Revert "Add gdb pretty printers for a wide variety of libc++ data structures."

This reverts commit d8c9f2f572fe06a34ccfc28ee9223b64d7d275d3.

llvm-svn: 370553

1 files changed, 0 insertions, 992 deletions

diff --git a/libcxx/utils/gdb/libcxx/printers.py b/libcxx/utils/gdb/libcxx/printers.py
deleted file mode 100644
index dc2f2e97aec..00000000000
--- a/libcxx/utils/gdb/libcxx/printers.py
+++ /dev/null
@@ -1,992 +0,0 @@
-#===----------------------------------------------------------------------===##
-#
-# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-# See https://llvm.org/LICENSE.txt for license information.
-# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-#
-#===----------------------------------------------------------------------===##
-"""GDB pretty-printers for libc++.
-
-These should work for objects compiled when _LIBCPP_ABI_UNSTABLE is defined
-and when it is undefined.
-"""
-
-from __future__ import print_function
-
-import re
-import gdb
-
-# One under-documented feature of the gdb pretty-printer API
-# is that clients can call any other member of the API
-# before they call to_string.
-# Therefore all self.FIELDs must be set in the pretty-printer's
-# __init__ function.
-
-_void_pointer_type = gdb.lookup_type("void").pointer()
-
-
-_long_int_type = gdb.lookup_type("unsigned long long")
-
-
-def addr_as_long(addr):
-    return int(addr.cast(_long_int_type))
-
-
-# The size of a pointer in bytes.
-_pointer_size = _void_pointer_type.sizeof
-
-
-def _remove_cxx_namespace(typename):
-    """Removed libc++ specific namespace from the type.
-
-    Arguments:
-      typename(string): A type, such as std::__u::something.
-
-    Returns:
-      A string without the libc++ specific part, such as std::something.
-    """
-
-    return re.sub("std::__.*?::", "std::", typename)
-
-
-def _remove_generics(typename):
-    """Remove generics part of the type. Assumes typename is not empty.
-
-    Arguments:
-      typename(string): A type such as std::my_collection<element>.
-
-    Returns:
-      The prefix up to the generic part, such as std::my_collection.
-    """
-
-    match = re.match("^([^<]+)", typename)
-    return match.group(1)
-
-
-# Some common substitutions on the types to reduce visual clutter (A user who
-# wants to see the actual details can always use print/r).
-_common_substitutions = [
-    ("std::basic_string<char, std::char_traits<char>, std::allocator<char> >",
-     "std::string"),
-]
-
-
-def _prettify_typename(gdb_type):
-    """Returns a pretty name for the type, or None if no name can be found.
-
-    Arguments:
-      gdb_type(gdb.Type): A type object.
-
-    Returns:
-      A string, without type_defs, libc++ namespaces, and common substitutions
-      applied.
-    """
-
-    type_without_typedefs = gdb_type.strip_typedefs()
-    typename = type_without_typedefs.name or type_without_typedefs.tag or \
-        str(type_without_typedefs)
-    result = _remove_cxx_namespace(typename)
-    for find_str, subst_str in _common_substitutions:
-        result = re.sub(find_str, subst_str, result)
-    return result
-
-
-def _typename_for_nth_generic_argument(gdb_type, n):
-    """Returns a pretty string for the nth argument of the given type.
-
-    Arguments:
-      gdb_type(gdb.Type): A type object, such as the one for std::map<int, int>
-      n: The (zero indexed) index of the argument to return.
-
-    Returns:
-      A string for the nth argument, such a "std::string"
-    """
-    element_type = gdb_type.template_argument(n)
-    return _prettify_typename(element_type)
-
-
-def _typename_with_n_generic_arguments(gdb_type, n):
-    """Return a string for the type with the first n (1, ...) generic args."""
-
-    base_type = _remove_generics(_prettify_typename(gdb_type))
-    arg_list = [base_type]
-    template = "%s<"
-    for i in range(n):
-        arg_list.append(_typename_for_nth_generic_argument(gdb_type, i))
-        template += "%s, "
-    result = (template[:-2] + ">") % tuple(arg_list)
-    return result
-
-
-def _typename_with_first_generic_argument(gdb_type):
-    return _typename_with_n_generic_arguments(gdb_type, 1)
-
-
-class StdTuplePrinter(object):
-    """Print a std::tuple."""
-
-    class _Children(object):
-        """Class to iterate over the tuple's children."""
-
-        def __init__(self, val):
-            self.val = val
-            self.child_iter = iter(self.val["__base_"].type.fields())
-            self.count = 0
-
-        def __iter__(self):
-            return self
-
-        def next(self):
-            # child_iter raises StopIteration when appropriate.
-            field_name = self.child_iter.next()
-            child = self.val["__base_"][field_name]["__value_"]
-            self.count += 1
-            return ("[%d]" % self.count, child)
-
-    def __init__(self, val):
-        self.val = val
-
-    def to_string(self):
-        typename = _remove_generics(_prettify_typename(self.val.type))
-        if not self.val.type.fields():
-            return "empty %s" % typename
-        return "%s containing" % typename
-
-    def children(self):
-        if not self.val.type.fields():
-            return iter(())
-        return self._Children(self.val)
-
-
-def _get_base_subobject(child_class_value, index=0):
-    """Returns the object's value in the form of the parent class at index.
-
-    This function effectively casts the child_class_value to the base_class's
-    type, but the type-to-cast to is stored in the field at index, and once
-    we know the field, we can just return the data.
-
-    Args:
-      child_class_value: the value to cast
-      index: the parent class index
-
-    Raises:
-      Exception: field at index was not a base-class field.
-    """
-
-    field = child_class_value.type.fields()[index]
-    if not field.is_base_class:
-        raise Exception("Not a base-class field.")
-    return child_class_value[field]
-
-
-def _value_of_pair_first(value):
-    """Convenience for _get_base_subobject, for the common case."""
-    return _get_base_subobject(value, 0)["__value_"]
-
-
-class StdStringPrinter(object):
-    """Print a std::string."""
-
-    def _get_short_size(self, short_field, short_size):
-        """Short size depends on both endianness and a compile-time define."""
-
-        # If the padding field is present after all this indirection, then string
-        # was compiled with _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT defined.
-        field = short_field.type.fields()[1].type.fields()[0]
-        libcpp_abi_alternate_string_layout = field.name and "__padding" in field.name
-
-        # Strictly, this only tells us the current mode, not how libcxx was
-        # compiled.
-        libcpp_big_endian = "big endian" in gdb.execute("show endian",
-                                                        to_string=True)
-
-        # This logical structure closely follows the original code (which is clearer
-        # in C++).  Keep them parallel to make them easier to compare.
-        if libcpp_abi_alternate_string_layout:
-            if libcpp_big_endian:
-                return short_size >> 1
-            else:
-                return short_size
-        elif libcpp_big_endian:
-            return short_size
-        else:
-            return short_size >> 1
-
-    def __init__(self, val):
-        self.val = val
-
-    def to_string(self):
-        """Build a python string from the data whether stored inline or separately."""
-
-        value_field = _value_of_pair_first(self.val["__r_"])
-        short_field = value_field["__s"]
-        short_size = short_field["__size_"]
-        if short_size == 0:
-            return ""
-        short_mask = self.val["__short_mask"]
-        # Counter intuitive to compare the size and short_mask to see if the string
-        # is long, but that's the way the implementation does it. Note that
-        # __is_long() doesn't use get_short_size in C++.
-        is_long = short_size & short_mask
-        if is_long:
-            long_field = value_field["__l"]
-            data = long_field["__data_"]
-            size = long_field["__size_"]
-        else:
-            data = short_field["__data_"]
-            size = self._get_short_size(short_field, short_size)
-        if hasattr(data, "lazy_string"):
-            return data.lazy_string(length=size)
-        return data.string(length=size)
-
-    def display_hint(self):
-        return "string"
-
-
-class StdUniquePtrPrinter(object):
-    """Print a std::unique_ptr."""
-
-    def __init__(self, val):
-        self.val = val
-        self.addr = _value_of_pair_first(self.val["__ptr_"])
-        self.pointee_type = self.val.type.template_argument(0)
-
-    def to_string(self):
-        typename = _remove_generics(_prettify_typename(self.val.type))
-        if not self.addr:
-            return "%s is nullptr" % typename
-        return ("%s<%s> containing" %
-                (typename,
-                 _remove_generics(_prettify_typename(self.pointee_type))))
-
-    def __iter__(self):
-        if self.addr:
-            yield "__ptr_", self.addr.cast(self.pointee_type.pointer())
-
-    def children(self):
-        return self
-
-
-class StdSharedPointerPrinter(object):
-    """Print a std::shared_ptr."""
-
-    def __init__(self, val):
-        self.val = val
-        self.addr = self.val["__ptr_"]
-
-    def to_string(self):
-        """Returns self as a string."""
-        typename = _remove_generics(_prettify_typename(self.val.type))
-        pointee_type = _remove_generics(
-            _prettify_typename(self.val.type.template_argument(0)))
-        if not self.addr:
-            return "%s is nullptr" % typename
-        refcount = self.val["__cntrl_"]
-        if refcount != 0:
-            usecount = refcount["__shared_owners_"] + 1
-            weakcount = refcount["__shared_weak_owners_"]
-            if usecount == 0:
-                state = "expired, weak %d" % weakcount
-            else:
-                state = "count %d, weak %d" % (usecount, weakcount)
-        return "%s<%s> %s containing" % (typename, pointee_type, state)
-
-    def __iter__(self):
-        if self.addr:
-            yield "__ptr_", self.addr
-
-    def children(self):
-        return self
-
-
-class StdVectorPrinter(object):
-    """Print a std::vector."""
-
-    class _VectorBoolIterator(object):
-        """Class to iterate over the bool vector's children."""
-
-        def __init__(self, begin, size, bits_per_word):
-            self.item = begin
-            self.size = size
-            self.bits_per_word = bits_per_word
-            self.count = 0
-            self.offset = 0
-
-        def __iter__(self):
-            return self
-
-        def next(self):
-            """Retrieve the next element."""
-
-            self.count += 1
-            if self.count > self.size:
-                raise StopIteration
-            entry = self.item.dereference()
-            if entry & (1 << self.offset):
-                outbit = 1
-            else:
-                outbit = 0
-            self.offset += 1
-            if self.offset >= self.bits_per_word:
-                self.item += 1
-                self.offset = 0
-            return ("[%d]" % self.count, outbit)
-
-    class _VectorIterator(object):
-        """Class to iterate over the non-bool vector's children."""
-
-        def __init__(self, begin, end):
-            self.item = begin
-            self.end = end
-            self.count = 0
-
-        def __iter__(self):
-            return self
-
-        def next(self):
-            self.count += 1
-            if self.item == self.end:
-                raise StopIteration
-            entry = self.item.dereference()
-            self.item += 1
-            return ("[%d]" % self.count, entry)
-
-    def __init__(self, val):
-        """Set val, length, capacity, and iterator for bool and normal vectors."""
-        self.val = val
-        self.typename = _remove_generics(_prettify_typename(val.type))
-        begin = self.val["__begin_"]
-        if self.val.type.template_argument(0).code == gdb.TYPE_CODE_BOOL:
-            self.typename += "<bool>"
-            self.length = self.val["__size_"]
-            bits_per_word = self.val["__bits_per_word"]
-            self.capacity = _value_of_pair_first(
-                self.val["__cap_alloc_"]) * bits_per_word
-            self.iterator = self._VectorBoolIterator(
-                begin, self.length, bits_per_word)
-        else:
-            end = self.val["__end_"]
-            self.length = end - begin
-            self.capacity = _get_base_subobject(
-                self.val["__end_cap_"])["__value_"] - begin
-            self.iterator = self._VectorIterator(begin, end)
-
-    def to_string(self):
-        return ("%s of length %d, capacity %d" %
-                (self.typename, self.length, self.capacity))
-
-    def children(self):
-        return self.iterator
-
-    def display_hint(self):
-        return "array"
-
-
-class StdBitsetPrinter(object):
-    """Print a std::bitset."""
-
-    def __init__(self, val):
-        self.val = val
-        self.n_words = int(self.val["__n_words"])
-        self.bits_per_word = int(self.val["__bits_per_word"])
-        if self.n_words == 1:
-            self.values = [int(self.val["__first_"])]
-        else:
-            self.values = [int(self.val["__first_"][index])
-                           for index in range(self.n_words)]
-
-    def to_string(self):
-        typename = _prettify_typename(self.val.type)
-        return "%s" % typename
-
-    def _byte_it(self, value):
-        index = -1
-        while value:
-            index += 1
-            will_yield = value % 2
-            value /= 2
-            if will_yield:
-                yield index
-
-    def _list_it(self):
-        for word_index in range(self.n_words):
-            current = self.values[word_index]
-            if current:
-                for n in self._byte_it(current):
-                    yield ("[%d]" % (word_index * self.bits_per_word + n), 1)
-
-    def __iter__(self):
-        return self._list_it()
-
-    def children(self):
-        return self
-
-
-class StdDequePrinter(object):
-    """Print a std::deque."""
-
-    def __init__(self, val):
-        self.val = val
-        self.size = int(_value_of_pair_first(val["__size_"]))
-        self.start_ptr = self.val["__map_"]["__begin_"]
-        self.first_block_start_index = int(self.val["__start_"])
-        self.node_type = self.start_ptr.type
-        self.block_size = self._calculate_block_size(
-            val.type.template_argument(0))
-
-    def _calculate_block_size(self, element_type):
-        """Calculates the number of elements in a full block."""
-        size = element_type.sizeof
-        # Copied from struct __deque_block_size implementation of libcxx.
-        return 4096 / size if size < 256 else 16
-
-    def _bucket_it(self, start_addr, start_index, end_index):
-        for i in range(start_index, end_index):
-            yield i, (start_addr.dereference() + i).dereference()
-
-    def _list_it(self):
-        """Primary iteration worker."""
-        num_emitted = 0
-        current_addr = self.start_ptr
-        start_index = self.first_block_start_index
-        while num_emitted < self.size:
-            end_index = min(start_index + self.size -
-                            num_emitted, self.block_size)
-            for _, elem in self._bucket_it(current_addr, start_index, end_index):
-                yield "", elem
-            num_emitted += end_index - start_index
-            current_addr = gdb.Value(addr_as_long(current_addr) + _pointer_size) \
-                              .cast(self.node_type)
-            start_index = 0
-
-    def to_string(self):
-        typename = _remove_generics(_prettify_typename(self.val.type))
-        if self.size:
-            return "%s with %d elements" % (typename, self.size)
-        return "%s is empty" % typename
-
-    def __iter__(self):
-        return self._list_it()
-
-    def children(self):
-        return self
-
-    def display_hint(self):
-        return "array"
-
-
-class StdListPrinter(object):
-    """Print a std::list."""
-
-    def __init__(self, val):
-        self.val = val
-        size_alloc_field = self.val["__size_alloc_"]
-        self.size = int(_value_of_pair_first(size_alloc_field))
-        dummy_node = self.val["__end_"]
-        self.nodetype = gdb.lookup_type(
-            re.sub("__list_node_base", "__list_node",
-                   str(dummy_node.type.strip_typedefs()))).pointer()
-        self.first_node = dummy_node["__next_"]
-
-    def to_string(self):
-        typename = _remove_generics(_prettify_typename(self.val.type))
-        if self.size:
-            return "%s with %d elements" % (typename, self.size)
-        return "%s is empty" % typename
-
-    def _list_iter(self):
-        current_node = self.first_node
-        for _ in range(self.size):
-            yield "", current_node.cast(self.nodetype).dereference()["__value_"]
-            current_node = current_node.dereference()["__next_"]
-
-    def __iter__(self):
-        return self._list_iter()
-
-    def children(self):
-        return self if self.nodetype else iter(())
-
-    def display_hint(self):
-        return "array"
-
-
-class StdQueueOrStackPrinter(object):
-    """Print a std::queue or std::stack."""
