Mark format! with must_use hint
Uses unstable feature https://github.com/rust-lang/rust/issues/94745
Part of #126475
First contribution to rust, please let me know if the blessing of tests is correct
Thanks `@bjorn3` for the help
Make casts of pointers to trait objects stricter
This is an attempt to `fix` https://github.com/rust-lang/rust/issues/120222 and https://github.com/rust-lang/rust/issues/120217.
This is done by adding restrictions on casting pointers to trait objects.
Before this PR the rules were as follows:
> When casting `*const X<dyn A>` -> `*const Y<dyn B>`, principal traits in `A` and `B` must refer to the same trait definition (or no trait).
With this PR the rules are changed to
> When casting `*const X<dyn Src>` -> `*const Y<dyn Dst>`
> - if `Dst` has a principal trait `DstP`,
> - `Src` must have a principal trait `SrcP`
> - `dyn SrcP` and `dyn DstP` must be the same type (modulo the trait object lifetime, `dyn T+'a` -> `dyn T+'b` is allowed)
> - Auto traits in `Dst` must be a subset of auto traits in `Src`
> - Not adhering to this is currently a FCW (warn-by-default + `FutureReleaseErrorReportInDeps`), instead of an error
> - if `Src` has a principal trait `Dst` must as well
> - this restriction will be removed in a follow up PR
This ensures that
1. Principal trait's generic arguments match (no `*const dyn Tr<A>` -> `*const dyn Tr<B>` casts, which are a problem for [#120222](https://github.com/rust-lang/rust/issues/120222))
2. Principal trait's lifetime arguments match (no `*const dyn Tr<'a>` -> `*const dyn Tr<'b>` casts, which are a problem for [#120217](https://github.com/rust-lang/rust/issues/120217))
3. No auto traits can be _added_ (this is a problem for arbitrary self types, see [this comment](https://github.com/rust-lang/rust/pull/120248#discussion_r1463835350))
Some notes:
- We only care about the metadata/last field, so you can still cast `*const dyn T` to `*const WithHeader<dyn T>`, etc
- The lifetime of the trait object itself (`dyn A + 'lt`) is not checked, so you can still cast `*mut FnOnce() + '_` to `*mut FnOnce() + 'static`, etc
- This feels fishy, but I couldn't come up with a reason it must be checked
The diagnostics are currently not great, to say the least, but as far as I can tell this correctly fixes the issues.
cc `@oli-obk` `@compiler-errors` `@lcnr`
Rollup of 10 pull requests
Successful merges:
- #126841 ([`macro_metavar_expr_concat`] Add support for literals)
- #126881 (Make `NEVER_TYPE_FALLBACK_FLOWING_INTO_UNSAFE` a deny-by-default lint in edition 2024)
- #126921 (Give VaList its own home)
- #127367 (Run alloc sync tests)
- #127431 (Use field ident spans directly instead of the full field span in diagnostics on local fields)
- #127437 (Uplift trait ref is knowable into `rustc_next_trait_solver`)
- #127439 (Uplift elaboration into `rustc_type_ir`)
- #127451 (Improve `run-make/output-type-permutations` code and improve `filename_not_in_denylist` API)
- #127452 (Fix intrinsic const parameter counting with `effects`)
- #127459 (rustdoc-json: add type/trait alias tests)
r? `@ghost`
`@rustbot` modify labels: rollup
Uplift elaboration into `rustc_type_ir`
Allows us to deduplicate and consolidate elaboration (including these stupid elaboration duplicate fns i added for pretty printing like 3 years ago) so I'm pretty hyped about this change :3
r? lcnr
Support tail calls in mir via `TerminatorKind::TailCall`
This is one of the interesting bits in tail call implementation — MIR support.
This adds a new `TerminatorKind` which represents a tail call:
```rust
TailCall {
func: Operand<'tcx>,
args: Vec<Operand<'tcx>>,
fn_span: Span,
},
```
*Structurally* this is very similar to a normal `Call` but is missing a few fields:
- `destination` — tail calls don't write to destination, instead they pass caller's destination to the callee (such that eventual `return` will write to the caller of the function that used tail call)
- `target` — similarly to `destination` tail calls pass the caller's return address to the callee, so there is nothing to do
- `unwind` — I _think_ this is applicable too, although it's a bit confusing
- `call_source` — `become` forbids operators and is not created as a lowering of something else; tail calls always come from HIR (at least for now)
It might be helpful to read the interpreter implementation to understand what `TailCall` means exactly, although I've tried documenting it too.
-----
There are a few `FIXME`-questions still left, ideally we'd be able to answer them during review ':)
-----
r? `@oli-obk`
cc `@scottmcm` `@DrMeepster` `@JakobDegen`
Update cargo
20 commits in a515d463427b3912ec0365d106791f88c1c14e1b..154fdac39ae9629954e19e9986fd2cf2cdd8d964
2024-07-02 20:53:36 +0000 to 2024-07-07 01:28:23 +0000
- test: relax redactions for rust-lang/rust (rust-lang/cargo#14203)
- use "bootstrap" instead of "rustbuild" (rust-lang/cargo#14207)
- test: migrate serveral files to snapbox (rust-lang/cargo#14180)
- Add rustdocflags to Unit's Debug impl (rust-lang/cargo#14201)
- Allow enabling `config-include` feature in config (rust-lang/cargo#14196)
- fix(test): Restore `does_not_contain` for check (rust-lang/cargo#14198)
- test: migrate patch, pkgid, proc_macro and progress to snapbox (rust-lang/cargo#14181)
- test: Migrate jobserver to snapbox (rust-lang/cargo#14191)
- chore(deps): update msrv (3 versions) to v1.77 (rust-lang/cargo#14186)
- test: migrate build_plan and build_script to snapbox (rust-lang/cargo#14193)
- test: migrate cfg and check to snapbox (rust-lang/cargo#14185)
- test: migrate install* and inheritable_workspace_fields to snapbox (rust-lang/cargo#14170)
- Pass rustflags to artifacts built with implicit targets when using target-applies-to-host (rust-lang/cargo#13900)
- test: Migrate network tests to snapbox (rust-lang/cargo#14187)
- test: migrate some files to snapbox (rust-lang/cargo#14113)
- test: Auto-redact `... after last build at ...`; Migrate `freshness` to Snapbox (rust-lang/cargo#14161)
- chore: fix some typos (rust-lang/cargo#14182)
- fix: improve message for inactive weak optional feature with edition2024 through unused dep collection (rust-lang/cargo#14026)
- test：migrate `doc/directory/docscrape` to snapbox (rust-lang/cargo#14171)
- test: Migrate git_auth to snapbox (rust-lang/cargo#14172)
Add an option to use "::" for the external crate prefix.
Fixes#11823 .
Hi I'm very new to rust-analyzer and not sure how the review process are. Can somebody take a look at this PR? thanks!
