Rewrite miri script in rust
This is a sketch of a rewrite of miri script in Rust. It does not include changes made in https://github.com/rust-lang/miri/pull/2908 yet. Environment variables are not properly propagated yet, which is something I plan to address.
This PR is mostly a heads-up about the ongoing effort and it's state.
It's definitely not the cleanest code I've seen in my life, but my first goal was feature/interface parity. I will iterate on it a bit before marking it as ready.
I wonder though how this should be integrated/tested. Are you aware of anyone using `./miri` in their scripts?
I guess we should keep existing `miri` script in place and let it run miri-script package directly?
CI should probably `cargo check` this package as well.
Fixes#2883
TB: Redefine trigger condition for protectors
The Coq formalization revealed that as currently implemented, read accesses did not always commute.
Indeed starting from a lazily initialized `Active` protected tag, applying a foreign read then a child read produces `Frozen`, but child read then foreign read triggers UB (because the child read initializes _before_ the `Active -> Frozen`).
This reformulation of when protectors trigger fixes that issue:
- instead of `Active + foreign read -> Frozen` and `Active -> Frozen` when protected is UB
- we do `Active + foreign read -> if protected { Disabled } else { Frozen }`
There is already precedent for transitions being dependent on the presence of a protector (`Reserved + foreign read -> if protected { Frozen } else { Reserved }`), and this has the nice side-effect of simplifying the protector trigger condition to just an equality check against `Disabled` since now there is protector UB iff a protected tag becomes `Disabled`.
In order not to introduce an extra `if`, it was decided that `Disabled -> Disabled` would be UB when protected, which was not the case previously. This is merely a theoretical for now because a protected `Disabled` is unreachable in the first place.
The extra test is not directly related to this modification, but also checks things related to protectors and lazy initialization.
Rename and allow `cast_ref_to_mut` lint
This PR is a small subset of https://github.com/rust-lang/rust/pull/112431, that is the renaming of the lint (`cast_ref_to_mut` -> `invalid_reference_casting`).
BUT also temporarily change the default level of the lint from deny-by-default to allow-by-default until https://github.com/rust-lang/rust/pull/112431 is merged.
r? `@Nilstrieb`
Diagnostic namespace
This PR implements the basic infrastructure for accepting the `#[diagnostic]` attribute tool namespace as specified in https://github.com/rust-lang/rfcs/pull/3368. Note: This RFC is not merged yet, but it seems like it will be accepted soon. I open this PR early on to get feedback on the actual implementation as soon as possible. This hopefully enables getting at least the diagnostic namespace to stable rust "soon", so that crates do not need to bump their MSRV if we stabilize actual attributes in this namespace.
This PR only adds infrastructure accept attributes from this namespace, it does not add any specific attribute. Therefore the compiler will emit a lint warning for each attribute that's actually used. This namespace is added behind a feature flag, so it will be only available on a nightly compiler for now.
cc `@estebank` as they've supported me in planing, specifying and implementing this feature.
Less `TokenTree` cloning
`TokenTreeCursor` has this comment on it:
```
// FIXME: Many uses of this can be replaced with by-reference iterator to avoid clones.
```
This PR completes that FIXME. It doesn't have much perf effect, but at least we now know that.
r? `@petrochenkov`
Revert "add tidy check that forbids issue ui test filenames"
This reverts commit 13e2abf6b3.
Reverting because an MCP was requested and it turned out there was a lack of a consensus on what to do in this area.
Build the first LLVM without LTO in try builds
Currently, we perform three LLVM builds in the Linux x64 dist builder, which is used for `try` builds:
1) "Normal" LLVM - takes ~5s to compile thanks to `sccache`, but ~8 minutes to link because of ThinLTO
2) PGO instrumented LLVM - same timings as 1)
3) PGO optimized LLVM - takes about 20 minutes to build
When I tried to disable LTO for build 1), it suddenly takes only about a minute to build, because the linking step is much faster. The first LLVM doesn't really need LTO all that much. Without it, it will be a bit slower to build `rustc` in two subsequent steps, but it seems that the ~7 minutes saved on linking it do win that back.
Btw, we can't use the host LLVM for build 1), because this LLVM then builds `rustc` in PGO instrumented mode, and we need the same compiler when later PGO optimizing `rustc`. And we want to use our in-house LLVM for that I think.
Replace in-tree `rustc_apfloat` with the new version of the crate
Replace the in-tree version of `rustc_apfloat` with the new version of the crate which has been correctly licensed. The new crate incorporates upstream changes from LLVM since the original port was done including many correctness fixes and has been extensively fuzz tested to validate correctness.
Fixes#100233Fixes#102403Fixes#113407Fixes#113409Fixes#55993Fixes#93224Closes#93225Closes#109573
Currently, Clippy, Miri, Rustfmt, and rustc all use an environment variable to
indicate that output should be blessed, but they use different variable names.
In order to improve consistency, this patch applies the following changes:
- Emit `RUSTC_BLESS` within `prepare_cargo_test` so it is always
available
- Change usage of `MIRI_BLESS` in the Miri subtree to use `RUSTC_BLESS`
- Change usage of `BLESS` in the Clippy subtree to `RUSTC_BLESS`
- Change usage of `BLESS` in the Rustfmt subtree to `RUSTC_BLESS`
- Adjust the blessable test in `rustc_errors` to use this same
convention
- Update documentation where applicable
Any tools that uses `RUSTC_BLESS` should check that it is set to any value
other than `"0"`.
compiletest: remove ci-specific remap-path-prefix
Now that we have fixed the underlying cause of long type name inconsistencies in #113893, we can remove the remap-path-prefix logic from CI
resolves#113424
interpret: make read/write methods generic
Instead of always having to call `into()` to convert things to `PlaceTy`/`OpTy`, make the relevant methods generic. This also means that when we read from an `MPlaceTy`, we avoid creating an intermediate `PlaceTy`.
This makes it feasible to remove the `Copy` from `MPlaceTy`. All the other `*Ty` interpreter types already had their `Copy` removed a while ago so this is only consistent. (And in fact we had one function that accidentally took `MPlaceTy` instead of `&MPlaceTy`.)
Split some functions with many arguments into builder pattern functions
r? `@estebank`
This doesn't resolve all of the ones in rustc, mostly because I need to do other cleanups in order to be able to use some builder derives from crates.io
Works around https://github.com/rust-lang/rust/issues/90672 by making `x test rustfmt --bless` format itself instead of testing that it is formatted
