diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/libcore/intrinsics.rs | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/src/libcore/intrinsics.rs b/src/libcore/intrinsics.rs index a194db52eb2..544fd4fb99f 100644 --- a/src/libcore/intrinsics.rs +++ b/src/libcore/intrinsics.rs @@ -1,6 +1,22 @@ //! Compiler intrinsics. //! //! The corresponding definitions are in `librustc_codegen_llvm/intrinsic.rs`. +//! The corresponding const implementations are in `librustc_mir/interpret/intrinsics.rs` +//! +//! # Const intrinsics +//! +//! Note: any changes to the constness of intrinsics should be discussed with the language team. +//! This includes changes in the stability of the constness. +//! +//! In order to make an intrinsic usable at compile-time, one needs to copy the implementation +//! from https://github.com/rust-lang/miri/blob/master/src/shims/intrinsics.rs to +//! `librustc_mir/interpret/intrinsics.rs` and add a +//! `#[rustc_const_unstable(feature = "foo", issue = "01234")]` to the intrinsic. +//! +//! If an intrinsic is supposed to be used from a `const fn` with a `rustc_const_stable` attribute, +//! the intrinsic's attribute must be `rustc_const_stable`, too. Such a change should not be done +//! without T-lang consulation, because it bakes a feature into the language that cannot be +//! replicated in user code without compiler support. //! //! # Volatiles //! |