diff --git a/CHANGELOG.md b/CHANGELOG.md index 3ef225559795..71671273c57b 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -4897,6 +4897,7 @@ Released 2018-09-13 [`implicit_return`]: https://rust-lang.github.io/rust-clippy/master/index.html#implicit_return [`implicit_saturating_add`]: https://rust-lang.github.io/rust-clippy/master/index.html#implicit_saturating_add [`implicit_saturating_sub`]: https://rust-lang.github.io/rust-clippy/master/index.html#implicit_saturating_sub +[`impossible_comparisons`]: https://rust-lang.github.io/rust-clippy/master/index.html#impossible_comparisons [`imprecise_flops`]: https://rust-lang.github.io/rust-clippy/master/index.html#imprecise_flops [`inconsistent_digit_grouping`]: https://rust-lang.github.io/rust-clippy/master/index.html#inconsistent_digit_grouping [`inconsistent_struct_constructor`]: https://rust-lang.github.io/rust-clippy/master/index.html#inconsistent_struct_constructor @@ -5191,6 +5192,7 @@ Released 2018-09-13 [`redundant_closure`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_closure [`redundant_closure_call`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_closure_call [`redundant_closure_for_method_calls`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_closure_for_method_calls +[`redundant_comparisons`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_comparisons [`redundant_else`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_else [`redundant_feature_names`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_feature_names [`redundant_field_names`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names diff --git a/clippy_lints/src/declared_lints.rs b/clippy_lints/src/declared_lints.rs index ea66c760a2f8..db114abfc869 100644 --- a/clippy_lints/src/declared_lints.rs +++ b/clippy_lints/src/declared_lints.rs @@ -518,6 +518,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::operators::FLOAT_CMP_CONST_INFO, crate::operators::FLOAT_EQUALITY_WITHOUT_ABS_INFO, crate::operators::IDENTITY_OP_INFO, + crate::operators::IMPOSSIBLE_COMPARISONS_INFO, crate::operators::INEFFECTIVE_BIT_MASK_INFO, crate::operators::INTEGER_DIVISION_INFO, crate::operators::MISREFACTORED_ASSIGN_OP_INFO, @@ -526,6 +527,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::operators::NEEDLESS_BITWISE_BOOL_INFO, crate::operators::OP_REF_INFO, crate::operators::PTR_EQ_INFO, + crate::operators::REDUNDANT_COMPARISONS_INFO, crate::operators::SELF_ASSIGNMENT_INFO, crate::operators::VERBOSE_BIT_MASK_INFO, crate::option_env_unwrap::OPTION_ENV_UNWRAP_INFO, diff --git a/clippy_lints/src/operators/const_comparisons.rs b/clippy_lints/src/operators/const_comparisons.rs new file mode 100644 index 000000000000..abe8df195434 --- /dev/null +++ b/clippy_lints/src/operators/const_comparisons.rs @@ -0,0 +1,207 @@ +#![allow(clippy::match_same_arms)] + +use std::cmp::Ordering; + +use clippy_utils::consts::{constant, Constant}; +use if_chain::if_chain; +use rustc_hir::{BinOpKind, Expr, ExprKind}; +use rustc_lint::LateContext; +use rustc_middle::ty::layout::HasTyCtxt; +use rustc_middle::ty::{Ty, TypeckResults}; +use rustc_span::source_map::{Span, Spanned}; + +use clippy_utils::diagnostics::span_lint_and_note; +use clippy_utils::source::snippet; +use clippy_utils::SpanlessEq; + +use super::{IMPOSSIBLE_COMPARISONS, REDUNDANT_COMPARISONS}; + +// Extract a comparison between a const and non-const +// Flip yoda conditionals, turnings expressions like `42 < x` into `x > 42` +fn comparison_to_const<'tcx>( + cx: &LateContext<'tcx>, + typeck: &TypeckResults<'tcx>, + expr: &'tcx Expr<'tcx>, +) -> Option<(CmpOp, &'tcx Expr<'tcx>, &'tcx