Merge branch 'develop' into stable

5 files changed, 433 insertions, 0 deletions

diff --git a/src/SMAPI/Framework/ModLoading/Rewriters/FieldReplaceRewriter.cs b/src/SMAPI/Framework/ModLoading/Rewriters/FieldReplaceRewriter.cs
new file mode 100644
index 00000000..63358b39
--- /dev/null
+++ b/src/SMAPI/Framework/ModLoading/Rewriters/FieldReplaceRewriter.cs
@@ -0,0 +1,50 @@
+using System;
+using System.Reflection;
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+using StardewModdingAPI.Framework.ModLoading.Finders;
+
+namespace StardewModdingAPI.Framework.ModLoading.Rewriters
+{
+    /// <summary>Rewrites references to one field with another.</summary>
+    internal class FieldReplaceRewriter : FieldFinder
+    {
+        /*********
+        ** Properties
+        *********/
+        /// <summary>The new field to reference.</summary>
+        private readonly FieldInfo ToField;
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="type">The type whose field to which references should be rewritten.</param>
+        /// <param name="fromFieldName">The field name to rewrite.</param>
+        /// <param name="toFieldName">The new field name to reference.</param>
+        public FieldReplaceRewriter(Type type, string fromFieldName, string toFieldName)
+            : base(type.FullName, fromFieldName, InstructionHandleResult.None)
+        {
+            this.ToField = type.GetField(toFieldName);
+            if (this.ToField == null)
+                throw new InvalidOperationException($"The {type.FullName} class doesn't have a {toFieldName} field.");
+        }
+
+        /// <summary>Perform the predefined logic for an instruction if applicable.</summary>
+        /// <param name="module">The assembly module containing the instruction.</param>
+        /// <param name="cil">The CIL processor.</param>
+        /// <param name="instruction">The instruction to handle.</param>
+        /// <param name="assemblyMap">Metadata for mapping assemblies to the current platform.</param>
+        /// <param name="platformChanged">Whether the mod was compiled on a different platform.</param>
+        public override InstructionHandleResult Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction, PlatformAssemblyMap assemblyMap, bool platformChanged)
+        {
+            if (!this.IsMatch(instruction))
+                return InstructionHandleResult.None;
+
+            FieldReference newRef = module.Import(this.ToField);
+            cil.Replace(instruction, cil.Create(instruction.OpCode, newRef));
+            return InstructionHandleResult.Rewritten;
+        }
+    }
+}
diff --git a/src/SMAPI/Framework/ModLoading/Rewriters/FieldToPropertyRewriter.cs b/src/SMAPI/Framework/ModLoading/Rewriters/FieldToPropertyRewriter.cs
new file mode 100644
index 00000000..a20b8bee
--- /dev/null
+++ b/src/SMAPI/Framework/ModLoading/Rewriters/FieldToPropertyRewriter.cs
@@ -0,0 +1,51 @@
+using System;
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+using StardewModdingAPI.Framework.ModLoading.Finders;
+
+namespace StardewModdingAPI.Framework.ModLoading.Rewriters
+{
+    /// <summary>Rewrites field references into property references.</summary>
+    internal class FieldToPropertyRewriter : FieldFinder
+    {
+        /*********
+        ** Properties
+        *********/
+        /// <summary>The type whose field to which references should be rewritten.</summary>
+        private readonly Type Type;
+
+        /// <summary>The field name to rewrite.</summary>
+        private readonly string FieldName;
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="type">The type whose field to which references should be rewritten.</param>
+        /// <param name="fieldName">The field name to rewrite.</param>
+        public FieldToPropertyRewriter(Type type, string fieldName)
+            : base(type.FullName, fieldName, InstructionHandleResult.None)
+        {
+            this.Type = type;
+            this.FieldName = fieldName;
+        }
+
+        /// <summary>Perform the predefined logic for an instruction if applicable.</summary>
+        /// <param name="module">The assembly module containing the instruction.</param>
+        /// <param name="cil">The CIL processor.</param>
+        /// <param name="instruction">The instruction to handle.</param>
+        /// <param name="assemblyMap">Metadata for mapping assemblies to the current platform.</param>
+        /// <param name="platformChanged">Whether the mod was compiled on a different platform.</param>
+        public override InstructionHandleResult Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction, PlatformAssemblyMap assemblyMap, bool platformChanged)
+        {
+            if (!this.IsMatch(instruction))
+                return InstructionHandleResult.None;
+
+            string methodPrefix = instruction.OpCode == OpCodes.Ldsfld || instruction.OpCode == OpCodes.Ldfld ? "get" : "set";
+            MethodReference propertyRef = module.Import(this.Type.GetMethod($"{methodPrefix}_{this.FieldName}"));
+            cil.Replace(instruction, cil.Create(OpCodes.Call, propertyRef));
+            return InstructionHandleResult.Rewritten;
+        }
+    }
+}
diff --git a/src/SMAPI/Framework/ModLoading/Rewriters/MethodParentRewriter.cs b/src/SMAPI/Framework/ModLoading/Rewriters/MethodParentRewriter.cs
