From 32ae21d14358a68b0358ccf32ffc7d665d69808b Mon Sep 17 00:00:00 2001
From: Mattia Giambirtone <nocturn9x@nocturn9x.space>
Date: Tue, 7 Mar 2023 11:41:37 +0100
Subject: [PATCH] Forbid use of automatic types in lambdas

---
 .../compiler/targets/bytecode/target.nim      | 46 ++-----------------
 1 file changed, 3 insertions(+), 43 deletions(-)

diff --git a/src/frontend/compiler/targets/bytecode/target.nim b/src/frontend/compiler/targets/bytecode/target.nim
index 1ded887..c2c9224 100644
--- a/src/frontend/compiler/targets/bytecode/target.nim
+++ b/src/frontend/compiler/targets/bytecode/target.nim
@@ -937,45 +937,6 @@ proc prepareAutoFunction(self: BytecodeCompiler, fn: Name, args: seq[tuple[name:
     return fn
 
 
-proc prepareAutoLambda(self: BytecodeCompiler, fn: Type, args: seq[tuple[name: string, kind: Type, default: Expression]]): Type =
-    ## "Prepares" an automatic lambda function
-    ## by instantiating a concrete version of it
-    ## along with its arguments
-    let idx = self.stackIndex
-    self.stackIndex = 1
-    var default: Expression
-    var node = LambdaExpr(fn.fun)
-    var fn = deepCopy(fn)
-    fn.isAuto = false
-    fn.compiled = false
-    # We now declare and typecheck the function's 
-    # arguments
-    for (argument, val) in zip(node.arguments, args):
-        if self.names.high() > 16777215:
-            self.error("cannot declare more than 16777215 variables at a time")
-        inc(self.stackIndex)
-        self.names.add(Name(depth: self.depth + 1,
-                            isPrivate: true,
-                            owner: self.currentModule,
-                            file: self.file,
-                            isConst: false,
-                            ident: argument.name,
-                            valueType: val.kind,
-                            codePos: 0,
-                            isLet: false,
-                            line: argument.name.token.line,
-                            belongsTo: self.currentFunction,
-                            kind: NameKind.Argument,
-                            node: argument.name,
-                            position: self.stackIndex,
-                            isReal: true
-                    ))
-    fn.args = args
-    fn.location = self.stackIndex
-    self.stackIndex = idx
-    return fn
-
-
 proc generateCall(self: BytecodeCompiler, fn: Name, args: seq[Expression], line: int) =
     ## Small wrapper that abstracts emitting a call instruction
     ## for a given function
@@ -1392,10 +1353,7 @@ method call(self: BytecodeCompiler, node: CallExpr, compile: bool = true): Type
         of NodeKind.lambdaExpr:
             var node = LambdaExpr(node.callee)
             var impl = self.lambdaExpr(node, compile=compile)
-            if impl.isAuto:
-                impl = self.prepareAutoLambda(impl, args)
-            result = impl
-            result = result.returnType
+            result = impl.returnType
             if compile:
                 self.generateCall(impl, argExpr, node.token.line)
         else:
@@ -1483,6 +1441,8 @@ method lambdaExpr(self: BytecodeCompiler, node: LambdaExpr, compile: bool = true
                             node: argument.name,
                             position: self.stackIndex
                     )
+        if name.valueType.kind == Auto:
+            self.error("due to current compiler limitations, automatic types cannot be used in lambdas", name.ident)
         if compile:
             self.names.add(name)
             inc(self.stackIndex)