[Python-checkins] bpo-36389: Add _PyObject_CheckConsistency() function (GH-12803)
Victor Stinner
webhook-mailer at python.org
Fri Apr 12 15:51:39 EDT 2019
https://github.com/python/cpython/commit/0fc91eef34a1d9194904fa093c9fbd711af0f26c
commit: 0fc91eef34a1d9194904fa093c9fbd711af0f26c
branch: master
author: Victor Stinner <vstinner at redhat.com>
committer: GitHub <noreply at github.com>
date: 2019-04-12T21:51:34+02:00
summary:
bpo-36389: Add _PyObject_CheckConsistency() function (GH-12803)
Add a new _PyObject_CheckConsistency() function which can be used to
help debugging. The function is available in release mode.
Add a 'check_content' parameter to _PyDict_CheckConsistency().
files:
M Include/cpython/object.h
M Include/internal/pycore_object.h
M Objects/dictobject.c
M Objects/object.c
M Objects/typeobject.c
M Objects/unicodeobject.c
diff --git a/Include/cpython/object.h b/Include/cpython/object.h
index 64d196a722ee..ba52a4835823 100644
--- a/Include/cpython/object.h
+++ b/Include/cpython/object.h
@@ -446,6 +446,21 @@ PyAPI_FUNC(void) _PyObject_AssertFailed(
int line,
const char *function);
+/* Check if an object is consistent. For example, ensure that the reference
+ counter is greater than or equal to 1, and ensure that ob_type is not NULL.
+
+ Call _PyObject_AssertFailed() if the object is inconsistent.
+
+ If check_content is zero, only check header fields: reduce the overhead.
+
+ The function always return 1. The return value is just here to be able to
+ write:
+
+ assert(_PyObject_CheckConsistency(obj, 1)); */
+PyAPI_FUNC(int) _PyObject_CheckConsistency(
+ PyObject *op,
+ int check_content);
+
#ifdef __cplusplus
}
#endif
diff --git a/Include/internal/pycore_object.h b/Include/internal/pycore_object.h
index a88b626332f1..c95595358a9e 100644
--- a/Include/internal/pycore_object.h
+++ b/Include/internal/pycore_object.h
@@ -10,6 +10,10 @@ extern "C" {
#include "pycore_pystate.h" /* _PyRuntime */
+PyAPI_FUNC(int) _PyType_CheckConsistency(PyTypeObject *type);
+PyAPI_FUNC(int) _PyUnicode_CheckConsistency(PyObject *op, int check_content);
+PyAPI_FUNC(int) _PyDict_CheckConsistency(PyObject *mp, int check_content);
+
/* Tell the GC to track this object.
*
* NB: While the object is tracked by the collector, it must be safe to call the
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 9ff009f6aa4e..9b5c0a3be9ab 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -449,77 +449,77 @@ static PyObject *empty_values[1] = { NULL };
/* Uncomment to check the dict content in _PyDict_CheckConsistency() */
/* #define DEBUG_PYDICT */
+#ifdef DEBUG_PYDICT
+# define ASSERT_CONSISTENT(op) assert(_PyDict_CheckConsistency((PyObject *)(op), 1))
+#else
+# define ASSERT_CONSISTENT(op) assert(_PyDict_CheckConsistency((PyObject *)(op), 0))
+#endif
-#ifndef NDEBUG
-static int
-_PyDict_CheckConsistency(PyDictObject *mp)
+
+int
+_PyDict_CheckConsistency(PyObject *op, int check_content)
{
-#define ASSERT(expr) _PyObject_ASSERT((PyObject *)mp, (expr))
+ _PyObject_ASSERT(op, PyDict_Check(op));
+ PyDictObject *mp = (PyDictObject *)op;
PyDictKeysObject *keys = mp->ma_keys;
int splitted = _PyDict_HasSplitTable(mp);
Py_ssize_t usable = USABLE_FRACTION(keys->dk_size);
-#ifdef DEBUG_PYDICT
- PyDictKeyEntry *entries = DK_ENTRIES(keys);
- Py_ssize_t i;
-#endif
- ASSERT(0 <= mp->ma_used && mp->ma_used <= usable);
- ASSERT(IS_POWER_OF_2(keys->dk_size));
- ASSERT(0 <= keys->dk_usable
