Exported functions not present in C DLL on x64 bit platforms, WHY ??

Discussion in 'Windows 64bit' started by Server Applications, Sep 4, 2006.

  1. Hi,

    I'am trying to port a 32bit application to 64bit.

    It is a dll and a exe (console) app. My problem is that the dll generated
    for the x64 platform does not contains any of the exported functions. The
    application crashes when it tries to call one of the functions located in
    the dll.

    Depency Walker also shows that they are missing. I can't figure out why. I
    have tried using a def file and __declspecs(dllexport). It does not work on
    the x64 bit platform. On the 32 bit platform they work perfect. If I run the
    32bit version on the 64, it works fine, but that is not what I want :-(

    I have tried to make some small test programs (dll + exe) from the visual
    studio templates, here the dll also has the same problem. The export
    functions are "invisible".

    The application is build with VS 2005 team edition on a 32 bit system. I
    have not tried to build on the 64 bit platform.

    Any ideas ??

    Jan A.
    Server Applications, Sep 4, 2006
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  2. Jan -
    This is, primarily, an enduser and IT Pro newsgroup, though there are a
    few developers who swing by periodically. You may get a faster response over
    in one of the MSDN newsgroups or on the MSDN "forums", if you can stand the
    web interface.

    Charlie Russel - MVP, Sep 4, 2006
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  3. Hi, I have no experience with porting stuff, but if I am not totally wrong
    about this, the 'calling-convention' of a DLL is 'special', your app may not
    get a respons from the DLL when it calls out for those functions, take a
    close look on this issue - and make sure that the calling-convention
    conforms to 64bit requirements. If Dependency Walker is 64bit aware on it's
    own, and not just running fine on 64bit, it may well be a victim of the very
    same thing, as I see it.

    And as Charlie said - there are other's that do it better.

    Tony. . .
    Tony Sperling, Sep 5, 2006
  4. Server Applications, Sep 5, 2006
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