diff --git a/clippy_lints/src/casts/cast_sign_loss.rs b/clippy_lints/src/casts/cast_sign_loss.rs index 1df5a25f674..8fd95d9654c 100644 --- a/clippy_lints/src/casts/cast_sign_loss.rs +++ b/clippy_lints/src/casts/cast_sign_loss.rs @@ -1,15 +1,47 @@ +use std::convert::Infallible; +use std::ops::ControlFlow; + use clippy_utils::consts::{constant, Constant}; use clippy_utils::diagnostics::span_lint; -use clippy_utils::{clip, method_chain_args, sext}; +use clippy_utils::visitors::{for_each_expr, Descend}; +use clippy_utils::{method_chain_args, sext}; use rustc_hir::{BinOpKind, Expr, ExprKind}; use rustc_lint::LateContext; -use rustc_middle::ty::{self, Ty, UintTy}; +use rustc_middle::ty::{self, Ty}; use super::CAST_SIGN_LOSS; -const METHODS_RET_POSITIVE: &[&str] = &["abs", "checked_abs", "rem_euclid", "checked_rem_euclid"]; +/// A list of methods that can never return a negative value. +/// Includes methods that panic rather than returning a negative value. +/// +/// Methods that can overflow and return a negative value must not be included in this list, +/// because casting their return values can still result in sign loss. +const METHODS_RET_POSITIVE: &[&str] = &[ + "checked_abs", + "saturating_abs", + "isqrt", + "checked_isqrt", + "rem_euclid", + "checked_rem_euclid", + "wrapping_rem_euclid", +]; -pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_op: &Expr<'_>, cast_from: Ty<'_>, cast_to: Ty<'_>) { +/// A list of methods that act like `pow()`. See `pow_call_result_sign()` for details. +/// +/// Methods that can overflow and return a negative value must not be included in this list, +/// because casting their return values can still result in sign loss. +const METHODS_POW: &[&str] = &["pow", "saturating_pow", "checked_pow"]; + +/// A list of methods that act like `unwrap()`, and don't change the sign of the inner value. +const METHODS_UNWRAP: &[&str] = &["unwrap", "unwrap_unchecked", "expect", "into_ok"]; + +pub(super) fn check<'cx>( + cx: &LateContext<'cx>, + expr: &Expr<'_>, + cast_op: &Expr<'_>, + cast_from: Ty<'cx>, + cast_to: Ty<'_>, +) { if should_lint(cx, cast_op, cast_from, cast_to) { span_lint( cx, @@ -20,35 +52,27 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_op: &Expr<'_>, c } } -fn should_lint(cx: &LateContext<'_>, cast_op: &Expr<'_>, cast_from: Ty<'_>, cast_to: Ty<'_>) -> bool { +fn should_lint<'cx>(cx: &LateContext<'cx>, cast_op: &Expr<'_>, cast_from: Ty<'cx>, cast_to: Ty<'_>) -> bool { match (cast_from.is_integral(), cast_to.is_integral()) { (true, true) => { if !cast_from.is_signed() || cast_to.is_signed() { return false; } - // Don't lint if `cast_op` is known to be positive. + // Don't lint if `cast_op` is known to be positive, ignoring overflow. if let Sign::ZeroOrPositive = expr_sign(cx, cast_op, cast_from) { return false; } - let (mut uncertain_count, mut negative_count) = (0, 0); - // Peel off possible binary expressions, e.g. x * x * y => [x, x, y] - let Some(exprs) = exprs_with_selected_binop_peeled(cast_op) else { - // Assume cast sign lose if we cannot determine the sign of `cast_op` - return true; - }; - for expr in exprs { - let ty = cx.typeck_results().expr_ty(expr); - match expr_sign(cx, expr, ty) { - Sign::Negative => negative_count += 1, - Sign::Uncertain => uncertain_count += 1, - Sign::ZeroOrPositive => (), - }; + if let Sign::ZeroOrPositive = expr_muldiv_sign(cx, cast_op) { + return false; } - // Lint if there are odd number of uncertain or negative results - uncertain_count % 2 == 1 || negative_count % 2 == 1 + if let Sign::ZeroOrPositive = expr_add_sign(cx, cast_op) { + return false; + } + + true }, (false, true) => !cast_to.is_signed(), @@ -57,7 +81,13 @@ fn should_lint(cx: &LateContext<'_>, cast_op: &Expr<'_>, cast_from: Ty<'_>, cast } } -fn get_const_int_eval(cx: &LateContext<'_>, expr: &Expr<'_>, ty: Ty<'_>) -> Option { +fn get_const_signed_int_eval<'cx>( + cx: &LateContext<'cx>, + expr: &Expr<'_>, + ty: impl Into>>, +) -> Option { + let ty = ty.into().unwrap_or_else(|| cx.typeck_results().expr_ty(expr)); + if let Constant::Int(n) = constant(cx, cx.typeck_results(), expr)? && let ty::Int(ity) = *ty.kind() { @@ -66,29 +96,52 @@ fn get_const_int_eval(cx: &LateContext<'_>, expr: &Expr<'_>, ty: Ty<'_>) -> Opti None } +fn get_const_unsigned_int_eval<'cx>( + cx: &LateContext<'cx>, + expr: &Expr<'_>, + ty: impl Into>>, +) -> Option { + let ty = ty.into().unwrap_or_else(|| cx.typeck_results().expr_ty(expr)); + + if let Constant::Int(n) = constant(cx, cx.typeck_results(), expr)? + && let ty::Uint(_ity) = *ty.kind() + { + return