| """ |
| Objective-C runtime wrapper for use by LLDB Python formatters |
| |
| part of The LLVM Compiler Infrastructure |
| This file is distributed under the University of Illinois Open Source |
| License. See LICENSE.TXT for details. |
| """ |
| import lldb |
| import cache |
| import attrib_fromdict |
| import functools |
| import Logger |
| |
| class Utilities: |
| @staticmethod |
| def read_ascii(process, pointer,max_len=128): |
| logger = Logger.Logger() |
| error = lldb.SBError() |
| content = None |
| try: |
| content = process.ReadCStringFromMemory(pointer,max_len,error) |
| except: |
| pass |
| if content == None or len(content) == 0 or error.fail == True: |
| return None |
| return content |
| |
| @staticmethod |
| def is_valid_pointer(pointer, pointer_size, allow_tagged=False, allow_NULL=False): |
| logger = Logger.Logger() |
| if pointer == None: |
| return False |
| if pointer == 0: |
| return allow_NULL |
| if allow_tagged and (pointer % 2) == 1: |
| return True |
| return ((pointer % pointer_size) == 0) |
| |
| # Objective-C runtime has a rule that pointers in a class_t will only have bits 0 thru 46 set |
| # so if any pointer has bits 47 thru 63 high we know that this is not a valid isa |
| @staticmethod |
| def is_allowed_pointer(pointer): |
| logger = Logger.Logger() |
| if pointer == None: |
| return False |
| return ((pointer & 0xFFFF800000000000) == 0) |
| |
| @staticmethod |
| def read_child_of(valobj,offset,type): |
| logger = Logger.Logger() |
| child = valobj.CreateChildAtOffset("childUNK",offset,type) |
| if child == None or child.IsValid() == False: |
| return None; |
| return child.GetValueAsUnsigned() |
| |
| @staticmethod |
| def is_valid_identifier(name): |
| logger = Logger.Logger() |
| if name is None: |
| return None |
| if len(name) == 0: |
| return None |
| # technically, the ObjC runtime does not enforce any rules about what name a class can have |
| # in practice, the commonly used byte values for a class name are the letters, digits and some |
| # symbols: $, %, -, _, . |
| # WARNING: this means that you cannot use this runtime implementation if you need to deal |
| # with class names that use anything but what is allowed here |
| ok_values = dict.fromkeys("$%_.-ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890") |
| return all(c in ok_values for c in name) |
| |
| @staticmethod |
| def check_is_osx_lion(target): |
| logger = Logger.Logger() |
| # assume the only thing that has a Foundation.framework is a Mac |
| # assume anything < Lion does not even exist |
| mod = target.module['Foundation'] |
| if mod == None or mod.IsValid() == False: |
| return None |
| ver = mod.GetVersion() |
| if ver == None or ver == []: |
| return None |
| return (ver[0] < 900) |
| |
| # a utility method that factors out code common to almost all the formatters |
| # takes in an SBValue and a metrics object |
| # returns a class_data and a wrapper (or None, if the runtime alone can't decide on a wrapper) |
| @staticmethod |
| def prepare_class_detection(valobj,statistics): |
| logger = Logger.Logger() |
| class_data = ObjCRuntime(valobj) |
| if class_data.is_valid() == False: |
| statistics.metric_hit('invalid_pointer',valobj) |
| wrapper = InvalidPointer_Description(valobj.GetValueAsUnsigned(0) == 0) |
| return class_data,wrapper |
| class_data = class_data.read_class_data() |
| if class_data.is_valid() == False: |
| statistics.metric_hit('invalid_isa',valobj) |
| wrapper = InvalidISA_Description() |
| return class_data,wrapper |
| if class_data.is_kvo(): |
