Thread::Backtrace::Location

Class

An object representation of a stack frame, initialized by Kernel#caller_locations.

For example:

# caller_locations.rb
def a(skip)
  caller_locations(skip)
end
def b(skip)
  a(skip)
end
def c(skip)
  b(skip)
end

c(0..2).map do |call|
  puts call.to_s
end

Running ruby caller_locations.rb will produce:

caller_locations.rb:2:in `a'
caller_locations.rb:5:in `b'
caller_locations.rb:8:in `c'

Here’s another example with a slightly different result:

# foo.rb
class Foo
  attr_accessor :locations
  def initialize(skip)
    @locations = caller_locations(skip)
  end
end

Foo.new(0..2).locations.map do |call|
  puts call.to_s
end

Now run ruby foo.rb and you should see:

init.rb:4:in `initialize'
init.rb:8:in `new'
init.rb:8:in `<main>'

Instance Methods

absolute_path

vm_backtrace.c View on GitHub

          
            static VALUE
location_absolute_path_m(VALUE self)
{
    return location_realpath(location_ptr(self));
}

Returns the full file path of this frame.

Same as path, except that it will return absolute path even if the frame is in the main script.

base_label

vm_backtrace.c View on GitHub

          
            static VALUE
location_base_label_m(VALUE self)
{
    return location_base_label(location_ptr(self));
}

Returns the base label of this frame.

Usually same as label, without decoration.

inspect

vm_backtrace.c View on GitHub

          
            static VALUE
location_inspect_m(VALUE self)
{
    return rb_str_inspect(location_to_str(location_ptr(self)));
}

Returns the same as calling inspect on the string representation of to_str

label

vm_backtrace.c View on GitHub

          
            static VALUE
location_label_m(VALUE self)
{
    return location_label(location_ptr(self));
}

Returns the label of this frame.

Usually consists of method, class, module, etc names with decoration.

Consider the following example:

def foo
  puts caller_locations(0).first.label

  1.times do
    puts caller_locations(0).first.label

    1.times do
      puts caller_locations(0).first.label
    end

  end
end

The result of calling foo is this:

label: foo
label: block in foo
label: block (2 levels) in foo

lineno

vm_backtrace.c View on GitHub

          
            static VALUE
location_lineno_m(VALUE self)
{
    return INT2FIX(location_lineno(location_ptr(self)));
}

Returns the line number of this frame.

For example, using caller_locations.rb from Thread::Backtrace::Location

loc = c(0..1).first
loc.lineno #=> 2

path

vm_backtrace.c View on GitHub

          
            static VALUE
location_path_m(VALUE self)
{
    const rb_iseq_t *iseq = location_iseq(location_ptr(self));
    return iseq ? rb_iseq_path(iseq) : Qnil;
}

Returns the file name of this frame. This will generally be an absolute path, unless the frame is in the main script, in which case it will be the script location passed on the command line.

For example, using caller_locations.rb from Thread::Backtrace::Location

loc = c(0..1).first
loc.path #=> caller_locations.rb

to_s

vm_backtrace.c View on GitHub

          
            static VALUE
location_to_str_m(VALUE self)
{
    return location_to_str(location_ptr(self));
}

Returns a Kernel#caller style string representing this frame.