Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

[3.10] gh-85267: Improvements to inspect.signature __text_signature__ handling (GH-98796) #100393

Merged
merged 1 commit into from
Dec 21, 2022

Conversation

hauntsaninja
Copy link
Contributor

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 GH-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 GH-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 GH-85267), I add constant folding of a couple binary operations to RewriteSymbolics.

(There's some discussion of making signature expression evaluation arbitrary powerful in GH-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 GH-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..
(cherry picked from commit 79311cb)

Co-authored-by: Shantanu 12621235+hauntsaninja@users.noreply.github.com

…ture__ handling (pythonGH-98796)

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 pythonGH-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 pythonGH-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 pythonGH-85267), I
add constant folding of a couple binary operations to RewriteSymbolics.

(There's some discussion of making signature expression evaluation
arbitrary powerful in pythonGH-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 pythonGH-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`..
(cherry picked from commit 79311cb)

Co-authored-by: Shantanu <12621235+hauntsaninja@users.noreply.github.com>
@JelleZijlstra JelleZijlstra merged commit 919045c into python:3.10 Dec 21, 2022
@hauntsaninja hauntsaninja deleted the backport-79311cb-3.10 branch December 21, 2022 05:28
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

3 participants