Currently a `{D,Subd}iagnosticMessage` can be created from any type that
impls `Into<String>`. That includes `&str`, `String`, and `Cow<'static,
str>`, which are reasonable. It also includes `&String`, which is pretty
weird, and results in many places making unnecessary allocations for
patterns like this:
```
self.fatal(&format!(...))
```
This creates a string with `format!`, takes a reference, passes the
reference to `fatal`, which does an `into()`, which clones the
reference, doing a second allocation. Two allocations for a single
string, bleh.
This commit changes the `From` impls so that you can only create a
`{D,Subd}iagnosticMessage` from `&str`, `String`, or `Cow<'static,
str>`. This requires changing all the places that currently create one
from a `&String`. Most of these are of the `&format!(...)` form
described above; each one removes an unnecessary static `&`, plus an
allocation when executed. There are also a few places where the existing
use of `&String` was more reasonable; these now just use `clone()` at
the call site.
As well as making the code nicer and more efficient, this is a step
towards possibly using `Cow<'static, str>` in
`{D,Subd}iagnosticMessage::{Str,Eager}`. That would require changing
the `From<&'a str>` impls to `From<&'static str>`, which is doable, but
I'm not yet sure if it's worthwhile.
This greatly simplifies how hard it is to set a custom bug report url; previously tools had to copy
the entire hook implementation.
- Switch clippy to the new hook
This also adds a `extra_info` callback so clippy can include its own version number, which differs
from rustc's.
- Call `install_ice_hook` in rustfmt
new lint: `manual_while_let_some`
This PR implements the lint I suggested [on zulip](https://rust-lang.zulipchat.com/#narrow/stream/257328-clippy/topic/lint.20on.20while.20pop.20unwrap).
It looks for while loops like these:
```rs
let mut numbers = vec![0, 1, 2];
while !numbers.is_empty() {
let number = numbers.pop().unwrap();
// use `number`
}
```
and suggests replacing it with a while-let loop, like this:
```rs
let mut numbers = vec![0, 1, 2];
while let Some(number) = numbers.pop() {
// use `number`
}
```
... which is more concise and idiomatic.
It only looks for `Vec::pop()` calls in the first statement of the loop body in an attempt to not trigger FPs (as pop might only be called conditionally).
changelog: new lint [`manual_while_let_some`]
Fix `items_after_test_module`: Ignore imported modules
Fixes#10713. It does a little bit of dark magic, but intention is what really counts.
changelog:[`items_after_test_module`]: Ignore imported modules (`mod foo;`) with no body.
fix new lints link
install nightly rust-docs
run linkcheck without nightly toolchain
remove nightly toolchain, add rust-docs component
Test Remark
Update basics.md
Update basics.md
Update basics.md
update workflow
add rust docs toolchain
Update remark.yml
workflow test
manual test
update book path
add linkcheck book to CI
Update lint_passes.md
Using `default` to construct a unit struct increases code complexity and
adds a function call. This can be avoided by simply removing the call to
`default` and simply construct by name.
