pombredanne/python-cxxfilt

Demangling C++ symbols in Python / interface to abi::__cxa_demangle

cxxfilt

Demangling C++ symbols in Python / interface to abi::__cxa_demangle

Usage

Install:

pip install cxxfilt

Use demangle to demangle a C++ mangled symbol name:

>>> import cxxfilt
>>> cxxfilt.demangle('_ZNSt22condition_variable_anyD2Ev')
'std::condition_variable_any::~condition_variable_any()'

Non-mangled name will be kept intact:

>>> cxxfilt.demangle('main')
'main'

To demangle an internal symbol, use external_only=False:

>>> cxxfilt.demangle('N3foo12BarExceptionE')
'N3foo12BarExceptionE'
>>> cxxfilt.demangle('N3foo12BarExceptionE', external_only=False)
'foo::BarException'

Invalid mangled names will trigger an InvalidName exception:

>>> cxxfilt.demangle('_ZQQ')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/path/to/python-cxxfilt/cxxfilt/__init__.py", line 77, in demangle
    return demangleb(mangled_name.encode()).decode()
  File "/path/to/python-cxxfilt/cxxfilt/__init__.py", line 69, in demangleb
    raise InvalidName(mangled_name)
cxxfilt.InvalidName: b'_ZQQ'

Use demangleb to demangle name in bytes:

>>> cxxfilt.demangleb(b'_ZNSt22condition_variable_anyD2Ev')
b'std::condition_variable_any::~condition_variable_any()'

Make custom Demangler objects to use specific C/C++ libraries:

>>> from ctypes.util import find_library
>>>
>>> d = cxxfilt.Demangler(find_library('c'), find_library('stdc++'))
>>> d
<Demangler libc='libc.so.6' libcxx='libstdc++.so.6'>
>>>
>>> d = cxxfilt.Demangler(find_library('c'), find_library('c++'))
>>> d
<Demangler libc='libc.so.6' libcxx='libc++.so.1'>
>>> d.demangle('_ZNSt22condition_variable_anyD2Ev')
'std::condition_variable_any::~condition_variable_any()'

Supported environments

Python 3.6 or greater.

Tested on Linux and macOS (see github actions). Should work on unix systems with libc and libc++/libstdc++.

Will not work on Windows (PR welcome though).

For Python 2.7 please use cxxfilt version < 0.3.

Changelog

0.3.0

• Added Demangler class.
• import cxxfilt no longer fails when there are no C/C++ libraries available. To check whether the default demangler is valid, use the expression: not isinstance(cxxfilt.default_demangler, cxxfilt.DeferedErrorDemangler).

Testing

run in shell:

pytest