Commit Graph

620 Commits

Author SHA1 Message Date
John Millikin
4e2797dd76 Implement Neg for signed non-zero integers.
Negating a non-zero integer currently requires unpacking to a
primitive and re-wrapping. Since negation of non-zero signed
integers always produces a non-zero result, it is safe to
implement `Neg` for `NonZeroI{N}`.

The new `impl` is marked as stable because trait implementations
for two stable types can't be marked unstable.
2023-04-20 14:27:29 +09:00
bors
3a5c8e91f0 Auto merge of #110393 - fee1-dead-contrib:rm-const-traits, r=oli-obk
Rm const traits in libcore

See [zulip thread](https://rust-lang.zulipchat.com/#narrow/stream/146212-t-compiler.2Fconst-eval/topic/.60const.20Trait.60.20removal.20or.20rework)

* [x] Bless ui tests
* [ ] Re constify some unstable functions with workarounds if they are needed
2023-04-19 13:03:40 +00:00
Deadbeef
4c6ddc036b fix library and rustdoc tests 2023-04-16 11:38:52 +00:00
Deadbeef
76dbe29104 rm const traits in libcore 2023-04-16 06:49:27 +00:00
est31
77821b2eb9 Remove unused unused_macros
The macro is always used
2023-04-16 08:35:39 +02:00
Tobias Decking
65c9c79d3f
remove obsolete test 2023-04-10 21:57:45 +02:00
Tobias Decking
0f96c71792 Improve the floating point parser in dec2flt.
* Remove all remaining traces of unsafe.
* Put `parse_8digits` inside a loop.
* Rework parsing of inf/NaN values.
2023-04-10 00:47:08 +02:00
Deadbeef
04a5d61161 Revert "Mark DoubleEndedIterator as #[const_trait] using rustc_do_not_const_check, implement const Iterator and DoubleEndedIterator for Range."
This reverts commit 8a9d6bf4fd.
2023-04-08 08:18:29 +00:00
Trevor Gross
dc4ba57566 Stabilize a portion of 'once_cell'
Move items not part of this stabilization to 'lazy_cell' or 'once_cell_try'
2023-03-29 18:04:44 -04:00
bors
cdbbce0a9e Auto merge of #108095 - soc:drop-contains, r=Amanieu
Drop unstable `Option::contains`, `Result::contains`, `Result::contains_err`

This is a proposal to drop the three functions `Option::contains`, `Result::contains` and `Result::contains_err`.

The discovery of `Option::is_some_with`/`Result::is_ok_with`/`Result::is_err_with` in https://github.com/rust-lang/rust/pull/93051 obviates the need for these methods (non-stabilization tracked in https://github.com/rust-lang/rust/issues/62358).

An additional benefit of change is that it avoids spurious error messages in IDEs, when `contains` is supplied by a third-party library:
![option-result-unstable](https://user-images.githubusercontent.com/42493/219127961-13cb559e-6ee8-4449-8dc9-d28d07270ad5.png)
2023-03-28 23:20:30 +00:00
The 8472
e29b27b4a4 replace advance_by returning usize with Result<(), NonZeroUsize> 2023-03-27 16:03:14 +02:00
The 8472
69db91b8b2 Change advance(_back)_by to return usize instead of Result<(), usize>
A successful advance is now signalled by returning `0` and other values now represent the remaining number
of steps that couldn't be advanced as opposed to the amount of steps that have been advanced during a partial advance_by.

This simplifies adapters a bit, replacing some `match`/`if` with arithmetic. Whether this is beneficial overall depends
on whether `advance_by` is mostly used as a building-block for other iterator methods and adapters or whether
we also see uses by users where `Result` might be more useful.
2023-03-27 14:11:49 +02:00
onestacked
8a9d6bf4fd Mark DoubleEndedIterator as #[const_trait] using rustc_do_not_const_check, implement const Iterator and DoubleEndedIterator for Range. 2023-03-18 09:17:37 +01:00
Mara Bos
96d252160e Update format_args!() test to account for inlining. 2023-03-16 11:21:50 +01:00
est31
999405059c Match unmatched backticks in library/ 2023-03-03 03:03:29 +01:00
Ralf Jung
229aef1f7d add missing feature in core/tests 2023-02-28 10:07:57 +01:00
Linus Färnstrand
6cb34492a6 Move IpAddr and SocketAddr to core 2023-02-26 13:50:08 +01:00
soc
3aa9f76a3a
Remove #![feature(option_result_contains)] from library/core/tests/lib.rs 2023-02-15 19:30:02 +00:00
bors
2d91939bb7 Auto merge of #107634 - scottmcm:array-drain, r=thomcc
Improve the `array::map` codegen

The `map` method on arrays [is documented as sometimes performing poorly](https://doc.rust-lang.org/std/primitive.array.html#note-on-performance-and-stack-usage), and after [a question on URLO](https://users.rust-lang.org/t/try-trait-residual-o-trait-and-try-collect-into-array/88510?u=scottmcm) prompted me to take another look at the core [`try_collect_into_array`](7c46fb2111/library/core/src/array/mod.rs (L865-L912)) function, I had some ideas that ended up working better than I'd expected.

There's three main ideas in here, split over three commits:
1. Don't use `array::IntoIter` when we can avoid it, since that seems to not get SRoA'd, meaning that every step writes things like loop counters into the stack unnecessarily
2. Don't return arrays in `Result`s unnecessarily, as that doesn't seem to optimize away even with `unwrap_unchecked` (perhaps because it needs to get moved into a new LLVM type to account for the discriminant)
3. Don't distract LLVM with all the `Option` dances when we know for sure we have enough items (like in `map` and `zip`).  This one's a larger commit as to do it I ended up adding a new `pub(crate)` trait, but hopefully those changes are still straight-forward.

(No libs-api changes; everything should be completely implementation-detail-internal.)

It's still not completely fixed -- I think it needs pcwalton's `memcpy` optimizations still (#103830) to get further -- but this seems to go much better than before.  And the remaining `memcpy`s are just `transmute`-equivalent (`[T; N] -> ManuallyDrop<[T; N]>` and `[MaybeUninit<T>; N] -> [T; N]`), so hopefully those will be easier to remove with LLVM16 than the previous subobject copies 🤞

r? `@thomcc`

As a simple example, this test
```rust
pub fn long_integer_map(x: [u32; 64]) -> [u32; 64] {
    x.map(|x| 13 * x + 7)
}
```
On nightly <https://rust.godbolt.org/z/xK7548TGj> takes `sub rsp, 808`
```llvm
start:
  %array.i.i.i.i = alloca [64 x i32], align 4
  %_3.sroa.5.i.i.i = alloca [65 x i32], align 4
  %_5.i = alloca %"core::iter::adapters::map::Map<core::array::iter::IntoIter<u32, 64>, [closure@/app/example.rs:2:11: 2:14]>", align 8
```
(and yes, that's a 6**5**-element array `alloca` despite 6**4**-element input and output)

But with this PR it's only `sub rsp, 520`
```llvm
start:
  %array.i.i.i.i.i.i = alloca [64 x i32], align 4
  %array1.i.i.i = alloca %"core::mem::manually_drop::ManuallyDrop<[u32; 64]>", align 4
```

Similarly, the loop it emits on nightly is scalar-only and horrifying
```nasm
.LBB0_1:
        mov     esi, 64
        mov     edi, 0
        cmp     rdx, 64
        je      .LBB0_3
        lea     rsi, [rdx + 1]
        mov     qword ptr [rsp + 784], rsi
        mov     r8d, dword ptr [rsp + 4*rdx + 528]
        mov     edi, 1
        lea     edx, [r8 + 2*r8]
        lea     r8d, [r8 + 4*rdx]
        add     r8d, 7
.LBB0_3:
        test    edi, edi
        je      .LBB0_11
        mov     dword ptr [rsp + 4*rcx + 272], r8d
        cmp     rsi, 64
        jne     .LBB0_6
        xor     r8d, r8d
        mov     edx, 64
        test    r8d, r8d
        jne     .LBB0_8
        jmp     .LBB0_11
.LBB0_6:
        lea     rdx, [rsi + 1]
        mov     qword ptr [rsp + 784], rdx
        mov     edi, dword ptr [rsp + 4*rsi + 528]
        mov     r8d, 1
        lea     esi, [rdi + 2*rdi]
        lea     edi, [rdi + 4*rsi]
        add     edi, 7
        test    r8d, r8d
        je      .LBB0_11
.LBB0_8:
        mov     dword ptr [rsp + 4*rcx + 276], edi
        add     rcx, 2
        cmp     rcx, 64
        jne     .LBB0_1
```

whereas with this PR it's unrolled and vectorized
```nasm
	vpmulld	ymm1, ymm0, ymmword ptr [rsp + 64]
	vpaddd	ymm1, ymm1, ymm2
	vmovdqu	ymmword ptr [rsp + 328], ymm1
	vpmulld	ymm1, ymm0, ymmword ptr [rsp + 96]
	vpaddd	ymm1, ymm1, ymm2
	vmovdqu	ymmword ptr [rsp + 360], ymm1
```
(though sadly still stack-to-stack)
2023-02-13 10:18:48 +00:00
Matthias Krüger
454ae9fb8b
Rollup merge of #107954 - RalfJung:tree-borrows-fix, r=m-ou-se
avoid mixing accesses of ptrs derived from a mutable ref and parent ptrs

``@Vanille-N`` is working on a successor for Stacked Borrows. It will mostly accept strictly more code than Stacked Borrows did, with one exception: the following pattern no longer works.
```rust
let mut root = 6u8;
let mref = &mut root;
let ptr = mref as *mut u8;
*ptr = 0; // Write
assert_eq!(root, 0); // Parent Read
*ptr = 0; // Attempted Write
```
This worked in Stacked Borrows kind of by accident: when doing the "parent read", under SB we Disable `mref`, but the raw ptrs derived from it remain usable. The fact that we can still use the "children" of a reference that is no longer usable is quite nasty and leads to some undesirable effects (in particular it is the major blocker for resolving https://github.com/rust-lang/unsafe-code-guidelines/issues/257). So in Tree Borrows we no longer do that; instead, reading from `root` makes `mref` and all its children read-only.

Due to other improvements in Tree Borrows, the entire Miri test suite still passes with this new behavior, and even the entire libcore and liballoc test suite, except for these 2 cases this PR fixes. Both of these involve code where the programmer wrote `&mut` but then used pointers derived from that reference in ways that alias with the parent pointer, which arguably is violating uniqueness. They are fixed by properly using raw pointers throughout.
2023-02-12 22:29:49 +01:00
Ralf Jung
c3a2e7a809 avoid mixing accesses of ptrs derived from a mutable ref and parent ptrs 2023-02-12 15:16:27 +01:00
bors
adb4bfd25d Auto merge of #105671 - lukas-code:depreciate-char, r=scottmcm
Use associated items of `char` instead of freestanding items in `core::char`

The associated functions and constants on `char` have been stable since 1.52 and the freestanding items have soft-deprecated since 1.62 (https://github.com/rust-lang/rust/pull/95566). This PR ~~marks them as "deprecated in future", similar to the integer and floating point modules (`core::{i32, f32}` etc)~~ replaces all uses of `core::char::*` with `char::*` to prepare for future deprecation of `core::char::*`.
2023-02-12 11:09:06 +00:00
Scott McMurray
5bc328fdef Allow canonicalizing the array::map loop in trusted cases 2023-02-04 16:44:51 -08:00
Scott McMurray
5a7342c3dd Stop using into_iter in array::map 2023-02-04 16:41:35 -08:00
Nikolai Vazquez
734a91358b Remove unnecessary &format!
These were likely from before the `PartialEq<str>` impl for `&String`.
2023-01-21 22:06:42 -05:00
André Vennberg
0b35f448f8 Remove various double spaces in source comments. 2023-01-14 17:22:04 +01:00
Lukas Markeffsky
76e216f29b Use associated items of char instead of freestanding items in core::char 2023-01-14 11:58:41 +01:00
Daniel Henry-Mantilla
48b7e2a5b9
Stabilize ::{core,std}::pin::pin! 2023-01-11 14:09:14 -08:00
nils
c962b07ed3
Rollup merge of #106570 - Xaeroxe:div-duration-tests, r=JohnTitor
add tests for div_duration_* functions

