Fix "consider borrowing" for else-if
Fixesrust-lang/rust#141810
When trying to suggest a borrow on a `if` or `block` expression, instead we now recurse into the `if` or `block`.
The comments in the code should explain the goal of the new code.
r? ``@jdonszelmann``
Add `const` support for float rounding methods
# Add `const` support for float rounding methods
This PR makes the following float rounding methods `const`:
- `f64::{floor, ceil, trunc, round, round_ties_even}`
- and the corresponding methods for `f16`, `f32` and `f128`
Tracking issue: https://github.com/rust-lang/rust/issues/141555
## Procedure
I followed c09ed3e767 as closely as I could in making float methods `const`, and also received great guidance from https://internals.rust-lang.org/t/const-rounding-methods-in-float-types/22957/3?u=ruancomelli.
## Note
This is my first code contribution to the Rust project, so please let me know if I missed anything - I'd be more than happy to revise and learn more. Thank you for taking the time to review it!
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.
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
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.
Add fast path for maybe-initializedness in liveness
r? `@matthewjasper`
Correct me if I'm wrong Matthew, but my understanding is that
1. `MaybeInitializedPlaces` is currently eagerly computed, in `do_mir_borrowck`
2. but this data is only used in liveness
3. and `liveness::trace` actually only uses it for drop-liveness
This PR moves the computation to `liveness::trace` which looks to be its only use-site. We also add a fast path there, so that it's only computed by drop-liveness.
This is interesting because 1) liveness is only computed for relevant live locals, 2) drop-liveness is only computed for relevant live locals with >0 drop points; 0 is the common case from our benchmarks, as far as I can tell, so even just computing the entire data lazily helps.
It seems possible to also reduce the domain here, and speed up the analysis for the cases where it has to be computed -- so I've left a fixme for that, and may look into it soon.
(I've come upon this while doing implementation work for polonius, so don't be too enamored with possible wins: the goal is to reduce the eventual polonius overhead and make it more palatable 😓)
This commit improves the Clone trait documentation to address confusion
around what "duplication" means for different types, especially for smart
pointers like Arc<Mutex<T>>.
Signed-off-by: xizheyin <xizheyin@smail.nju.edu.cn>
Rollup of 8 pull requests
Successful merges:
- rust-lang/rust#140825 (Add Range parameter to `BTreeMap::extract_if` and `BTreeSet::extract_if`)
- rust-lang/rust#141077 (Fix the issue of typo of comma in arm parsing)
- rust-lang/rust#141237 (Implement ((un)checked_)exact_div methods for integers)
- rust-lang/rust#141494 (mir-opt: Do not transform non-int type in match_branches)
- rust-lang/rust#141609 (core: begin deduplicating pointer docs)
- rust-lang/rust#141768 (ci: use arm to calculate job matrix)
- rust-lang/rust#141771 (Increase timeout for new bors try builds)
- rust-lang/rust#141781 (Fix spans for unsafe binders)
r? `@ghost`
`@rustbot` modify labels: rollup
core: begin deduplicating pointer docs
this also cleans up two inconsistancies:
1. both doctests on the ::add methods were actually calling the const version.
2. on of the ::offset methods was missing a line of clarification.
part of https://github.com/rust-lang/rust/issues/139190
Implement ((un)checked_)exact_div methods for integers
tracking issue: #139911
I see that there might still be some bikeshedding to be done, so if people want changes to this implementation, I'm happy to make those. I did also see that there was a previous attempt at this PR (#116632), but I'm not sure why it got closed.
