rust/compiler/rustc_builtin_macros
bors 70e04bd88d Auto merge of #111748 - nnethercote:Cow-DiagnosticMessage, r=WaffleLapkin
Use `Cow` in `{D,Subd}iagnosticMessage`.

Each of `{D,Subd}iagnosticMessage::{Str,Eager}` has a comment:
```
// FIXME(davidtwco): can a `Cow<'static, str>` be used here?
```
This commit answers that question in the affirmative. It's not the most compelling change ever, but it might be worth merging.

This requires changing the `impl<'a> From<&'a str>` impls to `impl From<&'static str>`, which involves a bunch of knock-on changes that require/result in call sites being a little more precise about exactly what kind of string they use to create errors, and not just `&str`. This will result in fewer unnecessary allocations, though this will not have any notable perf effects given that these are error paths.

Note that I was lazy within Clippy, using `to_string` in a few places to preserve the existing string imprecision. I could have used `impl Into<{D,Subd}iagnosticMessage>` in various places as is done in the compiler, but that would have required changes to *many* call sites (mostly changing `&format("...")` to `format!("...")`) which didn't seem worthwhile.

r? `@WaffleLapkin`
2023-05-29 07:10:44 +00:00
..
src Auto merge of #111748 - nnethercote:Cow-DiagnosticMessage, r=WaffleLapkin 2023-05-29 07:10:44 +00:00
Cargo.toml Use GrowableBitSet to store positional indexes in asm! 2023-05-02 16:42:36 +01:00
messages.ftl Ensure Fluent messages are in alphabetical order 2023-05-25 23:49:35 +00:00