1950 lines
64 KiB
Python
Executable File
1950 lines
64 KiB
Python
Executable File
#!/usr/bin/python
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'''
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From gdb 7 onwards, gdb's build can be configured --with-python, allowing gdb
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to be extended with Python code e.g. for library-specific data visualizations,
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such as for the C++ STL types. Documentation on this API can be seen at:
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http://sourceware.org/gdb/current/onlinedocs/gdb/Python-API.html
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This python module deals with the case when the process being debugged (the
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"inferior process" in gdb parlance) is itself python, or more specifically,
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linked against libpython. In this situation, almost every item of data is a
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(PyObject*), and having the debugger merely print their addresses is not very
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enlightening.
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This module embeds knowledge about the implementation details of libpython so
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that we can emit useful visualizations e.g. a string, a list, a dict, a frame
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giving file/line information and the state of local variables
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In particular, given a gdb.Value corresponding to a PyObject* in the inferior
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process, we can generate a "proxy value" within the gdb process. For example,
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given a PyObject* in the inferior process that is in fact a PyListObject*
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holding three PyObject* that turn out to be PyBytesObject* instances, we can
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generate a proxy value within the gdb process that is a list of bytes
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instances:
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[b"foo", b"bar", b"baz"]
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Doing so can be expensive for complicated graphs of objects, and could take
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some time, so we also have a "write_repr" method that writes a representation
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of the data to a file-like object. This allows us to stop the traversal by
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having the file-like object raise an exception if it gets too much data.
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With both "proxyval" and "write_repr" we keep track of the set of all addresses
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visited so far in the traversal, to avoid infinite recursion due to cycles in
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the graph of object references.
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We try to defer gdb.lookup_type() invocations for python types until as late as
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possible: for a dynamically linked python binary, when the process starts in
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the debugger, the libpython.so hasn't been dynamically loaded yet, so none of
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the type names are known to the debugger
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The module also extends gdb with some python-specific commands.
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'''
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# NOTE: some gdbs are linked with Python 3, so this file should be dual-syntax
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# compatible (2.6+ and 3.0+). See #19308.
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from __future__ import print_function
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import gdb
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import os
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import locale
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import sys
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if sys.version_info[0] >= 3:
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unichr = chr
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xrange = range
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long = int
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# Look up the gdb.Type for some standard types:
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# Those need to be refreshed as types (pointer sizes) may change when
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# gdb loads different executables
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def _type_char_ptr():
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return gdb.lookup_type('char').pointer() # char*
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def _type_unsigned_char_ptr():
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return gdb.lookup_type('unsigned char').pointer() # unsigned char*
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def _type_unsigned_short_ptr():
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return gdb.lookup_type('unsigned short').pointer()
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def _type_unsigned_int_ptr():
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return gdb.lookup_type('unsigned int').pointer()
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def _sizeof_void_p():
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return gdb.lookup_type('void').pointer().sizeof
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# value computed later, see PyUnicodeObjectPtr.proxy()
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_is_pep393 = None
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Py_TPFLAGS_HEAPTYPE = (1 << 9)
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Py_TPFLAGS_LONG_SUBCLASS = (1 << 24)
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Py_TPFLAGS_LIST_SUBCLASS = (1 << 25)
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Py_TPFLAGS_TUPLE_SUBCLASS = (1 << 26)
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Py_TPFLAGS_BYTES_SUBCLASS = (1 << 27)
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Py_TPFLAGS_UNICODE_SUBCLASS = (1 << 28)
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Py_TPFLAGS_DICT_SUBCLASS = (1 << 29)
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Py_TPFLAGS_BASE_EXC_SUBCLASS = (1 << 30)
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Py_TPFLAGS_TYPE_SUBCLASS = (1 << 31)
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MAX_OUTPUT_LEN=1024
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hexdigits = "0123456789abcdef"
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ENCODING = locale.getpreferredencoding()
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EVALFRAME = '_PyEval_EvalFrameDefault'
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class NullPyObjectPtr(RuntimeError):
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pass
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def safety_limit(val):
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# Given an integer value from the process being debugged, limit it to some
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# safety threshold so that arbitrary breakage within said process doesn't
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# break the gdb process too much (e.g. sizes of iterations, sizes of lists)
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return min(val, 1000)
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def safe_range(val):
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# As per range, but don't trust the value too much: cap it to a safety
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# threshold in case the data was corrupted
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return xrange(safety_limit(int(val)))
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if sys.version_info[0] >= 3:
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def write_unicode(file, text):
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file.write(text)
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else:
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def write_unicode(file, text):
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# Write a byte or unicode string to file. Unicode strings are encoded to
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# ENCODING encoding with 'backslashreplace' error handler to avoid
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# UnicodeEncodeError.
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if isinstance(text, unicode):
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text = text.encode(ENCODING, 'backslashreplace')
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file.write(text)
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try:
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os_fsencode = os.fsencode
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except AttributeError:
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def os_fsencode(filename):
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if not isinstance(filename, unicode):
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return filename
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encoding = sys.getfilesystemencoding()
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if encoding == 'mbcs':
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# mbcs doesn't support surrogateescape
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return filename.encode(encoding)
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encoded = []
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for char in filename:
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# surrogateescape error handler
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if 0xDC80 <= ord(char) <= 0xDCFF:
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byte = chr(ord(char) - 0xDC00)
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else:
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byte = char.encode(encoding)
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encoded.append(byte)
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return ''.join(encoded)
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class StringTruncated(RuntimeError):
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pass
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class TruncatedStringIO(object):
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'''Similar to io.StringIO, but can truncate the output by raising a
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StringTruncated exception'''
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def __init__(self, maxlen=None):
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self._val = ''
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self.maxlen = maxlen
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def write(self, data):
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if self.maxlen:
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if len(data) + len(self._val) > self.maxlen:
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# Truncation:
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self._val += data[0:self.maxlen - len(self._val)]
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raise StringTruncated()
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self._val += data
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def getvalue(self):
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return self._val
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class PyObjectPtr(object):
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"""
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Class wrapping a gdb.Value that's either a (PyObject*) within the
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inferior process, or some subclass pointer e.g. (PyBytesObject*)
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There will be a subclass for every refined PyObject type that we care
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about.
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Note that at every stage the underlying pointer could be NULL, point
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to corrupt data, etc; this is the debugger, after all.
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"""
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_typename = 'PyObject'
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def __init__(self, gdbval, cast_to=None):
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if cast_to:
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self._gdbval = gdbval.cast(cast_to)
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else:
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self._gdbval = gdbval
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def field(self, name):
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'''
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Get the gdb.Value for the given field within the PyObject, coping with
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some python 2 versus python 3 differences.
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Various libpython types are defined using the "PyObject_HEAD" and
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"PyObject_VAR_HEAD" macros.
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In Python 2, this these are defined so that "ob_type" and (for a var
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object) "ob_size" are fields of the type in question.
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In Python 3, this is defined as an embedded PyVarObject type thus:
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PyVarObject ob_base;
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so that the "ob_size" field is located insize the "ob_base" field, and
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the "ob_type" is most easily accessed by casting back to a (PyObject*).
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'''
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if self.is_null():
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raise NullPyObjectPtr(self)
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if name == 'ob_type':
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pyo_ptr = self._gdbval.cast(PyObjectPtr.get_gdb_type())
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return pyo_ptr.dereference()[name]
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if name == 'ob_size':
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pyo_ptr = self._gdbval.cast(PyVarObjectPtr.get_gdb_type())
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return pyo_ptr.dereference()[name]
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# General case: look it up inside the object:
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return self._gdbval.dereference()[name]
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def pyop_field(self, name):
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'''
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Get a PyObjectPtr for the given PyObject* field within this PyObject,
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coping with some python 2 versus python 3 differences.
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'''
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return PyObjectPtr.from_pyobject_ptr(self.field(name))
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def write_field_repr(self, name, out, visited):
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'''
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Extract the PyObject* field named "name", and write its representation
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to file-like object "out"
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'''
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field_obj = self.pyop_field(name)
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field_obj.write_repr(out, visited)
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def get_truncated_repr(self, maxlen):
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'''
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Get a repr-like string for the data, but truncate it at "maxlen" bytes
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(ending the object graph traversal as soon as you do)
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'''
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out = TruncatedStringIO(maxlen)
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try:
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self.write_repr(out, set())
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except StringTruncated:
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# Truncation occurred:
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return out.getvalue() + '...(truncated)'
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# No truncation occurred:
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return out.getvalue()
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def type(self):
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return PyTypeObjectPtr(self.field('ob_type'))
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def is_null(self):
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return 0 == long(self._gdbval)
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def is_optimized_out(self):
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'''
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Is the value of the underlying PyObject* visible to the debugger?
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This can vary with the precise version of the compiler used to build
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Python, and the precise version of gdb.
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See e.g. https://bugzilla.redhat.com/show_bug.cgi?id=556975 with
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PyEval_EvalFrameEx's "f"
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'''
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return self._gdbval.is_optimized_out
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def safe_tp_name(self):
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try:
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ob_type = self.type()
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tp_name = ob_type.field('tp_name')
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return tp_name.string()
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# NullPyObjectPtr: NULL tp_name?
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# RuntimeError: Can't even read the object at all?
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# UnicodeDecodeError: Failed to decode tp_name bytestring
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except (NullPyObjectPtr, RuntimeError, UnicodeDecodeError):
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return 'unknown'
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def proxyval(self, visited):
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'''
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Scrape a value from the inferior process, and try to represent it
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within the gdb process, whilst (hopefully) avoiding crashes when
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the remote data is corrupt.
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Derived classes will override this.
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For example, a PyIntObject* with ob_ival 42 in the inferior process
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should result in an int(42) in this process.
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visited: a set of all gdb.Value pyobject pointers already visited
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whilst generating this value (to guard against infinite recursion when
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visiting object graphs with loops). Analogous to Py_ReprEnter and
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Py_ReprLeave
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'''
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class FakeRepr(object):
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"""
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Class representing a non-descript PyObject* value in the inferior
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process for when we don't have a custom scraper, intended to have
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a sane repr().
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"""
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def __init__(self, tp_name, address):
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self.tp_name = tp_name
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self.address = address
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def __repr__(self):
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# For the NULL pointer, we have no way of knowing a type, so
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# special-case it as per
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# http://bugs.python.org/issue8032#msg100882
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if self.address == 0:
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return '0x0'
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return '<%s at remote 0x%x>' % (self.tp_name, self.address)
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return FakeRepr(self.safe_tp_name(),
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long(self._gdbval))
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def write_repr(self, out, visited):
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'''
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Write a string representation of the value scraped from the inferior
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process to "out", a file-like object.
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'''
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# Default implementation: generate a proxy value and write its repr
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# However, this could involve a lot of work for complicated objects,
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# so for derived classes we specialize this
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return out.write(repr(self.proxyval(visited)))
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@classmethod
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def subclass_from_type(cls, t):
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'''
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Given a PyTypeObjectPtr instance wrapping a gdb.Value that's a
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(PyTypeObject*), determine the corresponding subclass of PyObjectPtr
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to use
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Ideally, we would look up the symbols for the global types, but that
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isn't working yet:
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(gdb) python print gdb.lookup_symbol('PyList_Type')[0].value
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Traceback (most recent call last):
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File "<string>", line 1, in <module>
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NotImplementedError: Symbol type not yet supported in Python scripts.
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Error while executing Python code.
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For now, we use tp_flags, after doing some string comparisons on the
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tp_name for some special-cases that don't seem to be visible through
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flags
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'''
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try:
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tp_name = t.field('tp_name').string()
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tp_flags = int(t.field('tp_flags'))
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# RuntimeError: NULL pointers
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# UnicodeDecodeError: string() fails to decode the bytestring
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except (RuntimeError, UnicodeDecodeError):
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# Handle any kind of error e.g. NULL ptrs by simply using the base
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# class
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return cls
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#print('tp_flags = 0x%08x' % tp_flags)
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#print('tp_name = %r' % tp_name)
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name_map = {'bool': PyBoolObjectPtr,
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'classobj': PyClassObjectPtr,
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'NoneType': PyNoneStructPtr,
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'frame': PyFrameObjectPtr,
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'set' : PySetObjectPtr,
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'frozenset' : PySetObjectPtr,
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'builtin_function_or_method' : PyCFunctionObjectPtr,
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'method-wrapper': wrapperobject,
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}
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if tp_name in name_map:
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return name_map[tp_name]
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if tp_flags & Py_TPFLAGS_HEAPTYPE:
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return HeapTypeObjectPtr
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if tp_flags & Py_TPFLAGS_LONG_SUBCLASS:
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return PyLongObjectPtr
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if tp_flags & Py_TPFLAGS_LIST_SUBCLASS:
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return PyListObjectPtr
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if tp_flags & Py_TPFLAGS_TUPLE_SUBCLASS:
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return PyTupleObjectPtr
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if tp_flags & Py_TPFLAGS_BYTES_SUBCLASS:
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return PyBytesObjectPtr
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if tp_flags & Py_TPFLAGS_UNICODE_SUBCLASS:
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return PyUnicodeObjectPtr
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if tp_flags & Py_TPFLAGS_DICT_SUBCLASS:
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return PyDictObjectPtr
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if tp_flags & Py_TPFLAGS_BASE_EXC_SUBCLASS:
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return PyBaseExceptionObjectPtr
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#if tp_flags & Py_TPFLAGS_TYPE_SUBCLASS:
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# return PyTypeObjectPtr
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# Use the base class:
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return cls
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@classmethod
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def from_pyobject_ptr(cls, gdbval):
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'''
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Try to locate the appropriate derived class dynamically, and cast
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the pointer accordingly.
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'''
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try:
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p = PyObjectPtr(gdbval)
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cls = cls.subclass_from_type(p.type())
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return cls(gdbval, cast_to=cls.get_gdb_type())
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except RuntimeError:
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# Handle any kind of error e.g. NULL ptrs by simply using the base
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# class
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pass
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return cls(gdbval)
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@classmethod
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def get_gdb_type(cls):
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return gdb.lookup_type(cls._typename).pointer()
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def as_address(self):
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return long(self._gdbval)
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class PyVarObjectPtr(PyObjectPtr):
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_typename = 'PyVarObject'
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class ProxyAlreadyVisited(object):
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'''
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Placeholder proxy to use when protecting against infinite recursion due to
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loops in the object graph.
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Analogous to the values emitted by the users of Py_ReprEnter and Py_ReprLeave
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'''
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def __init__(self, rep):
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self._rep = rep
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def __repr__(self):
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return self._rep
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def _write_instance_repr(out, visited, name, pyop_attrdict, address):
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'''Shared code for use by all classes:
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write a representation to file-like object "out"'''
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out.write('<')
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out.write(name)
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# Write dictionary of instance attributes:
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if isinstance(pyop_attrdict, PyDictObjectPtr):
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out.write('(')
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first = True
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for pyop_arg, pyop_val in pyop_attrdict.iteritems():
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if not first:
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out.write(', ')
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first = False
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out.write(pyop_arg.proxyval(visited))
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out.write('=')
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pyop_val.write_repr(out, visited)
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out.write(')')
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out.write(' at remote 0x%x>' % address)
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class InstanceProxy(object):
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def __init__(self, cl_name, attrdict, address):
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self.cl_name = cl_name
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self.attrdict = attrdict
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self.address = address
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def __repr__(self):
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if isinstance(self.attrdict, dict):
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kwargs = ', '.join(["%s=%r" % (arg, val)
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for arg, val in self.attrdict.iteritems()])
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return '<%s(%s) at remote 0x%x>' % (self.cl_name,
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kwargs, self.address)
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else:
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return '<%s at remote 0x%x>' % (self.cl_name,
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self.address)
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def _PyObject_VAR_SIZE(typeobj, nitems):
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if _PyObject_VAR_SIZE._type_size_t is None:
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_PyObject_VAR_SIZE._type_size_t = gdb.lookup_type('size_t')
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return ( ( typeobj.field('tp_basicsize') +
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nitems * typeobj.field('tp_itemsize') +
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(_sizeof_void_p() - 1)
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) & ~(_sizeof_void_p() - 1)
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).cast(_PyObject_VAR_SIZE._type_size_t)
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_PyObject_VAR_SIZE._type_size_t = None
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class HeapTypeObjectPtr(PyObjectPtr):
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_typename = 'PyObject'
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def get_attr_dict(self):
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'''
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Get the PyDictObject ptr representing the attribute dictionary
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(or None if there's a problem)
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'''
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try:
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typeobj = self.type()
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dictoffset = int_from_int(typeobj.field('tp_dictoffset'))
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if dictoffset != 0:
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if dictoffset < 0:
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type_PyVarObject_ptr = gdb.lookup_type('PyVarObject').pointer()
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tsize = int_from_int(self._gdbval.cast(type_PyVarObject_ptr)['ob_size'])
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if tsize < 0:
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tsize = -tsize
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size = _PyObject_VAR_SIZE(typeobj, tsize)
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dictoffset += size
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assert dictoffset > 0
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assert dictoffset % _sizeof_void_p() == 0
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dictptr = self._gdbval.cast(_type_char_ptr()) + dictoffset
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PyObjectPtrPtr = PyObjectPtr.get_gdb_type().pointer()
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dictptr = dictptr.cast(PyObjectPtrPtr)
|
|
return PyObjectPtr.from_pyobject_ptr(dictptr.dereference())
|
|
except RuntimeError:
|
|
# Corrupt data somewhere; fail safe
|
|
pass
|
|
|
|
# Not found, or some kind of error:
|
|
return None
|
|
|
|
def proxyval(self, visited):
|
|
'''
|
|
Support for classes.
|
|
|
|
Currently we just locate the dictionary using a transliteration to
|
|
python of _PyObject_GetDictPtr, ignoring descriptors
|
|
'''
|
|
# Guard against infinite loops:
|
|
if self.as_address() in visited:
|
|
return ProxyAlreadyVisited('<...>')
|
|
visited.add(self.as_address())
|
|
|
|
pyop_attr_dict = self.get_attr_dict()
|
|
if pyop_attr_dict:
|
|
attr_dict = pyop_attr_dict.proxyval(visited)
|
|
else:
|
|
attr_dict = {}
|
|
tp_name = self.safe_tp_name()
|
|
|
|
# Class:
|
|
return InstanceProxy(tp_name, attr_dict, long(self._gdbval))
|
|
|
|
def write_repr(self, out, visited):
|
|
# Guard against infinite loops:
|
|
if self.as_address() in visited:
|
|
out.write('<...>')
|
|
return
|
|
visited.add(self.as_address())
|
|
|
|
pyop_attrdict = self.get_attr_dict()
|
|
_write_instance_repr(out, visited,
|
|
self.safe_tp_name(), pyop_attrdict, self.as_address())
|
|
|
|
class ProxyException(Exception):
|
|
def __init__(self, tp_name, args):
|
|
self.tp_name = tp_name
|
|
self.args = args
|
|
|
|
def __repr__(self):
|
|
return '%s%r' % (self.tp_name, self.args)
|
|
|
|
class PyBaseExceptionObjectPtr(PyObjectPtr):
|
|
"""
|
|
Class wrapping a gdb.Value that's a PyBaseExceptionObject* i.e. an exception
|
|
within the process being debugged.
|
|
"""
|
|
_typename = 'PyBaseExceptionObject'
|
|
|
|
def proxyval(self, visited):
|
|
# Guard against infinite loops:
|
|
if self.as_address() in visited:
|
|
return ProxyAlreadyVisited('(...)')
|
|
visited.add(self.as_address())
|
|
arg_proxy = self.pyop_field('args').proxyval(visited)
|
|
return ProxyException(self.safe_tp_name(),
|
|
arg_proxy)
|
|
|
|
def write_repr(self, out, visited):
|
|
# Guard against infinite loops:
|
|
if self.as_address() in visited:
|
|
out.write('(...)')
|
|
return
|
|
visited.add(self.as_address())
|
|
|
|
out.write(self.safe_tp_name())
|
|
self.write_field_repr('args', out, visited)
|
|
|
|
class PyClassObjectPtr(PyObjectPtr):
|
|
"""
|
|
Class wrapping a gdb.Value that's a PyClassObject* i.e. a <classobj>
|
|
instance within the process being debugged.
|
|
"""
|
|
_typename = 'PyClassObject'
|
|
|
|
|
|
class BuiltInFunctionProxy(object):
|
|
def __init__(self, ml_name):
|
|
self.ml_name = ml_name
|
|
|
|
def __repr__(self):
|
|
return "<built-in function %s>" % self.ml_name
|
|
|
|
class BuiltInMethodProxy(object):
|
|
def __init__(self, ml_name, pyop_m_self):
|
|
self.ml_name = ml_name
|
|
self.pyop_m_self = pyop_m_self
|
|
|
|
def __repr__(self):
|
|
return ('<built-in method %s of %s object at remote 0x%x>'
|
|
% (self.ml_name,
|
|
self.pyop_m_self.safe_tp_name(),
|
|
self.pyop_m_self.as_address())
|
|
)
|
|
|
|
class PyCFunctionObjectPtr(PyObjectPtr):
|
|
"""
|
|
Class wrapping a gdb.Value that's a PyCFunctionObject*
|
|
(see Include/methodobject.h and Objects/methodobject.c)
|
|
"""
|
|
_typename = 'PyCFunctionObject'
|
|
|
|
def proxyval(self, visited):
|
|
m_ml = self.field('m_ml') # m_ml is a (PyMethodDef*)
|
|
try:
|
|
ml_name = m_ml['ml_name'].string()
|
|
except UnicodeDecodeError:
|
|
ml_name = '<ml_name:UnicodeDecodeError>'
|
|
|
|
pyop_m_self = self.pyop_field('m_self')
|
|
if pyop_m_self.is_null():
|
|
return BuiltInFunctionProxy(ml_name)
|
|
else:
|
|
return BuiltInMethodProxy(ml_name, pyop_m_self)
|
|
|
|
|
|
class PyCodeObjectPtr(PyObjectPtr):
|
|
"""
|
|
Class wrapping a gdb.Value that's a PyCodeObject* i.e. a <code> instance
|
|
within the process being debugged.
|
|
"""
|
|
_typename = 'PyCodeObject'
|
|
|
|
def addr2line(self, addrq):
|
|
'''
|
|
Get the line number for a given bytecode offset
|
|
|
|
Analogous to PyCode_Addr2Line; translated from pseudocode in
|
|
Objects/lnotab_notes.txt
|
|
'''
|
|
co_lnotab = self.pyop_field('co_lnotab').proxyval(set())
|
|
|
|
# Initialize lineno to co_firstlineno as per PyCode_Addr2Line
|
|
# not 0, as lnotab_notes.txt has it:
|
|
lineno = int_from_int(self.field('co_firstlineno'))
|
|
|
|
addr = 0
|
|
for addr_incr, line_incr in zip(co_lnotab[::2], co_lnotab[1::2]):
|
|
addr += ord(addr_incr)
|
|
if addr > addrq:
|
|
return lineno
|
|
lineno += ord(line_incr)
|
|
return lineno
|
|
|
|
|
|
class PyDictObjectPtr(PyObjectPtr):
|
|
"""
|
|
Class wrapping a gdb.Value that's a PyDictObject* i.e. a dict instance
|
|
within the process being debugged.
|
|
"""
|
|
_typename = 'PyDictObject'
|
|
|
|
def iteritems(self):
|
|
'''
|
|
Yields a sequence of (PyObjectPtr key, PyObjectPtr value) pairs,
|
|
analogous to dict.iteritems()
|
|
'''
|
|
keys = self.field('ma_keys')
|
|
values = self.field('ma_values')
|
|
entries, nentries = self._get_entries(keys)
|
|
for i in safe_range(nentries):
|
|
ep = entries[i]
|
|
if long(values):
|
|
pyop_value = PyObjectPtr.from_pyobject_ptr(values[i])
|
|
else:
|
|
pyop_value = PyObjectPtr.from_pyobject_ptr(ep['me_value'])
|
|
if not pyop_value.is_null():
|
|
pyop_key = PyObjectPtr.from_pyobject_ptr(ep['me_key'])
|
|
yield (pyop_key, pyop_value)
|
|
|
|
def proxyval(self, visited):
|
|
# Guard against infinite loops:
|
|
if self.as_address() in visited:
|
|
return ProxyAlreadyVisited('{...}')
|
|
visited.add(self.as_address())
|
|
|
|
result = {}
|
|
for pyop_key, pyop_value in self.iteritems():
|
|
proxy_key = pyop_key.proxyval(visited)
|
|
proxy_value = pyop_value.proxyval(visited)
|
|
result[proxy_key] = proxy_value
|
|
return result
|
|
|
|
def write_repr(self, out, visited):
|
|
# Guard against infinite loops:
|
|
if self.as_address() in visited:
|
|
out.write('{...}')
|
|
return
|
|
visited.add(self.as_address())
|
|
|
|
out.write('{')
|
|
first = True
|
|
for pyop_key, pyop_value in self.iteritems():
|
|
if not first:
|
|
out.write(', ')
|
|
first = False
|
|
pyop_key.write_repr(out, visited)
|
|
out.write(': ')
|
|
pyop_value.write_repr(out, visited)
|
|
out.write('}')
|
|
|
|
def _get_entries(self, keys):
|
|
dk_nentries = int(keys['dk_nentries'])
|
|
dk_size = int(keys['dk_size'])
|
|
try:
|
|
# <= Python 3.5
|
|
return keys['dk_entries'], dk_size
|
|
except RuntimeError:
|
|
# >= Python 3.6
|
|
pass
|
|
|
|
if dk_size <= 0xFF:
|
|
offset = dk_size
|
|
elif dk_size <= 0xFFFF:
|
|
offset = 2 * dk_size
|
|
elif dk_size <= 0xFFFFFFFF:
|
|
offset = 4 * dk_size
|
|
else:
|
|
offset = 8 * dk_size
|
|
|
|
ent_addr = keys['dk_indices'].address
|
|
ent_addr = ent_addr.cast(_type_unsigned_char_ptr()) + offset
|
|
ent_ptr_t = gdb.lookup_type('PyDictKeyEntry').pointer()
|
|
ent_addr = ent_addr.cast(ent_ptr_t)
|
|
|
|
return ent_addr, dk_nentries
|
|
|
|
|
|
class PyListObjectPtr(PyObjectPtr):
|
|
_typename = 'PyListObject'
|
|
|
|
def __getitem__(self, i):
|
|
# Get the gdb.Value for the (PyObject*) with the given index:
|
|
field_ob_item = self.field('ob_item')
|
|
return field_ob_item[i]
|
|
|
|
def proxyval(self, visited):
|
|
# Guard against infinite loops:
|
|
if self.as_address() in visited:
|
|
return ProxyAlreadyVisited('[...]')
