From 1ee1e7b29b098b190895cdcaa5651bcd5a587335 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Vouillon?= <jerome.vouillon@gmail.com>
Date: Tue, 17 Dec 2024 18:23:43 +0100
Subject: [PATCH 1/5] Wasm AST: add extern.convert_any

---
 compiler/lib-wasm/code_generation.ml   | 3 ++-
 compiler/lib-wasm/gc_target.ml         | 3 ++-
 compiler/lib-wasm/initialize_locals.ml | 3 ++-
 compiler/lib-wasm/wasm_ast.ml          | 1 +
 compiler/lib-wasm/wasm_output.ml       | 8 +++++++-
 compiler/lib-wasm/wat_output.ml        | 1 +
 6 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/compiler/lib-wasm/code_generation.ml b/compiler/lib-wasm/code_generation.ml
index cd23a3db7e..03f279eb6b 100644
--- a/compiler/lib-wasm/code_generation.ml
+++ b/compiler/lib-wasm/code_generation.ml
@@ -453,7 +453,8 @@ let rec is_smi e =
   | RefNull _
   | Br_on_cast _
   | Br_on_cast_fail _
-  | Try _ -> false
+  | Try _
+  | ExternConvertAny _ -> false
   | BinOp ((F32 _ | F64 _), _, _) | RefTest _ | RefEq _ -> true
   | IfExpr (_, _, ift, iff) -> is_smi ift && is_smi iff
 
diff --git a/compiler/lib-wasm/gc_target.ml b/compiler/lib-wasm/gc_target.ml
index cd82902c31..6ae3a48b6c 100644
--- a/compiler/lib-wasm/gc_target.ml
+++ b/compiler/lib-wasm/gc_target.ml
@@ -513,7 +513,8 @@ module Value = struct
     | ArrayLen e'
     | StructGet (_, _, _, e')
     | RefCast (_, e')
-    | RefTest (_, e') -> effect_free e'
+    | RefTest (_, e')
+    | ExternConvertAny e' -> effect_free e'
     | BinOp (_, e1, e2)
     | ArrayNew (_, e1, e2)
     | ArrayNewData (_, _, e1, e2)
diff --git a/compiler/lib-wasm/initialize_locals.ml b/compiler/lib-wasm/initialize_locals.ml
index 5e15235725..c4ecfe8c4e 100644
--- a/compiler/lib-wasm/initialize_locals.ml
+++ b/compiler/lib-wasm/initialize_locals.ml
@@ -46,7 +46,8 @@ let rec scan_expression ctx e =
   | RefCast (_, e')
   | RefTest (_, e')
   | Br_on_cast (_, _, _, e')
-  | Br_on_cast_fail (_, _, _, e') -> scan_expression ctx e'
+  | Br_on_cast_fail (_, _, _, e')
+  | ExternConvertAny e' -> scan_expression ctx e'
   | BinOp (_, e', e'')
   | ArrayNew (_, e', e'')
   | ArrayNewData (_, _, e', e'')
diff --git a/compiler/lib-wasm/wasm_ast.ml b/compiler/lib-wasm/wasm_ast.ml
index a23addc4a2..9ca66d6578 100644
--- a/compiler/lib-wasm/wasm_ast.ml
+++ b/compiler/lib-wasm/wasm_ast.ml
@@ -166,6 +166,7 @@ type expression =
   | Br_on_cast_fail of int * ref_type * ref_type * expression
   | IfExpr of value_type * expression * expression * expression
   | Try of func_type * instruction list * (var * int * value_type) list
+  | ExternConvertAny of expression
 
 and instruction =
   | Drop of expression
diff --git a/compiler/lib-wasm/wasm_output.ml b/compiler/lib-wasm/wasm_output.ml
index febd2c650e..78f38b9ac0 100644
--- a/compiler/lib-wasm/wasm_output.ml
+++ b/compiler/lib-wasm/wasm_output.ml
@@ -658,6 +658,11 @@ end = struct
             output_instruction st ch (Br (l + 1, Some (Pop ty))))
           catches;
         output_byte ch 0X0B
+    | ExternConvertAny e' ->
+        Feature.require gc;
+        output_expression st ch e';
+        output_byte ch 0xFB;
+        output_byte ch 0x1B
 
   and output_instruction st ch i =
     match i with
@@ -871,7 +876,8 @@ end = struct
     | RefCast (_, e')
     | RefTest (_, e')
     | Br_on_cast (_, _, _, e')
-    | Br_on_cast_fail (_, _, _, e') -> expr_function_references e' set
+    | Br_on_cast_fail (_, _, _, e')
+    | ExternConvertAny e' -> expr_function_references e' set
     | BinOp (_, e', e'')
     | ArrayNew (_, e', e'')
     | ArrayNewData (_, _, e', e'')
diff --git a/compiler/lib-wasm/wat_output.ml b/compiler/lib-wasm/wat_output.ml
index 27c2307801..cc332d7d87 100644
--- a/compiler/lib-wasm/wat_output.ml
+++ b/compiler/lib-wasm/wat_output.ml
@@ -457,6 +457,7 @@ let expression_or_instructions ctx st in_function =
                              @ instruction (Wasm_ast.Br (i + 1, Some (Pop ty))))))
                       catches))
         ]
+    | ExternConvertAny e' -> [ List (Atom "extern.convert_any" :: expression e') ]
   and instruction i =
     match i with
     | Drop e -> [ List (Atom "drop" :: expression e) ]

From 06c5e7e0b02d2d080923d8504f484b4426f9b72a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Vouillon?= <jerome.vouillon@gmail.com>
Date: Fri, 4 Apr 2025 16:41:16 +0200
Subject: [PATCH 2/5] Wasm AST: add unreachable

---
 compiler/lib-wasm/initialize_locals.ml | 2 +-
 compiler/lib-wasm/tail_call.ml         | 1 +
 compiler/lib-wasm/wasm_ast.ml          | 1 +
 compiler/lib-wasm/wasm_output.ml       | 3 ++-
 compiler/lib-wasm/wat_output.ml        | 1 +
 5 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/compiler/lib-wasm/initialize_locals.ml b/compiler/lib-wasm/initialize_locals.ml
index c4ecfe8c4e..d359f3bda3 100644
--- a/compiler/lib-wasm/initialize_locals.ml
+++ b/compiler/lib-wasm/initialize_locals.ml
@@ -95,7 +95,7 @@ and scan_instruction ctx i =
       scan_instructions ctx l;
       scan_instructions ctx l'
   | CallInstr (_, l) | Return_call (_, l) -> scan_expressions ctx l
-  | Br (_, None) | Return None | Rethrow _ | Nop | Event _ -> ()
+  | Br (_, None) | Return None | Rethrow _ | Nop | Unreachable | Event _ -> ()
   | ArraySet (_, e, e', e'') ->
       scan_expression ctx e;
       scan_expression ctx e';
diff --git a/compiler/lib-wasm/tail_call.ml b/compiler/lib-wasm/tail_call.ml
index dfaadad9da..b52142d72d 100644
--- a/compiler/lib-wasm/tail_call.ml
+++ b/compiler/lib-wasm/tail_call.ml
@@ -59,6 +59,7 @@ let rec instruction ~tail i =
   | StructSet _
   | Return_call _
   | Return_call_ref _
+  | Unreachable
   | Event _ -> i
 
 and instructions ~tail l =
diff --git a/compiler/lib-wasm/wasm_ast.ml b/compiler/lib-wasm/wasm_ast.ml
index 9ca66d6578..b1518d1f1c 100644
--- a/compiler/lib-wasm/wasm_ast.ml
+++ b/compiler/lib-wasm/wasm_ast.ml
@@ -188,6 +188,7 @@ and instruction =
   | StructSet of var * int * expression * expression
   | Return_call of var * expression list
   | Return_call_ref of var * expression * expression list
+  | Unreachable
   | Event of Parse_info.t  (** Location information *)
 
 type import_desc =
diff --git a/compiler/lib-wasm/wasm_output.ml b/compiler/lib-wasm/wasm_output.ml
index 78f38b9ac0..1d1e84d412 100644
--- a/compiler/lib-wasm/wasm_output.ml
+++ b/compiler/lib-wasm/wasm_output.ml
@@ -759,6 +759,7 @@ end = struct
         output_expression st ch e';
         output_byte ch 0x15;
         output_uint ch (Hashtbl.find st.type_names typ)
+    | Unreachable -> output_byte ch 0x00
     | Event _ -> ()
 
   let output_globals ch (st, global_idx, fields) =
@@ -940,7 +941,7 @@ end = struct
           ~f:(fun set i -> expr_function_references i set)
           ~init:(expr_function_references e' set)
           l
-    | Event _ -> set
+    | Unreachable | Event _ -> set
 
   let function_references fields set =
     List.fold_left
diff --git a/compiler/lib-wasm/wat_output.ml b/compiler/lib-wasm/wat_output.ml
index cc332d7d87..00759f7e89 100644
--- a/compiler/lib-wasm/wat_output.ml
+++ b/compiler/lib-wasm/wat_output.ml
@@ -535,6 +535,7 @@ let expression_or_instructions ctx st in_function =
             :: index st.type_names typ
             :: List.concat (List.map ~f:expression (l @ [ e ])))
         ]
+    | Unreachable -> [ List [ Atom "unreachable" ] ]
     | Event Parse_info.{ src = None | Some ""; _ } -> [ Comment "@" ]
     | Event Parse_info.{ src = Some src; col; line; _ } ->
         let loc = Format.sprintf "%s:%d:%d" src line col in

From 21b546abc57354500f1ea427c74c56369e9df2af Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Vouillon?= <jerome.vouillon@gmail.com>
Date: Fri, 28 Mar 2025 17:38:36 +0100
Subject: [PATCH 3/5] Wasm AST: add heap types 'struct', 'array' and 'none'

---
 compiler/lib-wasm/code_generation.ml | 31 +++++++++++++++++++++++-----
 compiler/lib-wasm/gc_target.ml       |  2 +-
 compiler/lib-wasm/wasm_ast.ml        |  3 +++
 compiler/lib-wasm/wasm_output.ml     |  4 ++++
 compiler/lib-wasm/wat_output.ml      |  3 +++
 5 files changed, 37 insertions(+), 6 deletions(-)

diff --git a/compiler/lib-wasm/code_generation.ml b/compiler/lib-wasm/code_generation.ml
index 03f279eb6b..5669b9ccb2 100644
--- a/compiler/lib-wasm/code_generation.ml
+++ b/compiler/lib-wasm/code_generation.ml
@@ -161,10 +161,31 @@ let heap_type_sub (ty : W.heap_type) (ty' : W.heap_type) st =
   match ty, ty' with
   | Func, Func
   | Extern, Extern
-  | (Any | Eq | I31 | Type _), Any
-  | (Eq | I31 | Type _), Eq
-  | I31, I31 -> true, st
+  | (Any | Eq | Struct | Array | I31 | None_ | Type _), Any
+  | (Eq | Struct | Array | I31 | None_ | Type _), Eq
+  | (None_ | Struct), Struct -> true, st
+  | (None_ | Array), Array -> true, st
+  | (None_ | I31), I31 -> true, st
+  | None_, None_ -> true, st
+  | Type t, Struct ->
+      ( (let type_field = Hashtbl.find st.context.types t in
+         match type_field.typ with
+         | Struct _ -> true
+         | Array _ | Func _ -> false)
+      , st )
+  | Type t, Array ->
+      ( (let type_field = Hashtbl.find st.context.types t in
+         match type_field.typ with
+         | Array _ -> true
+         | Struct _ | Func _ -> false)
+      , st )
   | Type t, Type t' -> type_index_sub t t' st
+  | None_, Type t ->
+      ( (let type_field = Hashtbl.find st.context.types t in
+         match type_field.typ with
+         | Struct _ | Array _ -> true
+         | Func _ -> false)
+      , st )
   (* Func and Extern are only in suptyping relation with themselves *)
   | Func, _
   | _, Func
@@ -172,8 +193,8 @@ let heap_type_sub (ty : W.heap_type) (ty' : W.heap_type) st =
   | _, Extern
   (* Any has no supertype *)
   | Any, _
-  (* I31, struct and arrays have no subtype (of a different kind) *)
-  | _, (I31 | Type _) -> false, st
+  (* I31, struct, array and none have no other subtype *)
+  | _, (I31 | Type _ | Struct | Array | None_) -> false, st
 
 let register_global name ?exported_name ?(constant = false) typ init st =
   st.context.other_fields <-
diff --git a/compiler/lib-wasm/gc_target.ml b/compiler/lib-wasm/gc_target.ml
index 6ae3a48b6c..8d44ab7630 100644
--- a/compiler/lib-wasm/gc_target.ml
+++ b/compiler/lib-wasm/gc_target.ml
@@ -479,7 +479,7 @@ module Value = struct
     | W.RefI31 _ -> (
         match typ.typ with
         | W.I31 | Eq | Any -> return (W.Const (I32 1l))
-        | Type _ | Func | Extern -> return (W.Const (I32 0l)))
+        | Struct | Array | Type _ | None_ | Func | Extern -> return (W.Const (I32 0l)))
     | GlobalGet nm -> (
         let* init = get_global nm in
         match init with
diff --git a/compiler/lib-wasm/wasm_ast.ml b/compiler/lib-wasm/wasm_ast.ml
index b1518d1f1c..980acc01c2 100644
--- a/compiler/lib-wasm/wasm_ast.ml
+++ b/compiler/lib-wasm/wasm_ast.ml
@@ -27,7 +27,10 @@ type heap_type =
   | Extern
   | Any
   | Eq
+  | Struct
+  | Array
   | I31
+  | None_
   | Type of var
 
 type ref_type =
diff --git a/compiler/lib-wasm/wasm_output.ml b/compiler/lib-wasm/wasm_output.ml
index 1d1e84d412..35a246d493 100644
--- a/compiler/lib-wasm/wasm_output.ml
+++ b/compiler/lib-wasm/wasm_output.ml
@@ -172,13 +172,17 @@ end = struct
     res
 
   (****)
+
   let output_heaptype type_names ch typ =
     match (typ : heap_type) with
+    | None_ -> output_byte ch 0x71
     | Func -> output_byte ch 0x70
     | Extern -> output_byte ch 0x6F
     | Any -> output_byte ch 0x6E
     | Eq -> output_byte ch 0x6D
     | I31 -> output_byte ch 0x6C
+    | Struct -> output_byte ch 0x6B
+    | Array -> output_byte ch 0x6A
     | Type nm -> output_sint ch (Hashtbl.find type_names nm)
 
   let output_valtype type_names ch (typ : value_type) =
diff --git a/compiler/lib-wasm/wat_output.ml b/compiler/lib-wasm/wat_output.ml
index 00759f7e89..e511791ec0 100644
--- a/compiler/lib-wasm/wat_output.ml
+++ b/compiler/lib-wasm/wat_output.ml
@@ -150,7 +150,10 @@ let heap_type st (ty : heap_type) =
   | Extern -> Atom "extern"
   | Any -> Atom "any"
   | Eq -> Atom "eq"
+  | Struct -> Atom "struct"
+  | Array -> Atom "array"
   | I31 -> Atom "i31"
+  | None_ -> Atom "none"
   | Type t -> index st.type_names t
 
 let ref_type st { nullable; typ } =

From b9c03081ec750f3a7a688d37f1c8b5f25e05a261 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Vouillon?= <jerome.vouillon@gmail.com>
Date: Fri, 4 Apr 2025 16:56:34 +0200
Subject: [PATCH 4/5] Wasm AST: possibility to provide an explicit function
 type

