Problem compiling .cpp file

Problem compiling .cpp file

[jblazi]

I have the following file:

#include <guile/gh.h>
#include <stdio.h>

SCM test_function(SCM n)
{
  printf("Die Zahl ist %d\n",SCM_INUM(n));
  return SCM_EOL;
}

void register_procs(void)
{
    gh_new_procedure("test_function",test_function,1,0,0);
}


void inner_main(int argc, char **argv)
{
    register_procs();
    gh_repl(argc, argv);
}

main(int argc,char *argv[])
{
    gh_enter(argc, argv, inner_main);
    return(0); /* never reached */
}

I am compiling the file with
 gcc -Iusr/include test2.c -o test2 -lguile -lm

This more or less works (it does not work really as I get error messages when 
I call the function test_function from Guile, but at least after the first 
call the text is displayed.)

But when I try to compile the same file as a .cpp file, it does not work:

Administrator@PAPUA-8ZRG78JQB ~/c-programme
$ mv test2.c test2.cpp

Administrator@PAPUA-8ZRG78JQB ~/c-programme
$ gcc -Iusr/include test2.cpp -o test2 -lguile -lm
test2.cpp: In function `void register_procs()':
test2.cpp:12: invalid conversion from `
   scm_unused_struct*(*)(scm_unused_struct*)' to `scm_unused_struct*(*)()'
*/

I use the latest Cygwin (with gcc 3.2) on Win2K.

Can anybody help me?

TIA,
-- 
Janos Blazi



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Problem compiling .cpp file

[jblazi]

I have the following file:

#include <guile/gh.h>
#include <stdio.h>

SCM test_function(SCM n)
{
  printf("Die Zahl ist %d\n",SCM_INUM(n));
  return SCM_EOL;
}

void register_procs(void)
{
    gh_new_procedure("test_function",test_function,1,0,0);
}


void inner_main(int argc, char **argv)
{
    register_procs();
    gh_repl(argc, argv);
}

main(int argc,char *argv[])
{
    gh_enter(argc, argv, inner_main);
    return(0); /* never reached */
}

I am compiling the file with
 gcc -Iusr/include test2.c -o test2 -lguile -lm

This more or less works (it does not work really as I get error messages when 
I call the function test_function from Guile, but at least after the first 
call the text is displayed.)

But when I try to compile the same file as a .cpp file, it does not work:

Administrator@PAPUA-8ZRG78JQB ~/c-programme
$ mv test2.c test2.cpp

Administrator@PAPUA-8ZRG78JQB ~/c-programme
$ gcc -Iusr/include test2.cpp -o test2 -lguile -lm
test2.cpp: In function `void register_procs()':
test2.cpp:12: invalid conversion from `
   scm_unused_struct*(*)(scm_unused_struct*)' to `scm_unused_struct*(*)()'
*/

I use the latest Cygwin (with gcc 3.2) on Win2K.

Can anybody help me?

TIA,
-- 
Janos Blazi



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Bug-guile mailing list
Bug-guile@gnu.org
http://mail.gnu.org/mailman/listinfo/bug-guile

Re: Problem compiling .cpp file

[Marius Vollmer]

jblazi <jblazi@gmx.de> writes:

> test2.cpp: In function `void register_procs()':
> test2.cpp:12: invalid conversion from `
>    scm_unused_struct*(*)(scm_unused_struct*)' to `scm_unused_struct*(*)()'
> */

You need to use an explicit cast in C++:

    gh_new_procedure("test_function",(SCM (*)())test_function,1,0,0);

You also should not use SCM_INUM.  It does no error checking and works
only with 'fixnums' (small integers).  Use scm_num2int instead:

    SCM test_function(SCM n)
    {
      printf ("Die Zahl ist %d\n", scm_num2int (n, 1, "test_function"));
      return SCM_EOL;
    }

-- 
GPG: D5D4E405 - 2F9B BCCC 8527 692A 04E3  331E FAF8 226A D5D4 E405


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