rust/clippy_lints/src/operators/modulo_one.rs
2022-06-28 12:51:30 -04:00

27 lines
850 B
Rust

use clippy_utils::diagnostics::span_lint;
use clippy_utils::{is_integer_const, unsext};
use rustc_hir::{BinOpKind, Expr};
use rustc_lint::LateContext;
use rustc_middle::ty;
use super::MODULO_ONE;
pub(crate) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, op: BinOpKind, right: &Expr<'_>) {
if op == BinOpKind::Rem {
if is_integer_const(cx, right, 1) {
span_lint(cx, MODULO_ONE, expr.span, "any number modulo 1 will be 0");
}
if let ty::Int(ity) = cx.typeck_results().expr_ty(right).kind() {
if is_integer_const(cx, right, unsext(cx.tcx, -1, *ity)) {
span_lint(
cx,
MODULO_ONE,
expr.span,
"any number modulo -1 will panic/overflow or result in 0",
);
}
};
}
}