diff options
| -rw-r--r-- | compiler/rustc_lint/src/lib.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/reference_casting.rs | 35 | ||||
| -rw-r--r-- | tests/ui/lint/reference_casting.rs | 13 | ||||
| -rw-r--r-- | tests/ui/lint/reference_casting.stderr | 73 |
4 files changed, 74 insertions, 49 deletions
diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs index 84434d585d3..6dafa4ae01d 100644 --- a/compiler/rustc_lint/src/lib.rs +++ b/compiler/rustc_lint/src/lib.rs @@ -200,7 +200,7 @@ late_lint_methods!( BoxPointers: BoxPointers, PathStatements: PathStatements, LetUnderscore: LetUnderscore, - InvalidReferenceCasting: InvalidReferenceCasting::default(), + InvalidReferenceCasting: InvalidReferenceCasting, // Depends on referenced function signatures in expressions UnusedResults: UnusedResults, NonUpperCaseGlobals: NonUpperCaseGlobals, diff --git a/compiler/rustc_lint/src/reference_casting.rs b/compiler/rustc_lint/src/reference_casting.rs index d540f473ae8..717d44cea33 100644 --- a/compiler/rustc_lint/src/reference_casting.rs +++ b/compiler/rustc_lint/src/reference_casting.rs @@ -1,8 +1,7 @@ use rustc_ast::Mutability; -use rustc_data_structures::fx::FxHashMap; -use rustc_hir::{def::Res, Expr, ExprKind, HirId, Local, QPath, StmtKind, UnOp}; +use rustc_hir::{Expr, ExprKind, UnOp}; use rustc_middle::ty::{self, TypeAndMut}; -use rustc_span::{sym, Span}; +use rustc_span::sym; use crate::{lints::InvalidReferenceCastingDiag, LateContext, LateLintPass, LintContext}; @@ -34,38 +33,18 @@ declare_lint! { "casts of `&T` to `&mut T` without interior mutability" } -#[derive(Default)] -pub struct InvalidReferenceCasting { - casted: FxHashMap<HirId, Span>, -} - -impl_lint_pass!(InvalidReferenceCasting => [INVALID_REFERENCE_CASTING]); +declare_lint_pass!(InvalidReferenceCasting => [INVALID_REFERENCE_CASTING]); impl<'tcx> LateLintPass<'tcx> for InvalidReferenceCasting { - fn check_stmt(&mut self, cx: &LateContext<'tcx>, stmt: &'tcx rustc_hir::Stmt<'tcx>) { - let StmtKind::Local(local) = stmt.kind else { - return; - }; - let Local { init: Some(init), els: None, .. } = local else { - return; - }; - - if is_cast_from_const_to_mut(cx, init) { - self.casted.insert(local.pat.hir_id, init.span); - } - } - fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) { let Some((is_assignment, e)) = is_operation_we_care_about(cx, expr) else { return; }; - let orig_cast = if is_cast_from_const_to_mut(cx, e) { - None - } else if let ExprKind::Path(QPath::Resolved(_, path)) = e.kind - && let Res::Local(hir_id) = &path.res - && let Some(orig_cast) = self.casted.get(hir_id) { - Some(*orig_cast) + let init = cx.expr_or_init(e); + + let orig_cast = if is_cast_from_const_to_mut(cx, init) { + if init.span != e.span { Some(init.span) } else { None } } else { return; }; diff --git a/tests/ui/lint/reference_casting.rs b/tests/ui/lint/reference_casting.rs index 7745d4ef4c3..18c66b2a13e 100644 --- a/tests/ui/lint/reference_casting.rs +++ b/tests/ui/lint/reference_casting.rs @@ -47,9 +47,19 @@ unsafe fn ref_to_mut() { let deferred = (std::ptr::from_ref(num) as *const i32 as *const i32).cast_mut() as *mut i32; let _num = &mut *deferred; //~^ ERROR casting `&T` to `&mut T` is undefined behavior + let deferred_rebind = deferred; + let _num = &mut *deferred_rebind; + //~^ ERROR casting `&T` to `&mut T` is undefined behavior let _num = &mut *(num as *const _ as usize as *mut i32); //~^ ERROR casting `&T` to `&mut T` is undefined behavior + static NUM: &'static i32 = &2; + let num = NUM as *const i32 as *mut i32; + let num = num; + let num = num; + let _num = &mut *num; + //~^ ERROR casting `&T` to `&mut T` is undefined behavior + unsafe fn generic_ref_cast_mut<T>(this: &T) -> &mut T { &mut *((this as *const _) as *mut _) //~^ ERROR casting `&T` to `&mut T` is undefined behavior @@ -94,6 +104,9 @@ unsafe fn assign_to_ref() { let value = num as *const i32 as *mut i32; *value = 1; //~^ ERROR assigning to `&T` is undefined behavior + let value_rebind = value; + *value_rebind = 1; + //~^ ERROR assigning to `&T` is undefined behavior *(num as *const i32).cast::<i32>().cast_mut() = 2; //~^ ERROR assigning to `&T` is undefined behavior *(num as *const _ as usize as *mut i32) = 2; diff --git a/tests/ui/lint/reference_casting.stderr b/tests/ui/lint/reference_casting.stderr index 1189942c809..d4e56048a8a 100644 --- a/tests/ui/lint/reference_casting.stderr +++ b/tests/ui/lint/reference_casting.stderr @@ -112,7 +112,18 @@ LL | let _num = &mut *deferred; = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` - --> $DIR/reference_casting.rs:50:16 + --> $DIR/reference_casting.rs:51:16 + | +LL | let deferred = (std::ptr::from_ref(num) as *const i32 as *const i32).cast_mut() as *mut i32; + | ---------------------------------------------------------------------------- casting happend here +... +LL | let _num = &mut *deferred_rebind; + | ^^^^^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> + +error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` + --> $DIR/reference_casting.rs:53:16 | LL | let _num = &mut *(num as *const _ as usize as *mut i32); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -120,7 +131,18 @@ LL | let _num = &mut *(num as *const _ as usize as *mut i32); = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` - --> $DIR/reference_casting.rs:54:9 + --> $DIR/reference_casting.rs:60:16 + | +LL | let num = NUM as *const i32 as *mut i32; + | ----------------------------- casting happend here +... +LL | let _num = &mut *num; + | ^^^^^^^^^ + | + = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> + +error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` + --> $DIR/reference_casting.rs:64:9 | LL | &mut *((this as *const _) as *mut _) | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -128,7 +150,7 @@ LL | &mut *((this as *const _) as *mut _) = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` - --> $DIR/reference_casting.rs:59:18 + --> $DIR/reference_casting.rs:69:18 | LL | unsafe { &mut *std::cell::UnsafeCell::raw_get(x as *const _ as *const _) } | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -136,7 +158,7 @@ LL | unsafe { &mut *std::cell::UnsafeCell::raw_get(x as *const _ as *con = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: casting `&T` to `&mut T` is undefined behavior, even if the reference is unused, consider instead using an `UnsafeCell` - --> $DIR/reference_casting.rs:64:18 + --> $DIR/reference_casting.rs:74:18 | LL | unsafe { &mut *std::cell::UnsafeCell::raw_get(x as *const _ as *const _) } | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -144,7 +166,7 @@ LL | unsafe { &mut *std::cell::UnsafeCell::raw_get(x as *const _ as *con = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:74:5 + --> $DIR/reference_casting.rs:84:5 | LL | *(a as *const _ as *mut _) = String::from("Replaced"); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -152,7 +174,7 @@ LL | *(a as *const _ as *mut _) = String::from("Replaced"); = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:76:5 + --> $DIR/reference_casting.rs:86:5 | LL | *(a as *const _ as *mut String) += " world"; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -160,7 +182,7 @@ LL | *(a as *const _ as *mut String) += " world"; = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:78:5 + --> $DIR/reference_casting.rs:88:5 | LL | *std::ptr::from_ref(num).cast_mut() += 1; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -168,7 +190,7 @@ LL | *std::ptr::from_ref(num).cast_mut() += 1; = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:80:5 + --> $DIR/reference_casting.rs:90:5 | LL | *std::ptr::from_ref({ num }).cast_mut() += 1; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -176,7 +198,7 @@ LL | *std::ptr::from_ref({ num }).cast_mut() += 1; = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:82:5 + --> $DIR/reference_casting.rs:92:5 | LL | *{ std::ptr::from_ref(num) }.cast_mut() += 1; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -184,7 +206,7 @@ LL | *{ std::ptr::from_ref(num) }.cast_mut() += 1; = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:84:5 + --> $DIR/reference_casting.rs:94:5 | LL | *(std::ptr::from_ref({ num }) as *mut i32) += 1; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -192,7 +214,7 @@ LL | *(std::ptr::from_ref({ num }) as *mut i32) += 1; = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:86:5 + --> $DIR/reference_casting.rs:96:5 | LL | *std::mem::transmute::<_, *mut i32>(num) += 1; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -200,7 +222,7 @@ LL | *std::mem::transmute::<_, *mut i32>(num) += 1; = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:88:5 + --> $DIR/reference_casting.rs:98:5 | LL | / std::ptr::write( LL | | @@ -212,7 +234,7 @@ LL | | ); = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:95:5 + --> $DIR/reference_casting.rs:105:5 | LL | let value = num as *const i32 as *mut i32; | ----------------------------- casting happend here @@ -222,7 +244,18 @@ LL | *value = 1; = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:97:5 + --> $DIR/reference_casting.rs:108:5 + | +LL | let value = num as *const i32 as *mut i32; + | ----------------------------- casting happend here +... +LL | *value_rebind = 1; + | ^^^^^^^^^^^^^^^^^ + | + = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> + +error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` + --> $DIR/reference_casting.rs:110:5 | LL | *(num as *const i32).cast::<i32>().cast_mut() = 2; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -230,7 +263,7 @@ LL | *(num as *const i32).cast::<i32>().cast_mut() = 2; = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:99:5 + --> $DIR/reference_casting.rs:112:5 | LL | *(num as *const _ as usize as *mut i32) = 2; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -238,7 +271,7 @@ LL | *(num as *const _ as usize as *mut i32) = 2; = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:101:5 + --> $DIR/reference_casting.rs:114:5 | LL | let value = num as *const i32 as *mut i32; | ----------------------------- casting happend here @@ -249,7 +282,7 @@ LL | std::ptr::write(value, 2); = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:103:5 + --> $DIR/reference_casting.rs:116:5 | LL | let value = num as *const i32 as *mut i32; | ----------------------------- casting happend here @@ -260,7 +293,7 @@ LL | std::ptr::write_unaligned(value, 2); = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:105:5 + --> $DIR/reference_casting.rs:118:5 | LL | let value = num as *const i32 as *mut i32; | ----------------------------- casting happend here @@ -271,12 +304,12 @@ LL | std::ptr::write_volatile(value, 2); = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell` - --> $DIR/reference_casting.rs:109:9 + --> $DIR/reference_casting.rs:122:9 | LL | *(this as *const _ as *mut _) = a; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html> -error: aborting due to 32 previous errors +error: aborting due to 35 previous errors |