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Description
In #121863 (comment), Mark suspected something is off in const interning for code objects. Indeed, there is. For example:
# a bit of setup
import sys
interned = sys.intern("foobar")
def f():
var = "foobar"
# my_tuple = (None, 'foobar'), but with an un-interned string
my_tuple = (None, str(b'foobar', 'ascii'))
print(id(my_tuple), id(my_tuple[1]))
# pass my_tuple as an input argument for a new code object
f.__code__.replace(co_consts=my_tuple)
# there's now a different object in the tuple!
print(id(my_tuple), id(my_tuple[1]))
I'm working on a change to:
- create new tuples instead of mutating old ones
- intern more strings before passing them to
PyCode
constructors, so that we usually don't need to create new tuples