|
|
visited.add(self.as_address())
|
|
|
|
result = [PyObjectPtr.from_pyobject_ptr(self[i]).proxyval(visited)
|
|
for i in safe_range(int_from_int(self.field('ob_size')))]
|
|
return result
|
|
|
|
def write_repr(self, out, visited):
|
|
# Guard against infinite loops:
|
|
if self.as_address() in visited:
|
|
out.write('[...]')
|
|
return
|
|
visited.add(self.as_address())
|
|
|
|
out.write('[')
|
|
for i in safe_range(int_from_int(self.field('ob_size'))):
|
|
if i > 0:
|
|
out.write(', ')
|
|
element = PyObjectPtr.from_pyobject_ptr(self[i])
|
|
element.write_repr(out, visited)
|
|
out.write(']')
|
|
|
|
class PyLongObjectPtr(PyObjectPtr):
|
|
_typename = 'PyLongObject'
|
|
|
|
def proxyval(self, visited):
|
|
'''
|
|
Python's Include/longobjrep.h has this declaration:
|
|
struct _longobject {
|
|
PyObject_VAR_HEAD
|
|
digit ob_digit[1];
|
|
};
|
|
|
|
with this description:
|
|
The absolute value of a number is equal to
|
|
SUM(for i=0 through abs(ob_size)-1) ob_digit[i] * 2**(SHIFT*i)
|
|
Negative numbers are represented with ob_size < 0;
|
|
zero is represented by ob_size == 0.
|
|
|
|
where SHIFT can be either:
|
|
#define PyLong_SHIFT 30
|
|
#define PyLong_SHIFT 15
|
|
'''
|
|
ob_size = long(self.field('ob_size'))
|
|
if ob_size == 0:
|
|
return 0
|
|
|
|
ob_digit = self.field('ob_digit')
|
|
|
|
if gdb.lookup_type('digit').sizeof == 2:
|
|
SHIFT = 15
|
|
else:
|
|
SHIFT = 30
|
|
|
|
digits = [long(ob_digit[i]) * 2**(SHIFT*i)
|
|
for i in safe_range(abs(ob_size))]
|
|
result = sum(digits)
|
|
if ob_size < 0:
|
|
result = -result
|
|
return result
|
|
|
|
def write_repr(self, out, visited):
|
|
# Write this out as a Python 3 int literal, i.e. without the "L" suffix
|
|
proxy = self.proxyval(visited)
|
|
out.write("%s" % proxy)
|
|
|
|
|
|
class PyBoolObjectPtr(PyLongObjectPtr):
|
|
"""
|
|
Class wrapping a gdb.Value that's a PyBoolObject* i.e. one of the two
|
|
<bool> instances (Py_True/Py_False) within the process being debugged.
|
|
"""
|
|
def proxyval(self, visited):
|
|
if PyLongObjectPtr.proxyval(self, visited):
|
|
return True
|
|
else:
|
|
return False
|
|
|
|
class PyNoneStructPtr(PyObjectPtr):
|
|
"""
|
|
Class wrapping a gdb.Value that's a PyObject* pointing to the
|
|
singleton (we hope) _Py_NoneStruct with ob_type PyNone_Type
|
|
"""
|
|
_typename = 'PyObject'
|
|
|
|
def proxyval(self, visited):
|
|
return None
|
|
|
|
|
|
class PyFrameObjectPtr(PyObjectPtr):
|
|
_typename = 'PyFrameObject'
|
|
|
|
def __init__(self, gdbval, cast_to=None):
|
|
PyObjectPtr.__init__(self, gdbval, cast_to)
|
|
|
|
if not self.is_optimized_out():
|
|
self.co = PyCodeObjectPtr.from_pyobject_ptr(self.field('f_code'))
|
|
self.co_name = self.co.pyop_field('co_name')
|
|
self.co_filename = self.co.pyop_field('co_filename')
|
|
|
|
self.f_lineno = int_from_int(self.field('f_lineno'))
|
|
self.f_lasti = int_from_int(self.field('f_lasti'))
|
|
self.co_nlocals = int_from_int(self.co.field('co_nlocals'))
|
|
self.co_varnames = PyTupleObjectPtr.from_pyobject_ptr(self.co.field('co_varnames'))
|
|
|
|
def iter_locals(self):
|
|
'''
|
|
Yield a sequence of (name,value) pairs of PyObjectPtr instances, for
|
|
the local variables of this frame
|
|
'''
|
|
if self.is_optimized_out():
|
|
return
|
|
|
|
f_localsplus = self.field('f_localsplus')
|
|
for i in safe_range(self.co_nlocals):
|
|
pyop_value = PyObjectPtr.from_pyobject_ptr(f_localsplus[i])
|
|
if not pyop_value.is_null():
|
|
pyop_name = PyObjectPtr.from_pyobject_ptr(self.co_varnames[i])
|
|
yield (pyop_name, pyop_value)
|
|
|
|
def iter_globals(self):
|
|
'''
|
|
Yield a sequence of (name,value) pairs of PyObjectPtr instances, for
|
|
the global variables of this frame
|
|
'''
|
|
if self.is_optimized_out():
|
|
return ()
|
|
|
|
pyop_globals = self.pyop_field('f_globals')
|
|
return pyop_globals.iteritems()
|
|
|
|
def iter_builtins(self):
|
|
'''
|
|
Yield a sequence of (name,value) pairs of PyObjectPtr instances, for
|
|
the builtin variables
|
|
'''
|
|
if self.is_optimized_out():
|
|
return ()
|
|
|
|
pyop_builtins = self.pyop_field('f_builtins')
|
|
return pyop_builtins.iteritems()
|
|
|
|
def get_var_by_name(self, name):
|
|
'''
|
|
Look for the named local variable, returning a (PyObjectPtr, scope) pair
|
|
where scope is a string 'local', 'global', 'builtin'
|
|
|
|
If not found, return (None, None)
|
|
'''
|
|
for pyop_name, pyop_value in self.iter_locals():
|
|
if name == pyop_name.proxyval(set()):
|
|
return pyop_value, 'local'
|
|
for pyop_name, pyop_value in self.iter_globals():
|
|
if name == pyop_name.proxyval(set()):
|
|
return pyop_value, 'global'
|
|
for pyop_name, pyop_value in self.iter_builtins():
|
|
if name == pyop_name.proxyval(set()):
|
|
return pyop_value, 'builtin'
|
|
return None, None
|
|
|
|
def filename(self):
|
|
'''Get the path of the current Python source file, as a string'''
|
|
if self.is_optimized_out():
|
|
return '(frame information optimized out)'
|
|
return self.co_filename.proxyval(set())
|
|
|
|
def current_line_num(self):
|
|
'''Get current line number as an integer (1-based)
|
|
|
|
Translated from PyFrame_GetLineNumber and PyCode_Addr2Line
|
|
|
|
See Objects/lnotab_notes.txt
|
|
'''
|
|
if self.is_optimized_out():
|
|
return None
|
|
f_trace = self.field('f_trace')
|
|
if long(f_trace) != 0:
|
|
# we have a non-NULL f_trace:
|
|
return self.f_lineno
|
|
|
|
try:
|
|
return self.co.addr2line(self.f_lasti)
|
|
except Exception:
|
|
# bpo-34989: addr2line() is a complex function, it can fail in many
|
|
# ways. For example, it fails with a TypeError on "FakeRepr" if
|
|
# gdb fails to load debug symbols. Use a catch-all "except
|
|
# Exception" to make the whole function safe. The caller has to
|
|
# handle None anyway for optimized Python.
|
|
return None
|
|
|
|
def current_line(self):
|
|
'''Get the text of the current source line as a string, with a trailing
|
|
newline character'''
|
|
if self.is_optimized_out():
|
|
return '(frame information optimized out)'
|
|
|
|
lineno = self.current_line_num()
|
|
if lineno is None:
|
|
return '(failed to get frame line number)'
|
|
|
|
filename = self.filename()
|
|
try:
|
|
with open(os_fsencode(filename), 'r') as fp:
|
|
lines = fp.readlines()
|
|
except IOError:
|
|
return None
|
|
|
|
try:
|
|
# Convert from 1-based current_line_num to 0-based list offset
|
|
return lines[lineno - 1]
|
|
except IndexError:
|
|
return None
|
|
|
|
def write_repr(self, out, visited):
|
|
if self.is_optimized_out():
|
|
out.write('(frame information optimized out)')
|
|
return
|
|
lineno = self.current_line_num()
|
|
lineno = str(lineno) if lineno is not None else "?"
|
|
out.write('Frame 0x%x, for file %s, line %s, in %s ('
|
|
% (self.as_address(),
|
|
self.co_filename.proxyval(visited),
|
|
lineno,
|
|
self.co_name.proxyval(visited)))
|
|
first = True
|
|
for pyop_name, pyop_value in self.iter_locals():
|
|
if not first:
|
|
out.write(', ')
|
|
first = False
|
|
|
|
out.write(pyop_name.proxyval(visited))
|
|
out.write('=')
|
|
pyop_value.write_repr(out, visited)
|
|
|
|
out.write(')')
|
|
|
|
def print_traceback(self):
|
|
if self.is_optimized_out():
|
|
sys.stdout.write(' (frame information optimized out)\n')
|
|
return
|
|
visited = set()
|
|
lineno = self.current_line_num()
|
|
lineno = str(lineno) if lineno is not None else "?"
|
|
sys.stdout.write(' File "%s", line %s, in %s\n'
|
|
% (self.co_filename.proxyval(visited),
|
|
lineno,
|
|
self.co_name.proxyval(visited)))
|
|
|
|
class PySetObjectPtr(PyObjectPtr):
|
|
_typename = 'PySetObject'
|
|
|
|
@classmethod
|
|
def _dummy_key(self):
|
|
return gdb.lookup_global_symbol('_PySet_Dummy').value()
|
|
|
|
def __iter__(self):
|
|
dummy_ptr = self._dummy_key()
|
|
table = self.field('table')
|
|
for i in safe_range(self.field('mask') + 1):
|
|
setentry = table[i]
|
|
key = setentry['key']
|
|
if key != 0 and key != dummy_ptr:
|
|
yield PyObjectPtr.from_pyobject_ptr(key)
|
|
|
|
def proxyval(self, visited):
|
|
# Guard against infinite loops:
|
|
if self.as_address() in visited:
|
|
return ProxyAlreadyVisited('%s(...)' % self.safe_tp_name())
|
|
visited.add(self.as_address())
|
|
|
|
members = (key.proxyval(visited) for key in self)
|
|
if self.safe_tp_name() == 'frozenset':
|
|
return frozenset(members)
|
|
else:
|
|
return set(members)
|
|
|
|
def write_repr(self, out, visited):
|
|
# Emulate Python 3's set_repr
|
|
tp_name = self.safe_tp_name()
|
|
|
|
# Guard against infinite loops:
|
|
if self.as_address() in visited:
|
|
out.write('(...)')
|
|
return
|
|
visited.add(self.as_address())
|
|
|
|
# Python 3's set_repr special-cases the empty set:
|
|
if not self.field('used'):
|
|
out.write(tp_name)
|
|
out.write('()')
|
|
return
|
|
|
|
# Python 3 uses {} for set literals:
|
|
if tp_name != 'set':
|
|
out.write(tp_name)
|
|
out.write('(')
|
|
|
|
out.write('{')
|
|
first = True
|
|
for key in self:
|
|
if not first:
|
|
out.write(', ')
|
|
first = False
|
|
key.write_repr(out, visited)
|
|
out.write('}')
|
|
|
|
if tp_name != 'set':
|
|
out.write(')')
|
|
|
|
|
|
class PyBytesObjectPtr(PyObjectPtr):
|
|
_typename = 'PyBytesObject'
|
|
|
|
def __str__(self):
|
|
field_ob_size = self.field('ob_size')
|
|
field_ob_sval = self.field('ob_sval')
|
|
char_ptr = field_ob_sval.address.cast(_type_unsigned_char_ptr())
|
|
return ''.join([chr(char_ptr[i]) for i in safe_range(field_ob_size)])
|
|
|
|
def proxyval(self, visited):
|
|
return str(self)
|
|
|
|
def write_repr(self, out, visited):
|
|
# Write this out as a Python 3 bytes literal, i.e. with a "b" prefix
|
|
|
|
# Get a PyStringObject* within the Python 2 gdb process:
|
|
proxy = self.proxyval(visited)
|
|
|
|
# Transliteration of Python 3's Objects/bytesobject.c:PyBytes_Repr
|
|
# to Python 2 code:
|
|
quote = "'"
|
|
if "'" in proxy and not '"' in proxy:
|
|
quote = '"'
|
|
out.write('b')
|
|
out.write(quote)
|
|
for byte in proxy:
|
|
if byte == quote or byte == '\\':
|
|
out.write('\\')
|
|
out.write(byte)
|
|
elif byte == '\t':
|
|
out.write('\\t')
|
|
elif byte == '\n':
|
|
out.write('\\n')
|
|
elif byte == '\r':
|
|
out.write('\\r')
|
|
elif byte < ' ' or ord(byte) >= 0x7f:
|
|
out.write('\\x')
|
|
out.write(hexdigits[(ord(byte) & 0xf0) >> 4])
|
|
out.write(hexdigits[ord(byte) & 0xf])
|
|
else:
|
|
out.write(byte)
|
|
out.write(quote)
|
|
|
|
class PyTupleObjectPtr(PyObjectPtr):
|
|
_typename = 'PyTupleObject'
|
|
|
|
def __getitem__(self, i):
|
|
# Get the gdb.Value for the (PyObject*) with the given index:
|
|
field_ob_item = self.field('ob_item')
|
|
return field_ob_item[i]
|
|
|
|
def proxyval(self, visited):
|
|
# Guard against infinite loops:
|
|
if self.as_address() in visited:
|
|
return ProxyAlreadyVisited('(...)')
|
|
visited.add(self.as_address())
|
|
|
|
result = tuple(PyObjectPtr.from_pyobject_ptr(self[i]).proxyval(visited)
|
|
for i in safe_range(int_from_int(self.field('ob_size'))))
|
|
return result
|
|
|
|
def write_repr(self, out, visited):
|
|
# Guard against infinite loops:
|
|
if self.as_address() in visited:
|
|
out.write('(...)')
|
|
return
|
|
visited.add(self.as_address())
|
|
|
|
out.write('(')
|
|
for i in safe_range(int_from_int(self.field('ob_size'))):
|
|
if i > 0:
|
|
out.write(', ')
|
|
element = PyObjectPtr.from_pyobject_ptr(self[i])
|
|
element.write_repr(out, visited)
|
|
if self.field('ob_size') == 1:
|
|
out.write(',)')
|
|
else:
|
|
out.write(')')
|
|
|
|
class PyTypeObjectPtr(PyObjectPtr):
|
|
_typename = 'PyTypeObject'
|
|
|
|
|
|
def _unichr_is_printable(char):
|
|
# Logic adapted from Python 3's Tools/unicode/makeunicodedata.py
|
|
if char == u" ":
|
|
return True
|
|
import unicodedata
|
|
return unicodedata.category(char) not in ("C", "Z")
|
|
|
|
if sys.maxunicode >= 0x10000:
|
|
_unichr = unichr
|
|
else:
|
|
# Needed for proper surrogate support if sizeof(Py_UNICODE) is 2 in gdb
|
|
def _unichr(x):
|
|
if x < 0x10000:
|
|
return unichr(x)
|
|
x -= 0x10000
|
|
ch1 = 0xD800 | (x >> 10)
|
|
ch2 = 0xDC00 | (x & 0x3FF)
|
|
return unichr(ch1) + unichr(ch2)
|
|
|
|
|
|
class PyUnicodeObjectPtr(PyObjectPtr):
|
|
_typename = 'PyUnicodeObject'
|
|
|
|
def char_width(self):
|
|
_type_Py_UNICODE = gdb.lookup_type('Py_UNICODE')
|
|
return _type_Py_UNICODE.sizeof
|
|
|
|
def proxyval(self, visited):
|
|
global _is_pep393
|
|
if _is_pep393 is None:
|
|
fields = gdb.lookup_type('PyUnicodeObject').target().fields()
|
|
_is_pep393 = 'data' in [f.name for f in fields]
|
|
if _is_pep393:
|
|
# Python 3.3 and newer
|
|
may_have_surrogates = False
|
|
compact = self.field('_base')
|
|
ascii = compact['_base']
|
|
state = ascii['state']
|
|
is_compact_ascii = (int(state['ascii']) and int(state['compact']))
|
|
if not int(state['ready']):
|
|
# string is not ready
|
|
field_length = long(compact['wstr_length'])
|
|
may_have_surrogates = True
|
|
field_str = ascii['wstr']
|
|
else:
|
|
field_length = long(ascii['length'])
|
|
if is_compact_ascii:
|
|
field_str = ascii.address + 1
|
|
elif int(state['compact']):
|
|
field_str = compact.address + 1
|
|
else:
|
|
field_str = self.field('data')['any']
|
|
repr_kind = int(state['kind'])
|
|
if repr_kind == 1:
|
|
field_str = field_str.cast(_type_unsigned_char_ptr())
|
|
elif repr_kind == 2:
|
|
field_str = field_str.cast(_type_unsigned_short_ptr())
|
|
elif repr_kind == 4:
|
|
field_str = field_str.cast(_type_unsigned_int_ptr())
|
|
else:
|
|
# Python 3.2 and earlier
|
|
field_length = long(self.field('length'))
|
|
field_str = self.field('str')
|
|
may_have_surrogates = self.char_width() == 2
|
|
|
|
# Gather a list of ints from the Py_UNICODE array; these are either
|
|
# UCS-1, UCS-2 or UCS-4 code points:
|
|
if not may_have_surrogates:
|
|
Py_UNICODEs = [int(field_str[i]) for i in safe_range(field_length)]
|
|
else:
