Bug fix: Unused declarations in catch blocks

Fix for issue: #4508

src/mo_frontend/typing.ml

@@ -1509,13 +1509,13 @@ and infer_exp'' env exp : T.typ =
     t
   | SwitchE (exp1, cases) ->
     let t1 = infer_exp_promote env exp1 in
-    let t = infer_cases env t1 T.Non cases in
+    let t = infer_cases env true t1 T.Non cases in
     if not env.pre then
       coverage_cases "switch" env cases t1 exp.at;
     t
   | TryE (exp1, cases) ->
     let t1 = infer_exp env exp1 in
-    let t2 = infer_cases env T.catch T.Non cases in
+    let t2 = infer_cases env false T.catch T.Non cases in
     if not env.pre then begin
       check_ErrorCap env "try" exp.at;
       coverage_cases "try handler" env cases T.catch exp.at
@@ -1975,15 +1975,17 @@ and infer_call env exp1 inst exp2 at t_expect_opt =
 
 (* Cases *)
 
-and infer_cases env t_pat t cases : T.typ =
-  List.fold_left (infer_case env t_pat) t cases
+and infer_cases env check_unused t_pat t cases : T.typ =
+  List.fold_left (infer_case env check_unused t_pat) t cases
 
-and infer_case env t_pat t case =
+and infer_case env check_unused t_pat t case =
   let {pat; exp} = case.it in
   let ve = check_pat env t_pat pat in
   let initial_usage = enter_scope env in
   let t' = recover_with T.Non (infer_exp (adjoin_vals env ve)) exp in
-  leave_scope env ve initial_usage;
+  if check_unused then
+    leave_scope env ve initial_usage
+  else ();
   let t'' = T.lub t t' in
   if not env.pre && inconsistent t'' [t; t'] then
     warn env case.at "M0101"
@@ -1998,8 +2000,11 @@ 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)

test/fail/ok/actor-match.tc.ok

@@ -1,2 +1,4 @@
 actor-match.mo:7.8-7.14: type error [M0114], object pattern cannot consume actor type
   actor {f : shared () -> (); g : shared () -> ()}
+actor-match.mo:7.9-7.10: warning [M0198], unused field f in object pattern (delete or rewrite as `f = _`)
+actor-match.mo:7.12-7.13: warning [M0198], unused field g in object pattern (delete or rewrite as `g = _`)

test/fail/ok/unused.tc.ok

@@ -5,5 +5,7 @@ unused.mo:9.9-9.15: warning [M0194], unused identifier unused (delete or rename
 unused.mo:11.6-11.7: warning [M0194], unused identifier g (delete or rename to wildcard `_` or `_g`)
 unused.mo:11.8-11.9: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
 unused.mo:15.5-15.8: warning [M0194], unused identifier hmm (delete or rename to wildcard `_` or `_hmm`)
+unused.mo:23.10-23.11: warning [M0194], unused identifier u (delete or rename to wildcard `_` or `_u`)
+unused.mo:24.8-24.9: warning [M0194], unused identifier o (delete or rename to wildcard `_` or `_o`)
 unused.mo:32.5-32.6: warning [M0194], unused identifier r (delete or rename to wildcard `_` or `_r`)
 unused.mo:32.29-32.30: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)

test/perf/ok/assetstorage.tc.ok

@@ -1,5 +1,10 @@
+assetstorage/List.mo:66.19-66.20: warning [M0194], unused identifier t (delete or rename to wildcard `_` or `_t`)
+assetstorage/List.mo:201.16-201.17: warning [M0194], unused identifier h (delete or rename to wildcard `_` or `_h`)
 assetstorage/Iter.mo:165.29-165.31: warning [M0194], unused identifier ix (delete or rename to wildcard `_` or `_ix`)
 assetstorage/RBTree.mo:45.10-45.13: warning [M0194], unused identifier res (delete or rename to wildcard `_` or `_res`)
 assetstorage/RBTree.mo:50.10-50.13: warning [M0194], unused identifier res (delete or rename to wildcard `_` or `_res`)
+assetstorage/RBTree.mo:179.15-179.16: warning [M0194], unused identifier c (delete or rename to wildcard `_` or `_c`)
 assetstorage/Char.mo:8.15-8.22: warning [M0194], unused identifier toUpper (delete or rename to wildcard `_` or `_toUpper`)
 assetstorage/Char.mo:11.15-11.22: warning [M0194], unused identifier toLower (delete or rename to wildcard `_` or `_toLower`)
+assetstorage/Text.mo:347.22-347.25: warning [M0194], unused identifier cs1 (delete or rename to wildcard `_` or `_cs1`)
+assetstorage/Text.mo:548.28-548.31: warning [M0194], unused identifier cs3 (delete or rename to wildcard `_` or `_cs3`)

