Improve redundant_pattern_matching

Add a note when the drop order change may result in different behaviour.
This commit is contained in:
Jason Newcomb 2021-01-03 14:01:01 -05:00
parent 586a99348c
commit b6581636bd
No known key found for this signature in database
GPG key ID: DA59E8643A37ED06
13 changed files with 579 additions and 89 deletions

View file

@ -423,7 +423,12 @@ declare_clippy_lint! {
/// **Why is this bad?** It's more concise and clear to just use the proper
/// utility function
///
/// **Known problems:** None.
/// **Known problems:** This will change the drop order for the matched type. Both `if let` and
/// `while let` will drop the value at the end of the block, both `if` and `while` will drop the
/// value before entering the block. For most types this change will not matter, but for a few
/// types this will not be an acceptable change (e.g. locks). See the
/// [reference](https://doc.rust-lang.org/reference/destructors.html#drop-scopes) for more about
/// drop order.
///
/// **Example:**
///
@ -1700,55 +1705,204 @@ where
mod redundant_pattern_match {
use super::REDUNDANT_PATTERN_MATCHING;
use clippy_utils::diagnostics::span_lint_and_then;
use clippy_utils::source::snippet;
use clippy_utils::source::{snippet, snippet_with_applicability};
use clippy_utils::ty::{implements_trait, is_type_diagnostic_item, is_type_lang_item, match_type};
use clippy_utils::{is_lang_ctor, is_qpath_def_path, is_trait_method, paths};
use if_chain::if_chain;
use rustc_ast::ast::LitKind;
use rustc_errors::Applicability;
use rustc_hir::LangItem::{OptionNone, OptionSome, PollPending, PollReady, ResultErr, ResultOk};
use rustc_hir::{Arm, Expr, ExprKind, MatchSource, PatKind, QPath};
use rustc_hir::{
intravisit::{walk_expr, ErasedMap, NestedVisitorMap, Visitor},
Arm, Block, Expr, ExprKind, LangItem, MatchSource, Node, PatKind, QPath,
};
use rustc_lint::LateContext;
use rustc_middle::ty::{self, subst::GenericArgKind, Ty};
use rustc_span::sym;
pub fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
if let ExprKind::Match(op, arms, ref match_source) = &expr.kind {
match match_source {
MatchSource::Normal => find_sugg_for_match(cx, expr, op, arms),
MatchSource::IfLetDesugar { .. } => find_sugg_for_if_let(cx, expr, op, arms, "if"),
MatchSource::WhileLetDesugar => find_sugg_for_if_let(cx, expr, op, arms, "while"),
MatchSource::IfLetDesugar { contains_else_clause } => {
find_sugg_for_if_let(cx, expr, op, &arms[0], "if", *contains_else_clause)
},
MatchSource::WhileLetDesugar => find_sugg_for_if_let(cx, expr, op, &arms[0], "while", false),
_ => {},
}
}
}
// Check if the drop order for a type matters
fn type_needs_ordered_drop(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
if !ty.needs_drop(cx.tcx, cx.param_env) {
false
} else if cx
.tcx
.lang_items()
.drop_trait()
.map_or(false, |id| !implements_trait(cx, ty, id, &[]))
{
// This type doesn't implement drop, so no side effects here.
// Check if any component type has any.
match ty.kind() {
ty::Tuple(_) => ty.tuple_fields().any(|ty| type_needs_ordered_drop(cx, ty)),
ty::Array(ty, _) => type_needs_ordered_drop(cx, ty),
ty::Adt(adt, subs) => adt
.all_fields()
.map(|f| f.ty(cx.tcx, subs))
.any(|ty| type_needs_ordered_drop(cx, ty)),
_ => true,
}
}
// Check for std types which implement drop, but only for memory allocation.
else if is_type_diagnostic_item(cx, ty, sym::vec_type)
|| is_type_lang_item(cx, ty, LangItem::OwnedBox)
|| is_type_diagnostic_item(cx, ty, sym::Rc)
|| is_type_diagnostic_item(cx, ty, sym::Arc)
|| is_type_diagnostic_item(cx, ty, sym::cstring_type)
|| match_type(cx, ty, &paths::BTREEMAP)
|| match_type(cx, ty, &paths::LINKED_LIST)
|| match_type(cx, ty, &paths::WEAK_RC)
|| match_type(cx, ty, &paths::WEAK_ARC)
{
// Check all of the generic arguments.
if let ty::Adt(_, subs) = ty.kind() {
subs.types().any(|ty| type_needs_ordered_drop(cx, ty))
} else {
true
}
} else {
true
}
}
// Extract the generic arguments out of a type
fn try_get_generic_ty(ty: Ty<'_>, index: usize) -> Option<Ty<'_>> {
if_chain! {
if let ty::Adt(_, subs) = ty.kind();
if let Some(sub) = subs.get(index);
if let GenericArgKind::Type(sub_ty) = sub.unpack();
then {
Some(sub_ty)
} else {
None
}
}
}
// Checks if there are any temporaries created in the given expression for which drop order
// matters.
fn temporaries_need_ordered_drop(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> bool {
struct V<'a, 'tcx> {
cx: &'a LateContext<'tcx>,
res: bool,
}
impl<'a, 'tcx> Visitor<'tcx> for V<'a, 'tcx> {
type Map = ErasedMap<'tcx>;
fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
NestedVisitorMap::None
}
fn visit_expr(&mut self, expr: &'tcx Expr<'tcx>) {
match expr.kind {
// Taking the reference of a value leaves a temporary
// e.g. In `&String::new()` the string is a temporary value.
// Remaining fields are temporary values
// e.g. In `(String::new(), 0).1` the string is a temporary value.
ExprKind::AddrOf(_, _, expr) | ExprKind::Field(expr, _) => {
if !matches!(expr.kind, ExprKind::Path(_)) {
if type_needs_ordered_drop(self.cx, self.cx.typeck_results().expr_ty(expr)) {
self.res = true;
} else {
self.visit_expr(expr);
}
}
},
// the base type is alway taken by reference.
// e.g. In `(vec![0])[0]` the vector is a temporary value.
ExprKind::Index(base, index) => {
if !matches!(base.kind, ExprKind::Path(_)) {
if type_needs_ordered_drop(self.cx, self.cx.typeck_results().expr_ty(base)) {
self.res = true;
} else {
self.visit_expr(base);
}
}
self.visit_expr(index);
},
// Method calls can take self by reference.
// e.g. In `String::new().len()` the string is a temporary value.
ExprKind::MethodCall(_, _, [self_arg, args @ ..], _) => {
if !matches!(self_arg.kind, ExprKind::Path(_)) {
let self_by_ref = self
.cx
.typeck_results()
.type_dependent_def_id(expr.hir_id)
.map_or(false, |id| self.cx.tcx.fn_sig(id).skip_binder().inputs()[0].is_ref());
if self_by_ref
&& type_needs_ordered_drop(self.cx, self.cx.typeck_results().expr_ty(self_arg))
{
self.res = true;
} else {
self.visit_expr(self_arg)
}
}
args.iter().for_each(|arg| self.visit_expr(arg));
},
// Either explicitly drops values, or changes control flow.
ExprKind::DropTemps(_)
| ExprKind::Ret(_)
| ExprKind::Break(..)
| ExprKind::Yield(..)
| ExprKind::Block(Block { expr: None, .. }, _)
| ExprKind::Loop(..) => (),
// Only consider the final expression.
ExprKind::Block(Block { expr: Some(expr), .. }, _) => self.visit_expr(expr),
_ => walk_expr(self, expr),
}
}
}
let mut v = V { cx, res: false };
v.visit_expr(expr);
v.res
}
fn find_sugg_for_if_let<'tcx>(
cx: &LateContext<'tcx>,
expr: &'tcx Expr<'_>,
op: &Expr<'_>,
arms: &[Arm<'_>],
op: &'tcx Expr<'tcx>,
arm: &Arm<'_>,
keyword: &'static str,
has_else: bool,
) {
// also look inside refs
let mut kind = &arms[0].pat.kind;
let mut kind = &arm.pat.kind;
// if we have &None for example, peel it so we can detect "if let None = x"
if let PatKind::Ref(inner, _mutability) = kind {
kind = &inner.kind;
}
let good_method = match kind {
let op_ty = cx.typeck_results().expr_ty(op);
// Determine which function should be used, and the type contained by the corresponding
// variant.
let (good_method, inner_ty) = match kind {
PatKind::TupleStruct(ref path, [sub_pat], _) => {
if let PatKind::Wild = sub_pat.kind {
if is_lang_ctor(cx, path, ResultOk) {
"is_ok()"
("is_ok()", try_get_generic_ty(op_ty, 0).unwrap_or(op_ty))
} else if is_lang_ctor(cx, path, ResultErr) {
"is_err()"
("is_err()", try_get_generic_ty(op_ty, 1).unwrap_or(op_ty))
} else if is_lang_ctor(cx, path, OptionSome) {
"is_some()"
("is_some()", op_ty)
} else if is_lang_ctor(cx, path, PollReady) {
"is_ready()"
("is_ready()", op_ty)
} else if is_qpath_def_path(cx, path, sub_pat.hir_id, &paths::IPADDR_V4) {
"is_ipv4()"
("is_ipv4()", op_ty)
} else if is_qpath_def_path(cx, path, sub_pat.hir_id, &paths::IPADDR_V6) {
"is_ipv6()"
("is_ipv6()", op_ty)
} else {
return;
}
@ -1757,17 +1911,36 @@ mod redundant_pattern_match {
}
},
PatKind::Path(ref path) => {
if is_lang_ctor(cx, path, OptionNone) {
let method = if is_lang_ctor(cx, path, OptionNone) {
"is_none()"
} else if is_lang_ctor(cx, path, PollPending) {
"is_pending()"
} else {
return;
}
};
// `None` and `Pending` don't have an inner type.
(method, cx.tcx.types.unit)
},
_ => return,
};
// If this is the last expression in a block or there is an else clause then the whole
// type needs to be considered, not just the inner type of the branch being matched on.
// Note the last expression in a block is dropped after all local bindings.
let check_ty = if has_else
|| (keyword == "if" && matches!(cx.tcx.hir().parent_iter(expr.hir_id).next(), Some((_, Node::Block(..)))))
{
op_ty
} else {
inner_ty
};
// All temporaries created in the scrutinee expression are dropped at the same time as the
// scrutinee would be, so they have to be considered as well.
// e.g. in `if let Some(x) = foo.lock().unwrap().baz.as_ref() { .. }` the lock will be held
// for the duration if body.
let needs_drop = type_needs_ordered_drop(cx, check_ty) || temporaries_need_ordered_drop(cx, op);
// check that `while_let_on_iterator` lint does not trigger
if_chain! {
if keyword == "while";
@ -1786,7 +1959,7 @@ mod redundant_pattern_match {
span_lint_and_then(
cx,
REDUNDANT_PATTERN_MATCHING,
arms[0].pat.span,
arm.pat.span,
&format!("redundant pattern matching, consider using `{}`", good_method),
|diag| {
// while let ... = ... { ... }
@ -1800,12 +1973,20 @@ mod redundant_pattern_match {
// while let ... = ... { ... }
// ^^^^^^^^^^^^^^^^^^^
let span = expr_span.until(op_span.shrink_to_hi());
diag.span_suggestion(
span,
"try this",
format!("{} {}.{}", keyword, snippet(cx, op_span, "_"), good_method),
Applicability::MachineApplicable, // snippet
);
let mut app = if needs_drop {
Applicability::MaybeIncorrect
} else {
Applicability::MachineApplicable
};
let sugg = snippet_with_applicability(cx, op_span, "_", &mut app);
diag.span_suggestion(span, "try this", format!("{} {}.{}", keyword, sugg, good_method), app);
if needs_drop {
diag.note("this will change drop order of the result, as well as all temporaries");
diag.note("add `#[allow(clippy::redundant_pattern_matching)]` if this is important");
}
},
);
}

View file

@ -0,0 +1,58 @@
// run-rustfix
// Issue #5746
#![warn(clippy::redundant_pattern_matching)]
#![allow(clippy::if_same_then_else)]
use std::task::Poll::{Pending, Ready};
fn main() {
let m = std::sync::Mutex::new((0, 0));
// Result
if m.lock().is_ok() {}
if Err::<(), _>(m.lock().unwrap().0).is_err() {}
{
if Ok::<_, std::sync::MutexGuard<()>>(()).is_ok() {}
}
if Ok::<_, std::sync::MutexGuard<()>>(()).is_ok() {
} else {
}
if Ok::<_, std::sync::MutexGuard<()>>(()).is_ok() {}
if Err::<std::sync::MutexGuard<()>, _>(()).is_err() {}
if Ok::<_, ()>(String::new()).is_ok() {}
if Err::<(), _>((String::new(), ())).is_err() {}
// Option
if Some(m.lock()).is_some() {}
if Some(m.lock().unwrap().0).is_some() {}
{
if None::<std::sync::MutexGuard<()>>.is_none() {}
}
if None::<std::sync::MutexGuard<()>>.is_none() {
} else {
}
if None::<std::sync::MutexGuard<()>>.is_none() {}
if Some(String::new()).is_some() {}
if Some((String::new(), ())).is_some() {}
// Poll
if Ready(m.lock()).is_ready() {}
if Ready(m.lock().unwrap().0).is_ready() {}
{
if Pending::<std::sync::MutexGuard<()>>.is_pending() {}
}
if Pending::<std::sync::MutexGuard<()>>.is_pending() {
} else {
}
if Pending::<std::sync::MutexGuard<()>>.is_pending() {}
if Ready(String::new()).is_ready() {}
if Ready((String::new(), ())).is_ready() {}
}

View file

@ -0,0 +1,58 @@
// run-rustfix
// Issue #5746
#![warn(clippy::redundant_pattern_matching)]
#![allow(clippy::if_same_then_else)]
use std::task::Poll::{Pending, Ready};
fn main() {
let m = std::sync::Mutex::new((0, 0));
// Result
if let Ok(_) = m.lock() {}
if let Err(_) = Err::<(), _>(m.lock().unwrap().0) {}
{
if let Ok(_) = Ok::<_, std::sync::MutexGuard<()>>(()) {}
}
if let Ok(_) = Ok::<_, std::sync::MutexGuard<()>>(()) {
} else {
}
if let Ok(_) = Ok::<_, std::sync::MutexGuard<()>>(()) {}
if let Err(_) = Err::<std::sync::MutexGuard<()>, _>(()) {}
if let Ok(_) = Ok::<_, ()>(String::new()) {}
if let Err(_) = Err::<(), _>((String::new(), ())) {}
// Option
if let Some(_) = Some(m.lock()) {}
if let Some(_) = Some(m.lock().unwrap().0) {}
{
if let None = None::<std::sync::MutexGuard<()>> {}
}
if let None = None::<std::sync::MutexGuard<()>> {
} else {
}
if let None = None::<std::sync::MutexGuard<()>> {}
if let Some(_) = Some(String::new()) {}
if let Some(_) = Some((String::new(), ())) {}
// Poll
if let Ready(_) = Ready(m.lock()) {}
if let Ready(_) = Ready(m.lock().unwrap().0) {}
{
if let Pending = Pending::<std::sync::MutexGuard<()>> {}
}
if let Pending = Pending::<std::sync::MutexGuard<()>> {
} else {
}
if let Pending = Pending::<std::sync::MutexGuard<()>> {}
if let Ready(_) = Ready(String::new()) {}
if let Ready(_) = Ready((String::new(), ())) {}
}

View file

@ -0,0 +1,171 @@
error: redundant pattern matching, consider using `is_ok()`
--> $DIR/redundant_pattern_matching_drop_order.rs:12:12
|
LL | if let Ok(_) = m.lock() {}
| -------^^^^^----------- help: try this: `if m.lock().is_ok()`
|
= note: `-D clippy::redundant-pattern-matching` implied by `-D warnings`
= note: this will change drop order of the result, as well as all temporaries
= note: add `#[allow(clippy::redundant_pattern_matching)]` if this is important
error: redundant pattern matching, consider using `is_err()`
--> $DIR/redundant_pattern_matching_drop_order.rs:13:12
|
LL | if let Err(_) = Err::<(), _>(m.lock().unwrap().0) {}
| -------^^^^^^------------------------------------ help: try this: `if Err::<(), _>(m.lock().unwrap().0).is_err()`
|
= note: this will change drop order of the result, as well as all temporaries
= note: add `#[allow(clippy::redundant_pattern_matching)]` if this is important
error: redundant pattern matching, consider using `is_ok()`
--> $DIR/redundant_pattern_matching_drop_order.rs:16:16
|
LL | if let Ok(_) = Ok::<_, std::sync::MutexGuard<()>>(()) {}
| -------^^^^^----------------------------------------- help: try this: `if Ok::<_, std::sync::MutexGuard<()>>(()).is_ok()`
|
= note: this will change drop order of the result, as well as all temporaries
= note: add `#[allow(clippy::redundant_pattern_matching)]` if this is important
error: redundant pattern matching, consider using `is_ok()`
--> $DIR/redundant_pattern_matching_drop_order.rs:18:12
|
LL | if let Ok(_) = Ok::<_, std::sync::MutexGuard<()>>(()) {
| -------^^^^^----------------------------------------- help: try this: `if Ok::<_, std::sync::MutexGuard<()>>(()).is_ok()`
|
= note: this will change drop order of the result, as well as all temporaries
= note: add `#[allow(clippy::redundant_pattern_matching)]` if this is important
error: redundant pattern matching, consider using `is_ok()`
--> $DIR/redundant_pattern_matching_drop_order.rs:21:12
|
LL | if let Ok(_) = Ok::<_, std::sync::MutexGuard<()>>(()) {}
| -------^^^^^----------------------------------------- help: try this: `if Ok::<_, std::sync::MutexGuard<()>>(()).is_ok()`
error: redundant pattern matching, consider using `is_err()`
--> $DIR/redundant_pattern_matching_drop_order.rs:22:12
|
LL | if let Err(_) = Err::<std::sync::MutexGuard<()>, _>(()) {}
| -------^^^^^^------------------------------------------ help: try this: `if Err::<std::sync::MutexGuard<()>, _>(()).is_err()`
error: redundant pattern matching, consider using `is_ok()`
--> $DIR/redundant_pattern_matching_drop_order.rs:24:12
|
LL | if let Ok(_) = Ok::<_, ()>(String::new()) {}
| -------^^^^^----------------------------- help: try this: `if Ok::<_, ()>(String::new()).is_ok()`
error: redundant pattern matching, consider using `is_err()`
--> $DIR/redundant_pattern_matching_drop_order.rs:25:12
|
LL | if let Err(_) = Err::<(), _>((String::new(), ())) {}
| -------^^^^^^------------------------------------ help: try this: `if Err::<(), _>((String::new(), ())).is_err()`
error: redundant pattern matching, consider using `is_some()`
--> $DIR/redundant_pattern_matching_drop_order.rs:28:12
|
LL | if let Some(_) = Some(m.lock()) {}
| -------^^^^^^^----------------- help: try this: `if Some(m.lock()).is_some()`
|
= note: this will change drop order of the result, as well as all temporaries
= note: add `#[allow(clippy::redundant_pattern_matching)]` if this is important
error: redundant pattern matching, consider using `is_some()`
--> $DIR/redundant_pattern_matching_drop_order.rs:29:12
|
LL | if let Some(_) = Some(m.lock().unwrap().0) {}
| -------^^^^^^^---------------------------- help: try this: `if Some(m.lock().unwrap().0).is_some()`
|
= note: this will change drop order of the result, as well as all temporaries
= note: add `#[allow(clippy::redundant_pattern_matching)]` if this is important
error: redundant pattern matching, consider using `is_none()`
--> $DIR/redundant_pattern_matching_drop_order.rs:32:16
|
LL | if let None = None::<std::sync::MutexGuard<()>> {}
| -------^^^^------------------------------------ help: try this: `if None::<std::sync::MutexGuard<()>>.is_none()`
|
= note: this will change drop order of the result, as well as all temporaries
= note: add `#[allow(clippy::redundant_pattern_matching)]` if this is important
error: redundant pattern matching, consider using `is_none()`
--> $DIR/redundant_pattern_matching_drop_order.rs:34:12
|
LL | if let None = None::<std::sync::MutexGuard<()>> {
| -------^^^^------------------------------------ help: try this: `if None::<std::sync::MutexGuard<()>>.is_none()`
|
= note: this will change drop order of the result, as well as all temporaries
= note: add `#[allow(clippy::redundant_pattern_matching)]` if this is important
error: redundant pattern matching, consider using `is_none()`
--> $DIR/redundant_pattern_matching_drop_order.rs:38:12
|
LL | if let None = None::<std::sync::MutexGuard<()>> {}
| -------^^^^------------------------------------ help: try this: `if None::<std::sync::MutexGuard<()>>.is_none()`
error: redundant pattern matching, consider using `is_some()`
--> $DIR/redundant_pattern_matching_drop_order.rs:40:12
|
LL | if let Some(_) = Some(String::new()) {}
| -------^^^^^^^---------------------- help: try this: `if Some(String::new()).is_some()`
error: redundant pattern matching, consider using `is_some()`
--> $DIR/redundant_pattern_matching_drop_order.rs:41:12
|
LL | if let Some(_) = Some((String::new(), ())) {}
| -------^^^^^^^---------------------------- help: try this: `if Some((String::new(), ())).is_some()`
error: redundant pattern matching, consider using `is_ready()`
--> $DIR/redundant_pattern_matching_drop_order.rs:44:12
|
LL | if let Ready(_) = Ready(m.lock()) {}
| -------^^^^^^^^------------------ help: try this: `if Ready(m.lock()).is_ready()`
|
= note: this will change drop order of the result, as well as all temporaries
= note: add `#[allow(clippy::redundant_pattern_matching)]` if this is important
error: redundant pattern matching, consider using `is_ready()`
--> $DIR/redundant_pattern_matching_drop_order.rs:45:12
|
LL | if let Ready(_) = Ready(m.lock().unwrap().0) {}
| -------^^^^^^^^----------------------------- help: try this: `if Ready(m.lock().unwrap().0).is_ready()`
|
= note: this will change drop order of the result, as well as all temporaries
= note: add `#[allow(clippy::redundant_pattern_matching)]` if this is important
error: redundant pattern matching, consider using `is_pending()`
--> $DIR/redundant_pattern_matching_drop_order.rs:48:16
|
LL | if let Pending = Pending::<std::sync::MutexGuard<()>> {}
| -------^^^^^^^--------------------------------------- help: try this: `if Pending::<std::sync::MutexGuard<()>>.is_pending()`
|
= note: this will change drop order of the result, as well as all temporaries
= note: add `#[allow(clippy::redundant_pattern_matching)]` if this is important
error: redundant pattern matching, consider using `is_pending()`
--> $DIR/redundant_pattern_matching_drop_order.rs:50:12
|
LL | if let Pending = Pending::<std::sync::MutexGuard<()>> {
| -------^^^^^^^--------------------------------------- help: try this: `if Pending::<std::sync::MutexGuard<()>>.is_pending()`
|
= note: this will change drop order of the result, as well as all temporaries
= note: add `#[allow(clippy::redundant_pattern_matching)]` if this is important
error: redundant pattern matching, consider using `is_pending()`
--> $DIR/redundant_pattern_matching_drop_order.rs:54:12
|
LL | if let Pending = Pending::<std::sync::MutexGuard<()>> {}
| -------^^^^^^^--------------------------------------- help: try this: `if Pending::<std::sync::MutexGuard<()>>.is_pending()`
error: redundant pattern matching, consider using `is_ready()`
--> $DIR/redundant_pattern_matching_drop_order.rs:56:12
|
LL | if let Ready(_) = Ready(String::new()) {}
| -------^^^^^^^^----------------------- help: try this: `if Ready(String::new()).is_ready()`
error: redundant pattern matching, consider using `is_ready()`
--> $DIR/redundant_pattern_matching_drop_order.rs:57:12
|
LL | if let Ready(_) = Ready((String::new(), ())) {}
| -------^^^^^^^^----------------------------- help: try this: `if Ready((String::new(), ())).is_ready()`
error: aborting due to 22 previous errors

