-// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-
-use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use crate::rustc::{declare_tool_lint, lint_array};
-use crate::rustc::ty::Ty;
-use crate::rustc::hir::*;
-use crate::rustc_data_structures::fx::FxHashMap;
+use crate::utils::{get_parent_expr, higher, same_tys, snippet, span_lint_and_then, span_note_and_lint};
+use crate::utils::{SpanlessEq, SpanlessHash};
+use rustc::hir::*;
+use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use rustc::ty::Ty;
+use rustc::{declare_lint_pass, declare_tool_lint};
+use rustc_data_structures::fx::FxHashMap;
+use smallvec::SmallVec;
use std::collections::hash_map::Entry;
use std::hash::BuildHasherDefault;
-use crate::syntax::symbol::LocalInternedString;
-use smallvec::SmallVec;
-use crate::utils::{SpanlessEq, SpanlessHash};
-use crate::utils::{get_parent_expr, in_macro, snippet, span_lint_and_then, span_note_and_lint};
-
-/// **What it does:** Checks for consecutive `if`s with the same condition.
-///
-/// **Why is this bad?** This is probably a copy & paste error.
-///
-/// **Known problems:** Hopefully none.
-///
-/// **Example:**
-/// ```rust
-/// if a == b {
-/// …
-/// } else if a == b {
-/// …
-/// }
-/// ```
-///
-/// Note that this lint ignores all conditions with a function call as it could
-/// have side effects:
-///
-/// ```rust
-/// if foo() {
-/// …
-/// } else if foo() { // not linted
-/// …
-/// }
-/// ```
+use syntax::symbol::LocalInternedString;
+
declare_clippy_lint! {
+ /// **What it does:** Checks for consecutive `if`s with the same condition.
+ ///
+ /// **Why is this bad?** This is probably a copy & paste error.
+ ///
+ /// **Known problems:** Hopefully none.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// if a == b {
+ /// …
+ /// } else if a == b {
+ /// …
+ /// }
+ /// ```
+ ///
+ /// Note that this lint ignores all conditions with a function call as it could
+ /// have side effects:
+ ///
+ /// ```ignore
+ /// if foo() {
+ /// …
+ /// } else if foo() { // not linted
+ /// …
+ /// }
+ /// ```
pub IFS_SAME_COND,
correctness,
"consecutive `ifs` with the same condition"
}
-/// **What it does:** Checks for `if/else` with the same body as the *then* part
-/// and the *else* part.
-///
-/// **Why is this bad?** This is probably a copy & paste error.
-///
-/// **Known problems:** Hopefully none.
-///
-/// **Example:**
-/// ```rust
-/// let foo = if … {
-/// 42
-/// } else {
-/// 42
-/// };
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for `if/else` with the same body as the *then* part
+ /// and the *else* part.
+ ///
+ /// **Why is this bad?** This is probably a copy & paste error.
+ ///
+ /// **Known problems:** Hopefully none.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// let foo = if … {
+ /// 42
+ /// } else {
+ /// 42
+ /// };
+ /// ```
pub IF_SAME_THEN_ELSE,
correctness,
"if with the same *then* and *else* blocks"
}
-/// **What it does:** Checks for `match` with identical arm bodies.
-///
-/// **Why is this bad?** This is probably a copy & paste error. If arm bodies
-/// are the same on purpose, you can factor them
-/// [using `|`](https://doc.rust-lang.org/book/patterns.html#multiple-patterns).
-///
-/// **Known problems:** False positive possible with order dependent `match`
-/// (see issue
-/// [#860](https://github.com/rust-lang-nursery/rust-clippy/issues/860)).
