*** This commit represents a complete reformatting of the LLDB source code

*** to conform to clang-format’s LLVM style.  This kind of mass change has
*** two obvious implications:

Firstly, merging this particular commit into a downstream fork may be a huge
effort.  Alternatively, it may be worth merging all changes up to this commit,
performing the same reformatting operation locally, and then discarding the
merge for this particular commit.  The commands used to accomplish this
reformatting were as follows (with current working directory as the root of
the repository):

    find . \( -iname "*.c" -or -iname "*.cpp" -or -iname "*.h" -or -iname "*.mm" \) -exec clang-format -i {} +
    find . -iname "*.py" -exec autopep8 --in-place --aggressive --aggressive {} + ;

The version of clang-format used was 3.9.0, and autopep8 was 1.2.4.

Secondly, “blame” style tools will generally point to this commit instead of
a meaningful prior commit.  There are alternatives available that will attempt
to look through this change and find the appropriate prior commit.  YMMV.

llvm-svn: 280751

1 files changed, 336 insertions, 310 deletions

diff --git a/lldb/examples/summaries/cocoa/CFString.py b/lldb/examples/summaries/cocoa/CFString.py
index 570fd8280e0..109d918a9de 100644
--- a/lldb/examples/summaries/cocoa/CFString.py
+++ b/lldb/examples/summaries/cocoa/CFString.py
@@ -11,315 +11,341 @@ import lldb
 import lldb.runtime.objc.objc_runtime
 import lldb.formatters.Logger
 
-def CFString_SummaryProvider (valobj,dict):
-	logger = lldb.formatters.Logger.Logger()
-	provider = CFStringSynthProvider(valobj,dict);
-	if provider.invalid == False:
-		try:
-			summary = provider.get_child_at_index(provider.get_child_index("content"))
-			if type(summary) == lldb.SBValue:
-				summary = summary.GetSummary()
-			else:
-				summary = '"' + summary + '"'
-		except:
-			summary = None
-		if summary == None:
-			summary = '<variable is not NSString>'
-		return '@'+summary
-	return ''
-
-def CFAttributedString_SummaryProvider (valobj,dict):
-	logger = lldb.formatters.Logger.Logger()
-	offset = valobj.GetTarget().GetProcess().GetAddressByteSize()
-	pointee = valobj.GetValueAsUnsigned(0)
-	summary = '<variable is not NSAttributedString>'
-	if pointee != None and pointee != 0:
-		pointee = pointee + offset
-		child_ptr = valobj.CreateValueFromAddress("string_ptr",pointee,valobj.GetType())
-		child = child_ptr.CreateValueFromAddress("string_data",child_ptr.GetValueAsUnsigned(),valobj.GetType()).AddressOf()
-		provider = CFStringSynthProvider(child,dict);
-		if provider.invalid == False:
-			try:
-				summary = provider.get_child_at_index(provider.get_child_index("content")).GetSummary();
-			except:
-				summary = '<variable is not NSAttributedString>'
-	if summary == None:
-		summary = '<variable is not NSAttributedString>'
-	return '@'+summary
-
-
-def __lldb_init_module(debugger,dict):
-	debugger.HandleCommand("type summary add -F CFString.CFString_SummaryProvider NSString CFStringRef CFMutableStringRef")
-	debugger.HandleCommand("type summary add -F CFString.CFAttributedString_SummaryProvider NSAttributedString")
+
+def CFString_SummaryProvider(valobj, dict):
+    logger = lldb.formatters.Logger.Logger()
+    provider = CFStringSynthProvider(valobj, dict)
+    if not provider.invalid:
+        try:
+            summary = provider.get_child_at_index(
+                provider.get_child_index("content"))
+            if isinstance(summary, lldb.SBValue):
+                summary = summary.GetSummary()
+            else:
+                summary = '"' + summary + '"'
+        except:
+            summary = None
+        if summary is None:
+            summary = '<variable is not NSString>'
+        return '@' + summary
+    return ''
+
+
+def CFAttributedString_SummaryProvider(valobj, dict):
+    logger = lldb.formatters.Logger.Logger()
+    offset = valobj.GetTarget().GetProcess().GetAddressByteSize()
+    pointee = valobj.GetValueAsUnsigned(0)
+    summary = '<variable is not NSAttributedString>'
+    if pointee is not None and pointee != 0:
+        pointee = pointee + offset
+        child_ptr = valobj.CreateValueFromAddress(
+            "string_ptr", pointee, valobj.GetType())
+        child = child_ptr.CreateValueFromAddress(
+            "string_data",
+            child_ptr.GetValueAsUnsigned(),
+            valobj.GetType()).AddressOf()
+        provider = CFStringSynthProvider(child, dict)
+        if not provider.invalid:
+            try:
+                summary = provider.get_child_at_index(
+                    provider.get_child_index("content")).GetSummary()
+            except:
+                summary = '<variable is not NSAttributedString>'
+    if summary is None:
+        summary = '<variable is not NSAttributedString>'
+    return '@' + summary
+
+
+def __lldb_init_module(debugger, dict):
+    debugger.HandleCommand(
+        "type summary add -F CFString.CFString_SummaryProvider NSString CFStringRef CFMutableStringRef")
+    debugger.HandleCommand(
+        "type summary add -F CFString.CFAttributedString_SummaryProvider NSAttributedString")
+
 
 class CFStringSynthProvider:
-	def __init__(self,valobj,dict):
-		logger = lldb.formatters.Logger.Logger()
-		self.valobj = valobj;
-		self.update()
-
-	# children other than "content" are for debugging only and must not be used in production code
-	def num_children(self):
-		logger = lldb.formatters.Logger.Logger()
-		if self.invalid:
-			return 0;
-		return 6;
-
-	def read_unicode(self, pointer,max_len=2048):
-		logger = lldb.formatters.Logger.Logger()
-		process = self.valobj.GetTarget().GetProcess()
-		error = lldb.SBError()
-		pystr = u''
-		# cannot do the read at once because the length value has
-		# a weird encoding. better play it safe here
-		while max_len > 0:
-			content = process.ReadMemory(pointer, 2, error)
-			new_bytes = bytearray(content)
-			b0 = new_bytes[0]
-			b1 = new_bytes[1]
-			pointer = pointer + 2
-			if b0 == 0 and b1 == 0:
-				break
-			# rearrange bytes depending on endianness
-			# (do we really need this or is Cocoa going to
-			#  use Windows-compatible little-endian even
-			#  if the target is big endian?)
-			if self.is_little:
-				value = b1 * 256 + b0
-			else:
-				value = b0 * 256 + b1
-			pystr = pystr + unichr(value)
-			# read max_len unicode values, not max_len bytes
-			max_len = max_len - 1
-		return pystr
-
-	# handle the special case strings
-	# only use the custom code for the tested LP64 case
-	def handle_special(self):
-		logger = lldb.formatters.Logger.Logger()
-		if self.is_64_bit == False:
-			# for 32bit targets, use safe ObjC code
-			return self.handle_unicode_string_safe()
-		offset = 12
-		pointer = self.valobj.GetValueAsUnsigned(0) + offset
-		pystr = self.read_unicode(pointer)
-		return self.valobj.CreateValueFromExpression("content",
-			"(char*)\"" + pystr.encode('utf-8') + "\"")
-
-	# last resort call, use ObjC code to read; the final aim is to