View file

@ -2,7 +2,12 @@
#![warn(clippy::all)]
#![warn(clippy::redundant_pattern_matching)]
#![allow(unused_must_use, clippy::needless_bool, clippy::match_like_matches_macro)]
#![allow(
unused_must_use,
clippy::needless_bool,
clippy::match_like_matches_macro,
clippy::if_same_then_else
)]
fn main() {
if None::<()>.is_none() {}

View file

@ -2,7 +2,12 @@
#![warn(clippy::all)]
#![warn(clippy::redundant_pattern_matching)]
#![allow(unused_must_use, clippy::needless_bool, clippy::match_like_matches_macro)]
#![allow(
unused_must_use,
clippy::needless_bool,
clippy::match_like_matches_macro,
clippy::if_same_then_else
)]
fn main() {
if let None = None::<()> {}

View file

@ -1,5 +1,5 @@
error: redundant pattern matching, consider using `is_none()`
--> $DIR/redundant_pattern_matching_option.rs:8:12
--> $DIR/redundant_pattern_matching_option.rs:13:12
|
LL | if let None = None::<()> {}
| -------^^^^------------- help: try this: `if None::<()>.is_none()`
@ -7,43 +7,43 @@ LL | if let None = None::<()> {}
= note: `-D clippy::redundant-pattern-matching` implied by `-D warnings`
error: redundant pattern matching, consider using `is_some()`
--> $DIR/redundant_pattern_matching_option.rs:10:12
--> $DIR/redundant_pattern_matching_option.rs:15:12
|
LL | if let Some(_) = Some(42) {}
| -------^^^^^^^----------- help: try this: `if Some(42).is_some()`
error: redundant pattern matching, consider using `is_some()`
--> $DIR/redundant_pattern_matching_option.rs:12:12
--> $DIR/redundant_pattern_matching_option.rs:17:12
|
LL | if let Some(_) = Some(42) {
| -------^^^^^^^----------- help: try this: `if Some(42).is_some()`
error: redundant pattern matching, consider using `is_some()`
--> $DIR/redundant_pattern_matching_option.rs:18:15
--> $DIR/redundant_pattern_matching_option.rs:23:15
|
LL | while let Some(_) = Some(42) {}
| ----------^^^^^^^----------- help: try this: `while Some(42).is_some()`
error: redundant pattern matching, consider using `is_none()`
--> $DIR/redundant_pattern_matching_option.rs:20:15
--> $DIR/redundant_pattern_matching_option.rs:25:15
|
LL | while let None = Some(42) {}
| ----------^^^^----------- help: try this: `while Some(42).is_none()`
error: redundant pattern matching, consider using `is_none()`
--> $DIR/redundant_pattern_matching_option.rs:22:15
--> $DIR/redundant_pattern_matching_option.rs:27:15
|
LL | while let None = None::<()> {}
| ----------^^^^------------- help: try this: `while None::<()>.is_none()`
error: redundant pattern matching, consider using `is_some()`
--> $DIR/redundant_pattern_matching_option.rs:25:15
--> $DIR/redundant_pattern_matching_option.rs:30:15
|
LL | while let Some(_) = v.pop() {
| ----------^^^^^^^---------- help: try this: `while v.pop().is_some()`
error: redundant pattern matching, consider using `is_some()`
--> $DIR/redundant_pattern_matching_option.rs:33:5
--> $DIR/redundant_pattern_matching_option.rs:38:5
|
LL | / match Some(42) {
LL | | Some(_) => true,
@ -52,7 +52,7 @@ LL | | };
| |_____^ help: try this: `Some(42).is_some()`
error: redundant pattern matching, consider using `is_none()`
--> $DIR/redundant_pattern_matching_option.rs:38:5
--> $DIR/redundant_pattern_matching_option.rs:43:5
|
LL | / match None::<()> {
LL | | Some(_) => false,
@ -61,7 +61,7 @@ LL | | };
| |_____^ help: try this: `None::<()>.is_none()`
error: redundant pattern matching, consider using `is_none()`
--> $DIR/redundant_pattern_matching_option.rs:43:13
--> $DIR/redundant_pattern_matching_option.rs:48:13
|
LL | let _ = match None::<()> {
| _____________^
@ -71,49 +71,49 @@ LL | | };
| |_____^ help: try this: `None::<()>.is_none()`
error: redundant pattern matching, consider using `is_some()`
--> $DIR/redundant_pattern_matching_option.rs:49:20
--> $DIR/redundant_pattern_matching_option.rs:54:20
|
LL | let _ = if let Some(_) = opt { true } else { false };
| -------^^^^^^^------ help: try this: `if opt.is_some()`
error: redundant pattern matching, consider using `is_some()`
--> $DIR/redundant_pattern_matching_option.rs:53:20
--> $DIR/redundant_pattern_matching_option.rs:58:20
|
LL | let _ = if let Some(_) = gen_opt() {
| -------^^^^^^^------------ help: try this: `if gen_opt().is_some()`
error: redundant pattern matching, consider using `is_none()`
--> $DIR/redundant_pattern_matching_option.rs:55:19
--> $DIR/redundant_pattern_matching_option.rs:60:19
|
LL | } else if let None = gen_opt() {
| -------^^^^------------ help: try this: `if gen_opt().is_none()`
error: redundant pattern matching, consider using `is_some()`
--> $DIR/redundant_pattern_matching_option.rs:74:12
--> $DIR/redundant_pattern_matching_option.rs:79:12
|
LL | if let Some(_) = Some(42) {}
| -------^^^^^^^----------- help: try this: `if Some(42).is_some()`
error: redundant pattern matching, consider using `is_none()`
--> $DIR/redundant_pattern_matching_option.rs:76:12
--> $DIR/redundant_pattern_matching_option.rs:81:12
|
LL | if let None = None::<()> {}
| -------^^^^------------- help: try this: `if None::<()>.is_none()`
error: redundant pattern matching, consider using `is_some()`
--> $DIR/redundant_pattern_matching_option.rs:78:15
--> $DIR/redundant_pattern_matching_option.rs:83:15
|
LL | while let Some(_) = Some(42) {}
| ----------^^^^^^^----------- help: try this: `while Some(42).is_some()`
error: redundant pattern matching, consider using `is_none()`
--> $DIR/redundant_pattern_matching_option.rs:80:15
--> $DIR/redundant_pattern_matching_option.rs:85:15
|
LL | while let None = None::<()> {}
| ----------^^^^------------- help: try this: `while None::<()>.is_none()`
error: redundant pattern matching, consider using `is_some()`
--> $DIR/redundant_pattern_matching_option.rs:82:5
--> $DIR/redundant_pattern_matching_option.rs:87:5
|
LL | / match Some(42) {
LL | | Some(_) => true,
@ -122,7 +122,7 @@ LL | | };
| |_____^ help: try this: `Some(42).is_some()`
error: redundant pattern matching, consider using `is_none()`
--> $DIR/redundant_pattern_matching_option.rs:87:5
--> $DIR/redundant_pattern_matching_option.rs:92:5
|
LL | / match None::<()> {
LL | | Some(_) => false,

View file

@ -2,7 +2,12 @@
#![warn(clippy::all)]
#![warn(clippy::redundant_pattern_matching)]
#![allow(unused_must_use, clippy::needless_bool, clippy::match_like_matches_macro)]
#![allow(
unused_must_use,
clippy::needless_bool,
clippy::match_like_matches_macro,
clippy::if_same_then_else
)]
use std::task::Poll::{self, Pending, Ready};

View file

@ -2,7 +2,12 @@
#![warn(clippy::all)]
#![warn(clippy::redundant_pattern_matching)]
#![allow(unused_must_use, clippy::needless_bool, clippy::match_like_matches_macro)]
#![allow(
unused_must_use,
clippy::needless_bool,
clippy::match_like_matches_macro,
clippy::if_same_then_else
)]
use std::task::Poll::{self, Pending, Ready};

View file

@ -1,5 +1,5 @@
error: redundant pattern matching, consider using `is_pending()`
--> $DIR/redundant_pattern_matching_poll.rs:10:12
--> $DIR/redundant_pattern_matching_poll.rs:15:12
|
LL | if let Pending = Pending::<()> {}
| -------^^^^^^^---------------- help: try this: `if Pending::<()>.is_pending()`
@ -7,37 +7,37 @@ LL | if let Pending = Pending::<()> {}
= note: `-D clippy::redundant-pattern-matching` implied by `-D warnings`
error: redundant pattern matching, consider using `is_ready()`
--> $DIR/redundant_pattern_matching_poll.rs:12:12
--> $DIR/redundant_pattern_matching_poll.rs:17:12
|
LL | if let Ready(_) = Ready(42) {}
| -------^^^^^^^^------------ help: try this: `if Ready(42).is_ready()`
error: redundant pattern matching, consider using `is_ready()`
--> $DIR/redundant_pattern_matching_poll.rs:14:12
--> $DIR/redundant_pattern_matching_poll.rs:19:12
|
LL | if let Ready(_) = Ready(42) {
| -------^^^^^^^^------------ help: try this: `if Ready(42).is_ready()`
error: redundant pattern matching, consider using `is_ready()`
--> $DIR/redundant_pattern_matching_poll.rs:20:15
--> $DIR/redundant_pattern_matching_poll.rs:25:15
|
LL | while let Ready(_) = Ready(42) {}
| ----------^^^^^^^^------------ help: try this: `while Ready(42).is_ready()`
error: redundant pattern matching, consider using `is_pending()`
--> $DIR/redundant_pattern_matching_poll.rs:22:15
--> $DIR/redundant_pattern_matching_poll.rs:27:15
|
LL | while let Pending = Ready(42) {}
| ----------^^^^^^^------------ help: try this: `while Ready(42).is_pending()`
error: redundant pattern matching, consider using `is_pending()`
--> $DIR/redundant_pattern_matching_poll.rs:24:15
--> $DIR/redundant_pattern_matching_poll.rs:29:15
|
LL | while let Pending = Pending::<()> {}
| ----------^^^^^^^---------------- help: try this: `while Pending::<()>.is_pending()`
error: redundant pattern matching, consider using `is_ready()`
--> $DIR/redundant_pattern_matching_poll.rs:30:5
--> $DIR/redundant_pattern_matching_poll.rs:35:5
|
LL | / match Ready(42) {
LL | | Ready(_) => true,
@ -46,7 +46,7 @@ LL | | };
| |_____^ help: try this: `Ready(42).is_ready()`
error: redundant pattern matching, consider using `is_pending()`
--> $DIR/redundant_pattern_matching_poll.rs:35:5
--> $DIR/redundant_pattern_matching_poll.rs:40:5
|
LL | / match Pending::<()> {
LL | | Ready(_) => false,
@ -55,7 +55,7 @@ LL | | };
| |_____^ help: try this: `Pending::<()>.is_pending()`
error: redundant pattern matching, consider using `is_pending()`
--> $DIR/redundant_pattern_matching_poll.rs:40:13
--> $DIR/redundant_pattern_matching_poll.rs:45:13
|
LL | let _ = match Pending::<()> {
| _____________^
@ -65,49 +65,49 @@ LL | | };
| |_____^ help: try this: `Pending::<()>.is_pending()`
error: redundant pattern matching, consider using `is_ready()`
--> $DIR/redundant_pattern_matching_poll.rs:46:20
--> $DIR/redundant_pattern_matching_poll.rs:51:20
|
LL | let _ = if let Ready(_) = poll { true } else { false };
| -------^^^^^^^^------- help: try this: `if poll.is_ready()`
error: redundant pattern matching, consider using `is_ready()`
--> $DIR/redundant_pattern_matching_poll.rs:50:20
--> $DIR/redundant_pattern_matching_poll.rs:55:20
|
LL | let _ = if let Ready(_) = gen_poll() {
| -------^^^^^^^^------------- help: try this: `if gen_poll().is_ready()`
error: redundant pattern matching, consider using `is_pending()`
--> $DIR/redundant_pattern_matching_poll.rs:52:19
--> $DIR/redundant_pattern_matching_poll.rs:57:19
|
LL | } else if let Pending = gen_poll() {
| -------^^^^^^^------------- help: try this: `if gen_poll().is_pending()`
error: redundant pattern matching, consider using `is_ready()`
--> $DIR/redundant_pattern_matching_poll.rs:68:12
--> $DIR/redundant_pattern_matching_poll.rs:73:12
|
LL | if let Ready(_) = Ready(42) {}
| -------^^^^^^^^------------ help: try this: `if Ready(42).is_ready()`
error: redundant pattern matching, consider using `is_pending()`
--> $DIR/redundant_pattern_matching_poll.rs:70:12
--> $DIR/redundant_pattern_matching_poll.rs:75:12
|
LL | if let Pending = Pending::<()> {}
| -------^^^^^^^---------------- help: try this: `if Pending::<()>.is_pending()`
error: redundant pattern matching, consider using `is_ready()`
--> $DIR/redundant_pattern_matching_poll.rs:72:15
--> $DIR/redundant_pattern_matching_poll.rs:77:15
|
LL | while let Ready(_) = Ready(42) {}
| ----------^^^^^^^^------------ help: try this: `while Ready(42).is_ready()`
error: redundant pattern matching, consider using `is_pending()`
--> $DIR/redundant_pattern_matching_poll.rs:74:15
--> $DIR/redundant_pattern_matching_poll.rs:79:15
|
LL | while let Pending = Pending::<()> {}
| ----------^^^^^^^---------------- help: try this: `while Pending::<()>.is_pending()`
error: redundant pattern matching, consider using `is_ready()`
--> $DIR/redundant_pattern_matching_poll.rs:76:5
--> $DIR/redundant_pattern_matching_poll.rs:81:5
|
LL | / match Ready(42) {
LL | | Ready(_) => true,
@ -116,7 +116,7 @@ LL | | };
| |_____^ help: try this: `Ready(42).is_ready()`
error: redundant pattern matching, consider using `is_pending()`
--> $DIR/redundant_pattern_matching_poll.rs:81:5
--> $DIR/redundant_pattern_matching_poll.rs:86:5
|
LL | / match Pending::<()> {
LL | | Ready(_) => false,

View file

@ -7,7 +7,8 @@
clippy::needless_bool,
clippy::match_like_matches_macro,
clippy::unnecessary_wraps,
deprecated
deprecated,
clippy::if_same_then_else
)]
fn main() {

View file

@ -7,7 +7,8 @@
clippy::needless_bool,
clippy::match_like_matches_macro,
clippy::unnecessary_wraps,
deprecated
deprecated,
clippy::if_same_then_else
)]
fn main() {

