llvm-project/lldb/examples/synthetic/libcxx.py

788 lines
28 KiB
Python

import lldb
import lldb.formatters.Logger
# libcxx STL formatters for LLDB
# These formatters are based upon the implementation of libc++ that
# ships with current releases of OS X - They will not work for other implementations
# of the standard C++ library - and they are bound to use the libc++-specific namespace
# the std::string summary is just an example for your convenience
# the actual summary that LLDB uses is C++ code inside the debugger's own core
# this could probably be made more efficient but since it only reads a handful of bytes at a time
# we probably don't need to worry too much about this for the time being
def make_string(F,L):
strval = ''
G = F.GetData().uint8
for X in range(L):
V = G[X]
if V == 0:
break
strval = strval + chr(V % 256)
return '"' + strval + '"'
# if we ever care about big-endian, these two functions might need to change
def is_short_string(value):
return True if (value & 1) == 0 else False
def extract_short_size(value):
return ((value >> 1) % 256)
# some of the members of libc++ std::string are anonymous or have internal names that convey
# no external significance - we access them by index since this saves a name lookup that would add
# no information for readers of the code, but when possible try to use meaningful variable names
def stdstring_SummaryProvider(valobj,dict):
logger = lldb.formatters.Logger.Logger()
r = valobj.GetChildAtIndex(0)
B = r.GetChildAtIndex(0)
first = B.GetChildAtIndex(0)
D = first.GetChildAtIndex(0)
l = D.GetChildAtIndex(0)
s = D.GetChildAtIndex(1)
D20 = s.GetChildAtIndex(0)
size_mode = D20.GetChildAtIndex(0).GetValueAsUnsigned(0)
if is_short_string(size_mode):
size = extract_short_size(size_mode)
return make_string(s.GetChildAtIndex(1),size)
else:
data_ptr = l.GetChildAtIndex(2)
size_vo = l.GetChildAtIndex(1)
size = size_vo.GetValueAsUnsigned(0)+1 # the NULL terminator must be accounted for
if size <= 1 or size == None: # should never be the case
return '""'
try:
data = data_ptr.GetPointeeData(0,size)
except:
return '""'
error = lldb.SBError()
strval = data.GetString(error,0)
if error.Fail():
return '<error:' + error.GetCString() + '>'
else:
return '"' + strval + '"'
class stdvector_SynthProvider:
def __init__(self, valobj, dict):
logger = lldb.formatters.Logger.Logger()
self.valobj = valobj;
def num_children(self):
logger = lldb.formatters.Logger.Logger()
try:
start_val = self.start.GetValueAsUnsigned(0)
finish_val = self.finish.GetValueAsUnsigned(0)
# Before a vector has been constructed, it will contain bad values
# so we really need to be careful about the length we return since
# uninitialized data can cause us to return a huge number. We need
# to also check for any of the start, finish or end of storage values
# being zero (NULL). If any are, then this vector has not been
# initialized yet and we should return zero
# Make sure nothing is NULL
if start_val == 0 or finish_val == 0:
return 0
# Make sure start is less than finish
if start_val >= finish_val:
return 0
num_children = (finish_val-start_val)
if (num_children % self.data_size) != 0:
return 0
else:
num_children = num_children/self.data_size
return num_children
except:
return 0;
def get_child_index(self,name):
logger = lldb.formatters.Logger.Logger()
try:
return int(name.lstrip('[').rstrip(']'))
except:
return -1
def get_child_at_index(self,index):
logger = lldb.formatters.Logger.Logger()
logger >> "Retrieving child " + str(index)
if index < 0:
return None;
if index >= self.num_children():
return None;
try:
offset = index * self.data_size
return self.start.CreateChildAtOffset('['+str(index)+']',offset,self.data_type)
except:
return None
def update(self):
logger = lldb.formatters.Logger.Logger()
try:
self.start = self.valobj.GetChildMemberWithName('__begin_')
self.finish = self.valobj.GetChildMemberWithName('__end_')
# the purpose of this field is unclear, but it is the only field whose type is clearly T* for a vector<T>
# if this ends up not being correct, we can use the APIs to get at template arguments
data_type_finder = self.valobj.GetChildMemberWithName('__end_cap_').GetChildMemberWithName('__first_')
