Fix interaction of record pattern synonyms and record wildcards

We were missing an appropiate *ConLike lookup in the case when
the pattern synonym was defined in a different module.

Reviewers: austin, bgamari, simonpj

Reviewed By: simonpj

Subscribers: simonpj, thomie

Differential Revision: https://phabricator.haskell.org/D2544

GHC Trac Issues: #11987

compiler/rename/RnEnv.hs

@@ -462,9 +462,9 @@ lookupConstructorFields con_name
              ; traceTc "lookupCF" (ppr con_name $$ ppr (lookupNameEnv field_env con_name) $$ ppr field_env)
              ; return (lookupNameEnv field_env con_name `orElse` []) }
           else
-          do { con <- tcLookupDataCon con_name
+          do { con <- tcLookupConLike con_name
              ; traceTc "lookupCF 2" (ppr con)
-             ; return (dataConFieldLabels con) } }
+             ; return (conLikeFieldLabels con) } }
 
 -----------------------------------------------
 -- Used for record construction and pattern matching

testsuite/tests/patsyn/should_compile/T11987.hs

+{-# LANGUAGE NamedFieldPuns, PatternSynonyms, RecordWildCards #-}
+module T11987 where
+
+import T11987a
+
+-- works
+namedFieldPuns :: (Int,Int)
+namedFieldPuns = let { x = 1; y = 2 } in Point { x, y }
+
+-- error: Pattern synonym ‘Point’ used as a data constructor
+recordWildCards :: (Int,Int)
+recordWildCards = let { x = 1; y = 2 } in Point { .. }

testsuite/tests/patsyn/should_compile/T11987a.hs

+{-# LANGUAGE NamedFieldPuns, PatternSynonyms, RecordWildCards #-}
+module T11987a where
+
+pattern Point :: Int -> Int -> (Int, Int)
+pattern Point{x, y} = (x, y)
+
+-- works
+sameFile :: (Int,Int)
+sameFile = let { x = 1; y = 2 } in Point { .. }

testsuite/tests/patsyn/should_compile/all.T

@@ -58,4 +58,5 @@ test('T12094', normal, compile, [''])
 test('T11977', normal, compile, [''])
 test('T12108', normal, compile, [''])
 test('T12484', normal, compile, [''])
-test('T12489', normal, compile, [''])
+test('T11987', normal, multimod_compile, ['T11987', '-v0'])
+