compiler produces wrong symbol in Fortran to C call

[Intel_C_Intel]

I am calling a C function defined in a static library as:

extern "C" long getnumparams(long* modHandle);

Dumpbin shows the object name as:

_getnumparams

which is what I would expect.

My Fortran codedefinesthis interface:

interface
integer function getnumparams(id)
!dec$attributes c, alias : '_getnumparams' :: getnumparams

integerid
end function getnumparams
end interface

and calls the routine thus:

numparams = getnumparams(myId)

The linker complains that it can't find

Linking...
Creating library Debug/myLib.lib and object Debug/myLib.exp
myRoutine.obj : error LNK2001: unresolved external symbol _GETNUMPARAMS@4

In other words, for an interface declaring a C function, it seems that the compiler is not applying the C attribute, i.e. not removing the @argument size name decoration. Can anyone see what I'm doing wrong, or is this a compiler bug?

[Intel_C_Intel]

btw, I am using CVF 6.6b.

[Steven_L_Intel1]

I would say that the interface isn't visible where you're doing the call.Note that the lowercase alias isn't used either.

[Intel_C_Intel]

Thanks for the quick reply Steve. I did manage to fix it almost as soon as I posted the second message! I put the interface into a module and it linked nicely.

However, I am still a bit confused. You say the interface isn't visible when the call is made. The interface was declared with the variable declarations in the subroutine that the C function was called from. The subroutine is in a fixed format file (.for). Thenew module is contained in a free format file.

What part of this is the magic incantation that makes it work?

[Steven_L_Intel1]

I would have to see the actual source in order to comment intelligently.

[Intel_C_Intel]

Here is an approximation of the 'before' code :

Code:

	subroutine someroutine()
	implicit none
	interface
	integer function getnumparams(id)
	!dec$attributes C, alias : '_getnumparams' :: getnumparams
			integer id
		end function getnumparams
	end interface
	
	integer nparms
	integer myid
!
	myid = 12
	nparms = getnumparms(myid)

	end

Moving the interface from this method to a new module fixes the link errors.

[Steven_L_Intel1]

Got it. You went past column 72 in the directive, since you're using fixed source form.

[Intel_C_Intel]

D'oh! Is my face red! Thanks for your help Steve.

[Steven_L_Intel1]

Happens all the time... Things such as this are why I always use free-form in my own coding.