1 use clippy_utils::{numeric_literal::NumericLiteral, source::snippet_with_context};
2 use rustc_errors::Applicability;
3 use rustc_hir::{BinOpKind, Expr, ExprKind};
4 use rustc_lint::{LateContext, LateLintPass, LintContext};
5 use rustc_middle::lint::in_external_macro;
6 use rustc_session::{declare_lint_pass, declare_tool_lint};
10 /// Warns for a Bitwise XOR (`^`) operator being probably confused as a powering. It will not trigger if any of the numbers are not in decimal.
11 /// ### Why is this bad?
12 /// It's most probably a typo and may lead to unexpected behaviours.
15 /// let x = 3_i32 ^ 4_i32;
19 /// let x = 3_i32.pow(4);
21 #[clippy::version = "1.66.0"]
22 pub SUSPICIOUS_XOR_USED_AS_POW,
24 "XOR (`^`) operator possibly used as exponentiation operator"
26 declare_lint_pass!(ConfusingXorAndPow => [SUSPICIOUS_XOR_USED_AS_POW]);
28 impl LateLintPass<'_> for ConfusingXorAndPow {
29 fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
30 if !in_external_macro(cx.sess(), expr.span) &&
31 let ExprKind::Binary(op, left, right) = &expr.kind &&
32 op.node == BinOpKind::BitXor &&
33 left.span.ctxt() == right.span.ctxt() &&
34 let ExprKind::Lit(lit_left) = &left.kind &&
35 let ExprKind::Lit(lit_right) = &right.kind &&
36 let snip_left = snippet_with_context(cx, lit_left.span, lit_left.span.ctxt(), "..", &mut Applicability::MaybeIncorrect) &&
37 let snip_right = snippet_with_context(cx, lit_right.span, lit_right.span.ctxt(), "..", &mut Applicability::MaybeIncorrect) &&
38 let Some(left_val) = NumericLiteral::from_lit_kind(&snip_left.0, &lit_left.node) &&
39 let Some(right_val) = NumericLiteral::from_lit_kind(&snip_right.0, &lit_right.node) &&
40 left_val.is_decimal() &&
41 right_val.is_decimal() {
42 clippy_utils::diagnostics::span_lint_and_sugg(
44 SUSPICIOUS_XOR_USED_AS_POW,
46 "`^` is not the exponentiation operator",
47 "did you mean to write",
48 format!("{}.pow({})", left_val.format(), right_val.format()),
49 Applicability::MaybeIncorrect,