Merge branch 'develop' into stable

24 files changed, 418 insertions, 396 deletions

diff --git a/src/SMAPI/Framework/ModLoading/AssemblyLoader.cs b/src/SMAPI/Framework/ModLoading/AssemblyLoader.cs
index f8c901e0..9fb5384e 100644
--- a/src/SMAPI/Framework/ModLoading/AssemblyLoader.cs
+++ b/src/SMAPI/Framework/ModLoading/AssemblyLoader.cs
@@ -76,10 +76,9 @@ namespace StardewModdingAPI.Framework.ModLoading
         /// <param name="mod">The mod for which the assembly is being loaded.</param>
         /// <param name="assemblyPath">The assembly file path.</param>
         /// <param name="assumeCompatible">Assume the mod is compatible, even if incompatible code is detected.</param>
-        /// <param name="rewriteInParallel">Whether to enable experimental parallel rewriting.</param>
         /// <returns>Returns the rewrite metadata for the preprocessed assembly.</returns>
         /// <exception cref="IncompatibleInstructionException">An incompatible CIL instruction was found while rewriting the assembly.</exception>
-        public Assembly Load(IModMetadata mod, string assemblyPath, bool assumeCompatible, bool rewriteInParallel)
+        public Assembly Load(IModMetadata mod, string assemblyPath, bool assumeCompatible)
         {
             // get referenced local assemblies
             AssemblyParseResult[] assemblies;
@@ -109,7 +108,7 @@ namespace StardewModdingAPI.Framework.ModLoading
                     continue;
 
                 // rewrite assembly
-                bool changed = this.RewriteAssembly(mod, assembly.Definition, loggedMessages, logPrefix: "      ", rewriteInParallel);
+                bool changed = this.RewriteAssembly(mod, assembly.Definition, loggedMessages, logPrefix: "      ");
 
                 // detect broken assembly reference
                 foreach (AssemblyNameReference reference in assembly.Definition.MainModule.AssemblyReferences)
@@ -263,10 +262,9 @@ namespace StardewModdingAPI.Framework.ModLoading
         /// <param name="assembly">The assembly to rewrite.</param>
         /// <param name="loggedMessages">The messages that have already been logged for this mod.</param>
         /// <param name="logPrefix">A string to prefix to log messages.</param>
-        /// <param name="rewriteInParallel">Whether to enable experimental parallel rewriting.</param>
         /// <returns>Returns whether the assembly was modified.</returns>
         /// <exception cref="IncompatibleInstructionException">An incompatible CIL instruction was found while rewriting the assembly.</exception>
-        private bool RewriteAssembly(IModMetadata mod, AssemblyDefinition assembly, HashSet<string> loggedMessages, string logPrefix, bool rewriteInParallel)
+        private bool RewriteAssembly(IModMetadata mod, AssemblyDefinition assembly, HashSet<string> loggedMessages, string logPrefix)
         {
             ModuleDefinition module = assembly.MainModule;
             string filename = $"{assembly.Name.Name}.dll";
@@ -294,6 +292,19 @@ namespace StardewModdingAPI.Framework.ModLoading
                 IEnumerable<TypeReference> typeReferences = module.GetTypeReferences().OrderBy(p => p.FullName);
                 foreach (TypeReference type in typeReferences)
                     this.ChangeTypeScope(type);
+
+                // rewrite types using custom attributes
+                foreach (TypeDefinition type in module.GetTypes())
+                {
+                    foreach (var attr in type.CustomAttributes)
+                    {
+                        foreach (var conField in attr.ConstructorArguments)
+                        {
+                            if (conField.Value is TypeReference typeRef)
+                                this.ChangeTypeScope(typeRef);
+                        }
+                    }
+                }
             }
 
             // find or rewrite code
@@ -307,15 +318,15 @@ namespace StardewModdingAPI.Framework.ModLoading
                         rewritten |= handler.Handle(module, type, replaceWith);
                     return rewritten;
                 },
-                rewriteInstruction: (ref Instruction instruction, ILProcessor cil, Action<Instruction> replaceWith) =>
+                rewriteInstruction: (ref Instruction instruction, ILProcessor cil) =>
                 {
                     bool rewritten = false;
                     foreach (IInstructionHandler handler in handlers)
-                        rewritten |= handler.Handle(module, cil, instruction, replaceWith);
+                        rewritten |= handler.Handle(module, cil, instruction);
                     return rewritten;
                 }
             );
-            bool anyRewritten = rewriter.RewriteModule(rewriteInParallel);
+            bool anyRewritten = rewriter.RewriteModule();
 
             // handle rewrite flags
             foreach (IInstructionHandler handler in handlers)
@@ -398,10 +409,10 @@ namespace StardewModdingAPI.Framework.ModLoading
             if (handler.Phrases.Any())
             {
                 foreach (string message in handler.Phrases)
-                    this.Monitor.LogOnce(template.Replace("$phrase", message));
+                    this.Monitor.LogOnce(loggedMessages, template.Replace("$phrase", message));
             }
             else
-                this.Monitor.LogOnce(template.Replace("$phrase", handler.DefaultPhrase ?? handler.GetType().Name));
+                this.Monitor.LogOnce(loggedMessages, template.Replace("$phrase", handler.DefaultPhrase ?? handler.GetType().Name));
         }
 
         /// <summary>Get the correct reference to use for compatibility with the current platform.</summary>
diff --git a/src/SMAPI/Framework/ModLoading/Finders/EventFinder.cs b/src/SMAPI/Framework/ModLoading/Finders/EventFinder.cs
index e1476b73..01ed153b 100644
--- a/src/SMAPI/Framework/ModLoading/Finders/EventFinder.cs
+++ b/src/SMAPI/Framework/ModLoading/Finders/EventFinder.cs
@@ -1,4 +1,3 @@
-using System;
 using Mono.Cecil;
 using Mono.Cecil.Cil;
 using StardewModdingAPI.Framework.ModLoading.Framework;
@@ -36,13 +35,8 @@ namespace StardewModdingAPI.Framework.ModLoading.Finders
             this.Result = result;
         }
 
-        /// <summary>Rewrite a CIL instruction reference if needed.</summary>
-        /// <param name="module">The assembly module containing the instruction.</param>
-        /// <param name="cil">The CIL processor.</param>
-        /// <param name="instruction">The CIL instruction to handle.</param>
-        /// <param name="replaceWith">Replaces the CIL instruction with a new one.</param>
-        /// <returns>Returns whether the instruction was changed.</returns>
-        public override bool Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction, Action<Instruction> replaceWith)
+        /// <inheritdoc />
+        public override bool Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction)
         {
             if (!this.Flags.Contains(this.Result) && this.IsMatch(instruction))
                 this.MarkFlag(this.Result);
diff --git a/src/SMAPI/Framework/ModLoading/Finders/FieldFinder.cs b/src/SMAPI/Framework/ModLoading/Finders/FieldFinder.cs
index c157ed9b..2c062243 100644
--- a/src/SMAPI/Framework/ModLoading/Finders/FieldFinder.cs
+++ b/src/SMAPI/Framework/ModLoading/Finders/FieldFinder.cs
@@ -1,4 +1,3 @@
-using System;
 using Mono.Cecil;
 using Mono.Cecil.Cil;
 using StardewModdingAPI.Framework.ModLoading.Framework;
@@ -36,13 +35,8 @@ namespace StardewModdingAPI.Framework.ModLoading.Finders
             this.Result = result;
         }
 
-        /// <summary>Rewrite a CIL instruction reference if needed.</summary>
-        /// <param name="module">The assembly module containing the instruction.</param>
-        /// <param name="cil">The CIL processor.</param>
-        /// <param name="instruction">The CIL instruction to handle.</param>
-        /// <param name="replaceWith">Replaces the CIL instruction with a new one.</param>
-        /// <returns>Returns whether the instruction was changed.</returns>
-        public override bool Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction, Action<Instruction> replaceWith)
+        /// <inheritdoc />
+        public override bool Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction)
         {
             if (!this.Flags.Contains(this.Result) && RewriteHelper.IsFieldReferenceTo(instruction, this.FullTypeName, this.FieldName))
                 this.MarkFlag(this.Result);
diff --git a/src/SMAPI/Framework/ModLoading/Finders/MethodFinder.cs b/src/SMAPI/Framework/ModLoading/Finders/MethodFinder.cs
index 82c93a7c..d2340f01 100644
--- a/src/SMAPI/Framework/ModLoading/Finders/MethodFinder.cs
+++ b/src/SMAPI/Framework/ModLoading/Finders/MethodFinder.cs
@@ -1,4 +1,3 @@
-using System;
 using Mono.Cecil;
 using Mono.Cecil.Cil;
 using StardewModdingAPI.Framework.ModLoading.Framework;
@@ -36,13 +35,8 @@ namespace StardewModdingAPI.Framework.ModLoading.Finders
             this.Result = result;
         }
 
-        /// <summary>Rewrite a CIL instruction reference if needed.</summary>
-        /// <param name="module">The assembly module containing the instruction.</param>
-        /// <param name="cil">The CIL processor.</param>
-        /// <param name="instruction">The CIL instruction to handle.</param>
-        /// <param name="replaceWith">Replaces the CIL instruction with a new one.</param>
-        /// <returns>Returns whether the instruction was changed.</returns>
-        public override bool Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction, Action<Instruction> replaceWith)
+        /// <inheritdoc />
+        public override bool Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction)
         {
             if (!this.Flags.Contains(this.Result) && this.IsMatch(instruction))
                 this.MarkFlag(this.Result);
diff --git a/src/SMAPI/Framework/ModLoading/Finders/PropertyFinder.cs b/src/SMAPI/Framework/ModLoading/Finders/PropertyFinder.cs
index c96d61a2..99344848 100644
--- a/src/SMAPI/Framework/ModLoading/Finders/PropertyFinder.cs
+++ b/src/SMAPI/Framework/ModLoading/Finders/PropertyFinder.cs
@@ -1,4 +1,3 @@
-using System;
 using Mono.Cecil;
 using Mono.Cecil.Cil;
 using StardewModdingAPI.Framework.ModLoading.Framework;
@@ -36,13 +35,8 @@ namespace StardewModdingAPI.Framework.ModLoading.Finders
             this.Result = result;
         }
 
-        /// <summary>Rewrite a CIL instruction reference if needed.</summary>
-        /// <param name="module">The assembly module containing the instruction.</param>
-        /// <param name="cil">The CIL processor.</param>
-        /// <param name="instruction">The CIL instruction to handle.</param>
-        /// <param name="replaceWith">Replaces the CIL instruction with a new one.</param>
-        /// <returns>Returns whether the instruction was changed.</returns>
-        public override bool Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction, Action<Instruction> replaceWith)
+        /// <inheritdoc />
+        public override bool Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction)
         {
             if (!this.Flags.Contains(this.Result) && this.IsMatch(instruction))
                 this.MarkFlag(this.Result);
diff --git a/src/SMAPI/Framework/ModLoading/Finders/ReferenceToMemberWithUnexpectedTypeFinder.cs b/src/SMAPI/Framework/ModLoading/Finders/ReferenceToMemberWithUnexpectedTypeFinder.cs
index a67cfa4f..b01a3240 100644
--- a/src/SMAPI/Framework/ModLoading/Finders/ReferenceToMemberWithUnexpectedTypeFinder.cs
+++ b/src/SMAPI/Framework/ModLoading/Finders/ReferenceToMemberWithUnexpectedTypeFinder.cs
@@ -1,4 +1,3 @@
-using System;
 using System.Collections.Generic;
 using System.Linq;
 using Mono.Cecil;
@@ -29,13 +28,8 @@ namespace StardewModdingAPI.Framework.ModLoading.Finders
             this.ValidateReferencesToAssemblies = new HashSet<string>(validateReferencesToAssemblies);
         }
 
-        /// <summary>Rewrite a CIL instruction reference if needed.</summary>
-        /// <param name="module">The assembly module containing the instruction.</param>
-        /// <param name="cil">The CIL processor.</param>
-        /// <param name="instruction">The CIL instruction to handle.</param>
-        /// <param name="replaceWith">Replaces the CIL instruction with a new one.</param>
-        /// <returns>Returns whether the instruction was changed.</returns>
-        public override bool Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction, Action<Instruction> replaceWith)
+        /// <inheritdoc />
+        public override bool Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction)
         {
             // field reference
             FieldReference fieldRef = RewriteHelper.AsFieldReference(instruction);
diff --git a/src/SMAPI/Framework/ModLoading/Finders/ReferenceToMissingMemberFinder.cs b/src/SMAPI/Framework/ModLoading/Finders/ReferenceToMissingMemberFinder.cs
index ebb62948..b64a255e 100644
--- a/src/SMAPI/Framework/ModLoading/Finders/ReferenceToMissingMemberFinder.cs
+++ b/src/SMAPI/Framework/ModLoading/Finders/ReferenceToMissingMemberFinder.cs
@@ -1,6 +1,4 @@
-using System;
 using System.Collections.Generic;
-using System.Linq;
 using Mono.Cecil;
 using Mono.Cecil.Cil;
 using StardewModdingAPI.Framework.ModLoading.Framework;
@@ -29,20 +27,15 @@ namespace StardewModdingAPI.Framework.ModLoading.Finders
             this.ValidateReferencesToAssemblies = new HashSet<string>(validateReferencesToAssemblies);
         }
 
-        /// <summary>Rewrite a CIL instruction reference if needed.</summary>
-        /// <param name="module">The assembly module containing the instruction.</param>
-        /// <param name="cil">The CIL processor.</param>
-        /// <param name="instruction">The CIL instruction to handle.</param>
-        /// <param name="replaceWith">Replaces the CIL instruction with a new one.</param>
-        /// <returns>Returns whether the instruction was changed.</returns>
-        public override bool Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction, Action<Instruction> replaceWith)
+        /// <inheritdoc />
+        public override bool Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction)
         {
             // field reference
             FieldReference fieldRef = RewriteHelper.AsFieldReference(instruction);
             if (fieldRef != null && this.ShouldValidate(fieldRef.DeclaringType))
             {
-                FieldDefinition target = fieldRef.DeclaringType.Resolve()?.Fields.FirstOrDefault(p => p.Name == fieldRef.Name);
-                if (target == null)
+                FieldDefinition target = fieldRef.Resolve();
+                if (target == null || target.HasConstant)
                 {
                     this.MarkFlag(InstructionHandleResult.NotCompatible, $"reference to {fieldRef.DeclaringType.FullName}.{fieldRef.Name} (no such field)");
                     return false;
@@ -56,7 +49,7 @@ namespace StardewModdingAPI.Framework.ModLoading.Finders
                 MethodDefinition target = methodRef.Resolve();
                 if (target == null)
                 {
-                    string phrase = null;
+                    string phrase;
                     if (this.IsProperty(methodRef))
                         phrase = $"reference to {methodRef.DeclaringType.FullName}.{methodRef.Name.Substring(4)} (no such property)";
                     else if (methodRef.Name == ".ctor")
diff --git a/src/SMAPI/Framework/ModLoading/Finders/TypeAssemblyFinder.cs b/src/SMAPI/Framework/ModLoading/Finders/TypeAssemblyFinder.cs
index a1ade536..24ab2eca 100644
--- a/src/SMAPI/Framework/ModLoading/Finders/TypeAssemblyFinder.cs
+++ b/src/SMAPI/Framework/ModLoading/Finders/TypeAssemblyFinder.cs
@@ -35,11 +35,7 @@ namespace StardewModdingAPI.Framework.ModLoading.Finders
             this.ShouldIgnore = shouldIgnore;
         }
 
-        /// <summary>Rewrite a type reference if needed.</summary>
-        /// <param name="module">The assembly module containing the instruction.</param>
-        /// <param name="type">The type definition to handle.</param>
-        /// <param name="replaceWith">Replaces the type reference with a new one.</param>
-        /// <returns>Returns whether the type was changed.</returns>
+        /// <inheritdoc />
         public override bool Handle(ModuleDefinition module, TypeReference type, Action<TypeReference> replaceWith)
         {
             if (type.Scope.Name == this.AssemblyName && this.ShouldIgnore?.Invoke(type) != true)
diff --git a/src/SMAPI/Framework/ModLoading/Finders/TypeFinder.cs b/src/SMAPI/Framework/ModLoading/Finders/TypeFinder.cs
index c285414a..bbd081e8 100644
--- a/src/SMAPI/Framework/ModLoading/Finders/TypeFinder.cs
+++ b/src/SMAPI/Framework/ModLoading/Finders/TypeFinder.cs
@@ -35,11 +35,7 @@ namespace StardewModdingAPI.Framework.ModLoading.Finders
             this.ShouldIgnore = shouldIgnore;
         }
 
-        /// <summary>Rewrite a type reference if needed.</summary>
-        /// <param name="module">The assembly module containing the instruction.</param>
-        /// <param name="type">The type definition to handle.</param>
-        /// <param name="replaceWith">Replaces the type reference with a new one.</param>
-        /// <returns>Returns whether the type was changed.</returns>
+        /// <inheritdoc />
         public override bool Handle(ModuleDefinition module, TypeReference type, Action<TypeReference> replaceWith)
         {
             if (type.FullName == this.FullTypeName && this.ShouldIgnore?.Invoke(type) != true)
diff --git a/src/SMAPI/Framework/ModLoading/Framework/BaseInstructionHandler.cs b/src/SMAPI/Framework/ModLoading/Framework/BaseInstructionHandler.cs
index fde37d68..624113b3 100644
--- a/src/SMAPI/Framework/ModLoading/Framework/BaseInstructionHandler.cs
+++ b/src/SMAPI/Framework/ModLoading/Framework/BaseInstructionHandler.cs
@@ -11,36 +11,27 @@ namespace StardewModdingAPI.Framework.ModLoading.Framework
         /*********
         ** Accessors
         *********/
-        /// <summary>A brief noun phrase indicating what the handler matches, used if <see cref="Phrases"/> is empty.</summary>
+        /// <inheritdoc />
         public string DefaultPhrase { get; }
 
-        /// <summary>The rewrite flags raised for the current module.</summary>
+        /// <inheritdoc />
         public ISet<InstructionHandleResult> Flags { get; } = new HashSet<InstructionHandleResult>();
 
-        /// <summary>The brief noun phrases indicating what the handler matched for the current module.</summary>
+        /// <inheritdoc />
         public ISet<string> Phrases { get; } = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
 
 
         /*********
         ** Public methods
         *********/
-        /// <summary>Rewrite a type reference if needed.</summary>
-        /// <param name="module">The assembly module containing the instruction.</param>
-        /// <param name="type">The type definition to handle.</param>
-        /// <param name="replaceWith">Replaces the type reference with a new one.</param>
-        /// <returns>Returns whether the type was changed.</returns>
+        /// <inheritdoc />
         public virtual bool Handle(ModuleDefinition module, TypeReference type, Action<TypeReference> replaceWith)
         {
             return false;
         }
 
-        /// <summary>Rewrite a CIL instruction reference if needed.</summary>
-        /// <param name="module">The assembly module containing the instruction.</param>
-        /// <param name="cil">The CIL processor.</param>
-        /// <param name="instruction">The CIL instruction to handle.</param>
-        /// <param name="replaceWith">Replaces the CIL instruction with a new one.</param>
-        /// <returns>Returns whether the instruction was changed.</returns>
-        public virtual bool Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction, Action<Instruction> replaceWith)
+        /// <inheritdoc />
+        public virtual bool Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction)
         {
             return false;
         }
@@ -50,7 +41,7 @@ namespace StardewModdingAPI.Framework.ModLoading.Framework
         ** Protected methods
         *********/
         /// <summary>Construct an instance.</summary>
-        /// <param name="defaultPhrase">A brief noun phrase indicating what the handler matches.</param>
+        /// <param name="defaultPhrase">A brief noun phrase indicating what the handler matches, used if <see cref="Phrases"/> is empty.</param>
         protected BaseInstructionHandler(string defaultPhrase)
         {
             this.DefaultPhrase = defaultPhrase;
diff --git a/src/SMAPI/Framework/ModLoading/Framework/RecursiveRewriter.cs b/src/SMAPI/Framework/ModLoading/Framework/RecursiveRewriter.cs
index 34c78c7d..ea29550a 100644
--- a/src/SMAPI/Framework/ModLoading/Framework/RecursiveRewriter.cs
+++ b/src/SMAPI/Framework/ModLoading/Framework/RecursiveRewriter.cs
@@ -1,8 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Mono.Cecil;
 using Mono.Cecil.Cil;
 using Mono.Collections.Generic;
@@ -24,9 +22,8 @@ namespace StardewModdingAPI.Framework.ModLoading.Framework
         /// <summary>Rewrite a CIL instruction in the assembly code.</summary>
         /// <param name="instruction">The current CIL instruction.</param>
         /// <param name="cil">The CIL instruction processor.</param>
-        /// <param name="replaceWith">Replaces the CIL instruction with the given instruction.</param>
         /// <returns>Returns whether the instruction was changed.</returns>
-        public delegate bool RewriteInstructionDelegate(ref Instruction instruction, ILProcessor cil, Action<Instruction> replaceWith);
+        public delegate bool RewriteInstructionDelegate(ref Instruction instruction, ILProcessor cil);
 
 
         /*********
@@ -57,59 +54,24 @@ namespace StardewModdingAPI.Framework.ModLoading.Framework
         }
 
         /// <summary>Rewrite the loaded module code.</summary>
-        /// <param name="rewriteInParallel">Whether to enable experimental parallel rewriting.</param>
         /// <returns>Returns whether the module was modified.</returns>
-        public bool RewriteModule(bool rewriteInParallel)
+        public bool RewriteModule()
         {
             IEnumerable<TypeDefinition> types = this.Module.GetTypes().Where(type => type.BaseType != null); // skip special types like <Module>
 
-            // experimental parallel rewriting
-            // This may cause intermittent startup errors and is disabled by default: https://github.com/Pathoschild/SMAPI/issues/721
-            if (rewriteInParallel)
-            {
-                int typesChanged = 0;
-                Exception exception = null;
-
-                Parallel.ForEach(types, type =>
-                {
-                    if (exception != null)
-                        return;
-
-                    bool changed = false;
-                    try
-                    {
-                        changed = this.RewriteTypeDefinition(type);
-                    }
-                    catch (Exception ex)
-                    {
-                        exception ??= ex;
-                    }
-
-                    if (changed)
-                        Interlocked.Increment(ref typesChanged);
-                });
+            bool changed = false;
 
-                return exception == null
-                    ? typesChanged > 0
-                    : throw new Exception($"Rewriting {this.Module.Name} failed.", exception);
+            try
+            {
+                foreach (var type in types)
+                    changed |= this.RewriteTypeDefinition(type);
             }
-
-            // non-parallel rewriting
+            catch (Exception ex)
             {
-                bool changed = false;
-
-                try
-                {
-                    foreach (var type in types)
-                        changed |= this.RewriteTypeDefinition(type);
-                }
-                catch (Exception ex)
-                {
-                    throw new Exception($"Rewriting {this.Module.Name} failed.", ex);
-                }
-
-                return changed;
+                throw new Exception($"Rewriting {this.Module.Name} failed.", ex);
             }
+
+            return changed;
         }
 
 
@@ -198,12 +160,7 @@ namespace StardewModdingAPI.Framework.ModLoading.Framework
 
             // instruction itself
             // (should be done after the above type rewrites to ensure valid types)
-            rewritten |= this.RewriteInstructionImpl(ref instruction, cil, newInstruction =>
-            {
-                rewritten = true;
-                cil.Replace(instruction, newInstruction);
-                instruction = newInstruction;
-            });
+            rewritten |= this.RewriteInstructionImpl(ref instruction, cil);
 
             return rewritten;
         }
diff --git a/src/SMAPI/Framework/ModLoading/Framework/RewriteHelper.cs b/src/SMAPI/Framework/ModLoading/Framework/RewriteHelper.cs
index 36058b86..207b6445 100644
--- a/src/SMAPI/Framework/ModLoading/Framework/RewriteHelper.cs
+++ b/src/SMAPI/Framework/ModLoading/Framework/RewriteHelper.cs
@@ -59,12 +59,30 @@ namespace StardewModdingAPI.Framework.ModLoading.Framework
                 : null;
         }
 
