[GHC] #7947: Name conflict with DerivingDataTypeable, StandaloneDeriving and qualified imports

[GHC]

#7947: Name conflict with DerivingDataTypeable, StandaloneDeriving and qualified
imports
-------------------------------------+-------------------------------------
        Reporter:  a.ulrich          |                   Owner:
            Type:  bug               |                  Status:  closed
        Priority:  normal            |               Milestone:
       Component:  Compiler (Type    |                 Version:  7.7
  checker)                           |
      Resolution:  fixed             |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
                                     |  Unknown/Multiple
 Type of failure:  GHC rejects       |               Test Case:
  valid program                      |  deriving/should_compile/T7947
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:
-------------------------------------+-------------------------------------

Comment (by Austin Seipp <austin@…>):

 In [changeset:"d4d34a73aacc225a8f28d7138137bf548c9e51cc/ghc"
 d4d34a73/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="d4d34a73aacc225a8f28d7138137bf548c9e51cc"
 Make derived names deterministic

 The names of auxiliary bindings end up in the interface file, and since
 uniques
 are nondeterministic, we end up with nondeterministic interface files.

 This uses the package and module name in the generated name, so I believe
 it
 should avoid problems from #7947 and be deterministic as well.

 The generated names look like this now:

   `$cLrlbmVwI3gpI8G2E6Hg3mO`

 and with `-ppr-debug`:

   `$c$aeson_70dylHtv1FFGeai1IoxcQr$Data.Aeson.Types.Internal$String`.

 Reviewed By: simonmar, austin, ezyang

 Differential Revision: https://phabricator.haskell.org/D1133

 GHC Trac Issues: #4012
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7947#comment:4>
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