[GHC] #9964: GHC crash with NOINLINE and weird IO stuff

7 Jan 2015


      #9964: GHC crash with NOINLINE and weird IO stuff
-------------------------------------+-------------------------------------
              Reporter:  dfeuer      |             Owner:
                  Type:  bug         |            Status:  new
              Priority:  normal      |         Milestone:
             Component:  Compiler    |           Version:  7.11
              Keywords:              |  Operating System:  Unknown/Multiple
          Architecture:              |   Type of failure:  Compile-time
  Unknown/Multiple                   |  crash
             Test Case:              |        Blocked By:
              Blocking:              |   Related Tickets:
Differential Revisions:              |
-------------------------------------+-------------------------------------
 {{{#!hs
 {-# LANGUAGE UnboxedTuples #-}
 module Crash where

 import GHC.Base

 crash :: IO Int
 crash = IO (\s ->
   let
     {-# NOINLINE s' #-}
     s' = s
   in (# s', 1::Int #))
 }}}

 This compiles under 7.6.3, but both 7.8.3 and head choke:

 {{{
 ghc: panic! (the 'impossible' happened)
   (GHC version 7.8.3 for x86_64-unknown-linux):
         StgCmmEnv: variable not found
     s{v sLw} [lid]
     local binds for:

 Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
 }}}

--
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9964
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