-use rustc::lint::*;
-use rustc::ty::Ty;
+use crate::utils::{get_parent_expr, in_macro, snippet, span_lint_and_then, span_note_and_lint};
+use crate::utils::{SpanlessEq, SpanlessHash};
use rustc::hir::*;
-use std::collections::HashMap;
+use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use rustc::ty::Ty;
+use rustc::{declare_tool_lint, lint_array};
+use rustc_data_structures::fx::FxHashMap;
+use smallvec::SmallVec;
use std::collections::hash_map::Entry;
-use syntax::symbol::InternedString;
-use syntax::util::small_vector::SmallVector;
-use utils::{SpanlessEq, SpanlessHash};
-use utils::{get_parent_expr, in_macro, snippet, span_lint_and_then, span_note_and_lint};
+use std::hash::BuildHasherDefault;
+use syntax::symbol::LocalInternedString;
/// **What it does:** Checks for consecutive `if`s with the same condition.
///
/// …
/// }
/// ```
-declare_lint! {
+declare_clippy_lint! {
pub IFS_SAME_COND,
- Warn,
+ correctness,
"consecutive `ifs` with the same condition"
}
/// 42
/// };
/// ```
-declare_lint! {
+declare_clippy_lint! {
pub IF_SAME_THEN_ELSE,
- Warn,
+ correctness,
"if with the same *then* and *else* blocks"
}
///
/// **Known problems:** False positive possible with order dependent `match`
/// (see issue
-/// [#860](https://github.com/rust-lang-nursery/rust-clippy/issues/860)).
+/// [#860](https://github.com/rust-lang/rust-clippy/issues/860)).
///
/// **Example:**
/// ```rust,ignore
/// Quz => quz(),
/// }
/// ```
-declare_lint! {
+declare_clippy_lint! {
pub MATCH_SAME_ARMS,
- Warn,
+ pedantic,
"`match` with identical arm bodies"
}
if !in_macro(expr.span) {
// skip ifs directly in else, it will be checked in the parent if
if let Some(&Expr {
- node: ExprIf(_, _, Some(ref else_expr)),
+ node: ExprKind::If(_, _, Some(ref else_expr)),
..
}) = get_parent_expr(cx, expr)
{
}
/// Implementation of `IF_SAME_THEN_ELSE`.
-fn lint_same_then_else(cx: &LateContext, blocks: &[&Block]) {
- let hash: &Fn(&&Block) -> u64 = &|block| -> u64 {
- let mut h = SpanlessHash::new(cx);
- h.hash_block(block);
- h.finish()
- };
-
- let eq: &Fn(&&Block, &&Block) -> bool = &|&lhs, &rhs| -> bool { SpanlessEq::new(cx).eq_block(lhs, rhs) };
+fn lint_same_then_else(cx: &LateContext<'_, '_>, blocks: &[&Block]) {
+ let eq: &dyn Fn(&&Block, &&Block) -> bool = &|&lhs, &rhs| -> bool { SpanlessEq::new(cx).eq_block(lhs, rhs) };
- if let Some((i, j)) = search_same(blocks, hash, eq) {
+ if let Some((i, j)) = search_same_sequenced(blocks, eq) {
span_note_and_lint(
cx,
IF_SAME_THEN_ELSE,
}
/// Implementation of `IFS_SAME_COND`.
-fn lint_same_cond(cx: &LateContext, conds: &[&Expr]) {
- let hash: &Fn(&&Expr) -> u64 = &|expr| -> u64 {
- let mut h = SpanlessHash::new(cx);
+fn lint_same_cond(cx: &LateContext<'_, '_>, conds: &[&Expr]) {
+ let hash: &dyn Fn(&&Expr) -> u64 = &|expr| -> u64 {
+ let mut h = SpanlessHash::new(cx, cx.tables);
h.hash_expr(expr);
h.finish()
};
- let eq: &Fn(&&Expr, &&Expr) -> bool = &|&lhs, &rhs| -> bool { SpanlessEq::new(cx).ignore_fn().eq_expr(lhs, rhs) };
+ let eq: &dyn Fn(&&Expr, &&Expr) -> bool =
+ &|&lhs, &rhs| -> bool { SpanlessEq::new(cx).ignore_fn().eq_expr(lhs, rhs) };
if let Some((i, j)) = search_same(conds, hash, eq) {
span_note_and_lint(
}
}
-/// Implementation if `MATCH_SAME_ARMS`.
-fn lint_match_arms(cx: &LateContext, expr: &Expr) {
- let hash = |arm: &Arm| -> u64 {
- let mut h = SpanlessHash::new(cx);
- h.hash_expr(&arm.body);
- h.finish()
- };
+/// Implementation of `MATCH_SAME_ARMS`.
+fn lint_match_arms(cx: &LateContext<'_, '_>, expr: &Expr) {
+ if let ExprKind::Match(_, ref arms, MatchSource::Normal) = expr.node {
+ let hash = |&(_, arm): &(usize, &Arm)| -> u64 {
+ let mut h = SpanlessHash::new(cx, cx.tables);
+ h.hash_expr(&arm.body);
+ h.finish()
+ };
- let eq = |lhs: &Arm, rhs: &Arm| -> bool {
- // Arms with a guard are ignored, those can’t always be merged together
- lhs.guard.is_none() && rhs.guard.is_none() &&
- SpanlessEq::new(cx).eq_expr(&lhs.body, &rhs.body) &&
- // all patterns should have the same bindings
- bindings(cx, &lhs.pats[0]) == bindings(cx, &rhs.pats[0])
- };
+ let eq = |&(lindex, lhs): &(usize, &Arm), &(rindex, rhs): &(usize, &Arm)| -> bool {
+ let min_index = usize::min(lindex, rindex);
+ let max_index = usize::max(lindex, rindex);
+ // Arms with a guard are ignored, those can’t always be merged together
+ // This is also the case for arms in-between each there is an arm with a guard
+ (min_index..=max_index).all(|index| arms[index].guard.is_none()) &&
+ SpanlessEq::new(cx).eq_expr(&lhs.body, &rhs.body) &&
+ // all patterns should have the same bindings
+ bindings(cx, &lhs.pats[0]) == bindings(cx, &rhs.pats[0])
+ };
- if let ExprMatch(_, ref arms, MatchSource::Normal) = expr.node {
- if let Some((i, j)) = search_same(arms, hash, eq) {
+ let indexed_arms: Vec<(usize, &Arm)> = arms.iter().enumerate().collect();
+ if let Some((&(_, i), &(_, j))) = search_same(&indexed_arms, hash, eq) {
span_lint_and_then(
cx,
MATCH_SAME_ARMS,
|db| {
db.span_note(i.body.span, "same as this");
- // Note: this does not use `span_suggestion` on purpose: there is no clean way
+ // Note: this does not use `span_suggestion_with_applicability` on purpose:
+ // there is no clean way
// to remove the other arm. Building a span and suggest to replace it to ""
// makes an even more confusing error message. Also in order not to make up a
// span for the whole pattern, the suggestion is only shown when there is only
// hiding all the subsequent arms, and rust won't compile
db.span_note(
i.body.span,
- &format!("`{}` has the same arm body as the `_` wildcard, consider removing it`", lhs),
+ &format!(
+ "`{}` has the same arm body as the `_` wildcard, consider removing it`",
+ lhs
+ ),
);
} else {
db.span_note(i.body.span, &format!("consider refactoring into `{} | {}`", lhs, rhs));
/// sequence of `if/else`.
/// Eg. would return `([a, b], [c, d, e])` for the expression
/// `if a { c } else if b { d } else { e }`.
