1 use clippy_utils::diagnostics::span_lint_and_sugg;
2 use itertools::Itertools;
3 use rustc_ast::ast::{Item, ItemKind, VisibilityKind};
4 use rustc_errors::Applicability;
5 use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
6 use rustc_middle::lint::in_external_macro;
7 use rustc_session::{declare_tool_lint, impl_lint_pass};
8 use rustc_span::symbol::Ident;
10 declare_clippy_lint! {
11 /// **What it does:** Checks for fully capitalized names and optionally names containing a capitalized acronym.
13 /// **Why is this bad?** In CamelCase, acronyms count as one word.
14 /// See [naming conventions](https://rust-lang.github.io/api-guidelines/naming.html#casing-conforms-to-rfc-430-c-case)
17 /// By default, the lint only triggers on fully-capitalized names.
18 /// You can use the `upper-case-acronyms-aggressive: true` config option to enable linting
19 /// on all camel case names
21 /// **Known problems:** When two acronyms are contiguous, the lint can't tell where
22 /// the first acronym ends and the second starts, so it suggests to lowercase all of
23 /// the letters in the second acronym.
28 /// struct HTTPResponse;
32 /// struct HttpResponse;
34 pub UPPER_CASE_ACRONYMS,
36 "capitalized acronyms are against the naming convention"
40 pub struct UpperCaseAcronyms {
41 upper_case_acronyms_aggressive: bool,
44 impl UpperCaseAcronyms {
45 pub fn new(aggressive: bool) -> Self {
47 upper_case_acronyms_aggressive: aggressive,
52 impl_lint_pass!(UpperCaseAcronyms => [UPPER_CASE_ACRONYMS]);
54 fn correct_ident(ident: &str) -> String {
55 let ident = ident.chars().rev().collect::<String>();
57 .split_inclusive(|x: char| !x.is_ascii_lowercase())
59 .map(|x| x.chars().rev().collect::<String>());
61 let mut ident = fragments.clone().next().unwrap();
62 for (ref prev, ref curr) in fragments.tuple_windows() {
65 .all(|s| s.len() == 1 && s.chars().next().unwrap().is_ascii_uppercase())
67 ident.push_str(&curr.to_ascii_lowercase());
75 fn check_ident(cx: &EarlyContext<'_>, ident: &Ident, be_aggressive: bool) {
76 let span = ident.span;
77 let ident = &ident.as_str();
78 let corrected = correct_ident(ident);
79 // warn if we have pure-uppercase idents
80 // assume that two-letter words are some kind of valid abbreviation like FP for false positive
82 if (ident.chars().all(|c| c.is_ascii_uppercase()) && ident.len() > 2)
83 // otherwise, warn if we have SOmeTHING lIKE THIs but only warn with the aggressive
84 // upper-case-acronyms-aggressive config option enabled
85 || (be_aggressive && ident != &corrected)
91 &format!("name `{}` contains a capitalized acronym", ident),
92 "consider making the acronym lowercase, except the initial letter",
94 Applicability::MaybeIncorrect,
99 impl EarlyLintPass for UpperCaseAcronyms {
100 fn check_item(&mut self, cx: &EarlyContext<'_>, it: &Item) {
101 // do not lint public items or in macros
102 if !in_external_macro(cx.sess(), it.span) && !matches!(it.vis.kind, VisibilityKind::Public) {
105 ItemKind::TyAlias(..) | ItemKind::Struct(..) | ItemKind::Trait(..)
107 check_ident(cx, &it.ident, self.upper_case_acronyms_aggressive);
108 } else if let ItemKind::Enum(ref enumdef, _) = it.kind {
109 // check enum variants seperately because again we only want to lint on private enums and
110 // the fn check_variant does not know about the vis of the enum of its variants
114 .for_each(|variant| check_ident(cx, &variant.ident, self.upper_case_acronyms_aggressive));