Improve Unused Declaration Detection (Switch/Catch Clauses, No Warnin…

…gs on Type Check Errors) (#4560) Fix for issue: #4508 * Correctly detect used and unused declaration in switch and try-catch clauses. Only warn on unused identifiers if type-checking is error-free (#4561) * Avoid potential spurious cascading warnings in the presence of type checker errors. Updated: * Expected warnings in Motoko test cases. * Refactoring of the Motoko base library to comply with the improved detection: dfinity/motoko-base#636
dfinity · Jun 7, 2024 · b88253d · b88253d
1 parent c899462
commit b88253d
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diff --git a/Changelog.md b/Changelog.md
@@ -1,5 +1,12 @@
 # Motoko compiler changelog
 
+## 0.11.2 (to come)
+
+* motoko (`moc`)
+
+  * bugfix: Fix the detection of unused declarations in switch and catch cases (#4560).
+  * improvement: Only warn on unused identifiers if type checking is error-free (#4560).
+
 ## 0.11.1 (2024-03-15)
 
 * motoko (`moc`)

diff --git a/src/lang_utils/diag.ml b/src/lang_utils/diag.ml
@@ -57,7 +57,7 @@ let add_msgs s ms = s := List.rev ms @ !s
 let get_msgs s = List.rev !s
 
 let has_errors : messages -> bool =
-  List.fold_left (fun b msg -> b || msg.sev == Error) false
+  List.exists (fun msg -> msg.sev == Error)
 
 let string_of_message msg =
   let code = match msg.sev, msg.code with
@@ -77,6 +77,8 @@ let print_message msg =
 
 let print_messages = List.iter print_message
 
+let is_error_free (ms: msg_store) = not (has_errors (get_msgs ms))
+
 let with_message_store f =
   let s = ref [] in
   let r = f s in

diff --git a/src/lang_utils/diag.mli b/src/lang_utils/diag.mli
@@ -57,6 +57,7 @@ the reported messages contain an error.
 *)
 
 type msg_store
+val is_error_free : msg_store -> bool
 val add_msg : msg_store -> message -> unit
 val add_msgs : msg_store -> messages -> unit
 val with_message_store : (msg_store -> 'a option) -> 'a result

diff --git a/src/mo_frontend/typing.ml b/src/mo_frontend/typing.ml
@@ -205,7 +205,7 @@ let ignore_warning_for_id id =
     false
 
 let detect_unused env inner_identifiers =
-  if env.check_unused then
+  if not env.pre && env.check_unused then
     T.Env.iter (fun id (_, at, kind) ->
       if (not (ignore_warning_for_id id)) && (is_unused_identifier env id) then
         add_unused_warning env (id, at, kind)
@@ -1998,8 +1998,11 @@ and check_cases env t_pat t cases =
 
 and check_case env t_pat t case =
   let {pat; exp} = case.it in
+  let initial_usage = enter_scope env in
   let ve = check_pat env t_pat pat in
-  recover (check_exp (adjoin_vals env ve) t) exp
+  let t' = recover (check_exp (adjoin_vals env ve) t) exp in
+  leave_scope env ve initial_usage;
+  t'
 
 and inconsistent t ts =
   T.opaque t && not (List.exists T.opaque ts)
@@ -2931,7 +2934,7 @@ let infer_prog scope pkg_opt async_cap prog : (T.typ * Scope.t) Diag.result =
              env0 with async = async_cap;
           } in
           let res = infer_block env prog.it prog.at true in
-          if pkg_opt = None then emit_unused_warnings env;
+          if pkg_opt = None && Diag.is_error_free msgs then emit_unused_warnings env;
           res
         ) prog
     )
@@ -3011,7 +3014,7 @@ let check_lib scope pkg_opt lib : Scope.t Diag.result =
               (* this shouldn't really happen, as an imported program should be rewritten to a module *)
               error env cub.at "M0000" "compiler bug: expected a module or actor class but found a program, i.e. a sequence of declarations"
           in
-          if pkg_opt = None then emit_unused_warnings env;
+          if pkg_opt = None && Diag.is_error_free msgs then emit_unused_warnings env;
           Scope.lib lib.note.filename imp_typ
         ) lib
     )

diff --git a/...un-drun/ignore-unused-actor-identifier.mo → test/fail/ignore-unused-actor-identifier.mo b/...un-drun/ignore-unused-actor-identifier.mo → test/fail/ignore-unused-actor-identifier.mo
diff --git a/test/fail/ok/M0127.tc.ok b/test/fail/ok/M0127.tc.ok
@@ -2,4 +2,3 @@ M0127.mo:2.3-2.40: type error [M0127], system function preupgrade is declared wi
   <system>Bool -> ()
 instead of expected type
   <system>() -> ()
-M0127.mo:2.26-2.29: warning [M0194], unused identifier foo (delete or rename to wildcard `_` or `_foo`)
diff --git a/test/fail/ok/abstract-msgs.tc.ok b/test/fail/ok/abstract-msgs.tc.ok
@@ -14,8 +14,3 @@ abstract-msgs.mo:16.34-16.35: type error [M0031], shared function has non-shared
   A__16
 abstract-msgs.mo:17.27-17.47: type error [M0032], shared function has non-shared return type
   A__17
-abstract-msgs.mo:2.33-2.34: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
-abstract-msgs.mo:4.11-4.14: warning [M0194], unused identifier foo (delete or rename to wildcard `_` or `_foo`)
-abstract-msgs.mo:5.25-5.26: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
-abstract-msgs.mo:23.38-23.41: warning [M0194], unused identifier bar (delete or rename to wildcard `_` or `_bar`)
-abstract-msgs.mo:23.42-23.43: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)
diff --git a/test/fail/ok/argument-subtyping.tc.ok b/test/fail/ok/argument-subtyping.tc.ok
@@ -2,7 +2,3 @@ argument-subtyping.mo:12.61-12.62: type error [M0096], expression of type
   shared Nat -> ()
 cannot produce expected type
   shared Text -> ()
-argument-subtyping.mo:2.11-2.14: warning [M0194], unused identifier foo (delete or rename to wildcard `_` or `_foo`)
-argument-subtyping.mo:5.11-5.14: warning [M0194], unused identifier foo (delete or rename to wildcard `_` or `_foo`)
-argument-subtyping.mo:8.11-8.14: warning [M0194], unused identifier foo (delete or rename to wildcard `_` or `_foo`)
-argument-subtyping.mo:9.11-9.14: warning [M0194], unused identifier foo (delete or rename to wildcard `_` or `_foo`)
diff --git a/test/fail/ok/asyncret2.tc.ok b/test/fail/ok/asyncret2.tc.ok
@@ -2,4 +2,3 @@ asyncret2.mo:1.54-1.57: type error [M0096], expression of type
   async<$call3> Int
 cannot produce expected type
   Int
-asyncret2.mo:1.6-1.11: warning [M0194], unused identifier call3 (delete or rename to wildcard `_` or `_call3`)
diff --git a/test/fail/ok/bad-async-sort.tc.ok b/test/fail/ok/bad-async-sort.tc.ok
@@ -16,7 +16,3 @@ Use keyword 'async*' (not 'async') to produce the expected type.
 bad-async-sort.mo:23.14-23.23: type error [M0183], async expression cannot produce expected async type 
   async<$anon4> ().
 Use keyword 'async' (not 'async*') to produce the expected type.
-bad-async-sort.mo:10.8-10.13: warning [M0194], unused identifier anon1 (delete or rename to wildcard `_` or `_anon1`)
-bad-async-sort.mo:14.8-14.13: warning [M0194], unused identifier anon2 (delete or rename to wildcard `_` or `_anon2`)
-bad-async-sort.mo:18.8-18.13: warning [M0194], unused identifier anon3 (delete or rename to wildcard `_` or `_anon3`)
-bad-async-sort.mo:22.8-22.13: warning [M0194], unused identifier anon4 (delete or rename to wildcard `_` or `_anon4`)
diff --git a/test/fail/ok/bad-unops.tc.ok b/test/fail/ok/bad-unops.tc.ok
@@ -15,7 +15,3 @@ bad-unops.mo:6.20-6.22: type error [M0111], operator pattern cannot consume expe
 bad-unops.mo:8.20-8.22: warning [M0146], this pattern is never matched
 bad-unops.mo:10.21-10.23: type error [M0111], operator pattern cannot consume expected type
   Int
-bad-unops.mo:1.5-1.6: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
