llvm-project/lldb/examples/synthetic/gnu_libstdcpp.py
Kate Stone b9c1b51e45 *** 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
2016-09-06 20:57:50 +00:00

481 lines
18 KiB
Python

import re
import lldb.formatters.Logger
# C++ STL formatters for LLDB
# These formatters are based upon the version of the GNU libstdc++
# as it ships with Mac OS X 10.6.8 thru 10.8.0
# You are encouraged to look at the STL implementation for your platform
# before relying on these formatters to do the right thing for your setup
class StdListSynthProvider:
def __init__(self, valobj, dict):
logger = lldb.formatters.Logger.Logger()
self.valobj = valobj
self.count = None
logger >> "Providing synthetic children for a list named " + \
str(valobj.GetName())
def next_node(self, node):
logger = lldb.formatters.Logger.Logger()
return node.GetChildMemberWithName('_M_next')
def is_valid(self, node):
logger = lldb.formatters.Logger.Logger()
valid = self.value(self.next_node(node)) != self.node_address
if valid:
logger >> "%s is valid" % str(self.valobj.GetName())
else:
logger >> "synthetic value is not valid"
return valid
def value(self, node):
logger = lldb.formatters.Logger.Logger()
value = node.GetValueAsUnsigned()
logger >> "synthetic value for {}: {}".format(
str(self.valobj.GetName()), value)
return value
# 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 not _list_uses_loop_detector:
logger >> "Asked not to use loop detection"
return False
slow = self.next
fast1 = self.next
fast2 = self.next
while self.is_valid(slow):
slow_value = self.value(slow)
fast1 = self.next_node(fast2)
fast2 = self.next_node(fast1)
if self.value(fast1) == slow_value or self.value(
fast2) == slow_value:
return True
slow = self.next_node(slow)
return False
def num_children(self):
logger = lldb.formatters.Logger.Logger()
if self.count is None:
# libstdc++ 6.0.21 added dedicated count field.
count_child = self.node.GetChildMemberWithName('_M_data')
if count_child and count_child.IsValid():
self.count = count_child.GetValueAsUnsigned(0)
if self.count is None:
self.count = self.num_children_impl()
return self.count
def num_children_impl(self):
logger = lldb.formatters.Logger.Logger()
try:
next_val = self.next.GetValueAsUnsigned(0)
prev_val = self.prev.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 = self.next
while current.GetChildMemberWithName(
'_M_next').GetValueAsUnsigned(0) != self.node_address:
size = size + 1
current = current.GetChildMemberWithName('_M_next')
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:
offset = index
current = self.next
while offset > 0:
current = current.GetChildMemberWithName('_M_next')
offset = offset - 1
return current.CreateChildAtOffset(
'[' + str(index) + ']',
2 * current.GetType().GetByteSize(),
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()
# preemptively setting this to None - we might end up changing our mind
# later
self.count = None
try:
impl = self.valobj.GetChildMemberWithName('_M_impl')
self.node = impl.GetChildMemberWithName('_M_node')
self.node_address = self.valobj.AddressOf().GetValueAsUnsigned(0)
self.next = self.node.GetChildMemberWithName('_M_next')
self.prev = self.node.GetChildMemberWithName('_M_prev')
self.data_type = self.extract_type()
self.data_size = self.data_type.GetByteSize()
except:
pass
def has_children(self):
return True
class StdVectorSynthProvider:
class StdVectorImplementation(object):
def __init__(self, valobj):
self.valobj = valobj
self.count = None
def num_children(self):
if self.count is None:
self.count = self.num_children_impl()
return self.count
def num_children_impl(self):
try:
start_val = self.start.GetValueAsUnsigned(0)
finish_val = self.finish.GetValueAsUnsigned(0)
end_val = self.end.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 or end_val == 0:
return 0
# Make sure start is less than finish
if start_val >= finish_val:
return 0
# Make sure finish is less than or equal to end of storage
if finish_val > end_val:
return 0
# if we have a struct (or other data type that the compiler pads to native word size)
# this check might fail, unless the sizeof() we get is itself incremented to take the
# padding bytes into account - on current clang it looks like
# this is the case
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_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):
# preemptively setting this to None - we might end up changing our
# mind later
self.count = None
try:
impl = self.valobj.GetChildMemberWithName('_M_impl')
self.start = impl.GetChildMemberWithName('_M_start')
self.finish = impl.GetChildMemberWithName('_M_finish')
self.end = impl.GetChildMemberWithName('_M_end_of_storage')
self.data_type = self.start.GetType().GetPointeeType()
self.data_size = self.data_type.GetByteSize()
# if any of these objects is invalid, it means there is no
# point in trying to fetch anything
if self.start.IsValid() and self.finish.IsValid(
) and self.end.IsValid() and self.data_type.IsValid():
self.count = None
else:
self.count = 0
except:
pass
return True
class StdVBoolImplementation(object):
def __init__(self, valobj, bool_type):
self.valobj = valobj
self.bool_type = bool_type
self.valid = False
def num_children(self):
if self.valid:
start = self.start_p.GetValueAsUnsigned(0)
finish = self.finish_p.GetValueAsUnsigned(0)
offset = self.offset.GetValueAsUnsigned(0)
if finish >= start:
return (finish - start) * 8 + offset
return 0
def get_child_at_index(self, index):
if index >= self.num_children():
return None
element_type = self.start_p.GetType().GetPointeeType()
element_bits = 8 * element_type.GetByteSize()
element_offset = (index / element_bits) * \
element_type.GetByteSize()
bit_offset = index % element_bits
element = self.start_p.CreateChildAtOffset(
'[' + str(index) + ']', element_offset, element_type)
bit = element.GetValueAsUnsigned(0) & (1 << bit_offset)
if bit != 0:
value_expr = "(bool)true"
else:
value_expr = "(bool)false"
return self.valobj.CreateValueFromExpression(
"[%d]" % index, value_expr)
def update(self):
try:
m_impl = self.valobj.GetChildMemberWithName('_M_impl')
self.m_start = m_impl.GetChildMemberWithName('_M_start')
self.m_finish = m_impl.GetChildMemberWithName('_M_finish')
self.start_p = self.m_start.GetChildMemberWithName('_M_p')
self.finish_p = self.m_finish.GetChildMemberWithName('_M_p')
self.offset = self.m_finish.GetChildMemberWithName('_M_offset')
self.valid = True
except:
self.valid = False
return True
def __init__(self, valobj, dict):
logger = lldb.formatters.Logger.Logger()
first_template_arg_type = valobj.GetType().GetTemplateArgumentType(0)
if str(first_template_arg_type.GetName()) == "bool":
self.impl = self.StdVBoolImplementation(
valobj, first_template_arg_type)
else:
self.impl = self.StdVectorImplementation(valobj)
logger >> "Providing synthetic children for a vector named " + \
str(valobj.GetName())
def num_children(self):
return self.impl.num_children()
def get_child_index(self, name):
try:
return int(name.lstrip('[').rstrip(']'))
except:
return -1
def get_child_at_index(self, index):
return self.impl.get_child_at_index(index)
def update(self):
return self.impl.update()
def has_children(self):
return True
class StdMapSynthProvider:
def __init__(self, valobj, dict):
logger = lldb.formatters.Logger.Logger()
self.valobj = valobj
self.count = None
logger >> "Providing synthetic children for a map named " + \
str(valobj.GetName())
# we need this function as a temporary workaround for rdar://problem/10801549
# which prevents us from extracting the std::pair<K,V> SBType out of the template
# arguments for _Rep_Type _M_t in the map itself - because we have to make up the
# typename and then find it, we may hit the situation were std::string has multiple
# names but only one is actually referenced in the debug information. hence, we need
# to replace the longer versions of std::string with the shorter one in order to be able
# to find the type name
def fixup_class_name(self, class_name):
logger = lldb.formatters.Logger.Logger()
if class_name == 'std::basic_string<char, std::char_traits<char>, std::allocator<char> >':
return 'std::basic_string<char>', True
if class_name == 'basic_string<char, std::char_traits<char>, std::allocator<char> >':
return 'std::basic_string<char>', True
if class_name == 'std::basic_string<char, std::char_traits<char>, std::allocator<char> >':
return 'std::basic_string<char>', True
if class_name == 'basic_string<char, std::char_traits<char>, std::allocator<char> >':
return 'std::basic_string<char>', True
return class_name, False
def update(self):
logger = lldb.formatters.Logger.Logger()
# preemptively setting this to None - we might end up changing our mind
# later
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.Mt = self.valobj.GetChildMemberWithName('_M_t')
self.Mimpl = self.Mt.GetChildMemberWithName('_M_impl')
self.Mheader = self.Mimpl.GetChildMemberWithName('_M_header')
map_type = self.valobj.GetType()
if map_type.IsReferenceType():
logger >> "Dereferencing type"
map_type = map_type.GetDereferencedType()
# Get the type of std::pair<key, value>. It is the first template
# argument type of the 4th template argument to std::map.
allocator_type = map_type.GetTemplateArgumentType(3)
self.data_type = allocator_type.GetTemplateArgumentType(0)
if not self.data_type:
# GCC does not emit DW_TAG_template_type_parameter for
# std::allocator<...>. For such a case, get the type of
# std::pair from a member of std::map.
rep_type = self.valobj.GetChildMemberWithName('_M_t').GetType()
self.data_type = rep_type.GetTypedefedType().GetTemplateArgumentType(1)
# from libstdc++ implementation of _M_root for rbtree
self.Mroot = self.Mheader.GetChildMemberWithName('_M_parent')
self.data_size = self.data_type.GetByteSize()
self.skip_size = self.Mheader.GetType().GetByteSize()
except:
pass
def num_children(self):
logger = lldb.formatters.Logger.Logger()
if self.count is None:
self.count = self.num_children_impl()
return self.count
def num_children_impl(self):
logger = lldb.formatters.Logger.Logger()
try:
root_ptr_val = self.node_ptr_value(self.Mroot)
if root_ptr_val == 0:
return 0
count = self.Mimpl.GetChildMemberWithName(
'_M_node_count').GetValueAsUnsigned(0)
logger >> "I have " + str(count) + " children available"
return count
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 >> "Being asked to fetch child[" + str(index) + "]"
if index < 0:
return None
if index >= self.num_children():
return None
if self.garbage:
logger >> "Returning None since we are a garbage tree"
return None
try:
offset = index
current = self.left(self.Mheader)
while offset > 0:
current = self.increment_node(current)
offset = offset - 1
# skip all the base stuff and get at the data
return current.CreateChildAtOffset(
'[' + str(index) + ']', self.skip_size, self.data_type)
except:
return None
# utility functions
def node_ptr_value(self, node):
logger = lldb.formatters.Logger.Logger()
return node.GetValueAsUnsigned(0)
def right(self, node):
logger = lldb.formatters.Logger.Logger()
return node.GetChildMemberWithName("_M_right")
def left(self, node):
logger = lldb.formatters.Logger.Logger()
return node.GetChildMemberWithName("_M_left")
def parent(self, node):
logger = lldb.formatters.Logger.Logger()
return node.GetChildMemberWithName("_M_parent")
# from libstdc++ implementation of iterator for rbtree
def increment_node(self, node):
logger = lldb.formatters.Logger.Logger()
max_steps = self.num_children()
if self.node_ptr_value(self.right(node)) != 0:
x = self.right(node)
max_steps -= 1
while self.node_ptr_value(self.left(x)) != 0:
x = self.left(x)
max_steps -= 1
logger >> str(max_steps) + " more to go before giving up"
if max_steps <= 0:
self.garbage = True
return None
return x
else:
x = node
y = self.parent(x)
max_steps -= 1
while(self.node_ptr_value(x) == self.node_ptr_value(self.right(y))):
x = y
y = self.parent(y)
max_steps -= 1
logger >> str(max_steps) + " more to go before giving up"
if max_steps <= 0:
self.garbage = True
return None
if self.node_ptr_value(self.right(x)) != self.node_ptr_value(y):
x = y
return x
def has_children(self):
return True
_list_uses_loop_detector = True