Normalize use of backticks in syntax for user-facing compiler messages

[alexreg]

This is more pedantry from me, and admittedly not very high-priority, but I have noticed that there are discrepancies between compiler error/informational messages where syntax is included in them – some use backticks around code syntax, some don't. Furthermore, some start with lower case (the vast majority), while some don't.

For example:

"attribute must be of the form `#[derive(Trait1, Trait2, ...)]`"

vs.

"type does not implement `fmt::Debug`; consider adding #[derive(Debug)] \

(an internal inconsistency in this second case too!)

It would be nice to normalise this according some guidelines. I'd imagine the guidelines should agree with rustdoc as much as possible, though starting all messages with lower case may be desirable, since it is "command-line fashion".

[fakenine]

Hello, I would like to work on this one! cc @varkor

[varkor]

@fakenine: I'm not sure of a principled way to go about this, but you can look in the compiler for error messages (coming from span_err and similar functions) and update any that have code in them to be surrounded by backticks. Running x.py test src/test/ui --bless then should update all the test files.

[alexreg]

Thanks @fakenine, sounds good.

[alexreg]

Unfortunately a lot of this will have to be done manually as @varkor hints at, but a good deal can be automated by searching with regexps, e.g. ".*[^`]#\[\w+ will find lines including a string terminator followed (eventually) by an attribute, where the attribute is not preceded by a backtick. You can probably make a shortlist of similar patterns and then create regexps for them.

[fakenine]

Thanks for the tips, I will look into that!

[alexreg]

Hi @fakenine. Any news on this so far? Let me know if you need advice or an initial cursory review!

[fakenine]

Hi @alexreg ! Thanks for the help. I was on holidays so I didn't get the time to start properly looking on it. I should be able to start this weekend

[alexreg]

No problem. Keep us posted, and feel free to ask here or on Discord. :-)

[fakenine]

Hello @alexreg! I have opened a WIP PR here #61901

There are indeed lots of changes to do manually and results to sort with the regexes, but I'm confident about it :)