Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!taumet!steve
From: steve@taumet.com (Stephen Clamage)
Newsgroups: comp.lang.c++
Subject: Re: signal in C++
Message-ID: <694@taumet.com>
Date: 25 Apr 91 18:43:23 GMT
References: <6475@male.EBay.Sun.COM>
Organization: Taumetric Corporation, San Diego
Lines: 27

chrisdc@mykids.EBay.Sun.COM (chris chang) writes:

>I am writing a C++ code under SunOS, am having a problem with using
>signal.  When I link the program, I get the following undefined 
>symbol from the loader: __signal__FiPFv_v.  Any idea?  Also, what is 
>the correct syntax for declaring the signal function prototype?

Boy, do we need a FAQ.  Any volunteers?  If someone will write it
up and maintain it, I will volunteer to review it.

You need to declare C library functions with
	extern "C"
Otherwise, the C++ compiler assumes they are C++ functions and assumes
a mangled name (type-safe linkage).  If you try to use the C header
files that come with SunOS, they do not have prototypes, but use
old-style C declarations.  These are unusable with C++.  I am told
that Sun C++ comes with its own set of header files with correct
C++ prototypes for all system functions (I have no direct experience
with Sun C++ however).

You don't say which C++ you are using.  If it doesn't supply C++
versions of the system include files, you will have to write your
own, put them in a convenient place, and use the -I directive to
get at them ahead of the standard include files.
-- 

Steve Clamage, TauMetric Corp, steve@taumet.com