self.data_type = data_type_finder.GetType().GetPointeeType()
self.data_size = self.data_type.GetByteSize()
except:
pass
def has_children(self):
return True
# Just an example: the actual summary is produced by a summary string: size=${svar%#}
def stdvector_SummaryProvider(valobj,dict):
prov = stdvector_SynthProvider(valobj,None)
return 'size=' + str(prov.num_children())
class stdlist_entry:
def __init__(self,entry):
logger = lldb.formatters.Logger.Logger()
self.entry = entry
def _next_impl(self):
logger = lldb.formatters.Logger.Logger()
return stdlist_entry(self.entry.GetChildMemberWithName('__next_'))
def _prev_impl(self):
logger = lldb.formatters.Logger.Logger()
return stdlist_entry(self.entry.GetChildMemberWithName('__prev_'))
def _value_impl(self):
logger = lldb.formatters.Logger.Logger()
return self.entry.GetValueAsUnsigned(0)
def _isnull_impl(self):
logger = lldb.formatters.Logger.Logger()
return self._value_impl() == 0
def _sbvalue_impl(self):
logger = lldb.formatters.Logger.Logger()
return self.entry
next = property(_next_impl,None)
value = property(_value_impl,None)
is_null = property(_isnull_impl,None)
sbvalue = property(_sbvalue_impl,None)
class stdlist_iterator:
def increment_node(self,node):
logger = lldb.formatters.Logger.Logger()
if node.is_null:
return None
return node.next
def __init__(self,node):
logger = lldb.formatters.Logger.Logger()
self.node = stdlist_entry(node) # we convert the SBValue to an internal node object on entry
def value(self):
logger = lldb.formatters.Logger.Logger()
return self.node.sbvalue # and return the SBValue back on exit
def next(self):
logger = lldb.formatters.Logger.Logger()
node = self.increment_node(self.node)
if node != None and node.sbvalue.IsValid() and not(node.is_null):
self.node = node
return self.value()
else:
return None
def advance(self,N):
logger = lldb.formatters.Logger.Logger()
if N < 0:
return None
if N == 0:
return self.value()
if N == 1:
return self.next()
while N > 0:
self.next()
N = N - 1
return self.value()
class stdlist_SynthProvider:
def __init__(self, valobj, dict):
logger = lldb.formatters.Logger.Logger()
self.valobj = valobj
self.count = None
def next_node(self,node):
logger = lldb.formatters.Logger.Logger()
return node.GetChildMemberWithName('__next_')
def value(self,node):
logger = lldb.formatters.Logger.Logger()
return node.GetValueAsUnsigned()
# Floyd's cycle-finding algorithm
# try to detect if this list has a loop
def has_loop(self):
global _list_uses_loop_detector
logger = lldb.formatters.Logger.Logger()
if _list_uses_loop_detector == False:
logger >> "Asked not to use loop detection"
return False
slow = stdlist_entry(self.head)
fast1 = stdlist_entry(self.head)
fast2 = stdlist_entry(self.head)
while slow.next.value != self.node_address:
slow_value = slow.value
fast1 = fast2.next
fast2 = fast1.next
if fast1.value == slow_value or fast2.value == slow_value:
return True
slow = slow.next
return False
def num_children(self):
global _list_capping_size
logger = lldb.formatters.Logger.Logger()
if self.count == None:
self.count = self.num_children_impl()
if self.count > _list_capping_size:
self.count = _list_capping_size
return self.count
def num_children_impl(self):
global _list_capping_size
logger = lldb.formatters.Logger.Logger()
try:
next_val = self.head.GetValueAsUnsigned(0)
prev_val = self.tail.GetValueAsUnsigned(0)
# After a std::list has been initialized, both next and prev will be non-NULL
if next_val == 0 or prev_val == 0:
return 0
if next_val == self.node_address:
return 0
if next_val == prev_val:
return 1
if self.has_loop():
return 0
size = 2
current = stdlist_entry(self.head)
while current.next.value != self.node_address:
size = size + 1
current = current.next
if size > _list_capping_size:
return _list_capping_size
return (size - 1)
except:
return 0;
def get_child_index(self,name):
logger = lldb.formatters.Logger.Logger()
try:
return int(name.lstrip('[').rstrip(']'))
except:
return -1
def get_child_at_index(self,index):
logger = lldb.formatters.Logger.Logger()
logger >> "Fetching child " + str(index)
if index < 0:
return None;
if index >= self.num_children():
return None;
try:
current = stdlist_iterator(self.head)
current = current.advance(index)