-fn if_sequence(mut expr: &Expr) -> (SmallVector<&Expr>, SmallVector<&Block>) {
- let mut conds = SmallVector::new();
- let mut blocks: SmallVector<&Block> = SmallVector::new();
+fn if_sequence(mut expr: &Expr) -> (SmallVec<[&Expr; 1]>, SmallVec<[&Block; 1]>) {
+ let mut conds = SmallVec::new();
+ let mut blocks: SmallVec<[&Block; 1]> = SmallVec::new();
- while let ExprIf(ref cond, ref then_expr, ref else_expr) = expr.node {
+ while let ExprKind::If(ref cond, ref then_expr, ref else_expr) = expr.node {
conds.push(&**cond);
- if let ExprBlock(ref block) = then_expr.node {
+ if let ExprKind::Block(ref block, _) = then_expr.node {
blocks.push(block);
} else {
- panic!("ExprIf node is not an ExprBlock");
+ panic!("ExprKind::If node is not an ExprKind::Block");
}
if let Some(ref else_expr) = *else_expr {
// final `else {..}`
if !blocks.is_empty() {
- if let ExprBlock(ref block) = expr.node {
+ if let ExprKind::Block(ref block, _) = expr.node {
blocks.push(&**block);
}
}
}
/// Return the list of bindings in a pattern.
-fn bindings<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, pat: &Pat) -> HashMap<InternedString, Ty<'tcx>> {
- fn bindings_impl<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, pat: &Pat, map: &mut HashMap<InternedString, Ty<'tcx>>) {
+fn bindings<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, pat: &Pat) -> FxHashMap<LocalInternedString, Ty<'tcx>> {
+ fn bindings_impl<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ pat: &Pat,
+ map: &mut FxHashMap<LocalInternedString, Ty<'tcx>>,
+ ) {
match pat.node {
PatKind::Box(ref pat) | PatKind::Ref(ref pat, _) => bindings_impl(cx, pat, map),
- PatKind::TupleStruct(_, ref pats, _) => for pat in pats {
- bindings_impl(cx, pat, map);
+ PatKind::TupleStruct(_, ref pats, _) => {
+ for pat in pats {
+ bindings_impl(cx, pat, map);
+ }
},
- PatKind::Binding(_, _, ref ident, ref as_pat) => {
- if let Entry::Vacant(v) = map.entry(ident.node.as_str()) {
+ PatKind::Binding(_, _, ident, ref as_pat) => {
+ if let Entry::Vacant(v) = map.entry(ident.as_str()) {
v.insert(cx.tables.pat_ty(pat));
}
if let Some(ref as_pat) = *as_pat {
bindings_impl(cx, as_pat, map);
}
},
- PatKind::Struct(_, ref fields, _) => for pat in fields {
- bindings_impl(cx, &pat.node.pat, map);
+ PatKind::Struct(_, ref fields, _) => {
+ for pat in fields {
+ bindings_impl(cx, &pat.node.pat, map);
+ }
},
- PatKind::Tuple(ref fields, _) => for pat in fields {
- bindings_impl(cx, pat, map);
+ PatKind::Tuple(ref fields, _) => {
+ for pat in fields {
+ bindings_impl(cx, pat, map);
+ }
},
PatKind::Slice(ref lhs, ref mid, ref rhs) => {
for pat in lhs {
}
}
- let mut result = HashMap::new();
+ let mut result = FxHashMap::default();
bindings_impl(cx, pat, &mut result);
result
}
+fn search_same_sequenced<T, Eq>(exprs: &[T], eq: Eq) -> Option<(&T, &T)>
+where
+ Eq: Fn(&T, &T) -> bool,
+{
+ for win in exprs.windows(2) {
+ if eq(&win[0], &win[1]) {
+ return Some((&win[0], &win[1]));
+ }
+ }
+ None
+}
+
fn search_same<T, Hash, Eq>(exprs: &[T], hash: Hash, eq: Eq) -> Option<(&T, &T)>
where
Hash: Fn(&T) -> u64,
};
}
- let mut map: HashMap<_, Vec<&_>> = HashMap::with_capacity(exprs.len());
+ let mut map: FxHashMap<_, Vec<&_>> =
+ FxHashMap::with_capacity_and_hasher(exprs.len(), BuildHasherDefault::default());
for expr in exprs {
match map.entry(hash(expr)) {
- Entry::Occupied(o) => for o in o.get() {
- if eq(o, expr) {
- return Some((o, expr));
+ Entry::Occupied(mut o) => {
+ for o in o.get() {
+ if eq(o, expr) {
+ return Some((o, expr));
+ }
}
+ o.get_mut().push(expr);
},
Entry::Vacant(v) => {
v.insert(vec![expr]);