-///
-/// **Example:**
-/// ```rust,ignore
-/// match foo {
-/// Bar => bar(),
-/// Quz => quz(),
-/// Baz => bar(), // <= oops
-/// }
-/// ```
-///
-/// This should probably be
-/// ```rust,ignore
-/// match foo {
-/// Bar => bar(),
-/// Quz => quz(),
-/// Baz => baz(), // <= fixed
-/// }
-/// ```
-///
-/// or if the original code was not a typo:
-/// ```rust,ignore
-/// match foo {
-/// Bar | Baz => bar(), // <= shows the intent better
-/// Quz => quz(),
-/// }
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for `match` with identical arm bodies.
+ ///
+ /// **Why is this bad?** This is probably a copy & paste error. If arm bodies
+ /// are the same on purpose, you can factor them
+ /// [using `|`](https://doc.rust-lang.org/book/patterns.html#multiple-patterns).
+ ///
+ /// **Known problems:** False positive possible with order dependent `match`
+ /// (see issue
+ /// [#860](https://github.com/rust-lang/rust-clippy/issues/860)).
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// match foo {
+ /// Bar => bar(),
+ /// Quz => quz(),
+ /// Baz => bar(), // <= oops
+ /// }
+ /// ```
+ ///
+ /// This should probably be
+ /// ```rust,ignore
+ /// match foo {
+ /// Bar => bar(),
+ /// Quz => quz(),
+ /// Baz => baz(), // <= fixed
+ /// }
+ /// ```
+ ///
+ /// or if the original code was not a typo:
+ /// ```rust,ignore
+ /// match foo {
+ /// Bar | Baz => bar(), // <= shows the intent better
+ /// Quz => quz(),
+ /// }
+ /// ```
pub MATCH_SAME_ARMS,
pedantic,
"`match` with identical arm bodies"
}
-#[derive(Copy, Clone, Debug)]
-pub struct CopyAndPaste;
-
-impl LintPass for CopyAndPaste {
- fn get_lints(&self) -> LintArray {
- lint_array![IFS_SAME_COND, IF_SAME_THEN_ELSE, MATCH_SAME_ARMS]
- }
-}
+declare_lint_pass!(CopyAndPaste => [IFS_SAME_COND, IF_SAME_THEN_ELSE, MATCH_SAME_ARMS]);
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for CopyAndPaste {
fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
- if !in_macro(expr.span) {
+ if !expr.span.from_expansion() {
// skip ifs directly in else, it will be checked in the parent if
- if let Some(&Expr {
- node: ExprKind::If(_, _, Some(ref else_expr)),
- ..
- }) = get_parent_expr(cx, expr)
- {
- if else_expr.id == expr.id {
- return;
+ if let Some(expr) = get_parent_expr(cx, expr) {
+ if let Some((_, _, Some(ref else_expr))) = higher::if_block(&expr) {
+ if else_expr.hir_id == expr.hir_id {
+ return;
+ }
}
}
h.finish()
};
- let eq: &dyn 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) {
+ for (i, j) in search_same(conds, hash, eq) {
span_note_and_lint(
cx,
IFS_SAME_COND,
}
/// Implementation of `MATCH_SAME_ARMS`.
-fn lint_match_arms(cx: &LateContext<'_, '_>, expr: &Expr) {
+fn lint_match_arms<'tcx>(cx: &LateContext<'_, 'tcx>, expr: &Expr) {
+ fn same_bindings<'tcx>(
+ cx: &LateContext<'_, 'tcx>,
+ lhs: &FxHashMap<LocalInternedString, Ty<'tcx>>,
+ rhs: &FxHashMap<LocalInternedString, Ty<'tcx>>,
+ ) -> bool {
+ lhs.len() == rhs.len()
+ && lhs
+ .iter()
+ .all(|(name, l_ty)| rhs.get(name).map_or(false, |r_ty| same_tys(cx, l_ty, r_ty)))
+ }
+
if let ExprKind::Match(_, ref arms, MatchSource::Normal) = expr.node {
let hash = |&(_, arm): &(usize, &Arm)| -> u64 {
let mut h = SpanlessHash::new(cx, cx.tables);
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])
+ same_bindings(cx, &bindings(cx, &lhs.pats[0]), &bindings(cx, &rhs.pats[0]))
};
let indexed_arms: Vec<(usize, &Arm)> = arms.iter().enumerate().collect();
- if let Some((&(_, i), &(_, j))) = search_same(&indexed_arms, hash, eq) {
+ for (&(_, i), &(_, j)) in 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_with_applicability` on purpose:
+ // Note: this does not use `span_suggestion` 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
// 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));
+ db.span_help(
+ i.pats[0].span,
+ &format!("consider refactoring into `{} | {}`", lhs, rhs),
+ );
}
}
},
}
}
-/// Return the list of condition expressions and the list of blocks in a
+/// Returns the list of condition expressions and the list of blocks in a
/// sequence of `if/else`.
