Stabilize cfg_target_vendor
This stabilizes the use of `cfg(target_vendor = "...")` and removes the corresponding `cfg_target_vendor` feature. Other unstable cfgs remain behind their existing feature gates.
This functionality was added back in 2015 in #28612 to complete the coverage of target tuples (`<arch><sub>-<vendor>-<os>-<env>`). [RFC 131](https://github.com/rust-lang/rfcs/blob/master/text/0131-target-specification.md) governs the target specification, not including `target_vendor` seems to have just been an oversight. `target_os`, `target_family`, and `target_arch` are stable as of 1.0.0. `target_env` was also not mentioned in RFC 131, was added in #24777, never behind a feature_gate, and insta-stable at 1.1.0.
The functionality is tested in [test/run-pass/cfg/cfg-target-vendor.rs](https://github.com/rust-lang/rust/blob/master/src/test/run-pass/cfg/cfg-target-vendor.rs).
Closes#29718
Use structured suggestions for nonstandard style lints
This PR modifies the lints in the nonstandard_style group to use structured suggestions. Note that there's a bit of tricky span calculation going on for the `crate_name` attribute. It also simplifies the code a bit: I don't think the "fallback" suggestions for these lints can actually be triggered.
Fixes#48103.
Fixes#52414.
Rollup of 4 pull requests
Successful merges:
- #56874 (Simplify foreign type rendering.)
- #57113 (Move diagnostics out from QueryJob and optimize for the case with no diagnostics)
- #57366 (Point at match discriminant on type error in match arm pattern)
- #57538 (librustc_mir: Fix ICE with slice patterns)
Failed merges:
- #57381 (Tweak output of type mismatch between "then" and `else` `if` arms)
r? @ghost
librustc_mir: Fix ICE with slice patterns
If a match arm does not include all fields in a structure and a later
pattern includes a field that is an array, we will attempt to use the
array type from the prior arm. When calculating the field type, treat
a array of an unknown size as a `TyErr`.
Fixes: #57472
Point at match discriminant on type error in match arm pattern
```
error[E0308]: mismatched types
--> src/main.rs:5:9
|
4 | let temp: usize = match a + b {
| ----- this expression has type `usize`
5 | Ok(num) => num,
| ^^^^^^^ expected usize, found enum `std::result::Result`
|
= note: expected type `usize`
found type `std::result::Result<_, _>`
```
Fix#57279.
NLL: Add union justifications to conflicting borrows.
Fixes#57100.
This PR adds justifications to error messages for conflicting borrows of union fields.
Where previously an error message would say ``cannot borrow `u.b` as mutable..``, it now says ``cannot borrow `u` (via `u.b`) as mutable..``.
r? @pnkfelix
If a match arm does not include all fields in a structure and a later
pattern includes a field that is an array, we will attempt to use the
array type from the prior arm. When calculating the field type, treat
a array of an unknown size as a TyErr.
Update the const fn tracking issue to the new metabug
The new `const fn` tracking issue is #57563. We don't want to point to a closed issue in the diagnostics (or FIXMEs), so these have been updated (from the old issue, #24111).
r? @Centril
...while still keeping ambiguity errors future-proofing for uniform paths.
This corner case is not going to be stabilized for 1.32 and needs some more general experiments about retrofitting 2018 import rules to 2015 edition
Rollup of 26 pull requests
Successful merges:
- #56425 (Redo the docs for Vec::set_len)
- #56906 (Issue #56905)
- #57042 (Don't call `FieldPlacement::count` when count is too large)
- #57175 (Stabilize `let` bindings and destructuring in constants and const fn)
- #57192 (Change std::error::Error trait documentation to talk about `source` instead of `cause`)
- #57296 (Fixed the link to the ? operator)
- #57368 (Use CMAKE_{C,CXX}_COMPILER_LAUNCHER for ccache)
- #57400 (Rustdoc: update Source Serif Pro and replace Heuristica italic)
- #57417 (rustdoc: use text-based doctest parsing if a macro is wrapping main)
- #57433 (Add link destination for `read-ownership`)
- #57434 (Remove `CrateNum::Invalid`.)
- #57441 (Supporting backtrace for x86_64-fortanix-unknown-sgx.)
- #57450 (actually take a slice in this example)
- #57459 (Reference tracking issue for inherent associated types in diagnostic)
- #57463 (docs: Fix some 'second-edition' links)
- #57466 (Remove outdated comment)
- #57493 (use structured suggestion when casting a reference)
- #57498 (make note of one more normalization that Paths do)
- #57499 (note that FromStr does not work for borrowed types)
- #57505 (Remove submodule step from README)
- #57510 (Add a profiles section to the manifest)
- #57511 (Fix undefined behavior)
- #57519 (Correct RELEASES.md for 1.32.0)
- #57522 (don't unwrap unexpected tokens in `format!`)
- #57530 (Fixing a typographical error.)
- #57535 (Stabilise irrefutable if-let and while-let patterns)
Failed merges:
r? @ghost
Reference tracking issue for inherent associated types in diagnostic
This makes it clearer that associated types in inherent impls are an intended feature, like the diagnostic for equality constraints in where clauses. (This is more helpful, because the lack of associated types is a confusing omission and it lets users more easily track the state of the feature.)
Stabilize `let` bindings and destructuring in constants and const fn
r? @Centril
This PR stabilizes the following features in constants and `const` functions:
* irrefutable destructuring patterns (e.g. `const fn foo((x, y): (u8, u8)) { ... }`)
* `let` bindings (e.g. `let x = 1;`)
* mutable `let` bindings (e.g. `let mut x = 1;`)
* assignment (e.g. `x = y`) and assignment operator (e.g. `x += y`) expressions, even where the assignment target is a projection (e.g. a struct field or index operation like `x[3] = 42`)
* expression statements (e.g. `3;`)
This PR does explicitly *not* stabilize:
* mutable references (i.e. `&mut T`)
* dereferencing mutable references
* refutable patterns (e.g. `Some(x)`)
* operations on `UnsafeCell` types (as that would need raw pointers and mutable references and such, not because it is explicitly forbidden. We can't explicitly forbid it as such values are OK as long as they aren't mutated.)
* We are not stabilizing `let` bindings in constants that use `&&` and `||` short circuiting operations. These are treated as `&` and `|` inside `const` and `static` items right now. If we stopped treating them as `&` and `|` after stabilizing `let` bindings, we'd break code like `let mut x = false; false && { x = true; false };`. So to use `let` bindings in constants you need to change `&&` and `||` to `&` and `|` respectively.
