[GHC] #14709: Extend the plugin mechanism to access program representation

[GHC]

#14709: Extend the plugin mechanism to access program representation
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        Reporter:  lazac             |                Owner:  (none)
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  GHC API           |              Version:  8.2.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |  https://phabricator.haskell.org/D4342
  https://ghc.haskell.org/trac/ghc/wiki/ExtendedPluginsProposal|
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Comment (by bgamari):

 > I can imagine tools that modify these representations as well

 Sure. The one thing I would really like to see considered is recompilation
 checking. Currently the existing plugin types are borderline unusable due
 to the lack of recompilation avoidance (see #7414).

 While you don't need to solve this issue in your patch (doing so will
 likely require deeper changes in GHC), we should try to think through
 which information the plugin will need to provide for the compiler to be
 able to assess whether recompilation is necessary and design the interface
 with this need in mind. This will avoid backwards-incompatible interface
 changes in the future.

 Writing down a few motivating examples of applications of the new plugin
 types may be a good place to start.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14709#comment:5>
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