1use rustc_abi::ExternAbi;
2use rustc_attr_data_structures::{AttributeKind, ReprAttr};
3use rustc_attr_parsing::AttributeParser;
4use rustc_hir::def::{DefKind, Res};
5use rustc_hir::intravisit::FnKind;
6use rustc_hir::{AttrArgs, AttrItem, Attribute, GenericParamKind, PatExprKind, PatKind};
7use rustc_middle::ty;
8use rustc_session::config::CrateType;
9use rustc_session::{declare_lint, declare_lint_pass};
10use rustc_span::def_id::LocalDefId;
11use rustc_span::{BytePos, Ident, Span, sym};
12use {rustc_ast as ast, rustc_hir as hir};
13
14use crate::lints::{
15 NonCamelCaseType, NonCamelCaseTypeSub, NonSnakeCaseDiag, NonSnakeCaseDiagSub,
16 NonUpperCaseGlobal, NonUpperCaseGlobalSub,
17};
18use crate::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
19
20#[derive(PartialEq)]
21pub(crate) enum MethodLateContext {
22 TraitAutoImpl,
23 TraitImpl,
24 PlainImpl,
25}
26
27pub(crate) fn method_context(cx: &LateContext<'_>, id: LocalDefId) -> MethodLateContext {
28 let item = cx.tcx.associated_item(id);
29 match item.container {
30 ty::AssocItemContainer::Trait => MethodLateContext::TraitAutoImpl,
31 ty::AssocItemContainer::Impl => match cx.tcx.impl_trait_ref(item.container_id(cx.tcx)) {
32 Some(_) => MethodLateContext::TraitImpl,
33 None => MethodLateContext::PlainImpl,
34 },
35 }
36}
37
38fn assoc_item_in_trait_impl(cx: &LateContext<'_>, ii: &hir::ImplItem<'_>) -> bool {
39 let item = cx.tcx.associated_item(ii.owner_id);
40 item.trait_item_def_id.is_some()
41}
42
43declare_lint! {
44 pub NON_CAMEL_CASE_TYPES,
63 Warn,
64 "types, variants, traits and type parameters should have camel case names"
65}
66
67declare_lint_pass!(NonCamelCaseTypes => [NON_CAMEL_CASE_TYPES]);
68
69fn char_has_case(c: char) -> bool {
73 let mut l = c.to_lowercase();
74 let mut u = c.to_uppercase();
75 while let Some(l) = l.next() {
76 match u.next() {
77 Some(u) if l != u => return true,
78 _ => {}
79 }
80 }
81 u.next().is_some()
82}
83
84fn is_camel_case(name: &str) -> bool {
85 let name = name.trim_matches('_');
86 if name.is_empty() {
87 return true;
88 }
89
90 !name.chars().next().unwrap().is_lowercase()
93 && !name.contains("__")
94 && !name.chars().collect::<Vec<_>>().array_windows().any(|&[fst, snd]| {
95 char_has_case(fst) && snd == '_' || char_has_case(snd) && fst == '_'
97 })
98}
99
100fn to_camel_case(s: &str) -> String {
101 s.trim_matches('_')
102 .split('_')
103 .filter(|component| !component.is_empty())
104 .map(|component| {
105 let mut camel_cased_component = String::new();
106
107 let mut new_word = true;
108 let mut prev_is_lower_case = true;
109
110 for c in component.chars() {
111 if prev_is_lower_case && c.is_uppercase() {
114 new_word = true;
115 }
116
117 if new_word {
118 camel_cased_component.extend(c.to_uppercase());
119 } else {
120 camel_cased_component.extend(c.to_lowercase());
121 }
122
123 prev_is_lower_case = c.is_lowercase();
124 new_word = false;
125 }
126
127 camel_cased_component
128 })
129 .fold((String::new(), None), |(acc, prev): (String, Option<String>), next| {
130 let join = if let Some(prev) = prev {
133 let l = prev.chars().last().unwrap();
134 let f = next.chars().next().unwrap();
135 !char_has_case(l) && !char_has_case(f)
136 } else {
137 false
138 };
139 (acc + if join { "_" } else { "" } + &next, Some(next))
140 })
141 .0
142}
143
144impl NonCamelCaseTypes {
145 fn check_case(&self, cx: &EarlyContext<'_>, sort: &str, ident: &Ident) {
146 let name = ident.name.as_str();
147
148 if !is_camel_case(name) {
149 let cc = to_camel_case(name);
150 let sub = if *name != cc {
151 NonCamelCaseTypeSub::Suggestion { span: ident.span, replace: cc }
152 } else {
153 NonCamelCaseTypeSub::Label { span: ident.span }
154 };
155 cx.emit_span_lint(
156 NON_CAMEL_CASE_TYPES,
157 ident.span,
158 NonCamelCaseType { sort, name, sub },
159 );
160 }
161 }
162}
163
164impl EarlyLintPass for NonCamelCaseTypes {
165 fn check_item(&mut self, cx: &EarlyContext<'_>, it: &ast::Item) {
166 let has_repr_c = matches!(
167 AttributeParser::parse_limited(cx.sess(), &it.attrs, sym::repr, it.span, true),
168 Some(Attribute::Parsed(AttributeKind::Repr(r))) if r.iter().any(|(r, _)| r == &ReprAttr::ReprC)
169 );
170
171 if has_repr_c {
172 return;
173 }
174
175 match &it.kind {
176 ast::ItemKind::TyAlias(box ast::TyAlias { ident, .. })
177 | ast::ItemKind::Enum(ident, ..)
