Feature #15338: Provide way for C extensions to query if global variable is defined

• Status: Open
• Assignee: -
• Target version: -

[graywolf (Gray Wolf)]

As far as I can tell, there is no way for C extension to check if global variable is defined. I can rb_gv_get, but that produces warning when $VERBOSE = true.

Let's introduce third function rb_gv_defined to complement rb_gv_get and rb_gv_set.

PS: At the moment I'm doing if (RTEST(rb_eval_string("defined?($XX) && $XX"))) { ... } but there's got to be a better way, right?

[normalperson (Eric Wong)]

https://bugs.ruby-lang.org/issues/15338

Let's introduce third function rb_gv_defined to complement rb_gv_get and rb_gv_set.

PS: At the moment I'm doing if (RTEST(rb_eval_string("defined?($XX) && $XX"))) { ... } but
there's got to be a better way, right?

I prefer we avoid adding more bloat to the public C API unless
it's a performance critical case. This doesn't seem
performance-critical to me.

[nobu (Nobuyoshi Nakada)]

As for the implementation, this rb_gv_defined will add new ID just by asking if the gv is defined.