-/// Eg. would return `([a, b], [c, d, e])` for the expression
+/// E.g., this returns `([a, b], [c, d, e])` for the expression
/// `if a { c } else if b { d } else { e }`.
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 ExprKind::If(ref cond, ref then_expr, ref else_expr) = expr.node {
+ while let Some((ref cond, ref then_expr, ref else_expr)) = higher::if_block(&expr) {
conds.push(&**cond);
if let ExprKind::Block(ref block, _) = then_expr.node {
blocks.push(block);
(conds, blocks)
}
-/// Return the list of bindings in a pattern.
+/// Returns the list of bindings in a pattern.
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>>) {
+ 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(_, _, ident, ref as_pat) => {
+ PatKind::Binding(.., ident, ref as_pat) => {
if let Entry::Vacant(v) = map.entry(ident.as_str()) {
v.insert(cx.tables.pat_ty(pat));
}
bindings_impl(cx, as_pat, map);
}
},
- PatKind::Struct(_, ref fields, _) => for pat in fields {
- bindings_impl(cx, &pat.node.pat, map);
+ PatKind::Or(ref fields) | 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::Struct(_, ref fields, _) => {
+ for pat in fields {
+ bindings_impl(cx, &pat.pat, map);
+ }
},
PatKind::Slice(ref lhs, ref mid, ref rhs) => {
for pat in lhs {
result
}
-
fn search_same_sequenced<T, Eq>(exprs: &[T], eq: Eq) -> Option<(&T, &T)>
where
Eq: Fn(&T, &T) -> bool,
None
}
-fn search_same<T, Hash, Eq>(exprs: &[T], hash: Hash, eq: Eq) -> Option<(&T, &T)>
+fn search_common_cases<'a, T, Eq>(exprs: &'a [T], eq: &Eq) -> Option<(&'a T, &'a T)>
where
- Hash: Fn(&T) -> u64,
Eq: Fn(&T, &T) -> bool,
{
- // common cases
if exprs.len() < 2 {
- return None;
+ None
} else if exprs.len() == 2 {
- return if eq(&exprs[0], &exprs[1]) {
+ if eq(&exprs[0], &exprs[1]) {
Some((&exprs[0], &exprs[1]))
} else {
None
- };
+ }
+ } else {
+ None
}
+}
- let mut map: FxHashMap<_, Vec<&_>> = FxHashMap::with_capacity_and_hasher(
- exprs.len(),
- BuildHasherDefault::default()
- );
+fn search_same<T, Hash, Eq>(exprs: &[T], hash: Hash, eq: Eq) -> Vec<(&T, &T)>
+where
+ Hash: Fn(&T) -> u64,
+ Eq: Fn(&T, &T) -> bool,
+{
+ if let Some(expr) = search_common_cases(&exprs, &eq) {
+ return vec![expr];
+ }
+
+ let mut match_expr_list: Vec<(&T, &T)> = Vec::new();
+
+ 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(mut o) => {
for o in o.get() {
if eq(o, expr) {
- return Some((o, expr));
+ match_expr_list.push((o, expr));
}
}
o.get_mut().push(expr);
}
}
- None
+ match_expr_list
}