bpo-36389: _PyObject_CheckConsistency() available in release mode (GH-16612)

bpo-36389, bpo-38376: The _PyObject_CheckConsistency() function is
now also available in release mode. For example, it can be used to
debug a crash in the visit_decref() function of the GC.

Modify the following functions to also work in release mode:

* _PyDict_CheckConsistency()
* _PyObject_CheckConsistency()
* _PyType_CheckConsistency()
* _PyUnicode_CheckConsistency()

Other changes:

* _PyMem_IsPtrFreed(ptr) now also returns 1 if ptr is NULL
  (equals to 0).
* _PyBytesWriter_CheckConsistency() now returns 1 and is only used
  with assert().
* Reorder _PyObject_Dump() to write safe fields first, and only
  attempt to render repr() at the end.
This commit is contained in:
Victor Stinner 2019-10-07 18:42:01 +02:00 committed by GitHub
parent 321def805a
commit 6876257eaa
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GPG key ID: 4AEE18F83AFDEB23
14 changed files with 155 additions and 140 deletions

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@ -155,8 +155,9 @@ PyAPI_FUNC(int) _PyMem_SetDefaultAllocator(
PyMemAllocatorEx *old_alloc);
/* Heuristic checking if a pointer value is newly allocated
(uninitialized) or newly freed. The pointer is not dereferenced, only the
pointer value is checked.
(uninitialized), newly freed or NULL (is equal to zero).
The pointer is not dereferenced, only the pointer value is checked.
The heuristic relies on the debug hooks on Python memory allocators which
fills newly allocated memory with CLEANBYTE (0xCD) and newly freed memory
@ -166,11 +167,13 @@ static inline int _PyMem_IsPtrFreed(void *ptr)
{
uintptr_t value = (uintptr_t)ptr;
#if SIZEOF_VOID_P == 8
return (value == (uintptr_t)0xCDCDCDCDCDCDCDCD
return (value == 0
|| value == (uintptr_t)0xCDCDCDCDCDCDCDCD
|| value == (uintptr_t)0xDDDDDDDDDDDDDDDD
|| value == (uintptr_t)0xFDFDFDFDFDFDFDFD);
#elif SIZEOF_VOID_P == 4
return (value == (uintptr_t)0xCDCDCDCD
return (value == 0
|| value == (uintptr_t)0xCDCDCDCD
|| value == (uintptr_t)0xDDDDDDDD
|| value == (uintptr_t)0xFDFDFDFD);
#else