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Diffstat (limited to 'compiler/GHC/Core/Subst.hs')
| -rw-r--r-- | compiler/GHC/Core/Subst.hs | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/compiler/GHC/Core/Subst.hs b/compiler/GHC/Core/Subst.hs index f1d104df66..d57a0e2bf0 100644 --- a/compiler/GHC/Core/Subst.hs +++ b/compiler/GHC/Core/Subst.hs @@ -343,6 +343,8 @@ instance Outputable Subst where substExprSC :: HasDebugCallStack => Subst -> CoreExpr -> CoreExpr -- Just like substExpr, but a no-op if the substitution is empty +-- Note that this does /not/ replace occurrences of free vars with +-- their canonical representatives in the in-scope set substExprSC subst orig_expr | isEmptySubst subst = orig_expr | otherwise = -- pprTrace "enter subst-expr" (doc $$ ppr orig_expr) $ @@ -628,6 +630,9 @@ substIdInfo subst new_id info ------------------ -- | Substitutes for the 'Id's within an unfolding +-- NB: substUnfolding /discards/ any unfolding without +-- without a Stable source. This is usually what we want, +-- but it may be a bit unexpected substUnfolding, substUnfoldingSC :: Subst -> Unfolding -> Unfolding -- Seq'ing on the returned Unfolding is enough to cause -- all the substitutions to happen completely |