diff options
| -rw-r--r-- | clippy_lints/src/methods/unnecessary_lazy_eval.rs | 12 | ||||
| -rw-r--r-- | tests/ui/unnecessary_lazy_eval.fixed | 3 | ||||
| -rw-r--r-- | tests/ui/unnecessary_lazy_eval.rs | 3 | ||||
| -rw-r--r-- | tests/ui/unnecessary_lazy_eval.stderr | 94 | ||||
| -rw-r--r-- | tests/ui/unnecessary_lazy_eval_unfixable.rs | 5 | ||||
| -rw-r--r-- | tests/ui/unnecessary_lazy_eval_unfixable.stderr | 10 |
6 files changed, 85 insertions, 42 deletions
diff --git a/clippy_lints/src/methods/unnecessary_lazy_eval.rs b/clippy_lints/src/methods/unnecessary_lazy_eval.rs index 47e2e744112..4a651396f14 100644 --- a/clippy_lints/src/methods/unnecessary_lazy_eval.rs +++ b/clippy_lints/src/methods/unnecessary_lazy_eval.rs @@ -2,6 +2,7 @@ use clippy_utils::diagnostics::span_lint_and_then; use clippy_utils::source::snippet; use clippy_utils::ty::is_type_diagnostic_item; use clippy_utils::{eager_or_lazy, is_from_proc_macro, usage}; +use hir::FnRetTy; use rustc_errors::Applicability; use rustc_hir as hir; use rustc_lint::LateContext; @@ -27,7 +28,7 @@ pub(super) fn check<'tcx>( let is_bool = cx.typeck_results().expr_ty(recv).is_bool(); if is_option || is_result || is_bool { - if let hir::ExprKind::Closure(&hir::Closure { body, .. }) = arg.kind { + if let hir::ExprKind::Closure(&hir::Closure { body, fn_decl, .. }) = arg.kind { let body = cx.tcx.hir().body(body); let body_expr = &body.value; @@ -48,7 +49,14 @@ pub(super) fn check<'tcx>( .iter() // bindings are checked to be unused above .all(|param| matches!(param.pat.kind, hir::PatKind::Binding(..) | hir::PatKind::Wild)) - { + && matches!( + fn_decl.output, + FnRetTy::DefaultReturn(_) + | FnRetTy::Return(hir::Ty { + kind: hir::TyKind::Infer, + .. + }) + ) { Applicability::MachineApplicable } else { // replacing the lambda may break type inference diff --git a/tests/ui/unnecessary_lazy_eval.fixed b/tests/ui/unnecessary_lazy_eval.fixed index 304e7b7fd7f..4778eaefdbd 100644 --- a/tests/ui/unnecessary_lazy_eval.fixed +++ b/tests/ui/unnecessary_lazy_eval.fixed @@ -5,6 +5,7 @@ #![allow(clippy::map_identity)] #![allow(clippy::needless_borrow)] #![allow(clippy::unnecessary_literal_unwrap)] +#![allow(clippy::unit_arg)] use std::ops::Deref; @@ -76,6 +77,8 @@ fn main() { let _ = opt.ok_or(2); let _ = nested_tuple_opt.unwrap_or(Some((1, 2))); let _ = cond.then_some(astronomers_pi); + let _ = true.then_some({}); + let _ = true.then_some({}); // Should lint - Builtin deref let r = &1; diff --git a/tests/ui/unnecessary_lazy_eval.rs b/tests/ui/unnecessary_lazy_eval.rs index ddfa6bb3ef6..d4b7fd31b1b 100644 --- a/tests/ui/unnecessary_lazy_eval.rs +++ b/tests/ui/unnecessary_lazy_eval.rs @@ -5,6 +5,7 @@ #![allow(clippy::map_identity)] #![allow(clippy::needless_borrow)] #![allow(clippy::unnecessary_literal_unwrap)] +#![allow(clippy::unit_arg)] use std::ops::Deref; @@ -76,6 +77,8 @@ fn main() { let _ = opt.ok_or_else(|| 2); let _ = nested_tuple_opt.unwrap_or_else(|| Some((1, 2))); let _ = cond.then(|| astronomers_pi); + let _ = true.then(|| -> _ {}); + let _ = true.then(|| {}); // Should lint - Builtin deref let r = &1; diff --git a/tests/ui/unnecessary_lazy_eval.stderr b/tests/ui/unnecessary_lazy_eval.stderr index 4f1ca374872..1b0db4759bb 100644 --- a/tests/ui/unnecessary_lazy_eval.stderr +++ b/tests/ui/unnecessary_lazy_eval.stderr @@ -1,5 +1,5 @@ error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:68:13 + --> $DIR/unnecessary_lazy_eval.rs:69:13 | LL | let _ = opt.unwrap_or_else(|| 2); | ^^^^-------------------- @@ -10,7 +10,7 @@ LL | let _ = opt.unwrap_or_else(|| 2); = help: to override `-D warnings` add `#[allow(clippy::unnecessary_lazy_evaluations)]` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:69:13 + --> $DIR/unnecessary_lazy_eval.rs:70:13 | LL | let _ = opt.unwrap_or_else(|| astronomers_pi); | ^^^^--------------------------------- @@ -18,7 +18,7 @@ LL | let _ = opt.unwrap_or_else(|| astronomers_pi); | help: use `unwrap_or(..)