test/perf/ok/dao.tc.ok

@@ -1,4 +1,8 @@
+assetstorage/List.mo:66.19-66.20: warning [M0194], unused identifier t (delete or rename to wildcard `_` or `_t`)
+assetstorage/List.mo:201.16-201.17: warning [M0194], unused identifier h (delete or rename to wildcard `_` or `_h`)
 assetstorage/Iter.mo:165.29-165.31: warning [M0194], unused identifier ix (delete or rename to wildcard `_` or `_ix`)
+assetstorage/AssocList.mo:158.20-158.22: warning [M0194], unused identifier v2 (delete or rename to wildcard `_` or `_v2`)
+assetstorage/AssocList.mo:313.20-313.22: warning [M0194], unused identifier v2 (delete or rename to wildcard `_` or `_v2`)
 assetstorage/Trie.mo:206.31-206.32: warning [M0194], unused identifier v (delete or rename to wildcard `_` or `_v`)
 assetstorage/Trie.mo:486.25-486.26: warning [M0194], unused identifier v (delete or rename to wildcard `_` or `_v`)
 assetstorage/Trie.mo:588.9-588.15: warning [M0194], unused identifier key_eq (delete or rename to wildcard `_` or `_key_eq`)

test/perf/ok/qr.tc.ok

@@ -1,5 +1,9 @@
 qr/option.mo:52.8-52.11: warning [M0194], unused identifier map (delete or rename to wildcard `_` or `_map`)
+qr/list.mo:124.21-124.22: warning [M0194], unused identifier t (delete or rename to wildcard `_` or `_t`)
+qr/list.mo:281.18-281.19: warning [M0194], unused identifier h (delete or rename to wildcard `_` or `_h`)
 qr/iter.mo:36.8-36.14: warning [M0194], unused identifier length (delete or rename to wildcard `_` or `_length`)
+qr/assocList.mo:105.25-105.27: warning [M0194], unused identifier v2 (delete or rename to wildcard `_` or `_v2`)
+qr/assocList.mo:179.25-179.27: warning [M0194], unused identifier v2 (delete or rename to wildcard `_` or `_v2`)
 qr/trie.mo:515.9-515.15: warning [M0194], unused identifier key_eq (delete or rename to wildcard `_` or `_key_eq`)
 qr/trie.mo:893.7-893.12: warning [M0194], unused identifier k3_eq (delete or rename to wildcard `_` or `_k3_eq`)
 qr/trie.mo:1447.61-1447.66: warning [M0194], unused identifier k1_eq (delete or rename to wildcard `_` or `_k1_eq`)

test/perf/ok/sha256.tc.ok

@@ -1 +1,3 @@
+sha256/List.mo:67.22-67.23: warning [M0194], unused identifier t (delete or rename to wildcard `_` or `_t`)
+sha256/List.mo:204.16-204.17: warning [M0194], unused identifier h (delete or rename to wildcard `_` or `_h`)
 sha256/Iter.mo:194.29-194.31: warning [M0194], unused identifier ix (delete or rename to wildcard `_` or `_ix`)

test/run-drun/ok/actor-class-mgmt-interp.tc.ok

@@ -0,0 +1,4 @@
+actor-class-mgmt-interp.mo:37.15-37.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+actor-class-mgmt-interp.mo:46.15-46.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+actor-class-mgmt-interp.mo:54.15-54.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+actor-class-mgmt-interp.mo:63.13-63.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)

test/run-drun/ok/composite-inspect-message.tc.ok

@@ -1 +1,2 @@
 composite-inspect-message.mo:17.8-17.14: warning [M0194], unused identifier caller (delete or rename to wildcard `_` or `_caller`)
+composite-inspect-message.mo:29.20-29.21: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)

test/run-drun/ok/error-codes.tc.ok

@@ -1 +1,3 @@
 error-codes.mo:8.16-8.23: warning [M0194], unused identifier invalid (delete or rename to wildcard `_` or `_invalid`)
+error-codes.mo:47.24-47.25: warning [M0194], unused identifier n (delete or rename to wildcard `_` or `_n`)
+error-codes.mo:48.28-48.36: warning [M0194], unused identifier err_code (delete or rename to wildcard `_` or `_err_code`)

test/run-drun/ok/from_candid_trap.tc.ok

@@ -0,0 +1 @@
+from_candid_trap.mo:11.13-11.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)

test/run-drun/ok/gc-trigger-acl.tc.ok

@@ -0,0 +1,2 @@
+gc-trigger-acl.mo:25.13-25.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+gc-trigger-acl.mo:38.13-38.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)

test/run-drun/ok/idl-record.tc.ok

@@ -0,0 +1 @@
+idl-record.mo:8.14-8.21: warning [M0194], unused identifier content (delete or rename to wildcard `_` or `_content`)

test/run-drun/ok/idl-sub-ho-neg.tc.ok

@@ -48,3 +48,22 @@ idl-sub-ho-neg.mo:103.28-103.29: warning [M0194], unused identifier n (delete or
 idl-sub-ho-neg.mo:103.41-103.42: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
 idl-sub-ho-neg.mo:103.56-103.57: warning [M0194], unused identifier r (delete or rename to wildcard `_` or `_r`)
 idl-sub-ho-neg.mo:103.75-103.76: warning [M0194], unused identifier v (delete or rename to wildcard `_` or `_v`)
+idl-sub-ho-neg.mo:131.15-131.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:145.15-145.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:159.15-159.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:173.15-173.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:187.15-187.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:201.15-201.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:215.15-215.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:232.15-232.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:248.15-248.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:264.15-264.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:279.15-279.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:296.15-296.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:313.15-313.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:330.15-330.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:346.15-346.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:362.15-362.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:377.15-377.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:394.15-394.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:411.15-411.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)

test/run-drun/ok/idl-sub-ho.tc.ok

@@ -26,3 +26,14 @@ idl-sub-ho.mo:78.26-78.27: warning [M0194], unused identifier n (delete or renam
 idl-sub-ho.mo:78.39-78.40: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
 idl-sub-ho.mo:78.54-78.55: warning [M0194], unused identifier r (delete or rename to wildcard `_` or `_r`)
 idl-sub-ho.mo:78.73-78.74: warning [M0194], unused identifier v (delete or rename to wildcard `_` or `_v`)
+idl-sub-ho.mo:100.15-100.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:111.15-111.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:122.15-122.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:133.15-133.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:145.15-145.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:159.15-159.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:173.15-173.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:188.15-188.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:203.15-203.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:217.15-217.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:232.15-232.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)

test/run-drun/ok/idl-sub-opt-any-record.tc.ok

@@ -5,3 +5,6 @@ idl-sub-opt-any-record.mo:15.24-15.25: warning [M0194], unused identifier a (del
 idl-sub-opt-any-record.mo:15.33-15.34: warning [M0194], unused identifier n (delete or rename to wildcard `_` or `_n`)
 idl-sub-opt-any-record.mo:16.24-16.25: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
 idl-sub-opt-any-record.mo:16.33-16.34: warning [M0194], unused identifier n (delete or rename to wildcard `_` or `_n`)
+idl-sub-opt-any-record.mo:31.15-31.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-opt-any-record.mo:46.15-46.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-opt-any-record.mo:60.15-60.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)

test/run-drun/ok/idl-sub-opt-any.tc.ok

@@ -9,3 +9,8 @@ idl-sub-opt-any.mo:17.23-17.24: warning [M0194], unused identifier n (delete or
 idl-sub-opt-any.mo:17.34-17.35: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
 idl-sub-opt-any.mo:18.23-18.24: warning [M0194], unused identifier n (delete or rename to wildcard `_` or `_n`)
 idl-sub-opt-any.mo:18.32-18.33: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
+idl-sub-opt-any.mo:33.15-33.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-opt-any.mo:48.15-48.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-opt-any.mo:62.15-62.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-opt-any.mo:76.15-76.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-opt-any.mo:91.15-91.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)

test/run-drun/ok/idl-sub-rec.tc.ok

@@ -7,3 +7,11 @@ idl-sub-rec.mo:54.5-54.6: warning [M0194], unused identifier a (delete or rename
 idl-sub-rec.mo:60.5-60.6: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)
 idl-sub-rec.mo:66.5-66.6: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
 idl-sub-rec.mo:72.5-72.6: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
+idl-sub-rec.mo:91.13-91.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-rec.mo:104.13-104.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-rec.mo:118.13-118.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-rec.mo:131.13-131.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-rec.mo:144.13-144.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-rec.mo:169.13-169.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-rec.mo:181.13-181.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-rec.mo:194.13-194.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)

test/run-drun/ok/inspect_message.tc.ok

@@ -1 +1,2 @@
 inspect_message.mo:14.8-14.14: warning [M0194], unused identifier caller (delete or rename to wildcard `_` or `_caller`)
+inspect_message.mo:26.20-26.21: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)

test/run-drun/ok/issue-3910.tc.ok

@@ -10,3 +10,5 @@ issue-3910.mo:7.11-7.12: warning [M0194], unused identifier r (delete or rename
 issue-3910.mo:12.13-12.17: warning [M0194], unused identifier trap (delete or rename to wildcard `_` or `_trap`)
 issue-3910.mo:24.11-24.12: warning [M0194], unused identifier r (delete or rename to wildcard `_` or `_r`)
 issue-3910.mo:29.13-29.17: warning [M0194], unused identifier trap (delete or rename to wildcard `_` or `_trap`)
+issue-3910.mo:52.11-52.12: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+issue-3910.mo:67.11-67.12: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)

test/run-drun/ok/local-throw.tc.ok

@@ -0,0 +1,3 @@
+local-throw.mo:14.19-14.22: warning [M0194], unused identifier sys (delete or rename to wildcard `_` or `_sys`)
+local-throw.mo:32.17-32.20: warning [M0194], unused identifier sys (delete or rename to wildcard `_` or `_sys`)
+local-throw.mo:45.14-45.17: warning [M0194], unused identifier sys (delete or rename to wildcard `_` or `_sys`)