如何从 XS 访问当前上下文？

Question

当用户从 main:: 包调用 XS 时，我们无法使用

caller_cx(0, NULL);

因为 main:: 和 XSUB DOC

没有框架

Note that XSUBs don't get a stack frame, so C will return information for the immediately-surrounding Perl code

如何获取调用 XSUB 的 file:line 信息、main:: 作用域的提示等信息？

Answer 1

从 mess_sv 复制（由 Perl API 函数 warn 和 croak 调用，它们附加行信息，如 Perl 函数 warn 和 die):

use strict;
use warnings;
use feature qw( say );

use Inline C => <<'__EOS__';

void testing() {
    dXSARGS;

    /*
     * Try and find the file and line for PL_op.  This will usually be
     * PL_curcop, but it might be a cop that has been optimised away.  We
     * can try to find such a cop by searching through the optree star ting
     * from the sibling of PL_curcop.
     */
    if (PL_curcop) {
        const COP *cop =
            Perl_closest_cop(aTHX_ PL_curcop, OpSIBLING(PL_curcop), PL_op, FALSE);
        if (!cop)
            cop = PL_curcop;

        if (CopLINE(cop)) {
            EXTEND(SP, 2);
            mPUSHs(newSVpv(OutCopFILE(cop), 0));
            mPUSHs(newSViv((IV)CopLINE(cop)));
            XSRETURN(2);
        }
    }

    XSRETURN(0);
}

__EOS__

say join ":", testing();

关于 PL_curcop here.

的一点点

如何从 XS 访问当前上下文？

How to get access to current context from XS?

perl

perl-xs

perlapi