InteropGen cleanup

Source/MochaTool.InteropGen/CodeGen/ManagedCodeGenerator.cs

@@ -1,31 +1,103 @@
-using System.CodeDom.Compiler;
+using MochaTool.InteropGen.Parsing;
+using System.CodeDom.Compiler;
+using System.Collections.Immutable;
 
-namespace MochaTool.InteropGen;
+namespace MochaTool.InteropGen.CodeGen;
 
-sealed class ManagedCodeGenerator : BaseCodeGenerator
+/// <summary>
+/// Contains functionality for generating C# code.
+/// </summary>
+internal static class ManagedCodeGenerator
 {
-	public ManagedCodeGenerator( List<IUnit> units ) : base( units )
+	/// <summary>
+	/// The namespace that all generated code will be under.
+	/// </summary>
+	private const string Namespace = "Mocha.Glue";
+
+	/// <summary>
+	/// An array containing all using declarations for generated code.
+	/// </summary>
+	private static readonly string[] Usings = new[]
 	{
-	}
-
-	private List<string> GetUsings()
+		"System.Runtime.InteropServices",
+		"System.Runtime.Serialization",
+		"Mocha.Common"
+	};
+
+	/// <summary>
+	/// The header to be used at the top of generated code.
+	/// </summary>
+	private static string Header => $"""
+	//------------------------------------------------------------------------------ 
+	// <auto-generated> 
+	// This code was generated by a tool. 
+	// InteropGen generated on {DateTime.Now}
+	// 
+	// Changes to this file may cause incorrect behavior and will be lost if 
+	// the code is regenerated. 
+	// </auto-generated> 
+	//------------------------------------------------------------------------------
+	""";
+
+	/// <summary>
+	/// Generates and returns C# code for a set of <see cref="IUnit"/>s.
+	/// </summary>
+	/// <param name="units">An enumerable list of <see cref="IUnit"/>s to generate code for.</param>
+	/// <returns>C# code representing the set of <see cref="IUnit"/>s passed.</returns>
+	internal static string GenerateCode( IEnumerable<IUnit> units )
 	{
-		return new() { "System.Runtime.InteropServices", "System.Runtime.Serialization", "Mocha.Common" };
-	}
+		var (baseTextWriter, writer) = Utils.CreateWriter();
 
-	private string GetNamespace()
-	{
-		return "Mocha.Glue";
+		// Write header.
+		writer.WriteLine( Header );
+		writer.WriteLine();
+
+		// Write using statements.
+		foreach ( var usingStatement in Usings )
+			writer.WriteLine( $"using {usingStatement};" );
+
+		// Write namespace.
+		writer.WriteLine();
+		writer.WriteLine( $"namespace {Namespace};" );
+		writer.WriteLine();
+
+		// Write each unit.
+		foreach ( var unit in units )
+		{
+			switch ( unit )
+			{
+				case Class c when c.IsNamespace:
+					GenerateNamespaceCode( writer, c );
+					break;
+				case Class c:
+					GenerateClassCode( writer, c );
+					break;
+				case Struct s:
+					GenerateStructCode( writer, s );
+					break;
+				default:
+					continue;
+			}
+
+			writer.WriteLine();
+		}
+
+		return baseTextWriter.ToString();
 	}
 
-	private void GenerateClassCode( ref IndentedTextWriter writer, Class sel )
+	/// <summary>
+	/// Generates C# code for a class.
+	/// </summary>
+	/// <param name="writer">The writer to append the code to.</param>
+	/// <param name="c">The class to write code for.</param>
+	private static void GenerateClassCode( IndentedTextWriter writer, Class c )
 	{
 		//
 		// Gather everything we need into nice lists
 		//
 		List<string> decls = new();
 
