upper_case_acronyms: move lint from style to pedantic lint group

[matthiaskrgr]

The lint does point out inconsistency with the Rust naming convention,
but the fact that rustc does not warn about the inconsistency by default
means that clippy probably should not warn by default either.

changelog: move upper_case_acronyms lint from style to pedantic group.

[rust-highfive]

r? @flip1995

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[flip1995]

@bors r+

Thanks!

[bors]

📌 Commit 0eefa61 has been approved by flip1995

[bors]

⌛ Testing commit 0eefa61 with merge 697f3b6...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: flip1995
Pushing 697f3b6 to master...

[XAMPPRocky]

the fact that rustc does not warn about the inconsistency by default
means that clippy probably should not warn by default either.

FWIW we just ran into some code that would be caught by this lint at Embark, and were surprised that this isn't a default warning by rustc. I think I would expect the opposite, that this lint warns by default and even be uplifted from clippy to rustc, since this naming convention for enum variants is actually part of RFC 430, and I would expect rustc to warn when things mismatch that RFC.

[matthiaskrgr]

Hmm.
In the rustc repo for example, the lint triggers almost 200 times.
Some examples: RWLock EOFWhileParsingObject ABI ELFv1 CFGuard TargetCPUs LTO IntEQ IntNE PGO LLVMRustResult MD5 RustdocGUI.

EofWhileParsingObject, Elfv1 IntNe LlvmRustResult read kind of weird and are not an improvement besides adhering to some arbitrary guideline in my opinion.

I'm open to a revert of my pr but perhaps we can discuss this in the upcoming clippy meeting tomorrow.

[matthiaskrgr]

@XAMPPRocky do you have some bugs that the lint found something like that?

[matthiaskrgr]

There are numerous projects that have allow(clippy::upper_case_acronyms) already:
https://github.com/search?p=1&q=%22clippy%3A%3Aupper_case_acronyms%22&type=Code

[XAMPPRocky]

The case we had looked something like this.

enum Direction {
    WEST,
    NORTH,
    EAST,
    SOUTH,
}

EofWhileParsingObject, Elfv1, IntNe, LlvmRustResult read kind of weird and are not an improvement besides adhering to some arbitrary guideline in my opinion.

I mean I think it’s no less arbitrary than non_camel_case_types, which rustc warns about by default. Though maybe if this was put in today it should be more conservative and just catch all uppercase or snake_case variants. To avoid setting off a lot of warnings.

[matthiaskrgr]

I see, I think it makes sense to still warn for fully upper-case names.
I quickly threw together a POC at master...matthiaskrgr:upper_case_acr
This will issues a warn-by-default warning for fully upper case idents that are longer than 2 characters (so FP is not linted but WEST is.

[matthiaskrgr]

#6788 moves the lint back to the style group.
It will warn by default on fully uppercase names like WEST.
If you turn on more aggressive linting in clippys config file via upper-case-acronyms-aggressive: true, it will also warn on LLVMRustResult.