Add a testcase demonstrating how precedence interacts with the lossless-cast lint.

This commit is contained in:
Dan Gohman 2017-08-30 16:45:36 -07:00
parent 35cf2715dc
commit ffa0bd24ed
2 changed files with 57 additions and 50 deletions

View file

@ -59,6 +59,7 @@ fn main() {
1.0f32 as f64;
// Test cast_lossless with an expression wrapped in parens
(1u8 + 1u8) as u16;
(1u16) + (1u8) as u16;
// Test cast_sign_loss
1i32 as u32;
1isize as usize;

View file

@ -314,151 +314,157 @@ error: casting u8 to u16 may become silently lossy if types change
61 | (1u8 + 1u8) as u16;
| ^^^^^^^^^^^^^^^^^^ help: try: `u16::from(1u8 + 1u8)`
error: casting i32 to u32 may lose the sign of the value
--> $DIR/cast.rs:63:5
error: casting u8 to u16 may become silently lossy if types change
--> $DIR/cast.rs:62:14
|
63 | 1i32 as u32;
62 | (1u16) + (1u8) as u16;
| ^^^^^^^^^^^^ help: try: `u16::from(1u8)`
error: casting i32 to u32 may lose the sign of the value
--> $DIR/cast.rs:64:5
|
64 | 1i32 as u32;
| ^^^^^^^^^^^
error: casting isize to usize may lose the sign of the value
--> $DIR/cast.rs:64:5
--> $DIR/cast.rs:65:5
|
64 | 1isize as usize;
65 | 1isize as usize;
| ^^^^^^^^^^^^^^^
error: casting isize to i8 may truncate the value
--> $DIR/cast.rs:67:5
--> $DIR/cast.rs:68:5
|
67 | 1isize as i8;
68 | 1isize as i8;
| ^^^^^^^^^^^^
error: casting isize to f64 causes a loss of precision on targets with 64-bit wide pointers (isize is 64 bits wide, but f64's mantissa is only 52 bits wide)
--> $DIR/cast.rs:68:5
--> $DIR/cast.rs:69:5
|
68 | 1isize as f64;
69 | 1isize as f64;
| ^^^^^^^^^^^^^
error: casting usize to f64 causes a loss of precision on targets with 64-bit wide pointers (usize is 64 bits wide, but f64's mantissa is only 52 bits wide)
--> $DIR/cast.rs:69:5
--> $DIR/cast.rs:70:5
|
69 | 1usize as f64;
70 | 1usize as f64;
| ^^^^^^^^^^^^^
error: casting isize to f32 causes a loss of precision (isize is 32 or 64 bits wide, but f32's mantissa is only 23 bits wide)
--> $DIR/cast.rs:70:5
--> $DIR/cast.rs:71:5
|
70 | 1isize as f32;
71 | 1isize as f32;
| ^^^^^^^^^^^^^
error: casting usize to f32 causes a loss of precision (usize is 32 or 64 bits wide, but f32's mantissa is only 23 bits wide)
--> $DIR/cast.rs:71:5
--> $DIR/cast.rs:72:5
|
71 | 1usize as f32;
72 | 1usize as f32;
| ^^^^^^^^^^^^^
error: casting isize to i32 may truncate the value on targets with 64-bit wide pointers
--> $DIR/cast.rs:72:5
--> $DIR/cast.rs:73:5
|
72 | 1isize as i32;
73 | 1isize as i32;
| ^^^^^^^^^^^^^
error: casting isize to u32 may lose the sign of the value
--> $DIR/cast.rs:73:5
--> $DIR/cast.rs:74:5
|
73 | 1isize as u32;
74 | 1isize as u32;
| ^^^^^^^^^^^^^
error: casting isize to u32 may truncate the value on targets with 64-bit wide pointers
--> $DIR/cast.rs:73:5
