Auto merge of #76637 - RalfJung:rollup-eaykf93, r=RalfJung

Rollup of 7 pull requests

Successful merges:

 - #76114 (Add saturating methods for `Duration`)
 - #76297 (rustdoc: fix min_const_generics with ty::Param)
 - #76484 (Add MaybeUninit::assume_init_drop.)
 - #76530 (Eliminate mut reference UB in Drop impl for Rc<T>)
 - #76583 (Update `std::os` module documentation.)
 - #76599 (Finish off revisions for const generics UI tests.)
 - #76615 (Add missing examples on binary core traits)

Failed merges:

r? `@ghost`

12 files changed, 95 insertions, 37 deletions

diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 1bdbad46755..9d784d24609 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -1364,16 +1364,16 @@ impl Clean<Type> for hir::Ty<'_> {
             TyKind::Slice(ref ty) => Slice(box ty.clean(cx)),
             TyKind::Array(ref ty, ref length) => {
                 let def_id = cx.tcx.hir().local_def_id(length.hir_id);
-                let length = match cx.tcx.const_eval_poly(def_id.to_def_id()) {
-                    Ok(length) => {
-                        print_const(cx, ty::Const::from_value(cx.tcx, length, cx.tcx.types.usize))
-                    }
-                    Err(_) => cx
-                        .sess()
-                        .source_map()
-                        .span_to_snippet(cx.tcx.def_span(def_id))
-                        .unwrap_or_else(|_| "_".to_string()),
-                };
+                // NOTE(min_const_generics): We can't use `const_eval_poly` for constants
+                // as we currently do not supply the parent generics to anonymous constants
+                // but do allow `ConstKind::Param`.
+                //
+                // `const_eval_poly` tries to to first substitute generic parameters which
+                // results in an ICE while manually constructing the constant and using `eval`
+                // does nothing for `ConstKind::Param`.
+                let ct = ty::Const::from_anon_const(cx.tcx, def_id);
+                let param_env = cx.tcx.param_env(def_id);
+                let length = print_const(cx, ct.eval(cx.tcx, param_env));
                 Array(box ty.clean(cx), length)
             }
             TyKind::Tup(ref tys) => Tuple(tys.clean(cx)),
diff --git a/src/test/rustdoc/const-generics/type-alias.rs b/src/test/rustdoc/const-generics/type-alias.rs
new file mode 100644
index 00000000000..3064d0701e3
--- /dev/null
+++ b/src/test/rustdoc/const-generics/type-alias.rs
@@ -0,0 +1,6 @@
+// ignore-tidy-linelength
+#![feature(min_const_generics)]
+#![crate_name = "foo"]
+
+// @has foo/type.CellIndex.html '//pre[@class="rust typedef"]' 'type CellIndex<const D: usize> = [i64; D];'
+pub type CellIndex<const D: usize> = [i64; D];
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/feature-gate-const_evaluatable_checked.stderr b/src/test/ui/const-generics/const_evaluatable_checked/feature-gate-const_evaluatable_checked.full.stderr
index 6e4a22a38b1..b2816367ea1 100644
--- a/src/test/ui/const-generics/const_evaluatable_checked/feature-gate-const_evaluatable_checked.stderr
+++ b/src/test/ui/const-generics/const_evaluatable_checked/feature-gate-const_evaluatable_checked.full.stderr
@@ -1,5 +1,5 @@
 error: constant expression depends on a generic parameter
-  --> $DIR/feature-gate-const_evaluatable_checked.rs:6:30
+  --> $DIR/feature-gate-const_evaluatable_checked.rs:9:30
    |
 LL | fn test<const N: usize>() -> Arr<N> where Arr<N>: Default {
    |                              ^^^^^^
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/feature-gate-const_evaluatable_checked.min.stderr b/src/test/ui/const-generics/const_evaluatable_checked/feature-gate-const_evaluatable_checked.min.stderr
new file mode 100644
index 00000000000..269710db164
--- /dev/null
+++ b/src/test/ui/const-generics/const_evaluatable_checked/feature-gate-const_evaluatable_checked.min.stderr
@@ -0,0 +1,10 @@
+error: generic parameters must not be used inside of non trivial constant values
+  --> $DIR/feature-gate-const_evaluatable_checked.rs:6:33
+   |
+LL | type Arr<const N: usize> = [u8; N - 1];
+   |                                 ^ non-trivial anonymous constants must not depend on the parameter `N`
+   |
+   = help: it is currently only allowed to use either `N` or `{ N }` as generic constants
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/feature-gate-const_evaluatable_checked.rs b/src/test/ui/const-generics/const_evaluatable_checked/feature-gate-const_evaluatable_checked.rs
index 941bd5e9e5d..af3090115f2 100644
--- a/src/test/ui/const-generics/const_evaluatable_checked/feature-gate-const_evaluatable_checked.rs
+++ b/src/test/ui/const-generics/const_evaluatable_checked/feature-gate-const_evaluatable_checked.rs
@@ -1,10 +1,13 @@
-#![feature(const_generics)]
-#![allow(incomplete_features)]
+// revisions: full min
+#![cfg_attr(full, feature(const_generics))]
+#![cfg_attr(full, allow(incomplete_features))]
+#![cfg_attr(min, feature(min_const_generics))]
 
 type Arr<const N: usize> = [u8; N - 1];
+//[min]~^ ERROR generic parameters must not be used inside of non trivial constant values
 
 fn test<const N: usize>() -> Arr<N> where Arr<N>: Default {
-    //~^ ERROR constant expression depends
+    //[full]~^ ERROR constant expression depends
     Default::default()
 }
 
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/simple.min.stderr b/src/test/ui/const-generics/const_evaluatable_checked/simple.min.stderr
new file mode 100644
index 00000000000..da8ccdaee41
--- /dev/null
+++ b/src/test/ui/const-generics/const_evaluatable_checked/simple.min.stderr
@@ -0,0 +1,10 @@
+error: generic parameters must not be used inside of non trivial constant values
+  --> $DIR/simple.rs:8:33
+   |
+LL | type Arr<const N: usize> = [u8; N - 1];
+   |                                 ^ non-trivial anonymous constants must not depend on the parameter `N`
+   |
+   = help: it is currently only allowed to use either `N` or `{ N }` as generic constants
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/simple.rs b/src/test/ui/const-generics/const_evaluatable_checked/simple.rs
index a7ead78b97b..27dc6b10320 100644
--- a/src/test/ui/const-generics/const_evaluatable_checked/simple.rs
+++ b/src/test/ui/const-generics/const_evaluatable_checked/simple.rs
@@ -1,8 +1,12 @@
-// run-pass
-#![feature(const_generics, const_evaluatable_checked)]
+// [full] run-pass
+// revisions: full min
+#![cfg_attr(full, feature(const_generics))]
+#![cfg_attr(min, feature(min_const_generics))]
+#![feature(const_evaluatable_checked)]
 #![allow(incomplete_features)]
 
 type Arr<const N: usize> = [u8; N - 1];
+//[min]~^ ERROR generic parameters must not be used inside of non trivial constant values
 
 fn test<const N: usize>() -> Arr<N> where Arr<N>: Default {
     Default::default()
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/simple_fail.stderr b/src/test/ui/const-generics/const_evaluatable_checked/simple_fail.full.stderr
index 1ac5e1d9553..104cab8667c 100644
--- a/src/test/ui/const-generics/const_evaluatable_checked/simple_fail.stderr
+++ b/src/test/ui/const-generics/const_evaluatable_checked/simple_fail.full.stderr
@@ -1,5 +1,5 @@
 error[E0080]: evaluation of constant value failed
-  --> $DIR/simple_fail.rs:4:33
+  --> $DIR/simple_fail.rs:7:33
    |
 LL | type Arr<const N: usize> = [u8; N - 1];
    |                                 ^^^^^ attempt to compute `0_usize - 1_usize` which would overflow
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/simple_fail.min.stderr b/src/test/ui/const-generics/const_evaluatable_checked/simple_fail.min.stderr
new file mode 100644
index 00000000000..042710f1327
--- /dev/null
+++ b/src/test/ui/const-generics/const_evaluatable_checked/simple_fail.min.stderr
@@ -0,0 +1,10 @@
+error: generic parameters must not be used inside of non trivial constant values
+  --> $DIR/simple_fail.rs:7:33
+   |
+LL | type Arr<const N: usize> = [u8; N - 1];
+   |                                 ^ non-trivial anonymous constants must not depend on the parameter `N`
+   |
+   = help: it is currently only allowed to use either `N` or `{ N }` as generic constants
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/simple_fail.rs b/src/test/ui/const-generics/const_evaluatable_checked/simple_fail.rs
index 1edf1885dd2..b15e0ff1839 100644
--- a/src/test/ui/const-generics/const_evaluatable_checked/simple_fail.rs
+++ b/src/test/ui/const-generics/const_evaluatable_checked/simple_fail.rs
@@ -1,7 +1,11 @@
-#![feature(const_generics, const_evaluatable_checked)]
+// revisions: full min
+#![cfg_attr(full, feature(const_generics))]
+#![cfg_attr(min, feature(min_const_generics))]
+#![feature(const_evaluatable_checked)]
 #![allow(incomplete_features)]
 
