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Move MatchOnVecItems into Matches lint pass

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This commit is contained in:
Jason Newcomb 2022-06-03 13:10:57 -04:00
parent b337f9e62e
commit 3d8d734150
6 changed files with 103 additions and 108 deletions
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2
clippy_lints/src/lib.register_lints.rs
View File

@ -258,7 +258,6 @@
map_err_ignore::MAP_ERR_IGNORE,
map_unit_fn::OPTION_MAP_UNIT_FN,
map_unit_fn::RESULT_MAP_UNIT_FN,
match_on_vec_items::MATCH_ON_VEC_ITEMS,
match_result_ok::MATCH_RESULT_OK,
match_str_case_mismatch::MATCH_STR_CASE_MISMATCH,
matches::COLLAPSIBLE_MATCH,
@ -267,6 +266,7 @@
matches::MATCH_AS_REF,
matches::MATCH_BOOL,
matches::MATCH_LIKE_MATCHES_MACRO,
matches::MATCH_ON_VEC_ITEMS,
matches::MATCH_OVERLAPPING_ARM,
matches::MATCH_REF_PATS,
matches::MATCH_SAME_ARMS,

2
clippy_lints/src/lib.register_pedantic.rs
View File

@ -51,8 +51,8 @@
LintId::of(macro_use::MACRO_USE_IMPORTS),
LintId::of(manual_assert::MANUAL_ASSERT),
LintId::of(manual_ok_or::MANUAL_OK_OR),
LintId::of(match_on_vec_items::MATCH_ON_VEC_ITEMS),
LintId::of(matches::MATCH_BOOL),
LintId::of(matches::MATCH_ON_VEC_ITEMS),
LintId::of(matches::MATCH_SAME_ARMS),
LintId::of(matches::MATCH_WILDCARD_FOR_SINGLE_VARIANTS),
LintId::of(matches::MATCH_WILD_ERR_ARM),

2
clippy_lints/src/lib.rs
View File

@ -286,7 +286,6 @@ macro_rules! declare_clippy_lint {
mod map_clone;
mod map_err_ignore;
mod map_unit_fn;
mod match_on_vec_items;
mod match_result_ok;
mod match_str_case_mismatch;
mod matches;
@ -815,7 +814,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
store.register_late_pass(|| Box::new(if_not_else::IfNotElse));
store.register_late_pass(|| Box::new(equatable_if_let::PatternEquality));
store.register_late_pass(|| Box::new(mut_mutex_lock::MutMutexLock));
store.register_late_pass(|| Box::new(match_on_vec_items::MatchOnVecItems));
store.register_late_pass(|| Box::new(manual_async_fn::ManualAsyncFn));
store.register_late_pass(|| Box::new(vec_resize_to_zero::VecResizeToZero));
store.register_late_pass(|| Box::new(panic_in_result_fn::PanicInResultFn));

104
clippy_lints/src/match_on_vec_items.rs
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@ -1,104 +0,0 @@
use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::source::snippet;
use clippy_utils::ty::{is_type_diagnostic_item, is_type_lang_item};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir::{Expr, ExprKind, LangItem, MatchSource};
use rustc_lint::{LateContext, LateLintPass, LintContext};
use rustc_middle::lint::in_external_macro;
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::sym;
declare_clippy_lint! {
/// ### What it does
/// Checks for `match vec[idx]` or `match vec[n..m]`.
///
/// ### Why is this bad?
/// This can panic at runtime.
///
/// ### Example
/// ```rust, no_run
/// let arr = vec![0, 1, 2, 3];
/// let idx = 1;
///
/// // Bad
/// match arr[idx] {
/// 0 => println!("{}", 0),
/// 1 => println!("{}", 3),
/// _ => {},
/// }
/// ```
/// Use instead:
/// ```rust, no_run
/// let arr = vec![0, 1, 2, 3];
/// let idx = 1;
///
/// // Good
/// match arr.get(idx) {
/// Some(0) => println!("{}", 0),
/// Some(1) => println!("{}", 3),
/// _ => {},
/// }
/// ```
#[clippy::version = "1.45.0"]
pub MATCH_ON_VEC_ITEMS,
pedantic,
"matching on vector elements can panic"
}
declare_lint_pass!(MatchOnVecItems => [MATCH_ON_VEC_ITEMS]);
impl<'tcx> LateLintPass<'tcx> for MatchOnVecItems {
fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
if_chain! {
if !in_external_macro(cx.sess(), expr.span);
if let ExprKind::Match(match_expr, _, MatchSource::Normal) = expr.kind;
if let Some(idx_expr) = is_vec_indexing(cx, match_expr);
if let ExprKind::Index(vec, idx) = idx_expr.kind;
then {
// FIXME: could be improved to suggest surrounding every pattern with Some(_),
// but only when `or_patterns` are stabilized.
span_lint_and_sugg(
cx,
MATCH_ON_VEC_ITEMS,
match_expr.span,
"indexing into a vector may panic",
"try this",
format!(
"{}.get({})",
snippet(cx, vec.span, ".."),
snippet(cx, idx.span, "..")
),
Applicability::MaybeIncorrect
);
}
}
}
}
fn is_vec_indexing<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> Option<&'tcx Expr<'tcx>> {
if_chain! {
if let ExprKind::Index(array, index) = expr.kind;
if is_vector(cx, array);
if !is_full_range(cx, index);
then {
return Some(expr);
}
}
None
}
fn is_vector(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
let ty = cx.typeck_results().expr_ty(expr);
let ty = ty.peel_refs();
is_type_diagnostic_item(cx, ty, sym::Vec)
}
fn is_full_range(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
let ty = cx.typeck_results().expr_ty(expr);
let ty = ty.peel_refs();
is_type_lang_item(cx, ty, LangItem::RangeFull)
}

