From 081f73954b24e87bbbd95ed20f9a504680b21d46 Mon Sep 17 00:00:00 2001 From: TennyZhuang Date: Sun, 2 Oct 2022 17:12:08 +0800 Subject: [PATCH 1/4] let unnecessary_cast work for trivial non_literal expressions Signed-off-by: TennyZhuang --- clippy_lints/src/casts/unnecessary_cast.rs | 15 ++++++++++++++- tests/ui/unnecessary_cast.fixed | 8 ++++++++ tests/ui/unnecessary_cast.rs | 8 ++++++++ tests/ui/unnecessary_cast.stderr | 8 +++++++- 4 files changed, 37 insertions(+), 2 deletions(-) diff --git a/clippy_lints/src/casts/unnecessary_cast.rs b/clippy_lints/src/casts/unnecessary_cast.rs index 031cedb90720..071fab1165d4 100644 --- a/clippy_lints/src/casts/unnecessary_cast.rs +++ b/clippy_lints/src/casts/unnecessary_cast.rs @@ -31,8 +31,10 @@ pub(super) fn check<'tcx>( } } + let cast_str = snippet_opt(cx, cast_expr.span).unwrap_or_default(); + if let Some(lit) = get_numeric_literal(cast_expr) { - let literal_str = snippet_opt(cx, cast_expr.span).unwrap_or_default(); + let literal_str = cast_str; if_chain! { if let LitKind::Int(n, _) = lit.node; @@ -81,6 +83,17 @@ pub(super) fn check<'tcx>( } }, } + } else if cast_from.kind() == cast_to.kind() && !in_external_macro(cx.sess(), expr.span) { + span_lint_and_sugg( + cx, + UNNECESSARY_CAST, + expr.span, + &format!("casting to the same type is unnecessary (`{cast_from}` -> `{cast_to}`)"), + "try", + cast_str, + Applicability::MachineApplicable, + ); + return true; } false diff --git a/tests/ui/unnecessary_cast.fixed b/tests/ui/unnecessary_cast.fixed index 70ec3e943807..94dc96427263 100644 --- a/tests/ui/unnecessary_cast.fixed +++ b/tests/ui/unnecessary_cast.fixed @@ -103,4 +103,12 @@ mod fixable { #[allow(clippy::precedence)] let _: f64 = -8.0_f64.exp(); // should suggest `-8.0_f64.exp()` here not to change code behavior } + + fn issue_9562_non_literal() { + fn foo() -> f32 { + 0. + } + + let _num = foo(); + } } diff --git a/tests/ui/unnecessary_cast.rs b/tests/ui/unnecessary_cast.rs index 36c1a87fab6e..e5150256f69a 100644 --- a/tests/ui/unnecessary_cast.rs +++ b/tests/ui/unnecessary_cast.rs @@ -103,4 +103,12 @@ mod fixable { #[allow(clippy::precedence)] let _: f64 = -(8.0 as f64).exp(); // should suggest `-8.0_f64.exp()` here not to change code behavior } + + fn issue_9562_non_literal() { + fn foo() -> f32 { + 0. + } + + let _num = foo() as f32; + } } diff --git a/tests/ui/unnecessary_cast.stderr b/tests/ui/unnecessary_cast.stderr index a52b92c339c8..e5c3dd5e53f8 100644 --- a/tests/ui/unnecessary_cast.stderr +++ b/tests/ui/unnecessary_cast.stderr @@ -174,5 +174,11 @@ error: casting float literal to `f64` is unnecessary LL | let _: f64 = -(8.0 as f64).exp(); // should suggest `-8.0_f64.exp()` here not to change code behavior | ^^^^^^^^^^^^ help: try: `8.0_f64` -error: aborting due to 29 previous errors +error: casting to the same type is unnecessary (`f32` -> `f32`) + --> $DIR/unnecessary_cast.rs:112:20 + | +LL | let _num = foo() as f32; + | ^^^^^^^^^^^^ help: try: `foo()` + +error: aborting due to 30 previous errors From f2043989ca5fc829de1bed045460366a030e8904 Mon Sep 17 00:00:00 2001 From: TennyZhuang Date: Sun, 2 Oct 2022 17:53:58 +0800 Subject: [PATCH 2/4] ignore the lint on some test files Signed-off-by: TennyZhuang --- tests/ui/floating_point_exp.fixed | 1 + tests/ui/floating_point_exp.rs | 1 + tests/ui/floating_point_exp.stderr | 10 ++--- tests/ui/floating_point_log.fixed | 2 +- tests/ui/floating_point_log.rs | 2 +- tests/ui/floating_point_logbase.fixed | 1 + tests/ui/floating_point_logbase.rs | 1 + tests/ui/floating_point_logbase.stderr | 10 ++--- tests/ui/floating_point_powf.fixed | 1 + tests/ui/floating_point_powf.rs | 1 + tests/ui/floating_point_powf.stderr | 62 +++++++++++++------------- tests/ui/floating_point_powi.fixed | 1 + tests/ui/floating_point_powi.rs | 1 + tests/ui/floating_point_powi.stderr | 10 ++--- tests/ui/manual_bits.fixed | 3 +- tests/ui/manual_bits.rs | 3 +- tests/ui/manual_bits.stderr | 58 ++++++++++++------------ tests/ui/ptr_offset_with_cast.fixed | 1 + tests/ui/ptr_offset_with_cast.rs | 1 + tests/ui/ptr_offset_with_cast.stderr | 4 +- 20 files changed, 93 insertions(+), 81 deletions(-) diff --git a/tests/ui/floating_point_exp.fixed b/tests/ui/floating_point_exp.fixed index c86a502d15f0..b9e3d89c2b29 100644 --- a/tests/ui/floating_point_exp.fixed +++ b/tests/ui/floating_point_exp.fixed @@ -1,5 +1,6 @@ // run-rustfix #![warn(clippy::imprecise_flops)] +#![allow(clippy::unnecessary_cast)] fn main() { let x = 2f32; diff --git a/tests/ui/floating_point_exp.rs b/tests/ui/floating_point_exp.rs index e59589f912a2..ef008dd9be05 100644 --- a/tests/ui/floating_point_exp.rs +++ b/tests/ui/floating_point_exp.rs @@ -1,5 +1,6 @@ // run-rustfix #![warn(clippy::imprecise_flops)] +#![allow(clippy::unnecessary_cast)] fn main() { let x = 2f32; diff --git a/tests/ui/floating_point_exp.stderr b/tests/ui/floating_point_exp.stderr index f84eede19872..b92fae56e421 100644 --- a/tests/ui/floating_point_exp.stderr +++ b/tests/ui/floating_point_exp.stderr @@ -1,5 +1,5 @@ error: (e.pow(x) - 1) can be computed more accurately - --> $DIR/floating_point_exp.rs:6:13 + --> $DIR/floating_point_exp.rs:7:13 | LL | let _ = x.exp() - 1.0; | ^^^^^^^^^^^^^ help: consider using: `x.exp_m1()` @@ -7,25 +7,25 @@ LL | let _ = x.exp() - 1.0; = note: `-D clippy::imprecise-flops` implied by `-D warnings` error: (e.pow(x) - 1) can be computed more accurately - --> $DIR/floating_point_exp.rs:7:13 + --> $DIR/floating_point_exp.rs:8:13 | LL | let _ = x.exp() - 1.0 + 2.0; | ^^^^^^^^^^^^^ help: consider using: `x.exp_m1()` error: (e.pow(x) - 1) can be computed more accurately - --> $DIR/floating_point_exp.rs:8:13 + --> $DIR/floating_point_exp.rs:9:13 | LL | let _ = (x as f32).exp() - 1.0 + 2.0; | ^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(x as f32).exp_m1()` error: (e.pow(x) - 1) can be computed more accurately - --> $DIR/floating_point_exp.rs:14:13 + --> $DIR/floating_point_exp.rs:15:13 | LL | let _ = x.exp() - 1.0; | ^^^^^^^^^^^^^ help: consider using: `x.exp_m1()` error: (e.pow(x) - 1) can be computed more accurately - --> $DIR/floating_point_exp.rs:15:13 + --> $DIR/floating_point_exp.rs:16:13 | LL | let _ = x.exp() - 1.0 + 2.0; | ^^^^^^^^^^^^^ help: consider using: `x.exp_m1()` diff --git a/tests/ui/floating_point_log.fixed b/tests/ui/floating_point_log.fixed index 4def9300bb7d..ee5406461600 100644 --- a/tests/ui/floating_point_log.fixed +++ b/tests/ui/floating_point_log.fixed @@ -1,5 +1,5 @@ // run-rustfix -#![allow(dead_code, clippy::double_parens)] +#![allow(dead_code, clippy::double_parens, clippy::unnecessary_cast)] #![warn(clippy::suboptimal_flops, clippy::imprecise_flops)] const TWO: f32 = 2.0; diff --git a/tests/ui/floating_point_log.rs b/tests/ui/floating_point_log.rs index 1e04caa7d2a8..0590670a50bc 100644 --- a/tests/ui/floating_point_log.rs +++ b/tests/ui/floating_point_log.rs @@ -1,5 +1,5 @@ // run-rustfix -#![allow(dead_code, clippy::double_parens)] +#![allow(dead_code, clippy::double_parens, clippy::unnecessary_cast)] #![warn(clippy::suboptimal_flops, clippy::imprecise_flops)] const TWO: f32 = 2.0; diff --git a/tests/ui/floating_point_logbase.fixed b/tests/ui/floating_point_logbase.fixed index 936462f94066..7347bf72cbea 100644 --- a/tests/ui/floating_point_logbase.fixed +++ b/tests/ui/floating_point_logbase.fixed @@ -1,5 +1,6 @@ // run-rustfix #![warn(clippy::suboptimal_flops)] +#![allow(clippy::unnecessary_cast)] fn main() { let x = 3f32; diff --git a/tests/ui/floating_point_logbase.rs b/tests/ui/floating_point_logbase.rs index 0b56fa8fa41f..ba5b8d406928 100644 --- a/tests/ui/floating_point_logbase.rs +++ b/tests/ui/floating_point_logbase.rs @@ -1,5 +1,6 @@ // run-rustfix #![warn(clippy::suboptimal_flops)] +#![allow(clippy::unnecessary_cast)] fn main() { let x = 3f32; diff --git a/tests/ui/floating_point_logbase.stderr b/tests/ui/floating_point_logbase.stderr index 384e3554cbbe..9d736b5e1a27 100644 --- a/tests/ui/floating_point_logbase.stderr +++ b/tests/ui/floating_point_logbase.stderr @@ -1,5 +1,5 @@ error: log base can be expressed more clearly - --> $DIR/floating_point_logbase.rs:7:13 + --> $DIR/floating_point_logbase.rs:8:13 | LL | let _ = x.ln() / y.ln(); | ^^^^^^^^^^^^^^^ help: consider using: `x.log(y)` @@ -7,25 +7,25 @@ LL | let _ = x.ln() / y.ln(); = note: `-D clippy::suboptimal-flops` implied by `-D warnings` error: log base can be expressed more clearly - --> $DIR/floating_point_logbase.rs:8:13 + --> $DIR/floating_point_logbase.rs:9:13 | LL | let _ = (x as f32).ln() / y.ln(); | ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(x as f32).log(y)` error: log base can be expressed more clearly - --> $DIR/floating_point_logbase.rs:9:13 + --> $DIR/floating_point_logbase.rs:10:13 | LL | let _ = x.log2() / y.log2(); | ^^^^^^^^^^^^^^^^^^^ help: consider using: `x.log(y)` error: log base can be expressed more clearly - --> $DIR/floating_point_logbase.rs:10:13 + --> $DIR/floating_point_logbase.rs:11:13 | LL | let _ = x.log10() / y.log10(); | ^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.log(y)` error: log base can be expressed more clearly - --> $DIR/floating_point_logbase.rs:11:13 + --> $DIR/floating_point_logbase.rs:12:13 | LL | let _ = x.log(5f32) / y.log(5f32); | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.log(y)` diff --git a/tests/ui/floating_point_powf.fixed b/tests/ui/floating_point_powf.fixed index e7ef45634dff..f7f93de29577 100644 --- a/tests/ui/floating_point_powf.fixed +++ b/tests/ui/floating_point_powf.fixed @@ -1,5 +1,6 @@ // run-rustfix #![warn(clippy::suboptimal_flops, clippy::imprecise_flops)] +#![allow(clippy::unnecessary_cast)] fn main() { let x = 3f32; diff --git a/tests/ui/floating_point_powf.rs b/tests/ui/floating_point_powf.rs index d749aa2d48a4..499fc0e15e47 100644 --- a/tests/ui/floating_point_powf.rs +++ b/tests/ui/floating_point_powf.rs @@ -1,5 +1,6 @@ // run-rustfix #![warn(clippy::suboptimal_flops, clippy::imprecise_flops)] +#![allow(clippy::unnecessary_cast)] fn main() { let x = 3f32; diff --git a/tests/ui/floating_point_powf.stderr b/tests/ui/floating_point_powf.stderr index e9693de8fc90..7c9d50db2f78 100644 --- a/tests/ui/floating_point_powf.stderr +++ b/tests/ui/floating_point_powf.stderr @@ -1,5 +1,5 @@ error: exponent for bases 2 and e can be computed more accurately - --> $DIR/floating_point_powf.rs:6:13 + --> $DIR/floating_point_powf.rs:7:13 | LL | let _ = 2f32.powf(x); | ^^^^^^^^^^^^ help: consider using: `x.exp2()` @@ -7,43 +7,43 @@ LL | let _ = 2f32.powf(x); = note: `-D clippy::suboptimal-flops` implied by `-D warnings` error: exponent for bases 2 and e can be computed more accurately - --> $DIR/floating_point_powf.rs:7:13 + --> $DIR/floating_point_powf.rs:8:13 | LL | let _ = 2f32.powf(3.1); | ^^^^^^^^^^^^^^ help: consider using: `3.1f32.exp2()` error: exponent for bases 2 and e can be computed more accurately - --> $DIR/floating_point_powf.rs:8:13 + --> $DIR/floating_point_powf.rs:9:13 | LL | let _ = 2f32.powf(-3.1); | ^^^^^^^^^^^^^^^ help: consider using: `(-3.1f32).exp2()` error: exponent for bases 2 and e can be computed more accurately - --> $DIR/floating_point_powf.rs:9:13 + --> $DIR/floating_point_powf.rs:10:13 | LL | let _ = std::f32::consts::E.powf(x); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.exp()` error: exponent for bases 2 and e can be computed more accurately - --> $DIR/floating_point_powf.rs:10:13 + --> $DIR/floating_point_powf.rs:11:13 | LL | let _ = std::f32::consts::E.powf(3.1); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `3.1f32.exp()` error: exponent for bases 2 and e can be computed more accurately - --> $DIR/floating_point_powf.rs:11:13 + --> $DIR/floating_point_powf.rs:12:13 | LL | let _ = std::f32::consts::E.powf(-3.1); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(-3.1f32).exp()` error: square-root of a number can be computed more efficiently and accurately - --> $DIR/floating_point_powf.rs:12:13 + --> $DIR/floating_point_powf.rs:13:13 | LL | let _ = x.powf(1.0 / 2.0); | ^^^^^^^^^^^^^^^^^ help: consider using: `x.sqrt()` error: cube-root of a number can be computed more accurately - --> $DIR/floating_point_powf.rs:13:13 + --> $DIR/floating_point_powf.rs:14:13 | LL | let _ = x.powf(1.0 / 3.0); | ^^^^^^^^^^^^^^^^^ help: consider using: `x.cbrt()` @@ -51,139 +51,139 @@ LL | let _ = x.powf(1.0 / 3.0); = note: `-D clippy::imprecise-flops` implied by `-D warnings` error: cube-root of a number can be computed more accurately - --> $DIR/floating_point_powf.rs:14:13 + --> $DIR/floating_point_powf.rs:15:13 | LL | let _ = (x as f32).powf(1.0 / 3.0); | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(x as f32).cbrt()` error: exponentiation with integer powers can be computed more efficiently - --> $DIR/floating_point_powf.rs:15:13 + --> $DIR/floating_point_powf.rs:16:13 | LL | let _ = x.powf(3.0); | ^^^^^^^^^^^ help: consider using: `x.powi(3)` error: exponentiation with integer powers can be computed more efficiently - --> $DIR/floating_point_powf.rs:16:13 + --> $DIR/floating_point_powf.rs:17:13 | LL | let _ = x.powf(-2.0); | ^^^^^^^^^^^^ help: consider using: `x.powi(-2)` error: exponentiation with integer powers can be computed more efficiently - --> $DIR/floating_point_powf.rs:17:13 + --> $DIR/floating_point_powf.rs:18:13 | LL | let _ = x.powf(16_777_215.0); | ^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.powi(16_777_215)` error: exponentiation with integer powers can be computed more efficiently - --> $DIR/floating_point_powf.rs:18:13 + --> $DIR/floating_point_powf.rs:19:13 | LL | let _ = x.powf(-16_777_215.0); | ^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.powi(-16_777_215)` error: exponentiation with integer powers can be computed more efficiently - --> $DIR/floating_point_powf.rs:19:13 + --> $DIR/floating_point_powf.rs:20:13 | LL | let _ = (x as f32).powf(-16_777_215.0); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(x as f32).powi(-16_777_215)` error: exponentiation with integer powers can be computed more efficiently - --> $DIR/floating_point_powf.rs:20:13 + --> $DIR/floating_point_powf.rs:21:13 | LL | let _ = (x as f32).powf(3.0); | ^^^^^^^^^^^^^^^^^^^^ help: consider using: `(x as f32).powi(3)` error: cube-root of a number can be computed more accurately - --> $DIR/floating_point_powf.rs:21:13 + --> $DIR/floating_point_powf.rs:22:13 | LL | let _ = (1.5_f32 + 1.0).powf(1.0 / 3.0); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(1.5_f32 + 1.0).cbrt()` error: cube-root of a number can be computed more accurately - --> $DIR/floating_point_powf.rs:22:13 + --> $DIR/floating_point_powf.rs:23:13 | LL | let _ = 1.5_f64.powf(1.0 / 3.0); | ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `1.5_f64.cbrt()` error: square-root of a number can be computed more efficiently and accurately - --> $DIR/floating_point_powf.rs:23:13 + --> $DIR/floating_point_powf.rs:24:13 | LL | let _ = 1.5_f64.powf(1.0 / 2.0); | ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `1.5_f64.sqrt()` error: exponentiation with integer powers can be computed more efficiently - --> $DIR/floating_point_powf.rs:24:13 + --> $DIR/floating_point_powf.rs:25:13 | LL | let _ = 1.5_f64.powf(3.0); | ^^^^^^^^^^^^^^^^^ help: consider using: `1.5_f64.powi(3)` error: exponent for bases 2 and e can be computed more accurately - --> $DIR/floating_point_powf.rs:33:13 + --> $DIR/floating_point_powf.rs:34:13 | LL | let _ = 2f64.powf(x); | ^^^^^^^^^^^^ help: consider using: `x.exp2()` error: exponent for bases 2 and e can be computed more accurately - --> $DIR/floating_point_powf.rs:34:13 + --> $DIR/floating_point_powf.rs:35:13 | LL | let _ = 2f64.powf(3.1); | ^^^^^^^^^^^^^^ help: consider using: `3.1f64.exp2()` error: exponent for bases 2 and e can be computed more accurately - --> $DIR/floating_point_powf.rs:35:13 + --> $DIR/floating_point_powf.rs:36:13 | LL | let _ = 2f64.powf(-3.1); | ^^^^^^^^^^^^^^^ help: consider using: `(-3.1f64).exp2()` error: exponent for