Re: [xmonad] darcs patch: strip generated binary

6 Feb 2009

      On 2009 Feb 5, at 11:24, Gwern Branwen wrote:
...
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On 2009 Feb 4, at 20:39, Gwern Branwen wrote:
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On Wed, Feb 4, 2009 at 7:51 PM, Don Stewart  wrote:
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How portable?
By a funny coincidence, I was messing with strip a few days ago (for
yi), and my discussion with dcoutts covered just this.
He told me that -optl-s was considered bad, as that option gets  
passed
to the linker and -s is apparently specific to GNU ld.
Er?  ld -s has worked since Version 7 UNIX.  Or is this about e.g.
Cygwin/mingw not implementing it?07:02:19 <dcoutts> gwern: -s is  
specific to the GNU linker I think. So
On Thu, Feb 5, 2009 at 10:43 AM, Brandon S. Allbery KF8NH
 wrote:
probably does not work on OSX, BSD, Solaris.
Solaris:

      -s    Strips symbolic information from the output file.  Any
            debugging  information,  that  is, .line, .debug*, and
            .stab*  sections,  and  their  associated   relocation
            entries  are  removed. Except for relocatable files, a
            symbol table  SHT_SYMTAB  and  its  associated  string
            table  section  are  not  created in the output object
            file. See also -z redlocsym.

FreeBSD, NetBSD: uses GNU ld

OSX 10.5:

      -s          Completely strip the output, including removing the  
symbol
                  table.  This file format variant is no longer  
supported.
                  This option is obsolete.

So we do have a portability issue, thanks to Apple changing a bunch of  
stuff relating to linking and object files in Leopard.  But:

        strip  no  longer  removes  relocation  entries  under  any   
condition.
        Instead, it updates the external relocation entries (and  
indirect  sym-
        bol table entries) to reflect the resulting symbol table.   
strip prints
        an error message for those symbols not in the  resulting   
symbol  table
        that  are  needed by an external relocation entry or an  
indirect symbol
        table.  The link editor ld(1) is the only program that can  
strip  relo-
        cation entries and know if it is safe to do so.

which to me says that strip can break working programs and is not  
recommended --- so strip isn't safe either on OSX.

And, for the record: from the 7th Research Edition manpages

	–s	‘Strip’ the output, that is, remove the symbol table and
		relocation bits to save space (but impair the usefulness
		of the debugger). This information can also be removed
		by strip(1).

ld -s goes back a long ways.

-- 
brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery@kf8nh.com
system administrator [openafs,heimdal,too many hats] allbery@ece.cmu.edu
electrical and computer engineering, carnegie mellon university    KF8NH