Miri CI: test aarch64-apple-darwin in PRs instead of the x86_64 target
The aarch64 target is more important, and also this ensures we cover all main architectures (x86_64, i686, aarch64) in PR CI.
std: clarify Clone trait documentation about duplication semantics
Closesrust-lang/rust#141138
The change explicitly explains that cloning behavior varies by type and clarifies that smart pointers (`Arc`, `Rc`) share the same underlying data. I've also added an example of cloning to Arc.
`slice.get(i)` should use a slice projection in MIR, like `slice[i]` does
`slice[i]` is built-in magic, so ends up being quite different from `slice.get(i)` in MIR, even though they're both doing nearly identical operations -- checking the length of the slice then getting a ref/ptr to the element if it's in-bounds.
This PR adds a `slice_get_unchecked` intrinsic for `impl SliceIndex for usize` to use to fix that, so it no longer needs to do a bunch of lines of pointer math and instead just gets the obvious single statement. (This is *not* used for the range versions, since `slice[i..]` and `slice[..k]` can't use the mir Slice projection as they're using fenceposts, not indices.)
I originally tried to do this with some kind of GVN pattern, but realized that I'm pretty sure it's not legal to optimize `BinOp::Offset` to `PlaceElem::Index` without an extremely complicated condition. Basically, the problem is that the `Index` projection on a dereferenced slice pointer *cares about the metadata*, since it's UB to `PlaceElem::Index` outside the range described by the metadata. But then you cast the fat pointer to a thin pointer then offset it, that *ignores* the slice length metadata, so it's possible to write things that are legal with `Offset` but would be UB if translated in the obvious way to `Index`. Checking (or even determining) the necessary conditions for that would be complicated and error-prone, whereas this intrinsic-based approach is quite straight-forward.
Zero backend changes, because it just lowers to MIR, so it's already supported naturally by CTFE/Miri/cg_llvm/cg_clif.
In the previous description it said there was a TOCTOU race but did not
explain exactly what the problem was. I sat down with the CVE, reviewed
its text, and created this explanation. This context should hopefully
help people understand the actual risk as-such.
Incidentally, it also fixes the capitalization on the name of Redox OS.
When determining when a function or method can be called from a `const`
context, the determination must be made on the instance, not on the
declaration. This makes a difference, for example, with `const_trait`
traits whose implementations may or may not be `const`.
it is non-trivial to reproduce this bug through rustdoc,
which uses this function less than clippy,
so the regression test was added as a unit test
instead of an integration test.
Add const support for the float rounding methods floor, ceil, trunc,
fract, round and round_ties_even.
This works by moving the calculation logic from
src/tools/miri/src/intrinsics/mod.rs
into
compiler/rustc_const_eval/src/interpret/intrinsics.rs.
All relevant method definitions were adjusted to include the `const`
keyword for all supported float types: f16, f32, f64 and f128.
The constness is hidden behind the feature gate
feature(const_float_round_methods)
which is tracked in
https://github.com/rust-lang/rust/issues/141555
This commit is a squash of the following commits:
- test: add tests that we expect to pass when float rounding becomes const
- feat: make float rounding methods `const`
- fix: replace `rustc_allow_const_fn_unstable(core_intrinsics)` attribute with `#[rustc_const_unstable(feature = "f128", issue = "116909")]` in `library/core/src/num/f128.rs`
- revert: undo update to `library/stdarch`
- refactor: replace multiple `float_<mode>_intrinsic` rounding methods with a single, parametrized one
- fix: add `#[cfg(not(bootstrap))]` to new const method tests
- test: add extra sign tests to check `+0.0` and `-0.0`
- revert: undo accidental changes to `round` docs
- fix: gate `const` float round method behind `const_float_round_methods`
- fix: remove unnecessary `#![feature(const_float_methods)]`
- fix: remove unnecessary `#![feature(const_float_methods)]` [2]
- revert: undo changes to `tests/ui/consts/const-eval/float_methods.rs`
- fix: adjust after rebase
- test: fix float tests
- test: add tests for `fract`
- chore: add commented-out `const_float_round_methods` feature gates to `f16` and `f128`
- fix: adjust NaN when rounding floats
- chore: add FIXME comment for de-duplicating float tests
- test: remove unnecessary test file `tests/ui/consts/const-eval/float_methods.rs`
- test: fix tests after upstream simplification of how float tests are run
Rollup of 8 pull requests
Successful merges:
- rust-lang/rust#140787 (Note expr being cast when encounter NonScalar cast error)
- rust-lang/rust#141112 (std: note that `std::str::from_utf8*` functions are aliases to `<str>::from_utf8*` methods)
- rust-lang/rust#141646 (Document what `distcheck` is intended to exercise)
- rust-lang/rust#141740 (Hir item kind field order)
- rust-lang/rust#141793 (`tests/ui`: A New Order [1/N])
- rust-lang/rust#141805 (Update `compiler-builtins` to 0.1.160)
- rust-lang/rust#141815 (Enable non-leaf Frame Pointers for mingw-w64 Arm64 Windows)
- rust-lang/rust#141819 (Fixes for building windows-gnullvm hosts)
r? `@ghost`
`@rustbot` modify labels: rollup
Enable non-leaf Frame Pointers for mingw-w64 Arm64 Windows
Based on https://github.com/rust-lang/rust/pull/140828
I don't have AArch64 Windows to test it, but I trust LLVM to handle it well.
`tests/ui`: A New Order [1/N]
not sure if i should say something about changes here, just part of rust-lang/rust#133895
but this is my very first time doing something like this, id love to keep contributing in this area later on, so any feedback is appreciated
also should say that im going to squash it after agreement on changes
r? `@jieyouxu`
mind if i name this PR series like "`tests/ui`: A New Order [N/N]", im not sure if it fits the project tone, so id like your approval first — but i think it sounds really neat (Star Wars reference)
this could be a first part :)
Note expr being cast when encounter NonScalar cast error
Fixes#140491
I added note for `expr` so that it doesn't treat `&x as T` as `&(x as T)` but `(&x) as T`. But I'm not sure if I want to add note for all NonScalar, maybe for specific `expr_ty`?
r? compiler
- Map compiler sources (corresponding to `rustc-dev` dist component)
with `/rustc-dev/{hash}`.
- Map non-compiler sources (corresponding to `rust-src` dist component
or other non-compiler sources) with `/rustc/{hash}`.
This allows the compiler to have the possibility of opportunistically
reverse the mapping. This is because
- `rust-src` unpacks sources to a path like
`$sysroot/lib/rustlib/src/rust`, whereas
- `rustc-dev` unpacks sources to a path like
`$sysroot/lib/rustlib/rustc-src/rust`
(Notice the `src` vs `rustc-src` difference.)
Do not move thread-locals before dropping
Fixesrust-lang/rust#140816. I also (potentially) improved the speed of `get_or_init` a bit by having an explicit hot/cold path.
We still move the value before dropping in the event of a recursive initialization (leading to double-initialization with one value being silently dropped). This is the old behavior, but changing this to panic instead would involve changing tests and also the other OS-specific `thread_local/os.rs` implementation, which is more than I'd like in this PR.
gold has been deprecated recently and is known to behave incorrectly
around Rust programs, including miscompiling `#[used(linker)]`.
Tell people to switch to a different linker instead.
Co-Authored-By: bjorn3 <17426603+bjorn3@users.noreply.github.com>
