From be92200af7ac732063500a96890ed0354dcc490b Mon Sep 17 00:00:00 2001
From: Yuki Okushi <huyuumi.dev@gmail.com>
Date: Fri, 14 Feb 2020 21:49:57 +0900
Subject: [PATCH] Check `has_typeck_tables` before calling `typeck_tables_of`

---
 src/librustc_mir/const_eval/eval_queries.rs |  5 ++++-
 src/test/ui/consts/issue-68684.rs           | 15 +++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)
 create mode 100644 src/test/ui/consts/issue-68684.rs

diff --git a/src/librustc_mir/const_eval/eval_queries.rs b/src/librustc_mir/const_eval/eval_queries.rs
index 2e8e4dac237..4fdabed54b8 100644
--- a/src/librustc_mir/const_eval/eval_queries.rs
+++ b/src/librustc_mir/const_eval/eval_queries.rs
@@ -288,7 +288,10 @@ pub fn const_eval_raw_provider<'tcx>(
     let cid = key.value;
     let def_id = cid.instance.def.def_id();
 
-    if def_id.is_local() && tcx.typeck_tables_of(def_id).tainted_by_errors {
+    if def_id.is_local()
+        && tcx.has_typeck_tables(def_id)
+        && tcx.typeck_tables_of(def_id).tainted_by_errors
+    {
         return Err(ErrorHandled::Reported);
     }
 
diff --git a/src/test/ui/consts/issue-68684.rs b/src/test/ui/consts/issue-68684.rs
new file mode 100644
index 00000000000..c98f199b60e
--- /dev/null
+++ b/src/test/ui/consts/issue-68684.rs
@@ -0,0 +1,15 @@
+// check-pass
+
+enum _Enum {
+    A(),
+}
+
+type _E = _Enum;
+
+const fn _a() -> _Enum {
+    _E::A()
+}
+
+const _A: _Enum = _a();
+
+fn main() {}