Show the example a warning occurred in if nil call site is given.

lib/rspec/support/warnings.rb

@@ -35,8 +35,11 @@ def self.warning(text, options={})
   def self.warn_with(message, options = {})
     call_site = options.fetch(:call_site) { CallerFilter.first_non_rspec_line }
     message << " Use #{options[:replacement]} instead." if options[:replacement]
-    message << " Called from #{call_site}." if call_site
+    if call_site
+      message << " Called from #{call_site}."
+    elsif RSpec.respond_to?(:current_example) && RSpec.current_example
+      message << " Warning occured in `#{RSpec.current_example.source_location.join(":")}`."
+    end
     ::Kernel.warn message
   end
-
 end

spec/rspec/support/warnings_spec.rb

@@ -99,6 +99,14 @@ def run_without_rspec_core
         RSpec.send(helper, 'Message', :replacement => 'Replacement')
       end
     end
+
+    it "includes the file and line of the spec if call site is nil" do
+      top_of_spec = __LINE__ - 1
+      run_without_rspec_core do
+        expect(::Kernel).to receive(:warn).with(/Warning occured.*warnings_spec.rb:#{top_of_spec}/)
+        RSpec.send(helper, "bees", :call_site => nil)
+      end
+    end
   end
 
   describe "#warning" do