# we do not return __value_ because then all our children would be named __value_
# we need to make a copy of __value__ with the right name - unfortunate
obj = current.GetChildMemberWithName('__value_')
obj_data = obj.GetData()
return self.valobj.CreateValueFromData('[' + str(index) + ']',obj_data,self.data_type)
except:
return None
def extract_type(self):
logger = lldb.formatters.Logger.Logger()
list_type = self.valobj.GetType().GetUnqualifiedType()
if list_type.IsReferenceType():
list_type = list_type.GetDereferencedType()
if list_type.GetNumberOfTemplateArguments() > 0:
data_type = list_type.GetTemplateArgumentType(0)
else:
data_type = None
return data_type
def update(self):
logger = lldb.formatters.Logger.Logger()
self.count = None
try:
impl = self.valobj.GetChildMemberWithName('__end_')
self.node_address = self.valobj.AddressOf().GetValueAsUnsigned(0)
self.head = impl.GetChildMemberWithName('__next_')
self.tail = impl.GetChildMemberWithName('__prev_')
self.data_type = self.extract_type()
self.data_size = self.data_type.GetByteSize()
except:
pass
def has_children(self):
return True
# Just an example: the actual summary is produced by a summary string: size=${svar%#}
def stdlist_SummaryProvider(valobj,dict):
prov = stdlist_SynthProvider(valobj,None)
return 'size=' + str(prov.num_children())
# a tree node - this class makes the syntax in the actual iterator nicer to read and maintain
class stdmap_iterator_node:
def _left_impl(self):
logger = lldb.formatters.Logger.Logger()
return stdmap_iterator_node(self.node.GetChildMemberWithName("__left_"))
def _right_impl(self):
logger = lldb.formatters.Logger.Logger()
return stdmap_iterator_node(self.node.GetChildMemberWithName("__right_"))
def _parent_impl(self):
logger = lldb.formatters.Logger.Logger()
return stdmap_iterator_node(self.node.GetChildMemberWithName("__parent_"))
def _value_impl(self):
logger = lldb.formatters.Logger.Logger()
return self.node.GetValueAsUnsigned(0)
def _sbvalue_impl(self):
logger = lldb.formatters.Logger.Logger()
return self.node
def _null_impl(self):
logger = lldb.formatters.Logger.Logger()
return self.value == 0
def __init__(self,node):
logger = lldb.formatters.Logger.Logger()
self.node = node
left = property(_left_impl,None)
right = property(_right_impl,None)
parent = property(_parent_impl,None)
value = property(_value_impl,None)
is_null = property(_null_impl,None)
sbvalue = property(_sbvalue_impl,None)
# a Python implementation of the tree iterator used by libc++
class stdmap_iterator:
def tree_min(self,x):
logger = lldb.formatters.Logger.Logger()
steps = 0
if x.is_null:
return None
while (not x.left.is_null):
x = x.left
steps += 1
if steps > self.max_count:
logger >> "Returning None - we overflowed"
return None
return x
def tree_max(self,x):
logger = lldb.formatters.Logger.Logger()
if x.is_null:
return None
while (not x.right.is_null):
x = x.right
return x
def tree_is_left_child(self,x):
logger = lldb.formatters.Logger.Logger()
if x.is_null:
return None
return True if x.value == x.parent.left.value else False
def increment_node(self,node):
logger = lldb.formatters.Logger.Logger()
if node.is_null:
return None
if not node.right.is_null:
return self.tree_min(node.right)
steps = 0
while (not self.tree_is_left_child(node)):
steps += 1
if steps > self.max_count:
logger >> "Returning None - we overflowed"
return None
node = node.parent
return node.parent
def __init__(self,node,max_count=0):
logger = lldb.formatters.Logger.Logger()
self.node = stdmap_iterator_node(node) # we convert the SBValue to an internal node object on entry
self.max_count = max_count
def value(self):
logger = lldb.formatters.Logger.Logger()
return self.node.sbvalue # and return the SBValue back on exit
def next(self):
logger = lldb.formatters.Logger.Logger()
node = self.increment_node(self.node)
if node != None and node.sbvalue.IsValid() and not(node.is_null):
self.node = node
return self.value()
else:
return None
def advance(self,N):
logger = lldb.formatters.Logger.Logger()
if N < 0:
return None
if N == 0:
return self.value()
if N == 1:
return self.next()
while N > 0:
if self.next() == None:
return None
N = N - 1
return self.value()
class stdmap_SynthProvider:
def __init__(self, valobj, dict):
logger = lldb.formatters.Logger.Logger()
self.valobj = valobj;
self.pointer_size = self.valobj.GetProcess().GetAddressByteSize()
self.count = None
def update(self):
logger = lldb.formatters.Logger.Logger()
self.count = None
try:
# we will set this to True if we find out that discovering a node in the map takes more steps than the overall size of the RB tree
# if this gets set to True, then we will merrily return None for any child from that moment on
self.garbage = False
self.tree = self.valobj.GetChildMemberWithName('__tree_')
self.root_node = self.tree.GetChildMemberWithName('__begin_node_')
# this data is either lazily-calculated, or cannot be inferred at this moment
# we still need to mark it as None, meaning "please set me ASAP"
self.data_type = None
self.data_size = None
self.skip_size = None
except:
pass
def num_children(self):
global _map_capping_size
logger = lldb.formatters.Logger.Logger()
if self.count == None:
self.count = self.num_children_impl()
if self.count > _map_capping_size:
self.count = _map_capping_size
return self.count
def num_children_impl(self):
logger = lldb.formatters.Logger.Logger()
try:
return self.valobj.GetChildMemberWithName('__tree_').GetChildMemberWithName('__pair3_').GetChildMemberWithName('__first_').GetValueAsUnsigned()
except:
return 0;
def has_children(self):
return True
def get_data_type(self):
logger = lldb.formatters.Logger.Logger()
if self.data_type == None or self.data_size == None:
if self.num_children() == 0:
return False
deref = self.root_node.Dereference()
if not(deref.IsValid()):
return False
value = deref.GetChildMemberWithName('__value_')
if not(value.IsValid()):
return False
self.data_type = value.GetType()
self.data_size = self.data_type.GetByteSize()
self.skip_size = None
return True
else:
return True
def get_value_offset(self,node):
logger = lldb.formatters.Logger.Logger()
if self.skip_size == None:
node_type = node.GetType()
fields_count = node_type.GetNumberOfFields()
for i in range(fields_count):
field = node_type.GetFieldAtIndex(i)
if field.GetName() == '__value_':
self.skip_size = field.GetOffsetInBytes()
break
return (self.skip_size != None)
def get_child_index(self,name):
logger = lldb.formatters.Logger.Logger()
try:
return int(name.lstrip('[').rstrip(']'))
except:
return -1
def get_child_at_index(self,index):
logger = lldb.formatters.Logger.Logger()
logger >> "Retrieving child " + str(index)
if index < 0:
return None
if index >= self.num_children():
return None;
if self.garbage:
logger >> "Returning None since this tree is garbage"
return None
try:
iterator = stdmap_iterator(self.root_node,max_count=self.num_children())
# the debug info for libc++ std::map is such that __begin_node_ has a very nice and useful type
# out of which we can grab the information we need - every other node has a less informative
# type which omits all value information and only contains housekeeping information for the RB tree
# hence, we need to know if we are at a node != 0, so that we can still get at the data
need_to_skip = (index > 0)
current = iterator.advance(index)
if current == None:
logger >> "Tree is garbage - returning None"
self.garbage = True
return None
if self.get_data_type():
if not(need_to_skip):
current = current.Dereference()
obj = current.GetChildMemberWithName('__value_')
obj_data = obj.GetData()
self.get_value_offset(current) # make sure we have a valid offset for the next items
# we do not return __value_ because then we would end up with a child named
# __value_ instead of [0]
return self.valobj.CreateValueFromData('[' + str(index) + ']',obj_data,self.data_type)
else:
# FIXME we need to have accessed item 0 before accessing any other item!
if self.skip_size == None:
logger >> "You asked for item > 0 before asking for item == 0, I will fetch 0 now then retry"
if self.get_child_at_index(0):
return self.get_child_at_index(index)
else:
logger >> "item == 0 could not be found. sorry, nothing can be done here."
return None
return current.CreateChildAtOffset('[' + str(index) + ']',self.skip_size,self.data_type)
else:
logger >> "Unable to infer data-type - returning None (should mark tree as garbage here?)"
