merge CIL finders & rewriters into one interface (#254)

4 files changed, 80 insertions, 12 deletions

diff --git a/src/StardewModdingAPI.AssemblyRewriters/Finders/EventFinder.cs b/src/StardewModdingAPI.AssemblyRewriters/Finders/EventFinder.cs
index 848e54ff..bcceee32 100644
--- a/src/StardewModdingAPI.AssemblyRewriters/Finders/EventFinder.cs
+++ b/src/StardewModdingAPI.AssemblyRewriters/Finders/EventFinder.cs
@@ -3,8 +3,8 @@ using Mono.Cecil.Cil;
 
 namespace StardewModdingAPI.AssemblyRewriters.Finders
 {
-    /// <summary>Finds CIL instructions that reference a given event.</summary>
-    public sealed class EventFinder : IInstructionFinder
+    /// <summary>Finds incompatible CIL instructions that reference a given event and throws an <see cref="IncompatibleInstructionException"/>.</summary>
+    public class EventFinder : IInstructionRewriter
     {
         /*********
         ** Properties
@@ -37,6 +37,22 @@ namespace StardewModdingAPI.AssemblyRewriters.Finders
             this.NounPhrase = nounPhrase ?? $"{fullTypeName}.{eventName} event";
         }
 
+        /// <summary>Rewrite a CIL instruction for compatibility.</summary>
+        /// <param name="module">The module being rewritten.</param>
+        /// <param name="cil">The CIL rewriter.</param>
+        /// <param name="instruction">The instruction to rewrite.</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>
+        /// <returns>Returns whether the instruction was rewritten.</returns>
+        /// <exception cref="IncompatibleInstructionException">The CIL instruction is not compatible, and can't be rewritten.</exception>
+        public bool Rewrite(ModuleDefinition module, ILProcessor cil, Instruction instruction, PlatformAssemblyMap assemblyMap, bool platformChanged)
+        {
+            if (!this.IsMatch(instruction, platformChanged))
+                return false;
+
+            throw new IncompatibleInstructionException(this.NounPhrase);
+        }
+
 
         /*********
         ** Protected methods
@@ -44,7 +60,7 @@ namespace StardewModdingAPI.AssemblyRewriters.Finders
         /// <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>
-        public bool IsMatch(Instruction instruction, bool platformChanged)
+        protected bool IsMatch(Instruction instruction, bool platformChanged)
         {
             MethodReference methodRef = RewriteHelper.AsMethodReference(instruction);
             return
diff --git a/src/StardewModdingAPI.AssemblyRewriters/Finders/FieldFinder.cs b/src/StardewModdingAPI.AssemblyRewriters/Finders/FieldFinder.cs
index 068119b8..cdfc3bd5 100644
--- a/src/StardewModdingAPI.AssemblyRewriters/Finders/FieldFinder.cs
+++ b/src/StardewModdingAPI.AssemblyRewriters/Finders/FieldFinder.cs
@@ -3,8 +3,8 @@ using Mono.Cecil.Cil;
 
 namespace StardewModdingAPI.AssemblyRewriters.Finders
 {
-    /// <summary>Finds CIL instructions that reference a given field.</summary>
-    public class FieldFinder : IInstructionFinder
+    /// <summary>Finds incompatible CIL instructions that reference a given field and throws an <see cref="IncompatibleInstructionException"/>.</summary>
+    public class FieldFinder : IInstructionRewriter
     {
         /*********
         ** Properties
@@ -37,6 +37,22 @@ namespace StardewModdingAPI.AssemblyRewriters.Finders
             this.NounPhrase = nounPhrase ?? $"{fullTypeName}.{fieldName} field";
         }
 
+        /// <summary>Rewrite a CIL instruction for compatibility.</summary>
+        /// <param name="module">The module being rewritten.</param>
+        /// <param name="cil">The CIL rewriter.</param>
+        /// <param name="instruction">The instruction to rewrite.</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>
+        /// <returns>Returns whether the instruction was rewritten.</returns>
+        /// <exception cref="IncompatibleInstructionException">The CIL instruction is not compatible, and can't be rewritten.</exception>
+        public virtual bool Rewrite(ModuleDefinition module, ILProcessor cil, Instruction instruction, PlatformAssemblyMap assemblyMap, bool platformChanged)
+        {
+            if (!this.IsMatch(instruction, platformChanged))
+                return false;
+
+            throw new IncompatibleInstructionException(this.NounPhrase);
+        }
+
 
