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| author | Tomasz Miąsko <tomasz.miasko@gmail.com> | 2020-12-29 00:00:00 +0000 |
|---|---|---|
| committer | Tomasz Miąsko <tomasz.miasko@gmail.com> | 2020-12-29 00:00:00 +0000 |
| commit | 5718cc2f9b32290dc34ce320076f92d90c00fb7d (patch) | |
| tree | 1fbd30e642e861f19c4cc6fe44df9c16ce740be5 | |
| parent | 158f8d034b15e65ba8dc0d066358dd0632bfcd6e (diff) | |
| download | rust-5718cc2f9b32290dc34ce320076f92d90c00fb7d.tar.gz rust-5718cc2f9b32290dc34ce320076f92d90c00fb7d.zip | |
Make forget intrinsic safe
| -rw-r--r-- | compiler/rustc_typeck/src/check/intrinsic.rs | 1 | ||||
| -rw-r--r-- | library/core/src/mem/mod.rs | 7 | ||||
| -rw-r--r-- | src/test/mir-opt/lower_intrinsics.forget.LowerIntrinsics.diff | 24 | ||||
| -rw-r--r-- | src/test/mir-opt/lower_intrinsics.rs | 2 |
4 files changed, 17 insertions, 17 deletions
diff --git a/compiler/rustc_typeck/src/check/intrinsic.rs b/compiler/rustc_typeck/src/check/intrinsic.rs index c3b0fc60b97..673dec6c7f9 100644 --- a/compiler/rustc_typeck/src/check/intrinsic.rs +++ b/compiler/rustc_typeck/src/check/intrinsic.rs @@ -92,6 +92,7 @@ pub fn intrinsic_operation_unsafety(intrinsic: Symbol) -> hir::Unsafety { | sym::rustc_peek | sym::maxnumf64 | sym::type_name + | sym::forget | sym::variant_count => hir::Unsafety::Normal, _ => hir::Unsafety::Unsafe, } diff --git a/library/core/src/mem/mod.rs b/library/core/src/mem/mod.rs index e84014c68a6..87956787242 100644 --- a/library/core/src/mem/mod.rs +++ b/library/core/src/mem/mod.rs @@ -151,9 +151,14 @@ pub const fn forget<T>(t: T) { #[inline] #[unstable(feature = "forget_unsized", issue = "none")] pub fn forget_unsized<T: ?Sized>(t: T) { + #[cfg(bootstrap)] // SAFETY: the forget intrinsic could be safe, but there's no point in making it safe since // we'll be implementing this function soon via `ManuallyDrop` - unsafe { intrinsics::forget(t) } + unsafe { + intrinsics::forget(t) + } + #[cfg(not(bootstrap))] + intrinsics::forget(t) } /// Returns the size of a type in bytes. diff --git a/src/test/mir-opt/lower_intrinsics.forget.LowerIntrinsics.diff b/src/test/mir-opt/lower_intrinsics.forget.LowerIntrinsics.diff index e9cc72f2138..096bba64c0b 100644 --- a/src/test/mir-opt/lower_intrinsics.forget.LowerIntrinsics.diff +++ b/src/test/mir-opt/lower_intrinsics.forget.LowerIntrinsics.diff @@ -4,27 +4,21 @@ fn forget(_1: T) -> () { debug t => _1; // in scope 0 at $DIR/lower_intrinsics.rs:18:18: 18:19 let mut _0: (); // return place in scope 0 at $DIR/lower_intrinsics.rs:18:24: 18:24 - let _2: (); // in scope 0 at $DIR/lower_intrinsics.rs:19:14: 19:41 - let mut _3: T; // in scope 0 at $DIR/lower_intrinsics.rs:19:39: 19:40 - scope 1 { - } + let mut _2: T; // in scope 0 at $DIR/lower_intrinsics.rs:19:30: 19:31 bb0: { - StorageLive(_2); // scope 0 at $DIR/lower_intrinsics.rs:19:5: 19:43 - StorageLive(_3); // scope 1 at $DIR/lower_intrinsics.rs:19:39: 19:40 - _3 = move _1; // scope 1 at $DIR/lower_intrinsics.rs:19:39: 19:40 -- _2 = std::intrinsics::forget::<T>(move _3) -> bb1; // scope 1 at $DIR/lower_intrinsics.rs:19:14: 19:41 + StorageLive(_2); // scope 0 at $DIR/lower_intrinsics.rs:19:30: 19:31 + _2 = move _1; // scope 0 at $DIR/lower_intrinsics.rs:19:30: 19:31 +- _0 = std::intrinsics::forget::<T>(move _2) -> bb1; // scope 0 at $DIR/lower_intrinsics.rs:19:5: 19:32 - // mir::Constant -- // + span: $DIR/lower_intrinsics.rs:19:14: 19:38 -- // + literal: Const { ty: unsafe extern "rust-intrinsic" fn(T) {std::intrinsics::forget::<T>}, val: Value(Scalar(<ZST>)) } -+ _2 = const (); // scope 1 at $DIR/lower_intrinsics.rs:19:14: 19:41 -+ goto -> bb1; // scope 1 at $DIR/lower_intrinsics.rs:19:14: 19:41 +- // + span: $DIR/lower_intrinsics.rs:19:5: 19:29 +- // + literal: Const { ty: extern "rust-intrinsic" fn(T) {std::intrinsics::forget::<T>}, val: Value(Scalar(<ZST>)) } ++ _0 = const (); // scope 0 at $DIR/lower_intrinsics.rs:19:5: 19:32 ++ goto -> bb1; // scope 0 at $DIR/lower_intrinsics.rs:19:5: 19:32 } bb1: { - StorageDead(_3); // scope 1 at $DIR/lower_intrinsics.rs:19:40: 19:41 - StorageDead(_2); // scope 0 at $DIR/lower_intrinsics.rs:19:43: 19:44 - _0 = const (); // scope 0 at $DIR/lower_intrinsics.rs:18:24: 20:2 + StorageDead(_2); // scope 0 at $DIR/lower_intrinsics.rs:19:31: 19:32 goto -> bb2; // scope 0 at $DIR/lower_intrinsics.rs:20:1: 20:2 } diff --git a/src/test/mir-opt/lower_intrinsics.rs b/src/test/mir-opt/lower_intrinsics.rs index 8d28354a5f1..d9891465dab 100644 --- a/src/test/mir-opt/lower_intrinsics.rs +++ b/src/test/mir-opt/lower_intrinsics.rs @@ -16,7 +16,7 @@ pub fn size_of<T>() -> usize { // EMIT_MIR lower_intrinsics.forget.LowerIntrinsics.diff pub fn forget<T>(t: T) { - unsafe { core::intrinsics::forget(t) }; + core::intrinsics::forget(t) } // EMIT_MIR lower_intrinsics.unreachable.LowerIntrinsics.diff |