NSData.py

"""
LLDB AppKit formatters

part of The LLVM Compiler Infrastructure
This file is distributed under the University of Illinois Open Source
License. See LICENSE.TXT for details.
"""
# summary provider for NSData
import lldb
import ctypes
import objc_runtime
import metrics
import Logger

statistics = metrics.Metrics()
statistics.add_metric('invalid_isa')
statistics.add_metric('invalid_pointer')
statistics.add_metric('unknown_class')
statistics.add_metric('code_notrun')

# despite the similary to synthetic children providers, these classes are not
# trying to provide anything but the length for an NSData, so they need not
# obey the interface specification for synthetic children providers
class NSConcreteData_SummaryProvider:
	def adjust_for_architecture(self):
		pass

	def __init__(self, valobj, params):
		logger = Logger.Logger()
		logger >> "NSConcreteData_SummaryProvider __init__"
		self.valobj = valobj;
		self.sys_params = params
		if not(self.sys_params.types_cache.NSUInteger):
			if self.sys_params.is_64_bit:
				self.sys_params.types_cache.NSUInteger = self.valobj.GetType().GetBasicType(lldb.eBasicTypeUnsignedLong)
			else:
				self.sys_params.types_cache.NSUInteger = self.valobj.GetType().GetBasicType(lldb.eBasicTypeUnsignedInt)
		self.update();

	def update(self):
		self.adjust_for_architecture();

	# one pointer is the ISA
	# then there are 32 bit worth of flags and other data
	# however, on 64bit systems these are padded to be a full
	# machine word long, which means we actually have two pointers
	# worth of data to skip
	def offset(self):
		return 2 * self.sys_params.pointer_size

	def length(self):
		logger = Logger.Logger()
		logger >> "NSConcreteData_SummaryProvider length"
		size = self.valobj.CreateChildAtOffset("count",
							self.offset(),
							self.sys_params.types_cache.NSUInteger)
		logger >> str(size)
		logger >> str(size.GetValueAsUnsigned(0))
		return size.GetValueAsUnsigned(0)


class NSDataUnknown_SummaryProvider:
	def adjust_for_architecture(self):
		pass

	def __init__(self, valobj, params):
		logger = Logger.Logger()
		logger >> "NSDataUnknown_SummaryProvider __init__"
		self.valobj = valobj;
		self.sys_params = params
		self.update();

	def update(self):
		self.adjust_for_architecture();

	def length(self):
		logger = Logger.Logger()
		logger >> "NSDataUnknown_SummaryProvider length"
		stream = lldb.SBStream()
		self.valobj.GetExpressionPath(stream)
		logger >> stream.GetData()
		num_children_vo = self.valobj.CreateValueFromExpression("count","(int)[" + stream.GetData() + " length]");
		logger >> "still in after expression: " + str(num_children_vo)
		if num_children_vo.IsValid():
			logger >> "wow - expr output is valid: " + str(num_children_vo.GetValueAsUnsigned())
			return num_children_vo.GetValueAsUnsigned(0)
		logger >> "invalid expr output - too bad"
		return '<variable is not NSData>'


def GetSummary_Impl(valobj):
	global statistics
	logger = Logger.Logger()
	logger >> "NSData GetSummary_Impl"
	class_data,wrapper = objc_runtime.Utilities.prepare_class_detection(valobj,statistics)
	if wrapper:
		logger >> "got a wrapper summary - using it"
		return wrapper
	
	name_string = class_data.class_name()
	logger >> "class name: " + name_string
	if name_string == 'NSConcreteData' or \
	   name_string == 'NSConcreteMutableData' or \
	   name_string == '__NSCFData':
		wrapper = NSConcreteData_SummaryProvider(valobj, class_data.sys_params)
		statistics.metric_hit('code_notrun',valobj)
	else:
		wrapper = NSDataUnknown_SummaryProvider(valobj, class_data.sys_params)
		statistics.metric_hit('unknown_class',valobj.GetName() + " seen as " + name_string)
	return wrapper;

def NSData_SummaryProvider (valobj,dict):
	logger = Logger.Logger()
	logger >> "NSData_SummaryProvider"
	provider = GetSummary_Impl(valobj);
	logger >> "found a summary provider, it is: " + str(provider)
	if provider != None:
		try:
			summary = provider.length();
		except:
			summary = None
		logger >> "got a summary: it is " + str(summary)
		if summary == None:
			summary = '<variable is not NSData>'
		elif isinstance(summary,basestring):
			pass
		else:
			if summary == 1:
				summary = '1 byte'
			else:
				summary = str(summary) + ' bytes'
		return summary
	return 'Summary Unavailable'

def NSData_SummaryProvider2 (valobj,dict):
	logger = Logger.Logger()
	logger >> "NSData_SummaryProvider2"
	provider = GetSummary_Impl(valobj);
	logger >> "found a summary provider, it is: " + str(provider)
	if provider != None:
		if isinstance(provider,objc_runtime.SpecialSituation_Description):
			return provider.message()
		try:
			summary = provider.length();
		except:
			summary = None
		logger >> "got a summary: it is " + str(summary)
		if summary == None:
			summary = '<variable is not CFData>'
		elif isinstance(summary,basestring):
			pass
		else:
			if summary == 1:
				summary = '@"1 byte"'
			else:
				summary = '@"' + str(summary) + ' bytes"'
		return summary
	return 'Summary Unavailable'

def __lldb_init_module(debugger,dict):
	debugger.HandleCommand("type summary add -F NSData.NSData_SummaryProvider NSData")
	debugger.HandleCommand("type summary add -F NSData.NSData_SummaryProvider2 CFDataRef CFMutableDataRef")