[GHC] #8405: experiment with using function-sections for linking (for smaller libs and executables)

[GHC]

#8405: experiment with using function-sections for linking (for smaller libs and
executables)
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        Reporter:  carter            |                   Owner:  olsner
            Type:  task              |                  Status:  new
        Priority:  normal            |               Milestone:  7.12.1
       Component:  Compiler          |                 Version:  7.6.3
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:
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Changes (by olsner):

 * owner:   => olsner


Comment:

 It seems GNU ld actually has scalability issues with very large numbers of
 sections too, unfortunately. Found out because I was building libHSghc
 with split sections, and getting 10 minute link times on some test cases
 with plugins linking statically against ghc... Since split-objs is
 specifically disabled for that code I simply disabled split-sections as
 well.

 A much cleaned up version of the patch now at
 https://github.com/olsner/ghc/commits/function-sections-2 - this adds a
 -split-sections flag that controls the splitting when compiling Haskell
 code. --gc-sections is always added to the linker command line. (Vague
 rationale being that after building libraries with split sections, we'll
 want to bring space savings to users without manual steps or extra flags
 building their programs/libraries.)

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8405#comment:11>
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