How to initialize GNU guile in a C++ command line tool?

[Basile Starynkevitch <basile@starynkevitch.net>]

Hello,


My platform is Linux Debian sid x86-64 or Linux Ubuntu 22.10 x86-64. 
Using package guile-3.0-dev (version 3.0.8-2).


I want to drive the Frama-C <https://frama-c.com/> static analyzer with 
a C++ driving program which uses (optionally) Guile to run Frama-C.

My current code (GPLv3+) in on github. Inside the small 
https://github.com/bstarynk/misc-basile/ repository (a small thing, 
containing various unrelated programs and scripts).

For the commit 
https://github.com/bstarynk/misc-basile/commit/6c478ca7cd2d43bc203d0f2b0881a0cdeabaf633 
when I uncomment the lines 501 and 805 there is a link failure.

My guile_has_been_initialized is my global boolean flag.


I coded:


     if (!guile_has_been_initialized)
         {
             guile_has_been_initialized=true;
#warning BUG here related to guile
             //scm_init_eval();


and the build is failing

+ /usr/bin/g++ -O -g -I/usr/include/guile/3.0 -pthread -rdynamic 
clever-framac.cc '-DGIT_ID="6c478ca7cd2d"' -ldl -lguile-3.0 -lgc 
-lpthread -ldl -o clever-framac
clever-framac.cc:500:2: warning: #warning BUG here related to guile [-Wcpp]
   500 | #warning BUG here related to guile
       |  ^~~~~~~
clever-framac.cc:503:2: warning: #warning do_evaluate_guile 
unimplemented [-Wcpp]
   503 | #warning do_evaluate_guile unimplemented
       |  ^~~~~~~
clever-framac.cc:720:2: warning: #warning unimplemented inner_guile [-Wcpp]
   720 | #warning unimplemented inner_guile
       |  ^~~~~~~
clever-framac.cc:726:2: warning: #warning unimplemented do_use_guile [-Wcpp]
   726 | #warning unimplemented do_use_guile
       |  ^~~~~~~
clever-framac.cc:804:2: warning: #warning BUG here related to guile [-Wcpp]
   804 | #warning BUG here related to guile
       |  ^~~~~~~
clever-framac.cc:807:2: warning: #warning unimplemented use Guile here 
[-Wcpp]
   807 | #warning unimplemented use Guile here
       |  ^~~~~~~
/usr/bin/ld: /tmp/cc51HoPM.o: in function `do_evaluate_guile(char const*)':
/home/basile/misc-basile/clever-framac.cc:501: undefined reference to 
`scm_init_eval'
collect2: error: ld returned 1 exit status


Where is my mistake? Notice that -lguile-3.0 is linked!



Thanks for your help.



NB. I might borrow some code from GUILE into http://refpersys.org/


-- 
Basile Starynkevitch<basile@starynkevitch.net>
(only mine opinions / les opinions sont miennes uniquement)
92340 Bourg-la-Reine, France
web page: starynkevitch.net/Basile/