-	# be able to strip this call away entirely and only do the read
-	# ourselves
-	def handle_unicode_string_safe(self):
-		return self.valobj.CreateValueFromExpression("content",
-			"(char*)\"" + self.valobj.GetObjectDescription() + "\"");
-
-	def handle_unicode_string(self):
-		logger = lldb.formatters.Logger.Logger()
-		# step 1: find offset
-		if self.inline:
-			pointer = self.valobj.GetValueAsUnsigned(0) + self.size_of_cfruntime_base();
-			if self.explicit == False:
-				# untested, use the safe code path
-				return self.handle_unicode_string_safe();
-			else:
-				# a full pointer is skipped here before getting to the live data
-				pointer = pointer + self.pointer_size
-		else:
-			pointer = self.valobj.GetValueAsUnsigned(0) + self.size_of_cfruntime_base()
-			# read 8 bytes here and make an address out of them
-			try:
-				char_type = self.valobj.GetType().GetBasicType(lldb.eBasicTypeChar).GetPointerType()
-				vopointer = self.valobj.CreateValueFromAddress("dummy",pointer,char_type);
-				pointer = vopointer.GetValueAsUnsigned(0)
-			except:
-				return self.valobj.CreateValueFromExpression("content",
-                                                             '(char*)"@\"invalid NSString\""')
-		# step 2: read Unicode data at pointer
-		pystr = self.read_unicode(pointer)
-		# step 3: return it
-		return pystr.encode('utf-8')
-
-	def handle_inline_explicit(self):
-		logger = lldb.formatters.Logger.Logger()
-		offset = 3*self.pointer_size
-		offset = offset + self.valobj.GetValueAsUnsigned(0)
-		return self.valobj.CreateValueFromExpression("content",
-				"(char*)(" + str(offset) + ")")
-
-	def handle_mutable_string(self):
-		logger = lldb.formatters.Logger.Logger()
-		offset = 2 * self.pointer_size
-		data = self.valobj.CreateChildAtOffset("content",
-			offset, self.valobj.GetType().GetBasicType(lldb.eBasicTypeChar).GetPointerType());
-		data_value = data.GetValueAsUnsigned(0)
-		if self.explicit and self.unicode:
-			return self.read_unicode(data_value).encode('utf-8')
-		else:
-			data_value = data_value + 1
-			return self.valobj.CreateValueFromExpression("content", "(char*)(" + str(data_value) + ")")
-
-	def handle_UTF8_inline(self):
-		logger = lldb.formatters.Logger.Logger()
-		offset = self.valobj.GetValueAsUnsigned(0) + self.size_of_cfruntime_base();
-		if self.explicit == False:
-			offset = offset + 1;
-		return self.valobj.CreateValueFromAddress("content",
-				offset, self.valobj.GetType().GetBasicType(lldb.eBasicTypeChar)).AddressOf();
-
-	def handle_UTF8_not_inline(self):
-		logger = lldb.formatters.Logger.Logger()
-		offset = self.size_of_cfruntime_base();
-		return self.valobj.CreateChildAtOffset("content",
-				offset,self.valobj.GetType().GetBasicType(lldb.eBasicTypeChar).GetPointerType());
-
-	def get_child_at_index(self,index):
-		logger = lldb.formatters.Logger.Logger()
-		logger >> "Querying for child [" + str(index) + "]"
-		if index == 0:
-			return self.valobj.CreateValueFromExpression("mutable",
-				str(int(self.mutable)));
-		if index == 1:
-			return self.valobj.CreateValueFromExpression("inline",
-				str(int(self.inline)));
-		if index == 2:
-			return self.valobj.CreateValueFromExpression("explicit",
-				str(int(self.explicit)));
-		if index == 3:
-			return self.valobj.CreateValueFromExpression("unicode",
-				str(int(self.unicode)));
-		if index == 4:
-			return self.valobj.CreateValueFromExpression("special",
-				str(int(self.special)));
-		if index == 5:
-			# we are handling the several possible combinations of flags.
