From 0093476a2c89f97e2eb467a184b44634f0123c2d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Hillerstr=C3=B6m?= <daniel.hillerstrom@ed.ac.uk>
Date: Thu, 25 Jan 2024 11:24:55 +0100
Subject: [PATCH] Resolve #17

This patch (re)installs the check for continuation type
well-formedness.

Currently, it allows only continuation types to be indexed by plain
function types.
---
 interpreter/valid/valid.ml | 4 +++-
 test/core/cont.wast        | 5 +++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/interpreter/valid/valid.ml b/interpreter/valid/valid.ml
index 9bb1459412..bb31ea8362 100644
--- a/interpreter/valid/valid.ml
+++ b/interpreter/valid/valid.ml
@@ -183,7 +183,9 @@ let check_func_type (c : context) (ft : func_type) at =
 
 let check_cont_type (c : context) (ct : cont_type) at =
   match ct with
-  | ContT ft -> check_heap_type c ft at
+  | ContT (VarHT (StatX x)) ->
+     let _dt = func_type c (x @@ at) in ()
+  | _ -> error at "ill-formed continuation type"
 
 let check_table_type (c : context) (tt : table_type) at =
   let TableT (lim, t) = tt in
diff --git a/test/core/cont.wast b/test/core/cont.wast
index c3ce4b18b8..6649917fe1 100644
--- a/test/core/cont.wast
+++ b/test/core/cont.wast
@@ -205,6 +205,11 @@
       (drop)))
   "non-continuation type 0")
 
+(assert_invalid
+  (module
+    (type $ct (cont $ct)))
+  "non-function type 0")
+
 ;; Simple state example
 
 (module $state