1 use crate::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
3 use rustc_attr as attr;
4 use rustc_errors::Applicability;
6 use rustc_hir::def::{DefKind, Res};
7 use rustc_hir::intravisit::FnKind;
8 use rustc_hir::{GenericParamKind, PatKind};
9 use rustc_span::symbol::sym;
10 use rustc_span::{symbol::Ident, BytePos, Span};
11 use rustc_target::spec::abi::Abi;
15 pub enum MethodLateContext {
21 pub fn method_context(cx: &LateContext<'_, '_>, id: hir::HirId) -> MethodLateContext {
22 let def_id = cx.tcx.hir().local_def_id(id);
23 let item = cx.tcx.associated_item(def_id);
24 match item.container {
25 ty::TraitContainer(..) => MethodLateContext::TraitAutoImpl,
26 ty::ImplContainer(cid) => match cx.tcx.impl_trait_ref(cid) {
27 Some(_) => MethodLateContext::TraitImpl,
28 None => MethodLateContext::PlainImpl,
34 pub NON_CAMEL_CASE_TYPES,
36 "types, variants, traits and type parameters should have camel case names"
39 declare_lint_pass!(NonCamelCaseTypes => [NON_CAMEL_CASE_TYPES]);
41 fn char_has_case(c: char) -> bool {
42 c.is_lowercase() || c.is_uppercase()
45 fn is_camel_case(name: &str) -> bool {
46 let name = name.trim_matches('_');
51 // start with a non-lowercase letter rather than non-uppercase
52 // ones (some scripts don't have a concept of upper/lowercase)
53 !name.chars().next().unwrap().is_lowercase()
54 && !name.contains("__")
55 && !name.chars().collect::<Vec<_>>().windows(2).any(|pair| {
56 // contains a capitalisable character followed by, or preceded by, an underscore
57 char_has_case(pair[0]) && pair[1] == '_' || char_has_case(pair[1]) && pair[0] == '_'
61 fn to_camel_case(s: &str) -> String {
64 .filter(|component| !component.is_empty())
66 let mut camel_cased_component = String::new();
68 let mut new_word = true;
69 let mut prev_is_lower_case = true;
71 for c in component.chars() {
72 // Preserve the case if an uppercase letter follows a lowercase letter, so that
73 // `camelCase` is converted to `CamelCase`.
74 if prev_is_lower_case && c.is_uppercase() {
79 camel_cased_component.push_str(&c.to_uppercase().to_string());
81 camel_cased_component.push_str(&c.to_lowercase().to_string());
84 prev_is_lower_case = c.is_lowercase();
90 .fold((String::new(), None), |(acc, prev): (String, Option<String>), next| {
91 // separate two components with an underscore if their boundary cannot
92 // be distinguished using a uppercase/lowercase case distinction
93 let join = if let Some(prev) = prev {
94 let l = prev.chars().last().unwrap();
95 let f = next.chars().next().unwrap();
96 !char_has_case(l) && !char_has_case(f)
100 (acc + if join { "_" } else { "" } + &next, Some(next))
105 impl NonCamelCaseTypes {
106 fn check_case(&self, cx: &EarlyContext<'_>, sort: &str, ident: &Ident) {
107 let name = &ident.name.as_str();
109 if !is_camel_case(name) {
110 let msg = format!("{} `{}` should have an upper camel case name", sort, name);
111 cx.struct_span_lint(NON_CAMEL_CASE_TYPES, ident.span, &msg)
114 "convert the identifier to upper camel case",
116 Applicability::MaybeIncorrect,
123 impl EarlyLintPass for NonCamelCaseTypes {
124 fn check_item(&mut self, cx: &EarlyContext<'_>, it: &ast::Item) {
128 .any(|attr| attr::find_repr_attrs(&cx.sess.parse_sess, attr).contains(&attr::ReprC));
135 ast::ItemKind::TyAlias(..)
136 | ast::ItemKind::Enum(..)
137 | ast::ItemKind::Struct(..)
138 | ast::ItemKind::Union(..) => self.check_case(cx, "type", &it.ident),
139 ast::ItemKind::Trait(..) => self.check_case(cx, "trait", &it.ident),
144 fn check_trait_item(&mut self, cx: &EarlyContext<'_>, it: &ast::AssocItem) {
145 if let ast::AssocItemKind::TyAlias(..) = it.kind {
146 self.check_case(cx, "associated type", &it.ident);
150 fn check_variant(&mut self, cx: &EarlyContext<'_>, v: &ast::Variant) {
151 self.check_case(cx, "variant", &v.ident);
154 fn check_generic_param(&mut self, cx: &EarlyContext<'_>, param: &ast::GenericParam) {
155 if let ast::GenericParamKind::Type { .. } = param.kind {
156 self.check_case(cx, "type parameter", ¶m.ident);
164 "variables, methods, functions, lifetime parameters and modules should have snake case names"
167 declare_lint_pass!(NonSnakeCase => [NON_SNAKE_CASE]);
170 fn to_snake_case(mut str: &str) -> String {
171 let mut words = vec![];
172 // Preserve leading underscores
173 str = str.trim_start_matches(|c: char| {
175 words.push(String::new());
181 for s in str.split('_') {
182 let mut last_upper = false;
183 let mut buf = String::new();
187 for ch in s.chars() {
188 if !buf.is_empty() && buf != "'" && ch.is_uppercase() && !last_upper {
192 last_upper = ch.is_uppercase();
193 buf.extend(ch.to_lowercase());
200 /// Checks if a given identifier is snake case, and reports a diagnostic if not.
201 fn check_snake_case(&self, cx: &LateContext<'_, '_>, sort: &str, ident: &Ident) {
202 fn is_snake_case(ident: &str) -> bool {
203 if ident.is_empty() {
206 let ident = ident.trim_start_matches('\'');
207 let ident = ident.trim_matches('_');
209 let mut allow_underscore = true;
210 ident.chars().all(|c| {
211 allow_underscore = match c {
212 '_' if !allow_underscore => return false,
214 // It would be more obvious to use `c.is_lowercase()`,
215 // but some characters do not have a lowercase form
216 c if !c.is_uppercase() => true,
223 let name = &ident.name.as_str();
225 if !is_snake_case(name) {
226 let sc = NonSnakeCase::to_snake_case(name);
228 let msg = format!("{} `{}` should have a snake case name", sort, name);
229 let mut err = cx.struct_span_lint(NON_SNAKE_CASE, ident.span, &msg);
231 // We have a valid span in almost all cases, but we don't have one when linting a crate
232 // name provided via the command line.
233 if !ident.span.is_dummy() {
236 "convert the identifier to snake case",
238 Applicability::MaybeIncorrect,
241 err.help(&format!("convert the identifier to snake case: `{}`", sc));
249 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NonSnakeCase {
252 cx: &LateContext<'_, '_>,
253 _: &'tcx hir::Mod<'tcx>,
257 if id != hir::CRATE_HIR_ID {
261 let crate_ident = if let Some(name) = &cx.tcx.sess.opts.crate_name {
262 Some(Ident::from_str(name))
264 attr::find_by_name(&cx.tcx.hir().attrs(hir::CRATE_HIR_ID), sym::crate_name)
265 .and_then(|attr| attr.meta())
267 meta.name_value_literal().and_then(|lit| {
268 if let ast::LitKind::Str(name, ..) = lit.kind {
269 // Discard the double quotes surrounding the literal.
273 .span_to_snippet(lit.span)
275 .and_then(|snippet| {
276 let left = snippet.find('"')?;
278 snippet.rfind('"').map(|pos| snippet.len() - pos)?;
282 .with_lo(lit.span.lo() + BytePos(left as u32 + 1))
283 .with_hi(lit.span.hi() - BytePos(right as u32)),
286 .unwrap_or_else(|| lit.span);
288 Some(Ident::new(name, sp))
296 if let Some(ident) = &crate_ident {
297 self.check_snake_case(cx, "crate", ident);
301 fn check_generic_param(&mut self, cx: &LateContext<'_, '_>, param: &hir::GenericParam<'_>) {
302 if let GenericParamKind::Lifetime { .. } = param.kind {
303 self.check_snake_case(cx, "lifetime", ¶m.name.ident());
309 cx: &LateContext<'_, '_>,
317 FnKind::Method(ident, ..) => match method_context(cx, id) {
318 MethodLateContext::PlainImpl => {
319 self.check_snake_case(cx, "method", ident);
321 MethodLateContext::TraitAutoImpl => {
322 self.check_snake_case(cx, "trait method", ident);
326 FnKind::ItemFn(ident, _, header, _, attrs) => {
327 // Skip foreign-ABI #[no_mangle] functions (Issue #31924)
328 if header.abi != Abi::Rust && attr::contains_name(attrs, sym::no_mangle) {
331 self.check_snake_case(cx, "function", ident);
333 FnKind::Closure(_) => (),
337 fn check_item(&mut self, cx: &LateContext<'_, '_>, it: &hir::Item<'_>) {
338 if let hir::ItemKind::Mod(_) = it.kind {
339 self.check_snake_case(cx, "module", &it.ident);
343 fn check_trait_item(&mut self, cx: &LateContext<'_, '_>, item: &hir::TraitItem<'_>) {
344 if let hir::TraitItemKind::Method(_, hir::TraitMethod::Required(pnames)) = item.kind {
345 self.check_snake_case(cx, "trait method", &item.ident);
346 for param_name in pnames {
347 self.check_snake_case(cx, "variable", param_name);
352 fn check_pat(&mut self, cx: &LateContext<'_, '_>, p: &hir::Pat<'_>) {
353 if let &PatKind::Binding(_, hid, ident, _) = &p.kind {
354 if let hir::Node::Pat(parent_pat) = cx.tcx.hir().get(cx.tcx.hir().get_parent_node(hid))
356 if let PatKind::Struct(_, field_pats, _) = &parent_pat.kind {
357 for field in field_pats.iter() {
358 if field.ident != ident {
359 // Only check if a new name has been introduced, to avoid warning
360 // on both the struct definition and this pattern.
361 self.check_snake_case(cx, "variable", &ident);
367 self.check_snake_case(cx, "variable", &ident);
371 fn check_struct_def(&mut self, cx: &LateContext<'_, '_>, s: &hir::VariantData<'_>) {
372 for sf in s.fields() {
373 self.check_snake_case(cx, "structure field", &sf.ident);
379 pub NON_UPPER_CASE_GLOBALS,
381 "static constants should have uppercase identifiers"
384 declare_lint_pass!(NonUpperCaseGlobals => [NON_UPPER_CASE_GLOBALS]);
386 impl NonUpperCaseGlobals {
387 fn check_upper_case(cx: &LateContext<'_, '_>, sort: &str, ident: &Ident) {
388 let name = &ident.name.as_str();
390 if name.chars().any(|c| c.is_lowercase()) {
391 let uc = NonSnakeCase::to_snake_case(&name).to_uppercase();
393 let msg = format!("{} `{}` should have an upper case name", sort, name);
394 cx.struct_span_lint(NON_UPPER_CASE_GLOBALS, ident.span, &msg)
397 "convert the identifier to upper case",
399 Applicability::MaybeIncorrect,
406 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NonUpperCaseGlobals {
407 fn check_item(&mut self, cx: &LateContext<'_, '_>, it: &hir::Item<'_>) {
409 hir::ItemKind::Static(..) if !attr::contains_name(&it.attrs, sym::no_mangle) => {
410 NonUpperCaseGlobals::check_upper_case(cx, "static variable", &it.ident);
412 hir::ItemKind::Const(..) => {
413 NonUpperCaseGlobals::check_upper_case(cx, "constant", &it.ident);
419 fn check_trait_item(&mut self, cx: &LateContext<'_, '_>, ti: &hir::TraitItem<'_>) {
420 if let hir::TraitItemKind::Const(..) = ti.kind {
421 NonUpperCaseGlobals::check_upper_case(cx, "associated constant", &ti.ident);
425 fn check_impl_item(&mut self, cx: &LateContext<'_, '_>, ii: &hir::ImplItem<'_>) {
426 if let hir::ImplItemKind::Const(..) = ii.kind {
427 NonUpperCaseGlobals::check_upper_case(cx, "associated constant", &ii.ident);
431 fn check_pat(&mut self, cx: &LateContext<'_, '_>, p: &hir::Pat<'_>) {
432 // Lint for constants that look like binding identifiers (#7526)
433 if let PatKind::Path(hir::QPath::Resolved(None, ref path)) = p.kind {
434 if let Res::Def(DefKind::Const, _) = path.res {
435 if path.segments.len() == 1 {
436 NonUpperCaseGlobals::check_upper_case(
438 "constant in pattern",
439 &path.segments[0].ident,
446 fn check_generic_param(&mut self, cx: &LateContext<'_, '_>, param: &hir::GenericParam<'_>) {
447 if let GenericParamKind::Const { .. } = param.kind {
448 NonUpperCaseGlobals::check_upper_case(cx, "const parameter", ¶m.name.ident());