Rollup of 9 pull requests
Successful merges:
- rust-lang/rust#142380 (Put negative implementors first and apply same ordering logic to foreign implementors)
- rust-lang/rust#146584 (remove duplicated columns from `rustc_error_code::error_codes!`)
- rust-lang/rust#148717 (Point at span within local macros even when error happens in nested external macro)
- rust-lang/rust#149565 (rustdoc: Add unstable `--merge-doctests=yes/no/auto` flag)
- rust-lang/rust#149770 (Rename some issue-* tests)
- rust-lang/rust#149807 (Use ubuntu:24.04 for the `x86_64-gnu-miri` job)
- rust-lang/rust#149850 (Remove "tidy" tool for `tests/rustdoc` testsuite)
- rust-lang/rust#149863 (Do not suggest moving expression out of for loop when hitting `break` from desugaring)
- rust-lang/rust#149867 (only resolve main in bin crates)
r? `@ghost`
`@rustbot` modify labels: rollup
Port `doc` attributes to new attribute API
Part of https://github.com/rust-lang/rust/issues/131229.
This PR ports the `doc` attributes to the new attribute API. However, there are things that will need to be fixed in a follow-up:
* Some part of `cfg_old.rs` are likely unused now, so they should be removed.
* Not all error/lints are emitted at the same time anymore, making them kinda less useful considering that you need to run and fix rustc/rustdoc multiple times to get through all of them.
* For coherency with the other attribute errors, I didn't modify the default output too much, meaning that we have some new messages now. I'll likely come back to that to check if the previous ones were better in a case-by-case approach.
* `doc(test(attr(...)))` is handled in a horrifying manner currently. Until we can handle it correctly with the `Attribute` system, it'll remain that thing we're all very ashamed of. 😈
* A type in rustdoc got its size increased, I'll check the impact on performance. But in any case, I plan to improve it in a follow-up so should be "ok".
* Because of error reporting, some fields of `Doc` are suboptimal, like `inline` which instead of being an `Option` is a `ThinVec` because we report the error later on. Part of the things I'm not super happy about but can be postponed to future me.
* In `src/librustdoc/clean/cfg.rs`, the `pub(crate) fn parse(cfg: &MetaItemInner) -> Result<Cfg, InvalidCfgError> {` function should be removed once `cfg_trace` has been ported to new `cfg` API.
* Size of type `DocFragment` went from 32 to 48. Would be nice to get it back to 32.
* ``malformed `doc` attribute input`` wasn't meant for so many candidates, should be improved.
* See how many of the checks in `check_attr` we can move to attribute parsing
* Port target checking to be in the attribute parser completely
* Fix target checking for `doc(alias)` on fields & patterns
And finally, once this PR is merged, I plan to finally stabilize `doc_cfg` feature. :)
cc `@jdonszelmann`
r? `@JonathanBrouwer`
`c_variadic`: make `VaList` abi-compatible with C
tracking issue: https://github.com/rust-lang/rust/issues/44930
related PR: rust-lang/rust#144529
On some platforms, the C `va_list` type is actually a single-element array of a struct (on other platforms it is just a pointer). In C, arrays passed as function arguments expirience array-to-pointer decay, which means that C will pass a pointer to the array in the caller instead of the array itself, and modifications to the array in the callee will be visible to the caller (this does not match Rust by-value semantics). However, for `va_list`, the C standard explicitly states that it is undefined behaviour to use a `va_list` after it has been passed by value to a function (in Rust parlance, the `va_list` is moved, not copied). This matches Rust's pass-by-value semantics, meaning that when the C `va_list` type is a single-element array of a struct, the ABI will match C as long as the Rust type is always be passed indirectly.
