rust-clippy/tests/ui/cast.rs

503 lines
16 KiB
Rust

//@no-rustfix
#![feature(repr128)]
#![feature(isqrt)]
#![allow(incomplete_features)]
#![warn(
clippy::cast_precision_loss,
clippy::cast_possible_truncation,
clippy::cast_sign_loss,
clippy::cast_possible_wrap
)]
#![allow(
clippy::cast_abs_to_unsigned,
clippy::no_effect,
clippy::unnecessary_min_or_max,
clippy::unnecessary_operation,
clippy::unnecessary_literal_unwrap,
clippy::identity_op
)]
// FIXME(f16_f128): add tests once const casting is available for these types
fn main() {
// Test clippy::cast_precision_loss
let x0 = 1i32;
x0 as f32;
//~^ ERROR: casting `i32` to `f32` causes a loss of precision (`i32` is 32 bits wide,
//~| NOTE: `-D clippy::cast-precision-loss` implied by `-D warnings`
let x1 = 1i64;
x1 as f32;
//~^ ERROR: casting `i64` to `f32` causes a loss of precision (`i64` is 64 bits wide,
x1 as f64;
//~^ ERROR: casting `i64` to `f64` causes a loss of precision (`i64` is 64 bits wide,
let x2 = 1u32;
x2 as f32;
//~^ ERROR: casting `u32` to `f32` causes a loss of precision (`u32` is 32 bits wide,
let x3 = 1u64;
x3 as f32;
//~^ ERROR: casting `u64` to `f32` causes a loss of precision (`u64` is 64 bits wide,
x3 as f64;
//~^ ERROR: casting `u64` to `f64` causes a loss of precision (`u64` is 64 bits wide,
// Test clippy::cast_possible_truncation
1f32 as i32;
//~^ ERROR: casting `f32` to `i32` may truncate the value
1f32 as u32;
//~^ ERROR: casting `f32` to `u32` may truncate the value
//~| ERROR: casting `f32` to `u32` may lose the sign of the value
//~| NOTE: `-D clippy::cast-sign-loss` implied by `-D warnings`
1f64 as f32;
//~^ ERROR: casting `f64` to `f32` may truncate the value
1i32 as i8;
//~^ ERROR: casting `i32` to `i8` may truncate the value
1i32 as u8;
//~^ ERROR: casting `i32` to `u8` may truncate the value
1f64 as isize;
//~^ ERROR: casting `f64` to `isize` may truncate the value
1f64 as usize;
//~^ ERROR: casting `f64` to `usize` may truncate the value
//~| ERROR: casting `f64` to `usize` may lose the sign of the value
1f32 as u32 as u16;
//~^ ERROR: casting `u32` to `u16` may truncate the value
//~| ERROR: casting `f32` to `u32` may truncate the value
//~| ERROR: casting `f32` to `u32` may lose the sign of the value
{
let _x: i8 = 1i32 as _;
//~^ ERROR: casting `i32` to `i8` may truncate the value
1f32 as i32;
//~^ ERROR: casting `f32` to `i32` may truncate the value
1f64 as i32;
//~^ ERROR: casting `f64` to `i32` may truncate the value
1f32 as u8;
//~^ ERROR: casting `f32` to `u8` may truncate the value
//~| ERROR: casting `f32` to `u8` may lose the sign of the value
}
// Test clippy::cast_possible_wrap
1u8 as i8;
//~^ ERROR: casting `u8` to `i8` may wrap around the value
//~| NOTE: `-D clippy::cast-possible-wrap` implied by `-D warnings`
1u16 as i16;
//~^ ERROR: casting `u16` to `i16` may wrap around the value
1u32 as i32;
//~^ ERROR: casting `u32` to `i32` may wrap around the value
1u64 as i64;
//~^ ERROR: casting `u64` to `i64` may wrap around the value
1usize as isize;
//~^ ERROR: casting `usize` to `isize` may wrap around the value
// should not wrap, usize is never 8 bits
1usize as i8;
//~^ ERROR: casting `usize` to `i8` may truncate the value
// wraps on 16 bit ptr size
1usize as i16;
//~^ ERROR: casting `usize` to `i16` may truncate the value
//~| ERROR: casting `usize` to `i16` may wrap around the value on targets with 16-bit
//~| NOTE: `usize` and `isize` may be as small as 16 bits on some platforms
// wraps on 32 bit ptr size
1usize as i32;
//~^ ERROR: casting `usize` to `i32` may truncate the value on targets with 64-bit wid
//~| ERROR: casting `usize` to `i32` may wrap around the value on targets with 32-bit
// wraps on 64 bit ptr size
1usize as i64;
