//! lint on indexing and slicing operations
use crate::consts::{constant, Constant};
-use crate::utils;
-use crate::utils::higher;
-use crate::utils::higher::Range;
-use rustc::declare_lint_pass;
-use rustc::hir::*;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::ty;
-use rustc_session::declare_tool_lint;
-use syntax::ast::RangeLimits;
+use crate::utils::{higher, span_lint, span_lint_and_help};
+use rustc_ast::ast::RangeLimits;
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
declare_clippy_lint! {
/// **What it does:** Checks for out of bounds array indexing with a constant
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for IndexingSlicing {
fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
if let ExprKind::Index(ref array, ref index) = &expr.kind {
- let ty = cx.tables.expr_ty(array);
+ let ty = cx.tables().expr_ty(array);
if let Some(range) = higher::range(cx, index) {
// Ranged indexes, i.e., &x[n..m], &x[n..], &x[..n] and &x[..]
if let ty::Array(_, s) = ty.kind {
- let size: u128 = s.eval_usize(cx.tcx, cx.param_env).into();
+ let size: u128 = if let Some(size) = s.try_eval_usize(cx.tcx, cx.param_env) {
+ size.into()
+ } else {
+ return;
+ };
let const_range = to_const_range(cx, range, size);
if let (Some(start), _) = const_range {
if start > size {
- utils::span_lint(
+ span_lint(
cx,
OUT_OF_BOUNDS_INDEXING,
range.start.map_or(expr.span, |start| start.span),
if let (_, Some(end)) = const_range {
if end > size {
- utils::span_lint(
+ span_lint(
cx,
OUT_OF_BOUNDS_INDEXING,
range.end.map_or(expr.span, |end| end.span),
(None, None) => return, // [..] is ok.
};
- utils::span_help_and_lint(cx, INDEXING_SLICING, expr.span, "slicing may panic.", help_msg);
+ span_lint_and_help(cx, INDEXING_SLICING, expr.span, "slicing may panic.", None, help_msg);
} else {
// Catchall non-range index, i.e., [n] or [n << m]
if let ty::Array(..) = ty.kind {
// Index is a constant uint.
- if let Some(..) = constant(cx, cx.tables, index) {
+ if let Some(..) = constant(cx, cx.tables(), index) {
// Let rustc's `const_err` lint handle constant `usize` indexing on arrays.
return;
}
}
- utils::span_help_and_lint(
+ span_lint_and_help(
cx,
INDEXING_SLICING,
expr.span,
"indexing may panic.",
+ None,
"Consider using `.get(n)` or `.get_mut(n)` instead",
);
}
/// the range. If the start or end is not constant, None is returned.
fn to_const_range<'a, 'tcx>(
cx: &LateContext<'a, 'tcx>,
- range: Range<'_>,
+ range: higher::Range<'_>,
array_size: u128,
) -> (Option<u128>, Option<u128>) {
- let s = range.start.map(|expr| constant(cx, cx.tables, expr).map(|(c, _)| c));
+ let s = range.start.map(|expr| constant(cx, cx.tables(), expr).map(|(c, _)| c));
let start = match s {
Some(Some(Constant::Int(x))) => Some(x),
Some(_) => None,
None => Some(0),
};
- let e = range.end.map(|expr| constant(cx, cx.tables, expr).map(|(c, _)| c));
+ let e = range.end.map(|expr| constant(cx, cx.tables(), expr).map(|(c, _)| c));
let end = match e {
Some(Some(Constant::Int(x))) => {
if range.limits == RangeLimits::Closed {