- && keys->dk_usable <= usable);
- ASSERT(0 <= keys->dk_nentries
- && keys->dk_nentries <= usable);
- ASSERT(keys->dk_usable + keys->dk_nentries <= usable);
+ _PyObject_ASSERT(op, 0 <= mp->ma_used && mp->ma_used <= usable);
+ _PyObject_ASSERT(op, IS_POWER_OF_2(keys->dk_size));
+ _PyObject_ASSERT(op, 0 <= keys->dk_usable && keys->dk_usable <= usable);
+ _PyObject_ASSERT(op, 0 <= keys->dk_nentries && keys->dk_nentries <= usable);
+ _PyObject_ASSERT(op, keys->dk_usable + keys->dk_nentries <= usable);
if (!splitted) {
/* combined table */
- ASSERT(keys->dk_refcnt == 1);
+ _PyObject_ASSERT(op, keys->dk_refcnt == 1);
}
-#ifdef DEBUG_PYDICT
- for (i=0; i < keys->dk_size; i++) {
- Py_ssize_t ix = dictkeys_get_index(keys, i);
- ASSERT(DKIX_DUMMY <= ix && ix <= usable);
- }
+ if (check_content) {
+ PyDictKeyEntry *entries = DK_ENTRIES(keys);
+ Py_ssize_t i;
+
+ for (i=0; i < keys->dk_size; i++) {
+ Py_ssize_t ix = dictkeys_get_index(keys, i);
+ _PyObject_ASSERT(op, DKIX_DUMMY <= ix && ix <= usable);
+ }
- for (i=0; i < usable; i++) {
- PyDictKeyEntry *entry = &entries[i];
- PyObject *key = entry->me_key;
+ for (i=0; i < usable; i++) {
+ PyDictKeyEntry *entry = &entries[i];
+ PyObject *key = entry->me_key;
- if (key != NULL) {
- if (PyUnicode_CheckExact(key)) {
- Py_hash_t hash = ((PyASCIIObject *)key)->hash;
- ASSERT(hash != -1);
- ASSERT(entry->me_hash == hash);
- }
- else {
- /* test_dict fails if PyObject_Hash() is called again */
- ASSERT(entry->me_hash != -1);
+ if (key != NULL) {
+ if (PyUnicode_CheckExact(key)) {
+ Py_hash_t hash = ((PyASCIIObject *)key)->hash;
+ _PyObject_ASSERT(op, hash != -1);
+ _PyObject_ASSERT(op, entry->me_hash == hash);
+ }
+ else {
+ /* test_dict fails if PyObject_Hash() is called again */
+ _PyObject_ASSERT(op, entry->me_hash != -1);
+ }
+ if (!splitted) {
+ _PyObject_ASSERT(op, entry->me_value != NULL);
+ }
}
- if (!splitted) {
- ASSERT(entry->me_value != NULL);
+
+ if (splitted) {
+ _PyObject_ASSERT(op, entry->me_value == NULL);
}
}
if (splitted) {
- ASSERT(entry->me_value == NULL);
+ /* splitted table */
+ for (i=0; i < mp->ma_used; i++) {
+ _PyObject_ASSERT(op, mp->ma_values[i] != NULL);
+ }
}
}
- if (splitted) {
- /* splitted table */
- for (i=0; i < mp->ma_used; i++) {
- ASSERT(mp->ma_values[i] != NULL);
- }
- }
-#endif
-
return 1;
-
-#undef ASSERT
}
-#endif
static PyDictKeysObject *new_keys_object(Py_ssize_t size)
@@ -614,7 +614,7 @@ new_dict(PyDictKeysObject *keys, PyObject **values)
mp->ma_values = values;
mp->ma_used = 0;
mp->ma_version_tag = DICT_NEXT_VERSION();
- assert(_PyDict_CheckConsistency(mp));
+ ASSERT_CONSISTENT(mp);
return (PyObject *)mp;
}
@@ -675,7 +675,7 @@ clone_combined_dict(PyDictObject *orig)
return NULL;
}
new->ma_used = orig->ma_used;
- assert(_PyDict_CheckConsistency(new));
+ ASSERT_CONSISTENT(new);
if (_PyObject_GC_IS_TRACKED(orig)) {
/* Maintain tracking. */
_PyObject_GC_TRACK(new);
@@ -1075,7 +1075,7 @@ insertdict(PyDictObject *mp, PyObject *key, Py_hash_t hash, PyObject *value)
mp->ma_keys->dk_usable--;
mp->ma_keys->dk_nentries++;
assert(mp->ma_keys->dk_usable >= 0);
- assert(_PyDict_CheckConsistency(mp));
+ ASSERT_CONSISTENT(mp);
return 0;
}
@@ -1094,7 +1094,7 @@ insertdict(PyDictObject *mp, PyObject *key, Py_hash_t hash, PyObject *value)
mp->ma_version_tag = DICT_NEXT_VERSION();
Py_XDECREF(old_value); /* which **CAN** re-enter (see issue #22653) */
- assert(_PyDict_CheckConsistency(mp));
+ ASSERT_CONSISTENT(mp);
Py_DECREF(key);
return 0;
@@ -1582,7 +1582,7 @@ delitem_common(PyDictObject *mp, Py_hash_t hash, Py_ssize_t ix,
Py_DECREF(old_key);
Py_DECREF(old_value);
- assert(_PyDict_CheckConsistency(mp));
+ ASSERT_CONSISTENT(mp);
return 0;
}
@@ -1722,7 +1722,7 @@ PyDict_Clear(PyObject *op)
assert(oldkeys->dk_refcnt == 1);
dictkeys_decref(oldkeys);
}
- assert(_PyDict_CheckConsistency(mp));
+ ASSERT_CONSISTENT(mp);
}
/* Internal version of PyDict_Next that returns a hash value in addition
@@ -1852,7 +1852,7 @@ _PyDict_Pop_KnownHash(PyObject *dict, PyObject *key, Py_hash_t hash, PyObject *d
ep->me_value = NULL;
Py_DECREF(old_key);
- assert(_PyDict_CheckConsistency(mp));
+ ASSERT_CONSISTENT(mp);
return old_value;
}
@@ -2434,7 +2434,7 @@ PyDict_MergeFromSeq2(PyObject *d, PyObject *seq2, int override)
}
i = 0;
- assert(_PyDict_CheckConsistency((PyDictObject *)d));
+ ASSERT_CONSISTENT(d);
goto Return;
Fail:
Py_XDECREF(item);
@@ -2586,7 +2586,7 @@ dict_merge(PyObject *a, PyObject *b, int override)
/* Iterator completed, via error */
return -1;
}
- assert(_PyDict_CheckConsistency((PyDictObject *)a));
+ ASSERT_CONSISTENT(a);
return 0;
}
@@ -2950,7 +2950,7 @@ PyDict_SetDefault(PyObject *d, PyObject *key, PyObject *defaultobj)
mp->ma_version_tag = DICT_NEXT_VERSION();
}
- assert(_PyDict_CheckConsistency(mp));
+ ASSERT_CONSISTENT(mp);
return value;
}
@@ -3069,7 +3069,7 @@ dict_popitem_impl(PyDictObject *self)
self->ma_keys->dk_nentries = i;
self->ma_used--;
self->ma_version_tag = DICT_NEXT_VERSION();
- assert(_PyDict_CheckConsistency(self));
+ ASSERT_CONSISTENT(self);
return res;
}
@@ -3275,7 +3275,7 @@ dict_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
Py_DECREF(self);
return NULL;
}
- assert(_PyDict_CheckConsistency(d));
+ ASSERT_CONSISTENT(d);
return self;
}
diff --git a/Objects/object.c b/Objects/object.c
index 3fad73c493db..e7ec7aec490f 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -2,6 +2,7 @@
/* Generic object operations; and implementation of None */
#include "Python.h"
+#include "pycore_object.h"
#include "pycore_pystate.h"
#include "pycore_context.h"
#include "frameobject.h"
@@ -19,6 +20,28 @@ _Py_IDENTIFIER(__bytes__);
_Py_IDENTIFIER(__dir__);
_Py_IDENTIFIER(__isabstractmethod__);
+
+int
+_PyObject_CheckConsistency(PyObject *op, int check_content)
+{
+ _PyObject_ASSERT(op, op != NULL);
+ _PyObject_ASSERT(op, !_PyObject_IsFreed(op));
+ _PyObject_ASSERT(op, Py_REFCNT(op) >= 1);
+
+ PyTypeObject *type = op->ob_type;
+ _PyObject_ASSERT(op, type != NULL);
+ _PyType_CheckConsistency(type);
+
+ if (PyUnicode_Check(op)) {
+ _PyUnicode_CheckConsistency(op, check_content);
+ }
+ else if (PyDict_Check(op)) {
+ _PyDict_CheckConsistency(op, check_content);
+ }
+ return 1;
+}
+
+
#ifdef Py_REF_DEBUG
Py_ssize_t _Py_RefTotal;
@@ -2136,7 +2159,13 @@ _PyObject_AssertFailed(PyObject *obj, const char *expr, const char *msg,
else if (_PyObject_IsFreed(obj)) {
/* It seems like the object memory has been freed:
don't access it to prevent a segmentation fault. */
- fprintf(stderr, "<Freed object>\n");
+ fprintf(stderr, "<object: freed>\n");
+ }
+ else if (Py_TYPE(obj) == NULL) {
+ fprintf(stderr, "<object: ob_type=NULL>\n");
+ }
+ else if (_PyObject_IsFreed((PyObject *)Py_TYPE(obj))) {
+ fprintf(stderr, "<object: freed type %p>\n", Py_TYPE(obj));
}
else {
/* Diplay the traceback where the object has been allocated.