Per https://github.com/rust-lang/rust/issues/63139#issuecomment-817070719

this adds unit tests for the functions that will hopefully effectively demonstrate that `div_duration` is ready to be stabilized.
2023-01-11 17:30:54 +01:00
Jacob Kiesel
9fd744b3e3 add tests for div_duration_* functions 2023-01-07 11:05:33 -07:00
Thom Chiovoloni
a4bf36e87b
Update rand in the stdlib tests, and remove the getrandom feature from it 2023-01-04 14:52:41 -08:00
David Tolnay
257e766c0c
Remove test of static Context
Context is no longer Sync so this doesn't work.

    error[E0277]: `*mut ()` cannot be shared between threads safely
      --> library/core/tests/task.rs:24:21
       |
    24 |     static CONTEXT: Context<'static> = Context::from_waker(&WAKER);
       |                     ^^^^^^^^^^^^^^^^ `*mut ()` cannot be shared between threads safely
       |
       = help: within `Context<'static>`, the trait `Sync` is not implemented for `*mut ()`
       = note: required because it appears within the type `PhantomData<*mut ()>`
       = note: required because it appears within the type `Context<'static>`
       = note: shared static variables must have a type that implements `Sync`
2023-01-02 10:33:23 -08:00
jonathanCogan
78691e3589 Update paths in comments. 2022-12-30 14:00:42 +01:00
jonathanCogan
db47071df2 Replace libstd, libcore, liballoc in line comments. 2022-12-30 14:00:42 +01:00
Pietro Albini
11191279b7 Update bootstrap cfg 2022-12-28 09:18:43 -05:00
Michael Goulet
4b668a1fee
Rollup merge of #103718 - matklad:infer-lazy, r=dtolnay
More inference-friendly API for lazy

The signature for new was

```
fn new<F>(f: F) -> Lazy<T, F>
```

Notably, with `F` unconstrained, `T` can be literally anything, and just `let _ = Lazy::new(|| 92)` would not typecheck.

This historiacally was a necessity -- `new` is a `const` function, it couldn't have any bounds. Today though, we can move `new` under the `F: FnOnce() -> T` bound, which gives the compiler enough data to infer the type of T from closure.
2022-12-27 12:33:33 -08:00
Michal Nazarewicz
28162ad970 char: µoptimise UTF-16 surrogates decoding
According to Godbolt¹, on x86_64 using binary and produces slightly
better code than using subtraction.  Readability of both is pretty
much equivalent so might just as well use the shorter option.

¹ https://rust.godbolt.org/z/9jM3ejbMx
2022-12-23 14:15:33 +01:00
Scott McMurray
9d68a1a74c Tune RepeatWith::try_fold and Take::for_each and Vec::extend_trusted 2022-11-24 19:14:19 -08:00
Manish Goregaokar
1dd515f273
Rollup merge of #83608 - Kimundi:index_many, r=Mark-Simulacrum
Add slice methods for indexing via an array of indices.

Disclaimer: It's been a while since I contributed to the main Rust repo, apologies in advance if this is large enough already that it should've been an RFC.

---

# Update:

- Based on feedback, removed the `&[T]` variant of this API, and removed the requirements for the indices to be sorted.

# Description

This adds the following slice methods to `core`:

```rust
impl<T> [T] {
    pub unsafe fn get_many_unchecked_mut<const N: usize>(&mut self, indices: [usize; N]) -> [&mut T; N];
    pub fn get_many_mut<const N: usize>(&mut self, indices: [usize; N]) -> Option<[&mut T; N]>;
}
```

This allows creating multiple mutable references to disjunct positions in a slice, which previously required writing some awkward code with `split_at_mut()` or `iter_mut()`. For the bound-checked variant, the indices are checked against each other and against the bounds of the slice, which requires `N * (N + 1) / 2` comparison operations.

This has a proof-of-concept standalone implementation here: https://crates.io/crates/index_many

Care has been taken that the implementation passes miri borrow checks, and generates straight-forward assembly (though this was only checked on x86_64).

