[GHC] #16045: improve dwarf support on OSX

[GHC]

#16045: improve dwarf support on OSX
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        Reporter:  carter        |                Owner:  (none)
            Type:  bug           |               Status:  new
        Priority:  normal        |            Milestone:
       Component:  Compiler      |              Version:  8.7
      Resolution:                |             Keywords:
Operating System:  MacOS X       |         Architecture:  x86_64 (amd64)
 Type of failure:  None/Unknown  |            Test Case:
      Blocked By:                |             Blocking:
 Related Tickets:                |  Differential Rev(s):
       Wiki Page:                |
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Comment (by fghibellini):

 From recent communication with @bgamari
 > At the moment it's not even possible to compile GHC with debug
 > symbols enabled due to apparent limitations in the MachO object format
 > (we seem to generate more sections than MachO can represent).
 >
 > It would be helpful if you could open a GHC ticket. ... it would be good
 > to record the current status of DWARF on Darwin.

 Currently https://ghc.haskell.org/trac/ghc/wiki/DWARF has a paragraph:
 > For Mac Os, debug information is kept separate from the binary, so we
 first have to package it using dsymutil:
 And from https://downloads.haskell.org/~ghc/latest/docs/html/users_guide
 /debug-info.html :
 > Under Mac OS X debug information is kept apart from the executable.
 After compiling the executable you’ll need to use the dsymutil utility to
 extract the debugging information and place them in the debug archive,

 Both pages make the user think that this is possible - I don't understand
 how the comments got there in the first place if there is no support for
 it.

 Would be nice to replace those comments with warnings so others don't
 spend time trying to understand why it doesn't work on their machine.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16045#comment:3>
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