Merge remote-tracking branch 'upstream/master' into rustup

[rust.git] / clippy_lints / src / matches / needless_match.rs

diff --git a/clippy_lints/src/matches/needless_match.rs b/clippy_lints/src/matches/needless_match.rs
index fa19cddd35ec7afff4258f68eb901967e01b411b..9cbffbe61f15243ec917430e446f7bba10325a5c 100644 (file)
--- a/clippy_lints/src/matches/needless_match.rs
+++ b/clippy_lints/src/matches/needless_match.rs
@@ -8,10 +8,10 @@
 };
 use rustc_errors::Applicability;
 use rustc_hir::LangItem::OptionNone;
-use rustc_hir::{Arm, BindingAnnotation, Expr, ExprKind, FnRetTy, Node, Pat, PatKind, Path, QPath};
+use rustc_hir::{Arm, BindingAnnotation, ByRef, Expr, ExprKind, FnRetTy, Guard, Node, Pat, PatKind, Path, QPath};
+use rustc_hir_analysis::hir_ty_to_ty;
 use rustc_lint::LateContext;
 use rustc_span::sym;
-use rustc_typeck::hir_ty_to_ty;
 
 pub(crate) fn check_match(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>], expr: &Expr<'_>) {
     if arms.len() > 1 && expr_ty_matches_p_ty(cx, ex, expr) && check_all_arms(cx, ex, arms) {
@@ -65,8 +65,26 @@ pub(crate) fn check_if_let<'tcx>(cx: &LateContext<'tcx>, ex: &Expr<'_>, if_let:
 fn check_all_arms(cx: &LateContext<'_>, match_expr: &Expr<'_>, arms: &[Arm<'_>]) -> bool {
     for arm in arms {
         let arm_expr = peel_blocks_with_stmt(arm.body);
+
+        if let Some(guard_expr) = &arm.guard {
+            match guard_expr {
+                // gives up if `pat if expr` can have side effects
+                Guard::If(if_cond) => {
+                    if if_cond.can_have_side_effects() {
+                        return false;
+                    }
+                },
+                // gives up `pat if let ...` arm
+                Guard::IfLet(_) => {
+                    return false;
+                },
+            };
+        }
+
         if let PatKind::Wild = arm.pat.kind {
-            return eq_expr_value(cx, match_expr, strip_return(arm_expr));
+            if !eq_expr_value(cx, match_expr, strip_return(arm_expr)) {
+                return false;
+            }
         } else if !pat_same_as_expr(arm.pat, arm_expr) {
             return false;
         }
@@ -171,8 +189,7 @@ fn pat_same_as_expr(pat: &Pat<'_>, expr: &Expr<'_>) -> bool {
                 },
             )),
         ) => {
-            return !matches!(annot, BindingAnnotation::Ref | BindingAnnotation::RefMut)
-                && pat_ident.name == first_seg.ident.name;
+            return !matches!(annot, BindingAnnotation(ByRef::Yes, _)) && pat_ident.name == first_seg.ident.name;
         },
         // Example: `Custom::TypeA => Custom::TypeB`, or `None => None`
         (PatKind::Path(QPath::Resolved(_, p_path)), ExprKind::Path(QPath::Resolved(_, e_path))) => {