1use rustc_abi::ExternAbi;
2use rustc_attr_data_structures::{AttributeKind, ReprAttr, find_attr};
3use rustc_attr_parsing::AttributeParser;
4use rustc_errors::Applicability;
5use rustc_hir::def::{DefKind, Res};
6use rustc_hir::def_id::DefId;
7use rustc_hir::intravisit::{FnKind, Visitor};
8use rustc_hir::{AttrArgs, AttrItem, Attribute, GenericParamKind, PatExprKind, PatKind};
9use rustc_middle::hir::nested_filter::All;
10use rustc_middle::ty;
11use rustc_session::config::CrateType;
12use rustc_session::{declare_lint, declare_lint_pass};
13use rustc_span::def_id::LocalDefId;
14use rustc_span::{BytePos, Ident, Span, sym};
15use {rustc_ast as ast, rustc_hir as hir};
16
17use crate::lints::{
18 NonCamelCaseType, NonCamelCaseTypeSub, NonSnakeCaseDiag, NonSnakeCaseDiagSub,
19 NonUpperCaseGlobal, NonUpperCaseGlobalSub, NonUpperCaseGlobalSubTool,
20};
21use crate::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
22
23#[derive(PartialEq)]
24pub(crate) enum MethodLateContext {
25 TraitAutoImpl,
26 TraitImpl,
27 PlainImpl,
28}
29
30pub(crate) fn method_context(cx: &LateContext<'_>, id: LocalDefId) -> MethodLateContext {
31 let item = cx.tcx.associated_item(id);
32 match item.container {
33 ty::AssocItemContainer::Trait => MethodLateContext::TraitAutoImpl,
34 ty::AssocItemContainer::Impl => match cx.tcx.impl_trait_ref(item.container_id(cx.tcx)) {
35 Some(_) => MethodLateContext::TraitImpl,
36 None => MethodLateContext::PlainImpl,
37 },
38 }
39}
40
41fn assoc_item_in_trait_impl(cx: &LateContext<'_>, ii: &hir::ImplItem<'_>) -> bool {
42 let item = cx.tcx.associated_item(ii.owner_id);
43 item.trait_item_def_id.is_some()
44}
45
46declare_lint! {
47 pub NON_CAMEL_CASE_TYPES,
66 Warn,
67 "types, variants, traits and type parameters should have camel case names"
68}
69
70declare_lint_pass!(NonCamelCaseTypes => [NON_CAMEL_CASE_TYPES]);
71
72fn char_has_case(c: char) -> bool {
76 let mut l = c.to_lowercase();
77 let mut u = c.to_uppercase();
78 while let Some(l) = l.next() {
79 match u.next() {
80 Some(u) if l != u => return true,
81 _ => {}
82 }
83 }
84 u.next().is_some()
85}
86
87fn is_camel_case(name: &str) -> bool {
88 let name = name.trim_matches('_');
89 if name.is_empty() {
90 return true;
91 }
92
93 !name.chars().next().unwrap().is_lowercase()
96 && !name.contains("__")
97 && !name.chars().collect::<Vec<_>>().array_windows().any(|&[fst, snd]| {
98 char_has_case(fst) && snd == '_' || char_has_case(snd) && fst == '_'
100 })
101}
102
103fn to_camel_case(s: &str) -> String {
104 s.trim_matches('_')
105 .split('_')
106 .filter(|component| !component.is_empty())
107 .map(|component| {
108 let mut camel_cased_component = String::new();
109
110 let mut new_word = true;
111 let mut prev_is_lower_case = true;
112
113 for c in component.chars() {
114 if prev_is_lower_case && c.is_uppercase() {
117 new_word = true;
118 }
119
120 if new_word {
121 camel_cased_component.extend(c.to_uppercase());
122 } else {
123 camel_cased_component.extend(c.to_lowercase());
124 }
125
126 prev_is_lower_case = c.is_lowercase();
127 new_word = false;
128 }
129
130 camel_cased_component
131 })
132 .fold((String::new(), None), |(acc, prev): (String, Option<String>), next| {
133 let join = if let Some(prev) = prev {
136 let l = prev.chars().last().unwrap();
137 let f = next.chars().next().unwrap();
138 !char_has_case(l) && !char_has_case(f)
139 } else {
140 false
141 };
142 (acc + if join { "_" } else { "" } + &next, Some(next))
143 })
144 .0
145}
146
147impl NonCamelCaseTypes {
148 fn check_case(&self, cx: &EarlyContext<'_>, sort: &str, ident: &Ident) {
149 let name = ident.name.as_str();
150
151 if !is_camel_case(name) {
152 let cc = to_camel_case(name);
153 let sub = if *name != cc {
154 NonCamelCaseTypeSub::Suggestion { span: ident.span, replace: cc }
155 } else {
156 NonCamelCaseTypeSub::Label { span: ident.span }
157 };
158 cx.emit_span_lint(
159 NON_CAMEL_CASE_TYPES,
160 ident.span,
161 NonCamelCaseType { sort, name, sub },
162 );
163 }
164 }
165}
166
167impl EarlyLintPass for NonCamelCaseTypes {
168 fn check_item(&mut self, cx: &EarlyContext<'_>, it: &ast::Item) {
169 let has_repr_c = matches!(
170 AttributeParser::parse_limited(cx.sess(), &it.attrs, sym::repr, it.span, it.id),
171 Some(Attribute::Parsed(AttributeKind::Repr { reprs, ..})) if reprs.iter().any(|(r, _)| r == &ReprAttr::ReprC)
172 );
173
174 if has_repr_c {
175 return;
176 }
177
178 match &it.kind {
179 ast::ItemKind::TyAlias(box ast::TyAlias { ident, .. })
180 | ast::ItemKind::Enum(ident, ..)
181 | ast::ItemKind::Struct(ident, ..)
182 | ast::ItemKind::Union(ident, ..) => self.check_case(cx, "type", ident),
183 ast::ItemKind::Trait(box ast::Trait { ident, .. }) => {
184 self.check_case(cx, "trait", ident)
185 }
186 ast::ItemKind::TraitAlias(ident, _, _) => self.check_case(cx, "trait alias", ident),
187
188 ast::ItemKind::Impl(box ast::Impl { of_trait: None, items, .. }) => {
191 for it in items {
192 if let ast::AssocItemKind::Type(alias) = &it.kind {
194 self.check_case(cx, "associated type", &alias.ident);
195 }
196 }
197 }
198 _ => (),
199 }
200 }
201
202 fn check_trait_item(&mut self, cx: &EarlyContext<'_>, it: &ast::AssocItem) {
203 if let ast::AssocItemKind::Type(alias) = &it.kind {
204 self.check_case(cx, "associated type", &alias.ident);
205 }
206 }
207
208 fn check_variant(&mut self, cx: &EarlyContext<'_>, v: &ast::Variant) {
209 self.check_case(cx, "variant", &v.ident);
210 }
211
212 fn check_generic_param(&mut self, cx: &EarlyContext<'_>, param: &ast::GenericParam) {
213 if let ast::GenericParamKind::Type { .. } = param.kind {
214 self.check_case(cx, "type parameter", ¶m.ident);
215 }
216 }
217}
218
219declare_lint! {
220 pub NON_SNAKE_CASE,
237 Warn,
238 "variables, methods, functions, lifetime parameters and modules should have snake case names"
239}
240
241declare_lint_pass!(NonSnakeCase => [NON_SNAKE_CASE]);
242
243impl NonSnakeCase {
244 fn to_snake_case(mut name: &str) -> String {
245 let mut words = vec![];
246 name = name.trim_start_matches(|c: char| {
248 if c == '_' {
249 words.push(String::new());
250 true
251 } else {
252 false
253 }
254 });
255 for s in name.split('_') {
256 let mut last_upper = false;
257 let mut buf = String::new();
258 if s.is_empty() {
259 continue;
260 }
261 for ch in s.chars() {
262 if !buf.is_empty() && buf != "'" && ch.is_uppercase() && !last_upper {
263 words.push(buf);
264 buf = String::new();
265 }
266 last_upper = ch.is_uppercase();
267 buf.extend(ch.to_lowercase());
268 }
269 words.push(buf);
270 }
271 words.join("_")
272 }
273
274 fn check_snake_case(&self, cx: &LateContext<'_>, sort: &str, ident: &Ident) {
276 fn is_snake_case(ident: &str) -> bool {
277 if ident.is_empty() {
278 return true;
279 }
280 let ident = ident.trim_start_matches('\'');
281 let ident = ident.trim_matches('_');
282
283 if ident.contains("__") {
284 return false;
285 }
286
287 !ident.chars().any(char::is_uppercase)
290 }
291
292 let name = ident.name.as_str();
293
294 if !is_snake_case(name) {
295 let span = ident.span;
296 let sc = NonSnakeCase::to_snake_case(name);
297 let sub = if name != sc {
300 if !span.is_dummy() {
303 let sc_ident = Ident::from_str_and_span(&sc, span);
304 if sc_ident.is_reserved() {
305 if sc_ident.name.can_be_raw() {
309 NonSnakeCaseDiagSub::RenameOrConvertSuggestion {
310 span,
311 suggestion: sc_ident,
312 }
313 } else {
314 NonSnakeCaseDiagSub::SuggestionAndNote { span }
315 }
316 } else {
317 NonSnakeCaseDiagSub::ConvertSuggestion { span, suggestion: sc.clone() }
318 }
319 } else {
320 NonSnakeCaseDiagSub::Help
321 }
322 } else {
323 NonSnakeCaseDiagSub::Label { span }
324 };
325 cx.emit_span_lint(NON_SNAKE_CASE, span, NonSnakeCaseDiag { sort, name, sc, sub });
326 }
327 }
328}
329
330impl<'tcx> LateLintPass<'tcx> for NonSnakeCase {
331 fn check_mod(&mut self, cx: &LateContext<'_>, _: &'tcx hir::Mod<'tcx>, id: hir::HirId) {
332 if id != hir::CRATE_HIR_ID {
333 return;
334 }
335
336 if cx.tcx.crate_types().iter().all(|&crate_type| crate_type == CrateType::Executable) {
340 return;
341 }
342
343 let crate_ident = if let Some(name) = &cx.tcx.sess.opts.crate_name {
344 Some(Ident::from_str(name))
345 } else {
346 ast::attr::find_by_name(cx.tcx.hir_attrs(hir::CRATE_HIR_ID), sym::crate_name).and_then(
347 |attr| {
348 if let Attribute::Unparsed(n) = attr
349 && let AttrItem { args: AttrArgs::Eq { eq_span: _, expr: lit }, .. } =
350 n.as_ref()
351 && let ast::LitKind::Str(name, ..) = lit.kind
352 {
353 let sp = cx
355 .sess()
356 .source_map()
357 .span_to_snippet(lit.span)
358 .ok()
359 .and_then(|snippet| {
360 let left = snippet.find('"')?;
361 let right = snippet.rfind('"').map(|pos| snippet.len() - pos)?;
362
363 Some(
364 lit.span
365 .with_lo(lit.span.lo() + BytePos(left as u32 + 1))
366 .with_hi(lit.span.hi() - BytePos(right as u32)),
367 )
368 })
369 .unwrap_or(lit.span);
370
371 Some(Ident::new(name, sp))
372 } else {
373 None
374 }
375 },
376 )
377 };
378
379 if let Some(ident) = &crate_ident {
380 self.check_snake_case(cx, "crate", ident);
381 }
382 }
383
384 fn check_generic_param(&mut self, cx: &LateContext<'_>, param: &hir::GenericParam<'_>) {
385 if let GenericParamKind::Lifetime { .. } = param.kind {
386 self.check_snake_case(cx, "lifetime", ¶m.name.ident());
387 }
388 }
389
390 fn check_fn(
391 &mut self,
392 cx: &LateContext<'_>,
393 fk: FnKind<'_>,
394 _: &hir::FnDecl<'_>,
395 _: &hir::Body<'_>,
396 _: Span,
397 id: LocalDefId,
398 ) {
399 match &fk {
400 FnKind::Method(ident, sig, ..) => match method_context(cx, id) {
401 MethodLateContext::PlainImpl => {
402 if sig.header.abi != ExternAbi::Rust
403 && find_attr!(cx.tcx.get_all_attrs(id), AttributeKind::NoMangle(..))
404 {
405 return;
406 }
407 self.check_snake_case(cx, "method", ident);
408 }
409 MethodLateContext::TraitAutoImpl => {
410 self.check_snake_case(cx, "trait method", ident);
411 }
412 _ => (),
413 },
414 FnKind::ItemFn(ident, _, header) => {
415 if header.abi != ExternAbi::Rust
417 && find_attr!(cx.tcx.get_all_attrs(id), AttributeKind::NoMangle(..))
418 {
419 return;
420 }
421 self.check_snake_case(cx, "function", ident);
422 }
423 FnKind::Closure => (),
424 }
425 }
426
427 fn check_item(&mut self, cx: &LateContext<'_>, it: &hir::Item<'_>) {
428 if let hir::ItemKind::Mod(ident, _) = it.kind {
429 self.check_snake_case(cx, "module", &ident);
430 }
431 }
432
433 fn check_ty(&mut self, cx: &LateContext<'_>, ty: &hir::Ty<'_, hir::AmbigArg>) {
434 if let hir::TyKind::FnPtr(hir::FnPtrTy { param_idents, .. }) = &ty.kind {
435 for param_ident in *param_idents {
436 if let Some(param_ident) = param_ident {
437 self.check_snake_case(cx, "variable", param_ident);
438 }
439 }
440 }
441 }
442
443 fn check_trait_item(&mut self, cx: &LateContext<'_>, item: &hir::TraitItem<'_>) {
444 if let hir::TraitItemKind::Fn(_, hir::TraitFn::Required(param_idents)) = item.kind {
445 self.check_snake_case(cx, "trait method", &item.ident);
446 for param_ident in param_idents {
447 if let Some(param_ident) = param_ident {
448 self.check_snake_case(cx, "variable", param_ident);
449 }
450 }
451 }
452 }
453
454 fn check_pat(&mut self, cx: &LateContext<'_>, p: &hir::Pat<'_>) {
455 if let PatKind::Binding(_, hid, ident, _) = p.kind {
456 if let hir::Node::PatField(field) = cx.tcx.parent_hir_node(hid) {
457 if !field.is_shorthand {
458 self.check_snake_case(cx, "variable", &ident);
461 }
462 return;
463 }
464 self.check_snake_case(cx, "variable", &ident);
465 }
466 }
467
468 fn check_struct_def(&mut self, cx: &LateContext<'_>, s: &hir::VariantData<'_>) {
469 for sf in s.fields() {
470 self.check_snake_case(cx, "structure field", &sf.ident);
471 }
472 }
473}
474
475declare_lint! {
476 pub NON_UPPER_CASE_GLOBALS,
492 Warn,
493 "static constants should have uppercase identifiers"
494}
495
496declare_lint_pass!(NonUpperCaseGlobals => [NON_UPPER_CASE_GLOBALS]);
497
498impl NonUpperCaseGlobals {
499 fn check_upper_case(cx: &LateContext<'_>, sort: &str, did: Option<LocalDefId>, ident: &Ident) {
500 let name = ident.name.as_str();
501 if name.chars().any(|c| c.is_lowercase()) {
502 let uc = NonSnakeCase::to_snake_case(name).to_uppercase();
503
504 let can_change_usages = if let Some(did) = did {
507 !cx.tcx.effective_visibilities(()).is_exported(did)
508 } else {
509 false
510 };
511
512 let sub = if *name != uc {
515 NonUpperCaseGlobalSub::Suggestion {
516 span: ident.span,
517 replace: uc.clone(),
518 applicability: if can_change_usages {
519 Applicability::MachineApplicable
520 } else {
521 Applicability::MaybeIncorrect
522 },
523 }
524 } else {
525 NonUpperCaseGlobalSub::Label { span: ident.span }
526 };
527
528 struct UsageCollector<'a, 'tcx> {
529 cx: &'tcx LateContext<'a>,
530 did: DefId,
531 collected: Vec<Span>,
532 }
533
534 impl<'v, 'tcx> Visitor<'v> for UsageCollector<'v, 'tcx> {
535 type NestedFilter = All;
536
537 fn maybe_tcx(&mut self) -> Self::MaybeTyCtxt {
538 self.cx.tcx
539 }
540
541 fn visit_path(
542 &mut self,
543 path: &rustc_hir::Path<'v>,
544 _id: rustc_hir::HirId,
545 ) -> Self::Result {
546 if let Some(final_seg) = path.segments.last()
547 && final_seg.res.opt_def_id() == Some(self.did)
548 {
549 self.collected.push(final_seg.ident.span);
550 }
551 }
552 }
553
554 cx.emit_span_lint_lazy(NON_UPPER_CASE_GLOBALS, ident.span, || {
555 let usages = if can_change_usages
558 && *name != uc
559 && let Some(did) = did
560 {
561 let mut usage_collector =
562 UsageCollector { cx, did: did.to_def_id(), collected: Vec::new() };
563 cx.tcx.hir_walk_toplevel_module(&mut usage_collector);
564 usage_collector
565 .collected
566 .into_iter()
567 .map(|span| NonUpperCaseGlobalSubTool { span, replace: uc.clone() })
568 .collect()
569 } else {
570 vec![]
571 };
572
573 NonUpperCaseGlobal { sort, name, sub, usages }
574 });
575 }
576 }
577}
578
579impl<'tcx> LateLintPass<'tcx> for NonUpperCaseGlobals {
580 fn check_item(&mut self, cx: &LateContext<'_>, it: &hir::Item<'_>) {
581 let attrs = cx.tcx.hir_attrs(it.hir_id());
582 match it.kind {
583 hir::ItemKind::Static(_, ident, ..)
584 if !find_attr!(attrs, AttributeKind::NoMangle(..)) =>
585 {
586 NonUpperCaseGlobals::check_upper_case(
587 cx,
588 "static variable",
589 Some(it.owner_id.def_id),
590 &ident,
591 );
592 }
593 hir::ItemKind::Const(ident, ..) => {
594 NonUpperCaseGlobals::check_upper_case(
595 cx,
596 "constant",
597 Some(it.owner_id.def_id),
598 &ident,
599 );
600 }
601 _ => {}
602 }
603 }
604
605 fn check_trait_item(&mut self, cx: &LateContext<'_>, ti: &hir::TraitItem<'_>) {
606 if let hir::TraitItemKind::Const(..) = ti.kind {
607 NonUpperCaseGlobals::check_upper_case(cx, "associated constant", None, &ti.ident);
608 }
609 }
610
611 fn check_impl_item(&mut self, cx: &LateContext<'_>, ii: &hir::ImplItem<'_>) {
612 if let hir::ImplItemKind::Const(..) = ii.kind
613 && !assoc_item_in_trait_impl(cx, ii)
614 {
615 NonUpperCaseGlobals::check_upper_case(cx, "associated constant", None, &ii.ident);
616 }
617 }
618
619 fn check_pat(&mut self, cx: &LateContext<'_>, p: &hir::Pat<'_>) {
620 if let PatKind::Expr(hir::PatExpr {
622 kind: PatExprKind::Path(hir::QPath::Resolved(None, path)),
623 ..
624 }) = p.kind
625 {
626 if let Res::Def(DefKind::Const, _) = path.res {
627 if let [segment] = path.segments {
628 NonUpperCaseGlobals::check_upper_case(
629 cx,
630 "constant in pattern",
631 None,
632 &segment.ident,
633 );
634 }
635 }
636 }
637 }
638
639 fn check_generic_param(&mut self, cx: &LateContext<'_>, param: &hir::GenericParam<'_>) {
640 if let GenericParamKind::Const { .. } = param.kind {
641 NonUpperCaseGlobals::check_upper_case(
642 cx,
643 "const parameter",
644 Some(param.def_id),
645 ¶m.name.ident(),
646 );
647 }
648 }
649}
650
651#[cfg(test)]
652mod tests;