diff --git a/clippy_lints/src/double_comparison.rs b/clippy_lints/src/double_comparison.rs
index e151918c1fb4..0171ac1e784f 100644
--- a/clippy_lints/src/double_comparison.rs
+++ b/clippy_lints/src/double_comparison.rs
@@ -40,15 +40,16 @@ declare_clippy_lint! {
     "unnecessary double comparisons that can be simplified"
 }
 
-pub struct DoubleComparisonPass;
+pub struct Pass;
 
-impl LintPass for DoubleComparisonPass {
+impl LintPass for Pass {
     fn get_lints(&self) -> LintArray {
         lint_array!(DOUBLE_COMPARISONS)
     }
 }
 
-impl<'a, 'tcx> DoubleComparisonPass {
+impl<'a, 'tcx> Pass {
+    #[allow(clippy::similar_names)]
     fn check_binop(
         &self,
         cx: &LateContext<'a, 'tcx>,
@@ -87,7 +88,7 @@ impl<'a, 'tcx> DoubleComparisonPass {
     }
 }
 
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DoubleComparisonPass {
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
         if let ExprKind::Binary(ref kind, ref lhs, ref rhs) = expr.node {
             self.check_binop(cx, kind.node, lhs, rhs, expr.span);
diff --git a/clippy_lints/src/enum_clike.rs b/clippy_lints/src/enum_clike.rs
index 313175aee849..315bc54cd179 100644
--- a/clippy_lints/src/enum_clike.rs
+++ b/clippy_lints/src/enum_clike.rs
@@ -63,16 +63,16 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnportableVariant {
                 let variant = &var.node;
                 if let Some(ref anon_const) = variant.disr_expr {
                     let param_env = ty::ParamEnv::empty();
-                    let did = cx.tcx.hir.body_owner_def_id(anon_const.body);
-                    let substs = Substs::identity_for_item(cx.tcx.global_tcx(), did);
-                    let instance = ty::Instance::new(did, substs);
-                    let cid = GlobalId {
+                    let def_id = cx.tcx.hir.body_owner_def_id(anon_const.body);
+                    let substs = Substs::identity_for_item(cx.tcx.global_tcx(), def_id);
+                    let instance = ty::Instance::new(def_id, substs);
+                    let c_id = GlobalId {
                         instance,
                         promoted: None
                     };
-                    let constant = cx.tcx.const_eval(param_env.and(cid)).ok();
+                    let constant = cx.tcx.const_eval(param_env.and(c_id)).ok();
                     if let Some(Constant::Int(val)) = constant.and_then(|c| miri_to_const(cx.tcx, c)) {
-                        let mut ty = cx.tcx.type_of(did);
+                        let mut ty = cx.tcx.type_of(def_id);
                         if let ty::Adt(adt, _) = ty.sty {
                             if adt.is_enum() {
                                 ty = adt.repr.discr_type().to_ty(cx.tcx);
diff --git a/clippy_lints/src/enum_variants.rs b/clippy_lints/src/enum_variants.rs
index 8d708f017203..16d1e40484d0 100644
--- a/clippy_lints/src/enum_variants.rs
+++ b/clippy_lints/src/enum_variants.rs
@@ -16,7 +16,7 @@ use crate::syntax::ast::*;
 use crate::syntax::source_map::Span;
 use crate::syntax::symbol::LocalInternedString;
 use crate::utils::{span_help_and_lint, span_lint};
-use crate::utils::{camel_case_from, camel_case_until, in_macro};
+use crate::utils::{camel_case, in_macro};
 
 /// **What it does:** Detects enumeration variants that are prefixed or suffixed
 /// by the same characters.
@@ -184,19 +184,19 @@ fn check_variant(
         }
     }
     let first = var2str(&def.variants[0]);
-    let mut pre = &first[..camel_case_until(&*first)];
-    let mut post = &first[camel_case_from(&*first)..];
+    let mut pre = &first[..camel_case::until(&*first)];
+    let mut post = &first[camel_case::from(&*first)..];
     for var in &def.variants {
         let name = var2str(var);
 
         let pre_match = partial_match(pre, &name);
         pre = &pre[..pre_match];
-        let pre_camel = camel_case_until(pre);
+        let pre_camel = camel_case::until(pre);
         pre = &pre[..pre_camel];
         while let Some((next, last)) = name[pre.len()..].chars().zip(pre.chars().rev()).next() {
             if next.is_lowercase() {
                 let last = pre.len() - last.len_utf8();
-                let last_camel = camel_case_until(&pre[..last]);
+                let last_camel = camel_case::until(&pre[..last]);
                 pre = &pre[..last_camel];
             } else {
                 break;
@@ -206,7 +206,7 @@ fn check_variant(
         let post_match = partial_rmatch(post, &name);
         let post_end = post.len() - post_match;
         post = &post[post_end..];
-        let post_camel = camel_case_from(post);
+        let post_camel = camel_case::from(post);
         post = &post[post_camel..];
     }
     let (what, value) = match (pre.is_empty(), post.is_empty()) {
@@ -255,6 +255,7 @@ impl EarlyLintPass for EnumVariantNames {
         assert!(last.is_some());
     }
 
+    #[allow(clippy::similar_names)]
     fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) {
         let item_name = item.ident.as_str();
         let item_name_chars = item_name.chars().count();
diff --git a/clippy_lints/src/eq_op.rs b/clippy_lints/src/eq_op.rs
index a454ea836950..dfe0c0180a77 100644
--- a/clippy_lints/src/eq_op.rs
+++ b/clippy_lints/src/eq_op.rs
@@ -63,6 +63,7 @@ impl LintPass for EqOp {
 }
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for EqOp {
+    #[allow(clippy::similar_names)]
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
         if let ExprKind::Binary(op, ref left, ref right) = e.node {
             if in_macro(e.span) {
diff --git a/clippy_lints/src/excessive_precision.rs b/clippy_lints/src/excessive_precision.rs
index 99668880f72e..15a8d47337aa 100644
--- a/clippy_lints/src/excessive_precision.rs
+++ b/clippy_lints/src/excessive_precision.rs
@@ -108,6 +108,7 @@ impl ExcessivePrecision {
     }
 }
 
+#[allow(clippy::doc_markdown)]
 /// Should we exclude the float because it has a `.0` or `.` suffix
 /// Ex 1_000_000_000.0
 /// Ex 1_000_000_000.
diff --git a/clippy_lints/src/if_let_redundant_pattern_matching.rs b/clippy_lints/src/if_let_redundant_pattern_matching.rs
index 8b42eaa528e7..bced0c9552d0 100644
--- a/clippy_lints/src/if_let_redundant_pattern_matching.rs
+++ b/clippy_lints/src/if_let_redundant_pattern_matching.rs
@@ -56,6 +56,7 @@ impl LintPass for Pass {
 }
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
+    #[allow(clippy::similar_names)]
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
         if let ExprKind::Match(ref op, ref arms, MatchSource::IfLetDesugar { .. }) = expr.node {
             if arms[0].pats.len() == 1 {
diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs
index 7cdc0f43b344..683d21322435 100644
--- a/clippy_lints/src/lib.rs
+++ b/clippy_lints/src/lib.rs
@@ -430,8 +430,8 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry<'_>, conf: &Conf) {
     reg.register_late_lint_pass(box fallible_impl_from::FallibleImplFrom);
     reg.register_late_lint_pass(box replace_consts::ReplaceConsts);
     reg.register_late_lint_pass(box types::UnitArg);
-    reg.register_late_lint_pass(box double_comparison::DoubleComparisonPass);
-    reg.register_late_lint_pass(box question_mark::QuestionMarkPass);
+    reg.register_late_lint_pass(box double_comparison::Pass);
+    reg.register_late_lint_pass(box question_mark::Pass);
     reg.register_late_lint_pass(box suspicious_trait_impl::SuspiciousImpl);
     reg.register_early_lint_pass(box multiple_crate_versions::Pass);
     reg.register_late_lint_pass(box map_unit_fn::Pass);
diff --git a/clippy_lints/src/map_unit_fn.rs b/clippy_lints/src/map_unit_fn.rs
index e620a1815ce8..503a2ee7032e 100644
--- a/clippy_lints/src/map_unit_fn.rs
+++ b/clippy_lints/src/map_unit_fn.rs
@@ -179,7 +179,7 @@ fn unit_closure<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'a hir::Expr) -> Op
     None
 }
 
-/// Builds a name for the let binding variable (var_arg)
+/// Builds a name for the let binding variable (`var_arg`)
 ///
 /// `x.field` => `x_field`
 /// `y` => `_y`
diff --git a/clippy_lints/src/question_mark.rs b/clippy_lints/src/question_mark.rs
index 0ec57e0be800..72d33e58cd30 100644
--- a/clippy_lints/src/question_mark.rs
+++ b/clippy_lints/src/question_mark.rs
@@ -45,15 +45,15 @@ declare_clippy_lint!{
 }
 
