[GHC] #10320: -ddump-to-file should create empty dump files when there was nothing to dump

[GHC]

#10320: -ddump-to-file should create empty dump files when there was nothing to
dump
-------------------------------------+-------------------------------------
        Reporter:  rwbarton          |                Owner:  tvv
            Type:  bug               |               Status:  patch
        Priority:  low               |            Milestone:
       Component:  Compiler          |              Version:  7.10.1
      Resolution:                    |             Keywords:  newcomer
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D1514
       Wiki Page:                    |
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Comment (by Ben Gamari <ben@…>):

 In [changeset:"8cba907ad404ba4005558b5a8966390159938172/ghc"
 8cba907a/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="8cba907ad404ba4005558b5a8966390159938172"
 Create empty dump files when there was nothing to dump

 This patch creates empty dump file when GHC was run with
 `-ddump-rule-firings` (or `-ddump-rule-rewrites`) and `-ddump-to-file`
 specified, and there were no rules applied. If dump already exists it
 will be overwritten by empty one.

 Test Plan: ./validate

 Reviewers: austin, thomie, bgamari

 Reviewed By: thomie, bgamari

 Subscribers: thomie

 Projects: #ghc

 Differential Revision: https://phabricator.haskell.org/D1514

 GHC Trac Issues: #10320
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10320#comment:6>
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