use crate::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext}; use rustc_ast as ast; use rustc_attr as attr; use rustc_errors::{fluent, Applicability}; use rustc_hir as hir; use rustc_hir::def::{DefKind, Res}; use rustc_hir::intravisit::FnKind; use rustc_hir::{GenericParamKind, PatKind}; use rustc_middle::ty; use rustc_span::symbol::sym; use rustc_span::{symbol::Ident, BytePos, Span}; use rustc_target::spec::abi::Abi; #[derive(PartialEq)] pub enum MethodLateContext { TraitAutoImpl, TraitImpl, PlainImpl, } pub fn method_context(cx: &LateContext<'_>, id: hir::HirId) -> MethodLateContext { let def_id = cx.tcx.hir().local_def_id(id); let item = cx.tcx.associated_item(def_id); match item.container { ty::TraitContainer => MethodLateContext::TraitAutoImpl, ty::ImplContainer => match cx.tcx.impl_trait_ref(item.container_id(cx.tcx)) { Some(_) => MethodLateContext::TraitImpl, None => MethodLateContext::PlainImpl, }, } } declare_lint! { /// The `non_camel_case_types` lint detects types, variants, traits and /// type parameters that don't have camel case names. /// /// ### Example /// /// ```rust /// struct my_struct; /// ``` /// /// {{produces}} /// /// ### Explanation /// /// The preferred style for these identifiers is to use "camel case", such /// as `MyStruct`, where the first letter should not be lowercase, and /// should not use underscores between letters. Underscores are allowed at /// the beginning and end of the identifier, as well as between /// non-letters (such as `X86_64`). pub NON_CAMEL_CASE_TYPES, Warn, "types, variants, traits and type parameters should have camel case names" } declare_lint_pass!(NonCamelCaseTypes => [NON_CAMEL_CASE_TYPES]); /// Some unicode characters *have* case, are considered upper case or lower case, but they *can't* /// be upper cased or lower cased. For the purposes of the lint suggestion, we care about being able /// to change the char's case. fn char_has_case(c: char) -> bool { let mut l = c.to_lowercase(); let mut u = c.to_uppercase(); while let Some(l) = l.next() { match u.next() { Some(u) if l != u => return true, _ => {} } } u.next().is_some() } fn is_camel_case(name: &str) -> bool { let name = name.trim_matches('_'); if name.is_empty() { return true; } // start with a non-lowercase letter rather than non-uppercase // ones (some scripts don't have a concept of upper/lowercase) !name.chars().next().unwrap().is_lowercase() && !name.contains("__") && !name.chars().collect::>().array_windows().any(|&[fst, snd]| { // contains a capitalisable character followed by, or preceded by, an underscore char_has_case(fst) && snd == '_' || char_has_case(snd) && fst == '_' }) } fn to_camel_case(s: &str) -> String { s.trim_matches('_') .split('_') .filter(|component| !component.is_empty()) .map(|component| { let mut camel_cased_component = String::new(); let mut new_word = true; let mut prev_is_lower_case = true; for c in component.chars() { // Preserve the case if an uppercase letter follows a lowercase letter, so that // `camelCase` is converted to `CamelCase`. if prev_is_lower_case && c.is_uppercase() { new_word = true; } if new_word { camel_cased_component.extend(c.to_uppercase()); } else { camel_cased_component.extend(c.to_lowercase()); } prev_is_lower_case = c.is_lowercase(); new_word = false; } camel_cased_component }) .fold((String::new(), None), |(acc, prev): (String, Option), next| { // separate two components with an underscore if their boundary cannot // be distinguished using an uppercase/lowercase case distinction let join = if let Some(prev) = prev { let l = prev.chars().last().unwrap(); let f = next.chars().next().unwrap(); !char_has_case(l) && !char_has_case(f) } else { false }; (acc + if join { "_" } else { "" } + &next, Some(next)) }) .0 } impl NonCamelCaseTypes { fn check_case(&self, cx: &EarlyContext<'_>, sort: &str, ident: &Ident) { let name = ident.name.as_str(); if !is_camel_case(name) { cx.struct_span_lint( NON_CAMEL_CASE_TYPES, ident.span, fluent::lint_non_camel_case_type, |lint| { let cc = to_camel_case(name); // We cannot provide meaningful suggestions // if the characters are in the category of "Lowercase Letter". if *name != cc { lint.span_suggestion( ident.span, fluent::suggestion, to_camel_case(name), Applicability::MaybeIncorrect, ); } else { lint.span_label(ident.span, fluent::label); } lint.set_arg("sort", sort); lint.set_arg("name", name); lint }, ) } } } impl EarlyLintPass for NonCamelCaseTypes { fn check_item(&mut self, cx: &EarlyContext<'_>, it: &ast::Item) { let has_repr_c = it .attrs .iter() .any(|attr| attr::find_repr_attrs(cx.sess(), attr).contains(&attr::ReprC)); if has_repr_c { return; } match it.kind { ast::ItemKind::TyAlias(..) | ast::ItemKind::Enum(..) | ast::ItemKind::Struct(..) | ast::ItemKind::Union(..) => self.check_case(cx, "type", &it.ident), ast::ItemKind::Trait(..) => self.check_case(cx, "trait", &it.ident), ast::ItemKind::TraitAlias(..) => self.check_case(cx, "trait alias", &it.ident), _ => (), } } fn check_trait_item(&mut self, cx: &EarlyContext<'_>, it: &ast::AssocItem) { if let ast::AssocItemKind::Type(..) = it.kind { self.check_case(cx, "associated type", &it.ident); } } fn check_variant(&mut self, cx: &EarlyContext<'_>, v: &ast::Variant) { self.check_case(cx, "variant", &v.ident); } fn check_generic_param(&mut self, cx: &EarlyContext<'_>, param: &ast::GenericParam) { if let ast::GenericParamKind::Type { .. } = param.kind { self.check_case(cx, "type parameter", ¶m.ident); } } } declare_lint! { /// The `non_snake_case` lint detects variables, methods, functions, /// lifetime parameters and modules that don't have snake case names. /// /// ### Example /// /// ```rust /// let MY_VALUE = 5; /// ``` /// /// {{produces}} /// /// ### Explanation /// /// The preferred style for these identifiers is to use "snake case", /// where all the characters are in lowercase, with words separated with a /// single underscore, such as `my_value`. pub NON_SNAKE_CASE, Warn, "variables, methods, functions, lifetime parameters and modules should have snake case names" } declare_lint_pass!(NonSnakeCase => [NON_SNAKE_CASE]); impl NonSnakeCase { fn to_snake_case(mut str: &str) -> String { let mut words = vec![]; // Preserve leading underscores str = str.trim_start_matches(|c: char| { if c == '_' { words.push(String::new()); true } else { false } }); for s in str.split('_') { let mut last_upper = false; let mut buf = String::new(); if s.is_empty() { continue; } for ch in s.chars() { if !buf.is_empty() && buf != "'" && ch.is_uppercase() && !last_upper { words.push(buf); buf = String::new(); } last_upper = ch.is_uppercase(); buf.extend(ch.to_lowercase()); } words.push(buf); } words.join("_") } /// Checks if a given identifier is snake case, and reports a diagnostic if not. fn check_snake_case(&self, cx: &LateContext<'_>, sort: &str, ident: &Ident) { fn is_snake_case(ident: &str) -> bool { if ident.is_empty() { return true; } let ident = ident.trim_start_matches('\''); let ident = ident.trim_matches('_'); let mut allow_underscore = true; ident.chars().all(|c| { allow_underscore = match c { '_' if !allow_underscore => return false, '_' => false, // It would be more obvious to use `c.is_lowercase()`, // but some characters do not have a lowercase form c if !c.is_uppercase() => true, _ => return false, }; true }) } let name = ident.name.as_str(); if !is_snake_case(name) { cx.struct_span_lint(NON_SNAKE_CASE, ident.span, fluent::lint_non_snake_case, |lint| { let sc = NonSnakeCase::to_snake_case(name); // We cannot provide meaningful suggestions // if the characters are in the category of "Uppercase Letter". if name != sc { // We have a valid span in almost all cases, but we don't have one when linting a crate // name provided via the command line. if !ident.span.is_dummy() { let sc_ident = Ident::from_str_and_span(&sc, ident.span); let (message, suggestion) = if sc_ident.is_reserved() { // We shouldn't suggest a reserved identifier to fix non-snake-case identifiers. // Instead, recommend renaming the identifier entirely or, if permitted, // escaping it to create a raw identifier. if sc_ident.name.can_be_raw() { (fluent::rename_or_convert_suggestion, sc_ident.to_string()) } else { lint.note(fluent::cannot_convert_note); (fluent::rename_suggestion, String::new()) } } else { (fluent::convert_suggestion, sc.clone()) }; lint.span_suggestion( ident.span, message, suggestion, Applicability::MaybeIncorrect, ); } else { lint.help(fluent::help); } } else { lint.span_label(ident.span, fluent::label); } lint.set_arg("sort", sort); lint.set_arg("name", name); lint.set_arg("sc", sc); lint }); } } } impl<'tcx> LateLintPass<'tcx> for NonSnakeCase { fn check_mod(&mut self, cx: &LateContext<'_>, _: &'tcx hir::Mod<'tcx>, id: hir::HirId) { if id != hir::CRATE_HIR_ID { return; } let crate_ident = if let Some(name) = &cx.tcx.sess.opts.crate_name { Some(Ident::from_str(name)) } else { cx.sess() .find_by_name(&cx.tcx.hir().attrs(hir::CRATE_HIR_ID), sym::crate_name) .and_then(|attr| attr.meta()) .and_then(|meta| { meta.name_value_literal().and_then(|lit| { if let ast::LitKind::Str(name, ..) = lit.kind { // Discard the double quotes surrounding the literal. let sp = cx .sess() .source_map() .span_to_snippet(lit.span) .ok() .and_then(|snippet| { let left = snippet.find('"')?; let right = snippet.rfind('"').map(|pos| snippet.len() - pos)?; Some( lit.span .with_lo(lit.span.lo() + BytePos(left as u32 + 1)) .with_hi(lit.span.hi() - BytePos(right as u32)), ) }) .unwrap_or(lit.span); Some(Ident::new(name, sp)) } else { None } }) }) }; if let Some(ident) = &crate_ident { self.check_snake_case(cx, "crate", ident); } } fn check_generic_param(&mut self, cx: &LateContext<'_>, param: &hir::GenericParam<'_>) { if let GenericParamKind::Lifetime { .. } = param.kind { self.check_snake_case(cx, "lifetime", ¶m.name.ident()); } } fn check_fn( &mut self, cx: &LateContext<'_>, fk: FnKind<'_>, _: &hir::FnDecl<'_>, _: &hir::Body<'_>, _: Span, id: hir::HirId, ) { let attrs = cx.tcx.hir().attrs(id); match &fk { FnKind::Method(ident, sig, ..) => match method_context(cx, id) { MethodLateContext::PlainImpl => { if sig.header.abi != Abi::Rust && cx.sess().contains_name(attrs, sym::no_mangle) { return; } self.check_snake_case(cx, "method", ident); } MethodLateContext::TraitAutoImpl => { self.check_snake_case(cx, "trait method", ident); } _ => (), }, FnKind::ItemFn(ident, _, header) => { // Skip foreign-ABI #[no_mangle] functions (Issue #31924) if header.abi != Abi::Rust && cx.sess().contains_name(attrs, sym::no_mangle) { return; } self.check_snake_case(cx, "function", ident); } FnKind::Closure => (), } } fn check_item(&mut self, cx: &LateContext<'_>, it: &hir::Item<'_>) { if let hir::ItemKind::Mod(_) = it.kind { self.check_snake_case(cx, "module", &it.ident); } } fn check_trait_item(&mut self, cx: &LateContext<'_>, item: &hir::TraitItem<'_>) { if let hir::TraitItemKind::Fn(_, hir::TraitFn::Required(pnames)) = item.kind { self.check_snake_case(cx, "trait method", &item.ident); for param_name in pnames { self.check_snake_case(cx, "variable", param_name); } } } fn check_pat(&mut self, cx: &LateContext<'_>, p: &hir::Pat<'_>) { if let PatKind::Binding(_, hid, ident, _) = p.kind { if let hir::Node::PatField(field) = cx.tcx.hir().get(cx.tcx.hir().get_parent_node(hid)) { if !field.is_shorthand { // Only check if a new name has been introduced, to avoid warning // on both the struct definition and this pattern. self.check_snake_case(cx, "variable", &ident); } return; } self.check_snake_case(cx, "variable", &ident); } } fn check_struct_def(&mut self, cx: &LateContext<'_>, s: &hir::VariantData<'_>) { for sf in s.fields() { self.check_snake_case(cx, "structure field", &sf.ident); } } } declare_lint! { /// The `non_upper_case_globals` lint detects static items that don't have /// uppercase identifiers. /// /// ### Example /// /// ```rust /// static max_points: i32 = 5; /// ``` /// /// {{produces}} /// /// ### Explanation /// /// The preferred style is for static item names to use all uppercase /// letters such as `MAX_POINTS`. pub NON_UPPER_CASE_GLOBALS, Warn, "static constants should have uppercase identifiers" } declare_lint_pass!(NonUpperCaseGlobals => [NON_UPPER_CASE_GLOBALS]); impl NonUpperCaseGlobals { fn check_upper_case(cx: &LateContext<'_>, sort: &str, ident: &Ident) { let name = ident.name.as_str(); if name.chars().any(|c| c.is_lowercase()) { cx.struct_span_lint( NON_UPPER_CASE_GLOBALS, ident.span, fluent::lint_non_upper_case_global, |lint| { let uc = NonSnakeCase::to_snake_case(&name).to_uppercase(); // We cannot provide meaningful suggestions // if the characters are in the category of "Lowercase Letter". if *name != uc { lint.span_suggestion( ident.span, fluent::suggestion, uc, Applicability::MaybeIncorrect, ); } else { lint.span_label(ident.span, fluent::label); } lint.set_arg("sort", sort); lint.set_arg("name", name); lint }, ) } } } impl<'tcx> LateLintPass<'tcx> for NonUpperCaseGlobals { fn check_item(&mut self, cx: &LateContext<'_>, it: &hir::Item<'_>) { let attrs = cx.tcx.hir().attrs(it.hir_id()); match it.kind { hir::ItemKind::Static(..) if !cx.sess().contains_name(attrs, sym::no_mangle) => { NonUpperCaseGlobals::check_upper_case(cx, "static variable", &it.ident); } hir::ItemKind::Const(..) => { NonUpperCaseGlobals::check_upper_case(cx, "constant", &it.ident); } _ => {} } } fn check_trait_item(&mut self, cx: &LateContext<'_>, ti: &hir::TraitItem<'_>) { if let hir::TraitItemKind::Const(..) = ti.kind { NonUpperCaseGlobals::check_upper_case(cx, "associated constant", &ti.ident); } } fn check_impl_item(&mut self, cx: &LateContext<'_>, ii: &hir::ImplItem<'_>) { if let hir::ImplItemKind::Const(..) = ii.kind { NonUpperCaseGlobals::check_upper_case(cx, "associated constant", &ii.ident); } } fn check_pat(&mut self, cx: &LateContext<'_>, p: &hir::Pat<'_>) { // Lint for constants that look like binding identifiers (#7526) if let PatKind::Path(hir::QPath::Resolved(None, ref path)) = p.kind { if let Res::Def(DefKind::Const, _) = path.res { if path.segments.len() == 1 { NonUpperCaseGlobals::check_upper_case( cx, "constant in pattern", &path.segments[0].ident, ); } } } } fn check_generic_param(&mut self, cx: &LateContext<'_>, param: &hir::GenericParam<'_>) { if let GenericParamKind::Const { .. } = param.kind { NonUpperCaseGlobals::check_upper_case(cx, "const parameter", ¶m.name.ident()); } } } #[cfg(test)] mod tests;