[GHC] #13792: Allow building using distro GCC on Windows

[GHC]

#13792: Allow building using distro GCC on Windows
-------------------------------------+-------------------------------------
        Reporter:  Phyx-             |                Owner:  Phyx-
            Type:  feature request   |               Status:  patch
        Priority:  normal            |            Milestone:  8.4.1
       Component:  Build System      |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Windows           |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D3637
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by Tamar Christina <tamar@…>):

 In [changeset:"fda094d000cf2c2874a8205c8212cb83b52259ef/ghc" fda094d/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="fda094d000cf2c2874a8205c8212cb83b52259ef"
 Provide way to build using existing C compiler on Windows.

 Summary:
 There are various distros that build GHC using their own C compilers
 such as MSYS2. Currently they have to patch the build scripts everytime.

 This patch provides the configure argument `--enable-distro-toolchain`
 which allows one to build using any C compiler on the path.

 This is also useful for testing new versions of GCC.

 Test Plan:
 ./configure --enable-distro-toolchain && make - && make THREADS=9 test
 ./validate

 Reviewers: austin, hvr, bgamari

 Reviewed By: bgamari

 Subscribers: rwbarton, thomie, erikd, #ghc_windows_task_force

 GHC Trac Issues: #13792

 Differential Revision: https://phabricator.haskell.org/D3637
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13792#comment:3>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler