[GHC] #10549: floatExpr tick break<2>

[GHC]

#10549: floatExpr tick break<2>
-------------------------------------+-------------------------------------
        Reporter:  NeilMitchell      |                   Owner:  bgamari
            Type:  bug               |                  Status:  patch
        Priority:  high              |               Milestone:  7.10.3
       Component:  Compiler          |                 Version:  7.10.2
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |               Test Case:  T10549
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:  Phab:D1128
-------------------------------------+-------------------------------------

Comment (by Ben Gamari <ben@…>):

 In [changeset:"eca9a1a17c12d01636417fb88bda5ee5fe34577f/ghc"
 eca9a1a1/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="eca9a1a17c12d01636417fb88bda5ee5fe34577f"
 Ensure DynFlags are consistent

 While we have always had makeDynFlagsConsistent to enforce a variety of
 consistency invariants on DynFlags, it hasn't been widely used.
 GHC.Main, for instance, ignored it entirely. This leads to issues like
 Trac #10549, where an OPTIONS_GHC pragma introduced an inconsistency,
 leading to a perplexing crash later in compilation.

 Here I add consistency checks in GHC.Main.set{Session,Program}DynFlags,
 closing this hole.

 Fixes #10549.

 Test Plan: Validate with T10549

 Reviewers: austin

 Subscribers: thomie

 Differential Revision: https://phabricator.haskell.org/D1128

 GHC Trac Issues: #10549
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10549#comment:10>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler