1 files changed, 104 insertions, 0 deletions
diff --git a/js/src/gdb/mozilla/JSString.py b/js/src/gdb/mozilla/JSString.py
new file mode 100644
index 0000000000..afcd320740
--- /dev/null
+++ b/js/src/gdb/mozilla/JSString.py
@@ -0,0 +1,104 @@
+# 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,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# 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)