Feature #7435: Exceptions should have backtrace_locations

• Status: Rejected
• Assignee: ko1 (Koichi Sasada)
• Target version: 2.6

[sam.saffron (Sam Saffron)]

Further to http://bugs.ruby-lang.org/issues/7051

def boom
raise "boom"
end

begin
boom
rescue => e
p e.backtrace
end

["t.rb:2:in boom'", "t.rb:6:in '"]

It seems exceptions still store backtraces in strings, shouldn't the backtrace be stored in RubyVM::Backtrace::Location objects and then optionally grabbed using backtrace_locations or backtrace depending on how you feel?

This means exceptions could be more efficient as filenames could easily be pinned in memory leading to significantly reduced allocation for exceptions.

[sam.saffron (Sam Saffron)]

ouch, this was meant to be a feature req not a bug ... cant figure out how to change

[zzak (zzak _)]

• Tracker changed from Bug to Feature
• Category set to core
• Status changed from Open to Assigned
• Assignee set to ko1 (Koichi Sasada)
• Target version set to 2.0.0

[zzak (zzak _)]

• Target version changed from 2.0.0 to 2.6

Sorry, meant next minor, as #7051

[ko1 (Koichi Sasada)]

(2012/11/26 7:02), sam.saffron (Sam Saffron) wrote:

This means exceptions could be more efficient as filenames could easily be pinned in memory leading to significantly reduced allocation for exceptions.

Current implementation does not make String array.
Please run the following code:

---

def foo
raise
end

begin
foo
rescue => e

e.backtrace # (X)

ObjectSpace.each_object(Array){|ary|
if ary.find{|obj| obj.is_a?(String) and /foo/ =~ obj}
p ary
end
}
end

---

If you run (X), then the code prints out backtrace object.

--
// SASADA Koichi at atdot dot net

[ko1 (Koichi Sasada)]

• Status changed from Assigned to Rejected

[ko1 (Koichi Sasada)]

One more comment.

Exception class has Exception#set_backtrace method, which set backtrace using string array. It conflicts with locations.

We need to solve this issue to support Exception#backtrace_locations.

[headius (Charles Nutter)]

I wish I had seen this before 2.0.0!

Perhaps set_backtrace should just cause backtrace_locations to return an empty array?

I really, really wish backtrace_locations had gotten into 2.0.0, so let's try to make this happen for 2.1.

[sawa (Tsuyoshi Sawada)]

Why is this issue closed? Is this problem solved? I think it is a very important feature that is missing.