return None
except Exception as err:
logger >> "Hit an exception: " + str(err)
return None
# Just an example: the actual summary is produced by a summary string: size=${svar%#}
def stdmap_SummaryProvider(valobj,dict):
prov = stdmap_SynthProvider(valobj,None)
return 'size=' + str(prov.num_children())
class stddeque_SynthProvider:
def __init__(self, valobj, d):
logger = lldb.formatters.Logger.Logger()
logger.write("init")
self.valobj = valobj
self.pointer_size = self.valobj.GetProcess().GetAddressByteSize()
self.count = None
try:
self.find_block_size()
except:
self.block_size = -1
self.element_size = -1
logger.write("block_size=%d, element_size=%d" % (self.block_size, self.element_size))
def find_block_size(self):
# in order to use the deque we must have the block size, or else
# it's impossible to know what memory addresses are valid
self.element_type = self.valobj.GetType().GetTemplateArgumentType(0)
self.element_size = self.element_type.GetByteSize()
# The code says this, but there must be a better way:
# template <class _Tp, class _Allocator>
# class __deque_base {
# static const difference_type __block_size = sizeof(value_type) < 256 ? 4096 / sizeof(value_type) : 16;
# }
if self.element_size < 256:
self.block_size = 4096 / self.element_size
else:
self.block_size = 16
def num_children(self):
global _deque_capping_size
logger = lldb.formatters.Logger.Logger()
if self.count is None:
return 0
return min(self.count, _deque_capping_size)
def has_children(self):
return True
def get_child_index(self,name):
logger = lldb.formatters.Logger.Logger()
try:
return int(name.lstrip('[').rstrip(']'))
except:
return -1
def get_child_at_index(self,index):
logger = lldb.formatters.Logger.Logger()
logger.write("Fetching child " + str(index))
if index < 0 or self.count is None:
return None;
if index >= self.num_children():
return None;
try:
i, j = divmod(self.start+index, self.block_size)
return self.first.CreateValueFromExpression('[' + str(index) + ']',
'*(*(%s + %d) + %d)' % (self.first.get_expr_path(), i, j))
except:
return None
def update(self):
logger = lldb.formatters.Logger.Logger()
try:
# A deque is effectively a two-dim array, with fixed width.
# 'map' contains pointers to the rows of this array. The
# full memory area allocated by the deque is delimited
# by 'first' and 'end_cap'. However, only a subset of this
# memory contains valid data since a deque may have some slack
# at the front and back in order to have O(1) insertion at
# both ends. The rows in active use are delimited by
# 'begin' and 'end'.
#
# To find the elements that are actually constructed, the 'start'
# variable tells which element in this NxM array is the 0th
# one, and the 'size' element gives the number of elements
# in the deque.
count = self.valobj.GetChildMemberWithName('__size_').GetChildMemberWithName('__first_').GetValueAsUnsigned(0)
# give up now if we cant access memory reliably
if self.block_size < 0:
logger.write("block_size < 0")
return
map_ = self.valobj.GetChildMemberWithName('__map_')
start = self.valobj.GetChildMemberWithName('__start_').GetValueAsUnsigned(0)
first = map_.GetChildMemberWithName('__first_')
map_first = first.GetValueAsUnsigned(0)
map_begin = map_.GetChildMemberWithName('__begin_').GetValueAsUnsigned(0)
map_end = map_.GetChildMemberWithName('__end_').GetValueAsUnsigned(0)
map_endcap= map_.GetChildMemberWithName('__end_cap_').GetChildMemberWithName('__first_').GetValueAsUnsigned(0)
# check consistency
if not map_first <= map_begin <= map_end <= map_endcap:
logger.write("map pointers are not monotonic")
return
total_rows, junk = divmod(map_endcap - map_first, self.pointer_size)
if junk:
logger.write("endcap-first doesnt align correctly")
return
active_rows, junk = divmod(map_end - map_begin, self.pointer_size)
if junk:
logger.write("end-begin doesnt align correctly")
return
start_row, junk = divmod(map_begin - map_first, self.pointer_size)
if junk:
logger.write("begin-first doesnt align correctly")
return
if not start_row*self.block_size <= start < (start_row+1)*self.block_size:
logger.write("0th element must be in the 'begin' row")
