Steve Hay <[EMAIL PROTECTED]> writes:
>How does an XSUB find out what package it is compiled into?
An XSUB isn't compiled into a package ;-)
Its CV is entered into a stash but its "body" (which is what __PACKAGE__
refrers to) doesn't really have any meaning. That is to say
"current package" (i.e. "current context op" i.e. PL_curcop) does not
change when you call an XSUB.
So CopSTASHPV(PL_curcop) gives you the name of the calling package
(if I have right macro name...)
This can be considered a feature ;-)
This is handy because it isn't easy to do caller() from XS ...
The XSUB "knows" what stash its CV in from the MODULE line.
For use in typemaps I think $Package will expands to current package
as declared on MODULE, but I don't think it is documented.
I seem to recall some "quoting issues" with using it.
But see lib/ExtUtils/typemap and T_STDIO et. al. for typical (mis)?use ;-)
Normally you only need to know for constructors to mimic 1 operand
form of bless - but that is discouraged you should pass class name
so it is inheritable:
void
new(char *Class,...)
{
...
sv_setsv(ST(0), sv_bless(newRV_noinc(inner_sv), gv_stashpv(Class,1)));
...
}
Note using 'Class' not 'class' to avoid keyword muddle if C++
gets its hands on things.
>
>It's easy in a pure Perl sub -- just use __PACKAGE__ -- but accessing
>that from an XSUB doesn't work (or at least, not like this):
>
>#include "EXTERN.h"
>#include "perl.h"
>#include "XSUB.h"
>
>MODULE = Foo PACKAGE = Foo
>
>void
>foo()
>PPCODE:
>{
> warn("I'm compiled into %s\n", SvPVX(eval_pv("__PACKAGE__", 0)));
>}
>
>The above outputs:
>
>I'm compiled into main
Actually it means "I was called from code compiled into main, so when I just
compiled that litteral I used that as the package to put the code
in and lexer expanded __PACKAGE__ to "main" for me.
>
>How do I get the "Foo" that I wanted?
warn("I'm compiled into "%s\n", "Foo"); // Match MODULE line ;-)
>
>- Steve
>
>
>
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