rewrite mod assembly loading (#229)

This greatly simplifies mod loading, eliminates the .cache folders by loading assemblies in memory, ensures DLLs are loaded in leaf-to-root order, and reduces log verbosity. These changes should address a range of issues, notably #221 and #226.

4 files changed, 0 insertions, 305 deletions

diff --git a/src/StardewModdingAPI/Framework/AssemblyRewriting/AssemblyTypeRewriter.cs b/src/StardewModdingAPI/Framework/AssemblyRewriting/AssemblyTypeRewriter.cs
deleted file mode 100644
index 9d4d6b11..00000000
--- a/src/StardewModdingAPI/Framework/AssemblyRewriting/AssemblyTypeRewriter.cs
+++ /dev/null
@@ -1,162 +0,0 @@
-using System.Collections.Generic;
-using System.Linq;
-using System.Reflection;
-using Mono.Cecil;
-using Mono.Cecil.Cil;
-using Mono.Cecil.Rocks;
-using StardewModdingAPI.AssemblyRewriters;
-
-namespace StardewModdingAPI.Framework.AssemblyRewriting
-{
-    /// <summary>Rewrites type references.</summary>
-    internal class AssemblyTypeRewriter
-    {
-        /*********
-        ** Properties
-        *********/
-        /// <summary>Metadata for mapping assemblies to the current <see cref="Platform"/>.</summary>
-        private readonly PlatformAssemblyMap AssemblyMap;
-
-        /// <summary>A type => assembly lookup for types which should be rewritten.</summary>
-        private readonly IDictionary<string, Assembly> TypeAssemblies;
-
-        /// <summary>Encapsulates monitoring and logging.</summary>
-        private readonly IMonitor Monitor;
-
-
-        /*********
-        ** Public methods
-        *********/
-        /// <summary>Construct an instance.</summary>
-        /// <param name="assemblyMap">Metadata for mapping assemblies to the current <see cref="Platform"/>.</param>
-        /// <param name="monitor">Encapsulates monitoring and logging.</param>
-        public AssemblyTypeRewriter(PlatformAssemblyMap assemblyMap, IMonitor monitor)
-        {
-            // save config
-            this.AssemblyMap = assemblyMap;
-            this.Monitor = monitor;
-
-            // collect type => assembly lookup
-            this.TypeAssemblies = new Dictionary<string, Assembly>();
-            foreach (Assembly assembly in assemblyMap.Targets)
-            {
-                ModuleDefinition module = this.AssemblyMap.TargetModules[assembly];
-                foreach (TypeDefinition type in module.GetTypes())
-                {
-                    if (!type.IsPublic)
-                        continue; // no need to rewrite
-                    if (type.Namespace.Contains("<"))
-                        continue; // ignore assembly metadata
-                    this.TypeAssemblies[type.FullName] = assembly;
-                }
-            }
-        }
-
-        /// <summary>Rewrite the types referenced by an assembly.</summary>
-        /// <param name="assembly">The assembly to rewrite.</param>
-        /// <returns>Returns whether the assembly was modified.</returns>
-        public bool RewriteAssembly(AssemblyDefinition assembly)
-        {
-            ModuleDefinition module = assembly.Modules.Single(); // technically an assembly can have multiple modules, but none of the build tools (including MSBuild) support it; simplify by assuming one module
-
-            // remove old assembly references
-            bool shouldRewrite = false;
-            for (int i = 0; i < module.AssemblyReferences.Count; i++)
-            {
-                if (this.AssemblyMap.RemoveNames.Any(name => module.AssemblyReferences[i].Name == name))
-                {
-                    this.Monitor.Log($"removing reference to {module.AssemblyReferences[i]}", LogLevel.Trace);
-                    shouldRewrite = true;
-                    module.AssemblyReferences.RemoveAt(i);
-                    i--;
-                }
-            }
-            if (!shouldRewrite)
-                return false;
-
-            // add target assembly references
-            foreach (AssemblyNameReference target in this.AssemblyMap.TargetReferences.Values)
-            {
-                this.Monitor.Log($"  adding reference to {target}", LogLevel.Trace);
-                module.AssemblyReferences.Add(target);
-            }
-
-            // rewrite type scopes to use target assemblies
-            IEnumerable<TypeReference> typeReferences = module.GetTypeReferences().OrderBy(p => p.FullName);
-            string lastTypeLogged = null;
-            foreach (TypeReference type in typeReferences)
-            {
-                this.ChangeTypeScope(type, shouldLog: type.FullName != lastTypeLogged);
-                lastTypeLogged = type.FullName;
-            }
-
-            // rewrite incompatible methods
-            IMethodRewriter[] methodRewriters = Constants.GetMethodRewriters().ToArray();
-            foreach (MethodDefinition method in this.GetMethods(module))
-            {
-                // skip methods with no rewritable method