bases 2 and e can be computed more accurately - --> $DIR/floating_point_powf.rs:36:13 + --> $DIR/floating_point_powf.rs:37:13 | LL | let _ = std::f64::consts::E.powf(x); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.exp()` error: exponent for bases 2 and e can be computed more accurately - --> $DIR/floating_point_powf.rs:37:13 + --> $DIR/floating_point_powf.rs:38:13 | LL | let _ = std::f64::consts::E.powf(3.1); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `3.1f64.exp()` error: exponent for bases 2 and e can be computed more accurately - --> $DIR/floating_point_powf.rs:38:13 + --> $DIR/floating_point_powf.rs:39:13 | LL | let _ = std::f64::consts::E.powf(-3.1); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(-3.1f64).exp()` error: square-root of a number can be computed more efficiently and accurately - --> $DIR/floating_point_powf.rs:39:13 + --> $DIR/floating_point_powf.rs:40:13 | LL | let _ = x.powf(1.0 / 2.0); | ^^^^^^^^^^^^^^^^^ help: consider using: `x.sqrt()` error: cube-root of a number can be computed more accurately - --> $DIR/floating_point_powf.rs:40:13 + --> $DIR/floating_point_powf.rs:41:13 | LL | let _ = x.powf(1.0 / 3.0); | ^^^^^^^^^^^^^^^^^ help: consider using: `x.cbrt()` error: exponentiation with integer powers can be computed more efficiently - --> $DIR/floating_point_powf.rs:41:13 + --> $DIR/floating_point_powf.rs:42:13 | LL | let _ = x.powf(3.0); | ^^^^^^^^^^^ help: consider using: `x.powi(3)` error: exponentiation with integer powers can be computed more efficiently - --> $DIR/floating_point_powf.rs:42:13 + --> $DIR/floating_point_powf.rs:43:13 | LL | let _ = x.powf(-2.0); | ^^^^^^^^^^^^ help: consider using: `x.powi(-2)` error: exponentiation with integer powers can be computed more efficiently - --> $DIR/floating_point_powf.rs:43:13 + --> $DIR/floating_point_powf.rs:44:13 | LL | let _ = x.powf(-2_147_483_648.0); | ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.powi(-2_147_483_648)` error: exponentiation with integer powers can be computed more efficiently - --> $DIR/floating_point_powf.rs:44:13 + --> $DIR/floating_point_powf.rs:45:13 | LL | let _ = x.powf(2_147_483_647.0); | ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.powi(2_147_483_647)` diff --git a/tests/ui/floating_point_powi.fixed b/tests/ui/floating_point_powi.fixed index 5758db7c6c82..68c81316930c 100644 --- a/tests/ui/floating_point_powi.fixed +++ b/tests/ui/floating_point_powi.fixed @@ -1,5 +1,6 @@ // run-rustfix #![warn(clippy::suboptimal_flops)] +#![allow(clippy::unnecessary_cast)] fn main() { let one = 1; diff --git a/tests/ui/floating_point_powi.rs b/tests/ui/floating_point_powi.rs index 5926bf1b0004..96101a487ee8 100644 --- a/tests/ui/floating_point_powi.rs +++ b/tests/ui/floating_point_powi.rs @@ -1,5 +1,6 @@ // run-rustfix #![warn(clippy::suboptimal_flops)] +#![allow(clippy::unnecessary_cast)] fn main() { let one = 1; diff --git a/tests/ui/floating_point_powi.stderr b/tests/ui/floating_point_powi.stderr index a3c74544212b..a651954a5f81 100644 --- a/tests/ui/floating_point_powi.stderr +++ b/tests/ui/floating_point_powi.stderr @@ -1,5 +1,5 @@ error: multiply and add expressions can be calculated more efficiently and accurately - --> $DIR/floating_point_powi.rs:9:13 + --> $DIR/floating_point_powi.rs:10:13 | LL | let _ = x.powi(2) + y; | ^^^^^^^^^^^^^ help: consider using: `x.mul_add(x, y)` @@ -7,25 +7,25 @@ LL | let _ = x.powi(2) + y; = note: `-D clippy::suboptimal-flops` implied by `-D warnings` error: multiply and add expressions can be calculated more efficiently and accurately - --> $DIR/floating_point_powi.rs:10:13 + --> $DIR/floating_point_powi.rs:11:13 | LL | let _ = x + y.powi(2); | ^^^^^^^^^^^^^ help: consider using: `y.mul_add(y, x)` error: multiply and add expressions can be calculated more efficiently and accurately - --> $DIR/floating_point_powi.rs:11:13 + --> $DIR/floating_point_powi.rs:12:13 | LL | let _ = x + (y as f32).powi(2); | ^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(y