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Re: Discarding unneeded object files

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Le 29/11/2019 à 19:36, Frederick Gotham a écrit :
> I have a 3rd party library which is 50 - 100 source files.
> 
> I compile this library to produce a static shared library. All of the object files are gathered together into an archive (In Linux, this is a ".a" file).
> 
> I then write my own program which links with this static library. For example:
> 
>      gcc main.c -o program -l:libmonkey.a
> 
> When the GNU linker links my own program with the archive file, it only links with the object files inside the archive which are needed.
> 
> If I had not created the archive file... If I had simply linked my own program with all of the 50-100 object files, then my program would have linked with every single object file -- possibly resulting in unreachable code in the output binary.
> 
> So... when the linker links with an archive file, it is smart enough to know which object files are needed, and which are not needed.
> 
> Is there any way to get a list of which object files are actually needed when a program links with an archive file? If I can get such a list, I can remove the redundant object files from the project, and then go on to tweak the object files that are actually needed.
> 
> I need to reduce a library of nearly a hundred source files, to about ten source files, and then go through each of these 10 source files an apply __attribute__ to every function.
> 

You should add the option -M or --print_map to the linker command line. 
This option will generate a listing of all the addresses of all the 
functions in the executable with their correspoçnding OBJECT FILE, so 
you can read the list of object files used very easily.

jacob

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Discarding unneeded object files Frederick Gotham <cauldwell.thomas@gmail.com> - 2019-11-29 10:36 -0800
  Re: Discarding unneeded object files Bart <bc@freeuk.com> - 2019-11-29 19:29 +0000
    Re: Discarding unneeded object files Frederick Gotham <cauldwell.thomas@gmail.com> - 2019-12-01 05:13 -0800
      Re: Discarding unneeded object files gazelle@shell.xmission.com (Kenny McCormack) - 2019-12-01 14:52 +0000
        Re: Discarding unneeded object files Frederick Gotham <cauldwell.thomas@gmail.com> - 2019-12-01 07:01 -0800
          Re: Discarding unneeded object files gazelle@shell.xmission.com (Kenny McCormack) - 2019-12-01 15:06 +0000
          Re: Discarding unneeded object files Richard Damon <Richard@Damon-Family.org> - 2019-12-01 19:32 -0500
            Re: Discarding unneeded object files Frederick Gotham <cauldwell.thomas@gmail.com> - 2019-12-02 00:00 -0800
        Re: Discarding unneeded object files David Brown <david.brown@hesbynett.no> - 2019-12-01 17:17 +0100
  Re: Discarding unneeded object files Richard Damon <Richard@Damon-Family.org> - 2019-11-29 14:30 -0500
  Re: Discarding unneeded object files jacobnavia <jacob@jacob.remcomp.fr> - 2019-11-30 23:44 +0100
  Re: Discarding unneeded object files Jorgen Grahn <grahn+nntp@snipabacken.se> - 2019-12-01 08:42 +0000
    Re: Discarding unneeded object files Frederick Gotham <cauldwell.thomas@gmail.com> - 2019-12-01 05:10 -0800
      Re: Discarding unneeded object files gazelle@shell.xmission.com (Kenny McCormack) - 2019-12-01 14:51 +0000
      Re: Discarding unneeded object files Ben Bacarisse <ben.usenet@bsb.me.uk> - 2019-12-01 17:26 +0000
        Re: Discarding unneeded object files gazelle@shell.xmission.com (Kenny McCormack) - 2019-12-01 17:43 +0000
          Re: Discarding unneeded object files Richard Damon <Richard@Damon-Family.org> - 2019-12-01 20:04 -0500
    Re: Discarding unneeded object files Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-12-01 09:39 -0800
      Re: Discarding unneeded object files gazelle@shell.xmission.com (Kenny McCormack) - 2019-12-01 17:45 +0000
      Re: Discarding unneeded object files Jorgen Grahn <grahn+nntp@snipabacken.se> - 2019-12-02 13:15 +0000
        Re: Discarding unneeded object files Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-12-06 22:05 -0800

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