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https://github.com/rust-lang/rust-clippy
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Auto merge of #8786 - Alexendoo:identity-op-suggestions, r=dswij,xFrednet
`identity_op`: add parenthesis to suggestions where required changelog: [`identity_op`]: add parenthesis to suggestions where required Follow up to #8730, wraps the cases we can't lint as-is in parenthesis rather than ignoring them Catches a couple new FPs with mixed operator precedences and `as` casts ```rust // such as 0 + { a } * 2; 0 + a as usize; ``` The suggestions are now applied using `span_lint_and_sugg` rather than appearing in just the message and have a `run-rustfix` test
This commit is contained in:
bors
commit
c41c410a90
6 changed files with 398 additions and 223 deletions
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@ -1,15 +1,14 @@
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use clippy_utils::get_parent_expr;
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use clippy_utils::source::snippet;
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use rustc_hir::{BinOp, BinOpKind, Expr, ExprKind};
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use clippy_utils::consts::{constant_full_int, constant_simple, Constant, FullInt};
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use clippy_utils::diagnostics::span_lint_and_sugg;
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use clippy_utils::source::snippet_with_applicability;
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use clippy_utils::{clip, unsext};
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use rustc_errors::Applicability;
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use rustc_hir::{BinOp, BinOpKind, Expr, ExprKind, Node};
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use rustc_lint::{LateContext, LateLintPass};
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use rustc_middle::ty;
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use rustc_session::{declare_lint_pass, declare_tool_lint};
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use rustc_span::source_map::Span;
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use clippy_utils::consts::{constant_full_int, constant_simple, Constant, FullInt};
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use clippy_utils::diagnostics::span_lint;
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use clippy_utils::{clip, unsext};
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declare_clippy_lint! {
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/// ### What it does
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/// Checks for identity operations, e.g., `x + 0`.
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@ -23,11 +22,6 @@ declare_clippy_lint! {
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/// # let x = 1;
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/// x / 1 + 0 * 1 - 0 | 0;
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/// ```
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///
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/// ### Known problems
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/// False negatives: `f(0 + if b { 1 } else { 2 } + 3);` is reducible to
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/// `f(if b { 1 } else { 2 } + 3);`. But the lint doesn't trigger for the code.
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/// See [#8724](https://github.com/rust-lang/rust-clippy/issues/8724)
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#[clippy::version = "pre 1.29.0"]
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pub IDENTITY_OP,
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complexity,
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@ -45,31 +39,22 @@ impl<'tcx> LateLintPass<'tcx> for IdentityOp {
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if !is_allowed(cx, *cmp, left, right) {
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match cmp.node {
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BinOpKind::Add | BinOpKind::BitOr | BinOpKind::BitXor => {
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if reducible_to_right(cx, expr, right) {
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check(cx, left, 0, expr.span, right.span);
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}
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check(cx, right, 0, expr.span, left.span);
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check(cx, left, 0, expr.span, right.span, needs_parenthesis(cx, expr, right));
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check(cx, right, 0, expr.span, left.span, Parens::Unneeded);
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},
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BinOpKind::Shl | BinOpKind::Shr | BinOpKind::Sub => {
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check(cx, right, 0, expr.span, left.span);
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check(cx, right, 0, expr.span, left.span, Parens::Unneeded);
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},
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BinOpKind::Mul => {
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if reducible_to_right(cx, expr, right) {
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check(cx, left, 1, expr.span, right.span);
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}
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check(cx, right, 1, expr.span, left.span);
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check(cx, left, 1, expr.span, right.span, needs_parenthesis(cx, expr, right));
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check(cx, right, 1, expr.span, left.span, Parens::Unneeded);
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},
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BinOpKind::Div => check(cx, right, 1, expr.span, left.span),
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BinOpKind::Div => check(cx, right, 1, expr.span, left.span, Parens::Unneeded),
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BinOpKind::BitAnd => {
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if reducible_to_right(cx, expr, right) {
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check(cx, left, -1, expr.span, right.span);
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}
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check(cx, right, -1, expr.span, left.span);
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},
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BinOpKind::Rem => {
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// Don't call reducible_to_right because N % N is always reducible to 1
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check_remainder(cx, left, right, expr.span, left.span);
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check(cx, left, -1, expr.span, right.span, needs_parenthesis(cx, expr, right));
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check(cx, right, -1, expr.span, left.span, Parens::Unneeded);
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},
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BinOpKind::Rem => check_remainder(cx, left, right, expr.span, left.span),
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_ => (),
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}
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}
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@ -77,24 +62,50 @@ impl<'tcx> LateLintPass<'tcx> for IdentityOp {
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}
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}
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/// Checks if `left op ..right` can be actually reduced to `right`
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/// e.g. `0 + if b { 1 } else { 2 } + if b { 3 } else { 4 }`
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/// cannot be reduced to `if b { 1 } else { 2 } + if b { 3 } else { 4 }`
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/// See #8724
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fn reducible_to_right(cx: &LateContext<'_>, binary: &Expr<'_>, right: &Expr<'_>) -> bool {
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if let ExprKind::If(..) | ExprKind::Match(..) | ExprKind::Block(..) | ExprKind::Loop(..) = right.kind {
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is_toplevel_binary(cx, binary)
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} else {
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true
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}
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#[derive(Copy, Clone)]
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enum Parens {
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Needed,
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Unneeded,
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}
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fn is_toplevel_binary(cx: &LateContext<'_>, must_be_binary: &Expr<'_>) -> bool {
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if let Some(parent) = get_parent_expr(cx, must_be_binary) && let ExprKind::Binary(..) = &parent.kind {
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false
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} else {
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true
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/// Checks if `left op right` needs parenthesis when reduced to `right`
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/// e.g. `0 + if b { 1 } else { 2 } + if b { 3 } else { 4 }` cannot be reduced
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/// to `if b { 1 } else { 2 } + if b { 3 } else { 4 }` where the `if` could be
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/// interpreted as a statement
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///
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/// See #8724
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fn needs_parenthesis(cx: &LateContext<'_>, binary: &Expr<'_>, right: &Expr<'_>) -> Parens {
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match right.kind {
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ExprKind::Binary(_, lhs, _) | ExprKind::Cast(lhs, _) => {
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// ensure we're checking against the leftmost expression of `right`
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//
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// ~~~ `lhs`
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// 0 + {4} * 2
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// ~~~~~~~ `right`
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return needs_parenthesis(cx, binary, lhs);
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},
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ExprKind::If(..) | ExprKind::Match(..) | ExprKind::Block(..) | ExprKind::Loop(..) => {},
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_ => return Parens::Unneeded,
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}
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let mut prev_id = binary.hir_id;
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for (_, node) in cx.tcx.hir().parent_iter(binary.hir_id) {
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if let Node::Expr(expr) = node
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&& let ExprKind::Binary(_, lhs, _) | ExprKind::Cast(lhs, _) = expr.kind
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&& lhs.hir_id == prev_id
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{
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// keep going until we find a node that encompasses left of `binary`
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prev_id = expr.hir_id;
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continue;
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}
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match node {
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Node::Block(_) | Node::Stmt(_) => break,
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_ => return Parens::Unneeded,
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};
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}
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Parens::Needed
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}
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fn is_allowed(cx: &LateContext<'_>, cmp: BinOp, left: &Expr<'_>, right: &Expr<'_>) -> bool {
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@ -115,11 +126,11 @@ fn check_remainder(cx: &LateContext<'_>, left: &Expr<'_>, right: &Expr<'_>, span
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(Some(FullInt::U(lv)), Some(FullInt::U(rv))) => lv < rv,
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_ => return,
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} {
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span_ineffective_operation(cx, span, arg);
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span_ineffective_operation(cx, span, arg, Parens::Unneeded);
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}
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}
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fn check(cx: &LateContext<'_>, e: &Expr<'_>, m: i8, span: Span, arg: Span) {
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fn check(cx: &LateContext<'_>, e: &Expr<'_>, m: i8, span: Span, arg: Span, parens: Parens) {
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if let Some(Constant::Int(v)) = constant_simple(cx, cx.typeck_results(), e).map(Constant::peel_refs) {
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let check = match *cx.typeck_results().expr_ty(e).peel_refs().kind() {
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ty::Int(ity) => unsext(cx.tcx, -1_i128, ity),
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@ -132,19 +143,27 @@ fn check(cx: &LateContext<'_>, e: &Expr<'_>, m: i8, span: Span, arg: Span) {
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1 => v == 1,
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_ => unreachable!(),
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} {
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span_ineffective_operation(cx, span, arg);
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span_ineffective_operation(cx, span, arg, parens);
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}
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}
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}
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fn span_ineffective_operation(cx: &LateContext<'_>, span: Span, arg: Span) {
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span_lint(
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fn span_ineffective_operation(cx: &LateContext<'_>, span: Span, arg: Span, parens: Parens) {
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let mut applicability = Applicability::MachineApplicable;
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let expr_snippet = snippet_with_applicability(cx, arg, "..", &mut applicability);
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let suggestion = match parens {
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Parens::Needed => format!("({expr_snippet})"),
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Parens::Unneeded => expr_snippet.into_owned(),
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};
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span_lint_and_sugg(
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cx,
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IDENTITY_OP,
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span,
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&format!(
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"the operation is ineffective. Consider reducing it to `{}`",
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snippet(cx, arg, "..")
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),
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"this operation has no effect",
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"consider reducing it to",
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suggestion,
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applicability,
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);
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}
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119
tests/ui/identity_op.fixed
Normal file
119
tests/ui/identity_op.fixed
Normal file
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@ -0,0 +1,119 @@
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// run-rustfix
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#![warn(clippy::identity_op)]
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#![allow(
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clippy::eq_op,
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clippy::no_effect,
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clippy::unnecessary_operation,
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clippy::op_ref,
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clippy::double_parens,
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unused
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)]
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use std::fmt::Write as _;
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const ONE: i64 = 1;
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const NEG_ONE: i64 = -1;
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const ZERO: i64 = 0;
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struct A(String);
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impl std::ops::Shl<i32> for A {
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type Output = A;
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fn shl(mut self, other: i32) -> Self {
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let _ = write!(self.0, "{}", other);
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self
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}
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}
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struct Length(u8);
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struct Meter;
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impl core::ops::Mul<Meter> for u8 {
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type Output = Length;
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fn mul(self, _: Meter) -> Length {
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Length(self)
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}
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}
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#[rustfmt::skip]
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fn main() {
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let x = 0;
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x;
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x;
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x + 1;
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x;
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1 + x;
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x - ZERO; //no error, as we skip lookups (for now)
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x;
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((ZERO)) | x; //no error, as we skip lookups (for now)
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x;
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x;
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x / ONE; //no error, as we skip lookups (for now)
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x / 2; //no false positive
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x & NEG_ONE; //no error, as we skip lookups (for now)
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x;
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let u: u8 = 0;
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u;
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1 << 0; // no error, this case is allowed, see issue 3430
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42;
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1;
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42;
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&x;
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x;
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let mut a = A("".into());
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let b = a << 0; // no error: non-integer
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1 * Meter; // no error: non-integer
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2;
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-2;
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2 + x;
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-2 + x;
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x + 1;
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(x + 1) % 3; // no error
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4 % 3; // no error
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4 % -3; // no error
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|
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// See #8724
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let a = 0;
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let b = true;
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(if b { 1 } else { 2 });
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(if b { 1 } else { 2 }) + if b { 3 } else { 4 };
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(match a { 0 => 10, _ => 20 });
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(match a { 0 => 10, _ => 20 }) + match a { 0 => 30, _ => 40 };
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(if b { 1 } else { 2 }) + match a { 0 => 30, _ => 40 };
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(match a { 0 => 10, _ => 20 }) + if b { 3 } else { 4 };
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(if b { 1 } else { 2 });
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|
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({ a }) + 3;
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({ a } * 2);
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(loop { let mut c = 0; if c == 10 { break c; } c += 1; }) + { a * 2 };
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|
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fn f(_: i32) {
|
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todo!();
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}
|
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f(a + { 8 * 5 });
|
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f(if b { 1 } else { 2 } + 3);
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const _: i32 = { 2 * 4 } + 3;
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const _: i32 = { 1 + 2 * 3 } + 3;
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|
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a as usize;
|
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let _ = a as usize;
|
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({ a } as usize);
|
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|
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2 * { a };
|
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(({ a } + 4));
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1;
|
||||
}
|
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|
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pub fn decide(a: bool, b: bool) -> u32 {
|
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(if a { 1 } else { 2 }) + if b { 3 } else { 5 }
|
||||
}
|
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|
|
@ -1,3 +1,15 @@
|
|||
// run-rustfix
|
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|
||||
#![warn(clippy::identity_op)]
|
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#![allow(
|
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clippy::eq_op,
|
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clippy::no_effect,
|
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clippy::unnecessary_operation,
|
||||
clippy::op_ref,
|
||||
clippy::double_parens,
|
||||
unused
|
||||
)]
|
||||
|
||||
use std::fmt::Write as _;
|
||||
|
||||
const ONE: i64 = 1;
|
||||
|
|
@ -24,14 +36,6 @@ impl core::ops::Mul<Meter> for u8 {
|
|||
}
|
||||
}
|
||||
|
||||
#[allow(
|
||||
clippy::eq_op,
|
||||
clippy::no_effect,
|
||||
clippy::unnecessary_operation,
|
||||
clippy::op_ref,
|
||||
clippy::double_parens
|
||||
)]
|
||||
#[warn(clippy::identity_op)]
|
||||
#[rustfmt::skip]
|
||||
fn main() {
|
||||
let x = 0;
|
||||
|
|
@ -82,29 +86,34 @@ fn main() {
|
|||
let a = 0;
|
||||
let b = true;
|
||||
0 + if b { 1 } else { 2 };
|
||||
0 + if b { 1 } else { 2 } + if b { 3 } else { 4 }; // no error
|
||||
0 + if b { 1 } else { 2 } + if b { 3 } else { 4 };
|
||||
0 + match a { 0 => 10, _ => 20 };
|
||||
0 + match a { 0 => 10, _ => 20 } + match a { 0 => 30, _ => 40 }; // no error
|
||||
0 + if b { 1 } else { 2 } + match a { 0 => 30, _ => 40 }; // no error
|
||||
0 + match a { 0 => 10, _ => 20 } + if b { 3 } else { 4 }; // no error
|
||||
|
||||
0 + if b { 0 + 1 } else { 2 };
|
||||
0 + match a { 0 => 0 + 10, _ => 20 };
|
||||
0 + if b { 0 + 1 } else { 2 } + match a { 0 => 0 + 30, _ => 40 };
|
||||
0 + match a { 0 => 10, _ => 20 } + match a { 0 => 30, _ => 40 };
|
||||
0 + if b { 1 } else { 2 } + match a { 0 => 30, _ => 40 };
|
||||
0 + match a { 0 => 10, _ => 20 } + if b { 3 } else { 4 };
|
||||
(if b { 1 } else { 2 }) + 0;
|
||||
|
||||
let _ = 0 + if 0 + 1 > 0 { 1 } else { 2 } + if 0 + 1 > 0 { 3 } else { 4 };
|
||||
let _ = 0 + match 0 + 1 { 0 => 10, _ => 20 } + match 0 + 1 { 0 => 30, _ => 40 };
|
||||
0 + { a } + 3;
|
||||
0 + { a } * 2;
|
||||
0 + loop { let mut c = 0; if c == 10 { break c; } c += 1; } + { a * 2 };
|
||||
|
||||
0 + if b { 1 } else { 2 } + if b { 3 } else { 4 } + 0;
|
||||
|
||||
0 + { a } + 3; // no error
|
||||
0 + loop { let mut c = 0; if c == 10 { break c; } c += 1; } + { a * 2 }; // no error
|
||||
|
||||
fn f(_: i32) {
|
||||
todo!();
|
||||
}
|
||||
f(1 * a + { 8 * 5 });
|
||||
f(0 + if b { 1 } else { 2 } + 3); // no error
|
||||
f(0 + if b { 1 } else { 2 } + 3);
|
||||
const _: i32 = { 2 * 4 } + 0 + 3;
|
||||
const _: i32 = 0 + { 1 + 2 * 3 } + 3; // no error
|
||||
const _: i32 = 0 + { 1 + 2 * 3 } + 3;
|
||||
|
||||
0 + a as usize;
|
||||
let _ = 0 + a as usize;
|
||||
0 + { a } as usize;
|
||||
|
||||
2 * (0 + { a });
|
||||
1 * ({ a } + 4);
|
||||
1 * 1;
|
||||
}
|
||||
|
||||
pub fn decide(a: bool, b: bool) -> u32 {
|
||||
0 + if a { 1 } else { 2 } + if b { 3 } else { 5 }
|
||||
}
|
||||
|
|
|
|||
|
|
@ -1,202 +1,238 @@
|
|||
error: the operation is ineffective. Consider reducing it to `x`
|
||||
--> $DIR/identity_op.rs:39:5
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:43:5
|
||||
|
|
||||
LL | x + 0;
|
||||
| ^^^^^
|
||||
| ^^^^^ help: consider reducing it to: `x`
|
||||
|
|
||||
= note: `-D clippy::identity-op` implied by `-D warnings`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `x`
|
||||
--> $DIR/identity_op.rs:40:5
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:44:5
|
||||
|
|
||||
LL | x + (1 - 1);
|
||||
| ^^^^^^^^^^^
|
||||
| ^^^^^^^^^^^ help: consider reducing it to: `x`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `x`
|
||||
--> $DIR/identity_op.rs:42:5
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:46:5
|
||||
|
|
||||
LL | 0 + x;
|
||||
| ^^^^^
|
||||
| ^^^^^ help: consider reducing it to: `x`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `x`
|
||||
--> $DIR/identity_op.rs:45:5
|
||||
|
|
||||
LL | x | (0);
|
||||
| ^^^^^^^
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `x`
|
||||
--> $DIR/identity_op.rs:48:5
|
||||
|
|
||||
LL | x * 1;
|
||||
| ^^^^^
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `x`
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:49:5
|
||||
|
|
||||
LL | 1 * x;
|
||||
| ^^^^^
|
||||
LL | x | (0);
|
||||
| ^^^^^^^ help: consider reducing it to: `x`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `x`
|
||||
--> $DIR/identity_op.rs:55:5
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:52:5
|
||||
|
|
||||
LL | x * 1;
|
||||
| ^^^^^ help: consider reducing it to: `x`
|
||||
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:53:5
|
||||
|
|
||||
LL | 1 * x;
|
||||
| ^^^^^ help: consider reducing it to: `x`
|
||||
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:59:5
|
||||
|
|
||||
LL | -1 & x;
|
||||
| ^^^^^^
|
||||
| ^^^^^^ help: consider reducing it to: `x`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `u`
|
||||
--> $DIR/identity_op.rs:58:5
|
||||
|
|
||||
LL | u & 255;
|
||||
| ^^^^^^^
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `42`
|
||||
--> $DIR/identity_op.rs:61:5
|
||||
|
|
||||
LL | 42 << 0;
|
||||
| ^^^^^^^
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `1`
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:62:5
|
||||
|
|
||||
LL | 1 >> 0;
|
||||
| ^^^^^^
|
||||
LL | u & 255;
|
||||
| ^^^^^^^ help: consider reducing it to: `u`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `42`
|
||||
--> $DIR/identity_op.rs:63:5
|
||||
|
|
||||
LL | 42 >> 0;
|
||||
| ^^^^^^^
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `&x`
|
||||
--> $DIR/identity_op.rs:64:5
|
||||
|
|
||||
LL | &x >> 0;
|
||||
| ^^^^^^^
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `x`
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:65:5
|
||||
|
|
||||
LL | x >> &0;
|
||||
| ^^^^^^^
|
||||
LL | 42 << 0;
|
||||
| ^^^^^^^ help: consider reducing it to: `42`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `2`
|
||||
--> $DIR/identity_op.rs:72:5
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:66:5
|
||||
|
|
||||
LL | 1 >> 0;
|
||||
| ^^^^^^ help: consider reducing it to: `1`
|
||||
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:67:5
|
||||
|
|
||||
LL | 42 >> 0;
|
||||
| ^^^^^^^ help: consider reducing it to: `42`
|
||||
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:68:5
|
||||
|
|
||||
LL | &x >> 0;
|
||||
| ^^^^^^^ help: consider reducing it to: `&x`
|
||||
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:69:5
|
||||
|
|
||||
LL | x >> &0;
|
||||
| ^^^^^^^ help: consider reducing it to: `x`
|
||||
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:76:5
|
||||
|
|
||||
LL | 2 % 3;
|
||||
| ^^^^^
|
||||
| ^^^^^ help: consider reducing it to: `2`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `-2`
|
||||
--> $DIR/identity_op.rs:73:5
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:77:5
|
||||
|
|
||||
LL | -2 % 3;
|
||||
| ^^^^^^
|
||||
| ^^^^^^ help: consider reducing it to: `-2`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `2`
|
||||
--> $DIR/identity_op.rs:74:5
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:78:5
|
||||
|
|
||||
LL | 2 % -3 + x;
|
||||
| ^^^^^^
|
||||
| ^^^^^^ help: consider reducing it to: `2`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `-2`
|
||||
--> $DIR/identity_op.rs:75:5
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:79:5
|
||||
|
|
||||
LL | -2 % -3 + x;
|
||||
| ^^^^^^^
|
||||
| ^^^^^^^ help: consider reducing it to: `-2`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `1`
|
||||
--> $DIR/identity_op.rs:76:9
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:80:9
|
||||
|
|
||||
LL | x + 1 % 3;
|
||||
| ^^^^^
|
||||
| ^^^^^ help: consider reducing it to: `1`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `if b { 1 } else { 2 }`
|
||||
--> $DIR/identity_op.rs:84:5
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:88:5
|
||||
|
|
||||
LL | 0 + if b { 1 } else { 2 };
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `(if b { 1 } else { 2 })`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `match a { 0 => 10, _ => 20 }`
|
||||
--> $DIR/identity_op.rs:86:5
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:89:5
|
||||
|
|
||||
LL | 0 + if b { 1 } else { 2 } + if b { 3 } else { 4 };
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `(if b { 1 } else { 2 })`
|
||||
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:90:5
|
||||
|
|
||||
LL | 0 + match a { 0 => 10, _ => 20 };
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `(match a { 0 => 10, _ => 20 })`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `if b { 0 + 1 } else { 2 }`
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:91:5
|
||||
|
|
||||
LL | 0 + if b { 0 + 1 } else { 2 };
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
||||
LL | 0 + match a { 0 => 10, _ => 20 } + match a { 0 => 30, _ => 40 };
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `(match a { 0 => 10, _ => 20 })`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `1`
|
||||
--> $DIR/identity_op.rs:91:16
|
||||
|
|
||||
LL | 0 + if b { 0 + 1 } else { 2 };
|
||||
| ^^^^^
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `match a { 0 => 0 + 10, _ => 20 }`
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:92:5
|
||||
|
|
||||
LL | 0 + match a { 0 => 0 + 10, _ => 20 };
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
||||
LL | 0 + if b { 1 } else { 2 } + match a { 0 => 30, _ => 40 };
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `(if b { 1 } else { 2 })`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `10`
|
||||
--> $DIR/identity_op.rs:92:25
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:93:5
|
||||
|
|
||||
LL | 0 + match a { 0 => 0 + 10, _ => 20 };
|
||||
| ^^^^^^
|
||||
LL | 0 + match a { 0 => 10, _ => 20 } + if b { 3 } else { 4 };
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `(match a { 0 => 10, _ => 20 })`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `1`
|
||||
--> $DIR/identity_op.rs:93:16
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:94:5
|
||||
|
|
||||
LL | 0 + if b { 0 + 1 } else { 2 } + match a { 0 => 0 + 30, _ => 40 };
|
||||
| ^^^^^
|
||||
LL | (if b { 1 } else { 2 }) + 0;
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `(if b { 1 } else { 2 })`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `30`
|
||||
--> $DIR/identity_op.rs:93:52
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:96:5
|
||||
|
|
||||
LL | 0 + if b { 0 + 1 } else { 2 } + match a { 0 => 0 + 30, _ => 40 };
|
||||
| ^^^^^^
|
||||
LL | 0 + { a } + 3;
|
||||
| ^^^^^^^^^ help: consider reducing it to: `({ a })`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `1`
