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Merged
upsj merged 2 commits into from
Sep 21, 2022
Merged

Improve gdb pretty-printer for newer libstdc++ #1114

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241e7a5
improve gdb pretty-printer for newer libstdc++
upsj Sep 9, 2022
bcb2c37
add reference to changes
upsj Sep 21, 2022
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70 changes: 54 additions & 16 deletions dev_tools/scripts/gdb-ginkgo.py
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Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,7 @@
#
# Based on the pretty-printers for libstdc++.

# Copyright (C) 2008-2020 Free Software Foundation, Inc.
# Copyright (C) 2008-2021 Free Software Foundation, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
Expand Down Expand Up @@ -51,7 +51,8 @@ def next(self):

_versioned_namespace = '__8::'


# new version adapted from https://gcc.gnu.org/pipermail/gcc-cvs/2021-November/356230.html
# necessary due to empty class optimization
def is_specialization_of(x, template_name):
"Test if a type is a given template instantiation."
global _versioned_namespace
Expand All @@ -63,28 +64,65 @@ def is_specialization_of(x, template_name):
expr = '^std::{}<.*>$'.format(template_name)
return re.match(expr, x) is not None

def get_template_arg_list(type_obj):
"Return a type's template arguments as a list"
n = 0
template_args = []
while True:
try:
template_args.append(type_obj.template_argument(n))
except:
return template_args
n += 1

def _tuple_impl_get(val):
"Return the tuple element stored in a _Tuple_impl<N, T> base class."
bases = val.type.fields()
if not bases[-1].is_base_class:
raise ValueError("Unsupported implementation for std::tuple: %s" % str(val.type))
# Get the _Head_base<N, T> base class:
head_base = val.cast(bases[-1].type)
fields = head_base.type.fields()
if len(fields) == 0:
raise ValueError("Unsupported implementation for std::tuple: %s" % str(val.type))
if fields[0].name == '_M_head_impl':
# The tuple element is the _Head_base::_M_head_impl data member.
return head_base['_M_head_impl']
elif fields[0].is_base_class:
# The tuple element is an empty base class of _Head_base.
# Cast to that empty base class.
return head_base.cast(fields[0].type)
else:
raise ValueError("Unsupported implementation for std::tuple: %s" % str(val.type))

def tuple_get(n, val):
"Return the result of std::get<n>(val) on a std::tuple"
tuple_size = len(get_template_arg_list(val.type))
if n > tuple_size:
raise ValueError("Out of range index for std::get<N> on std::tuple")
# Get the first _Tuple_impl<0, T...> base class:
node = val.cast(val.type.fields()[0].type)
while n > 0:
# Descend through the base classes until the Nth one.
node = node.cast(node.type.fields()[0].type)
n -= 1
return _tuple_impl_get(node)

def get_unique_ptr_data_ptr(val):
impl_type = val.type.fields()[0].type.tag
"Return the result of val.get() on a std::unique_ptr"
# std::unique_ptr<T, D> contains a std::tuple<D::pointer, D>,
# either as a direct data member _M_t (the old implementation)
# or within a data member of type __uniq_ptr_data.
impl_type = val.type.fields()[0].type.strip_typedefs()
# Check for new implementations first:
if is_specialization_of(impl_type, '__uniq_ptr_data') \
or is_specialization_of(impl_type, '__uniq_ptr_impl'):
or is_specialization_of(impl_type, '__uniq_ptr_impl'):
tuple_member = val['_M_t']['_M_t']
elif is_specialization_of(impl_type, 'tuple'):
tuple_member = val['_M_t']
else:
raise ValueError(
"Unsupported unique_ptr impl: {}".format(impl_type))
tuple_impl_type = tuple_member.type.fields()[0].type # _Tuple_impl
tuple_head_type = tuple_impl_type.fields()[1].type # _Head_base
head_field = tuple_head_type.fields()[0]
if head_field.name == '_M_head_impl':
return tuple_member['_M_head_impl']
elif head_field.is_base_class:
return tuple_member.cast(head_field.type)
else:
raise ValueError(
"Unsupported tuple impl in unique_ptr: {}".format(impl_type))
raise ValueError("Unsupported implementation for unique_ptr: %s" % str(impl_type))
return tuple_get(0, tuple_member)


class GkoArrayPrinter:
Expand Down