//! lint on blocks unnecessarily using >= with a + 1 or - 1
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::source::snippet_opt;
use rustc_ast::ast::{BinOpKind, Expr, ExprKind, Lit, LitKind};
use rustc_errors::Applicability;
use rustc_lint::{EarlyContext, EarlyLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
-use crate::utils::{snippet_opt, span_lint_and_then};
-
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `x >= y + 1` or `x - 1 >= y` (and `<=`) in a block
- ///
+ /// ### What it does
+ /// Checks for usage of `x >= y + 1` or `x - 1 >= y` (and `<=`) in a block
///
- /// **Why is this bad?** Readability -- better to use `> y` instead of `>= y + 1`.
+ /// ### Why is this bad?
+ /// Readability -- better to use `> y` instead of `>= y + 1`.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// # let x = 1;
/// # let y = 1;
/// # let y = 1;
/// if x > y {}
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub INT_PLUS_ONE,
complexity,
"instead of using `x >= y + 1`, use `x > y`"
#[derive(Copy, Clone)]
enum Side {
- LHS,
- RHS,
+ Lhs,
+ Rhs,
}
impl IntPlusOne {
match (lhskind.node, &lhslhs.kind, &lhsrhs.kind) {
// `-1 + x`
(BinOpKind::Add, &ExprKind::Lit(ref lit), _) if Self::check_lit(lit, -1) => {
- Self::generate_recommendation(cx, binop, lhsrhs, rhs, Side::LHS)
+ Self::generate_recommendation(cx, binop, lhsrhs, rhs, Side::Lhs)
},
// `x - 1`
(BinOpKind::Sub, _, &ExprKind::Lit(ref lit)) if Self::check_lit(lit, 1) => {
- Self::generate_recommendation(cx, binop, lhslhs, rhs, Side::LHS)
+ Self::generate_recommendation(cx, binop, lhslhs, rhs, Side::Lhs)
},
_ => None,
}
match (&rhslhs.kind, &rhsrhs.kind) {
// `y + 1` and `1 + y`
(&ExprKind::Lit(ref lit), _) if Self::check_lit(lit, 1) => {
- Self::generate_recommendation(cx, binop, rhsrhs, lhs, Side::RHS)
+ Self::generate_recommendation(cx, binop, rhsrhs, lhs, Side::Rhs)
},
(_, &ExprKind::Lit(ref lit)) if Self::check_lit(lit, 1) => {
- Self::generate_recommendation(cx, binop, rhslhs, lhs, Side::RHS)
+ Self::generate_recommendation(cx, binop, rhslhs, lhs, Side::Rhs)
},
_ => None,
}
- }
+ },
// case where `x + 1 <= ...` or `1 + x <= ...`
(BinOpKind::Le, &ExprKind::Binary(ref lhskind, ref lhslhs, ref lhsrhs), _)
if lhskind.node == BinOpKind::Add =>
match (&lhslhs.kind, &lhsrhs.kind) {
// `1 + x` and `x + 1`
(&ExprKind::Lit(ref lit), _) if Self::check_lit(lit, 1) => {
- Self::generate_recommendation(cx, binop, lhsrhs, rhs, Side::LHS)
+ Self::generate_recommendation(cx, binop, lhsrhs, rhs, Side::Lhs)
},
(_, &ExprKind::Lit(ref lit)) if Self::check_lit(lit, 1) => {
- Self::generate_recommendation(cx, binop, lhslhs, rhs, Side::LHS)
+ Self::generate_recommendation(cx, binop, lhslhs, rhs, Side::Lhs)
},
_ => None,
}
- }
+ },
// case where `... >= y - 1` or `... >= -1 + y`
(BinOpKind::Le, _, &ExprKind::Binary(ref rhskind, ref rhslhs, ref rhsrhs)) => {
match (rhskind.node, &rhslhs.kind, &rhsrhs.kind) {
// `-1 + y`
(BinOpKind::Add, &ExprKind::Lit(ref lit), _) if Self::check_lit(lit, -1) => {
- Self::generate_recommendation(cx, binop, rhsrhs, lhs, Side::RHS)
+ Self::generate_recommendation(cx, binop, rhsrhs, lhs, Side::Rhs)
},
// `y - 1`
(BinOpKind::Sub, _, &ExprKind::Lit(ref lit)) if Self::check_lit(lit, 1) => {
- Self::generate_recommendation(cx, binop, rhslhs, lhs, Side::RHS)
+ Self::generate_recommendation(cx, binop, rhslhs, lhs, Side::Rhs)
},
_ => None,
}
if let Some(snippet) = snippet_opt(cx, node.span) {
if let Some(other_side_snippet) = snippet_opt(cx, other_side.span) {
let rec = match side {
- Side::LHS => Some(format!("{} {} {}", snippet, binop_string, other_side_snippet)),
- Side::RHS => Some(format!("{} {} {}", other_side_snippet, binop_string, snippet)),
+ Side::Lhs => Some(format!("{} {} {}", snippet, binop_string, other_side_snippet)),
+ Side::Rhs => Some(format!("{} {} {}", other_side_snippet, binop_string, snippet)),
};
return rec;
}
}
fn emit_warning(cx: &EarlyContext<'_>, block: &Expr, recommendation: String) {
- span_lint_and_then(
+ span_lint_and_sugg(
cx,
INT_PLUS_ONE,
block.span,
- "Unnecessary `>= y + 1` or `x - 1 >=`",
- |diag| {
- diag.span_suggestion(
- block.span,
- "change it to",
- recommendation,
- Applicability::MachineApplicable, // snippet
- );
- },
+ "unnecessary `>= y + 1` or `x - 1 >=`",
+ "change it to",
+ recommendation,
+ Applicability::MachineApplicable, // snippet
);
}
}
impl EarlyLintPass for IntPlusOne {
fn check_expr(&mut self, cx: &EarlyContext<'_>, item: &Expr) {
if let ExprKind::Binary(ref kind, ref lhs, ref rhs) = item.kind {
- if let Some(ref rec) = Self::check_binop(cx, kind.node, lhs, rhs) {
- Self::emit_warning(cx, item, rec.clone());
+ if let Some(rec) = Self::check_binop(cx, kind.node, lhs, rhs) {
+ Self::emit_warning(cx, item, rec);
}
}
}