Commit Graph

1792 Commits

Author SHA1 Message Date
bors
2c106885d5 Auto merge of #85457 - jyn514:remove-doc-include, r=GuillaumeGomez
Remove `doc(include)`

This nightly feature is redundant now that `extended_key_value_attributes` is stable (https://github.com/rust-lang/rust/pull/83366). `@rust-lang/rustdoc` not sure if you think this needs FCP; there was already an FCP in #82539, but technically it was for deprecating, not removing the feature altogether.

This should not be merged before #83366.

cc `@petrochenkov`
2021-06-05 03:36:26 +00:00
Felix S. Klock II
5f6016f125 Revert PRs 81238 and 82967 (which made copy and copy_nonoverlapping intrinsics).
This is to address issue 84297.
2021-06-04 16:44:28 -04:00
Felix S. Klock II
cebfcd3256 Revert tests added by PR 81167. 2021-06-04 16:44:28 -04:00
Felix S. Klock II
9d96b0ed8c Revert effects of PRs 81167 and 83091.
This is preparation for reverting 81238 for short-term resolution of issue 84297.
2021-06-04 16:03:45 -04:00
Joshua Nelson
7411a9e7cc rustdoc: link to stable/beta docs consistently in documentation
## User-facing changes

- Intra-doc links to primitives that currently go to rust-lang.org/nightly/std/primitive.x.html will start going to channel that rustdoc was built with. Nightly will continue going to /nightly; Beta will link to /beta; stable compilers will link to /1.52.1 (or whatever version they were built as).
- Cross-crate links from std to core currently go to /nightly unconditionally. They will start going to /1.52.0 on stable channels (but remain the same on nightly channels).
- Intra-crate links from std to std (or core to core) currently go to the same URL they are hosted at; they will continue to do so. Notably, this is different from everything else because it can preserve the distinction between /stable and /1.52.0 by using relative links.

Note that "links" includes both intra-doc links and rustdoc's own
automatically generated hyperlinks.

 ## Implementation changes

- Update the testsuite to allow linking to /beta and /1.52.1 in docs
- Use an html_root_url for the standard library that's dependent on the channel

  This avoids linking to nightly docs on stable.

- Update rustdoc to use channel-dependent links for primitives from an
  unknown crate

- Set DOC_RUST_LANG_ORG_CHANNEL from bootstrap to ensure it's in sync
- Include doc.rust-lang.org in the channel
2021-06-04 14:18:21 -04:00
Joshua Nelson
15fec1fb80 Remove doc(include) 2021-06-04 08:05:54 -04:00
Yuki Okushi
0a12431962
Rollup merge of #85963 - m-ou-se:constructor-type-name, r=yaahc
Show `::{{constructor}}` in std::any::type_name().

Fix #84666

Before:
```
[src/main.rs:6] type_name::<T>() = "playground::Velocity"
[src/main.rs:6] type_name::<T>() = "playground::Velocity"
```

After:
```
[src/main.rs:6] type_name::<T>() = "scratchpad::Velocity::{{constructor}}"
[src/main.rs:6] type_name::<T>() = "scratchpad::Velocity"
```

cc ``@scottmcm``
2021-06-04 13:43:02 +09:00
Yuki Okushi
f6aaf05363
Rollup merge of #85888 - steffahn:fix_internal_trustedrandomaccess_docs, r=Mark-Simulacrum
Fix typo in internal documentation for `TrustedRandomAccess`

`next_back` is a method of DoubleEndedIterator, not Iterator.
2021-06-04 13:42:55 +09:00
The8472
dbc43ece10 Revert "implement TrustedRandomAccess for Take iterator adapter"
This reverts commit 37a5b515e9.
2021-06-03 21:47:59 +02:00
Mara Bos
e3b19e5c25 Add test for issue 84666. 2021-06-03 16:13:45 +02:00
Yuki Okushi
bd18686b5f
Rollup merge of #85877 - est31:intra_doc_links, r=jyn514
Intra doc link-ify a reference to a function
2021-06-03 14:35:34 +09:00
Muhammad Mominul Huque
507d97b26e Update expressions where we can use array's IntoIterator implementation 2021-06-02 16:09:04 +06:00
Muhammad Mominul Huque
01d4d46f66 Replace IntoIter::new with IntoIterator::into_iter in std 2021-06-02 16:09:04 +06:00
bors
c4f186f0ea Auto merge of #85687 - m-ou-se:new-prelude, r=yaahc
New prelude

RFC: rust-lang/rfcs#3114
Tracking issue: https://github.com/rust-lang/rust/issues/85684
2021-06-02 02:36:44 +00:00
Frank Steffahn
c5233b7d4b Fix typo in internal documentation for TrustedRandomAccess
`next_back` is a method of DoubleEndedIterator, not Iterator.
2021-06-01 13:18:20 +02:00
Guillaume Gomez
f4d3f32f45
Rollup merge of #85826 - jsha:npo, r=joshtriplett
Mention "null pointer optimization" in option docs.

I had seen people discuss "null pointer optimization," but when I tried to find official documentation (using Google), the `std::option` page didn't show up, because it doesn't use that term. Hopefully adding the term will help others find it in the future.
2021-06-01 11:29:44 +02:00
est31
a0228d9b87 Intra doc link-ify a reference to a function 2021-06-01 05:04:48 +02:00
bors
bff138dbd9 Auto merge of #85754 - the8472:revert-83770, r=Mark-Simulacrum
Revert "Auto merge of #83770 - the8472:tra-extend, r=Mark-Simulacrum"

Due to a performance regression that didn't show up in the original perf run
this reverts commit 9111b8ae97 (#83770), reversing
changes made to 9a700d2947.