--> $DIR/cast.rs:74:5
|
73 | 1isize as u32;
74 | 1isize as u32;
| ^^^^^^^^^^^^^
error: casting usize to u32 may truncate the value on targets with 64-bit wide pointers
--> $DIR/cast.rs:74:5
--> $DIR/cast.rs:75:5
|
74 | 1usize as u32;
75 | 1usize as u32;
| ^^^^^^^^^^^^^
error: casting usize to i32 may truncate the value on targets with 64-bit wide pointers
--> $DIR/cast.rs:75:5
--> $DIR/cast.rs:76:5
|
75 | 1usize as i32;
76 | 1usize as i32;
| ^^^^^^^^^^^^^
error: casting usize to i32 may wrap around the value on targets with 32-bit wide pointers
--> $DIR/cast.rs:75:5
--> $DIR/cast.rs:76:5
|
75 | 1usize as i32;
76 | 1usize as i32;
| ^^^^^^^^^^^^^
error: casting i64 to isize may truncate the value on targets with 32-bit wide pointers
--> $DIR/cast.rs:77:5
--> $DIR/cast.rs:78:5
|
77 | 1i64 as isize;
78 | 1i64 as isize;
| ^^^^^^^^^^^^^
error: casting i64 to usize may lose the sign of the value
--> $DIR/cast.rs:78:5
--> $DIR/cast.rs:79:5
|
78 | 1i64 as usize;
79 | 1i64 as usize;
| ^^^^^^^^^^^^^
error: casting i64 to usize may truncate the value on targets with 32-bit wide pointers
--> $DIR/cast.rs:78:5
--> $DIR/cast.rs:79:5
|
78 | 1i64 as usize;
79 | 1i64 as usize;
| ^^^^^^^^^^^^^
error: casting u64 to isize may truncate the value on targets with 32-bit wide pointers
--> $DIR/cast.rs:79:5
--> $DIR/cast.rs:80:5
|
79 | 1u64 as isize;
80 | 1u64 as isize;
| ^^^^^^^^^^^^^
error: casting u64 to isize may wrap around the value on targets with 64-bit wide pointers
--> $DIR/cast.rs:79:5
--> $DIR/cast.rs:80:5
|
79 | 1u64 as isize;
80 | 1u64 as isize;
| ^^^^^^^^^^^^^
error: casting u64 to usize may truncate the value on targets with 32-bit wide pointers
--> $DIR/cast.rs:80:5
--> $DIR/cast.rs:81:5
|
80 | 1u64 as usize;
81 | 1u64 as usize;
| ^^^^^^^^^^^^^
error: casting u32 to isize may wrap around the value on targets with 32-bit wide pointers
--> $DIR/cast.rs:81:5
--> $DIR/cast.rs:82:5
|
81 | 1u32 as isize;
82 | 1u32 as isize;
| ^^^^^^^^^^^^^
error: casting i32 to usize may lose the sign of the value
--> $DIR/cast.rs:84:5
--> $DIR/cast.rs:85:5
|
84 | 1i32 as usize;
85 | 1i32 as usize;
| ^^^^^^^^^^^^^
error: casting to the same type is unnecessary (`i32` -> `i32`)
--> $DIR/cast.rs:86:5
--> $DIR/cast.rs:87:5
|
86 | 1i32 as i32;
87 | 1i32 as i32;
| ^^^^^^^^^^^
|
= note: `-D unnecessary-cast` implied by `-D warnings`
error: casting to the same type is unnecessary (`f32` -> `f32`)
--> $DIR/cast.rs:87:5
--> $DIR/cast.rs:88:5
|
87 | 1f32 as f32;
88 | 1f32 as f32;
| ^^^^^^^^^^^
error: casting to the same type is unnecessary (`bool` -> `bool`)
--> $DIR/cast.rs:88:5
--> $DIR/cast.rs:89:5
|
88 | false as bool;
89 | false as bool;
| ^^^^^^^^^^^^^
error: aborting due to 75 previous errors
error: aborting due to 76 previous errors