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Multiple symbols definition

Cournapeau David cournape@atr.jp
Wed Aug 31 02:02:00 GMT 2005 
On Tue, 2005-08-30 at 09:23 -0700, David Daney wrote:
> Cournapeau David wrote:
> > Hi, 
> > 
> > 	I would like to know where I could find an good explanation about the
> > way that multiple definitions of one symbol are resolved at link time
> > and runtime ? My problem is that I would like to control the way that
> > multiple definition for one symbol are resolved, ie force to resolve the
> > symbol in one particular library. 
> > 
> > 	For example, let's say I want to wrap malloc calls in my dynamic
> > library, is it possible to link against a small wrapper library which
> > would define its own malloc, and to force the linker to resolve to this
> > wrapper library , and not to the C library ?
> > 
> 
> It sounds like you want to use --wrap.  The example in the ld 
> documentation for --wrap is nearly identical to what you describe.
> 
> David Daney
> 
The problem of wrap is that is does not wrap the calls made through
dynamic libraries. Let's say I am programming a library libbar, which
calls some functions of libfoo. The malloc calls in libfoo are not (and
cannot be, as far as I understood from one on my former question on this
list) wrapped when using --wrap, because the symbols are already
resolved in libfoo.

David
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