Mirrors/rust-clippy
2
0
Fork 0
mirror of https://github.com/rust-lang/rust-clippy synced 2024-11-11 07:34:18 +00:00
Code Issues Projects Releases Packages Wiki Activity

Fix redundant closure bugs

Browse source
This commit is contained in:
Cameron Steffen 2021-09-09 15:35:26 -05:00
parent 1a524783b1
commit 5782dc0eb9
9 changed files with 229 additions and 232 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

242
clippy_lints/src/eta_reduction.rs
View file

@ -1,16 +1,16 @@
use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then};
use clippy_utils::higher::VecArgs;
use clippy_utils::source::snippet_opt;
use clippy_utils::ty::{implements_trait, type_is_unsafe_function};
use clippy_utils::usage::UsedAfterExprVisitor;
use clippy_utils::{get_enclosing_loop_or_closure, higher};
use clippy_utils::{is_adjusted, iter_input_pats};
use clippy_utils::{get_enclosing_loop_or_closure, higher, path_to_local_id};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir::{def_id, Expr, ExprKind, Param, PatKind, QPath};
use rustc_lint::{LateContext, LateLintPass, LintContext};
use rustc_middle::lint::in_external_macro;
use rustc_middle::ty::{self, ClosureKind, Ty};
use rustc_hir::def_id::DefId;
use rustc_hir::{Expr, ExprKind, Param, PatKind, Unsafety};
use rustc_lint::{LateContext, LateLintPass};
use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow};
use rustc_middle::ty::subst::Subst;
use rustc_middle::ty::{self, ClosureKind, Ty, TypeFoldable};
use rustc_session::{declare_lint_pass, declare_tool_lint};
declare_clippy_lint! {
@ -52,12 +52,6 @@ declare_clippy_lint! {
/// ### Why is this bad?
/// It's unnecessary to create the closure.
///
/// ### Known problems
/// [#3071](https://github.com/rust-lang/rust-clippy/issues/3071),
/// [#3942](https://github.com/rust-lang/rust-clippy/issues/3942),
/// [#4002](https://github.com/rust-lang/rust-clippy/issues/4002)
///
///
/// ### Example
/// ```rust,ignore
/// Some('a').map(|s| s.to_uppercase());
@ -75,32 +69,16 @@ declare_lint_pass!(EtaReduction => [REDUNDANT_CLOSURE, REDUNDANT_CLOSURE_FOR_MET
impl<'tcx> LateLintPass<'tcx> for EtaReduction {
fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
if in_external_macro(cx.sess(), expr.span) {
if expr.span.from_expansion() {
return;
}
match expr.kind {
ExprKind::Call(_, args) | ExprKind::MethodCall(_, _, args, _) => {
for arg in args {
// skip `foo(macro!())`
if arg.span.ctxt() == expr.span.ctxt() {
check_closure(cx, arg);
}
}
},
_ => (),
}
}
}
fn check_closure<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
if let ExprKind::Closure(_, decl, eid, _, _) = expr.kind {
let body = cx.tcx.hir().body(eid);
let ex = &body.value;
if ex.span.ctxt() != expr.span.ctxt() {
if decl.inputs.is_empty() {
if let Some(VecArgs::Vec(&[])) = higher::VecArgs::hir(cx, ex) {
let body = match expr.kind {
ExprKind::Closure(_, _, id, _, _) => cx.tcx.hir().body(id),
_ => return,
};
if body.value.span.from_expansion() {
if body.params.is_empty() {
if let Some(VecArgs::Vec(&[])) = higher::VecArgs::hir(cx, &body.value) {
// replace `|| vec![]` with `Vec::new`
span_lint_and_sugg(
cx,
@ -117,33 +95,30 @@ fn check_closure<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
return;
}
let closure_ty = cx.typeck_results().expr_ty(expr);
if_chain!(
if let ExprKind::Call(caller, args) = ex.kind;
if let ExprKind::Path(_) = caller.kind;
// Not the same number of arguments, there is no way the closure is the same as the function return;
if args.len() == decl.inputs.len();
// Are the expression or the arguments type-adjusted? Then we need the closure
if !(is_adjusted(cx, ex) || args.iter().any(|arg| is_adjusted(cx, arg)));
let fn_ty = cx.typeck_results().expr_ty(caller);
if matches!(fn_ty.kind(), ty::FnDef(_, _) | ty::FnPtr(_) | ty::Closure(_, _));
if !type_is_unsafe_function(cx, fn_ty);
if compare_inputs(&mut iter_input_pats(decl, body), &mut args.iter());
if let ExprKind::Call(callee, args) = body.value.kind;
if let ExprKind::Path(_) = callee.kind;
if check_inputs(cx, body.params, args);
let callee_ty = cx.typeck_results().expr_ty_adjusted(callee);
let call_ty = cx.typeck_results().type_dependent_def_id(body.value.hir_id)
.map_or(callee_ty, |id| cx.tcx.type_of(id));
if check_sig(cx, closure_ty, call_ty);
let substs = cx.typeck_results().node_substs(callee.hir_id);
// This fixes some false positives that I don't entirely understand
if substs.is_empty() || !cx.typeck_results().expr_ty(expr).has_late_bound_regions();
// A type param function ref like `T::f` is not 'static, however
// it is if cast like `T::f as fn()`. This seems like a rustc bug.
if !substs.types().any(|t| matches!(t.kind(), ty::Param(_)));
then {
span_lint_and_then(cx, REDUNDANT_CLOSURE, expr.span, "redundant closure", |diag| {
if let Some(mut snippet) = snippet_opt(cx, caller.span) {
if let Some(mut snippet) = snippet_opt(cx, callee.span) {
if_chain! {
if let ty::Closure(_, substs) = fn_ty.kind();
if let ty::Closure(_, substs) = callee_ty.peel_refs().kind();
if let ClosureKind::FnMut = substs.as_closure().kind();
if UsedAfterExprVisitor::is_found(cx, caller)
|| get_enclosing_loop_or_closure(cx.tcx, expr).is_some();
if get_enclosing_loop_or_closure(cx.tcx, expr).is_some()
|| UsedAfterExprVisitor::is_found(cx, callee);
then {
// Mutable closure is used after current expr; we cannot consume it.
@ -162,110 +137,79 @@ fn check_closure<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
);
if_chain!(
if let ExprKind::MethodCall(path, _, args, _) = ex.kind;
// Not the same number of arguments, there is no way the closure is the same as the function return;
if args.len() == decl.inputs.len();
// Are the expression or the arguments type-adjusted? Then we need the closure
if !(is_adjusted(cx, ex) || args.iter().skip(1).any(|arg| is_adjusted(cx, arg)));
let method_def_id = cx.typeck_results().type_dependent_def_id(ex.hir_id).unwrap();
if !type_is_unsafe_function(cx, cx.tcx.type_of(method_def_id));
if compare_inputs(&mut iter_input_pats(decl, body), &mut args.iter());
if let Some(name) = get_ufcs_type_name(cx, method_def_id, &args[0]);
if let ExprKind::MethodCall(path, _, args, _) = body.value.kind;
if check_inputs(cx, body.params, args);
let method_def_id = cx.typeck_results().type_dependent_def_id(body.value.hir_id).unwrap();
let substs = cx.typeck_results().node_substs(body.value.hir_id);
let call_ty = cx.tcx.type_of(method_def_id).subst(cx.tcx, substs);
if check_sig(cx, closure_ty, call_ty);
then {
span_lint_and_sugg(
cx,
REDUNDANT_CLOSURE_FOR_METHOD_CALLS,
expr.span,
"redundant closure",
"replace the closure with the method itself",
format!("{}::{}", name, path.ident.name),
Applicability::MachineApplicable,
);
span_lint_and_then(cx, REDUNDANT_CLOSURE_FOR_METHOD_CALLS, expr.span, "redundant closure", |diag| {
let name = get_ufcs_type_name(cx, method_def_id);
diag.span_suggestion(
expr.span,
"replace the closure with the method itself",
format!("{}::{}", name, path.ident.name),
Applicability::MachineApplicable,
);
})
}
);
}
}
/// Tries to determine the type for universal function call to be used instead of the closure
fn get_ufcs_type_name(cx: &LateContext<'_>, method_def_id: def_id::DefId, self_arg: &Expr<'_>) -> Option<String> {
let expected_type_of_self = &cx.tcx.fn_sig(method_def_id).inputs_and_output().skip_binder()[0];
let actual_type_of_self = &cx.typeck_results().node_type(self_arg.hir_id);
if let Some(trait_id) = cx.tcx.trait_of_item(method_def_id) {
if match_borrow_depth(expected_type_of_self, actual_type_of_self)
&& implements_trait(cx, actual_type_of_self, trait_id, &[])
{
return Some(cx.tcx.def_path_str(trait_id));
}
fn check_inputs(cx: &LateContext<'_>, params: &[Param<'_>], call_args: &[Expr<'_>]) -> bool {
if params.len() != call_args.len() {
return false;
}
cx.tcx.impl_of_method(method_def_id).and_then(|_| {
//a type may implicitly implement other type's methods (e.g. Deref)
if match_types(expected_type_of_self, actual_type_of_self) {
Some(get_type_name(cx, actual_type_of_self))
} else {
None
std::iter::zip(params, call_args).all(|(param, arg)| {
match param.pat.kind {
PatKind::Binding(_, id, ..) if path_to_local_id(arg, id) => {},
_ => return false,
}
match *cx.typeck_results().expr_adjustments(arg) {
[] => true,
[Adjustment {
kind: Adjust::Deref(None),
..
}, Adjustment {
kind: Adjust::Borrow(AutoBorrow::Ref(_, mu2)),
..
}] => {
// re-borrow with the same mutability is allowed
let ty = cx.typeck_results().expr_ty(arg);
matches!(*ty.kind(), ty::Ref(.., mu1) if mu1 == mu2.into())
},
_ => false,
}
})
}
fn match_borrow_depth(lhs: Ty<'_>, rhs: Ty<'_>) -> bool {
match (&lhs.kind(), &rhs.kind()) {
(ty::Ref(_, t1, mut1), ty::Ref(_, t2, mut2)) => mut1 == mut2 && match_borrow_depth(t1, t2),
(l, r) => !matches!((l, r), (ty::Ref(_, _, _), _) | (_, ty::Ref(_, _, _))),
fn check_sig<'tcx>(cx: &LateContext<'tcx>, closure_ty: Ty<'tcx>, call_ty: Ty<'tcx>) -> bool {
let call_sig = call_ty.fn_sig(cx.tcx);
if call_sig.unsafety() == Unsafety::Unsafe {
return false;
}
if !closure_ty.has_late_bound_regions() {
return true;
}
let substs = match closure_ty.kind() {
ty::Closure(_, substs) => substs,
_ => return false,
};
let closure_sig = cx.tcx.signature_unclosure(substs.as_closure().sig(), Unsafety::Normal);
cx.tcx.erase_late_bound_regions(closure_sig) == cx.tcx.erase_late_bound_regions(call_sig)
}
fn match_types(lhs: Ty<'_>, rhs: Ty<'_>) -> bool {
match (&lhs.kind(), &rhs.kind()) {
(ty::Bool, ty::Bool)
| (ty::Char, ty::Char)
| (ty::Int(_), ty::Int(_))
| (ty::Uint(_), ty::Uint(_))
| (ty::Str, ty::Str) => true,
(ty::Ref(_, t1, mut1), ty::Ref(_, t2, mut2)) => mut1 == mut2 && match_types(t1, t2),
(ty::Array(t1, _), ty::Array(t2, _)) | (ty::Slice(t1), ty::Slice(t2)) => match_types(t1, t2),
(ty::Adt(def1, _), ty::Adt(def2, _)) => def1 == def2,
(_, _) => false,
}
}
fn get_type_name(cx: &LateContext<'_>, ty: Ty<'_>) -> String {
match ty.kind() {
ty::Adt(t, _) => cx.tcx.def_path_str(t.did),
ty::Ref(_, r, _) => get_type_name(cx, r),
_ => ty.to_string(),
}
}
fn compare_inputs(
closure_inputs: &mut dyn Iterator<Item = &Param<'_>>,
call_args: &mut dyn Iterator<Item = &Expr<'_>>,
) -> bool {
for (closure_input, function_arg) in closure_inputs.zip(call_args) {
if let PatKind::Binding(_, _, ident, _) = closure_input.pat.kind {
// XXXManishearth Should I be checking the binding mode here?
if let ExprKind::Path(QPath::Resolved(None, p)) = function_arg.kind {
if p.segments.len() != 1 {
// If it's a proper path, it can't be a local variable
return false;
}
if p.segments[0].ident.name != ident.name {
// The two idents should be the same
return false;
}
} else {
return false;
fn get_ufcs_type_name(cx: &LateContext<'_>, method_def_id: DefId) -> String {
match cx.tcx.associated_item(method_def_id).container {
ty::TraitContainer(def_id) => cx.tcx.def_path_str(def_id),
ty::ImplContainer(def_id) => {
let ty = cx.tcx.type_of(def_id);
match ty.kind() {
ty::Adt(adt, _) => cx.tcx.def_path_str(adt.did),
_ => ty.to_string(),
}
} else {
return false;
}
},
}
true
}

63
tests/ui/eta.fixed
View file

@ -14,7 +14,7 @@
clippy::needless_borrow
)]
use std::path::PathBuf;
use std::path::{Path, PathBuf};
macro_rules! mac {
() => {
@ -30,19 +30,18 @@ macro_rules! closure_mac {
fn main() {
let a = Some(1u8).map(foo);
meta(foo);
let c = Some(1u8).map(|a| {1+2; foo}(a));
true.then(|| mac!()); // don't lint function in macro expansion
Some(1).map(closure_mac!()); // don't lint closure in macro expansion
let _: Option<Vec<u8>> = true.then(std::vec::Vec::new); // special case vec!
let d = Some(1u8).map(|a| foo((|b| foo2(b))(a))); //is adjusted?
all(&[1, 2, 3], &2, |x, y| below(x, y)); //is adjusted
let d = Some(1u8).map(|a| foo(foo2(a))); //is adjusted?
all(&[1, 2, 3], &2, below); //is adjusted
unsafe {
Some(1u8).map(|a| unsafe_fn(a)); // unsafe fn
}
// See #815
let e = Some(1u8).map(|a| divergent(a));
let e = Some(1u8).map(divergent);
let e = Some(1u8).map(generic);
let e = Some(1u8).map(generic);
// See #515
@ -90,24 +89,17 @@ impl<'a> std::ops::Deref for TestStruct<'a> {
fn test_redundant_closures_containing_method_calls() {
let i = 10;
let e = Some(TestStruct { some_ref: &i }).map(TestStruct::foo);
let e = Some(TestStruct { some_ref: &i }).map(TestStruct::foo);
let e = Some(TestStruct { some_ref: &i }).map(TestTrait::trait_foo);
let e = Some(TestStruct { some_ref: &i }).map(|a| a.trait_foo_ref());
let e = Some(TestStruct { some_ref: &i }).map(TestTrait::trait_foo);
let e = Some(&mut vec![1, 2, 3]).map(std::vec::Vec::clear);
let e = Some(&mut vec![1, 2, 3]).map(std::vec::Vec::clear);
unsafe {
let e = Some(TestStruct { some_ref: &i }).map(|a| a.foo_unsafe());
}
let e = Some("str").map(std::string::ToString::to_string);
let e = Some("str").map(str::to_string);
let e = Some('a').map(char::to_uppercase);
let e = Some('a').map(char::to_uppercase);
let e: std::vec::Vec<usize> = vec!['a', 'b', 'c'].iter().map(|c| c.len_utf8()).collect();
let e: std::vec::Vec<char> = vec!['a', 'b', 'c'].iter().map(char::to_ascii_uppercase).collect();
let e: std::vec::Vec<char> = vec!['a', 'b', 'c'].iter().map(char::to_ascii_uppercase).collect();
let p = Some(PathBuf::new());
let e = p.as_ref().and_then(|s| s.to_str());
let e = Some(PathBuf::new()).as_ref().and_then(|s| s.to_str());
let c = Some(TestStruct { some_ref: &i })
.as_ref()
.map(|c| c.to_ascii_uppercase());
@ -119,10 +111,6 @@ fn test_redundant_closures_containing_method_calls() {
t.iter().filter(|x| x.trait_foo_ref());
t.iter().map(|x| x.trait_foo_ref());
}
let mut some = Some(|x| x * x);
let arr = [Ok(1), Err(2)];
let _: Vec<_> = arr.iter().map(|x| x.map_err(|e| some.take().unwrap()(e))).collect();
}
struct Thunk<T>(Box<dyn FnMut() -> T>);
@ -145,13 +133,6 @@ fn foobar() {
thunk.unwrap()
}
fn meta<F>(f: F)
where
F: Fn(u8),
{
f(1u8)
}
fn foo(_: u8) {}
fn foo2(_: u8) -> u8 {
@ -180,7 +161,7 @@ fn generic<T>(_: T) -> u8 {
}
fn passes_fn_mut(mut x: Box<dyn FnMut()>) {
requires_fn_once(|| x());
requires_fn_once(x);
}
fn requires_fn_once<T: FnOnce()>(_: T) {}
@ -236,3 +217,35 @@ fn mutable_closure_in_loop() {
Some(1).map(&mut closure);
}
}
fn late_bound_lifetimes() {
fn take_asref_path<P: AsRef<Path>>(path: P) {}
fn map_str<F>(thunk: F)
where
F: FnOnce(&str),
{
}
fn map_str_to_path<F>(thunk: F)
where
F: FnOnce(&str) -> &Path,
{
}
map_str(|s| take_asref_path(s));
map_str_to_path(std::convert::AsRef::as_ref);
}
mod type_param_bound {
trait Trait {
fn fun();
}
fn take<T: 'static>(_: T) {}
fn test<X: Trait>() {
// don't lint, but it's questionable that rust requires a cast
take(|| X::fun());
take(X::fun as fn());
}
}