-		foreach ( var method in sel.Methods )
+		foreach ( var method in c.Methods )
 		{
 			var returnType = Utils.GetManagedType( method.ReturnType );
 			var name = method.Name;
@@ -56,13 +128,13 @@ private void GenerateClassCode( ref IndentedTextWriter writer, Class sel )
 			// any parameters. The return type is the last type argument passed to
 			// the delegate.
 			//
-			decls.Add( $"private static {delegateSignature} _{name} = ({delegateSignature})Mocha.Common.Global.UnmanagedArgs.__{sel.Name}_{name}MethodPtr;" );
+			decls.Add( $"private static {delegateSignature} _{name} = ({delegateSignature})Mocha.Common.Global.UnmanagedArgs.__{c.Name}_{name}MethodPtr;" );
 		}
 
 		//
 		// Write shit
 		//
-		writer.WriteLine( $"public unsafe class {sel.Name} : INativeGlue" );
+		writer.WriteLine( $"public unsafe class {c.Name} : INativeGlue" );
 		writer.WriteLine( "{" );
 		writer.Indent++;
 
@@ -71,18 +143,16 @@ private void GenerateClassCode( ref IndentedTextWriter writer, Class sel )
 		// Decls
 		writer.WriteLine();
 		foreach ( var decl in decls )
-		{
 			writer.WriteLine( decl );
-		}
 		writer.WriteLine();
 
 		// Ctor
-		if ( sel.Methods.Any( x => x.IsConstructor ) )
+		if ( c.Methods.Any( x => x.IsConstructor ) )
 		{
-			var ctor = sel.Methods.First( x => x.IsConstructor );
+			var ctor = c.Methods.First( x => x.IsConstructor );
 			var managedCtorArgs = string.Join( ", ", ctor.Parameters.Select( x => $"{Utils.GetManagedType( x.Type )} {x.Name}" ) );
 
-			writer.WriteLine( $"public {sel.Name}( {managedCtorArgs} )" );
+			writer.WriteLine( $"public {c.Name}( {managedCtorArgs} )" );
 			writer.WriteLine( "{" );
 			writer.Indent++;
 
@@ -94,7 +164,7 @@ private void GenerateClassCode( ref IndentedTextWriter writer, Class sel )
 		}
 
 		// Methods
-		foreach ( var method in sel.Methods )
+		foreach ( var method in c.Methods )
 		{
 			writer.WriteLine();
 
@@ -122,7 +192,7 @@ private void GenerateClassCode( ref IndentedTextWriter writer, Class sel )
 			writer.Indent++;
 
 			// Spin up a MemoryContext instance
-			writer.WriteLine( $"using var ctx = new MemoryContext( \"{sel.Name}.{name}\" );" );
+			writer.WriteLine( $"using var ctx = new MemoryContext( \"{c.Name}.{name}\" );" );
 
 			//
 			// Gather function body
@@ -131,7 +201,7 @@ private void GenerateClassCode( ref IndentedTextWriter writer, Class sel )
 
 			// We need to pass the instance in if this is not a static method
 			if ( !method.IsStatic )
-				paramsAndInstance = paramsAndInstance.Prepend( new Variable( "NativePtr", "IntPtr" ) ).ToList();
+				paramsAndInstance = paramsAndInstance.Prepend( new Variable( "NativePtr", "IntPtr" ) ).ToImmutableArray();
 
 			// Gather function call arguments. Make sure that we're passing in a pointer for everything
 			var paramNames = paramsAndInstance.Select( x => "ctx.GetPtr( " + x.Name + " )" );
@@ -175,30 +245,38 @@ private void GenerateClassCode( ref IndentedTextWriter writer, Class sel )
 		writer.WriteLine( "}" );
 	}
 
-	private void GenerateStructCode( ref IndentedTextWriter writer, Structure sel )
+	/// <summary>
+	/// Generates C# code for a struct.
+	/// </summary>
+	/// <param name="writer">The writer to append the code to.</param>
+	/// <param name="s">The struct to write code for.</param>
+	private static void GenerateStructCode( IndentedTextWriter writer, Struct s )
 	{
 		writer.WriteLine( $"[StructLayout( LayoutKind.Sequential )]" );
-		writer.WriteLine( $"public struct {sel.Name}" );
+		writer.WriteLine( $"public struct {s.Name}" );
 		writer.WriteLine( "{" );
 		writer.Indent++;
 
-		foreach ( var field in sel.Fields )
-		{
+		foreach ( var field in s.Fields )
 			writer.WriteLine( $"public {Utils.GetManagedType( field.Type )} {field.Name};" );
-		}
 
 		writer.Indent--;
 		writer.WriteLine( "}" );
 	}
 
-	private void GenerateNamespaceCode( ref IndentedTextWriter writer, Class sel )
+	/// <summary>
+	/// Generates C# code for a namespace.
+	/// </summary>
+	/// <param name="writer">The writer to append the code to.</param>
+	/// <param name="ns">The namespace to write code for.</param>
+	private static void GenerateNamespaceCode( IndentedTextWriter writer, Class ns )
 	{
 		//
 		// Gather everything we need into nice lists
 		//
 		List<string> decls = new();
 
-		foreach ( var method in sel.Methods )
+		foreach ( var method in ns.Methods )
 		{
 			var returnType = Utils.GetManagedType( method.ReturnType );
 			var name = method.Name;
@@ -220,24 +298,22 @@ private void GenerateNamespaceCode( ref IndentedTextWriter writer, Class sel )
 			// any parameters. The return type is the last type argument passed to
 			// the delegate.
 			//
-			decls.Add( $"private static {delegateSignature} _{name} = ({delegateSignature})Mocha.Common.Global.UnmanagedArgs.__{sel.Name}_{name}MethodPtr;" );
+			decls.Add( $"private static {delegateSignature} _{name} = ({delegateSignature})Mocha.Common.Global.UnmanagedArgs.__{ns.Name}_{name}MethodPtr;" );
 		}
 
 		//
 		// Write shit
 		//
-		writer.WriteLine( $"public static unsafe class {sel.Name}" );
+		writer.WriteLine( $"public static unsafe class {ns.Name}" );
 		writer.WriteLine( "{" );
 		writer.Indent++;
 
 		writer.WriteLine();
 		foreach ( var decl in decls )
-		{
 			writer.WriteLine( decl );
-		}
 
 		// Methods
-		foreach ( var method in sel.Methods )
+		foreach ( var method in ns.Methods )
 		{
 			writer.WriteLine();
 
@@ -252,10 +328,9 @@ private void GenerateNamespaceCode( ref IndentedTextWriter writer, Class sel )
 			writer.Indent++;
 
 			// Spin up a MemoryContext instance
-			writer.WriteLine( $"using var ctx = new MemoryContext( \"{sel.Name}.{name}\" );" );
+			writer.WriteLine( $"using var ctx = new MemoryContext( \"{ns.Name}.{name}\" );" );
 
-			var @params = method.Parameters;
-			var paramNames = @params.Select( x => "ctx.GetPtr( " + x.Name + " )" );
+			var paramNames = method.Parameters.Select( x => "ctx.GetPtr( " + x.Name + " )" );
 			var functionCallArgs = string.Join( ", ", paramNames );
 
 			if ( returnsPointer )
@@ -293,39 +368,4 @@ private void GenerateNamespaceCode( ref IndentedTextWriter writer, Class sel )
 		writer.Indent--;
 		writer.WriteLine( "}" );
 	}
-
-	public string GenerateManagedCode()
-	{
-		var (baseTextWriter, writer) = Utils.CreateWriter();
-
-		writer.WriteLine( GetHeader() );
-		writer.WriteLine();
-
-		foreach ( var usingStatement in GetUsings() )
-			writer.WriteLine( $"using {usingStatement};" );
-
-		writer.WriteLine();
-		writer.WriteLine( $"namespace {GetNamespace()};" );
-		writer.WriteLine();
-
-		foreach ( var unit in Units )
-		{
-			if ( unit is Class c )
-			{
-				if ( c.IsNamespace )
-					GenerateNamespaceCode( ref writer, c );
-				else
-					GenerateClassCode( ref writer, c );
-			}
-
-			if ( unit is Structure s )
-			{
-				GenerateStructCode( ref writer, s );
-			}
-
-			writer.WriteLine();
-		}
-
-		return baseTextWriter.ToString();
-	}
 }