[GHC] #13845: Runtime linker too eagerly checks for symbol names

[GHC]

#13845: Runtime linker too eagerly checks for symbol names
-------------------------------------+-------------------------------------
           Reporter:  RyanGlScott    |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Runtime        |           Version:  8.0.1
  System (Linker)                    |
           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:
-------------------------------------+-------------------------------------
 I discovered this bug in https://github.com/haskell-
 foundation/foundation/issues/326. Take this file:

 {{{#!hs
 module Main (main) where

 foreign import ccall "notAThing"
   notAThing :: IO ()

 main :: IO ()
 main = putStrLn "Hello, World!"
 }}}

 Compiling and running this file works without issue. But if you try to use
 the runtime linker, things go haywire:

 {{{
 $ C:\Users\RyanGlScott\Software\ghc\inplace\bin\runghc Bug.hs
 ghc-stage2.exe: ^^ Could not load 'notAThing', dependency unresolved. See
 top entry above.

 Bug.hs:
 ByteCodeLink: can't find label
 During interactive linking, GHCi couldn't find the following symbol:
   notAThing
 This may be due to you not asking GHCi to load extra object files,
 archives or DLLs needed by your current session.  Restart GHCi, specifying
 the missing library using the -L/path/to/object/dir and -lmissinglibname
 flags, or simply by naming the relevant files on the GHCi command line.
 Alternatively, this link failure might indicate a bug in GHCi.
 If you suspect the latter, please send a bug report to:
   glasgow-haskell-bugs at haskell.org
 }}}

 This isn't just limited to Windows, since the same thing happens on Linux.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13845>
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