-use rustc::lint::*;
-use syntax::codemap::Span;
-use syntax::parse::token::InternedString;
+use crate::utils::{span_lint, span_lint_and_then};
+use rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
+use rustc::{declare_tool_lint, lint_array};
use syntax::ast::*;
use syntax::attr;
-use syntax::visit::{Visitor, walk_block, walk_pat, walk_expr};
-use utils::{span_lint_and_then, in_macro, span_lint};
+use syntax::source_map::Span;
+use syntax::symbol::LocalInternedString;
+use syntax::visit::{walk_block, walk_expr, walk_pat, Visitor};
-/// **What it does:** This lint warns about names that are very similar and thus confusing
-///
-/// **Why is this bad?** It's hard to distinguish between names that differ only by a single character
-///
-/// **Known problems:** None?
-///
-/// **Example:** `checked_exp` and `checked_expr`
-declare_lint! {
+declare_clippy_lint! {
+ /// **What it does:** Checks for names that are very similar and thus confusing.
+ ///
+ /// **Why is this bad?** It's hard to distinguish between names that differ only
+ /// by a single character.
+ ///
+ /// **Known problems:** None?
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// let checked_exp = something;
+ /// let checked_expr = something_else;
+ /// ```
pub SIMILAR_NAMES,
- Allow,
+ pedantic,
"similarly named items and bindings"
}
-/// **What it does:** This lint warns about having too many variables whose name consists of a single character
-///
-/// **Why is this bad?** It's hard to memorize what a variable means without a descriptive name.
-///
-/// **Known problems:** None?
-///
-/// **Example:** let (a, b, c, d, e, f, g) = (...);
-declare_lint! {
+declare_clippy_lint! {
+ /// **What it does:** Checks for too many variables whose name consists of a
+ /// single character.
+ ///
+ /// **Why is this bad?** It's hard to memorize what a variable means without a
+ /// descriptive name.
+ ///
+ /// **Known problems:** None?
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// let (a, b, c, d, e, f, g) = (...);
+ /// ```
pub MANY_SINGLE_CHAR_NAMES,
- Warn,
+ style,
"too many single character bindings"
}
+declare_clippy_lint! {
+ /// **What it does:** Checks if you have variables whose name consists of just
+ /// underscores and digits.
+ ///
+ /// **Why is this bad?** It's hard to memorize what a variable means without a
+ /// descriptive name.
+ ///
+ /// **Known problems:** None?
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let _1 = 1;
+ /// let ___1 = 1;
+ /// let __1___2 = 11;
+ /// ```
+ pub JUST_UNDERSCORES_AND_DIGITS,
+ style,
+ "unclear name"
+}
+
pub struct NonExpressiveNames {
- pub max_single_char_names: u64,
+ pub single_char_binding_names_threshold: u64,
}
impl LintPass for NonExpressiveNames {
fn get_lints(&self) -> LintArray {
- lint_array!(SIMILAR_NAMES, MANY_SINGLE_CHAR_NAMES)
+ lint_array!(SIMILAR_NAMES, MANY_SINGLE_CHAR_NAMES, JUST_UNDERSCORES_AND_DIGITS)
+ }
+
+ fn name(&self) -> &'static str {
+ "NoneExpressiveNames"
}
}
struct ExistingName {
- interned: InternedString,
+ interned: LocalInternedString,
span: Span,
len: usize,
whitelist: &'static [&'static str],
}
-struct SimilarNamesLocalVisitor<'a, 'b: 'a> {
+struct SimilarNamesLocalVisitor<'a, 'tcx: 'a> {
names: Vec<ExistingName>,
- cx: &'a EarlyContext<'b>,
+ cx: &'a EarlyContext<'tcx>,
lint: &'a NonExpressiveNames,
single_char_names: Vec<char>,
}
// this list contains lists of names that are allowed to be similar
// the assumption is that no name is ever contained in multiple lists.
-#[cfg_attr(rustfmt, rustfmt_skip)]
-const WHITELIST: &'static [&'static [&'static str]] = &[
+#[rustfmt::skip]
+const WHITELIST: &[&[&str]] = &[
&["parsed", "parser"],
&["lhs", "rhs"],
&["tx", "rx"],
&["set", "get"],
+ &["args", "arms"],
+ &["qpath", "path"],
+ &["lit", "lint"],
];
-struct SimilarNamesNameVisitor<'a, 'b: 'a, 'c: 'b>(&'a mut SimilarNamesLocalVisitor<'b, 'c>);
+struct SimilarNamesNameVisitor<'a: 'b, 'tcx: 'a, 'b>(&'b mut SimilarNamesLocalVisitor<'a, 'tcx>);
-impl<'a, 'b, 'c> Visitor for SimilarNamesNameVisitor<'a, 'b, 'c> {
- fn visit_pat(&mut self, pat: &Pat) {
+impl<'a, 'tcx: 'a, 'b> Visitor<'tcx> for SimilarNamesNameVisitor<'a, 'tcx, 'b> {
+ fn visit_pat(&mut self, pat: &'tcx Pat) {
match pat.node {
- PatKind::Ident(_, id, _) => self.check_name(id.span, id.node.name),
+ PatKind::Ident(_, ident, _) => self.check_name(ident.span, ident.name),
PatKind::Struct(_, ref fields, _) => {
for field in fields {
if !field.node.is_shorthand {
self.visit_pat(&field.node.pat);
}
}
- }
+ },
_ => 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]> {
}
fn whitelisted(interned_name: &str, list: &[&str]) -> bool {
- if list.iter().any(|&name| interned_name == name) {
- return true;
- }
- for name in list {
- // name_*
- if interned_name.chars().zip(name.chars()).all(|(l, r)| l == r) {
- return true;
- }
- // *_name
- if interned_name.chars().rev().zip(name.chars().rev()).all(|(l, r)| l == r) {
- return true;
- }
- }
- false
+ list.iter()
+ .any(|&name| interned_name.starts_with(name) || interned_name.ends_with(name))
}
-impl<'a, 'b, 'c> SimilarNamesNameVisitor<'a, 'b, 'c> {
+impl<'a, 'tcx, 'b> SimilarNamesNameVisitor<'a, 'tcx, 'b> {
fn check_short_name(&mut self, c: char, span: Span) {
// make sure we ignore shadowing
if self.0.single_char_names.contains(&c) {
return;
}
self.0.single_char_names.push(c);
- if self.0.single_char_names.len() as u64 >= self.0.lint.max_single_char_names {
- span_lint(self.0.cx,
- MANY_SINGLE_CHAR_NAMES,
- span,
- &format!("{}th binding whose name is just one char", self.0.single_char_names.len()));
+ if self.0.single_char_names.len() as u64 >= self.0.lint.single_char_binding_names_threshold {
+ span_lint(
+ self.0.cx,
+ MANY_SINGLE_CHAR_NAMES,
+ span,
+ &format!(
+ "{}th binding whose name is just one char",
+ self.0.single_char_names.len()
+ ),
+ );
}
}
+ #[allow(clippy::too_many_lines)]
fn check_name(&mut self, span: Span, name: Name) {
- if in_macro(self.0.cx, span) {
- return;
- }
let interned_name = name.as_str();
if interned_name.chars().any(char::is_uppercase) {
return;
}
+ if interned_name.chars().all(|c| c.is_digit(10) || c == '_') {
+ span_lint(
+ self.0.cx,
+ JUST_UNDERSCORES_AND_DIGITS,
+ span,
+ "consider choosing a more descriptive name",
+ );
+ return;
+ }
let count = interned_name.chars().count();
if count < 3 {
if count == 1 {
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: char, b: char| a == b || a.is_numeric() && b.is_numeric();
+ let eq_or_numeric = |(a, b): (char, char)| a == b || a.is_numeric() && b.is_numeric();
- if eq_or_numeric(first_i, first_e) {
+ 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(|&(i, e)| !eq_or_numeric(i, e)).count() != 1 {
+ 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(|(i, e)| eq_or_numeric(i, e)) {
+ 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;
} 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(|(i, e)| eq_or_numeric(i, e)) {