Some(n); + } + None +} + +#[derive(Copy, Clone, Debug, Eq, PartialEq)] enum Sign { ZeroOrPositive, Negative, Uncertain, } -fn expr_sign(cx: &LateContext<'_>, expr: &Expr<'_>, ty: Ty<'_>) -> Sign { +fn expr_sign<'cx>(cx: &LateContext<'cx>, expr: &Expr<'_>, ty: impl Into>>) -> Sign { // Try evaluate this expr first to see if it's positive - if let Some(val) = get_const_int_eval(cx, expr, ty) { + if let Some(val) = get_const_signed_int_eval(cx, expr, ty) { return if val >= 0 { Sign::ZeroOrPositive } else { Sign::Negative }; } + if let Some(_val) = get_const_unsigned_int_eval(cx, expr, None) { + return Sign::ZeroOrPositive; + } + // Calling on methods that always return non-negative values. if let ExprKind::MethodCall(path, caller, args, ..) = expr.kind { let mut method_name = path.ident.name.as_str(); - if method_name == "unwrap" - && let Some(arglist) = method_chain_args(expr, &["unwrap"]) + // Peel unwrap(), expect(), etc. + while let Some(&found_name) = METHODS_UNWRAP.iter().find(|&name| &method_name == name) + && let Some(arglist) = method_chain_args(expr, &[found_name]) && let ExprKind::MethodCall(inner_path, ..) = &arglist[0].0.kind { + // The original type has changed, but we can't use `ty` here anyway, because it has been + // moved. method_name = inner_path.ident.name.as_str(); } - if method_name == "pow" + if METHODS_POW.iter().any(|&name| method_name == name) && let [arg] = args { return pow_call_result_sign(cx, caller, arg); @@ -100,53 +153,182 @@ fn expr_sign(cx: &LateContext<'_>, expr: &Expr<'_>, ty: Ty<'_>) -> Sign { Sign::Uncertain } -/// Return the sign of the `pow` call's result. +/// Return the sign of the `pow` call's result, ignoring overflow. /// -/// If the caller is a positive number, the result is always positive, -/// If the `power_of` is a even number, the result is always positive as well, -/// Otherwise a [`Sign::Uncertain`] will be returned. -fn pow_call_result_sign(cx: &LateContext<'_>, caller: &Expr<'_>, power_of: &Expr<'_>) -> Sign { - let caller_ty = cx.typeck_results().expr_ty(caller); - if let Some(caller_val) = get_const_int_eval(cx, caller, caller_ty) - && caller_val >= 0 - { - return Sign::ZeroOrPositive; +/// If the base is positive, the result is always positive. +/// If the exponent is a even number, the result is always positive, +/// Otherwise, if the base is negative, and the exponent is an odd number, the result is always +/// negative. +/// +/// Otherwise, returns [`Sign::Uncertain`]. +fn pow_call_result_sign(cx: &LateContext<'_>, base: &Expr<'_>, exponent: &Expr<'_>) -> Sign { + let base_sign = expr_sign(cx, base, None); + + // Rust's integer pow() functions take an unsigned exponent. + let exponent_val = get_const_unsigned_int_eval(cx, exponent, None); + let exponent_is_even = exponent_val.map(|val| val % 2 == 0); + + match (base_sign, exponent_is_even) { + // Non-negative bases always return non-negative results, ignoring overflow. + (Sign::ZeroOrPositive, _) | + // Any base raised to an even exponent is non-negative. + // These both hold even if we don't know the value of the base. + (_, Some(true)) + => Sign::ZeroOrPositive, + + // A negative base raised to an odd exponent is non-negative. + (Sign::Negative, Some(false)) => Sign::Negative, + + // Negative/unknown base to an unknown exponent, or unknown base to an odd exponent. + // Could be negative or positive depending on the actual values. + (Sign::Negative | Sign::Uncertain, None) | + (Sign::Uncertain, Some(false)) => Sign::Uncertain, + } +} + +/// Peels binary operators such as [`BinOpKind::Mul`] or [`BinOpKind::Rem`], +/// where the result could always be positive. See [`exprs_with_muldiv_binop_peeled()`] for details. +/// +/// Returns the sign of the list of peeled expressions. +fn expr_muldiv_sign(cx: &LateContext<'_>, expr: &Expr<'_>) -> Sign { + let mut negative_count = 0; + + // Peel off possible binary expressions, for example: + // x * x / y => [x, x, y] + // a % b => [a] + let exprs = exprs_with_muldiv_binop_peeled(expr); + for expr in exprs { + match expr_sign(cx, expr, None) { + Sign::Negative => negative_count += 1, + // A mul/div is: + // - uncertain if there are any uncertain values (because they could be negative or positive), + Sign::Uncertain => return Sign::Uncertain, + Sign::ZeroOrPositive => (), + }; } - if let Some(Constant::Int(n)) = constant(cx, cx.typeck_results(), power_of) - && clip(cx.tcx, n, UintTy::U32) % 2 == 0 - { - return Sign::ZeroOrPositive; + // A mul/div is: + // - negative if there are an odd number of negative values, + // - positive or zero otherwise. + if negative_count % 2 == 1 { + Sign::Negative + } else { + Sign::ZeroOrPositive + } +} + +/// Peels binary operators such as [`BinOpKind::Add`], where the result could always be positive. +/// See [`exprs_with_add_binop_peeled()`] for details. +/// +/// Returns the sign of the list of peeled expressions. +fn expr_add_sign(cx: &LateContext<'_>, expr: &Expr<'_>) -> Sign { + let mut negative_count = 0; + let mut positive_count = 0; + + // Peel off possible binary expressions, for example: + // a + b + c => [a, b, c] + let exprs = exprs_with_add_binop_peeled(expr); + for expr in exprs { + match expr_sign(cx, expr, None) { + Sign::Negative => negative_count += 1, + // A sum is: + // - uncertain if there are any uncertain values (because they could be negative or positive), + Sign::Uncertain => return Sign::Uncertain, + Sign::ZeroOrPositive => positive_count += 1, + }; } - Sign::Uncertain + // A sum is: + // - positive or zero if there are only positive (or zero) values, + // - negative if there are only negative (or zero) values, or + // - uncertain if there are both. + // We could split Zero out into its own variant, but we don't yet. + if negative_count == 0 { + Sign::ZeroOrPositive + } else if positive_count == 0 { + Sign::Negative + } else { + Sign::Uncertain + } } /// Peels binary operators such as [`BinOpKind::Mul`], [`BinOpKind::Div`] or [`BinOpKind::Rem`], -/// which the result could always be positive under certain condition. +/// where the result depends on: +/// - the number of negative values in the entire expression, or +/// - the number of negative values on the left hand side of the expression. +/// Ignores overflow. /// -/// Other operators such as `+`/`-` causing the result's sign hard to determine, which we will -/// return `None` -fn exprs_with_selected_binop_peeled<'a>(expr: &'a Expr<'_>) -> Option>> { - #[inline] - fn collect_operands<'a>(expr: &'a Expr<'a>, operands: &mut Vec<&'a Expr<'a>>) -> Option<()> { - match expr.kind { - ExprKind::Binary(op, lhs, rhs) => { - if matches!(op.node, BinOpKind::Mul | BinOpKind::Div | BinOpKind::Rem) { - collect_operands(lhs, operands); - operands.push(rhs); - } else { - // Things are complicated when there are other binary ops exist, - // abort checking by returning `None` for now. - return None; - } - }, - _ => operands.push(expr), - } - Some(()) - } - +/// +/// Expressions using other operators are preserved, so we can try to evaluate them later. +fn exprs_with_muldiv_binop_peeled<'e>(expr: &'e Expr<'_>) -> Vec<&'e Expr<'e>> { let mut res = vec![]; - collect_operands(expr, &mut res)?; - Some(res) + + for_each_expr(expr, |sub_expr| -> ControlFlow { + // We don't check for mul/div/rem methods here, but we could. + if let ExprKind::Binary(op, lhs, _rhs) = sub_expr.kind { + if matches!(op.node, BinOpKind::Mul | BinOpKind::Div) { + // For binary operators where both sides contribute to the sign of the result, + // collect all their operands, recursively. This ignores overflow. + ControlFlow::Continue(Descend::Yes) + } else if matches!(op.node, BinOpKind::Rem | BinOpKind::Shr) { + // For binary operators where the left hand side determines the sign of the result, + // only collect that side, recursively. Overflow panics, so this always holds. + // + // Large left shifts turn negatives into zeroes, so we can't use it here. + // + // > Given remainder = dividend % divisor, the remainder will have the same sign as the dividend + // > ... + // > Arithmetic right shift on signed integer types + // https://doc.rust-lang.org/reference/expressions/operator-expr.html#arithmetic-and-logical-binary-operators + + // We want to descend into the lhs, but skip the rhs. + // That's tricky to do using for_each_expr(), so we just keep the lhs intact. + res.push(lhs); + ControlFlow::Continue(Descend::No) + } else { + // The sign of the result of other binary operators depends on the values of the operands, + // so try to evaluate the expression. + res.push(sub_expr); + ControlFlow::Continue(Descend::No) + } + } else { + // For other expressions, including unary operators and constants, try to evaluate the expression. + res.push(sub_expr); + ControlFlow::Continue(Descend::No) + } + }); + + res +} + +/// Peels binary operators such as [`BinOpKind::Add`], where the result depends on: +/// - all the expressions being positive, or +/// - all the expressions being negative. +/// Ignores overflow. +/// +/// Expressions using other operators are preserved, so we can try to evaluate them later. +fn exprs_with_add_binop_peeled<'e>(expr: &'e Expr<'_>) -> Vec<&'e Expr<'e>> { + let mut res = vec![]; + + for_each_expr(expr, |sub_expr| -> ControlFlow { + // We don't check for add methods here, but we could. + if let ExprKind::Binary(op, _lhs, _rhs) = sub_expr.kind { + if matches!(op.node, BinOpKind::Add) { + // For binary operators where both sides contribute to the sign of the result, + // collect all their operands, recursively. This ignores overflow. + ControlFlow::Continue(Descend::Yes) + } else { + // The sign of the result of other binary operators depends on the values of the operands, + // so try to evaluate the expression. + res.push(sub_expr); + ControlFlow::Continue(Descend::No) + } + } else { + // For other expressions, including unary operators and constants, try to evaluate the expression. + res.push(sub_expr); + ControlFlow::Continue(Descend::No) + } + }); + + res } diff --git a/tests/ui/cast.rs b/tests/ui/cast.rs index e9476c80ccb..a7331ddc7d0 100644 --- a/tests/ui/cast.rs +++ b/tests/ui/cast.rs @@ -1,6 +1,7 @@ //@no-rustfix #![feature(repr128)] +#![feature(isqrt)] #![allow(incomplete_features)] #![warn( clippy::cast_precision_loss, @@ -116,20 +117,40 @@ fn main() { i64::MAX as u64; i128::MAX as u128; - (-1i8).abs() as u8; - (-1i16).abs() as u16; - (-1i32).abs() as u32; + (-1i8).saturating_abs() as u8; + // abs() can return a negative value in release builds + (i8::MIN).abs() as u8; + //~^ ERROR: casting `i8` to `u8` may lose the sign of the value + (-1i16).saturating_abs() as u16; + (-1i32).saturating_abs() as u32; (-1i64).abs() as u64; (-1isize).abs() as usize; (-1i8).checked_abs().unwrap() as u8; + (i8::MIN).checked_abs().unwrap() as u8; (-1i16).checked_abs().unwrap() as u16; (-1i32).checked_abs().unwrap() as u32; - (-1i64).checked_abs().unwrap() as u64; - (-1isize).checked_abs().unwrap() as usize; + // SAFETY: -1 is a small number which will always return Some + (unsafe { (-1i64).checked_abs().unwrap_unchecked() }) as u64; + (-1isize).checked_abs().expect("-1 is a small number") as usize; + + (-1i8).isqrt() as u8; + (i8::MIN).isqrt() as u8; + (-1i16).isqrt() as u16; + (-1i32).isqrt() as u32; + (-1i64).isqrt() as u64; + (-1isize).isqrt() as usize; + + (-1i8).checked_isqrt().unwrap() as u8; + (i8::MIN).checked_isqrt().unwrap() as u8; + (-1i16).checked_isqrt().unwrap() as u16; + (-1i32).checked_isqrt().unwrap() as u32; + // SAFETY: -1 is a small number which will always return Some + (unsafe { (-1i64).checked_isqrt().unwrap_unchecked() }) as u64; + (-1isize).checked_isqrt().expect("-1 is a small number") as usize; (-1i8).rem_euclid(1i8) as u8; - (-1i8).rem_euclid(1i8) as u16; + (-1i8).wrapping_rem_euclid(1i8) as u16; (-1i16).rem_euclid(1i16) as u16; (-1i16).rem_euclid(1i16) as u32; (-1i32).rem_euclid(1i32) as u32; @@ -138,7 +159,7 @@ fn main() { (-1i64).rem_euclid(1i64) as u128; (-1isize).rem_euclid(1isize) as usize; (1i8).rem_euclid(-1i8) as u8; - (1i8).rem_euclid(-1i8) as u16; + (1i8).wrapping_rem_euclid(-1i8) as u16; (1i16).rem_euclid(-1i16) as u16; (1i16).rem_euclid(-1i16) as u32; (1i32).rem_euclid(-1i32) as u32; @@ -371,14 +392,25 @@ fn square(x: i16) -> u32 { let x = x as i32; (x * x) as u32; x.pow(2) as u32; - (-2_i32).pow(2) as u32 + (-2_i32).saturating_pow(2) as u32 } let _a = |x: i32| -> u32 { (x * x * x * x) as u32 }; + (2_i32).checked_pow(3).unwrap() as u32; (-2_i32).pow(3) as u32; //~^ ERROR: casting `i32` to `u32` may lose the sign of the value + (3_i32 % 2) as u32; + (3_i32 % -2) as u32; + (-5_i32 % 2) as u32; + //~^ ERROR: casting `i32` to `u32` may lose the sign of the value + (-5_i32 % -2) as u32; + //~^ ERROR: casting `i32` to `u32` may lose the sign of the value + (2_i32 >> 1) as u32; + (-2_i32 >> 1) as u32; + //~^ ERROR: casting `i32` to `u32` may lose the sign of the value + let x: i32 = 10; (x * x) as u32; (x * x * x) as u32; @@ -387,12 +419,22 @@ fn square(x: i16) -> u32 { let y: i16 = -2; (y * y * y * y * -2) as u16; //~^ ERROR: casting `i16` to `u16` may lose the sign of the value - (y * y * y * y * 2) as u16; - (y * y * y * 2) as u16; + (y * y * y / y * 2) as u16; + (y * y / y * 2) as u16; //~^ ERROR: casting `i16` to `u16` may lose the sign of the value - (y * y * y * -2) as u16; + (y / y * y * -2) as u16; //~^ ERROR: casting `i16` to `u16` may lose the sign of the value + (y + y + y + -2) as u16; + //~^ ERROR: casting `i16` to `u16` may lose the sign of the value + (y + y + y + 2) as u16; + //~^ ERROR: casting `i16` to `u16` may lose the sign of the value + + let z: i16 = 2; + (z + -2) as u16; + //~^ ERROR: casting `i16` to `u16` may