-			# for each known combination we have a function that knows how to
-			# go fetch the data from memory instead of running code. if a string is not
-			# correctly displayed, one should start by finding a combination of flags that
-			# makes it different from these known cases, and provide a new reader function
-			# if this is not possible, a new flag might have to be made up (like the "special" flag
-			# below, which is not a real flag in CFString), or alternatively one might need to use
-			# the ObjC runtime helper to detect the new class and deal with it accordingly
-			#print 'mutable = ' + str(self.mutable)
-			#print 'inline = ' + str(self.inline)
-			#print 'explicit = ' + str(self.explicit)
-			#print 'unicode = ' + str(self.unicode)
-			#print 'special = ' + str(self.special)
-			if self.mutable == True:
-				return self.handle_mutable_string()
-			elif self.inline == True and self.explicit == True and \
-			   self.unicode == False and self.special == False and \
-			   self.mutable == False:
-				return self.handle_inline_explicit()
-			elif self.unicode == True:
-				return self.handle_unicode_string();
-			elif self.special == True:
-				return self.handle_special();
-			elif self.inline == True:
-				return self.handle_UTF8_inline();
-			else:
-				return self.handle_UTF8_not_inline();
-
-	def get_child_index(self,name):
-		logger = lldb.formatters.Logger.Logger()
-		logger >> "Querying for child ['" + str(name) + "']"
-		if name == "content":
-			return self.num_children() - 1;
-		if name == "mutable":
-			return 0;
-		if name == "inline":
-			return 1;
-		if name == "explicit":
-			return 2;
-		if name == "unicode":
-			return 3;
-		if name == "special":
-			return 4;
-
-	# CFRuntimeBase is defined as having an additional
-	# 4 bytes (padding?) on LP64 architectures
-	# to get its size we add up sizeof(pointer)+4
-	# and then add 4 more bytes if we are on a 64bit system
-	def size_of_cfruntime_base(self):
-		logger = lldb.formatters.Logger.Logger()
-		return self.pointer_size+4+(4 if self.is_64_bit else 0)
-
-	# the info bits are part of the CFRuntimeBase structure
-	# to get at them we have to skip a uintptr_t and then get
-	# at the least-significant byte of a 4 byte array. If we are
-	# on big-endian this means going to byte 3, if we are on
-	# little endian (OSX & iOS), this means reading byte 0
-	def offset_of_info_bits(self):
-		logger = lldb.formatters.Logger.Logger()
-		offset = self.pointer_size
-		if self.is_little == False:
-			offset = offset + 3;
-		return offset;
-
-	def read_info_bits(self):
-		logger = lldb.formatters.Logger.Logger()
-		cfinfo = self.valobj.CreateChildAtOffset("cfinfo",
-					self.offset_of_info_bits(),
-					self.valobj.GetType().GetBasicType(lldb.eBasicTypeChar));
-		cfinfo.SetFormat(11)
-		info = cfinfo.GetValue();
-		if info != None:
-			self.invalid = False;
-			return int(info,0);
-		else:
-			self.invalid = True;
-			return None;
-
-	# calculating internal flag bits of the CFString object
-	# this stuff is defined and discussed in CFString.c
-	def is_mutable(self):
-		logger = lldb.formatters.Logger.Logger()
-		return (self.info_bits & 1) == 1;
-
-	def is_inline(self):
-		logger = lldb.formatters.Logger.Logger()
-		return (self.info_bits & 0x60) == 0;
-
-	# this flag's name is ambiguous, it turns out
-	# we must skip a length byte to get at the data
-	# when this flag is False
-	def has_explicit_length(self):
-		logger = lldb.formatters.Logger.Logger()
-		return (self.info_bits & (1 | 4)) != 4;
-
-	# probably a subclass of NSString. obtained this from [str pathExtension]
-	# here info_bits = 0 and Unicode data at the start of the padding word
-	# in the long run using the isa value might be safer as a way to identify this
-	# instead of reading the info_bits
-	def is_special_case(self):
-		logger = lldb.formatters.Logger.Logger()
-		return self.info_bits == 0;
-
-	def is_unicode(self):
-		logger = lldb.formatters.Logger.Logger()
-		return (self.info_bits & 0x10) == 0x10;
-
-	# preparing ourselves to read into memory
-	# by adjusting architecture-specific info
-	def adjust_for_architecture(self):
-		logger = lldb.formatters.Logger.Logger()
-		self.pointer_size = self.valobj.GetTarget().GetProcess().GetAddressByteSize()
-		self.is_64_bit = self.pointer_size == 8
