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| author | Edward Z. Yang <ezyang@cs.stanford.edu> | 2017-07-28 18:25:12 -0400 |
|---|---|---|
| committer | Ben Gamari <ben@smart-cactus.org> | 2017-07-28 18:25:13 -0400 |
| commit | 9e9fb57c37c62bb6c90f15b173c5d3632121c66a (patch) | |
| tree | 1311492c2ac4cfa534801939538bd0430068baff /compiler/iface | |
| parent | 121fee99496d5f5d53a8cd6b08c13a0b6bb9069d (diff) | |
| download | haskell-9e9fb57c37c62bb6c90f15b173c5d3632121c66a.tar.gz | |
Fix hs-boot knot-tying with record wild cards.
Fixes #13710.
Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>
Test Plan: validate
Reviewers: bgamari, austin, simonpj
Reviewed By: simonpj
Subscribers: simonpj, rwbarton, thomie
GHC Trac Issues: #13710
Differential Revision: https://phabricator.haskell.org/D3743
Diffstat (limited to 'compiler/iface')
| -rw-r--r-- | compiler/iface/TcIface.hs | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/compiler/iface/TcIface.hs b/compiler/iface/TcIface.hs index b3119b2446..9e0616518f 100644 --- a/compiler/iface/TcIface.hs +++ b/compiler/iface/TcIface.hs @@ -915,7 +915,14 @@ tcIfaceDataCons tycon_name tycon tc_tybinders if_cons ; ~(eq_spec, theta, arg_tys, stricts) <- forkM (mk_doc dc_name) $ do { eq_spec <- tcIfaceEqSpec spec ; theta <- tcIfaceCtxt ctxt - ; arg_tys <- mapM tcIfaceType args + -- This fixes #13710. The enclosing lazy thunk gets + -- forced when typechecking record wildcard pattern + -- matching (it's not completely clear why this + -- tuple is needed), which causes trouble if one of + -- the argument types was recursively defined. + -- See also Note [Tying the knot] + ; arg_tys <- forkM (mk_doc dc_name <+> text "arg_tys") + $ mapM tcIfaceType args ; stricts <- mapM tc_strict if_stricts -- The IfBang field can mention -- the type itself; hence inside forkM |