diff options
| -rw-r--r-- | clippy_utils/src/ty.rs | 19 | ||||
| -rw-r--r-- | tests/ui/uninit.rs | 23 | ||||
| -rw-r--r-- | tests/ui/uninit.stderr | 12 | ||||
| -rw-r--r-- | tests/ui/uninit_vec.rs | 27 | ||||
| -rw-r--r-- | tests/ui/uninit_vec.stderr | 33 |
5 files changed, 83 insertions, 31 deletions
diff --git a/clippy_utils/src/ty.rs b/clippy_utils/src/ty.rs index f1c6f1dddd8..0b47234647f 100644 --- a/clippy_utils/src/ty.rs +++ b/clippy_utils/src/ty.rs @@ -16,9 +16,9 @@ use rustc_infer::infer::{ use rustc_lint::LateContext; use rustc_middle::mir::interpret::{ConstValue, Scalar}; use rustc_middle::ty::{ - self, AdtDef, AliasTy, AssocKind, Binder, BoundRegion, FnSig, IntTy, List, ParamEnv, Predicate, PredicateKind, - Region, RegionKind, SubstsRef, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor, - UintTy, VariantDef, VariantDiscr, + self, layout::ValidityRequirement, AdtDef, AliasTy, AssocKind, Binder, BoundRegion, FnSig, IntTy, List, ParamEnv, + Predicate, PredicateKind, Region, RegionKind, SubstsRef, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, + TypeVisitableExt, TypeVisitor, UintTy, VariantDef, VariantDiscr, }; use rustc_middle::ty::{GenericArg, GenericArgKind}; use rustc_span::symbol::Ident; @@ -538,13 +538,12 @@ pub fn same_type_and_consts<'tcx>(a: Ty<'tcx>, b: Ty<'tcx>) -> bool { } /// Checks if a given type looks safe to be uninitialized. -pub fn is_uninit_value_valid_for_ty(cx: &LateContext<'_>, ty: Ty<'_>) -> bool { - match *ty.kind() { - ty::Array(component, _) => is_uninit_value_valid_for_ty(cx, component), - ty::Tuple(types) => types.iter().all(|ty| is_uninit_value_valid_for_ty(cx, ty)), - ty::Adt(adt, _) => cx.tcx.lang_items().maybe_uninit() == Some(adt.did()), - _ => false, - } +pub fn is_uninit_value_valid_for_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool { + cx.tcx + .check_validity_requirement((ValidityRequirement::Uninit, cx.param_env.and(ty))) + // For types containing generic parameters we cannot get a layout to check. + // Therefore, we are conservative and assume that they don't allow uninit. + .unwrap_or(false) } /// Gets an iterator over all predicates which apply to the given item. diff --git a/tests/ui/uninit.rs b/tests/ui/uninit.rs index 21131731708..412b36b4ee8 100644 --- a/tests/ui/uninit.rs +++ b/tests/ui/uninit.rs @@ -3,13 +3,15 @@ use std::mem::{self, MaybeUninit}; +union MyOwnMaybeUninit { + value: u8, + uninit: (), +} + fn main() { let _: usize = unsafe { MaybeUninit::uninit().assume_init() }; - // edge case: For now we lint on empty arrays - let _: [u8; 0] = unsafe { MaybeUninit::uninit().assume_init() }; - - // edge case: For now we accept unit tuples + // This is OK, because ZSTs do not contain data. let _: () = unsafe { MaybeUninit::uninit().assume_init() }; // This is OK, because `MaybeUninit` allows uninitialized data. @@ -21,6 +23,19 @@ fn main() { // This is OK, because all constitutent types are uninit-compatible. let _: (MaybeUninit<usize>, [MaybeUninit<bool>; 2]) = unsafe { MaybeUninit::uninit().assume_init() }; + // This is OK, because our own MaybeUninit is just as fine as the one from core. + let _: MyOwnMaybeUninit = unsafe { MaybeUninit::uninit().assume_init() }; + + // This is OK, because empty arrays don't contain data. + let _: [u8; 0] = unsafe { MaybeUninit::uninit().assume_init() }; + // Was a false negative. let _: usize = unsafe { mem::MaybeUninit::uninit().assume_init() }; + + polymorphic::<()>(); + + fn polymorphic<T>() { + // We are conservative around polymorphic types. + let _: T = unsafe { mem::MaybeUninit::uninit().assume_init() }; + } } diff --git a/tests/ui/uninit.stderr b/tests/ui/uninit.stderr index 15ef2349489..9e01b9a4aa8 100644 --- a/tests/ui/uninit.stderr +++ b/tests/ui/uninit.stderr @@ -1,5 +1,5 @@ error: this call for this type may be undefined behavior - --> $DIR/uninit.rs:7:29 + --> $DIR/uninit.rs:12:29 | LL | let _: usize = unsafe { MaybeUninit::uninit().assume_init() }; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -7,15 +7,15 @@ LL | let _: usize = unsafe { MaybeUninit::uninit().assume_init() }; = note: `#[deny(clippy::uninit_assumed_init)]` on by default error: this call for this type may be undefined behavior - --> $DIR/uninit.rs:10:31 + --> $DIR/uninit.rs:33:29 | -LL | let _: [u8; 0] = unsafe { MaybeUninit::uninit().assume_init() }; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | let _: usize = unsafe { mem::MaybeUninit::uninit().assume_init() }; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: this call for this type may be undefined behavior - --> $DIR/uninit.rs:25:29 + --> $DIR/uninit.rs:39:29 | -LL | let _: usize = unsafe { mem::MaybeUninit::uninit().assume_init() }; +LL | let _: T = unsafe { mem::MaybeUninit::uninit().assume_init() }; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to 3 