remove dead code
The condition
`if obligation.recursion_depth >= 0`
is always true since `recursion_depth` is `usize`.
The else branch is dead code and can be removed.
Found by Clippy.
Fixes#68251
Enable leak sanitizer test case
* Use `black_box` to avoid memory leak removal during optimization.
* Leak multiple objects to make test case more robust.
Don't use f64 shims for f32 cmath functions on non 32-bit x86 MSVC
These shims are only needed on 32-bit x86. Additionally since https://reviews.llvm.org/rL268875 LLVM handles adding the shims itself for the intrinsics.
The condition
if obligation.recursion_depth >= 0
is always true since recursion_depth is usize.
The else branch is dead code and can be removed.
Found by Clippy.
Fixes#68251
Rollup of 5 pull requests
Successful merges:
- #67780 (Move some queries from rustc::ty to librustc_ty.)
- #68096 (Clean up some diagnostics by making them more consistent)
- #68223 (Use 3.6 instead of 3.5 in float fract() documentation)
- #68265 (Fix some issue numbers of unstable features)
- #68266 (Changed docs for f32 and f64.)
Failed merges:
- #68204 (Use named fields for `{ast,hir}::ItemKind::Impl`)
r? @ghost
Use 3.6 instead of 3.5 in float fract() documentation
It is not self-explanatory whether the fract() function inverts the fractional part of negative numbers. This change clarifies this possible question (so that it is `.6` not `.4`)
Clean up some diagnostics by making them more consistent
In general:
- Diagnostic should start with a lowercase letter.
- Diagnostics should not end with a full stop.
- Ellipses contain three dots.
- Backticks should encode Rust code.
I also reworded a couple of messages to make them read more clearly.
It might be sensible to create a style guide for diagnostics, so these informal conventions are written down somewhere, after which we could audit the existing diagnostics.
r? @Centril
Use pointer offset instead of deref for A/Rc::into_raw
Internals thread: https://internals.rust-lang.org/t/rc-and-internal-mutability/11463/2?u=cad97
The current implementation of (`A`)`Rc::into_raw` uses the `Deref::deref` implementation to get the pointer-to-data that is returned. This is problematic in the proposed Stacked Borrow rules, as this only gets shared provenance over the data location. (Note that the strong/weak counts are `UnsafeCell` (`Cell`/`Atomic`) so shared provenance can still mutate them, but the data itself is not.) When promoted back to a real reference counted pointer, the restored pointer can be used for mutation through `::get_mut` (if it is the only surviving reference). However, this mutates through a pointer ultimately derived from a `&T` borrow, violating the Stacked Borrow rules.
There are three known potential solutions to this issue:
- Stacked Borrows is wrong, liballoc is correct.
- Fully admit (`A`)`Rc` as an "internal mutability" type and store the data payload in an `UnsafeCell` like the strong/weak counts are. (Note: this is not needed generally since the `RcBox`/`ArcInner` is stored behind a shared `NonNull` which maintains shared write provenance as a raw pointer.)
- Adjust `into_raw` to do direct manipulation of the pointer (like `from_raw`) so that it maintains write provenance and doesn't derive the pointer from a reference.
This PR implements the third option, as recommended by @RalfJung.
Potential future work: provide `as_raw` and `clone_raw` associated functions to allow the [`&T` -> (`A`)`Rc<T>` pattern](https://internals.rust-lang.org/t/rc-and-internal-mutability/11463/2?u=cad97) to be used soundly without creating (`A`)`Rc` from references.
* Move tests from src/test/run-make-fulldeps to src/test/ui.
* Fix memory sanitizer test to detect the intended issue rather than
an unrelated one caused by the use of an uninstrumented std.
It is not self-explanatory whether the fract() function inverts the fractional part of negative numbers.
Co-Authored-By: Mateusz Mikuła <mati865@users.noreply.github.com>
Add some regression tests
Closes#64848 (fixed by #67631)
Closes#65918 (ICE is hidden by #67000, no longer ICE)
Closes#66473 (fixed by #68084)
Closes#67550 (set mir-opt-level to 3)
r? @Centril
Optimize size/speed of Unicode datasets
The overall implementation has the same general idea as the prior approach,
which was based on a compressed trie structure, but modified to use less space
(and, coincidentally, be an overall performance improvement).
Sizes | Old | New | New/current
-- | -- | -- | --
Alphabetic | 4616 | 2982 | 64.60%
Case_Ignorable | 3144 | 2112 | 67.18%
Cased | 2376 | 934 | 39.31%
Cc | 19 | 43 | 226.32%
Grapheme_Extend | 3072 | 1734 | 56.45%
Lowercase | 2328 | 985 | 42.31%
N | 2648 | 1239 | 46.79%
Uppercase | 1978 | 934 | 47.22%
White_Space | 241 | 140 | 58.09%
| | |
Total | 20422 | 11103 | 54.37%
This table shows the size of the old and new tables in bytes. The most important
of these tables is "Grapheme_Extend", as it is present in essentially all Rust
programs due to being called from `str`'s Debug impl (`char::escape_debug`). In
a representative case given by this [blog post] for the embedded world, the
shrinking in this PR shrinks the final binary by 1,604 bytes, from 14,440 to
12,836.
The performance of these new tables, based on the (rough) benchmark of linearly
scanning the entire valid set of chars, querying for each `is_*`, is roughly
~50% better, though in some cases is either on par or slightly (3-5%) worse. In
practice, I believe the size benefits of this PR are the main concern. The new
implementation has been tested to be equivalent to the current nightly in terms
of returned values on the set of valid chars.
A (relatively) high-level explanation of the specific compression scheme used
can be found [in the generator].
This is split into three commits -- the first adds the generator which produces
the Rust code for the tables, the second adds support code for the lookup, and
the third actually swaps the current implementation out for the new one.
[blog post]: https://jamesmunns.com/blog/fmt-unreasonably-expensive/
[in the generator]: https://github.com/Mark-Simulacrum/rust/blob/unicode-tables/src/tools/unicode-table-generator/src/raw_emitter.rs
Promoteds can contain raw pointers, but these must still only point to immutable allocations
fixes#67601
r? @RalfJung
cc @wesleywiser in order to not change behaviour in this PR, const prop uses the constant rules for interning, but at least there's an explicit mode for it now that we can think about this in the future
