[GHC] #8944: Warn instead of stopping on misplaced Haddock comments

[GHC]

#8944: Warn instead of stopping on misplaced Haddock comments
-------------------------------------+-------------------------------------
              Reporter:  Fuuzetsu    |            Owner:
                  Type:  feature     |           Status:  new
  request                            |        Milestone:
              Priority:  normal      |          Version:  7.9
             Component:  Compiler    |         Keywords:
  (Parser)                           |     Architecture:  Unknown/Multiple
            Resolution:              |       Difficulty:  Unknown
      Operating System:              |       Blocked By:
  Unknown/Multiple                   |  Related Tickets:
       Type of failure:              |
  None/Unknown                       |
             Test Case:              |
              Blocking:              |
Differential Revisions:  Phab:D452   |
-------------------------------------+-------------------------------------

Comment (by rodlogic):

 I didn't know that {{{make 2}}} existed, thanks for the tip.

 There is one thing that bothers me, though. It seems that it is going to
 be quite hard to get the parser behaving the same with/without the haddock
 flag (granted it may not be such an important problem). We'll need to
 change happy rules everywhere to make it accept the same source files.
 Wouldn't it make more sense to have comments in general (as opposed to
 haddock specific documentation attached to specific declarations) as first
 class AST nodes that can be included/excluded based on a general parse-
 comments flag? This way a parser plugin could be added to the pipeline,
 consume the AST with comments, and parse the comments however it wants
 based on whether it is before or after a declaration. And haddock could be
 completely independent from the GHC parser.

 I understand that this may be a big change that is not worth pursuing at
 this point in time, but I am curious about what your opinion is.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8944#comment:8>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler