Commit 267d31c1 authored by Ben Gamari's avatar Ben Gamari 🐢 Committed by Marge Bot
Browse files

base: Use keepAlive# in Foreign.Marshal.Alloc

parent 2de81332
......@@ -116,19 +116,6 @@ alloca :: forall a b . Storable a => (Ptr a -> IO b) -> IO b
alloca =
allocaBytesAligned (sizeOf (undefined :: a)) (alignment (undefined :: a))
-- Note [NOINLINE for touch#]
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~
-- Both allocaBytes and allocaBytesAligned use the touch#, which is notoriously
-- fragile in the presence of simplification (see #14346). In particular, the
-- simplifier may drop the continuation containing the touch# if it can prove
-- that the action passed to allocaBytes will not return. The hack introduced to
-- fix this for 8.2.2 is to mark allocaBytes as NOINLINE, ensuring that the
-- simplifier can't see the divergence.
--
-- These can be removed once #14375 is fixed, which suggests that we instead do
-- away with touch# in favor of a primitive that will capture the scoping left
-- implicit in the case of touch#.
-- |@'allocaBytes' n f@ executes the computation @f@, passing as argument
-- a pointer to a temporarily allocated block of memory of @n@ bytes.
-- The block of memory is sufficiently aligned for any of the basic
......@@ -143,12 +130,8 @@ allocaBytes (I# size) action = IO $ \ s0 ->
case unsafeFreezeByteArray# mbarr# s1 of { (# s2, barr# #) ->
let addr = Ptr (byteArrayContents# barr#) in
case action addr of { IO action' ->
case action' s2 of { (# s3, r #) ->
case touch# barr# s3 of { s4 ->
(# s4, r #)
}}}}}
-- See Note [NOINLINE for touch#]
{-# NOINLINE allocaBytes #-}
keepAlive# barr# s2 action'
}}}
allocaBytesAligned :: Int -> Int -> (Ptr a -> IO b) -> IO b
allocaBytesAligned (I# size) (I# align) action = IO $ \ s0 ->
......@@ -156,12 +139,8 @@ allocaBytesAligned (I# size) (I# align) action = IO $ \ s0 ->
case unsafeFreezeByteArray# mbarr# s1 of { (# s2, barr# #) ->
let addr = Ptr (byteArrayContents# barr#) in
case action addr of { IO action' ->
case action' s2 of { (# s3, r #) ->
case touch# barr# s3 of { s4 ->
(# s4, r #)
}}}}}
-- See Note [NOINLINE for touch#]
{-# NOINLINE allocaBytesAligned #-}
keepAlive# barr# s2 action'
}}}
-- |Resize a memory area that was allocated with 'malloc' or 'mallocBytes'
-- to the size needed to store values of type @b@. The returned pointer
......
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