gh-133157: remove usage of _Py_NO_SANITIZE_UNDEFINED in pyexpat
#134050
Conversation
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
This comment was marked as resolved.
This comment was marked as resolved.
This comment was marked as resolved.
This comment was marked as resolved.
|
Hum, looks like it worked. But I don't know why the pointer alternative didn't work (in clang it does?). I guess it's because of some optimization and it got eliminated (or maybe what I did was also a UB c:) |
bateller
approved these changes
May 15, 2025
picnixz
commented
May 20, 2025
|
@encukou Could you have a look at this one please? I don't have a better alternative than using hacky unions (though it's a recommended construction as per ISO C11) |
picnixz
force-pushed
the
fix/ubsan/expat-133157
branch
from
aac33de to
a4cf579
Compare
encukou
added a commit
to encukou/cpython
that referenced
this pull request
Jun 10, 2025
|
I think this could be simpler, see #135346. But I might be missing something. |
|
Closing in favor of #135346 |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 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Outdated suggestions cannot be applied.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.
IIUC ISO C11, we can use "union casts" (which are actually compound literals, and thus constructors) to pass use unions. The idea is to consider each different function pointer as a union of possible function pointers and store them as such. In some sense, we're doing singledispatch with known registered types.