use crate::utils::{span_lint, span_lint_and_then};
-use rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, impl_lint_pass};
-use syntax::ast::*;
-use syntax::attr;
-use syntax::source_map::Span;
-use syntax::symbol::LocalInternedString;
-use syntax::visit::{walk_block, walk_expr, walk_pat, Visitor};
+use rustc_ast::ast::{
+ Arm, AssocItem, AssocItemKind, Attribute, Block, FnDecl, FnKind, Item, ItemKind, Local, Pat,
+ PatKind,
+};
+use rustc_ast::visit::{walk_block, walk_expr, walk_pat, Visitor};
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_middle::lint::in_external_macro;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::source_map::Span;
+use rustc_span::sym;
+use rustc_span::symbol::{Ident, Symbol};
+use std::cmp::Ordering;
declare_clippy_lint! {
/// **What it does:** Checks for names that are very similar and thus confusing.
impl_lint_pass!(NonExpressiveNames => [SIMILAR_NAMES, MANY_SINGLE_CHAR_NAMES, JUST_UNDERSCORES_AND_DIGITS]);
struct ExistingName {
- interned: LocalInternedString,
+ interned: Symbol,
span: Span,
len: usize,
- whitelist: &'static [&'static str],
+ exemptions: &'static [&'static str],
}
struct SimilarNamesLocalVisitor<'a, 'tcx> {
fn check_single_char_names(&self) {
let num_single_char_names = self.single_char_names.iter().flatten().count();
let threshold = self.lint.single_char_binding_names_threshold;
- if num_single_char_names as u64 >= threshold {
+ if num_single_char_names as u64 > threshold {
let span = self
.single_char_names
.iter()
// this list contains lists of names that are allowed to be similar
// the assumption is that no name is ever contained in multiple lists.
#[rustfmt::skip]
-const WHITELIST: &[&[&str]] = &[
+const ALLOWED_TO_BE_SIMILAR: &[&[&str]] = &[
&["parsed", "parser"],
&["lhs", "rhs"],
&["tx", "rx"],
impl<'a, 'tcx, 'b> Visitor<'tcx> for SimilarNamesNameVisitor<'a, 'tcx, 'b> {
fn visit_pat(&mut self, pat: &'tcx Pat) {
- match pat.node {
- PatKind::Ident(_, ident, _) => self.check_ident(ident),
+ match pat.kind {
+ PatKind::Ident(_, ident, _) => {
+ if !pat.span.from_expansion() {
+ self.check_ident(ident);
+ }
+ },
PatKind::Struct(_, ref fields, _) => {
for field in fields {
if !field.is_shorthand {
_ => walk_pat(self, pat),
}
}
- fn visit_mac(&mut self, _mac: &Mac) {
- // do not check macs
- }
}
-fn get_whitelist(interned_name: &str) -> Option<&'static [&'static str]> {
- for &allow in WHITELIST {
- if whitelisted(interned_name, allow) {
- return Some(allow);
+#[must_use]
+fn get_exemptions(interned_name: &str) -> Option<&'static [&'static str]> {
+ for &list in ALLOWED_TO_BE_SIMILAR {
+ if allowed_to_be_similar(interned_name, list) {
+ return Some(list);
}
}
None
}
-fn whitelisted(interned_name: &str, list: &[&str]) -> bool {
+#[must_use]
+fn allowed_to_be_similar(interned_name: &str, list: &[&str]) -> bool {
list.iter()
.any(|&name| interned_name.starts_with(name) || interned_name.ends_with(name))
}
);
return;
}
+ if interned_name.starts_with('_') {
+ // these bindings are typically unused or represent an ignored portion of a destructuring pattern
+ return;
+ }
let count = interned_name.chars().count();
if count < 3 {
if count == 1 {
return;
}
for existing_name in &self.0.names {
- if whitelisted(&interned_name, existing_name.whitelist) {
+ if allowed_to_be_similar(&interned_name, existing_name.exemptions) {
continue;
}
let mut split_at = None;
- if existing_name.len > count {
- if existing_name.len - count != 1 || levenstein_not_1(&interned_name, &existing_name.interned) {
- continue;
- }
- } else if existing_name.len < count {
- if count - existing_name.len != 1 || levenstein_not_1(&existing_name.interned, &interned_name) {
- continue;
- }
- } else {
- let mut interned_chars = interned_name.chars();
- let mut existing_chars = existing_name.interned.chars();
- let first_i = interned_chars.next().expect("we know we have at least one char");
- let first_e = existing_chars.next().expect("we know we have at least one char");
- let eq_or_numeric = |(a, b): (char, char)| a == b || a.is_numeric() && b.is_numeric();
-
- if eq_or_numeric((first_i, first_e)) {
- let last_i = interned_chars.next_back().expect("we know we have at least two chars");
- let last_e = existing_chars.next_back().expect("we know we have at least two chars");
- if eq_or_numeric((last_i, last_e)) {
- if interned_chars
- .zip(existing_chars)
- .filter(|&ie| !eq_or_numeric(ie))
- .count()
- != 1
- {
- continue;
+ match existing_name.len.cmp(&count) {
+ Ordering::Greater => {
+ if existing_name.len - count != 1
+ || levenstein_not_1(&interned_name, &existing_name.interned.as_str())
+ {
+ continue;
+ }
+ },
+ Ordering::Less => {
+ if count - existing_name.len != 1
+ || levenstein_not_1(&existing_name.interned.as_str(), &interned_name)
+ {
+ continue;
+ }
+ },
+ Ordering::Equal => {
+ let mut interned_chars = interned_name.chars();
+ let interned_str = existing_name.interned.as_str();
+ let mut existing_chars = interned_str.chars();
+ let first_i = interned_chars.next().expect("we know we have at least one char");
+ let first_e = existing_chars.next().expect("we know we have at least one char");
+ let eq_or_numeric = |(a, b): (char, char)| a == b || a.is_numeric() && b.is_numeric();
+
+ if eq_or_numeric((first_i, first_e)) {
+ let last_i = interned_chars.next_back().expect("we know we have at least two chars");
+ let last_e = existing_chars.next_back().expect("we know we have at least two chars");
+ if eq_or_numeric((last_i, last_e)) {
+ if interned_chars
+ .zip(existing_chars)
+ .filter(|&ie| !eq_or_numeric(ie))
+ .count()
+ != 1
+ {
+ continue;
+ }
+ } else {
+ let second_last_i = interned_chars
+ .next_back()
+ .expect("we know we have at least three chars");
+ let second_last_e = existing_chars
+ .next_back()
+ .expect("we know we have at least three chars");
+ if !eq_or_numeric((second_last_i, second_last_e))
+ || second_last_i == '_'
+ || !interned_chars.zip(existing_chars).all(eq_or_numeric)
+ {
+ // allowed similarity foo_x, foo_y
+ // or too many chars differ (foo_x, boo_y) or (foox, booy)
+ continue;
+ }
+ split_at = interned_name.char_indices().rev().next().map(|(i, _)| i);
}
} else {
- let second_last_i = interned_chars
- .next_back()
- .expect("we know we have at least three chars");
- let second_last_e = existing_chars
- .next_back()
- .expect("we know we have at least three chars");
- if !eq_or_numeric((second_last_i, second_last_e))
- || second_last_i == '_'
+ let second_i = interned_chars.next().expect("we know we have at least two chars");
+ let second_e = existing_chars.next().expect("we know we have at least two chars");
+ if !eq_or_numeric((second_i, second_e))
+ || second_i == '_'
|| !interned_chars.zip(existing_chars).all(eq_or_numeric)
{
- // allowed similarity foo_x, foo_y
- // or too many chars differ (foo_x, boo_y) or (foox, booy)
+ // allowed similarity x_foo, y_foo
+ // or too many chars differ (x_foo, y_boo) or (xfoo, yboo)
continue;
}
- split_at = interned_name.char_indices().rev().next().map(|(i, _)| i);
- }
- } else {
- let second_i = interned_chars.next().expect("we know we have at least two chars");
- let second_e = existing_chars.next().expect("we know we have at least two chars");
- if !eq_or_numeric((second_i, second_e))
- || second_i == '_'
- || !interned_chars.zip(existing_chars).all(eq_or_numeric)
- {
- // allowed similarity x_foo, y_foo
- // or too many chars differ (x_foo, y_boo) or (xfoo, yboo)
- continue;
+ split_at = interned_name.chars().next().map(char::len_utf8);
}
- split_at = interned_name.chars().next().map(char::len_utf8);
- }
+ },
}
span_lint_and_then(
self.0.cx,
return;
}
self.0.names.push(ExistingName {
- whitelist: get_whitelist(&interned_name).unwrap_or(&[]),
- interned: interned_name,
+ exemptions: get_exemptions(&interned_name).unwrap_or(&[]),
+ interned: ident.name,
span: ident.span,
len: count,
});
fn visit_item(&mut self, _: &Item) {
// do not recurse into inner items
}
- fn visit_mac(&mut self, _mac: &Mac) {
- // do not check macs
- }
}
impl EarlyLintPass for NonExpressiveNames {
fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) {
- if let ItemKind::Fn(ref decl, _, _, ref blk) = item.node {
- do_check(self, cx, &item.attrs, decl, blk);
+ if in_external_macro(cx.sess, item.span) {
+ return;
+ }
+
+ if let ItemKind::Fn(box FnKind(_, ref sig, _, Some(ref blk))) = item.kind {
+ do_check(self, cx, &item.attrs, &sig.decl, blk);
}
}
- fn check_impl_item(&mut self, cx: &EarlyContext<'_>, item: &ImplItem) {
- if let ImplItemKind::Method(ref sig, ref blk) = item.node {
+ fn check_impl_item(&mut self, cx: &EarlyContext<'_>, item: &AssocItem) {
+ if in_external_macro(cx.sess, item.span) {
+ return;
+ }
+
+ if let AssocItemKind::Fn(box FnKind(_, ref sig, _, Some(ref blk))) = item.kind {
do_check(self, cx, &item.attrs, &sig.decl, blk);
}
}
}
fn do_check(lint: &mut NonExpressiveNames, cx: &EarlyContext<'_>, attrs: &[Attribute], decl: &FnDecl, blk: &Block) {
- if !attr::contains_name(attrs, sym!(test)) {
+ if !attrs.iter().any(|attr| attr.has_name(sym::test)) {
let mut visitor = SimilarNamesLocalVisitor {
names: Vec::new(),
cx,
}
/// Precondition: `a_name.chars().count() < b_name.chars().count()`.
+#[must_use]
fn levenstein_not_1(a_name: &str, b_name: &str) -> bool {
debug_assert!(a_name.chars().count() < b_name.chars().count());
let mut a_chars = a_name.chars();
if let Some(b2) = b_chars.next() {
// check if there's just one character inserted
return a != b2 || a_chars.ne(b_chars);
- } else {
- // tuple
- // ntuple
- return true;
}
+ // tuple
+ // ntuple
+ return true;
}
// for item in items
true