-		self.is_little = self.valobj.GetTarget().GetProcess().GetByteOrder() == lldb.eByteOrderLittle
-
-	# reading info bits out of the CFString and computing
-	# useful values to get at the real data
-	def compute_flags(self):
-		logger = lldb.formatters.Logger.Logger()
-		self.info_bits = self.read_info_bits();
-		if self.info_bits == None:
-			return;
-		self.mutable = self.is_mutable();
-		self.inline = self.is_inline();
-		self.explicit = self.has_explicit_length();
-		self.unicode = self.is_unicode();
-		self.special = self.is_special_case();
-
-	def update(self):
-		logger = lldb.formatters.Logger.Logger()
-		self.adjust_for_architecture();
-		self.compute_flags();
+
+    def __init__(self, valobj, dict):
+        logger = lldb.formatters.Logger.Logger()
+        self.valobj = valobj
+        self.update()
+
+    # children other than "content" are for debugging only and must not be
+    # used in production code
+    def num_children(self):
+        logger = lldb.formatters.Logger.Logger()
+        if self.invalid:
+            return 0
+        return 6
+
+    def read_unicode(self, pointer, max_len=2048):
+        logger = lldb.formatters.Logger.Logger()
+        process = self.valobj.GetTarget().GetProcess()
+        error = lldb.SBError()
+        pystr = u''
+        # cannot do the read at once because the length value has
+        # a weird encoding. better play it safe here
+        while max_len > 0:
+            content = process.ReadMemory(pointer, 2, error)
+            new_bytes = bytearray(content)
+            b0 = new_bytes[0]
+            b1 = new_bytes[1]
+            pointer = pointer + 2
+            if b0 == 0 and b1 == 0:
+                break
+            # rearrange bytes depending on endianness
+            # (do we really need this or is Cocoa going to
+            #  use Windows-compatible little-endian even
+            #  if the target is big endian?)
+            if self.is_little:
+                value = b1 * 256 + b0
+            else:
+                value = b0 * 256 + b1
+            pystr = pystr + unichr(value)
+            # read max_len unicode values, not max_len bytes
+            max_len = max_len - 1
+        return pystr
+
+    # handle the special case strings
+    # only use the custom code for the tested LP64 case
+    def handle_special(self):
+        logger = lldb.formatters.Logger.Logger()
+        if not self.is_64_bit:
+            # for 32bit targets, use safe ObjC code
+            return self.handle_unicode_string_safe()
+        offset = 12
+        pointer = self.valobj.GetValueAsUnsigned(0) + offset
+        pystr = self.read_unicode(pointer)
+        return self.valobj.CreateValueFromExpression(
+            "content", "(char*)\"" + pystr.encode('utf-8') + "\"")
+
+    # last resort call, use ObjC code to read; the final aim is to
+    # be able to strip this call away entirely and only do the read
+    # ourselves
+    def handle_unicode_string_safe(self):
+        return self.valobj.CreateValueFromExpression(
+            "content", "(char*)\"" + self.valobj.GetObjectDescription() + "\"")
+
+    def handle_unicode_string(self):
+        logger = lldb.formatters.Logger.Logger()
+        # step 1: find offset
+        if self.inline:
+            pointer = self.valobj.GetValueAsUnsigned(
+                0) + self.size_of_cfruntime_base()
+            if not self.explicit:
+                # untested, use the safe code path
+                return self.handle_unicode_string_safe()
+            else:
+                # a full pointer is skipped here before getting to the live
+                # data
+                pointer = pointer + self.pointer_size
+        else:
+            pointer = self.valobj.GetValueAsUnsigned(
+                0) + self.size_of_cfruntime_base()
+            # read 8 bytes here and make an address out of them
+            try:
+                char_type = self.valobj.GetType().GetBasicType(
+                    lldb.eBasicTypeChar).GetPointerType()
+                vopointer = self.valobj.CreateValueFromAddress(
+                    "dummy", pointer, char_type)
+                pointer = vopointer.GetValueAsUnsigned(0)
+            except:
+                return self.valobj.CreateValueFromExpression(
+                    "content", '(char*)"@\"invalid NSString\""')
+        # step 2: read Unicode data at pointer
+        pystr = self.read_unicode(pointer)
+        # step 3: return it
+        return pystr.encode('utf-8')
+
+    def handle_inline_explicit(self):
+        logger = lldb.formatters.Logger.Logger()
+        offset = 3 * self.pointer_size
+        offset = offset + self.valobj.GetValueAsUnsigned(0)
+        return self.valobj.CreateValueFromExpression(
+            "content", "(char*)(" + str(offset) + ")")
+
+    def handle_mutable_string(self):
+        logger = lldb.formatters.Logger.Logger()
+        offset = 2 * self.pointer_size
+        data = self.valobj.CreateChildAtOffset(
+            "content", offset, self.valobj.GetType().GetBasicType(
+                lldb.eBasicTypeChar).GetPointerType())
+        data_value = data.GetValueAsUnsigned(0)
+        if self.explicit and self.unicode:
+            return self.read_unicode(data_value).encode('utf-8')
+        else:
+            data_value = data_value + 1
+            return self.valobj.CreateValueFromExpression(
+                "content", "(char*)(" + str(data_value) + ")")
+
+    def handle_UTF8_inline(self):
+        logger = lldb.formatters.Logger.Logger()
+        offset = self.valobj.GetValueAsUnsigned(
+            0) + self.size_of_cfruntime_base()
+        if not self.explicit:
+            offset = offset + 1
+        return self.valobj.CreateValueFromAddress(
+            "content", offset, self.valobj.GetType().GetBasicType(
+                lldb.eBasicTypeChar)).AddressOf()
+
+    def handle_UTF8_not_inline(self):
+        logger = lldb.formatters.Logger.Logger()
+        offset = self.size_of_cfruntime_base()
+        return self.valobj.CreateChildAtOffset(
+            "content", offset, self.valobj.GetType().GetBasicType(
+                lldb.eBasicTypeChar).GetPointerType())
+
+    def get_child_at_index(self, index):
+        logger = lldb.formatters.Logger.Logger()
+        logger >> "Querying for child [" + str(index) + "]"
+        if index == 0:
+            return self.valobj.CreateValueFromExpression(
+                "mutable", str(int(self.mutable)))
+        if index == 1:
+            return self.valobj.CreateValueFromExpression("inline",
+                                                         str(int(self.inline)))
+        if index == 2:
+            return self.valobj.CreateValueFromExpression(
+                "explicit", str(int(self.explicit)))
+        if index == 3:
+            return self.valobj.CreateValueFromExpression(
+                "unicode", str(int(self.unicode)))
+        if index == 4:
+            return self.valobj.CreateValueFromExpression(
+                "special", str(int(self.special)))
+        if index == 5:
+            # we are handling the several possible combinations of flags.
+            # for each known combination we have a function that knows how to
+            # go fetch the data from memory instead of running code. if a string is not
+            # correctly displayed, one should start by finding a combination of flags that
+            # makes it different from these known cases, and provide a new reader function
+            # if this is not possible, a new flag might have to be made up (like the "special" flag
+            # below, which is not a real flag in CFString), or alternatively one might need to use
+            # the ObjC runtime helper to detect the new class and deal with it accordingly
+            # print 'mutable = ' + str(self.mutable)
+            # print 'inline = ' + str(self.inline)
+            # print 'explicit = ' + str(self.explicit)
+            # print 'unicode = ' + str(self.unicode)
+            # print 'special = ' + str(self.special)
+            if self.mutable:
+                return self.handle_mutable_string()
+            elif self.inline and self.explicit and \
+                    self.unicode == False and self.special == False and \
+                    self.mutable == False:
+                return self.handle_inline_explicit()
+            elif self.unicode:
+                return self.handle_unicode_string()
+            elif self.special:
+                return self.handle_special()
+            elif self.inline:
+                return self.handle_UTF8_inline()
+            else:
+                return self.handle_UTF8_not_inline()
+
+    def get_child_index(self, name):
+        logger = lldb.formatters.Logger.Logger()
+        logger >> "Querying for child ['" + str(name) + "']"
+        if name == "content":
+            return self.num_children() - 1
+        if name == "mutable":
+            return 0
+        if name == "inline":
+            return 1
+        if name == "explicit":
+            return 2
+        if name == "unicode":
+            return 3
+        if name == "special":
+            return 4
+
+    # CFRuntimeBase is defined as having an additional
+    # 4 bytes (padding?) on LP64 architectures
+    # to get its size we add up sizeof(pointer)+4
+    # and then add 4 more bytes if we are on a 64bit system
+    def size_of_cfruntime_base(self):
+        logger = lldb.formatters.Logger.Logger()
+        return self.pointer_size + 4 + (4 if self.is_64_bit else 0)
+
+    # the info bits are part of the CFRuntimeBase structure
+    # to get at them we have to skip a uintptr_t and then get
+    # at the least-significant byte of a 4 byte array. If we are
+    # on big-endian this means going to byte 3, if we are on
+    # little endian (OSX & iOS), this means reading byte 0
+    def offset_of_info_bits(self):
+        logger = lldb.formatters.Logger.Logger()
+        offset = self.pointer_size
+        if not self.is_little:
+            offset = offset + 3
+        return offset
+
+    def read_info_bits(self):
+        logger = lldb.formatters.Logger.Logger()
+        cfinfo = self.valobj.CreateChildAtOffset(
+            "cfinfo",
+            self.offset_of_info_bits(),
+            self.valobj.GetType().GetBasicType(
+                lldb.eBasicTypeChar))
+        cfinfo.SetFormat(11)
+        info = cfinfo.GetValue()
+        if info is not None:
+            self.invalid = False
+            return int(info, 0)
+        else:
+            self.invalid = True
+            return None
+
+    # calculating internal flag bits of the CFString object
+    # this stuff is defined and discussed in CFString.c
+    def is_mutable(self):
+        logger = lldb.formatters.Logger.Logger()
+        return (self.info_bits & 1) == 1
+
+    def is_inline(self):
+        logger = lldb.formatters.Logger.Logger()
+        return (self.info_bits & 0x60) == 0
+
+    # this flag's name is ambiguous, it turns out
+    # we must skip a length byte to get at the data
+    # when this flag is False
+    def has_explicit_length(self):
+        logger = lldb.formatters.Logger.Logger()
+        return (self.info_bits & (1 | 4)) != 4
+
+    # probably a subclass of NSString. obtained this from [str pathExtension]
+    # here info_bits = 0 and Unicode data at the start of the padding word
+    # in the long run using the isa value might be safer as a way to identify this
+    # instead of reading the info_bits
+    def is_special_case(self):
+        logger = lldb.formatters.Logger.Logger()
+        return self.info_bits == 0
+
+    def is_unicode(self):
+        logger = lldb.formatters.Logger.Logger()
+        return (self.info_bits & 0x10) == 0x10
+
+    # preparing ourselves to read into memory
+    # by adjusting architecture-specific info
+    def adjust_for_architecture(self):
+        logger = lldb.formatters.Logger.Logger()
+        self.pointer_size = self.valobj.GetTarget().GetProcess().GetAddressByteSize()
+        self.is_64_bit = self.pointer_size == 8
+        self.is_little = self.valobj.GetTarget().GetProcess(
+        ).GetByteOrder() == lldb.eByteOrderLittle
+
+    # reading info bits out of the CFString and computing
+    # useful values to get at the real data
+    def compute_flags(self):
+        logger = lldb.formatters.Logger.Logger()
+        self.info_bits = self.read_info_bits()
+        if self.info_bits is None:
+            return
+        self.mutable = self.is_mutable()
+        self.inline = self.is_inline()
+        self.explicit = self.has_explicit_length()
+        self.unicode = self.is_unicode()
+        self.special = self.is_special_case()
+
+    def update(self):
+        logger = lldb.formatters.Logger.Logger()
+        self.adjust_for_architecture()
+        self.compute_flags()