Added check for next_multiple_of in manual_div_ceil

mnemonikr · mnemonikr · commit fb09156d835f · 2025-12-13T09:53:27.000-08:00
diff --git a/clippy_lints/src/operators/manual_div_ceil.rs b/clippy_lints/src/operators/manual_div_ceil.rs
@@ -1,13 +1,14 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::msrvs::{self, Msrv};
+use clippy_utils::res::{MaybeDef, MaybeQPath};
 use clippy_utils::sugg::{Sugg, has_enclosing_paren};
 use clippy_utils::{SpanlessEq, sym};
 use rustc_ast::{BinOpKind, LitIntType, LitKind, UnOp};
 use rustc_data_structures::packed::Pu128;
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::LateContext;
-use rustc_middle::ty::{self};
+use rustc_middle::ty::{self, Ty};
 use rustc_span::source_map::Spanned;
 
 use super::MANUAL_DIV_CEIL;
@@ -16,59 +17,84 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, op: BinOpKind, lhs: &
     let mut applicability = Applicability::MachineApplicable;
 
     if op == BinOpKind::Div
-        && check_int_ty_and_feature(cx, lhs)
-        && check_int_ty_and_feature(cx, rhs)
-        && let ExprKind::Binary(inner_op, inner_lhs, inner_rhs) = lhs.kind
+        && check_int_ty_and_feature(cx, cx.typeck_results().expr_ty(lhs))
+        && check_int_ty_and_feature(cx, cx.typeck_results().expr_ty(rhs))
         && msrv.meets(cx, msrvs::DIV_CEIL)
     {
-        // (x + (y - 1)) / y
-        if let ExprKind::Binary(sub_op, sub_lhs, sub_rhs) = inner_rhs.kind
-            && inner_op.node == BinOpKind::Add
-            && sub_op.node == BinOpKind::Sub
-            && check_literal(sub_rhs)
-            && check_eq_expr(cx, sub_lhs, rhs)
-        {
-            build_suggestion(cx, expr, inner_lhs, rhs, &mut applicability);
-            return;
-        }
+        match lhs.kind {
+            ExprKind::Binary(inner_op, inner_lhs, inner_rhs) => {
+                // (x + (y - 1)) / y
+                if let ExprKind::Binary(sub_op, sub_lhs, sub_rhs) = inner_rhs.kind
+                    && inner_op.node == BinOpKind::Add
+                    && sub_op.node == BinOpKind::Sub
+                    && check_literal(sub_rhs)
+                    && check_eq_expr(cx, sub_lhs, rhs)
+                {
+                    build_suggestion(cx, expr, inner_lhs, rhs, &mut applicability);
+                    return;
+                }
 
-        // ((y - 1) + x) / y
-        if let ExprKind::Binary(sub_op, sub_lhs, sub_rhs) = inner_lhs.kind
-            && inner_op.node == BinOpKind::Add
-            && sub_op.node == BinOpKind::Sub
-            && check_literal(sub_rhs)
-            && check_eq_expr(cx, sub_lhs, rhs)
-        {
-            build_suggestion(cx, expr, inner_rhs, rhs, &mut applicability);
-            return;
-        }
+                // ((y - 1) + x) / y
+                if let ExprKind::Binary(sub_op, sub_lhs, sub_rhs) = inner_lhs.kind
+                    && inner_op.node == BinOpKind::Add
+                    && sub_op.node == BinOpKind::Sub
+                    && check_literal(sub_rhs)
+                    && check_eq_expr(cx, sub_lhs, rhs)
+                {
+                    build_suggestion(cx, expr, inner_rhs, rhs, &mut applicability);
+                    return;
+                }
 
-        // (x + y - 1) / y
-        if let ExprKind::Binary(add_op, add_lhs, add_rhs) = inner_lhs.kind
-            && inner_op.node == BinOpKind::Sub
-            && add_op.node == BinOpKind::Add
-            && check_literal(inner_rhs)
-            && check_eq_expr(cx, add_rhs, rhs)
-        {
-            build_suggestion(cx, expr, add_lhs, rhs, &mut applicability);
-        }
+                // (x + y - 1) / y
+                if let ExprKind::Binary(add_op, add_lhs, add_rhs) = inner_lhs.kind
+                    && inner_op.node == BinOpKind::Sub
+                    && add_op.node == BinOpKind::Add
+                    && check_literal(inner_rhs)
+                    && check_eq_expr(cx, add_rhs, rhs)
+                {
+                    build_suggestion(cx, expr, add_lhs, rhs, &mut applicability);
+                }
 
-        // (x + (Y - 1)) / Y
-        if inner_op.node == BinOpKind::Add && differ_by_one(inner_rhs, rhs) {
-            build_suggestion(cx, expr, inner_lhs, rhs, &mut applicability);
-        }
+                // (x + (Y - 1)) / Y
+                if inner_op.node == BinOpKind::Add && differ_by_one(inner_rhs, rhs) {
+                    build_suggestion(cx, expr, inner_lhs, rhs, &mut applicability);
+                }
 