---
 compiler/lib-wasm/curry.ml       | 63 ++++++++++++++++++++++++++++----
 compiler/lib-wasm/generate.ml    | 25 ++++++++++---
 compiler/lib-wasm/wasm_ast.ml    |  3 +-
 compiler/lib-wasm/wasm_output.ml |  9 +++--
 compiler/lib-wasm/wat_output.ml  | 11 ++++--
 5 files changed, 90 insertions(+), 21 deletions(-)

diff --git a/compiler/lib-wasm/curry.ml b/compiler/lib-wasm/curry.ml
index 0d96ad5cb9..f383d55da5 100644
--- a/compiler/lib-wasm/curry.ml
+++ b/compiler/lib-wasm/curry.ml
@@ -102,7 +102,14 @@ module Make (Target : Target_sig.S) = struct
     let param_names = args @ [ f ] in
     let locals, body = function_body ~context ~param_names ~body in
     W.Function
-      { name; exported_name = None; typ = func_type 1; param_names; locals; body }
+      { name
+      ; exported_name = None
+      ; typ = None
+      ; signature = func_type 1
+      ; param_names
+      ; locals
+      ; body
+      }
 
   let curry_name n m = Printf.sprintf "curry_%d_%d" n m
 
@@ -130,7 +137,14 @@ module Make (Target : Target_sig.S) = struct
     let param_names = [ x; f ] in
     let locals, body = function_body ~context ~param_names ~body in
     W.Function
-      { name; exported_name = None; typ = func_type 1; param_names; locals; body }
+      { name
+      ; exported_name = None
+      ; typ = None
+      ; signature = func_type 1
+      ; param_names
+      ; locals
+      ; body
+      }
     :: functions
 
   let curry ~arity ~name = curry ~arity arity ~name
@@ -174,7 +188,14 @@ module Make (Target : Target_sig.S) = struct
     let param_names = args @ [ f ] in
     let locals, body = function_body ~context ~param_names ~body in
     W.Function
-      { name; exported_name = None; typ = func_type 2; param_names; locals; body }
+      { name
+      ; exported_name = None
+      ; typ = None
+      ; signature = func_type 2
+      ; param_names
+      ; locals
+      ; body
+      }
 
   let cps_curry_name n m = Printf.sprintf "cps_curry_%d_%d" n m
 
@@ -206,7 +227,14 @@ module Make (Target : Target_sig.S) = struct
     let param_names = [ x; cont; f ] in
     let locals, body = function_body ~context ~param_names ~body in
     W.Function
-      { name; exported_name = None; typ = func_type 2; param_names; locals; body }
+      { name
+      ; exported_name = None
+      ; typ = None
+      ; signature = func_type 2
+      ; param_names
+      ; locals
+      ; body
+      }
     :: functions
 
   let cps_curry ~arity ~name = cps_curry ~arity arity ~name
@@ -243,7 +271,14 @@ module Make (Target : Target_sig.S) = struct
     let param_names = l @ [ f ] in
     let locals, body = function_body ~context ~param_names ~body in
     W.Function
-      { name; exported_name = None; typ = func_type arity; param_names; locals; body }
+      { name
+      ; exported_name = None
+      ; typ = None
+      ; signature = func_type arity
+      ; param_names
+      ; locals
+      ; body
+      }
 
   let cps_apply ~context ~arity ~name =
     assert (arity > 2);
@@ -283,7 +318,14 @@ module Make (Target : Target_sig.S) = struct
     let param_names = l @ [ f ] in
     let locals, body = function_body ~context ~param_names ~body in
     W.Function
-      { name; exported_name = None; typ = func_type arity; param_names; locals; body }
+      { name
+      ; exported_name = None
+      ; typ = None
+      ; signature = func_type arity
+      ; param_names
+      ; locals
+      ; body
+      }
 
