Remove scopes from generator

src/compiler/NubLang/Generation/QBE/QBEGenerator.cs

@@ -17,15 +17,12 @@ public class QBEGenerator
     private readonly List<StringLiteral> _stringLiterals = [];
     private readonly Stack<string> _breakLabels = [];
     private readonly Stack<string> _continueLabels = [];
-    private readonly Stack<Scope> _scopes = [];
     private int _tmpIndex;
     private int _labelIndex;
     private int _cStringLiteralIndex;
     private int _stringLiteralIndex;
     private bool _codeIsReachable = true;
 
-    private Scope Scope => _scopes.Peek();
-
     public QBEGenerator(TypedSyntaxTree syntaxTree, TypedDefinitionTable definitionTable)
     {
         _syntaxTree = syntaxTree;
@@ -39,7 +36,6 @@ public class QBEGenerator
         _stringLiterals.Clear();
         _breakLabels.Clear();
         _continueLabels.Clear();
-        _scopes.Clear();
         _tmpIndex = 0;
         _labelIndex = 0;
         _cStringLiteralIndex = 0;
@@ -364,14 +360,7 @@ public class QBEGenerator
         _writer.WriteLine(") {");
         _writer.WriteLine("@start");
 
-        var scope = new Scope();
+        EmitBlock(funcDef.Body);
-
-        foreach (var parameter in funcDef.Signature.Parameters)
-        {
-            scope.Declare(parameter.Name, new Val("%" + parameter.Name, parameter.Type, false));
-        }
-
-        EmitBlock(funcDef.Body, scope);
 
         // Implicit return for void functions if no explicit return has been set
         if (funcDef.Signature.ReturnType is VoidTypeNode && funcDef.Body.Statements is [.., not ReturnNode])
@@ -408,15 +397,7 @@ public class QBEGenerator
             _writer.WriteLine(") {");
             _writer.WriteLine("@start");
 
-            var scope = new Scope();
+            EmitBlock(function.Body);
-
-            scope.Declare("this", new Val("%this", structDef.Type, false));
-            foreach (var parameter in function.Signature.Parameters)
-            {
-                scope.Declare(parameter.Name, new Val("%" + parameter.Name, parameter.Type, false));
-            }
-
-            EmitBlock(function.Body, scope);
 
             // Implicit return for void functions if no explicit return has been set
             if (function.Signature.ReturnType is VoidTypeNode && function.Body.Statements is [.., not ReturnNode])
@@ -479,10 +460,8 @@ public class QBEGenerator
         }
     }
 
-    private void EmitBlock(BlockNode block, Scope? scope = null)
+    private void EmitBlock(BlockNode block)
     {
-        _scopes.Push(scope ?? Scope.SubScope());
-
         foreach (var statement in block.Statements)
         {
             if (_codeIsReachable)
@@ -491,8 +470,6 @@ public class QBEGenerator
             }
         }
 
-        _scopes.Pop();
-
         _codeIsReachable = true;
     }
 
@@ -599,8 +576,6 @@ public class QBEGenerator
             var value = EmitCreateCopyOrInitialize(variableDeclaration.Assignment.Value);
             EmitStore(variableDeclaration.Assignment.Value.Type, value, name);
         }
-
-        Scope.Declare(variableDeclaration.Name, new Val(name, variableDeclaration.Type, true));
     }
 
     private void EmitWhile(WhileNode whileStatement)
@@ -1321,29 +1296,3 @@ public class CStringLiteral(string value, string name)
 }
 
 public record Val(string Name, TypeNode Type, bool IsLValue);
-
-public class Scope(Scope? parent = null)
-{
-    private readonly Dictionary<string, Val> _variables = [];
-
-    public Val Lookup(string name)
-    {
-        var variable = _variables.GetValueOrDefault(name);
-        if (variable != null)
-        {
-            return variable;
-        }
-
-        return parent?.Lookup(name) ?? throw new UnreachableException($"Variable '{name}' not found");
-    }
-
-    public void Declare(string name, Val value)
-    {
-        _variables.Add(name, value);
-    }
-
-    public Scope SubScope()
-    {
-        return new Scope(this);
-    }
-}