#11315: GHC doesn't restore split objects -------------------------------------+------------------------------------- Reporter: snowleopard | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.3 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- While working on the new Shake-based build system I came across an annoying problem related to missing split objects ([#note see note]). I still don't fully understand the reasons behind the problem, but I found that GHC doesn't restore missing split objects, as explained in the example below. I think this is a bug, but maybe this is actually a missing feature. I think it shouldn't be difficult to fix. {{{#!hs module Test (test) where test :: Int test = 0 }}} I compile the above with `ghc -split-objs Test.hs` and get two split object files in `Test_o_split`. Then if I delete any of these files, or even the whole folder, and rerun `ghc -split-objs Test.hs` the compiler doesn't bother to restore split objects, pretending that everything is up- to-date. However, if I delete `Test.o` all object files are restored. Another related issue reported by Neil Mitchell (which may be worth a separate ticket) is that even if we corrupt `Test.o` and rerun `ghc -split-objs Test.hs`, the compiler doesn't restore the object file (nor missing split objects) to the consistent state. ---- [=#note Note:] The problem I have is described here: https://github.com/snowleopard/shaking-up-ghc/issues/30. It's not necessary to follow the link to understand this ticket, however I'd appreciate any insight you might have about the reasons behind the problem and/or a possible solution. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11315 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler