flt2dec: replace for loop by iter_mut
Perf is explored in https://github.com/rust-lang/rust/issues/144118, which initially showed small losses, but then also showed significant gains. Both are real, but given the smallness of the losses, this seems a good change.
opt-dist: make `artifact-dir` an absolute path for `opt-dist local`
...like for CI environments. the same logic applied as for `build_dir`. fixes the issue where some intermediate steps fail due to path being relative to an active directory
r? Kobzol
try-job: dist-x86_64-msvc
try-job: dist-x86_64-linux
Don't use another main test file as auxiliary
In this case, the exact extern crate isn't very important, it just needs to not be another main test file.
This is part of the changes needed to address the spurious failures from a main test `../removing-extern-crate.rs` being both an auxiliary and a main test file, causing fs races due to multiple `rustc` processes in multiple test threads trying to build the main test file both as a main test and also as an auxiliary at around the same time.
Part 1 of rust-lang/rust#144237.
r? ``@RalfJung`` (or compiler)
clippy: make tests work in stage 1
This finally fixes https://github.com/rust-lang/rust/issues/78717 :)
Similar to what Miri already does, the clippy test step needs to carefully consider which compiler is used to build clippy and which compiler is linked into clippy (and thus must be used to build the test dependencies). On top of that we have some extra complications that Miri avoided by using `cargo-miri` for building its test dependencies: we need cargo to use the right rustc and the right sysroot, but https://github.com/rust-lang/cargo/issues/4423 makes this quite hard to do. See the long comment in `src/tools/clippy/tests/compile-test.rs` for details.
Some clippy tests tried to import rustc crates; that fundamentally requires a full bootstrap loop so it cannot work in stage 1. I had to kind of guess what those tests were doing so I don't know if my changes there make any sense.
Cc ```@flip1995``` ```@Kobzol```
Add `ToolTarget` to bootstrap
Oh, you thought I'm done with refactoring bootstrap tools? Na-ah, think again! After the failure of https://github.com/rust-lang/rust/pull/143581, `ToolTarget` is back with a vengeance. This time, I implemented the test changes and tool cleanups without forcing these tools to be built with the stage0 compiler.
There are still some small wins though, `LlvmBitcodeLinker` now starts at stage 1, and not stage 2. Cargo should also be ported to this new mode, but I'm leaving that for a follow-up PR.
Hopefully X-th time's the charm 🤞
r? `@jieyouxu`
Simplify discriminant codegen for niche-encoded variants which don't wrap across an integer boundary
Inspired by rust-lang/rust#139729, this attempts to be a much-simpler and more-localized change while still making a difference. (Specifically, this does not try to solve the problem with select-sinking, leaving that to be fixed by https://github.com/llvm/llvm-project/issues/134024 -- once it gets released -- instead of in rustc's codegen.)
What this *does* improve is checking for the variant in a 3+ variant enum when that variant is the type providing the niche. Something like `if let Foo::WithBool(_) = ...` previously compiled to `ugt(add(x, -2), 2)`, which is non-trivial to think about because it's depending on the unsigned wrapping to shift the 0/1 up above 2. With this PR it compiles to just `ult(x, 2)`, which is probably what you'd have written yourself if you were doing it by hand to look for "is this byte a bool?".
That's done by leaving most of the codegen alone, but adding a couple new special cases to the `is_niche` check. The default looks at the relative discriminant, but in the common cases where there's no wraparound involved, we can just check the original value, rather than the offsetted one.
The first commit just adds some tests, so the best way to see the effect of this change is to look at the second commit and how it updates the test expectations.