-                bool hasMethodToRewrite = method.Body.Instructions.Any(op => (op.OpCode == OpCodes.Call || op.OpCode == OpCodes.Callvirt) && methodRewriters.Any(rewriter => rewriter.ShouldRewrite((MethodReference)op.Operand)));
-                if (!hasMethodToRewrite)
-                    continue;
-
-                // rewrite method references
-                method.Body.SimplifyMacros();
-                ILProcessor cil = method.Body.GetILProcessor();
-                Instruction[] instructions = cil.Body.Instructions.ToArray();
-                foreach (Instruction op in instructions)
-                {
-                    if (op.OpCode == OpCodes.Call || op.OpCode == OpCodes.Callvirt)
-                    {
-                        IMethodRewriter rewriter = methodRewriters.FirstOrDefault(p => p.ShouldRewrite((MethodReference)op.Operand));
-                        if (rewriter != null)
-                        {
-                            MethodReference methodRef = (MethodReference)op.Operand;
-                            this.Monitor.Log($"rewriting method reference {methodRef.DeclaringType.FullName}.{methodRef.Name}", LogLevel.Trace);
-                            rewriter.Rewrite(module, cil, op, methodRef, this.AssemblyMap);
-                        }
-                    }
-                }
-                method.Body.OptimizeMacros();
-            }
-            return true;
-        }
-
-
-        /*********
-        ** Private methods
-        *********/
-        /// <summary>Get the correct reference to use for compatibility with the current platform.</summary>
-        /// <param name="type">The type reference to rewrite.</param>
-        /// <param name="shouldLog">Whether to log a message.</param>
-        private void ChangeTypeScope(TypeReference type, bool shouldLog)
-        {
-            // check skip conditions
-            if (type == null || type.FullName.StartsWith("System."))
-                return;
-
-            // get assembly
-            Assembly assembly;
-            if (!this.TypeAssemblies.TryGetValue(type.FullName, out assembly))
-                return;
-
-            // replace scope
-            AssemblyNameReference assemblyRef = this.AssemblyMap.TargetReferences[assembly];
-            if (shouldLog)
-                this.Monitor.Log($"redirecting {type.FullName} from {type.Scope.Name} to {assemblyRef.Name}", LogLevel.Trace);
-            type.Scope = assemblyRef;
-        }
-
-        /// <summary>Get all methods in a module.</summary>
-        /// <param name="module">The module to search.</param>
-        private IEnumerable<MethodDefinition> GetMethods(ModuleDefinition module)
-        {
-            return (
-                from type in module.GetTypes()
-                where type.HasMethods
-                from method in type.Methods
-                where method.HasBody
-                select method
-            );
-        }
-    }
-}
diff --git a/src/StardewModdingAPI/Framework/AssemblyRewriting/CacheEntry.cs b/src/StardewModdingAPI/Framework/AssemblyRewriting/CacheEntry.cs
deleted file mode 100644
index 4c3b86fe..00000000
--- a/src/StardewModdingAPI/Framework/AssemblyRewriting/CacheEntry.cs
+++ /dev/null
@@ -1,61 +0,0 @@
-using System.IO;
-using StardewModdingAPI.AssemblyRewriters;
-
-namespace StardewModdingAPI.Framework.AssemblyRewriting
-{
-    /// <summary>Represents cached metadata for a rewritten assembly.</summary>
-    internal class CacheEntry
-    {
-        /*********
-        ** Accessors
-        *********/
-        /// <summary>The MD5 hash for the original assembly.</summary>
-        public readonly string Hash;
-
-        /// <summary>The SMAPI version used to rewrite the assembly.</summary>
-        public readonly string ApiVersion;
-
-        /// <summary>The target platform.</summary>
-        public readonly Platform Platform;
-
-        /// <summary>The <see cref="System.Environment.MachineName"/> value for the machine used to rewrite the assembly.</summary>
-        public readonly string MachineName;
-
-        /// <summary>Whether to use the cached assembly instead of the original assembly.</summary>
-        public readonly bool UseCachedAssembly;
-
-
-        /*********
-        ** Public methods
-        *********/
-        /// <summary>Construct an instance.</summary>
-        /// <param name="hash">The MD5 hash for the original assembly.</param>
-        /// <param name="apiVersion">The SMAPI version used to rewrite the assembly.</param>
-        /// <param name="platform">The target platform.</param>
-        /// <param name="machineName">The <see cref="System.Environment.MachineName"/> value for the machine used to rewrite the assembly.</param>
-        /// <param name="useCachedAssembly">Whether to use the cached assembly instead of the original assembly.</param>
-        public CacheEntry(string hash, string apiVersion, Platform platform, string machineName, bool useCachedAssembly)
-        {
-            this.Hash = hash;
-            this.ApiVersion = apiVersion;
-            this.Platform = platform;
