From e4e1242769d41c29f5814d6317f8497f285b3b15 Mon Sep 17 00:00:00 2001
From: Eduard Burtescu <edy.burt@gmail.com>
Date: Tue, 16 Feb 2016 18:37:32 +0200
Subject: [PATCH] Print fn type parameters for TyFnDef.

---
 src/librustc/util/ppaux.rs            | 15 ++++++++---
 src/test/compile-fail/fn-item-type.rs | 37 +++++++++++++++++++++------
 src/test/pretty/issue-4264.pp         |  6 +++--
 3 files changed, 45 insertions(+), 13 deletions(-)

diff --git a/src/librustc/util/ppaux.rs b/src/librustc/util/ppaux.rs
index 2b5674ed116a..8fd784cbde7a 100644
--- a/src/librustc/util/ppaux.rs
+++ b/src/librustc/util/ppaux.rs
@@ -822,10 +822,19 @@ impl<'tcx> fmt::Display for ty::TypeVariants<'tcx> {
                 }
 
                 try!(write!(f, "{}", bare_fn.sig.0));
+                try!(ty::tls::with(|tcx| {
+                    write!(f, " {{{}", tcx.item_path_str(def_id))
+                }));
 
-                write!(f, " {{{}}}", ty::tls::with(|tcx| {
-                    tcx.item_path_str(def_id)
-                }))
+                let tps = substs.types.get_slice(subst::FnSpace);
+                if tps.len() >= 1 {
+                    try!(write!(f, "::<{}", tps[0]));
+                    for &ty in &tps[1..] {
+                        try!(write!(f, ", {}", ty));
+                    }
+                    try!(write!(f, ">"));
+                }
+                write!(f, "}}")
             }
             TyFnPtr(ref bare_fn) => {
                 if bare_fn.unsafety == hir::Unsafety::Unsafe {
diff --git a/src/test/compile-fail/fn-item-type.rs b/src/test/compile-fail/fn-item-type.rs
index 5015810ff477..775e22f0428b 100644
--- a/src/test/compile-fail/fn-item-type.rs
+++ b/src/test/compile-fail/fn-item-type.rs
@@ -11,23 +11,44 @@
 // Test that the types of distinct fn items are not compatible by
 // default. See also `run-pass/fn-item-type-*.rs`.
 
-fn foo(x: isize) -> isize { x * 2 }
-fn bar(x: isize) -> isize { x * 4 }
+fn foo<T>(x: isize) -> isize { x * 2 }
+fn bar<T>(x: isize) -> isize { x * 4 }
 
 fn eq<T>(x: T, y: T) { }
 
+trait Foo { fn foo() { /* this is a default fn */ } }
+impl<T> Foo for T { /* `foo` is still default here */ }
+
 fn main() {
-    let f = if true { foo } else { bar };
+    let f = if true { foo::<u8> } else { bar::<u8> };
     //~^ ERROR if and else have incompatible types
-    //~| expected `fn(isize) -> isize {foo}`
-    //~| found `fn(isize) -> isize {bar}`
+    //~| expected `fn(isize) -> isize {foo::<u8>}`
+    //~| found `fn(isize) -> isize {bar::<u8>}`
     //~| expected fn item,
     //~| found a different fn item
 
-    eq(foo, bar);
+    eq(foo::<u8>, bar::<u8>);
     //~^ ERROR mismatched types
-    //~|  expected `fn(isize) -> isize {foo}`
-    //~|  found `fn(isize) -> isize {bar}`
+    //~|  expected `fn(isize) -> isize {foo::<u8>}`
+    //~|  found `fn(isize) -> isize {bar::<u8>}`
     //~|  expected fn item
     //~|  found a different fn item
+
+    eq(foo::<u8>, foo::<i8>);
+    //~^ ERROR mismatched types
+    //~|  expected `fn(isize) -> isize {foo::<u8>}`
+    //~|  found `fn(isize) -> isize {foo::<i8>}`
+
+    eq(bar::<String>, bar::<Vec<u8>>);
+    //~^ ERROR mismatched types
+    //~|  expected `fn(isize) -> isize {bar::<collections::string::String>}`
+    //~|  found `fn(isize) -> isize {bar::<collections::vec::Vec<u8>>}`
+    //~|  expected struct `collections::string::String`
+    //~|  found struct `collections::vec::Vec`
+
+    // Make sure we distinguish between trait methods correctly.
+    eq(<u8 as Foo>::foo, <u16 as Foo>::foo);
+    //~^ ERROR mismatched types
+    //~|  expected `fn() {Foo::foo}`
+    //~|  found `fn() {Foo::foo}`
 }
diff --git a/src/test/pretty/issue-4264.pp b/src/test/pretty/issue-4264.pp
index 835f7fc96c63..0347631aeb33 100644
--- a/src/test/pretty/issue-4264.pp
+++ b/src/test/pretty/issue-4264.pp
@@ -86,8 +86,10 @@ pub fn id<T>(x: T) -> T { (x as T) }
 pub fn use_id() {
     let _ =
         ((id::<[i32; (3 as usize)]> as
-             fn([i32; 3]) -> [i32; 3] {id})(([(1 as i32), (2 as i32),
-                                              (3 as i32)] as [i32; 3])) as
+             fn([i32; 3]) -> [i32; 3] {id::<[i32; 3]>})(([(1 as i32),
+                                                          (2 as i32),
+                                                          (3 as i32)] as
+                                                            [i32; 3])) as
             [i32; 3]);
 }
 fn main() { }