# Example

```rust
let v = &mut [1, 2, 3, 4];
let [a, b] = v.get_many_mut([0, 2]).unwrap();
std::mem::swap(a, b);
*v += 100;
assert_eq!(v, &[3, 2, 101, 4]);
```

# Codegen Examples

<details>
  <summary>Click to expand!</summary>

Disclaimer: Taken from local tests with the standalone implementation.

## Unchecked Indexing:

```rust
pub unsafe fn example_unchecked(slice: &mut [usize], indices: [usize; 3]) -> [&mut usize; 3] {
    slice.get_many_unchecked_mut(indices)
}
```

```nasm
example_unchecked:
 mov     rcx, qword, ptr, [r9]
 mov     r8, qword, ptr, [r9, +, 8]
 mov     r9, qword, ptr, [r9, +, 16]
 lea     rcx, [rdx, +, 8*rcx]
 lea     r8, [rdx, +, 8*r8]
 lea     rdx, [rdx, +, 8*r9]
 mov     qword, ptr, [rax], rcx
 mov     qword, ptr, [rax, +, 8], r8
 mov     qword, ptr, [rax, +, 16], rdx
 ret
```

## Checked Indexing (Option):

```rust
pub unsafe fn example_option(slice: &mut [usize], indices: [usize; 3]) -> Option<[&mut usize; 3]> {
    slice.get_many_mut(indices)
}
```

```nasm
 mov     r10, qword, ptr, [r9, +, 8]
 mov     rcx, qword, ptr, [r9, +, 16]
 cmp     rcx, r10
 je      .LBB0_7
 mov     r9, qword, ptr, [r9]
 cmp     rcx, r9
 je      .LBB0_7
 cmp     rcx, r8
 jae     .LBB0_7
 cmp     r10, r9
 je      .LBB0_7
 cmp     r9, r8
 jae     .LBB0_7
 cmp     r10, r8
 jae     .LBB0_7
 lea     r8, [rdx, +, 8*r9]
 lea     r9, [rdx, +, 8*r10]
 lea     rcx, [rdx, +, 8*rcx]
 mov     qword, ptr, [rax], r8
 mov     qword, ptr, [rax, +, 8], r9
 mov     qword, ptr, [rax, +, 16], rcx
 ret
.LBB0_7:
 mov     qword, ptr, [rax], 0
 ret
```

## Checked Indexing (Panic):

```rust
pub fn example_panic(slice: &mut [usize], indices: [usize; 3]) -> [&mut usize; 3] {
    let len = slice.len();
    match slice.get_many_mut(indices) {
        Some(s) => s,
        None => {
            let tmp = indices;
            index_many::sorted_bound_check_failed(&tmp, len)
        }
    }
}
```

```nasm
example_panic:
 sub     rsp, 56
 mov     rax, qword, ptr, [r9]
 mov     r10, qword, ptr, [r9, +, 8]
 mov     r9, qword, ptr, [r9, +, 16]
 cmp     r9, r10
 je      .LBB0_6
 cmp     r9, rax
 je      .LBB0_6
 cmp     r9, r8
 jae     .LBB0_6
 cmp     r10, rax
 je      .LBB0_6
 cmp     rax, r8
 jae     .LBB0_6
 cmp     r10, r8
 jae     .LBB0_6
 lea     rax, [rdx, +, 8*rax]
 lea     r8, [rdx, +, 8*r10]
 lea     rdx, [rdx, +, 8*r9]
 mov     qword, ptr, [rcx], rax
 mov     qword, ptr, [rcx, +, 8], r8
 mov     qword, ptr, [rcx, +, 16], rdx
 mov     rax, rcx
 add     rsp, 56
 ret
.LBB0_6:
 mov     qword, ptr, [rsp, +, 32], rax
 mov     qword, ptr, [rsp, +, 40], r10
 mov     qword, ptr, [rsp, +, 48], r9
 lea     rcx, [rsp, +, 32]
 mov     edx, 3
 call    index_many::bound_check_failed
 ud2
```
</details>

# Extensions

There are multiple optional extensions to this.

## Indexing With Ranges

This could easily be expanded to allow indexing with `[I; N]` where `I: SliceIndex<Self>`.  I wanted to keep the initial implementation simple, so I didn't include it yet.