55
tests/ui/eta.rs
View file

@ -14,7 +14,7 @@
clippy::needless_borrow
)]
use std::path::PathBuf;
use std::path::{Path, PathBuf};
macro_rules! mac {
() => {
@ -30,7 +30,6 @@ macro_rules! closure_mac {
fn main() {
let a = Some(1u8).map(|a| foo(a));
meta(|a| foo(a));
let c = Some(1u8).map(|a| {1+2; foo}(a));
true.then(|| mac!()); // don't lint function in macro expansion
Some(1).map(closure_mac!()); // don't lint closure in macro expansion
@ -90,24 +89,17 @@ impl<'a> std::ops::Deref for TestStruct<'a> {
fn test_redundant_closures_containing_method_calls() {
let i = 10;
let e = Some(TestStruct { some_ref: &i }).map(|a| a.foo());
let e = Some(TestStruct { some_ref: &i }).map(TestStruct::foo);
let e = Some(TestStruct { some_ref: &i }).map(|a| a.trait_foo());
let e = Some(TestStruct { some_ref: &i }).map(|a| a.trait_foo_ref());
let e = Some(TestStruct { some_ref: &i }).map(TestTrait::trait_foo);
let e = Some(&mut vec![1, 2, 3]).map(|v| v.clear());
let e = Some(&mut vec![1, 2, 3]).map(std::vec::Vec::clear);
unsafe {
let e = Some(TestStruct { some_ref: &i }).map(|a| a.foo_unsafe());
}
let e = Some("str").map(|s| s.to_string());
let e = Some("str").map(str::to_string);
let e = Some('a').map(|s| s.to_uppercase());
let e = Some('a').map(char::to_uppercase);
let e: std::vec::Vec<usize> = vec!['a', 'b', 'c'].iter().map(|c| c.len_utf8()).collect();
let e: std::vec::Vec<char> = vec!['a', 'b', 'c'].iter().map(|c| c.to_ascii_uppercase()).collect();
let e: std::vec::Vec<char> = vec!['a', 'b', 'c'].iter().map(char::to_ascii_uppercase).collect();
let p = Some(PathBuf::new());
let e = p.as_ref().and_then(|s| s.to_str());
let e = Some(PathBuf::new()).as_ref().and_then(|s| s.to_str());
let c = Some(TestStruct { some_ref: &i })
.as_ref()
.map(|c| c.to_ascii_uppercase());
@ -119,10 +111,6 @@ fn test_redundant_closures_containing_method_calls() {
t.iter().filter(|x| x.trait_foo_ref());
t.iter().map(|x| x.trait_foo_ref());
}
let mut some = Some(|x| x * x);
let arr = [Ok(1), Err(2)];
let _: Vec<_> = arr.iter().map(|x| x.map_err(|e| some.take().unwrap()(e))).collect();
}
struct Thunk<T>(Box<dyn FnMut() -> T>);
@ -145,13 +133,6 @@ fn foobar() {
thunk.unwrap()
}
fn meta<F>(f: F)
where
F: Fn(u8),
{
f(1u8)
}
fn foo(_: u8) {}
fn foo2(_: u8) -> u8 {
@ -236,3 +217,35 @@ fn mutable_closure_in_loop() {
Some(1).map(|n| closure(n));
}
}
fn late_bound_lifetimes() {
fn take_asref_path<P: AsRef<Path>>(path: P) {}
fn map_str<F>(thunk: F)
where
F: FnOnce(&str),
{
}
fn map_str_to_path<F>(thunk: F)
where
F: FnOnce(&str) -> &Path,
{
}
map_str(|s| take_asref_path(s));
map_str_to_path(|s| s.as_ref());
}
mod type_param_bound {
trait Trait {
fn fun();
}
fn take<T: 'static>(_: T) {}
fn test<X: Trait>() {
// don't lint, but it's questionable that rust requires a cast
take(|| X::fun());
take(X::fun as fn());
}
}

