Embedding perl and exposing xs functions

BUU has asked for the wisdom of the Perl Monks concerning the following question:

Basically I'm trying to create a file that creates an embedded perl interpreter and exposes various XS functions to the created interpreter. I wish to do this in the same file mainly for simplicity reasons, I actually need to run this code inside of a much larger project and I think it will simplify things a great deal to have easy access to the functions I'm wrapping. Here's the code:

#include <EXTERN.h>               /* from the Perl distribution     */
#include <perl.h>                 /* from the Perl distribution     */
#include <XSUB.h>
#include <stdlib.h>

static PerlInterpreter *my_perl;  /***    The Perl interpreter    ***/

void say( char *m )
{
    printf("I am say: %s", m );
}

XS(XS_Module_say); /* prototype to pass -Wmissing-prototypes */
XS(XS_Module_say)
{
    dXSARGS;
    if (items != 1)
  Perl_croak(aTHX_ "Usage: Module::say(message)");
    {
  char *  message = (char *)SvPV_nolen(ST(0));

  say(message);
    }
    XSRETURN_EMPTY;
}

#ifdef __cplusplus
extern "C"
#endif
XS(boot_Module); /* prototype to pass -Wmissing-prototypes */
XS(boot_Module)
{
    dXSARGS;
    char* file = __FILE__;

    XS_VERSION_BOOTCHECK ;

        newXS("Module::say", XS_Module_say, file);
    XSRETURN_YES;
}

int main(int argc, char **argv, char **env)
{
    char *embedding = { "", "-e", "0" };

    PERL_SYS_INIT3(&argc,&argv,&env);
    my_perl = perl_alloc();
    perl_construct(my_perl);
    PL_exit_flags |= PERL_EXIT_DESTRUCT_END;
    perl_parse(my_perl, NULL, argc, argv, (char **)NULL);
    perl_run(my_perl);
    perl_destruct(my_perl);
    perl_free(my_perl);
    PERL_SYS_TERM();
}
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The problem is when I run it, I see no sign of my XS function ("say") in either main:: or Module::. It occurred to me that perhaps I need to call "boot_Module", which apparently takes two arguments: a perl_interpreter, which I have, and a CV*, which I don't. I've tried various combinations of arguments to boot_Module, but it constantly segfaults. What is the right thing to pass?

Comment on Embedding perl and exposing xs functions Download Code

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Re: Embedding perl and exposing xs functions
by PodMaster (Abbot) on Dec 19, 2005 at 09:37 UTC

static void xs_init (pTHX);
EXTERN_C void boot_DynaLoader (pTHX_ CV* cv);
EXTERN_C void boot_Module (pTHX_ CV* cv);

EXTERN_C void
xs_init(pTHX)
{
    char *file = __FILE__;
    dXSUB_SYS;

    /* DynaLoader is a special case */
    newXS("DynaLoader::boot_DynaLoader", boot_DynaLoader, file);
    newXS("Module::bootstrap", boot_Module, file);
}
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    perl_parse(my_perl, NULL, argc, argv, (char **)NULL);
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    perl_parse(my_perl, xs_init, argc, argv, (char **)NULL);
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C:\>interp -e "Module::bootstrap();Module::say()"
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MJD says "you can't just make shit up and expect the computer to know what you mean, retardo!"
I run a Win32 PPM repository for perl 5.6.x and 5.8.x -- I take requests (README).
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Re^2: Embedding perl and exposing xs functions

by BUU (Prior) on Dec 19, 2005 at 19:34 UTC

Oh god, that's so obvious now that you've told me. I must have read that section a dozen times. Much thanks!

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