## Panicking Variant

We could also add this method:

```rust
impl<T> [T] {
    fn index_many_mut<const N: usize>(&mut self, indices: [usize; N]) -> [&mut T; N];
}
```

This would work similar to the regular index operator and panic with out-of-bound indices. The advantage would be that we could more easily ensure good codegen with a useful panic message, which is non-trivial with the `Option` variant.

This is implemented in the standalone implementation, and used as basis for the codegen examples here and there.
2022-11-22 01:26:05 -05:00
Marvin Löbel
3fe37b8c6e Add get_many_mut methods to slice 2022-11-20 11:19:11 -05:00
Ralf Jung
428ab59fb7 enable fuzzy_provenance_casts in libcore+tests 2022-11-20 16:04:16 +01:00
Ralf Jung
2bb28c174b avoid non-strict-provenance casts in libcore tests 2022-11-20 09:58:29 +01:00
Yuki Okushi
785237d392
Rollup merge of #104435 - scottmcm:iter-repeat-n, r=thomcc
`VecDeque::resize` should re-use the buffer in the passed-in element

Today it always copies it for *every* appended element, but one of those clones is avoidable.

This adds `iter::repeat_n` (https://github.com/rust-lang/rust/issues/104434) as the primitive needed to do this.  If this PR is acceptable, I'll also use this in `Vec` rather than its custom `ExtendElement` type & infrastructure that is harder to share between multiple different containers:

101e1822c3/library/alloc/src/vec/mod.rs (L2479-L2492)
2022-11-20 13:15:59 +09:00
Lukas Markeffsky
c9c017dfb5 update provenance test
* fix allocation alignment for 16bit platforms
* add edge case where `stride % align != 0` on pointers with provenance
2022-11-19 16:58:02 +01:00
Lukas Markeffsky
9e5d497b67 fix const align_offset implementation 2022-11-19 16:57:58 +01:00
Lukas Markeffsky
2ef9a8ae0f add coretests for is_aligned 2022-11-19 16:47:42 +01:00
Lukas Markeffsky
8cf6b16185 add coretests for const align_offset 2022-11-19 16:47:38 +01:00
Manish Goregaokar
6b09d60f82
Rollup merge of #103378 - nagisa:fix-infinite-offset, r=scottmcm
Fix mod_inv termination for the last iteration

On usize=u64 platforms, the 4th iteration would overflow the `mod_gate` back to 0. Similarly for usize=u32 platforms, the 3rd iteration would overflow much the same way.

I tested various approaches to resolving this, including approaches with `saturating_mul` and `widening_mul` to a double usize. Turns out LLVM likes `mul_with_overflow` the best. In fact now, that LLVM can see the iteration count is limited, it will happily unroll the loop into a nice linear sequence.

You will also notice that the code around the loop got simplified somewhat. Now that LLVM is handling the loop nicely, there isn’t any more reasons to manually unroll the first iteration out of the loop (though looking at the code today I’m not sure all that complexity was necessary in the first place).

Fixes #103361
2022-11-18 17:48:16 -05:00
bors
e702534763 Auto merge of #102935 - ajtribick:display-float-0.5-fixed-0, r=scottmcm
Fix inconsistent rounding of 0.5 when formatted to 0 decimal places

As described in #70336, when displaying values to zero decimal places the value of 0.5 is rounded to 1, which is inconsistent with the display of other half-integer values which round to even.

From testing the flt2dec implementation, it looks like this comes down to the condition in the fixed-width Dragon implementation where an empty buffer is treated as a case to apply rounding up. I believe the change below fixes it and updates only the relevant tests.

Nevertheless I am aware this is very much a core piece of functionality, so please take a very careful look to make sure I haven't missed anything. I hope this change does not break anything in the wider ecosystem as having a consistent rounding behaviour in floating point formatting is in my opinion a useful feature to have.

Resolves #70336
2022-11-16 07:20:30 +00:00
Scott McMurray
d62b903892 VecDeque::resize should re-use the buffer in the passed-in element
Today it always copies it for *every* appended element, but one of those clones is avoidable.
2022-11-15 00:53:26 -08:00