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 4c3909c098c4..37df4d23e4c1 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -131,8 +131,7 @@ skip_signature(const char *doc)
return NULL;
}
-#ifndef NDEBUG
-static int
+int
_PyType_CheckConsistency(PyTypeObject *type)
{
#define ASSERT(expr) _PyObject_ASSERT((PyObject *)type, (expr))
@@ -142,14 +141,16 @@ _PyType_CheckConsistency(PyTypeObject *type)
return 1;
}
+ ASSERT(!_PyObject_IsFreed((PyObject *)type));
+ ASSERT(Py_REFCNT(type) >= 1);
+ ASSERT(PyType_Check(type));
+
ASSERT(!(type->tp_flags & Py_TPFLAGS_READYING));
- ASSERT(type->tp_mro != NULL && PyTuple_Check(type->tp_mro));
ASSERT(type->tp_dict != NULL);
- return 1;
+ return 1;
#undef ASSERT
}
-#endif
static const char *
_PyType_DocWithoutSignature(const char *name, const char *internal_doc)
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index e00dc37974f8..f6e68c94df55 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -401,23 +401,20 @@ PyUnicode_GetMax(void)
#endif
}
-#ifdef Py_DEBUG
int
_PyUnicode_CheckConsistency(PyObject *op, int check_content)
{
-#define ASSERT(expr) _PyObject_ASSERT(op, (expr))
-
PyASCIIObject *ascii;
unsigned int kind;
- ASSERT(PyUnicode_Check(op));
+ _PyObject_ASSERT(op, PyUnicode_Check(op));
ascii = (PyASCIIObject *)op;
kind = ascii->state.kind;
if (ascii->state.ascii == 1 && ascii->state.compact == 1) {
- ASSERT(kind == PyUnicode_1BYTE_KIND);
- ASSERT(ascii->state.ready == 1);
+ _PyObject_ASSERT(op, kind == PyUnicode_1BYTE_KIND);
+ _PyObject_ASSERT(op, ascii->state.ready == 1);
}
else {
PyCompactUnicodeObject *compact = (PyCompactUnicodeObject *)op;
@@ -425,41 +422,41 @@ _PyUnicode_CheckConsistency(PyObject *op, int check_content)
if (ascii->state.compact == 1) {
data = compact + 1;
- ASSERT(kind == PyUnicode_1BYTE_KIND
- || kind == PyUnicode_2BYTE_KIND
- || kind == PyUnicode_4BYTE_KIND);
- ASSERT(ascii->state.ascii == 0);
- ASSERT(ascii->state.ready == 1);
- ASSERT (compact->utf8 != data);
+ _PyObject_ASSERT(op, kind == PyUnicode_1BYTE_KIND
+ || kind == PyUnicode_2BYTE_KIND
+ || kind == PyUnicode_4BYTE_KIND);
+ _PyObject_ASSERT(op, ascii->state.ascii == 0);
+ _PyObject_ASSERT(op, ascii->state.ready == 1);
+ _PyObject_ASSERT(op, compact->utf8 != data);
}
else {
PyUnicodeObject *unicode = (PyUnicodeObject *)op;
data = unicode->data.any;
if (kind == PyUnicode_WCHAR_KIND) {
- ASSERT(ascii->length == 0);
- ASSERT(ascii->hash == -1);
- ASSERT(ascii->state.compact == 0);
- ASSERT(ascii->state.ascii == 0);
- ASSERT(ascii->state.ready == 0);
- ASSERT(ascii->state.interned == SSTATE_NOT_INTERNED);
- ASSERT(ascii->wstr != NULL);
- ASSERT(data == NULL);
- ASSERT(compact->utf8 == NULL);
+ _PyObject_ASSERT(op, ascii->length == 0);
+ _PyObject_ASSERT(op, ascii->hash == -1);
+ _PyObject_ASSERT(op, ascii->state.compact == 0);
+ _PyObject_ASSERT(op, ascii->state.ascii == 0);
+ _PyObject_ASSERT(op, ascii->state.ready == 0);