In the old implementation, this ABI was achieved by having two separate types: `VaList` was the type that needed to be used when passing a `VaList` as a function parameter, whereas `VaListImpl` was the actual `va_list` type that was correct everywhere else. This however is quite confusing, as there are lots of footguns: it is easy to cause bugs by mixing them up (e.g. the C function `void foo(va_list va)` was equivalent to the Rust `fn foo(va: VaList)` whereas the C function `void bar(va_list* va)` was equivalent to the Rust `fn foo(va: *mut VaListImpl)`, not `fn foo(va: *mut VaList)` as might be expected); also converting from `VaListImpl` to `VaList` with `as_va_list()` had platform specific behaviour: on single-element array of a struct platforms it would return a `VaList` referencing the original `VaListImpl`, whereas on other platforms it would return a cioy,
In this PR, there is now just a single `VaList` type (renamed from `VaListImpl`) which represents the C `va_list` type and will just work in all positions. Instead of having a separate type just to make the ABI work, rust-lang/rust#144529 adds a `#[rustc_pass_indirectly_in_non_rustic_abis]` attribute, which when applied to a struct will force the struct to be passed indirectly by non-Rustic calling conventions. This PR then implements the `VaList` rework, making use of the new attribute on all platforms where the C `va_list` type is a single-element array of a struct.
Cleanup of the `VaList` API and implementation is also included in this PR: since it was decided it was OK to experiment with Rust requiring that not calling `va_end` is not undefined behaviour (https://github.com/rust-lang/rust/issues/141524#issuecomment-3028383594), I've removed the `with_copy` method as it was redundant to the `Clone` impl (the `Drop` impl of `VaList` is a no-op as `va_end` is a no-op on all known platforms).
Previous discussion: rust-lang/rust#141524 and [t-compiler > c_variadic API and ABI](https://rust-lang.zulipchat.com/#narrow/channel/131828-t-compiler/topic/c_variadic.20API.20and.20ABI)
Tracking issue: https://github.com/rust-lang/rust/issues/44930
r? `@joshtriplett`
Remove `#[const_trait]`
Remove `#[const_trait]` since we now have `const trait`. Update all structured diagnostics that still suggested the attribute.
r? ```@rust-lang/project-const-traits```
Add check for `+=` typo in let chains
Fixes https://github.com/rust-lang/rust/issues/147664
it does affect only cases where variable exist in scope, because if the variable is not exist in scope, the suggestion will not make any sense
I wanted to add suggestion for case where variable does not in scope to fix `y += 1` to `let y = 1` but I guess it's too much (not too much work, but too much wild predict of what user wants)? if it's good addition in your opinion I can add this in follow up
in other things I guess impl is pretty much self-explanatory, if you see there is some possibilities to improve code or/and some _edge-cases_ that I could overlooked feel free to tell about it
ah, also about why I think this change is good and why I originally took it, so it seems to me that this is possible to make this typo (I explained this in comment a little), like, both `+` and `=` is the same button (in most of layouts) and for this reasons I didn't added something like `-=` it seems more harder to make this typo
r? diagnostics
Further tighten up relaxed bounds
Follow-up to rust-lang/rust#142693, rust-lang/rust#135331 and rust-lang/rust#135841.
Fixesrust-lang/rust#143122.
* Reject relaxed bounds `?Trait` in the bounds of trait aliases.
Just like `trait Trait {}` doesn't mean `trait Trait: Sized {}` and we therefore reject `trait Trait: ?Sized {}`, `trait Trait =;` (sic!) doesn't mean `trait Trait = Sized;` (never did!) and as a logical consequence `trait Trait = ?Sized;` is meaningless and should be forbidden.
* Don't permit `?Sized` in more places (e.g., supertrait bounds, trait object types) if feature `more_maybe_bounds` is enabled.
That internal feature is only meant to allow the user to define & use *new* default traits (that have fewer rules to follow for now to ease experimentation).
* Unconditionally check that the `Trait` in `?Trait` is a default trait.
Previously, we would only perform this check in selected places which was very brittle and led to bugs slipping through.
* Slightly improve diagnostics.
Perform unused assignment and unused variables lints on MIR.
