#8834: 64-bit windows cabal.exe segfaults in GC ----------------------------------+---------------------------------- Reporter: awson | Owner: Type: bug | Status: patch Priority: highest | Milestone: 7.8.1 Component: Compiler | Version: 7.8.1-rc2 Resolution: | Keywords: Operating System: Windows | Architecture: x86_64 (amd64) Type of failure: Runtime crash | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: ----------------------------------+---------------------------------- Comment (by jstolarek): awson, great bisecting job here! The intention behind the faulty commit is that both older and newer implementations are semantically identical (which turns out not to be the case) but the newer one avoids code duplication.
I think your analysis is right, that it is the change to okToInline that is at fault.
Two other possibilities include: 1. `conflict` function 2. instance definition for `GlobalReg` datatype in [[GhcFile(compiler/cmm/CmmNode.hs)]] in the `DefinerOfRegs`. That's the place were we say what global registers are defined (and therefore clobbered) by each Cmm node. awson, to pin this bug we have to know the difference between correct and incorrect Cmm. Could you compile your minimal example with GHC HEAD (which will give us the segfaulting Cmm) and with your patched version (which will give us working Cmm) and upload them here? Dump the Cmm with `-ddump- cmm` flag. I see that you're calling `print` in your example. My experience is that it adds a lot of extra Cmm to analyse. Could you see if splitting your code into two modules also causes the bug: {{{ module T8834 where import qualified Data.ByteString.Char8 as BSS T8834 :: IO Int T8834 = do cache <- BSS.readFile "00-index.cache" return (length $ BSS.lines cache) }}} {{{ module Main where import T8834 main :: IO () main = T8834 >>= print }}} If this also causes the bug then most likely we only need Cmm dump for `T8834` module. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8834#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler