diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/rustc_const_eval/src/interpret/call.rs | 1 | ||||
| -rw-r--r-- | compiler/rustc_feature/src/builtin_attrs.rs | 6 |
2 files changed, 5 insertions, 2 deletions
diff --git a/compiler/rustc_const_eval/src/interpret/call.rs b/compiler/rustc_const_eval/src/interpret/call.rs index 0f2b22f035b..97f7242b336 100644 --- a/compiler/rustc_const_eval/src/interpret/call.rs +++ b/compiler/rustc_const_eval/src/interpret/call.rs @@ -234,6 +234,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> { // so we implement a type-based check that reflects the guaranteed rules for ABI compatibility. if self.layout_compat(caller_abi.layout, callee_abi.layout)? { // Ensure that our checks imply actual ABI compatibility for this concrete call. + // (This can fail e.g. if `#[rustc_nonnull_optimization_guaranteed]` is used incorrectly.) assert!(caller_abi.eq_abi(callee_abi)); Ok(true) } else { diff --git a/compiler/rustc_feature/src/builtin_attrs.rs b/compiler/rustc_feature/src/builtin_attrs.rs index fa5f152132a..efb582fde1b 100644 --- a/compiler/rustc_feature/src/builtin_attrs.rs +++ b/compiler/rustc_feature/src/builtin_attrs.rs @@ -859,8 +859,10 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[ rustc_attr!( rustc_nonnull_optimization_guaranteed, Normal, template!(Word), WarnFollowing, EncodeCrossCrate::Yes, - "the `#[rustc_nonnull_optimization_guaranteed]` attribute is just used to enable \ - niche optimizations in libcore and libstd and will never be stable", + "the `#[rustc_nonnull_optimization_guaranteed]` attribute is just used to document \ + guaranteed niche optimizations in libcore and libstd and will never be stable\n\ + (note that the compiler does not even check whether the type indeed is being non-null-optimized; \ + it is your responsibility to ensure that the attribute is only used on types that are optimized)", ), // ========================================================================== |