Path: utzoo!attcan!uunet!spool.mu.edu!uwm.edu!bionet!agate!usenet.ins.cwru.edu!odin!chet
From: chet@odin.INS.CWRU.Edu (Chet Ramey)
Newsgroups: comp.sys.next
Subject: Re: Library function redefinition
Message-ID: <1991Mar1.143756.12400@usenet.ins.cwru.edu>
Date: 1 Mar 91 14:37:56 GMT
References: <1991Feb28.190319.22658@usenet.ins.cwru.edu>
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Reply-To: chet@po.CWRU.Edu
Organization: Case Western Reserve Univ. Cleveland, Ohio, (USA)
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I wrote:

>I just got a NeXT box for a couple of days, and the first thing I built was
>bash (of course ;-).  When trying to use private versions of functions in
>libsys_s.a, this error results:
>
>>variables.o definition of _getenv in section (__TEXT,__text)
>>/lib/libsys_s.a(getenv.o) definition of absolute _getenv (value 0x50025d0)
>
>Is there a switch to cc or ld that will allow you to use a private version
>of a library function?

Before I get any more mail telling me to comment out the private getenv
definition, let me explain what I am after.

Bash (the Gnu Bourne-Again SHell) provides a private definition of getenv
that searches the list of exported variables (those variables passed to
children of the shell as the environment).  This is so the libraries that
Bash uses, most notably readline, will get the `intuitive' definition of
environment variables when they call getenv().  TERM, for instance. 

The `traditional' Unix linker satisfies only unresolved external references
from libraries.  This allows you to provide an application with a custom
malloc, for instance, and have all of the libraries that use malloc cooperate.
It seems that the NeXT/Mach ld simply maps the library into my process's
address space, and damn any symbols that I already defined.

What I would like is a switch to cc or ld that restores the traditional
behavior, even in the presence of shared libraries.  If it can't be done,
that's OK, too.

Chet
-- 
Chet Ramey				``Now, somehow we've brought our sins
Network Services Group			  back physically -- and they're
Case Western Reserve University		  pissed.''
chet@ins.CWRU.Edu		My opinions are just those, and mine alone.