Suppress the triggering of some lints in derived structures

Author: c410-f3r

clippy_lints/src/operators/arithmetic_side_effects.rs

@@ -1,4 +1,5 @@
 use super::ARITHMETIC_SIDE_EFFECTS;
+use clippy_utils::is_from_proc_macro;
 use clippy_utils::{
     consts::{constant, constant_simple, Constant},
     diagnostics::span_lint,
@@ -122,6 +123,9 @@ impl ArithmeticSideEffects {
         lhs: &hir::Expr<'tcx>,
         rhs: &hir::Expr<'tcx>,
     ) {
+        if is_from_proc_macro(cx, expr) {
+            return;
+        }
         if constant_simple(cx, cx.typeck_results(), expr).is_some() {
             return;
         }
@@ -191,6 +195,9 @@ impl ArithmeticSideEffects {
         un_expr: &hir::Expr<'tcx>,
         un_op: hir::UnOp,
     ) {
+        if is_from_proc_macro(cx, expr) {
+            return;
+        }
         let hir::UnOp::Neg = un_op else { return; };
         if constant(cx, cx.typeck_results(), un_expr).is_some() {
             return;

clippy_lints/src/operators/numeric_arithmetic.rs

@@ -1,12 +1,12 @@
+use super::{FLOAT_ARITHMETIC, INTEGER_ARITHMETIC};
 use clippy_utils::consts::constant_simple;
 use clippy_utils::diagnostics::span_lint;
+use clippy_utils::is_from_proc_macro;
 use clippy_utils::is_integer_literal;
 use rustc_hir as hir;
 use rustc_lint::LateContext;
 use rustc_span::source_map::Span;
 
-use super::{FLOAT_ARITHMETIC, INTEGER_ARITHMETIC};
-
 #[derive(Default)]
 pub struct Context {
     expr_id: Option<hir::HirId>,
@@ -15,8 +15,10 @@ pub struct Context {
     const_span: Option<Span>,
 }
 impl Context {
-    fn skip_expr(&mut self, e: &hir::Expr<'_>) -> bool {
-        self.expr_id.is_some() || self.const_span.map_or(false, |span| span.contains(e.span))
+    fn skip_expr<'tcx>(&mut self, cx: &LateContext<'tcx>, e: &'tcx hir::Expr<'_>) -> bool {
+        self.expr_id.is_some()
+            || self.const_span.map_or(false, |span| span.contains(e.span))
+            || is_from_proc_macro(cx, e)
     }
 
     pub fn check_binary<'tcx>(
@@ -27,7 +29,7 @@ impl Context {
         l: &'tcx hir::Expr<'_>,
         r: &'tcx hir::Expr<'_>,
     ) {
-        if self.skip_expr(expr) {
+        if self.skip_expr(cx, expr) {
             return;
         }
         match op {
@@ -73,7 +75,7 @@ impl Context {
     }
 
     pub fn check_negate<'tcx>(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, arg: &'tcx hir::Expr<'_>) {
-        if self.skip_expr(expr) {
+        if self.skip_expr(cx, expr) {
             return;
         }
         let ty = cx.typeck_results().expr_ty(arg);

tests/ui/arithmetic_side_effects.rs

@@ -1,3 +1,5 @@
+// aux-build:proc_macro_derive.rs
+
 #![allow(
     clippy::assign_op_pattern,
     clippy::erasing_op,
@@ -11,6 +13,8 @@
 #![feature(const_mut_refs, inline_const, saturating_int_impl)]
 #![warn(clippy::arithmetic_side_effects)]
 
+extern crate proc_macro_derive;
+
 use core::num::{Saturating, Wrapping};
 
 const ONE: i32 = 1;
@@ -19,6 +23,9 @@ const ZERO: i32 = 0;
 #[derive(Clone, Copy)]
 pub struct Custom;
 
+#[derive(proc_macro_derive::ShadowDerive)]
+pub struct Nothing;
+
 macro_rules! impl_arith {
     ( $( $_trait:ident, $lhs:ty, $rhs:ty, $method:ident; )* ) => {
         $(