#10415: ForeignPtr touched in FFI wrapper is never discarded -------------------------------------+------------------------------------- Reporter: Deewiant | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 7.10.1 Resolution: invalid | Keywords: Operating System: Linux | Architecture: x86_64 Type of failure: Runtime | (amd64) performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by Deewiant): No, you're absolutely right. I suspected that the compiler couldn't reasonably do anything here due to the danger of the wrapper being "squirreled away" as you say. :-) What I thought might be possible is some sort of proof based on things like: 1. In the example, the wrapper is immediately discarded, so there's no need for it to live at all, really. 2. Perhaps a "safe" foreign call is only made immediately next to the wrapper allocation and the wrapper is not referenced elsewhere, so the compiler could see where its lifetime ends. But I didn't realize that the wrappers are functions that require manual freeing! `freeHaskellFunPtr` is something I was missing entirely. I was looking in the FFI sections of the Haskell 2010 report to see if there was anything like that for freeing wrapper functions, but apparently I should've looked elsewhere too. Thanks, and sorry for the noise. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10415#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler