Fix opaque types resulting from projections in function signature
When we normalize the types in a function signature, we may end up
resolving a projection to an opaque type (e.g. `Self::MyType` when
we have `type MyType = impl SomeTrait`). When the projection is
resolved, we will instantiate the generic parameters into fresh
inference variables.
While we do want to normalize projections to opaque types, we don't want
to replace the explicit generic parameters (e.g. `T` in `impl
MyTrait<T>`) with inference variables. We want the opaque type in the
function signature to be eligible to be a defining use of that opaque
type - adding inference variables prevents this, since the opaque type
substs now appears to refer to some specific type, rather than a generic
type.
To resolve this issue, we inspect the opaque types in the function
signature after normalization. Any inference variables in the substs are
replaced with the corresponding generic parameter in the identity substs
(e.g. `T` in `impl MyTrait<T>`). Note that normalization is the only way
that we can end up with inference variables in opaque substs in a
function signature - users have no way of getting inference variables
into a function signature.
Note that all of this refers to the opaque type (ty::Opaque) and its
subst - *not* to the underlying type.
Fixes#59342
Update cargo, rls, books.
## nomicon
1 commits in 58e36e0e08dec5a379ac568827c058e25990d6cd..041c46e692a2592853aeca132c8dfe8eb5a79a9e
2019-10-30 08:14:24 -0500 to 2019-11-20 16:46:45 +0100
- Update unsafe-code-guidelines link (rust-lang-nursery/nomicon#175)
## cargo
15 commits in 8280633db680dec5bfe1de25156d1a1d53e6d190..750cb1482e4d0e74822cded7ab8b3c677ed8b041
2019-11-11 23:17:05 +0000 to 2019-11-23 23:06:36 +0000
- Some random comments and docstrings. (rust-lang/cargo#7625)
- Add value OUT_DIR to build-script-executed JSON message (rust-lang/cargo#7622)
- Update documentation for custom target dependencies. (rust-lang/cargo#7623)
- Document private items for binary crates by default (rust-lang/cargo#7593)
- Extend documentation on security concerns of crate names in a registry. (rust-lang/cargo#7616)
- Stabilize install-upgrade. (rust-lang/cargo#7560)
- Turn the new lock file format on by default (rust-lang/cargo#7579)
- bump im-rc version (rust-lang/cargo#7609)
- Ignore file lock errors if unsupported, on Windows (rust-lang/cargo#7602)
- Add hack for fwdansi change. (rust-lang/cargo#7607)
- Document Cargo's JSON output. (rust-lang/cargo#7595)
- Remove "cargo login" from user input when asking for login token. (rust-lang/cargo#7588)
- Fix all Clippy suggestions (but not add it to CI 🙃) (rust-lang/cargo#7574)
- Add kind/platform info to `cargo metadata` (rust-lang/cargo#7132)
- Update core-foundation requirement from 0.6.0 to 0.7.0 (rust-lang/cargo#7585)
## reference
2 commits in 45558c464fb458affbcdcb34323946da45c8a117..9e843aeb4df083522c7277179bbaa25d0507731c
2019-11-08 14:47:35 +0100 to 2019-11-24 17:44:04 +0100
- Minor never type additions. (rust-lang-nursery/reference#723)
- Update associated-items.md. "it"->is (rust-lang-nursery/reference#721)
## book
3 commits in e79dd62aa63396714278d484d91d48826737f47f..81ebaa2a3f88d4d106516c489682e64cacba4f60
2019-10-30 07:33:12 -0500 to 2019-11-15 08:30:04 -0800
- small fix ch04-03 & code block typo ch07-02 (rust-lang/book#2138)
- Adapt content of Chapter 16.3 in order to be consistent with improved compiler message (rust-lang/book#1779)
- [Rust 1.35] Remove FnBox and use builtin impl FnOnce for Box<FnOnce()> instead. (rust-lang/book#1906)
## rls
3 commits in 5db91c7b94ca81eead6b25bcf6196b869a44ece0..9ec2b8cb57c87517bcb506ac302eae339ffa2025
2019-10-30 16:04:39 +0100 to 2019-11-24 23:16:11 +0100
- Fix test for latest nightly. (rust-lang-nursery/rls#1595)
- doc: contributing: Remove outdated LSP extension (rust-lang-nursery/rls#1594)
- Update cargo. (rust-lang-nursery/rls#1591)
## rust-by-example
1 commits in dcee312c66267eb5a2f6f1561354003950e29105..4835e025826729827a94fdeb7cb85fed288d08bb
2019-10-31 11:26:53 -0300 to 2019-11-14 09:20:43 -0300
- crates: fix suggested value for --crate-type flag (rust-lang/rust-by-example#1292)
## edition-guide
1 commits in f553fb26c60c4623ea88a1cfe731eafe0643ce34..6601cab4666596494a569f94aa63b7b3230e9769
2019-10-30 08:27:42 -0500 to 2019-11-22 12:08:58 -0500
- Remove final nursery reference
GitHub Actions: preparations, part 1
This PR adds the first batch of commits in preparation for GitHub Actions:
* Added GitHub Actions support in `src/ci/shared.sh` and bootstrap.
* Addded a `setup-environment.sh` script which guesses and sets the `DEPLOY`, `DEPLOY_ALT` and `IMAGE` environment variables automatically, to reduce the verbosity of the CI configuration.
This PR does **not** yet add any builders on GitHub Actions.
r? @alexcrichton
Add unix::process::CommandExt::arg0
This allows argv[0] to be overridden on the executable's command-line. This also makes the program
executed independent of argv[0].
Does Fuchsia have the same semantics? I'm assuming so.
Addresses: #66510
Preserve whitespace inside one-backtick codeblocks
Previously this was only done inside short docblocks (e.g., summary
lines), but we should also do so in general.
Fixes#65555
Use proc-macro to derive HashStable everywhere
Hello,
A second proc-macro is added to derive HashStable for crates librustc depends on.
This proc-macro `HashStable_Generic` (to bikeshed) allows to decouple code and strip much of librustc's boilerplate.
Still, two implementations `Span` and `TokenKind` require to be placed in librustc.
The latter only depends on the `bug` macro. Advise welcome on how to sever that link.
A trait `StableHasingContextLike` has been introduced at each crate root,
in order to handle those implementations which require librustc's very `StableHashingContext`.
This overall effort allowed to remove the `impl_stable_hash_for` macro.
Each commit passes the `x.py check`.
I still have to double check there was no change in the implementation.
Ast address-of
This is the parts of #64588 that don't affect MIR. If an address-of expression makes it to MIR lowering we error and lower to the best currently expressible approximation to limit further errors.
r? @Centril
Previously tidy would require that the `feature = "name_of_feature"`
part of the stability attribute was on the same line as the `#[stable(`
/ `#[unstable(` opening part of the attribute, and that `)]` was on the
same line as the last key-value pair.
That didn't work with rustfmt's preferred layout of long attributes,
which is like:
#[unstable(
feature = "c_variadic",
reason = "the `c_variadic` feature has not been properly tested on \
all supported platforms",
issue = "44930"
)]
