }
+                    if (pushed > 0 && stackDatas.Count > 0)
+                    {
+                        _evalStackTopDataTypeAfterInstructions[inst] = stackDatas.Last();
+                    }
                 }
                 foreach (BasicBlock outBb in block.outBlocks)
                 {
diff --git a/Editor/ObfuscatorBuilder.cs b/Editor/ObfuscatorBuilder.cs
index fc983e2..87b39b3 100644
--- a/Editor/ObfuscatorBuilder.cs
+++ b/Editor/ObfuscatorBuilder.cs
@@ -160,7 +160,7 @@ namespace Obfuz
                     obfuscatedAssemblyOutputPath = settings.GetObfuscatedAssemblyOutputPath(target),
                     obfuscatedAssemblyTempOutputPath = settings.GetObfuscatedAssemblyTempOutputPath(target),
                     enabledObfuscationPasses = settings.obfuscationPassSettings.enabledPasses,
-                    obfuscationPassRuleConfigFiles = settings.obfuscationPassSettings.ruleFiles.ToList(),
+                    obfuscationPassRuleConfigFiles = settings.obfuscationPassSettings.ruleFiles?.ToList() ?? new List<string>(),
                     obfuscationPasses = new List<IObfuscationPass>(),
                 },
             };
diff --git a/Editor/Settings/AssemblySettings.cs b/Editor/Settings/AssemblySettings.cs
index 669b12e..9792351 100644
--- a/Editor/Settings/AssemblySettings.cs
+++ b/Editor/Settings/AssemblySettings.cs
@@ -23,7 +23,7 @@ namespace Obfuz.Settings
 
         public List<string> GetAssembliesToObfuscate()
         {
-            var asses = new List<string>(assembliesToObfuscate);
+            var asses = new List<string>(assembliesToObfuscate ?? Array.Empty<string>());
             if (obfuscateObfuzRuntime && !asses.Contains(ConstValues.ObfuzRuntimeAssemblyName))
             {
                 asses.Add(ConstValues.ObfuzRuntimeAssemblyName);
@@ -34,7 +34,7 @@ namespace Obfuz.Settings
         public List<string> GetObfuscationRelativeAssemblyNames()
         {
             var asses = GetAssembliesToObfuscate();
-            asses.AddRange(nonObfuscatedButReferencingObfuscatedAssemblies);
+            asses.AddRange(nonObfuscatedButReferencingObfuscatedAssemblies ?? Array.Empty<string>());
             return asses;
         }
     }
diff --git a/Editor/Settings/CallObfuscationSettings.cs b/Editor/Settings/CallObfuscationSettings.cs
index 32099fb..3bc2150 100644
--- a/Editor/Settings/CallObfuscationSettings.cs
+++ b/Editor/Settings/CallObfuscationSettings.cs
@@ -29,7 +29,7 @@ namespace Obfuz.Settings
         {
             return new CallObfuscationSettingsFacade
             {
-                ruleFiles = ruleFiles.ToList(),
+                ruleFiles = ruleFiles?.ToList() ?? new List<string>(),
                 obfuscationLevel = obfuscationLevel,
                 maxProxyMethodCountPerDispatchMethod = maxProxyMethodCountPerDispatchMethod,
             };
diff --git a/Editor/Settings/ConstEncryptionSettings.cs b/Editor/Settings/ConstEncryptionSettings.cs
index ff4967b..6baffbc 100644
--- a/Editor/Settings/ConstEncryptionSettings.cs
+++ b/Editor/Settings/ConstEncryptionSettings.cs
@@ -25,7 +25,7 @@ namespace Obfuz.Settings
         {
             return new ConstEncryptionSettingsFacade
             {
-                ruleFiles = ruleFiles.ToList(),
+                ruleFiles = ruleFiles?.ToList() ?? new List<string>(),
                 encryptionLevel = encryptionLevel,
             };
         }
diff --git a/Editor/Settings/ExprObfuscationSettings.cs b/Editor/Settings/ExprObfuscationSettings.cs
index 3b854a1..c4d0f75 100644
--- a/Editor/Settings/ExprObfuscationSettings.cs
+++ b/Editor/Settings/ExprObfuscationSettings.cs
@@ -20,7 +20,7 @@ namespace Obfuz.Settings
         {
             return new ExprObfuscationSettingsFacade
             {
-                ruleFiles = new List<string>(ruleFiles),
+                ruleFiles = new List<string>(ruleFiles ?? Array.Empty<string>()),
             };
         }
     }
diff --git a/Editor/Settings/FieldEncryptionSettings.cs b/Editor/Settings/FieldEncryptionSettings.cs
index df3ea14..460eca1 100644
--- a/Editor/Settings/FieldEncryptionSettings.cs
+++ b/Editor/Settings/FieldEncryptionSettings.cs
@@ -25,7 +25,7 @@ namespace Obfuz.Settings
         {
             return new FieldEncryptionSettingsFacade
             {
-                ruleFiles = ruleFiles.ToList(),
+                ruleFiles = ruleFiles?.ToList() ?? new List<string>(),
                 encryptionLevel = encryptionLevel,
             };
         }