-
-    def __init__(self, val):
-        self.val = val
-        self.underlying = val["c"]
-
-    def to_string(self):
-        typename = _remove_generics(_prettify_typename(self.val.type))
-        return "%s wrapping" % typename
-
-    def children(self):
-        return iter([("", self.underlying)])
-
-    def display_hint(self):
-        return "array"
-
-
-class StdPriorityQueuePrinter(object):
-    """Print a std::priority_queue."""
-
-    def __init__(self, val):
-        self.val = val
-        self.underlying = val["c"]
-
-    def to_string(self):
-        # TODO(tamur): It would be nice to print the top element. The technical
-        # difficulty is that, the implementation refers to the underlying
-        # container, which is a generic class. libstdcxx pretty printers do not
-        # print the top element.
-        typename = _remove_generics(_prettify_typename(self.val.type))
-        return "%s wrapping" % typename
-
-    def children(self):
-        return iter([("", self.underlying)])
-
-    def display_hint(self):
-        return "array"
-
-
-class RBTreeUtils(object):
-    """Utility class for std::(multi)map, and std::(multi)set and iterators."""
-
-    def __init__(self, cast_type, root):
-        self.cast_type = cast_type
-        self.root = root
-
-    def left_child(self, node):
-        result = node.cast(self.cast_type).dereference()["__left_"]
-        return result
-
-    def right_child(self, node):
-        result = node.cast(self.cast_type).dereference()["__right_"]
-        return result
-
-    def parent(self, node):
-        """Return the parent of node, if it exists."""
-        # If this is the root, then from the algorithm's point of view, it has no
-        # parent.
-        if node == self.root:
-            return None
-
-        # We don't have enough information to tell if this is the end_node (which
-        # doesn't have a __parent_ field), or the root (which doesn't have a parent
-        # from the algorithm's point of view), so cast_type may not be correct for
-        # this particular node. Use heuristics.
-
-        # The end_node's left child is the root. Note that when printing interators
-        # in isolation, the root is unknown.
-        if self.left_child(node) == self.root:
-            return None
-
-        parent = node.cast(self.cast_type).dereference()["__parent_"]
-        # If the value at the offset of __parent_ doesn't look like a valid pointer,
-        # then assume that node is the end_node (and therefore has no parent).
-        # End_node type has a pointer embedded, so should have pointer alignment.
-        if addr_as_long(parent) % _void_pointer_type.alignof:
-            return None
-        # This is ugly, but the only other option is to dereference an invalid
-        # pointer.  0x8000 is fairly arbitrary, but has had good results in
-        # practice.  If there was a way to tell if a pointer is invalid without
-        # actually dereferencing it and spewing error messages, that would be ideal.
-        if parent < 0x8000:
-            return None
-        return parent
-
-    def is_left_child(self, node):
-        parent = self.parent(node)
-        return parent is not None and self.left_child(parent) == node
-
-    def is_right_child(self, node):
-        parent = self.parent(node)
-        return parent is not None and self.right_child(parent) == node
-
-
-class AbstractRBTreePrinter(object):
-    """Abstract super class for std::(multi)map, and std::(multi)set."""
-
-    def __init__(self, val):
-        self.val = val
-        tree = self.val["__tree_"]
-        self.size = int(_value_of_pair_first(tree["__pair3_"]))
-        dummy_root = tree["__pair1_"]
-        root = _value_of_pair_first(dummy_root)["__left_"]
-        cast_type = self._init_cast_type(val.type)
-        self.util = RBTreeUtils(cast_type, root)
-
-    def _get_key_value(self, node):
-        """Subclasses should override to return a list of values to yield."""
-        raise NotImplementedError
-
-    def _traverse(self):
-        """Traverses the binary search tree in order."""