Since since is expected to have the inverse impact it should probably be rollup=never.

r? `@Mark-Simulacrum`
2021-05-30 04:12:44 +00:00
bors
9a72afa7dd Auto merge of #83772 - jhpratt:revamp-step-trait, r=Mark-Simulacrum
Make `Step` trait safe to implement

This PR makes a few modifications to the `Step` trait that I believe better position it for stabilization in the short term. In particular,

1. `unsafe trait TrustedStep` is introduced, indicating that the implementation of `Step` for a given type upholds all stated invariants (which have remained unchanged). This is gated behind a new `trusted_step` feature, as stabilization is realistically blocked on min_specialization.
2. The `Step` trait is internally specialized on the `TrustedStep` trait, which avoids a serious performance regression.
3. `TrustedLen` is implemented for `T: TrustedStep` as the latter's invariants subsume the former's.
4. The `Step` trait is no longer `unsafe`, as the invariants must not be relied upon by unsafe code (unless the type implements `TrustedStep`).
5. `TrustedStep` is implemented for all types that implement `Step` in the standard library and compiler.
6. The `step_trait_ext` feature is merged into the `step_trait` feature. I was unable to find any reasoning for the features being split; the `_unchecked` methods need not necessarily be stabilized at the same time, but I think it is useful to have them under the same feature flag.

All existing implementations of `Step` will be broken, as it is not possible to `unsafe impl` a safe trait. Given this trait only exists on nightly, I feel this breakage is acceptable. The blanket `impl<T: Step> TrustedLen for T` will likely cause some minor breakage, but this should be covered by the equivalent impl for `TrustedStep`.

Hopefully these changes are sufficient to place `Step` in decent position for stabilization, which would allow user-defined types to be used with `a..b` syntax.
2021-05-30 01:21:39 +00:00
Jacob Hoffman-Andrews
79575a1a8e Mention "null pointer optimization" in option docs. 2021-05-29 09:57:12 -07:00
ltdk
2a40f2423a Add inherent unchecked_shl, unchecked_shr to integers 2021-05-28 22:54:39 -04:00
Guillaume Gomez
e30192ac5c
Rollup merge of #85730 - Smittyvb:iter-min-max-floats, r=m-ou-se
Mention workaround for floats in Iterator::{min, max}

`Iterator::{min, max}` can't be used with iterators of floats due to NaN issues. This suggests a workaround in the documentation of those functions.
2021-05-27 20:08:21 +02:00
Peter Todd
5b2076ff01
Revert #85176 addition of clone_from for ManuallyDrop
Forwarding `clone_from` to the inner value changes the observable
behavior, as previously the inner value would *not* be dropped by the
default implementation.
2021-05-27 14:01:16 -04:00
The8472
f72c60a39a Revert "Auto merge of #83770 - the8472:tra-extend, r=Mark-Simulacrum"
Due to a performance regression that didn't show up in the original perf run
this reverts commit 9111b8ae97, reversing
changes made to 9a700d2947.
2021-05-27 18:17:09 +02:00
Dylan DPC
de1d7dbd0f
Rollup merge of #85689 - m-ou-se:array-intoiter-3, r=estebank
Remove Iterator #[rustc_on_unimplemented]s that no longer apply.

Now that `IntoIterator` is implemented for arrays, all the `rustc_on_unimplemented` for arrays of ranges (e.g. `for _ in [1..3] {}`) no longer apply, since they are now valid Rust.

Separated these from #85670, because we should discuss a potential new (clippy?) lint for these.

Until Rust 1.52, `for _ in [1..3] {}` produced:

```
error[E0277]: `[std::ops::Range<{integer}>; 1]` is not an iterator
 --> src/main.rs:2:14
  |
2 |     for _ in [1..3] {}
  |              ^^^^^^ if you meant to iterate between two values, remove the square brackets
  |
  = help: the trait `std::iter::Iterator` is not implemented for `[std::ops::Range<{integer}>; 1]`
  = note: `[start..end]` is an array of one `Range`; you might have meant to have a `Range` without the brackets: `start..end`
  = note: required by `std::iter::IntoIterator::into_iter`
```

But in Rust 1.53 and later, it compiles fine. It iterates over the array by value, for one iteration with the element `1..3`.

This is probably a mistake, which is no longer caught. Should we have a lint for it? Should Clippy have a lint for it?

cc ```@estebank``` ```@flip1995```

cc https://github.com/rust-lang/rust/issues/84513
2021-05-27 03:02:10 +02:00
Smittyvb
b00f6fc8a1
don't use unneeded closure
Co-authored-by: Alphyr <47725341+a1phyr@users.noreply.github.com>
2021-05-26 20:38:50 -04:00
Smittyvb
7146a05a43
don't use unneeded closure
Co-authored-by: Alphyr <47725341+a1phyr@users.noreply.github.com>
2021-05-26 20:38:43 -04:00
Jacob Pratt
35ce36812a
Unify feature flags as step_trait
While stdlib implementations of the unchecked methods require unchecked
math, there is no reason to gate it behind this for external users. The
reasoning for a separate `step_trait_ext` feature is unclear, and as
such has been merged as well.
2021-05-26 18:07:10 -04:00
Jacob Pratt
bc2f0fb5a9
Specialize implementations
Implementations in stdlib are now optimized as they were before.
2021-05-26 18:07:09 -04:00
Smitty
e7a3ada210 Mention float workaround in Iterator::{min,max} 2021-05-26 17:15:54 -04:00
bors
9111b8ae97 Auto merge of #83770 - the8472:tra-extend, r=Mark-Simulacrum
Add `TrustedRandomAccess` specialization for `Vec::extend()`

This should do roughly the same as the `TrustedLen` specialization but result in less IR by using `__iterator_get_unchecked`
instead of `Iterator::for_each`

Conflicting specializations are manually prioritized by grouping them under yet another helper trait.
2021-05-26 19:22:31 +00:00
Dylan DPC
9ee87c7e00
Rollup merge of #85712 - BlackHoleFox:fix-iter-typo, r=jyn514
Fix typo in core::array::IntoIter comment

Saw a small typo reading some internal comments and decided to just throw this up to fix it for future readers.
2021-05-26 13:32:12 +02:00
Dylan DPC
f3b10dd709
Rollup merge of #85679 - hch12907:master, r=Mark-Simulacrum
Remove num_as_ne_bytes feature

From the discussion in #76976, it is determined that eventual results of the safe transmute work as a more general mechanism will let these conversions happen in safe code without needing specialized methods.

Merging this PR closes #76976 and resolves #64464. Several T-libs members have raised their opinion that it doesn't pull its weight as a standalone method, and so we should not track it as a specific thing to add.
2021-05-26 13:32:11 +02:00
Dylan DPC
3c2a709620
Rollup merge of #85678 - lukas-code:matches2021, r=dtolnay
fix `matches!` and `assert_matches!` on edition 2021

Previously this code failed to compile on edition 2021. [(Playground)](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=53960f2f051f641777b9e458da747707)
```rust
fn main() {
    matches!((), ());
}
```
```
   Compiling playground v0.0.1 (/playground)
error: `$pattern:pat` may be followed by `|`, which is not allowed for `pat` fragments
    |
    = note: allowed there are: `=>`, `,`, `=`, `if` or `in`

error: aborting due to previous error

error: could not compile `playground`

To learn more, run the command again with --verbose.
```
2021-05-26 13:32:10 +02:00
Dylan DPC
12ab323d0e
Rollup merge of #85670 - m-ou-se:array-intoiter-1, r=scottmcm
Remove arrays/IntoIterator message from Iterator trait.

Arrays implement IntoIterator since 1.53.

cc https://github.com/rust-lang/rust/issues/84513
2021-05-26 13:32:09 +02:00
BlackHoleFox
d1b69cf89b Fix typo in core::array::IntoIter comment 2021-05-26 02:37:39 -05:00
Yuki Okushi
587de8e5f9
Rollup merge of #85645 - scottmcm:demote-from-into-try, r=yaahc
Demote `ControlFlow::{from|into}_try` to `pub(crate)`

They have mediocre names and non-obvious semantics, so personally I don't think they're worth trying to stabilize, and thus might as well just be internal (they're used for convenience in iterator adapters), not something shown in the rustdocs.

I don't think anyone actually wanted to use them outside `core` -- they just got made public-but-unstable along with the whole type in https://github.com/rust-lang/rust/pull/76204 that promoted `LoopState` from an internal type to the exposed `ControlFlow` type.

cc https://github.com/rust-lang/rust/issues/75744, the tracking issue they mention.
cc https://github.com/rust-lang/rust/pull/85608, the PR where I'm proposing stabilizing the type.
2021-05-26 13:31:02 +09:00
Yuki Okushi
b7b9ce3df8
Rollup merge of #85610 - SkiFire13:fix-copy-within-provenance, r=oli-obk
Fix pointer provenance in <[T]>::copy_within

Previously the `self.as_mut_ptr()` invalidated the pointer created by the first `self.as_ptr()`. This also triggered miri when run with `-Zmiri-track-raw-pointers`
2021-05-26 13:31:00 +09:00
Jacob Pratt
a875876027
Make Range implementation safe 2021-05-26 00:12:06 -04:00
Jacob Pratt
641c8cd875
Limit TrustedLen impls to core types 2021-05-26 00:12:06 -04:00
Mara Bos
caf6faf951 Remove Iterator #[rustc_on_unimplemented]s that no longer apply. 2021-05-25 20:20:05 +02:00
Mara Bos
04a4a8225b Add new traits to 2021 prelude. 2021-05-25 19:58:50 +02:00
Mara Bos
e37ef7a842 Add tracking issue for edition-specific preludes. 2021-05-25 19:58:39 +02:00
Hoe Hao Cheng
0baf89810f Remove num_as_ne_bytes feature 2021-05-25 22:48:08 +08:00
Lukas Markeffsky
3ed90e2424 fix matches! and assert_matches! on edition 2021 2021-05-25 16:44:20 +02:00
Mara Bos
8d954fa589 Remove arrays/IntoIterator message from Iterator trait. 2021-05-25 15:48:14 +02:00
Guillaume Gomez
46615598a9
Rollup merge of #85644 - tialaramex:master, r=dtolnay
Better English for documenting when to use unimplemented!()

I don't think "plan of using" is correct here. I considered "plan on using" but eventually decided "plan to use" is better.
2021-05-25 13:05:15 +02:00
bors
a7890c7952 Auto merge of #84985 - pietroalbini:bootstrap-1.54, r=Mark-Simulacrum
Bump bootstrap compiler to beta 1.53.0

This PR bumps the bootstrap compiler to version 1.53.0 beta, as part of our usual release process (this was supposed to be Wednesday's step, but creating the beta release took longer than expected).

The PR also includes the "Bootstrap: skip rustdoc fingerprint for building docs" commit, see the reasoning [on Zulip](https://zulip-archive.rust-lang.org/241545trelease/88450153betabootstrap.html).

r? `@Mark-Simulacrum`
2021-05-25 05:48:00 +00:00
Scott McMurray
b63f7f9965 Demote ControlFlow::{from|into}_try to pub(crate) 2021-05-24 14:29:44 -07:00
Nick Lamb
54ccf95af2 Better English for documenting when to use unimplemented!() 2021-05-24 22:21:05 +01:00
bors
ef0ec303fa Auto merge of #85596 - scottmcm:more-on-unimplemented, r=estebank
Extend `rustc_on_implemented` to improve more `?` error messages

`_Self` could match the generic definition; this adds that functionality for matching the generic definition of type parameters too.

Your advice welcome on the wording of all these messages, and which things belong in the message/label/note.

r? `@estebank`
2021-05-24 15:24:38 +00:00
Pietro Albini
9e22b844dd remove cfg(bootstrap) 2021-05-24 11:07:48 -04:00
bors
6f6919231e Auto merge of #85601 - klensy:padint-example-fix, r=dtolnay
fix pad_integral example

pad_integral's parameter `is_nonnegative - whether the original integer was either positive or zero`, but in example it checked as `self.nb > 0`, so it previously printed `-0` for `format!("{}", Foo::new(0)`, what is wrong.
2021-05-24 10:02:55 +00:00
Scott McMurray
65a0a8b386 Stabilize ops::ControlFlow (just the type) 2021-05-23 13:20:05 -07:00
Giacomo Stevanato
d7341f3c4b Don't reborrow self when computing the dest pointer in <[T]>::copy_within 2021-05-23 22:00:32 +02:00
bstrie
ed75d62fd5
Update std::array module doc header
Extremely outdated; not only are traits implemented on arrays of arbitrary length, those implementations are documented on the primitive type, not in this module.
2021-05-23 15:55:27 -04:00
Scott McMurray
8be67998a1 Extend rustc_on_implemented to improve a ?-on-ControlFlow error message 2021-05-23 07:18:02 -07:00
klensy
7c0db6f0f1 fix pad_integral example 2021-05-23 14:48:16 +03:00
bors
af2ed1b518 Auto merge of #85482 - scottmcm:more-try-bootstrap, r=yaahc
`#[cfg(bootstrap)]` out `NoneError` and other v1 try_trait stuff

Closes #46871

r? `@yaahc`
2021-05-21 13:46:04 +00:00
bors
35bab923c8 Auto merge of #85486 - RalfJung:rollup-4ibcxuu, r=RalfJung
Rollup of 8 pull requests

Successful merges:

 - #84717 (impl FromStr for proc_macro::Literal)
 - #85169 (Add method-toggle to <details> for methods)
 - #85287 (Expose `Concurrent` (private type in public i'face))
 - #85315 (adding time complexity for partition_in_place iter method)
 - #85439 (Add diagnostic item to `CStr`)
 - #85464 (Fix UB in documented example for `ptr::swap`)
 - #85470 (Fix invalid CSS rules for a:hover)
 - #85472 (CTFE Machine: do not expose Allocation)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2021-05-20 07:39:24 +00:00
bors
a426fc37f2 Auto merge of #85391 - Mark-Simulacrum:opt-tostring, r=scottmcm
Avoid zero-length memcpy in formatting

This has two separate and somewhat orthogonal commits. The first change adjusts the ToString general impl for all types that implement Display; it no longer uses the full format machinery, rather directly falling onto a `std::fmt::Display::fmt` call. The second change directly adjusts the general core::fmt::write function which handles the production of format_args! to avoid zero-length push_str calls.

Both changes target the fact that push_str will still call memmove internally (or a similar function), as it doesn't know the length of the passed string. For zero-length strings in particular, this is quite expensive, and even for very short (several bytes long) strings, this is also expensive. Future work in this area may wish to have us fallback to write_char or similar, which may be cheaper on the (typically) short strings between the interpolated pieces in format_args!.
2021-05-20 00:55:27 +00:00
Ralf Jung
2065c4b096
Rollup merge of #85464 - steffahn:fix_ub_in_ptr_swap_docs, r=dtolnay
Fix UB in documented example for `ptr::swap`

Compare [this (short) discussion on zulip](https://rust-lang.zulipchat.com/#narrow/stream/122651-general/topic/Pointers.20to.20overlapping.20arrays) (or [in the archive](https://zulip-archive.rust-lang.org/122651general/92017Pointerstooverlappingarrays.html), if you don’t have an account).

``@rustbot`` label T-doc T-libs
2021-05-20 00:19:08 +02:00
Ralf Jung
c1c4cd57b3
Rollup merge of #85315 - satylogin:master, r=yaahc
adding time complexity for partition_in_place iter method

I feel that one thing missing from rust docs compared to cpp references is existence of time complexity for all methods and functions. While it would be humongous task to include it for everything in single go, it is still doable if we as community keep on adding it in relevant places as and when we find them.

This PR adds the time complexity for partition_in_place method in iter.
2021-05-20 00:19:02 +02:00
bors
df70463ea5 Auto merge of #85340 - the8472:no-inplaceiterable-on-peekable, r=yaahc
remove InPlaceIterable marker from Peekable due to unsoundness

The unsoundness is not in Peekable per se, it rather is due to the
interaction between Peekable being able to hold an extra item
and vec::IntoIter's clone implementation shortening the allocation.

An alternative solution would be to change IntoIter's clone implementation
to keep enough spare capacity available.

fixes #85322
2021-05-19 21:50:45 +00:00
Scott McMurray
58a85d55e8 #[cfg(bootstrap)] out the v1 try_trait stuff 2021-05-19 13:32:15 -07:00
Frank Steffahn
f9752b4930 Fix UB in documented example for ptr::swap 2021-05-19 14:09:23 +02:00
bors
9f8012e3aa Auto merge of #85458 - jackh726:rollup-zvvybmt, r=jackh726
Rollup of 8 pull requests

Successful merges:

 - #83366 (Stabilize extended_key_value_attributes)
 - #83767 (Fix v0 symbol mangling bug)
 - #84883 (compiletest: "fix" FileCheck with --allow-unused-prefixes)
 - #85274 (Only pass --[no-]gc-sections if linker is GNU ld.)
 - #85297 (bootstrap: build cargo only if requested in tools)
 - #85396 (rustdoc: restore header sizes)
 - #85425 (Fix must_use on `Option::is_none`)
 - #85438 (Fix escape handling)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2021-05-19 04:44:09 +00:00
Jack Huey
e113a4f77b
Rollup merge of #85425 - mbartlett21:patch-1, r=scottmcm
Fix must_use on `Option::is_none`

This fixes the `#[must_use = ...]` on `Option::is_none` to have a working suggestion.
2021-05-18 22:36:18 -04:00
Jack Huey
3c99dcd82d
Rollup merge of #83366 - jyn514:stabilize-key-value-attrs, r=petrochenkov
Stabilize extended_key_value_attributes

Closes https://github.com/rust-lang/rust/issues/44732. Closes https://github.com/rust-lang/rust/issues/78835. Closes https://github.com/rust-lang/rust/issues/82768 (by making it irrelevant).

 # Stabilization report

 ## Summary

This stabilizes using macro expansion in key-value attributes, like so:

 ```rust
 #[doc = include_str!("my_doc.md")]
 struct S;

 #[path = concat!(env!("OUT_DIR"), "/generated.rs")]
 mod m;
 ```

See Petrochenkov's excellent blog post [on internals](https://internals.rust-lang.org/t/macro-expansion-points-in-attributes/11455)
for alternatives that were considered and rejected ("why accept no more and no less?")

This has been available on nightly since 1.50 with no major issues.

## Notes

### Accepted syntax

The parser accepts arbitrary Rust expressions in this position, but any expression other than a macro invocation will ultimately lead to an error because it is not expected by the built-in expression forms (e.g., `#[doc]`).  Note that decorators and the like may be able to observe other expression forms.

### Expansion ordering

Expansion of macro expressions in "inert" attributes occurs after decorators have executed, analogously to macro expressions appearing in the function body or other parts of decorator input.

There is currently no way for decorators to accept macros in key-value position if macro expansion must be performed before the decorator executes (if the macro can simply be copied into the output for later expansion, that can work).

## Test cases

 - https://github.com/rust-lang/rust/blob/master/src/test/ui/attributes/key-value-expansion-on-mac.rs
 - https://github.com/rust-lang/rust/blob/master/src/test/rustdoc/external-doc.rs

The feature has also been dogfooded extensively in the compiler and
standard library:

- https://github.com/rust-lang/rust/pull/83329
- https://github.com/rust-lang/rust/pull/83230
- https://github.com/rust-lang/rust/pull/82641
- https://github.com/rust-lang/rust/pull/80534

## Implementation history

- Initial proposal: https://github.com/rust-lang/rust/issues/55414#issuecomment-554005412
- Experiment to see how much code it would break: https://github.com/rust-lang/rust/pull/67121
- Preliminary work to restrict expansion that would conflict with this
feature: https://github.com/rust-lang/rust/pull/77271
- Initial implementation: https://github.com/rust-lang/rust/pull/78837
- Fix for an ICE: https://github.com/rust-lang/rust/pull/80563

## Unresolved Questions

~~https://github.com/rust-lang/rust/pull/83366#issuecomment-805180738 listed some concerns, but they have been resolved as of this final report.~~

 ## Additional Information

 There are two workarounds that have a similar effect for `#[doc]`
attributes on nightly. One is to emulate this behavior by using a limited version of this feature that was stabilized for historical reasons:

```rust
macro_rules! forward_inner_docs {
    ($e:expr => $i:item) => {
        #[doc = $e]
        $i
    };
}

forward_inner_docs!(include_str!("lib.rs") => struct S {});
```

This also works for other attributes (like `#[path = concat!(...)]`).
The other is to use `doc(include)`:

```rust
 #![feature(external_doc)]
 #[doc(include = "lib.rs")]
 struct S {}
```

The first works, but is non-trivial for people to discover, and
difficult to read and maintain. The second is a strange special-case for
a particular use of the macro. This generalizes it to work for any use
case, not just including files.

I plan to remove `doc(include)` when this is stabilized
(https://github.com/rust-lang/rust/pull/82539). The `forward_inner_docs`
workaround will still compile without warnings, but I expect it to be
used less once it's no longer necessary.
2021-05-18 22:35:54 -04:00
bors
3d31363338 Auto merge of #85176 - a1phyr:impl_clone_from, r=yaahc
Override `clone_from` for some types

Override `clone_from` method of the `Clone` trait for:
- `cell::RefCell`
- `cmp::Reverse`
- `io::Cursor`
- `mem::ManuallyDrop`

This can bring performance improvements.
2021-05-19 02:17:41 +00:00
The8472
60a900ee10 remove InPlaceIterable marker from Peekable due to unsoundness
The unsoundness is not in Peekable per se, it rather is due to the
interaction between Peekable being able to hold an extra item
and vec::IntoIter's clone implementation shortening the allocation.

An alternative solution would be to change IntoIter's clone implementation
to keep enough spare capacity available.
2021-05-19 01:41:09 +02:00
bors
4e3e6db011 Auto merge of #84767 - scottmcm:try_trait_actual, r=lcnr
Implement the new desugaring from `try_trait_v2`

~~Currently blocked on https://github.com/rust-lang/rust/issues/84782, which has a PR in https://github.com/rust-lang/rust/pull/84811~~ Rebased atop that fix.

`try_trait_v2` tracking issue: https://github.com/rust-lang/rust/issues/84277

Unfortunately this is already touching a ton of things, so if you have suggestions for good ways to split it up, I'd be happy to hear them.  (The combination between the use in the library, the compiler changes, the corresponding diagnostic differences, even MIR tests mean that I don't really have a great plan for it other than trying to have decently-readable commits.

r? `@ghost`

~~(This probably shouldn't go in during the last week before the fork anyway.)~~ Fork happened.
2021-05-18 20:50:01 +00:00
Guillaume Gomez
a181806b8c
Rollup merge of #85338 - lopopolo:core-iter-repeat-gh-81292, r=joshtriplett
Implement more Iterator methods on core::iter::Repeat

`core::iter::Repeat` always returns the same element, which means we can
do better than implementing most `Iterator` methods in terms of
`Iterator::next`.

Fixes #81292.

#81292 raises the question of whether these changes violate the contract of `core::iter::Repeat`, but as far as I can tell `core::iter::repeat` doesn't make any guarantees around how it calls `Clone::clone`.
2021-05-18 14:08:46 +02:00
Joshua Nelson
e48b6b4599 Stabilize extended_key_value_attributes
# Stabilization report

 ## Summary

This stabilizes using macro expansion in key-value attributes, like so:

 ```rust
 #[doc = include_str!("my_doc.md")]
 struct S;

 #[path = concat!(env!("OUT_DIR"), "/generated.rs")]
 mod m;
 ```

See the changes to the reference for details on what macros are allowed;
see Petrochenkov's excellent blog post [on internals](https://internals.rust-lang.org/t/macro-expansion-points-in-attributes/11455)
for alternatives that were considered and rejected ("why accept no more
and no less?")

This has been available on nightly since 1.50 with no major issues.

 ## Notes

 ### Accepted syntax

The parser accepts arbitrary Rust expressions in this position, but any expression other than a macro invocation will ultimately lead to an error because it is not expected by the built-in expression forms (e.g., `#[doc]`).  Note that decorators and the like may be able to observe other expression forms.

 ### Expansion ordering

Expansion of macro expressions in "inert" attributes occurs after decorators have executed, analogously to macro expressions appearing in the function body or other parts of decorator input.

There is currently no way for decorators to accept macros in key-value position if macro expansion must be performed before the decorator executes (if the macro can simply be copied into the output for later expansion, that can work).

 ## Test cases

 - https://github.com/rust-lang/rust/blob/master/src/test/ui/attributes/key-value-expansion-on-mac.rs
 - https://github.com/rust-lang/rust/blob/master/src/test/rustdoc/external-doc.rs

The feature has also been dogfooded extensively in the compiler and
standard library:

- https://github.com/rust-lang/rust/pull/83329
- https://github.com/rust-lang/rust/pull/83230
- https://github.com/rust-lang/rust/pull/82641
- https://github.com/rust-lang/rust/pull/80534

 ## Implementation history

- Initial proposal: https://github.com/rust-lang/rust/issues/55414#issuecomment-554005412
- Experiment to see how much code it would break: https://github.com/rust-lang/rust/pull/67121
- Preliminary work to restrict expansion that would conflict with this
feature: https://github.com/rust-lang/rust/pull/77271
- Initial implementation: https://github.com/rust-lang/rust/pull/78837
- Fix for an ICE: https://github.com/rust-lang/rust/pull/80563

 ## Unresolved Questions

~~https://github.com/rust-lang/rust/pull/83366#issuecomment-805180738 listed some concerns, but they have been resolved as of this final report.~~

 ## Additional Information

 There are two workarounds that have a similar effect for `#[doc]`
attributes on nightly. One is to emulate this behavior by using a limited version of this feature that was stabilized for historical reasons:

```rust
macro_rules! forward_inner_docs {
    ($e:expr => $i:item) => {
        #[doc = $e]
        $i
    };
}

forward_inner_docs!(include_str!("lib.rs") => struct S {});
```

This also works for other attributes (like `#[path = concat!(...)]`).
The other is to use `doc(include)`:

```rust
 #![feature(external_doc)]
 #[doc(include = "lib.rs")]
 struct S {}
```

The first works, but is non-trivial for people to discover, and
difficult to read and maintain. The second is a strange special-case for
a particular use of the macro. This generalizes it to work for any use
case, not just including files.

I plan to remove `doc(include)` when this is stabilized. The
`forward_inner_docs` workaround will still compile without warnings, but
I expect it to be used less once it's no longer necessary.
2021-05-18 01:01:36 -04:00
mbartlett21
18b0e7bf2c
Fix must_use on Option::is_none
This fixes the `#[must_use = ...]` on `Option::is_none` to have a working suggestion.
2021-05-18 13:40:26 +10:00
Satyarth Agrahari
85e4177184 adding algorithm explanation for partition_in_place iter method and bounding complexity to current implementation 2021-05-18 07:59:16 +05:30
Mark Rousskov
c7c9336469 Avoid zero-length write_str in fmt::write 2021-05-17 09:30:58 -04:00
Mark Rousskov
80ac15f667 Optimize default ToString impl
This avoids a zero-length write_str call, which boils down to a zero-length
memmove and ultimately costs quite a few instructions on some workloads.

This is approximately a 0.33% instruction count win on diesel-check.
2021-05-17 09:29:02 -04:00
VillSnow
5db13c529c Make partition_point to forward to binary_search_by 2021-05-17 19:13:41 +09:00
The8472
39e492a2be mark internal inplace_iteration traits as hidden 2021-05-16 19:36:21 +02:00
Ryan Lopopolo
963bd3b643
Implement more Iterator methods on core::iter::Repeat
`core::iter::Repeat` always returns the same element, which means we can
do better than implementing most `Iterator` methods in terms of
`Iterator::next`.

Fixes #81292.
2021-05-15 10:37:05 -07:00
Guillaume Gomez
62b834fb9f
Rollup merge of #84751 - Soveu:is_char_boundary_opt, r=Amanieu
str::is_char_boundary - slight optimization

Current `str::is_char_boundary` implementation emits slightly more instructions, because it includes an additional branch for `index == s.len()`
```rust
pub fn is_char_boundary(s: &str, index: usize) -> bool {
    if index == 0 || index == s.len() {
        return true;
    }
    match s.as_bytes().get(index) {
        None => false,
        Some(&b) => (b as i8) >= -0x40,
    }
}
```
Just changing the place of `index == s.len()` merges it with `index < s.len()` from `s.as_bytes().get(index)`
```rust
pub fn is_char_boundary2(s: &str, index: usize) -> bool {
    if index == 0 {
        return true;
    }

    match s.as_bytes().get(index) {
        // For some reason, LLVM likes this comparison here more
        None => index == s.len(),
        // This is bit magic equivalent to: b < 128 || b >= 192
        Some(&b) => (b as i8) >= -0x40,
    }
}
```
This one has better codegen on every platform, except powerpc
<details><summary>x86 codegen</summary>
<p>

```nasm
example::is_char_boundary:
        mov     al, 1
        test    rdx, rdx
        je      .LBB0_5
        cmp     rsi, rdx
        je      .LBB0_5
        cmp     rsi, rdx
        jbe     .LBB0_3
        cmp     byte ptr [rdi + rdx], -65
        setg    al
.LBB0_5:
        ret
.LBB0_3:
        xor     eax, eax
        ret

example::is_char_boundary2:
        test    rdx, rdx
        je      .LBB1_1
        cmp     rsi, rdx
        jbe     .LBB1_4
        cmp     byte ptr [rdi + rdx], -65
        setg    al
        ret
.LBB1_1:  ; technically this branch is the same as LBB1_4
        mov     al, 1
        ret
.LBB1_4:
        sete    al
        ret
 ```
</p>
</details>

<details><summary>aarch64 codegen</summary>
<p>

```as
example::is_char_boundary:
        mov     x8, x0
        mov     w0, #1
        cbz     x2, .LBB0_4
        cmp     x1, x2
        b.eq    .LBB0_4
        b.ls    .LBB0_5
        ldrsb   w8, [x8, x2]
        cmn     w8, #65
        cset    w0, gt
.LBB0_4:
        ret
.LBB0_5:
        mov     w0, wzr
        ret

example::is_char_boundary2:
        cbz     x2, .LBB1_3
        cmp     x1, x2
        b.ls    .LBB1_4
        ldrsb   w8, [x0, x2]
        cmn     w8, #65
        cset    w0, gt
        ret
.LBB1_3:
        mov     w0, #1
        ret
.LBB1_4:
        cset    w0, eq
        ret
```

</p>
</details>

<details><summary>riscv64gc codegen</summary>
<p>

example::is_char_boundary:
        seqz    a3, a2
        xor     a4, a1, a2
        seqz    a4, a4
        or      a4, a4, a3
        addi    a3, zero, 1
        bnez    a4, .LBB0_3
        bgeu    a2, a1, .LBB0_4
        add     a0, a0, a2
        lb      a0, 0(a0)
        addi    a1, zero, -65
        slt     a3, a1, a0
.LBB0_3:
        mv      a0, a3
        ret
.LBB0_4:
        mv      a0, zero
        ret

example::is_char_boundary2:
        beqz    a2, .LBB1_3
        bgeu    a2, a1, .LBB1_4
        add     a0, a0, a2
        lb      a0, 0(a0)
        addi    a1, zero, -65
        slt     a0, a1, a0
        ret
.LBB1_3:
        addi    a0, zero, 1
        ret
.LBB1_4:
        xor     a0, a1, a2
        seqz    a0, a0
        ret

</p>
</details>

[Link to godbolt](https://godbolt.org/z/K8avEz8Gr)

`@rustbot` label: A-codegen
2021-05-15 17:56:47 +02:00
Satyarth Agrahari
196050305c adding time complexity for partition_in_place iter method 2021-05-15 10:50:02 +05:30
Amanieu d'Antras
5918ee4317 Add support for const operands and options to global_asm!
On x86, the default syntax is also switched to Intel to match asm!
2021-05-13 22:31:57 +01:00
Guillaume Gomez
16c825485f
Rollup merge of #85177 - tspiteri:wrapping-bits, r=joshtriplett
add BITS associated constant to core::num::Wrapping

This keeps `Wrapping` synchronized with the primitives it wraps as for the #32463 `wrapping_int_impl` feature.
2021-05-13 15:54:13 +02:00
bors
31bd868c39 Auto merge of #85218 - kornelski:pointerinline, r=scottmcm
#[inline(always)] on basic pointer methods

Retryng #85201 with only inlining pointer methods. The goal is to make pointers behave just like pointers in O0, mainly to reduce overhead in debug builds.

cc `@scottmcm`
2021-05-12 21:50:27 +00:00
bors
28e2b29b89 Auto merge of #84730 - sexxi-goose:rox-auto-trait, r=nikomatsakis
Add auto traits and clone trait migrations for RFC2229

This PR
- renames the existent RFC2229 migration `disjoint_capture_drop_reorder` to `disjoint_capture_migration`
- add additional migrations for auto traits and clone trait

Closes rust-lang/project-rfc-2229#29
Closes rust-lang/project-rfc-2229#28

r? `@nikomatsakis`
2021-05-12 13:33:32 +00:00
Kornel
3773740719 #[inline(always)] on basic pointer methods 2021-05-12 10:10:28 +01:00
Trevor Spiteri
a381e29117 add BITS associated constant to core::num::Wrapping
This keeps `Wrapping` synchronized with the primitives it wraps as for
the #32463 `wrapping_int_impl` feature.
2021-05-11 13:36:43 +02:00
Benoît du Garreau
9332ac3bfc Override clone_from for some types 2021-05-11 13:00:34 +02:00
Dylan DPC
7107c89970
Rollup merge of #85096 - clarfonthey:const_unchecked, r=oli-obk
Make unchecked_{add,sub,mul} inherent methods unstably const

The intrinsics are marked as being stably const (even though they're not stable by nature of being intrinsics), but the currently-unstable inherent versions are not marked as const. This fixes this inconsistency. Split out of #85017,

r? `@oli-obk`
2021-05-10 16:15:02 +02:00
Scott McMurray
bf0e34c001 PR feedback 2021-05-09 22:05:02 -07:00
ltdk
e6b12c8e4f Fix Step feature flag, make tidy lint more useful to find things like this 2021-05-09 17:15:54 -04:00
ltdk
380bbe8d47 Make unchecked_{add,sub,mul} inherent methods unstably const 2021-05-09 16:29:40 -04:00
Dylan DPC
aaf23892ab
Rollup merge of #84871 - richkadel:no-coverage-unstable-only, r=nagisa
Disallows `#![feature(no_coverage)]` on stable and beta (using standard crate-level gating)

Fixes: #84836

Removes the function-level feature gating solution originally implemented, and solves the same problem using `allow_internal_unstable`, so normal crate-level feature gating mechanism can still be used (which disallows the feature on stable and beta).

I tested this, building the compiler with and without `CFG_DISABLE_UNSTABLE_FEATURES=1`

With unstable features disabled, I get the expected result as shown here:

```shell
$ ./build/x86_64-unknown-linux-gnu/stage1/bin/rustc     src/test/run-make-fulldeps/coverage/no_cov_crate.rs
error[E0554]: `#![feature]` may not be used on the dev release channel
 --> src/test/run-make-fulldeps/coverage/no_cov_crate.rs:2:1
  |
2 | #![feature(no_coverage)]
  | ^^^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to previous error

For more information about this error, try `rustc --explain E0554`.
```

r? ````@Mark-Simulacrum````
cc: ````@tmandry```` ````@wesleywiser````
2021-05-07 00:38:40 +02:00
Dylan DPC
7835c7802d
Rollup merge of #84755 - jyn514:core-links, r=kennytm
Allow using `core::` in intra-doc links within core itself

I came up with this idea ages ago, but rustdoc used to ICE on it. Now it doesn't.

Helps with https://github.com/rust-lang/rust/issues/73445. Doesn't fix it completely since `extern crate self as std;` in std still gives strange errors.
2021-05-07 00:38:38 +02:00
Scott McMurray
b7a6c4a905 Perf Experiment: Wait, what if I just skip the trait alias 2021-05-06 11:37:46 -07:00
Scott McMurray
3d9660111c Fix rustdoc::private-intra-doc-links errors in the docs 2021-05-06 11:37:46 -07:00
Scott McMurray
4a7ceea930 Better rustc_on_unimplemented, and UI test fixes 2021-05-06 11:37:45 -07:00
Scott McMurray
266a72637a Simple library test updates 2021-05-06 11:37:45 -07:00