Skip to content

_MIPS_SIM comparison may contain undefined identifiers for _ABI #132026

Closed
Closed
_MIPS_SIM comparison may contain undefined identifiers for _ABI#132026
Labels
OS-unsupportedbuildThe build process and cross-buildtype-bugAn unexpected behavior, bug, or error

Description

@sigv
sigv
opened on Apr 2, 2025

Bug report

Bug description:

#include <Python.h>

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:

In file included from /usr/include/python3.13/Python.h:14,
                 from example.c:1:
/usr/include/python3.13/pyconfig.h:59:20: error: "_ABIO32" is not defined, evaluates to 0 [-Werror=undef]
   59 | #  if _MIPS_SIM == _ABIO32
      |                    ^~~~~~~
/usr/include/python3.13/pyconfig.h:61:22: error: "_ABIN32" is not defined, evaluates to 0 [-Werror=undef]
   61 | #  elif _MIPS_SIM == _ABIN32
      |                      ^~~~~~~

CPython versions tested on:

3.13

Operating systems tested on:

Linux

Linked PRs

Activity

  1. sigv
    added
    type-bugAn unexpected behavior, bug, or error
    on Apr 2, 2025
  2. sigv
    added 2 commits that reference this issue on Apr 2, 2025

    pythongh-132026: Ensure _MIPS_SIM has defined _ABI identifiers for co…

    7492f2b

    pythongh-132026: Ensure _MIPS_SIM has defined _ABI identifiers for co…

    d76f84e
  3. tomasr8
    added
    buildThe build process and cross-build
    on Apr 4, 2025
  4. picnixz
    added
    interpreter-core(Objects, Python, Grammar, and Parser dirs)
    OS-unsupported
    and removed
    interpreter-core(Objects, Python, Grammar, and Parser dirs)
    on Apr 4, 2025
  5. github-project-automation
    added this to Unsupported platformson Apr 4, 2025
  6. sigv
    added 2 commits that reference this issue on Apr 6, 2025

    pythongh-132026: Ensure _MIPS_SIM has defined _ABI identifiers for co…

    5dea448

    pythongh-132026: Ensure _MIPS_SIM has defined _ABI identifiers for co…

    f37099c

  7. sigv commented on Apr 6, 2025

    @sigv
    sigv
    on Apr 6, 2025
    ContributorAuthor

    This should be added to Platform: MIPS on Unsupported platforms board.

  8. sigv
    added a commit that references this issue on Apr 6, 2025

    pythongh-132026: Ensure _MIPS_SIM has defined _ABI identifiers for co…

    da82bea
  9. sigv
    added a commit that references this issue on Apr 14, 2025

    pythongh-132026: Ensure _MIPS_SIM has defined _ABI identifiers for co…

    af87dfe
  10. zware
    added a commit that references this issue on Apr 27, 2025

    gh-132026: Ensure _MIPS_SIM has defined _ABI identifiers for comparis…

    6985e2e
  11. miss-islington
    added a commit that references this issue on Apr 28, 2025

    pythongh-132026: Ensure _MIPS_SIM has defined _ABI identifiers for co…

    7735662
  12. zware
    added a commit that references this issue on Apr 28, 2025

    [3.13] gh-132026: Ensure _MIPS_SIM has defined _ABI identifiers for c…

    507b4fa

  13. zware commented on Apr 28, 2025

    @zware
    zware
    on Apr 28, 2025
    Member

    Merged and backported; thanks for the report and patch!

  14. zware
    closed this as completedon Apr 28, 2025
  15. github-project-automation
    moved this to Done in Unsupported platformson Apr 28, 2025
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Metadata

Metadata

Assignees

No one assigned

    Labels

    OS-unsupportedbuildThe build process and cross-buildtype-bugAn unexpected behavior, bug, or error

    Projects

    Milestone

    No milestone

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions