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Rollup merge of #103402 - joshtriplett:niche-wrap-fix, r=oli-obk

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Fix wrapped valid-range handling in ty_find_init_error

Rust's niche handling allows for wrapping valid ranges with end < start;
for instance, a valid range with start=43 and end=41 means a niche of
42. Most places in the compiler handle this correctly, but
`ty_find_init_error` assumed that `lo > 0` means the type cannot contain a
zero.

Fix it to handle wrapping ranges.
This commit is contained in:
Michael Howell 2022-10-23 14:48:17 -07:00 committed by GitHub
parent 646e0d370d 36662dfc83
commit 9f06fbd1ad
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
3 changed files with 73 additions and 52 deletions
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5
compiler/rustc_lint/src/builtin.rs
View file

@ -2526,7 +2526,10 @@ impl<'tcx> LateLintPass<'tcx> for InvalidValue {
// return `Bound::Excluded`. (And we have tests checking that we
// handle the attribute correctly.)
// We don't add a span since users cannot declare such types anyway.
(Bound::Included(lo), _) if lo > 0 => {
(Bound::Included(lo), Bound::Included(hi)) if 0 < lo && lo < hi => {
return Some((format!("`{}` must be non-null", ty), None));
}
(Bound::Included(lo), Bound::Unbounded) if 0 < lo => {
return Some((format!("`{}` must be non-null", ty), None));
}
(Bound::Included(_), _) | (_, Bound::Included(_))

7
src/test/ui/lint/invalid_value.rs
View file

@ -44,6 +44,10 @@ enum TwoUninhabited {
B(Void),
}
#[rustc_layout_scalar_valid_range_start(254)]
#[rustc_layout_scalar_valid_range_end(1)]
pub(crate) struct WrapAroundRange(u8);
#[allow(unused)]
fn generic<T: 'static>() {
unsafe {
@ -131,6 +135,9 @@ fn main() {
let _val: *const [()] = mem::zeroed();
let _val: *const [()] = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
let _val: WrapAroundRange = mem::zeroed();
let _val: WrapAroundRange = mem::uninitialized(); //~ ERROR: does not permit being left uninitialized
// Things where 0 is okay due to rustc implementation details,
// but that are not guaranteed to keep working.
let _val: Result<i32, i32> = mem::zeroed();

113
src/test/ui/lint/invalid_value.stderr
View file

@ -1,5 +1,5 @@
error: the type `&T` does not permit zero-initialization
--> $DIR/invalid_value.rs:50:32
--> $DIR/invalid_value.rs:54:32
|
LL | let _val: &'static T = mem::zeroed();
| ^^^^^^^^^^^^^
@ -15,7 +15,7 @@ LL | #![deny(invalid_value)]
| ^^^^^^^^^^^^^
error: the type `&T` does not permit being left uninitialized
--> $DIR/invalid_value.rs:51:32
--> $DIR/invalid_value.rs:55:32
|
LL | let _val: &'static T = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -26,7 +26,7 @@ LL | let _val: &'static T = mem::uninitialized();
= note: references must be non-null
error: the type `Wrap<&T>` does not permit zero-initialization
--> $DIR/invalid_value.rs:53:38
--> $DIR/invalid_value.rs:57:38
|
LL | let _val: Wrap<&'static T> = mem::zeroed();
| ^^^^^^^^^^^^^
@ -41,7 +41,7 @@ LL | struct Wrap<T> { wrapped: T }
| ^^^^^^^^^^
error: the type `Wrap<&T>` does not permit being left uninitialized
--> $DIR/invalid_value.rs:54:38
--> $DIR/invalid_value.rs:58:38
|
LL | let _val: Wrap<&'static T> = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -56,7 +56,7 @@ LL | struct Wrap<T> { wrapped: T }
| ^^^^^^^^^^
error: the type `!` does not permit zero-initialization
--> $DIR/invalid_value.rs:61:23
--> $DIR/invalid_value.rs:65:23
|
LL | let _val: ! = mem::zeroed();
| ^^^^^^^^^^^^^
@ -67,7 +67,7 @@ LL | let _val: ! = mem::zeroed();
