Do not trigger integer_division_remainder_used in macros

clippy_lints/src/operators/integer_division_remainder_used.rs

@@ -1,3 +1,4 @@
+use crate::clippy_utils::source::HasSession;
 use clippy_utils::diagnostics::span_lint;
 use rustc_ast::BinOpKind;
 use rustc_hir::Expr;
@@ -13,11 +14,12 @@ pub(super) fn check(cx: &LateContext<'_>, op: BinOpKind, lhs: &Expr<'_>, rhs: &E
         && let rhs_ty = cx.typeck_results().expr_ty(rhs)
         && let ty::Int(_) | ty::Uint(_) = lhs_ty.peel_refs().kind()
         && let ty::Int(_) | ty::Uint(_) = rhs_ty.peel_refs().kind()
+        && !span.in_external_macro(cx.sess().source_map())
     {
         span_lint(
             cx,
             INTEGER_DIVISION_REMAINDER_USED,
-            span.source_callsite(),
+            span,
             format!("use of `{}` has been disallowed in this context", op.as_str()),
         );
     }

tests/ui/integer_division_remainder_used.rs

@@ -1,5 +1,5 @@
+//@aux-build: proc_macros.rs
 #![warn(clippy::integer_division_remainder_used)]
-#![allow(unused_variables)]
 #![allow(clippy::op_ref)]
 
 struct CustomOps(pub i32);
@@ -47,4 +47,18 @@ fn main() {
     let w = CustomOps(3);
     let x = CustomOps(4);
     let z = w % x;
+
+    macro_rules! mac {
+        ($a:expr, $b:expr) => {
+            a % b
+            //~^ integer_division_remainder_used
+        };
+    }
+    // should not trigger if from expansion in external macro
+    let issue17048 = mac!(a, b);
+    let issue17048 = proc_macros::external! {{
+        let a = 10;
+        let b = 5;
+        a % b
+    }};
 }

tests/ui/integer_division_remainder_used.stderr

@@ -55,5 +55,16 @@ error: use of `/` has been disallowed in this context
 LL |     let i = a / &4;
    |             ^^^^^^
 
-error: aborting due to 9 previous errors
+error: use of `%` has been disallowed in this context
+  --> tests/ui/integer_division_remainder_used.rs:53:13
+   |
+LL |             a % b
+   |             ^^^^^
+...
+LL |     let issue17048 = mac!(a, b);
+   |                      ---------- in this macro invocation
+   |
+   = note: this error originates in the macro `mac` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 10 previous errors