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add signed ints to unn- transmutes to ensure feature parity #140804

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Merged
merged 1 commit into from
May 9, 2025
Merged

add signed ints to unn- transmutes to ensure feature parity #140804

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27 changes: 27 additions & 0 deletions compiler/rustc_mir_transform/src/check_unnecessary_transmutes.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -55,18 +55,45 @@ impl<'a, 'tcx> UnnecessaryTransmuteChecker<'a, 'tcx> {
},
// char → u32
(Char, Uint(UintTy::U32)) => err(format!("u32::from({arg})")),
// char (→ u32) → i32
(Char, Int(IntTy::I32)) => err(format!("u32::from({arg}).cast_signed()")),
// u32 → char
(Uint(UintTy::U32), Char) => Error {
sugg: format!("char::from_u32_unchecked({arg})"),
help: Some("consider `char::from_u32(…).unwrap()`"),
span,
},
// i32 → char
(Int(IntTy::I32), Char) => Error {
sugg: format!("char::from_u32_unchecked(i32::cast_unsigned({arg}))"),
help: Some("consider `char::from_u32(i32::cast_unsigned(…)).unwrap()`"),
span,
},
// uNN → iNN
(Uint(ty), Int(_)) => err(format!("{}::cast_signed({arg})", ty.name_str())),
// iNN → uNN
(Int(ty), Uint(_)) => err(format!("{}::cast_unsigned({arg})", ty.name_str())),
// fNN → xsize
(Float(ty), Uint(UintTy::Usize)) => {
err(format!("{}::to_bits({arg}) as usize", ty.name_str()))
}
(Float(ty), Int(IntTy::Isize)) => {
err(format!("{}::to_bits({arg}) as isize", ty.name_str()))
}
// fNN (→ uNN) → iNN
(Float(ty), Int(..)) => err(format!("{}::to_bits({arg}).cast_signed()", ty.name_str())),
// fNN → uNN
(Float(ty), Uint(..)) => err(format!("{}::to_bits({arg})", ty.name_str())),
// xsize → fNN
(Uint(UintTy::Usize) | Int(IntTy::Isize), Float(ty)) => {
err(format!("{}::from_bits({arg} as _)", ty.name_str(),))
}
// iNN (→ uNN) → fNN
(Int(int_ty), Float(ty)) => err(format!(
"{}::from_bits({}::cast_unsigned({arg}))",
ty.name_str(),
int_ty.name_str()
)),
// uNN → fNN
(Uint(_), Float(ty)) => err(format!("{}::from_bits({arg})", ty.name_str())),
// bool → { x8 }
Expand Down
1 change: 1 addition & 0 deletions src/tools/miri/tests/pass/shims/x86/intrinsics-x86-sse2.rs
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Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@
// We're testing x86 target specific features
//@only-target: x86_64 i686
#![allow(unnecessary_transmutes)]
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Please leave an empty line between module-level attributes and the module contents.


#[cfg(target_arch = "x86")]
use std::arch::x86::*;
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9 changes: 9 additions & 0 deletions tests/ui/transmute/unnecessary-transmutation.fixed
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Original file line number Diff line number Diff line change
Expand Up @@ -49,6 +49,10 @@ fn main() {
//~^ ERROR
let y: char = char::from_u32_unchecked(y);
//~^ ERROR
let y: i32 = u32::from('🐱').cast_signed();
//~^ ERROR
let y: char = char::from_u32_unchecked(i32::cast_unsigned(y));
//~^ ERROR

let x: u16 = i16::cast_unsigned(8i16);
//~^ ERROR
Expand All @@ -72,6 +76,11 @@ fn main() {
let y: u64 = f64::to_bits(2.0);
//~^ ERROR

let y: f64 = f64::from_bits(i64::cast_unsigned(1i64));
//~^ ERROR
let y: i64 = f64::to_bits(1f64).cast_signed();
//~^ ERROR

let z: bool = (1u8 == 1);
//~^ ERROR
let z: u8 = (z) as u8;
Expand Down
9 changes: 9 additions & 0 deletions tests/ui/transmute/unnecessary-transmutation.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -49,6 +49,10 @@ fn main() {
//~^ ERROR
let y: char = transmute(y);
//~^ ERROR
let y: i32 = transmute('🐱');
//~^ ERROR
let y: char = transmute(y);
//~^ ERROR

let x: u16 = transmute(8i16);
//~^ ERROR
Expand All @@ -72,6 +76,11 @@ fn main() {
let y: u64 = transmute(2.0);
//~^ ERROR

let y: f64 = transmute(1i64);
//~^ ERROR
let y: i64 = transmute(1f64);
//~^ ERROR

let z: bool = transmute(1u8);
//~^ ERROR
let z: u8 = transmute(z);
Expand Down
54 changes: 40 additions & 14 deletions tests/ui/transmute/unnecessary-transmutation.stderr
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Original file line number Diff line number Diff line change
Expand Up @@ -154,82 +154,108 @@ LL | let y: char = transmute(y);
= help: consider `char::from_u32(…).unwrap()`

error: unnecessary transmute
--> $DIR/unnecessary-transmutation.rs:53:22
--> $DIR/unnecessary-transmutation.rs:52:22
|
LL | let y: i32 = transmute('🐱');
| ^^^^^^^^^^^^^^^ help: replace this with: `u32::from('🐱').cast_signed()`

error: unnecessary transmute
--> $DIR/unnecessary-transmutation.rs:54:23
|
LL | let y: char = transmute(y);
| ^^^^^^^^^^^^ help: replace this with: `char::from_u32_unchecked(i32::cast_unsigned(y))`
|
= help: consider `char::from_u32(i32::cast_unsigned(…)).unwrap()`

error: unnecessary transmute
--> $DIR/unnecessary-transmutation.rs:57:22
|
LL | let x: u16 = transmute(8i16);
| ^^^^^^^^^^^^^^^ help: replace this with: `i16::cast_unsigned(8i16)`

error: unnecessary transmute
--> $DIR/unnecessary-transmutation.rs:55:22
--> $DIR/unnecessary-transmutation.rs:59:22
|
LL | let x: i16 = transmute(x);
| ^^^^^^^^^^^^ help: replace this with: `u16::cast_signed(x)`

error: unnecessary transmute
--> $DIR/unnecessary-transmutation.rs:57:22
--> $DIR/unnecessary-transmutation.rs:61:22
|
LL | let x: u32 = transmute(4i32);
| ^^^^^^^^^^^^^^^ help: replace this with: `i32::cast_unsigned(4i32)`

error: unnecessary transmute
--> $DIR/unnecessary-transmutation.rs:59:22
--> $DIR/unnecessary-transmutation.rs:63:22
|
LL | let x: i32 = transmute(x);
| ^^^^^^^^^^^^ help: replace this with: `u32::cast_signed(x)`

error: unnecessary transmute
--> $DIR/unnecessary-transmutation.rs:61:22
--> $DIR/unnecessary-transmutation.rs:65:22
|
LL | let x: u64 = transmute(7i64);
| ^^^^^^^^^^^^^^^ help: replace this with: `i64::cast_unsigned(7i64)`

error: unnecessary transmute
--> $DIR/unnecessary-transmutation.rs:63:22
--> $DIR/unnecessary-transmutation.rs:67:22
|
LL | let x: i64 = transmute(x);
| ^^^^^^^^^^^^ help: replace this with: `u64::cast_signed(x)`

error: unnecessary transmute
--> $DIR/unnecessary-transmutation.rs:66:22
--> $DIR/unnecessary-transmutation.rs:70:22
|
LL | let y: f32 = transmute(1u32);
| ^^^^^^^^^^^^^^^ help: replace this with: `f32::from_bits(1u32)`

error: unnecessary transmute
--> $DIR/unnecessary-transmutation.rs:68:22
--> $DIR/unnecessary-transmutation.rs:72:22
|
LL | let y: u32 = transmute(y);
| ^^^^^^^^^^^^ help: replace this with: `f32::to_bits(y)`

error: unnecessary transmute
--> $DIR/unnecessary-transmutation.rs:70:22
--> $DIR/unnecessary-transmutation.rs:74:22
|
LL | let y: f64 = transmute(3u64);
| ^^^^^^^^^^^^^^^ help: replace this with: `f64::from_bits(3u64)`

error: unnecessary transmute
--> $DIR/unnecessary-transmutation.rs:72:22
--> $DIR/unnecessary-transmutation.rs:76:22
|
LL | let y: u64 = transmute(2.0);
| ^^^^^^^^^^^^^^ help: replace this with: `f64::to_bits(2.0)`

error: unnecessary transmute
--> $DIR/unnecessary-transmutation.rs:75:23
--> $DIR/unnecessary-transmutation.rs:79:22
|
LL | let y: f64 = transmute(1i64);
| ^^^^^^^^^^^^^^^ help: replace this with: `f64::from_bits(i64::cast_unsigned(1i64))`

error: unnecessary transmute
--> $DIR/unnecessary-transmutation.rs:81:22
|
LL | let y: i64 = transmute(1f64);
| ^^^^^^^^^^^^^^^ help: replace this with: `f64::to_bits(1f64).cast_signed()`

error: unnecessary transmute
--> $DIR/unnecessary-transmutation.rs:84:23
|
LL | let z: bool = transmute(1u8);
| ^^^^^^^^^^^^^^ help: replace this with: `(1u8 == 1)`

error: unnecessary transmute
--> $DIR/unnecessary-transmutation.rs:77:21
--> $DIR/unnecessary-transmutation.rs:86:21
|
LL | let z: u8 = transmute(z);
| ^^^^^^^^^^^^ help: replace this with: `(z) as u8`

error: unnecessary transmute
--> $DIR/unnecessary-transmutation.rs:82:21
--> $DIR/unnecessary-transmutation.rs:91:21
|
LL | let z: i8 = transmute(z);
| ^^^^^^^^^^^^ help: replace this with: `(z) as i8`

error: aborting due to 32 previous errors
error: aborting due to 36 previous errors

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