178 | ast::ItemKind::Struct(ident, ..)
179 | ast::ItemKind::Union(ident, ..) => self.check_case(cx, "type", ident),
180 ast::ItemKind::Trait(box ast::Trait { ident, .. }) => {
181 self.check_case(cx, "trait", ident)
182 }
183 ast::ItemKind::TraitAlias(ident, _, _) => self.check_case(cx, "trait alias", ident),
184
185 ast::ItemKind::Impl(box ast::Impl { of_trait: None, items, .. }) => {
188 for it in items {
189 if let ast::AssocItemKind::Type(alias) = &it.kind {
191 self.check_case(cx, "associated type", &alias.ident);
192 }
193 }
194 }
195 _ => (),
196 }
197 }
198
199 fn check_trait_item(&mut self, cx: &EarlyContext<'_>, it: &ast::AssocItem) {
200 if let ast::AssocItemKind::Type(alias) = &it.kind {
201 self.check_case(cx, "associated type", &alias.ident);
202 }
203 }
204
205 fn check_variant(&mut self, cx: &EarlyContext<'_>, v: &ast::Variant) {
206 self.check_case(cx, "variant", &v.ident);
207 }
208
209 fn check_generic_param(&mut self, cx: &EarlyContext<'_>, param: &ast::GenericParam) {
210 if let ast::GenericParamKind::Type { .. } = param.kind {
211 self.check_case(cx, "type parameter", ¶m.ident);
212 }
213 }
214}
215
216declare_lint! {
217 pub NON_SNAKE_CASE,
234 Warn,
235 "variables, methods, functions, lifetime parameters and modules should have snake case names"
236}
237
238declare_lint_pass!(NonSnakeCase => [NON_SNAKE_CASE]);
239
240impl NonSnakeCase {
241 fn to_snake_case(mut name: &str) -> String {
242 let mut words = vec![];
243 name = name.trim_start_matches(|c: char| {
245 if c == '_' {
246 words.push(String::new());
247 true
248 } else {
249 false
250 }
251 });
252 for s in name.split('_') {
253 let mut last_upper = false;
254 let mut buf = String::new();
255 if s.is_empty() {
256 continue;
257 }
258 for ch in s.chars() {
259 if !buf.is_empty() && buf != "'" && ch.is_uppercase() && !last_upper {
260 words.push(buf);
261 buf = String::new();
262 }
263 last_upper = ch.is_uppercase();
264 buf.extend(ch.to_lowercase());
265 }
266 words.push(buf);
267 }
268 words.join("_")
269 }
270
271 fn check_snake_case(&self, cx: &LateContext<'_>, sort: &str, ident: &Ident) {
273 fn is_snake_case(ident: &str) -> bool {
274 if ident.is_empty() {
275 return true;
276 }
277 let ident = ident.trim_start_matches('\'');
278 let ident = ident.trim_matches('_');
279
280 if ident.contains("__") {
281 return false;
282 }
283
284 !ident.chars().any(char::is_uppercase)
287 }
288
289 let name = ident.name.as_str();
290
291 if !is_snake_case(name) {
292 let span = ident.span;
293 let sc = NonSnakeCase::to_snake_case(name);
294 let sub = if name != sc {
297 if !span.is_dummy() {
300 let sc_ident = Ident::from_str_and_span(&sc, span);
301 if sc_ident.is_reserved() {
302 if sc_ident.name.can_be_raw() {
306 NonSnakeCaseDiagSub::RenameOrConvertSuggestion {
307 span,
308 suggestion: sc_ident,
309 }
310 } else {
311 NonSnakeCaseDiagSub::SuggestionAndNote { span }
312 }
313 } else {
314 NonSnakeCaseDiagSub::ConvertSuggestion { span, suggestion: sc.clone() }
315 }
316 } else {
317 NonSnakeCaseDiagSub::Help
318 }
319 } else {
320 NonSnakeCaseDiagSub::Label { span }
321 };
322 cx.emit_span_lint(NON_SNAKE_CASE, span, NonSnakeCaseDiag { sort, name, sc, sub });
323 }
324 }
325}
326
327impl<'tcx> LateLintPass<'tcx> for NonSnakeCase {
328 fn check_mod(&mut self, cx: &LateContext<'_>, _: &'tcx hir::Mod<'tcx>, id: hir::HirId) {
329 if id != hir::CRATE_HIR_ID {
330 return;
331 }
332
333 if cx.tcx.crate_types().iter().all(|&crate_type| crate_type == CrateType::Executable) {
337 return;
338 }
339
340 let crate_ident = if let Some(name) = &cx.tcx.sess.opts.crate_name {
341 Some(Ident::from_str(name))
342 } else {
343 ast::attr::find_by_name(cx.tcx.hir_attrs(hir::CRATE_HIR_ID), sym::crate_name).and_then(
344 |attr| {
345 if let Attribute::Unparsed(n) = attr
346 && let AttrItem { args: AttrArgs::Eq { eq_span: _, expr: lit }, .. } =
347 n.as_ref()
348 && let ast::LitKind::Str(name, ..) = lit.kind
349 {
350 let sp = cx
352 .sess()
353 .source_map()
354 .span_to_snippet(lit.span)
355 .ok()
356 .and_then(|snippet| {
357 let left = snippet.find('"')?;
358 let right = snippet.rfind('"').map(|pos| snippet.len() - pos)?;
359
360 Some(
361 lit.span
362 .with_lo(lit.span.lo() + BytePos(left as u32 + 1))
363 .with_hi(lit.span.hi() - BytePos(right as u32)),
364 )
365 })
366 .unwrap_or(lit.span);
367
368 Some(Ident::new(name, sp))
369 } else {
370 None
371 }
372 },
373 )
374 };
375
376 if let Some(ident) = &crate_ident {
377 self.check_snake_case(cx, "crate", ident);
378 }
379 }
380
381 fn check_generic_param(&mut self, cx: &LateContext<'_>, param: &hir::GenericParam<'_>) {
382 if let GenericParamKind::Lifetime { .. } = param.kind {
383 self.check_snake_case(cx, "lifetime", ¶m.name.ident());
384 }
385 }
386
387 fn check_fn(
388 &mut self,
389 cx: &LateContext<'_>,
390 fk: FnKind<'_>,
391 _: &hir::FnDecl<'_>,
392 _: &hir::Body<'_>,
393 _: Span,
394 id: LocalDefId,
395 ) {
396 match &fk {
397 FnKind::Method(ident, sig, ..) => match method_context(cx, id) {
398 MethodLateContext::PlainImpl => {
399 if sig.header.abi != ExternAbi::Rust && cx.tcx.has_attr(id, sym::no_mangle) {
400 return;
401 }
402 self.check_snake_case(cx, "method", ident);
403 }
404 MethodLateContext::TraitAutoImpl => {
405 self.check_snake_case(cx, "trait method", ident);
406 }
407 _ => (),
408 },
409 FnKind::ItemFn(ident, _, header) => {
410 if header.abi != ExternAbi::Rust && cx.tcx.has_attr(id, sym::no_mangle) {
412 return;
413 }
414 self.check_snake_case(cx, "function", ident);
415 }
416 FnKind::Closure => (),
417 }
418 }
419
420 fn check_item(&mut self, cx: &LateContext<'_>, it: &hir::Item<'_>) {
421 if let hir::ItemKind::Mod(ident, _) = it.kind {
422 self.check_snake_case(cx, "module", &ident);
423 }
424 }
425
426 fn check_ty(&mut self, cx: &LateContext<'_>, ty: &hir::Ty<'_, hir::AmbigArg>) {
427 if let hir::TyKind::BareFn(hir::BareFnTy { param_idents, .. }) = &ty.kind {
428 for param_ident in *param_idents {
429 if let Some(param_ident) = param_ident {
430 self.check_snake_case(cx, "variable", param_ident);
431 }
432 }
433 }
434 }
435
436 fn check_trait_item(&mut self, cx: &LateContext<'_>, item: &hir::TraitItem<'_>) {
437 if let hir::TraitItemKind::Fn(_, hir::TraitFn::Required(param_idents)) = item.kind {
438 self.check_snake_case(cx, "trait method", &item.ident);
439 for param_ident in param_idents {
440 if let Some(param_ident) = param_ident {
441 self.check_snake_case(cx, "variable", param_ident);
442 }
443 }
444 }
445 }
446
447 fn check_pat(&mut self, cx: &LateContext<'_>, p: &hir::Pat<'_>) {
448 if let PatKind::Binding(_, hid, ident, _) = p.kind {
449 if let hir::Node::PatField(field) = cx.tcx.parent_hir_node(hid) {
450 if !field.is_shorthand {
451 self.check_snake_case(cx, "variable", &ident);
454 }
455 return;
456 }
457 self.check_snake_case(cx, "variable", &ident);
458 }
459 }
460
461 fn check_struct_def(&mut self, cx: &LateContext<'_>, s: &hir::VariantData<'_>) {
462 for sf in s.fields() {
463 self.check_snake_case(cx, "structure field", &sf.ident);
464 }
465 }
466}
467
468declare_lint! {
469 pub NON_UPPER_CASE_GLOBALS,
485 Warn,
486 "static constants should have uppercase identifiers"
487}
488
489declare_lint_pass!(NonUpperCaseGlobals => [NON_UPPER_CASE_GLOBALS]);
490
491impl NonUpperCaseGlobals {
492 fn check_upper_case(cx: &LateContext<'_>, sort: &str, ident: &Ident) {
493 let name = ident.name.as_str();
494 if name.chars().any(|c| c.is_lowercase()) {
495 let uc = NonSnakeCase::to_snake_case(name).to_uppercase();
496 let sub = if *name != uc {
499 NonUpperCaseGlobalSub::Suggestion { span: ident.span, replace: uc }
500 } else {
501 NonUpperCaseGlobalSub::Label { span: ident.span }
502 };
503 cx.emit_span_lint(
504 NON_UPPER_CASE_GLOBALS,
505 ident.span,
506 NonUpperCaseGlobal { sort, name, sub },
507 );
508 }
509 }
510}
511
512impl<'tcx> LateLintPass<'tcx> for NonUpperCaseGlobals {
513 fn check_item(&mut self, cx: &LateContext<'_>, it: &hir::Item<'_>) {
514 let attrs = cx.tcx.hir_attrs(it.hir_id());
515 match it.kind {
516 hir::ItemKind::Static(ident, ..)
517 if !ast::attr::contains_name(attrs, sym::no_mangle) =>
518 {
519 NonUpperCaseGlobals::check_upper_case(cx, "static variable", &ident);
520 }
521 hir::ItemKind::Const(ident, ..) => {
522 NonUpperCaseGlobals::check_upper_case(cx, "constant", &ident);
523 }
524 _ => {}
525 }
526 }
527
528 fn check_trait_item(&mut self, cx: &LateContext<'_>, ti: &hir::TraitItem<'_>) {
529 if let hir::TraitItemKind::Const(..) = ti.kind {
530 NonUpperCaseGlobals::check_upper_case(cx, "associated constant", &ti.ident);
531 }
532 }
533
534 fn check_impl_item(&mut self, cx: &LateContext<'_>, ii: &hir::ImplItem<'_>) {
535 if let hir::ImplItemKind::Const(..) = ii.kind
536 && !assoc_item_in_trait_impl(cx, ii)
537 {
538 NonUpperCaseGlobals::check_upper_case(cx, "associated constant", &ii.ident);
539 }
540 }
541
542 fn check_pat(&mut self, cx: &LateContext<'_>, p: &hir::Pat<'_>) {
543 if let PatKind::Expr(hir::PatExpr {
545 kind: PatExprKind::Path(hir::QPath::Resolved(None, path)),
546 ..
547 }) = p.kind
548 {
549 if let Res::Def(DefKind::Const, _) = path.res {
550 if let [segment] = path.segments {
551 NonUpperCaseGlobals::check_upper_case(
552 cx,
553 "constant in pattern",
554 &segment.ident,
555 );
556 }
557 }
558 }
559 }
560
561 fn check_generic_param(&mut self, cx: &LateContext<'_>, param: &hir::GenericParam<'_>) {
562 if let GenericParamKind::Const { .. } = param.kind {
563 NonUpperCaseGlobals::check_upper_case(cx, "const parameter", ¶m.name.ident());
564 }
565 }
566}
567
568#[cfg(test)]
569mod tests;