[GHC] #10358: ApiAnnotations : PatBind gives wrong SrcSpan for the pattern.

[GHC]

#10358: ApiAnnotations : PatBind gives wrong SrcSpan for the pattern.
-------------------------------------+-------------------------------------
        Reporter:  alanz             |                   Owner:  alanz
            Type:  bug               |                  Status:  patch
        Priority:  normal            |               Milestone:  7.10.2
       Component:  Compiler          |                 Version:  7.10.1
  (Parser)                           |                Keywords:
      Resolution:                    |  ApiAnnotations
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  None/Unknown      |  Unknown/Multiple
      Blocked By:                    |               Test Case:
 Related Tickets:                    |                Blocking:
                                     |  Differential Revisions:  Phab:D873
-------------------------------------+-------------------------------------

Comment (by Alan Zimmerman <alan.zimm@…>):

 In [changeset:"ecc3d6be218b1c7a36ee3f2f36c4f3ac4f45c34f/ghc"]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="ecc3d6be218b1c7a36ee3f2f36c4f3ac4f45c34f"
 ApiAnnotations : PatBind gives wrong SrcSpan for the pattern.

 Summary:
 The production for decl_no_th starts

     decl_no_th :: { Located (OrdList (LHsDecl RdrName)) }
             : sigdecl               { $1 }

             | '!' aexp rhs  {% do { let { e = sLL $1 $> (SectionR (sL1 $1
 (HsVar bang_RDR)) $2) };
                                     pat <- checkPattern empty e;
     ...

 The e value should be just the pattern, excluding the rhs, but the span
 created includes the rhs.

 Test Plan: ./validate

 Reviewers: hvr, austin

 Reviewed By: austin

 Subscribers: bgamari, thomie, mpickering

 Differential Revision: https://phabricator.haskell.org/D873

 GHC Trac Issues: #10358
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10358#comment:3>
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