use clippy_utils::diagnostics::{multispan_sugg, span_lint, span_lint_and_then};
+use clippy_utils::get_enclosing_block;
+use clippy_utils::macros::{find_assert_eq_args, first_node_macro_backtrace};
use clippy_utils::source::snippet;
use clippy_utils::ty::{implements_trait, is_copy};
-use clippy_utils::{ast_utils::is_useless_with_eq_exprs, eq_expr_value, higher, in_macro, is_expn_of};
+use clippy_utils::{ast_utils::is_useless_with_eq_exprs, eq_expr_value, is_in_test_function};
use if_chain::if_chain;
use rustc_errors::Applicability;
-use rustc_hir::{BinOpKind, BorrowKind, Expr, ExprKind, StmtKind};
+use rustc_hir::{
+ def::Res, def_id::DefId, BinOpKind, BorrowKind, Expr, ExprKind, GenericArg, ItemKind, QPath, Ty, TyKind,
+};
use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::{self, TyS};
use rustc_session::{declare_lint_pass, declare_tool_lint};
declare_clippy_lint! {
- /// **What it does:** Checks for equal operands to comparison, logical and
+ /// ### What it does
+ /// Checks for equal operands to comparison, logical and
/// bitwise, difference and division binary operators (`==`, `>`, etc., `&&`,
/// `||`, `&`, `|`, `^`, `-` and `/`).
///
- /// **Why is this bad?** This is usually just a typo or a copy and paste error.
+ /// ### Why is this bad?
+ /// This is usually just a typo or a copy and paste error.
///
- /// **Known problems:** False negatives: We had some false positives regarding
+ /// ### Known problems
+ /// False negatives: We had some false positives regarding
/// calls (notably [racer](https://github.com/phildawes/racer) had one instance
/// of `x.pop() && x.pop()`), so we removed matching any function or method
/// calls. We may introduce a list of known pure functions in the future.
///
- /// **Example:**
+ /// ### Example
/// ```rust
/// # let x = 1;
/// if x + 1 == x + 1 {}
/// # let b = 4;
/// assert_eq!(a, a);
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub EQ_OP,
correctness,
"equal operands on both sides of a comparison or bitwise combination (e.g., `x == x`)"
}
declare_clippy_lint! {
- /// **What it does:** Checks for arguments to `==` which have their address
+ /// ### What it does
+ /// Checks for arguments to `==` which have their address
/// taken to satisfy a bound
/// and suggests to dereference the other argument instead
///
- /// **Why is this bad?** It is more idiomatic to dereference the other argument.
+ /// ### Why is this bad?
+ /// It is more idiomatic to dereference the other argument.
///
- /// **Known problems:** None
+ /// ### Known problems
+ /// None
///
- /// **Example:**
+ /// ### Example
/// ```ignore
/// // Bad
/// &x == y
/// // Good
/// x == *y
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub OP_REF,
style,
"taking a reference to satisfy the type constraints on `==`"
declare_lint_pass!(EqOp => [EQ_OP, OP_REF]);
-const ASSERT_MACRO_NAMES: [&str; 4] = ["assert_eq", "assert_ne", "debug_assert_eq", "debug_assert_ne"];
-
impl<'tcx> LateLintPass<'tcx> for EqOp {
#[allow(clippy::similar_names, clippy::too_many_lines)]
fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
- if let ExprKind::Block(block, _) = e.kind {
- for stmt in block.stmts {
- for amn in &ASSERT_MACRO_NAMES {
- if_chain! {
- if is_expn_of(stmt.span, amn).is_some();
- if let StmtKind::Semi(matchexpr) = stmt.kind;
- if let Some(macro_args) = higher::extract_assert_macro_args(matchexpr);
- if macro_args.len() == 2;
- let (lhs, rhs) = (macro_args[0], macro_args[1]);
- if eq_expr_value(cx, lhs, rhs);
-
- then {
- span_lint(
- cx,
- EQ_OP,
- lhs.span.to(rhs.span),
- &format!("identical args used in this `{}!` macro call", amn),
- );
- }
- }
- }
+ if_chain! {
+ if let Some((macro_call, macro_name)) = first_node_macro_backtrace(cx, e).find_map(|macro_call| {
+ let name = cx.tcx.item_name(macro_call.def_id);
+ matches!(name.as_str(), "assert_eq" | "assert_ne" | "debug_assert_eq" | "debug_assert_ne")
+ .then(|| (macro_call, name))
+ });
+ if let Some((lhs, rhs, _)) = find_assert_eq_args(cx, e, macro_call.expn);
+ if eq_expr_value(cx, lhs, rhs);
+ if macro_call.is_local();
+ if !is_in_test_function(cx.tcx, e.hir_id);
+ then {
+ span_lint(
+ cx,
+ EQ_OP,
+ lhs.span.to(rhs.span),
+ &format!("identical args used in this `{}!` macro call", macro_name),
+ );
}
}
if let ExprKind::Binary(op, left, right) = e.kind {
}
let macro_with_not_op = |expr_kind: &ExprKind<'_>| {
if let ExprKind::Unary(_, expr) = *expr_kind {
- in_macro(expr.span)
+ expr.span.from_expansion()
} else {
false
}
if macro_with_not_op(&left.kind) || macro_with_not_op(&right.kind) {
return;
}
- if is_useless_with_eq_exprs(op.node.into()) && eq_expr_value(cx, left, right) {
+ if is_useless_with_eq_exprs(op.node.into())
+ && eq_expr_value(cx, left, right)
+ && !is_in_test_function(cx.tcx, e.hir_id)
+ {
span_lint(
cx,
EQ_OP,
let rty = cx.typeck_results().expr_ty(r);
let lcpy = is_copy(cx, lty);
let rcpy = is_copy(cx, rty);
+ if let Some((self_ty, other_ty)) = in_impl(cx, e, trait_id) {
+ if (are_equal(cx, rty, self_ty) && are_equal(cx, lty, other_ty))
+ || (are_equal(cx, rty, other_ty) && are_equal(cx, lty, self_ty))
+ {
+ return; // Don't lint
+ }
+ }
// either operator autorefs or both args are copyable
if (requires_ref || (lcpy && rcpy)) && implements_trait(cx, lty, trait_id, &[rty.into()]) {
span_lint_and_then(
// &foo == bar
(&ExprKind::AddrOf(BorrowKind::Ref, _, l), _) => {
let lty = cx.typeck_results().expr_ty(l);
+ if let Some((self_ty, other_ty)) = in_impl(cx, e, trait_id) {
+ let rty = cx.typeck_results().expr_ty(right);
+ if (are_equal(cx, rty, self_ty) && are_equal(cx, lty, other_ty))
+ || (are_equal(cx, rty, other_ty) && are_equal(cx, lty, self_ty))
+ {
+ return; // Don't lint
+ }
+ }
let lcpy = is_copy(cx, lty);
if (requires_ref || lcpy)
&& implements_trait(cx, lty, trait_id, &[cx.typeck_results().expr_ty(right).into()])
// foo == &bar
(_, &ExprKind::AddrOf(BorrowKind::Ref, _, r)) => {
let rty = cx.typeck_results().expr_ty(r);
+ if let Some((self_ty, other_ty)) = in_impl(cx, e, trait_id) {
+ let lty = cx.typeck_results().expr_ty(left);
+ if (are_equal(cx, rty, self_ty) && are_equal(cx, lty, other_ty))
+ || (are_equal(cx, rty, other_ty) && are_equal(cx, lty, self_ty))
+ {
+ return; // Don't lint
+ }
+ }
let rcpy = is_copy(cx, rty);
if (requires_ref || rcpy)
&& implements_trait(cx, cx.typeck_results().expr_ty(left), trait_id, &[rty.into()])
}
}
}
+
+fn in_impl<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>, bin_op: DefId) -> Option<(&'tcx Ty<'tcx>, &'tcx Ty<'tcx>)> {
+ if_chain! {
+ if let Some(block) = get_enclosing_block(cx, e.hir_id);
+ if let Some(impl_def_id) = cx.tcx.impl_of_method(block.hir_id.owner.to_def_id());
+ let item = cx.tcx.hir().expect_item(impl_def_id.expect_local());
+ if let ItemKind::Impl(item) = &item.kind;
+ if let Some(of_trait) = &item.of_trait;
+ if let Some(seg) = of_trait.path.segments.last();
+ if let Some(Res::Def(_, trait_id)) = seg.res;
+ if trait_id == bin_op;
+ if let Some(generic_args) = seg.args;
+ if let Some(GenericArg::Type(other_ty)) = generic_args.args.last();
+
+ then {
+ Some((item.self_ty, other_ty))
+ }
+ else {
+ None
+ }
+ }
+}
+
+fn are_equal<'tcx>(cx: &LateContext<'tcx>, middle_ty: &TyS<'_>, hir_ty: &Ty<'_>) -> bool {
+ if_chain! {
+ if let ty::Adt(adt_def, _) = middle_ty.kind();
+ if let Some(local_did) = adt_def.did.as_local();
+ let item = cx.tcx.hir().expect_item(local_did);
+ let middle_ty_id = item.def_id.to_def_id();
+ if let TyKind::Path(QPath::Resolved(_, path)) = hir_ty.kind;
+ if let Res::Def(_, hir_ty_id) = path.res;
+
+ then {
+ hir_ty_id == middle_ty_id
+ }
+ else {
+ false
+ }
+ }
+}