Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!wuarchive!kuhub.cc.ukans.edu!markv
From: markv@kuhub.cc.ukans.edu
Newsgroups: comp.sys.amiga.tech
Subject: Re: Lattice C -- %f format
Message-ID: <22329.25e2b2f2@kuhub.cc.ukans.edu>
Date: 21 Feb 90 21:25:37 GMT
References: <2427@se-sd.NCR.COM>
Distribution: na
Organization: University of Kansas Academic Computing Services
Lines: 55

> I get an "undefined symbol" message at link time when I compile
> and link the following test program on Lattice C 5.04 --
> 
> #include <stdio.h>
> 
> main()
> {
>   float fl = 1.0;
>   printf("%f\n", fl);
> }
> 
> I simply compiled it and linked it by typing "lc -L dummy" (
> the program was dummy.c).  

Yes, you need to say "lc -Lm dummy".  The m tells lc to tell BLink to
use the lcm.lib (default math library).  You can tell lc "-LXXX" where
XXX is the name of any link library (minus the lc).  So to use the FFP
library instead (lcmffp) as an example say "lc -Lmffp dummy".

By the way, the Lattice 5.04 libraries have some bugs in their
handling of the %f stuff, (CodeProbe does too).  These are fixed with
the 5.04a pathes which are available on BIX or the Lattice BBS.
 
> The problem is definetly with the %f format, it works fine if the
> float is replaced by an int and %d is used.

Yes, printf() does a function call to convert the %f, and that
function is in the math libraries.
 
> I am an experienced C programmer but completely new to programming
> on the Amiga.   I suspect that the linker is not pulling in some
> floating point library.

The Blink (or lc driving Blink) never automatically pulls in the math
libraries, even if you give a floating point option to the compiler
phase on the lc command line.
 
> Please email any help to ewing@se-sd.sandiego.ncr.com.  My apologies
> if this  is completely bone-headed or has been discussed ad infinitum
> (I couldn't find any reference in my perusal of newuser).

The documentation is fairly fuzzy on the details of which .lib or .o
file is needed and does what, etc.
 
> Dave Ewing
> ewing@se-sd.sandiego.ncr.com
-- 
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