-bad-unops.mo:2.5-2.6: warning [M0194], unused identifier b (delete or rename to wildcard `_` or `_b`)
-bad-unops.mo:3.5-3.6: warning [M0194], unused identifier c (delete or rename to wildcard `_` or `_c`)
-bad-unops.mo:4.5-4.6: warning [M0194], unused identifier d (delete or rename to wildcard `_` or `_d`)
diff --git a/test/fail/ok/bang-fail.tc.ok b/test/fail/ok/bang-fail.tc.ok
@@ -12,8 +12,3 @@ bang-fail.mo:18.17-18.19: type error [M0096], expression of type
   ()
 cannot produce expected type
   Nat
-bang-fail.mo:1.6-1.12: warning [M0194], unused identifier wrong1 (delete or rename to wildcard `_` or `_wrong1`)
-bang-fail.mo:5.6-5.12: warning [M0194], unused identifier wrong2 (delete or rename to wildcard `_` or `_wrong2`)
-bang-fail.mo:9.6-9.12: warning [M0194], unused identifier wrong3 (delete or rename to wildcard `_` or `_wrong3`)
-bang-fail.mo:13.6-13.12: warning [M0194], unused identifier wrong4 (delete or rename to wildcard `_` or `_wrong4`)
-bang-fail.mo:17.6-17.12: warning [M0194], unused identifier wrong5 (delete or rename to wildcard `_` or `_wrong5`)
diff --git a/test/fail/ok/bounds-mismatch.tc.ok b/test/fail/ok/bounds-mismatch.tc.ok
@@ -66,19 +66,3 @@ cannot produce expected type
 bounds-mismatch.mo:125.21-128.4: warning [M0074], this array has type
   [Any]
 because elements have inconsistent types
-bounds-mismatch.mo:2.10-2.11: warning [M0194], unused identifier g (delete or rename to wildcard `_` or `_g`)
-bounds-mismatch.mo:7.10-7.11: warning [M0194], unused identifier g (delete or rename to wildcard `_` or `_g`)
-bounds-mismatch.mo:12.10-12.11: warning [M0194], unused identifier g (delete or rename to wildcard `_` or `_g`)
-bounds-mismatch.mo:17.10-17.11: warning [M0194], unused identifier g (delete or rename to wildcard `_` or `_g`)
-bounds-mismatch.mo:22.10-22.11: warning [M0194], unused identifier g (delete or rename to wildcard `_` or `_g`)
-bounds-mismatch.mo:27.10-27.11: warning [M0194], unused identifier g (delete or rename to wildcard `_` or `_g`)
-bounds-mismatch.mo:32.10-32.11: warning [M0194], unused identifier g (delete or rename to wildcard `_` or `_g`)
-bounds-mismatch.mo:37.10-37.11: warning [M0194], unused identifier g (delete or rename to wildcard `_` or `_g`)
-bounds-mismatch.mo:75.6-75.7: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)
-bounds-mismatch.mo:81.6-81.7: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)
-bounds-mismatch.mo:87.6-87.7: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)
-bounds-mismatch.mo:93.6-93.7: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)
-bounds-mismatch.mo:99.6-99.7: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)
-bounds-mismatch.mo:106.6-106.7: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)
-bounds-mismatch.mo:126.41-126.42: warning [M0194], unused identifier b (delete or rename to wildcard `_` or `_b`)
-bounds-mismatch.mo:127.41-127.42: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
diff --git a/test/fail/ok/check-record.tc.ok b/test/fail/ok/check-record.tc.ok
@@ -14,5 +14,3 @@ check-record.mo:24.9-24.27: type error [M0096], expression of type
   {a : Nat}
 cannot produce expected type
   {b : Nat}
-check-record.mo:6.5-6.6: warning [M0194], unused identifier r (delete or rename to wildcard `_` or `_r`)
-check-record.mo:20.7-20.8: warning [M0194], unused identifier b (delete or rename to wildcard `_` or `_b`)
diff --git a/test/fail/ok/const-var-array.tc.ok b/test/fail/ok/const-var-array.tc.ok
@@ -1,3 +1,2 @@
 const-var-array.mo:1.17-1.22: type error [M0091], mutable array expression cannot produce expected type
   [Nat]