+ 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(|c| c.len_utf8());
+ split_at = interned_name.chars().next().map(char::len_utf8);
}
}
- span_lint_and_then(self.0.cx,
- SIMILAR_NAMES,
- span,
- "binding's name is too similar to existing binding",
- |diag| {
- diag.span_note(existing_name.span, "existing binding defined here");
- if let Some(split) = split_at {
- diag.span_help(span,
- &format!("separate the discriminating character by an \
- underscore like: `{}_{}`",
- &interned_name[..split],
- &interned_name[split..]));
- }
- });
+ span_lint_and_then(
+ self.0.cx,
+ SIMILAR_NAMES,
+ span,
+ "binding's name is too similar to existing binding",
+ |diag| {
+ diag.span_note(existing_name.span, "existing binding defined here");
+ if let Some(split) = split_at {
+ diag.span_help(
+ span,
+ &format!(
+ "separate the discriminating character by an \
+ underscore like: `{}_{}`",
+ &interned_name[..split],
+ &interned_name[split..]
+ ),
+ );
+ }
+ },
+ );
return;
}
self.0.names.push(ExistingName {
whitelist: get_whitelist(&interned_name).unwrap_or(&[]),
interned: interned_name,
- span: span,
+ span,
len: count,
});
}
}
}
-impl<'a, 'b> Visitor for SimilarNamesLocalVisitor<'a, 'b> {
- fn visit_local(&mut self, local: &Local) {
+impl<'a, 'tcx> Visitor<'tcx> for SimilarNamesLocalVisitor<'a, 'tcx> {
+ fn visit_local(&mut self, local: &'tcx Local) {
if let Some(ref init) = local.init {
self.apply(|this| walk_expr(this, &**init));
}
- // add the pattern after the expression because the bindings aren't available yet in the init expression
+ // add the pattern after the expression because the bindings aren't available
+ // yet in the init
+ // expression
SimilarNamesNameVisitor(self).visit_pat(&*local.pat);
}
- fn visit_block(&mut self, blk: &Block) {
+ fn visit_block(&mut self, blk: &'tcx Block) {
self.apply(|this| walk_block(this, blk));
}
- fn visit_arm(&mut self, arm: &Arm) {
+ fn visit_arm(&mut self, arm: &'tcx Arm) {
self.apply(|this| {
- // just go through the first pattern, as either all patterns bind the same bindings or rustc would have errored much earlier
+ // just go through the first pattern, as either all patterns
+ // bind the same bindings or rustc would have errored much earlier
SimilarNamesNameVisitor(this).visit_pat(&arm.pats[0]);
this.apply(|this| walk_expr(this, &arm.body));
});
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 {
- if !attr::contains_name(&item.attrs, "test") {
- let mut visitor = SimilarNamesLocalVisitor {
- names: Vec::new(),
- cx: cx,
- lint: self,
- single_char_names: Vec::new(),
- };
- // initialize with function arguments
- for arg in &decl.inputs {
- SimilarNamesNameVisitor(&mut visitor).visit_pat(&arg.pat);
- }
- // walk all other bindings
- walk_block(&mut visitor, blk);
- }
+ 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);
+ }
+ }
+
+ fn check_impl_item(&mut self, cx: &EarlyContext<'_>, item: &ImplItem) {
+ if let ImplItemKind::Method(ref sig, ref blk) = item.node {
+ 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, "test") {
+ let mut visitor = SimilarNamesLocalVisitor {
+ names: Vec::new(),
+ cx,
+ lint,
+ single_char_names: Vec::new(),
+ };
+ // initialize with function arguments
+ for arg in &decl.inputs {
+ SimilarNamesNameVisitor(&mut visitor).visit_pat(&arg.pat);
}
+ // walk all other bindings
+ walk_block(&mut visitor, blk);
}
}