This makes a couple related changes to inspect.signature's behaviour
when parsing a signature from `__text_signature__`.
First, `inspect.signature` is documented as only raising ValueError or
TypeError. However, in some cases, we could raise RuntimeError. This PR
changes that, thereby fixing #83685.
(Note that the new ValueErrors in RewriteSymbolics are caught and then
reraised with a message)
Second, `inspect.signature` could randomly drop parameters that it
didn't understand (corresponding to `return None` in the `p` function).
This is the core issue in #85267. I think this is very surprising
behaviour and it seems better to fail outright.
Third, adding this new failure broke a couple tests. To fix them (and to
e.g. allow `inspect.signature(select.epoll.register)` as in #85267), I
add constant folding of a couple binary operations to RewriteSymbolics.
(There's some discussion of making signature expression evaluation
arbitrary powerful in #68155. I think that's out of scope. The
additional constant folding here is pretty straightforward, useful, and
not much of a slippery slope)
Fourth, while #85267 is incorrect about the cause of the issue, it turns
out if you had consecutive newlines in __text_signature__, you'd get
`tokenize.TokenError`.
Finally, the `if name is invalid:` code path was dead, since
`parse_name` never returned `invalid`.
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Christian Heimes <christian@python.org>
Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com>
Fixes https://github.com/python/cpython/issues/89051
This introduces a new decorator `@inspect.markcoroutinefunction`,
which, applied to a sync function, makes it appear async to
`inspect.iscoroutinefunction()`.
The presence of this macro indicates that a particular instruction
may be considered for conversion to a register-based format
(see https://github.com/faster-cpython/ideas/issues/485).
An invariant (currently unchecked) is that `DEOPT_IF()` may only
occur *before* `DECREF_INPUTS()`, and `ERROR_IF()` may only occur
*after* it. One reason not to check this is that there are a few
places where we insert *two* `DECREF_INPUTS()` calls, in different
branches of the code. The invariant checking would have to be able
to do some flow control analysis to understand this.
Note that many instructions, especially specialized ones,
can't be converted to use this macro straightforwardly.
This is because the generator currently only generates plain
`Py_DECREF(variable)` statements, and cannot generate
things like `_Py_DECREF_SPECIALIZED()` let alone deal with
`_PyList_AppendTakeRef()`.
