[PPL-devel] Is Cygwin special?

16 Jan 2006

      I have something that runs under GNU/Linux and does not run
under Cygwin.  It all boils down to something very simple.
I have two files:

$ cat main.cc
#include <SWI-Prolog.h>

int
main(int, char** argv) {
   char* pl_args[2];
   pl_args[0] = argv[0];
   pl_args[1] = 0;
   if (!PL_initialise(1, pl_args))
     PL_halt(1);

   predicate_t pred = PL_predicate("mymain", 0, "user");
   term_t h0 = PL_new_term_refs(0);
   int ret_val = PL_call_predicate(0, PL_Q_NORMAL, pred, h0);
   PL_halt(ret_val ? 0 : 1);
}
$ cat mymain.pl
mymain :-
         write('mymain/0 called!'), nl.

I compile them under GNU/Linux:

$ g++ -I/usr/local/lib/pl-5.6.2/include -c main.cc
$ plld -v -cc gcc -c++ g++ -ld g++ -o test.exe main.o mymain.pl
         eval `pl -dump-runtime-variables`
                 CC="gcc"
                 PLBASE="/usr/local/lib/pl-5.6.2"
                 PLARCH="i686-linux"
                 PLLIBS="-lgmp -ldl -lreadline -lncursesw -lm -lrt"
                 PLLIB="-lpl"
                 PLLDFLAGS="-export-dynamic  -O3 -pthread"
                 PLSOEXT="so"
                 PLTHREADS="yes"
         g++ -o test.exe -export-dynamic  -O3 -pthread main.o -L/usr/local/lib/pl-5.6.2/lib/i686-linux -lpl -lgmp -ldl -lreadline -lncursesw -lm -lrt
         pl -f none -F none -g true -t "consult(['mymain.pl']),qsave_program('pltmp-8678',[goal='\$welcome',toplevel=prolog,init_file=none])"
% mymain.pl compiled 0.00 sec, 2,004 bytes
% halt
         cat pltmp-8678 >> test.exe
         chmod 775 test.exe
         rm pltmp-8678

I compile them in exactly the same way under Cygwin
(note: same version of SWI-Prolog, configured in the same way and
installed in the same place):

$ g++ -I/usr/local/lib/pl-5.6.2/include -c main.cc
$ plld -v -cc gcc -c++ g++ -ld g++ -o test.exe main.o mymain.pl
eval `pl -dump-runtime-variables`
% mymain.pl compiled 0.00 sec, 1,984 bytes
% halt
		CC="gcc"
		PLBASE="/usr/local/lib/pl-5.6.2"
		PLARCH="i686-cygwin"
		PLLIBS="-lgmp -lreadline -lncurses -lm -lpthread"
		PLLIB="-lpl"
		PLLDFLAGS="-export-dynamic  -O3"
		PLSOEXT="dll"
		PLTHREADS="yes"
	g++ -o test.exe -export-dynamic  -O3 main.o -L/usr/local/lib/pl-5.6.2/lib/i686-cygwin -lpl -lgmp -lreadline -lncurses -lm -lpthread
	pl -f none -F none -g true -t "consult(['mymain.pl']),qsave_program('pltmp-3416.exe',[goal='\$welcome',toplevel=prolog,init_file=none])"
	cat pltmp-3416.exe >> test.exe
	chmod 755 test.exe
	rm pltmp-3416.exe

However, when I run the result under GNU/Linux I get:

$ ./test.exe
Welcome to SWI-Prolog (Multi-threaded, Version 5.6.2)
Copyright (c) 1990-2005 University of Amsterdam.
SWI-Prolog comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to redistribute it under certain conditions.
Please visit http://www.swi-prolog.org for details.

For help, use ?- help(Topic). or ?- apropos(Word).

mymain/0 called!
$

When I run under Cygwin I get:

$ ./test.exe
Welcome to SWI-Prolog (Multi-threaded, Version 5.6.2)
Copyright (c) 1990-2005 University of Amsterdam.
SWI-Prolog comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to redistribute it under certain conditions.
Please visit http://www.swi-prolog.org for details.

For help, use ?- help(Topic). or ?- apropos(Word).

ERROR: Undefined procedure: mymain/0

What am I missing?
All the best,

     Roberto

-- 
Prof. Roberto Bagnara
Computer Science Group
Department of Mathematics, University of Parma, Italy
http://www.cs.unipr.it/~bagnara/
mailto:bagnara@cs.unipr.it