-        // ((Y - 1) + x) / Y
-        if inner_op.node == BinOpKind::Add && differ_by_one(inner_lhs, rhs) {
-            build_suggestion(cx, expr, inner_rhs, rhs, &mut applicability);
-        }
+                // ((Y - 1) + x) / Y
+                if inner_op.node == BinOpKind::Add && differ_by_one(inner_lhs, rhs) {
+                    build_suggestion(cx, expr, inner_rhs, rhs, &mut applicability);
+                }
 
-        // (x - (-Y - 1)) / Y
-        if inner_op.node == BinOpKind::Sub
-            && let ExprKind::Unary(UnOp::Neg, abs_div_rhs) = rhs.kind
-            && differ_by_one(abs_div_rhs, inner_rhs)
-        {
-            build_suggestion(cx, expr, inner_lhs, rhs, &mut applicability);
+                // (x - (-Y - 1)) / Y
+                if inner_op.node == BinOpKind::Sub
+                    && let ExprKind::Unary(UnOp::Neg, abs_div_rhs) = rhs.kind
+                    && differ_by_one(abs_div_rhs, inner_rhs)
+                {
+                    build_suggestion(cx, expr, inner_lhs, rhs, &mut applicability);
+                }
+            },
+            ExprKind::MethodCall(method, receiver, [next_multiple_of_arg], _) => {
+                // x.next_multiple_of(Y) / Y
+                if method.ident.name == sym::next_multiple_of
+                    && check_int_ty_and_feature(cx, cx.typeck_results().expr_ty(receiver))
+                    && check_eq_expr(cx, next_multiple_of_arg, rhs)
+                {
+                    build_suggestion(cx, expr, receiver, rhs, &mut applicability);
+                }
+            },
+            ExprKind::Call(callee, [receiver, next_multiple_of_arg]) => {
+                // int_type::next_multiple_of(x, Y)
+                if let Some(impl_ty_binder) = callee
+                    .ty_rel_def_if_named(cx, sym::next_multiple_of)
+                    .assoc_fn_parent(cx)
+                    .opt_impl_ty(cx)
+                    && check_int_ty_and_feature(cx, impl_ty_binder.skip_binder())
+                    && check_eq_expr(cx, next_multiple_of_arg, rhs)
+                {
+                    build_suggestion(cx, expr, receiver, rhs, &mut applicability);
+                }
+            },
+            _ => (),
         }
     }
 }
@@ -91,8 +117,7 @@ fn differ_by_one(small_expr: &Expr<'_>, large_expr: &Expr<'_>) -> bool {
     }
 }
 
-fn check_int_ty_and_feature(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
-    let expr_ty = cx.typeck_results().expr_ty(expr);
+fn check_int_ty_and_feature(cx: &LateContext<'_>, expr_ty: Ty<'_>) -> bool {
     match expr_ty.peel_refs().kind() {
         ty::Uint(_) => true,
         ty::Int(_) => cx.tcx.features().enabled(sym::int_roundings),
diff --git a/clippy_utils/src/sym.rs b/clippy_utils/src/sym.rs
@@ -244,6 +244,7 @@ generate! {
     next_back,
     next_if,
     next_if_eq,
+    next_multiple_of,
     next_tuple,
     nth,
     ok,
diff --git a/tests/ui/manual_div_ceil.fixed b/tests/ui/manual_div_ceil.fixed
@@ -105,3 +105,32 @@ fn issue_15705(size: u64, c: &u64) {
     let _ = size.div_ceil(*c);
     //~^ manual_div_ceil
 }
+
+struct MyStruct(u32);
+impl MyStruct {
+    // Method matching name on different type should not trigger lint
+    fn next_multiple_of(self, y: u32) -> u32 {
+        self.0.next_multiple_of(y)
+    }
+}
+
+fn issue_16219() {
+    let x = 33u32;
+
+    // Lint.
+    let _ = x.div_ceil(8);
+    //~^ manual_div_ceil
+    let _ = x.div_ceil(8);
+    //~^ manual_div_ceil
+
+    let y = &x;
+    let _ = y.div_ceil(8);
+    //~^ manual_div_ceil
+
+    // No lint.
+    let _ = x.next_multiple_of(8) / 7;
+    let _ = x.next_multiple_of(7) / 8;
+
+    let z = MyStruct(x);
+    let _ = z.next_multiple_of(8) / 8;
+}
diff --git a/tests/ui/manual_div_ceil.rs b/tests/ui/manual_div_ceil.rs
@@ -105,3 +105,32 @@ fn issue_15705(size: u64, c: &u64) {
     let _ = (size + c - 1) / c;
     //~^ manual_div_ceil
 }
+
+struct MyStruct(u32);
+impl MyStruct {
+    // Method matching name on different type should not trigger lint
+    fn next_multiple_of(self, y: u32) -> u32 {
+        self.0.next_multiple_of(y)
+    }
+}
+
+fn issue_16219() {
+    let x = 33u32;
+
+    // Lint.
+    let _ = x.next_multiple_of(8) / 8;
+    //~^ manual_div_ceil
+    let _ = u32::next_multiple_of(x, 8) / 8;
+    //~^ manual_div_ceil
+
+    let y = &x;
+    let _ = y.next_multiple_of(8) / 8;
+    //~^ manual_div_ceil
+
+    // No lint.
+    let _ = x.next_multiple_of(8) / 7;
+    let _ = x.next_multiple_of(7) / 8;
+
+    let z = MyStruct(x);
+    let _ = z.next_multiple_of(8) / 8;
+}
diff --git a/tests/ui/manual_div_ceil.stderr b/tests/ui/manual_div_ceil.stderr
@@ -131,5 +131,23 @@ error: manually reimplementing `div_ceil`
 LL |     let _ = (size + c - 1) / c;
    |             ^^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `size.div_ceil(*c)`
 
