bpo-40052: Fix alignment issue in PyVectorcall_Function() #19133
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I've added my github username to my account on bugs.python.org and signed the CA. However I think it might take some time till the system gets the update. |
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In file included from /usr/include/python3.8/Python.h:147:
In file included from /usr/include/python3.8/abstract.h:837:
/usr/include/python3.8/cpython/abstract.h:91:11: error: cast from 'char *' to 'vectorcallfunc *'
(aka 'struct _object *(**)(struct _object *, struct _object *const *, unsigned long, struct _object *)')
increases required alignment from 1 to 8 [-Werror,-Wcast-align]
ptr = (vectorcallfunc*)(((char *)callable) + offset);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
Signed-off-by: Andreas Schneider <[email protected]>
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| ptr = (vectorcallfunc *)(((char *)callable) + offset); | ||
| return *ptr; | ||
| vc.data = (char *)callable + offset; | ||
| return *vc.ptr; |
There was a problem hiding this comment.
I don't think this is better. The correct, idiomatic solution is something like:
vectorcallfunc *ptr;
memcpy(ptr, (char *) callable + offset, sizeof(ptr));
return *ptr;There was a problem hiding this comment.
(also, note that any decent compiler will optimize the memcpy call away)
| @@ -215,7 +219,8 @@ PyVectorcall_Call(PyObject *callable, PyObject *tuple, PyObject *kwargs) | |||
| Py_TYPE(callable)->tp_name); | |||
| return NULL; | |||
| } | |||
| vectorcallfunc func = *(vectorcallfunc *)(((char *)callable) + offset); | |||
| vc.data = (char *)callable + offset; | |||
| vectorcallfunc func = *vc.ptr; | |||
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A Python core developer has requested some changes be made to your pull request before we can consider merging it. If you could please address their requests along with any other requests in other reviews from core developers that would be appreciated. Once you have made the requested changes, please leave a comment on this pull request containing the phrase And if you don't make the requested changes, you will be poked with soft cushions! |
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In my experience, memcpy() is good solution for such problem. |
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I've made a PR with the suggested |
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Closing in favour of #23999. |
https://bugs.python.org/issue40052