auto merge of #19466 : nikomatsakis/rust/recursion-limit, r=eddyb

This is particularly important for deeply nested types, which generate deeply nested impls. This is a fix for #19318. It's possible we could also improve this particular case not to increment the recursion count, but it's worth being able to adjust the recursion limit anyhow.

cc @jdm 
r? @pcwalton

src/test/compile-fail/recursion_limit.rs

@@ -0,0 +1,51 @@
+// Copyright 2014 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.
+
+// Test that the recursion limit can be changed. In this case, we have
+// deeply nested types that will fail the `Send` check by overflow
+// when the recursion limit is set very low.
+
+#![feature(macro_rules)]
+#![allow(dead_code)]
+#![recursion_limit="10"]
+
+macro_rules! link {
+    ($id:ident, $t:ty) => {
+        enum $id { $id($t) }
+    }
+}
+
+link!(A,B)
+link!(B,C)
+link!(C,D)
+link!(D,E)
+link!(E,F)
+link!(F,G)
+link!(G,H)
+link!(H,I)
+link!(I,J)
+link!(J,K)
+link!(K,L)
+link!(L,M)
+link!(M,N)
+
+enum N { N(uint) }
+
+fn is_send<T:Send>() { }
+
+fn main() {
+    is_send::<A>();
+    //~^ ERROR overflow evaluating
+    //~^^ NOTE consider adding a `#![recursion_limit="20"]` attribute to your crate
+    //~^^^ NOTE must be implemented
+    //~^^^^ ERROR overflow evaluating
+    //~^^^^^ NOTE consider adding a `#![recursion_limit="20"]` attribute to your crate
+    //~^^^^^^ NOTE must be implemented
+}

src/test/compile-fail/unboxed-closures-type-mismatch.rs

@@ -14,6 +14,6 @@ use std::ops::FnMut;
 
 pub fn main() {
     let mut f = |&mut: x: int, y: int| -> int { x + y };
-    let z = f.call_mut((1u, 2));    //~ ERROR not implemented
+    let z = f.call_mut((1u, 2));    //~ ERROR type mismatch
     println!("{}", z);
 }

src/test/compile-fail/unboxed-closures-vtable-mismatch.rs

@@ -18,7 +18,7 @@ fn call_it<F:FnMut<(int,int),int>>(y: int, mut f: F) -> int {
 
 pub fn main() {
     let f = |&mut: x: uint, y: int| -> int { (x as int) + y };
-    let z = call_it(3, f);  //~ ERROR not implemented
+    let z = call_it(3, f);  //~ ERROR type mismatch
     println!("{}", z);
 }