Remove redundant check_for_macros AST pass.

Author: jseyfried

src/librustc_driver/driver.rs

@@ -747,10 +747,6 @@ pub fn phase_2_configure_and_expand(sess: &Session,
                  "prelude injection",
                  || syntax::std_inject::maybe_inject_prelude(&sess.parse_sess, krate));
 
-    time(time_passes,
-         "checking that all macro invocations are gone",
-         || syntax::ext::expand::check_for_macros(&sess.parse_sess, &krate));
-
     time(time_passes,
          "checking for inline asm in case the target doesn't support it",
          || no_asm::check_crate(sess, &krate));

src/libsyntax/ext/expand.rs

@@ -25,7 +25,6 @@ use feature_gate::{self, Features};
 use fold;
 use fold::*;
 use util::move_map::MoveMap;
-use parse;
 use parse::token::{fresh_mark, fresh_name, intern, keywords};
 use ptr::P;
 use util::small_vector::SmallVector;
@@ -1212,24 +1211,6 @@ fn mark_tts(tts: &[TokenTree], m: Mrk) -> Vec<TokenTree> {
     noop_fold_tts(tts, &mut Marker{mark:m, expn_id: None})
 }
 
-/// Check that there are no macro invocations left in the AST:
-pub fn check_for_macros(sess: &parse::ParseSess, krate: &ast::Crate) {
-    visit::walk_crate(&mut MacroExterminator{sess:sess}, krate);
-}
-
-/// A visitor that ensures that no macro invocations remain in an AST.
-struct MacroExterminator<'a>{
-    sess: &'a parse::ParseSess
-}
-
-impl<'a, 'v> Visitor<'v> for MacroExterminator<'a> {
-    fn visit_mac(&mut self, mac: &ast::Mac) {
-        self.sess.span_diagnostic.span_bug(mac.span,
-                                           "macro exterminator: expected AST \
-                                           with no macro invocations");
-    }
-}
-
 
 #[cfg(test)]
 mod tests {