Enable NLL migrate mode on the 2015 edition
## What is in this PR?
* Remove the `-Zborrowck=ast` flag option from rustc.
* The default in the 2015 edition is now `-Zborrowck=migrate`.
* The 2018 edition default is unchanged: it's still `-Zborrowck=migrate`.
* Enable two-phase borrows (currently toggled via the `-Ztwo-phase-borrows` flag) on all editions.
* Remove most dead code that handled these options.
* Update tests for the above changes.
## What is *not* in this PR?
These are left for future PRs
* Use `-Zborrowck=mir` in NLL compare mode tests (#56993)
* Remove the `-Zborrowck=compare` option (#59193)
* Remove the `-Ztwo-phase-borrows` flag. It's kept, as a flag that does nothing so that perf.rlo has time to stop using it (cc @Mark-Simulacrum)
* Remove MIR typeck as its own MIR pass - it's now run by NLL.
* Enabling `-Zborrowck=mir` by default (#58781)
* Replace `allow_bind_by_move_patterns_with_guards` and `check_for_mutation_in_guard_via_ast_walk` with just using the feature gate. (#59192)
Soundness issues that are fixed by NLL will stay open until full NLL is emitting hard errors. However, these diagnostics and completeness issues can now be closed:
Closes#18330Closes#22323Closes#23591Closes#26736Closes#27487Closes#28092Closes#28970Closes#29733Closes#30104Closes#38915Closes#39908Closes#43407Closes#47524Closes#48540Closes#49073Closes#52614Closes#55085Closes#56093Closes#56496Closes#57804
cc #43234
r? @pnkfelix
cc @rust-lang/lang
cc @rust-lang/wg-compiler-nll
save-analysis: Use serde instead of libserialize to dump JSON data
This breaks the save-analysis infrastructure (which also includes `rls-{analysis, data, span}` crates) from depending on rustc_serialize and so we can start moving them to being supported on stable without implementing `Decodable` et al. by hand for data structures defined there.
Notable benefits:
- we drop the awkward raw byte `PathBuf` [serialization](https://gist.github.com/Xanewok/f4fe8564d0dc0c3ab1dbc244279ff895) (until now (de)serialized as `&[u8]`)
- [faster](https://github.com/serde-rs/json-benchmark) (hopefully noticeable for inner crate dependencies for the RLS workloads)
- we can easily explore the binary serialization backend (which we planned to do for save-analysis anyway)
~This should be merged together with an update to RLS (https://github.com/rust-lang/rls/pull/1435), which technically could be included right now because we can use the bundled `rls-analysis` here directly, however I'd prefer to publish this to crates.io first (https://github.com/rust-lang/rls/pull/1434, cc @nrc) and use the published version, instead.~
Includes https://github.com/rust-lang/rls/pull/1436.
@matklad @nikomatsakis This is also important for the potential RLS 1.0 - 2.0 bridge we talked about on Zulip today
Fix fn front matter parsing ICE from invalid code.
Fixes#60075.
This PR fixes an "unreachable code" ICE that results from parsing
invalid code where the compiler is expecting the next trait item
declaration in the middle of the previous trait item due to extra
closing braces.
r? @estebank (thanks for the minimized test case)
This commit fixes an "unreachable code" ICE that results from parsing
invalid code where the compiler is expecting the next trait item
declaration in the middle of the previous trait item due to extra
closing braces.
When looking at the documentation for `std::f32` or `std::str`, for
example, it is easy to get confused and assume `std::f32` and `f32`
are the same thing. Because of this, it is not uncommon to attempt
writing `f32::consts::PI` instead of the correct
`std::f32::consts::PI`. When encountering the former, which results
in an access error due to it being an inexistent path, try to access
the same path under `std`. If this succeeds, this information is
stored for later tweaking of the final E0599 to provide an
appropriate suggestion.
This suggestion applies to both E0233 and E0599 and is only checked
when the first ident of a path corresponds to a primitive type.
Resolve inconsistency in error messages between "parameter" and "variable".
The inconsistency was introduced in 104fe1c4db (#33619), when a label saying `type variable` was added to an error with a message talking about `type parameters`.
Given that `parameter` is far more prevalent when referring to generics in the context of Rust, IMO it should be that in both the message and the label.
r? @nikomatsakis or @estebank
Add test checking that Index<T: ?Sized> works
I've noticed that we have an `Idx: ?Sized` bound on the **index** in the `Index`, which seems strange given that we accept index by value. My guess is that it was meant to be removed in https://github.com/rust-lang/rust/pull/23601, but was overlooked.
If I remove this bound, `./x.py src/libstd/ src/libcore/` passes, which means at least that this is not covered by test.
I think there's three things we can do here:
* run crater with the bound removed to check if there are any regressions, and merge this, to be consistent with other operator traits
* run crater, get regressions, write a test for this with a note that "hey, we tried to fix it, its unfixable"
* decide, in the light of by-value DSTs, that this is a feature rather than a bug, and add a test
cc @rust-lang/libs
EDIT: the forth alternative is that there exist a genuine reason why this is the case, but I failed to see it :D