` instead: `unwrap_or(astronomers_pi)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:70:13 + --> $DIR/unnecessary_lazy_eval.rs:71:13 | LL | let _ = opt.unwrap_or_else(|| ext_str.some_field); | ^^^^------------------------------------- @@ -26,7 +26,7 @@ LL | let _ = opt.unwrap_or_else(|| ext_str.some_field); | help: use `unwrap_or(..)` instead: `unwrap_or(ext_str.some_field)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:72:13 + --> $DIR/unnecessary_lazy_eval.rs:73:13 | LL | let _ = opt.and_then(|_| ext_opt); | ^^^^--------------------- @@ -34,7 +34,7 @@ LL | let _ = opt.and_then(|_| ext_opt); | help: use `and(..)` instead: `and(ext_opt)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:73:13 + --> $DIR/unnecessary_lazy_eval.rs:74:13 | LL | let _ = opt.or_else(|| ext_opt); | ^^^^------------------- @@ -42,7 +42,7 @@ LL | let _ = opt.or_else(|| ext_opt); | help: use `or(..)` instead: `or(ext_opt)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:74:13 + --> $DIR/unnecessary_lazy_eval.rs:75:13 | LL | let _ = opt.or_else(|| None); | ^^^^---------------- @@ -50,7 +50,7 @@ LL | let _ = opt.or_else(|| None); | help: use `or(..)` instead: `or(None)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:75:13 + --> $DIR/unnecessary_lazy_eval.rs:76:13 | LL | let _ = opt.get_or_insert_with(|| 2); | ^^^^------------------------ @@ -58,7 +58,7 @@ LL | let _ = opt.get_or_insert_with(|| 2); | help: use `get_or_insert(..)` instead: `get_or_insert(2)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:76:13 + --> $DIR/unnecessary_lazy_eval.rs:77:13 | LL | let _ = opt.ok_or_else(|| 2); | ^^^^---------------- @@ -66,7 +66,7 @@ LL | let _ = opt.ok_or_else(|| 2); | help: use `ok_or(..)` instead: `ok_or(2)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:77:13 + --> $DIR/unnecessary_lazy_eval.rs:78:13 | LL | let _ = nested_tuple_opt.unwrap_or_else(|| Some((1, 2))); | ^^^^^^^^^^^^^^^^^------------------------------- @@ -74,15 +74,31 @@ LL | let _ = nested_tuple_opt.unwrap_or_else(|| Some((1, 2))); | help: use `unwrap_or(..)` instead: `unwrap_or(Some((1, 2)))` error: unnecessary closure used with `bool::then` - --> $DIR/unnecessary_lazy_eval.rs:78:13 + --> $DIR/unnecessary_lazy_eval.rs:79:13 | LL | let _ = cond.then(|| astronomers_pi); | ^^^^^----------------------- | | | help: use `then_some(..)` instead: `then_some(astronomers_pi)` +error: unnecessary closure used with `bool::then` + --> $DIR/unnecessary_lazy_eval.rs:80:13 + | +LL | let _ = true.then(|| -> _ {}); + | ^^^^^---------------- + | | + | help: use `then_some(..)` instead: `then_some({})` + +error: unnecessary closure used with `bool::then` + --> $DIR/unnecessary_lazy_eval.rs:81:13 + | +LL | let _ = true.then(|| {}); + | ^^^^^----------- + | | + | help: use `then_some(..)` instead: `then_some({})` + error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:82:13 + --> $DIR/unnecessary_lazy_eval.rs:85:13 | LL | let _ = Some(1).unwrap_or_else(|| *r); | ^^^^^^^^--------------------- @@ -90,7 +106,7 @@ LL | let _ = Some(1).unwrap_or_else(|| *r); | help: use `unwrap_or(..)