-type Arr<const N: usize> = [u8; N - 1]; //~ ERROR evaluation of constant
+type Arr<const N: usize> = [u8; N - 1]; //[full]~ ERROR evaluation of constant
+//[min]~^ ERROR generic parameters must not be used inside of non trivial constant values
 
 fn test<const N: usize>() -> Arr<N> where Arr<N>: Sized {
     todo!()
diff --git a/src/test/ui/const-generics/type-dependent/auxiliary/type_dependent_lib.rs b/src/test/ui/const-generics/type-dependent/auxiliary/type_dependent_lib.rs
index c8db91b62b5..aa85376bf0d 100644
--- a/src/test/ui/const-generics/type-dependent/auxiliary/type_dependent_lib.rs
+++ b/src/test/ui/const-generics/type-dependent/auxiliary/type_dependent_lib.rs
@@ -1,5 +1,6 @@
-#![feature(const_generics)]
-#![allow(incomplete_features)]
+#![cfg_attr(full, feature(const_generics))]
+#![cfg_attr(full, allow(incomplete_features))]
+#![cfg_attr(min, feature(min_const_generics))]
 
 pub struct Struct<const N: usize>(());
 
diff --git a/src/test/ui/consts/duration-consts-2.rs b/src/test/ui/consts/duration-consts-2.rs
index c8b39399331..bc0969e4f1f 100644
--- a/src/test/ui/consts/duration-consts-2.rs
+++ b/src/test/ui/consts/duration-consts-2.rs
@@ -3,6 +3,7 @@
 #![feature(const_panic)]
 #![feature(duration_consts_2)]
 #![feature(div_duration)]
+#![feature(duration_saturating_ops)]
 
 use std::time::Duration;
 
@@ -15,29 +16,29 @@ fn duration() {
 
     const MAX : Duration = Duration::new(u64::MAX, 1_000_000_000 - 1);
 
-    const MAX_ADD_ZERO : Option<Duration> = MAX.checked_add(ZERO);
-    assert_eq!(MAX_ADD_ZERO, Some(MAX));
+    const MAX_CHECKED_ADD_ZERO : Option<Duration> = MAX.checked_add(ZERO);
+    assert_eq!(MAX_CHECKED_ADD_ZERO, Some(MAX));
 
-    const MAX_ADD_ONE : Option<Duration> = MAX.checked_add(ONE);
-    assert_eq!(MAX_ADD_ONE, None);
+    const MAX_CHECKED_ADD_ONE : Option<Duration> = MAX.checked_add(ONE);
+    assert_eq!(MAX_CHECKED_ADD_ONE, None);
 
-    const ONE_SUB_ONE : Option<Duration> = ONE.checked_sub(ONE);
-    assert_eq!(ONE_SUB_ONE, Some(ZERO));
+    const ONE_CHECKED_SUB_ONE : Option<Duration> = ONE.checked_sub(ONE);
+    assert_eq!(ONE_CHECKED_SUB_ONE, Some(ZERO));
 
-    const ZERO_SUB_ONE : Option<Duration> = ZERO.checked_sub(ONE);
-    assert_eq!(ZERO_SUB_ONE, None);
+    const ZERO_CHECKED_SUB_ONE : Option<Duration> = ZERO.checked_sub(ONE);
+    assert_eq!(ZERO_CHECKED_SUB_ONE, None);
 
-    const ONE_MUL_ONE : Option<Duration> = ONE.checked_mul(1);
-    assert_eq!(ONE_MUL_ONE, Some(ONE));
+    const ONE_CHECKED_MUL_ONE : Option<Duration> = ONE.checked_mul(1);
+    assert_eq!(ONE_CHECKED_MUL_ONE, Some(ONE));
 
-    const MAX_MUL_TWO : Option<Duration> = MAX.checked_mul(2);
-    assert_eq!(MAX_MUL_TWO, None);
+    const MAX_CHECKED_MUL_TWO : Option<Duration> = MAX.checked_mul(2);
+    assert_eq!(MAX_CHECKED_MUL_TWO, None);
 
-    const ONE_DIV_ONE : Option<Duration> = ONE.checked_div(1);
-    assert_eq!(ONE_DIV_ONE, Some(ONE));
+    const ONE_CHECKED_DIV_ONE : Option<Duration> = ONE.checked_div(1);
+    assert_eq!(ONE_CHECKED_DIV_ONE, Some(ONE));
 
-    const ONE_DIV_ZERO : Option<Duration> = ONE.checked_div(0);
-    assert_eq!(ONE_DIV_ZERO, None);
+    const ONE_CHECKED_DIV_ZERO : Option<Duration> = ONE.checked_div(0);
+    assert_eq!(ONE_CHECKED_DIV_ZERO, None);
 
     const MAX_AS_F32 : f32 = MAX.as_secs_f32();
     assert_eq!(MAX_AS_F32, 18446744000000000000.0_f32);
@@ -50,6 +51,15 @@ fn duration() {
 
     const ONE_AS_F64 : f64 = ONE.div_duration_f64(ONE);
     assert_eq!(ONE_AS_F64, 1.0_f64);
+
+    const MAX_SATURATING_ADD_ONE : Duration = MAX.saturating_add(ONE);
+    assert_eq!(MAX_SATURATING_ADD_ONE, MAX);
+
+    const ZERO_SATURATING_SUB_ONE : Duration = ZERO.saturating_sub(ONE);
+    assert_eq!(ZERO_SATURATING_SUB_ONE, ZERO);
+
+    const MAX_SATURATING_MUL_TWO : Duration = MAX.saturating_mul(2);
+    assert_eq!(MAX_SATURATING_MUL_TWO, MAX);
 }
 
 fn main() {