= note: the `!` type has no valid value
error: the type `!` does not permit being left uninitialized
--> $DIR/invalid_value.rs:62:23
--> $DIR/invalid_value.rs:66:23
|
LL | let _val: ! = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -78,7 +78,7 @@ LL | let _val: ! = mem::uninitialized();
= note: the `!` type has no valid value
error: the type `(i32, !)` does not permit zero-initialization
--> $DIR/invalid_value.rs:64:30
--> $DIR/invalid_value.rs:68:30
|
LL | let _val: (i32, !) = mem::zeroed();
| ^^^^^^^^^^^^^
@ -89,7 +89,7 @@ LL | let _val: (i32, !) = mem::zeroed();
= note: the `!` type has no valid value
error: the type `(i32, !)` does not permit being left uninitialized
--> $DIR/invalid_value.rs:65:30
--> $DIR/invalid_value.rs:69:30
|
LL | let _val: (i32, !) = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -100,7 +100,7 @@ LL | let _val: (i32, !) = mem::uninitialized();
= note: integers must not be uninitialized
error: the type `Void` does not permit zero-initialization
--> $DIR/invalid_value.rs:67:26
--> $DIR/invalid_value.rs:71:26
|
LL | let _val: Void = mem::zeroed();
| ^^^^^^^^^^^^^
@ -115,7 +115,7 @@ LL | enum Void {}
| ^^^^^^^^^
error: the type `Void` does not permit being left uninitialized
--> $DIR/invalid_value.rs:68:26
--> $DIR/invalid_value.rs:72:26
|
LL | let _val: Void = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -130,7 +130,7 @@ LL | enum Void {}
| ^^^^^^^^^
error: the type `&i32` does not permit zero-initialization
--> $DIR/invalid_value.rs:70:34
--> $DIR/invalid_value.rs:74:34
|
LL | let _val: &'static i32 = mem::zeroed();
| ^^^^^^^^^^^^^
@ -141,7 +141,7 @@ LL | let _val: &'static i32 = mem::zeroed();
= note: references must be non-null
error: the type `&i32` does not permit being left uninitialized
--> $DIR/invalid_value.rs:71:34
--> $DIR/invalid_value.rs:75:34
|
LL | let _val: &'static i32 = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -152,7 +152,7 @@ LL | let _val: &'static i32 = mem::uninitialized();
= note: references must be non-null
error: the type `Ref` does not permit zero-initialization
--> $DIR/invalid_value.rs:73:25
--> $DIR/invalid_value.rs:77:25
|
LL | let _val: Ref = mem::zeroed();
| ^^^^^^^^^^^^^
@ -167,7 +167,7 @@ LL | struct Ref(&'static i32);
| ^^^^^^^^^^^^
error: the type `Ref` does not permit being left uninitialized
--> $DIR/invalid_value.rs:74:25
--> $DIR/invalid_value.rs:78:25
|
LL | let _val: Ref = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -182,7 +182,7 @@ LL | struct Ref(&'static i32);
| ^^^^^^^^^^^^
error: the type `fn()` does not permit zero-initialization
--> $DIR/invalid_value.rs:76:26
--> $DIR/invalid_value.rs:80:26
|
LL | let _val: fn() = mem::zeroed();
| ^^^^^^^^^^^^^
@ -193,7 +193,7 @@ LL | let _val: fn() = mem::zeroed();
= note: function pointers must be non-null
error: the type `fn()` does not permit being left uninitialized
--> $DIR/invalid_value.rs:77:26
--> $DIR/invalid_value.rs:81:26
|
LL | let _val: fn() = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -204,7 +204,7 @@ LL | let _val: fn() = mem::uninitialized();
= note: function pointers must be non-null
error: the type `Wrap<fn()>` does not permit zero-initialization
--> $DIR/invalid_value.rs:79:32
--> $DIR/invalid_value.rs:83:32
|
LL | let _val: Wrap<fn()> = mem::zeroed();
| ^^^^^^^^^^^^^
@ -219,7 +219,7 @@ LL | struct Wrap<T> { wrapped: T }
| ^^^^^^^^^^
error: the type `Wrap<fn()>` does not permit being left uninitialized
--> $DIR/invalid_value.rs:80:32
--> $DIR/invalid_value.rs:84:32
|
LL | let _val: Wrap<fn()> = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -234,7 +234,7 @@ LL | struct Wrap<T> { wrapped: T }
| ^^^^^^^^^^
error: the type `WrapEnum<fn()>` does not permit zero-initialization
--> $DIR/invalid_value.rs:82:36
--> $DIR/invalid_value.rs:86:36
|
LL | let _val: WrapEnum<fn()> = mem::zeroed();
| ^^^^^^^^^^^^^
@ -249,7 +249,7 @@ LL | enum WrapEnum<T> { Wrapped(T) }
| ^
error: the type `WrapEnum<fn()>` does not permit being left uninitialized
--> $DIR/invalid_value.rs:83:36
--> $DIR/invalid_value.rs:87:36
|
LL | let _val: WrapEnum<fn()> = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -264,7 +264,7 @@ LL | enum WrapEnum<T> { Wrapped(T) }
| ^
error: the type `Wrap<(RefPair, i32)>` does not permit zero-initialization
--> $DIR/invalid_value.rs:85:42
--> $DIR/invalid_value.rs:89:42
|
LL | let _val: Wrap<(RefPair, i32)> = mem::zeroed();
| ^^^^^^^^^^^^^
@ -279,7 +279,7 @@ LL | struct RefPair((&'static i32, i32));
| ^^^^^^^^^^^^^^^^^^^
error: the type `Wrap<(RefPair, i32)>` does not permit being left uninitialized
--> $DIR/invalid_value.rs:86:42
--> $DIR/invalid_value.rs:90:42
|
LL | let _val: Wrap<(RefPair, i32)> = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -294,7 +294,7 @@ LL | struct RefPair((&'static i32, i32));
| ^^^^^^^^^^^^^^^^^^^
error: the type `NonNull<i32>` does not permit zero-initialization
--> $DIR/invalid_value.rs:88:34
--> $DIR/invalid_value.rs:92:34
|
LL | let _val: NonNull<i32> = mem::zeroed();
| ^^^^^^^^^^^^^
@ -305,7 +305,7 @@ LL | let _val: NonNull<i32> = mem::zeroed();
= note: `std::ptr::NonNull<i32>` must be non-null
error: the type `NonNull<i32>` does not permit being left uninitialized
--> $DIR/invalid_value.rs:89:34
--> $DIR/invalid_value.rs:93:34
|
LL | let _val: NonNull<i32> = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -316,7 +316,7 @@ LL | let _val: NonNull<i32> = mem::uninitialized();
= note: `std::ptr::NonNull<i32>` must be non-null
error: the type `(NonZeroU32, i32)` does not permit zero-initialization
--> $DIR/invalid_value.rs:91:39
--> $DIR/invalid_value.rs:95:39
|
LL | let _val: (NonZeroU32, i32) = mem::zeroed();
| ^^^^^^^^^^^^^
@ -327,7 +327,7 @@ LL | let _val: (NonZeroU32, i32) = mem::zeroed();
= note: `std::num::NonZeroU32` must be non-null
error: the type `(NonZeroU32, i32)` does not permit being left uninitialized
--> $DIR/invalid_value.rs:92:39
--> $DIR/invalid_value.rs:96:39
|
LL | let _val: (NonZeroU32, i32) = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -338,7 +338,7 @@ LL | let _val: (NonZeroU32, i32) = mem::uninitialized();
= note: `std::num::NonZeroU32` must be non-null
error: the type `*const dyn Send` does not permit zero-initialization
--> $DIR/invalid_value.rs:94:37
--> $DIR/invalid_value.rs:98:37
|
LL | let _val: *const dyn Send = mem::zeroed();
| ^^^^^^^^^^^^^
@ -349,7 +349,7 @@ LL | let _val: *const dyn Send = mem::zeroed();
= note: the vtable of a wide raw pointer must be non-null
error: the type `*const dyn Send` does not permit being left uninitialized
--> $DIR/invalid_value.rs:95:37
--> $DIR/invalid_value.rs:99:37
|
LL | let _val: *const dyn Send = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -360,7 +360,7 @@ LL | let _val: *const dyn Send = mem::uninitialized();
= note: the vtable of a wide raw pointer must be non-null
error: the type `[fn(); 2]` does not permit zero-initialization
--> $DIR/invalid_value.rs:97:31
--> $DIR/invalid_value.rs:101:31
|
LL | let _val: [fn(); 2] = mem::zeroed();
| ^^^^^^^^^^^^^
@ -371,7 +371,7 @@ LL | let _val: [fn(); 2] = mem::zeroed();
= note: function pointers must be non-null
error: the type `[fn(); 2]` does not permit being left uninitialized
