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 1573 matching lines @@
   def do_list(self, smth):
     """
      List all available memory regions.
     """
     def print_region(reader, start, size, location):
       print "  %s - %s (%d bytes)" % (reader.FormatIntPtr(start),
                                       reader.FormatIntPtr(start + size),
                                       size)
     print "Available memory regions:"
     self.reader.ForEachMemoryRegion(print_region)
+    
+  def do_ascii(self, address):

[Michael Starzinger, 2012/07/03 11:43:16]

How about naming this command "dascii" or just "da", because it belongs to the
"dump" category.

[Yang, 2012/07/03 11:51:11]

Done.

+    """
+    Print ASCII string starting at specified address.

[Michael Starzinger, 2012/07/03 11:43:16]

Indent that by one space for consistency.

[Yang, 2012/07/03 11:51:11]

Done.

+    """
+    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" % string

[Michael Starzinger, 2012/07/03 11:43:16]

Maybe we should put parentheses around the string. I am not sure about that,
I'll leave it up to you.

[Yang, 2012/07/03 11:51:11]

Quotes don't work that well since the string may not terminate cleanly (I don't
try to detect null termination, but assume the string to terminate when the
ASCII content ends).

 
 
 EIP_PROXIMITY = 64
 
 CONTEXT_FOR_ARCH = {
     MD_CPU_ARCHITECTURE_AMD64:
       ['rax', 'rbx', 'rcx', 'rdx', 'rdi', 'rsi', 'rbp', 'rsp', 'rip'],
     MD_CPU_ARCHITECTURE_X86:
       ['eax', 'ebx', 'ecx', 'edx', 'edi', 'esi', 'ebp', 'esp', 'eip']
 }
@@ skipping 69 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])