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| author | Matthew Pickering <matthewtpickering@gmail.com> | 2022-02-08 16:23:43 +0000 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2022-03-02 14:09:13 -0500 |
| commit | 81b7c4361c0e3da403e0fcf42cc7faae2ca3db9a (patch) | |
| tree | 71886afe57e4f4dc68b50e248eeaf188c3c74820 | |
| parent | b27b2af3fab48e21aabcc9441967c4dd7a6a75ea (diff) | |
| download | haskell-81b7c4361c0e3da403e0fcf42cc7faae2ca3db9a.tar.gz | |
Make -dannot-lint not panic on let bound type variables
After certain simplifier passes we end up with let bound type variables
which are immediately inlined in the next pass. The core diff utility
implemented by -dannot-lint failed to take these into account and
paniced.
Progress towards #20965
| -rw-r--r-- | compiler/GHC/Core/Utils.hs | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/compiler/GHC/Core/Utils.hs b/compiler/GHC/Core/Utils.hs index 3116b6bd04..baefb7712b 100644 --- a/compiler/GHC/Core/Utils.hs +++ b/compiler/GHC/Core/Utils.hs @@ -2181,8 +2181,9 @@ diffBinds top env binds1 = go (length binds1) env binds1 else (warn env binds1 binds2, env) go fuel env ((bndr1,expr1):binds1) binds2 | let matchExpr (bndr,expr) = - (not top || null (diffIdInfo env bndr bndr1)) && + (isTyVar bndr || not top || null (diffIdInfo env bndr bndr1)) && null (diffExpr top (rnBndr2 env bndr1 bndr) expr1 expr) + , (binds2l, (bndr2,_):binds2r) <- break matchExpr binds2 = go (length binds1) (rnBndr2 env bndr1 bndr2) binds1 (binds2l ++ binds2r) @@ -2205,6 +2206,12 @@ diffBinds top env binds1 = go (length binds1) env binds1 diffBind env (bndr1,expr1) (bndr2,expr2) | ds@(_:_) <- diffExpr top env expr1 expr2 = locBind "in binding" bndr1 bndr2 ds + -- Special case for TyVar, which we checked were bound to the same types in + -- diffExpr, but don't have any IdInfo we would panic if called diffIdInfo. + -- These let-bound types are created temporarily by the simplifier but inlined + -- immediately. + | isTyVar bndr1 && isTyVar bndr2 + = [] | otherwise = diffIdInfo env bndr1 bndr2 |