--> $DIR/invalid_value.rs:98:31
--> $DIR/invalid_value.rs:102:31
|
LL | let _val: [fn(); 2] = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -382,7 +382,7 @@ LL | let _val: [fn(); 2] = mem::uninitialized();
= note: function pointers must be non-null
error: the type `TwoUninhabited` does not permit zero-initialization
--> $DIR/invalid_value.rs:100:36
--> $DIR/invalid_value.rs:104:36
|
LL | let _val: TwoUninhabited = mem::zeroed();
| ^^^^^^^^^^^^^
@ -397,7 +397,7 @@ LL | enum TwoUninhabited {
| ^^^^^^^^^^^^^^^^^^^
error: the type `TwoUninhabited` does not permit being left uninitialized
--> $DIR/invalid_value.rs:101:36
--> $DIR/invalid_value.rs:105:36
|
LL | let _val: TwoUninhabited = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -412,7 +412,7 @@ LL | enum TwoUninhabited {
| ^^^^^^^^^^^^^^^^^^^
error: the type `OneFruitNonZero` does not permit zero-initialization
--> $DIR/invalid_value.rs:103:37
--> $DIR/invalid_value.rs:107:37
|
LL | let _val: OneFruitNonZero = mem::zeroed();
| ^^^^^^^^^^^^^
@ -427,7 +427,7 @@ LL | Banana(NonZeroU32),
| ^^^^^^^^^^
error: the type `OneFruitNonZero` does not permit being left uninitialized
--> $DIR/invalid_value.rs:104:37
--> $DIR/invalid_value.rs:108:37
|
LL | let _val: OneFruitNonZero = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -442,7 +442,7 @@ LL | Banana(NonZeroU32),
| ^^^^^^^^^^
error: the type `bool` does not permit being left uninitialized
--> $DIR/invalid_value.rs:108:26
--> $DIR/invalid_value.rs:112:26
|
LL | let _val: bool = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -453,7 +453,7 @@ LL | let _val: bool = mem::uninitialized();
= note: booleans must be either `true` or `false`
error: the type `Wrap<char>` does not permit being left uninitialized
--> $DIR/invalid_value.rs:111:32
--> $DIR/invalid_value.rs:115:32
|
LL | let _val: Wrap<char> = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -468,7 +468,7 @@ LL | struct Wrap<T> { wrapped: T }
| ^^^^^^^^^^
error: the type `NonBig` does not permit being left uninitialized
--> $DIR/invalid_value.rs:114:28
--> $DIR/invalid_value.rs:118:28
|
LL | let _val: NonBig = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -479,7 +479,7 @@ LL | let _val: NonBig = mem::uninitialized();
= note: `NonBig` must be initialized inside its custom valid range
error: the type `Fruit` does not permit being left uninitialized
--> $DIR/invalid_value.rs:117:27
--> $DIR/invalid_value.rs:121:27
|
LL | let _val: Fruit = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -494,7 +494,7 @@ LL | enum Fruit {
| ^^^^^^^^^^
error: the type `[bool; 2]` does not permit being left uninitialized
--> $DIR/invalid_value.rs:120:31
--> $DIR/invalid_value.rs:124:31
|
LL | let _val: [bool; 2] = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -505,7 +505,7 @@ LL | let _val: [bool; 2] = mem::uninitialized();
= note: booleans must be either `true` or `false`
error: the type `i32` does not permit being left uninitialized
--> $DIR/invalid_value.rs:123:25
--> $DIR/invalid_value.rs:127:25
|
LL | let _val: i32 = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -516,7 +516,7 @@ LL | let _val: i32 = mem::uninitialized();
= note: integers must not be uninitialized
error: the type `f32` does not permit being left uninitialized
--> $DIR/invalid_value.rs:126:25
--> $DIR/invalid_value.rs:130:25
|
LL | let _val: f32 = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -527,7 +527,7 @@ LL | let _val: f32 = mem::uninitialized();
= note: floats must not be uninitialized
error: the type `*const ()` does not permit being left uninitialized
