Check for enabled int_roundings feature in manual_div_ceil

Author: belyakov-am

clippy_lints/src/manual_div_ceil.rs

@@ -10,6 +10,7 @@ use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{self};
 use rustc_session::impl_lint_pass;
+use rustc_span::symbol::Symbol;
 
 declare_clippy_lint! {
     /// ### What it does
@@ -60,8 +61,8 @@ impl<'tcx> LateLintPass<'tcx> for ManualDivCeil {
         let mut applicability = Applicability::MachineApplicable;
 
         if let ExprKind::Binary(div_op, div_lhs, div_rhs) = expr.kind
-            && check_int_ty(cx, div_lhs)
-            && check_int_ty(cx, div_rhs)
+            && check_int_ty_and_feature(cx, div_lhs)
+            && check_int_ty_and_feature(cx, div_rhs)
             && div_op.node == BinOpKind::Div
         {
             // (x + (y - 1)) / y
@@ -104,9 +105,18 @@ impl<'tcx> LateLintPass<'tcx> for ManualDivCeil {
     extract_msrv_attr!(LateContext);
 }
 
-fn check_int_ty(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+fn check_int_ty_and_feature(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
     let expr_ty = cx.typeck_results().expr_ty(expr);
-    matches!(expr_ty.peel_refs().kind(), ty::Int(_) | ty::Uint(_))
+    match expr_ty.peel_refs().kind() {
+        ty::Uint(_) => true,
+        ty::Int(_) => cx
+            .tcx
+            .features()
+            .declared_features
+            .contains(&Symbol::intern("int_roundings")),
+
+        _ => false,
+    }
 }
 
 fn check_literal(expr: &Expr<'_>) -> bool {

tests/ui/manual_div_ceil.fixed

@@ -1,25 +1,30 @@
 #![warn(clippy::manual_div_ceil)]
-#![feature(int_roundings)]
 
 fn main() {
-    let x = 7_i32;
-    let y = 4_i32;
-    let z_u: u32 = 11;
+    let x = 7_u32;
+    let y = 4_u32;
+    let z = 11_u32;
 
     // Lint.
     let _ = x.div_ceil(y);
     let _ = x.div_ceil(y);
     let _ = x.div_ceil(y);
 
-    let _ = 7_i32.div_ceil(4);
-
-    let _ = (z_u as i32).div_ceil(y);
-    let _ = (7_u32 as i32).div_ceil(y);
+    let _ = 7_u32.div_ceil(4);
+    let _ = (7_i32 as u32).div_ceil(4);
 
     // No lint.
     let _ = (x + (y - 2)) / y;
     let _ = (x + (y + 1)) / y;
 
-    let z = 3_i32;
     let _ = (x + (y - 1)) / z;
+
+    let x_i = 7_i32;
+    let y_i = 4_i32;
+    let z_i = 11_i32;
+
+    // No lint because `int_roundings` feature is not enabled.
+    let _ = (z as i32 + (y_i - 1)) / y_i;
+    let _ = (7_u32 as i32 + (y_i - 1)) / y_i;
+    let _ = (7_u32 as i32 + (4 - 1)) / 4;
 }

tests/ui/manual_div_ceil.rs

@@ -1,25 +1,30 @@
 #![warn(clippy::manual_div_ceil)]
-#![feature(int_roundings)]
 
 fn main() {
-    let x = 7_i32;
-    let y = 4_i32;
-    let z_u: u32 = 11;
+    let x = 7_u32;
+    let y = 4_u32;
+    let z = 11_u32;
 
     // Lint.
     let _ = (x + (y - 1)) / y;
     let _ = ((y - 1) + x) / y;
     let _ = (x + y - 1) / y;
 
-    let _ = (7_i32 + (4 - 1)) / 4;
-
-    let _ = (z_u as i32 + (y - 1)) / y;
-    let _ = (7_u32 as i32 + (y - 1)) / y;
+    let _ = (7_u32 + (4 - 1)) / 4;
+    let _ = (7_i32 as u32 + (4 - 1)) / 4;
 
     // No lint.
     let _ = (x + (y - 2)) / y;
     let _ = (x + (y + 1)) / y;
 
-    let z = 3_i32;
     let _ = (x + (y - 1)) / z;
+
+    let x_i = 7_i32;
+    let y_i = 4_i32;
+    let z_i = 11_i32;
+
+    // No lint because `int_roundings` feature is not enabled.
+    let _ = (z as i32 + (y_i - 1)) / y_i;
+    let _ = (7_u32 as i32 + (y_i - 1)) / y_i;
+    let _ = (7_u32 as i32 + (4 - 1)) / 4;
 }

tests/ui/manual_div_ceil.stderr

@@ -1,5 +1,5 @@
 error: manually reimplementing `div_ceil`
-  --> tests/ui/manual_div_ceil.rs:10:13
+  --> tests/ui/manual_div_ceil.rs:9:13
    |
 LL |     let _ = (x + (y - 1)) / y;
    |             ^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `x.div_ceil(y)`
@@ -8,34 +8,28 @@ LL |     let _ = (x + (y - 1)) / y;
    = help: to override `-D warnings` add `#[allow(clippy::manual_div_ceil)]`
 
 error: manually reimplementing `div_ceil`
-  --> tests/ui/manual_div_ceil.rs:11:13
+  --> tests/ui/manual_div_ceil.rs:10:13
    |
 LL |     let _ = ((y - 1) + x) / y;
    |             ^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `x.div_ceil(y)`
 