         /*********
         ** Protected methods
@@ -44,7 +60,7 @@ namespace StardewModdingAPI.AssemblyRewriters.Finders
         /// <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>
-        public bool IsMatch(Instruction instruction, bool platformChanged)
+        protected bool IsMatch(Instruction instruction, bool platformChanged)
         {
             FieldReference fieldRef = RewriteHelper.AsFieldReference(instruction);
             return
diff --git a/src/StardewModdingAPI.AssemblyRewriters/Finders/MethodFinder.cs b/src/StardewModdingAPI.AssemblyRewriters/Finders/MethodFinder.cs
index d174bacd..2efcbb0f 100644
--- a/src/StardewModdingAPI.AssemblyRewriters/Finders/MethodFinder.cs
+++ b/src/StardewModdingAPI.AssemblyRewriters/Finders/MethodFinder.cs
@@ -3,8 +3,8 @@ using Mono.Cecil.Cil;
 
 namespace StardewModdingAPI.AssemblyRewriters.Finders
 {
-    /// <summary>Finds CIL instructions that reference a given method.</summary>
-    public class MethodFinder : IInstructionFinder
+    /// <summary>Finds incompatible CIL instructions that reference a given method and throws an <see cref="IncompatibleInstructionException"/>.</summary>
+    public class MethodFinder : IInstructionRewriter
     {
         /*********
         ** Properties
@@ -37,6 +37,22 @@ namespace StardewModdingAPI.AssemblyRewriters.Finders
             this.NounPhrase = nounPhrase ?? $"{fullTypeName}.{methodName} method";
         }
 
+        /// <summary>Rewrite a CIL instruction for compatibility.</summary>
+        /// <param name="module">The module being rewritten.</param>
+        /// <param name="cil">The CIL rewriter.</param>
+        /// <param name="instruction">The instruction to rewrite.</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>
+        /// <returns>Returns whether the instruction was rewritten.</returns>
+        /// <exception cref="IncompatibleInstructionException">The CIL instruction is not compatible, and can't be rewritten.</exception>
+        public bool Rewrite(ModuleDefinition module, ILProcessor cil, Instruction instruction, PlatformAssemblyMap assemblyMap, bool platformChanged)
+        {
+            if (!this.IsMatch(instruction, platformChanged))
+                return false;
+
+            throw new IncompatibleInstructionException(this.NounPhrase);
+        }
+
 
         /*********
         ** Protected methods
@@ -44,7 +60,7 @@ namespace StardewModdingAPI.AssemblyRewriters.Finders
         /// <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>
-        public bool IsMatch(Instruction instruction, bool platformChanged)
+        protected bool IsMatch(Instruction instruction, bool platformChanged)
         {
             MethodReference methodRef = RewriteHelper.AsMethodReference(instruction);
             return
diff --git a/src/StardewModdingAPI.AssemblyRewriters/Finders/TypeFinder.cs b/src/StardewModdingAPI.AssemblyRewriters/Finders/TypeFinder.cs
index 8f492d5f..96cbb229 100644
--- a/src/StardewModdingAPI.AssemblyRewriters/Finders/TypeFinder.cs
+++ b/src/StardewModdingAPI.AssemblyRewriters/Finders/TypeFinder.cs
@@ -4,8 +4,8 @@ using Mono.Cecil.Cil;
 
 namespace StardewModdingAPI.AssemblyRewriters.Finders
 {
-    /// <summary>Finds CIL instructions that reference a given type.</summary>
-    public class TypeFinder : IInstructionFinder
+    /// <summary>Finds incompatible CIL instructions that reference a given type and throws an <see cref="IncompatibleInstructionException"/>.</summary>
+    public class TypeFinder : IInstructionRewriter
     {
         /*********
         ** Accessors
@@ -33,10 +33,30 @@ namespace StardewModdingAPI.AssemblyRewriters.Finders
             this.NounPhrase = nounPhrase ?? $"{fullTypeName} type";
         }
 
+        /// <summary>Rewrite a CIL instruction for compatibility.</summary>
+        /// <param name="module">The module being rewritten.</param>
+        /// <param name="cil">The CIL rewriter.</param>
+        /// <param name="instruction">The instruction to rewrite.</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>
+        /// <returns>Returns whether the instruction was rewritten.</returns>
+        /// <exception cref="IncompatibleInstructionException">The CIL instruction is not compatible, and can't be rewritten.</exception>
+        public virtual bool Rewrite(ModuleDefinition module, ILProcessor cil, Instruction instruction, PlatformAssemblyMap assemblyMap, bool platformChanged)
+        {
+            if (!this.IsMatch(instruction, platformChanged))
+                return false;
+
+            throw new IncompatibleInstructionException(this.NounPhrase);
+        }
+
+
+        /*********
+        ** 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>
-        public bool IsMatch(Instruction instruction, bool platformChanged)
+        protected bool IsMatch(Instruction instruction, bool platformChanged)
         {
             string fullName = this.FullTypeName;