68
tests/ui/eta.stderr
View file

@ -7,19 +7,19 @@ LL | let a = Some(1u8).map(|a| foo(a));
= note: `-D clippy::redundant-closure` implied by `-D warnings`
error: redundant closure
--> $DIR/eta.rs:33:10
|
LL | meta(|a| foo(a));
| ^^^^^^^^^^ help: replace the closure with the function itself: `foo`
error: redundant closure
--> $DIR/eta.rs:37:40
--> $DIR/eta.rs:36:40
|
LL | let _: Option<Vec<u8>> = true.then(|| vec![]); // special case vec!
| ^^^^^^^^^ help: replace the closure with `Vec::new`: `std::vec::Vec::new`
error: redundant closure
--> $DIR/eta.rs:37:35
|
LL | let d = Some(1u8).map(|a| foo((|b| foo2(b))(a))); //is adjusted?
| ^^^^^^^^^^^^^ help: replace the closure with the function itself: `foo2`
error: this expression borrows a reference (`&u8`) that is immediately dereferenced by the compiler
--> $DIR/eta.rs:39:21
--> $DIR/eta.rs:38:21
|
LL | all(&[1, 2, 3], &&2, |x, y| below(x, y)); //is adjusted
| ^^^ help: change this to: `&2`
@ -27,13 +27,25 @@ LL | all(&[1, 2, 3], &&2, |x, y| below(x, y)); //is adjusted
= note: `-D clippy::needless-borrow` implied by `-D warnings`
error: redundant closure
--> $DIR/eta.rs:46:27
--> $DIR/eta.rs:38:26
|
LL | all(&[1, 2, 3], &&2, |x, y| below(x, y)); //is adjusted
| ^^^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `below`
error: redundant closure
--> $DIR/eta.rs:44:27
|
LL | let e = Some(1u8).map(|a| divergent(a));
| ^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `divergent`
error: redundant closure
--> $DIR/eta.rs:45:27
|
LL | let e = Some(1u8).map(|a| generic(a));
| ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `generic`
error: redundant closure
--> $DIR/eta.rs:92:51
--> $DIR/eta.rs:91:51
|
LL | let e = Some(TestStruct { some_ref: &i }).map(|a| a.foo());
| ^^^^^^^^^^^ help: replace the closure with the method itself: `TestStruct::foo`
@ -41,70 +53,82 @@ LL | let e = Some(TestStruct { some_ref: &i }).map(|a| a.foo());
= note: `-D clippy::redundant-closure-for-method-calls` implied by `-D warnings`
error: redundant closure
--> $DIR/eta.rs:94:51
--> $DIR/eta.rs:92:51
|
LL | let e = Some(TestStruct { some_ref: &i }).map(|a| a.trait_foo());
| ^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `TestTrait::trait_foo`
error: redundant closure
--> $DIR/eta.rs:97:42
--> $DIR/eta.rs:94:42
|
LL | let e = Some(&mut vec![1, 2, 3]).map(|v| v.clear());
| ^^^^^^^^^^^^^ help: replace the closure with the method itself: `std::vec::Vec::clear`
error: redundant closure
--> $DIR/eta.rs:102:29
--> $DIR/eta.rs:98:29
|
LL | let e = Some("str").map(|s| s.to_string());
| ^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `std::string::ToString::to_string`
error: redundant closure
--> $DIR/eta.rs:104:27
--> $DIR/eta.rs:99:27
|
LL | let e = Some('a').map(|s| s.to_uppercase());
| ^^^^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `char::to_uppercase`
error: redundant closure
--> $DIR/eta.rs:107:65
--> $DIR/eta.rs:101:65
|
LL | let e: std::vec::Vec<char> = vec!['a', 'b', 'c'].iter().map(|c| c.to_ascii_uppercase()).collect();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace the closure with the method itself: `char::to_ascii_uppercase`
error: redundant closure
--> $DIR/eta.rs:190:27
--> $DIR/eta.rs:164:22
|
LL | requires_fn_once(|| x());
| ^^^^^^ help: replace the closure with the function itself: `x`
error: redundant closure
--> $DIR/eta.rs:171:27
|
LL | let a = Some(1u8).map(|a| foo_ptr(a));
| ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `foo_ptr`
error: redundant closure
--> $DIR/eta.rs:195:27
--> $DIR/eta.rs:176:27
|
LL | let a = Some(1u8).map(|a| closure(a));
| ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `closure`
error: redundant closure
--> $DIR/eta.rs:227:28
--> $DIR/eta.rs:208:28
|
LL | x.into_iter().for_each(|x| add_to_res(x));
| ^^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `&mut add_to_res`
error: redundant closure
--> $DIR/eta.rs:228:28
--> $DIR/eta.rs:209:28
|
LL | y.into_iter().for_each(|x| add_to_res(x));
| ^^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `&mut add_to_res`
error: redundant closure
--> $DIR/eta.rs:229:28
--> $DIR/eta.rs:210:28
|
LL | z.into_iter().for_each(|x| add_to_res(x));
| ^^^^^^^^^^^^^^^^^ help: replace the closure with the function itself: `add_to_res`
error: redundant closure
--> $DIR/eta.rs:236:21
--> $DIR/eta.rs:217:21
|
LL | Some(1).map(|n| closure(n));
| ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `&mut closure`
error: aborting due to 17 previous errors
error: redundant closure
--> $DIR/eta.rs:236:21
|
LL | map_str_to_path(|s| s.as_ref());
| ^^^^^^^^^^^^^^ help: replace the closure with the method itself: `std::convert::AsRef::as_ref`
error: aborting due to 21 previous errors

1
tests/ui/map_flatten.fixed
View file

@ -4,6 +4,7 @@
#![allow(clippy::let_underscore_drop)]
#![allow(clippy::missing_docs_in_private_items)]
#![allow(clippy::map_identity)]
#![allow(clippy::redundant_closure)]
#![allow(clippy::unnecessary_wraps)]
#![feature(result_flattening)]

1
tests/ui/map_flatten.rs
View file

@ -4,6 +4,7 @@
#![allow(clippy::let_underscore_drop)]
#![allow(clippy::missing_docs_in_private_items)]
#![allow(clippy::map_identity)]
#![allow(clippy::redundant_closure)]
#![allow(clippy::unnecessary_wraps)]
#![feature(result_flattening)]

14
tests/ui/map_flatten.stderr
View file

@ -1,5 +1,5 @@
error: called `map(..).flatten()` on an `Iterator`
--> $DIR/map_flatten.rs:17:46
--> $DIR/map_flatten.rs:18:46
|
LL | let _: Vec<_> = vec![5_i8; 6].into_iter().map(option_id).flatten().collect();
| ^^^^^^^^^^^^^^^^^^^^^^^^^ help: try using `filter_map` instead: `.filter_map(option_id)`
@ -7,37 +7,37 @@ LL | let _: Vec<_> = vec![5_i8; 6].into_iter().map(option_id).flatten().coll
= note: `-D clippy::map-flatten` implied by `-D warnings`
error: called `map(..).flatten()` on an `Iterator`
--> $DIR/map_flatten.rs:18:46
--> $DIR/map_flatten.rs:19:46
|
LL | let _: Vec<_> = vec![5_i8; 6].into_iter().map(option_id_ref).flatten().collect();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try using `filter_map` instead: `.filter_map(option_id_ref)`
error: called `map(..).flatten()` on an `Iterator`
--> $DIR/map_flatten.rs:19:46
--> $DIR/map_flatten.rs:20:46
|
LL | let _: Vec<_> = vec![5_i8; 6].into_iter().map(option_id_closure).flatten().collect();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try using `filter_map` instead: `.filter_map(option_id_closure)`
error: called `map(..).flatten()` on an `Iterator`
--> $DIR/map_flatten.rs:20:46
--> $DIR/map_flatten.rs:21:46
|
LL | let _: Vec<_> = vec![5_i8; 6].into_iter().map(|x| x.checked_add(1)).flatten().collect();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try using `filter_map` instead: `.filter_map(|x| x.checked_add(1))`
error: called `map(..).flatten()` on an `Iterator`
--> $DIR/map_flatten.rs:23:46
--> $DIR/map_flatten.rs:24:46
|
LL | let _: Vec<_> = vec![5_i8; 6].into_iter().map(|x| 0..x).flatten().collect();
| ^^^^^^^^^^^^^^^^^^^^^^^^ help: try using `flat_map` instead: `.flat_map(|x| 0..x)`
error: called `map(..).flatten()` on an `Option`
--> $DIR/map_flatten.rs:26:39
