js/src/gdb/mozilla/JSString.py

   1 # Pretty-printers for SpiderMonkey strings.
   2
   3 import gdb
   4 import mozilla.prettyprinters
   5 from mozilla.prettyprinters import pretty_printer, ptr_pretty_printer
   6
   7 try:
   8     chr(10000) # UPPER RIGHT PENCIL
   9 except ValueError as exc: # yuck, we are in Python 2.x, so chr() is 8-bit
  10     chr = unichr # replace with teh unicodes
  11
  12 # Forget any printers from previous loads of this module.
  13 mozilla.prettyprinters.clear_module_printers(__name__)
  14
  15 # Cache information about the JSString type for this objfile.
  16 class JSStringTypeCache(object):
  17     def __init__(self, cache):
  18         dummy = gdb.Value(0).cast(cache.JSString_ptr_t)
  19         self.ROPE_FLAGS = dummy['ROPE_FLAGS']
  20         self.ATOM_BIT = dummy['ATOM_BIT']
  21         self.INLINE_CHARS_BIT = dummy['INLINE_CHARS_BIT']
  22         self.TYPE_FLAGS_MASK = dummy['TYPE_FLAGS_MASK']
  23         self.LATIN1_CHARS_BIT = dummy['LATIN1_CHARS_BIT']
  24
  25 class Common(mozilla.prettyprinters.Pointer):
  26     def __init__(self, value, cache):
  27         super(Common, self).__init__(value, cache)
  28         if not cache.mod_JSString:
  29             cache.mod_JSString = JSStringTypeCache(cache)
  30         self.stc = cache.mod_JSString
  31
  32 @ptr_pretty_printer("JSString")
  33 class JSStringPtr(Common):
  34     def display_hint(self):
  35         return "string"
  36
  37     def jschars(self):
  38         d = self.value['d']
  39         length = d['u1']['length']
  40         flags = d['u1']['flags']
  41         is_rope = ((flags & self.stc.TYPE_FLAGS_MASK) == self.stc.ROPE_FLAGS)
  42         if is_rope:
  43             for c in JSStringPtr(d['s']['u2']['left'], self.cache).jschars():
  44                 yield c
  45             for c in JSStringPtr(d['s']['u3']['right'], self.cache).jschars():
  46                 yield c
  47         else:
  48             is_inline = (flags & self.stc.INLINE_CHARS_BIT) != 0
  49             is_latin1 = (flags & self.stc.LATIN1_CHARS_BIT) != 0
  50             if is_inline:
  51                 if is_latin1:
  52                     chars = d['inlineStorageLatin1']
  53                 else:
  54                     chars = d['inlineStorageTwoByte']
  55             else:
  56                 if is_latin1:
  57                     chars = d['s']['u2']['nonInlineCharsLatin1']
  58                 else:
  59                     chars = d['s']['u2']['nonInlineCharsTwoByte']
  60             for i in range(length):
  61                 yield chars[i]
  62
  63     def to_string(self):
  64         s = u''
  65         for c in self.jschars():
  66             s += chr(c)
  67         return s
  68
  69 @ptr_pretty_printer("JSAtom")
  70 class JSAtomPtr(Common):
  71     def to_string(self):
  72         return self.value.cast(self.cache.JSString_ptr_t)