awesome: arbitrary expressions excepted without braces

packages/core-macro/Cargo.toml

@@ -16,6 +16,7 @@ proc-macro = true
 
 [dependencies]
 once_cell = "1.8"
+proc-macro-error = "1.0.4"
 proc-macro2 = { version = "1.0.6" }
 quote = "1.0"
 syn = { version = "1.0.11", features = ["full", "extra-traits"] }