[GHC] #16260: Use of plugins causes -XSafe to fail

[GHC]

#16260: Use of plugins causes -XSafe to fail
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        Reporter:  watashi           |                Owner:  watashi
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.7
      Resolution:  fixed             |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by mpickering):

 My reasoning is that if a consumer decides that they don't care about Safe
 Haskell then they can use `-fno-safe-haskell` and skip the checks.
 However, if a user does care about safe haskell then they would care if
 one of their dependencies was modified with a plugin, this kind of
 situation is easy to achieve when using nix for example. If it is up to
 the plugin authors to be prudent, I imagine that none of them will be.

 Perhaps if we just modify the `Sf_Ignore` constructor to be `Sf_Ignore
 SafeHaskellMode` to record the mode it is ignoring then that would solve
 your problem?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16260#comment:7>
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