Creation of import libraries for Windows

[dnewbie]

On Thursday, 10 January 2013 at 17:29:13 UTC, Phil Lavoie wrote:
> Hi all,
>
> This is actually a duplicate of my post on the D.learn forums 
> :).
> I am concerned that it hasn't been answered only because it is 
> in a less popular sub forum. I'll try to make it short.
>
> This websites recommends implib for the creation of import 
> library therefore I have been using it. When I compile + link 
> my code containing "extern( Windows )" function declarations, I 
> get the following messages:
> Error 42: Symbol Undefined _functionName at ordinal (generic case)
> Error 42: Symbol Undefined _glGetIntegerv at 8 (just an example)
>
> Let's hypothesize that I am using "shared.dll" and I would like 
> to "statically" link against it using an import library. I use 
> this command: implib /noi /system shared.lib ..\shared.dll
> To generate the import library. Once done, I make sure the 
> linker finds it and rebuild the program. I get the same errors.


Hello Phil Lavoie.
Yes, sometimes implib works and sometimes it doesn't.

Please check
http://blogs.msdn.com/b/oldnewthing/archive/2006/07/27/679634.aspx

"The fact that names in import libraries are decorated means that 
it is doubly crucial that you use the official import library for 
the DLL you wish to use rather than trying to manufacture one 
with an import library generation tool. As we noted earlier, the 
tool won't know whether the ordinal assigned to a named function 
was by design or merely coincidental. But what's more, the tool 
won't know what decorations to apply to the function (if the name 
was exported under an undecorated name). Consequently, your 
attempts to call the function will fail to link since the 
decorations will most likely not match up."

> Therefore, I looked into the import library only to find that 
> no exported symbols have and ordinal appended (@someInt), 
> CONTRARILY to the symbols you can find in the import library 
> provided by the compiler (..\D\windows\lib\*).

.. at someInt is actually called a 'decoration'.

>
> So... how were those generated in the first place (what makes 
> them have those ordinals, was this an automated process or did 
> someone actually wrote the module definition files by hand)?

I can't give you an exact answer (I'm not from Digital Mars :)), 
but I believe they used 
http://www.digitalmars.com/ctg/coffimplib.html against the 
official .libs from the Windows SDK. Writing .def by hand is also 
an option.


> How and why is extern( Windows ) generating symbol calls 
> expecting ordinals for stdcall conventions (how does it know 
> that _glGetIntegerv has an ordinal of 8 for example)? Is the 
> ordinal a desirable requirement for those calls?
>

From
http://msdn.microsoft.com/en-us/library/zxk0tw93(v=vs.71).aspx
"An underscore (_) is prefixed to the name. The name is followed 
by the at sign (@) followed by the number of bytes (in decimal) 
in the argument list. Therefore, the function declared as int 
func( int a, double b ) is decorated as follows: _func at 12"

Conclusion
If you have the shared.dll only, try 'implib' or 'implib 
/system'. This may not work if the .dll contains stdcall 
functions exported as 'undecorated'.
If you have the official shared.lib, try coffimplib.
If you have both shared.dll and shared.h, you can write a module 
definition file by hand.