--> $DIR/map_flatten.rs:27:39
|
LL | let _: Option<_> = (Some(Some(1))).map(|x| x).flatten();
| ^^^^^^^^^^^^^^^^^^^^^ help: try using `and_then` instead: `.and_then(|x| x)`
error: called `map(..).flatten()` on an `Result`
--> $DIR/map_flatten.rs:29:41
--> $DIR/map_flatten.rs:30:41
|
LL | let _: Result<_, &str> = (Ok(Ok(1))).map(|x| x).flatten();
| ^^^^^^^^^^^^^^^^^^^^^ help: try using `and_then` instead: `.and_then(|x| x)`

5
tests/ui/semicolon_if_nothing_returned.rs
View file

@ -1,4 +1,5 @@
#![warn(clippy::semicolon_if_nothing_returned)]
#![allow(clippy::redundant_closure)]
#![feature(label_break_value)]
fn get_unit() {}
@ -30,8 +31,8 @@ fn unsafe_checks_error() {
use std::ptr;
let mut s = MaybeUninit::<String>::uninit();
let _d = || unsafe {
ptr::drop_in_place(s.as_mut_ptr())
let _d = || unsafe {
ptr::drop_in_place(s.as_mut_ptr())
};
}

12
tests/ui/semicolon_if_nothing_returned.stderr
View file

@ -1,5 +1,5 @@
error: consider adding a `;` to the last statement for consistent formatting
--> $DIR/semicolon_if_nothing_returned.rs:8:5
--> $DIR/semicolon_if_nothing_returned.rs:9:5
|
LL | println!("Hello")
| ^^^^^^^^^^^^^^^^^ help: add a `;` here: `println!("Hello");`
@ -7,27 +7,27 @@ LL | println!("Hello")
= note: `-D clippy::semicolon-if-nothing-returned` implied by `-D warnings`
error: consider adding a `;` to the last statement for consistent formatting
--> $DIR/semicolon_if_nothing_returned.rs:12:5
--> $DIR/semicolon_if_nothing_returned.rs:13:5
|
LL | get_unit()
| ^^^^^^^^^^ help: add a `;` here: `get_unit();`
error: consider adding a `;` to the last statement for consistent formatting
--> $DIR/semicolon_if_nothing_returned.rs:17:5
--> $DIR/semicolon_if_nothing_returned.rs:18:5
|
LL | y = x + 1
| ^^^^^^^^^ help: add a `;` here: `y = x + 1;`
error: consider adding a `;` to the last statement for consistent formatting
--> $DIR/semicolon_if_nothing_returned.rs:23:9
--> $DIR/semicolon_if_nothing_returned.rs:24:9
|
LL | hello()
| ^^^^^^^ help: add a `;` here: `hello();`
error: consider adding a `;` to the last statement for consistent formatting
--> $DIR/semicolon_if_nothing_returned.rs:34:9
--> $DIR/semicolon_if_nothing_returned.rs:35:9
|
LL | ptr::drop_in_place(s.as_mut_ptr())
LL | ptr::drop_in_place(s.as_mut_ptr())
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: add a `;` here: `ptr::drop_in_place(s.as_mut_ptr());`
error: aborting due to 5 previous errors