Revamp AssemblyPatcher and patcher plugins

BepInEx.Preloader.Core/Patching/Attributes.cs

@@ -0,0 +1,129 @@
+using System;
+using System.Linq;
+using Mono.Cecil;
+using Version = SemVer.Version;
+
+namespace BepInEx.Preloader.Core.Patching
+{
+    /// <summary>
+    ///     This attribute denotes that a class is a patcher plugin, and specifies the required metadata.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Class)]
+    public class PatcherPluginInfoAttribute : Attribute
+    {
+        /// <param name="GUID">The unique identifier of the plugin. Should not change between plugin versions.</param>
+        /// <param name="Name">The user friendly name of the plugin. Is able to be changed between versions.</param>
+        /// <param name="Version">The specific version of the plugin.</param>
+        public PatcherPluginInfoAttribute(string GUID, string Name, string Version)
+        {
+            this.GUID = GUID;
+            this.Name = Name;
+            this.Version = TryParseLongVersion(Version);
+        }
+
+        /// <summary>
+        ///     The unique identifier of the plugin. Should not change between plugin versions.
+        /// </summary>
+        public string GUID { get; protected set; }
+
+
+        /// <summary>
+        ///     The user friendly name of the plugin. Is able to be changed between versions.
+        /// </summary>
+        public string Name { get; protected set; }
+
+
+        /// <summary>
+        ///     The specific version of the plugin.
+        /// </summary>
+        public Version Version { get; protected set; }
+
+        private static Version TryParseLongVersion(string version)
+        {
+            if (Version.TryParse(version, out var v))
+                return v;
+
+            // no System.Version.TryParse() on .NET 3.5
+            try
+            {
+                var longVersion = new System.Version(version);
+
+                return new Version(longVersion.Major, longVersion.Minor,
+                                   longVersion.Build != -1 ? longVersion.Build : 0);
+            }
+            catch { }
+
+            return null;
+        }
+
+        internal static PatcherPluginInfoAttribute FromCecilType(TypeDefinition td)
+        {
+            var attr = MetadataHelper.GetCustomAttributes<PatcherPluginInfoAttribute>(td, false).FirstOrDefault();
+
+            if (attr == null)
+                return null;
+
+            return new PatcherPluginInfoAttribute((string)attr.ConstructorArguments[0].Value,
+                                                  (string)attr.ConstructorArguments[1].Value,
+                                                  (string)attr.ConstructorArguments[2].Value);
+        }
+
+        internal static PatcherPluginInfoAttribute FromType(Type type)
+        {
+            var attributes = type.GetCustomAttributes(typeof(PatcherPluginInfoAttribute), false);
+
+            if (attributes.Length == 0)
+                return null;
+
+            return (PatcherPluginInfoAttribute)attributes[0];
+        }
+    }
+
+    /// <summary>
+    /// Defines an assembly that a patch method will target.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Method)]
+    public class TargetAssemblyAttribute : Attribute
+    {
+        /// <summary>
+        /// Marker used to indicate all possible assemblies to be targeted by a patch method.
+        /// </summary>
+        public const string AllAssemblies = "_all";
+
+        /// <summary>
+        /// The short filename of the assembly to target.
+        /// </summary>
+        public string TargetAssembly { get; }
+
+        /// <param name="targetAssembly">The short filename of the assembly. Use <see cref="AllAssemblies"/> to mark all possible assemblies as targets.</param>
+        public TargetAssemblyAttribute(string targetAssembly)
+        {
+            TargetAssembly = targetAssembly;
+        }
+    }
+
+    /// <summary>
+    /// Defines a type that a patch method will target.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Method)]
+    public class TargetTypeAttribute : Attribute
+    {
+        /// <summary>
+        /// The short filename of the assembly to target.
+        /// </summary>
+        public string TargetAssembly { get; }
+
+        /// <summary>
+        /// The full name of the type to target for patching.
+        /// </summary>
+        public string TargetType { get; }
+
+        /// <param name="targetAssembly">The short filename of the assembly of which <paramref name="targetType"/> belongs to.</param>
+        /// <param name="targetType">The full name of the type to target for patching.</param>
+        public TargetTypeAttribute(string targetAssembly, string targetType)
+        {
+            TargetAssembly = targetAssembly;
+            TargetType = targetType;
+        }
+    }
+}