+use crate::utils::{get_parent_expr, higher, in_macro_or_desugar, 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::{declare_tool_lint, lint_array};
use rustc::ty::Ty;
-use rustc::hir::*;
-use std::collections::HashMap;
+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 syntax::symbol::LocalInternedString;
-use rustc_data_structures::small_vec::OneVector;
-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
-/// …
-/// }
-/// ```
+
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 !in_macro_or_desugar(expr.span) {
// 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) {
span_note_and_lint(
};
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,
- j.body.span,
- "this `match` has identical arm bodies",
- |db| {
- db.span_note(i.body.span, "same as this");
-
- // 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
- // span for the whole pattern, the suggestion is only shown when there is only
- // one pattern. The user should know about `|` if they are already using it…
-
- if i.pats.len() == 1 && j.pats.len() == 1 {
- let lhs = snippet(cx, i.pats[0].span, "<pat1>");
- let rhs = snippet(cx, j.pats[0].span, "<pat2>");
-
- if let PatKind::Wild = j.pats[0].node {
- // if the last arm is _, then i could be integrated into _
- // note that i.pats[0] cannot be _, because that would mean that we're
- // 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),
- );
- } else {
- db.span_note(i.body.span, &format!("consider refactoring into `{} | {}`", lhs, rhs));
+ search_same_list(&indexed_arms, hash, eq).map(|item| {
+ for match_expr in item {
+ let (&(_, i), &(_, j)) = match_expr;
+
+ span_lint_and_then(
+ cx,
+ MATCH_SAME_ARMS,
+ j.body.span,
+ "this `match` has identical arm bodies",
+ |db| {
+ db.span_note(i.body.span, "same as this");
+
+ // 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
+ // span for the whole pattern, the suggestion is only shown when there is only
+ // one pattern. The user should know about `|` if they are already using it…
+
+ if i.pats.len() == 1 && j.pats.len() == 1 {
+ let lhs = snippet(cx, i.pats[0].span, "<pat1>");
+ let rhs = snippet(cx, j.pats[0].span, "<pat2>");
+
+ if let PatKind::Wild = j.pats[0].node {
+ // if the last arm is _, then i could be integrated into _
+ // note that i.pats[0] cannot be _, because that would mean that we're
+ // 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
+ ),
+ );
+ } else {
+ db.span_note(i.body.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) -> (OneVector<&Expr>, OneVector<&Block>) {
- let mut conds = OneVector::new();
- let mut blocks: OneVector<&Block> = OneVector::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 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.
-fn bindings<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, pat: &Pat) -> HashMap<LocalInternedString, Ty<'tcx>> {
- fn bindings_impl<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, pat: &Pat, map: &mut HashMap<LocalInternedString, Ty<'tcx>>) {
+/// 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>>,
+ ) {
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::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,
};
}
- 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)) {
None
}
+
+fn search_same_list<T, Hash, Eq>(exprs: &[T], hash: Hash, eq: Eq) -> Option<Vec<(&T, &T)>>
+where
+ Hash: Fn(&T) -> u64,
+ Eq: Fn(&T, &T) -> bool,
+{
+ 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) {
+ match_expr_list.push((o, expr));
+ }
+ }
+ o.get_mut().push(expr);
+ },
+ Entry::Vacant(v) => {
+ v.insert(vec![expr]);
+ },
+ }
+ }
+
+ if match_expr_list.is_empty() {
+ None
+ } else {
+ Some(match_expr_list)
+ }
+}
projects / rust.git / blobdiff