Add: -location option

lib/rake/application.rb

@@ -112,6 +112,8 @@ def top_level
           display_tasks_and_comments
         elsif options.show_prereqs
           display_prerequisites
+        elsif options.show_location
+          display_location
         else
           top_level_tasks.each { |task_name| invoke_task(task_name) }
         end
@@ -334,6 +336,12 @@ def display_tasks_and_comments # :nodoc:
       end
     end
 
+    # Display the location of the Rakefile.
+    def display_location
+      rakefile, location = find_rakefile_location
+      puts File.join(location, rakefile)
+    end
+
     def terminal_width # :nodoc:
       if @terminal_columns.nonzero?
         result = @terminal_columns
@@ -498,6 +506,10 @@ def standard_rake_options # :nodoc:
             "Include LIBDIR in the search path for required modules.",
             lambda { |value| $:.push(value) }
           ],
+          ["--location", "-l",
+            "Display the location of Rakefile, then exit.",
+            lambda { |value| options.show_location = true }
+          ],
           ["--multitask", "-m",
             "Treat all tasks as multitasks.",
             lambda { |value| options.always_multitask = true }
@@ -816,6 +828,7 @@ def set_default_options # :nodoc:
       options.nosearch                   = false
       options.rakelib                    = %w[rakelib]
       options.show_all_tasks             = false
+      options.show_location              = false
       options.show_prereqs               = false
       options.show_task_pattern          = nil
       options.show_tasks                 = nil