54 lines
1.8 KiB
Rust
54 lines
1.8 KiB
Rust
use clippy_utils::diagnostics::span_lint_and_sugg;
|
|
use clippy_utils::source::snippet_with_applicability;
|
|
use clippy_utils::ty::is_type_diagnostic_item;
|
|
use rustc_ast::LitKind;
|
|
use rustc_data_structures::packed::Pu128;
|
|
use rustc_errors::Applicability;
|
|
use rustc_hir as hir;
|
|
use rustc_lint::LateContext;
|
|
use rustc_span::source_map::Spanned;
|
|
use rustc_span::sym;
|
|
|
|
use super::GET_FIRST;
|
|
|
|
pub(super) fn check<'tcx>(
|
|
cx: &LateContext<'tcx>,
|
|
expr: &'tcx hir::Expr<'_>,
|
|
recv: &'tcx hir::Expr<'_>,
|
|
arg: &'tcx hir::Expr<'_>,
|
|
) {
|
|
if let Some(method_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id)
|
|
&& let Some(impl_id) = cx.tcx.impl_of_method(method_id)
|
|
&& let identity = cx.tcx.type_of(impl_id).instantiate_identity()
|
|
&& let hir::ExprKind::Lit(Spanned {
|
|
node: LitKind::Int(Pu128(0), _),
|
|
..
|
|
}) = arg.kind
|
|
{
|
|
if identity.is_slice() {
|
|
let mut app = Applicability::MachineApplicable;
|
|
let slice_name = snippet_with_applicability(cx, recv.span, "..", &mut app);
|
|
span_lint_and_sugg(
|
|
cx,
|
|
GET_FIRST,
|
|
expr.span,
|
|
format!("accessing first element with `{slice_name}.get(0)`"),
|
|
"try",
|
|
format!("{slice_name}.first()"),
|
|
app,
|
|
);
|
|
} else if is_type_diagnostic_item(cx, identity, sym::VecDeque) {
|
|
let mut app = Applicability::MachineApplicable;
|
|
let slice_name = snippet_with_applicability(cx, recv.span, "..", &mut app);
|
|
span_lint_and_sugg(
|
|
cx,
|
|
GET_FIRST,
|
|
expr.span,
|
|
format!("accessing first element with `{slice_name}.get(0)`"),
|
|
"try",
|
|
format!("{slice_name}.front()"),
|
|
app,
|
|
);
|
|
}
|
|
}
|
|
}
|