From e90a0be923906ded7c79d6168a11b8b68d85fd72 Mon Sep 17 00:00:00 2001
From: Oliver Schneider <git-spam-no-reply9815368754983@oli-obk.de>
Date: Tue, 17 May 2016 16:34:15 +0200
Subject: [PATCH] simplify `mut_mut` lint
---
src/mut_mut.rs | 64 ++++++++++++++++++--------------------------------
1 file changed, 23 insertions(+), 41 deletions(-)
diff --git a/src/mut_mut.rs b/src/mut_mut.rs
index 7b7b5ecdf4e7..4147e288c4f6 100644
--- a/src/mut_mut.rs
+++ b/src/mut_mut.rs
@@ -28,50 +28,32 @@ impl LintPass for MutMut {
impl LateLintPass for MutMut {
fn check_expr(&mut self, cx: &LateContext, expr: &Expr) {
- check_expr_mut(cx, expr)
- }
-
- fn check_ty(&mut self, cx: &LateContext, ty: &Ty) {
- unwrap_mut(ty).and_then(unwrap_mut).map_or((), |_| {
- span_lint(cx, MUT_MUT, ty.span, "generally you want to avoid `&mut &mut _` if possible");
- });
- }
-}
-
-fn check_expr_mut(cx: &LateContext, expr: &Expr) {
- fn unwrap_addr(expr: &Expr) -> Option<&Expr> {
- match expr.node {
- ExprAddrOf(MutMutable, ref e) => Some(e),
- _ => None,
+ if in_external_macro(cx, expr.span) {
+ return;
}
- }
- if in_external_macro(cx, expr.span) {
- return;
+ if let ExprAddrOf(MutMutable, ref e) = expr.node {
+ if let ExprAddrOf(MutMutable, _) = e.node {
+ span_lint(cx,
+ MUT_MUT,
+ expr.span,
+ "generally you want to avoid `&mut &mut _` if possible");
+ } else {
+ if let TyRef(_, TypeAndMut { mutbl: MutMutable, .. }) = cx.tcx.expr_ty(e).sty {
+ span_lint(cx,
+ MUT_MUT,
+ expr.span,
+ "this expression mutably borrows a mutable reference. Consider reborrowing");
+ }
+ }
+ }
}
- unwrap_addr(expr).map_or((), |e| {
- unwrap_addr(e).map_or_else(|| {
- if let TyRef(_, TypeAndMut { mutbl: MutMutable, .. }) = cx.tcx.expr_ty(e).sty {
- span_lint(cx,
- MUT_MUT,
- expr.span,
- "this expression mutably borrows a mutable reference. Consider \
- reborrowing");
- }
- },
- |_| {
- span_lint(cx,
- MUT_MUT,
- expr.span,
- "generally you want to avoid `&mut &mut _` if possible");
- })
- })
-}
-
-fn unwrap_mut(ty: &Ty) -> Option<&Ty> {
- match ty.node {
- TyRptr(_, MutTy { ty: ref pty, mutbl: MutMutable }) => Some(pty),
- _ => None,
+ fn check_ty(&mut self, cx: &LateContext, ty: &Ty) {
+ if let TyRptr(_, MutTy { ty: ref pty, mutbl: MutMutable }) = ty.node {
+ if let TyRptr(_, MutTy { mutbl: MutMutable, .. }) = pty.node {
+ span_lint(cx, MUT_MUT, ty.span, "generally you want to avoid `&mut &mut _` if possible");
+ }
+ }
}
}