//~^ ERROR: casting `usize` to `i64` may wrap around the value on targets with 64-bit
// should not wrap, isize is never 8 bits
1u8 as isize;
// wraps on 16 bit ptr size
1u16 as isize;
//~^ ERROR: casting `u16` to `isize` may wrap around the value on targets with 16-bit
//~| NOTE: `usize` and `isize` may be as small as 16 bits on some platforms
// wraps on 32 bit ptr size
1u32 as isize;
//~^ ERROR: casting `u32` to `isize` may wrap around the value on targets with 32-bit
// wraps on 64 bit ptr size
1u64 as isize;
//~^ ERROR: casting `u64` to `isize` may truncate the value on targets with 32-bit wid
//~| ERROR: casting `u64` to `isize` may wrap around the value on targets with 64-bit
// Test clippy::cast_sign_loss
1i32 as u32;
-1i32 as u32;
//~^ ERROR: casting `i32` to `u32` may lose the sign of the value
1isize as usize;
-1isize as usize;
//~^ ERROR: casting `isize` to `usize` may lose the sign of the value
0i8 as u8;
i8::MAX as u8;
i16::MAX as u16;
i32::MAX as u32;
i64::MAX as u64;
i128::MAX as u128;
(-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;
// 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).wrapping_rem_euclid(1i8) as u16;
(-1i16).rem_euclid(1i16) as u16;
(-1i16).rem_euclid(1i16) as u32;
(-1i32).rem_euclid(1i32) as u32;
(-1i32).rem_euclid(1i32) as u64;
(-1i64).rem_euclid(1i64) as u64;
(-1i64).rem_euclid(1i64) as u128;
(-1isize).rem_euclid(1isize) as usize;
(1i8).rem_euclid(-1i8) as u8;
(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;
(1i32).rem_euclid(-1i32) as u64;
(1i64).rem_euclid(-1i64) as u64;
(1i64).rem_euclid(-1i64) as u128;
(1isize).rem_euclid(-1isize) as usize;
(-1i8).checked_rem_euclid(1i8).unwrap() as u8;
(-1i8).checked_rem_euclid(1i8).unwrap() as u16;
(-1i16).checked_rem_euclid(1i16).unwrap() as u16;
(-1i16).checked_rem_euclid(1i16).unwrap() as u32;
(-1i32).checked_rem_euclid(1i32).unwrap() as u32;
(-1i32).checked_rem_euclid(1i32).unwrap() as u64;
(-1i64).checked_rem_euclid(1i64).unwrap() as u64;
(-1i64).checked_rem_euclid(1i64).unwrap() as u128;
(-1isize).checked_rem_euclid(1isize).unwrap() as usize;
(1i8).checked_rem_euclid(-1i8).unwrap() as u8;
(1i8).checked_rem_euclid(-1i8).unwrap() as u16;
(1i16).checked_rem_euclid(-1i16).unwrap() as u16;
(1i16).checked_rem_euclid(-1i16).unwrap() as u32;
(1i32).checked_rem_euclid(-1i32).unwrap() as u32;
(1i32).checked_rem_euclid(-1i32).unwrap() as u64;
(1i64).checked_rem_euclid(-1i64).unwrap() as u64;
(1i64).checked_rem_euclid(-1i64).unwrap() as u128;
(1isize).checked_rem_euclid(-1isize).unwrap() as usize;
// no lint for `cast_possible_truncation`
// with `signum` method call (see issue #5395)
let x: i64 = 5;
let _ = x.signum() as i32;
let s = x.signum();
let _ = s as i32;
// Test for signed min
// should be linted because signed
(-99999999999i64).min(1) as i8;
//~^ ERROR: casting `i64` to `i8` may truncate the value
// Test for various operations that remove enough bits for the result to fit
(999999u64 & 1) as u8;
(999999u64 % 15) as u8;
(999999u64 / 0x1_0000_0000_0000) as u16;
({ 999999u64 >> 56 }) as u8;
({
let x = 999999u64;
x.min(1)
}) as u8;
999999u64.clamp(0, 255) as u8;
// should still be linted
999999u64.clamp(0, 256) as u8;
//~^ ERROR: casting `u64` to `u8` may truncate the value
#[derive(Clone, Copy)]
enum E1 {
A,
B,
C,
}
impl E1 {
fn test(self) {
// Don't lint. `0..=2` fits in u8
let _ = self as u8;
}
}
#[derive(Clone, Copy)]
enum E2 {
A = 255,
B,
}
impl E2 {
fn test(self) {
let _ = self as u8;
//~^ ERROR: casting `main::E2` to `u8` may truncate the value
let _ = Self::B as u8;
//~^ ERROR: casting `main::E2::B` to `u8` will truncate the value
//~| NOTE: `-D clippy::cast-enum-truncation` implied by `-D warnings`
// Don't lint. `255..=256` fits in i16
let _ = self as i16;
// Don't lint.
