-use crate::utils::{get_parent_expr, higher, in_macro_or_desugar, snippet, span_lint_and_then, span_note_and_lint};
+use crate::utils::{
+ get_parent_expr, higher, in_macro_or_desugar, 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};
}
/// 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();