gh-132026: Ensure _MIPS_SIM has defined _ABI identifiers for comparison #132027
+14
−12
Conversation
This file contains 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
|
All commit authors signed the Contributor License Agreement. |
|
Most changes to Python require a NEWS entry. Add one using the blurb_it web app or the blurb command-line tool. If this change has little impact on Python users, wait for a maintainer to apply the |
|
Heads up: On Python 3.13 and older, this logic is not yet moved to |
|
All commit authors signed the Contributor License Agreement. |
sigv
force-pushed
the
gh-132026
branch
3 times, most recently
from
f37099c to
da82bea
Compare
…mparison When built on a MIPS architecture, `_MIPS_SIM` is used to determine architecture specifics. The value is expected to match either `_ABIO32`, `_ABIN32` or `_ABI64`. In `gcc` config/mips/mips.h these values are defined as compiler `builtin_define` inside of a switch/case. That means, mips64el and mips64 architectures know about `_ABI64` but don't know about `_ABIO32` and `_ABIN32`. In turn, when CPython tries to use them in comparison, they may be undefined identifiers. In default compiler behavior, the undefined identifier will be evaluated as zero, and it will not match `_MIPS_SIM`. However, the issues pop up when `-Wundef` (or, even worse, `-Werror=undef`) compiler flag is enabled. Then suddenly it's visible as a warning or error.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
When building C code on a MIPS architecture,
_MIPS_SIMis used to determine architecture specifics. The value is expected to match either_ABIO32,_ABIN32or_ABI64.In
gccconfig/mips/mips.h these values are defined as compilerbuiltin_defineinside of a switch/case. That means, mips64el and mips64 architectures know about_ABI64but don't know about_ABIO32and_ABIN32. In turn, when CPython tries to use them in comparison, they may be undefined identifiers.In default compiler behavior, the undefined identifier will be evaluated as zero, and it will not match
_MIPS_SIM. However, the issues pop up when-Wundef(or, even worse,-Werror=undef) compiler flag is enabled. Then suddenly it's visible as a warning or error.