use rustc::lint::*;
-use rustc::middle::ty;
+use rustc::ty;
use rustc_front::hir::*;
use std::collections::HashMap;
use std::collections::hash_map::Entry;
/// **What it does:** This lint checks for `match` with identical arm bodies.
///
-/// **Why is this bad?** This is probably a copy & paste error.
+/// **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:** Hopefully none.
///
/// match foo {
/// Bar => bar(),
/// Quz => quz(),
-/// Baz => bar(), // <= oups
+/// Baz => bar(), // <= oops
/// }
/// ```
declare_lint! {
impl LintPass for CopyAndPaste {
fn get_lints(&self) -> LintArray {
- lint_array![
- IFS_SAME_COND,
- IF_SAME_THEN_ELSE,
- MATCH_SAME_ARMS
- ]
+ lint_array![IFS_SAME_COND, IF_SAME_THEN_ELSE, MATCH_SAME_ARMS]
}
}
/// Implementation of `IF_SAME_THEN_ELSE`.
fn lint_same_then_else(cx: &LateContext, blocks: &[&Block]) {
- let hash : &Fn(&&Block) -> u64 = &|block| -> u64 {
+ 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)
- };
+ let eq: &Fn(&&Block, &&Block) -> bool = &|&lhs, &rhs| -> bool { SpanlessEq::new(cx).eq_block(lhs, rhs) };
if let Some((i, j)) = search_same(blocks, hash, eq) {
- span_note_and_lint(cx, IF_SAME_THEN_ELSE, j.span, "this `if` has identical blocks", i.span, "same as this");
+ span_note_and_lint(cx,
+ IF_SAME_THEN_ELSE,
+ j.span,
+ "this `if` has identical blocks",
+ i.span,
+ "same as this");
}
}
/// Implementation of `IFS_SAME_COND`.
fn lint_same_cond(cx: &LateContext, conds: &[&Expr]) {
- let hash : &Fn(&&Expr) -> u64 = &|expr| -> u64 {
+ let hash: &Fn(&&Expr) -> u64 = &|expr| -> u64 {
let mut h = SpanlessHash::new(cx);
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: &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(cx, IFS_SAME_COND, j.span, "this `if` has the same condition as a previous if", i.span, "same as this");
+ span_note_and_lint(cx,
+ IFS_SAME_COND,
+ j.span,
+ "this `if` has the same condition as a previous if",
+ i.span,
+ "same as this");
}
}
};
let eq = |lhs: &Arm, rhs: &Arm| -> bool {
- SpanlessEq::new(cx).eq_expr(&lhs.body, &rhs.body) &&
+ // 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])
};
if let ExprMatch(_, ref arms, MatchSource::Normal) = expr.node {
- if let Some((i, j)) = search_same(&**arms, hash, eq) {
- span_note_and_lint(cx, MATCH_SAME_ARMS, j.body.span, "this `match` has identical arm bodies", i.body.span, "same as this");
+ if let Some((i, j)) = search_same(&arms, hash, eq) {
+ span_note_and_lint(cx,
+ MATCH_SAME_ARMS,
+ j.body.span,
+ "this `match` has identical arm bodies",
+ i.body.span,
+ "same as this");
}
}
}
if let Some(ref else_expr) = *else_expr {
expr = else_expr;
- }
- else {
+ } else {
break;
}
}
fn bindings<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, pat: &Pat) -> HashMap<InternedString, ty::Ty<'tcx>> {
fn bindings_impl<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, pat: &Pat, map: &mut HashMap<InternedString, ty::Ty<'tcx>>) {
match pat.node {
- PatBox(ref pat) | PatRegion(ref pat, _) => bindings_impl(cx, pat, map),
- PatEnum(_, Some(ref pats)) => {
+ PatKind::Box(ref pat) | PatKind::Ref(ref pat, _) => bindings_impl(cx, pat, map),
+ PatKind::TupleStruct(_, Some(ref pats)) => {
for pat in pats {
bindings_impl(cx, pat, map);
}
}
- PatIdent(_, ref ident, ref as_pat) => {
+ PatKind::Ident(_, ref ident, ref as_pat) => {
if let Entry::Vacant(v) = map.entry(ident.node.name.as_str()) {
v.insert(cx.tcx.pat_ty(pat));
}
if let Some(ref as_pat) = *as_pat {
bindings_impl(cx, as_pat, map);
}
- },
- PatStruct(_, ref fields, _) => {
+ }
+ PatKind::Struct(_, ref fields, _) => {
for pat in fields {
bindings_impl(cx, &pat.node.pat, map);
}
}
- PatTup(ref fields) => {
+ PatKind::Tup(ref fields) => {
for pat in fields {
bindings_impl(cx, pat, map);
}
}
- PatVec(ref lhs, ref mid, ref rhs) => {
+ PatKind::Vec(ref lhs, ref mid, ref rhs) => {
for pat in lhs {
bindings_impl(cx, pat, map);
}
bindings_impl(cx, pat, map);
}
}
- PatEnum(..) | PatLit(..) | PatQPath(..) | PatRange(..) | PatWild => (),
+ PatKind::TupleStruct(..) |
+ PatKind::Lit(..) |
+ PatKind::QPath(..) |
+ PatKind::Range(..) |
+ PatKind::Wild |
+ PatKind::Path(..) => (),
}
}
result
}
-fn search_same<T, Hash, Eq>(exprs: &[T],
- hash: Hash,
- eq: Eq) -> Option<(&T, &T)>
-where Hash: Fn(&T) -> u64,
- Eq: Fn(&T, &T) -> bool {
+fn search_same<T, Hash, Eq>(exprs: &[T], hash: Hash, eq: Eq) -> Option<(&T, &T)>
+ where Hash: Fn(&T) -> u64,
+ Eq: Fn(&T, &T) -> bool
+{
// common cases
if exprs.len() < 2 {
return None;
- }
- else if exprs.len() == 2 {
+ } else if exprs.len() == 2 {
return if eq(&exprs[0], &exprs[1]) {
Some((&exprs[0], &exprs[1]))
- }
- else {
+ } else {
None
- }
+ };
}
- let mut map : HashMap<_, Vec<&_>> = HashMap::with_capacity(exprs.len());
+ let mut map: HashMap<_, Vec<&_>> = HashMap::with_capacity(exprs.len());
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))
+ return Some((&o, expr));
}
}
}
- Entry::Vacant(v) => { v.insert(vec![expr]); }
+ Entry::Vacant(v) => {
+ v.insert(vec![expr]);
+ }
}
}
projects / rust.git / blobdiff