Document proper usage of `fmt::Error` and `fmt()`'s `Result`.
I've seen several newcomers wonder why `fmt::Error` doesn't have any error detail information, or propose to return it in response to an error condition found inside a `impl fmt::Display for MyType`.
That is incorrect, per [a lone paragraph of the `fmt` module's documentation](https://doc.rust-lang.org/1.78.0/std/fmt/index.html#formatting-traits). However, users looking to implement a formatting trait won't necessarily look there. Therefore, let's add the critical information (that formatting per se is infallible) to all the involved items: every `fmt()` method, and `fmt::Error`.
This PR is not intended to make any novel claims about `fmt`; only to repeat an existing one in places where it will be more visible.
Refactor Apple `target_abi`
This was bundled together with `Arch`, which complicated a few code paths and meant we had to do more string matching than necessary.
CC `@BlackHoleFox` as you've worked on the Apple target spec before
Related: Is there a reason why `Target`/`TargetOptions` use `StaticCow` for so many things, instead of an enum with defined values (and perhaps a catch-all case for custom target json files)? Tagging `@Nilstrieb,` as you might know?
Add @saethlin to some triagebot groups
I think this is a reasonable approximation of what I can review, and should encourage people to request me.
r? scottmcm
Fix typo in ManuallyDrop's documentation
```diff
- /// A wrapper to inhibit compiler from automatically calling `T`’s destructor.
+ /// A wrapper to inhibit the compiler from automatically calling `T`’s destructor.
```
Update ena to 0.14.3
Includes https://github.com/rust-lang/ena/pull/53, which removes a trivial `Self: Sized` bound that prevents `ena` from building on the new solver.
Remove feature from documentation examples
Add rustc_const_stable attribute to stabilized functions
Update intra-doc link for `u8::is_ascii_whitespace` on `&[u8]` functions
I added `PlaceValue` in 123775, but kept that one line-by-line simple because it touched so many places.
This goes through to add more helpers & docs, and change some `PlaceRef` to `PlaceValue` where the type didn't need to be included.
No behaviour changes.
Rollup of 5 pull requests
Successful merges:
- #124233 (Add `-lmingwex` second time in `mingw_libs`)
- #124318 (ignore generics args in attribute paths)
- #124899 (bootstrap: add comments for the automatic dry run)
- #124904 (reachable computation: extend explanation of what this does, and why)
- #124930 (Make sure we consume a generic arg when checking mistyped turbofish)
r? `@ghost`
`@rustbot` modify labels: rollup
Make sure we consume a generic arg when checking mistyped turbofish
When recovering un-turbofish-ed args in expr position (e.g. `let x = a<T, U>();` in `check_mistyped_turbofish_with_multiple_type_params`, we used `parse_seq_to_before_end` to parse the fake generic args; however, it used `parse_generic_arg` which *optionally* parses a generic arg. If it doesn't end up parsing an arg, it returns `Ok(None)` and consumes no tokens. If we don't find a delimiter after this (`,`), we try parsing *another* element. In this case, we just infinitely loop looking for a subsequent element.
We can fix this by making sure that we either parse a generic arg or error in `parse_seq_to_before_end`'s callback.
Fixes#124897
reachable computation: extend explanation of what this does, and why
Follow-up to https://github.com/rust-lang/rust/pull/122769. I had the time to think about this some more, in particular in the context of https://github.com/rust-lang/rust/issues/119214, so I felt it was worth extending these comments some more.
I also gave up on the context of "externally reachable" as it is not called that way anywhere else in the compiler.
Cc `@tmiasko` `@saethlin`
ignore generics args in attribute paths
Fixes#97006Fixes#123911Fixes#123912
This patch ensures that we no longer have to handle invalid generic arguments in attribute paths.
r? `@petrochenkov`
Add `-lmingwex` second time in `mingw_libs`
Upcoming mingw-w64 releases will contain small math functions refactor which moved implementation around. As a result functions like `lgamma`
now depend on libraries in this order:
`libmingwex.a` -> `libmsvcrt.a` -> `libmingwex.a`.
Fixes#124221
Avoid `alloca`s in codegen for simple `mir::Aggregate` statements
The core idea here is to remove the abstraction penalty of simple newtypes in codegen.
Even something simple like constructing a
```rust
#[repr(transparent)] struct Foo(u32);
```
forces an `alloca` to be generated in nightly right now.
Certainly LLVM can optimize that away, but it would be nice if it didn't have to.
Quick example:
```rust
#[repr(transparent)]
pub struct Transparent32(u32);
#[no_mangle]
pub fn make_transparent(x: u32) -> Transparent32 {
let a = Transparent32(x);
a
}
```
on nightly we produce <https://rust.godbolt.org/z/zcvoM79ae>
```llvm
define noundef i32 `@make_transparent(i32` noundef %x) unnamed_addr #0 {
%a = alloca i32, align 4
store i32 %x, ptr %a, align 4
%0 = load i32, ptr %a, align 4, !noundef !3
ret i32 %0
}
```
but after this PR we produce
```llvm
define noundef i32 `@make_transparent(i32` noundef %x) unnamed_addr #0 {
start:
ret i32 %x
}
```
(even before the optimizer runs).
* Remove A: Clone bound from Rc::assume_init, Rc::downcast, and Rc::downcast_unchecked.
* Make From<Rc<[T; N]>> for Rc<[T]> allocator-aware.
Internal changes:
* Made Arc::internal_into_inner_with_allocator method into Arc::into_inner_with_allocator associated fn.
* Add private Rc::into_inner_with_allocator (to match Arc), so other fns don't have to juggle ManuallyDrop.
Rename some `FulfillmentErrorCode`/`ObligationCauseCode` variants to be less redundant
1. Rename some `FulfillmentErrorCode` variants.
2. Always use `ObligationCauseCode::` to prefix a code, rather than using a glob import and naming them through `traits::`.
3. Rename some `ObligationCauseCode` variants -- I wasn't particularly thorough with thinking of a new names for these, so could workshop them if necessary.
4. Misc stuff from renaming.
r? lcnr