new file mode 100644
index 00000000..974fcf4c
--- /dev/null
+++ b/src/SMAPI/Framework/ModLoading/Rewriters/MethodParentRewriter.cs
@@ -0,0 +1,88 @@
+using System;
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+
+namespace StardewModdingAPI.Framework.ModLoading.Rewriters
+{
+    /// <summary>Rewrites method references from one parent type to another if the signatures match.</summary>
+    internal class MethodParentRewriter : IInstructionHandler
+    {
+        /*********
+        ** Properties
+        *********/
+        /// <summary>The type whose methods to remap.</summary>
+        private readonly Type FromType;
+
+        /// <summary>The type with methods to map to.</summary>
+        private readonly Type ToType;
+
+        /// <summary>Whether to only rewrite references if loading the assembly on a different platform than it was compiled on.</summary>
+        private readonly bool OnlyIfPlatformChanged;
+
+
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>A brief noun phrase indicating what the instruction finder matches.</summary>
+        public string NounPhrase { get; }
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="fromType">The type whose methods to remap.</param>
+        /// <param name="toType">The type with methods to map to.</param>
+        /// <param name="onlyIfPlatformChanged">Whether to only rewrite references if loading the assembly on a different platform than it was compiled on.</param>
+        public MethodParentRewriter(Type fromType, Type toType, bool onlyIfPlatformChanged = false)
+        {
+            this.FromType = fromType;
+            this.ToType = toType;
+            this.NounPhrase = $"{fromType.Name} methods";
+            this.OnlyIfPlatformChanged = onlyIfPlatformChanged;
+        }
+
+        /// <summary>Perform the predefined logic for a method if applicable.</summary>
+        /// <param name="module">The assembly module containing the instruction.</param>
+        /// <param name="method">The method definition containing the instruction.</param>
+        /// <param name="assemblyMap">Metadata for mapping assemblies to the current platform.</param>
+        /// <param name="platformChanged">Whether the mod was compiled on a different platform.</param>
+        public InstructionHandleResult Handle(ModuleDefinition module, MethodDefinition method, PlatformAssemblyMap assemblyMap, bool platformChanged)
+        {
+            return InstructionHandleResult.None;
+        }
+
+        /// <summary>Perform the predefined logic for an instruction if applicable.</summary>
+        /// <param name="module">The assembly module containing the instruction.</param>
+        /// <param name="cil">The CIL processor.</param>
+        /// <param name="instruction">The instruction to handle.</param>
+        /// <param name="assemblyMap">Metadata for mapping assemblies to the current platform.</param>
+        /// <param name="platformChanged">Whether the mod was compiled on a different platform.</param>
+        public InstructionHandleResult Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction, PlatformAssemblyMap assemblyMap, bool platformChanged)
+        {
+            if (!this.IsMatch(instruction, platformChanged))
+                return InstructionHandleResult.None;
+
+            MethodReference methodRef = (MethodReference)instruction.Operand;
+            methodRef.DeclaringType = module.Import(this.ToType);
+            return InstructionHandleResult.Rewritten;
+        }
+
+
+        /*********
+        ** Protected methods
+        *********/
+        /// <summary>Get whether a CIL instruction matches.</summary>
+        /// <param name="instruction">The IL instruction.</param>
+        /// <param name="platformChanged">Whether the mod was compiled on a different platform.</param>
+        protected bool IsMatch(Instruction instruction, bool platformChanged)
+        {
+            MethodReference methodRef = RewriteHelper.AsMethodReference(instruction);
+            return
+                methodRef != null
+                && (platformChanged || !this.OnlyIfPlatformChanged)
+                && methodRef.DeclaringType.FullName == this.FromType.FullName
+                && RewriteHelper.HasMatchingSignature(this.ToType, methodRef);
+        }
+    }
+}
diff --git a/src/SMAPI/Framework/ModLoading/Rewriters/TypeReferenceRewriter.cs b/src/SMAPI/Framework/ModLoading/Rewriters/TypeReferenceRewriter.cs
new file mode 100644
index 00000000..74f2fcdd
--- /dev/null
+++ b/src/SMAPI/Framework/ModLoading/Rewriters/TypeReferenceRewriter.cs
@@ -0,0 +1,154 @@
+using System;
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+using StardewModdingAPI.Framework.ModLoading.Finders;
+
+namespace StardewModdingAPI.Framework.ModLoading.Rewriters
+{
+    /// <summary>Rewrites all references to a type.</summary>
+    internal class TypeReferenceRewriter : TypeFinder
+    {
+        /*********
+        ** Properties
+        *********/
+        /// <summary>The full type name to which to find references.</summary>
+        private readonly string FromTypeName;
+
+        /// <summary>The new type to reference.</summary>
+        private readonly Type ToType;