   let dummy ~context ~cps ~arity ~name =
     let arity = if cps then arity + 1 else arity in
@@ -311,7 +353,14 @@ module Make (Target : Target_sig.S) = struct
     let param_names = l @ [ f ] in
     let locals, body = function_body ~context ~param_names ~body in
     W.Function
-      { name; exported_name = None; typ = func_type arity; param_names; locals; body }
+      { name
+      ; exported_name = None
+      ; typ = None
+      ; signature = func_type arity
+      ; param_names
+      ; locals
+      ; body
+      }
 
   let f ~context =
     IntMap.iter
diff --git a/compiler/lib-wasm/generate.ml b/compiler/lib-wasm/generate.ml
index 45f76c6f27..6cae2506b4 100644
--- a/compiler/lib-wasm/generate.ml
+++ b/compiler/lib-wasm/generate.ml
@@ -1055,8 +1055,9 @@ module Generate (Target : Target_sig.S) = struct
           (match name_opt with
           | None -> Option.map ~f:(fun name -> name ^ ".init") unit_name
           | Some _ -> None)
+      ; typ = None
+      ; signature = func_type param_count
       ; param_names
-      ; typ = func_type param_count
       ; locals
       ; body
       }
@@ -1064,7 +1065,7 @@ module Generate (Target : Target_sig.S) = struct
 
   let init_function ~context ~to_link =
     let name = Code.Var.fresh_n "initialize" in
-    let typ = { W.params = []; result = [ Value.value ] } in
+    let signature = { W.params = []; result = [ Value.value ] } in
     let locals, body =
       function_body
         ~context
@@ -1073,7 +1074,10 @@ module Generate (Target : Target_sig.S) = struct
           (List.fold_right
              ~f:(fun name cont ->
                let* f =
-                 register_import ~import_module:"OCaml" ~name:(name ^ ".init") (Fun typ)
+                 register_import
+                   ~import_module:"OCaml"
+                   ~name:(name ^ ".init")
+                   (Fun signature)
                in
                let* () = instr (Drop (Call (f, []))) in
                cont)
@@ -1081,17 +1085,26 @@ module Generate (Target : Target_sig.S) = struct
              to_link)
     in
     context.other_fields <-
-      W.Function { name; exported_name = None; typ; param_names = []; locals; body }
+      W.Function
+        { name
+        ; exported_name = None
+        ; typ = None
+        ; signature
+        ; param_names = []
+        ; locals
+        ; body
+        }
       :: context.other_fields;
     name
 
   let entry_point context toplevel_fun entry_name =
-    let typ, param_names, body = entry_point ~toplevel_fun in
+    let signature, param_names, body = entry_point ~toplevel_fun in
     let locals, body = function_body ~context ~param_names ~body in
     W.Function
       { name = Var.fresh_n "entry_point"
       ; exported_name = Some entry_name
-      ; typ
+      ; typ = None
+      ; signature
       ; param_names
       ; locals
       ; body
diff --git a/compiler/lib-wasm/wasm_ast.ml b/compiler/lib-wasm/wasm_ast.ml
index 980acc01c2..d50325fff2 100644
--- a/compiler/lib-wasm/wasm_ast.ml
+++ b/compiler/lib-wasm/wasm_ast.ml
@@ -210,7 +210,8 @@ type module_field =
   | Function of
       { name : var
       ; exported_name : string option
-      ; typ : func_type
+      ; typ : var option
+      ; signature : func_type
       ; param_names : var list
       ; locals : (var * value_type) list
       ; body : instruction list
diff --git a/compiler/lib-wasm/wasm_output.ml b/compiler/lib-wasm/wasm_output.ml
index 35a246d493..408dc538bd 100644
--- a/compiler/lib-wasm/wasm_output.ml
+++ b/compiler/lib-wasm/wasm_output.ml
@@ -220,10 +220,13 @@ end = struct
     List.fold_left
       ~f:(fun acc field ->
         match field with
-        | Function { typ; _ } | Import { desc = Fun typ; _ } -> func_type acc typ
+        | Function { typ = None; signature; _ } | Import { desc = Fun signature; _ } ->
+            func_type acc signature
         | Import { desc = Tag typ; _ } -> func_type acc { params = [ typ ]; result = [] }
         | Type l -> explicit_definition acc l
-        | Import { desc = Global _; _ } | Data _ | Global _ | Tag _ -> acc)
+        | Function { typ = Some _; _ }
+        | Import { desc = Global _; _ }
+        | Data _ | Global _ | Tag _ -> acc)
       ~init:acc
       fields
 
