1 files changed, 73 insertions, 0 deletions
diff --git a/src/test/ui/const-generics/early/macro_rules-braces.rs b/src/test/ui/const-generics/early/macro_rules-braces.rs
new file mode 100644
index 000000000..0ae914635
--- /dev/null
+++ b/src/test/ui/const-generics/early/macro_rules-braces.rs
@@ -0,0 +1,73 @@
+mod m {
+    pub const P: usize = 0;
+}
+
+const Q: usize = 0;
+
+fn test<const N: usize>() {
+    struct Foo<const M: usize>;
+    macro_rules! foo {
+        ($x:expr) => {
+            [u8; $x]
+        }
+    }
+    macro_rules! bar {
+        ($x:expr) => {
+            [u8; { $x }]
+        }
+    }
+    macro_rules! baz {
+        ( $x:expr) => {
+            Foo<$x>
+        }
+    }
+    macro_rules! biz {
+        ($x:expr) => {
+            Foo<{ $x }>
+        };
+    }
+
+    let _: foo!(N);
+    let _: foo!({ N });
+    let _: foo!({{ N }}); //~ ERROR generic parameters may not
+    let _: foo!(Q);
+    let _: foo!(m::P);
+    let _: bar!(N);
+    let _: bar!({ N }); //~ ERROR generic parameters may not
+    let _: bar!(Q);
+    let _: bar!(m::P);
+    let _: baz!(N);
+    let _: baz!({ N });
+    let _: baz!({{ N }}); //~ ERROR generic parameters may not
+    let _: baz!(Q);
+    let _: baz!({ m::P });
+    let _: baz!(m::P); //~ ERROR expressions must be enclosed in braces
+    let _: biz!(N);
+    let _: biz!({ N }); //~ ERROR generic parameters may not
+    let _: biz!(Q);
+    let _: biz!(m::P);
+    let _: foo!(3);
+    let _: foo!({ 3 });
+    let _: foo!({{ 3 }});
+    let _: bar!(3);
+    let _: bar!({ 3 });
+    let _: baz!(3);
+    let _: baz!({ 3 });
+    let _: baz!({{ 3 }});
+    let _: biz!(3);
+    let _: biz!({ 3 });
+    let _: foo!(10 + 7);
+    let _: foo!({ 10 + 7 });
+    let _: foo!({{ 10 + 7 }});
+    let _: bar!(10 + 7);
+    let _: bar!({ 10 + 7 });
+    let _: baz!(10 + 7); //~ ERROR expressions must be enclosed in braces
+    let _: baz!({ 10 + 7 });
+    let _: baz!({{ 10 + 7 }});
+    let _: biz!(10 + 7);
+    let _: biz!({ 10 + 7 });
+}
+
+fn main() {
+    test::<3>();
+}