1 files changed, 80 insertions, 0 deletions
diff --git a/jni/ruby/lib/irb/frame.rb b/jni/ruby/lib/irb/frame.rb
new file mode 100644
index 0000000..4a1d080
--- /dev/null
+++ b/jni/ruby/lib/irb/frame.rb
@@ -0,0 +1,80 @@
+#
+#   frame.rb -
+#   	$Release Version: 0.9$
+#   	$Revision: 47112 $
+#   	by Keiju ISHITSUKA(Nihon Rational Software Co.,Ltd)
+#
+# --
+#
+#
+#
+
+require "e2mmap"
+
+module IRB
+  class Frame
+    extend Exception2MessageMapper
+    def_exception :FrameOverflow, "frame overflow"
+    def_exception :FrameUnderflow, "frame underflow"
+
+    # Default number of stack frames
+    INIT_STACK_TIMES = 3
+    # Default number of frames offset
+    CALL_STACK_OFFSET = 3
+
+    # Creates a new stack frame
+    def initialize
+      @frames = [TOPLEVEL_BINDING] * INIT_STACK_TIMES
+    end
+
+    # Used by Kernel#set_trace_func to register each event in the call stack
+    def trace_func(event, file, line, id, binding)
+      case event
+      when 'call', 'class'
+        @frames.push binding
+      when 'return', 'end'
+        @frames.pop
+      end
+    end
+
+    # Returns the +n+ number of frames on the call stack from the last frame
+    # initialized.
+    #
+    # Raises FrameUnderflow if there are no frames in the given stack range.
+    def top(n = 0)
+      bind = @frames[-(n + CALL_STACK_OFFSET)]
+      Fail FrameUnderflow unless bind
+      bind
+    end
+
+    # Returns the +n+ number of frames on the call stack from the first frame
+    # initialized.
+    #
+    # Raises FrameOverflow if there are no frames in the given stack range.
+    def bottom(n = 0)
+      bind = @frames[n]
+      Fail FrameOverflow unless bind
+      bind
+    end
+
+    # Convenience method for Frame#bottom
+    def Frame.bottom(n = 0)
+      @backtrace.bottom(n)
+    end
+
+    # Convenience method for Frame#top
+    def Frame.top(n = 0)
+      @backtrace.top(n)
+    end
+
+    # Returns the binding context of the caller from the last frame initialized
+    def Frame.sender
+      eval "self", @backtrace.top
+    end
+
+    @backtrace = Frame.new
+    set_trace_func proc{|event, file, line, id, binding, klass|
+      @backtrace.trace_func(event, file, line, id, binding)
+    }
+  end
+end