lose the sign of the value + (z + z + 2) as u16; + fn foo(a: i32, b: i32, c: i32) -> u32 { (a * a * b * b * c * c) as u32; (a * b * c) as u32; @@ -409,8 +451,9 @@ fn foo(a: i32, b: i32, c: i32) -> u32 { //~^ ERROR: casting `i32` to `u32` may lose the sign of the value (a / b + b * c) as u32; //~^ ERROR: casting `i32` to `u32` may lose the sign of the value - a.pow(3) as u32; + a.saturating_pow(3) as u32; //~^ ERROR: casting `i32` to `u32` may lose the sign of the value (a.abs() * b.pow(2) / c.abs()) as u32 + //~^ ERROR: casting `i32` to `u32` may lose the sign of the value } } diff --git a/tests/ui/cast.stderr b/tests/ui/cast.stderr index e2bcf94734e..dd5d339b81b 100644 --- a/tests/ui/cast.stderr +++ b/tests/ui/cast.stderr @@ -1,5 +1,5 @@ error: casting `i32` to `f32` causes a loss of precision (`i32` is 32 bits wide, but `f32`'s mantissa is only 23 bits wide) - --> tests/ui/cast.rs:16:5 + --> tests/ui/cast.rs:17:5 | LL | x0 as f32; | ^^^^^^^^^ @@ -8,37 +8,37 @@ LL | x0 as f32; = help: to override `-D warnings` add `#[allow(clippy::cast_precision_loss)]` error: casting `i64` to `f32` causes a loss of precision (`i64` is 64 bits wide, but `f32`'s mantissa is only 23 bits wide) - --> tests/ui/cast.rs:20:5 + --> tests/ui/cast.rs:21:5 | LL | x1 as f32; | ^^^^^^^^^ error: casting `i64` to `f64` causes a loss of precision (`i64` is 64 bits wide, but `f64`'s mantissa is only 52 bits wide) - --> tests/ui/cast.rs:22:5 + --> tests/ui/cast.rs:23:5 | LL | x1 as f64; | ^^^^^^^^^ error: casting `u32` to `f32` causes a loss of precision (`u32` is 32 bits wide, but `f32`'s mantissa is only 23 bits wide) - --> tests/ui/cast.rs:25:5 + --> tests/ui/cast.rs:26:5 | LL | x2 as f32; | ^^^^^^^^^ error: casting `u64` to `f32` causes a loss of precision (`u64` is 64 bits wide, but `f32`'s mantissa is only 23 bits wide) - --> tests/ui/cast.rs:28:5 + --> tests/ui/cast.rs:29:5 | LL | x3 as f32; | ^^^^^^^^^ error: casting `u64` to `f64` causes a loss of precision (`u64` is 64 bits wide, but `f64`'s mantissa is only 52 bits wide) - --> tests/ui/cast.rs:30:5 + --> tests/ui/cast.rs:31:5 | LL | x3 as f64; | ^^^^^^^^^ error: casting `f32` to `i32` may truncate the value - --> tests/ui/cast.rs:33:5 + --> tests/ui/cast.rs:34:5 | LL | 1f32 as i32; | ^^^^^^^^^^^ @@ -48,7 +48,7 @@ LL | 1f32 as i32; = help: to override `-D warnings` add `#[allow(clippy::cast_possible_truncation)]` error: casting `f32` to `u32` may truncate the value - --> tests/ui/cast.rs:35:5 + --> tests/ui/cast.rs:36:5 | LL | 1f32 as u32; | ^^^^^^^^^^^ @@ -56,7 +56,7 @@ LL | 1f32 as u32; = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ... error: casting `f32` to `u32` may lose the sign of the value - --> tests/ui/cast.rs:35:5 + --> tests/ui/cast.rs:36:5 | LL | 1f32 as u32; | ^^^^^^^^^^^ @@ -65,7 +65,7 @@ LL | 1f32 as u32; = help: to override `-D warnings` add `#[allow(clippy::cast_sign_loss)]` error: casting `f64` to `f32` may truncate the value - --> tests/ui/cast.rs:39:5 + --> tests/ui/cast.rs:40:5 | LL | 1f64 as f32; | ^^^^^^^^^^^ @@ -73,7 +73,7 @@ LL | 1f64 as f32; = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ... error: casting `i32` to `i8` may truncate the value - --> tests/ui/cast.rs:41:5 + --> tests/ui/cast.rs:42:5 | LL | 1i32 as i8; | ^^^^^^^^^^ @@ -85,7 +85,7 @@ LL | i8::try_from(1i32); | ~~~~~~~~~~~~~~~~~~ error: casting `i32` to `u8` may truncate the value - --> tests/ui/cast.rs:43:5 + --> tests/ui/cast.rs:44:5 | LL | 1i32 as u8; | ^^^^^^^^^^ @@ -97,7 +97,7 @@ LL | u8::try_from(1i32); | ~~~~~~~~~~~~~~~~~~ error: casting `f64` to `isize` may truncate the value - --> tests/ui/cast.rs:45:5 + --> tests/ui/cast.rs:46:5 | LL | 1f64 as isize; | ^^^^^^^^^^^^^ @@ -105,7 +105,7 @@ LL | 1f64 as isize; = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ... error: casting `f64` to `usize` may truncate the value - --> tests/ui/cast.rs:47:5 + --> tests/ui/cast.rs:48:5 | LL | 1f64 as usize; | ^^^^^^^^^^^^^ @@ -113,13 +113,13 @@ LL | 1f64 as usize; = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ... error: casting `f64` to `usize` may lose the sign of the value - --> tests/ui/cast.rs:47:5 + --> tests/ui/cast.rs:48:5 | LL | 1f64 as usize; | ^^^^^^^^^^^^^ error: casting `u32` to `u16` may truncate the value - --> tests/ui/cast.rs:50:5 + --> tests/ui/cast.rs:51:5 | LL | 1f32 as u32 as u16; | ^^^^^^^^^^^^^^^^^^ @@ -131,7 +131,7 @@ LL | u16::try_from(1f32 as u32); | ~~~~~~~~~~~~~~~~~~~~~~~~~~ error: casting `f32` to `u32` may truncate the value - --> tests/ui/cast.rs:50:5 + --> tests/ui/cast.rs:51:5 | LL | 1f32 as u32 as