Expr<'tcx>, Constant<'tcx>, Ty<'tcx>)> { + if_chain! { + if let ExprKind::Binary(operator, left, right) = expr.kind; + if let Ok(cmp_op) = CmpOp::try_from(operator.node); + then { + match (constant(cx, typeck, left), constant(cx, typeck, right)) { + (Some(_), Some(_)) => None, + (_, Some(con)) => Some((cmp_op, left, right, con, typeck.expr_ty(right))), + (Some(con), _) => Some((cmp_op.reverse(), right, left, con, typeck.expr_ty(left))), + _ => None, + } + } else { + None + } + } +} + +pub(super) fn check<'tcx>( + cx: &LateContext<'tcx>, + and_op: Spanned, + left_cond: &'tcx Expr<'tcx>, + right_cond: &'tcx Expr<'tcx>, + span: Span, +) { + if_chain! { + // Ensure that the binary operator is && + if and_op.node == BinOpKind::And; + + // Check that both operands to '&&' are themselves a binary operation + // The `comparison_to_const` step also checks this, so this step is just an optimization + if let ExprKind::Binary(_, _, _) = left_cond.kind; + if let ExprKind::Binary(_, _, _) = right_cond.kind; + + let typeck = cx.typeck_results(); + + // Check that both operands to '&&' compare a non-literal to a literal + if let Some((left_cmp_op, left_expr, left_const_expr, left_const, left_type)) = + comparison_to_const(cx, typeck, left_cond); + if let Some((right_cmp_op, right_expr, right_const_expr, right_const, right_type)) = + comparison_to_const(cx, typeck, right_cond); + + if left_type == right_type; + + // Check that the same expression is compared in both comparisons + if SpanlessEq::new(cx).eq_expr(left_expr, right_expr); + + if !left_expr.can_have_side_effects(); + + // Compare the two constant expressions + if let Some(ordering) = Constant::partial_cmp(cx.tcx(), left_type, &left_const, &right_const); + + // Rule out the `x >= 42 && x <= 42` corner case immediately + // Mostly to simplify the implementation, but it is also covered by `clippy::double_comparisons` + if !matches!( + (&left_cmp_op, &right_cmp_op, ordering), + (CmpOp::Le | CmpOp::Ge, CmpOp::Le | CmpOp::Ge, Ordering::Equal) + ); + + then { + if left_cmp_op.direction() == right_cmp_op.direction() { + let lhs_str = snippet(cx, left_cond.span, ""); + let rhs_str = snippet(cx, right_cond.span, ""); + // We already know that either side of `&&` has no effect, + // but emit a different error message depending on which side it is + if left_side_is_useless(left_cmp_op, ordering) { + span_lint_and_note( + cx, + REDUNDANT_COMPARISONS, + span, + "left-hand side of `&&` operator has no effect", + Some(left_cond.span.until(right_cond.span)), + &format!("`if `{rhs_str}` evaluates to true, {lhs_str}` will always evaluate to true as well"), + ); + } else { + span_lint_and_note( + cx, + REDUNDANT_COMPARISONS, + span, + "right-hand side of `&&` operator has no effect", + Some(and_op.span.to(right_cond.span)), + &format!("`if `{lhs_str}` evaluates to true, {rhs_str}` will always evaluate to true as well"), + ); + } + // We could autofix this error but choose not to, + // because code triggering this lint probably not behaving correctly in the first place + } + else if !comparison_is_possible(left_cmp_op.direction(), ordering) { + let expr_str = snippet(cx, left_expr.span, ".."); + let lhs_str = snippet(cx, left_const_expr.span, ""); + let rhs_str = snippet(cx, right_const_expr.span, ""); + let note = match ordering { + Ordering::Less => format!("since `{lhs_str}` < `{rhs_str}`, the expression evaluates to false for any value of `{expr_str}`"), + Ordering::Equal => format!("`{expr_str}` cannot simultaneously be greater than and less than `{lhs_str}`"), + Ordering::Greater => format!("since `{lhs_str}` > `{rhs_str}`, the expression evaluates to false for any value of `{expr_str}`"), + }; + span_lint_and_note( + cx, + IMPOSSIBLE_COMPARISONS, + span, + "boolean expression will never evaluate to 'true'", + None, + ¬e, + ); + }; + } + } +} + +fn left_side_is_useless(left_cmp_op: CmpOp, ordering: Ordering) -> bool { + // Special-case for equal constants with an inclusive comparison + if ordering == Ordering::Equal { + match left_cmp_op { + CmpOp::Lt | CmpOp::Gt => false, + CmpOp::Le | CmpOp::Ge => true, + } + } else { + match (left_cmp_op.direction(), ordering) { + (CmpOpDirection::Lesser, Ordering::Less) => false, + (CmpOpDirection::Lesser, Ordering::Equal) => false, + (CmpOpDirection::Lesser, Ordering::Greater) => true, + (CmpOpDirection::Greater, Ordering::Less) => true, + (CmpOpDirection::Greater, Ordering::Equal) => false, + (CmpOpDirection::Greater, Ordering::Greater) => false, + } + } +} + +fn comparison_is_possible(left_cmp_direction: CmpOpDirection, ordering: Ordering) -> bool { + match (left_cmp_direction, ordering) { + (CmpOpDirection::Lesser, Ordering::Less | Ordering::Equal) => false, + (CmpOpDirection::Lesser, Ordering::Greater) => true, + (CmpOpDirection::Greater, Ordering::Greater | Ordering::Equal) => false, + (CmpOpDirection::Greater, Ordering::Less) => true, + } +} + +#[derive(PartialEq, Eq, Clone, Copy)] +enum CmpOpDirection { + Lesser, + Greater, +} + +#[derive(Clone, Copy)] +enum CmpOp { + Lt, + Le, + Ge, + Gt, +} + +impl CmpOp { + fn reverse(self) -> Self { + match self { + CmpOp::Lt => CmpOp::Gt, + CmpOp::Le => CmpOp::Ge, + CmpOp::Ge => CmpOp::Le, + CmpOp::Gt => CmpOp::Lt, + } + } + + fn direction(self) -> CmpOpDirection { + match self { + CmpOp::Lt => CmpOpDirection::Lesser, + CmpOp::Le => CmpOpDirection::Lesser, + CmpOp::Ge => CmpOpDirection::Greater, + CmpOp::Gt => CmpOpDirection::Greater, + } + } +} + +impl TryFrom for CmpOp { + type Error = (); + + fn try_from(bin_op: BinOpKind) -> Result { + match bin_op { + BinOpKind::Lt => Ok(CmpOp::Lt), + BinOpKind::Le => Ok(CmpOp::Le), + BinOpKind::Ge => Ok(CmpOp::Ge), + BinOpKind::Gt => Ok(CmpOp::Gt), + _ => Err(()), + } + } +} diff --git a/clippy_lints/src/operators/mod.rs b/clippy_lints/src/operators/mod.rs index 2cf15adda01a..4635e1164cd3 100644 --- a/clippy_lints/src/operators/mod.rs +++ b/clippy_lints/src/operators/mod.rs @@ -2,6 +2,7 @@ mod absurd_extreme_comparisons; mod assign_op_pattern; mod bit_mask; mod cmp_owned; +mod const_comparisons; mod double_comparison; mod duration_subsec; mod eq_op; @@ -298,6 +299,45 @@ declare_clippy_lint! { "unnecessary double comparisons that can be simplified" } +declare_clippy_lint! { + /// ### What it does + /// Checks for double comparisons that can never succeed + /// + /// ### Why is this bad? + /// The whole expression can be replaced by `false`, + /// which is probably not the programmer's intention + /// + /// ### Example + /// ```rust + /// # let status_code = 200; + /// if status_code <= 400 && status_code > 500 {} + /// ``` + #[clippy::version = "1.71.0"] + pub IMPOSSIBLE_COMPARISONS, + correctness, + "double comparisons that will never evaluate to `true`" +} + +declare_clippy_lint! { + /// ### What it does + /// Checks for ineffective double comparisons against constants. + /// + /// ### Why is this bad? + /// Only one of the comparisons has any effect on the result, the programmer + /// probably intended to flip one of the comparison operators, or compare a + /// different value entirely. + /// + /// ### Example + /// ```rust + /// # let status_code = 200; + /// if status_code <= 400 && status_code < 500 {} + /// ``` + #[clippy::version = "1.71.0"] + pub REDUNDANT_COMPARISONS, + correctness, + "double comparisons where one of them can be removed" +} + declare_clippy_lint! { /// ### What it does /// Checks for calculation of subsecond microseconds or milliseconds @@ -742,6 +782,8 @@ impl_lint_pass!