-            this.MachineName = machineName;
-            this.UseCachedAssembly = useCachedAssembly;
-        }
-
-        /// <summary>Get whether the cache entry is up-to-date for the given assembly hash.</summary>
-        /// <param name="paths">The paths for the cached assembly.</param>
-        /// <param name="hash">The MD5 hash of the original assembly.</param>
-        /// <param name="currentVersion">The current SMAPI version.</param>
-        /// <param name="platform">The target platform.</param>
-        /// <param name="machineName">The <see cref="System.Environment.MachineName"/> value for the machine reading the assembly.</param>
-        public bool IsUpToDate(CachePaths paths, string hash, ISemanticVersion currentVersion, Platform platform, string machineName)
-        {
-            return hash == this.Hash
-                && this.ApiVersion == currentVersion.ToString()
-                && this.Platform == platform
-                && this.MachineName == machineName
-                && (!this.UseCachedAssembly || File.Exists(paths.Assembly));
-        }
-    }
-}
\ No newline at end of file
diff --git a/src/StardewModdingAPI/Framework/AssemblyRewriting/CachePaths.cs b/src/StardewModdingAPI/Framework/AssemblyRewriting/CachePaths.cs
deleted file mode 100644
index 18861873..00000000
--- a/src/StardewModdingAPI/Framework/AssemblyRewriting/CachePaths.cs
+++ /dev/null
@@ -1,33 +0,0 @@
-namespace StardewModdingAPI.Framework.AssemblyRewriting
-{
-    /// <summary>Contains the paths for an assembly's cached data.</summary>
-    internal struct CachePaths
-    {
-        /*********
-        ** Accessors
-        *********/
-        /// <summary>The directory path which contains the assembly.</summary>
-        public string Directory { get; }
-
-        /// <summary>The file path of the assembly file.</summary>
-        public string Assembly { get; }
-
-        /// <summary>The file path containing the assembly metadata.</summary>
-        public string Metadata { get; }
-
-
-        /*********
-        ** Public methods
-        *********/
-        /// <summary>Construct an instance.</summary>
-        /// <param name="directory">The directory path which contains the assembly.</param>
-        /// <param name="assembly">The file path of the assembly file.</param>
-        /// <param name="metadata">The file path containing the assembly metadata.</param>
-        public CachePaths(string directory, string assembly, string metadata)
-        {
-            this.Directory = directory;
-            this.Assembly = assembly;
-            this.Metadata = metadata;
-        }
-    }
-}
\ No newline at end of file
diff --git a/src/StardewModdingAPI/Framework/AssemblyRewriting/RewriteResult.cs b/src/StardewModdingAPI/Framework/AssemblyRewriting/RewriteResult.cs
deleted file mode 100644
index 8f34bb20..00000000
--- a/src/StardewModdingAPI/Framework/AssemblyRewriting/RewriteResult.cs
+++ /dev/null
@@ -1,49 +0,0 @@
-namespace StardewModdingAPI.Framework.AssemblyRewriting
-{
-    /// <summary>Metadata about a preprocessed assembly.</summary>
-    internal class RewriteResult
-    {
-        /*********
-        ** Accessors
-        *********/
-        /// <summary>The original assembly path.</summary>
-        public readonly string OriginalAssemblyPath;
-
-        /// <summary>The cache paths.</summary>
-        public readonly CachePaths CachePaths;
-
-        /// <summary>The rewritten assembly bytes.</summary>
-        public readonly byte[] AssemblyBytes;
-
-        /// <summary>The MD5 hash for the original assembly.</summary>
-        public readonly string Hash;
-
-        /// <summary>Whether to use the cached assembly instead of the original assembly.</summary>
-        public readonly bool UseCachedAssembly;
-
-        /// <summary>Whether this data is newer than the cache.</summary>
-        public readonly bool IsNewerThanCache;
-
-
-
-        /*********
-        ** Public methods
-        *********/
-        /// <summary>Construct an instance.</summary>
-        /// <param name="originalAssemblyPath"></param>
-        /// <param name="cachePaths">The cache paths.</param>
-        /// <param name="assemblyBytes">The rewritten assembly bytes.</param>
-        /// <param name="hash">The MD5 hash for the original assembly.</param>
-        /// <param name="useCachedAssembly">Whether to use the cached assembly instead of the original assembly.</param>
-        /// <param name="isNewerThanCache">Whether this data is newer than the cache.</param>
-        public RewriteResult(string originalAssemblyPath, CachePaths cachePaths, byte[] assemblyBytes, string hash, bool useCachedAssembly, bool isNewerThanCache)
-        {
-            this.OriginalAssemblyPath = originalAssemblyPath;
-            this.CachePaths = cachePaths;
-            this.Hash = hash;
-            this.AssemblyBytes = assemblyBytes;
-            this.UseCachedAssembly = useCachedAssembly;
-            this.IsNewerThanCache = isNewerThanCache;
-        }
-    }
-}