epoll test: further clean up check_epoll_wait
Given that `check_epoll_wait` compared the length of the two slices, I don't think it was possible for it to ever return `false`. It's also strange to have some requirements checked inside the function and some checked by the caller, so let's just move it all inside the function.
Cc `@tiif` -- did I miss anything?
add 'project' process guidlines for larger contributions
Fixes https://github.com/rust-lang/miri/issues/3443
I am honestly not entirely sure what the consensus from what issue was. I feel like the epoll PR worked reasonably well, and not having been closely involved I am not sure which process `@oli-obk` followed there. Compared to the first draft in #3443 I tried to make this less formal and framed more as guidelines than hard rules.
Migrate `validate_json.py` script to rust in `run-make/rustdoc-map-file` test
This PR fixes the FIXME I added for future-me who become present-me. :')
Since there are multiple `run-make` tests using python scripts, I suppose more of them will migrate to Rust, hence why I added the `jzon` public reexport to the `run-make-support` crate.
cc `@jieyouxu`
r? `@Kobzol`
Migrate `reproducible-build` `run-make` test to rmake
Part of #121876 and the associated [Google Summer of Code project](https://blog.rust-lang.org/2024/05/01/gsoc-2024-selected-projects.html).
This will likely fail. Locally, rustc errors with `linker 'linker' not found` on line 36 while the file exists according to the dir-debug statement before it.
If this gets fixed and the test passes, further developments may include:
- [x] There may be some leftovers from each test - `test_in_tmpdir` may therefore be required.
- [ ] Try jobs on all ignored architectures.
- [x] A potential refactor with a struct and a custom function like #128410 so this isn't just a huge stream of `rfs` and `rustc`. This is a little bit harder to do in this test considering the variability present in each test case.
// try-job: x86_64-msvc // windows jobs passed in a prior run
// try-job: x86_64-mingw
// try-job: i686-msvc
// try-job: i686-mingw
try-job: aarch64-apple
try-job: aarch64-gnu
try-job: armhf-gnu
try-job: test-various
try-job: dist-various-1
FD: remove big surrounding RefCell, simplify socketpair
A while ago, I added the big implicit RefCell for all file descriptions since it avoided interior mutability in `eventfd`. However, this requires us to hold the RefCell "lock" around the entire invocation of the `read`/`write` methods on an FD, which is not great. For instance, if an FD wants to update epoll notifications from inside its `read`/`write`, it is very crucial that the notification check does not end up accessing the FD itself. Such cycles, however, occur naturally:
- eventfd wants to update notifications for itself
- socketfd wants to update notifications on its "peer", which will in turn check *its* peer to see whether that buffer is empty -- and my peer's peer is myself.
This then also lets us simplify socketpair, which currently holds a weak reference to its peer *and* a weak reference to the peer's buffer -- that was previously needed precisely to avoid this issue.
Make unused states of Reserved unrepresentable
In the [previous TB update](https://github.com/rust-lang/miri/pull/3742) we discovered that the existence of `Reserved + !ty_is_freeze + protected` is undesirable.
This has the side effect of making `Reserved { conflicted: true, ty_is_freeze: false }` unreachable.
As such it is desirable that this state would also be unrepresentable.
This PR eliminates the unused configuration by changing
```rs
enum PermissionPriv {
Reserved { ty_is_freeze: bool, conflicted: bool },
...
}
```
into
```rs
enum PermissionPriv {
ReservedFrz { conflicted: bool },
ReservedIM,
...
}
```
but this is not the only solution and `Reserved(Activable | Conflicted | InteriorMut)` could be discussed.
In addition to making the unreachable state not representable anymore, this change has the nice side effect of enabling `foreign_read` to no longer depend explicitly on the `protected` flag.
Currently waiting for
- `@JoJoDeveloping` to confirm that this is the same representation of `Reserved` as what is being implemented in simuliris,
- `@RalfJung` to approve that this does not introduce too much overhead in the trusted codebase.
detect incompatible CI rustc options more precisely
Previously, the logic here was simply checking whether the option was set in `config.toml`. This approach was not manageable in our CI runners as we set so many options in config.toml. In reality, those values are not incompatible since they are usually the same value used to generate the CI rustc. Now, the new logic compares the configuration values with the values used to generate the CI rustc, so we get more precise results and make the process more manageable.
r? Kobzol
Blocker for https://github.com/rust-lang/rust/pull/122709
Port `run-make/libtest-json` and `run-make/libtest-junit` to rmake
Unlike #126773, this is just a straightforward port to `rmake`, without attempting to switch to compiletest or get rid of the (trivial) Python scripts.
Part of #121876.
r? ````@jieyouxu````
try-job: x86_64-msvc
try-job: i686-mingw
try-job: test-various
try-job: aarch64-gnu
try-job: aarch64-apple
