[GHC] #9245: In absence of recursive imports, hs-boot files not checked for consistency

[GHC]

#9245: In absence of recursive imports, hs-boot files not checked for consistency
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        Reporter:  ezyang              |            Owner:  ezyang
            Type:  bug                 |           Status:  new
        Priority:  normal              |        Milestone:
       Component:  Compiler            |          Version:  7.9
      Resolution:                      |         Keywords:
Operating System:  Unknown/Multiple    |     Architecture:
 Type of failure:  Compile-time crash  |  Unknown/Multiple
       Test Case:                      |       Difficulty:  Unknown
        Blocking:                      |       Blocked By:
                                       |  Related Tickets:
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Comment (by Edward Z. Yang <ezyang@…>):

 In [changeset:"0763a2f2eec4f6d9933fe17ee0d4a3a57823e6bf/ghc"]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="0763a2f2eec4f6d9933fe17ee0d4a3a57823e6bf"
 Fix #9245 by always checking hi-boot for consistency if we find one.

 Summary:
 What this fix does is reorder how we look for hi-boot files: we
 unconditionally check for an hi-boot file, and if we don't find one, we
 check the import graph to see if there was circularity.  This is as
 opposed to the previous scheme (check for circularity, then load hi-boot
 file).

 This costs us an extra file system access every typecheck, which
 is not the best.

 Signed-off-by: Edward Z. Yang <ezyang at cs.stanford.edu>

 Test Plan: Validate and check for compiler regressions in nofib

 Reviewers: simonpj, austin

 Subscribers: simonmar, relrod, carter

 Differential Revision: https://phabricator.haskell.org/D30
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9245#comment:3>
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