Auto merge of rust-lang#9714 - Alexendoo:bool-to-int-if-let, r=xFrednet

Fix `bool_to_int_with_if` false positive with `if let`

Fixes rust-lang#9706

changelog: FP: [`bool_to_int_with_if`]: Now ignores `if let` statements

Author: bors

clippy_lints/src/bool_to_int_with_if.rs

@@ -1,3 +1,4 @@
+use clippy_utils::higher::If;
 use rustc_ast::LitKind;
 use rustc_hir::{Block, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
@@ -52,9 +53,9 @@ impl<'tcx> LateLintPass<'tcx> for BoolToIntWithIf {
 }
 
 fn check_if_else<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx rustc_hir::Expr<'tcx>) {
-    if let ExprKind::If(check, then, Some(else_)) = expr.kind
+    if let Some(If { cond, then, r#else: Some(r#else) }) = If::hir(expr)
         && let Some(then_lit) = int_literal(then)
-        && let Some(else_lit) = int_literal(else_)
+        && let Some(else_lit) = int_literal(r#else)
     {
         let inverted = if is_integer_literal(then_lit, 1) && is_integer_literal(else_lit, 0) {
             false
@@ -66,7 +67,7 @@ fn check_if_else<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx rustc_hir::Expr<'tcx>
         };
         let mut applicability = Applicability::MachineApplicable;
         let snippet = {
-            let mut sugg = Sugg::hir_with_applicability(cx, check, "..", &mut applicability);
+            let mut sugg = Sugg::hir_with_applicability(cx, cond, "..", &mut applicability);
             if inverted {
                 sugg = !sugg;
             }

tests/ui/bool_to_int_with_if.fixed

@@ -1,5 +1,6 @@
 // run-rustfix
 
+#![feature(let_chains)]
 #![warn(clippy::bool_to_int_with_if)]
 #![allow(unused, dead_code, clippy::unnecessary_operation, clippy::no_effect)]
 
@@ -91,3 +92,22 @@ fn side_effect() {}
 fn cond(a: bool, b: bool) -> bool {
     a || b
 }
+
+enum Enum {
+    A,
+    B,
+}
+
+fn if_let(a: Enum, b: Enum) {
+    if let Enum::A = a {
+        1
+    } else {
+        0
+    };
+
+    if let Enum::A = a && let Enum::B = b {
+        1
+    } else {
+        0
+    };
+}

tests/ui/bool_to_int_with_if.rs

@@ -1,5 +1,6 @@
 // run-rustfix
 
+#![feature(let_chains)]
 #![warn(clippy::bool_to_int_with_if)]
 #![allow(unused, dead_code, clippy::unnecessary_operation, clippy::no_effect)]
 
@@ -123,3 +124,22 @@ fn side_effect() {}
 fn cond(a: bool, b: bool) -> bool {
     a || b
 }
+
+enum Enum {
+    A,
+    B,
+}
+
+fn if_let(a: Enum, b: Enum) {
+    if let Enum::A = a {
+        1
+    } else {
+        0
+    };
+
+    if let Enum::A = a && let Enum::B = b {
+        1
+    } else {
+        0
+    };
+}

tests/ui/bool_to_int_with_if.stderr

@@ -1,5 +1,5 @@
 error: boolean to int conversion using if
-  --> $DIR/bool_to_int_with_if.rs:15:5
+  --> $DIR/bool_to_int_with_if.rs:16:5
    |
 LL | /     if a {
 LL | |         1
@@ -12,7 +12,7 @@ LL | |     };
    = note: `-D clippy::bool-to-int-with-if` implied by `-D warnings`
 
 error: boolean to int conversion using if
-  --> $DIR/bool_to_int_with_if.rs:20:5
+  --> $DIR/bool_to_int_with_if.rs:21:5
    |
 LL | /     if a {
 LL | |         0
@@ -24,7 +24,7 @@ LL | |     };
    = note: `!a as i32` or `(!a).into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> $DIR/bool_to_int_with_if.rs:25:5
+  --> $DIR/bool_to_int_with_if.rs:26:5
    |
 LL | /     if !a {
 LL | |         1
@@ -36,7 +36,7 @@ LL | |     };
    = note: `!a as i32` or `(!a).into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> $DIR/bool_to_int_with_if.rs:30:5
+  --> $DIR/bool_to_int_with_if.rs:31:5
    |
 LL | /     if a || b {
 LL | |         1
@@ -48,7 +48,7 @@ LL | |     };
    = note: `(a || b) as i32` or `(a || b).into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> $DIR/bool_to_int_with_if.rs:35:5
+  --> $DIR/bool_to_int_with_if.rs:36:5
    |
 LL | /     if cond(a, b) {
 LL | |         1
@@ -60,7 +60,7 @@ LL | |     };
    = note: `cond(a, b) as i32` or `cond(a, b).into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> $DIR/bool_to_int_with_if.rs:40:5
+  --> $DIR/bool_to_int_with_if.rs:41:5
    |
 LL | /     if x + y < 4 {
 LL | |         1
@@ -72,7 +72,7 @@ LL | |     };
    = note: `(x + y < 4) as i32` or `(x + y < 4).into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> $DIR/bool_to_int_with_if.rs:49:12
+  --> $DIR/bool_to_int_with_if.rs:50:12
    |
 LL |       } else if b {
    |  ____________^
@@ -85,7 +85,7 @@ LL | |     };
    = note: `b as i32` or `b.into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> $DIR/bool_to_int_with_if.rs:58:12
+  --> $DIR/bool_to_int_with_if.rs:59:12
    |
 LL |       } else if b {
    |  ____________^
@@ -98,7 +98,7 @@ LL | |     };
    = note: `!b as i32` or `(!b).into()` can also be valid options
 
 error: boolean to int conversion using if
-  --> $DIR/bool_to_int_with_if.rs:118:5
+  --> $DIR/bool_to_int_with_if.rs:119:5
    |
 LL |     if a { 1 } else { 0 }
    |     ^^^^^^^^^^^^^^^^^^^^^ help: replace with from: `u8::from(a)`