From 2e193f7db79045846a5327530bc8ed37221e94d7 Mon Sep 17 00:00:00 2001
From: Mazdak Farrokhzad <twingoow@gmail.com>
Date: Wed, 24 Jul 2019 01:24:19 +0200
Subject: [PATCH 1/2] Add test self-in-enum-definition

---
 .../self-in-enum-definition.rs                |  8 ++++++
 .../self-in-enum-definition.stderr            | 28 +++++++++++++++++++
 2 files changed, 36 insertions(+)
 create mode 100644 src/test/ui/type-alias-enum-variants/self-in-enum-definition.rs
 create mode 100644 src/test/ui/type-alias-enum-variants/self-in-enum-definition.stderr

diff --git a/src/test/ui/type-alias-enum-variants/self-in-enum-definition.rs b/src/test/ui/type-alias-enum-variants/self-in-enum-definition.rs
new file mode 100644
index 0000000000000..6dc73ee4ff763
--- /dev/null
+++ b/src/test/ui/type-alias-enum-variants/self-in-enum-definition.rs
@@ -0,0 +1,8 @@
+#[repr(u8)]
+enum Alpha {
+    V1 = 41,
+    V2 = Self::V1 as u8 + 1, // OK -- but why?
+    V3 = Self::V1 {} as u8 + 2, //~ ERROR cycle detected when const-evaluating
+}
+
+fn main() {}
diff --git a/src/test/ui/type-alias-enum-variants/self-in-enum-definition.stderr b/src/test/ui/type-alias-enum-variants/self-in-enum-definition.stderr
new file mode 100644
index 0000000000000..0a90d5ed488a8
--- /dev/null
+++ b/src/test/ui/type-alias-enum-variants/self-in-enum-definition.stderr
@@ -0,0 +1,28 @@
+error[E0391]: cycle detected when const-evaluating + checking `Alpha::V3::{{constant}}#0`
+  --> $DIR/self-in-enum-definition.rs:5:10
+   |
+LL |     V3 = Self::V1 {} as u8 + 2,
+   |          ^^^^^^^^
+   |
+note: ...which requires const-evaluating `Alpha::V3::{{constant}}#0`...
+  --> $DIR/self-in-enum-definition.rs:5:10
+   |
+LL |     V3 = Self::V1 {} as u8 + 2,
+   |          ^^^^^^^^
+   = note: ...which requires computing layout of `Alpha`...
+   = note: ...which again requires const-evaluating + checking `Alpha::V3::{{constant}}#0`, completing the cycle
+note: cycle used when collecting item types in top-level module
+  --> $DIR/self-in-enum-definition.rs:1:1
+   |
+LL | / #[repr(u8)]
+LL | | enum Alpha {
+LL | |     V1 = 41,
+LL | |     V2 = Self::V1 as u8 + 1, // OK -- but why?
+...  |
+LL | |
+LL | | fn main() {}
+   | |____________^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0391`.

From 7fdfe8b85476f5178df651dd836d556c2bf7917f Mon Sep 17 00:00:00 2001
From: Mazdak Farrokhzad <twingoow@gmail.com>
Date: Wed, 24 Jul 2019 11:36:17 +0200
Subject: [PATCH 2/2] Refer to #50072 re. hack.

---
 src/test/ui/type-alias-enum-variants/self-in-enum-definition.rs | 2 +-
 .../ui/type-alias-enum-variants/self-in-enum-definition.stderr  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/test/ui/type-alias-enum-variants/self-in-enum-definition.rs b/src/test/ui/type-alias-enum-variants/self-in-enum-definition.rs
index 6dc73ee4ff763..63b21faa62bd2 100644
--- a/src/test/ui/type-alias-enum-variants/self-in-enum-definition.rs
+++ b/src/test/ui/type-alias-enum-variants/self-in-enum-definition.rs
@@ -1,7 +1,7 @@
 #[repr(u8)]
 enum Alpha {
     V1 = 41,
-    V2 = Self::V1 as u8 + 1, // OK -- but why?
+    V2 = Self::V1 as u8 + 1, // OK; See #50072.
     V3 = Self::V1 {} as u8 + 2, //~ ERROR cycle detected when const-evaluating
 }
 
diff --git a/src/test/ui/type-alias-enum-variants/self-in-enum-definition.stderr b/src/test/ui/type-alias-enum-variants/self-in-enum-definition.stderr
index 0a90d5ed488a8..dc4050e44abb1 100644
--- a/src/test/ui/type-alias-enum-variants/self-in-enum-definition.stderr
+++ b/src/test/ui/type-alias-enum-variants/self-in-enum-definition.stderr
@@ -17,7 +17,7 @@ note: cycle used when collecting item types in top-level module
 LL | / #[repr(u8)]
 LL | | enum Alpha {
 LL | |     V1 = 41,
-LL | |     V2 = Self::V1 as u8 + 1, // OK -- but why?
+LL | |     V2 = Self::V1 as u8 + 1, // OK; See #50072.
 ...  |
 LL | |
 LL | | fn main() {}