-        current = self.util.root
-        skip_left_child = False
-        while True:
-            if not skip_left_child and self.util.left_child(current):
-                current = self.util.left_child(current)
-                continue
-            skip_left_child = False
-            for key_value in self._get_key_value(current):
-                yield "", key_value
-            right_child = self.util.right_child(current)
-            if right_child:
-                current = right_child
-                continue
-            while self.util.is_right_child(current):
-                current = self.util.parent(current)
-            if self.util.is_left_child(current):
-                current = self.util.parent(current)
-                skip_left_child = True
-                continue
-            break
-
-    def __iter__(self):
-        return self._traverse()
-
-    def children(self):
-        return self if self.util.cast_type and self.size > 0 else iter(())
-
-    def to_string(self):
-        typename = _remove_generics(_prettify_typename(self.val.type))
-        if self.size:
-            return "%s with %d elements" % (typename, self.size)
-        return "%s is empty" % typename
-
-
-class StdMapPrinter(AbstractRBTreePrinter):
-    """Print a std::map or std::multimap."""
-
-    def _init_cast_type(self, val_type):
-        map_it_type = gdb.lookup_type(
-            str(val_type) + "::iterator").strip_typedefs()
-        tree_it_type = map_it_type.template_argument(0)
-        node_ptr_type = tree_it_type.template_argument(1)
-        return node_ptr_type
-
-    def display_hint(self):
-        return "map"
-
-    def _get_key_value(self, node):
-        key_value = node.cast(self.util.cast_type).dereference()[
-            "__value_"]["__cc"]
-        return [key_value["first"], key_value["second"]]
-
-
-class StdSetPrinter(AbstractRBTreePrinter):
-    """Print a std::set."""
-
-    def _init_cast_type(self, val_type):
-        set_it_type = gdb.lookup_type(
-            str(val_type) + "::iterator").strip_typedefs()
-        node_ptr_type = set_it_type.template_argument(1)
-        return node_ptr_type
-
-    def display_hint(self):
-        return "array"
-
-    def _get_key_value(self, node):
-        key_value = node.cast(self.util.cast_type).dereference()["__value_"]
-        return [key_value]
-
-
-class AbstractRBTreeIteratorPrinter(object):
-    """Abstract super class for std::(multi)map, and std::(multi)set iterator."""
-
-    def _initialize(self, val, typename):
-        self.typename = typename
-        self.val = val
-        self.addr = self.val["__ptr_"]
-        cast_type = self.val.type.template_argument(1)
-        self.util = RBTreeUtils(cast_type, None)
-        if self.addr:
-            self.node = self.addr.cast(cast_type).dereference()
-
-    def _is_valid_node(self):
-        if not self.util.parent(self.addr):
-            return False
-        return self.util.is_left_child(self.addr) or \
-            self.util.is_right_child(self.addr)
-
-    def to_string(self):
-        if not self.addr:
-            return "%s is nullptr" % self.typename
-        return "%s " % self.typename
-
-    def _get_node_value(self, node):
-        raise NotImplementedError
-
-    def __iter__(self):
-        addr_str = "[%s]" % str(self.addr)
-        if not self._is_valid_node():
-            yield addr_str, " end()"
-        else:
-            yield addr_str, self._get_node_value(self.node)
-
-    def children(self):
-        return self if self.addr else iter(())
-
-
-class MapIteratorPrinter(AbstractRBTreeIteratorPrinter):
-    """Print a std::(multi)map iterator."""
-
-    def __init__(self, val):
-        self._initialize(val["__i_"],
-                         _remove_generics(_prettify_typename(val.type)))
-
-    def _get_node_value(self, node):
-        return node["__value_"]["__cc"]
-
-
-class SetIteratorPrinter(AbstractRBTreeIteratorPrinter):
-    """Print a std::(multi)set iterator."""
-
-    def __init__(self, val):
-        self._initialize(val, _remove_generics(_prettify_typename(val.type)))
-
-    def _get_node_value(self, node):
-        return node["__value_"]
-
-
-class StdFposPrinter(object):
-    """Print a std::fpos or std::streampos."""
-
-    def __init__(self, val):
-        self.val = val
-
-    def to_string(self):
-        typename = _remove_generics(_prettify_typename(self.val.type))
-        offset = self.val["__off_"]
-        state = self.val["__st_"]
-        count = state["__count"]
-        value = state["__value"]["__wch"]
-        return "%s with stream offset:%s with state: {count:%s value:%s}" % (
-            typename, offset, count, value)
-
-
-class AbstractUnorderedCollectionPrinter(object):
-    """Abstract super class for std::unordered_(multi)[set|map]."""
