Fixes bug where input arguments could be shadowed by mem variables.

Author: modlfo

dune-project

@@ -15,7 +15,7 @@
 (package
  (name vult)
  (synopsis "Transcompiler for DSP audio")
- (depends ocaml dune containers pla js_of_ocaml js_of_ocaml-ppx ounit yojson)
+ (depends ocaml dune containers pla js_of_ocaml js_of_ocaml-ppx ounit yojson (ocamlformat (= "0.27.0")))
 )
 
 ; removes the Dune__exe prefix

runtime/vultin.cpp

@@ -152,7 +152,7 @@ fix16_t fix_random() {
   return (fix16_t)temp;
 }
 
-int irandom() { return (int)rand(); }
+int int_random() { return (int)rand(); }
 
 void float_print(float value) { printf("%f\n", value); }
 void fix_print(fix16_t value) { printf("%f\n", fix_to_float(value)); }

runtime/vultin.hpp

@@ -205,7 +205,7 @@ static_inline int16_t *int16_wrap_array(const int16_t x[]) { return (int16_t *)x
 /* Random numbers */
 float float_random();
 fix16_t fix_random();
-int irandom();
+int int_random();
 
 /* Print values */
 void float_print(float value);

src/core/env.ml

@@ -454,6 +454,26 @@ let checkDuplicatedVal (locals : var Map.t list) (name : string) (loc : Loc.t) :
     locals
 
 
+(* Helper: Check if any argument names conflict with mem variables in the context *)
+let checkArgumentsAgainstContext (context : context) (args : Typed.arg list) : unit =
+  match context with
+  | Some (_, { descr = Record members; _ }) ->
+    CCList.iter
+      (fun ({ name; loc; _ } : Typed.arg) ->
+        match Map.find name members with
+        | None -> ()
+        | Some found ->
+          Error.raiseError
+            ("Function parameter '"
+            ^ name
+            ^ "' shadows a mem variable declared at "
+            ^ Loc.to_string_readable found.loc
+            ^ ". Rename the parameter or the mem variable to avoid this conflict.")
+            loc)
+      args
+  | _ -> ()
+
+
 (* Helper: Create a reporter for mem variable updates that handles type unification *)
 let makeMemReporter (unify : Typed.type_ -> Typed.type_ -> bool) (t : Typed.type_) (found : var) (value : var) : var =
   if unify found.t t then
@@ -689,6 +709,7 @@ let enterFunction (env : env) (name : string) (args : Typed.arg list) (ret : Typ
     env * path * (Typed.type_ list * Typed.type_) =
   let m = getCurrentModule env in
   let context = getCurrentContext env in
+  let () = checkArgumentsAgainstContext context args in
   let report (found : f) =
     Error.raiseError ("A function with the name '" ^ found.path.id ^ "' has already been declared.") loc
   in

test/errors/error46.base

@@ -0,0 +1,4 @@
+Function parameter 'value' shadows a mem variable declared at line 2, columns 7-12. Rename the parameter or the mem variable to avoid this conflict.
+}
+and helper(value:bool) : real {
+           ^^^^^

test/errors/error46.vult

@@ -0,0 +1,8 @@
+fun process(input:real) {
+   mem value;
+   value = input;
+}
+and helper(value:bool) : real {
+   if (value) return 1.0;
+   else return 0.0;
+}

test/test.ml

@@ -149,6 +149,7 @@ let errors_files =
   ; "error43.vult"
   ; "error44.vult"
   ; "error45.vult"
+  ; "error46.vult"
   ]
 
 

vult.opam

@@ -15,6 +15,7 @@ depends: [
   "js_of_ocaml-ppx"
   "ounit"
   "yojson"
+  "ocamlformat" {= "0.27.0"}
   "odoc" {with-doc}
 ]
 build: [