Add statx shim for linux target
This is an attempt to fix: https://github.com/rust-lang/miri/issues/999 (for linux only)
Currently there is one problem that I haven't been able to solve. `std::fs::metadata` fails because the creation time is not available even though it is provided in the shim code.
In order to inform the caller that the field was provided, the `stx_flag` field must have the bits of `STATX_BTIME` set (which they are). The creation time is in the `stx_btime` field of the `statx` struct (see [1]). The relevant code in `libstd` is here (probably?): https://github.com/rust-lang/rust/blob/master/src/libstd/sys/unix/fs.rs#L322
Another important point is that we are just providing the fields that are available in "all" platforms (this is, without using any platform specific traits or so). This can be improved later.
References:
[1] Man page: http://man7.org/linux/man-pages/man2/statx.2.html
[2] libc `statx` struct: https://docs.rs/libc/0.2.63/libc/struct.statx.html
Edit: The problem is that my filesystem is not providing it and I thought all filesystems could provide it. I changed the code so it only provides those dates if they are available. now we are ready to go.
r? @RalfJung @oli-obk
Fixes#658
This commit adds support for unwinding after a panic. It requires a
companion rustc PR to be merged, in order for the necessary hooks to
work properly.
Currently implemented:
* Selecting between unwind/abort mode based on the rustc Session
* Properly popping off stack frames, unwinding back the caller
* Running 'unwind' blocks in Mir terminators
Not yet implemented:
* 'Abort' terminators
This PR was getting fairly large, so I decided to open it for review without
implementing 'Abort' terminator support. This could either be added on
to this PR, or merged separately.