 #[derive(Copy, Clone)]
-pub struct QuestionMarkPass;
+pub struct Pass;
 
-impl LintPass for QuestionMarkPass {
+impl LintPass for Pass {
     fn get_lints(&self) -> LintArray {
         lint_array!(QUESTION_MARK)
     }
 }
 
-impl QuestionMarkPass {
+impl Pass {
     /// Check if the given expression on the given context matches the following structure:
     ///
     /// ```ignore
@@ -145,7 +145,7 @@ impl QuestionMarkPass {
     }
 }
 
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for QuestionMarkPass {
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
         Self::check_is_none_and_early_return_none(cx, expr);
     }
diff --git a/clippy_lints/src/transmute.rs b/clippy_lints/src/transmute.rs
index 0d49f5de2652..801b6db63f5e 100644
--- a/clippy_lints/src/transmute.rs
+++ b/clippy_lints/src/transmute.rs
@@ -227,6 +227,7 @@ impl LintPass for Transmute {
 }
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Transmute {
+    #[allow(clippy::similar_names)]
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
         if let ExprKind::Call(ref path_expr, ref args) = e.node {
             if let ExprKind::Path(ref qpath) = path_expr.node {
diff --git a/clippy_lints/src/utils/camel_case.rs b/clippy_lints/src/utils/camel_case.rs
index 2b60e2c32faa..5ce1e08d8b53 100644
--- a/clippy_lints/src/utils/camel_case.rs
+++ b/clippy_lints/src/utils/camel_case.rs
@@ -10,7 +10,7 @@
 
 /// Return the index of the character after the first camel-case component of
 /// `s`.
-pub fn camel_case_until(s: &str) -> usize {
+pub fn until(s: &str) -> usize {
     let mut iter = s.char_indices();
     if let Some((_, first)) = iter.next() {
         if !first.is_uppercase() {
@@ -43,7 +43,7 @@ pub fn camel_case_until(s: &str) -> usize {
 }
 
 /// Return index of the last camel-case component of `s`.
-pub fn camel_case_from(s: &str) -> usize {
+pub fn from(s: &str) -> usize {
     let mut iter = s.char_indices().rev();
     if let Some((_, first)) = iter.next() {
         if !first.is_lowercase() {
@@ -73,52 +73,52 @@ pub fn camel_case_from(s: &str) -> usize {
 
 #[cfg(test)]
 mod test {
-    use super::{camel_case_from, camel_case_until};
+    use super::{from, until};
 
     #[test]
     fn from_full() {
-        assert_eq!(camel_case_from("AbcDef"), 0);
-        assert_eq!(camel_case_from("Abc"), 0);
+        assert_eq!(from("AbcDef"), 0);
+        assert_eq!(from("Abc"), 0);
     }
 
     #[test]
     fn from_partial() {
-        assert_eq!(camel_case_from("abcDef"), 3);
-        assert_eq!(camel_case_from("aDbc"), 1);
+        assert_eq!(from("abcDef"), 3);
+        assert_eq!(from("aDbc"), 1);
     }
 
     #[test]
     fn from_not() {
-        assert_eq!(camel_case_from("AbcDef_"), 7);
-        assert_eq!(camel_case_from("AbcDD"), 5);
+        assert_eq!(from("AbcDef_"), 7);
+        assert_eq!(from("AbcDD"), 5);
     }
 
     #[test]
     fn from_caps() {
-        assert_eq!(camel_case_from("ABCD"), 4);
+        assert_eq!(from("ABCD"), 4);
     }
 
     #[test]
     fn until_full() {
-        assert_eq!(camel_case_until("AbcDef"), 6);
-        assert_eq!(camel_case_until("Abc"), 3);
+        assert_eq!(until("AbcDef"), 6);
+        assert_eq!(until("Abc"), 3);
     }
 
     #[test]
     fn until_not() {
-        assert_eq!(camel_case_until("abcDef"), 0);
-        assert_eq!(camel_case_until("aDbc"), 0);
+        assert_eq!(until("abcDef"), 0);
+        assert_eq!(until("aDbc"), 0);
     }
 
     #[test]
     fn until_partial() {
-        assert_eq!(camel_case_until("AbcDef_"), 6);
-        assert_eq!(camel_case_until("CallTypeC"), 8);
-        assert_eq!(camel_case_until("AbcDD"), 3);
+        assert_eq!(until("AbcDef_"), 6);
+        assert_eq!(until("CallTypeC"), 8);
+        assert_eq!(until("AbcDD"), 3);
     }
 
     #[test]
     fn until_caps() {
-        assert_eq!(camel_case_until("ABCD"), 0);
+        assert_eq!(until("ABCD"), 0);
     }
-}
\ No newline at end of file
+}
diff --git a/clippy_lints/src/utils/hir_utils.rs b/clippy_lints/src/utils/hir_utils.rs
index bc55c22979b5..7a0b28d15d87 100644
--- a/clippy_lints/src/utils/hir_utils.rs
+++ b/clippy_lints/src/utils/hir_utils.rs
@@ -73,6 +73,7 @@ impl<'a, 'tcx: 'a> SpanlessEq<'a, 'tcx> {
             && both(&left.expr, &right.expr, |l, r| self.eq_expr(l, r))
     }
 
+    #[allow(clippy::similar_names)]
     pub fn eq_expr(&mut self, left: &Expr, right: &Expr) -> bool {
         if self.ignore_fn && differing_macro_contexts(left.span, right.span) {
             return false;
@@ -208,6 +209,7 @@ impl<'a, 'tcx: 'a> SpanlessEq<'a, 'tcx> {
         }
     }
 
+    #[allow(clippy::similar_names)]
     fn eq_qpath(&mut self, left: &QPath, right: &QPath) -> bool {
         match (left, right) {
             (&QPath::Resolved(ref lty, ref lpath), &QPath::Resolved(ref rty, ref rpath)) => {
@@ -262,6 +264,7 @@ impl<'a, 'tcx: 'a> SpanlessEq<'a, 'tcx> {
         self.eq_ty_kind(&left.node, &right.node)
     }
 
+    #[allow(clippy::similar_names)]
     pub fn eq_ty_kind(&mut self, left: &TyKind, right: &TyKind) -> bool {
         match (left, right) {
             (&TyKind::Slice(ref l_vec), &TyKind::Slice(ref r_vec)) => self.eq_ty(l_vec, r_vec),
diff --git a/clippy_lints/src/utils/inspector.rs b/clippy_lints/src/utils/inspector.rs
index 841aaaabdfa7..ea48aa9ab5e7 100644
--- a/clippy_lints/src/utils/inspector.rs
+++ b/clippy_lints/src/utils/inspector.rs
@@ -166,6 +166,7 @@ fn print_decl(cx: &LateContext<'_, '_>, decl: &hir::Decl) {
     }
 }
 
+#[allow(clippy::similar_names)]
 fn print_expr(cx: &LateContext<'_, '_>, expr: &hir::Expr, indent: usize) {
     let ind = "  ".repeat(indent);
     println!("{}+", ind);
@@ -424,6 +425,7 @@ fn print_item(cx: &LateContext<'_, '_>, item: &hir::Item) {
     }
 }
 
+#[allow(clippy::similar_names)]
 fn print_pat(cx: &LateContext<'_, '_>, pat: &hir::Pat, indent: usize) {
     let ind = "  ".repeat(indent);
     println!("{}+", ind);
diff --git a/clippy_lints/src/utils/mod.rs b/clippy_lints/src/utils/mod.rs
index 2a9b1cb0a102..05356f8d3856 100644
--- a/clippy_lints/src/utils/mod.rs
+++ b/clippy_lints/src/utils/mod.rs
@@ -33,8 +33,7 @@ use crate::syntax::source_map::{Span, DUMMY_SP};
 use crate::syntax::errors::DiagnosticBuilder;
 use crate::syntax::symbol::keywords;
 
-mod camel_case;
-pub use self::camel_case::{camel_case_from, camel_case_until};
+pub mod camel_case;
 
 pub mod comparisons;
 pub mod conf;
diff --git a/clippy_lints/src/utils/usage.rs b/clippy_lints/src/utils/usage.rs
index d26ffc715e87..f3af698ffa2f 100644
--- a/clippy_lints/src/utils/usage.rs
+++ b/clippy_lints/src/utils/usage.rs
@@ -54,6 +54,7 @@ struct MutVarsDelegate {
 }
 
 impl<'tcx> MutVarsDelegate {
+    #[allow(clippy::similar_names)]
     fn update(&mut self, cat: &'tcx Categorization<'_>) {
         match *cat {
             Categorization::Local(id) => {