Add tests for the drop behavior of some control flow constructs
In #100513 it was shown that the drop behaviour of let_chains is not correct currently. Since drop behaviour is something pretty subtle, this adds explicit tests for the drop behavior of `if`, `if let` and `match` to make sure that it does not regress in the future.
The `println!`s were left in to make debugging easier in case something goes wrong, but they are not required for the test.
rustdoc: Merge source code pages HTML elements together
We realized that the HTML generated for the source code pages could be improved quite a lot. This PR is a first pass toward this goal. Some explanations: it merges similar classes elements (even when there are white characters in between).
There is an exception to this: if this is an ident, I also merged it with "unclassified" elements. This part is up to debate and can be very easily removed as the check is performed in one place (in the `can_merge` function).
EDIT: The `ident` is now only kept in the code for the `span` it contains but it is not rendered into the HTML.
So now some numbers:
For these ones, on each page, I run this JS: `document.getElementsByTagName('*').length`. The goal is to count the number of DOM elements. I took some pages that seemed big, but don't hesitate to check some others.
| file name | before this PR | with this PR | diff | without ident | diff |
|-|-|-|-|-|-|
| std/lib.rs.html (source link on std crate page) | 3455 | 2776 | 20.7% | 2387 | 31% |
| alloc/vec/mod.rs.html (source on Vec type page) | 11012 | 8084 | 26.6% | 6682 | 39.4% |
| alloc/string.rs.html (source on String type page) | 10800 | 8214 | 24% | 6712 | 37.9% |
| std/sync/mutex.rs.html (source on Mutex type page) | 2953 | 2403 | 18.7% | 2139 | 27.6% |
You can test it [here](https://rustdoc.crud.net/imperio/merge-html-elements-together/src/std/lib.rs.html).
cc `@jsha`
r? `@notriddle`
In #100513 it was shown that the drop behavior of let_chains is not correct
currently. Since drop behavior is something pretty subtle, this adds
explicit tests for the drop behavior of `if`, `if let` and `match` to
make sure that it does not regress in the future.
The `println!`s were left in to make debugging easier in case something
goes wrong, but they are not required for the test.
orphan check: rationalize our handling of constants
cc `@rust-lang/types` `@rust-lang/project-const-generics` on whether you agree with this reasoning.
r? types
Argument type error improvements
Motivated by this interesting code snippet:
```rust
#[derive(Copy, Clone)]
struct Wrapper<T>(T);
fn foo(_: fn(i32), _: Wrapper<i32>) {}
fn f(_: u32) {}
fn main() {
let w = Wrapper::<isize>(1isize);
foo(f, w);
}
```
Which currently errors like:
```
error[E0308]: arguments to this function are incorrect
--> src/main.rs:10:5
|
10 | foo(f, w);
| ^^^ - - expected `i32`, found `isize`
| |
| expected `i32`, found `u32`
|
= note: expected fn pointer `fn(i32)`
found fn item `fn(u32) {f}`
= note: expected struct `Wrapper<i32>`
found struct `Wrapper<isize>`
note: function defined here
--> src/main.rs:4:4
|
4 | fn foo(_: fn(i32), _: Wrapper<i32>) {}
| ^^^ ---------- ---------------
```
Specifically, that double `expected .. found ..` which is very difficult to correlate to the types in the arguments. Also, the fact that "expected `i32`, found `isize`" and the other argument mismatch label don't even really explain what's going on here.
After this PR:
```
error[E0308]: arguments to this function are incorrect
--> $DIR/two-mismatch-notes.rs:10:5
|
LL | foo(f, w);
| ^^^
|
note: expected fn pointer, found fn item
--> $DIR/two-mismatch-notes.rs:10:9
|
LL | foo(f, w);
| ^
= note: expected fn pointer `fn(i32)`
found fn item `fn(u32) {f}`
note: expected struct `Wrapper`, found a different struct `Wrapper`
--> $DIR/two-mismatch-notes.rs:10:12
|
LL | foo(f, w);
| ^
= note: expected struct `Wrapper<i32>`
found struct `Wrapper<isize>`
note: function defined here
--> $DIR/two-mismatch-notes.rs:4:4
|
LL | fn foo(_: fn(i32), _: Wrapper<i32>) {}
| ^^^ ---------- ---------------
error: aborting due to previous error
For more information about this error, try `rustc --explain E0308`.
```
Yeah, it's a bit verbose, but much clearer IMO.
---
Open to discussions about how this could be further improved. Motivated by `@jyn514's` [tweet](https://mobile.twitter.com/joshuayn514/status/1558042020601634816) here.
Rustdoc-Json: Add `Path` type for traits.
Avoids using `Type` for trait fields, as a trait must always be a path, and not any other kind of type.
``@rustbot`` modify labels: +A-rustdoc-json +T-rustdoc
Closes#100106
Erase regions better in `promote_candidate`
Use `tcx.erase_regions` instead of manually walking through the substs.... this also makes the code slightly simpler 🙈Fixes#100360Fixes#89851
`@!has` (and `@!matches`) with two arguments used to treat the second
argument as a literal string of HTML code. Now, that feature has been
renamed into `@!hasraw` (and `@!matchesraw`), and the arity-2 `@!has`
version is an error.
These uses thought the second argument was being treated as an XPath, as
with the arity-3 version, but in fact was being treated as literal HTML.
Because these were checking for the *absence* of the string, the tests
silently did nothing -- an XPath string won't ever be showing up in the
test's generated HTML!
For the most part, the macro actually worked with _ slugs, but the prefix_something -> prefix::something
conversion was not implemented.
We don't want to accept - slugs for consistency reasons.
We thus error if a name is found with - inside.
This ensures a consistent style.
Add two let else regression tests
Adds a regression test for #94176, as it was fixed by #98574 but doesn't have a regression test. The PR also incorporates a commit from #94012 which added a test for an issue discovered in that PR.
Originally they have been part of #99291, but I've moved them out in the hopes of getting them merged more quickly, as that PR is already open since a month, and so that #99291 can focus on the drop order part of things.
Closes#94176Closes#96961 -- dupe of #94176