@@ -338,7 +341,7 @@ end = struct
       List.fold_left
         ~f:(fun acc field ->
           match field with
-          | Function { typ; _ } -> typ :: acc
+          | Function { signature; _ } -> signature :: acc
           | Type _ | Import _ | Data _ | Global _ | Tag _ -> acc)
         ~init:[]
         fields
diff --git a/compiler/lib-wasm/wat_output.ml b/compiler/lib-wasm/wat_output.ml
index e511791ec0..714138033f 100644
--- a/compiler/lib-wasm/wat_output.ml
+++ b/compiler/lib-wasm/wat_output.ml
@@ -550,7 +550,7 @@ let expression ctx st = fst (expression_or_instructions ctx st false)
 
 let instructions ctx st = snd (expression_or_instructions ctx st true)
 
-let funct ctx st name exported_name typ param_names locals body =
+let funct ctx st name exported_name typ signature param_names locals body =
   let st =
     { st with
       local_names =
@@ -562,7 +562,10 @@ let funct ctx st name exported_name typ param_names locals body =
   in
   List
     ((Atom "func" :: index st.func_names name :: export exported_name)
-    @ func_type st ~param_names typ
+    @ (match typ with
+      | None -> []
+      | Some typ -> [ List [ Atom "type"; index st.type_names typ ] ])
+    @ func_type st ~param_names signature
     @ List.map
         ~f:(fun (i, t) -> List [ Atom "local"; index st.local_names i; value_type st t ])
         locals
@@ -617,8 +620,8 @@ let type_field st { name; typ; supertype; final } =
 
 let field ctx st f =
   match f with
-  | Function { name; exported_name; typ; param_names; locals; body } ->
-      [ funct ctx st name exported_name typ param_names locals body ]
+  | Function { name; exported_name; typ; signature; param_names; locals; body } ->
+      [ funct ctx st name exported_name typ signature param_names locals body ]
   | Global { name; exported_name; typ; init } ->
       [ List
           (Atom "global"

From 926ecb3dc09a6433edff99d9cbe2ec69c03d8263 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Vouillon?= <jerome.vouillon@gmail.com>
Date: Fri, 4 Apr 2025 16:32:13 +0200
Subject: [PATCH 5/5] Wasm linker: fix parsing of recursive groups of types

The initial size of that type mapping table is the number of entry in
the type section. Since a recursive group entry corresponds to one entry
but can contain several types, we may have to resize it.
---
 compiler/lib-wasm/wasm_link.ml | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/compiler/lib-wasm/wasm_link.ml b/compiler/lib-wasm/wasm_link.ml
index a53fc34a4d..6026ce1683 100644
--- a/compiler/lib-wasm/wasm_link.ml
+++ b/compiler/lib-wasm/wasm_link.ml
@@ -697,6 +697,12 @@ module Read = struct
         let pos = st.type_index_count in
         let pos' = add_rectype types ty in
         let count = Array.length ty in
+        let len = Array.length st.type_mapping in
+        if pos + count > len
+        then (
+          let m = Array.make (len + (len / 5) + count) 0 in
+          Array.blit ~src:st.type_mapping ~src_pos:0 ~dst:m ~dst_pos:0 ~len;
+          st.type_mapping <- m);
         for i = 0 to count - 1 do
           st.type_mapping.(pos + i) <- pos' + i
         done;