let _ = Self::A as u8;
}
}
#[derive(Clone, Copy)]
enum E3 {
A = -1,
B,
C = 50,
}
impl E3 {
fn test(self) {
// Don't lint. `-1..=50` fits in i8
let _ = self as i8;
}
}
#[derive(Clone, Copy)]
enum E4 {
A = -128,
B,
}
impl E4 {
fn test(self) {
// Don't lint. `-128..=-127` fits in i8
let _ = self as i8;
}
}
#[derive(Clone, Copy)]
enum E5 {
A = -129,
B = 127,
}
impl E5 {
fn test(self) {
let _ = self as i8;
//~^ ERROR: casting `main::E5` to `i8` may truncate the value
let _ = Self::A as i8;
//~^ ERROR: casting `main::E5::A` to `i8` will truncate the value
// Don't lint. `-129..=127` fits in i16
let _ = self as i16;
// Don't lint.
let _ = Self::B as u8;
}
}
#[derive(Clone, Copy)]
#[repr(u32)]
enum E6 {
A = u16::MAX as u32,
B,
}
impl E6 {
fn test(self) {
let _ = self as i16;
//~^ ERROR: casting `main::E6` to `i16` may truncate the value
// Don't lint. `2^16-1` fits in u16
let _ = Self::A as u16;
// Don't lint. `2^16-1..=2^16` fits in u32
let _ = self as u32;
// Don't lint.
let _ = Self::A as u16;
}
}
#[derive(Clone, Copy)]
#[repr(u64)]
enum E7 {
A = u32::MAX as u64,
B,
}
impl E7 {
fn test(self) {
let _ = self as usize;
//~^ ERROR: casting `main::E7` to `usize` may truncate the value on targets wi
// Don't lint.
let _ = Self::A as usize;
// Don't lint. `2^32-1..=2^32` fits in u64
let _ = self as u64;
}
}
#[derive(Clone, Copy)]
#[repr(i128)]
enum E8 {
A = i128::MIN,
B,
C = 0,
D = i128::MAX,
}
impl E8 {
fn test(self) {
// Don't lint. `-(2^127)..=2^127-1` fits it i128
let _ = self as i128;
}
}
#[derive(Clone, Copy)]
#[repr(u128)]
enum E9 {
A,
B = u128::MAX,
}
impl E9 {
fn test(self) {
// Don't lint.
let _ = Self::A as u8;
// Don't lint. `0..=2^128-1` fits in u128
let _ = self as u128;
}
}
#[derive(Clone, Copy)]
#[repr(usize)]
enum E10 {
A,
B = u32::MAX as usize,
}
impl E10 {
fn test(self) {
let _ = self as u16;
//~^ ERROR: casting `main::E10` to `u16` may truncate the value
// Don't lint.
let _ = Self::B as u32;
// Don't lint.
let _ = self as u64;
}
}
}
fn avoid_subtract_overflow(q: u32) {
let c = (q >> 16) as u8;
//~^ ERROR: casting `u32` to `u8` may truncate the value
c as usize;
let c = (q / 1000) as u8;
//~^ ERROR: casting `u32` to `u8` may truncate the value
c as usize;
}
fn issue11426() {
(&42u8 >> 0xa9008fb6c9d81e42_0e25730562a601c8_u128) as usize;
}
fn issue11642() {
fn square(x: i16) -> u32 {
let x = x as i32;
(x * x) as u32;
x.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;
//~^ ERROR: casting `i32` to `u32` may lose the sign of the value
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;
//~^ 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
(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;
//~^ ERROR: casting `i32` to `u32` may lose the sign of the value
(a * -b * c) as u32;
//~^ ERROR: casting `i32` to `u32` may lose the sign of the value
(a * b * c * c) as u32;
(a * -2) as u32;
//~^ ERROR: casting `i32` to `u32` may lose the sign of the value
(a * b * c * -2) as u32;
//~^ ERROR: casting `i32` to `u32` may lose the sign of the value
(a / b) as u32;
(a / b * c) as 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.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
}
}
fn issue11738() {
macro_rules! m {
() => {
let _ = i32::MIN as u32; // cast_sign_loss
let _ = u32::MAX as u8; // cast_possible_truncation
let _ = std::f64::consts::PI as f32; // cast_possible_truncation
let _ = 0i8 as i32; // cast_lossless
};
}
m!();
}
fn issue12506() -> usize {
let bar: Result<Option<i64>, u32> = Ok(Some(10));
bar.unwrap().unwrap() as usize
}
fn issue12721() {
fn x() -> u64 {
u64::MAX
}
// Don't lint.
(255 & 999999u64) as u8;
// Don't lint.
let _ = ((x() & 255) & 999999) as u8;
// Don't lint.
let _ = (999999 & (x() & 255)) as u8;
(256 & 999999u64) as u8;
//~^ ERROR: casting `u64` to `u8` may truncate the value
(255 % 999999u64) as u8;
//~^ ERROR: casting `u64` to `u8` may truncate the value
}