|
|
# A more elaborate routine if sizeof(Py_UNICODE) is 2 in the
|
|
# inferior process: we must join surrogate pairs.
|
|
Py_UNICODEs = []
|
|
i = 0
|
|
limit = safety_limit(field_length)
|
|
while i < limit:
|
|
ucs = int(field_str[i])
|
|
i += 1
|
|
if ucs < 0xD800 or ucs >= 0xDC00 or i == field_length:
|
|
Py_UNICODEs.append(ucs)
|
|
continue
|
|
# This could be a surrogate pair.
|
|
ucs2 = int(field_str[i])
|
|
if ucs2 < 0xDC00 or ucs2 > 0xDFFF:
|
|
continue
|
|
code = (ucs & 0x03FF) << 10
|
|
code |= ucs2 & 0x03FF
|
|
code += 0x00010000
|
|
Py_UNICODEs.append(code)
|
|
i += 1
|
|
|
|
# Convert the int code points to unicode characters, and generate a
|
|
# local unicode instance.
|
|
# This splits surrogate pairs if sizeof(Py_UNICODE) is 2 here (in gdb).
|
|
result = u''.join([
|
|
(_unichr(ucs) if ucs <= 0x10ffff else '\ufffd')
|
|
for ucs in Py_UNICODEs])
|
|
return result
|
|
|
|
def write_repr(self, out, visited):
|
|
# Write this out as a Python 3 str literal, i.e. without a "u" prefix
|
|
|
|
# Get a PyUnicodeObject* within the Python 2 gdb process:
|
|
proxy = self.proxyval(visited)
|
|
|
|
# Transliteration of Python 3's Object/unicodeobject.c:unicode_repr
|
|
# to Python 2:
|
|
if "'" in proxy and '"' not in proxy:
|
|
quote = '"'
|
|
else:
|
|
quote = "'"
|
|
out.write(quote)
|
|
|
|
i = 0
|
|
while i < len(proxy):
|
|
ch = proxy[i]
|
|
i += 1
|
|
|
|
# Escape quotes and backslashes
|
|
if ch == quote or ch == '\\':
|
|
out.write('\\')
|
|
out.write(ch)
|
|
|
|
# Map special whitespace to '\t', \n', '\r'
|
|
elif ch == '\t':
|
|
out.write('\\t')
|
|
elif ch == '\n':
|
|
out.write('\\n')
|
|
elif ch == '\r':
|
|
out.write('\\r')
|
|
|
|
# Map non-printable US ASCII to '\xhh' */
|
|
elif ch < ' ' or ch == 0x7F:
|
|
out.write('\\x')
|
|
out.write(hexdigits[(ord(ch) >> 4) & 0x000F])
|
|
out.write(hexdigits[ord(ch) & 0x000F])
|
|
|
|
# Copy ASCII characters as-is
|
|
elif ord(ch) < 0x7F:
|
|
out.write(ch)
|
|
|
|
# Non-ASCII characters
|
|
else:
|
|
ucs = ch
|
|
ch2 = None
|
|
if sys.maxunicode < 0x10000:
|
|
# If sizeof(Py_UNICODE) is 2 here (in gdb), join
|
|
# surrogate pairs before calling _unichr_is_printable.
|
|
if (i < len(proxy)
|
|
and 0xD800 <= ord(ch) < 0xDC00 \
|
|
and 0xDC00 <= ord(proxy[i]) <= 0xDFFF):
|
|
ch2 = proxy[i]
|
|
ucs = ch + ch2
|
|
i += 1
|
|
|
|
# Unfortuately, Python 2's unicode type doesn't seem
|
|
# to expose the "isprintable" method
|
|
printable = _unichr_is_printable(ucs)
|
|
if printable:
|
|
try:
|
|
ucs.encode(ENCODING)
|
|
except UnicodeEncodeError:
|
|
printable = False
|
|
|
|
# Map Unicode whitespace and control characters
|
|
# (categories Z* and C* except ASCII space)
|
|
if not printable:
|
|
if ch2 is not None:
|
|
# Match Python 3's representation of non-printable
|
|
# wide characters.
|
|
code = (ord(ch) & 0x03FF) << 10
|
|
code |= ord(ch2) & 0x03FF
|
|
code += 0x00010000
|
|
else:
|
|
code = ord(ucs)
|
|
|
|
# Map 8-bit characters to '\\xhh'
|
|
if code <= 0xff:
|
|
out.write('\\x')
|
|
out.write(hexdigits[(code >> 4) & 0x000F])
|
|
out.write(hexdigits[code & 0x000F])
|
|
# Map 21-bit characters to '\U00xxxxxx'
|
|
elif code >= 0x10000:
|
|
out.write('\\U')
|
|
out.write(hexdigits[(code >> 28) & 0x0000000F])
|
|
out.write(hexdigits[(code >> 24) & 0x0000000F])
|
|
out.write(hexdigits[(code >> 20) & 0x0000000F])
|
|
out.write(hexdigits[(code >> 16) & 0x0000000F])
|
|
out.write(hexdigits[(code >> 12) & 0x0000000F])
|
|
out.write(hexdigits[(code >> 8) & 0x0000000F])
|
|
out.write(hexdigits[(code >> 4) & 0x0000000F])
|
|
out.write(hexdigits[code & 0x0000000F])
|
|
# Map 16-bit characters to '\uxxxx'
|
|
else:
|
|
out.write('\\u')
|
|
out.write(hexdigits[(code >> 12) & 0x000F])
|
|
out.write(hexdigits[(code >> 8) & 0x000F])
|
|
out.write(hexdigits[(code >> 4) & 0x000F])
|
|
out.write(hexdigits[code & 0x000F])
|
|
else:
|
|
# Copy characters as-is
|
|
out.write(ch)
|
|
if ch2 is not None:
|
|
out.write(ch2)
|
|
|
|
out.write(quote)
|
|
|
|
|
|
class wrapperobject(PyObjectPtr):
|
|
_typename = 'wrapperobject'
|
|
|
|
def safe_name(self):
|
|
try:
|
|
name = self.field('descr')['d_base']['name'].string()
|
|
return repr(name)
|
|
except (NullPyObjectPtr, RuntimeError, UnicodeDecodeError):
|
|
return '<unknown name>'
|
|
|
|
def safe_tp_name(self):
|
|
try:
|
|
return self.field('self')['ob_type']['tp_name'].string()
|
|
except (NullPyObjectPtr, RuntimeError, UnicodeDecodeError):
|
|
return '<unknown tp_name>'
|
|
|
|
def safe_self_addresss(self):
|
|
try:
|
|
address = long(self.field('self'))
|
|
return '%#x' % address
|
|
except (NullPyObjectPtr, RuntimeError):
|
|
return '<failed to get self address>'
|
|
|
|
def proxyval(self, visited):
|
|
name = self.safe_name()
|
|
tp_name = self.safe_tp_name()
|
|
self_address = self.safe_self_addresss()
|
|
return ("<method-wrapper %s of %s object at %s>"
|
|
% (name, tp_name, self_address))
|
|
|
|
def write_repr(self, out, visited):
|
|
proxy = self.proxyval(visited)
|
|
out.write(proxy)
|
|
|
|
|
|
def int_from_int(gdbval):
|
|
return int(str(gdbval))
|
|
|
|
|
|
def stringify(val):
|
|
# TODO: repr() puts everything on one line; pformat can be nicer, but
|
|
# can lead to v.long results; this function isolates the choice
|
|
if True:
|
|
return repr(val)
|
|
else:
|
|
from pprint import pformat
|
|
return pformat(val)
|
|
|
|
|
|
class PyObjectPtrPrinter:
|
|
"Prints a (PyObject*)"
|
|
|
|
def __init__ (self, gdbval):
|
|
self.gdbval = gdbval
|
|
|
|
def to_string (self):
|
|
pyop = PyObjectPtr.from_pyobject_ptr(self.gdbval)
|
|
if True:
|
|
return pyop.get_truncated_repr(MAX_OUTPUT_LEN)
|
|
else:
|
|
# Generate full proxy value then stringify it.
|
|
# Doing so could be expensive
|
|
proxyval = pyop.proxyval(set())
|
|
return stringify(proxyval)
|
|
|
|
def pretty_printer_lookup(gdbval):
|
|
type = gdbval.type.unqualified()
|
|
if type.code != gdb.TYPE_CODE_PTR:
|
|
return None
|
|
|
|
type = type.target().unqualified()
|
|
t = str(type)
|
|
if t in ("PyObject", "PyFrameObject", "PyUnicodeObject", "wrapperobject"):
|
|
return PyObjectPtrPrinter(gdbval)
|
|
|
|
"""
|
|
During development, I've been manually invoking the code in this way:
|
|
(gdb) python
|
|
|
|
import sys
|
|
sys.path.append('/home/david/coding/python-gdb')
|
|
import libpython
|
|
end
|
|
|
|
then reloading it after each edit like this:
|
|
(gdb) python reload(libpython)
|
|
|
|
The following code should ensure that the prettyprinter is registered
|
|
if the code is autoloaded by gdb when visiting libpython.so, provided
|
|
that this python file is installed to the same path as the library (or its
|
|
.debug file) plus a "-gdb.py" suffix, e.g:
|
|
/usr/lib/libpython2.6.so.1.0-gdb.py
|
|
/usr/lib/debug/usr/lib/libpython2.6.so.1.0.debug-gdb.py
|
|
"""
|
|
def register (obj):
|
|
if obj is None:
|
|
obj = gdb
|
|
|
|
# Wire up the pretty-printer
|
|
obj.pretty_printers.append(pretty_printer_lookup)
|
|
|
|
register (gdb.current_objfile ())
|
|
|
|
|
|
|
|
# Unfortunately, the exact API exposed by the gdb module varies somewhat
|
|
# from build to build
|
|
# See http://bugs.python.org/issue8279?#msg102276
|
|
|
|
class Frame(object):
|
|
'''
|
|
Wrapper for gdb.Frame, adding various methods
|
|
'''
|
|
def __init__(self, gdbframe):
|
|
self._gdbframe = gdbframe
|
|
|
|
def older(self):
|
|
older = self._gdbframe.older()
|
|
if older:
|
|
return Frame(older)
|
|
else:
|
|
return None
|
|
|
|
def newer(self):
|
|
newer = self._gdbframe.newer()
|
|
if newer:
|
|
return Frame(newer)
|
|
else:
|
|
return None
|
|
|
|
def select(self):
|
|
'''If supported, select this frame and return True; return False if unsupported
|
|
|
|
Not all builds have a gdb.Frame.select method; seems to be present on Fedora 12
|
|
onwards, but absent on Ubuntu buildbot'''
|
|
if not hasattr(self._gdbframe, 'select'):
|
|
print ('Unable to select frame: '
|
|
'this build of gdb does not expose a gdb.Frame.select method')
|
|
return False
|
|
self._gdbframe.select()
|
|
return True
|
|
|
|
def get_index(self):
|
|
'''Calculate index of frame, starting at 0 for the newest frame within
|
|
this thread'''
|
|
index = 0
|
|
# Go down until you reach the newest frame:
|
|
iter_frame = self
|
|
while iter_frame.newer():
|
|
index += 1
|
|
iter_frame = iter_frame.newer()
|
|
return index
|
|
|
|
# We divide frames into:
|
|
# - "python frames":
|
|
# - "bytecode frames" i.e. PyEval_EvalFrameEx
|
|
# - "other python frames": things that are of interest from a python
|
|
# POV, but aren't bytecode (e.g. GC, GIL)
|
|
# - everything else
|
|
|
|
def is_python_frame(self):
|
|
'''Is this a _PyEval_EvalFrameDefault frame, or some other important
|
|
frame? (see is_other_python_frame for what "important" means in this
|
|
context)'''
|
|
if self.is_evalframe():
|
|
return True
|
|
if self.is_other_python_frame():
|
|
return True
|
|
return False
|
|
|
|
def is_evalframe(self):
|
|
'''Is this a _PyEval_EvalFrameDefault frame?'''
|
|
if self._gdbframe.name() == EVALFRAME:
|
|
'''
|
|
I believe we also need to filter on the inline
|
|
struct frame_id.inline_depth, only regarding frames with
|
|
an inline depth of 0 as actually being this function
|
|
|
|
So we reject those with type gdb.INLINE_FRAME
|
|
'''
|
|
if self._gdbframe.type() == gdb.NORMAL_FRAME:
|
|
# We have a _PyEval_EvalFrameDefault frame:
|
|
return True
|
|
|
|
return False
|
|
|
|
def is_other_python_frame(self):
|
|
'''Is this frame worth displaying in python backtraces?
|
|
Examples:
|
|
- waiting on the GIL
|
|
- garbage-collecting
|
|
- within a CFunction
|
|
If it is, return a descriptive string
|
|
For other frames, return False
|
|
'''
|
|
if self.is_waiting_for_gil():
|
|
return 'Waiting for the GIL'
|
|
|
|
if self.is_gc_collect():
|
|
return 'Garbage-collecting'
|
|
|
|
# Detect invocations of PyCFunction instances:
|
|
frame = self._gdbframe
|
|
caller = frame.name()
|
|
if not caller:
|
|
return False
|
|
|
|
if caller in ('_PyCFunction_FastCallDict',
|
|
'_PyCFunction_FastCallKeywords'):
|
|
arg_name = 'func'
|
|
# Within that frame:
|
|
# "func" is the local containing the PyObject* of the
|
|
# PyCFunctionObject instance
|
|
# "f" is the same value, but cast to (PyCFunctionObject*)
|
|
# "self" is the (PyObject*) of the 'self'
|
|
try:
|
|
# Use the prettyprinter for the func:
|
|
func = frame.read_var(arg_name)
|
|
return str(func)
|
|
except ValueError:
|
|
return ('PyCFunction invocation (unable to read %s: '
|
|
'missing debuginfos?)' % arg_name)
|
|
except RuntimeError:
|
|
return 'PyCFunction invocation (unable to read %s)' % arg_name
|
|
|
|
if caller == 'wrapper_call':
|
|
arg_name = 'wp'
|
|
try:
|
|
func = frame.read_var(arg_name)
|
|
return str(func)
|
|
except ValueError:
|
|
return ('<wrapper_call invocation (unable to read %s: '
|
|
'missing debuginfos?)>' % arg_name)
|
|
except RuntimeError:
|
|
return '<wrapper_call invocation (unable to read %s)>' % arg_name
|
|
|
|
# This frame isn't worth reporting:
|
|
return False
|
|
|
|
def is_waiting_for_gil(self):
|
|
'''Is this frame waiting on the GIL?'''
|
|
# This assumes the _POSIX_THREADS version of Python/ceval_gil.h:
|
|
name = self._gdbframe.name()
|
|
if name:
|
|
return 'pthread_cond_timedwait' in name
|
|
|
|
def is_gc_collect(self):
|
|
'''Is this frame "collect" within the garbage-collector?'''
|
|
return self._gdbframe.name() == 'collect'
|
|
|
|
def get_pyop(self):
|
|
try:
|
|
f = self._gdbframe.read_var('f')
|
|
frame = PyFrameObjectPtr.from_pyobject_ptr(f)
|
|
if not frame.is_optimized_out():
|
|
return frame
|
|
# gdb is unable to get the "f" argument of PyEval_EvalFrameEx()
|
|
# because it was "optimized out". Try to get "f" from the frame
|
|
# of the caller, PyEval_EvalCodeEx().
|
|
orig_frame = frame
|
|
caller = self._gdbframe.older()
|
|
if caller:
|
|
f = caller.read_var('f')
|
|
frame = PyFrameObjectPtr.from_pyobject_ptr(f)
|
|
if not frame.is_optimized_out():
|
|
return frame
|
|
return orig_frame
|
|
except ValueError:
|
|
return None
|
|
|
|
@classmethod
|
|
def get_selected_frame(cls):
|
|
_gdbframe = gdb.selected_frame()
|
|
if _gdbframe:
|
|
return Frame(_gdbframe)
|
|
return None
|
|
|
|
@classmethod
|
|
def get_selected_python_frame(cls):
|
|
'''Try to obtain the Frame for the python-related code in the selected
|
|
frame, or None'''
|
|
try:
|
|
frame = cls.get_selected_frame()
|
|
except gdb.error:
|
|
# No frame: Python didn't start yet
|
|
return None
|
|
|
|
while frame:
|
|
if frame.is_python_frame():
|
|
return frame
|
|
frame = frame.older()
|
|
|
|
# Not found:
|
|
return None
|
|
|
|
@classmethod
|
|
def get_selected_bytecode_frame(cls):
|
|
'''Try to obtain the Frame for the python bytecode interpreter in the
|
|
selected GDB frame, or None'''
|
|
frame = cls.get_selected_frame()
|
|
|
|
while frame:
|
|
if frame.is_evalframe():
|
|
return frame
|
|
frame = frame.older()
|
|
|
|
# Not found:
|
|
return None
|
|
|
|
def print_summary(self):
|
|
if self.is_evalframe():
|
|
pyop = self.get_pyop()
|
|
if pyop:
|
|
line = pyop.get_truncated_repr(MAX_OUTPUT_LEN)
|
|
write_unicode(sys.stdout, '#%i %s\n' % (self.get_index(), line))
|
|
if not pyop.is_optimized_out():
|
|
line = pyop.current_line()
|
|
if line is not None:
|
|
sys.stdout.write(' %s\n' % line.strip())
|
|
else:
|
|
sys.stdout.write('#%i (unable to read python frame information)\n' % self.get_index())
|
|
else:
|
|
info = self.is_other_python_frame()
|
|
if info:
|
|
sys.stdout.write('#%i %s\n' % (self.get_index(), info))
|
|
else:
|
|
sys.stdout.write('#%i\n' % self.get_index())
|
|
|
|
def print_traceback(self):
|
|
if self.is_evalframe():
|
|
pyop = self.get_pyop()
|
|
if pyop:
|
|
pyop.print_traceback()
|
|
if not pyop.is_optimized_out():
|
|
line = pyop.current_line()
|
|
if line is not None:
|
|
sys.stdout.write(' %s\n' % line.strip())
|
|
else:
|
|
sys.stdout.write(' (unable to read python frame information)\n')
|
|
else:
|
|
info = self.is_other_python_frame()
|
|
if info:
|
|
sys.stdout.write(' %s\n' % info)
|
|
else:
|
|
sys.stdout.write(' (not a python frame)\n')
|
|
|
|
class PyList(gdb.Command):
|
|
'''List the current Python source code, if any
|
|
|
|
Use
|
|
py-list START
|
|
to list at a different line number within the python source.
