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Author vstinner
Recipients python-dev, serhiy.storchaka, vstinner
Date 2016-12-04.23:11:18
SpamBayes Score -1.0
Marked as misclassified Yes
Message-id <>
When I wrote the _PyObject_CallArg1(), it looks as a cool hack:

#define _PyObject_CallArg1(func, arg) \
    _PyObject_FastCall((func), (PyObject **)&(arg), 1)

It hacks the declaration of an explicit "stack" like:

   PyObject *stack[1];
   stack[0] = arg;
   res = _PyObject_FastCall(func, stack, 1);

And I expected that the C compiler magically computes the memory address of the argument. But it seems like requesting the memory address of an argument allocates something on the C stack.

On x86_64, first function arguments are passed with CPU registers. Maybe requesting the memory address of an argument requires to allocate a local variable, copy the register into the variable, to get the address of the local variable?

So, I suggest to *remove* the _PyObject_CallArg1() macro, and use existing functions like PyObject_CallFunctionObjArgs().

What do you think Serhiy?
Date User Action Args
2016-12-04 23:11:19vstinnersetrecipients: + vstinner, python-dev, serhiy.storchaka
2016-12-04 23:11:19vstinnersetmessageid: <>
2016-12-04 23:11:19vstinnerlinkissue28858 messages
2016-12-04 23:11:18vstinnercreate