diff options
4 files changed, 63 insertions, 12 deletions
diff --git a/compiler/rustc_const_eval/src/transform/check_consts/resolver.rs b/compiler/rustc_const_eval/src/transform/check_consts/resolver.rs index 2420f31ac08..fcce829eba4 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/resolver.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/resolver.rs @@ -94,11 +94,10 @@ where } } - fn address_of_allows_mutation(&self, mt: mir::Mutability, place: mir::Place<'tcx>) -> bool { - match mt { - mir::Mutability::Mut => true, - mir::Mutability::Not => self.shared_borrow_allows_mutation(place), - } + fn address_of_allows_mutation(&self, _mt: mir::Mutability, _place: mir::Place<'tcx>) -> bool { + // Exact set of permissions granted by AddressOf is undecided. Conservatively assume that + // it might allow mutation until resolution of #56604. + true } fn ref_allows_mutation(&self, kind: mir::BorrowKind, place: mir::Place<'tcx>) -> bool { @@ -110,7 +109,7 @@ where } } - /// `&` and `&raw` only allow mutation if the borrowed place is `!Freeze`. + /// `&` only allow mutation if the borrowed place is `!Freeze`. /// /// This assumes that it is UB to take the address of a struct field whose type is /// `Freeze`, then use pointer arithmetic to derive a pointer to a *different* field of diff --git a/src/test/ui/consts/qualif-indirect-mutation-fail.rs b/src/test/ui/consts/qualif-indirect-mutation-fail.rs index cedead00fec..f74a25a346f 100644 --- a/src/test/ui/consts/qualif-indirect-mutation-fail.rs +++ b/src/test/ui/consts/qualif-indirect-mutation-fail.rs @@ -2,6 +2,7 @@ #![feature(const_mut_refs)] #![feature(const_precise_live_drops)] #![feature(const_swap)] +#![feature(raw_ref_op)] // Mutable borrow of a field with drop impl. pub const fn f() { @@ -42,3 +43,22 @@ pub const fn g2<T>() { let _ = x.is_some(); let _y = x; //~ ERROR destructors cannot be evaluated } + +// Mutable raw reference to a Drop type. +pub const fn address_of_mut() { + let mut x: Option<String> = None; //~ ERROR destructors cannot be evaluated + &raw mut x; + + let mut y: Option<String> = None; //~ ERROR destructors cannot be evaluated + std::ptr::addr_of_mut!(y); +} + +// Const raw reference to a Drop type. Conservatively assumed to allow mutation +// until resolution of https://github.com/rust-lang/rust/issues/56604. +pub const fn address_of_const() { + let x: Option<String> = None; //~ ERROR destructors cannot be evaluated + &raw const x; + + let y: Option<String> = None; //~ ERROR destructors cannot be evaluated + std::ptr::addr_of!(y); +} diff --git a/src/test/ui/consts/qualif-indirect-mutation-fail.stderr b/src/test/ui/consts/qualif-indirect-mutation-fail.stderr index aa6ed465594..713df12b7a5 100644 --- a/src/test/ui/consts/qualif-indirect-mutation-fail.stderr +++ b/src/test/ui/consts/qualif-indirect-mutation-fail.stderr @@ -1,33 +1,57 @@ error[E0493]: destructors cannot be evaluated at compile-time - --> $DIR/qualif-indirect-mutation-fail.rs:8:9 + --> $DIR/qualif-indirect-mutation-fail.rs:9:9 | LL | let mut a: (u32, Option<String>) = (0, None); | ^^^^^ constant functions cannot evaluate destructors error[E0493]: destructors cannot be evaluated at compile-time - --> $DIR/qualif-indirect-mutation-fail.rs:14:9 + --> $DIR/qualif-indirect-mutation-fail.rs:15:9 | LL | let mut x = None; | ^^^^^ constants cannot evaluate destructors error[E0493]: destructors cannot be evaluated at compile-time - --> $DIR/qualif-indirect-mutation-fail.rs:30:9 + --> $DIR/qualif-indirect-mutation-fail.rs:31:9 | LL | let _z = x; | ^^ constants cannot evaluate destructors error[E0493]: destructors cannot be evaluated at compile-time - --> $DIR/qualif-indirect-mutation-fail.rs:35:9 + --> $DIR/qualif-indirect-mutation-fail.rs:36:9 | LL | let x: Option<T> = None; | ^ constant functions cannot evaluate destructors error[E0493]: destructors cannot be evaluated at compile-time - --> $DIR/qualif-indirect-mutation-fail.rs:43:9 + --> $DIR/qualif-indirect-mutation-fail.rs:44:9 | LL | let _y = x; | ^^ constant functions cannot evaluate destructors -error: aborting due to 5 previous errors +error[E0493]: destructors cannot be evaluated at compile-time + --> $DIR/qualif-indirect-mutation-fail.rs:52:9 + | +LL | let mut y: Option<String> = None; + | ^^^^^ constant functions cannot evaluate destructors + +error[E0493]: destructors cannot be evaluated at compile-time + --> $DIR/qualif-indirect-mutation-fail.rs:49:9 + | +LL | let mut x: Option<String> = None; + | ^^^^^ constant functions cannot evaluate destructors + +error[E0493]: destructors cannot be evaluated at compile-time + --> $DIR/qualif-indirect-mutation-fail.rs:62:9 + | +LL | let y: Option<String> = None; + | ^ constant functions cannot evaluate destructors + +error[E0493]: destructors cannot be evaluated at compile-time + --> $DIR/qualif-indirect-mutation-fail.rs:59:9 + | +LL | let x: Option<String> = None; + | ^ constant functions cannot evaluate destructors + +error: aborting due to 9 previous errors For more information about this error, try `rustc --explain E0493`. diff --git a/src/test/ui/consts/qualif-indirect-mutation-pass.rs b/src/test/ui/consts/qualif-indirect-mutation-pass.rs index 35a9b70a5f6..06af6a03b8f 100644 --- a/src/test/ui/consts/qualif-indirect-mutation-pass.rs +++ b/src/test/ui/consts/qualif-indirect-mutation-pass.rs @@ -3,6 +3,7 @@ #![feature(const_mut_refs)] #![feature(const_precise_live_drops)] +// Mutable reference allows only mutation of !Drop place. pub const fn f() { let mut x: (Option<String>, u32) = (None, 0); let mut a = 10; @@ -10,7 +11,14 @@ pub const fn f() { x.1 = a; } +// Mutable reference allows only mutation of !Drop place. pub const fn g() { let mut a: (u32, Option<String>) = (0, None); let _ = &mut a.0; } + +// Shared reference does not allow for mutation. +pub const fn h() { + let x: Option<String> = None; + let _ = &x; +} |