]> git.lizzy.rs Git - rust.git/blobdiff - clippy_lints/src/non_expressive_names.rs
Merge commit '0e87918536b9833bbc6c683d1f9d51ee2bf03ef1' into clippyup
[rust.git] / clippy_lints / src / non_expressive_names.rs
index 847eb0eaf025d51d233f87fab8b76d4384b7fe97..4c8bceaf2cb8bf90e66be13c3fbb72941d56dae5 100644 (file)
@@ -1,13 +1,15 @@
-use crate::utils::{span_lint, span_lint_and_then};
+use clippy_utils::diagnostics::{span_lint, span_lint_and_then};
 use rustc_ast::ast::{
-    Arm, AssocItem, AssocItemKind, Attribute, Block, FnDecl, Ident, Item, ItemKind, Local, Mac, Pat, PatKind,
+    Arm, AssocItem, AssocItemKind, Attribute, Block, FnDecl, FnKind, Item, ItemKind, Local, Pat,
+    PatKind,
 };
-use rustc_ast::attr;
 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::symbol::SymbolStr;
+use rustc_span::sym;
+use rustc_span::symbol::{Ident, Symbol};
 use std::cmp::Ordering;
 
 declare_clippy_lint! {
@@ -74,10 +76,10 @@ pub struct NonExpressiveNames {
 impl_lint_pass!(NonExpressiveNames => [SIMILAR_NAMES, MANY_SINGLE_CHAR_NAMES, JUST_UNDERSCORES_AND_DIGITS]);
 
 struct ExistingName {
-    interned: SymbolStr,
+    interned: Symbol,
     span: Span,
     len: usize,
-    whitelist: &'static [&'static str],
+    exemptions: &'static [&'static str],
 }
 
 struct SimilarNamesLocalVisitor<'a, 'tcx> {
@@ -93,7 +95,7 @@ impl<'a, 'tcx> 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()
@@ -116,7 +118,7 @@ fn check_single_char_names(&self) {
 // 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"],
@@ -131,7 +133,11 @@ fn check_single_char_names(&self) {
 impl<'a, 'tcx, 'b> Visitor<'tcx> for SimilarNamesNameVisitor<'a, 'tcx, 'b> {
     fn visit_pat(&mut self, pat: &'tcx Pat) {
         match pat.kind {
-            PatKind::Ident(_, ident, _) => self.check_ident(ident),
+            PatKind::Ident(_, ident, _) => {
+                if !pat.span.from_expansion() {
+                    self.check_ident(ident);
+                }
+            },
             PatKind::Struct(_, ref fields, _) => {
                 for field in fields {
                     if !field.is_shorthand {
@@ -145,23 +151,20 @@ fn visit_pat(&mut self, pat: &'tcx Pat) {
             _ => walk_pat(self, pat),
         }
     }
-    fn visit_mac(&mut self, _mac: &Mac) {
-        // do not check macs
-    }
 }
 
 #[must_use]
-fn get_whitelist(interned_name: &str) -> Option<&'static [&'static str]> {
-    for &allow in WHITELIST {
-        if whitelisted(interned_name, allow) {
-            return Some(allow);
+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
 }
 
 #[must_use]
-fn whitelisted(interned_name: &str, list: &[&str]) -> bool {
+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))
 }
@@ -199,6 +202,10 @@ fn check_ident(&mut self, ident: Ident) {
             );
             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 {
@@ -207,24 +214,29 @@ fn check_ident(&mut self, ident: Ident) {
             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;
             match existing_name.len.cmp(&count) {
                 Ordering::Greater => {
-                    if existing_name.len - count != 1 || levenstein_not_1(&interned_name, &existing_name.interned) {
+                    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, &interned_name) {
+                    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 mut existing_chars = existing_name.interned.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();
@@ -296,8 +308,8 @@ fn check_ident(&mut self, ident: Ident) {
             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,
         });
@@ -347,27 +359,32 @@ fn visit_arm(&mut self, arm: &'tcx Arm) {
     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 sig, _, Some(ref blk)) = item.kind {
+        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: &AssocItem) {
-        if let AssocItemKind::Fn(_, ref sig, _, Some(ref blk)) = item.kind {
+        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,
@@ -399,11 +416,10 @@ fn levenstein_not_1(a_name: &str, b_name: &str) -> bool {
         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