Rebase of https://github.com/rust-lang/rust/pull/101500
Fixes https://github.com/rust-lang/rust/issues/51003.
The first commit moves detection of uninhabited types from the current liveness pass to MIR building.
In order to keep the same level of diagnostics, I had to instrument MIR a little more:
- keep for which original local a guard local is created;
- store in the `VarBindingForm` the list of introducer places and whether this was a shorthand pattern.
I am not very proud of the handling of self-assignments. The proposed scheme is in two parts: first detect probable self-assignments, by pattern matching on MIR, and second treat them specially during dataflow analysis. I welcome ideas.
Please review carefully the changes in tests. There are many small changes to behaviour, and I'm not sure all of them are desirable.
Rehome 30 `tests/ui/issues/` tests to other subdirectories under `tests/ui/` [#4 of Batch #2]
Part of rust-lang/rust#133895
Methodology:
1. Refer to the previously written `tests/ui/SUMMARY.md`
2. Find an appropriate category for the test, using the original issue thread and the test contents.
3. Add the issue URL at the bottom (not at the top, as that would mess up stderr line numbers)
4. Rename the tests to make their purpose clearer
Inspired by the methodology that `@Kivooeo` was using.
r? `@jieyouxu`
test: Subtract code_offset from width for ui_testing
`annotate-snippets` does not have a "UI test" mode like `rustc`, [where the code offset is not subtracted from the column width](f34ba774c7/compiler/rustc_errors/src/emitter.rs (L1985-L1987)). This makes it so `annotate-snippets` will shift the output for some very long tests 5 - 7 columns to the left. As part of my work to have `rustc` use `annotate-snippets`, and to reduce the test differences between the two, I figured it would be best if `rustc` started subtracting the code offset from the width as well.
The first commit exists to keep the test output changes of adding a new line to a test separate from adding the `--diagnostic-width` flag in the second commit. This makes it easier to verify that adding the flag does not affect the test's output.
[Zulip discussion](https://rust-lang.zulipchat.com/#narrow/channel/147480-t-compiler.2Fdiagnostics/topic/annotate-snippets.20hurdles)
only replace the intended comma in pattern suggestions
Only suggest to replace the intended comma, not all bars in the pattern.
Fixesrust-lang/rust#143330.
This continues rust-lang/rust#143331, the credit for making the fix goes to `@A4-Tacks.` I just blessed tests and added a regression test.
Tweak handling of "struct like start" where a struct isn't supported
This improves the case where someone tries to write a `match` expr where the patterns have type ascription syntax. Makes them less verbose, by giving up on the first encounter in the block, and makes them more accurate by only treating them as a struct literal if successfully parsed as such.
Before, encountering something like `match a { b:` would confuse the parser and think everything after `match` *must* be a struct, and if it wasn't it would generate a cascade of unnecessary diagnostics.
This improves the case where someone tries to write a `match` expr where the patterns have type ascription syntax. Makes them less verbose, by giving up on the first encounter in the block, and makes them more accurate by only treating them as a struct literal if successfuly parsed as such.
c-variadic: allow c-variadic inherent and trait methods
tracking issue: https://github.com/rust-lang/rust/issues/44930
Continuing the work of https://github.com/rust-lang/rust/pull/146342, allow inherent and trait methods to be c-variadic. However, a trait that contains a c-variadic method is no longer dyn-compatible.
There is, presumably, some way to make c-variadic methods dyn-compatible. However currently, we don't have confidence that it'll work reliably: when methods from a `dyn` object are cast to a function pointer, a `ReifyShim` is created. If that shim is c-variadic, it would need to forward the C variable argument list.
That does appear to work, because the `va_list` is not represented in MIR at all in this case, so the registers from the call site are untouched by the shim and can be read by the actual implementation. That just does not seem like a solid implementation.
Also, intuitively, why would c-variadic function, primarily needed for FFI, need to be used with `dyn` objects at all? We can revisit this limitation if a need arises.
r? `@workingjubilee`