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="fromTypeFullName">The full type name to which to find references.</param>
+        /// <param name="toType">The new type to reference.</param>
+        public TypeReferenceRewriter(string fromTypeFullName, Type toType)
+            : base(fromTypeFullName, InstructionHandleResult.None)
+        {
+            this.FromTypeName = fromTypeFullName;
+            this.ToType = toType;
+        }
+
+        /// <summary>Perform the predefined logic for a method if applicable.</summary>
+        /// <param name="module">The assembly module containing the instruction.</param>
+        /// <param name="method">The method definition containing the instruction.</param>
+        /// <param name="assemblyMap">Metadata for mapping assemblies to the current platform.</param>
+        /// <param name="platformChanged">Whether the mod was compiled on a different platform.</param>
+        public override InstructionHandleResult Handle(ModuleDefinition module, MethodDefinition method, PlatformAssemblyMap assemblyMap, bool platformChanged)
+        {
+            bool rewritten = false;
+
+            // return type
+            if (this.IsMatch(method.ReturnType))
+            {
+                method.ReturnType = this.RewriteIfNeeded(module, method.ReturnType);
+                rewritten = true;
+            }
+
+            // parameters
+            foreach (ParameterDefinition parameter in method.Parameters)
+            {
+                if (this.IsMatch(parameter.ParameterType))
+                {
+                    parameter.ParameterType = this.RewriteIfNeeded(module, parameter.ParameterType);
+                    rewritten = true;
+                }
+            }
+
+            // generic parameters
+            for (int i = 0; i < method.GenericParameters.Count; i++)
+            {
+                var parameter = method.GenericParameters[i];
+                if (this.IsMatch(parameter))
+                {
+                    TypeReference newType = this.RewriteIfNeeded(module, parameter);
+                    if (newType != parameter)
+                        method.GenericParameters[i] = new GenericParameter(parameter.Name, newType);
+                    rewritten = true;
+                }
+            }
+
+            // local variables
+            foreach (VariableDefinition variable in method.Body.Variables)
+            {
+                if (this.IsMatch(variable.VariableType))
+                {
+                    variable.VariableType = this.RewriteIfNeeded(module, variable.VariableType);
+                    rewritten = true;
+                }
+            }
+
+            return rewritten
+                ? InstructionHandleResult.Rewritten
+                : InstructionHandleResult.None;
+        }
+
+        /// <summary>Perform the predefined logic for an instruction if applicable.</summary>
+        /// <param name="module">The assembly module containing the instruction.</param>
+        /// <param name="cil">The CIL processor.</param>
+        /// <param name="instruction">The instruction to handle.</param>
+        /// <param name="assemblyMap">Metadata for mapping assemblies to the current platform.</param>
+        /// <param name="platformChanged">Whether the mod was compiled on a different platform.</param>
+        public override InstructionHandleResult Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction, PlatformAssemblyMap assemblyMap, bool platformChanged)
+        {
+            if (!this.IsMatch(instruction) && !instruction.ToString().Contains(this.FromTypeName))
+                return InstructionHandleResult.None;
+
+            // field reference
+            FieldReference fieldRef = RewriteHelper.AsFieldReference(instruction);
+            if (fieldRef != null)
+            {
+                fieldRef.DeclaringType = this.RewriteIfNeeded(module, fieldRef.DeclaringType);
+                fieldRef.FieldType = this.RewriteIfNeeded(module, fieldRef.FieldType);
+            }
+
+            // method reference
+            MethodReference methodRef = RewriteHelper.AsMethodReference(instruction);
+            if (methodRef != null)
+            {
+                methodRef.DeclaringType = this.RewriteIfNeeded(module, methodRef.DeclaringType);
+                methodRef.ReturnType = this.RewriteIfNeeded(module, methodRef.ReturnType);
+                foreach (var parameter in methodRef.Parameters)
+                    parameter.ParameterType = this.RewriteIfNeeded(module, parameter.ParameterType);
+            }
+
+            // type reference
+            if (instruction.Operand is TypeReference typeRef)
+            {
+                TypeReference newRef = this.RewriteIfNeeded(module, typeRef);
+                if (typeRef != newRef)
+                    cil.Replace(instruction, cil.Create(instruction.OpCode, newRef));
+            }
+
+            return InstructionHandleResult.Rewritten;
+        }
+
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>Get the adjusted type reference if it matches, else the same value.</summary>
+        /// <param name="module">The assembly module containing the instruction.</param>
+        /// <param name="type">The type to replace if it matches.</param>
+        private TypeReference RewriteIfNeeded(ModuleDefinition module, TypeReference type)
+        {
+            // root type
+            if (type.FullName == this.FromTypeName)
+                return module.Import(this.ToType);
+
+            // generic arguments
+            if (type is GenericInstanceType genericType)
+            {
+                for (int i = 0; i < genericType.GenericArguments.Count; i++)
+                    genericType.GenericArguments[i] = this.RewriteIfNeeded(module, genericType.GenericArguments[i]);
+            }
+
+            // generic parameters (e.g. constraints)
+            for (int i = 0; i < type.GenericParameters.Count; i++)
+                type.GenericParameters[i] = new GenericParameter(this.RewriteIfNeeded(module, type.GenericParameters[i]));
+
+            return type;
+        }
+    }
+}
diff --git a/src/SMAPI/Framework/ModLoading/Rewriters/VirtualEntryCallRemover.cs b/src/SMAPI/Framework/ModLoading/Rewriters/VirtualEntryCallRemover.cs
new file mode 100644
index 00000000..322a7df1
--- /dev/null
+++ b/src/SMAPI/Framework/ModLoading/Rewriters/VirtualEntryCallRemover.cs
@@ -0,0 +1,90 @@
+using System;
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+
+namespace StardewModdingAPI.Framework.ModLoading.Rewriters
+{
+    /// <summary>Rewrites virtual calls to the <see cref="Mod.Entry"/> method.</summary>
+    internal class VirtualEntryCallRemover : IInstructionHandler
+    {
+        /*********
+        ** Properties
+        *********/
+        /// <summary>The type containing the method.</summary>
+        private readonly Type ToType;
+
+        /// <summary>The name of the method.</summary>
+        private readonly string MethodName;
+
+
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>A brief noun phrase indicating what the instruction finder matches.</summary>
+        public string NounPhrase { get; }
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        public VirtualEntryCallRemover()
+        {
+            this.ToType = typeof(Mod);
+            this.MethodName = nameof(Mod.Entry);
+            this.NounPhrase = $"{this.ToType.Name}::{this.MethodName}";
+        }
+
+        /// <summary>Perform the predefined logic for a method if applicable.</summary>
+        /// <param name="module">The assembly module containing the instruction.</param>
+        /// <param name="method">The method definition containing the instruction.</param>
+        /// <param name="assemblyMap">Metadata for mapping assemblies to the current platform.</param>
+        /// <param name="platformChanged">Whether the mod was compiled on a different platform.</param>
+        public InstructionHandleResult Handle(ModuleDefinition module, MethodDefinition method, PlatformAssemblyMap assemblyMap, bool platformChanged)
+        {
+            return InstructionHandleResult.None;
+        }
+
+        /// <summary>Perform the predefined logic for an instruction if applicable.</summary>
+        /// <param name="module">The assembly module containing the instruction.</param>
+        /// <param name="cil">The CIL processor.</param>
+        /// <param name="instruction">The instruction to handle.</param>
+        /// <param name="assemblyMap">Metadata for mapping assemblies to the current platform.</param>
+        /// <param name="platformChanged">Whether the mod was compiled on a different platform.</param>
+        public InstructionHandleResult Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction, PlatformAssemblyMap assemblyMap, bool platformChanged)
+        {
+            if (!this.IsMatch(instruction))
+                return InstructionHandleResult.None;
+
+            // get instructions comprising method call
+            int index = cil.Body.Instructions.IndexOf(instruction);
+            Instruction loadArg0 = cil.Body.Instructions[index - 2];
+            Instruction loadArg1 = cil.Body.Instructions[index - 1];
+            if (loadArg0.OpCode != OpCodes.Ldarg_0)
+                throw new InvalidOperationException($"Unexpected instruction sequence while removing virtual {this.ToType.Name}.{this.MethodName} call: found {loadArg0.OpCode.Name} instead of {OpCodes.Ldarg_0.Name}");
+            if (loadArg1.OpCode != OpCodes.Ldarg_1)
+                throw new InvalidOperationException($"Unexpected instruction sequence while removing virtual {this.ToType.Name}.{this.MethodName} call: found {loadArg1.OpCode.Name} instead of {OpCodes.Ldarg_1.Name}");
+
+            // remove method call
+            cil.Remove(loadArg0);
+            cil.Remove(loadArg1);
+            cil.Remove(instruction);
+            return InstructionHandleResult.Rewritten;
+        }
+
+
+        /*********
+        ** Protected methods
+        *********/
+        /// <summary>Get whether a CIL instruction matches.</summary>
+        /// <param name="instruction">The IL instruction.</param>
+        protected bool IsMatch(Instruction instruction)
+        {
+            MethodReference methodRef = RewriteHelper.AsMethodReference(instruction);
+            return
+                methodRef != null
+                && methodRef.DeclaringType.FullName == this.ToType.FullName
+                && methodRef.Name == this.MethodName;
+        }
+    }
+}