+        /// <summary>Get the CIL instruction to load a value onto the stack.</summary>
+        /// <param name="rawValue">The constant value to inject.</param>
+        /// <returns>Returns the instruction, or <c>null</c> if the value type isn't supported.</returns>
+        public static Instruction GetLoadValueInstruction(object rawValue)
+        {
+            return rawValue switch
+            {
+                null => Instruction.Create(OpCodes.Ldnull),
+                bool value => Instruction.Create(value ? OpCodes.Ldc_I4_1 : OpCodes.Ldc_I4_0),
+                int value => Instruction.Create(OpCodes.Ldc_I4, value), // int32
+                long value => Instruction.Create(OpCodes.Ldc_I8, value), // int64
+                float value => Instruction.Create(OpCodes.Ldc_R4, value), // float32
+                double value => Instruction.Create(OpCodes.Ldc_R8, value), // float64
+                string value => Instruction.Create(OpCodes.Ldstr, value),
+                _ => null
+            };
+        }
+
         /// <summary>Get whether a type matches a type reference.</summary>
         /// <param name="type">The defined type.</param>
         /// <param name="reference">The type reference.</param>
         public static bool IsSameType(Type type, TypeReference reference)
         {
-            // 
+            //
             // duplicated by IsSameType(TypeReference, TypeReference) below
             //
 
@@ -139,7 +157,7 @@ namespace StardewModdingAPI.Framework.ModLoading.Framework
         /// <param name="reference">The method reference.</param>
         public static bool HasMatchingSignature(MethodBase definition, MethodReference reference)
         {
-            // 
+            //
             // duplicated by HasMatchingSignature(MethodDefinition, MethodReference) below
             //
 
@@ -165,7 +183,7 @@ namespace StardewModdingAPI.Framework.ModLoading.Framework
         /// <param name="reference">The method reference.</param>
         public static bool HasMatchingSignature(MethodDefinition definition, MethodReference reference)
         {
-            // 
+            //
             // duplicated by HasMatchingSignature(MethodBase, MethodReference) above
             //
 
diff --git a/src/SMAPI/Framework/ModLoading/IInstructionHandler.cs b/src/SMAPI/Framework/ModLoading/IInstructionHandler.cs
index e6de6785..17c9ba68 100644
--- a/src/SMAPI/Framework/ModLoading/IInstructionHandler.cs
+++ b/src/SMAPI/Framework/ModLoading/IInstructionHandler.cs
@@ -35,8 +35,7 @@ namespace StardewModdingAPI.Framework.ModLoading
         /// <param name="module">The assembly module containing the instruction.</param>
         /// <param name="cil">The CIL processor.</param>
         /// <param name="instruction">The CIL instruction to handle.</param>
-        /// <param name="replaceWith">Replaces the CIL instruction with a new one.</param>
         /// <returns>Returns whether the instruction was changed.</returns>
-        bool Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction, Action<Instruction> replaceWith);
+        bool Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction);
     }
 }
diff --git a/src/SMAPI/Framework/ModLoading/ModFailReason.cs b/src/SMAPI/Framework/ModLoading/ModFailReason.cs
new file mode 100644
index 00000000..cd4623e7
--- /dev/null
+++ b/src/SMAPI/Framework/ModLoading/ModFailReason.cs
@@ -0,0 +1,27 @@
+namespace StardewModdingAPI.Framework.ModLoading
+{
+    /// <summary>Indicates why a mod could not be loaded.</summary>
+    internal enum ModFailReason
+    {
+        /// <summary>The mod has been disabled by prefixing its folder with a dot.</summary>
+        DisabledByDotConvention,
+
+        /// <summary>Multiple copies of the mod are installed.</summary>
+        Duplicate,
+
+        /// <summary>The mod has incompatible code instructions, needs a newer SMAPI version, or is marked 'assume broken' in the SMAPI metadata list.</summary>
+        Incompatible,
+
+        /// <summary>The mod's manifest is missing or invalid.</summary>
+        InvalidManifest,
+
+        /// <summary>The mod was deemed compatible, but SMAPI failed w