-use clippy_utils::diagnostics::span_lint_and_sugg;
-use clippy_utils::{ast_utils, is_direct_expn_of};
-use rustc_ast::ast::{Expr, ExprKind, Lit, LitKind};
+use clippy_utils::{diagnostics::span_lint_and_sugg, higher, is_direct_expn_of, ty::implements_trait};
+use rustc_ast::ast::LitKind;
use rustc_errors::Applicability;
-use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_hir::{Expr, ExprKind, Lit};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::symbol::Ident;
declare_clippy_lint! {
/// ### What it does
declare_lint_pass!(BoolAssertComparison => [BOOL_ASSERT_COMPARISON]);
-fn is_bool_lit(e: &Expr) -> bool {
+fn is_bool_lit(e: &Expr<'_>) -> bool {
matches!(
e.kind,
ExprKind::Lit(Lit {
- kind: LitKind::Bool(_),
+ node: LitKind::Bool(_),
..
})
) && !e.span.from_expansion()
}
-impl EarlyLintPass for BoolAssertComparison {
- fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &Expr) {
+fn is_impl_not_trait_with_bool_out(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) -> bool {
+ let ty = cx.typeck_results().expr_ty(e);
+
+ cx.tcx
+ .lang_items()
+ .not_trait()
+ .filter(|trait_id| implements_trait(cx, ty, *trait_id, &[]))
+ .and_then(|trait_id| {
+ cx.tcx.associated_items(trait_id).find_by_name_and_kind(
+ cx.tcx,
+ Ident::from_str("Output"),
+ ty::AssocKind::Type,
+ trait_id,
+ )
+ })
+ .map_or(false, |assoc_item| {
+ let proj = cx.tcx.mk_projection(assoc_item.def_id, cx.tcx.mk_substs_trait(ty, &[]));
+ let nty = cx.tcx.normalize_erasing_regions(cx.param_env, proj);
+
+ nty.is_bool()
+ })
+}
+
+impl<'tcx> LateLintPass<'tcx> for BoolAssertComparison {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
let macros = ["assert_eq", "debug_assert_eq"];
let inverted_macros = ["assert_ne", "debug_assert_ne"];
for mac in macros.iter().chain(inverted_macros.iter()) {
- if let Some(span) = is_direct_expn_of(e.span, mac) {
- if let Some([a, b]) = ast_utils::extract_assert_macro_args(e) {
- let nb_bool_args = is_bool_lit(a) as usize + is_bool_lit(b) as usize;
+ if let Some(span) = is_direct_expn_of(expr.span, mac) {
+ if let Some(args) = higher::extract_assert_macro_args(expr) {
+ if let [a, b, ..] = args[..] {
+ let nb_bool_args = is_bool_lit(a) as usize + is_bool_lit(b) as usize;
+
+ if nb_bool_args != 1 {
+ // If there are two boolean arguments, we definitely don't understand
+ // what's going on, so better leave things as is...
+ //
+ // Or there is simply no boolean and then we can leave things as is!
+ return;
+ }
- if nb_bool_args != 1 {
- // If there are two boolean arguments, we definitely don't understand
- // what's going on, so better leave things as is...
- //
- // Or there is simply no boolean and then we can leave things as is!
+ if !is_impl_not_trait_with_bool_out(cx, a) || !is_impl_not_trait_with_bool_out(cx, b) {
+ // At this point the expression which is not a boolean
+ // literal does not implement Not trait with a bool output,
+ // so we cannot suggest to rewrite our code
+ return;
+ }
+
+ let non_eq_mac = &mac[..mac.len() - 3];
+ span_lint_and_sugg(
+ cx,
+ BOOL_ASSERT_COMPARISON,
+ span,
+ &format!("used `{}!` with a literal bool", mac),
+ "replace it with",
+ format!("{}!(..)", non_eq_mac),
+ Applicability::MaybeIncorrect,
+ );
return;
}
-
- let non_eq_mac = &mac[..mac.len() - 3];
- span_lint_and_sugg(
- cx,
- BOOL_ASSERT_COMPARISON,
- span,
- &format!("used `{}!` with a literal bool", mac),
- "replace it with",
- format!("{}!(..)", non_eq_mac),
- Applicability::MaybeIncorrect,
- );
- return;
}
}
}