|
|
|
|
Use
|
|
py-list START, END
|
|
to list a specific range of lines within the python source.
|
|
'''
|
|
|
|
def __init__(self):
|
|
gdb.Command.__init__ (self,
|
|
"py-list",
|
|
gdb.COMMAND_FILES,
|
|
gdb.COMPLETE_NONE)
|
|
|
|
|
|
def invoke(self, args, from_tty):
|
|
import re
|
|
|
|
start = None
|
|
end = None
|
|
|
|
m = re.match(r'\s*(\d+)\s*', args)
|
|
if m:
|
|
start = int(m.group(0))
|
|
end = start + 10
|
|
|
|
m = re.match(r'\s*(\d+)\s*,\s*(\d+)\s*', args)
|
|
if m:
|
|
start, end = map(int, m.groups())
|
|
|
|
# py-list requires an actual PyEval_EvalFrameEx frame:
|
|
frame = Frame.get_selected_bytecode_frame()
|
|
if not frame:
|
|
print('Unable to locate gdb frame for python bytecode interpreter')
|
|
return
|
|
|
|
pyop = frame.get_pyop()
|
|
if not pyop or pyop.is_optimized_out():
|
|
print('Unable to read information on python frame')
|
|
return
|
|
|
|
filename = pyop.filename()
|
|
lineno = pyop.current_line_num()
|
|
if lineno is None:
|
|
print('Unable to read python frame line number')
|
|
return
|
|
|
|
if start is None:
|
|
start = lineno - 5
|
|
end = lineno + 5
|
|
|
|
if start<1:
|
|
start = 1
|
|
|
|
try:
|
|
f = open(os_fsencode(filename), 'r')
|
|
except IOError as err:
|
|
sys.stdout.write('Unable to open %s: %s\n'
|
|
% (filename, err))
|
|
return
|
|
with f:
|
|
all_lines = f.readlines()
|
|
# start and end are 1-based, all_lines is 0-based;
|
|
# so [start-1:end] as a python slice gives us [start, end] as a
|
|
# closed interval
|
|
for i, line in enumerate(all_lines[start-1:end]):
|
|
linestr = str(i+start)
|
|
# Highlight current line:
|
|
if i + start == lineno:
|
|
linestr = '>' + linestr
|
|
sys.stdout.write('%4s %s' % (linestr, line))
|
|
|
|
|
|
# ...and register the command:
|
|
PyList()
|
|
|
|
def move_in_stack(move_up):
|
|
'''Move up or down the stack (for the py-up/py-down command)'''
|
|
frame = Frame.get_selected_python_frame()
|
|
if not frame:
|
|
print('Unable to locate python frame')
|
|
return
|
|
|
|
while frame:
|
|
if move_up:
|
|
iter_frame = frame.older()
|
|
else:
|
|
iter_frame = frame.newer()
|
|
|
|
if not iter_frame:
|
|
break
|
|
|
|
if iter_frame.is_python_frame():
|
|
# Result:
|
|
if iter_frame.select():
|
|
iter_frame.print_summary()
|
|
return
|
|
|
|
frame = iter_frame
|
|
|
|
if move_up:
|
|
print('Unable to find an older python frame')
|
|
else:
|
|
print('Unable to find a newer python frame')
|
|
|
|
class PyUp(gdb.Command):
|
|
'Select and print the python stack frame that called this one (if any)'
|
|
def __init__(self):
|
|
gdb.Command.__init__ (self,
|
|
"py-up",
|
|
gdb.COMMAND_STACK,
|
|
gdb.COMPLETE_NONE)
|
|
|
|
|
|
def invoke(self, args, from_tty):
|
|
move_in_stack(move_up=True)
|
|
|
|
class PyDown(gdb.Command):
|
|
'Select and print the python stack frame called by this one (if any)'
|
|
def __init__(self):
|
|
gdb.Command.__init__ (self,
|
|
"py-down",
|
|
gdb.COMMAND_STACK,
|
|
gdb.COMPLETE_NONE)
|
|
|
|
|
|
def invoke(self, args, from_tty):
|
|
move_in_stack(move_up=False)
|
|
|
|
# Not all builds of gdb have gdb.Frame.select
|
|
if hasattr(gdb.Frame, 'select'):
|
|
PyUp()
|
|
PyDown()
|
|
|
|
class PyBacktraceFull(gdb.Command):
|
|
'Display the current python frame and all the frames within its call stack (if any)'
|
|
def __init__(self):
|
|
gdb.Command.__init__ (self,
|
|
"py-bt-full",
|
|
gdb.COMMAND_STACK,
|
|
gdb.COMPLETE_NONE)
|
|
|
|
|
|
def invoke(self, args, from_tty):
|
|
frame = Frame.get_selected_python_frame()
|
|
if not frame:
|
|
print('Unable to locate python frame')
|
|
return
|
|
|
|
while frame:
|
|
if frame.is_python_frame():
|
|
frame.print_summary()
|
|
frame = frame.older()
|
|
|
|
PyBacktraceFull()
|
|
|
|
class PyBacktrace(gdb.Command):
|
|
'Display the current python frame and all the frames within its call stack (if any)'
|
|
def __init__(self):
|
|
gdb.Command.__init__ (self,
|
|
"py-bt",
|
|
gdb.COMMAND_STACK,
|
|
gdb.COMPLETE_NONE)
|
|
|
|
|
|
def invoke(self, args, from_tty):
|
|
frame = Frame.get_selected_python_frame()
|
|
if not frame:
|
|
print('Unable to locate python frame')
|
|
return
|
|
|
|
sys.stdout.write('Traceback (most recent call first):\n')
|
|
while frame:
|
|
if frame.is_python_frame():
|
|
frame.print_traceback()
|
|
frame = frame.older()
|
|
|
|
PyBacktrace()
|
|
|
|
class PyPrint(gdb.Command):
|
|
'Look up the given python variable name, and print it'
|
|
def __init__(self):
|
|
gdb.Command.__init__ (self,
|
|
"py-print",
|
|
gdb.COMMAND_DATA,
|
|
gdb.COMPLETE_NONE)
|
|
|
|
|
|
def invoke(self, args, from_tty):
|
|
name = str(args)
|
|
|
|
frame = Frame.get_selected_python_frame()
|
|
if not frame:
|
|
print('Unable to locate python frame')
|
|
return
|
|
|
|
pyop_frame = frame.get_pyop()
|
|
if not pyop_frame:
|
|
print('Unable to read information on python frame')
|
|
return
|
|
|
|
pyop_var, scope = pyop_frame.get_var_by_name(name)
|
|
|
|
if pyop_var:
|
|
print('%s %r = %s'
|
|
% (scope,
|
|
name,
|
|
pyop_var.get_truncated_repr(MAX_OUTPUT_LEN)))
|
|
else:
|
|
print('%r not found' % name)
|
|
|
|
PyPrint()
|
|
|
|
class PyLocals(gdb.Command):
|
|
'Look up the given python variable name, and print it'
|
|
def __init__(self):
|
|
gdb.Command.__init__ (self,
|
|
"py-locals",
|
|
gdb.COMMAND_DATA,
|
|
gdb.COMPLETE_NONE)
|
|
|
|
|
|
def invoke(self, args, from_tty):
|
|
name = str(args)
|
|
|
|
frame = Frame.get_selected_python_frame()
|
|
if not frame:
|
|
print('Unable to locate python frame')
|
|
return
|
|
|
|
pyop_frame = frame.get_pyop()
|
|
if not pyop_frame:
|
|
print('Unable to read information on python frame')
|
|
return
|
|
|
|
for pyop_name, pyop_value in pyop_frame.iter_locals():
|
|
print('%s = %s'
|
|
% (pyop_name.proxyval(set()),
|
|
pyop_value.get_truncated_repr(MAX_OUTPUT_LEN)))
|
|
|
|
PyLocals()
|