From 477108d382c325134b8578dc327804a157caa19e Mon Sep 17 00:00:00 2001 From: Jacherr Date: Fri, 15 Mar 2024 23:05:59 +0000 Subject: [PATCH] FP: `cast_lossless`: disable lint when casting to (u)128 from any (u)int type --- clippy_lints/src/casts/cast_lossless.rs | 7 ++-- tests/ui/cast_lossless_integer.fixed | 6 ++++ tests/ui/cast_lossless_integer.rs | 6 ++++ tests/ui/cast_lossless_integer.stderr | 44 ++++++++++++------------- 4 files changed, 39 insertions(+), 24 deletions(-) diff --git a/clippy_lints/src/casts/cast_lossless.rs b/clippy_lints/src/casts/cast_lossless.rs index fe0dd7f2eae6..86f4332d05aa 100644 --- a/clippy_lints/src/casts/cast_lossless.rs +++ b/clippy_lints/src/casts/cast_lossless.rs @@ -6,7 +6,7 @@ use clippy_utils::ty::is_isize_or_usize; use rustc_errors::Applicability; use rustc_hir::{Expr, ExprKind, QPath, TyKind}; use rustc_lint::LateContext; -use rustc_middle::ty::{self, FloatTy, Ty}; +use rustc_middle::ty::{self, FloatTy, Ty, UintTy}; use super::{utils, CAST_LOSSLESS}; @@ -77,7 +77,10 @@ pub(super) fn check( fn should_lint(cx: &LateContext<'_>, expr: &Expr<'_>, cast_from: Ty<'_>, cast_to: Ty<'_>, msrv: &Msrv) -> bool { // Do not suggest using From in consts/statics until it is valid to do so (see #2267). - if in_constant(cx, expr.hir_id) { + // + // If destination is u128, do not lint because source type cannot be larger + // If source is bool, still lint due to the lint message differing (refers to style) + if in_constant(cx, expr.hir_id) || (!cast_from.is_bool() && matches!(cast_to.kind(), ty::Uint(UintTy::U128))) { return false; } diff --git a/tests/ui/cast_lossless_integer.fixed b/tests/ui/cast_lossless_integer.fixed index 1b826e0c6007..291556a97741 100644 --- a/tests/ui/cast_lossless_integer.fixed +++ b/tests/ui/cast_lossless_integer.fixed @@ -2,6 +2,7 @@ #![warn(clippy::cast_lossless)] type I64 = i64; +type U128 = u128; fn main() { // Test clippy::cast_lossless with casts to integer types @@ -28,6 +29,11 @@ fn main() { let _ = u16::from(1u8 + 1u8); let _ = I64::from(1i8); + + // Do not lint if destination type is u128 + // see https://github.com/rust-lang/rust-clippy/issues/12492 + let _ = 1u8 as u128; + let _ = 1u8 as U128; } // The lint would suggest using `f64::from(input)` here but the `XX::from` function is not const, diff --git a/tests/ui/cast_lossless_integer.rs b/tests/ui/cast_lossless_integer.rs index f63bbf8577d7..a917c7a371d8 100644 --- a/tests/ui/cast_lossless_integer.rs +++ b/tests/ui/cast_lossless_integer.rs @@ -2,6 +2,7 @@ #![warn(clippy::cast_lossless)] type I64 = i64; +type U128 = u128; fn main() { // Test clippy::cast_lossless with casts to integer types @@ -28,6 +29,11 @@ fn main() { let _ = (1u8 + 1u8) as u16; let _ = 1i8 as I64; + + // Do not lint if destination type is u128 + // see https://github.com/rust-lang/rust-clippy/issues/12492 + let _ = 1u8 as u128; + let _ = 1u8 as U128; } // The lint would suggest using `f64::from(input)` here but the `XX::from` function is not const, diff --git a/tests/ui/cast_lossless_integer.stderr b/tests/ui/cast_lossless_integer.stderr index 0c4b5aee62de..aaece9392856 100644 --- a/tests/ui/cast_lossless_integer.stderr +++ b/tests/ui/cast_lossless_integer.stderr @@ -1,5 +1,5 @@ error: casting `i8` to `i16` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:8:13 + --> tests/ui/cast_lossless_integer.rs:9:13 | LL | let _ = 1i8 as i16; | ^^^^^^^^^^ help: try: `i16::from(1i8)` @@ -8,127 +8,127 @@ LL | let _ = 1i8 as i16; = help: to override `-D warnings` add `#[allow(clippy::cast_lossless)]` error: casting `i8` to `i32` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:9:13 + --> tests/ui/cast_lossless_integer.rs:10:13 | LL | let _ = 1i8 as i32; | ^^^^^^^^^^ help: try: `i32::from(1i8)` error: casting `i8` to `i64` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:10:13 + --> tests/ui/cast_lossless_integer.rs:11:13 | LL | let _ = 1i8 as i64; | ^^^^^^^^^^ help: try: `i64::from(1i8)` error: casting `u8` to `i16` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:11:13 + --> tests/ui/cast_lossless_integer.rs:12:13 | LL | let _ = 1u8 as i16; | ^^^^^^^^^^ help: try: `i16::from(1u8)` error: casting `u8` to `i32` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:12:13 + --> tests/ui/cast_lossless_integer.rs:13:13 | LL | let _ = 1u8 as i32; | ^^^^^^^^^^ help: try: `i32::from(1u8)` error: casting `u8` to `i64` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:13:13 + --> tests/ui/cast_lossless_integer.rs:14:13 | LL | let _ = 1u8 as i64; | ^^^^^^^^^^ help: try: `i64::from(1u8)` error: casting `u8` to `u16` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:14:13 + --> tests/ui/cast_lossless_integer.rs:15:13 | LL | let _ = 1u8 as u16; | ^^^^^^^^^^ help: try: `u16::from(1u8)` error: casting `u8` to `u32` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:15:13 + --> tests/ui/cast_lossless_integer.rs:16:13 | LL | let _ = 1u8 as u32; | ^^^^^^^^^^ help: try: `u32::from(1u8)` error: casting `u8` to `u64` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:16:13 + --> tests/ui/cast_lossless_integer.rs:17:13 | LL | let _ = 1u8 as u64; | ^^^^^^^^^^ help: try: `u64::from(1u8)` error: casting `i16` to `i32` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:17:13 + --> tests/ui/cast_lossless_integer.rs:18:13 | LL | let _ = 1i16 as i32; | ^^^^^^^^^^^ help: try: `i32::from(1i16)` error: casting `i16` to `i64` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:18:13 + --> tests/ui/cast_lossless_integer.rs:19:13 | LL | let _ = 1i16 as i64; | ^^^^^^^^^^^ help: try: `i64::from(1i16)` error: casting `u16` to `i32` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:19:13 + --> tests/ui/cast_lossless_integer.rs:20:13 | LL | let _ = 1u16 as i32; | ^^^^^^^^^^^ help: try: `i32::from(1u16)` error: casting `u16` to `i64` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:20:13 + --> tests/ui/cast_lossless_integer.rs:21:13 | LL | let _ = 1u16 as i64; | ^^^^^^^^^^^ help: try: `i64::from(1u16)` error: casting `u16` to `u32` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:21:13 + --> tests/ui/cast_lossless_integer.rs:22:13 | LL | let _ = 1u16 as u32; | ^^^^^^^^^^^ help: try: `u32::from(1u16)` error: casting `u16` to `u64` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:22:13 + --> tests/ui/cast_lossless_integer.rs:23:13 | LL | let _ = 1u16 as u64; | ^^^^^^^^^^^ help: try: `u64::from(1u16)` error: casting `i32` to `i64` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:23:13 + --> tests/ui/cast_lossless_integer.rs:24:13 | LL | let _ = 1i32 as i64; | ^^^^^^^^^^^ help: try: `i64::from(1i32)` error: casting `u32` to `i64` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:24:13 + --> tests/ui/cast_lossless_integer.rs:25:13 | LL | let _ = 1u32 as i64; | ^^^^^^^^^^^ help: try: `i64::from(1u32)` error: casting `u32` to `u64` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:25:13 + --> tests/ui/cast_lossless_integer.rs:26:13 | LL | let _ = 1u32 as u64; | ^^^^^^^^^^^ help: try: `u64::from(1u32)` error: casting `u8` to `u16` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:28:13 + --> tests/ui/cast_lossless_integer.rs:29:13 | LL | let _ = (1u8 + 1u8) as u16; | ^^^^^^^^^^^^^^^^^^ help: try: `u16::from(1u8 + 1u8)` error: casting `i8` to `I64` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:30:13 + --> tests/ui/cast_lossless_integer.rs:31:13 | LL | let _ = 1i8 as I64; | ^^^^^^^^^^ help: try: `I64::from(1i8)` error: casting `i8` to `i32` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:64:13 + --> tests/ui/cast_lossless_integer.rs:70:13 | LL | let _ = sign_cast!(x, u8, i8) as i32; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `i32::from(sign_cast!(x, u8, i8))` error: casting `i8` to `i32` may become silently lossy if you later change the type - --> tests/ui/cast_lossless_integer.rs:65:13 + --> tests/ui/cast_lossless_integer.rs:71:13 | LL | let _ = (sign_cast!(x, u8, i8) + 1) as i32; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `i32::from(sign_cast!(x, u8, i8) + 1)`