Home Original page

PE-COFF and import tables

Pedro Alves pedro@codesourcery.com
Sun May 10 12:05:00 GMT 2009 
On Sunday 10 May 2009 12:42:01, Vincent R. wrote:

> I tried to understand why only _fileno and _strdup are put in a separate
> entry and the only common
> point is the fact these two symbols are actually defines and also that they
> are defined in libcoredll.a 
> and in libceoldname.a
> 
> in libcoredll.a they are defined as : _strdup and _fileno (prefixed by a _)
> in libceoldname.a they are defined as : strdup and fileno

The underscored versions are what really exists in coredll.dll.  lib*oldname.a
is a compatibility import lib that through .def file magic allows references
to a few non-underscored functions to still link and resolve to the underscored
versions, otherwise, this wouldn't link:

 int main ()
 {
    strdup (0);
 }

, because there's no real strdup function in MSFT's runtimes.

The proper way to write that for Windows would be:

 int main ()
 {
    _strdup (0);
 }

, but, this is a portability nuisance, hence, the magic *oldname.a
import lib.

You have references to both `strdup' and `fileno' somewhere
in your code.

-- 
Pedro Alves
More information about the Binutils mailing list