Added preliminary remote breakpoint support

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@102 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

railties/Rakefile

@@ -21,7 +21,8 @@ TEST_DIRS   = %w( fixtures unit functional mocks mocks/development mocks/testing
 
 LOG_FILES    = %w( apache.log development.log test.log production.log )
 HTML_FILES   = %w( 404.html 500.html index.html )
-SCRIPT_FILES = %w( generate )
+SCRIPT_FILES = %w( generate breakpoint_client envcon )
+BIN_FILES    = %w( breakpointing envcon )
 GENERATORS   = %w( controller mailer model scaffold )
 
 VENDOR_LIBS = %w( actionpack activerecord actionmailer railties )
@@ -96,7 +97,7 @@ end
 desc "Make copies of all the default content of ties"
 task :copy_ties_content => [ 
   :copy_rootfiles, :copy_dispatches, :copy_html_files, :copy_abstract_application,
-  :copy_configs, :copy_generators, :copy_test_helpers, :copy_docs_in_public,
+  :copy_configs, :copy_generators, :copy_binfiles, :copy_test_helpers, :copy_docs_in_public,
   :copy_app_doc_readme ]
 
 task :copy_dispatches do
@@ -150,6 +151,14 @@ task :copy_generators do
   end
 end
 
+task :copy_binfiles do
+  BIN_FILES.each do |file|
+    dest_file = File.join(PKG_DESTINATION, 'script', file)
+    cp File.join('bin', file), dest_file
+    chmod 0755, dest_file
+  end
+end
+
 task :copy_rootfiles do
   cp "fresh_rakefile", "#{PKG_DESTINATION}/Rakefile"
   cp "README", "#{PKG_DESTINATION}/README"

railties/bin/breakpointing

@@ -0,0 +1,2 @@
+#!/usr/local/bin/ruby
+require 'breakpoint_client'

railties/environments/development.rb

@@ -1,3 +1,12 @@
 ActionController::Base.consider_all_requests_local = true
 ActionController::Base.reload_dependencies         = true
 ActiveRecord::Base.reload_associations             = true
+
+require 'breakpoint'
+require 'irb/completion'
+# Change the port (default: 42531) here in case you are
+# on shared hosting. Note that you should set up a SSH
+# tunnel when you want to connect from a different
+# computer over the internet. See the documentation of
+# Breakpoint.activate_drb for how to do that.
+Breakpoint.activate_drb('druby://localhost:42531')

railties/fresh_rakefile

@@ -43,6 +43,7 @@ Rake::RDocTask.new("apidoc") { |rdoc|
   rdoc.title    = "Rails Framework Documentation"
   rdoc.options << '--line-numbers --inline-source'
   rdoc.rdoc_files.include('README')
+  rdoc.rdoc_files.include('lib/breakpoint.rb')
   rdoc.rdoc_files.include('vendor/railties/CHANGELOG')
   rdoc.rdoc_files.include('vendor/railties/MIT-LICENSE')
   rdoc.rdoc_files.include('vendor/activerecord/README')

railties/lib/binding_of_caller.rb

@@ -0,0 +1,81 @@
+begin
+  require 'simplecc'
+rescue LoadError
+  def Continuation.create(*args, &block)
+    cc = nil; result = callcc {|c| cc = c; block.call(cc) if block and args.empty?}
+    result ||= args
+    return *[cc, *result]
+  end
+end
+
+# This method returns the binding of the method that called your
+# method. It will raise an Exception when you're not inside a method.
+#
+# It's used like this:
+#   def inc_counter(amount = 1)
+#     Binding.of_caller do |binding|
+#       # Create a lambda that will increase the variable 'counter'
+#       # in the caller of this method when called.
+#       inc = eval("lambda { |arg| counter += arg }", binding)
+#       # We can refer to amount from inside this block safely.
+#       inc.call(amount)
+#     end
+#     # No other statements can go here. Put them inside the block.
+#   end
+#   counter = 0
+#   2.times { inc_counter }
+#   counter # => 2
+#
+# Binding.of_caller must be the last statement in the method.
+# This means that you will have to put everything you want to
+# do after the call to Binding.of_caller into the block of it.
+# This should be no problem however, because Ruby has closures.
+# If you don't do this an Exception will be raised. Because of
+# the way that Binding.of_caller is implemented it has to be
+# done this way.
+def Binding.of_caller(&block)
+  old_critical = Thread.critical
+  Thread.critical = true
+  count = 0
+  cc, result, error, extra_data = Continuation.create(nil, nil)
+  error.call if error
+
+  tracer = lambda do |*args|
+    type, context, extra_data = args[0], args[4], args
+    if type == "return"
+      count += 1
+      # First this method and then calling one will return --
+      # the trace event of the second event gets the context
+      # of the method which called the method that called this
+      # method.
+      if count == 2
+        # It would be nice if we could restore the trace_func
+        # that was set before we swapped in our own one, but
+        # this is impossible without overloading set_trace_func
+        # in current Ruby.
+        set_trace_func(nil)
+        cc.call(eval("binding", context), nil, extra_data)
+      end
+    elsif type == "line" then
+      nil
+    elsif type == "c-return" and extra_data[3] == :set_trace_func then
+      nil
+    else
+      set_trace_func(nil)
+      error_msg = "Binding.of_caller used in non-method context or " +
+        "trailing statements of method using it aren't in the block."
+      cc.call(nil, lambda { raise(ArgumentError, error_msg) }, nil)
+    end
+  end
+
+  unless result
+    set_trace_func(tracer)
+    return nil
+  else
+    Thread.critical = old_critical
+    case block.arity
+      when 1 then yield(result)
+      else yield(result, extra_data)        
+    end
+  end
+end