mozilla/rust — pull request #12998 by huonw (2014-03-18 12:16:46+00:00)
Title: syntax: allow `trace_macros!` and `log_syntax!` in item position.

syntax: allow `trace_macros!` and `log_syntax!` in item position.

Previously

trace_macros!(true)
fn main() {}

would complain about `trace_macros` being an expression macro in item
position. This is a pointless limitation, because the macro is purely
compile-time, with no runtime effect. (And similarly for log_syntax.)