From b0625eb7127683e301c37e3d7fb8e3c8a6f66456 Mon Sep 17 00:00:00 2001
From: Ellen <supbscripter@gmail.com>
Date: Wed, 27 Jan 2021 02:42:18 +0000
Subject: boop, ur abstract consts are now expanded

---
 .../nested-abstract-consts-1.rs                    | 22 +++++++++++++++
 .../nested-abstract-consts-2.rs                    | 32 ++++++++++++++++++++++
 .../nested_uneval_unification-1.rs                 | 32 ++++++++++++++++++++++
 .../nested_uneval_unification-2.rs                 | 26 ++++++++++++++++++
 4 files changed, 112 insertions(+)
 create mode 100644 src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-1.rs
 create mode 100644 src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-2.rs
 create mode 100644 src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-1.rs
 create mode 100644 src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-2.rs

(limited to 'src')

diff --git a/src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-1.rs b/src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-1.rs
new file mode 100644
index 00000000000..124cd317da5
--- /dev/null
+++ b/src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-1.rs
@@ -0,0 +1,22 @@
+// run-pass
+#![feature(const_generics, const_evaluatable_checked)]
+#![allow(incomplete_features)]
+
+fn callee<const M2: usize>() -> usize
+where
+    [u8; M2 + 1]: Sized,
+{
+    M2
+}
+
+fn caller<const N1: usize>() -> usize
+where
+    [u8; N1 + 1]: Sized,
+    [u8; (N1 + 1) + 1]: Sized,
+{
+    callee::<{ N1 + 1 }>()
+}
+
+fn main() {
+    assert_eq!(caller::<4>(), 5);
+}
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-2.rs b/src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-2.rs
new file mode 100644
index 00000000000..5936662dadb
--- /dev/null
+++ b/src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-2.rs
@@ -0,0 +1,32 @@
+// run-pass
+#![feature(const_evaluatable_checked, const_generics)]
+#![allow(incomplete_features)]
+
+struct Generic<const K: u64>;
+
+struct ConstU64<const K: u64>;
+
+impl<const K: u64> Generic<K>
+where
+    ConstU64<{ K - 1 }>: ,
+{
+    fn foo(self) -> u64 {
+        K
+    }
+}
+
+impl<const K: u64> Generic<K>
+where
+    ConstU64<{ K - 1 }>: ,
+    ConstU64<{ K + 1 }>: ,
+    ConstU64<{ K + 1 - 1 }>: ,
+{
+    fn bar(self) -> u64 {
+        let x: Generic<{ K + 1 }> = Generic;
+        x.foo()
+    }
+}
+
+fn main() {
+    assert_eq!((Generic::<10>).bar(), 11);
+}
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-1.rs b/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-1.rs
new file mode 100644
index 00000000000..ff0f2efaee9
--- /dev/null
+++ b/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-1.rs
@@ -0,0 +1,32 @@
+// run-pass
+#![feature(const_generics, const_evaluatable_checked)]
+#![allow(incomplete_features)]
+
+fn zero_init<const N: usize>() -> Substs1<N>
+where
+    [u8; N + 1]: ,
+{
+    Substs1([0; N + 1])
+}
+struct Substs1<const N: usize>([u8; N + 1])
+where
+    [(); N + 1]: ;
+
+fn substs2<const M: usize>() -> Substs1<{ M * 2 }>
+where
+    [(); { M * 2 } + 1]: ,
+{
+    zero_init::<{ M * 2 }>()
+}
+
+fn substs3<const L: usize>() -> Substs1<{ (L - 1) * 2 }>
+where
+    [(); (L - 1)]: ,
+    [(); (L - 1) * 2 + 1]: ,
+{
+    substs2::<{ L - 1 }>()
+}
+
+fn main() {
+    assert_eq!(substs3::<2>().0, [0; 3]);
+}
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-2.rs b/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-2.rs
new file mode 100644
index 00000000000..806f7ba9203
--- /dev/null
+++ b/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-2.rs
@@ -0,0 +1,26 @@
+// run-pass
+#![feature(const_generics, const_evaluatable_checked)]
+#![allow(incomplete_features, unused_parens, unused_braces)]
+
+fn zero_init<const N: usize>() -> Substs1<{ (N) }>
+where
+    [u8; { (N) }]: ,
+{
+    Substs1([0; { (N) }])
+}
+
+struct Substs1<const N: usize>([u8; { (N) }])
+where
+    [(); { (N) }]: ;
+
+fn substs2<const M: usize>() -> Substs1<{ (M) }> {
+    zero_init::<{ (M) }>()
+}
+
+fn substs3<const L: usize>() -> Substs1<{ (L) }> {
+    substs2::<{ (L) }>()
+}
+
+fn main() {
+    assert_eq!(substs3::<2>().0, [0; 2]);
+}
-- 
cgit 1.4.1-3-g733a5


From f4261772d8d4e2d4fb7e9dd4685b995a7176e506 Mon Sep 17 00:00:00 2001
From: Ellen <supbscripter@gmail.com>
Date: Wed, 27 Jan 2021 14:46:43 +0000
Subject: comments

---
 compiler/rustc_trait_selection/src/traits/const_evaluatable.rs        | 4 +++-
 .../const_evaluatable_checked/nested-abstract-consts-1.rs             | 2 ++
 .../const_evaluatable_checked/nested-abstract-consts-2.rs             | 2 ++
 .../const_evaluatable_checked/nested_uneval_unification-1.rs          | 2 ++
 .../const_evaluatable_checked/nested_uneval_unification-2.rs          | 2 ++
 5 files changed, 11 insertions(+), 1 deletion(-)