-const-var-array.mo:1.5-1.6: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
diff --git a/test/fail/ok/const-var-field.tc.ok b/test/fail/ok/const-var-field.tc.ok
@@ -2,4 +2,3 @@ const-var-field.mo:1.21-1.48: type error [M0096], expression of type
   {var x : Nat}
 cannot produce expected type
   {x : Nat}
-const-var-field.mo:1.5-1.6: warning [M0194], unused identifier o (delete or rename to wildcard `_` or `_o`)
diff --git a/test/fail/ok/f-bounds-fail.tc.ok b/test/fail/ok/f-bounds-fail.tc.ok
@@ -174,30 +174,3 @@ f-bounds-fail.mo:82.26-82.27: type error [M0096], expression of type
   B__13
 cannot produce expected type
   C__9
-f-bounds-fail.mo:3.5-3.6: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)
-f-bounds-fail.mo:5.6-5.9: warning [M0194], unused identifier f2a (delete or rename to wildcard `_` or `_f2a`)
-f-bounds-fail.mo:7.6-7.9: warning [M0194], unused identifier f2b (delete or rename to wildcard `_` or `_f2b`)
-f-bounds-fail.mo:9.6-9.9: warning [M0194], unused identifier f3a (delete or rename to wildcard `_` or `_f3a`)
-f-bounds-fail.mo:10.6-10.9: warning [M0194], unused identifier f3b (delete or rename to wildcard `_` or `_f3b`)
-f-bounds-fail.mo:11.6-11.9: warning [M0194], unused identifier f3c (delete or rename to wildcard `_` or `_f3c`)
-f-bounds-fail.mo:45.6-45.8: warning [M0194], unused identifier u0 (delete or rename to wildcard `_` or `_u0`)
-f-bounds-fail.mo:46.6-46.8: warning [M0194], unused identifier u1 (delete or rename to wildcard `_` or `_u1`)
-f-bounds-fail.mo:47.6-47.8: warning [M0194], unused identifier u2 (delete or rename to wildcard `_` or `_u2`)
-f-bounds-fail.mo:48.6-48.8: warning [M0194], unused identifier u3 (delete or rename to wildcard `_` or `_u3`)
-f-bounds-fail.mo:49.6-49.8: warning [M0194], unused identifier u4 (delete or rename to wildcard `_` or `_u4`)
-f-bounds-fail.mo:50.6-50.8: warning [M0194], unused identifier u5 (delete or rename to wildcard `_` or `_u5`)
-f-bounds-fail.mo:51.6-51.8: warning [M0194], unused identifier u6 (delete or rename to wildcard `_` or `_u6`)
-f-bounds-fail.mo:53.6-53.8: warning [M0194], unused identifier v0 (delete or rename to wildcard `_` or `_v0`)
-f-bounds-fail.mo:54.6-54.8: warning [M0194], unused identifier v1 (delete or rename to wildcard `_` or `_v1`)
-f-bounds-fail.mo:55.6-55.8: warning [M0194], unused identifier v2 (delete or rename to wildcard `_` or `_v2`)
-f-bounds-fail.mo:56.6-56.8: warning [M0194], unused identifier v3 (delete or rename to wildcard `_` or `_v3`)
-f-bounds-fail.mo:57.6-57.8: warning [M0194], unused identifier v4 (delete or rename to wildcard `_` or `_v4`)
-f-bounds-fail.mo:58.6-58.8: warning [M0194], unused identifier v5 (delete or rename to wildcard `_` or `_v5`)
-f-bounds-fail.mo:59.6-59.8: warning [M0194], unused identifier v6 (delete or rename to wildcard `_` or `_v6`)
-f-bounds-fail.mo:61.6-61.8: warning [M0194], unused identifier w0 (delete or rename to wildcard `_` or `_w0`)
-f-bounds-fail.mo:62.6-62.8: warning [M0194], unused identifier w1 (delete or rename to wildcard `_` or `_w1`)
-f-bounds-fail.mo:63.6-63.8: warning [M0194], unused identifier w2 (delete or rename to wildcard `_` or `_w2`)
-f-bounds-fail.mo:64.6-64.8: warning [M0194], unused identifier w3 (delete or rename to wildcard `_` or `_w3`)
-f-bounds-fail.mo:65.6-65.8: warning [M0194], unused identifier w4 (delete or rename to wildcard `_` or `_w4`)
-f-bounds-fail.mo:66.6-66.8: warning [M0194], unused identifier w5 (delete or rename to wildcard `_` or `_w5`)
-f-bounds-fail.mo:67.6-67.8: warning [M0194], unused identifier w6 (delete or rename to wildcard `_` or `_w6`)