` instead: `unwrap_or(*r)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:84:13 + --> $DIR/unnecessary_lazy_eval.rs:87:13 | LL | let _ = Some(1).unwrap_or_else(|| *b); | ^^^^^^^^--------------------- @@ -98,7 +114,7 @@ LL | let _ = Some(1).unwrap_or_else(|| *b); | help: use `unwrap_or(..)` instead: `unwrap_or(*b)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:86:13 + --> $DIR/unnecessary_lazy_eval.rs:89:13 | LL | let _ = Some(1).as_ref().unwrap_or_else(|| &r); | ^^^^^^^^^^^^^^^^^--------------------- @@ -106,7 +122,7 @@ LL | let _ = Some(1).as_ref().unwrap_or_else(|| &r); | help: use `unwrap_or(..)` instead: `unwrap_or(&r)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:87:13 + --> $DIR/unnecessary_lazy_eval.rs:90:13 | LL | let _ = Some(1).as_ref().unwrap_or_else(|| &b); | ^^^^^^^^^^^^^^^^^--------------------- @@ -114,7 +130,7 @@ LL | let _ = Some(1).as_ref().unwrap_or_else(|| &b); | help: use `unwrap_or(..)` instead: `unwrap_or(&b)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:90:13 + --> $DIR/unnecessary_lazy_eval.rs:93:13 | LL | let _ = Some(10).unwrap_or_else(|| 2); | ^^^^^^^^^-------------------- @@ -122,7 +138,7 @@ LL | let _ = Some(10).unwrap_or_else(|| 2); | help: use `unwrap_or(..)` instead: `unwrap_or(2)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:91:13 + --> $DIR/unnecessary_lazy_eval.rs:94:13 | LL | let _ = Some(10).and_then(|_| ext_opt); | ^^^^^^^^^--------------------- @@ -130,7 +146,7 @@ LL | let _ = Some(10).and_then(|_| ext_opt); | help: use `and(..)` instead: `and(ext_opt)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:92:28 + --> $DIR/unnecessary_lazy_eval.rs:95:28 | LL | let _: Option<usize> = None.or_else(|| ext_opt); | ^^^^^------------------- @@ -138,7 +154,7 @@ LL | let _: Option<usize> = None.or_else(|| ext_opt); | help: use `or(..)` instead: `or(ext_opt)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:93:13 + --> $DIR/unnecessary_lazy_eval.rs:96:13 | LL | let _ = None.get_or_insert_with(|| 2); | ^^^^^------------------------ @@ -146,7 +162,7 @@ LL | let _ = None.get_or_insert_with(|| 2); | help: use `get_or_insert(..)` instead: `get_or_insert(2)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:94:35 + --> $DIR/unnecessary_lazy_eval.rs:97:35 | LL | let _: Result<usize, usize> = None.ok_or_else(|| 2); | ^^^^^---------------- @@ -154,7 +170,7 @@ LL | let _: Result<usize, usize> = None.ok_or_else(|| 2); | help: use `ok_or(..)` instead: `ok_or(2)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:95:28 + --> $DIR/unnecessary_lazy_eval.rs:98:28 | LL | let _: Option<usize> = None.or_else(|| None); | ^^^^^---------------- @@ -162,7 +178,7 @@ LL | let _: Option<usize> = None.or_else(|| None); | help: use `or(..)` instead: `or(None)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:98:13 + --> $DIR/unnecessary_lazy_eval.rs:101:13 | LL | let _ = deep.0.unwrap_or_else(|| 2); | ^^^^^^^-------------------- @@ -170,7 +186,7 @@ LL | let _ = deep.0.unwrap_or_else(|| 2); | help: use `unwrap_or(..)` instead: `unwrap_or(2)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:99:13 + --> $DIR/unnecessary_lazy_eval.rs:102:13 | LL | let _ = deep.0.and_then(|_| ext_opt); | ^^^^^^^--------------------- @@ -178,7 +194,7 @@ LL | let _ = deep.0.and_then(|_| ext_opt); | help: use `and(..)` instead: `and(ext_opt)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:100:13 + --> $DIR/unnecessary_lazy_eval.rs:103:13 | LL | let _ = deep.0.or_else(|| None); | ^^^^^^^---------------- @@ -186,7 +202,7 @@ LL | let _ = deep.0.or_else(|| None); | help: use `or(..)` instead: `or(None)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:101:13 + --> $DIR/unnecessary_lazy_eval.rs:104:13 | LL | let _ = deep.0.get_or_insert_with(|| 2); | ^^^^^^^------------------------ @@ -194,7 +210,7 @@ LL | let _ = deep.0.get_or_insert_with(|| 2); | help: use `get_or_insert(..)` instead: `get_or_insert(2)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:102:13 + --> $DIR/unnecessary_lazy_eval.rs:105:13 | LL | let _ = deep.0.ok_or_else(|| 2); | ^^^^^^^---------------- @@ -202,7 +218,7 @@ LL | let _ = deep.0.ok_or_else(|| 2); | help: use `ok_or(..)` instead: `ok_or(2)` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:132:28 + --> $DIR/unnecessary_lazy_eval.rs:135:28 | LL | let _: Option<usize> = None.or_else(|| Some(3)); | ^^^^^------------------- @@ -210,7 +226,7 @@ LL | let _: Option<usize> = None.or_else(|| Some(3)); | help: use `or(..)` instead: `or(Some(3))` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:133:13 + --> $DIR/unnecessary_lazy_eval.rs:136:13 | LL | let _ = deep.0.or_else(|| Some(3)); | ^^^^^^^------------------- @@ -218,7 +234,7 @@ LL | let _ = deep.0.or_else(|| Some(3)); | help: use `or(..)` instead: `or(Some(3))` error: unnecessary closure used to substitute value for `Option::None` - --> $DIR/unnecessary_lazy_eval.rs:134:13 + --> $DIR/unnecessary_lazy_eval.rs:137:13 | LL | let _ = opt.or_else(|| Some(3)); | ^^^^------------------- @@ -226,7 +242,7 @@ LL | let _ = opt.or_else(|| Some(3)); | help: use `or(..)` instead: `or(Some(3))` error: unnecessary closure used to substitute value for `Result::Err` - --> $DIR/unnecessary_lazy_eval.rs:140:13 + --> $DIR/unnecessary_lazy_eval.rs:143:13 | LL | let _ = res2.unwrap_or_else(|_| 2); | ^^^^^--------------------- @@ -234,7 +250,7 @@ LL | let _ = res2.unwrap_or_else(|_| 2); | help: use `unwrap_or(..)` instead: `unwrap_or(2)` error: unnecessary closure used to substitute value for `Result::Err` - --> $DIR/unnecessary_lazy_eval.rs:141:13 + --> $DIR/unnecessary_lazy_eval.rs:144:13 | LL | let _ = res2.unwrap_or_else(|_| astronomers_pi); | ^^^^^---------------------------------- @@ -242,7 +258,7 @@ LL | let _ = res2.unwrap_or_else(|_| astronomers_pi); | help: use `unwrap_or(..)` instead: `unwrap_or(astronomers_pi)` error: unnecessary closure used to substitute value for `Result::Err` - --> $DIR/unnecessary_lazy_eval.rs:142:13 + --> $DIR/unnecessary_lazy_eval.rs:145:13 | LL | let _ = res2.unwrap_or_else(|_| ext_str.some_field); | ^^^^^-------------------------------------- @@ -250,7 +266,7 @@ LL | let _ = res2.unwrap_or_else(|_| ext_str.some_field); | help: use `unwrap_or(..)` instead: `unwrap_or(ext_str.some_field)` error: unnecessary closure used to substitute value for `Result::Err` - --> $DIR/unnecessary_lazy_eval.rs:164:35 + --> $DIR/unnecessary_lazy_eval.rs:167:35 | LL | let _: Result<usize, usize> = res.and_then(|_| Err(2)); | ^^^^-------------------- @@ -258,7 +274,7 @@ LL | let _: Result<usize, usize> = res.and_then(|_| Err(2)); | help: use `and(..)` instead: `and(Err(2))` error: unnecessary closure used to substitute value for `Result::Err` - --> $DIR/unnecessary_lazy_eval.rs:165:35 + --> $DIR/unnecessary_lazy_eval.rs:168:35 | LL | let _: Result<usize, usize> = res.and_then(|_| Err(astronomers_pi)); | ^^^^--------------------------------- @@ -266,7 +282,7 @@ LL | let _: Result<usize, usize> = res.and_then(|_| Err(astronomers_pi)); | help: use `and(..)` instead: `and(Err(astronomers_pi))` error: unnecessary closure used to substitute value for `Result::Err` - --> $DIR/unnecessary_lazy_eval.rs:166:35 + --> $DIR/unnecessary_lazy_eval.rs:169:35 | LL | let _: Result<usize, usize> = res.and_then(|_| Err(ext_str.some_field)); | ^^^^------------------------------------- @@ -274,7 +290,7 @@ LL | let _: Result<usize, usize> = res.and_then(|_| Err(ext_str.some_field)) | help: use `and(..)` instead: `and(Err(ext_str.some_field))` error: unnecessary closure used to substitute value for `Result::Err` - --> $DIR/unnecessary_lazy_eval.rs:168:35 + --> $DIR/unnecessary_lazy_eval.rs:171:35 | LL | let _: Result<usize, usize> = res.or_else(|_| Ok(2)); | ^^^^------------------ @@ -282,7 +298,7 @@ LL | let _: Result<usize, usize> = res.or_else(|_| Ok(2)); | help: use `or(..)` instead: `or(Ok(2))` error: unnecessary closure used to substitute value for `Result::Err` - --> $DIR/unnecessary_lazy_eval.rs:169:35 + --> $DIR/unnecessary_lazy_eval.rs:172:35 | LL | let _: Result<usize, usize> = res.or_else(|_| Ok(astronomers_pi)); | ^^^^------------------------------- @@ -290,7 +306,7 @@ LL | let _: Result<usize, usize> = res.or_else(|_| Ok(astronomers_pi)); | help: use `or(..)` instead: `or(Ok(astronomers_pi))` error: unnecessary closure used to substitute value for `Result::Err` - --> $DIR/unnecessary_lazy_eval.rs:170:35 + --> $DIR/unnecessary_lazy_eval.rs:173:35 | LL | let _: Result<usize, usize> = res.or_else(|_| Ok(ext_str.some_field)); | ^^^^----------------------------------- @@ -298,7 +314,7 @@ LL | let _: Result<usize, usize> = res.or_else(|_| Ok(ext_str.some_field)); | help: use `or(..)` instead: `or(Ok(ext_str.some_field))` error: unnecessary closure used to substitute value for `Result::Err` - --> $DIR/unnecessary_lazy_eval.rs:171:35 + --> $DIR/unnecessary_lazy_eval.rs:174:35 | LL | let _: Result<usize, usize> = res. | ___________________________________^ @@ -312,5 +328,5 @@ LL | | or_else(|_| Ok(ext_str.some_field)); | | | help: use `or(..)` instead: `or(Ok(ext_str.some_field))` -error: aborting due to 38 previous errors +error: aborting due to 40 previous errors diff --git a/tests/ui/unnecessary_lazy_eval_unfixable.rs b/tests/ui/unnecessary_lazy_eval_unfixable.rs index 33685bfb738..412d4aaafb4 100644 --- a/tests/ui/unnecessary_lazy_eval_unfixable.rs +++ b/tests/ui/unnecessary_lazy_eval_unfixable.rs @@ -25,3 +25,8 @@ fn main() { let arr = [(Some(1),)]; Some(&0).and_then(|&i| arr[i].0); } + +fn issue11672() { + // Return type annotation helps type inference and removing it can break code + let _ = true.then(|| -> &[u8] { &[] }); +} diff --git a/tests/ui/unnecessary_lazy_eval_unfixable.stderr b/tests/ui/unnecessary_lazy_eval_unfixable.stderr index 27fa560d4d7..95b02be91ca 100644 --- a/tests/ui/unnecessary_lazy_eval_unfixable.stderr +++ b/tests/ui/unnecessary_lazy_eval_unfixable.stderr @@ -25,5 +25,13 @@ LL | let _ = Ok(1).unwrap_or_else(|SomeStruct { .. }| 2); | | | help: use `unwrap_or(..)` instead: `unwrap_or(2)` -error: aborting due to 3 previous errors +error: unnecessary closure used with `bool::then` + --> $DIR/unnecessary_lazy_eval_unfixable.rs:31:13 + | +LL | let _ = true.then(|| -> &[u8] { &[] }); + | ^^^^^------------------------- + | | + | help: use `then_some(..)` instead: `then_some({ &[] })` + +error: aborting due to 4 previous errors |