-
-    def __init__(self, val):
-        self.val = val
-        self.table = val["__table_"]
-        self.sentinel = self.table["__p1_"]
-        self.size = int(_value_of_pair_first(self.table["__p2_"]))
-        node_base_type = self.sentinel.type.template_argument(0)
-        self.cast_type = node_base_type.template_argument(0)
-
-    def _list_it(self, sentinel_ptr):
-        next_ptr = _value_of_pair_first(sentinel_ptr)["__next_"]
-        while str(next_ptr.cast(_void_pointer_type)) != "0x0":
-            next_val = next_ptr.cast(self.cast_type).dereference()
-            for key_value in self._get_key_value(next_val):
-                yield "", key_value
-            next_ptr = next_val["__next_"]
-
-    def to_string(self):
-        typename = _remove_generics(_prettify_typename(self.val.type))
-        if self.size:
-            return "%s with %d elements" % (typename, self.size)
-        return "%s is empty" % typename
-
-    def _get_key_value(self, node):
-        """Subclasses should override to return a list of values to yield."""
-        raise NotImplementedError
-
-    def children(self):
-        return self if self.cast_type and self.size > 0 else iter(())
-
-    def __iter__(self):
-        return self._list_it(self.sentinel)
-
-
-class StdUnorderedSetPrinter(AbstractUnorderedCollectionPrinter):
-    """Print a std::unordered_(multi)set."""
-
-    def _get_key_value(self, node):
-        return [node["__value_"]]
-
-    def display_hint(self):
-        return "array"
-
-
-class StdUnorderedMapPrinter(AbstractUnorderedCollectionPrinter):
-    """Print a std::unordered_(multi)map."""
-
-    def _get_key_value(self, node):
-        key_value = node["__value_"]["__cc"]
-        return [key_value["first"], key_value["second"]]
-
-    def display_hint(self):
-        return "map"
-
-
-class AbstractHashMapIteratorPrinter(object):
-    """Abstract class for unordered collection iterators."""
-
-    def _initialize(self, val, addr):
-        self.val = val
-        self.typename = _remove_generics(_prettify_typename(self.val.type))
-        self.addr = addr
-        if self.addr:
-            self.node = self.addr.cast(self.cast_type).dereference()
-
-    def _get_key_value(self):
-        """Subclasses should override to return a list of values to yield."""
-        raise NotImplementedError
-
-    def to_string(self):
-        if not self.addr:
-            return "%s = end()" % self.typename
-        return "%s " % self.typename
-
-    def children(self):
-        return self if self.addr else iter(())
-
-    def __iter__(self):
-        for key_value in self._get_key_value():
-            yield "", key_value
-
-
-class StdUnorderedSetIteratorPrinter(AbstractHashMapIteratorPrinter):
-    """Print a std::(multi)set iterator."""
-
-    def __init__(self, val):
-        self.cast_type = val.type.template_argument(0)
-        self._initialize(val, val["__node_"])
-
-    def _get_key_value(self):
-        return [self.node["__value_"]]
-
-    def display_hint(self):
-        return "array"
-
-
-class StdUnorderedMapIteratorPrinter(AbstractHashMapIteratorPrinter):
-    """Print a std::(multi)map iterator."""
-
-    def __init__(self, val):
-        self.cast_type = val.type.template_argument(0).template_argument(0)
-        self._initialize(val, val["__i_"]["__node_"])
-
-    def _get_key_value(self):
-        key_value = self.node["__value_"]["__cc"]
-        return [key_value["first"], key_value["second"]]
-
-    def display_hint(self):
-        return "map"
-
-
-def _remove_std_prefix(typename):
-    match = re.match("^std::(.+)", typename)
-    return match.group(1) if match is not None else ""
-
-
-class LibcxxPrettyPrinter(object):
-    """PrettyPrinter object so gdb-commands like 'info pretty-printers' work."""
-
-    def __init__(self, name):
-        super(LibcxxPrettyPrinter, self).__init__()
-        self.name = name
-        self.enabled = True
-
-        self.lookup = {
-            "basic_string": StdStringPrinter,
-            "string": StdStringPrinter,
-            "tuple": StdTuplePrinter,
-            "unique_ptr": StdUniquePtrPrinter,
-            "shared_ptr": StdSharedPointerPrinter,
-            "weak_ptr": StdSharedPointerPrinter,
-            "bitset": StdBitsetPrinter,
-            "deque": StdDequePrinter,
-            "list": StdListPrinter,
-            "queue": StdQueueOrStackPrinter,
-            "stack": StdQueueOrStackPrinter,
-            "priority_queue": StdPriorityQueuePrinter,
-            "map": StdMapPrinter,
-            "multimap": StdMapPrinter,
-            "set": StdSetPrinter,
-            "multiset": StdSetPrinter,
-            "vector": StdVectorPrinter,
-            "__map_iterator": MapIteratorPrinter,
-            "__map_const_iterator": MapIteratorPrinter,
-            "__tree_iterator": SetIteratorPrinter,
-            "__tree_const_iterator": SetIteratorPrinter,
-            "fpos": StdFposPrinter,
-            "unordered_set": StdUnorderedSetPrinter,
-            "unordered_multiset": StdUnorderedSetPrinter,
-            "unordered_map": StdUnorderedMapPrinter,
-            "unordered_multimap": StdUnorderedMapPrinter,
-            "__hash_map_iterator": StdUnorderedMapIteratorPrinter,
-            "__hash_map_const_iterator": StdUnorderedMapIteratorPrinter,
-            "__hash_iterator": StdUnorderedSetIteratorPrinter,
-            "__hash_const_iterator": StdUnorderedSetIteratorPrinter,
-        }
-
-        self.subprinters = []
-        for name, subprinter in self.lookup.items():
-            # Subprinters and names are used only for the rarely used command "info
-            # pretty" (and related), so the name of the first data structure it prints
-            # is a reasonable choice.
-            if subprinter not in self.subprinters:
-                subprinter.name = name
-                self.subprinters.append(subprinter)
-
-    def __call__(self, val):
-        """Return the pretty printer for a val, if the type is supported."""
-
-        # Do not handle any type that is not a struct/class.
-        if val.type.strip_typedefs().code != gdb.TYPE_CODE_STRUCT:
-            return None
-
-        # Don't attempt types known to be inside libstdcxx.
-        typename = val.type.name or val.type.tag or str(val.type)
-        match = re.match("^std::(__.*?)::", typename)
-        if match is None or match.group(1) in ["__cxx1998",
-                                               "__debug",
-                                               "__7",
-                                               "__g"]:
-            return None
-
-        # Handle any using declarations or other typedefs.
-        typename = _prettify_typename(val.type)
-        if not typename:
-            return None
-        without_generics = _remove_generics(typename)
-        lookup_name = _remove_std_prefix(without_generics)
-        if lookup_name in self.lookup:
-            return self.lookup[lookup_name](val)
-        return None
-
-
-_libcxx_printer_name = "libcxx_pretty_printer"
-
-
-# These are called for every binary object file, which could be thousands in
-# certain pathological cases. Limit our pretty printers to the progspace.
-def _register_libcxx_printers(event):
-    progspace = event.new_objfile.progspace
-    if not getattr(progspace, _libcxx_printer_name, False):
-        print("Loading libc++ pretty-printers.")
-        gdb.printing.register_pretty_printer(
-            progspace, LibcxxPrettyPrinter(_libcxx_printer_name))
-        setattr(progspace, _libcxx_printer_name, True)
-
-
-def _unregister_libcxx_printers(event):
-    progspace = event.progspace
-    if getattr(progspace, _libcxx_printer_name, False):
-        for printer in progspace.pretty_printers:
-            if getattr(printer, "name", "none") == _libcxx_printer_name:
-                progspace.pretty_printers.remove(printer)
-                setattr(progspace, _libcxx_printer_name, False)
-                break
-
-
-def register_libcxx_printer_loader():
-    """Register event handlers to load libc++ pretty-printers."""
-    gdb.events.new_objfile.connect(_register_libcxx_printers)
-    gdb.events.clear_objfiles.connect(_unregister_libcxx_printers)