 error: manually reimplementing `div_ceil`
-  --> tests/ui/manual_div_ceil.rs:12:13
+  --> tests/ui/manual_div_ceil.rs:11:13
    |
 LL |     let _ = (x + y - 1) / y;
    |             ^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `x.div_ceil(y)`
 
 error: manually reimplementing `div_ceil`
-  --> tests/ui/manual_div_ceil.rs:14:13
+  --> tests/ui/manual_div_ceil.rs:13:13
    |
-LL |     let _ = (7_i32 + (4 - 1)) / 4;
-   |             ^^^^^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `7_i32.div_ceil(4)`
+LL |     let _ = (7_u32 + (4 - 1)) / 4;
+   |             ^^^^^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `7_u32.div_ceil(4)`
 
 error: manually reimplementing `div_ceil`
-  --> tests/ui/manual_div_ceil.rs:16:13
-   |
-LL |     let _ = (z_u as i32 + (y - 1)) / y;
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `(z_u as i32).div_ceil(y)`
-
-error: manually reimplementing `div_ceil`
-  --> tests/ui/manual_div_ceil.rs:17:13
+  --> tests/ui/manual_div_ceil.rs:14:13
    |
-LL |     let _ = (7_u32 as i32 + (y - 1)) / y;
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `(7_u32 as i32).div_ceil(y)`
+LL |     let _ = (7_i32 as u32 + (4 - 1)) / 4;
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `(7_i32 as u32).div_ceil(4)`
 
-error: aborting due to 6 previous errors
+error: aborting due to 5 previous errors
 

tests/ui/manual_div_ceil_with_feature.fixed

@@ -0,0 +1,25 @@
+#![warn(clippy::manual_div_ceil)]
+#![feature(int_roundings)]
+
+fn main() {
+    let x = 7_i32;
+    let y = 4_i32;
+    let z = 3_i32;
+    let z_u: u32 = 11;
+
+    // Lint.
+    let _ = x.div_ceil(y);
+    let _ = x.div_ceil(y);
+    let _ = x.div_ceil(y);
+
+    let _ = 7_i32.div_ceil(4);
+    let _ = (7_i32 as u32).div_ceil(4);
+    let _ = (7_u32 as i32).div_ceil(4);
+    let _ = z_u.div_ceil(4);
+
+    // No lint.
+    let _ = (x + (y - 2)) / y;
+    let _ = (x + (y + 1)) / y;
+
+    let _ = (x + (y - 1)) / z;
+}

tests/ui/manual_div_ceil_with_feature.rs

@@ -0,0 +1,25 @@
+#![warn(clippy::manual_div_ceil)]
+#![feature(int_roundings)]
+
+fn main() {
+    let x = 7_i32;
+    let y = 4_i32;
+    let z = 3_i32;
+    let z_u: u32 = 11;
+
+    // Lint.
+    let _ = (x + (y - 1)) / y;
+    let _ = ((y - 1) + x) / y;
+    let _ = (x + y - 1) / y;
+
+    let _ = (7_i32 + (4 - 1)) / 4;
+    let _ = (7_i32 as u32 + (4 - 1)) / 4;
+    let _ = (7_u32 as i32 + (4 - 1)) / 4;
+    let _ = (z_u + (4 - 1)) / 4;
+
+    // No lint.
+    let _ = (x + (y - 2)) / y;
+    let _ = (x + (y + 1)) / y;
+
+    let _ = (x + (y - 1)) / z;
+}

tests/ui/manual_div_ceil_with_feature.stderr

@@ -0,0 +1,47 @@
+error: manually reimplementing `div_ceil`
+  --> tests/ui/manual_div_ceil_with_feature.rs:11:13
+   |
+LL |     let _ = (x + (y - 1)) / y;
+   |             ^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `x.div_ceil(y)`
+   |
+   = note: `-D clippy::manual-div-ceil` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::manual_div_ceil)]`
+
+error: manually reimplementing `div_ceil`
+  --> tests/ui/manual_div_ceil_with_feature.rs:12:13
+   |
+LL |     let _ = ((y - 1) + x) / y;
+   |             ^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `x.div_ceil(y)`
+
+error: manually reimplementing `div_ceil`
+  --> tests/ui/manual_div_ceil_with_feature.rs:13:13
+   |
+LL |     let _ = (x + y - 1) / y;
+   |             ^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `x.div_ceil(y)`
+
+error: manually reimplementing `div_ceil`
+  --> tests/ui/manual_div_ceil_with_feature.rs:15:13
+   |
+LL |     let _ = (7_i32 + (4 - 1)) / 4;
+   |             ^^^^^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `7_i32.div_ceil(4)`
+
+error: manually reimplementing `div_ceil`
+  --> tests/ui/manual_div_ceil_with_feature.rs:16:13
+   |
+LL |     let _ = (7_i32 as u32 + (4 - 1)) / 4;
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `(7_i32 as u32).div_ceil(4)`
+
+error: manually reimplementing `div_ceil`
+  --> tests/ui/manual_div_ceil_with_feature.rs:17:13
+   |
+LL |     let _ = (7_u32 as i32 + (4 - 1)) / 4;
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `(7_u32 as i32).div_ceil(4)`
+
+error: manually reimplementing `div_ceil`
+  --> tests/ui/manual_div_ceil_with_feature.rs:18:13
+   |
+LL |     let _ = (z_u + (4 - 1)) / 4;
+   |             ^^^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `z_u.div_ceil(4)`
+
+error: aborting due to 7 previous errors
+