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@ordinal (generic case)
Error 42: Symbol Undefined _glGetIntegerv@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\*).
..@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@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.