(limited to 'src')

diff --git a/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs b/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs
index 272588ad516..b587ed6487e 100644
--- a/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs
+++ b/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs
@@ -612,6 +612,9 @@ pub(super) fn try_unify<'tcx>(
     mut a: AbstractConst<'tcx>,
     mut b: AbstractConst<'tcx>,
 ) -> bool {
+    // We substitute generics repeatedly to allow AbstractConsts to unify where a
+    // ConstKind::Unevalated could be turned into an AbstractConst that would unify e.g.
+    // Param(N) should unify with Param(T), substs: [Unevaluated("T2", [Unevaluated("T3", [Param(N)])])]
     while let Node::Leaf(a_ct) = a.root() {
         let a_ct = a_ct.subst(tcx, a.substs);
         match AbstractConst::from_const(tcx, a_ct) {
@@ -620,7 +623,6 @@ pub(super) fn try_unify<'tcx>(
             Err(_) => return true,
         }
     }
-
     while let Node::Leaf(b_ct) = b.root() {
         let b_ct = b_ct.subst(tcx, b.substs);
         match AbstractConst::from_const(tcx, b_ct) {
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-1.rs b/src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-1.rs
index 124cd317da5..0fe84c1cd2a 100644
--- a/src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-1.rs
+++ b/src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-1.rs
@@ -20,3 +20,5 @@ where
 fn main() {
     assert_eq!(caller::<4>(), 5);
 }
+
+// Test that the ``(N1 + 1) + 1`` bound on ``caller`` satisfies the ``M2 + 1`` bound on ``callee``
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-2.rs b/src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-2.rs
index 5936662dadb..fe5c2237a76 100644
--- a/src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-2.rs
+++ b/src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-2.rs
@@ -30,3 +30,5 @@ where
 fn main() {
     assert_eq!((Generic::<10>).bar(), 11);
 }
+
+// Test that the ``ConstU64<{ K + 1 - 1}>`` bound on ``bar``'s impl block satisfies the ``ConstU64<{K - 1}>`` bound on ``foo``'s impl block
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-1.rs b/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-1.rs
index ff0f2efaee9..f686bfd1d2b 100644
--- a/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-1.rs
+++ b/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-1.rs
@@ -30,3 +30,5 @@ where
 fn main() {
     assert_eq!(substs3::<2>().0, [0; 3]);
 }
+
+// Test that the ``{ (L - 1) * 2 + 1 }`` bound on ``substs3`` satisfies the ``{ N + 1 }`` bound on ``Substs1``
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-2.rs b/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-2.rs
index 806f7ba9203..4cdfb107417 100644
--- a/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-2.rs
+++ b/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-2.rs
@@ -24,3 +24,5 @@ fn substs3<const L: usize>() -> Substs1<{ (L) }> {
 fn main() {
     assert_eq!(substs3::<2>().0, [0; 2]);
 }
+
+// Test that the implicit ``{ (L) }`` bound on ``substs3`` satisfies the ``{ (N) }`` bound on ``Substs1``
-- 
cgit 1.4.1-3-g733a5


From ab421a176240a658ed02e8eee70b7ea211c087e3 Mon Sep 17 00:00:00 2001
From: Ellen <supbscripter@gmail.com>
Date: Wed, 27 Jan 2021 15:09:17 +0000
Subject: fix tidy errors

---
 .../const_evaluatable_checked/nested-abstract-consts-2.rs              | 3 ++-
 .../const_evaluatable_checked/nested_uneval_unification-1.rs           | 3 ++-
 .../const_evaluatable_checked/nested_uneval_unification-2.rs           | 3 ++-
 3 files changed, 6 insertions(+), 3 deletions(-)

(limited to 'src')

diff --git a/src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-2.rs b/src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-2.rs
index fe5c2237a76..4f588238e23 100644
--- a/src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-2.rs
+++ b/src/test/ui/const-generics/const_evaluatable_checked/nested-abstract-consts-2.rs
@@ -31,4 +31,5 @@ fn main() {
     assert_eq!((Generic::<10>).bar(), 11);
 }
 
-// Test that the ``ConstU64<{ K + 1 - 1}>`` bound on ``bar``'s impl block satisfies the ``ConstU64<{K - 1}>`` bound on ``foo``'s impl block
+// Test that the ``ConstU64<{ K + 1 - 1}>`` bound on ``bar``'s impl block satisfies the
+// ``ConstU64<{K - 1}>`` bound on ``foo``'s impl block
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-1.rs b/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-1.rs
index f686bfd1d2b..1428f774b0d 100644
--- a/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-1.rs
+++ b/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-1.rs
@@ -31,4 +31,5 @@ fn main() {
     assert_eq!(substs3::<2>().0, [0; 3]);
 }
 
-// Test that the ``{ (L - 1) * 2 + 1 }`` bound on ``substs3`` satisfies the ``{ N + 1 }`` bound on ``Substs1``
+// Test that the ``{ (L - 1) * 2 + 1 }`` bound on ``substs3`` satisfies the
+// ``{ N + 1 }`` bound on ``Substs1``
diff --git a/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-2.rs b/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-2.rs
index 4cdfb107417..be8219a7446 100644
--- a/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-2.rs
+++ b/src/test/ui/const-generics/const_evaluatable_checked/nested_uneval_unification-2.rs
@@ -25,4 +25,5 @@ fn main() {
     assert_eq!(substs3::<2>().0, [0; 2]);
 }
 
-// Test that the implicit ``{ (L) }`` bound on ``substs3`` satisfies the ``{ (N) }`` bound on ``Substs1``
+// Test that the implicit ``{ (L) }`` bound on ``substs3`` satisfies the
+// ``{ (N) }`` bound on ``Substs1``
-- 
cgit 1.4.1-3-g733a5