Add function to grokdump shell to print ASCII string.

tools/grokdump.py

 #!/usr/bin/env python
 #
 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 1504 matching lines @@
      Interpret memory at the given address as being on a V8 heap page
      and print information about the page header (if available).
     """
     address = int(address, 16)
     page_address = address & ~self.heap.PageAlignmentMask()
     if self.reader.IsValidAddress(page_address):
       raise NotImplementedError
     else:
       print "Page header is not available!"
 
+  def do_da(self, address):
+    """
+     Print ASCII string starting at specified address.
+    """
+    address = int(address, 16)
+    string = ""
+    while self.reader.IsValidAddress(address):
+      code = self.reader.ReadU8(address)
+      if code < 128:
+        string += chr(code)
+      else:
+        break
+      address += 1
+    if string == "":
+      print "Not an ASCII string at %s" % self.reader.FormatIntPtr(address)
+    else:
+      print "%s\n" % string
+
   def do_k(self, arguments):
     """
      Teach V8 heap layout information to the inspector. This increases
      the amount of annotations the inspector can produce while dumping
      data. The first page of each heap space is of particular interest
      because it contains known objects that do not move.
     """
     self.padawan.PrintKnowledge()
 
   def do_km(self, address):
@@ skipping 138 matching lines @@
   parser = optparse.OptionParser(USAGE)
   parser.add_option("-s", "--shell", dest="shell", action="store_true",
                     help="start an interactive inspector shell")
   parser.add_option("-f", "--full", dest="full", action="store_true",
                     help="dump all information contained in the minidump")
   options, args = parser.parse_args()
   if len(args) != 1:
     parser.print_help()
     sys.exit(1)
   AnalyzeMinidump(options, args[0])