Separate contract feature gates for the internal machinery

The extended syntax for function signature that includes contract clauses
should never be user exposed versus the interface we want to ship
externally eventually.

Author: pnkfelix

core/src/contracts.rs

@@ -8,7 +8,7 @@ pub use crate::macros::builtin::contracts_requires as requires;
 /// Emitted by rustc as a desugaring of `#[requires(PRED)] fn foo(x: X) { ... }`
 /// into: `fn foo(x: X) { check_requires(|| PRED) ... }`
 #[cfg(not(bootstrap))]
-#[unstable(feature = "rustc_contracts", issue = "none" /* compiler-team#759 */)]
+#[unstable(feature = "rustc_contracts_internals", issue = "133866" /* compiler-team#759 */)]
 #[lang = "contract_check_requires"]
 #[track_caller]
 pub fn check_requires<C: FnOnce() -> bool>(c: C) {
@@ -21,7 +21,7 @@ pub fn check_requires<C: FnOnce() -> bool>(c: C) {
 /// into: `fn foo() { let _check = build_check_ensures(|ret| PRED) ... [return _check(R);] ... }`
 /// (including the implicit return of the tail expression, if any).
 #[cfg(not(bootstrap))]
-#[unstable(feature = "rustc_contracts", issue = "none" /* compiler-team#759 */)]
+#[unstable(feature = "rustc_contracts_internals", issue = "133866" /* compiler-team#759 */)]
 #[lang = "contract_build_check_ensures"]
 #[track_caller]
 pub fn build_check_ensures<Ret, C>(c: C) -> impl (FnOnce(Ret) -> Ret) + Copy

core/src/intrinsics/mod.rs

@@ -4071,8 +4071,8 @@ pub const unsafe fn const_deallocate(_ptr: *mut u8, _size: usize, _align: usize)
 /// checking is turned on, so that we can specify contracts in libstd
 /// and let an end user opt into turning them on.
 #[cfg(not(bootstrap))]
-#[rustc_const_unstable(feature = "rustc_contracts", issue = "none" /* compiler-team#759 */)]
-#[unstable(feature = "rustc_contracts", issue = "none" /* compiler-team#759 */)]
+#[rustc_const_unstable(feature = "rustc_contracts_internals", issue = "133866" /* compiler-team#759 */)]
+#[unstable(feature = "rustc_contracts_internals", issue = "133866" /* compiler-team#759 */)]
 #[inline(always)]
 #[rustc_intrinsic]
 pub const fn contract_checks() -> bool {
@@ -4083,14 +4083,14 @@ pub const fn contract_checks() -> bool {
 }
 
 #[cfg(not(bootstrap))]
-#[unstable(feature = "rustc_contracts", issue = "none" /* compiler-team#759 */)]
+#[unstable(feature = "rustc_contracts_internals", issue = "133866" /* compiler-team#759 */)]
 #[rustc_intrinsic]
 pub fn contract_check_requires<C: FnOnce() -> bool>(c: C) -> bool {
     c()
 }
 
 #[cfg(not(bootstrap))]
-#[unstable(feature = "rustc_contracts", issue = "none" /* compiler-team#759 */)]
+#[unstable(feature = "rustc_contracts_internals", issue = "133866" /* compiler-team#759 */)]
 #[rustc_intrinsic]
 pub fn contract_check_ensures<'a, Ret, C: FnOnce(&'a Ret) -> bool>(ret: &'a Ret, c: C) -> bool {
     c(ret)

core/src/lib.rs

@@ -249,7 +249,7 @@ pub mod autodiff {
 }
 
 #[cfg(not(bootstrap))]
-#[unstable(feature = "rustc_contracts", issue = "none")]
+#[unstable(feature = "rustc_contracts", issue = "133866")]
 pub mod contracts;
 
 #[unstable(feature = "cfg_match", issue = "115585")]

core/src/macros/mod.rs

@@ -1783,8 +1783,8 @@ pub(crate) mod builtin {
     /// eventually parsed as a unary closure expression that is
     /// invoked on a reference to the return value.
     #[cfg(not(bootstrap))]
-    #[unstable(feature = "rustc_contracts", issue = "none")]
-    #[allow_internal_unstable(core_intrinsics)]
+    #[unstable(feature = "rustc_contracts", issue = "133866")]
+    #[allow_internal_unstable(rustc_contracts_internals)]
     #[rustc_builtin_macro]
     pub macro contracts_ensures($item:item) {
         /* compiler built-in */
@@ -1796,8 +1796,8 @@ pub(crate) mod builtin {
     /// eventually parsed as an boolean expression with access to the
     /// function's formal parameters
     #[cfg(not(bootstrap))]
-    #[unstable(feature = "rustc_contracts", issue = "none")]
-    #[allow_internal_unstable(core_intrinsics)]
+    #[unstable(feature = "rustc_contracts", issue = "133866")]
+    #[allow_internal_unstable(rustc_contracts_internals)]
     #[rustc_builtin_macro]
     pub macro contracts_requires($item:item) {
         /* compiler built-in */