Perl_API get_sv and SvIV_set

[BUU]

I'm playing with patching the perl source and am attempting to create a new super global variable for nefarious purposes. I've added the following code to one of the opcodes in pp_ctl.c:

SV* super_i;
super_i = get_sv("main::buu_test_i", TRUE);
SvIV_set(super_i, 42);

Which *seems* to work properly. Unfortunately once I compile I can't seem to access my new variable from perl code. That is, when I try to print out what I think is the variable I just set I get undef. Do I need some special magic to make it accessible from perl, or do I need a specific perl command to invoke it? (I've tried $buu_test_i, $main::buu_test_i, and so on).

[salva]

you also have to tell perl that the integer on the IV slot is good with SvIOK_on():

SV* super_i;
super_i = get_sv("main::buu_test_i", TRUE);
SvIV_set(super_i, 42);
SvIOK_on(super_i);

[BUU]

Ah, you are completely correct and it works happily. However I wonder if you could answer another question. I am trying to find an op that gets called at the 'end' of every loop, just before the next iteration begins. Is there any such beast? The B module seems to imply that pp_redo is called, but in my tests it doesn't seem to be. Any ideas?

[Util]

It sounds like you are looking for the opcode equivalent of the 'continue' statement. From a casual look at the differences in the output of these two commands:

perl -MO=Concise -e 'while ($z == 1) { $x=2;} continue {$y=3;}'
perl -MO=Concise -e 'while ($z == 1) { $x=2;}'

I would guess that the opcode is 'pp_next'.