Introduce `feature(generic_const_parameter_types)`
Allows to define const generic parameters whose type depends on other generic parameters, e.g. `Foo<const N: usize, const ARR: [u8; N]>;`
Wasn't going to implement for this for a while until we could implement it with `bad_inference.rs` resolved but apparently the project simd folks would like to be able to use this for some intrinsics and the inference issue isn't really a huge problem there aiui. (cc ``@workingjubilee`` )
```
error[E0614]: type `(..., ..., ..., ...)` cannot be dereferenced
--> $DIR/long-E0614.rs:10:5
|
LL | *x;
| ^^ can't be dereferenced
|
= note: the full name for the type has been written to '$TEST_BUILD_DIR/$FILE.long-type-hash.txt'
= note: consider using `--verbose` to print the full type name to the console
```
remove `#[rustc_intrinsic_must_be_overridde]`
In https://github.com/rust-lang/rust/pull/135031, we gained support for just leaving away the body. Now that the bootstrap compiler got bumped, stop using the old style and remove support for it.
r? `@oli-obk`
There are a few more mentions of this attribute in RA code that I didn't touch; Cc `@rust-lang/rust-analyzer`
After the stabilization PR was opened, `extern "system"` functions were
added to `extended_varargs_abi_support`. This has a number of questions
regarding it that were not discussed and were somewhat surprising.
It deserves to be considered as its own feature, separate from
`extended_varargs_abi_support`.
```
error[E0610]: `{integer}` is a primitive type and therefore doesn't have fields
--> $DIR/attempted-access-non-fatal.rs:7:15
|
LL | let _ = 2.l;
| ^
|
help: if intended to be a floating point literal, consider adding a `0` after the period and a `f64` suffix
|
LL - let _ = 2.l;
LL + let _ = 2.0f64;
|
```
- duplicates of crateresolve1 are used in a couple error-codes tests
- also fix the note in crateresolve1 to link to these other duplicates,
now that E0523 has been merged into E0464
Reword resolve errors caused by likely missing crate in dep tree
Reword label and add `help`:
```
error[E0432]: unresolved import `some_novel_crate`
--> f704.rs:1:5
|
1 | use some_novel_crate::Type;
| ^^^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `some_novel_crate`
|
= help: if you wanted to use a crate named `some_novel_crate`, use `cargo add some_novel_crate` to add it to your `Cargo.toml`
```
Fix#133137.
```
error[E0432]: unresolved import `some_novel_crate`
--> file.rs:1:5
|
1 | use some_novel_crate::Type;
| ^^^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `some_novel_crate`
```
On resolve errors where there might be a missing crate, mention `cargo add foo`:
```
error[E0433]: failed to resolve: use of unresolved module or unlinked crate `nope`
--> $DIR/conflicting-impl-with-err.rs:4:11
|
LL | impl From<nope::Thing> for Error {
| ^^^^ use of unresolved module or unlinked crate `nope`
|
= help: if you wanted to use a crate named `nope`, use `cargo add nope` to add it to your `Cargo.toml`
```
This CL makes a number of small changes to dyn compatibility errors:
- "object safety" has been renamed to "dyn-compatibility" throughout
- "Convert to enum" suggestions are no longer generated when there
exists a type-generic impl of the trait or an impl for `dyn OtherTrait`
- Several error messages are reorganized for user readability
Additionally, the dyn compatibility error creation code has been
split out into functions.
cc #132713
cc #133267
remove support for the (unstable) #[start] attribute
As explained by `@Noratrieb:`
`#[start]` should be deleted. It's nothing but an accidentally leaked implementation detail that's a not very useful mix between "portable" entrypoint logic and bad abstraction.
I think the way the stable user-facing entrypoint should work (and works today on stable) is pretty simple:
- `std`-using cross-platform programs should use `fn main()`. the compiler, together with `std`, will then ensure that code ends up at `main` (by having a platform-specific entrypoint that gets directed through `lang_start` in `std` to `main` - but that's just an implementation detail)
- `no_std` platform-specific programs should use `#![no_main]` and define their own platform-specific entrypoint symbol with `#[no_mangle]`, like `main`, `_start`, `WinMain` or `my_embedded_platform_wants_to_start_here`. most of them only support a single platform anyways, and need cfg for the different platform's ways of passing arguments or other things *anyways*
`#[start]` is in a super weird position of being neither of those two. It tries to pretend that it's cross-platform, but its signature is a total lie. Those arguments are just stubbed out to zero on ~~Windows~~ wasm, for example. It also only handles the platform-specific entrypoints for a few platforms that are supported by `std`, like Windows or Unix-likes. `my_embedded_platform_wants_to_start_here` can't use it, and neither could a libc-less Linux program.
So we have an attribute that only works in some cases anyways, that has a signature that's a total lie (and a signature that, as I might want to add, has changed recently, and that I definitely would not be comfortable giving *any* stability guarantees on), and where there's a pretty easy way to get things working without it in the first place.
Note that this feature has **not** been RFCed in the first place.
*This comment was posted [in May](https://github.com/rust-lang/rust/issues/29633#issuecomment-2088596042) and so far nobody spoke up in that issue with a usecase that would require keeping the attribute.*
Closes https://github.com/rust-lang/rust/issues/29633
try-job: x86_64-gnu-nopt
try-job: x86_64-msvc-1
try-job: x86_64-msvc-2
try-job: test-various
Rework dyn trait lowering to stop being so intertwined with trait alias expansion
This PR reworks the trait object lowering code to stop handling trait aliases so funky, and removes the `TraitAliasExpander` in favor of a much simpler design. This refactoring is important for making the code that I'm writing in https://github.com/rust-lang/rust/pull/133397 understandable and easy to maintain, so the diagnostics regressions are IMO inevitable.
In the old trait object lowering code, we used to be a bit sloppy with the lists of traits in their unexpanded and expanded forms. This PR largely rewrites this logic to expand the trait aliases *once* and handle them more responsibly throughout afterwards.
Please review this with whitespace disabled.
r? lcnr
Collect all unreachable fields in a single struct literal struct and emit a single error, instead of one error per private field.
```
error[E0451]: fields `beta` and `gamma` of struct `Alpha` are private
--> $DIR/visibility.rs:18:13
|
LL | let _x = Alpha {
| ----- in this type
LL | beta: 0,
| ^^^^^^^ private field
LL | ..
| ^^ field `gamma` is private
```
