[GHC] #11759: can't decompose ghc.exe path

[GHC]

#11759: can't decompose ghc.exe path
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        Reporter:  erisco            |                Owner:  Phyx-
            Type:  feature request   |               Status:  patch
        Priority:  normal            |            Milestone:  8.2.1
       Component:  Driver            |              Version:  7.8.3
      Resolution:                    |             Keywords:
Operating System:  Windows           |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  Other             |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D2101
       Wiki Page:                    |
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Comment (by Tamar Christina <tamar@…>):

 In [changeset:"a3922083e8f41fc236972564dc2978f2a2d4ec13/ghc" a392208/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="a3922083e8f41fc236972564dc2978f2a2d4ec13"
 Resolve symlinks when attempting to find GHC's lib folder on Windows

 Summary:
 Systools makes some pretty hard assumptions about where GHC is on Windows.
 One of these is that ghc be in a folder named `bin` and that `../lib`
 exists.

 This pattern doesn't hold for symlinks as a link `C:\ghc-bin\`
 pointing to `C:\ghc\ghc-7.10.3\bin` will break this assumption.

 This patch resolves symlinks by finding where they point to and uses that
 location
 as the base for GHC.

 This uses an API that's been introduced in Vista. For older systems it
 falls back to
 the current behavior of not resolving symlinks.

 Test Plan:
 1) Create symlink to GHC's bin folder.
 2) Run GHC from that folder.

 Reviewers: austin, bgamari

 Reviewed By: austin

 Subscribers: #ghc_windows_task_force, thomie

 Differential Revision: https://phabricator.haskell.org/D2101

 GHC Trac Issues: #11759
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11759#comment:3>
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