gh-148390: fix undefined behavior of memoryview(...).cast("?")#148454
Open
picnixz wants to merge 2 commits intopython:mainfrom
Open
gh-148390: fix undefined behavior of memoryview(...).cast("?")#148454picnixz wants to merge 2 commits intopython:mainfrom
memoryview(...).cast("?")#148454picnixz wants to merge 2 commits intopython:mainfrom
Conversation
picnixz
requested review from
encukou,
serhiy-storchaka,
skirpichev and
vstinner
Member
StanFromIreland
left a comment
StanFromIreland
left a comment
There was a problem hiding this comment.
If the UB is fixed, please remove it from the suppressions list:
cpython/Tools/ubsan/suppressions.txt
Lines 12 to 13 in 3ab94d6
skirpichev
approved these changes
Apr 13, 2026
Member
skirpichev
left a comment
skirpichev
left a comment
There was a problem hiding this comment.
Looks good.
Though, maybe move macro closer to unpack_single() definition?
Member
Author
The problem is that it's being used in two places so... I preferred moving it where we had "helpers". |
| } | ||
|
|
||
| // Return 0 if PTR represents "false", and 1 otherwise. | ||
| #define UNPACK_TO_BOOL(PTR) (memcmp((PTR), &(_Bool){0}, sizeof(_Bool)) != 0) |
Member
There was a problem hiding this comment.
What version of C supports &(_Bool){0}? It was not supported prior to C99, but does C99 support this?
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
4 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
memoryview.cast("?")has undocumented undefined behavior #148390