src/tools/clippy/clippy_lints/src/operators/double_comparison.rs

   1 use clippy_utils::diagnostics::span_lint_and_sugg;
   2 use clippy_utils::eq_expr_value;
   3 use clippy_utils::source::snippet_with_applicability;
   4 use rustc_errors::Applicability;
   5 use rustc_hir::{BinOpKind, Expr, ExprKind};
   6 use rustc_lint::LateContext;
   7 use rustc_span::source_map::Span;
   8
   9 use super::DOUBLE_COMPARISONS;
  10
  11 #[expect(clippy::similar_names)]
  12 pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, op: BinOpKind, lhs: &'tcx Expr<'_>, rhs: &'tcx Expr<'_>, span: Span) {
  13     let (lkind, llhs, lrhs, rkind, rlhs, rrhs) = match (&lhs.kind, &rhs.kind) {
  14         (ExprKind::Binary(lb, llhs, lrhs), ExprKind::Binary(rb, rlhs, rrhs)) => {
  15             (lb.node, llhs, lrhs, rb.node, rlhs, rrhs)
  16         },
  17         _ => return,
  18     };
  19     if !(eq_expr_value(cx, llhs, rlhs) && eq_expr_value(cx, lrhs, rrhs)) {
  20         return;
  21     }
  22     macro_rules! lint_double_comparison {
  23         ($op:tt) => {{
  24             let mut applicability = Applicability::MachineApplicable;
  25             let lhs_str = snippet_with_applicability(cx, llhs.span, "", &mut applicability);
  26             let rhs_str = snippet_with_applicability(cx, lrhs.span, "", &mut applicability);
  27             let sugg = format!("{} {} {}", lhs_str, stringify!($op), rhs_str);
  28             span_lint_and_sugg(
  29                 cx,
  30                 DOUBLE_COMPARISONS,
  31                 span,
  32                 "this binary expression can be simplified",
  33                 "try",
  34                 sugg,
  35                 applicability,
  36             );
  37         }};
  38     }
  39     match (op, lkind, rkind) {
  40         (BinOpKind::Or, BinOpKind::Eq, BinOpKind::Lt) | (BinOpKind::Or, BinOpKind::Lt, BinOpKind::Eq) => {
  41             lint_double_comparison!(<=);
  42         },
  43         (BinOpKind::Or, BinOpKind::Eq, BinOpKind::Gt) | (BinOpKind::Or, BinOpKind::Gt, BinOpKind::Eq) => {
  44             lint_double_comparison!(>=);
  45         },
  46         (BinOpKind::Or, BinOpKind::Lt, BinOpKind::Gt) | (BinOpKind::Or, BinOpKind::Gt, BinOpKind::Lt) => {
  47             lint_double_comparison!(!=);
  48         },
  49         (BinOpKind::And, BinOpKind::Le, BinOpKind::Ge) | (BinOpKind::And, BinOpKind::Ge, BinOpKind::Le) => {
  50             lint_double_comparison!(==);
  51         },
  52         _ => (),
  53     };
  54 }