CGAL users discussion list

[Marc Glisse <>]

On Fri, 13 May 2011, Gaurav Kanade wrote:

> I am a new user of CGAL and have some problems with issues involving
> linking libraries.

This is not really a CGAL question but a general question about linking.

> I use the command
>
> g++ -lCGAL -lCGAL_Core Scenario.cpp
> /usr/bin/ld: /tmp/ccydV8IU.o: undefined reference to symbol 'mpfr_set_q'
> /usr/bin/ld: note: 'mpfr_set_q' is defined in DSO
> /usr/lib64/libmpfr.so.1 so try adding it to the linker command line
> /usr/lib64/libmpfr.so.1: could not read symbols: Invalid operation
> collect2: ld returned 1 exit status
>
> Now based upon the suggestion it gave me I tried to link the file
> libmpfr.so.1 and then it gives
>
> g++ -lCGAL -lCGAL_Core -llibmpfr.so.1 Scenario.cpp
> /usr/bin/ld: cannot find -llibmpfr.so.1
> collect2: ld returned 1 exit status
>
> I know that the file exists in /usr/lib64 as I can see it there ...
> any idea how to resolve this ?

Look at -lCGAL. Do you have a file CGAL in /usr/lib64? What you actually 
have is a file called libCGAL.so (or libCGAL.a). As explained in the man 
pages of gcc and ld, -lsmurf corresponds to the file libsmurf.so. So you 
actually want -lmpfr (and probably -lgmp afterwards).

--
Marc Glisse