Overhaul improper_ctypes output
This snowballed into a rather big set of improvements to the diagnostics of the improper_ctypes lint. See commits for details, including effects of each change on the `compile-fail/improper-ctypes.rs` test (now a UI test), which is pretty gnarly and hopefully not representative of real code, but covers a lot of different error cases.
Fixes#42050
detect wrong number of args when type-checking a closure
Instead of creating inference variables for those argument types, use
the trait error-reporting code to give a nicer error. This also
improves some other spans for existing tests.
Fixes#47244
r? @estebank
Fix span of visibility
This PR
1. adds a closing parenthesis to the span of `Visibility::Crate` (e.g. `pub(crate)`). The current span only covers `pub(crate`.
2. adds a `span` field to `Visibility::Restricted`. This span covers the entire visibility expression (e.g. `pub (in self)`). Currently all we can have is a span for `Path`.
This PR is motivated by the bug found in rustfmt (https://github.com/rust-lang-nursery/rustfmt/issues/2398).
The first change is a strict improvement IMHO. The second change may not be desirable, as it adds a field which is currently not used by the compiler.
rustc_mir: handle all aggregate kinds in, and always run, the deaggregator.
This helps with removing`Rvalue::Aggregate` from the MIR, and with enabling more optimizations.
r? @nikomatsakis
Update .mailmap with my real name
Good morning, the Rust team!
Once upon a time I was a modest-scale contributor. Sadly, various turbulences made me step away from my participation in the project. It's great to see how far it's gone.
I would appreciate it if you accepted this small change to the .mailmap file so that it shows my real name as back then I was using an alias. If doubts arise if I am the same person, I will be happy to provide further evidence. :)
Kind regards.
rustdoc: move manual "extern crate" statements outside automatic "fn main"s in doctests
Gated on https://github.com/rust-lang/rust/pull/48095 - I based the branch atop that so i could show off the change in one of its tests, the actual change in this PR is just the last commit
There are a handful of unfortunate assumptions in the way rustdoc processes `extern crate` statements in doctests:
1. In the absence of an `extern crate` statement in the test, if the test also uses the local crate name, it will automatically insert an `extern crate cratename;` statement into the test.
2. If the doctest *does* include an `extern crate` statement, rustdoc will not automatically insert one, on the assumption that doing so would introduce a duplicate import.
3. If a doctest does not have the substring `fn main` outside a comment, rustdoc will wrap the whole doctest in a generated `fn main` so it can be compiled.
In short, whenever you write a doctest like this...
```rust
//! extern crate my_crate;
//! my_crate::some_cool_thing();
```
...rustdoc will turn it into (something like) this:
```rust
fn main() {
extern crate my_crate;
my_crate::some_cool_thing();
}
```
This creates issues when compiled, because now `my_crate` isn't even properly in scope! This forces people who want to have multiple crates in their doctests (or an explicit `extern crate` statement) to also manually include their own `fn main`, so rustdoc doesn't put their imports in the wrong place.
This PR just taps into another processing step rustdoc does to doctests: Whenever you add an `#![inner_attribute]` to the beginning of a doctest, rustdoc will actually splice those out and put it before the generated `fn main`. Now, we can just do the same with `extern crate`s at the beginning, too, and get a much nicer experience.
Now, the above example will be converted into this:
```rust
extern crate my_crate;
fn main() {
my_crate::some_cool_thing();
}
```
Generate documentation for auto-trait impls
A new section is added to both both struct and trait doc pages.
On struct/enum pages, a new 'Auto Trait Implementations' section displays any synthetic implementations for auto traits. Currently, this is only done for Send and Sync.
On trait pages, a new 'Auto Implementors' section displays all types which automatically implement the trait. Effectively, this is a list of all public types in the standard library.
Synthesized impls for a particular auto trait ('synthetic impls') take generic bounds into account. For example, a type
```rust
struct Foo<T>(T)
```
will have 'impl<T> Send for Foo<T> where T: Send' generated for it.
Manual implementations of auto traits are also taken into account. If we have
the following types:
```rust
struct Foo<T>(T)
struct Wrapper<T>(Foo<T>)
unsafe impl<T> Send for Wrapper<T>' // pretend that Wrapper<T> makes this sound somehow
```
Then Wrapper will have the following impl generated:
```rust
impl<T> Send for Wrapper<T>
```
reflecting the fact that 'T: Send' need not hold for 'Wrapper<T>: Send' to hold
Lifetimes, HRTBS, and projections (e.g. '<T as Iterator>::Item') are taken into account by synthetic impls:
However, if a type can *never* implement a particular auto trait (e.g. `struct MyStruct<T>(*const T)`), then a negative impl will be generated (in this case, `impl<T> !Send for MyStruct<T>`)
All of this means that a user should be able to copy-paste a syntheticimpl into their code, without any observable changes in behavior (assuming the rest of the program remains unchanged).
Current document takes 2^4, which is equal to 4^2.
This example is not very helpful for those unfamiliar with math words in English and thus rely on example codes.
