enable macro visits in deriving

src/libsyntax_ext/deriving/generic/mod.rs

@@ -192,7 +192,7 @@ use std::collections::HashSet;
 use std::vec;
 
 use syntax::abi::Abi;
-use syntax::ast::{self, EnumDef, Expr, Ident, Generics, VariantData, BinOpKind, PatKind};
+use syntax::ast::{self, EnumDef, Expr, Ident, Generics, Mac, VariantData, BinOpKind, PatKind};
 use syntax::attr;
 use syntax::attr::AttrMetaMethods;
 use syntax::ext::base::{ExtCtxt, Annotatable};
@@ -371,6 +371,10 @@ fn find_type_parameters(ty: &ast::Ty, ty_param_names: &[ast::Name]) -> Vec<P<ast
 
             visit::walk_ty(self, ty)
         }
+
+        fn visit_mac(&mut self, mac: &'a Mac) {
+            visit::walk_mac(self, mac)
+        }
     }
 
     let mut visitor = Visitor {

src/test/run-pass/derive-type-macros.rs

@@ -0,0 +1,28 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+//
+// regression test for #32950
+
+#![feature(type_macros)]
+
+macro_rules! passthru {
+    ($t:ty) => { $t }
+}
+
+#[derive(Debug)]
+struct Thing<T> {
+    thing: passthru!(T)
+}
+
+fn main() {
+    let t: passthru!(Thing<passthru!(i32)>) = Thing { thing: 42 };
+    println!("{:?}", t);
+}
+