expand: Do not ICE when a legacy AST-based macro attribute produces and empty expression

2 files changed, 31 insertions, 0 deletions

diff --git a/src/test/ui/macros/attr-empty-expr.rs b/src/test/ui/macros/attr-empty-expr.rs
new file mode 100644
index 00000000000..d4d1a3ee71e
--- /dev/null
+++ b/src/test/ui/macros/attr-empty-expr.rs
@@ -0,0 +1,11 @@
+// AST-based macro attributes expanding to an empty expression produce an error and not ICE.
+
+#![feature(custom_test_frameworks)]
+#![feature(stmt_expr_attributes)]
+#![feature(test)]
+
+fn main() {
+    let _ = #[test] 0; //~ ERROR removing an expression is not supported in this position
+    let _ = #[bench] 1; //~ ERROR removing an expression is not supported in this position
+    let _ = #[test_case] 2; //~ ERROR removing an expression is not supported in this position
+}
diff --git a/src/test/ui/macros/attr-empty-expr.stderr b/src/test/ui/macros/attr-empty-expr.stderr
new file mode 100644
index 00000000000..53721053bcc
--- /dev/null
+++ b/src/test/ui/macros/attr-empty-expr.stderr
@@ -0,0 +1,20 @@
+error: removing an expression is not supported in this position
+  --> $DIR/attr-empty-expr.rs:8:13
+   |
+LL |     let _ = #[test] 0;
+   |             ^^^^^^^
+
+error: removing an expression is not supported in this position
+  --> $DIR/attr-empty-expr.rs:9:13
+   |
+LL |     let _ = #[bench] 1;
+   |             ^^^^^^^^
+
+error: removing an expression is not supported in this position
+  --> $DIR/attr-empty-expr.rs:10:13
+   |
+LL |     let _ = #[test_case] 2;
+   |             ^^^^^^^^^^^^
+
+error: aborting due to 3 previous errors
+