diff --git a/test/fail/ok/inference.tc.ok b/test/fail/ok/inference.tc.ok
@@ -155,19 +155,3 @@ because no instantiation of T__117 makes
   {type x = Nat}  <:  {x : T__117}
 inference.mo:183.8-183.21: type error [M0045], wrong number of type arguments: expected 2 but got 0
 inference.mo:186.8-186.15: type error [M0045], wrong number of type arguments: expected 1 but got 0
-inference.mo:11.14-11.15: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)
-inference.mo:51.6-51.11: warning [M0194], unused identifier mult1 (delete or rename to wildcard `_` or `_mult1`)
-inference.mo:53.6-53.11: warning [M0194], unused identifier mult2 (delete or rename to wildcard `_` or `_mult2`)
-inference.mo:56.16-56.17: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)
-inference.mo:75.19-75.20: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
-inference.mo:88.23-88.24: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
-inference.mo:89.23-89.24: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
-inference.mo:90.23-90.24: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
-inference.mo:135.6-135.7: warning [M0194], unused identifier g (delete or rename to wildcard `_` or `_g`)
-inference.mo:136.20-136.21: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
-inference.mo:140.6-140.7: warning [M0194], unused identifier h (delete or rename to wildcard `_` or `_h`)
-inference.mo:141.20-141.21: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
-inference.mo:145.6-145.7: warning [M0194], unused identifier i (delete or rename to wildcard `_` or `_i`)
-inference.mo:150.6-150.7: warning [M0194], unused identifier j (delete or rename to wildcard `_` or `_j`)
-inference.mo:155.6-155.7: warning [M0194], unused identifier k (delete or rename to wildcard `_` or `_k`)
-inference.mo:180.19-180.20: warning [M0194], unused identifier u (delete or rename to wildcard `_` or `_u`)
diff --git a/test/fail/ok/issue-3318.tc.ok b/test/fail/ok/issue-3318.tc.ok
@@ -22,16 +22,3 @@ issue-3318.mo:33.43-33.44: type error [M0096], expression of type
   (Nat, Nat) -> ((Nat, Nat))
 cannot produce expected type
   ((Nat, Nat)) -> ((Nat, Nat))
-issue-3318.mo:2.13-2.14: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)
-issue-3318.mo:11.6-11.8: warning [M0194], unused identifier t0 (delete or rename to wildcard `_` or `_t0`)
-issue-3318.mo:14.6-14.8: warning [M0194], unused identifier t1 (delete or rename to wildcard `_` or `_t1`)
-issue-3318.mo:17.6-17.8: warning [M0194], unused identifier t2 (delete or rename to wildcard `_` or `_t2`)
-issue-3318.mo:20.6-20.8: warning [M0194], unused identifier t3 (delete or rename to wildcard `_` or `_t3`)
-issue-3318.mo:23.6-23.8: warning [M0194], unused identifier t4 (delete or rename to wildcard `_` or `_t4`)
-issue-3318.mo:26.6-26.8: warning [M0194], unused identifier t5 (delete or rename to wildcard `_` or `_t5`)
-issue-3318.mo:29.6-29.8: warning [M0194], unused identifier t6 (delete or rename to wildcard `_` or `_t6`)
-issue-3318.mo:32.6-32.8: warning [M0194], unused identifier t7 (delete or rename to wildcard `_` or `_t7`)
-issue-3318.mo:35.6-35.8: warning [M0194], unused identifier t8 (delete or rename to wildcard `_` or `_t8`)
-issue-3318.mo:40.6-40.8: warning [M0194], unused identifier u0 (delete or rename to wildcard `_` or `_u0`)
-issue-3318.mo:42.6-42.8: warning [M0194], unused identifier u1 (delete or rename to wildcard `_` or `_u1`)
-issue-3318.mo:44.6-44.8: warning [M0194], unused identifier u2 (delete or rename to wildcard `_` or `_u2`)
diff --git a/test/fail/ok/issue2062.tc.ok b/test/fail/ok/issue2062.tc.ok
@@ -2,4 +2,3 @@ issue2062.mo:2.3-3.11: type error [M0096], expression of type
   ()
 cannot produce expected type
   Nat
-issue2062.mo:1.6-1.9: warning [M0194], unused identifier fac (delete or rename to wildcard `_` or `_fac`)
diff --git a/test/fail/ok/missing-semi.tc.ok b/test/fail/ok/missing-semi.tc.ok
@@ -4,4 +4,3 @@ missing-semi.mo:3.5-4.1: info, this looks like an unintended function call, perh
 missing-semi.mo:9.3-9.7: type error [M0097], expected function type, but expression produces type
   ()
 missing-semi.mo:9.7-10.3: info, this looks like an unintended function call, perhaps a missing ';'?
-missing-semi.mo:7.6-7.7: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)
diff --git a/test/fail/ok/non_static_module.tc.ok b/test/fail/ok/non_static_module.tc.ok
@@ -10,13 +10,3 @@ non_static_module.mo:11.4-11.13: type error [M0014], non-static expression in li
 non_static_module.mo:20.12-20.15: type error [M0014], non-static expression in library or module
 non_static_module.mo:21.12-21.19: type error [M0014], non-static expression in library or module
 non_static_module.mo:22.4-22.13: type error [M0014], non-static expression in library or module
-non_static_module.mo:5.7-5.8: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
-non_static_module.mo:6.7-6.8: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
-non_static_module.mo:8.10-8.16: warning [M0194], unused identifier WrongO (delete or rename to wildcard `_` or `_WrongO`)
-non_static_module.mo:11.8-11.9: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
-non_static_module.mo:14.10-14.13: warning [M0194], unused identifier OkO (delete or rename to wildcard `_` or `_OkO`)
-non_static_module.mo:16.9-16.10: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
-non_static_module.mo:19.10-19.16: warning [M0194], unused identifier WrongM (delete or rename to wildcard `_` or `_WrongM`)
-non_static_module.mo:22.8-22.9: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
-non_static_module.mo:25.10-25.13: warning [M0194], unused identifier OkM (delete or rename to wildcard `_` or `_OkM`)
-non_static_module.mo:27.9-27.10: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
diff --git a/test/fail/ok/object-ext-poly.tc.ok b/test/fail/ok/object-ext-poly.tc.ok
@@ -2,4 +2,3 @@ object-ext-poly.mo:2.5-2.32: type error [M0096], expression of type
   {a : Int; b : Char; c : Text}
 cannot produce expected type
   A__9
-object-ext-poly.mo:1.6-1.9: warning [M0194], unused identifier mix (delete or rename to wildcard `_` or `_mix`)
diff --git a/test/fail/ok/objpat-infer.tc.ok b/test/fail/ok/objpat-infer.tc.ok
@@ -20,4 +20,3 @@ objpat-infer.mo:35.15-35.23: type error [M0096], expression of type
   actor {}
 cannot produce expected type
   {}
-objpat-infer.mo:17.17-17.18: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
diff --git a/test/fail/ok/one-tuple-ambiguity.tc.ok b/test/fail/ok/one-tuple-ambiguity.tc.ok
@@ -2,5 +2,3 @@ one-tuple-ambiguity.mo:16.3-16.5: type error [M0050], literal of type
   Nat
 does not have expected type
   (Nat, Bool)
-one-tuple-ambiguity.mo:13.9-13.10: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
-one-tuple-ambiguity.mo:13.18-13.19: warning [M0194], unused identifier b (delete or rename to wildcard `_` or `_b`)
diff --git a/test/fail/ok/pat-inconsistent.tc.ok b/test/fail/ok/pat-inconsistent.tc.ok
@@ -12,4 +12,3 @@ pat-inconsistent.mo:58.1-60.2: warning [M0145], this switch of type
 does not cover value
   #sparrows
 pat-inconsistent.mo:64.10-64.18: warning [M0146], this pattern is never matched
-pat-inconsistent.mo:62.6-62.12: warning [M0194], unused identifier absurd (delete or rename to wildcard `_` or `_absurd`)