libraries/base/Foreign/Marshal/Alloc.hs¶
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#.
