Skip to content

Avoid false unreachable and redundant-expr warnings in loops. #18433

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.

Sign up for GitHub

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

Merged
hauntsaninja merged 3 commits into from
Jan 12, 2025
Merged

Avoid false unreachable and redundant-expr warnings in loops. #18433

Changes from 1 commit
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
53d894a
Avoid false `unreachable` and `redundant-expr` warnings in loops.
tyralla Jan 9, 2025
9b54ab1
Do not enable `REDUNDANT_EXPR` accidentally.
tyralla Jan 10, 2025
f0fac6d
refactor
tyralla Jan 12, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Prev Previous commit
refactor
  • Loading branch information
@tyralla
tyralla committed Jan 12, 2025
commit f0fac6dbb805217218e546a632c7b661155df0ce
12 changes: 5 additions & 7 deletions mypy/checker.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -595,11 +595,9 @@ def accept_loop(

# Disable error types that we cannot safely identify in intermediate iteration steps:
warn_unreachable = self.options.warn_unreachable
if warn_unreachable:
self.options.warn_unreachable = False
warn_redundant = codes.REDUNDANT_EXPR in self.options.enabled_error_codes
if warn_redundant:
self.options.enabled_error_codes.remove(codes.REDUNDANT_EXPR)
self.options.warn_unreachable = False
self.options.enabled_error_codes.discard(codes.REDUNDANT_EXPR)

while True:
with self.binder.frame_context(can_skip=True, break_frame=2, continue_frame=1):
Expand All @@ -610,10 +608,10 @@ def accept_loop(
partials_old = partials_new

# If necessary, reset the modified options and make up for the postponed error checks:
self.options.warn_unreachable = warn_unreachable
if warn_redundant:
self.options.enabled_error_codes.add(codes.REDUNDANT_EXPR)
if warn_unreachable or warn_redundant:
Copy link
Copy Markdown
Member

@ilevkivskyi ilevkivskyi Jan 11, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

IMO this if and the two ifs above are only making the logic more obscure. It should be simply: store, set, restore.

Copy link
Copy Markdown
Collaborator Author

@tyralla tyralla Jan 12, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I removed the two ifs above (one of them by using set.discard instead of set.remove). However, removing the third if would mean unnecessary calls of self.accept(body) in cases where neither unreachable nor redundant-expr are enabled. But I adjusted the latter according to @hauntsaninja's suggestion, which might look a little clearer.

self.options.warn_unreachable = warn_unreachable
if warn_redundant:
self.options.enabled_error_codes.add(codes.REDUNDANT_EXPR)
with self.binder.frame_context(can_skip=True, break_frame=2, continue_frame=1):
self.accept(body)

Expand Down