Opaque types cannot be used in extern declarations, and normally cannot
exist in fields - except with type aliases to `impl Trait` and
projections which normalize to them.
Signed-off-by: David Wood <david@davidtw.co>
This commit modifies `transparent_newtype_field` so that it handles
projections with generic parameters, where `normalize_erasing_regions`
would ICE.
Signed-off-by: David Wood <david@davidtw.co>
tag/niche terminology cleanup
The term "discriminant" was used in two ways throughout the compiler:
* every enum variant has a corresponding discriminant, that can be given explicitly with `Variant = N`.
* that discriminant is then encoded in memory to store which variant is active -- but this encoded form of the discriminant was also often called "discriminant", even though it is conceptually quite different (e.g., it can be smaller in size, or even use niche-filling).
After discussion with @eddyb, this renames the second term to "tag". The way the tag is encoded can be either `TagEncoding::Direct` (formerly `DiscriminantKind::Tag`) or `TagEncoding::Niche` (formerly `DiscrimianntKind::Niche`).
This finally resolves some long-standing confusion I had about the handling of variant indices and discriminants, which surfaced in https://github.com/rust-lang/rust/pull/72419.
(There is also a `DiscriminantKind` type in libcore, it remains unaffected. I think this corresponds to the discriminant, not the tag, so that seems all right.)
r? @eddyb
Tweak "non-primitive cast" error
- Suggest borrowing expression if it would allow cast to work.
- Suggest using `<Type>::from(<expr>)` when appropriate.
- Minor tweak to `;` typo suggestion.
Partily address #47136.
Make new type param suggestion more targetted
Do not suggest new type param when encountering a missing type in an ADT
field with generic parameters.
Fix#72640.
Further tweak lifetime errors involving `dyn Trait` and `impl Trait` in return position
* Suggest substituting `'static` lifetime in impl/dyn `Trait + 'static` instead of `Trait + 'static + '_`
* When `'static` is explicit, also suggest constraining argument with it
* Reduce verbosity of suggestion message and mention lifetime in label
* Tweak output for overlapping required/captured spans
* Give these errors an error code
Follow up to #72543.
r? @nikomatsakis
Improve diagnostics for `let x += 1`
Fixes(?) #66736
The code responsible for the `E0404` errors is [here](https://github.com/rust-lang/rust/blob/master/src/librustc_parse/parser/ty.rs#L399-L424) which I don't think can be easily modified to prevent emitting an error in one specific case. Because of this I couldn't get rid of `E0404` and instead added `E0067` along with a help message which will fix the problem.
r? @estebank
Make novel structural match violations not a `bug`
Fixes (on master) #73431.
Ideally, `CustomEq` would emit a strict subset of the structural match errors that are found by `search_for_structural_match_violation`, since it allows more cases due to value-based reasoning. However, const qualification is more conservative than `search_for_structural_match_violation` around associated constants, since qualification does not try to substitute type parameters.
In the long term, we should probably make const qualification work for generic associated constants, but I don't like extending its capabilities even further.
r? @pnkfelix
Allow the `asm!` macro to accept a series of template arguments, and
interpret them as if they were concatenated with a '\n' between them.
This allows writing an `asm!` where each line of assembly appears in a
separate template string argument.
This syntax makes it possible for rustfmt to reliably format and indent
each line of assembly, without risking changes to the inside of a
template string. It also avoids the complexity of having the user
carefully format and indent a multi-line string (including where to put
the surrounding quotes), and avoids the extra indentation and lines of a
call to `concat!`.
For example, rewriting the second example from the [blog post on the new
inline assembly
syntax](https://blog.rust-lang.org/inside-rust/2020/06/08/new-inline-asm.html)
using multiple template strings:
```rust
fn main() {
let mut bits = [0u8; 64];
for value in 0..=1024u64 {
let popcnt;
unsafe {
asm!(
" popcnt {popcnt}, {v}",
"2:",
" blsi rax, {v}",
" jz 1f",
" xor {v}, rax",
" tzcnt rax, rax",
" stosb",
" jmp 2b",
"1:",
v = inout(reg) value => _,
popcnt = out(reg) popcnt,
out("rax") _, // scratch
inout("rdi") bits.as_mut_ptr() => _,
);
}
println!("bits of {}: {:?}", value, &bits[0..popcnt]);
}
}
```
Note that all the template strings must appear before all other
arguments; you cannot, for instance, provide a series of template
strings intermixed with the corresponding operands.
In order to get srcloc mappings right for macros that generate
multi-line string literals, create one line_span for each
line in the string literal, each pointing to the macro.
Make `rustc_parse_format::Parser::curarg` `pub`, so that we can
propagate it from one template string argument to the next.
- Suggest borrowing expression if it would allow cast to work.
- Suggest using `<Type>::from(<expr>)` when appropriate.
- Minor tweak to `;` typo suggestion.
Partily address #47136.
Rollup of 10 pull requests
Successful merges:
- #72707 (Use min_specialization in the remaining rustc crates)
- #72740 (On recursive ADT, provide indirection structured suggestion)
- #72879 (Miri: avoid tracking current location three times)
- #72938 (Stabilize Option::zip)
- #73086 (Rename "cyclone" to "apple-a7" per changes in upstream LLVM)
- #73104 (Example about explicit mutex dropping)
- #73139 (Add methods to go from a nul-terminated Vec<u8> to a CString)
- #73296 (Remove vestigial CI job msvc-aux.)
- #73304 (Revert heterogeneous SocketAddr PartialEq impls)
- #73331 (extend network support for HermitCore)
Failed merges:
r? @ghost
Miri: avoid tracking current location three times
Miri tracks the current instruction to execute in the call stack, but it also additionally has two `TyCtxtAt` that carry a `Span` that also tracks the current instruction. That is quite silly, so this PR uses `TyCtxt` instead, and then uses a method for computing the current span when a `TyCtxtAt` is needed. Having less redundant (semi-)global state seems like a good improvement to me. :D
To keep the ConstProp errors the same, I had to add the option to `error_to_const_error` to overwrite the span. Also for some reason this changes cycle errors a bit -- not sure if we are now better or worse as giving those queries the right span. (It is unfortunately quite easy to accidentally use `DUMMY_SP` by calling the query on a `TyCtxt` instead of a `TyCtxtAt`.)
r? @oli-obk @eddyb
