[GHC] #8951: genSym uses atomic_inc but doesn't link arm_atomic_spin_lock

[GHC]

#8951: genSym uses atomic_inc but doesn't link arm_atomic_spin_lock
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              Reporter:  cjwatson    |            Owner:
                  Type:  bug         |           Status:  new
              Priority:  normal      |        Milestone:  7.8.4
             Component:  Build       |          Version:  7.8.1-rc1
  System                             |         Keywords:
            Resolution:              |     Architecture:  arm
      Operating System:  Linux       |       Difficulty:  Unknown
       Type of failure:  Building    |       Blocked By:
  GHC failed                         |  Related Tickets:
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
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Comment (by bgamari):

 Hmm, so the symbols in question are defined in `rts/OldARMAtomic.c`. These
 are necessary as this build occurred on an ARMv5 box. It appears
 `OldARMAtomic.o` is being compiled into `libRTS` so this raises the
 question of why it's not being found by the linker.

 nomeata, however, is doing his builds on ARMv7 hardware. In light of this
 it's likely that there are two bugs here:

   1. nomeata's build is using the pre-ARMv6 fallbacks unnecessarily
   2. the pre-ARMv6 fallbacks aren't compiled/linked properly

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8951#comment:6>
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