How to find source_location of the code executed by super?

Question

class C1
  def pr
    puts 'C1'
  end
end

class C2 < C1
  def pr
    puts 'C2'
    super
    puts self.method(:pr).source_location
  end
end

c = C2.new
c.pr

In the program above is it possible to obtain location of the code executed by super (C1::pr in our case) as well as we obtain the location of C2::pr code using source_location method?

Answer 1

From ruby 2.2 you can use super_method like this:

Class A
  def pr
    puts "pr"
  end
end

Class B < A
  def pr
    puts "Super method: #{method(:pr).super_method}"
  end
end

As super_method returns a Method, you can chain them to find the ancestor:

def ancestor(m)
  m = method(m) if m.is_a? Symbol
  super_m = m.super_method
  if super_m.nil?
    return m
  else
    return ancestor super_m
  end
end

Answer 2

You just have to get to the superclass, then use instance_method to get the method from the superclass.

class C2 < C1
  def pr
    puts "C2"
    super
    puts "Child: #{self.method(:pr).source_location}"
    puts "Parent: #{self.class.superclass.instance_method(:pr).source_location}"
  end
end

EDIT—regarding the comment about checking the ancestry chain, it (surprisingly) seems to be unnecessary.

class C1
  def pr
    puts "C1"
  end
end

class C2 < C1; end

class C3 < C2
  def pr
    puts "C3"
    super
    puts "Child source location: #{self.method(:pr).source_location}"
    puts "Parent source location: #{self.class.superclass.instance_method(:pr).source_location}"
  end
end

c = C3.new
c.pr

prints

C3
C1
Child source location: ["source_location.rb", 10]
Parent source location: ["source_location.rb", 2]

Answer 3

As per @bukk530, super_method gets you what you want but a good way to access it via the console is

ClassName.new.method(:method_name).super_method.source_location