Implement edition hygiene for keywords
Determine "keywordness" of an identifier in its hygienic context.
cc https://github.com/rust-lang/rust/pull/49611
I've resurrected `proc` as an Edition-2015-only keyword for testing purposes, but it should probably be buried again. EDIT: `proc` is removed again.
Improve format string errors
Point at format string position inside the formatting string:
```
error: invalid format string: unmatched `}` found
--> $DIR/format-string-error.rs:21:22
|
LL | let _ = format!("}");
| ^ unmatched `}` in format string
```
Explain that argument names can't start with an underscore:
```
error: invalid format string: invalid argument name `_foo`
--> $DIR/format-string-error.rs:15:23
|
LL | let _ = format!("{_foo}", _foo = 6usize);
| ^^^^ invalid argument name in format string
|
= note: argument names cannot start with an underscore
```
Fix#23476.
The more accurate spans will only be seen when using `format!` directly, when using `println!` the diagnostics machinery makes the span be the entire statement.
Switch to bootstrapping from 1.27
It's possible the Float trait could be removed from core, but I couldn't tell whether it was intended to be removed or not. @SimonSapin may be able to comment more here; we can presumably also do that in a follow up PR as this one is already quite large.
Ensure derive(PartialOrd) is no longer accidentally exponential
Previously, two comparison operations would be generated for each field, each of which could delegate to another derived PartialOrd. Now we use ordering and optional chaining to ensure each pair of fields is only compared once, addressing https://github.com/rust-lang/rust/issues/49650#issuecomment-379467572.
Closes#49505.
r? @Manishearth (sorry for changing it again so soon!)
Close#50755
Rollup of 12 pull requests
Successful merges:
- #50302 (Add query search order check)
- #50320 (Fix invalid path generation in rustdoc search)
- #50349 (Rename "show type declaration" to "show declaration")
- #50360 (Clarify wordings of the `unstable_name_collision` lint.)
- #50365 (Use two vectors in nearest_common_ancestor.)
- #50393 (Allow unaligned reads in constants)
- #50401 (Revert "Implement FromStr for PathBuf")
- #50406 (Forbid constructing empty identifiers from concat_idents)
- #50407 (Always inline simple BytePos and CharPos methods.)
- #50416 (check if the token is a lifetime before parsing)
- #50417 (Update Cargo)
- #50421 (Fix ICE when using a..=b in a closure.)
Failed merges:
Previously, two comparison operations would be generated for each field, each of which could delegate to another derived PartialOrd. Now we use ordering and optional chaining to ensure each pair of fields is only compared once.
Provide better names for builtin deriving-generated attributes
First attempt at fixing #49967
Not in love with any choices here, don't be shy if you aren't happy with anything :)
I've tested that this produces nicer names in documentation, and that it no longer has issues conflicting with constants with the same name. (I guess we _could_ make a test for that... unsure if that would be valuable)
In all cases I took the names from the methods as declared in the relevant trait.
In some cases I had to prepend the names with _ otherwise there were errors about un-used variables. I'm uneasy with the inconsistency... do they all need to be like that? Is there a way to generate an alternate impl or use a different name (`_`?) in the cases where the arguments are not used?
Lastly the gensym addition to Ident I implemented largely as suggested, but I want to point out it's a little circuitous (at least, as far as I understand it). `cx.ident_of(name)` is just `Ident::from_str`, so we create an Ident then another Ident from it. `Ident::with_empty_ctxt(Symbol::gensym(string))` may or may not be equivalent, I don't know if it's important to intern it _then_ gensym it. It seems like either we could use that, or if we do want a new method to make this convenient, it could be on Ident instead (`from_str_gensymed`?)