|
||||
--> $DIR/identity_op.rs:95:20
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:97:5
|
||||
|
|
||||
LL | let _ = 0 + if 0 + 1 > 0 { 1 } else { 2 } + if 0 + 1 > 0 { 3 } else { 4 };
|
||||
| ^^^^^
|
||||
LL | 0 + { a } * 2;
|
||||
| ^^^^^^^^^^^^^ help: consider reducing it to: `({ a } * 2)`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `1`
|
||||
--> $DIR/identity_op.rs:95:52
|
||||
|
|
||||
LL | let _ = 0 + if 0 + 1 > 0 { 1 } else { 2 } + if 0 + 1 > 0 { 3 } else { 4 };
|
||||
| ^^^^^
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `1`
|
||||
--> $DIR/identity_op.rs:96:23
|
||||
|
|
||||
LL | let _ = 0 + match 0 + 1 { 0 => 10, _ => 20 } + match 0 + 1 { 0 => 30, _ => 40 };
|
||||
| ^^^^^
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `1`
|
||||
--> $DIR/identity_op.rs:96:58
|
||||
|
|
||||
LL | let _ = 0 + match 0 + 1 { 0 => 10, _ => 20 } + match 0 + 1 { 0 => 30, _ => 40 };
|
||||
| ^^^^^
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `0 + if b { 1 } else { 2 } + if b { 3 } else { 4 }`
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:98:5
|
||||
|
|
||||
LL | 0 + if b { 1 } else { 2 } + if b { 3 } else { 4 } + 0;
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
||||
LL | 0 + loop { let mut c = 0; if c == 10 { break c; } c += 1; } + { a * 2 };
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `(loop { let mut c = 0; if c == 10 { break c; } c += 1; })`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `a`
|
||||
--> $DIR/identity_op.rs:106:7
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:103:7
|
||||
|
|
||||
LL | f(1 * a + { 8 * 5 });
|
||||
| ^^^^^
|
||||
| ^^^^^ help: consider reducing it to: `a`
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `{ 2 * 4 }`
|
||||
--> $DIR/identity_op.rs:108:20
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:104:7
|
||||
|
|
||||
LL | f(0 + if b { 1 } else { 2 } + 3);
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `if b { 1 } else { 2 }`
|
||||
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:105:20
|
||||
|
|
||||
LL | const _: i32 = { 2 * 4 } + 0 + 3;
|
||||
| ^^^^^^^^^^^^^
|
||||
| ^^^^^^^^^^^^^ help: consider reducing it to: `{ 2 * 4 }`
|
||||
|
||||
error: aborting due to 33 previous errors
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:106:20
|
||||
|
|
||||
LL | const _: i32 = 0 + { 1 + 2 * 3 } + 3;
|
||||
| ^^^^^^^^^^^^^^^^^ help: consider reducing it to: `{ 1 + 2 * 3 }`
|
||||
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:108:5
|
||||
|
|
||||
LL | 0 + a as usize;
|
||||
| ^^^^^^^^^^^^^^ help: consider reducing it to: `a as usize`
|
||||
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:109:13
|
||||
|
|
||||
LL | let _ = 0 + a as usize;
|
||||
| ^^^^^^^^^^^^^^ help: consider reducing it to: `a as usize`
|
||||
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:110:5
|
||||
|
|
||||
LL | 0 + { a } as usize;
|
||||
| ^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `({ a } as usize)`
|
||||
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:112:9
|
||||
|
|
||||
LL | 2 * (0 + { a });
|
||||
| ^^^^^^^^^^^ help: consider reducing it to: `{ a }`
|
||||
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:113:5
|
||||
|
|
||||
LL | 1 * ({ a } + 4);
|
||||
| ^^^^^^^^^^^^^^^ help: consider reducing it to: `(({ a } + 4))`
|
||||
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:114:5
|
||||
|
|
||||
LL | 1 * 1;
|
||||
| ^^^^^ help: consider reducing it to: `1`
|
||||
|
||||
error: this operation has no effect
|
||||
--> $DIR/identity_op.rs:118:5
|
||||
|
|
||||
LL | 0 + if a { 1 } else { 2 } + if b { 3 } else { 5 }
|
||||
| ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider reducing it to: `(if a { 1 } else { 2 })`
|
||||
|
||||
error: aborting due to 39 previous errors
|
||||
|
||||
|
|
|
|||
|
|
@ -1,5 +1,5 @@
|
|||
#![warn(clippy::modulo_one)]
|
||||
#![allow(clippy::no_effect, clippy::unnecessary_operation)]
|
||||
#![allow(clippy::no_effect, clippy::unnecessary_operation, clippy::identity_op)]
|
||||
|
||||
static STATIC_ONE: usize = 2 - 1;
|
||||
static STATIC_NEG_ONE: i64 = 1 - 2;
|
||||
|
|
|
|||
|
|
@ -38,14 +38,6 @@ error: any number modulo -1 will panic/overflow or result in 0
|
|||
LL | i32::MIN % (-1); // also caught by rustc
|
||||
| ^^^^^^^^^^^^^^^
|
||||
|
||||
error: the operation is ineffective. Consider reducing it to `1`
|
||||
--> $DIR/modulo_one.rs:13:22
|
||||
|
|
||||
LL | const ONE: u32 = 1 * 1;
|
||||
| ^^^^^
|
||||
|
|
||||
= note: `-D clippy::identity-op` implied by `-D warnings`
|
||||
|
||||
error: any number modulo 1 will be 0
|
||||
--> $DIR/modulo_one.rs:17:5
|
||||
|
|
||||
|
|
@ -64,5 +56,5 @@ error: any number modulo -1 will panic/overflow or result in 0
|
|||
LL | INT_MIN % NEG_ONE; // also caught by rustc
|
||||
| ^^^^^^^^^^^^^^^^^
|
||||
|
||||
error: aborting due to 10 previous errors
|
||||
error: aborting due to 9 previous errors
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue