Better error message

Co-Authored-By: Jonas Schievink <[email protected]>

Author: korken89

macros/src/lib.rs

@@ -839,7 +839,7 @@ fn check_attr_whitelist(attrs: &[Attribute]) -> Result<(), TokenStream> {
                 return Err(
                     parse::Error::new(
                         attr.span(),
-                        "cortex-m-rt does not support multiple attributes on the same function",
+                        "multiple cortex-m-rt attributes are not supported on the same function",
                     )
                     .to_compile_error()
                     .into(),

tests/compile-fail/whitelist-double-attr.rs

@@ -7,7 +7,7 @@ extern crate panic_halt;
 use cortex_m_rt::{entry, exception};
 
 #[exception]
-#[entry] //~ ERROR cortex-m-rt does not support multiple attributes on the same function
+#[entry] //~ ERROR multiple cortex-m-rt attributes are not supported on the same function
 fn SVCall() -> ! {
     loop {}
 }