-use crate::consts::{constant, Constant};
+use clippy_utils::consts::{constant, Constant};
use clippy_utils::diagnostics::{span_lint, span_lint_and_sugg, span_lint_and_then};
use clippy_utils::source::{snippet, snippet_opt, snippet_with_applicability};
use clippy_utils::sugg::Sugg;
use rustc_ast::ast::RangeLimits;
use rustc_errors::Applicability;
use rustc_hir::{BinOpKind, Expr, ExprKind, PathSegment, QPath};
-use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_lint::{LateContext, LateLintPass};
use rustc_middle::ty;
use rustc_semver::RustcVersion;
use rustc_session::{declare_tool_lint, impl_lint_pass};
use std::cmp::Ordering;
declare_clippy_lint! {
- /// **What it does:** Checks for zipping a collection with the range of
+ /// ### What it does
+ /// Checks for zipping a collection with the range of
/// `0.._.len()`.
///
- /// **Why is this bad?** The code is better expressed with `.enumerate()`.
+ /// ### Why is this bad?
+ /// The code is better expressed with `.enumerate()`.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// # let x = vec![1];
/// x.iter().zip(0..x.len());
/// # let x = vec![1];
/// x.iter().enumerate();
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub RANGE_ZIP_WITH_LEN,
complexity,
"zipping iterator with a range when `enumerate()` would do"
}
declare_clippy_lint! {
- /// **What it does:** Checks for exclusive ranges where 1 is added to the
+ /// ### What it does
+ /// Checks for exclusive ranges where 1 is added to the
/// upper bound, e.g., `x..(y+1)`.
///
- /// **Why is this bad?** The code is more readable with an inclusive range
+ /// ### Why is this bad?
+ /// The code is more readable with an inclusive range
/// like `x..=y`.
///
- /// **Known problems:** Will add unnecessary pair of parentheses when the
- /// expression is not wrapped in a pair but starts with a opening parenthesis
+ /// ### Known problems
+ /// Will add unnecessary pair of parentheses when the
+ /// expression is not wrapped in a pair but starts with an opening parenthesis
/// and ends with a closing one.
/// I.e., `let _ = (f()+1)..(f()+1)` results in `let _ = ((f()+1)..=f())`.
///
/// `RangeBounds` trait
/// ([#3307](https://github.com/rust-lang/rust-clippy/issues/3307)).
///
- /// **Example:**
+ /// ### Example
/// ```rust,ignore
/// for x..(y+1) { .. }
/// ```
/// ```rust,ignore
/// for x..=y { .. }
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub RANGE_PLUS_ONE,
pedantic,
"`x..(y+1)` reads better as `x..=y`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for inclusive ranges where 1 is subtracted from
+ /// ### What it does
+ /// Checks for inclusive ranges where 1 is subtracted from
/// the upper bound, e.g., `x..=(y-1)`.
///
- /// **Why is this bad?** The code is more readable with an exclusive range
+ /// ### Why is this bad?
+ /// The code is more readable with an exclusive range
/// like `x..y`.
///
- /// **Known problems:** This will cause a warning that cannot be fixed if
+ /// ### Known problems
+ /// This will cause a warning that cannot be fixed if
/// the consumer of the range only accepts a specific range type, instead of
/// the generic `RangeBounds` trait
/// ([#3307](https://github.com/rust-lang/rust-clippy/issues/3307)).
///
- /// **Example:**
+ /// ### Example
/// ```rust,ignore
/// for x..=(y-1) { .. }
/// ```
/// ```rust,ignore
/// for x..y { .. }
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub RANGE_MINUS_ONE,
pedantic,
"`x..=(y-1)` reads better as `x..y`"
}
declare_clippy_lint! {
- /// **What it does:** Checks for range expressions `x..y` where both `x` and `y`
+ /// ### What it does
+ /// Checks for range expressions `x..y` where both `x` and `y`
/// are constant and `x` is greater or equal to `y`.
///
- /// **Why is this bad?** Empty ranges yield no values so iterating them is a no-op.
+ /// ### Why is this bad?
+ /// Empty ranges yield no values so iterating them is a no-op.
/// Moreover, trying to use a reversed range to index a slice will panic at run-time.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
- ///
+ /// ### Example
/// ```rust,no_run
/// fn main() {
/// (10..=0).for_each(|x| println!("{}", x));
/// let sub = &arr[1..3];
/// }
/// ```
+ #[clippy::version = "1.45.0"]
pub REVERSED_EMPTY_RANGES,
correctness,
"reversing the limits of range expressions, resulting in empty ranges"
}
declare_clippy_lint! {
- /// **What it does:** Checks for expressions like `x >= 3 && x < 8` that could
+ /// ### What it does
+ /// Checks for expressions like `x >= 3 && x < 8` that could
/// be more readably expressed as `(3..8).contains(x)`.
///
- /// **Why is this bad?** `contains` expresses the intent better and has less
+ /// ### Why is this bad?
+ /// `contains` expresses the intent better and has less
/// failure modes (such as fencepost errors or using `||` instead of `&&`).
///
- /// **Known problems:** None.
- ///
- /// **Example:**
- ///
+ /// ### Example
/// ```rust
/// // given
/// let x = 6;
///# let x = 6;
/// assert!((3..8).contains(&x));
/// ```
+ #[clippy::version = "1.49.0"]
pub MANUAL_RANGE_CONTAINS,
style,
"manually reimplementing {`Range`, `RangeInclusive`}`::contains`"
impl<'tcx> LateLintPass<'tcx> for Ranges {
fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
match expr.kind {
- ExprKind::MethodCall(path, _, args, _) => {
+ ExprKind::MethodCall(path, args, _) => {
check_range_zip_with_len(cx, path, args, expr.span);
},
ExprKind::Binary(ref op, l, r) => {
if path.ident.as_str() == "zip";
if let [iter, zip_arg] = args;
// `.iter()` call
- if let ExprKind::MethodCall(iter_path, _, iter_args, _) = iter.kind;
+ if let ExprKind::MethodCall(iter_path, iter_args, _) = iter.kind;
if iter_path.ident.name == sym::iter;
// range expression in `.zip()` call: `0..x.len()`
- if let Some(higher::Range { start: Some(start), end: Some(end), .. }) = higher::range(zip_arg);
+ if let Some(higher::Range { start: Some(start), end: Some(end), .. }) = higher::Range::hir(zip_arg);
if is_integer_const(cx, start, 0);
// `.len()` call
- if let ExprKind::MethodCall(len_path, _, len_args, _) = end.kind;
- if len_path.ident.name == sym!(len) && len_args.len() == 1;
+ if let ExprKind::MethodCall(len_path, len_args, _) = end.kind;
+ if len_path.ident.name == sym::len && len_args.len() == 1;
// `.iter()` and `.len()` called on same `Path`
if let ExprKind::Path(QPath::Resolved(_, iter_path)) = iter_args[0].kind;
if let ExprKind::Path(QPath::Resolved(_, len_path)) = len_args[0].kind;
start,
end: Some(end),
limits: RangeLimits::HalfOpen
- }) = higher::range(expr);
+ }) = higher::Range::hir(expr);
if let Some(y) = y_plus_one(cx, end);
then {
let span = if expr.span.from_expansion() {
span,
"an inclusive range would be more readable",
|diag| {
- let start = start.map_or(String::new(), |x| Sugg::hir(cx, x, "x").to_string());
- let end = Sugg::hir(cx, y, "y");
+ let start = start.map_or(String::new(), |x| Sugg::hir(cx, x, "x").maybe_par().to_string());
+ let end = Sugg::hir(cx, y, "y").maybe_par();
if let Some(is_wrapped) = &snippet_opt(cx, span) {
if is_wrapped.starts_with('(') && is_wrapped.ends_with(')') {
diag.span_suggestion(
// inclusive range minus one: `x..=(y-1)`
fn check_inclusive_range_minus_one(cx: &LateContext<'_>, expr: &Expr<'_>) {
if_chain! {
- if let Some(higher::Range { start, end: Some(end), limits: RangeLimits::Closed }) = higher::range(expr);
+ if let Some(higher::Range { start, end: Some(end), limits: RangeLimits::Closed }) = higher::Range::hir(expr);
if let Some(y) = y_minus_one(cx, end);
then {
span_lint_and_then(
expr.span,
"an exclusive range would be more readable",
|diag| {
- let start = start.map_or(String::new(), |x| Sugg::hir(cx, x, "x").to_string());
- let end = Sugg::hir(cx, y, "y");
+ let start = start.map_or(String::new(), |x| Sugg::hir(cx, x, "x").maybe_par().to_string());
+ let end = Sugg::hir(cx, y, "y").maybe_par();
diag.span_suggestion(
expr.span,
"use",
fn is_for_loop_arg(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
let mut cur_expr = expr;
while let Some(parent_expr) = get_parent_expr(cx, cur_expr) {
- match higher::for_loop(parent_expr) {
- Some((_, args, _, _)) if args.hir_id == expr.hir_id => return true,
+ match higher::ForLoop::hir(parent_expr) {
+ Some(higher::ForLoop { arg, .. }) if arg.hir_id == expr.hir_id => return true,
_ => cur_expr = parent_expr,
}
}
}
if_chain! {
- if let Some(higher::Range { start: Some(start), end: Some(end), limits }) = higher::range(expr);
+ if let Some(higher::Range { start: Some(start), end: Some(end), limits }) = higher::Range::hir(expr);
let ty = cx.typeck_results().expr_ty(start);
if let ty::Int(_) | ty::Uint(_) = ty.kind();
if let Some((start_idx, _)) = constant(cx, cx.typeck_results(), start);