[GHC] #15837: Hadrian should build dynamically linked ghc binary

[GHC]

#15837: Hadrian should build dynamically linked ghc binary
-------------------------------------+-------------------------------------
        Reporter:  davide            |                Owner:  davide
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Build System      |              Version:  8.6.1
  (Hadrian)                          |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D5385
       Wiki Page:                    |  Phab:D5327
-------------------------------------+-------------------------------------

Comment (by davide):

 When looking at the output of make I get:

 {{{
 $ find . -name "*ffi*.so*" -or -name "*ffi*.a*"
 ./libffi/build/x86_64-unknown-linux-gnu/.libs/libffi_convenience.a
 ./libffi/build/x86_64-unknown-linux-gnu/.libs/libffi.so.7.1.0
 ./libffi/build/x86_64-unknown-linux-gnu/.libs/libffi.so.7
 ./libffi/build/x86_64-unknown-linux-gnu/.libs/libffi.so
 ./libffi/build/x86_64-unknown-linux-gnu/.libs/libffi.a
 ./libffi/build/inst/lib/libffi.so.7.1.0
 ./libffi/build/inst/lib/libffi.so.7
 ./libffi/build/inst/lib/libffi.so
 ./libffi/build/inst/lib/libffi.a
 ./rts/dist/build/libCffi_p.a
 ./rts/dist/build/libffi.so
 ./rts/dist/build/libffi.so.7
 ./rts/dist/build/libffi.so.7.1.0
 ./rts/dist/build/libCffi_l.a
 ./rts/dist/build/libCffi_debug.a
 ./rts/dist/build/libCffi_thr.a
 ./rts/dist/build/libCffi_thr_debug.a
 ./rts/dist/build/libCffi_thr_l.a
 ./rts/dist/build/libCffi_thr_p.a
 ./rts/dist/build/libCffi_thr_debug_p.a
 ./rts/dist/build/libCffi_debug_p.a
 ./rts/dist/build/libCffi.a
 }}}

 Note that all the `libCffi*.a` files are identical, and all `libCffi*.so`
 files are identical.

 == Dynamic

 This matches closely with my previous comments, but with the addition of
 some extra versioned .so files. Note the symlinks:

 {{{
 $ ls -l _build/stage1/libffi/build/inst/lib/libffi.so*
 lrwxrwxrwx 1 david david    15 Dec  6 10:28
 _build/stage1/libffi/build/inst/lib/libffi.so -> libffi.so.7.1.0
 lrwxrwxrwx 1 david david    15 Dec  6 10:28
 _build/stage1/libffi/build/inst/lib/libffi.so.7 -> libffi.so.7.1.0
 -rwxr-xr-x 1 david david 70232 Dec  6 10:28
 _build/stage1/libffi/build/inst/lib/libffi.so.7.1.0
 }}}

 == Static
 This matches hadrians behavior w.r.t static libffi. On that grounds I'm
 going to leave the static libs behavior as is, but add a note about
 possible simplification here: only copy a single .a file as we will do
 with the dynamic version.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15837#comment:19>
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