return
end_row = start_row + active_rows
if not count:
if active_rows:
logger.write("empty deque but begin!=end")
return
elif not (end_row-1)*self.block_size <= start+count < end_row*self.block_size:
logger.write("nth element must be before the 'end' row")
return
logger.write("update success: count=%r, start=%r, first=%r" % (count,start,first))
# if consistent, save all we really need:
self.count = count
self.start = start
self.first = first
except:
self.count = None
self.start = None
self.map_first = None
self.map_begin = None
class stdsharedptr_SynthProvider:
def __init__(self, valobj, d):
logger = lldb.formatters.Logger.Logger()
logger.write("init")
self.valobj = valobj
#self.element_ptr_type = self.valobj.GetType().GetTemplateArgumentType(0).GetPointerType()
self.ptr = None
self.cntrl = None
process = valobj.GetProcess()
self.endianness = process.GetByteOrder()
self.pointer_size = process.GetAddressByteSize()
self.count_type = valobj.GetType().GetBasicType(lldb.eBasicTypeUnsignedLong)
def num_children(self):
return 1
def has_children(self):
return True
def get_child_index(self,name):
if name=="__ptr_":
return 0
if name=="count":
return 1
if name=="weak_count":
return 2
return -1
def get_child_at_index(self,index):
if index == 0:
return self.ptr
if index == 1:
if self.cntrl == None:
count = 0
else:
count = 1 + self.cntrl.GetChildMemberWithName('__shared_owners_').GetValueAsSigned()
return self.valobj.CreateValueFromData("count",
lldb.SBData.CreateDataFromUInt64Array(self.endianness, self.pointer_size, [count]),
self.count_type)
if index == 2:
if self.cntrl == None:
count = 0
else:
count = 1 + self.cntrl.GetChildMemberWithName('__shared_weak_owners_').GetValueAsSigned()
return self.valobj.CreateValueFromData("weak_count",
lldb.SBData.CreateDataFromUInt64Array(self.endianness, self.pointer_size, [count]),
self.count_type)
return None
def update(self):
logger = lldb.formatters.Logger.Logger()
self.ptr = self.valobj.GetChildMemberWithName('__ptr_')#.Cast(self.element_ptr_type)
cntrl = self.valobj.GetChildMemberWithName('__cntrl_')
if cntrl.GetValueAsUnsigned(0):
self.cntrl = cntrl.Dereference()
else:
self.cntrl = None
# we can use two different categories for old and new formatters - type names are different enough that we should make no confusion
# talking with libc++ developer: "std::__1::class_name is set in stone until we decide to change the ABI. That shouldn't happen within a 5 year time frame"
def __lldb_init_module(debugger,dict):
debugger.HandleCommand('type summary add -F libcxx.stdstring_SummaryProvider "std::__1::string" -w libcxx')
debugger.HandleCommand('type summary add -F libcxx.stdstring_SummaryProvider "std::__1::basic_string<char, class std::__1::char_traits<char>, class std::__1::allocator<char> >" -w libcxx')
debugger.HandleCommand('type synthetic add -l libcxx.stdvector_SynthProvider -x "^(std::__1::)vector<.+>$" -w libcxx')
debugger.HandleCommand('type summary add -F libcxx.stdvector_SummaryProvider -e -x "^(std::__1::)vector<.+>$" -w libcxx')
debugger.HandleCommand('type synthetic add -l libcxx.stdlist_SynthProvider -x "^(std::__1::)list<.+>$" -w libcxx')
debugger.HandleCommand('type summary add -F libcxx.stdlist_SummaryProvider -e -x "^(std::__1::)list<.+>$" -w libcxx')
debugger.HandleCommand('type synthetic add -l libcxx.stdmap_SynthProvider -x "^(std::__1::)map<.+> >$" -w libcxx')
debugger.HandleCommand('type summary add -F libcxx.stdmap_SummaryProvider -e -x "^(std::__1::)map<.+> >$" -w libcxx')
debugger.HandleCommand("type category enable libcxx")
debugger.HandleCommand('type synthetic add -l libcxx.stddeque_SynthProvider -x "^(std::__1::)deque<.+>$" -w libcxx')
debugger.HandleCommand('type synthetic add -l libcxx.stdsharedptr_SynthProvider -x "^(std::__1::)shared_ptr<.+>$" -w libcxx')
# turns out the structs look the same, so weak_ptr can be handled the same!
debugger.HandleCommand('type synthetic add -l libcxx.stdsharedptr_SynthProvider -x "^(std::__1::)weak_ptr<.+>$" -w libcxx')
_map_capping_size = 255
_list_capping_size = 255
_list_uses_loop_detector = True
_deque_capping_size = 255