feat(ppx): print unprocessed alert when finding uncurried attribute (…

…#947)
melange-re · Nov 30, 2023 · e883821 · e883821
1 parent 28565d3
commit e883821
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Showing 3 changed files with 44 additions and 6 deletions.
diff --git a/Changes.md b/Changes.md
@@ -78,7 +78,8 @@ Unreleased
 - Introduce an `unprocessed` alert to detect unprocessed Melange code, hinting
   users to preprocess with `melange.ppx`
   ([#911](https://github.com/melange-re/melange/pull/911),
-  [#945](https://github.com/melange-re/melange/pull/945))
+  [#945](https://github.com/melange-re/melange/pull/945),
+  [#947](https://github.com/melange-re/melange/pull/947))
 
 2.1.0 2023-10-22
 ---------------

diff --git a/jscomp/core/mel_ast_invariant.ml b/jscomp/core/mel_ast_invariant.ml
@@ -70,12 +70,24 @@ let emit_external_warnings : Ast_iterator.iterator =
       {
         Warnings.kind = "unprocessed";
         message =
-          "[%@mel.*] attributes found in external declaration. Did you forget \
+          "`[@mel.*]' attributes found in external declaration. Did you forget \
            to preprocess with `melange.ppx'?";
         def = Location.none;
         use = loc;
       }
   in
+  let print_unprocessed_uncurried_alert ~loc =
+    Location.prerr_alert loc
+      {
+        Warnings.kind = "unprocessed";
+        message =
+          "Found uncurried (`[@u]') attribute. Did you forget to preprocess \
+           with `melange.ppx'?";
+        def = Location.none;
+        use = loc;
+      }
+  in
+
   let super = Ast_iterator.default_iterator in
   {
     super with
@@ -89,6 +101,15 @@ let emit_external_warnings : Ast_iterator.iterator =
         | _ -> super.signature_item self sigi);
     expr =
       (fun self a ->
+        (match
+           List.find_opt
+             ~f:(fun { Parsetree.attr_name = { txt; _ }; _ } -> txt = "u")
+             a.pexp_attributes
+         with
+        | Some { attr_name = { loc; _ }; _ } ->
+            print_unprocessed_uncurried_alert ~loc
+        | None -> ());
+
         match a.pexp_desc with
         | Pexp_constant const -> check_constant a.pexp_loc `expr const
         | Pexp_apply ({ pexp_desc = Pexp_ident { txt = Lident op; loc }; _ }, _)

diff --git a/test/blackbox-tests/unprocessed-attributes.t b/test/blackbox-tests/unprocessed-attributes.t
@@ -23,12 +23,13 @@
   File "x.mli", line 2, characters 0-67:
   2 | external some_external : unit -> t = "" [@@mel.module "forgot-ppx"]
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-  Alert unprocessed: [%@mel.*] attributes found in external declaration. Did you forget to preprocess with `melange.ppx'?
+  Alert unprocessed: `[@mel.*]' attributes found in external declaration. Did you forget to preprocess with `melange.ppx'?
   File "x.ml", line 2, characters 0-67:
   2 | external some_external : unit -> t = "" [@@mel.module "forgot-ppx"]
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-  Alert unprocessed: [%@mel.*] attributes found in external declaration. Did you forget to preprocess with `melange.ppx'?
+  Alert unprocessed: `[@mel.*]' attributes found in external declaration. Did you forget to preprocess with `melange.ppx'?
 
+  $ rm x.mli
   $ cat > x.ml <<EOF
   > let () = ref 0 |. incr
   > let () = foo##bar
@@ -37,15 +38,30 @@
   File "x.ml", line 1, characters 15-17:
   1 | let () = ref 0 |. incr
                      ^^
-  Alert unprocessed: [%@mel.*] attributes found in external declaration. Did you forget to preprocess with `melange.ppx'?
+  Alert unprocessed: `[@mel.*]' attributes found in external declaration. Did you forget to preprocess with `melange.ppx'?
 
   File "x.ml", line 2, characters 12-14:
   2 | let () = foo##bar
                   ^^
-  Alert unprocessed: [%@mel.*] attributes found in external declaration. Did you forget to preprocess with `melange.ppx'?
+  Alert unprocessed: `[@mel.*]' attributes found in external declaration. Did you forget to preprocess with `melange.ppx'?
 
   File "x.ml", line 1, characters 15-17:
   1 | let () = ref 0 |. incr
                      ^^
   Error: '|.' is not a valid value identifier.
   [1]
+
+  $ cat > x.ml <<EOF
+  > let x = fun [@u] () -> 42
+  > let y = (x () [@u])
+  > EOF
+  $ dune build @melange
+  File "x.ml", line 1, characters 14-15:
+  1 | let x = fun [@u] () -> 42
+                    ^
+  Alert unprocessed: Found uncurried (`[@u]') attribute. Did you forget to preprocess with `melange.ppx'?
+
+  File "x.ml", line 2, characters 16-17:
+  2 | let y = (x () [@u])
+                      ^
+  Alert unprocessed: Found uncurried (`[@u]') attribute. Did you forget to preprocess with `melange.ppx'?