Remove unneeded FIXMEs comments in search index generation
Original comment:
> Instead of recreating a new `vec` for each arguments, we re-use the same. The impact on performance should be minor but worth a try.
After testing it, we reached the conclusion that the code readability drop wasn't worth the almost unnoticeable performance improvement.
r? `@camelid`
This commit refactors linker argument generation to leverage a helper
function that abstracts away details governing how these arguments are
transformed and provided to the linker.
This fixes the misuse of the `-exported_symbols_list` when an ld-like
linker is used rather than a compiler. A compiler would expect
`-Wl,-exported_symbols_list,path` but ld would expect
`-exported_symbols_list` and `path` as two seperate arguments. Prior
to this change, an ld-like linker was given
`-exported_symbols_list,path`.
Linker arguments must transformed when Rust is interacting with the
linker through a compiler. This commit introduces a helper function
that abstracts away details of this transformation.
Fix trait object error code
closes#90768
I `grep`:d and changed the occurrences that seemed relevant. Please let me know what you think and if anything is missing!
When suggesting references, substitutions were being forgotten and some types were misused. This led to at
least one ICE and other incorrectly emitted diagnostics. This has been fixed; in some cases this leads to
diagnostics changing, and tests have been adjusted.
Stabilize `const_raw_ptr_deref` for `*const T`
This stabilizes dereferencing immutable raw pointers in const contexts.
It does not stabilize `*mut T` dereferencing. This is behind the
same feature gate as mutable references.
closes https://github.com/rust-lang/rust/issues/51911
Make RawVec private to alloc
RawVec was previously exposed for compiler-internal use (libarena specifically) in 1acbb0a935
Since it is unstable, doc-hidden and has no associated tracking issue it was never meant for public use. And since
it is no longer used outside alloc itself it can be made private again.
Also remove some functions that are dead due to lack of internal users.
Before, you could have the confusing situation where the command to
generate a component had no relation to the name of that component (e.g.
the `rustc` component was generated with `src/librustc`). This changes
the name to make them match up.
proc_macro: Add an expand_expr method to TokenStream
This feature is aimed at giving proc macros access to powers similar to those used by builtin macros such as `format_args!` or `concat!`. These macros are able to accept macros in place of string literal parameters, such as the format string, as they perform recursive macro expansion while being expanded.
This can be especially useful in many cases thanks to helper macros like `concat!`, `stringify!` and `include_str!` which are often used to construct string literals at compile-time in user code.
For now, this method only allows expanding macros which produce literals, although more expressions will be supported before the method is stabilized.
In earlier versions of this PR, this method exclusively returned `Literal`, and spans on returned literals were stripped of expansion context before being returned to be as conservative as possible about permission leakage. The method's naming has been generalized to eventually support arbitrary expressions, and the context stripping has been removed (https://github.com/rust-lang/rust/pull/87264#discussion_r674863279), which should allow for more general APIs like "format_args_implicits" (https://github.com/rust-lang/rust/issues/67984) to be supported as well.
## API Surface
```rust
impl TokenStream {
pub fn expand_expr(&self) -> Result<TokenStream, ExpandError>;
}
#[non_exhaustive]
pub struct ExpandError;
impl Debug for ExpandError { ... }
impl Display for ExpandError { ... }
impl Error for ExpandError {}
impl !Send for ExpandError {}
impl !Sync for ExpandError {}
```
Re-enable `copy[_nonoverlapping]()` debug-checks
This commit re-enables the debug checks for valid usages of the two functions `copy()` and `copy_nonoverlapping()`. Those checks were commented out in #79684 in order to make the functions const. All that's been left was a FIXME, that could not be resolved until there is was way to only do the checks at runtime.
Since #89247 there is such a way: `const_eval_select()`. This commit uses that new intrinsic in order to either do nothing (at compile time) or to do the old checks (at runtime).
The change itself is rather small: in order to make the checks usable with `const_eval_select`, they are moved into a local function (one for `copy` and one for `copy_nonoverlapping` to keep symmetry).
The change does not break referential transparency, as there is nothing you can do at compile time, which you cannot do on runtime without getting undefined behavior. The CTFE-engine won't allow missuses. The other way round is also fine.
I've refactored the code to use `#[cfg(debug_assertions)]` on the new items. If that is not desired, the second commit can be dropped.
I haven't added any checks, as I currently don't know, how to test this properly.
Closes#90012.
cc `@rust-lang/lang,` `@rust-lang/libs` and `@rust-lang/wg-const-eval` (as those teams are linked in the issue above).
pub use core::simd;
A portable abstraction over SIMD has been a major pursuit in recent years for several programming languages. In Rust, `std::arch` offers explicit SIMD acceleration via compiler intrinsics, but it does so at the cost of having to individually maintain each and every single such API, and is almost completely `unsafe` to use. `core::simd` offers safe abstractions that are resolved to the appropriate SIMD instructions by LLVM during compilation, including scalar instructions if that is all that is available.
`core::simd` is enabled by the `#![portable_simd]` nightly feature tracked in https://github.com/rust-lang/rust/issues/86656 and is introduced here by pulling in the https://github.com/rust-lang/portable-simd repository as a subtree. We built the repository out-of-tree to allow faster compilation and a stochastic test suite backed by the proptest crate to verify that different targets, features, and optimizations produce the same result, so that using this library does not introduce any surprises. As these tests are technically non-deterministic, and thus can introduce overly interesting Heisenbugs if included in the rustc CI, they are visible in the commit history of the subtree but do nothing here. Some tests **are** introduced via the documentation, but these use deterministic asserts.
There are multiple unsolved problems with the library at the current moment, including a want for better documentation, technical issues with LLVM scalarizing and lowering to libm, room for improvement for the APIs, and so far I have not added the necessary plumbing for allowing the more experimental or libm-dependent APIs to be used. However, I thought it would be prudent to open this for review in its current condition, as it is both usable and it is likely I am going to learn something else needs to be fixed when bors tries this out.
The major types are
- `core::simd::Simd<T, N>`
- `core::simd::Mask<T, N>`
There is also the `LaneCount` struct, which, together with the SimdElement and SupportedLaneCount traits, limit the implementation's maximum support to vectors we know will actually compile and provide supporting logic for bitmasks. I'm hoping to simplify at least some of these out of the way as the compiler and library evolve.
Since our musl targets link to a version of musl we build and bundle
with the targets, if users need to debug into musl or generate
backtraces which contain parts of the musl library, they will be unable
to do so unless we enable and ship the debug info.
This patch changes our dist builds so they enabled debug info when
building musl. This patch also includes a fix for CFI detection in
musl's `configure` script which has been posted upstream[1].
The net effect of this is that we now ship debug info for musl in those
targets. This adds ~90kb to those artifacts but running `strip` on
binaries produced removes all of that. For a "hello world" Rust binary
on x86_64, the numbers are:
| | debug | release | release + strip |
| - | - | - | - |
| without musl debuginfo | 507kb | 495kb | 410kb |
| with musl debuginfo | 595kb | 584kb | 410kb |
Once stripped, the final binaries are the same size (down to the byte).
[1]: https://www.openwall.com/lists/musl/2021/10/21/2
These are working well for *unsigned* types, for the the signed ones there are a bunch of questions about what the semantics and API should be. And for the main "helpers for big integer implementations" use, there's no need for the signed versions anyway.
And there are plenty of other methods which exist for unsigned types but not signed ones, like `next_power_of_two`, so this isn't unusual.
Fixes 90541
These tests just verify some basic APIs of core::simd function, and
guarantees that attempting to access the wrong things doesn't work.
The majority of tests are stochastic, and so remain upstream, but
a few deterministic tests arrive in the subtree as doc tests.
This enables programmers to use a safe alternative to the current
`extern "platform-intrinsics"` API for writing portable SIMD code.
This is `#![feature(portable_simd)]` as tracked in #86656
This feature is aimed at giving proc macros access to powers similar to
those used by builtin macros such as `format_args!` or `concat!`. These
macros are able to accept macros in place of string literal parameters,
such as the format string, as they perform recursive macro expansion
while being expanded.
This can be especially useful in many cases thanks to helper macros like
`concat!`, `stringify!` and `include_str!` which are often used to
construct string literals at compile-time in user code.
For now, this method only allows expanding macros which produce
literals, although more expresisons will be supported before the method
is stabilized.
Document `unreachable!` custom panic message
The `unreachable!` docs previously did not mention that there was a second form, `unreachable!("message")` that could be used to specify a custom panic message,
The docs now mention this feature in the same wording as currently used for `unimplemented!`:
https://doc.rust-lang.org/core/macro.unimplemented.html#panics
Add more comments to explain the code to generate the search index
Fixes#90766.
I tried to put comments when the code wasn't easy to understand at first sight and added more documentation on the recursive function. Please tell me if I misused the terminology or if comments can be improved or added into other places.
r? `@notriddle`
Shorten Span of unused macro lints
The span has been reduced to the actual ident of the macro, instead of linting the
*whole* macro.
Closes#90745
r? ``@estebank``
Rename WASI's `FileTypeExt::is_character_device` to
`FileTypeExt::is_char_device`, for consistency with the Unix
`FileTypeExt::is_char_device`.
Also, add a `FileTypeExt::is_socket` function, for consistency with the
Unix `FileTypeExt::is_socket` function.
For small types with padding, the current implementation is UB because it does integer operations on uninit values. But LLVM has gotten smarter since I wrote the previous implementation in 2017, so remove all the manual magic and just write it in such a way that LLVM will vectorize. This code is much simpler (albeit nuanced) and has very little `unsafe`, and is actually faster to boot!
