Auto merge of #9130 - c410-f3r:arith, r=llogiq

Add `Arithmetic` lint

Fixes https://github.com/rust-lang/rust-clippy/issues/8903

r? `@llogiq`

changelog: Add `Arithmetic` lint

5 files changed, 80 insertions, 0 deletions

diff --git a/tests/ui-toml/arithmetic_allowed/arithmetic_allowed.rs b/tests/ui-toml/arithmetic_allowed/arithmetic_allowed.rs
new file mode 100644
index 00000000000..195fabdbf71
--- /dev/null
+++ b/tests/ui-toml/arithmetic_allowed/arithmetic_allowed.rs
@@ -0,0 +1,24 @@
+#![warn(clippy::arithmetic)]
+
+use core::ops::Add;
+
+#[derive(Clone, Copy)]
+struct Point {
+    x: i32,
+    y: i32,
+}
+
+impl Add for Point {
+    type Output = Self;
+
+    fn add(self, other: Self) -> Self {
+        todo!()
+    }
+}
+
+fn main() {
+    let _ = Point { x: 1, y: 0 } + Point { x: 2, y: 3 };
+
+    let point: Point = Point { x: 1, y: 0 };
+    let _ = point + point;
+}
diff --git a/tests/ui-toml/arithmetic_allowed/clippy.toml b/tests/ui-toml/arithmetic_allowed/clippy.toml
new file mode 100644
index 00000000000..cc40570b12a
--- /dev/null
+++ b/tests/ui-toml/arithmetic_allowed/clippy.toml
@@ -0,0 +1 @@
+arithmetic-allowed = ["Point"]
diff --git a/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr b/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr
index 1d87fd91a25..fe5139c4768 100644
--- a/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr
+++ b/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr
@@ -3,6 +3,7 @@ error: error reading Clippy's configuration file `$DIR/clippy.toml`: unknown fie
            allow-expect-in-tests
            allow-unwrap-in-tests
            allowed-scripts
+           arithmetic-allowed
            array-size-threshold
            avoid-breaking-exported-api
            await-holding-invalid-types
diff --git a/tests/ui/arithmetic.fixed b/tests/ui/arithmetic.fixed
new file mode 100644
index 00000000000..a2a1c4394c2
--- /dev/null
+++ b/tests/ui/arithmetic.fixed
@@ -0,0 +1,27 @@
+// run-rustfix
+
+#![allow(clippy::unnecessary_owned_empty_strings)]
+#![feature(saturating_int_impl)]
+#![warn(clippy::arithmetic)]
+
+use core::num::{Saturating, Wrapping};
+
+pub fn hard_coded_allowed() {
+    let _ = Saturating(0u32) + Saturating(0u32);
+    let _ = String::new() + "";
+    let _ = Wrapping(0u32) + Wrapping(0u32);
+
+    let saturating: Saturating<u32> = Saturating(0u32);
+    let string: String = String::new();
+    let wrapping: Wrapping<u32> = Wrapping(0u32);
+
+    let inferred_saturating = saturating + saturating;
+    let inferred_string = string + "";
+    let inferred_wrapping = wrapping + wrapping;
+
+    let _ = inferred_saturating + inferred_saturating;
+    let _ = inferred_string + "";
+    let _ = inferred_wrapping + inferred_wrapping;
+}
+
+fn main() {}
diff --git a/tests/ui/arithmetic.rs b/tests/ui/arithmetic.rs
new file mode 100644
index 00000000000..a2a1c4394c2
--- /dev/null
+++ b/tests/ui/arithmetic.rs
@@ -0,0 +1,27 @@
+// run-rustfix
+
+#![allow(clippy::unnecessary_owned_empty_strings)]
+#![feature(saturating_int_impl)]
+#![warn(clippy::arithmetic)]
+
+use core::num::{Saturating, Wrapping};
+
+pub fn hard_coded_allowed() {
+    let _ = Saturating(0u32) + Saturating(0u32);
+    let _ = String::new() + "";
+    let _ = Wrapping(0u32) + Wrapping(0u32);
+
+    let saturating: Saturating<u32> = Saturating(0u32);
+    let string: String = String::new();
+    let wrapping: Wrapping<u32> = Wrapping(0u32);
+
+    let inferred_saturating = saturating + saturating;
+    let inferred_string = string + "";
+    let inferred_wrapping = wrapping + wrapping;
+
+    let _ = inferred_saturating + inferred_saturating;
+    let _ = inferred_string + "";
+    let _ = inferred_wrapping + inferred_wrapping;
+}
+
+fn main() {}