View file

@ -1,5 +1,5 @@
error: redundant pattern matching, consider using `is_ok()`
--> $DIR/redundant_pattern_matching_result.rs:15:12
--> $DIR/redundant_pattern_matching_result.rs:16:12
|
LL | if let Ok(_) = &result {}
| -------^^^^^---------- help: try this: `if result.is_ok()`
@ -7,31 +7,31 @@ LL | if let Ok(_) = &result {}
= note: `-D clippy::redundant-pattern-matching` implied by `-D warnings`
error: redundant pattern matching, consider using `is_ok()`
--> $DIR/redundant_pattern_matching_result.rs:17:12
--> $DIR/redundant_pattern_matching_result.rs:18:12
|
LL | if let Ok(_) = Ok::<i32, i32>(42) {}
| -------^^^^^--------------------- help: try this: `if Ok::<i32, i32>(42).is_ok()`
error: redundant pattern matching, consider using `is_err()`
--> $DIR/redundant_pattern_matching_result.rs:19:12
--> $DIR/redundant_pattern_matching_result.rs:20:12
|
LL | if let Err(_) = Err::<i32, i32>(42) {}
| -------^^^^^^---------------------- help: try this: `if Err::<i32, i32>(42).is_err()`
error: redundant pattern matching, consider using `is_ok()`
--> $DIR/redundant_pattern_matching_result.rs:21:15
--> $DIR/redundant_pattern_matching_result.rs:22:15
|
LL | while let Ok(_) = Ok::<i32, i32>(10) {}
| ----------^^^^^--------------------- help: try this: `while Ok::<i32, i32>(10).is_ok()`
error: redundant pattern matching, consider using `is_err()`
--> $DIR/redundant_pattern_matching_result.rs:23:15
--> $DIR/redundant_pattern_matching_result.rs:24:15
|
LL | while let Err(_) = Ok::<i32, i32>(10) {}
| ----------^^^^^^--------------------- help: try this: `while Ok::<i32, i32>(10).is_err()`
error: redundant pattern matching, consider using `is_ok()`
--> $DIR/redundant_pattern_matching_result.rs:33:5
--> $DIR/redundant_pattern_matching_result.rs:34:5
|
LL | / match Ok::<i32, i32>(42) {
LL | | Ok(_) => true,
@ -40,7 +40,7 @@ LL | | };
| |_____^ help: try this: `Ok::<i32, i32>(42).is_ok()`
error: redundant pattern matching, consider using `is_err()`
--> $DIR/redundant_pattern_matching_result.rs:38:5
--> $DIR/redundant_pattern_matching_result.rs:39:5
|
LL | / match Ok::<i32, i32>(42) {
LL | | Ok(_) => false,
@ -49,7 +49,7 @@ LL | | };
| |_____^ help: try this: `Ok::<i32, i32>(42).is_err()`
error: redundant pattern matching, consider using `is_err()`
--> $DIR/redundant_pattern_matching_result.rs:43:5
--> $DIR/redundant_pattern_matching_result.rs:44:5
|
LL | / match Err::<i32, i32>(42) {
LL | | Ok(_) => false,
@ -58,7 +58,7 @@ LL | | };
| |_____^ help: try this: `Err::<i32, i32>(42).is_err()`
error: redundant pattern matching, consider using `is_ok()`
--> $DIR/redundant_pattern_matching_result.rs:48:5
--> $DIR/redundant_pattern_matching_result.rs:49:5
|
LL | / match Err::<i32, i32>(42) {
LL | | Ok(_) => true,
@ -67,73 +67,73 @@ LL | | };
| |_____^ help: try this: `Err::<i32, i32>(42).is_ok()`
error: redundant pattern matching, consider using `is_ok()`
--> $DIR/redundant_pattern_matching_result.rs:53:20
--> $DIR/redundant_pattern_matching_result.rs:54:20
|
LL | let _ = if let Ok(_) = Ok::<usize, ()>(4) { true } else { false };
| -------^^^^^--------------------- help: try this: `if Ok::<usize, ()>(4).is_ok()`
error: redundant pattern matching, consider using `is_ok()`
--> $DIR/redundant_pattern_matching_result.rs:59:20
--> $DIR/redundant_pattern_matching_result.rs:60:20
|
LL | let _ = if let Ok(_) = gen_res() {
| -------^^^^^------------ help: try this: `if gen_res().is_ok()`
error: redundant pattern matching, consider using `is_err()`
--> $DIR/redundant_pattern_matching_result.rs:61:19
--> $DIR/redundant_pattern_matching_result.rs:62:19
|
LL | } else if let Err(_) = gen_res() {
| -------^^^^^^------------ help: try this: `if gen_res().is_err()`
error: redundant pattern matching, consider using `is_some()`
--> $DIR/redundant_pattern_matching_result.rs:84:19
--> $DIR/redundant_pattern_matching_result.rs:85:19
|
LL | while let Some(_) = r#try!(result_opt()) {}
| ----------^^^^^^^----------------------- help: try this: `while r#try!(result_opt()).is_some()`
error: redundant pattern matching, consider using `is_some()`
--> $DIR/redundant_pattern_matching_result.rs:85:16
--> $DIR/redundant_pattern_matching_result.rs:86:16
|
LL | if let Some(_) = r#try!(result_opt()) {}
| -------^^^^^^^----------------------- help: try this: `if r#try!(result_opt()).is_some()`
error: redundant pattern matching, consider using `is_some()`
--> $DIR/redundant_pattern_matching_result.rs:91:12
--> $DIR/redundant_pattern_matching_result.rs:92:12
|
LL | if let Some(_) = m!() {}
| -------^^^^^^^------- help: try this: `if m!().is_some()`
error: redundant pattern matching, consider using `is_some()`
--> $DIR/redundant_pattern_matching_result.rs:92:15
--> $DIR/redundant_pattern_matching_result.rs:93:15
|
LL | while let Some(_) = m!() {}
| ----------^^^^^^^------- help: try this: `while m!().is_some()`
error: redundant pattern matching, consider using `is_ok()`
--> $DIR/redundant_pattern_matching_result.rs:110:12
--> $DIR/redundant_pattern_matching_result.rs:111:12
|
LL | if let Ok(_) = Ok::<i32, i32>(42) {}
| -------^^^^^--------------------- help: try this: `if Ok::<i32, i32>(42).is_ok()`
error: redundant pattern matching, consider using `is_err()`
--> $DIR/redundant_pattern_matching_result.rs:112:12
--> $DIR/redundant_pattern_matching_result.rs:113:12
|
LL | if let Err(_) = Err::<i32, i32>(42) {}
| -------^^^^^^---------------------- help: try this: `if Err::<i32, i32>(42).is_err()`
error: redundant pattern matching, consider using `is_ok()`
--> $DIR/redundant_pattern_matching_result.rs:114:15
--> $DIR/redundant_pattern_matching_result.rs:115:15
|
LL | while let Ok(_) = Ok::<i32, i32>(10) {}
| ----------^^^^^--------------------- help: try this: `while Ok::<i32, i32>(10).is_ok()`
error: redundant pattern matching, consider using `is_err()`
--> $DIR/redundant_pattern_matching_result.rs:116:15
--> $DIR/redundant_pattern_matching_result.rs:117:15
|
LL | while let Err(_) = Ok::<i32, i32>(10) {}
| ----------^^^^^^--------------------- help: try this: `while Ok::<i32, i32>(10).is_err()`
error: redundant pattern matching, consider using `is_ok()`
--> $DIR/redundant_pattern_matching_result.rs:118:5
--> $DIR/redundant_pattern_matching_result.rs:119:5
|
LL | / match Ok::<i32, i32>(42) {
LL | | Ok(_) => true,
@ -142,7 +142,7 @@ LL | | };
| |_____^ help: try this: `Ok::<i32, i32>(42).is_ok()`
error: redundant pattern matching, consider using `is_err()`
--> $DIR/redundant_pattern_matching_result.rs:123:5
--> $DIR/redundant_pattern_matching_result.rs:124:5
|
LL | / match Err::<i32, i32>(42) {
LL | | Ok(_) => false,