Skip to content

Building Python in 32-bit mode on Windows emits multiple compiler warnings #161625

Closed

Description

@vstinner

Example on GHA Windows / Build and test (Win32, switch-case): https://github.com/python/cpython/actions/runs/42495002560/job/128775403307

Modules\_remote_debugging\object_reading.c(282,69): warning C4244: 'initializing': conversion from 'uint64_t' to 'Py_ssize_t', possible loss of data
Modules\_remote_debugging\gc_stats.c(92,9): warning C4244: 'initializing': conversion from 'uint64_t' to 'uintptr_t', possible loss of data
Modules\_remote_debugging\frames.c(468,32): warning C4244: 'function': conversion from 'uint64_t' to 'uintptr_t', possible loss of data
Modules\_remote_debugging\frames.c(489,33): warning C4244: 'function': conversion from 'uint64_t' to 'uintptr_t', possible loss of data
Modules\_remote_debugging\frames.c(500,32): warning C4244: 'function': conversion from 'uint64_t' to 'uintptr_t', possible loss of data
Modules\_remote_debugging\threads.c(450,29): warning C4244: 'initializing': conversion from 'uint64_t' to 'uintptr_t', possible loss of data
Modules\_remote_debugging\threads.c(452,50): warning C4244: 'initializing': conversion from 'uint64_t' to 'uintptr_t', possible loss of data
Modules\_remote_debugging\binary_io_reader.c(368,41): warning C4244: 'function': conversion from 'uint64_t' to 'size_t', possible loss of data
Modules\_remote_debugging\binary_io_reader.c(379,27): warning C4244: 'initializing': conversion from 'uint64_t' to 'size_t', possible loss of data
Modules\_remote_debugging\binary_io_reader.c(414,41): warning C4244: 'function': conversion from 'uint64_t' to 'size_t', possible loss of data
Modules\_remote_debugging\binary_io_reader.c(426,27): warning C4244: 'initializing': conversion from 'uint64_t' to 'size_t', possible loss of data
Modules\_remote_debugging\binary_io_reader.c(697,64): warning C4244: '=': conversion from 'uint64_t' to 'size_t', possible loss of data
Modules\_remote_debugging\binary_io_reader.c(874,31): warning C4244: '=': conversion from 'uint64_t' to 'size_t', possible loss of data
Modules\_remote_debugging\binary_io_reader.c(919,31): warning C4244: '=': conversion from 'uint64_t' to 'size_t', possible loss of data
Modules\_remote_debugging\binary_io_reader.c(1265,55): warning C4018: '<': signed/unsigned mismatch

Modules\_uuidmodule.c(302,50): warning C4244: 'initializing': conversion from 'uint64_t' to 'Py_ssize_t', possible loss of data

I'm working on a fix.

Linked PRs

Activity

  1. added
    buildThe build process and cross-build
    type-refactorCode refactoring (with no changes in behavior)
    on Nov 8, 2026
  2. self-assigned this
    on Nov 8, 2026
  3. changed the title [-]Buildind Python in 32-bit mode on Windows emits multiple compiler warnings[/-] [+]Building Python in 32-bit mode on Windows emits multiple compiler warnings[/+] on Nov 8, 2026
  4. added 5 commits that reference this issue on Nov 8, 2026
  5. added a commit that references this issue on Nov 8, 2026
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Metadata

Metadata

Assignees

Labels

buildThe build process and cross-buildtype-refactorCode refactoring (with no changes in behavior)

Projects

No projects

    Milestone

    No milestone

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions