Please refer to bug: https://jira.codehaus.org/browse/JRUBY-6705
I reduced this bug to the following code snippet. My comments and
questions follow this snippet
--------------------------------------------------------------------------------------
class Object
def self.const_missing(*args)
puts "in const_missing! #{args.inspect}"
raise "this_will_get_lost!"
rescue Exception => e
puts "Got exception: #{e}"
end
end
begin
raise "will_not_get_lost_1"
rescue Exception => e
puts "Got exception: #{e}"
end
defined?(Foo::Bar)
begin
raise "will_not_get_lost_2"
rescue Exception => e
puts "Got exception: #{e}"
end
--------------------------------------------------------------------------------------
If you run this on 1.7 master, you will notice that the exception within
const_missing will not be printed out in the rescue handler. But, if you
revert my commit "20632af6e1fa511fd9b762beda2a60d39bf3c859", this code
snippet will work as expected (unrelated observation: in -X+C mode, the
const_missing method doesn't run in either case). I think my fixes in
that commit are "correct" and are in the right direction. I dont think the
hacky $! set should be around in the interpreter or compiler (AST or IR).
Those checks were working around lost sets of "$!" when exceptions were
being raised. I traced one of the instances to RubyThread and fixed it.
But, as part of this bug report, I found a more important one -- where $!
was not being set by any code that runs as part of an ancestor defined?
call in the call stack. This bug is caused by the check on line 239 of
org.jruby.exceptions.RaiseException.java. So, I wanted to check if someone
knows more about why $! setting is being suppressed when in defined? code.
Clearly, the interpreter/compiler hack that sets $! to the received
exception essentially gets around that check. So, it looks like a
different solution should be possible -- I haven't yet attempted to get rid
of the check in RaiseException.java and see what happens ... but, before I
did that, I thought I would check first.
Subbu.