as f32).mul_add(y as f32, x)` error: multiply and add expressions can be calculated more efficiently and accurately - --> $DIR/floating_point_powi.rs:12:13 + --> $DIR/floating_point_powi.rs:13:13 | LL | let _ = (x.powi(2) + y).sqrt(); | ^^^^^^^^^^^^^^^ help: consider using: `x.mul_add(x, y)` error: multiply and add expressions can be calculated more efficiently and accurately - --> $DIR/floating_point_powi.rs:13:13 + --> $DIR/floating_point_powi.rs:14:13 | LL | let _ = (x + y.powi(2)).sqrt(); | ^^^^^^^^^^^^^^^ help: consider using: `y.mul_add(y, x)` diff --git a/tests/ui/manual_bits.fixed b/tests/ui/manual_bits.fixed index 386360dbdcdb..e7f8cd878ca7 100644 --- a/tests/ui/manual_bits.fixed +++ b/tests/ui/manual_bits.fixed @@ -6,7 +6,8 @@ clippy::useless_conversion, path_statements, unused_must_use, - clippy::unnecessary_operation + clippy::unnecessary_operation, + clippy::unnecessary_cast )] use std::mem::{size_of, size_of_val}; diff --git a/tests/ui/manual_bits.rs b/tests/ui/manual_bits.rs index 62638f047eb0..7b1d15495287 100644 --- a/tests/ui/manual_bits.rs +++ b/tests/ui/manual_bits.rs @@ -6,7 +6,8 @@ clippy::useless_conversion, path_statements, unused_must_use, - clippy::unnecessary_operation + clippy::unnecessary_operation, + clippy::unnecessary_cast )] use std::mem::{size_of, size_of_val}; diff --git a/tests/ui/manual_bits.stderr b/tests/ui/manual_bits.stderr index 69c591a203d3..652fafbc41d8 100644 --- a/tests/ui/manual_bits.stderr +++ b/tests/ui/manual_bits.stderr @@ -1,5 +1,5 @@ error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:15:5 + --> $DIR/manual_bits.rs:16:5 | LL | size_of::() * 8; | ^^^^^^^^^^^^^^^^^^^ help: consider using: `i8::BITS as usize` @@ -7,169 +7,169 @@ LL | size_of::() * 8; = note: `-D clippy::manual-bits` implied by `-D warnings` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:16:5 + --> $DIR/manual_bits.rs:17:5 | LL | size_of::() * 8; | ^^^^^^^^^^^^^^^^^^^^ help: consider using: `i16::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:17:5 + --> $DIR/manual_bits.rs:18:5 | LL | size_of::() * 8; | ^^^^^^^^^^^^^^^^^^^^ help: consider using: `i32::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:18:5 + --> $DIR/manual_bits.rs:19:5 | LL | size_of::() * 8; | ^^^^^^^^^^^^^^^^^^^^ help: consider using: `i64::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:19:5 + --> $DIR/manual_bits.rs:20:5 | LL | size_of::() * 8; | ^^^^^^^^^^^^^^^^^^^^^ help: consider using: `i128::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:20:5 + --> $DIR/manual_bits.rs:21:5 | LL | size_of::() * 8; | ^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `isize::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:22:5 + --> $DIR/manual_bits.rs:23:5 | LL | size_of::() * 8; | ^^^^^^^^^^^^^^^^^^^ help: consider using: `u8::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:23:5 + --> $DIR/manual_bits.rs:24:5 | LL | size_of::() * 8; | ^^^^^^^^^^^^^^^^^^^^ help: consider using: `u16::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:24:5 + --> $DIR/manual_bits.rs:25:5 | LL | size_of::() * 8; | ^^^^^^^^^^^^^^^^^^^^ help: consider using: `u32::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:25:5 + --> $DIR/manual_bits.rs:26:5 | LL | size_of::() * 8; | ^^^^^^^^^^^^^^^^^^^^ help: consider using: `u64::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:26:5 + --> $DIR/manual_bits.rs:27:5 | LL | size_of::() * 8; | ^^^^^^^^^^^^^^^^^^^^^ help: consider using: `u128::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:27:5 + --> $DIR/manual_bits.rs:28:5 | LL | size_of::() * 8; | ^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `usize::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:29:5 + --> $DIR/manual_bits.rs:30:5 | LL | 8 * size_of::(); | ^^^^^^^^^^^^^^^^^^^ help: consider using: `i8::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:30:5 + --> $DIR/manual_bits.rs:31:5 | LL | 8 * size_of::(); | ^^^^^^^^^^^^^^^^^^^^ help: consider using: `i16::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:31:5 + --> $DIR/manual_bits.rs:32:5 | LL | 8 * size_of::(); | ^^^^^^^^^^^^^^^^^^^^ help: consider using: `i32::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:32:5 + --> $DIR/manual_bits.rs:33:5 | LL | 8 * size_of::(); | ^^^^^^^^^^^^^^^^^^^^ help: consider using: `i64::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:33:5 + --> $DIR/manual_bits.rs:34:5 | LL | 8 * size_of::(); | ^^^^^^^^^^^^^^^^^^^^^ help: consider using: `i128::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:34:5 + --> $DIR/manual_bits.rs:35:5 | LL | 8 * size_of::(); | ^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `isize::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:36:5 + --> $DIR/manual_bits.rs:37:5 | LL | 8 * size_of::(); | ^^^^^^^^^^^^^^^^^^^ help: consider using: `u8::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:37:5 + --> $DIR/manual_bits.rs:38:5 | LL | 8 * size_of::(); | ^^^^^^^^^^^^^^^^^^^^ help: consider using: `u16::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:38:5 + --> $DIR/manual_bits.rs:39:5 | LL | 8 * size_of::(); | ^^^^^^^^^^^^^^^^^^^^ help: consider using: `u32::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:39:5 + --> $DIR/manual_bits.rs:40:5 | LL | 8 * size_of::(); | ^^^^^^^^^^^^^^^^^^^^ help: consider using: `u64::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:40:5 + --> $DIR/manual_bits.rs:41:5 | LL | 8 * size_of::(); | ^^^^^^^^^^^^^^^^^^^^^ help: consider using: `u128::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:41:5 + --> $DIR/manual_bits.rs:42:5 | LL | 8 * size_of::(); | ^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `usize::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:51:5 + --> $DIR/manual_bits.rs:52:5 | LL | size_of::() * 8; | ^^^^^^^^^^^^^^^^^^^^^ help: consider using: `Word::BITS as usize` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:55:18 + --> $DIR/manual_bits.rs:56:18 | LL | let _: u32 = (size_of::() * 8) as u32; | ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `u128::BITS` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:56:18 + --> $DIR/manual_bits.rs:57:18 | LL | let _: u32 = (size_of::() * 8).try_into().unwrap(); | ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `u128::BITS` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:57:13 + --> $DIR/manual_bits.rs:58:13 | LL | let _ = (size_of::() * 8).pow(5); | ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(u128::BITS as usize)` error: usage of `mem::size_of::()` to obtain the size of `T` in bits - --> $DIR/manual_bits.rs:58:14 + --> $DIR/manual_bits.rs:59:14 | LL | let _ = &(size_of::() * 8); | ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(u128::BITS as usize)` diff --git a/tests/ui/ptr_offset_with_cast.fixed b/tests/ui/ptr_offset_with_cast.fixed index 718e391e8bf6..c57e2990fb95 100644 --- a/tests/ui/ptr_offset_with_cast.fixed +++ b/tests/ui/ptr_offset_with_cast.fixed @@ -1,4 +1,5 @@ // run-rustfix +#![allow(clippy::unnecessary_cast)] fn main() { let vec = vec![b'a', b'b', b'c']; diff --git a/tests/ui/ptr_offset_with_cast.rs b/tests/ui/ptr_offset_with_cast.rs index f613742c741e..3de7997acddd 100644 --- a/tests/ui/ptr_offset_with_cast.rs +++ b/tests/ui/ptr_offset_with_cast.rs @@ -1,4 +1,5 @@ // run-rustfix +#![allow(clippy::unnecessary_cast)] fn main() { let vec = vec![b'a', b'b', b'c']; diff --git a/tests/ui/ptr_offset_with_cast.stderr b/tests/ui/ptr_offset_with_cast.stderr index fd45224ca067..3ba40593d644 100644 --- a/tests/ui/ptr_offset_with_cast.stderr +++ b/tests/ui/ptr_offset_with_cast.stderr @@ -1,5 +1,5 @@ error: use of `offset` with a `usize` casted to an `isize` - --> $DIR/ptr_offset_with_cast.rs:12:17 + --> $DIR/ptr_offset_with_cast.rs:13:17 | LL | let _ = ptr.offset(offset_usize as isize); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `ptr.add(offset_usize)` @@ -7,7 +7,7 @@ LL | let _ = ptr.offset(offset_usize as isize); = note: `-D clippy::ptr-offset-with-cast` implied by `-D warnings` error: use of `wrapping_offset` with a `usize` casted to an `isize` - --> $DIR/ptr_offset_with_cast.rs:16:17 + --> $DIR/ptr_offset_with_cast.rs:17:17 | LL | let _ = ptr.wrapping_offset(offset_usize as isize); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `ptr.wrapping_add(offset_usize)` From bff811bfdf117ac737d44452c8aa645dd516f8a0 Mon Sep 17 00:00:00 2001 From: TennyZhuang Date: Sun, 2 Oct 2022 18:41:13 +0800 Subject: [PATCH 3/4] extract common codes Signed-off-by: TennyZhuang --- clippy_lints/src/casts/unnecessary_cast.rs | 28 ++++++++-------------- 1 file changed, 10 insertions(+), 18 deletions(-) diff --git a/clippy_lints/src/casts/unnecessary_cast.rs b/clippy_lints/src/casts/unnecessary_cast.rs index 071fab1165d4..610e8f712f49 100644 --- a/clippy_lints/src/casts/unnecessary_cast.rs +++ b/clippy_lints/src/casts/unnecessary_cast.rs @@ -34,7 +34,7 @@ pub(super) fn check<'tcx>( let cast_str = snippet_opt(cx, cast_expr.span).unwrap_or_default(); if let Some(lit) = get_numeric_literal(cast_expr) { - let literal_str = cast_str; + let literal_str = &cast_str; if_chain! { if let LitKind::Int(n, _) = lit.node; @@ -52,10 +52,12 @@ pub(super) fn check<'tcx>( match lit.node { LitKind::Int(_, LitIntType::Unsuffixed) if cast_to.is_integral() => { - lint_unnecessary_cast(cx, expr, &literal_str, cast_from, cast_to); + lint_unnecessary_cast(cx, expr, literal_str, cast_from, cast_to); + return true; }, LitKind::Float(_, LitFloatType::Unsuffixed) if cast_to.is_floating_point() => { - lint_unnecessary_cast(cx, expr, &literal_str, cast_from, cast_to); + lint_unnecessary_cast(cx, expr, literal_str, cast_from, cast_to); + return true; }, LitKind::Int(_, LitIntType::Unsuffixed) | LitKind::Float(_, LitFloatType::Unsuffixed) => {}, LitKind::Int(_, LitIntType::Signed(_) | LitIntType::Unsigned(_)) @@ -65,25 +67,15 @@ pub(super) fn check<'tcx>( if let Some(src) = snippet_opt(cx, cast_expr.span) { if let Some(num_lit) = NumericLiteral::from_lit_kind(&src, &lit.node) { lint_unnecessary_cast(cx, expr, num_lit.integer, cast_from, cast_to); + return true; } } }, - _ => { - if cast_from.kind() == cast_to.kind() && !in_external_macro(cx.sess(), expr.span) { - span_lint_and_sugg( - cx, - UNNECESSARY_CAST, - expr.span, - &format!("casting to the same type is unnecessary (`{cast_from}` -> `{cast_to}`)"), - "try", - literal_str, - Applicability::MachineApplicable, - ); - return true; - } - }, + _ => {}, } - } else if cast_from.kind() == cast_to.kind() && !in_external_macro(cx.sess(), expr.span) { + } + + if cast_from.kind() == cast_to.kind() && !in_external_macro(cx.sess(), expr.span) { span_lint_and_sugg( cx, UNNECESSARY_CAST, From c9b93143d52ed3393602db29c1e31db03e0fdab2 Mon Sep 17 00:00:00 2001 From: TennyZhuang Date: Sun, 2 Oct 2022 19:04:33 +0800 Subject: [PATCH 4/4] fix some logics Signed-off-by: TennyZhuang --- clippy_lints/src/casts/unnecessary_cast.rs | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/clippy_lints/src/casts/unnecessary_cast.rs b/clippy_lints/src/casts/unnecessary_cast.rs index 610e8f712f49..21ed7f4844cc 100644 --- a/clippy_lints/src/casts/unnecessary_cast.rs +++ b/clippy_lints/src/casts/unnecessary_cast.rs @@ -53,13 +53,15 @@ pub(super) fn check<'tcx>( match lit.node { LitKind::Int(_, LitIntType::Unsuffixed) if cast_to.is_integral() => { lint_unnecessary_cast(cx, expr, literal_str, cast_from, cast_to); - return true; + return false; }, LitKind::Float(_, LitFloatType::Unsuffixed) if cast_to.is_floating_point() => { lint_unnecessary_cast(cx, expr, literal_str, cast_from, cast_to); - return true; + return false; + }, + LitKind::Int(_, LitIntType::Unsuffixed) | LitKind::Float(_, LitFloatType::Unsuffixed) => { + return false; }, - LitKind::Int(_, LitIntType::Unsuffixed) | LitKind::Float(_, LitFloatType::Unsuffixed) => {}, LitKind::Int(_, LitIntType::Signed(_) | LitIntType::Unsigned(_)) | LitKind::Float(_, LitFloatType::Suffixed(_)) if cast_from.kind() == cast_to.kind() =>