+ _PyObject_ASSERT(op, ascii->state.interned == SSTATE_NOT_INTERNED);
+ _PyObject_ASSERT(op, ascii->wstr != NULL);
+ _PyObject_ASSERT(op, data == NULL);
+ _PyObject_ASSERT(op, compact->utf8 == NULL);
}
else {
- ASSERT(kind == PyUnicode_1BYTE_KIND
- || kind == PyUnicode_2BYTE_KIND
- || kind == PyUnicode_4BYTE_KIND);
- ASSERT(ascii->state.compact == 0);
- ASSERT(ascii->state.ready == 1);
- ASSERT(data != NULL);
+ _PyObject_ASSERT(op, kind == PyUnicode_1BYTE_KIND
+ || kind == PyUnicode_2BYTE_KIND
+ || kind == PyUnicode_4BYTE_KIND);
+ _PyObject_ASSERT(op, ascii->state.compact == 0);
+ _PyObject_ASSERT(op, ascii->state.ready == 1);
+ _PyObject_ASSERT(op, data != NULL);
if (ascii->state.ascii) {
- ASSERT (compact->utf8 == data);
- ASSERT (compact->utf8_length == ascii->length);
+ _PyObject_ASSERT(op, compact->utf8 == data);
+ _PyObject_ASSERT(op, compact->utf8_length == ascii->length);
}
else
- ASSERT (compact->utf8 != data);
+ _PyObject_ASSERT(op, compact->utf8 != data);
}
}
if (kind != PyUnicode_WCHAR_KIND) {
@@ -471,20 +468,20 @@ _PyUnicode_CheckConsistency(PyObject *op, int check_content)
#endif
)
{
- ASSERT(ascii->wstr == data);
- ASSERT(compact->wstr_length == ascii->length);
+ _PyObject_ASSERT(op, ascii->wstr == data);
+ _PyObject_ASSERT(op, compact->wstr_length == ascii->length);
} else
- ASSERT(ascii->wstr != data);
+ _PyObject_ASSERT(op, ascii->wstr != data);
}
if (compact->utf8 == NULL)
- ASSERT(compact->utf8_length == 0);
+ _PyObject_ASSERT(op, compact->utf8_length == 0);
if (ascii->wstr == NULL)
- ASSERT(compact->wstr_length == 0);
+ _PyObject_ASSERT(op, compact->wstr_length == 0);
}
- /* check that the best kind is used */
- if (check_content && kind != PyUnicode_WCHAR_KIND)
- {
+
+ /* check that the best kind is used: O(n) operation */
+ if (check_content && kind != PyUnicode_WCHAR_KIND) {
Py_ssize_t i;
Py_UCS4 maxchar = 0;
void *data;
@@ -499,27 +496,25 @@ _PyUnicode_CheckConsistency(PyObject *op, int check_content)
}
if (kind == PyUnicode_1BYTE_KIND) {
if (ascii->state.ascii == 0) {
- ASSERT(maxchar >= 128);
- ASSERT(maxchar <= 255);
+ _PyObject_ASSERT(op, maxchar >= 128);
+ _PyObject_ASSERT(op, maxchar <= 255);
}
else
- ASSERT(maxchar < 128);
+ _PyObject_ASSERT(op, maxchar < 128);
}
else if (kind == PyUnicode_2BYTE_KIND) {
- ASSERT(maxchar >= 0x100);
- ASSERT(maxchar <= 0xFFFF);
+ _PyObject_ASSERT(op, maxchar >= 0x100);
+ _PyObject_ASSERT(op, maxchar <= 0xFFFF);
}
else {
- ASSERT(maxchar >= 0x10000);
- ASSERT(maxchar <= MAX_UNICODE);
+ _PyObject_ASSERT(op, maxchar >= 0x10000);
+ _PyObject_ASSERT(op, maxchar <= MAX_UNICODE);
}
- ASSERT(PyUnicode_READ(kind, data, ascii->length) == 0);
+ _PyObject_ASSERT(op, PyUnicode_READ(kind, data, ascii->length) == 0);
}
return 1;
-
-#undef ASSERT
}
-#endif
+
static PyObject*
unicode_result_wchar(PyObject *unicode)
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