| class_data = class_data.get_superclass() |
| if class_data.is_valid() == False: |
| statistics.metric_hit('invalid_isa',valobj) |
| wrapper = InvalidISA_Description() |
| return class_data,wrapper |
| return class_data,None |
| |
| |
| class RoT_Data: |
| def __init__(self,rot_pointer,params): |
| logger = Logger.Logger() |
| if (Utilities.is_valid_pointer(rot_pointer.GetValueAsUnsigned(),params.pointer_size, allow_tagged=False)): |
| self.sys_params = params |
| self.valobj = rot_pointer |
| #self.flags = Utilities.read_child_of(self.valobj,0,self.sys_params.uint32_t) |
| #self.instanceStart = Utilities.read_child_of(self.valobj,4,self.sys_params.uint32_t) |
| self.instanceSize = None # lazy fetching |
| offset = 24 if self.sys_params.is_64_bit else 16 |
| #self.ivarLayoutPtr = Utilities.read_child_of(self.valobj,offset,self.sys_params.addr_ptr_type) |
| self.namePointer = Utilities.read_child_of(self.valobj,offset,self.sys_params.types_cache.addr_ptr_type) |
| self.check_valid() |
| else: |
| logger >> "Marking as invalid - rot is invalid" |
| self.valid = False |
| if self.valid: |
| self.name = Utilities.read_ascii(self.valobj.GetTarget().GetProcess(),self.namePointer) |
| if not(Utilities.is_valid_identifier(self.name)): |
| logger >> "Marking as invalid - name is invalid" |
| self.valid = False |
| |
| # perform sanity checks on the contents of this class_ro_t |
| def check_valid(self): |
| self.valid = True |
| # misaligned pointers seem to be possible for this field |
| #if not(Utilities.is_valid_pointer(self.namePointer,self.sys_params.pointer_size,allow_tagged=False)): |
| # self.valid = False |
| # pass |
| |
| def __str__(self): |
| logger = Logger.Logger() |
| return \ |
| "instanceSize = " + hex(self.instance_size()) + "\n" + \ |
| "namePointer = " + hex(self.namePointer) + " --> " + self.name |
| |
| def is_valid(self): |
| return self.valid |
| |
| def instance_size(self,align=False): |
| logger = Logger.Logger() |
| if self.is_valid() == False: |
| return None |
| if self.instanceSize == None: |
| self.instanceSize = Utilities.read_child_of(self.valobj,8,self.sys_params.types_cache.uint32_t) |
| if align: |
| unalign = self.instance_size(False) |
| if self.sys_params.is_64_bit: |
| return ((unalign + 7) & ~7) % 0x100000000 |
| else: |
| return ((unalign + 3) & ~3) % 0x100000000 |
| else: |
| return self.instanceSize |
| |
| class RwT_Data: |
| def __init__(self,rwt_pointer,params): |
| logger = Logger.Logger() |
| if (Utilities.is_valid_pointer(rwt_pointer.GetValueAsUnsigned(),params.pointer_size, allow_tagged=False)): |
| self.sys_params = params |
| self.valobj = rwt_pointer |
| #self.flags = Utilities.read_child_of(self.valobj,0,self.sys_params.uint32_t) |
| #self.version = Utilities.read_child_of(self.valobj,4,self.sys_params.uint32_t) |
| self.roPointer = Utilities.read_child_of(self.valobj,8,self.sys_params.types_cache.addr_ptr_type) |
| self.check_valid() |
| else: |
| logger >> "Marking as invalid - rwt is invald" |
| self.valid = False |
| if self.valid: |
| self.rot = self.valobj.CreateValueFromAddress("rot",self.roPointer,self.sys_params.types_cache.addr_ptr_type).AddressOf() |
| self.data = RoT_Data(self.rot,self.sys_params) |
| |
| # perform sanity checks on the contents of this class_rw_t |
| def check_valid(self): |
| logger = Logger.Logger() |
| self.valid = True |
| if not(Utilities.is_valid_pointer(self.roPointer,self.sys_params.pointer_size,allow_tagged=False)): |
| logger >> "Marking as invalid - ropointer is invalid" |
| self.valid = False |
| |
| def __str__(self): |
| logger = Logger.Logger() |
| return \ |
| "roPointer = " + hex(self.roPointer) |
| |
| def is_valid(self): |
| logger = Logger.Logger() |
| if self.valid: |
| return self.data.is_valid() |
| return False |
| |
| class Class_Data_V2: |
| def __init__(self,isa_pointer,params): |
| logger = Logger.Logger() |
| if (isa_pointer != None) and (Utilities.is_valid_pointer(isa_pointer.GetValueAsUnsigned(),params.pointer_size, allow_tagged=False)): |
| self.sys_params = params |
| self.valobj = isa_pointer |
| self.check_valid() |
| else: |
| logger >> "Marking as invalid - isa is invalid or None" |
| self.valid = False |
| if self.valid: |
| self.rwt = self.valobj.CreateValueFromAddress("rwt",self.dataPointer,self.sys_params.types_cache.addr_ptr_type).AddressOf() |
| self.data = RwT_Data(self.rwt,self.sys_params) |
| |
| # perform sanity checks on the contents of this class_t |
| # this call tries to minimize the amount of data fetched- as soon as we have "proven" |
| # that we have an invalid object, we stop reading |
| def check_valid(self): |
| logger = Logger.Logger() |
| self.valid = True |
| |
| self.isaPointer = Utilities.read_child_of(self.valobj,0,self.sys_params.types_cache.addr_ptr_type) |
| if not(Utilities.is_valid_pointer(self.isaPointer,self.sys_params.pointer_size,allow_tagged=False)): |
| logger >> "Marking as invalid - isaPointer is invalid" |
| self.valid = False |
| return |
| if not(Utilities.is_allowed_pointer(self.isaPointer)): |
| logger >> "Marking as invalid - isaPointer is not allowed" |
| self.valid = False |
| return |
| |
| self.cachePointer = Utilities.read_child_of(self.valobj,2*self.sys_params.pointer_size,self.sys_params.types_cache.addr_ptr_type) |
| if not(Utilities.is_valid_pointer(self.cachePointer,self.sys_params.pointer_size,allow_tagged=False)): |
| logger >> "Marking as invalid - cachePointer is invalid" |
| self.valid = False |
| return |
| if not(Utilities.is_allowed_pointer(self.cachePointer)): |
| logger >> "Marking as invalid - cachePointer is not allowed" |
| self.valid = False |
| return |
| |
| self.vtablePointer = Utilities.read_child_of(self.valobj,3*self.sys_params.pointer_size,self.sys_params.types_cache.addr_ptr_type) |
| if not(Utilities.is_valid_pointer(self.vtablePointer,self.sys_params.pointer_size,allow_tagged=False)): |
| logger >> "Marking as invalid - vtablePointer is invalid" |
| self.valid = False |
| return |
| if not(Utilities.is_allowed_pointer(self.vtablePointer)): |
| logger >> "Marking as invalid - vtablePointer is not allowed" |
| self.valid = False |
| return |
| |
| self.dataPointer = Utilities.read_child_of(self.valobj,4*self.sys_params.pointer_size,self.sys_params.types_cache.addr_ptr_type) |
| if not(Utilities.is_valid_pointer(self.dataPointer,self.sys_params.pointer_size,allow_tagged=False)): |
| logger >> "Marking as invalid - dataPointer is invalid" |
| self.valid = False |
| return |
| if not(Utilities.is_allowed_pointer(self.dataPointer)): |
| logger >> "Marking as invalid - dataPointer is not allowed" |
| self.valid = False |
| return |
| |
| self.superclassIsaPointer = Utilities.read_child_of(self.valobj,1*self.sys_params.pointer_size,self.sys_params.types_cache.addr_ptr_type) |
| if not(Utilities.is_valid_pointer(self.superclassIsaPointer,self.sys_params.pointer_size,allow_tagged=False, allow_NULL=True)): |
| logger >> "Marking as invalid - superclassIsa is invalid" |
| self.valid = False |
| return |
| if not(Utilities.is_allowed_pointer(self.superclassIsaPointer)): |
| logger >> "Marking as invalid - superclassIsa is not allowed" |
| self.valid = False |
| return |
| |
| # in general, KVO is implemented by transparently subclassing |
| # however, there could be exceptions where a class does something else |
| # internally to implement the feature - this method will have no clue that a class |
| # has been KVO'ed unless the standard implementation technique is used |
| def is_kvo(self): |
| logger = Logger.Logger() |
| if self.is_valid(): |
| if self.class_name().startswith("NSKVONotifying_"): |
| return True |
| return False |
| |
| # some CF classes have a valid ObjC isa in their CFRuntimeBase |
| # but instead of being class-specific this isa points to a match-'em-all class |
| # which is __NSCFType (the versions without __ also exists and we are matching to it |
| # just to be on the safe side) |
| def is_cftype(self): |
| logger = Logger.Logger() |
| if self.is_valid(): |
| return self.class_name() == '__NSCFType' or self.class_name() == 'NSCFType' |
| |
| def get_superclass(self): |
| logger = Logger.Logger() |
| if self.is_valid(): |
| parent_isa_pointer = self.valobj.CreateChildAtOffset("parent_isa", |
| self.sys_params.pointer_size, |
| self.sys_params.addr_ptr_type) |
| return Class_Data_V2(parent_isa_pointer,self.sys_params) |
| else: |
| return None |
| |
| def class_name(self): |
| logger = Logger.Logger() |
| if self.is_valid(): |
| return self.data.data.name |
| else: |
| return None |
| |
| def is_valid(self): |
| logger = Logger.Logger() |
| if self.valid: |
| return self.data.is_valid() |
| return False |
| |
| def __str__(self): |
| logger = Logger.Logger() |
| return 'isaPointer = ' + hex(self.isaPointer) + "\n" + \ |
| "superclassIsaPointer = " + hex(self.superclassIsaPointer) + "\n" + \ |
| "cachePointer = " + hex(self.cachePointer) + "\n" + \ |
| "vtablePointer = " + hex(self.vtablePointer) + "\n" + \ |
| "data = " + hex(self.dataPointer) |
| |
| def is_tagged(self): |
| return False |
| |
| def instance_size(self,align=False): |
| logger = Logger.Logger() |
| if self.is_valid() == False: |
| return None |
| return self.rwt.rot.instance_size(align) |
| |
| # runtime v1 is much less intricate than v2 and stores relevant information directly in the class_t object |
| class Class_Data_V1: |
| def __init__(self,isa_pointer,params): |
| logger = Logger.Logger() |
| if (isa_pointer != None) and (Utilities.is_valid_pointer(isa_pointer.GetValueAsUnsigned(),params.pointer_size, allow_tagged=False)): |
| self.valid = True |
| self.sys_params = params |
| self.valobj = isa_pointer |
| self.check_valid() |
| else: |
| logger >> "Marking as invalid - isaPointer is invalid or None" |
| self.valid = False |
| if self.valid: |
| self.name = Utilities.read_ascii(self.valobj.GetTarget().GetProcess(),self.namePointer) |
| if not(Utilities.is_valid_identifier(self.name)): |
| logger >> "Marking as invalid - name is not valid" |
| self.valid = False |
| |
| # perform sanity checks on the contents of this class_t |
| def check_valid(self): |
| logger = Logger.Logger() |
| self.valid = True |
| |
| self.isaPointer = Utilities.read_child_of(self.valobj,0,self.sys_params.types_cache.addr_ptr_type) |
| if not(Utilities.is_valid_pointer(self.isaPointer,self.sys_params.pointer_size,allow_tagged=False)): |
| logger >> "Marking as invalid - isaPointer is invalid" |
| self.valid = False |
| return |
| |
| self.superclassIsaPointer = Utilities.read_child_of(self.valobj,1*self.sys_params.pointer_size,self.sys_params.types_cache.addr_ptr_type) |
| if not(Utilities.is_valid_pointer(self.superclassIsaPointer,self.sys_params.pointer_size,allow_tagged=False,allow_NULL=True)): |
| logger >> "Marking as invalid - superclassIsa is invalid" |
| self.valid = False |
| return |
| |
| self.namePointer = Utilities.read_child_of(self.valobj,2*self.sys_params.pointer_size,self.sys_params.types_cache.addr_ptr_type) |
| #if not(Utilities.is_valid_pointer(self.namePointer,self.sys_params.pointer_size,allow_tagged=False,allow_NULL=False)): |
| # self.valid = False |
| # return |
| |
| # in general, KVO is implemented by transparently subclassing |
| # however, there could be exceptions where a class does something else |
| # internally to implement the feature - this method will have no clue that a class |
| # has been KVO'ed unless the standard implementation technique is used |
| def is_kvo(self): |
| logger = Logger.Logger() |
| if self.is_valid(): |
| if self.class_name().startswith("NSKVONotifying_"): |
| return True |
| return False |
| |
| # some CF classes have a valid ObjC isa in their CFRuntimeBase |
| # but instead of being class-specific this isa points to a match-'em-all class |
| # which is __NSCFType (the versions without __ also exists and we are matching to it |
| # just to be on the safe side) |
| def is_cftype(self): |
| logger = Logger.Logger() |
| if self.is_valid(): |
| return self.class_name() == '__NSCFType' or self.class_name() == 'NSCFType' |
| |
| def get_superclass(self): |
| logger = Logger.Logger() |
| if self.is_valid(): |
| parent_isa_pointer = self.valobj.CreateChildAtOffset("parent_isa", |
| self.sys_params.pointer_size, |
| self.sys_params.addr_ptr_type) |
| return Class_Data_V1(parent_isa_pointer,self.sys_params) |
| else: |
| return None |
| |
| def class_name(self): |
| logger = Logger.Logger() |
| if self.is_valid(): |
| return self.name |
| else: |
| return None |
| |
| def is_valid(self): |
| return self.valid |
| |
| def __str__(self): |
| logger = Logger.Logger() |
| return 'isaPointer = ' + hex(self.isaPointer) + "\n" + \ |
| "superclassIsaPointer = " + hex(self.superclassIsaPointer) + "\n" + \ |
| "namePointer = " + hex(self.namePointer) + " --> " + self.name + \ |
| "instanceSize = " + hex(self.instanceSize()) + "\n" |
| |
| def is_tagged(self): |
| return False |
| |
| def instance_size(self,align=False): |
| logger = Logger.Logger() |
| if self.is_valid() == False: |
| return None |
| if self.instanceSize == None: |
| self.instanceSize = Utilities.read_child_of(self.valobj,5*self.sys_params.pointer_size,self.sys_params.types_cache.addr_ptr_type) |
| if align: |
| unalign = self.instance_size(False) |
| if self.sys_params.is_64_bit: |
| return ((unalign + 7) & ~7) % 0x100000000 |
| else: |
| return ((unalign + 3) & ~3) % 0x100000000 |
| else: |
| return self.instanceSize |
| |
| # these are the only tagged pointers values for current versions |
| # of OSX - they might change in future OS releases, and no-one is |
| # advised to rely on these values, or any of the bitmasking formulas |
| # in TaggedClass_Data. doing otherwise is at your own risk |
| TaggedClass_Values_Lion = {1 : 'NSNumber', \ |
| 5: 'NSManagedObject', \ |
| 6: 'NSDate', \ |
| 7: 'NSDateTS' }; |
| TaggedClass_Values_NMOS = {0: 'NSAtom', \ |
| 3 : 'NSNumber', \ |
| 4: 'NSDateTS', \ |
| 5: 'NSManagedObject', \ |
| 6: 'NSDate' }; |
| |
| class TaggedClass_Data: |
| def __init__(self,pointer,params): |
| logger = Logger.Logger() |
| global TaggedClass_Values_Lion,TaggedClass_Values_NMOS |
| self.valid = True |
| self.name = None |
| self.sys_params = params |
| self.valobj = pointer |
| self.val = (pointer & ~0x0000000000000000FF) >> 8 |
| self.class_bits = (pointer & 0xE) >> 1 |
| self.i_bits = (pointer & 0xF0) >> 4 |
| |
| if self.sys_params.is_lion: |
| if self.class_bits in TaggedClass_Values_Lion: |
| self.name = TaggedClass_Values_Lion[self.class_bits] |
| else: |
| logger >> "Marking as invalid - not a good tagged pointer for Lion" |
| self.valid = False |
| else: |
| if self.class_bits in TaggedClass_Values_NMOS: |
| self.name = TaggedClass_Values_NMOS[self.class_bits] |
| else: |
| logger >> "Marking as invalid - not a good tagged pointer for NMOS" |
| self.valid = False |
| |
| |
| def is_valid(self): |
| return self.valid |
| |
| def class_name(self): |
| logger = Logger.Logger() |
| if self.is_valid(): |
| return self.name |
| else: |
| return False |
| |
| def value(self): |
| return self.val if self.is_valid() else None |
| |
| def info_bits(self): |
| return self.i_bits if self.is_valid() else None |
| |
| def is_kvo(self): |
| return False |
| |
| def is_cftype(self): |
| return False |
| |
| # we would need to go around looking for the superclass or ask the runtime |
| # for now, we seem not to require support for this operation so we will merrily |
| # pretend to be at a root point in the hierarchy |
| def get_superclass(self): |
| return None |
| |
| # anything that is handled here is tagged |
| def is_tagged(self): |
| return True |
| |
| # it seems reasonable to say that a tagged pointer is the size of a pointer |
| def instance_size(self,align=False): |
| logger = Logger.Logger() |
| if self.is_valid() == False: |
| return None |
| return self.sys_params.pointer_size |
| |
| |
| class InvalidClass_Data: |
| def __init__(self): |
| pass |
| def is_valid(self): |
| return False |
| |
| @functools.total_ordering |
| class Version: |
| def __init__(self, major, minor, release, build_string): |
| self._major = major |
| self._minor = minor |
| self._release = release |
| self._build_string = build_string |
| |
| def get_major(self): |
| return self._major |
| def get_minor(self): |
| return self._minor |
| def get_release(self): |
| return self._release |
| def get_build_string(self): |
| return self._build_string |
| |
| major = property(get_major,None) |
| minor = property(get_minor,None) |
| release = property(get_release,None) |
| build_string = property(get_build_string,None) |
| |
| def __lt__(self,other): |
| if (self.major < other.major): |
| return True |
| if (self.minor < other.minor): |
| return True |
| if (self.release < other.release): |
| return True |
| # build strings are not compared since they are heavily platform-dependent and might not always |
| # be available |
| return False |
| |
| def __eq__(self,other): |
| return (self.major == other.major) and \ |
| (self.minor == other.minor) and \ |
| (self.release == other.release) and \ |
| (self.build_string == other.build_string) |
| |
| runtime_version = cache.Cache() |
| os_version = cache.Cache() |
| types_caches = cache.Cache() |
| isa_caches = cache.Cache() |
| |
| class SystemParameters: |
| def __init__(self,valobj): |
| logger = Logger.Logger() |
| self.adjust_for_architecture(valobj) |
| self.adjust_for_process(valobj) |
| |
| def adjust_for_process(self, valobj): |
| logger = Logger.Logger() |
| global runtime_version |
| global os_version |
| global types_caches |
| global isa_caches |
| |
| process = valobj.GetTarget().GetProcess() |
| self.pid = process.GetProcessID() |
| |
| if runtime_version.look_for_key(self.pid): |
| self.runtime_version = runtime_version.get_value(self.pid) |
| else: |
| self.runtime_version = ObjCRuntime.runtime_version(process) |
| runtime_version.add_item(self.pid,self.runtime_version) |
| |
| if os_version.look_for_key(self.pid): |
| self.is_lion = os_version.get_value(self.pid) |
| else: |
| self.is_lion = Utilities.check_is_osx_lion(valobj.GetTarget()) |
| os_version.add_item(self.pid,self.is_lion) |
| |
| if types_caches.look_for_key(self.pid): |
| self.types_cache = types_caches.get_value(self.pid) |
| else: |
| self.types_cache = attrib_fromdict.AttributesDictionary(allow_reset=False) |
| self.types_cache.addr_type = valobj.GetType().GetBasicType(lldb.eBasicTypeUnsignedLong) |
| self.types_cache.addr_ptr_type = self.types_cache.addr_type.GetPointerType() |
| self.types_cache.uint32_t = valobj.GetType().GetBasicType(lldb.eBasicTypeUnsignedInt) |
| types_caches.add_item(self.pid,self.types_cache) |
| |
| if isa_caches.look_for_key(self.pid): |
| self.isa_cache = isa_caches.get_value(self.pid) |
| else: |
| self.isa_cache = cache.Cache() |
| isa_caches.add_item(self.pid,self.isa_cache) |
| |
| def adjust_for_architecture(self,valobj): |
| process = valobj.GetTarget().GetProcess() |
| self.pointer_size = process.GetAddressByteSize() |
| self.is_64_bit = (self.pointer_size == 8) |
| self.is_little = (process.GetByteOrder() == lldb.eByteOrderLittle) |
| self.cfruntime_size = 16 if self.is_64_bit else 8 |
| |
| # a simple helper function that makes it more explicit that one is calculating |
| # an offset that is made up of X pointers and Y bytes of additional data |
| # taking into account pointer size - if you know there is going to be some padding |
| # you can pass that in and it will be taken into account (since padding may be different between |
| # 32 and 64 bit versions, you can pass padding value for both, the right one will be used) |
| def calculate_offset(self, num_pointers = 0, bytes_count = 0, padding32 = 0, padding64 = 0): |
| value = bytes_count + num_pointers*self.pointer_size |
| return value + padding64 if self.is_64_bit else value + padding32 |
| |
| class ObjCRuntime: |
| |
| # the ObjC runtime has no explicit "version" field that we can use |
| # instead, we discriminate v1 from v2 by looking for the presence |
| # of a well-known section only present in v1 |
| @staticmethod |
| def runtime_version(process): |
| logger = Logger.Logger() |
| if process.IsValid() == False: |
| logger >> "No process - bailing out" |
| return None |
| target = process.GetTarget() |
| num_modules = target.GetNumModules() |
| module_objc = None |
| for idx in range(num_modules): |
| module = target.GetModuleAtIndex(idx) |
| if module.GetFileSpec().GetFilename() == 'libobjc.A.dylib': |
| module_objc = module |
| break |
| if module_objc == None or module_objc.IsValid() == False: |
| logger >> "no libobjc - bailing out" |
| return None |
| num_sections = module.GetNumSections() |
| section_objc = None |
| for idx in range(num_sections): |
| section = module.GetSectionAtIndex(idx) |
| if section.GetName() == '__OBJC': |
| section_objc = section |
| break |
| if section_objc != None and section_objc.IsValid(): |
| logger >> "found __OBJC: v1" |
| return 1 |
| logger >> "no __OBJC: v2" |
| return 2 |
| |
| @staticmethod |
| def runtime_from_isa(isa): |
| logger = Logger.Logger() |
| runtime = ObjCRuntime(isa) |
| runtime.isa = isa |
| return runtime |
| |
| def __init__(self,valobj): |
| logger = Logger.Logger() |
| self.valobj = valobj |
| self.adjust_for_architecture() |
| self.sys_params = SystemParameters(self.valobj) |
| self.unsigned_value = self.valobj.GetValueAsUnsigned() |
| self.isa_value = None |
| |
| def adjust_for_architecture(self): |
| pass |
| |
| # an ObjC pointer can either be tagged or must be aligned |
| def is_tagged(self): |
| logger = Logger.Logger() |
| if self.valobj is None: |
| return False |
| return (Utilities.is_valid_pointer(self.unsigned_value,self.sys_params.pointer_size, allow_tagged=True) and \ |
| not(Utilities.is_valid_pointer(self.unsigned_value,self.sys_params.pointer_size, allow_tagged=False))) |
| |
| def is_valid(self): |
| logger = Logger.Logger() |
| if self.valobj is None: |
| return False |
| if self.valobj.IsInScope() == False: |
| return False |
| return Utilities.is_valid_pointer(self.unsigned_value,self.sys_params.pointer_size, allow_tagged=True) |
| |
| def is_nil(self): |
| return self.unsigned_value == 0 |
| |
| def read_isa(self): |
| logger = Logger.Logger() |
| if self.isa_value != None: |
| logger >> "using cached isa" |
| return self.isa_value |
| isa_pointer = self.valobj.CreateChildAtOffset("cfisa", |
| 0, |
| self.sys_params.types_cache.addr_ptr_type) |
| if isa_pointer == None or isa_pointer.IsValid() == False: |
| logger >> "invalid isa - bailing out" |
| return None; |
| if isa_pointer.GetValueAsUnsigned(1) == 1: |
| logger >> "invalid isa value - bailing out" |
| return None; |
| self.isa_value = isa_pointer |
| return isa_pointer |
| |
| def read_class_data(self): |
| logger = Logger.Logger() |
| global isa_cache |
| if self.is_tagged(): |
| # tagged pointers only exist in ObjC v2 |
| if self.sys_params.runtime_version == 2: |
| logger >> "on v2 and tagged - maybe" |
| # not every odd-valued pointer is actually tagged. most are just plain wrong |
| # we could try and predetect this before even creating a TaggedClass_Data object |
| # but unless performance requires it, this seems a cleaner way to tackle the task |
| tentative_tagged = TaggedClass_Data(self.unsigned_value,self.sys_params) |
| if tentative_tagged.is_valid(): |
| logger >> "truly tagged" |
| return tentative_tagged |
| else: |
| logger >> "not tagged - error" |
| return InvalidClass_Data() |
| else: |
| logger >> "on v1 and tagged - error" |
| return InvalidClass_Data() |
| if self.is_valid() == False: |
| return InvalidClass_Data() |
| isa = self.read_isa() |
| if isa == None: |
| return InvalidClass_Data() |
| isa_value = isa.GetValueAsUnsigned(1) |
| if isa_value == 1: |
| return InvalidClass_Data() |
| data = self.sys_params.isa_cache.get_value(isa_value,default=None) |
| if data != None: |
| return data |
| if self.sys_params.runtime_version == 2: |
| data = Class_Data_V2(isa,self.sys_params) |
| else: |
| data = Class_Data_V1(isa,self.sys_params) |
| if data == None: |
| return InvalidClass_Data() |
| if data.is_valid(): |
| self.sys_params.isa_cache.add_item(isa_value,data,ok_to_replace=True) |
| return data |
| |
| # these classes below can be used by the data formatters to provide a consistent message that describes a given runtime-generated situation |
| class SpecialSituation_Description: |
| def message(self): |
| return '' |
| |
| class InvalidPointer_Description(SpecialSituation_Description): |
| |
| def __init__(self,nil): |
| self.is_nil = nil |
| |
| def message(self): |
| if self.is_nil: |
| return '@"<nil>"' |
| else: |
| return '<invalid pointer>' |
| |
| class InvalidISA_Description(SpecialSituation_Description): |
| |
| def __init__(self): |
| pass |
| |
| def message(self): |
| return '<not an Objective-C object>' |
| |