(Operators => [ INEFFECTIVE_BIT_MASK, VERBOSE_BIT_MASK, DOUBLE_COMPARISONS, + IMPOSSIBLE_COMPARISONS, + REDUNDANT_COMPARISONS, DURATION_SUBSEC, EQ_OP, OP_REF, @@ -786,6 +828,7 @@ impl<'tcx> LateLintPass<'tcx> for Operators { bit_mask::check(cx, e, op.node, lhs, rhs); verbose_bit_mask::check(cx, e, op.node, lhs, rhs, self.verbose_bit_mask_threshold); double_comparison::check(cx, op.node, lhs, rhs, e.span); + const_comparisons::check(cx, op, lhs, rhs, e.span); duration_subsec::check(cx, e, op.node, lhs, rhs); float_equality_without_abs::check(cx, e, op.node, lhs, rhs); integer_division::check(cx, e, op.node, lhs, rhs); diff --git a/clippy_utils/src/consts.rs b/clippy_utils/src/consts.rs index 061086c4fc20..63dfd2145b84 100644 --- a/clippy_utils/src/consts.rs +++ b/clippy_utils/src/consts.rs @@ -329,7 +329,7 @@ pub struct ConstEvalLateContext<'a, 'tcx> { } impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> { - fn new(lcx: &'a LateContext<'tcx>, typeck_results: &'a ty::TypeckResults<'tcx>) -> Self { + pub fn new(lcx: &'a LateContext<'tcx>, typeck_results: &'a ty::TypeckResults<'tcx>) -> Self { Self { lcx, typeck_results, diff --git a/tests/ui/const_comparisons.rs b/tests/ui/const_comparisons.rs new file mode 100644 index 000000000000..8e265c9141c1 --- /dev/null +++ b/tests/ui/const_comparisons.rs @@ -0,0 +1,93 @@ +#![allow(unused)] +#![warn(clippy::impossible_comparisons)] +#![warn(clippy::redundant_comparisons)] +#![allow(clippy::no_effect)] +#![allow(clippy::short_circuit_statement)] +#![allow(clippy::manual_range_contains)] + +const STATUS_BAD_REQUEST: u16 = 400; +const STATUS_SERVER_ERROR: u16 = 500; + +struct Status { + code: u16, +} + +impl PartialEq for Status { + fn eq(&self, other: &u16) -> bool { + self.code == *other + } +} + +impl PartialOrd for Status { + fn partial_cmp(&self, other: &u16) -> Option { + self.code.partial_cmp(other) + } +} + +impl PartialEq for u16 { + fn eq(&self, other: &Status) -> bool { + *self == other.code + } +} + +impl PartialOrd for u16 { + fn partial_cmp(&self, other: &Status) -> Option { + self.partial_cmp(&other.code) + } +} + +fn main() { + let status_code = 500; // Value doesn't matter for the lint + let status = Status { code: status_code }; + + status_code >= 400 && status_code < 500; // Correct + status_code <= 400 && status_code > 500; + status_code > 500 && status_code < 400; + status_code < 500 && status_code > 500; + + // More complex expressions + status_code < { 400 } && status_code > { 500 }; + status_code < STATUS_BAD_REQUEST && status_code > STATUS_SERVER_ERROR; + status_code <= u16::MIN + 1 && status_code > STATUS_SERVER_ERROR; + status_code < STATUS_SERVER_ERROR && status_code > STATUS_SERVER_ERROR; + + // Comparing two different types, via the `impl PartialOrd for Status` + status < { 400 } && status > { 500 }; + status < STATUS_BAD_REQUEST && status > STATUS_SERVER_ERROR; + status <= u16::MIN + 1 && status > STATUS_SERVER_ERROR; + status < STATUS_SERVER_ERROR && status > STATUS_SERVER_ERROR; + + // Yoda conditions + 500 <= status_code && 600 > status_code; // Correct + 500 <= status_code && status_code <= 600; // Correct + 500 >= status_code && 600 < status_code; // Incorrect + 500 >= status_code && status_code > 600; // Incorrect + + // Yoda conditions, comparing two different types + 500 <= status && 600 > status; // Correct + 500 <= status && status <= 600; // Correct + 500 >= status && 600 < status; // Incorrect + 500 >= status && status > 600; // Incorrect + + // Expressions where one of the sides has no effect + status_code < 200 && status_code <= 299; + status_code > 200 && status_code >= 299; + + status_code >= 500 && status_code > 500; // Useless left + status_code > 500 && status_code >= 500; // Useless right + status_code <= 500 && status_code < 500; // Useless left + status_code < 500 && status_code <= 500; // Useless right + + // Other types + let name = "Steve"; + name < "Jennifer" && name > "Shannon"; + + let numbers = [1, 2]; + numbers < [3, 4] && numbers > [5, 6]; + + let letter = 'a'; + letter < 'b' && letter > 'c'; + + let area = 42.0; + area < std::f32::consts::E && area > std::f32::consts::PI; +} diff --git a/tests/ui/const_comparisons.stderr b/tests/ui/const_comparisons.stderr new file mode 100644 index 000000000000..90e6db647621 --- /dev/null +++ b/tests/ui/const_comparisons.stderr @@ -0,0 +1,228 @@ +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:44:5 + | +LL | status_code <= 400 && status_code > 500; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: since `400` < `500`, the expression evaluates to false for any value of `status_code` + = note: `-D clippy::impossible-comparisons` implied by `-D warnings` + +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:45:5 + | +LL | status_code > 500 && status_code < 400; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: since `500` > `400`, the expression evaluates to false for any value of `status_code` + +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:46:5 + | +LL | status_code < 500 && status_code > 500; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: `status_code` cannot simultaneously be greater than and less than `500` + +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:49:5 + | +LL | status_code < { 400 } && status_code > { 500 }; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: since `{ 400 }` < `{ 500 }`, the expression evaluates to false for any value of `status_code` + +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:50:5 + | +LL | status_code < STATUS_BAD_REQUEST && status_code > STATUS_SERVER_ERROR; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: since `STATUS_BAD_REQUEST` < `STATUS_SERVER_ERROR`, the expression evaluates to false for any value of `status_code` + +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:51:5 + | +LL | status_code <= u16::MIN + 1 && status_code > STATUS_SERVER_ERROR; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: since `u16::MIN + 1` < `STATUS_SERVER_ERROR`, the expression evaluates to false for any value of `status_code` + +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:52:5 + | +LL | status_code < STATUS_SERVER_ERROR && status_code > STATUS_SERVER_ERROR; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: `status_code` cannot simultaneously be greater than and less than `STATUS_SERVER_ERROR` + +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:55:5 + | +LL | status < { 400 } && status > { 500 }; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: since `{ 400 }` < `{ 500 }`, the expression evaluates to false for any value of `status` + +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:56:5 + | +LL | status < STATUS_BAD_REQUEST && status > STATUS_SERVER_ERROR; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: since `STATUS_BAD_REQUEST` < `STATUS_SERVER_ERROR`, the expression evaluates to false for any value of `status` + +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:57:5 + | +LL | status <= u16::MIN + 1 && status > STATUS_SERVER_ERROR; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: since `u16::MIN + 1` < `STATUS_SERVER_ERROR`, the expression evaluates to false for any value of `status` + +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:58:5 + | +LL | status < STATUS_SERVER_ERROR && status > STATUS_SERVER_ERROR; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: `status` cannot simultaneously be greater than and less than `STATUS_SERVER_ERROR` + +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:63:5 + | +LL | 500 >= status_code && 600 < status_code; // Incorrect + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: since `500` < `600`, the expression evaluates to false for any value of `status_code` + +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:64:5 + | +LL | 500 >= status_code && status_code > 600; // Incorrect + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: since `500` < `600`, the expression evaluates to false for any value of `status_code` + +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:69:5 + | +LL | 500 >= status && 600 < status; // Incorrect + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: since `500` < `600`, the expression evaluates to false for any value of `status` + +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:70:5 + | +LL | 500 >= status && status > 600; // Incorrect + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: since `500` < `600`, the expression evaluates to false for any value of `status` + +error: right-hand side of `&&` operator has no effect + --> $DIR/const_comparisons.rs:73:5 + | +LL | status_code < 200 && status_code <= 299; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +note: `if `status_code < 200` evaluates to true, status_code <= 299` will always evaluate to true as well + --> $DIR/const_comparisons.rs:73:23 + | +LL | status_code < 200 && status_code <= 299; + | ^^^^^^^^^^^^^^^^^^^^^ + = note: `-D clippy::redundant-comparisons` implied by `-D warnings` + +error: left-hand side of `&&` operator has no effect + --> $DIR/const_comparisons.rs:74:5 + | +LL | status_code > 200 && status_code >= 299; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +note: `if `status_code >= 299` evaluates to true, status_code > 200` will always evaluate to true as well + --> $DIR/const_comparisons.rs:74:5 + | +LL | status_code > 200 && status_code >= 299; + | ^^^^^^^^^^^^^^^^^^^^^ + +error: left-hand side of `&&` operator has no effect + --> $DIR/const_comparisons.rs:76:5 + | +LL | status_code >= 500 && status_code > 500; // Useless left + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +note: `if `status_code > 500` evaluates to true, status_code >= 500` will always evaluate to true as well + --> $DIR/const_comparisons.rs:76:5 + | +LL | status_code >= 500 && status_code > 500; // Useless left + | ^^^^^^^^^^^^^^^^^^^^^^ + +error: right-hand side of `&&` operator has no effect + --> $DIR/const_comparisons.rs:77:5 + | +LL | status_code > 500 && status_code >= 500; // Useless right + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +note: `if `status_code > 500` evaluates to true, status_code >= 500` will always evaluate to true as well + --> $DIR/const_comparisons.rs:77:23 + | +LL | status_code > 500 && status_code >= 500; // Useless right + | ^^^^^^^^^^^^^^^^^^^^^ + +error: left-hand side of `&&` operator has no effect + --> $DIR/const_comparisons.rs:78:5 + | +LL | status_code <= 500 && status_code < 500; // Useless left + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +note: `if `status_code < 500` evaluates to true, status_code <= 500` will always evaluate to true as well + --> $DIR/const_comparisons.rs:78:5 + | +LL | status_code <= 500 && status_code < 500; // Useless left + | ^^^^^^^^^^^^^^^^^^^^^^ + +error: right-hand side of `&&` operator has no effect + --> $DIR/const_comparisons.rs:79:5 + | +LL | status_code < 500 && status_code <= 500; // Useless right + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +note: `if `status_code < 500` evaluates to true, status_code <= 500` will always evaluate to true as well + --> $DIR/const_comparisons.rs:79:23 + | +LL | status_code < 500 && status_code <= 500; // Useless right + | ^^^^^^^^^^^^^^^^^^^^^ + +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:83:5 + | +LL | name < "Jennifer" && name > "Shannon"; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: since `"Jennifer"` < `"Shannon"`, the expression evaluates to false for any value of `name` + +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:86:5 + | +LL | numbers < [3, 4] && numbers > [5, 6]; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: since `[3, 4]` < `[5, 6]`, the expression evaluates to false for any value of `numbers` + +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:89:5 + | +LL | letter < 'b' && letter > 'c'; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: since `'b'` < `'c'`, the expression evaluates to false for any value of `letter` + +error: boolean expression will never evaluate to 'true' + --> $DIR/const_comparisons.rs:92:5 + | +LL | area < std::f32::consts::E && area > std::f32::consts::PI; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: since `std::f32::consts::E` < `std::f32::consts::PI`, the expression evaluates to false for any value of `area` + +error: aborting due to 25 previous errors + diff --git a/tests/ui/range_contains.fixed b/tests/ui/range_contains.fixed index 0a92ee7c8dd3..47c5248118ea 100644 --- a/tests/ui/range_contains.fixed +++ b/tests/ui/range_contains.fixed @@ -5,6 +5,8 @@ #![allow(clippy::no_effect)] #![allow(clippy::short_circuit_statement)] #![allow(clippy::unnecessary_operation)] +#![allow(clippy::impossible_comparisons)] +#![allow(clippy::redundant_comparisons)] fn main() { let x = 9_i32; diff --git a/tests/ui/range_contains.rs b/tests/ui/range_contains.rs index 7a83be609571..a35315a649d8 100644 --- a/tests/ui/range_contains.rs +++ b/tests/ui/range_contains.rs @@ -5,6 +5,8 @@ #![allow(clippy::no_effect)] #![allow(clippy::short_circuit_statement)] #![allow(clippy::unnecessary_operation)] +#![allow(clippy::impossible_comparisons)] +#![allow(clippy::redundant_comparisons)] fn main() { let x = 9_i32; diff --git a/tests/ui/range_contains.stderr b/tests/ui/range_contains.stderr index ea34023a4664..1265db695bfb 100644 --- a/tests/ui/range_contains.stderr +++ b/tests/ui/range_contains.stderr @@ -1,5 +1,5 @@ error: manual `Range::contains` implementation - --> $DIR/range_contains.rs:13:5 + --> $DIR/range_contains.rs:15:5 | LL | x >= 8 && x < 12; | ^^^^^^^^^^^^^^^^ help: use: `(8..12).contains(&x)` @@ -7,121 +7,121 @@ LL | x >= 8 && x < 12; = note: `-D clippy::manual-range-contains` implied by `-D warnings` error: manual `Range::contains` implementation - --> $DIR/range_contains.rs:14:5 + --> $DIR/range_contains.rs:16:5 | LL | x < 42 && x >= 21; | ^^^^^^^^^^^^^^^^^ help: use: `(21..42).contains(&x)` error: manual `Range::contains` implementation - --> $DIR/range_contains.rs:15:5 + --> $DIR/range_contains.rs:17:5 | LL | 100 > x && 1 <= x; | ^^^^^^^^^^^^^^^^^ help: use: `(1..100).contains(&x)` error: manual `RangeInclusive::contains` implementation - --> $DIR/range_contains.rs:18:5 + --> $DIR/range_contains.rs:20:5 | LL | x >= 9 && x <= 99; | ^^^^^^^^^^^^^^^^^ help: use: `(9..=99).contains(&x)` error: manual `RangeInclusive::contains` implementation - --> $DIR/range_contains.rs:19:5 + --> $DIR/range_contains.rs:21:5 | LL | x <= 33 && x >= 1; | ^^^^^^^^^^^^^^^^^ help: use: `(1..=33).contains(&x)` error: manual `RangeInclusive::contains` implementation - --> $DIR/range_contains.rs:20:5 + --> $DIR/range_contains.rs:22:5 | LL | 999 >= x && 1 <= x; | ^^^^^^^^^^^^^^^^^^ help: use: `(1..=999).contains(&x)` error: manual `!Range::contains` implementation - --> $DIR/range_contains.rs:23:5 + --> $DIR/range_contains.rs:25:5 | LL | x < 8 || x >= 12; | ^^^^^^^^^^^^^^^^ help: use: `!(8..12).contains(&x)` error: manual `!Range::contains` implementation - --> $DIR/range_contains.rs:24:5 + --> $DIR/range_contains.rs:26:5 | LL | x >= 42 || x < 21; | ^^^^^^^^^^^^^^^^^ help: use: `!(21..42).contains(&x)` error: manual `!Range::contains` implementation - --> $DIR/range_contains.rs:25:5 + --> $DIR/range_contains.rs:27:5 | LL | 100 <= x || 1 > x; | ^^^^^^^^^^^^^^^^^ help: use: `!(1..100).contains(&x)` error: manual `!RangeInclusive::contains` implementation - --> $DIR/range_contains.rs:28:5 + --> $DIR/range_contains.rs:30:5 | LL | x < 9 || x > 99; | ^^^^^^^^^^^^^^^ help: use: `!(9..=99).contains(&x)` error: manual `!RangeInclusive::contains` implementation - --> $DIR/range_contains.rs:29:5 + --> $DIR/range_contains.rs:31:5 | LL | x > 33 || x < 1; | ^^^^^^^^^^^^^^^ help: use: `!(1..=33).contains(&x)` error: manual `!RangeInclusive::contains` implementation - --> $DIR/range_contains.rs:30:5 + --> $DIR/range_contains.rs:32:5 | LL | 999 < x || 1 > x; | ^^^^^^^^^^^^^^^^ help: use: `!(1..=999).contains(&x)` error: manual `Range::contains` implementation - --> $DIR/range_contains.rs:45:5 + --> $DIR/range_contains.rs:47:5 | LL | y >= 0. && y < 1.; | ^^^^^^^^^^^^^^^^^ help: use: `(0. ..1.).contains(&y)` error: manual `!RangeInclusive::contains` implementation - --> $DIR/range_contains.rs:46:5 + --> $DIR/range_contains.rs:48:5 | LL | y < 0. || y > 1.; | ^^^^^^^^^^^^^^^^ help: use: `!(0. ..=1.).contains(&y)` error: manual `RangeInclusive::contains` implementation - --> $DIR/range_contains.rs:49:5 + --> $DIR/range_contains.rs:51:5 | LL | x >= -10 && x <= 10; | ^^^^^^^^^^^^^^^^^^^ help: use: `(-10..=10).contains(&x)` error: manual `RangeInclusive::contains` implementation - --> $DIR/range_contains.rs:51:5 + --> $DIR/range_contains.rs:53:5 | LL | y >= -3. && y <= 3.; | ^^^^^^^^^^^^^^^^^^^ help: use: `(-3. ..=3.).contains(&y)` error: manual `RangeInclusive::contains` implementation - --> $DIR/range_contains.rs:56:30 + --> $DIR/range_contains.rs:58:30 | LL | (x >= 0) && (x <= 10) && (z >= 0) && (z <= 10); | ^^^^^^^^^^^^^^^^^^^^^ help: use: `(0..=10).contains(&z)` error: manual `RangeInclusive::contains` implementation - --> $DIR/range_contains.rs:56:5 + --> $DIR/range_contains.rs:58:5 | LL | (x >= 0) && (x <= 10) && (z >= 0) && (z <= 10); | ^^^^^^^^^^^^^^^^^^^^^ help: use: `(0..=10).contains(&x)` error: manual `!Range::contains` implementation - --> $DIR/range_contains.rs:57:29 + --> $DIR/range_contains.rs:59:29 | LL | (x < 0) || (x >= 10) || (z < 0) || (z >= 10); | ^^^^^^^^^^^^^^^^^^^^ help: use: `!(0..10).contains(&z)` error: manual `!Range::contains` implementation - --> $DIR/range_contains.rs:57:5 + --> $DIR/range_contains.rs:59:5 | LL | (x < 0) || (x >= 10) || (z < 0) || (z >= 10); | ^^^^^^^^^^^^^^^^^^^^ help: use: `!(0..10).contains(&x)` error: manual `Range::contains` implementation - --> $DIR/range_contains.rs:76:5 + --> $DIR/range_contains.rs:78:5 | LL | x >= 8 && x < 35; | ^^^^^^^^^^^^^^^^ help: use: `(8..35).contains(&x)`