The reallocation trigger for unpacking star args with unknown length
did not take into account the number of fixed args remaining. So it was
possible that the unpacked iterators could take up exactly the memory
allocated then nothing would be left for fixed args after the star args.
This causes a segfault crash.
This is fixed by taking into account the remaining number of fixed args
in the check to decide whether to realloc yet or not.
Signed-off-by: David Lechner <david@pybricks.com>
This fixes code coverage for the case where a *arg without __len__ is
unpacked and uses exactly the amount of memory that was allocated for
kw args. This triggers the code branch where the memory for the kw args
gets reallocated since it was used already by the *arg unpacking.
Signed-off-by: David Lechner <david@pybricks.com>
This is a partial implementation of PEP 448 to allow unpacking multiple
star args in a function or method call.
This is implemented by changing the emitted bytecodes so that both
positional args and star args are stored as positional args. A bitmap is
added to indicate if an argument at a given position is a positional
argument or a star arg.
In the generated code, this new bitmap takes the place of the old star arg.
It is stored as a small int, so this means only the first N arguments can
be star args where N is the number of bits in a small int.
The runtime is modified to interpret this new bytecode format while still
trying to perform as few memory reallocations as possible.
Signed-off-by: David Lechner <david@pybricks.com>
