Cheng Shao pushed to branch wip/fast-binary at Glasgow Haskell Compiler / GHC

Commits:

• 31136101
  by Cheng Shao at 2026-01-07T23:41:02+01:00

  compiler: make getPrim eagerly evaluate its result
  
  This commit makes `GHC.Utils.Binary.getPrim` eagerly evaluate its
  result, to avoid accidental laziness when future patches build other
  binary parsers using `getPrim`.
  

1 changed file:

• compiler/GHC/Utils/Binary.hs

Changes:

   ix <- readFastMutInt ix_r

   when (ix + size > sz_r) $

       ioError (mkIOError eofErrorType "Data.Binary.getPrim" Nothing Nothing)

-  w <- unsafeWithForeignPtr arr_r $ \p -> f (p `plusPtr` ix)

+  !w <- unsafeWithForeignPtr arr_r $ \p -> f (p `plusPtr` ix)

     -- This is safe WRT #17760 as we we guarantee that the above line doesn't

     -- diverge

   writeFastMutInt ix_r (ix + size)