-error: aborting due to 20 previous errors
+error: manually reimplementing `div_ceil`
+  --> tests/ui/manual_div_ceil.rs:121:13
+   |
+LL |     let _ = x.next_multiple_of(8) / 8;
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `x.div_ceil(8)`
+
+error: manually reimplementing `div_ceil`
+  --> tests/ui/manual_div_ceil.rs:123:13
+   |
+LL |     let _ = u32::next_multiple_of(x, 8) / 8;
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `x.div_ceil(8)`
+
+error: manually reimplementing `div_ceil`
+  --> tests/ui/manual_div_ceil.rs:127:13
+   |
+LL |     let _ = y.next_multiple_of(8) / 8;
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `y.div_ceil(8)`
+
+error: aborting due to 23 previous errors
 
diff --git a/tests/ui/manual_div_ceil_with_feature.fixed b/tests/ui/manual_div_ceil_with_feature.fixed
@@ -84,3 +84,32 @@ fn issue_13950() {
     let _ = y.div_ceil(-7);
     //~^ manual_div_ceil
 }
+
+struct MyStruct(i32);
+impl MyStruct {
+    // Method matching name on different type should not trigger lint
+    fn next_multiple_of(self, y: i32) -> i32 {
+        self.0.next_multiple_of(y)
+    }
+}
+
+fn issue_16219() {
+    let x = 33i32;
+
+    // Lint.
+    let _ = x.div_ceil(8);
+    //~^ manual_div_ceil
+    let _ = x.div_ceil(8);
+    //~^ manual_div_ceil
+
+    let y = &x;
+    let _ = y.div_ceil(8);
+    //~^ manual_div_ceil
+
+    // No lint.
+    let _ = x.next_multiple_of(8) / 7;
+    let _ = x.next_multiple_of(7) / 8;
+
+    let z = MyStruct(x);
+    let _ = z.next_multiple_of(8) / 8;
+}
diff --git a/tests/ui/manual_div_ceil_with_feature.rs b/tests/ui/manual_div_ceil_with_feature.rs
@@ -84,3 +84,32 @@ fn issue_13950() {
     let _ = (y - 8) / -7;
     //~^ manual_div_ceil
 }
+
+struct MyStruct(i32);
+impl MyStruct {
+    // Method matching name on different type should not trigger lint
+    fn next_multiple_of(self, y: i32) -> i32 {
+        self.0.next_multiple_of(y)
+    }
+}
+
+fn issue_16219() {
+    let x = 33i32;
+
+    // Lint.
+    let _ = x.next_multiple_of(8) / 8;
+    //~^ manual_div_ceil
+    let _ = i32::next_multiple_of(x, 8) / 8;
+    //~^ manual_div_ceil
+
+    let y = &x;
+    let _ = y.next_multiple_of(8) / 8;
+    //~^ manual_div_ceil
+
+    // No lint.
+    let _ = x.next_multiple_of(8) / 7;
+    let _ = x.next_multiple_of(7) / 8;
+
+    let z = MyStruct(x);
+    let _ = z.next_multiple_of(8) / 8;
+}
diff --git a/tests/ui/manual_div_ceil_with_feature.stderr b/tests/ui/manual_div_ceil_with_feature.stderr
@@ -139,5 +139,23 @@ error: manually reimplementing `div_ceil`
 LL |     let _ = (y - 8) / -7;
    |             ^^^^^^^^^^^^ help: consider using `.div_ceil()`: `y.div_ceil(-7)`
 
-error: aborting due to 23 previous errors
+error: manually reimplementing `div_ceil`
+  --> tests/ui/manual_div_ceil_with_feature.rs:100:13
+   |
+LL |     let _ = x.next_multiple_of(8) / 8;
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `x.div_ceil(8)`
+
+error: manually reimplementing `div_ceil`
+  --> tests/ui/manual_div_ceil_with_feature.rs:102:13
+   |
+LL |     let _ = i32::next_multiple_of(x, 8) / 8;
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `x.div_ceil(8)`
+
+error: manually reimplementing `div_ceil`
+  --> tests/ui/manual_div_ceil_with_feature.rs:106:13
+   |
+LL |     let _ = y.next_multiple_of(8) / 8;
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `.div_ceil()`: `y.div_ceil(8)`
+
+error: aborting due to 26 previous errors
 
