aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/tools/cython/Cython/Runtime/refnanny.pyx
blob: d4b873fe97affa3c2776750b2ad49371984f7ccf (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
# cython: language_level=3, auto_pickle=False

from cpython.ref cimport PyObject, Py_INCREF, Py_DECREF, Py_XDECREF, Py_XINCREF
from cpython.exc cimport PyErr_Fetch, PyErr_Restore
from cpython.pystate cimport PyThreadState_Get

cimport cython

loglevel = 0
reflog = []

cdef log(level, action, obj, lineno):
    if loglevel >= level:
        reflog.append((lineno, action, id(obj)))

LOG_NONE, LOG_ALL = range(2)

@cython.final
cdef class Context(object):
    cdef readonly object name, filename
    cdef readonly dict refs
    cdef readonly list errors
    cdef readonly Py_ssize_t start

    def __cinit__(self, name, line=0, filename=None):
        self.name = name
        self.start = line
        self.filename = filename
        self.refs = {} # id -> (count, [lineno])
        self.errors = []

    cdef regref(self, obj, lineno, bint is_null):
        log(LOG_ALL, u'regref', u"<NULL>" if is_null else obj, lineno)
        if is_null:
            self.errors.append(f"NULL argument on line {lineno}")
            return
        id_ = id(obj)
        count, linenumbers = self.refs.get(id_, (0, []))
        self.refs[id_] = (count + 1, linenumbers)
        linenumbers.append(lineno)

    cdef bint delref(self, obj, lineno, bint is_null) except -1:
        # returns whether it is ok to do the decref operation
        log(LOG_ALL, u'delref', u"<NULL>" if is_null else obj, lineno)
        if is_null:
            self.errors.append(f"NULL argument on line {lineno}")
            return False
        id_ = id(obj)
        count, linenumbers = self.refs.get(id_, (0, []))
        if count == 0:
            self.errors.append(f"Too many decrefs on line {lineno}, reference acquired on lines {linenumbers!r}")
            return False
        elif count == 1:
            del self.refs[id_]
            return True
        else:
            self.refs[id_] = (count - 1, linenumbers)
            return True

    cdef end(self):
        if self.refs:
            msg = u"References leaked:"
            for count, linenos in self.refs.itervalues():
                msg += f"\n  ({count}) acquired on lines: {u', '.join([f'{x}' for x in linenos])}"
            self.errors.append(msg)
        if self.errors:
            return u"\n".join([u'REFNANNY: '+error for error in self.errors])
        else:
            return None

cdef void report_unraisable(object e=None):
    try:
        if e is None:
            import sys
            e = sys.exc_info()[1]
        print(f"refnanny raised an exception: {e}")
    except:
        pass # We absolutely cannot exit with an exception

# All Python operations must happen after any existing
# exception has been fetched, in case we are called from
# exception-handling code.

cdef PyObject* SetupContext(char* funcname, int lineno, char* filename) except NULL:
    if Context is None:
        # Context may be None during finalize phase.
        # In that case, we don't want to be doing anything fancy
        # like caching and resetting exceptions.
        return NULL
    cdef (PyObject*) type = NULL, value = NULL, tb = NULL, result = NULL
    PyThreadState_Get()
    PyErr_Fetch(&type, &value, &tb)
    try:
        ctx = Context(funcname, lineno, filename)
        Py_INCREF(ctx)
        result = <PyObject*>ctx
    except Exception, e:
        report_unraisable(e)
    PyErr_Restore(type, value, tb)
    return result

cdef void GOTREF(PyObject* ctx, PyObject* p_obj, int lineno):
    if ctx == NULL: return
    cdef (PyObject*) type = NULL, value = NULL, tb = NULL
    PyErr_Fetch(&type, &value, &tb)
    try:
        try:
            if p_obj is NULL:
                (<Context>ctx).regref(None, lineno, True)
            else:
                (<Context>ctx).regref(<object>p_obj, lineno, False)
        except:
            report_unraisable()
    except:
        # __Pyx_GetException may itself raise errors
        pass
    PyErr_Restore(type, value, tb)

cdef int GIVEREF_and_report(PyObject* ctx, PyObject* p_obj, int lineno):
    if ctx == NULL: return 1
    cdef (PyObject*) type = NULL, value = NULL, tb = NULL
    cdef bint decref_ok = False
    PyErr_Fetch(&type, &value, &tb)
    try:
        try:
            if p_obj is NULL:
                decref_ok = (<Context>ctx).delref(None, lineno, True)
            else:
                decref_ok = (<Context>ctx).delref(<object>p_obj, lineno, False)
        except:
            report_unraisable()
    except:
        # __Pyx_GetException may itself raise errors
        pass
    PyErr_Restore(type, value, tb)
    return decref_ok

cdef void GIVEREF(PyObject* ctx, PyObject* p_obj, int lineno):
    GIVEREF_and_report(ctx, p_obj, lineno)

cdef void INCREF(PyObject* ctx, PyObject* obj, int lineno):
    Py_XINCREF(obj)
    PyThreadState_Get()
    GOTREF(ctx, obj, lineno)

cdef void DECREF(PyObject* ctx, PyObject* obj, int lineno):
    if GIVEREF_and_report(ctx, obj, lineno):
        Py_XDECREF(obj)
    PyThreadState_Get()

cdef void FinishContext(PyObject** ctx):
    if ctx == NULL or ctx[0] == NULL: return
    cdef (PyObject*) type = NULL, value = NULL, tb = NULL
    cdef object errors = None
    cdef Context context
    PyThreadState_Get()
    PyErr_Fetch(&type, &value, &tb)
    try:
        try:
            context = <Context>ctx[0]
            errors = context.end()
            if errors:
                print(f"{context.filename.decode('latin1')}: {context.name.decode('latin1')}()")
                print(errors)
            context = None
        except:
            report_unraisable()
    except:
        # __Pyx_GetException may itself raise errors
        pass
    Py_XDECREF(ctx[0])
    ctx[0] = NULL
    PyErr_Restore(type, value, tb)

ctypedef struct RefNannyAPIStruct:
  void (*INCREF)(PyObject*, PyObject*, int)
  void (*DECREF)(PyObject*, PyObject*, int)
  void (*GOTREF)(PyObject*, PyObject*, int)
  void (*GIVEREF)(PyObject*, PyObject*, int)
  PyObject* (*SetupContext)(char*, int, char*) except NULL
  void (*FinishContext)(PyObject**)

cdef RefNannyAPIStruct api
api.INCREF = INCREF
api.DECREF =  DECREF
api.GOTREF =  GOTREF
api.GIVEREF = GIVEREF
api.SetupContext = SetupContext
api.FinishContext = FinishContext

cdef extern from "Python.h":
    object PyLong_FromVoidPtr(void*)

RefNannyAPI = PyLong_FromVoidPtr(<void*>&api)