previous errors diff --git a/tests/ui/uninit_vec.rs b/tests/ui/uninit_vec.rs index 194e4fc157e..59ec64a7ab1 100644 --- a/tests/ui/uninit_vec.rs +++ b/tests/ui/uninit_vec.rs @@ -7,6 +7,11 @@ struct MyVec { vec: Vec<u8>, } +union MyOwnMaybeUninit { + value: u8, + uninit: (), +} + fn main() { // with_capacity() -> set_len() should be detected let mut vec: Vec<u8> = Vec::with_capacity(1000); @@ -97,4 +102,26 @@ fn main() { unsafe { vec.set_len(0); } + + // ZSTs should not be detected + let mut vec: Vec<()> = Vec::with_capacity(1000); + unsafe { + vec.set_len(10); + } + + // unions should not be detected + let mut vec: Vec<MyOwnMaybeUninit> = Vec::with_capacity(1000); + unsafe { + vec.set_len(10); + } + + polymorphic::<()>(); + + fn polymorphic<T>() { + // We are conservative around polymorphic types. + let mut vec: Vec<T> = Vec::with_capacity(1000); + unsafe { + vec.set_len(10); + } + } } diff --git a/tests/ui/uninit_vec.stderr b/tests/ui/uninit_vec.stderr index 77fc689f076..9cdf0c95ad9 100644 --- a/tests/ui/uninit_vec.stderr +++ b/tests/ui/uninit_vec.stderr @@ -1,5 +1,5 @@ error: calling `set_len()` immediately after reserving a buffer creates uninitialized values - --> $DIR/uninit_vec.rs:12:5 + --> $DIR/uninit_vec.rs:17:5 | LL | let mut vec: Vec<u8> = Vec::with_capacity(1000); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -11,7 +11,7 @@ LL | vec.set_len(200); = note: `-D clippy::uninit-vec` implied by `-D warnings` error: calling `set_len()` immediately after reserving a buffer creates uninitialized values - --> $DIR/uninit_vec.rs:18:5 + --> $DIR/uninit_vec.rs:23:5 | LL | vec.reserve(1000); | ^^^^^^^^^^^^^^^^^^ @@ -22,7 +22,7 @@ LL | vec.set_len(200); = help: initialize the buffer or wrap the content in `MaybeUninit` error: calling `set_len()` on empty `Vec` creates out-of-bound values - --> $DIR/uninit_vec.rs:24:5 + --> $DIR/uninit_vec.rs:29:5 | LL | let mut vec: Vec<u8> = Vec::new(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -31,7 +31,7 @@ LL | vec.set_len(200); | ^^^^^^^^^^^^^^^^ error: calling `set_len()` on empty `Vec` creates out-of-bound values - --> $DIR/uninit_vec.rs:30:5 + --> $DIR/uninit_vec.rs:35:5 | LL | let mut vec: Vec<u8> = Default::default(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -40,7 +40,7 @@ LL | vec.set_len(200); | ^^^^^^^^^^^^^^^^ error: calling `set_len()` on empty `Vec` creates out-of-bound values - --> $DIR/uninit_vec.rs:35:5 + --> $DIR/uninit_vec.rs:40:5 | LL | let mut vec: Vec<u8> = Vec::default(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -49,7 +49,7 @@ LL | vec.set_len(200); | ^^^^^^^^^^^^^^^^ error: calling `set_len()` immediately after reserving a buffer creates uninitialized values - --> $DIR/uninit_vec.rs:49:5 + --> $DIR/uninit_vec.rs:54:5 | LL | let mut vec: Vec<u8> = Vec::with_capacity(1000); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -60,7 +60,7 @@ LL | vec.set_len(200); = help: initialize the buffer or wrap the content in `MaybeUninit` error: calling `set_len()` immediately after reserving a buffer creates uninitialized values - --> $DIR/uninit_vec.rs:58:5 + --> $DIR/uninit_vec.rs:63:5 | LL | my_vec.vec.reserve(1000); | ^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -71,7 +71,7 @@ LL | my_vec.vec.set_len(200); = help: initialize the buffer or wrap the content in `MaybeUninit` error: calling `set_len()` immediately after reserving a buffer creates uninitialized values - --> $DIR/uninit_vec.rs:63:5 + --> $DIR/uninit_vec.rs:68:5 | LL | my_vec.vec = Vec::with_capacity(1000); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -82,7 +82,7 @@ LL | my_vec.vec.set_len(200); = help: initialize the buffer or wrap the content in `MaybeUninit` error: calling `set_len()` immediately after reserving a buffer creates uninitialized values - --> $DIR/uninit_vec.rs:42:9 + --> $DIR/uninit_vec.rs:47:9 | LL | let mut vec: Vec<u8> = Vec::with_capacity(1000); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -92,7 +92,7 @@ LL | vec.set_len(200); = help: initialize the buffer or wrap the content in `MaybeUninit` error: calling `set_len()` immediately after reserving a buffer creates uninitialized values - --> $DIR/uninit_vec.rs:45:9 + --> $DIR/uninit_vec.rs:50:9 | LL | vec.reserve(1000); | ^^^^^^^^^^^^^^^^^^ @@ -101,5 +101,16 @@ LL | vec.set_len(200); | = help: initialize the buffer or wrap the content in `MaybeUninit` -error: aborting due to 10 previous errors +error: calling `set_len()` immediately after reserving a buffer creates uninitialized values + --> $DIR/uninit_vec.rs:122:9 + | +LL | let mut vec: Vec<T> = Vec::with_capacity(1000); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | unsafe { +LL | vec.set_len(10); + | ^^^^^^^^^^^^^^^ + | + = help: initialize the buffer or wrap the content in `MaybeUninit` + +error: aborting due to 11 previous errors |