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

111 lines
3.8 KiB
Python

import lldb
_map_capping_size = 255
class libcxx_hash_table_SynthProvider:
def __init__(self, valobj, dict):
self.valobj = valobj
self.num_elements = None
self.next_element = None
self.bucket_count = None
def update(self):
logger = lldb.formatters.Logger.Logger()
self.num_elements = None
self.next_element = None
self.bucket_count = None
try:
# unordered_map is made up of a hash_map, which has 4 pieces in it:
# bucket list :
# array of buckets
# p1 (pair):
# first - pointer to first loaded element
# p2 (pair):
# first - number of elements
# second - hash function
# p3 (pair):
# first - max_load_factor
# second - equality operator function
#
# For display, we actually don't need to go inside the buckets, since 'p1' has a way to iterate over all
# the elements directly.
#
# We will calculate other values about the map because they will be useful for the summary.
#
table = self.valobj.GetChildMemberWithName('__table_')
bl_ptr = table.GetChildMemberWithName('__bucket_list_').GetChildMemberWithName('__ptr_')
self.bucket_array_ptr = bl_ptr.GetChildMemberWithName('__first_').GetValueAsUnsigned(0)
self.bucket_count = bl_ptr.GetChildMemberWithName('__second_').GetChildMemberWithName('__data_').GetChildMemberWithName('__first_').GetValueAsUnsigned(0)
logger >> "Bucket count = %r" % self.bucket_count
self.begin_ptr = table.GetChildMemberWithName('__p1_').GetChildMemberWithName('__first_').GetChildMemberWithName('__next_')
self.num_elements = table.GetChildMemberWithName('__p2_').GetChildMemberWithName('__first_').GetValueAsUnsigned(0)
self.max_load_factor = table.GetChildMemberWithName('__p3_').GetChildMemberWithName('__first_').GetValueAsUnsigned(0)
logger >> "Num elements = %r" % self.num_elements
# save the pointers as we get them
# -- don't access this first element if num_element==0!
self.elements_cache = []
if self.num_elements:
self.next_element = self.begin_ptr
else:
self.next_element = None
except Exception as e:
logger >> "Caught exception: %r" % e
pass
def num_children(self):
global _map_capping_size
num_elements = self.num_elements
if num_elements is not None:
if num_elements > _map_capping_size:
num_elements = _map_capping_size
return num_elements
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 >> "Retrieving child " + str(index)
if index < 0:
return None
if index >= self.num_children():
return None
# extend
logger >> " : cache size starts with %d elements" % len(self.elements_cache)
while index >= len(self.elements_cache):
# if we hit the end before we get the index, give up:
if not self.next_element:
logger >> " : hit end of list"
return None
node = self.next_element.Dereference()
value = node.GetChildMemberWithName('__value_')
hash_value = node.GetChildMemberWithName('__hash_').GetValueAsUnsigned()
self.elements_cache.append((value, hash_value))
self.next_element = node.GetChildMemberWithName('__next_')
if not self.next_element.GetValueAsUnsigned(0):
self.next_element = None
# hit the index! so we have the value
logger >> " : cache size ends with %d elements" % len(self.elements_cache)
value, hash_value = self.elements_cache[index]
return self.valobj.CreateValueFromData('[%d] <hash %d>'%(index,hash_value), value.GetData(), value.GetType())
def __lldb_init_module(debugger,dict):
debugger.HandleCommand('type synthetic add -l unordered_multi.libcxx_hash_table_SynthProvider -x "^(std::__1::)unordered_(multi)?(map|set)<.+> >$" -w libcxx')