Source code
Revision control
Copy as Markdown
Other Tools
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this file,
# Pretty-printers for SpiderMonkey strings.
import gdb
import mozilla.prettyprinters
from mozilla.CellHeader import get_header_length_and_flags
from mozilla.prettyprinters import ptr_pretty_printer
try:
chr(10000) # UPPER RIGHT PENCIL
except ValueError: # yuck, we are in Python 2.x, so chr() is 8-bit
chr = unichr # replace with teh unicodes
# Forget any printers from previous loads of this module.
mozilla.prettyprinters.clear_module_printers(__name__)
class JSStringTypeCache(object):
# Cache information about the JSString type for this objfile.
def __init__(self, cache):
dummy = gdb.Value(0).cast(cache.JSString_ptr_t)
self.ATOM_BIT = dummy["ATOM_BIT"]
self.LINEAR_BIT = dummy["LINEAR_BIT"]
self.INLINE_CHARS_BIT = dummy["INLINE_CHARS_BIT"]
self.TYPE_FLAGS_MASK = dummy["TYPE_FLAGS_MASK"]
self.LATIN1_CHARS_BIT = dummy["LATIN1_CHARS_BIT"]
class Common(mozilla.prettyprinters.Pointer):
def __init__(self, value, cache):
super(Common, self).__init__(value, cache)
if not cache.mod_JSString:
cache.mod_JSString = JSStringTypeCache(cache)
self.stc = cache.mod_JSString
@ptr_pretty_printer("JSString")
class JSStringPtr(Common):
def display_hint(self):
return "string"
def chars(self):
d = self.value["d"]
length, flags = get_header_length_and_flags(self.value, self.cache)
corrupt = {
0x2F2F2F2F: "JS_FRESH_NURSERY_PATTERN",
0x2B2B2B2B: "JS_SWEPT_NURSERY_PATTERN",
0xE5E5E5E5: "jemalloc freed memory",
}.get(flags & 0xFFFFFFFF)
if corrupt:
for ch in "<CORRUPT:%s>" % corrupt:
yield ch
return
is_rope = (flags & self.stc.LINEAR_BIT) == 0
if is_rope:
for c in JSStringPtr(d["s"]["u2"]["left"], self.cache).chars():
yield c
for c in JSStringPtr(d["s"]["u3"]["right"], self.cache).chars():
yield c
else:
is_inline = (flags & self.stc.INLINE_CHARS_BIT) != 0
is_latin1 = (flags & self.stc.LATIN1_CHARS_BIT) != 0
if is_inline:
if is_latin1:
chars = d["inlineStorageLatin1"]
else:
chars = d["inlineStorageTwoByte"]
else:
if is_latin1:
chars = d["s"]["u2"]["nonInlineCharsLatin1"]
else:
chars = d["s"]["u2"]["nonInlineCharsTwoByte"]
for i in range(int(length)):
yield chars[i]
def to_string(self, maxlen=200):
s = ""
invalid_chars_allowed = 2
for c in self.chars():
if len(s) >= maxlen:
s += "..."
break
try:
# Convert from gdb.Value to string.
s += chr(c)
except ValueError:
if invalid_chars_allowed == 0:
s += "<TOO_MANY_INVALID_CHARS>"
break
else:
invalid_chars_allowed -= 1
s += "\\x%04x" % (c & 0xFFFF)
return s
@ptr_pretty_printer("JSAtom")
class JSAtomPtr(Common):
def to_string(self):
return self.value.cast(self.cache.JSString_ptr_t)