--> $DIR/invalid_value.rs:129:31
--> $DIR/invalid_value.rs:133:31
|
LL | let _val: *const () = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -538,7 +538,7 @@ LL | let _val: *const () = mem::uninitialized();
= note: raw pointers must not be uninitialized
error: the type `*const [()]` does not permit being left uninitialized
--> $DIR/invalid_value.rs:132:33
--> $DIR/invalid_value.rs:136:33
|
LL | let _val: *const [()] = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -548,8 +548,19 @@ LL | let _val: *const [()] = mem::uninitialized();
|
= note: raw pointers must not be uninitialized
error: the type `WrapAroundRange` does not permit being left uninitialized
--> $DIR/invalid_value.rs:139:37
|
LL | let _val: WrapAroundRange = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
| |
| this code causes undefined behavior when executed
| help: use `MaybeUninit<T>` instead, and only call `assume_init` after initialization is done
|
= note: `WrapAroundRange` must be initialized inside its custom valid range
error: the type `Result<i32, i32>` does not permit being left uninitialized
--> $DIR/invalid_value.rs:137:38
--> $DIR/invalid_value.rs:144:38
|
LL | let _val: Result<i32, i32> = mem::uninitialized();
| ^^^^^^^^^^^^^^^^^^^^
@ -564,7 +575,7 @@ LL | pub enum Result<T, E> {
| ^^^^^^^^^^^^^^^^^^^^^
error: the type `&i32` does not permit zero-initialization
--> $DIR/invalid_value.rs:145:34
--> $DIR/invalid_value.rs:152:34
|
LL | let _val: &'static i32 = mem::transmute(0usize);
| ^^^^^^^^^^^^^^^^^^^^^^
@ -575,7 +586,7 @@ LL | let _val: &'static i32 = mem::transmute(0usize);
= note: references must be non-null
error: the type `&[i32]` does not permit zero-initialization
--> $DIR/invalid_value.rs:146:36
--> $DIR/invalid_value.rs:153:36
|
LL | let _val: &'static [i32] = mem::transmute((0usize, 0usize));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@ -586,7 +597,7 @@ LL | let _val: &'static [i32] = mem::transmute((0usize, 0usize));
= note: references must be non-null
error: the type `NonZeroU32` does not permit zero-initialization
--> $DIR/invalid_value.rs:147:32
--> $DIR/invalid_value.rs:154:32
|
LL | let _val: NonZeroU32 = mem::transmute(0);
| ^^^^^^^^^^^^^^^^^
@ -597,7 +608,7 @@ LL | let _val: NonZeroU32 = mem::transmute(0);
= note: `std::num::NonZeroU32` must be non-null
error: the type `NonNull<i32>` does not permit zero-initialization
--> $DIR/invalid_value.rs:150:34
--> $DIR/invalid_value.rs:157:34
|
LL | let _val: NonNull<i32> = MaybeUninit::zeroed().assume_init();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@ -608,7 +619,7 @@ LL | let _val: NonNull<i32> = MaybeUninit::zeroed().assume_init();
= note: `std::ptr::NonNull<i32>` must be non-null
error: the type `NonNull<i32>` does not permit being left uninitialized
--> $DIR/invalid_value.rs:151:34
--> $DIR/invalid_value.rs:158:34
|
LL | let _val: NonNull<i32> = MaybeUninit::uninit().assume_init();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@ -619,7 +630,7 @@ LL | let _val: NonNull<i32> = MaybeUninit::uninit().assume_init();
= note: `std::ptr::NonNull<i32>` must be non-null
error: the type `bool` does not permit being left uninitialized
--> $DIR/invalid_value.rs:152:26
--> $DIR/invalid_value.rs:159:26
|
LL | let _val: bool = MaybeUninit::uninit().assume_init();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@ -629,5 +640,5 @@ LL | let _val: bool = MaybeUninit::uninit().assume_init();
|
= note: booleans must be either `true` or `false`
error: aborting due to 50 previous errors
error: aborting due to 51 previous errors