u16; | ^^^^^^^^^^^ @@ -139,13 +139,13 @@ LL | 1f32 as u32 as u16; = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ... error: casting `f32` to `u32` may lose the sign of the value - --> tests/ui/cast.rs:50:5 + --> tests/ui/cast.rs:51:5 | LL | 1f32 as u32 as u16; | ^^^^^^^^^^^ error: casting `i32` to `i8` may truncate the value - --> tests/ui/cast.rs:55:22 + --> tests/ui/cast.rs:56:22 | LL | let _x: i8 = 1i32 as _; | ^^^^^^^^^ @@ -157,7 +157,7 @@ LL | let _x: i8 = 1i32.try_into(); | ~~~~~~~~~~~~~~~ error: casting `f32` to `i32` may truncate the value - --> tests/ui/cast.rs:57:9 + --> tests/ui/cast.rs:58:9 | LL | 1f32 as i32; | ^^^^^^^^^^^ @@ -165,7 +165,7 @@ LL | 1f32 as i32; = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ... error: casting `f64` to `i32` may truncate the value - --> tests/ui/cast.rs:59:9 + --> tests/ui/cast.rs:60:9 | LL | 1f64 as i32; | ^^^^^^^^^^^ @@ -173,7 +173,7 @@ LL | 1f64 as i32; = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ... error: casting `f32` to `u8` may truncate the value - --> tests/ui/cast.rs:61:9 + --> tests/ui/cast.rs:62:9 | LL | 1f32 as u8; | ^^^^^^^^^^ @@ -181,13 +181,13 @@ LL | 1f32 as u8; = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ... error: casting `f32` to `u8` may lose the sign of the value - --> tests/ui/cast.rs:61:9 + --> tests/ui/cast.rs:62:9 | LL | 1f32 as u8; | ^^^^^^^^^^ error: casting `u8` to `i8` may wrap around the value - --> tests/ui/cast.rs:66:5 + --> tests/ui/cast.rs:67:5 | LL | 1u8 as i8; | ^^^^^^^^^ @@ -196,31 +196,31 @@ LL | 1u8 as i8; = help: to override `-D warnings` add `#[allow(clippy::cast_possible_wrap)]` error: casting `u16` to `i16` may wrap around the value - --> tests/ui/cast.rs:69:5 + --> tests/ui/cast.rs:70:5 | LL | 1u16 as i16; | ^^^^^^^^^^^ error: casting `u32` to `i32` may wrap around the value - --> tests/ui/cast.rs:71:5 + --> tests/ui/cast.rs:72:5 | LL | 1u32 as i32; | ^^^^^^^^^^^ error: casting `u64` to `i64` may wrap around the value - --> tests/ui/cast.rs:73:5 + --> tests/ui/cast.rs:74:5 | LL | 1u64 as i64; | ^^^^^^^^^^^ error: casting `usize` to `isize` may wrap around the value - --> tests/ui/cast.rs:75:5 + --> tests/ui/cast.rs:76:5 | LL | 1usize as isize; | ^^^^^^^^^^^^^^^ error: casting `usize` to `i8` may truncate the value - --> tests/ui/cast.rs:78:5 + --> tests/ui/cast.rs:79:5 | LL | 1usize as i8; | ^^^^^^^^^^^^ @@ -232,7 +232,7 @@ LL | i8::try_from(1usize); | ~~~~~~~~~~~~~~~~~~~~ error: casting `usize` to `i16` may truncate the value - --> tests/ui/cast.rs:81:5 + --> tests/ui/cast.rs:82:5 | LL | 1usize as i16; | ^^^^^^^^^^^^^ @@ -244,7 +244,7 @@ LL | i16::try_from(1usize); | ~~~~~~~~~~~~~~~~~~~~~ error: casting `usize` to `i16` may wrap around the value on targets with 16-bit wide pointers - --> tests/ui/cast.rs:81:5 + --> tests/ui/cast.rs:82:5 | LL | 1usize as i16; | ^^^^^^^^^^^^^ @@ -253,7 +253,7 @@ LL | 1usize as i16; = note: for more information see https://doc.rust-lang.org/reference/types/numeric.html#machine-dependent-integer-types error: casting `usize` to `i32` may truncate the value on targets with 64-bit wide pointers - --> tests/ui/cast.rs:86:5 + --> tests/ui/cast.rs:87:5 | LL | 1usize as i32; | ^^^^^^^^^^^^^ @@ -265,19 +265,19 @@ LL | i32::try_from(1usize); | ~~~~~~~~~~~~~~~~~~~~~ error: casting `usize` to `i32` may wrap around the value on targets with 32-bit wide pointers - --> tests/ui/cast.rs:86:5 + --> tests/ui/cast.rs:87:5 | LL | 1usize as i32; | ^^^^^^^^^^^^^ error: casting `usize` to `i64` may wrap around the value on targets with 64-bit wide pointers - --> tests/ui/cast.rs:90:5 + --> tests/ui/cast.rs:91:5 | LL | 1usize as i64; | ^^^^^^^^^^^^^ error: casting `u16` to `isize` may wrap around the value on targets with 16-bit wide pointers - --> tests/ui/cast.rs:95:5 + --> tests/ui/cast.rs:96:5 | LL | 1u16 as isize; | ^^^^^^^^^^^^^ @@ -286,13 +286,13 @@ LL | 1u16 as isize; = note: for more information see https://doc.rust-lang.org/reference/types/numeric.html#machine-dependent-integer-types error: casting `u32` to `isize` may wrap around the value on targets with 32-bit wide pointers - --> tests/ui/cast.rs:99:5 + --> tests/ui/cast.rs:100:5 | LL | 1u32 as isize; | ^^^^^^^^^^^^^ error: casting `u64` to `isize` may truncate the value on targets with 32-bit wide pointers - --> tests/ui/cast.rs:102:5 + --> tests/ui/cast.rs:103:5 | LL | 1u64 as isize; | ^^^^^^^^^^^^^ @@ -304,25 +304,55 @@ LL | isize::try_from(1u64); | ~~~~~~~~~~~~~~~~~~~~~ error: casting `u64` to `isize` may wrap around the value on targets with 64-bit wide pointers - --> tests/ui/cast.rs:102:5 + --> tests/ui/cast.rs:103:5 | LL | 1u64 as isize; | ^^^^^^^^^^^^^ error: casting `i32` to `u32` may lose the sign of the value - --> tests/ui/cast.rs:107:5 + --> tests/ui/cast.rs:108:5 | LL | -1i32 as u32; | ^^^^^^^^^^^^ error: casting `isize` to `usize` may lose the sign of the value - --> tests/ui/cast.rs:110:5 + --> tests/ui/cast.rs:111:5 | LL | -1isize as usize; | ^^^^^^^^^^^^^^^^ +error: casting `i8` to `u8` may lose the sign of the value + --> tests/ui/cast.rs:122:5 + | +LL | (i8::MIN).abs() as u8; + | ^^^^^^^^^^^^^^^^^^^^^ + +error: casting `i64` to `u64` may lose the sign of the value + --> tests/ui/cast.rs:126:5 + | +LL | (-1i64).abs() as u64; + | ^^^^^^^^^^^^^^^^^^^^ + +error: casting `isize` to `usize` may lose the sign of the value + --> tests/ui/cast.rs:127:5 + | +LL | (-1isize).abs() as usize; + | ^^^^^^^^^^^^^^^^^^^^^^^^ + +error: casting `i64` to `u64` may lose the sign of the value + --> tests/ui/cast.rs:134:5 + | +LL | (unsafe { (-1i64).checked_abs().unwrap_unchecked() }) as u64; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: casting `i64` to `u64` may lose the sign of the value + --> tests/ui/cast.rs:149:5 + | +LL | (unsafe { (-1i64).checked_isqrt().unwrap_unchecked() }) as u64; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + error: casting `i64` to `i8` may truncate the value - --> tests/ui/cast.rs:179:5 + --> tests/ui/cast.rs:200:5 | LL | (-99999999999i64).min(1) as i8; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -334,7 +364,7 @@ LL | i8::try_from((-99999999999i64).min(1)); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: casting `u64` to `u8` may truncate the value - --> tests/ui/cast.rs:193:5 + --> tests/ui/cast.rs:214:5 | LL | 999999u64.clamp(0, 256) as u8; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -346,7 +376,7 @@ LL | u8::try_from(999999u64.clamp(0, 256)); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: casting `main::E2` to `u8` may truncate the value - --> tests/ui/cast.rs:216:21 + --> tests/ui/cast.rs:237:21 | LL | let _ = self as u8; | ^^^^^^^^^^ @@ -358,7 +388,7 @@ LL | let _ = u8::try_from(self); | ~~~~~~~~~~~~~~~~~~ error: casting `main::E2::B` to `u8` will truncate the value - --> tests/ui/cast.rs:218:21 + --> tests/ui/cast.rs:239:21 | LL | let _ = Self::B as u8; | ^^^^^^^^^^^^^ @@ -367,7 +397,7 @@ LL | let _ = Self::B as u8; = help: to override `-D warnings` add `#[allow(clippy::cast_enum_truncation)]` error: casting `main::E5` to `i8` may truncate the value - --> tests/ui/cast.rs:260:21 + --> tests/ui/cast.rs:281:21 | LL | let _ = self as i8; | ^^^^^^^^^^ @@ -379,13 +409,13 @@ LL | let _ = i8::try_from(self); | ~~~~~~~~~~~~~~~~~~ error: casting `main::E5::A` to `i8` will truncate the value - --> tests/ui/cast.rs:262:21 + --> tests/ui/cast.rs:283:21 | LL | let _ = Self::A as i8; | ^^^^^^^^^^^^^ error: casting `main::E6` to `i16` may truncate the value - --> tests/ui/cast.rs:279:21 + --> tests/ui/cast.rs:300:21 | LL | let _ = self as i16; | ^^^^^^^^^^^ @@ -397,7 +427,7 @@ LL | let _ = i16::try_from(self); | ~~~~~~~~~~~~~~~~~~~ error: casting `main::E7` to `usize` may truncate the value on targets with 32-bit wide pointers - --> tests/ui/cast.rs:298:21 + --> tests/ui/cast.rs:319:21 | LL | let _ = self as usize; | ^^^^^^^^^^^^^ @@ -409,7 +439,7 @@ LL | let _ = usize::try_from(self); | ~~~~~~~~~~~~~~~~~~~~~ error: casting `main::E10` to `u16` may truncate the value - --> tests/ui/cast.rs:345:21 + --> tests/ui/cast.rs:366:21 | LL | let _ = self as u16; | ^^^^^^^^^^^ @@ -421,7 +451,7 @@ LL | let _ = u16::try_from(self); | ~~~~~~~~~~~~~~~~~~~ error: casting `u32` to `u8` may truncate the value - --> tests/ui/cast.rs:356:13 + --> tests/ui/cast.rs:377:13 | LL | let c = (q >> 16) as u8; | ^^^^^^^^^^^^^^^ @@ -433,7 +463,7 @@ LL | let c = u8::try_from(q >> 16); | ~~~~~~~~~~~~~~~~~~~~~ error: casting `u32` to `u8` may truncate the value - --> tests/ui/cast.rs:360:13 + --> tests/ui/cast.rs:381:13 | LL | let c = (q / 1000) as u8; | ^^^^^^^^^^^^^^^^ @@ -445,76 +475,180 @@ LL | let c = u8::try_from(q / 1000); | ~~~~~~~~~~~~~~~~~~~~~~ error: casting `i32` to `u32` may lose the sign of the value - --> tests/ui/cast.rs:379:5 + --> tests/ui/cast.rs:393:9 + | +LL | (x * x) as u32; + | ^^^^^^^^^^^^^^ + +error: casting `i32` to `u32` may lose the sign of the value + --> tests/ui/cast.rs:398:32 + | +LL | let _a = |x: i32| -> u32 { (x * x * x * x) as u32 }; + | ^^^^^^^^^^^^^^^^^^^^^^ + +error: casting `i32` to `u32` may lose the sign of the value + --> tests/ui/cast.rs:400:5 + | +LL | (2_i32).checked_pow(3).unwrap() as u32; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: casting `i32` to `u32` may lose the sign of the value + --> tests/ui/cast.rs:401:5 | LL | (-2_i32).pow(3) as u32; | ^^^^^^^^^^^^^^^^^^^^^^ error: casting `i32` to `u32` may lose the sign of the value - --> tests/ui/cast.rs:384:5 + --> tests/ui/cast.rs:406:5 + | +LL | (-5_i32 % 2) as u32; + | ^^^^^^^^^^^^^^^^^^^ + +error: casting `i32` to `u32` may lose the sign of the value + --> tests/ui/cast.rs:408:5 + | +LL | (-5_i32 % -2) as u32; + | ^^^^^^^^^^^^^^^^^^^^ + +error: casting `i32` to `u32` may lose the sign of the value + --> tests/ui/cast.rs:411:5 + | +LL | (-2_i32 >> 1) as u32; + | ^^^^^^^^^^^^^^^^^^^^ + +error: casting `i32` to `u32` may lose the sign of the value + --> tests/ui/cast.rs:415:5 + | +LL | (x * x) as u32; + | ^^^^^^^^^^^^^^ + +error: casting `i32` to `u32` may lose the sign of the value + --> tests/ui/cast.rs:416:5 | LL | (x * x * x) as u32; | ^^^^^^^^^^^^^^^^^^ error: casting `i16` to `u16` may lose the sign of the value - --> tests/ui/cast.rs:388:5 + --> tests/ui/cast.rs:420:5 | LL | (y * y * y * y * -2) as u16; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: casting `i16` to `u16` may lose the sign of the value - --> tests/ui/cast.rs:391:5 + --> tests/ui/cast.rs:422:5 | -LL | (y * y * y * 2) as u16; +LL | (y * y * y / y * 2) as u16; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: casting `i16` to `u16` may lose the sign of the value + --> tests/ui/cast.rs:423:5 + | +LL | (y * y / y * 2) as u16; | ^^^^^^^^^^^^^^^^^^^^^^ error: casting `i16` to `u16` may lose the sign of the value - --> tests/ui/cast.rs:393:5 + --> tests/ui/cast.rs:425:5 | -LL | (y * y * y * -2) as u16; +LL | (y / y * y * -2) as u16; | ^^^^^^^^^^^^^^^^^^^^^^^ +error: equal expressions as operands to `/` + --> tests/ui/cast.rs:425:6 + | +LL | (y / y * y * -2) as u16; + | ^^^^^ + | + = note: `#[deny(clippy::eq_op)]` on by default + +error: casting `i16` to `u16` may lose the sign of the value + --> tests/ui/cast.rs:428:5 + | +LL | (y + y + y + -2) as u16; + | ^^^^^^^^^^^^^^^^^^^^^^^ + +error: casting `i16` to `u16` may lose the sign of the value + --> tests/ui/cast.rs:430:5 + | +LL | (y + y + y + 2) as u16; + | ^^^^^^^^^^^^^^^^^^^^^^ + +error: casting `i16` to `u16` may lose the sign of the value + --> tests/ui/cast.rs:434:5 + | +LL | (z + -2) as u16; + | ^^^^^^^^^^^^^^^ + +error: casting `i16` to `u16` may lose the sign of the value + --> tests/ui/cast.rs:436:5 + | +LL | (z + z + 2) as u16; + | ^^^^^^^^^^^^^^^^^^ + error: casting `i32` to `u32` may lose the sign of the value - --> tests/ui/cast.rs:398:9 + --> tests/ui/cast.rs:439:9 + | +LL | (a * a * b * b * c * c) as u32; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: casting `i32` to `u32` may lose the sign of the value + --> tests/ui/cast.rs:440:9 | LL | (a * b * c) as u32; | ^^^^^^^^^^^^^^^^^^ error: casting `i32` to `u32` may lose the sign of the value - --> tests/ui/cast.rs:400:9 + --> tests/ui/cast.rs:442:9 | LL | (a * -b * c) as u32; | ^^^^^^^^^^^^^^^^^^^ error: casting `i32` to `u32` may lose the sign of the value - --> tests/ui/cast.rs:403:9 + --> tests/ui/cast.rs:444:9 + | +LL | (a * b * c * c) as u32; + | ^^^^^^^^^^^^^^^^^^^^^^ + +error: casting `i32` to `u32` may lose the sign of the value + --> tests/ui/cast.rs:445:9 | LL | (a * -2) as u32; | ^^^^^^^^^^^^^^^ error: casting `i32` to `u32` may lose the sign of the value - --> tests/ui/cast.rs:405:9 + --> tests/ui/cast.rs:447:9 | LL | (a * b * c * -2) as u32; | ^^^^^^^^^^^^^^^^^^^^^^^ error: casting `i32` to `u32` may lose the sign of the value - --> tests/ui/cast.rs:408:9 + --> tests/ui/cast.rs:449:9 + | +LL | (a / b) as u32; + | ^^^^^^^^^^^^^^ + +error: casting `i32` to `u32` may lose the sign of the value + --> tests/ui/cast.rs:450:9 | LL | (a / b * c) as u32; | ^^^^^^^^^^^^^^^^^^ error: casting `i32` to `u32` may lose the sign of the value - --> tests/ui/cast.rs:410:9 + --> tests/ui/cast.rs:452:9 | LL | (a / b + b * c) as u32; | ^^^^^^^^^^^^^^^^^^^^^^ error: casting `i32` to `u32` may lose the sign of the value - --> tests/ui/cast.rs:412:9 + --> tests/ui/cast.rs:454:9 | -LL | a.pow(3) as u32; - | ^^^^^^^^^^^^^^^ +LL | a.saturating_pow(3) as u32; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ -error: aborting due to 63 previous errors +error: casting `i32` to `u32` may lose the sign of the value + --> tests/ui/cast.rs:456:9 + | +LL | (a.abs() * b.pow(2) / c.abs()) as u32 + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: aborting due to 85 previous errors