ref

compiler/NubLang/Generation/Generator.cs

@@ -10,6 +10,7 @@ public class Generator
     private readonly CompilationUnit _compilationUnit;
     private readonly IndentedTextWriter _writer;
     private readonly Stack<List<DeferNode>> _deferStack = [];
+    private readonly Stack<List<string>> _refCleanupStack = [];
     private int _tmpIndex;
 
     public Generator(CompilationUnit compilationUnit)
@@ -32,6 +33,12 @@ public class Generator
     public string Emit()
     {
         _writer.WriteLine("""
+                          #include <stddef.h>
+
+                          void *rc_alloc(size_t size, void (*destructor)(void *self));
+                          void rc_retain(void *obj);
+                          void rc_release(void *obj);
+
                           struct nub_string
                           {
                               unsigned long long length;
@@ -262,31 +269,35 @@ public class Generator
                 EmitStatement(blockDefers[i].Statement);
             }
 
+            var refCleanups = _refCleanupStack.Peek();
+            foreach (var refCleanup in refCleanups)
+            {
+                _writer.WriteLine($"rc_release({refCleanup});");
+            }
+
             _writer.WriteLine("return;");
         }
         else
         {
             var returnValue = EmitExpression(returnNode.Value);
 
-            if (_deferStack.Peek().Count != 0)
-            {
-                var tmp = NewTmp();
-                _writer.WriteLine($"{CType.Create(returnNode.Value.Type, tmp)} = {returnValue};");
+            var tmp = NewTmp();
+            _writer.WriteLine($"{CType.Create(returnNode.Value.Type, tmp)} = {returnValue};");
 
-                var blockDefers = _deferStack.Peek();
-                for (var i = blockDefers.Count - 1; i >= 0; i--)
-                {
-                    EmitStatement(blockDefers[i].Statement);
-                }
-
-                EmitLine(returnNode.Tokens.FirstOrDefault());
-                _writer.WriteLine($"return {tmp};");
-            }
-            else
+            var blockDefers = _deferStack.Peek();
+            for (var i = blockDefers.Count - 1; i >= 0; i--)
             {
-                EmitLine(returnNode.Tokens.FirstOrDefault());
-                _writer.WriteLine($"return {returnValue};");
+                EmitStatement(blockDefers[i].Statement);
             }
+
+            var refCleanups = _refCleanupStack.Peek();
+            foreach (var refCleanup in refCleanups)
+            {
+                _writer.WriteLine($"rc_release({refCleanup});");
+            }
+
+            EmitLine(returnNode.Tokens.FirstOrDefault());
+            _writer.WriteLine($"return {tmp};");
         }
     }
 
@@ -345,6 +356,8 @@ public class Generator
             FuncCallNode funcCallNode => EmitFuncCall(funcCallNode),
             FuncIdentifierNode funcIdentifierNode => FuncName(funcIdentifierNode.ModuleToken.Value, funcIdentifierNode.NameToken.Value, funcIdentifierNode.ExternSymbolToken?.Value),
             AddressOfNode addressOfNode => EmitAddressOf(addressOfNode),
+            RefDereferenceNode refDereferenceNode => EmitRefDereference(refDereferenceNode),
+            RefStructInitializerNode refStructInitializerNode => EmitRefStructInitializer(refStructInitializerNode),
             SizeNode sizeBuiltinNode => $"sizeof({CType.Create(sizeBuiltinNode.TargetType)})",
             SliceIndexAccessNode sliceIndexAccessNode => EmitSliceArrayIndexAccess(sliceIndexAccessNode),
             StringLiteralNode stringLiteralNode => EmitStringLiteral(stringLiteralNode),
@@ -489,6 +502,38 @@ public class Generator
         return $"&{value}";
     }
 
+    private string EmitRefDereference(RefDereferenceNode refDereferenceNode)
+    {
+        var pointer = EmitExpression(refDereferenceNode.Target);
+        return $"*{pointer}";
+    }
+
+    private string EmitRefStructInitializer(RefStructInitializerNode refStructInitializerNode)
+    {
+        var type = (NubRefType)refStructInitializerNode.Type;
+        var structType = (NubStructType)type.BaseType;
+
+        var tmp = NewTmp();
+        _writer.WriteLine($"{CType.Create(type)} {tmp} = ({CType.Create(type)})rc_alloc(sizeof({CType.Create(structType)}), NULL);");
+
+        var initValues = new List<string>();
+        foreach (var initializer in refStructInitializerNode.Initializers)
+        {
+            var value = EmitExpression(initializer.Value);
+            initValues.Add($".{initializer.Key.Value} = {value}");
+        }
+
+        var initString = initValues.Count == 0
+            ? "0"
+            : string.Join(", ", initValues);
+
+        _writer.WriteLine($"*{tmp} = ({CType.Create(structType)}){{{initString}}};");
+
+        _refCleanupStack.Peek().Add(tmp);
+
+        return tmp;
+    }
+
     private string EmitSliceArrayIndexAccess(SliceIndexAccessNode sliceIndexAccessNode)
     {
         var targetType = (NubSliceType)sliceIndexAccessNode.Target.Type;
@@ -581,6 +626,7 @@ public class Generator
     private void EmitBlock(BlockNode blockNode)
     {
         _deferStack.Push([]);
+        _refCleanupStack.Push([]);
 
         foreach (var statementNode in blockNode.Statements)
         {
@@ -592,5 +638,11 @@ public class Generator
         {
             EmitStatement(blockDefers[i].Statement);
         }
+
+        var refCleanups = _refCleanupStack.Pop();
+        foreach (var refCleanup in refCleanups)
+        {
+            _writer.WriteLine($"rc_release({refCleanup});");
+        }
     }
 }