Windows MSVC Toolchains & Linking

MSVC #pragma comment(lib, ...) Embedded References

• CPython's MSVC headers embed #pragma comment(lib, "python3xx.lib") into generated .obj files. MSVC link.exe automatically searches for python3xx.lib in library search paths during linking.
• Citation: Microsoft Learn comment pragma (“Places a library-search record in the object file... The linker searches for this library the same way as if you had named it on the command line”).

PEP 3149 ABI Tag Prefix (cp vs. cpython-)

• Windows CPython ABI tags use the cp prefix (e.g., cp311, cp312t) whereas POSIX platforms use cpython- (e.g., cpython-311).
• Citation: PEP 3149 — ABI version tagged .so files (“The tag starts with cpython- followed by the Python major and minor version without dots... followed by build flags”).

Windows Platform Tag Derivation

• Windows platform tags for Python C extensions evaluate to win_amd64 (x86_64/amd64), win_arm64 (aarch64/arm64), or win32 (32-bit x86).
• platform.machine() Normalization: On Windows, platform.machine() returns uppercase ("AMD64", "ARM64"). Always normalize with .lower() when deriving PEP 508 markers or resolving platform tags.
• Citation: PEP 425 — Compatibility Tags for Built Distributions.

Windows CPython SOABI & ABI Infix Support

• CPython on Windows natively supports loading ABI-tagged .pyd files containing platform tags (e.g., foo.cp314-win_amd64.pyd, foo.cp311-win_amd64.pyd).
• SOABI on Windows includes both the ABI prefix and platform tag (e.g., cp311-win_amd64).