initial import

.autotest

@@ -0,0 +1,27 @@
+require 'autotest/restart'
+
+# Autotest.add_hook :initialize do |at|
+#   at.extra_files << "../some/external/dependency.rb"
+#
+#   at.libs << ":../some/external"
+#
+#   at.add_exception 'vendor'
+#
+#   at.add_mapping(/dependency.rb/) do |f, _|
+#     at.files_matching(/test_.*rb$/)
+#   end
+#
+#   %w(TestA TestB).each do |klass|
+#     at.extra_class_map[klass] = "test/test_misc.rb"
+#   end
+# end
+
+# Autotest.add_hook :run_command do |at|
+#   system "rake build"
+# end
+
+# Local variables:
+# mode: ruby
+# End:
+#
+# vim: syntax=ruby

History.txt

@@ -0,0 +1,6 @@
+=== 1.0.0 / 2009-08-12
+
+* 1 major enhancement
+
+  * Birthday!
+

Manifest.txt

@@ -0,0 +1,13 @@
+.autotest
+History.txt
+Manifest.txt
+README.txt
+Rakefile
+bin/trepan-backend
+ext/extconf.rb
+ext/reref.c
+lib/trepan.rb
+lib/trepan/exception.rb
+test/test_roundtrip.rb
+test/test_trepan_tool.rb
+test/test_value.rb

README.txt

@@ -0,0 +1,71 @@
+= trepan
+
+* http://rubyforge.org/projects/trepan
+
+== DESCRIPTION:
+
+Trepan is a Kernel extension which augments Kernel#caller's results
+with the function's arguments at each level.
+
+== FEATURES/PROBLEMS:
+
+== SYNOPSIS:
+
+Regular Kernel#enhanced_caller:
+
+  require 'trepan'
+
+  def something(foo) enhanced_caller end
+  stack = something( 42 )
+  p stack.first.args # [ 42 ]
+
+Fancy Exception#backtrace:
+
+  require 'trepan/exception'
+  def something(foo) raise end
+  begin
+    something( 42 )
+  rescue Exception => e
+    p e.backtrace.first.args # [ 42 ]
+  end
+
+== REQUIREMENTS:
+
+Requires:
+
+* MRI Ruby 1.8 compiled with symbols
+* gdb
+* bash
+* make
+* a working C compiler
+
+== INSTALL:
+
+Install this gem like any other gem:
+
+  $ gem install trepan
+
+== LICENSE:
+
+(The MIT License)
+
+Copyright (c) 2009 Josh ben Jore
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+'Software'), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Rakefile

@@ -0,0 +1,36 @@
+require 'rubygems'
+require 'hoe'
+require 'rbconfig'
+
+EXT = "ext/reref.#{Config::CONFIG['DLEXT']}"
+
+class Trepan
+  # !!!: Duplicated in lib/trepan.rb
+  VERSION = '1.0.0'
+end
+
+Hoe.spec 'trepan' do
+  | p |
+
+  # self.rubyforge_name = 'trepanx' # if different than 'trepan'
+
+  p.spec_extras[:extensions] = 'ext/extconf.rb'
+  p.clean_globs << EXT << 'ext/*.o' << 'ext/Makefile'
+
+  p.developer('Josh ben Jore', 'twists@gmail.com')
+end
+
+task :test => EXT
+
+file EXT => [ 'ext/extconf.rb', 'ext/reref.c' ] do
+  Dir.chdir( 'ext' ) do
+    ruby 'extconf.rb'
+    sh 'make'
+  end
+end
+
+# Local variables:
+# mode: ruby
+# End:
+#
+# vim: syntax=ruby

bin/trepan-backend

@@ -0,0 +1,74 @@
+#!/usr/bin/env ruby
+
+require 'expect'
+
+# TODO: use Getopt::Long
+# TODO: use Pod::Usage
+#
+pid = ARGV[0]
+cmd = "bash -c 'gdb --quiet --nw --nx --pid #{pid} 2>/dev/null'"
+
+# Attach to the other Ruby process with GDB and script the interaction
+# with Expect
+#
+IO.popen(cmd, 'r+') do
+  |gdb|
+
+  # Wait for start-up
+  #
+  gdb.expect( /\(gdb\)/ ) do
+
+    # Send for the backtrace
+    #
+    gdb.print( "backtrace\n" )
+  end
+
+  # Wait for the backtrace
+  #
+  gdb.expect( /\(gdb\)/ ) do
+    | bufa |
+
+    # Parse the backtrace to get the list of C pointers to the arguments.
+    # 
+    buf = bufa.to_s
+    argv_pointers =
+      buf.scan( /rb_call .+?argc=(\d+).+?argv=(0x[[:xdigit:]]+)/ )
+
+    # Dereference each pointer to get the (VALUE) we can hand back to Ruby
+    #
+    argv_pointers.each_index do
+      | argv_index |
+      argc, argv = argv_pointers[ argv_index ]
+
+      # Capture all arguments
+      #
+      1.upto( argc.to_i ) do
+        | nth |
+        nth_index = nth - 1
+
+        # Capture an argument
+        #
+        gdb.print( "print *( #{nth_index} + (VALUE*)#{argv} )\n" )
+        gdb.expect( /= [[:xdigit:]]+\n/ ) do
+          | p |
+          value = /= (\d+)/.match( p[0] )
+          puts "VALUE[#{argv_index}][#{nth_index}]=#{value[1]}"
+        end
+
+        # Ensure we got a prompt back
+        #
+        gdb.expect( /\(gdb\)/ )
+      end
+    end
+
+    # Shut down GDB and let the other process resume
+    #
+    gdb.print( "detach\nquit\n" )
+  end
+end
+
+# Local variables:
+# mode: ruby
+# End:
+#
+# vim: syntax=ruby

ext/extconf.rb

@@ -0,0 +1,10 @@
+#!/usr/bin/env ruby
+$preload = false
+require 'mkmf'
+create_makefile('reref')
+
+# Local variables:
+# mode: ruby
+# End:
+#
+# vim: syntax=ruby

ext/reref.c

@@ -0,0 +1,50 @@
+#include "ruby.h"
+
+extern VALUE rb_cObject;
+extern VALUE rb_cFixnum;
+
+/*
+ * call-seq:
+ *    obj.__value__   => (VALUE*)obj
+ *
+ * Returns an object's C (VALUE) for use in correlating Ruby objects
+ * to C objects.
+ */
+VALUE
+rb___value__(ref)
+    VALUE ref;
+{
+    return 1 | (ref << 1);
+}
+
+/*
+ * call-seq:
+ *    fixnum.__object__   => obj
+ *
+ * Dereferences a fixnum to produce Ruby object.
+ */
+VALUE
+rb___object__(ref)
+    VALUE ref;
+{
+    return (VALUE)NUM2INT(ref);
+}
+
+void
+Init_reref(void)
+{
+    rb_define_method(rb_cObject,"__value__",rb___value__, 0);
+    rb_define_method(rb_cFixnum,"__object__",rb___object__,0);
+}
+
+/*
+ * Local variables:
+ * mode: c
+ * c-indentation-style: bsd
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * tab-width: 8
+ * End:
+ *
+ * ex: set ts=8 sts=4 sw=4 noet:
+ */

lib/trepan.rb

@@ -0,0 +1,94 @@
+require 'rbconfig'
+require 'reref'
+
+module Kernel
+  def enhanced_caller
+    Trepan.enhanced_caller
+  end
+end
+
+module Trepan
+  # !!!: Duplicated in Rakefile
+  VERSION = '1.0.0'
+
+  # Construct the path to the ruby interpreter
+  #
+  RUBY   = File.join(
+    Config::CONFIG['bindir'],
+    "#{Config::CONFIG['ruby_install_name']}#{Config::CONFIG['EXEEXT']}"
+  )
+
+  # Construct the path the trepan program
+  #
+  TREPAN = File.join( Config::CONFIG['bindir'], 'trepan-backend' )
+
+  # === Description
+  # TODO: description goes here
+  #
+  # === Returns
+  # TODO: description goes here
+  #
+  def enhanced_caller
+
+    # Disable GC for a moment so I won't suffer a bad pointer while
+    # I'm plucking objects right out of memory.
+    #
+    gc_was_disabled = GC.disable
+
+    # Open my own brain for inspection. This is going to produce a
+    # bunch of data like:
+    #
+    #   VALUE[0][0] = 85
+    #   VALUE[0][1] = ...
+    #
+    my_brain = `#{ruby} #{trepane_rb} #{$$}`
+
+
+    # Reach into our memory and pluck some objects out.
+    #
+    caller_argv = []
+    my_brain.scan( /VALUE\[(\d+)\]\[(\d+)\]=(\d+)/ ) do
+      | match |
+
+      caller_ix = match[0].to_i
+      argv_ix   = match[1].to_i
+      pointer   = match[2].to_i
+
+      caller_argv[caller_ix] ||= []
+      caller_argv[argv_ix] = pointer.__object__
+    end
+
+    # Re-enable GC if relevant because I've finished capturing
+    # everything
+    #
+    if gc_was_disabled
+      GC.enable
+    end
+
+    # The top level of caller_argv ought to have the Kernel.`...`
+    # function call so remove it.
+    #
+    stack = Kernel.caller
+    while caller_argv.length > stack.length
+      caller_argv.shift
+    end
+
+    # Make the enhanced caller results
+    #
+    stack.
+      zip( caller_argv )\
+      .collect do
+        | src, args |
+        {
+          :src => src,
+          :args => args
+        }
+      end
+  end
+end
+
+# Local variables:
+# mode: ruby
+# End:
+#
+# vim: syntax=ruby