61
clippy_lints/src/matches/match_on_vec_items.rs Normal file
View File

@ -0,0 +1,61 @@
use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::source::snippet;
use clippy_utils::ty::{is_type_diagnostic_item, is_type_lang_item};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir::{Expr, ExprKind, LangItem};
use rustc_lint::LateContext;
use rustc_span::sym;
use super::MATCH_ON_VEC_ITEMS;
pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, scrutinee: &'tcx Expr<'_>) {
if_chain! {
if let Some(idx_expr) = is_vec_indexing(cx, scrutinee);
if let ExprKind::Index(vec, idx) = idx_expr.kind;
then {
// FIXME: could be improved to suggest surrounding every pattern with Some(_),
// but only when `or_patterns` are stabilized.
span_lint_and_sugg(
cx,
MATCH_ON_VEC_ITEMS,
scrutinee.span,
"indexing into a vector may panic",
"try this",
format!(
"{}.get({})",
snippet(cx, vec.span, ".."),
snippet(cx, idx.span, "..")
),
Applicability::MaybeIncorrect
);
}
}
}
fn is_vec_indexing<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> Option<&'tcx Expr<'tcx>> {
if_chain! {
if let ExprKind::Index(array, index) = expr.kind;
if is_vector(cx, array);
if !is_full_range(cx, index);
then {
return Some(expr);
}
}
None
}
fn is_vector(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
let ty = cx.typeck_results().expr_ty(expr);
let ty = ty.peel_refs();
is_type_diagnostic_item(cx, ty, sym::Vec)
}
fn is_full_range(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
let ty = cx.typeck_results().expr_ty(expr);
let ty = ty.peel_refs();
is_type_lang_item(cx, ty, LangItem::RangeFull)
}

40
clippy_lints/src/matches/mod.rs
View File

@ -14,6 +14,7 @@
mod match_as_ref;
mod match_bool;
mod match_like_matches;
mod match_on_vec_items;
mod match_ref_pats;
mod match_same_arms;
mod match_single_binding;
@ -678,6 +679,43 @@
"finds patterns that can be encoded more concisely with `Option::unwrap_or` or `Result::unwrap_or`"
}
declare_clippy_lint! {
/// ### What it does
/// Checks for `match vec[idx]` or `match vec[n..m]`.
///
/// ### Why is this bad?
/// This can panic at runtime.
///
/// ### Example
/// ```rust, no_run
/// let arr = vec![0, 1, 2, 3];
/// let idx = 1;
///
/// // Bad
/// match arr[idx] {
/// 0 => println!("{}", 0),
/// 1 => println!("{}", 3),
/// _ => {},
/// }
/// ```
/// Use instead:
/// ```rust, no_run
/// let arr = vec![0, 1, 2, 3];
/// let idx = 1;
///
/// // Good
/// match arr.get(idx) {
/// Some(0) => println!("{}", 0),
/// Some(1) => println!("{}", 3),
/// _ => {},
/// }
/// ```
#[clippy::version = "1.45.0"]
pub MATCH_ON_VEC_ITEMS,
pedantic,
"matching on vector elements can panic"
}
#[derive(Default)]
pub struct Matches {
msrv: Option<RustcVersion>,
@ -714,6 +752,7 @@ pub fn new(msrv: Option<RustcVersion>) -> Self {
NEEDLESS_MATCH,
COLLAPSIBLE_MATCH,
MANUAL_UNWRAP_OR,
MATCH_ON_VEC_ITEMS,
]);
impl<'tcx> LateLintPass<'tcx> for Matches {
@ -750,6 +789,7 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
match_wild_enum::check(cx, ex, arms);
match_as_ref::check(cx, ex, arms, expr);
needless_match::check_match(cx, ex, arms, expr);
match_on_vec_items::check(cx, ex);
if !in_constant(cx, expr.hir_id) {
manual_unwrap_or::check(cx, expr, ex, arms);