Bug: MapViewOfFile returns an isize in 0.48

[sunfishcode]

Which crate is this about?

windows-sys

Crate version

0.48.0

Summary

It appears in 0.48 that MapViewOfFile changed from returning *mut c_void to returning MEMORYMAPPEDVIEW_HANDLE, which is an isize.

According to the MapViewOfFile documentation, the return type is LPVOID and the return value does represent an address. Representing it as a pointer would more convenient for typical use cases which use it as a pointer, and would be friendlier to strict provenance checks.

Toolchain version/configuration

No response

Reproducible example

No response

Crate manifest

No response

Expected behavior

No response

Actual behavior

No response

Additional comments

No response

[ChrisDenton]

See also microsoft/win32metadata#561 where this change was made

[sunfishcode]

The reasoning about strict provenance in #1643 seems to be that it's ok that handles are represented as isize because they're never used as pointers by applications.

However now, it seems there exists a thing which is a handle, and that is also used as a pointer by applications.

[riverar]

Looks like a metadata bug and should have never been marked as returning a handle. Will re-open that bug.

[kennykerr]

Yes, this is a bug in the win32 metadata.

[kennykerr]

Looks like this was tweaked in the Win32 metadata microsoft/win32metadata#561 so I'll close this - let me know if there's anything else you need.

[kennykerr]

FYI: microsoft/win32metadata#1533