Change the type for the macro body to also store the span.

Note: the body is the part of the macro syntax between the {}.

src/comp/syntax/ext/log_syntax.rs

@@ -3,7 +3,7 @@ import syntax::ast;
 import std::io::writer_util;
 
 fn expand_syntax_ext(cx: ext_ctxt, sp: codemap::span, arg: @ast::expr,
-                     _body: option<str>) -> @ast::expr {
+                     _body: ast::mac_body) -> @ast::expr {
 
     cx.print_backtrace();
     std::io::stdout().write_line(print::pprust::expr_to_str(arg));