Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!crdgw1!rpi!leah!emb978
From: emb978@leah.Albany.Edu (Eric M. Boehm)
Newsgroups: comp.lang.c++
Subject: Calling C++ functions from MASM using Zortech 2.0
Keywords: MASM, name mangling, Zortech, C++
Message-ID: <2343@leah.Albany.Edu>
Date: 20 Dec 89 23:57:10 GMT
Organization: The University at Albany, Computer Services Center
Lines: 35

I ran into a little problem while trying to recompile a multitasking
demo from DDJ (by Tom(?) Green). The demo ran fine under Zortech 1.07
but now it doesn't link.

I fixed the problem with calling assembler functions from c++ by using:
extern "C" {...}

However, the assembler file (timer.asm) wants to call:

task_image far * task_control::task_switch(task_image far *, unsigned
int, signal *);

The problem is that name mangling creates an identifier 53 characters
long and masm only accepts 31 character identifiers. I tried a hack (my
apologies if this is obviously dumb) by:

typedef task_image far * (*taskptr)(task_image far*, unsigned int,
signal *);
taskptr x = task_control::task_switch;

The compiler first didn't like it because the function was private. I
made it public and then it was a syntax error (expected '(' after
task_switch).

I haven't looked yet at the proper way to declare pointers to member
functions (which is probably why I got a syntax error) but I don't think
that will work since Zortech 2.0 doesn't support pointers to members.

Any solutions (obvious or otherwise) would be appreciated.


-- 
Eric M. Boehm
EMB978@leah.Albany.EDU
EMB978@ALBNYVMS.BITNET