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| author | Simon Peyton Jones <simonpj@microsoft.com> | 2020-02-24 09:03:08 +0000 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2020-03-10 12:31:15 -0400 |
| commit | 7b2c827b7b68f0ade7f4ae66e7033fdb84d75a5f (patch) | |
| tree | 2d3a26c4d5099af19c08411f2b3a84a5a2e90ab9 /compiler/stranal | |
| parent | 5ba01d83a2078acce789a9d5f111efa4d4ffc616 (diff) | |
| download | haskell-7b2c827b7b68f0ade7f4ae66e7033fdb84d75a5f.tar.gz | |
Comments only
Clarify code added in #17852 and MR !2724
Diffstat (limited to 'compiler/stranal')
| -rw-r--r-- | compiler/stranal/WwLib.hs | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/compiler/stranal/WwLib.hs b/compiler/stranal/WwLib.hs index 5d4325766b..49e8a7f70b 100644 --- a/compiler/stranal/WwLib.hs +++ b/compiler/stranal/WwLib.hs @@ -1179,8 +1179,14 @@ mk_absent_let dflags fam_envs arg -- (for the sake of the "empty case scrutinee not known to -- diverge for sure lint" warning) arg_ty = idType arg + + -- Normalise the type to have best chance of finding an absent literal + -- e.g. (#17852) data unlifted N = MkN Int# + -- f :: N -> a -> a + -- f _ x = x (co, nty) = topNormaliseType_maybe fam_envs arg_ty `orElse` (mkRepReflCo arg_ty, arg_ty) + abs_rhs = mkAbsentErrorApp arg_ty msg msg = showSDoc (gopt_set dflags Opt_SuppressUniques) (ppr arg <+> ppr (idType arg)) |