New submission from Ed Schouten: CloudABI is a sandboxed UNIX-like environment (https://mail.python.org/pipermail/python-dev/2016-July/145708.html). As it implements a security framework similar to FreeBSD's Capsicum, file system access is only permitted by using POSIX-2008-style directory file descriptors. To explain it simply, the API is as follows:
- Take POSIX 2008 - Remove all the non-*at() functions - Remove AT_FDCWD It would be nice if Python could support CloudABI out of the box, but in my opinion this should be done in a way that's as unintrusive as possible. We shouldn't make a mess out of Python, just to support CloudABI. I've been looking at Python's posixmodule and I think there's some low-hanging fruit. We can make changes that significantly reduce the size of our patchset for CloudABI, while also making the existing code easier to understand: - When support for *at() functions was added, they didn't replace the calls to the non-*at() functions. The non-*at() functions are still invoked when dir_fd == AT_FDCWD. This can be changed to invoke the *at() functions unconditionally. The advantage of this approach is that AT_FDCWD then only needs to be used in dir_fd_converter() and a small number of other places. It also means that the code builds on systems that don't prove the non-*at() functions. - The *_DIR_FD_CONVERTER macros aren't used in a small number of places, requiring us to do additional checks against AT_FDCWD in os_*_impl(). In os.link(), os.rename() and os.replace(), we call into dir_fd_converter() unconditionally, only to let the respective implementation functions perform additional checks. If dir_fd_unavailable() would be used instead, the implementations would be cleaner. The attached patch does this refactoring, also making some minor cleanups along the way. ---------- components: Extension Modules files: posixmodule-refactoring.diff keywords: patch messages: 272114 nosy: EdSchouten priority: normal severity: normal status: open title: [posixmodule] [Refactoring patch] Simply call into *at() functions unconditionally when present versions: Python 3.6 Added file: http://bugs.python.org/file44033/posixmodule-refactoring.diff _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue27701> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
